1 /* 2 ** 2001-09-15 3 ** 4 ** The author disclaims copyright to this source code. In place of 5 ** a legal notice, here is a blessing: 6 ** 7 ** May you do good and not evil. 8 ** May you find forgiveness for yourself and forgive others. 9 ** May you share freely, never taking more than you give. 10 ** 11 ************************************************************************* 12 ** This header file defines the interface that the SQLite library 13 ** presents to client programs. If a C-function, structure, datatype, 14 ** or constant definition does not appear in this file, then it is 15 ** not a published API of SQLite, is subject to change without 16 ** notice, and should not be referenced by programs that use SQLite. 17 ** 18 ** Some of the definitions that are in this file are marked as 19 ** "experimental". Experimental interfaces are normally new 20 ** features recently added to SQLite. We do not anticipate changes 21 ** to experimental interfaces but reserve the right to make minor changes 22 ** if experience from use "in the wild" suggest such changes are prudent. 23 ** 24 ** The official C-language API documentation for SQLite is derived 25 ** from comments in this file. This file is the authoritative source 26 ** on how SQLite interfaces are supposed to operate. 27 ** 28 ** The name of this file under configuration management is "sqlite.h.in". 29 ** The makefile makes some minor changes to this file (such as inserting 30 ** the version number) and changes its name to "sqlite3.h" as 31 ** part of the build process. 32 */ 33 #ifndef SQLITE3_H 34 #define SQLITE3_H 35 #include <stdarg.h> /* Needed for the definition of va_list */ 36 37 /* 38 ** Make sure we can call this stuff from C++. 39 */ 40 #ifdef __cplusplus 41 extern "C" { 42 #endif 43 44 45 /* 46 ** Facilitate override of interface linkage and calling conventions. 47 ** Be aware that these macros may not be used within this particular 48 ** translation of the amalgamation and its associated header file. 49 ** 50 ** The SQLITE_EXTERN and SQLITE_API macros are used to instruct the 51 ** compiler that the target identifier should have external linkage. 52 ** 53 ** The SQLITE_CDECL macro is used to set the calling convention for 54 ** public functions that accept a variable number of arguments. 55 ** 56 ** The SQLITE_APICALL macro is used to set the calling convention for 57 ** public functions that accept a fixed number of arguments. 58 ** 59 ** The SQLITE_STDCALL macro is no longer used and is now deprecated. 60 ** 61 ** The SQLITE_CALLBACK macro is used to set the calling convention for 62 ** function pointers. 63 ** 64 ** The SQLITE_SYSAPI macro is used to set the calling convention for 65 ** functions provided by the operating system. 66 ** 67 ** Currently, the SQLITE_CDECL, SQLITE_APICALL, SQLITE_CALLBACK, and 68 ** SQLITE_SYSAPI macros are used only when building for environments 69 ** that require non-default calling conventions. 70 */ 71 #ifndef SQLITE_EXTERN 72 # define SQLITE_EXTERN extern 73 #endif 74 #ifndef SQLITE_API 75 # define SQLITE_API 76 #endif 77 #ifndef SQLITE_CDECL 78 # define SQLITE_CDECL 79 #endif 80 #ifndef SQLITE_APICALL 81 # define SQLITE_APICALL 82 #endif 83 #ifndef SQLITE_STDCALL 84 # define SQLITE_STDCALL SQLITE_APICALL 85 #endif 86 #ifndef SQLITE_CALLBACK 87 # define SQLITE_CALLBACK 88 #endif 89 #ifndef SQLITE_SYSAPI 90 # define SQLITE_SYSAPI 91 #endif 92 93 /* 94 ** These no-op macros are used in front of interfaces to mark those 95 ** interfaces as either deprecated or experimental. New applications 96 ** should not use deprecated interfaces - they are supported for backwards 97 ** compatibility only. Application writers should be aware that 98 ** experimental interfaces are subject to change in point releases. 99 ** 100 ** These macros used to resolve to various kinds of compiler magic that 101 ** would generate warning messages when they were used. But that 102 ** compiler magic ended up generating such a flurry of bug reports 103 ** that we have taken it all out and gone back to using simple 104 ** noop macros. 105 */ 106 #define SQLITE_DEPRECATED 107 #define SQLITE_EXPERIMENTAL 108 109 /* 110 ** Ensure these symbols were not defined by some previous header file. 111 */ 112 #ifdef SQLITE_VERSION 113 # undef SQLITE_VERSION 114 #endif 115 #ifdef SQLITE_VERSION_NUMBER 116 # undef SQLITE_VERSION_NUMBER 117 #endif 118 119 /* 120 ** CAPI3REF: Compile-Time Library Version Numbers 121 ** 122 ** ^(The [SQLITE_VERSION] C preprocessor macro in the sqlite3.h header 123 ** evaluates to a string literal that is the SQLite version in the 124 ** format "X.Y.Z" where X is the major version number (always 3 for 125 ** SQLite3) and Y is the minor version number and Z is the release number.)^ 126 ** ^(The [SQLITE_VERSION_NUMBER] C preprocessor macro resolves to an integer 127 ** with the value (X*1000000 + Y*1000 + Z) where X, Y, and Z are the same 128 ** numbers used in [SQLITE_VERSION].)^ 129 ** The SQLITE_VERSION_NUMBER for any given release of SQLite will also 130 ** be larger than the release from which it is derived. Either Y will 131 ** be held constant and Z will be incremented or else Y will be incremented 132 ** and Z will be reset to zero. 133 ** 134 ** Since [version 3.6.18] ([dateof:3.6.18]), 135 ** SQLite source code has been stored in the 136 ** <a href="http://fossil-scm.org/">Fossil configuration management 137 ** system</a>. ^The SQLITE_SOURCE_ID macro evaluates to 138 ** a string which identifies a particular check-in of SQLite 139 ** within its configuration management system. ^The SQLITE_SOURCE_ID 140 ** string contains the date and time of the check-in (UTC) and a SHA1 141 ** or SHA3-256 hash of the entire source tree. If the source code has 142 ** been edited in any way since it was last checked in, then the last 143 ** four hexadecimal digits of the hash may be modified. 144 ** 145 ** See also: [sqlite3_libversion()], 146 ** [sqlite3_libversion_number()], [sqlite3_sourceid()], 147 ** [sqlite_version()] and [sqlite_source_id()]. 148 */ 149 #define SQLITE_VERSION "3.50.2" 150 #define SQLITE_VERSION_NUMBER 3050002 151 #define SQLITE_SOURCE_ID "2025-06-28 14:00:48 2af157d77fb1304a74176eaee7fbc7c7e932d946bf25325e9c26c91db19e3079" 152 153 /* 154 ** CAPI3REF: Run-Time Library Version Numbers 155 ** KEYWORDS: sqlite3_version sqlite3_sourceid 156 ** 157 ** These interfaces provide the same information as the [SQLITE_VERSION], 158 ** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros 159 ** but are associated with the library instead of the header file. ^(Cautious 160 ** programmers might include assert() statements in their application to 161 ** verify that values returned by these interfaces match the macros in 162 ** the header, and thus ensure that the application is 163 ** compiled with matching library and header files. 164 ** 165 ** <blockquote><pre> 166 ** assert( sqlite3_libversion_number()==SQLITE_VERSION_NUMBER ); 167 ** assert( strncmp(sqlite3_sourceid(),SQLITE_SOURCE_ID,80)==0 ); 168 ** assert( strcmp(sqlite3_libversion(),SQLITE_VERSION)==0 ); 169 ** </pre></blockquote>)^ 170 ** 171 ** ^The sqlite3_version[] string constant contains the text of [SQLITE_VERSION] 172 ** macro. ^The sqlite3_libversion() function returns a pointer to the 173 ** to the sqlite3_version[] string constant. The sqlite3_libversion() 174 ** function is provided for use in DLLs since DLL users usually do not have 175 ** direct access to string constants within the DLL. ^The 176 ** sqlite3_libversion_number() function returns an integer equal to 177 ** [SQLITE_VERSION_NUMBER]. ^(The sqlite3_sourceid() function returns 178 ** a pointer to a string constant whose value is the same as the 179 ** [SQLITE_SOURCE_ID] C preprocessor macro. Except if SQLite is built 180 ** using an edited copy of [the amalgamation], then the last four characters 181 ** of the hash might be different from [SQLITE_SOURCE_ID].)^ 182 ** 183 ** See also: [sqlite_version()] and [sqlite_source_id()]. 184 */ 185 SQLITE_API SQLITE_EXTERN const char sqlite3_version[]; 186 SQLITE_API const char *sqlite3_libversion(void); 187 SQLITE_API const char *sqlite3_sourceid(void); 188 SQLITE_API int sqlite3_libversion_number(void); 189 190 /* 191 ** CAPI3REF: Run-Time Library Compilation Options Diagnostics 192 ** 193 ** ^The sqlite3_compileoption_used() function returns 0 or 1 194 ** indicating whether the specified option was defined at 195 ** compile time. ^The SQLITE_ prefix may be omitted from the 196 ** option name passed to sqlite3_compileoption_used(). 197 ** 198 ** ^The sqlite3_compileoption_get() function allows iterating 199 ** over the list of options that were defined at compile time by 200 ** returning the N-th compile time option string. ^If N is out of range, 201 ** sqlite3_compileoption_get() returns a NULL pointer. ^The SQLITE_ 202 ** prefix is omitted from any strings returned by 203 ** sqlite3_compileoption_get(). 204 ** 205 ** ^Support for the diagnostic functions sqlite3_compileoption_used() 206 ** and sqlite3_compileoption_get() may be omitted by specifying the 207 ** [SQLITE_OMIT_COMPILEOPTION_DIAGS] option at compile time. 208 ** 209 ** See also: SQL functions [sqlite_compileoption_used()] and 210 ** [sqlite_compileoption_get()] and the [compile_options pragma]. 211 */ 212 #ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS 213 SQLITE_API int sqlite3_compileoption_used(const char *zOptName); 214 SQLITE_API const char *sqlite3_compileoption_get(int N); 215 #else 216 # define sqlite3_compileoption_used(X) 0 217 # define sqlite3_compileoption_get(X) ((void*)0) 218 #endif 219 220 /* 221 ** CAPI3REF: Test To See If The Library Is Threadsafe 222 ** 223 ** ^The sqlite3_threadsafe() function returns zero if and only if 224 ** SQLite was compiled with mutexing code omitted due to the 225 ** [SQLITE_THREADSAFE] compile-time option being set to 0. 226 ** 227 ** SQLite can be compiled with or without mutexes. When 228 ** the [SQLITE_THREADSAFE] C preprocessor macro is 1 or 2, mutexes 229 ** are enabled and SQLite is threadsafe. When the 230 ** [SQLITE_THREADSAFE] macro is 0, 231 ** the mutexes are omitted. Without the mutexes, it is not safe 232 ** to use SQLite concurrently from more than one thread. 233 ** 234 ** Enabling mutexes incurs a measurable performance penalty. 235 ** So if speed is of utmost importance, it makes sense to disable 236 ** the mutexes. But for maximum safety, mutexes should be enabled. 237 ** ^The default behavior is for mutexes to be enabled. 238 ** 239 ** This interface can be used by an application to make sure that the 240 ** version of SQLite that it is linking against was compiled with 241 ** the desired setting of the [SQLITE_THREADSAFE] macro. 242 ** 243 ** This interface only reports on the compile-time mutex setting 244 ** of the [SQLITE_THREADSAFE] flag. If SQLite is compiled with 245 ** SQLITE_THREADSAFE=1 or =2 then mutexes are enabled by default but 246 ** can be fully or partially disabled using a call to [sqlite3_config()] 247 ** with the verbs [SQLITE_CONFIG_SINGLETHREAD], [SQLITE_CONFIG_MULTITHREAD], 248 ** or [SQLITE_CONFIG_SERIALIZED]. ^(The return value of the 249 ** sqlite3_threadsafe() function shows only the compile-time setting of 250 ** thread safety, not any run-time changes to that setting made by 251 ** sqlite3_config(). In other words, the return value from sqlite3_threadsafe() 252 ** is unchanged by calls to sqlite3_config().)^ 253 ** 254 ** See the [threading mode] documentation for additional information. 255 */ 256 SQLITE_API int sqlite3_threadsafe(void); 257 258 /* 259 ** CAPI3REF: Database Connection Handle 260 ** KEYWORDS: {database connection} {database connections} 261 ** 262 ** Each open SQLite database is represented by a pointer to an instance of 263 ** the opaque structure named "sqlite3". It is useful to think of an sqlite3 264 ** pointer as an object. The [sqlite3_open()], [sqlite3_open16()], and 265 ** [sqlite3_open_v2()] interfaces are its constructors, and [sqlite3_close()] 266 ** and [sqlite3_close_v2()] are its destructors. There are many other 267 ** interfaces (such as 268 ** [sqlite3_prepare_v2()], [sqlite3_create_function()], and 269 ** [sqlite3_busy_timeout()] to name but three) that are methods on an 270 ** sqlite3 object. 271 */ 272 typedef struct sqlite3 sqlite3; 273 274 /* 275 ** CAPI3REF: 64-Bit Integer Types 276 ** KEYWORDS: sqlite_int64 sqlite_uint64 277 ** 278 ** Because there is no cross-platform way to specify 64-bit integer types 279 ** SQLite includes typedefs for 64-bit signed and unsigned integers. 280 ** 281 ** The sqlite3_int64 and sqlite3_uint64 are the preferred type definitions. 282 ** The sqlite_int64 and sqlite_uint64 types are supported for backwards 283 ** compatibility only. 284 ** 285 ** ^The sqlite3_int64 and sqlite_int64 types can store integer values 286 ** between -9223372036854775808 and +9223372036854775807 inclusive. ^The 287 ** sqlite3_uint64 and sqlite_uint64 types can store integer values 288 ** between 0 and +18446744073709551615 inclusive. 289 */ 290 #ifdef SQLITE_INT64_TYPE 291 typedef SQLITE_INT64_TYPE sqlite_int64; 292 # ifdef SQLITE_UINT64_TYPE 293 typedef SQLITE_UINT64_TYPE sqlite_uint64; 294 # else 295 typedef unsigned SQLITE_INT64_TYPE sqlite_uint64; 296 # endif 297 #elif defined(_MSC_VER) || defined(__BORLANDC__) 298 typedef __int64 sqlite_int64; 299 typedef unsigned __int64 sqlite_uint64; 300 #else 301 typedef long long int sqlite_int64; 302 typedef unsigned long long int sqlite_uint64; 303 #endif 304 typedef sqlite_int64 sqlite3_int64; 305 typedef sqlite_uint64 sqlite3_uint64; 306 307 /* 308 ** If compiling for a processor that lacks floating point support, 309 ** substitute integer for floating-point. 310 */ 311 #ifdef SQLITE_OMIT_FLOATING_POINT 312 # define double sqlite3_int64 313 #endif 314 315 /* 316 ** CAPI3REF: Closing A Database Connection 317 ** DESTRUCTOR: sqlite3 318 ** 319 ** ^The sqlite3_close() and sqlite3_close_v2() routines are destructors 320 ** for the [sqlite3] object. 321 ** ^Calls to sqlite3_close() and sqlite3_close_v2() return [SQLITE_OK] if 322 ** the [sqlite3] object is successfully destroyed and all associated 323 ** resources are deallocated. 324 ** 325 ** Ideally, applications should [sqlite3_finalize | finalize] all 326 ** [prepared statements], [sqlite3_blob_close | close] all [BLOB handles], and 327 ** [sqlite3_backup_finish | finish] all [sqlite3_backup] objects associated 328 ** with the [sqlite3] object prior to attempting to close the object. 329 ** ^If the database connection is associated with unfinalized prepared 330 ** statements, BLOB handlers, and/or unfinished sqlite3_backup objects then 331 ** sqlite3_close() will leave the database connection open and return 332 ** [SQLITE_BUSY]. ^If sqlite3_close_v2() is called with unfinalized prepared 333 ** statements, unclosed BLOB handlers, and/or unfinished sqlite3_backups, 334 ** it returns [SQLITE_OK] regardless, but instead of deallocating the database 335 ** connection immediately, it marks the database connection as an unusable 336 ** "zombie" and makes arrangements to automatically deallocate the database 337 ** connection after all prepared statements are finalized, all BLOB handles 338 ** are closed, and all backups have finished. The sqlite3_close_v2() interface 339 ** is intended for use with host languages that are garbage collected, and 340 ** where the order in which destructors are called is arbitrary. 341 ** 342 ** ^If an [sqlite3] object is destroyed while a transaction is open, 343 ** the transaction is automatically rolled back. 344 ** 345 ** The C parameter to [sqlite3_close(C)] and [sqlite3_close_v2(C)] 346 ** must be either a NULL 347 ** pointer or an [sqlite3] object pointer obtained 348 ** from [sqlite3_open()], [sqlite3_open16()], or 349 ** [sqlite3_open_v2()], and not previously closed. 350 ** ^Calling sqlite3_close() or sqlite3_close_v2() with a NULL pointer 351 ** argument is a harmless no-op. 352 */ 353 SQLITE_API int sqlite3_close(sqlite3*); 354 SQLITE_API int sqlite3_close_v2(sqlite3*); 355 356 /* 357 ** The type for a callback function. 358 ** This is legacy and deprecated. It is included for historical 359 ** compatibility and is not documented. 360 */ 361 typedef int (*sqlite3_callback)(void*,int,char**, char**); 362 363 /* 364 ** CAPI3REF: One-Step Query Execution Interface 365 ** METHOD: sqlite3 366 ** 367 ** The sqlite3_exec() interface is a convenience wrapper around 368 ** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()], 369 ** that allows an application to run multiple statements of SQL 370 ** without having to use a lot of C code. 371 ** 372 ** ^The sqlite3_exec() interface runs zero or more UTF-8 encoded, 373 ** semicolon-separate SQL statements passed into its 2nd argument, 374 ** in the context of the [database connection] passed in as its 1st 375 ** argument. ^If the callback function of the 3rd argument to 376 ** sqlite3_exec() is not NULL, then it is invoked for each result row 377 ** coming out of the evaluated SQL statements. ^The 4th argument to 378 ** sqlite3_exec() is relayed through to the 1st argument of each 379 ** callback invocation. ^If the callback pointer to sqlite3_exec() 380 ** is NULL, then no callback is ever invoked and result rows are 381 ** ignored. 382 ** 383 ** ^If an error occurs while evaluating the SQL statements passed into 384 ** sqlite3_exec(), then execution of the current statement stops and 385 ** subsequent statements are skipped. ^If the 5th parameter to sqlite3_exec() 386 ** is not NULL then any error message is written into memory obtained 387 ** from [sqlite3_malloc()] and passed back through the 5th parameter. 388 ** To avoid memory leaks, the application should invoke [sqlite3_free()] 389 ** on error message strings returned through the 5th parameter of 390 ** sqlite3_exec() after the error message string is no longer needed. 391 ** ^If the 5th parameter to sqlite3_exec() is not NULL and no errors 392 ** occur, then sqlite3_exec() sets the pointer in its 5th parameter to 393 ** NULL before returning. 394 ** 395 ** ^If an sqlite3_exec() callback returns non-zero, the sqlite3_exec() 396 ** routine returns SQLITE_ABORT without invoking the callback again and 397 ** without running any subsequent SQL statements. 398 ** 399 ** ^The 2nd argument to the sqlite3_exec() callback function is the 400 ** number of columns in the result. ^The 3rd argument to the sqlite3_exec() 401 ** callback is an array of pointers to strings obtained as if from 402 ** [sqlite3_column_text()], one for each column. ^If an element of a 403 ** result row is NULL then the corresponding string pointer for the 404 ** sqlite3_exec() callback is a NULL pointer. ^The 4th argument to the 405 ** sqlite3_exec() callback is an array of pointers to strings where each 406 ** entry represents the name of corresponding result column as obtained 407 ** from [sqlite3_column_name()]. 408 ** 409 ** ^If the 2nd parameter to sqlite3_exec() is a NULL pointer, a pointer 410 ** to an empty string, or a pointer that contains only whitespace and/or 411 ** SQL comments, then no SQL statements are evaluated and the database 412 ** is not changed. 413 ** 414 ** Restrictions: 415 ** 416 ** <ul> 417 ** <li> The application must ensure that the 1st parameter to sqlite3_exec() 418 ** is a valid and open [database connection]. 419 ** <li> The application must not close the [database connection] specified by 420 ** the 1st parameter to sqlite3_exec() while sqlite3_exec() is running. 421 ** <li> The application must not modify the SQL statement text passed into 422 ** the 2nd parameter of sqlite3_exec() while sqlite3_exec() is running. 423 ** <li> The application must not dereference the arrays or string pointers 424 ** passed as the 3rd and 4th callback parameters after it returns. 425 ** </ul> 426 */ 427 SQLITE_API int sqlite3_exec( 428 sqlite3*, /* An open database */ 429 const char *sql, /* SQL to be evaluated */ 430 int (*callback)(void*,int,char**,char**), /* Callback function */ 431 void *, /* 1st argument to callback */ 432 char **errmsg /* Error msg written here */ 433 ); 434 435 /* 436 ** CAPI3REF: Result Codes 437 ** KEYWORDS: {result code definitions} 438 ** 439 ** Many SQLite functions return an integer result code from the set shown 440 ** here in order to indicate success or failure. 441 ** 442 ** New error codes may be added in future versions of SQLite. 443 ** 444 ** See also: [extended result code definitions] 445 */ 446 #define SQLITE_OK 0 /* Successful result */ 447 /* beginning-of-error-codes */ 448 #define SQLITE_ERROR 1 /* Generic error */ 449 #define SQLITE_INTERNAL 2 /* Internal logic error in SQLite */ 450 #define SQLITE_PERM 3 /* Access permission denied */ 451 #define SQLITE_ABORT 4 /* Callback routine requested an abort */ 452 #define SQLITE_BUSY 5 /* The database file is locked */ 453 #define SQLITE_LOCKED 6 /* A table in the database is locked */ 454 #define SQLITE_NOMEM 7 /* A malloc() failed */ 455 #define SQLITE_READONLY 8 /* Attempt to write a readonly database */ 456 #define SQLITE_INTERRUPT 9 /* Operation terminated by sqlite3_interrupt()*/ 457 #define SQLITE_IOERR 10 /* Some kind of disk I/O error occurred */ 458 #define SQLITE_CORRUPT 11 /* The database disk image is malformed */ 459 #define SQLITE_NOTFOUND 12 /* Unknown opcode in sqlite3_file_control() */ 460 #define SQLITE_FULL 13 /* Insertion failed because database is full */ 461 #define SQLITE_CANTOPEN 14 /* Unable to open the database file */ 462 #define SQLITE_PROTOCOL 15 /* Database lock protocol error */ 463 #define SQLITE_EMPTY 16 /* Internal use only */ 464 #define SQLITE_SCHEMA 17 /* The database schema changed */ 465 #define SQLITE_TOOBIG 18 /* String or BLOB exceeds size limit */ 466 #define SQLITE_CONSTRAINT 19 /* Abort due to constraint violation */ 467 #define SQLITE_MISMATCH 20 /* Data type mismatch */ 468 #define SQLITE_MISUSE 21 /* Library used incorrectly */ 469 #define SQLITE_NOLFS 22 /* Uses OS features not supported on host */ 470 #define SQLITE_AUTH 23 /* Authorization denied */ 471 #define SQLITE_FORMAT 24 /* Not used */ 472 #define SQLITE_RANGE 25 /* 2nd parameter to sqlite3_bind out of range */ 473 #define SQLITE_NOTADB 26 /* File opened that is not a database file */ 474 #define SQLITE_NOTICE 27 /* Notifications from sqlite3_log() */ 475 #define SQLITE_WARNING 28 /* Warnings from sqlite3_log() */ 476 #define SQLITE_ROW 100 /* sqlite3_step() has another row ready */ 477 #define SQLITE_DONE 101 /* sqlite3_step() has finished executing */ 478 /* end-of-error-codes */ 479 480 /* 481 ** CAPI3REF: Extended Result Codes 482 ** KEYWORDS: {extended result code definitions} 483 ** 484 ** In its default configuration, SQLite API routines return one of 30 integer 485 ** [result codes]. However, experience has shown that many of 486 ** these result codes are too coarse-grained. They do not provide as 487 ** much information about problems as programmers might like. In an effort to 488 ** address this, newer versions of SQLite (version 3.3.8 [dateof:3.3.8] 489 ** and later) include 490 ** support for additional result codes that provide more detailed information 491 ** about errors. These [extended result codes] are enabled or disabled 492 ** on a per database connection basis using the 493 ** [sqlite3_extended_result_codes()] API. Or, the extended code for 494 ** the most recent error can be obtained using 495 ** [sqlite3_extended_errcode()]. 496 */ 497 #define SQLITE_ERROR_MISSING_COLLSEQ (SQLITE_ERROR | (1<<8)) 498 #define SQLITE_ERROR_RETRY (SQLITE_ERROR | (2<<8)) 499 #define SQLITE_ERROR_SNAPSHOT (SQLITE_ERROR | (3<<8)) 500 #define SQLITE_IOERR_READ (SQLITE_IOERR | (1<<8)) 501 #define SQLITE_IOERR_SHORT_READ (SQLITE_IOERR | (2<<8)) 502 #define SQLITE_IOERR_WRITE (SQLITE_IOERR | (3<<8)) 503 #define SQLITE_IOERR_FSYNC (SQLITE_IOERR | (4<<8)) 504 #define SQLITE_IOERR_DIR_FSYNC (SQLITE_IOERR | (5<<8)) 505 #define SQLITE_IOERR_TRUNCATE (SQLITE_IOERR | (6<<8)) 506 #define SQLITE_IOERR_FSTAT (SQLITE_IOERR | (7<<8)) 507 #define SQLITE_IOERR_UNLOCK (SQLITE_IOERR | (8<<8)) 508 #define SQLITE_IOERR_RDLOCK (SQLITE_IOERR | (9<<8)) 509 #define SQLITE_IOERR_DELETE (SQLITE_IOERR | (10<<8)) 510 #define SQLITE_IOERR_BLOCKED (SQLITE_IOERR | (11<<8)) 511 #define SQLITE_IOERR_NOMEM (SQLITE_IOERR | (12<<8)) 512 #define SQLITE_IOERR_ACCESS (SQLITE_IOERR | (13<<8)) 513 #define SQLITE_IOERR_CHECKRESERVEDLOCK (SQLITE_IOERR | (14<<8)) 514 #define SQLITE_IOERR_LOCK (SQLITE_IOERR | (15<<8)) 515 #define SQLITE_IOERR_CLOSE (SQLITE_IOERR | (16<<8)) 516 #define SQLITE_IOERR_DIR_CLOSE (SQLITE_IOERR | (17<<8)) 517 #define SQLITE_IOERR_SHMOPEN (SQLITE_IOERR | (18<<8)) 518 #define SQLITE_IOERR_SHMSIZE (SQLITE_IOERR | (19<<8)) 519 #define SQLITE_IOERR_SHMLOCK (SQLITE_IOERR | (20<<8)) 520 #define SQLITE_IOERR_SHMMAP (SQLITE_IOERR | (21<<8)) 521 #define SQLITE_IOERR_SEEK (SQLITE_IOERR | (22<<8)) 522 #define SQLITE_IOERR_DELETE_NOENT (SQLITE_IOERR | (23<<8)) 523 #define SQLITE_IOERR_MMAP (SQLITE_IOERR | (24<<8)) 524 #define SQLITE_IOERR_GETTEMPPATH (SQLITE_IOERR | (25<<8)) 525 #define SQLITE_IOERR_CONVPATH (SQLITE_IOERR | (26<<8)) 526 #define SQLITE_IOERR_VNODE (SQLITE_IOERR | (27<<8)) 527 #define SQLITE_IOERR_AUTH (SQLITE_IOERR | (28<<8)) 528 #define SQLITE_IOERR_BEGIN_ATOMIC (SQLITE_IOERR | (29<<8)) 529 #define SQLITE_IOERR_COMMIT_ATOMIC (SQLITE_IOERR | (30<<8)) 530 #define SQLITE_IOERR_ROLLBACK_ATOMIC (SQLITE_IOERR | (31<<8)) 531 #define SQLITE_IOERR_DATA (SQLITE_IOERR | (32<<8)) 532 #define SQLITE_IOERR_CORRUPTFS (SQLITE_IOERR | (33<<8)) 533 #define SQLITE_IOERR_IN_PAGE (SQLITE_IOERR | (34<<8)) 534 #define SQLITE_LOCKED_SHAREDCACHE (SQLITE_LOCKED | (1<<8)) 535 #define SQLITE_LOCKED_VTAB (SQLITE_LOCKED | (2<<8)) 536 #define SQLITE_BUSY_RECOVERY (SQLITE_BUSY | (1<<8)) 537 #define SQLITE_BUSY_SNAPSHOT (SQLITE_BUSY | (2<<8)) 538 #define SQLITE_BUSY_TIMEOUT (SQLITE_BUSY | (3<<8)) 539 #define SQLITE_CANTOPEN_NOTEMPDIR (SQLITE_CANTOPEN | (1<<8)) 540 #define SQLITE_CANTOPEN_ISDIR (SQLITE_CANTOPEN | (2<<8)) 541 #define SQLITE_CANTOPEN_FULLPATH (SQLITE_CANTOPEN | (3<<8)) 542 #define SQLITE_CANTOPEN_CONVPATH (SQLITE_CANTOPEN | (4<<8)) 543 #define SQLITE_CANTOPEN_DIRTYWAL (SQLITE_CANTOPEN | (5<<8)) /* Not Used */ 544 #define SQLITE_CANTOPEN_SYMLINK (SQLITE_CANTOPEN | (6<<8)) 545 #define SQLITE_CORRUPT_VTAB (SQLITE_CORRUPT | (1<<8)) 546 #define SQLITE_CORRUPT_SEQUENCE (SQLITE_CORRUPT | (2<<8)) 547 #define SQLITE_CORRUPT_INDEX (SQLITE_CORRUPT | (3<<8)) 548 #define SQLITE_READONLY_RECOVERY (SQLITE_READONLY | (1<<8)) 549 #define SQLITE_READONLY_CANTLOCK (SQLITE_READONLY | (2<<8)) 550 #define SQLITE_READONLY_ROLLBACK (SQLITE_READONLY | (3<<8)) 551 #define SQLITE_READONLY_DBMOVED (SQLITE_READONLY | (4<<8)) 552 #define SQLITE_READONLY_CANTINIT (SQLITE_READONLY | (5<<8)) 553 #define SQLITE_READONLY_DIRECTORY (SQLITE_READONLY | (6<<8)) 554 #define SQLITE_ABORT_ROLLBACK (SQLITE_ABORT | (2<<8)) 555 #define SQLITE_CONSTRAINT_CHECK (SQLITE_CONSTRAINT | (1<<8)) 556 #define SQLITE_CONSTRAINT_COMMITHOOK (SQLITE_CONSTRAINT | (2<<8)) 557 #define SQLITE_CONSTRAINT_FOREIGNKEY (SQLITE_CONSTRAINT | (3<<8)) 558 #define SQLITE_CONSTRAINT_FUNCTION (SQLITE_CONSTRAINT | (4<<8)) 559 #define SQLITE_CONSTRAINT_NOTNULL (SQLITE_CONSTRAINT | (5<<8)) 560 #define SQLITE_CONSTRAINT_PRIMARYKEY (SQLITE_CONSTRAINT | (6<<8)) 561 #define SQLITE_CONSTRAINT_TRIGGER (SQLITE_CONSTRAINT | (7<<8)) 562 #define SQLITE_CONSTRAINT_UNIQUE (SQLITE_CONSTRAINT | (8<<8)) 563 #define SQLITE_CONSTRAINT_VTAB (SQLITE_CONSTRAINT | (9<<8)) 564 #define SQLITE_CONSTRAINT_ROWID (SQLITE_CONSTRAINT |(10<<8)) 565 #define SQLITE_CONSTRAINT_PINNED (SQLITE_CONSTRAINT |(11<<8)) 566 #define SQLITE_CONSTRAINT_DATATYPE (SQLITE_CONSTRAINT |(12<<8)) 567 #define SQLITE_NOTICE_RECOVER_WAL (SQLITE_NOTICE | (1<<8)) 568 #define SQLITE_NOTICE_RECOVER_ROLLBACK (SQLITE_NOTICE | (2<<8)) 569 #define SQLITE_NOTICE_RBU (SQLITE_NOTICE | (3<<8)) 570 #define SQLITE_WARNING_AUTOINDEX (SQLITE_WARNING | (1<<8)) 571 #define SQLITE_AUTH_USER (SQLITE_AUTH | (1<<8)) 572 #define SQLITE_OK_LOAD_PERMANENTLY (SQLITE_OK | (1<<8)) 573 #define SQLITE_OK_SYMLINK (SQLITE_OK | (2<<8)) /* internal use only */ 574 575 /* 576 ** CAPI3REF: Flags For File Open Operations 577 ** 578 ** These bit values are intended for use in the 579 ** 3rd parameter to the [sqlite3_open_v2()] interface and 580 ** in the 4th parameter to the [sqlite3_vfs.xOpen] method. 581 ** 582 ** Only those flags marked as "Ok for sqlite3_open_v2()" may be 583 ** used as the third argument to the [sqlite3_open_v2()] interface. 584 ** The other flags have historically been ignored by sqlite3_open_v2(), 585 ** though future versions of SQLite might change so that an error is 586 ** raised if any of the disallowed bits are passed into sqlite3_open_v2(). 587 ** Applications should not depend on the historical behavior. 588 ** 589 ** Note in particular that passing the SQLITE_OPEN_EXCLUSIVE flag into 590 ** [sqlite3_open_v2()] does *not* cause the underlying database file 591 ** to be opened using O_EXCL. Passing SQLITE_OPEN_EXCLUSIVE into 592 ** [sqlite3_open_v2()] has historically be a no-op and might become an 593 ** error in future versions of SQLite. 594 */ 595 #define SQLITE_OPEN_READONLY 0x00000001 /* Ok for sqlite3_open_v2() */ 596 #define SQLITE_OPEN_READWRITE 0x00000002 /* Ok for sqlite3_open_v2() */ 597 #define SQLITE_OPEN_CREATE 0x00000004 /* Ok for sqlite3_open_v2() */ 598 #define SQLITE_OPEN_DELETEONCLOSE 0x00000008 /* VFS only */ 599 #define SQLITE_OPEN_EXCLUSIVE 0x00000010 /* VFS only */ 600 #define SQLITE_OPEN_AUTOPROXY 0x00000020 /* VFS only */ 601 #define SQLITE_OPEN_URI 0x00000040 /* Ok for sqlite3_open_v2() */ 602 #define SQLITE_OPEN_MEMORY 0x00000080 /* Ok for sqlite3_open_v2() */ 603 #define SQLITE_OPEN_MAIN_DB 0x00000100 /* VFS only */ 604 #define SQLITE_OPEN_TEMP_DB 0x00000200 /* VFS only */ 605 #define SQLITE_OPEN_TRANSIENT_DB 0x00000400 /* VFS only */ 606 #define SQLITE_OPEN_MAIN_JOURNAL 0x00000800 /* VFS only */ 607 #define SQLITE_OPEN_TEMP_JOURNAL 0x00001000 /* VFS only */ 608 #define SQLITE_OPEN_SUBJOURNAL 0x00002000 /* VFS only */ 609 #define SQLITE_OPEN_SUPER_JOURNAL 0x00004000 /* VFS only */ 610 #define SQLITE_OPEN_NOMUTEX 0x00008000 /* Ok for sqlite3_open_v2() */ 611 #define SQLITE_OPEN_FULLMUTEX 0x00010000 /* Ok for sqlite3_open_v2() */ 612 #define SQLITE_OPEN_SHAREDCACHE 0x00020000 /* Ok for sqlite3_open_v2() */ 613 #define SQLITE_OPEN_PRIVATECACHE 0x00040000 /* Ok for sqlite3_open_v2() */ 614 #define SQLITE_OPEN_WAL 0x00080000 /* VFS only */ 615 #define SQLITE_OPEN_NOFOLLOW 0x01000000 /* Ok for sqlite3_open_v2() */ 616 #define SQLITE_OPEN_EXRESCODE 0x02000000 /* Extended result codes */ 617 618 /* Reserved: 0x00F00000 */ 619 /* Legacy compatibility: */ 620 #define SQLITE_OPEN_MASTER_JOURNAL 0x00004000 /* VFS only */ 621 622 623 /* 624 ** CAPI3REF: Device Characteristics 625 ** 626 ** The xDeviceCharacteristics method of the [sqlite3_io_methods] 627 ** object returns an integer which is a vector of these 628 ** bit values expressing I/O characteristics of the mass storage 629 ** device that holds the file that the [sqlite3_io_methods] 630 ** refers to. 631 ** 632 ** The SQLITE_IOCAP_ATOMIC property means that all writes of 633 ** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 634 ** mean that writes of blocks that are nnn bytes in size and 635 ** are aligned to an address which is an integer multiple of 636 ** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 637 ** that when data is appended to a file, the data is appended 638 ** first then the size of the file is extended, never the other 639 ** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 640 ** information is written to disk in the same order as calls 641 ** to xWrite(). The SQLITE_IOCAP_POWERSAFE_OVERWRITE property means that 642 ** after reboot following a crash or power loss, the only bytes in a 643 ** file that were written at the application level might have changed 644 ** and that adjacent bytes, even bytes within the same sector are 645 ** guaranteed to be unchanged. The SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 646 ** flag indicates that a file cannot be deleted when open. The 647 ** SQLITE_IOCAP_IMMUTABLE flag indicates that the file is on 648 ** read-only media and cannot be changed even by processes with 649 ** elevated privileges. 650 ** 651 ** The SQLITE_IOCAP_BATCH_ATOMIC property means that the underlying 652 ** filesystem supports doing multiple write operations atomically when those 653 ** write operations are bracketed by [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] and 654 ** [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]. 655 ** 656 ** The SQLITE_IOCAP_SUBPAGE_READ property means that it is ok to read 657 ** from the database file in amounts that are not a multiple of the 658 ** page size and that do not begin at a page boundary. Without this 659 ** property, SQLite is careful to only do full-page reads and write 660 ** on aligned pages, with the one exception that it will do a sub-page 661 ** read of the first page to access the database header. 662 */ 663 #define SQLITE_IOCAP_ATOMIC 0x00000001 664 #define SQLITE_IOCAP_ATOMIC512 0x00000002 665 #define SQLITE_IOCAP_ATOMIC1K 0x00000004 666 #define SQLITE_IOCAP_ATOMIC2K 0x00000008 667 #define SQLITE_IOCAP_ATOMIC4K 0x00000010 668 #define SQLITE_IOCAP_ATOMIC8K 0x00000020 669 #define SQLITE_IOCAP_ATOMIC16K 0x00000040 670 #define SQLITE_IOCAP_ATOMIC32K 0x00000080 671 #define SQLITE_IOCAP_ATOMIC64K 0x00000100 672 #define SQLITE_IOCAP_SAFE_APPEND 0x00000200 673 #define SQLITE_IOCAP_SEQUENTIAL 0x00000400 674 #define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 0x00000800 675 #define SQLITE_IOCAP_POWERSAFE_OVERWRITE 0x00001000 676 #define SQLITE_IOCAP_IMMUTABLE 0x00002000 677 #define SQLITE_IOCAP_BATCH_ATOMIC 0x00004000 678 #define SQLITE_IOCAP_SUBPAGE_READ 0x00008000 679 680 /* 681 ** CAPI3REF: File Locking Levels 682 ** 683 ** SQLite uses one of these integer values as the second 684 ** argument to calls it makes to the xLock() and xUnlock() methods 685 ** of an [sqlite3_io_methods] object. These values are ordered from 686 ** lest restrictive to most restrictive. 687 ** 688 ** The argument to xLock() is always SHARED or higher. The argument to 689 ** xUnlock is either SHARED or NONE. 690 */ 691 #define SQLITE_LOCK_NONE 0 /* xUnlock() only */ 692 #define SQLITE_LOCK_SHARED 1 /* xLock() or xUnlock() */ 693 #define SQLITE_LOCK_RESERVED 2 /* xLock() only */ 694 #define SQLITE_LOCK_PENDING 3 /* xLock() only */ 695 #define SQLITE_LOCK_EXCLUSIVE 4 /* xLock() only */ 696 697 /* 698 ** CAPI3REF: Synchronization Type Flags 699 ** 700 ** When SQLite invokes the xSync() method of an 701 ** [sqlite3_io_methods] object it uses a combination of 702 ** these integer values as the second argument. 703 ** 704 ** When the SQLITE_SYNC_DATAONLY flag is used, it means that the 705 ** sync operation only needs to flush data to mass storage. Inode 706 ** information need not be flushed. If the lower four bits of the flag 707 ** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics. 708 ** If the lower four bits equal SQLITE_SYNC_FULL, that means 709 ** to use Mac OS X style fullsync instead of fsync(). 710 ** 711 ** Do not confuse the SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags 712 ** with the [PRAGMA synchronous]=NORMAL and [PRAGMA synchronous]=FULL 713 ** settings. The [synchronous pragma] determines when calls to the 714 ** xSync VFS method occur and applies uniformly across all platforms. 715 ** The SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags determine how 716 ** energetic or rigorous or forceful the sync operations are and 717 ** only make a difference on Mac OSX for the default SQLite code. 718 ** (Third-party VFS implementations might also make the distinction 719 ** between SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL, but among the 720 ** operating systems natively supported by SQLite, only Mac OSX 721 ** cares about the difference.) 722 */ 723 #define SQLITE_SYNC_NORMAL 0x00002 724 #define SQLITE_SYNC_FULL 0x00003 725 #define SQLITE_SYNC_DATAONLY 0x00010 726 727 /* 728 ** CAPI3REF: OS Interface Open File Handle 729 ** 730 ** An [sqlite3_file] object represents an open file in the 731 ** [sqlite3_vfs | OS interface layer]. Individual OS interface 732 ** implementations will 733 ** want to subclass this object by appending additional fields 734 ** for their own use. The pMethods entry is a pointer to an 735 ** [sqlite3_io_methods] object that defines methods for performing 736 ** I/O operations on the open file. 737 */ 738 typedef struct sqlite3_file sqlite3_file; 739 struct sqlite3_file { 740 const struct sqlite3_io_methods *pMethods; /* Methods for an open file */ 741 }; 742 743 /* 744 ** CAPI3REF: OS Interface File Virtual Methods Object 745 ** 746 ** Every file opened by the [sqlite3_vfs.xOpen] method populates an 747 ** [sqlite3_file] object (or, more commonly, a subclass of the 748 ** [sqlite3_file] object) with a pointer to an instance of this object. 749 ** This object defines the methods used to perform various operations 750 ** against the open file represented by the [sqlite3_file] object. 751 ** 752 ** If the [sqlite3_vfs.xOpen] method sets the sqlite3_file.pMethods element 753 ** to a non-NULL pointer, then the sqlite3_io_methods.xClose method 754 ** may be invoked even if the [sqlite3_vfs.xOpen] reported that it failed. The 755 ** only way to prevent a call to xClose following a failed [sqlite3_vfs.xOpen] 756 ** is for the [sqlite3_vfs.xOpen] to set the sqlite3_file.pMethods element 757 ** to NULL. 758 ** 759 ** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or 760 ** [SQLITE_SYNC_FULL]. The first choice is the normal fsync(). 761 ** The second choice is a Mac OS X style fullsync. The [SQLITE_SYNC_DATAONLY] 762 ** flag may be ORed in to indicate that only the data of the file 763 ** and not its inode needs to be synced. 764 ** 765 ** The integer values to xLock() and xUnlock() are one of 766 ** <ul> 767 ** <li> [SQLITE_LOCK_NONE], 768 ** <li> [SQLITE_LOCK_SHARED], 769 ** <li> [SQLITE_LOCK_RESERVED], 770 ** <li> [SQLITE_LOCK_PENDING], or 771 ** <li> [SQLITE_LOCK_EXCLUSIVE]. 772 ** </ul> 773 ** xLock() upgrades the database file lock. In other words, xLock() moves the 774 ** database file lock in the direction NONE toward EXCLUSIVE. The argument to 775 ** xLock() is always one of SHARED, RESERVED, PENDING, or EXCLUSIVE, never 776 ** SQLITE_LOCK_NONE. If the database file lock is already at or above the 777 ** requested lock, then the call to xLock() is a no-op. 778 ** xUnlock() downgrades the database file lock to either SHARED or NONE. 779 ** If the lock is already at or below the requested lock state, then the call 780 ** to xUnlock() is a no-op. 781 ** The xCheckReservedLock() method checks whether any database connection, 782 ** either in this process or in some other process, is holding a RESERVED, 783 ** PENDING, or EXCLUSIVE lock on the file. It returns, via its output 784 ** pointer parameter, true if such a lock exists and false otherwise. 785 ** 786 ** The xFileControl() method is a generic interface that allows custom 787 ** VFS implementations to directly control an open file using the 788 ** [sqlite3_file_control()] interface. The second "op" argument is an 789 ** integer opcode. The third argument is a generic pointer intended to 790 ** point to a structure that may contain arguments or space in which to 791 ** write return values. Potential uses for xFileControl() might be 792 ** functions to enable blocking locks with timeouts, to change the 793 ** locking strategy (for example to use dot-file locks), to inquire 794 ** about the status of a lock, or to break stale locks. The SQLite 795 ** core reserves all opcodes less than 100 for its own use. 796 ** A [file control opcodes | list of opcodes] less than 100 is available. 797 ** Applications that define a custom xFileControl method should use opcodes 798 ** greater than 100 to avoid conflicts. VFS implementations should 799 ** return [SQLITE_NOTFOUND] for file control opcodes that they do not 800 ** recognize. 801 ** 802 ** The xSectorSize() method returns the sector size of the 803 ** device that underlies the file. The sector size is the 804 ** minimum write that can be performed without disturbing 805 ** other bytes in the file. The xDeviceCharacteristics() 806 ** method returns a bit vector describing behaviors of the 807 ** underlying device: 808 ** 809 ** <ul> 810 ** <li> [SQLITE_IOCAP_ATOMIC] 811 ** <li> [SQLITE_IOCAP_ATOMIC512] 812 ** <li> [SQLITE_IOCAP_ATOMIC1K] 813 ** <li> [SQLITE_IOCAP_ATOMIC2K] 814 ** <li> [SQLITE_IOCAP_ATOMIC4K] 815 ** <li> [SQLITE_IOCAP_ATOMIC8K] 816 ** <li> [SQLITE_IOCAP_ATOMIC16K] 817 ** <li> [SQLITE_IOCAP_ATOMIC32K] 818 ** <li> [SQLITE_IOCAP_ATOMIC64K] 819 ** <li> [SQLITE_IOCAP_SAFE_APPEND] 820 ** <li> [SQLITE_IOCAP_SEQUENTIAL] 821 ** <li> [SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN] 822 ** <li> [SQLITE_IOCAP_POWERSAFE_OVERWRITE] 823 ** <li> [SQLITE_IOCAP_IMMUTABLE] 824 ** <li> [SQLITE_IOCAP_BATCH_ATOMIC] 825 ** <li> [SQLITE_IOCAP_SUBPAGE_READ] 826 ** </ul> 827 ** 828 ** The SQLITE_IOCAP_ATOMIC property means that all writes of 829 ** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 830 ** mean that writes of blocks that are nnn bytes in size and 831 ** are aligned to an address which is an integer multiple of 832 ** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 833 ** that when data is appended to a file, the data is appended 834 ** first then the size of the file is extended, never the other 835 ** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 836 ** information is written to disk in the same order as calls 837 ** to xWrite(). 838 ** 839 ** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill 840 ** in the unread portions of the buffer with zeros. A VFS that 841 ** fails to zero-fill short reads might seem to work. However, 842 ** failure to zero-fill short reads will eventually lead to 843 ** database corruption. 844 */ 845 typedef struct sqlite3_io_methods sqlite3_io_methods; 846 struct sqlite3_io_methods { 847 int iVersion; 848 int (*xClose)(sqlite3_file*); 849 int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst); 850 int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst); 851 int (*xTruncate)(sqlite3_file*, sqlite3_int64 size); 852 int (*xSync)(sqlite3_file*, int flags); 853 int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize); 854 int (*xLock)(sqlite3_file*, int); 855 int (*xUnlock)(sqlite3_file*, int); 856 int (*xCheckReservedLock)(sqlite3_file*, int *pResOut); 857 int (*xFileControl)(sqlite3_file*, int op, void *pArg); 858 int (*xSectorSize)(sqlite3_file*); 859 int (*xDeviceCharacteristics)(sqlite3_file*); 860 /* Methods above are valid for version 1 */ 861 int (*xShmMap)(sqlite3_file*, int iPg, int pgsz, int, void volatile**); 862 int (*xShmLock)(sqlite3_file*, int offset, int n, int flags); 863 void (*xShmBarrier)(sqlite3_file*); 864 int (*xShmUnmap)(sqlite3_file*, int deleteFlag); 865 /* Methods above are valid for version 2 */ 866 int (*xFetch)(sqlite3_file*, sqlite3_int64 iOfst, int iAmt, void **pp); 867 int (*xUnfetch)(sqlite3_file*, sqlite3_int64 iOfst, void *p); 868 /* Methods above are valid for version 3 */ 869 /* Additional methods may be added in future releases */ 870 }; 871 872 /* 873 ** CAPI3REF: Standard File Control Opcodes 874 ** KEYWORDS: {file control opcodes} {file control opcode} 875 ** 876 ** These integer constants are opcodes for the xFileControl method 877 ** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()] 878 ** interface. 879 ** 880 ** <ul> 881 ** <li>[[SQLITE_FCNTL_LOCKSTATE]] 882 ** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging. This 883 ** opcode causes the xFileControl method to write the current state of 884 ** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED], 885 ** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE]) 886 ** into an integer that the pArg argument points to. 887 ** This capability is only available if SQLite is compiled with [SQLITE_DEBUG]. 888 ** 889 ** <li>[[SQLITE_FCNTL_SIZE_HINT]] 890 ** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS 891 ** layer a hint of how large the database file will grow to be during the 892 ** current transaction. This hint is not guaranteed to be accurate but it 893 ** is often close. The underlying VFS might choose to preallocate database 894 ** file space based on this hint in order to help writes to the database 895 ** file run faster. 896 ** 897 ** <li>[[SQLITE_FCNTL_SIZE_LIMIT]] 898 ** The [SQLITE_FCNTL_SIZE_LIMIT] opcode is used by in-memory VFS that 899 ** implements [sqlite3_deserialize()] to set an upper bound on the size 900 ** of the in-memory database. The argument is a pointer to a [sqlite3_int64]. 901 ** If the integer pointed to is negative, then it is filled in with the 902 ** current limit. Otherwise the limit is set to the larger of the value 903 ** of the integer pointed to and the current database size. The integer 904 ** pointed to is set to the new limit. 905 ** 906 ** <li>[[SQLITE_FCNTL_CHUNK_SIZE]] 907 ** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS 908 ** extends and truncates the database file in chunks of a size specified 909 ** by the user. The fourth argument to [sqlite3_file_control()] should 910 ** point to an integer (type int) containing the new chunk-size to use 911 ** for the nominated database. Allocating database file space in large 912 ** chunks (say 1MB at a time), may reduce file-system fragmentation and 913 ** improve performance on some systems. 914 ** 915 ** <li>[[SQLITE_FCNTL_FILE_POINTER]] 916 ** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer 917 ** to the [sqlite3_file] object associated with a particular database 918 ** connection. See also [SQLITE_FCNTL_JOURNAL_POINTER]. 919 ** 920 ** <li>[[SQLITE_FCNTL_JOURNAL_POINTER]] 921 ** The [SQLITE_FCNTL_JOURNAL_POINTER] opcode is used to obtain a pointer 922 ** to the [sqlite3_file] object associated with the journal file (either 923 ** the [rollback journal] or the [write-ahead log]) for a particular database 924 ** connection. See also [SQLITE_FCNTL_FILE_POINTER]. 925 ** 926 ** <li>[[SQLITE_FCNTL_SYNC_OMITTED]] 927 ** No longer in use. 928 ** 929 ** <li>[[SQLITE_FCNTL_SYNC]] 930 ** The [SQLITE_FCNTL_SYNC] opcode is generated internally by SQLite and 931 ** sent to the VFS immediately before the xSync method is invoked on a 932 ** database file descriptor. Or, if the xSync method is not invoked 933 ** because the user has configured SQLite with 934 ** [PRAGMA synchronous | PRAGMA synchronous=OFF] it is invoked in place 935 ** of the xSync method. In most cases, the pointer argument passed with 936 ** this file-control is NULL. However, if the database file is being synced 937 ** as part of a multi-database commit, the argument points to a nul-terminated 938 ** string containing the transactions super-journal file name. VFSes that 939 ** do not need this signal should silently ignore this opcode. Applications 940 ** should not call [sqlite3_file_control()] with this opcode as doing so may 941 ** disrupt the operation of the specialized VFSes that do require it. 942 ** 943 ** <li>[[SQLITE_FCNTL_COMMIT_PHASETWO]] 944 ** The [SQLITE_FCNTL_COMMIT_PHASETWO] opcode is generated internally by SQLite 945 ** and sent to the VFS after a transaction has been committed immediately 946 ** but before the database is unlocked. VFSes that do not need this signal 947 ** should silently ignore this opcode. Applications should not call 948 ** [sqlite3_file_control()] with this opcode as doing so may disrupt the 949 ** operation of the specialized VFSes that do require it. 950 ** 951 ** <li>[[SQLITE_FCNTL_WIN32_AV_RETRY]] 952 ** ^The [SQLITE_FCNTL_WIN32_AV_RETRY] opcode is used to configure automatic 953 ** retry counts and intervals for certain disk I/O operations for the 954 ** windows [VFS] in order to provide robustness in the presence of 955 ** anti-virus programs. By default, the windows VFS will retry file read, 956 ** file write, and file delete operations up to 10 times, with a delay 957 ** of 25 milliseconds before the first retry and with the delay increasing 958 ** by an additional 25 milliseconds with each subsequent retry. This 959 ** opcode allows these two values (10 retries and 25 milliseconds of delay) 960 ** to be adjusted. The values are changed for all database connections 961 ** within the same process. The argument is a pointer to an array of two 962 ** integers where the first integer is the new retry count and the second 963 ** integer is the delay. If either integer is negative, then the setting 964 ** is not changed but instead the prior value of that setting is written 965 ** into the array entry, allowing the current retry settings to be 966 ** interrogated. The zDbName parameter is ignored. 967 ** 968 ** <li>[[SQLITE_FCNTL_PERSIST_WAL]] 969 ** ^The [SQLITE_FCNTL_PERSIST_WAL] opcode is used to set or query the 970 ** persistent [WAL | Write Ahead Log] setting. By default, the auxiliary 971 ** write ahead log ([WAL file]) and shared memory 972 ** files used for transaction control 973 ** are automatically deleted when the latest connection to the database 974 ** closes. Setting persistent WAL mode causes those files to persist after 975 ** close. Persisting the files is useful when other processes that do not 976 ** have write permission on the directory containing the database file want 977 ** to read the database file, as the WAL and shared memory files must exist 978 ** in order for the database to be readable. The fourth parameter to 979 ** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 980 ** That integer is 0 to disable persistent WAL mode or 1 to enable persistent 981 ** WAL mode. If the integer is -1, then it is overwritten with the current 982 ** WAL persistence setting. 983 ** 984 ** <li>[[SQLITE_FCNTL_POWERSAFE_OVERWRITE]] 985 ** ^The [SQLITE_FCNTL_POWERSAFE_OVERWRITE] opcode is used to set or query the 986 ** persistent "powersafe-overwrite" or "PSOW" setting. The PSOW setting 987 ** determines the [SQLITE_IOCAP_POWERSAFE_OVERWRITE] bit of the 988 ** xDeviceCharacteristics methods. The fourth parameter to 989 ** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 990 ** That integer is 0 to disable zero-damage mode or 1 to enable zero-damage 991 ** mode. If the integer is -1, then it is overwritten with the current 992 ** zero-damage mode setting. 993 ** 994 ** <li>[[SQLITE_FCNTL_OVERWRITE]] 995 ** ^The [SQLITE_FCNTL_OVERWRITE] opcode is invoked by SQLite after opening 996 ** a write transaction to indicate that, unless it is rolled back for some 997 ** reason, the entire database file will be overwritten by the current 998 ** transaction. This is used by VACUUM operations. 999 ** 1000 ** <li>[[SQLITE_FCNTL_VFSNAME]] 1001 ** ^The [SQLITE_FCNTL_VFSNAME] opcode can be used to obtain the names of 1002 ** all [VFSes] in the VFS stack. The names are of all VFS shims and the 1003 ** final bottom-level VFS are written into memory obtained from 1004 ** [sqlite3_malloc()] and the result is stored in the char* variable 1005 ** that the fourth parameter of [sqlite3_file_control()] points to. 1006 ** The caller is responsible for freeing the memory when done. As with 1007 ** all file-control actions, there is no guarantee that this will actually 1008 ** do anything. Callers should initialize the char* variable to a NULL 1009 ** pointer in case this file-control is not implemented. This file-control 1010 ** is intended for diagnostic use only. 1011 ** 1012 ** <li>[[SQLITE_FCNTL_VFS_POINTER]] 1013 ** ^The [SQLITE_FCNTL_VFS_POINTER] opcode finds a pointer to the top-level 1014 ** [VFSes] currently in use. ^(The argument X in 1015 ** sqlite3_file_control(db,SQLITE_FCNTL_VFS_POINTER,X) must be 1016 ** of type "[sqlite3_vfs] **". This opcodes will set *X 1017 ** to a pointer to the top-level VFS.)^ 1018 ** ^When there are multiple VFS shims in the stack, this opcode finds the 1019 ** upper-most shim only. 1020 ** 1021 ** <li>[[SQLITE_FCNTL_PRAGMA]] 1022 ** ^Whenever a [PRAGMA] statement is parsed, an [SQLITE_FCNTL_PRAGMA] 1023 ** file control is sent to the open [sqlite3_file] object corresponding 1024 ** to the database file to which the pragma statement refers. ^The argument 1025 ** to the [SQLITE_FCNTL_PRAGMA] file control is an array of 1026 ** pointers to strings (char**) in which the second element of the array 1027 ** is the name of the pragma and the third element is the argument to the 1028 ** pragma or NULL if the pragma has no argument. ^The handler for an 1029 ** [SQLITE_FCNTL_PRAGMA] file control can optionally make the first element 1030 ** of the char** argument point to a string obtained from [sqlite3_mprintf()] 1031 ** or the equivalent and that string will become the result of the pragma or 1032 ** the error message if the pragma fails. ^If the 1033 ** [SQLITE_FCNTL_PRAGMA] file control returns [SQLITE_NOTFOUND], then normal 1034 ** [PRAGMA] processing continues. ^If the [SQLITE_FCNTL_PRAGMA] 1035 ** file control returns [SQLITE_OK], then the parser assumes that the 1036 ** VFS has handled the PRAGMA itself and the parser generates a no-op 1037 ** prepared statement if result string is NULL, or that returns a copy 1038 ** of the result string if the string is non-NULL. 1039 ** ^If the [SQLITE_FCNTL_PRAGMA] file control returns 1040 ** any result code other than [SQLITE_OK] or [SQLITE_NOTFOUND], that means 1041 ** that the VFS encountered an error while handling the [PRAGMA] and the 1042 ** compilation of the PRAGMA fails with an error. ^The [SQLITE_FCNTL_PRAGMA] 1043 ** file control occurs at the beginning of pragma statement analysis and so 1044 ** it is able to override built-in [PRAGMA] statements. 1045 ** 1046 ** <li>[[SQLITE_FCNTL_BUSYHANDLER]] 1047 ** ^The [SQLITE_FCNTL_BUSYHANDLER] 1048 ** file-control may be invoked by SQLite on the database file handle 1049 ** shortly after it is opened in order to provide a custom VFS with access 1050 ** to the connection's busy-handler callback. The argument is of type (void**) 1051 ** - an array of two (void *) values. The first (void *) actually points 1052 ** to a function of type (int (*)(void *)). In order to invoke the connection's 1053 ** busy-handler, this function should be invoked with the second (void *) in 1054 ** the array as the only argument. If it returns non-zero, then the operation 1055 ** should be retried. If it returns zero, the custom VFS should abandon the 1056 ** current operation. 1057 ** 1058 ** <li>[[SQLITE_FCNTL_TEMPFILENAME]] 1059 ** ^Applications can invoke the [SQLITE_FCNTL_TEMPFILENAME] file-control 1060 ** to have SQLite generate a 1061 ** temporary filename using the same algorithm that is followed to generate 1062 ** temporary filenames for TEMP tables and other internal uses. The 1063 ** argument should be a char** which will be filled with the filename 1064 ** written into memory obtained from [sqlite3_malloc()]. The caller should 1065 ** invoke [sqlite3_free()] on the result to avoid a memory leak. 1066 ** 1067 ** <li>[[SQLITE_FCNTL_MMAP_SIZE]] 1068 ** The [SQLITE_FCNTL_MMAP_SIZE] file control is used to query or set the 1069 ** maximum number of bytes that will be used for memory-mapped I/O. 1070 ** The argument is a pointer to a value of type sqlite3_int64 that 1071 ** is an advisory maximum number of bytes in the file to memory map. The 1072 ** pointer is overwritten with the old value. The limit is not changed if 1073 ** the value originally pointed to is negative, and so the current limit 1074 ** can be queried by passing in a pointer to a negative number. This 1075 ** file-control is used internally to implement [PRAGMA mmap_size]. 1076 ** 1077 ** <li>[[SQLITE_FCNTL_TRACE]] 1078 ** The [SQLITE_FCNTL_TRACE] file control provides advisory information 1079 ** to the VFS about what the higher layers of the SQLite stack are doing. 1080 ** This file control is used by some VFS activity tracing [shims]. 1081 ** The argument is a zero-terminated string. Higher layers in the 1082 ** SQLite stack may generate instances of this file control if 1083 ** the [SQLITE_USE_FCNTL_TRACE] compile-time option is enabled. 1084 ** 1085 ** <li>[[SQLITE_FCNTL_HAS_MOVED]] 1086 ** The [SQLITE_FCNTL_HAS_MOVED] file control interprets its argument as a 1087 ** pointer to an integer and it writes a boolean into that integer depending 1088 ** on whether or not the file has been renamed, moved, or deleted since it 1089 ** was first opened. 1090 ** 1091 ** <li>[[SQLITE_FCNTL_WIN32_GET_HANDLE]] 1092 ** The [SQLITE_FCNTL_WIN32_GET_HANDLE] opcode can be used to obtain the 1093 ** underlying native file handle associated with a file handle. This file 1094 ** control interprets its argument as a pointer to a native file handle and 1095 ** writes the resulting value there. 1096 ** 1097 ** <li>[[SQLITE_FCNTL_WIN32_SET_HANDLE]] 1098 ** The [SQLITE_FCNTL_WIN32_SET_HANDLE] opcode is used for debugging. This 1099 ** opcode causes the xFileControl method to swap the file handle with the one 1100 ** pointed to by the pArg argument. This capability is used during testing 1101 ** and only needs to be supported when SQLITE_TEST is defined. 1102 ** 1103 ** <li>[[SQLITE_FCNTL_NULL_IO]] 1104 ** The [SQLITE_FCNTL_NULL_IO] opcode sets the low-level file descriptor 1105 ** or file handle for the [sqlite3_file] object such that it will no longer 1106 ** read or write to the database file. 1107 ** 1108 ** <li>[[SQLITE_FCNTL_WAL_BLOCK]] 1109 ** The [SQLITE_FCNTL_WAL_BLOCK] is a signal to the VFS layer that it might 1110 ** be advantageous to block on the next WAL lock if the lock is not immediately 1111 ** available. The WAL subsystem issues this signal during rare 1112 ** circumstances in order to fix a problem with priority inversion. 1113 ** Applications should <em>not</em> use this file-control. 1114 ** 1115 ** <li>[[SQLITE_FCNTL_ZIPVFS]] 1116 ** The [SQLITE_FCNTL_ZIPVFS] opcode is implemented by zipvfs only. All other 1117 ** VFS should return SQLITE_NOTFOUND for this opcode. 1118 ** 1119 ** <li>[[SQLITE_FCNTL_RBU]] 1120 ** The [SQLITE_FCNTL_RBU] opcode is implemented by the special VFS used by 1121 ** the RBU extension only. All other VFS should return SQLITE_NOTFOUND for 1122 ** this opcode. 1123 ** 1124 ** <li>[[SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]] 1125 ** If the [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] opcode returns SQLITE_OK, then 1126 ** the file descriptor is placed in "batch write mode", which 1127 ** means all subsequent write operations will be deferred and done 1128 ** atomically at the next [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]. Systems 1129 ** that do not support batch atomic writes will return SQLITE_NOTFOUND. 1130 ** ^Following a successful SQLITE_FCNTL_BEGIN_ATOMIC_WRITE and prior to 1131 ** the closing [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] or 1132 ** [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE], SQLite will make 1133 ** no VFS interface calls on the same [sqlite3_file] file descriptor 1134 ** except for calls to the xWrite method and the xFileControl method 1135 ** with [SQLITE_FCNTL_SIZE_HINT]. 1136 ** 1137 ** <li>[[SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]] 1138 ** The [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] opcode causes all write 1139 ** operations since the previous successful call to 1140 ** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be performed atomically. 1141 ** This file control returns [SQLITE_OK] if and only if the writes were 1142 ** all performed successfully and have been committed to persistent storage. 1143 ** ^Regardless of whether or not it is successful, this file control takes 1144 ** the file descriptor out of batch write mode so that all subsequent 1145 ** write operations are independent. 1146 ** ^SQLite will never invoke SQLITE_FCNTL_COMMIT_ATOMIC_WRITE without 1147 ** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]. 1148 ** 1149 ** <li>[[SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE]] 1150 ** The [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE] opcode causes all write 1151 ** operations since the previous successful call to 1152 ** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be rolled back. 1153 ** ^This file control takes the file descriptor out of batch write mode 1154 ** so that all subsequent write operations are independent. 1155 ** ^SQLite will never invoke SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE without 1156 ** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]. 1157 ** 1158 ** <li>[[SQLITE_FCNTL_LOCK_TIMEOUT]] 1159 ** The [SQLITE_FCNTL_LOCK_TIMEOUT] opcode is used to configure a VFS 1160 ** to block for up to M milliseconds before failing when attempting to 1161 ** obtain a file lock using the xLock or xShmLock methods of the VFS. 1162 ** The parameter is a pointer to a 32-bit signed integer that contains 1163 ** the value that M is to be set to. Before returning, the 32-bit signed 1164 ** integer is overwritten with the previous value of M. 1165 ** 1166 ** <li>[[SQLITE_FCNTL_BLOCK_ON_CONNECT]] 1167 ** The [SQLITE_FCNTL_BLOCK_ON_CONNECT] opcode is used to configure the 1168 ** VFS to block when taking a SHARED lock to connect to a wal mode database. 1169 ** This is used to implement the functionality associated with 1170 ** SQLITE_SETLK_BLOCK_ON_CONNECT. 1171 ** 1172 ** <li>[[SQLITE_FCNTL_DATA_VERSION]] 1173 ** The [SQLITE_FCNTL_DATA_VERSION] opcode is used to detect changes to 1174 ** a database file. The argument is a pointer to a 32-bit unsigned integer. 1175 ** The "data version" for the pager is written into the pointer. The 1176 ** "data version" changes whenever any change occurs to the corresponding 1177 ** database file, either through SQL statements on the same database 1178 ** connection or through transactions committed by separate database 1179 ** connections possibly in other processes. The [sqlite3_total_changes()] 1180 ** interface can be used to find if any database on the connection has changed, 1181 ** but that interface responds to changes on TEMP as well as MAIN and does 1182 ** not provide a mechanism to detect changes to MAIN only. Also, the 1183 ** [sqlite3_total_changes()] interface responds to internal changes only and 1184 ** omits changes made by other database connections. The 1185 ** [PRAGMA data_version] command provides a mechanism to detect changes to 1186 ** a single attached database that occur due to other database connections, 1187 ** but omits changes implemented by the database connection on which it is 1188 ** called. This file control is the only mechanism to detect changes that 1189 ** happen either internally or externally and that are associated with 1190 ** a particular attached database. 1191 ** 1192 ** <li>[[SQLITE_FCNTL_CKPT_START]] 1193 ** The [SQLITE_FCNTL_CKPT_START] opcode is invoked from within a checkpoint 1194 ** in wal mode before the client starts to copy pages from the wal 1195 ** file to the database file. 1196 ** 1197 ** <li>[[SQLITE_FCNTL_CKPT_DONE]] 1198 ** The [SQLITE_FCNTL_CKPT_DONE] opcode is invoked from within a checkpoint 1199 ** in wal mode after the client has finished copying pages from the wal 1200 ** file to the database file, but before the *-shm file is updated to 1201 ** record the fact that the pages have been checkpointed. 1202 ** 1203 ** <li>[[SQLITE_FCNTL_EXTERNAL_READER]] 1204 ** The EXPERIMENTAL [SQLITE_FCNTL_EXTERNAL_READER] opcode is used to detect 1205 ** whether or not there is a database client in another process with a wal-mode 1206 ** transaction open on the database or not. It is only available on unix.The 1207 ** (void*) argument passed with this file-control should be a pointer to a 1208 ** value of type (int). The integer value is set to 1 if the database is a wal 1209 ** mode database and there exists at least one client in another process that 1210 ** currently has an SQL transaction open on the database. It is set to 0 if 1211 ** the database is not a wal-mode db, or if there is no such connection in any 1212 ** other process. This opcode cannot be used to detect transactions opened 1213 ** by clients within the current process, only within other processes. 1214 ** 1215 ** <li>[[SQLITE_FCNTL_CKSM_FILE]] 1216 ** The [SQLITE_FCNTL_CKSM_FILE] opcode is for use internally by the 1217 ** [checksum VFS shim] only. 1218 ** 1219 ** <li>[[SQLITE_FCNTL_RESET_CACHE]] 1220 ** If there is currently no transaction open on the database, and the 1221 ** database is not a temp db, then the [SQLITE_FCNTL_RESET_CACHE] file-control 1222 ** purges the contents of the in-memory page cache. If there is an open 1223 ** transaction, or if the db is a temp-db, this opcode is a no-op, not an error. 1224 ** </ul> 1225 */ 1226 #define SQLITE_FCNTL_LOCKSTATE 1 1227 #define SQLITE_FCNTL_GET_LOCKPROXYFILE 2 1228 #define SQLITE_FCNTL_SET_LOCKPROXYFILE 3 1229 #define SQLITE_FCNTL_LAST_ERRNO 4 1230 #define SQLITE_FCNTL_SIZE_HINT 5 1231 #define SQLITE_FCNTL_CHUNK_SIZE 6 1232 #define SQLITE_FCNTL_FILE_POINTER 7 1233 #define SQLITE_FCNTL_SYNC_OMITTED 8 1234 #define SQLITE_FCNTL_WIN32_AV_RETRY 9 1235 #define SQLITE_FCNTL_PERSIST_WAL 10 1236 #define SQLITE_FCNTL_OVERWRITE 11 1237 #define SQLITE_FCNTL_VFSNAME 12 1238 #define SQLITE_FCNTL_POWERSAFE_OVERWRITE 13 1239 #define SQLITE_FCNTL_PRAGMA 14 1240 #define SQLITE_FCNTL_BUSYHANDLER 15 1241 #define SQLITE_FCNTL_TEMPFILENAME 16 1242 #define SQLITE_FCNTL_MMAP_SIZE 18 1243 #define SQLITE_FCNTL_TRACE 19 1244 #define SQLITE_FCNTL_HAS_MOVED 20 1245 #define SQLITE_FCNTL_SYNC 21 1246 #define SQLITE_FCNTL_COMMIT_PHASETWO 22 1247 #define SQLITE_FCNTL_WIN32_SET_HANDLE 23 1248 #define SQLITE_FCNTL_WAL_BLOCK 24 1249 #define SQLITE_FCNTL_ZIPVFS 25 1250 #define SQLITE_FCNTL_RBU 26 1251 #define SQLITE_FCNTL_VFS_POINTER 27 1252 #define SQLITE_FCNTL_JOURNAL_POINTER 28 1253 #define SQLITE_FCNTL_WIN32_GET_HANDLE 29 1254 #define SQLITE_FCNTL_PDB 30 1255 #define SQLITE_FCNTL_BEGIN_ATOMIC_WRITE 31 1256 #define SQLITE_FCNTL_COMMIT_ATOMIC_WRITE 32 1257 #define SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE 33 1258 #define SQLITE_FCNTL_LOCK_TIMEOUT 34 1259 #define SQLITE_FCNTL_DATA_VERSION 35 1260 #define SQLITE_FCNTL_SIZE_LIMIT 36 1261 #define SQLITE_FCNTL_CKPT_DONE 37 1262 #define SQLITE_FCNTL_RESERVE_BYTES 38 1263 #define SQLITE_FCNTL_CKPT_START 39 1264 #define SQLITE_FCNTL_EXTERNAL_READER 40 1265 #define SQLITE_FCNTL_CKSM_FILE 41 1266 #define SQLITE_FCNTL_RESET_CACHE 42 1267 #define SQLITE_FCNTL_NULL_IO 43 1268 #define SQLITE_FCNTL_BLOCK_ON_CONNECT 44 1269 1270 /* deprecated names */ 1271 #define SQLITE_GET_LOCKPROXYFILE SQLITE_FCNTL_GET_LOCKPROXYFILE 1272 #define SQLITE_SET_LOCKPROXYFILE SQLITE_FCNTL_SET_LOCKPROXYFILE 1273 #define SQLITE_LAST_ERRNO SQLITE_FCNTL_LAST_ERRNO 1274 1275 1276 /* 1277 ** CAPI3REF: Mutex Handle 1278 ** 1279 ** The mutex module within SQLite defines [sqlite3_mutex] to be an 1280 ** abstract type for a mutex object. The SQLite core never looks 1281 ** at the internal representation of an [sqlite3_mutex]. It only 1282 ** deals with pointers to the [sqlite3_mutex] object. 1283 ** 1284 ** Mutexes are created using [sqlite3_mutex_alloc()]. 1285 */ 1286 typedef struct sqlite3_mutex sqlite3_mutex; 1287 1288 /* 1289 ** CAPI3REF: Loadable Extension Thunk 1290 ** 1291 ** A pointer to the opaque sqlite3_api_routines structure is passed as 1292 ** the third parameter to entry points of [loadable extensions]. This 1293 ** structure must be typedefed in order to work around compiler warnings 1294 ** on some platforms. 1295 */ 1296 typedef struct sqlite3_api_routines sqlite3_api_routines; 1297 1298 /* 1299 ** CAPI3REF: File Name 1300 ** 1301 ** Type [sqlite3_filename] is used by SQLite to pass filenames to the 1302 ** xOpen method of a [VFS]. It may be cast to (const char*) and treated 1303 ** as a normal, nul-terminated, UTF-8 buffer containing the filename, but 1304 ** may also be passed to special APIs such as: 1305 ** 1306 ** <ul> 1307 ** <li> sqlite3_filename_database() 1308 ** <li> sqlite3_filename_journal() 1309 ** <li> sqlite3_filename_wal() 1310 ** <li> sqlite3_uri_parameter() 1311 ** <li> sqlite3_uri_boolean() 1312 ** <li> sqlite3_uri_int64() 1313 ** <li> sqlite3_uri_key() 1314 ** </ul> 1315 */ 1316 typedef const char *sqlite3_filename; 1317 1318 /* 1319 ** CAPI3REF: OS Interface Object 1320 ** 1321 ** An instance of the sqlite3_vfs object defines the interface between 1322 ** the SQLite core and the underlying operating system. The "vfs" 1323 ** in the name of the object stands for "virtual file system". See 1324 ** the [VFS | VFS documentation] for further information. 1325 ** 1326 ** The VFS interface is sometimes extended by adding new methods onto 1327 ** the end. Each time such an extension occurs, the iVersion field 1328 ** is incremented. The iVersion value started out as 1 in 1329 ** SQLite [version 3.5.0] on [dateof:3.5.0], then increased to 2 1330 ** with SQLite [version 3.7.0] on [dateof:3.7.0], and then increased 1331 ** to 3 with SQLite [version 3.7.6] on [dateof:3.7.6]. Additional fields 1332 ** may be appended to the sqlite3_vfs object and the iVersion value 1333 ** may increase again in future versions of SQLite. 1334 ** Note that due to an oversight, the structure 1335 ** of the sqlite3_vfs object changed in the transition from 1336 ** SQLite [version 3.5.9] to [version 3.6.0] on [dateof:3.6.0] 1337 ** and yet the iVersion field was not increased. 1338 ** 1339 ** The szOsFile field is the size of the subclassed [sqlite3_file] 1340 ** structure used by this VFS. mxPathname is the maximum length of 1341 ** a pathname in this VFS. 1342 ** 1343 ** Registered sqlite3_vfs objects are kept on a linked list formed by 1344 ** the pNext pointer. The [sqlite3_vfs_register()] 1345 ** and [sqlite3_vfs_unregister()] interfaces manage this list 1346 ** in a thread-safe way. The [sqlite3_vfs_find()] interface 1347 ** searches the list. Neither the application code nor the VFS 1348 ** implementation should use the pNext pointer. 1349 ** 1350 ** The pNext field is the only field in the sqlite3_vfs 1351 ** structure that SQLite will ever modify. SQLite will only access 1352 ** or modify this field while holding a particular static mutex. 1353 ** The application should never modify anything within the sqlite3_vfs 1354 ** object once the object has been registered. 1355 ** 1356 ** The zName field holds the name of the VFS module. The name must 1357 ** be unique across all VFS modules. 1358 ** 1359 ** [[sqlite3_vfs.xOpen]] 1360 ** ^SQLite guarantees that the zFilename parameter to xOpen 1361 ** is either a NULL pointer or string obtained 1362 ** from xFullPathname() with an optional suffix added. 1363 ** ^If a suffix is added to the zFilename parameter, it will 1364 ** consist of a single "-" character followed by no more than 1365 ** 11 alphanumeric and/or "-" characters. 1366 ** ^SQLite further guarantees that 1367 ** the string will be valid and unchanged until xClose() is 1368 ** called. Because of the previous sentence, 1369 ** the [sqlite3_file] can safely store a pointer to the 1370 ** filename if it needs to remember the filename for some reason. 1371 ** If the zFilename parameter to xOpen is a NULL pointer then xOpen 1372 ** must invent its own temporary name for the file. ^Whenever the 1373 ** xFilename parameter is NULL it will also be the case that the 1374 ** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE]. 1375 ** 1376 ** The flags argument to xOpen() includes all bits set in 1377 ** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()] 1378 ** or [sqlite3_open16()] is used, then flags includes at least 1379 ** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]. 1380 ** If xOpen() opens a file read-only then it sets *pOutFlags to 1381 ** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be set. 1382 ** 1383 ** ^(SQLite will also add one of the following flags to the xOpen() 1384 ** call, depending on the object being opened: 1385 ** 1386 ** <ul> 1387 ** <li> [SQLITE_OPEN_MAIN_DB] 1388 ** <li> [SQLITE_OPEN_MAIN_JOURNAL] 1389 ** <li> [SQLITE_OPEN_TEMP_DB] 1390 ** <li> [SQLITE_OPEN_TEMP_JOURNAL] 1391 ** <li> [SQLITE_OPEN_TRANSIENT_DB] 1392 ** <li> [SQLITE_OPEN_SUBJOURNAL] 1393 ** <li> [SQLITE_OPEN_SUPER_JOURNAL] 1394 ** <li> [SQLITE_OPEN_WAL] 1395 ** </ul>)^ 1396 ** 1397 ** The file I/O implementation can use the object type flags to 1398 ** change the way it deals with files. For example, an application 1399 ** that does not care about crash recovery or rollback might make 1400 ** the open of a journal file a no-op. Writes to this journal would 1401 ** also be no-ops, and any attempt to read the journal would return 1402 ** SQLITE_IOERR. Or the implementation might recognize that a database 1403 ** file will be doing page-aligned sector reads and writes in a random 1404 ** order and set up its I/O subsystem accordingly. 1405 ** 1406 ** SQLite might also add one of the following flags to the xOpen method: 1407 ** 1408 ** <ul> 1409 ** <li> [SQLITE_OPEN_DELETEONCLOSE] 1410 ** <li> [SQLITE_OPEN_EXCLUSIVE] 1411 ** </ul> 1412 ** 1413 ** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be 1414 ** deleted when it is closed. ^The [SQLITE_OPEN_DELETEONCLOSE] 1415 ** will be set for TEMP databases and their journals, transient 1416 ** databases, and subjournals. 1417 ** 1418 ** ^The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction 1419 ** with the [SQLITE_OPEN_CREATE] flag, which are both directly 1420 ** analogous to the O_EXCL and O_CREAT flags of the POSIX open() 1421 ** API. The SQLITE_OPEN_EXCLUSIVE flag, when paired with the 1422 ** SQLITE_OPEN_CREATE, is used to indicate that file should always 1423 ** be created, and that it is an error if it already exists. 1424 ** It is <i>not</i> used to indicate the file should be opened 1425 ** for exclusive access. 1426 ** 1427 ** ^At least szOsFile bytes of memory are allocated by SQLite 1428 ** to hold the [sqlite3_file] structure passed as the third 1429 ** argument to xOpen. The xOpen method does not have to 1430 ** allocate the structure; it should just fill it in. Note that 1431 ** the xOpen method must set the sqlite3_file.pMethods to either 1432 ** a valid [sqlite3_io_methods] object or to NULL. xOpen must do 1433 ** this even if the open fails. SQLite expects that the sqlite3_file.pMethods 1434 ** element will be valid after xOpen returns regardless of the success 1435 ** or failure of the xOpen call. 1436 ** 1437 ** [[sqlite3_vfs.xAccess]] 1438 ** ^The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS] 1439 ** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to 1440 ** test whether a file is readable and writable, or [SQLITE_ACCESS_READ] 1441 ** to test whether a file is at least readable. The SQLITE_ACCESS_READ 1442 ** flag is never actually used and is not implemented in the built-in 1443 ** VFSes of SQLite. The file is named by the second argument and can be a 1444 ** directory. The xAccess method returns [SQLITE_OK] on success or some 1445 ** non-zero error code if there is an I/O error or if the name of 1446 ** the file given in the second argument is illegal. If SQLITE_OK 1447 ** is returned, then non-zero or zero is written into *pResOut to indicate 1448 ** whether or not the file is accessible. 1449 ** 1450 ** ^SQLite will always allocate at least mxPathname+1 bytes for the 1451 ** output buffer xFullPathname. The exact size of the output buffer 1452 ** is also passed as a parameter to both methods. If the output buffer 1453 ** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is 1454 ** handled as a fatal error by SQLite, vfs implementations should endeavor 1455 ** to prevent this by setting mxPathname to a sufficiently large value. 1456 ** 1457 ** The xRandomness(), xSleep(), xCurrentTime(), and xCurrentTimeInt64() 1458 ** interfaces are not strictly a part of the filesystem, but they are 1459 ** included in the VFS structure for completeness. 1460 ** The xRandomness() function attempts to return nBytes bytes 1461 ** of good-quality randomness into zOut. The return value is 1462 ** the actual number of bytes of randomness obtained. 1463 ** The xSleep() method causes the calling thread to sleep for at 1464 ** least the number of microseconds given. ^The xCurrentTime() 1465 ** method returns a Julian Day Number for the current date and time as 1466 ** a floating point value. 1467 ** ^The xCurrentTimeInt64() method returns, as an integer, the Julian 1468 ** Day Number multiplied by 86400000 (the number of milliseconds in 1469 ** a 24-hour day). 1470 ** ^SQLite will use the xCurrentTimeInt64() method to get the current 1471 ** date and time if that method is available (if iVersion is 2 or 1472 ** greater and the function pointer is not NULL) and will fall back 1473 ** to xCurrentTime() if xCurrentTimeInt64() is unavailable. 1474 ** 1475 ** ^The xSetSystemCall(), xGetSystemCall(), and xNestSystemCall() interfaces 1476 ** are not used by the SQLite core. These optional interfaces are provided 1477 ** by some VFSes to facilitate testing of the VFS code. By overriding 1478 ** system calls with functions under its control, a test program can 1479 ** simulate faults and error conditions that would otherwise be difficult 1480 ** or impossible to induce. The set of system calls that can be overridden 1481 ** varies from one VFS to another, and from one version of the same VFS to the 1482 ** next. Applications that use these interfaces must be prepared for any 1483 ** or all of these interfaces to be NULL or for their behavior to change 1484 ** from one release to the next. Applications must not attempt to access 1485 ** any of these methods if the iVersion of the VFS is less than 3. 1486 */ 1487 typedef struct sqlite3_vfs sqlite3_vfs; 1488 typedef void (*sqlite3_syscall_ptr)(void); 1489 struct sqlite3_vfs { 1490 int iVersion; /* Structure version number (currently 3) */ 1491 int szOsFile; /* Size of subclassed sqlite3_file */ 1492 int mxPathname; /* Maximum file pathname length */ 1493 sqlite3_vfs *pNext; /* Next registered VFS */ 1494 const char *zName; /* Name of this virtual file system */ 1495 void *pAppData; /* Pointer to application-specific data */ 1496 int (*xOpen)(sqlite3_vfs*, sqlite3_filename zName, sqlite3_file*, 1497 int flags, int *pOutFlags); 1498 int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir); 1499 int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut); 1500 int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut); 1501 void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename); 1502 void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg); 1503 void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void); 1504 void (*xDlClose)(sqlite3_vfs*, void*); 1505 int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut); 1506 int (*xSleep)(sqlite3_vfs*, int microseconds); 1507 int (*xCurrentTime)(sqlite3_vfs*, double*); 1508 int (*xGetLastError)(sqlite3_vfs*, int, char *); 1509 /* 1510 ** The methods above are in version 1 of the sqlite_vfs object 1511 ** definition. Those that follow are added in version 2 or later 1512 */ 1513 int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*); 1514 /* 1515 ** The methods above are in versions 1 and 2 of the sqlite_vfs object. 1516 ** Those below are for version 3 and greater. 1517 */ 1518 int (*xSetSystemCall)(sqlite3_vfs*, const char *zName, sqlite3_syscall_ptr); 1519 sqlite3_syscall_ptr (*xGetSystemCall)(sqlite3_vfs*, const char *zName); 1520 const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName); 1521 /* 1522 ** The methods above are in versions 1 through 3 of the sqlite_vfs object. 1523 ** New fields may be appended in future versions. The iVersion 1524 ** value will increment whenever this happens. 1525 */ 1526 }; 1527 1528 /* 1529 ** CAPI3REF: Flags for the xAccess VFS method 1530 ** 1531 ** These integer constants can be used as the third parameter to 1532 ** the xAccess method of an [sqlite3_vfs] object. They determine 1533 ** what kind of permissions the xAccess method is looking for. 1534 ** With SQLITE_ACCESS_EXISTS, the xAccess method 1535 ** simply checks whether the file exists. 1536 ** With SQLITE_ACCESS_READWRITE, the xAccess method 1537 ** checks whether the named directory is both readable and writable 1538 ** (in other words, if files can be added, removed, and renamed within 1539 ** the directory). 1540 ** The SQLITE_ACCESS_READWRITE constant is currently used only by the 1541 ** [temp_store_directory pragma], though this could change in a future 1542 ** release of SQLite. 1543 ** With SQLITE_ACCESS_READ, the xAccess method 1544 ** checks whether the file is readable. The SQLITE_ACCESS_READ constant is 1545 ** currently unused, though it might be used in a future release of 1546 ** SQLite. 1547 */ 1548 #define SQLITE_ACCESS_EXISTS 0 1549 #define SQLITE_ACCESS_READWRITE 1 /* Used by PRAGMA temp_store_directory */ 1550 #define SQLITE_ACCESS_READ 2 /* Unused */ 1551 1552 /* 1553 ** CAPI3REF: Flags for the xShmLock VFS method 1554 ** 1555 ** These integer constants define the various locking operations 1556 ** allowed by the xShmLock method of [sqlite3_io_methods]. The 1557 ** following are the only legal combinations of flags to the 1558 ** xShmLock method: 1559 ** 1560 ** <ul> 1561 ** <li> SQLITE_SHM_LOCK | SQLITE_SHM_SHARED 1562 ** <li> SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE 1563 ** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED 1564 ** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE 1565 ** </ul> 1566 ** 1567 ** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as 1568 ** was given on the corresponding lock. 1569 ** 1570 ** The xShmLock method can transition between unlocked and SHARED or 1571 ** between unlocked and EXCLUSIVE. It cannot transition between SHARED 1572 ** and EXCLUSIVE. 1573 */ 1574 #define SQLITE_SHM_UNLOCK 1 1575 #define SQLITE_SHM_LOCK 2 1576 #define SQLITE_SHM_SHARED 4 1577 #define SQLITE_SHM_EXCLUSIVE 8 1578 1579 /* 1580 ** CAPI3REF: Maximum xShmLock index 1581 ** 1582 ** The xShmLock method on [sqlite3_io_methods] may use values 1583 ** between 0 and this upper bound as its "offset" argument. 1584 ** The SQLite core will never attempt to acquire or release a 1585 ** lock outside of this range 1586 */ 1587 #define SQLITE_SHM_NLOCK 8 1588 1589 1590 /* 1591 ** CAPI3REF: Initialize The SQLite Library 1592 ** 1593 ** ^The sqlite3_initialize() routine initializes the 1594 ** SQLite library. ^The sqlite3_shutdown() routine 1595 ** deallocates any resources that were allocated by sqlite3_initialize(). 1596 ** These routines are designed to aid in process initialization and 1597 ** shutdown on embedded systems. Workstation applications using 1598 ** SQLite normally do not need to invoke either of these routines. 1599 ** 1600 ** A call to sqlite3_initialize() is an "effective" call if it is 1601 ** the first time sqlite3_initialize() is invoked during the lifetime of 1602 ** the process, or if it is the first time sqlite3_initialize() is invoked 1603 ** following a call to sqlite3_shutdown(). ^(Only an effective call 1604 ** of sqlite3_initialize() does any initialization. All other calls 1605 ** are harmless no-ops.)^ 1606 ** 1607 ** A call to sqlite3_shutdown() is an "effective" call if it is the first 1608 ** call to sqlite3_shutdown() since the last sqlite3_initialize(). ^(Only 1609 ** an effective call to sqlite3_shutdown() does any deinitialization. 1610 ** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^ 1611 ** 1612 ** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown() 1613 ** is not. The sqlite3_shutdown() interface must only be called from a 1614 ** single thread. All open [database connections] must be closed and all 1615 ** other SQLite resources must be deallocated prior to invoking 1616 ** sqlite3_shutdown(). 1617 ** 1618 ** Among other things, ^sqlite3_initialize() will invoke 1619 ** sqlite3_os_init(). Similarly, ^sqlite3_shutdown() 1620 ** will invoke sqlite3_os_end(). 1621 ** 1622 ** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success. 1623 ** ^If for some reason, sqlite3_initialize() is unable to initialize 1624 ** the library (perhaps it is unable to allocate a needed resource such 1625 ** as a mutex) it returns an [error code] other than [SQLITE_OK]. 1626 ** 1627 ** ^The sqlite3_initialize() routine is called internally by many other 1628 ** SQLite interfaces so that an application usually does not need to 1629 ** invoke sqlite3_initialize() directly. For example, [sqlite3_open()] 1630 ** calls sqlite3_initialize() so the SQLite library will be automatically 1631 ** initialized when [sqlite3_open()] is called if it has not be initialized 1632 ** already. ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT] 1633 ** compile-time option, then the automatic calls to sqlite3_initialize() 1634 ** are omitted and the application must call sqlite3_initialize() directly 1635 ** prior to using any other SQLite interface. For maximum portability, 1636 ** it is recommended that applications always invoke sqlite3_initialize() 1637 ** directly prior to using any other SQLite interface. Future releases 1638 ** of SQLite may require this. In other words, the behavior exhibited 1639 ** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the 1640 ** default behavior in some future release of SQLite. 1641 ** 1642 ** The sqlite3_os_init() routine does operating-system specific 1643 ** initialization of the SQLite library. The sqlite3_os_end() 1644 ** routine undoes the effect of sqlite3_os_init(). Typical tasks 1645 ** performed by these routines include allocation or deallocation 1646 ** of static resources, initialization of global variables, 1647 ** setting up a default [sqlite3_vfs] module, or setting up 1648 ** a default configuration using [sqlite3_config()]. 1649 ** 1650 ** The application should never invoke either sqlite3_os_init() 1651 ** or sqlite3_os_end() directly. The application should only invoke 1652 ** sqlite3_initialize() and sqlite3_shutdown(). The sqlite3_os_init() 1653 ** interface is called automatically by sqlite3_initialize() and 1654 ** sqlite3_os_end() is called by sqlite3_shutdown(). Appropriate 1655 ** implementations for sqlite3_os_init() and sqlite3_os_end() 1656 ** are built into SQLite when it is compiled for Unix, Windows, or OS/2. 1657 ** When [custom builds | built for other platforms] 1658 ** (using the [SQLITE_OS_OTHER=1] compile-time 1659 ** option) the application must supply a suitable implementation for 1660 ** sqlite3_os_init() and sqlite3_os_end(). An application-supplied 1661 ** implementation of sqlite3_os_init() or sqlite3_os_end() 1662 ** must return [SQLITE_OK] on success and some other [error code] upon 1663 ** failure. 1664 */ 1665 SQLITE_API int sqlite3_initialize(void); 1666 SQLITE_API int sqlite3_shutdown(void); 1667 SQLITE_API int sqlite3_os_init(void); 1668 SQLITE_API int sqlite3_os_end(void); 1669 1670 /* 1671 ** CAPI3REF: Configuring The SQLite Library 1672 ** 1673 ** The sqlite3_config() interface is used to make global configuration 1674 ** changes to SQLite in order to tune SQLite to the specific needs of 1675 ** the application. The default configuration is recommended for most 1676 ** applications and so this routine is usually not necessary. It is 1677 ** provided to support rare applications with unusual needs. 1678 ** 1679 ** <b>The sqlite3_config() interface is not threadsafe. The application 1680 ** must ensure that no other SQLite interfaces are invoked by other 1681 ** threads while sqlite3_config() is running.</b> 1682 ** 1683 ** The first argument to sqlite3_config() is an integer 1684 ** [configuration option] that determines 1685 ** what property of SQLite is to be configured. Subsequent arguments 1686 ** vary depending on the [configuration option] 1687 ** in the first argument. 1688 ** 1689 ** For most configuration options, the sqlite3_config() interface 1690 ** may only be invoked prior to library initialization using 1691 ** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()]. 1692 ** The exceptional configuration options that may be invoked at any time 1693 ** are called "anytime configuration options". 1694 ** ^If sqlite3_config() is called after [sqlite3_initialize()] and before 1695 ** [sqlite3_shutdown()] with a first argument that is not an anytime 1696 ** configuration option, then the sqlite3_config() call will return SQLITE_MISUSE. 1697 ** Note, however, that ^sqlite3_config() can be called as part of the 1698 ** implementation of an application-defined [sqlite3_os_init()]. 1699 ** 1700 ** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK]. 1701 ** ^If the option is unknown or SQLite is unable to set the option 1702 ** then this routine returns a non-zero [error code]. 1703 */ 1704 SQLITE_API int sqlite3_config(int, ...); 1705 1706 /* 1707 ** CAPI3REF: Configure database connections 1708 ** METHOD: sqlite3 1709 ** 1710 ** The sqlite3_db_config() interface is used to make configuration 1711 ** changes to a [database connection]. The interface is similar to 1712 ** [sqlite3_config()] except that the changes apply to a single 1713 ** [database connection] (specified in the first argument). 1714 ** 1715 ** The second argument to sqlite3_db_config(D,V,...) is the 1716 ** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code 1717 ** that indicates what aspect of the [database connection] is being configured. 1718 ** Subsequent arguments vary depending on the configuration verb. 1719 ** 1720 ** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if 1721 ** the call is considered successful. 1722 */ 1723 SQLITE_API int sqlite3_db_config(sqlite3*, int op, ...); 1724 1725 /* 1726 ** CAPI3REF: Memory Allocation Routines 1727 ** 1728 ** An instance of this object defines the interface between SQLite 1729 ** and low-level memory allocation routines. 1730 ** 1731 ** This object is used in only one place in the SQLite interface. 1732 ** A pointer to an instance of this object is the argument to 1733 ** [sqlite3_config()] when the configuration option is 1734 ** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC]. 1735 ** By creating an instance of this object 1736 ** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC]) 1737 ** during configuration, an application can specify an alternative 1738 ** memory allocation subsystem for SQLite to use for all of its 1739 ** dynamic memory needs. 1740 ** 1741 ** Note that SQLite comes with several [built-in memory allocators] 1742 ** that are perfectly adequate for the overwhelming majority of applications 1743 ** and that this object is only useful to a tiny minority of applications 1744 ** with specialized memory allocation requirements. This object is 1745 ** also used during testing of SQLite in order to specify an alternative 1746 ** memory allocator that simulates memory out-of-memory conditions in 1747 ** order to verify that SQLite recovers gracefully from such 1748 ** conditions. 1749 ** 1750 ** The xMalloc, xRealloc, and xFree methods must work like the 1751 ** malloc(), realloc() and free() functions from the standard C library. 1752 ** ^SQLite guarantees that the second argument to 1753 ** xRealloc is always a value returned by a prior call to xRoundup. 1754 ** 1755 ** xSize should return the allocated size of a memory allocation 1756 ** previously obtained from xMalloc or xRealloc. The allocated size 1757 ** is always at least as big as the requested size but may be larger. 1758 ** 1759 ** The xRoundup method returns what would be the allocated size of 1760 ** a memory allocation given a particular requested size. Most memory 1761 ** allocators round up memory allocations at least to the next multiple 1762 ** of 8. Some allocators round up to a larger multiple or to a power of 2. 1763 ** Every memory allocation request coming in through [sqlite3_malloc()] 1764 ** or [sqlite3_realloc()] first calls xRoundup. If xRoundup returns 0, 1765 ** that causes the corresponding memory allocation to fail. 1766 ** 1767 ** The xInit method initializes the memory allocator. For example, 1768 ** it might allocate any required mutexes or initialize internal data 1769 ** structures. The xShutdown method is invoked (indirectly) by 1770 ** [sqlite3_shutdown()] and should deallocate any resources acquired 1771 ** by xInit. The pAppData pointer is used as the only parameter to 1772 ** xInit and xShutdown. 1773 ** 1774 ** SQLite holds the [SQLITE_MUTEX_STATIC_MAIN] mutex when it invokes 1775 ** the xInit method, so the xInit method need not be threadsafe. The 1776 ** xShutdown method is only called from [sqlite3_shutdown()] so it does 1777 ** not need to be threadsafe either. For all other methods, SQLite 1778 ** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the 1779 ** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which 1780 ** it is by default) and so the methods are automatically serialized. 1781 ** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other 1782 ** methods must be threadsafe or else make their own arrangements for 1783 ** serialization. 1784 ** 1785 ** SQLite will never invoke xInit() more than once without an intervening 1786 ** call to xShutdown(). 1787 */ 1788 typedef struct sqlite3_mem_methods sqlite3_mem_methods; 1789 struct sqlite3_mem_methods { 1790 void *(*xMalloc)(int); /* Memory allocation function */ 1791 void (*xFree)(void*); /* Free a prior allocation */ 1792 void *(*xRealloc)(void*,int); /* Resize an allocation */ 1793 int (*xSize)(void*); /* Return the size of an allocation */ 1794 int (*xRoundup)(int); /* Round up request size to allocation size */ 1795 int (*xInit)(void*); /* Initialize the memory allocator */ 1796 void (*xShutdown)(void*); /* Deinitialize the memory allocator */ 1797 void *pAppData; /* Argument to xInit() and xShutdown() */ 1798 }; 1799 1800 /* 1801 ** CAPI3REF: Configuration Options 1802 ** KEYWORDS: {configuration option} 1803 ** 1804 ** These constants are the available integer configuration options that 1805 ** can be passed as the first argument to the [sqlite3_config()] interface. 1806 ** 1807 ** Most of the configuration options for sqlite3_config() 1808 ** will only work if invoked prior to [sqlite3_initialize()] or after 1809 ** [sqlite3_shutdown()]. The few exceptions to this rule are called 1810 ** "anytime configuration options". 1811 ** ^Calling [sqlite3_config()] with a first argument that is not an 1812 ** anytime configuration option in between calls to [sqlite3_initialize()] and 1813 ** [sqlite3_shutdown()] is a no-op that returns SQLITE_MISUSE. 1814 ** 1815 ** The set of anytime configuration options can change (by insertions 1816 ** and/or deletions) from one release of SQLite to the next. 1817 ** As of SQLite version 3.42.0, the complete set of anytime configuration 1818 ** options is: 1819 ** <ul> 1820 ** <li> SQLITE_CONFIG_LOG 1821 ** <li> SQLITE_CONFIG_PCACHE_HDRSZ 1822 ** </ul> 1823 ** 1824 ** New configuration options may be added in future releases of SQLite. 1825 ** Existing configuration options might be discontinued. Applications 1826 ** should check the return code from [sqlite3_config()] to make sure that 1827 ** the call worked. The [sqlite3_config()] interface will return a 1828 ** non-zero [error code] if a discontinued or unsupported configuration option 1829 ** is invoked. 1830 ** 1831 ** <dl> 1832 ** [[SQLITE_CONFIG_SINGLETHREAD]] <dt>SQLITE_CONFIG_SINGLETHREAD</dt> 1833 ** <dd>There are no arguments to this option. ^This option sets the 1834 ** [threading mode] to Single-thread. In other words, it disables 1835 ** all mutexing and puts SQLite into a mode where it can only be used 1836 ** by a single thread. ^If SQLite is compiled with 1837 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1838 ** it is not possible to change the [threading mode] from its default 1839 ** value of Single-thread and so [sqlite3_config()] will return 1840 ** [SQLITE_ERROR] if called with the SQLITE_CONFIG_SINGLETHREAD 1841 ** configuration option.</dd> 1842 ** 1843 ** [[SQLITE_CONFIG_MULTITHREAD]] <dt>SQLITE_CONFIG_MULTITHREAD</dt> 1844 ** <dd>There are no arguments to this option. ^This option sets the 1845 ** [threading mode] to Multi-thread. In other words, it disables 1846 ** mutexing on [database connection] and [prepared statement] objects. 1847 ** The application is responsible for serializing access to 1848 ** [database connections] and [prepared statements]. But other mutexes 1849 ** are enabled so that SQLite will be safe to use in a multi-threaded 1850 ** environment as long as no two threads attempt to use the same 1851 ** [database connection] at the same time. ^If SQLite is compiled with 1852 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1853 ** it is not possible to set the Multi-thread [threading mode] and 1854 ** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1855 ** SQLITE_CONFIG_MULTITHREAD configuration option.</dd> 1856 ** 1857 ** [[SQLITE_CONFIG_SERIALIZED]] <dt>SQLITE_CONFIG_SERIALIZED</dt> 1858 ** <dd>There are no arguments to this option. ^This option sets the 1859 ** [threading mode] to Serialized. In other words, this option enables 1860 ** all mutexes including the recursive 1861 ** mutexes on [database connection] and [prepared statement] objects. 1862 ** In this mode (which is the default when SQLite is compiled with 1863 ** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access 1864 ** to [database connections] and [prepared statements] so that the 1865 ** application is free to use the same [database connection] or the 1866 ** same [prepared statement] in different threads at the same time. 1867 ** ^If SQLite is compiled with 1868 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1869 ** it is not possible to set the Serialized [threading mode] and 1870 ** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1871 ** SQLITE_CONFIG_SERIALIZED configuration option.</dd> 1872 ** 1873 ** [[SQLITE_CONFIG_MALLOC]] <dt>SQLITE_CONFIG_MALLOC</dt> 1874 ** <dd> ^(The SQLITE_CONFIG_MALLOC option takes a single argument which is 1875 ** a pointer to an instance of the [sqlite3_mem_methods] structure. 1876 ** The argument specifies 1877 ** alternative low-level memory allocation routines to be used in place of 1878 ** the memory allocation routines built into SQLite.)^ ^SQLite makes 1879 ** its own private copy of the content of the [sqlite3_mem_methods] structure 1880 ** before the [sqlite3_config()] call returns.</dd> 1881 ** 1882 ** [[SQLITE_CONFIG_GETMALLOC]] <dt>SQLITE_CONFIG_GETMALLOC</dt> 1883 ** <dd> ^(The SQLITE_CONFIG_GETMALLOC option takes a single argument which 1884 ** is a pointer to an instance of the [sqlite3_mem_methods] structure. 1885 ** The [sqlite3_mem_methods] 1886 ** structure is filled with the currently defined memory allocation routines.)^ 1887 ** This option can be used to overload the default memory allocation 1888 ** routines with a wrapper that simulations memory allocation failure or 1889 ** tracks memory usage, for example. </dd> 1890 ** 1891 ** [[SQLITE_CONFIG_SMALL_MALLOC]] <dt>SQLITE_CONFIG_SMALL_MALLOC</dt> 1892 ** <dd> ^The SQLITE_CONFIG_SMALL_MALLOC option takes single argument of 1893 ** type int, interpreted as a boolean, which if true provides a hint to 1894 ** SQLite that it should avoid large memory allocations if possible. 1895 ** SQLite will run faster if it is free to make large memory allocations, 1896 ** but some application might prefer to run slower in exchange for 1897 ** guarantees about memory fragmentation that are possible if large 1898 ** allocations are avoided. This hint is normally off. 1899 ** </dd> 1900 ** 1901 ** [[SQLITE_CONFIG_MEMSTATUS]] <dt>SQLITE_CONFIG_MEMSTATUS</dt> 1902 ** <dd> ^The SQLITE_CONFIG_MEMSTATUS option takes single argument of type int, 1903 ** interpreted as a boolean, which enables or disables the collection of 1904 ** memory allocation statistics. ^(When memory allocation statistics are 1905 ** disabled, the following SQLite interfaces become non-operational: 1906 ** <ul> 1907 ** <li> [sqlite3_hard_heap_limit64()] 1908 ** <li> [sqlite3_memory_used()] 1909 ** <li> [sqlite3_memory_highwater()] 1910 ** <li> [sqlite3_soft_heap_limit64()] 1911 ** <li> [sqlite3_status64()] 1912 ** </ul>)^ 1913 ** ^Memory allocation statistics are enabled by default unless SQLite is 1914 ** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory 1915 ** allocation statistics are disabled by default. 1916 ** </dd> 1917 ** 1918 ** [[SQLITE_CONFIG_SCRATCH]] <dt>SQLITE_CONFIG_SCRATCH</dt> 1919 ** <dd> The SQLITE_CONFIG_SCRATCH option is no longer used. 1920 ** </dd> 1921 ** 1922 ** [[SQLITE_CONFIG_PAGECACHE]] <dt>SQLITE_CONFIG_PAGECACHE</dt> 1923 ** <dd> ^The SQLITE_CONFIG_PAGECACHE option specifies a memory pool 1924 ** that SQLite can use for the database page cache with the default page 1925 ** cache implementation. 1926 ** This configuration option is a no-op if an application-defined page 1927 ** cache implementation is loaded using the [SQLITE_CONFIG_PCACHE2]. 1928 ** ^There are three arguments to SQLITE_CONFIG_PAGECACHE: A pointer to 1929 ** 8-byte aligned memory (pMem), the size of each page cache line (sz), 1930 ** and the number of cache lines (N). 1931 ** The sz argument should be the size of the largest database page 1932 ** (a power of two between 512 and 65536) plus some extra bytes for each 1933 ** page header. ^The number of extra bytes needed by the page header 1934 ** can be determined using [SQLITE_CONFIG_PCACHE_HDRSZ]. 1935 ** ^It is harmless, apart from the wasted memory, 1936 ** for the sz parameter to be larger than necessary. The pMem 1937 ** argument must be either a NULL pointer or a pointer to an 8-byte 1938 ** aligned block of memory of at least sz*N bytes, otherwise 1939 ** subsequent behavior is undefined. 1940 ** ^When pMem is not NULL, SQLite will strive to use the memory provided 1941 ** to satisfy page cache needs, falling back to [sqlite3_malloc()] if 1942 ** a page cache line is larger than sz bytes or if all of the pMem buffer 1943 ** is exhausted. 1944 ** ^If pMem is NULL and N is non-zero, then each database connection 1945 ** does an initial bulk allocation for page cache memory 1946 ** from [sqlite3_malloc()] sufficient for N cache lines if N is positive or 1947 ** of -1024*N bytes if N is negative, . ^If additional 1948 ** page cache memory is needed beyond what is provided by the initial 1949 ** allocation, then SQLite goes to [sqlite3_malloc()] separately for each 1950 ** additional cache line. </dd> 1951 ** 1952 ** [[SQLITE_CONFIG_HEAP]] <dt>SQLITE_CONFIG_HEAP</dt> 1953 ** <dd> ^The SQLITE_CONFIG_HEAP option specifies a static memory buffer 1954 ** that SQLite will use for all of its dynamic memory allocation needs 1955 ** beyond those provided for by [SQLITE_CONFIG_PAGECACHE]. 1956 ** ^The SQLITE_CONFIG_HEAP option is only available if SQLite is compiled 1957 ** with either [SQLITE_ENABLE_MEMSYS3] or [SQLITE_ENABLE_MEMSYS5] and returns 1958 ** [SQLITE_ERROR] if invoked otherwise. 1959 ** ^There are three arguments to SQLITE_CONFIG_HEAP: 1960 ** An 8-byte aligned pointer to the memory, 1961 ** the number of bytes in the memory buffer, and the minimum allocation size. 1962 ** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts 1963 ** to using its default memory allocator (the system malloc() implementation), 1964 ** undoing any prior invocation of [SQLITE_CONFIG_MALLOC]. ^If the 1965 ** memory pointer is not NULL then the alternative memory 1966 ** allocator is engaged to handle all of SQLites memory allocation needs. 1967 ** The first pointer (the memory pointer) must be aligned to an 8-byte 1968 ** boundary or subsequent behavior of SQLite will be undefined. 1969 ** The minimum allocation size is capped at 2**12. Reasonable values 1970 ** for the minimum allocation size are 2**5 through 2**8.</dd> 1971 ** 1972 ** [[SQLITE_CONFIG_MUTEX]] <dt>SQLITE_CONFIG_MUTEX</dt> 1973 ** <dd> ^(The SQLITE_CONFIG_MUTEX option takes a single argument which is a 1974 ** pointer to an instance of the [sqlite3_mutex_methods] structure. 1975 ** The argument specifies alternative low-level mutex routines to be used 1976 ** in place the mutex routines built into SQLite.)^ ^SQLite makes a copy of 1977 ** the content of the [sqlite3_mutex_methods] structure before the call to 1978 ** [sqlite3_config()] returns. ^If SQLite is compiled with 1979 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1980 ** the entire mutexing subsystem is omitted from the build and hence calls to 1981 ** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will 1982 ** return [SQLITE_ERROR].</dd> 1983 ** 1984 ** [[SQLITE_CONFIG_GETMUTEX]] <dt>SQLITE_CONFIG_GETMUTEX</dt> 1985 ** <dd> ^(The SQLITE_CONFIG_GETMUTEX option takes a single argument which 1986 ** is a pointer to an instance of the [sqlite3_mutex_methods] structure. The 1987 ** [sqlite3_mutex_methods] 1988 ** structure is filled with the currently defined mutex routines.)^ 1989 ** This option can be used to overload the default mutex allocation 1990 ** routines with a wrapper used to track mutex usage for performance 1991 ** profiling or testing, for example. ^If SQLite is compiled with 1992 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1993 ** the entire mutexing subsystem is omitted from the build and hence calls to 1994 ** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will 1995 ** return [SQLITE_ERROR].</dd> 1996 ** 1997 ** [[SQLITE_CONFIG_LOOKASIDE]] <dt>SQLITE_CONFIG_LOOKASIDE</dt> 1998 ** <dd> ^(The SQLITE_CONFIG_LOOKASIDE option takes two arguments that determine 1999 ** the default size of [lookaside memory] on each [database connection]. 2000 ** The first argument is the 2001 ** size of each lookaside buffer slot ("sz") and the second is the number of 2002 ** slots allocated to each database connection ("cnt").)^ 2003 ** ^(SQLITE_CONFIG_LOOKASIDE sets the <i>default</i> lookaside size. 2004 ** The [SQLITE_DBCONFIG_LOOKASIDE] option to [sqlite3_db_config()] can 2005 ** be used to change the lookaside configuration on individual connections.)^ 2006 ** The [-DSQLITE_DEFAULT_LOOKASIDE] option can be used to change the 2007 ** default lookaside configuration at compile-time. 2008 ** </dd> 2009 ** 2010 ** [[SQLITE_CONFIG_PCACHE2]] <dt>SQLITE_CONFIG_PCACHE2</dt> 2011 ** <dd> ^(The SQLITE_CONFIG_PCACHE2 option takes a single argument which is 2012 ** a pointer to an [sqlite3_pcache_methods2] object. This object specifies 2013 ** the interface to a custom page cache implementation.)^ 2014 ** ^SQLite makes a copy of the [sqlite3_pcache_methods2] object.</dd> 2015 ** 2016 ** [[SQLITE_CONFIG_GETPCACHE2]] <dt>SQLITE_CONFIG_GETPCACHE2</dt> 2017 ** <dd> ^(The SQLITE_CONFIG_GETPCACHE2 option takes a single argument which 2018 ** is a pointer to an [sqlite3_pcache_methods2] object. SQLite copies of 2019 ** the current page cache implementation into that object.)^ </dd> 2020 ** 2021 ** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt> 2022 ** <dd> The SQLITE_CONFIG_LOG option is used to configure the SQLite 2023 ** global [error log]. 2024 ** (^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a 2025 ** function with a call signature of void(*)(void*,int,const char*), 2026 ** and a pointer to void. ^If the function pointer is not NULL, it is 2027 ** invoked by [sqlite3_log()] to process each logging event. ^If the 2028 ** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op. 2029 ** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is 2030 ** passed through as the first parameter to the application-defined logger 2031 ** function whenever that function is invoked. ^The second parameter to 2032 ** the logger function is a copy of the first parameter to the corresponding 2033 ** [sqlite3_log()] call and is intended to be a [result code] or an 2034 ** [extended result code]. ^The third parameter passed to the logger is 2035 ** log message after formatting via [sqlite3_snprintf()]. 2036 ** The SQLite logging interface is not reentrant; the logger function 2037 ** supplied by the application must not invoke any SQLite interface. 2038 ** In a multi-threaded application, the application-defined logger 2039 ** function must be threadsafe. </dd> 2040 ** 2041 ** [[SQLITE_CONFIG_URI]] <dt>SQLITE_CONFIG_URI 2042 ** <dd>^(The SQLITE_CONFIG_URI option takes a single argument of type int. 2043 ** If non-zero, then URI handling is globally enabled. If the parameter is zero, 2044 ** then URI handling is globally disabled.)^ ^If URI handling is globally 2045 ** enabled, all filenames passed to [sqlite3_open()], [sqlite3_open_v2()], 2046 ** [sqlite3_open16()] or 2047 ** specified as part of [ATTACH] commands are interpreted as URIs, regardless 2048 ** of whether or not the [SQLITE_OPEN_URI] flag is set when the database 2049 ** connection is opened. ^If it is globally disabled, filenames are 2050 ** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the 2051 ** database connection is opened. ^(By default, URI handling is globally 2052 ** disabled. The default value may be changed by compiling with the 2053 ** [SQLITE_USE_URI] symbol defined.)^ 2054 ** 2055 ** [[SQLITE_CONFIG_COVERING_INDEX_SCAN]] <dt>SQLITE_CONFIG_COVERING_INDEX_SCAN 2056 ** <dd>^The SQLITE_CONFIG_COVERING_INDEX_SCAN option takes a single integer 2057 ** argument which is interpreted as a boolean in order to enable or disable 2058 ** the use of covering indices for full table scans in the query optimizer. 2059 ** ^The default setting is determined 2060 ** by the [SQLITE_ALLOW_COVERING_INDEX_SCAN] compile-time option, or is "on" 2061 ** if that compile-time option is omitted. 2062 ** The ability to disable the use of covering indices for full table scans 2063 ** is because some incorrectly coded legacy applications might malfunction 2064 ** when the optimization is enabled. Providing the ability to 2065 ** disable the optimization allows the older, buggy application code to work 2066 ** without change even with newer versions of SQLite. 2067 ** 2068 ** [[SQLITE_CONFIG_PCACHE]] [[SQLITE_CONFIG_GETPCACHE]] 2069 ** <dt>SQLITE_CONFIG_PCACHE and SQLITE_CONFIG_GETPCACHE 2070 ** <dd> These options are obsolete and should not be used by new code. 2071 ** They are retained for backwards compatibility but are now no-ops. 2072 ** </dd> 2073 ** 2074 ** [[SQLITE_CONFIG_SQLLOG]] 2075 ** <dt>SQLITE_CONFIG_SQLLOG 2076 ** <dd>This option is only available if sqlite is compiled with the 2077 ** [SQLITE_ENABLE_SQLLOG] pre-processor macro defined. The first argument should 2078 ** be a pointer to a function of type void(*)(void*,sqlite3*,const char*, int). 2079 ** The second should be of type (void*). The callback is invoked by the library 2080 ** in three separate circumstances, identified by the value passed as the 2081 ** fourth parameter. If the fourth parameter is 0, then the database connection 2082 ** passed as the second argument has just been opened. The third argument 2083 ** points to a buffer containing the name of the main database file. If the 2084 ** fourth parameter is 1, then the SQL statement that the third parameter 2085 ** points to has just been executed. Or, if the fourth parameter is 2, then 2086 ** the connection being passed as the second parameter is being closed. The 2087 ** third parameter is passed NULL In this case. An example of using this 2088 ** configuration option can be seen in the "test_sqllog.c" source file in 2089 ** the canonical SQLite source tree.</dd> 2090 ** 2091 ** [[SQLITE_CONFIG_MMAP_SIZE]] 2092 ** <dt>SQLITE_CONFIG_MMAP_SIZE 2093 ** <dd>^SQLITE_CONFIG_MMAP_SIZE takes two 64-bit integer (sqlite3_int64) values 2094 ** that are the default mmap size limit (the default setting for 2095 ** [PRAGMA mmap_size]) and the maximum allowed mmap size limit. 2096 ** ^The default setting can be overridden by each database connection using 2097 ** either the [PRAGMA mmap_size] command, or by using the 2098 ** [SQLITE_FCNTL_MMAP_SIZE] file control. ^(The maximum allowed mmap size 2099 ** will be silently truncated if necessary so that it does not exceed the 2100 ** compile-time maximum mmap size set by the 2101 ** [SQLITE_MAX_MMAP_SIZE] compile-time option.)^ 2102 ** ^If either argument to this option is negative, then that argument is 2103 ** changed to its compile-time default. 2104 ** 2105 ** [[SQLITE_CONFIG_WIN32_HEAPSIZE]] 2106 ** <dt>SQLITE_CONFIG_WIN32_HEAPSIZE 2107 ** <dd>^The SQLITE_CONFIG_WIN32_HEAPSIZE option is only available if SQLite is 2108 ** compiled for Windows with the [SQLITE_WIN32_MALLOC] pre-processor macro 2109 ** defined. ^SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit unsigned integer value 2110 ** that specifies the maximum size of the created heap. 2111 ** 2112 ** [[SQLITE_CONFIG_PCACHE_HDRSZ]] 2113 ** <dt>SQLITE_CONFIG_PCACHE_HDRSZ 2114 ** <dd>^The SQLITE_CONFIG_PCACHE_HDRSZ option takes a single parameter which 2115 ** is a pointer to an integer and writes into that integer the number of extra 2116 ** bytes per page required for each page in [SQLITE_CONFIG_PAGECACHE]. 2117 ** The amount of extra space required can change depending on the compiler, 2118 ** target platform, and SQLite version. 2119 ** 2120 ** [[SQLITE_CONFIG_PMASZ]] 2121 ** <dt>SQLITE_CONFIG_PMASZ 2122 ** <dd>^The SQLITE_CONFIG_PMASZ option takes a single parameter which 2123 ** is an unsigned integer and sets the "Minimum PMA Size" for the multithreaded 2124 ** sorter to that integer. The default minimum PMA Size is set by the 2125 ** [SQLITE_SORTER_PMASZ] compile-time option. New threads are launched 2126 ** to help with sort operations when multithreaded sorting 2127 ** is enabled (using the [PRAGMA threads] command) and the amount of content 2128 ** to be sorted exceeds the page size times the minimum of the 2129 ** [PRAGMA cache_size] setting and this value. 2130 ** 2131 ** [[SQLITE_CONFIG_STMTJRNL_SPILL]] 2132 ** <dt>SQLITE_CONFIG_STMTJRNL_SPILL 2133 ** <dd>^The SQLITE_CONFIG_STMTJRNL_SPILL option takes a single parameter which 2134 ** becomes the [statement journal] spill-to-disk threshold. 2135 ** [Statement journals] are held in memory until their size (in bytes) 2136 ** exceeds this threshold, at which point they are written to disk. 2137 ** Or if the threshold is -1, statement journals are always held 2138 ** exclusively in memory. 2139 ** Since many statement journals never become large, setting the spill 2140 ** threshold to a value such as 64KiB can greatly reduce the amount of 2141 ** I/O required to support statement rollback. 2142 ** The default value for this setting is controlled by the 2143 ** [SQLITE_STMTJRNL_SPILL] compile-time option. 2144 ** 2145 ** [[SQLITE_CONFIG_SORTERREF_SIZE]] 2146 ** <dt>SQLITE_CONFIG_SORTERREF_SIZE 2147 ** <dd>The SQLITE_CONFIG_SORTERREF_SIZE option accepts a single parameter 2148 ** of type (int) - the new value of the sorter-reference size threshold. 2149 ** Usually, when SQLite uses an external sort to order records according 2150 ** to an ORDER BY clause, all fields required by the caller are present in the 2151 ** sorted records. However, if SQLite determines based on the declared type 2152 ** of a table column that its values are likely to be very large - larger 2153 ** than the configured sorter-reference size threshold - then a reference 2154 ** is stored in each sorted record and the required column values loaded 2155 ** from the database as records are returned in sorted order. The default 2156 ** value for this option is to never use this optimization. Specifying a 2157 ** negative value for this option restores the default behavior. 2158 ** This option is only available if SQLite is compiled with the 2159 ** [SQLITE_ENABLE_SORTER_REFERENCES] compile-time option. 2160 ** 2161 ** [[SQLITE_CONFIG_MEMDB_MAXSIZE]] 2162 ** <dt>SQLITE_CONFIG_MEMDB_MAXSIZE 2163 ** <dd>The SQLITE_CONFIG_MEMDB_MAXSIZE option accepts a single parameter 2164 ** [sqlite3_int64] parameter which is the default maximum size for an in-memory 2165 ** database created using [sqlite3_deserialize()]. This default maximum 2166 ** size can be adjusted up or down for individual databases using the 2167 ** [SQLITE_FCNTL_SIZE_LIMIT] [sqlite3_file_control|file-control]. If this 2168 ** configuration setting is never used, then the default maximum is determined 2169 ** by the [SQLITE_MEMDB_DEFAULT_MAXSIZE] compile-time option. If that 2170 ** compile-time option is not set, then the default maximum is 1073741824. 2171 ** 2172 ** [[SQLITE_CONFIG_ROWID_IN_VIEW]] 2173 ** <dt>SQLITE_CONFIG_ROWID_IN_VIEW 2174 ** <dd>The SQLITE_CONFIG_ROWID_IN_VIEW option enables or disables the ability 2175 ** for VIEWs to have a ROWID. The capability can only be enabled if SQLite is 2176 ** compiled with -DSQLITE_ALLOW_ROWID_IN_VIEW, in which case the capability 2177 ** defaults to on. This configuration option queries the current setting or 2178 ** changes the setting to off or on. The argument is a pointer to an integer. 2179 ** If that integer initially holds a value of 1, then the ability for VIEWs to 2180 ** have ROWIDs is activated. If the integer initially holds zero, then the 2181 ** ability is deactivated. Any other initial value for the integer leaves the 2182 ** setting unchanged. After changes, if any, the integer is written with 2183 ** a 1 or 0, if the ability for VIEWs to have ROWIDs is on or off. If SQLite 2184 ** is compiled without -DSQLITE_ALLOW_ROWID_IN_VIEW (which is the usual and 2185 ** recommended case) then the integer is always filled with zero, regardless 2186 ** if its initial value. 2187 ** </dl> 2188 */ 2189 #define SQLITE_CONFIG_SINGLETHREAD 1 /* nil */ 2190 #define SQLITE_CONFIG_MULTITHREAD 2 /* nil */ 2191 #define SQLITE_CONFIG_SERIALIZED 3 /* nil */ 2192 #define SQLITE_CONFIG_MALLOC 4 /* sqlite3_mem_methods* */ 2193 #define SQLITE_CONFIG_GETMALLOC 5 /* sqlite3_mem_methods* */ 2194 #define SQLITE_CONFIG_SCRATCH 6 /* No longer used */ 2195 #define SQLITE_CONFIG_PAGECACHE 7 /* void*, int sz, int N */ 2196 #define SQLITE_CONFIG_HEAP 8 /* void*, int nByte, int min */ 2197 #define SQLITE_CONFIG_MEMSTATUS 9 /* boolean */ 2198 #define SQLITE_CONFIG_MUTEX 10 /* sqlite3_mutex_methods* */ 2199 #define SQLITE_CONFIG_GETMUTEX 11 /* sqlite3_mutex_methods* */ 2200 /* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */ 2201 #define SQLITE_CONFIG_LOOKASIDE 13 /* int int */ 2202 #define SQLITE_CONFIG_PCACHE 14 /* no-op */ 2203 #define SQLITE_CONFIG_GETPCACHE 15 /* no-op */ 2204 #define SQLITE_CONFIG_LOG 16 /* xFunc, void* */ 2205 #define SQLITE_CONFIG_URI 17 /* int */ 2206 #define SQLITE_CONFIG_PCACHE2 18 /* sqlite3_pcache_methods2* */ 2207 #define SQLITE_CONFIG_GETPCACHE2 19 /* sqlite3_pcache_methods2* */ 2208 #define SQLITE_CONFIG_COVERING_INDEX_SCAN 20 /* int */ 2209 #define SQLITE_CONFIG_SQLLOG 21 /* xSqllog, void* */ 2210 #define SQLITE_CONFIG_MMAP_SIZE 22 /* sqlite3_int64, sqlite3_int64 */ 2211 #define SQLITE_CONFIG_WIN32_HEAPSIZE 23 /* int nByte */ 2212 #define SQLITE_CONFIG_PCACHE_HDRSZ 24 /* int *psz */ 2213 #define SQLITE_CONFIG_PMASZ 25 /* unsigned int szPma */ 2214 #define SQLITE_CONFIG_STMTJRNL_SPILL 26 /* int nByte */ 2215 #define SQLITE_CONFIG_SMALL_MALLOC 27 /* boolean */ 2216 #define SQLITE_CONFIG_SORTERREF_SIZE 28 /* int nByte */ 2217 #define SQLITE_CONFIG_MEMDB_MAXSIZE 29 /* sqlite3_int64 */ 2218 #define SQLITE_CONFIG_ROWID_IN_VIEW 30 /* int* */ 2219 2220 /* 2221 ** CAPI3REF: Database Connection Configuration Options 2222 ** 2223 ** These constants are the available integer configuration options that 2224 ** can be passed as the second parameter to the [sqlite3_db_config()] interface. 2225 ** 2226 ** The [sqlite3_db_config()] interface is a var-args functions. It takes a 2227 ** variable number of parameters, though always at least two. The number of 2228 ** parameters passed into sqlite3_db_config() depends on which of these 2229 ** constants is given as the second parameter. This documentation page 2230 ** refers to parameters beyond the second as "arguments". Thus, when this 2231 ** page says "the N-th argument" it means "the N-th parameter past the 2232 ** configuration option" or "the (N+2)-th parameter to sqlite3_db_config()". 2233 ** 2234 ** New configuration options may be added in future releases of SQLite. 2235 ** Existing configuration options might be discontinued. Applications 2236 ** should check the return code from [sqlite3_db_config()] to make sure that 2237 ** the call worked. ^The [sqlite3_db_config()] interface will return a 2238 ** non-zero [error code] if a discontinued or unsupported configuration option 2239 ** is invoked. 2240 ** 2241 ** <dl> 2242 ** [[SQLITE_DBCONFIG_LOOKASIDE]] 2243 ** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt> 2244 ** <dd> The SQLITE_DBCONFIG_LOOKASIDE option is used to adjust the 2245 ** configuration of the [lookaside memory allocator] within a database 2246 ** connection. 2247 ** The arguments to the SQLITE_DBCONFIG_LOOKASIDE option are <i>not</i> 2248 ** in the [DBCONFIG arguments|usual format]. 2249 ** The SQLITE_DBCONFIG_LOOKASIDE option takes three arguments, not two, 2250 ** so that a call to [sqlite3_db_config()] that uses SQLITE_DBCONFIG_LOOKASIDE 2251 ** should have a total of five parameters. 2252 ** <ol> 2253 ** <li><p>The first argument ("buf") is a 2254 ** pointer to a memory buffer to use for lookaside memory. 2255 ** The first argument may be NULL in which case SQLite will allocate the 2256 ** lookaside buffer itself using [sqlite3_malloc()]. 2257 ** <li><P>The second argument ("sz") is the 2258 ** size of each lookaside buffer slot. Lookaside is disabled if "sz" 2259 ** is less than 8. The "sz" argument should be a multiple of 8 less than 2260 ** 65536. If "sz" does not meet this constraint, it is reduced in size until 2261 ** it does. 2262 ** <li><p>The third argument ("cnt") is the number of slots. Lookaside is disabled 2263 ** if "cnt"is less than 1. The "cnt" value will be reduced, if necessary, so 2264 ** that the product of "sz" and "cnt" does not exceed 2,147,418,112. The "cnt" 2265 ** parameter is usually chosen so that the product of "sz" and "cnt" is less 2266 ** than 1,000,000. 2267 ** </ol> 2268 ** <p>If the "buf" argument is not NULL, then it must 2269 ** point to a memory buffer with a size that is greater than 2270 ** or equal to the product of "sz" and "cnt". 2271 ** The buffer must be aligned to an 8-byte boundary. 2272 ** The lookaside memory 2273 ** configuration for a database connection can only be changed when that 2274 ** connection is not currently using lookaside memory, or in other words 2275 ** when the value returned by [SQLITE_DBSTATUS_LOOKASIDE_USED] is zero. 2276 ** Any attempt to change the lookaside memory configuration when lookaside 2277 ** memory is in use leaves the configuration unchanged and returns 2278 ** [SQLITE_BUSY]. 2279 ** If the "buf" argument is NULL and an attempt 2280 ** to allocate memory based on "sz" and "cnt" fails, then 2281 ** lookaside is silently disabled. 2282 ** <p> 2283 ** The [SQLITE_CONFIG_LOOKASIDE] configuration option can be used to set the 2284 ** default lookaside configuration at initialization. The 2285 ** [-DSQLITE_DEFAULT_LOOKASIDE] option can be used to set the default lookaside 2286 ** configuration at compile-time. Typical values for lookaside are 1200 for 2287 ** "sz" and 40 to 100 for "cnt". 2288 ** </dd> 2289 ** 2290 ** [[SQLITE_DBCONFIG_ENABLE_FKEY]] 2291 ** <dt>SQLITE_DBCONFIG_ENABLE_FKEY</dt> 2292 ** <dd> ^This option is used to enable or disable the enforcement of 2293 ** [foreign key constraints]. This is the same setting that is 2294 ** enabled or disabled by the [PRAGMA foreign_keys] statement. 2295 ** The first argument is an integer which is 0 to disable FK enforcement, 2296 ** positive to enable FK enforcement or negative to leave FK enforcement 2297 ** unchanged. The second parameter is a pointer to an integer into which 2298 ** is written 0 or 1 to indicate whether FK enforcement is off or on 2299 ** following this call. The second parameter may be a NULL pointer, in 2300 ** which case the FK enforcement setting is not reported back. </dd> 2301 ** 2302 ** [[SQLITE_DBCONFIG_ENABLE_TRIGGER]] 2303 ** <dt>SQLITE_DBCONFIG_ENABLE_TRIGGER</dt> 2304 ** <dd> ^This option is used to enable or disable [CREATE TRIGGER | triggers]. 2305 ** There should be two additional arguments. 2306 ** The first argument is an integer which is 0 to disable triggers, 2307 ** positive to enable triggers or negative to leave the setting unchanged. 2308 ** The second parameter is a pointer to an integer into which 2309 ** is written 0 or 1 to indicate whether triggers are disabled or enabled 2310 ** following this call. The second parameter may be a NULL pointer, in 2311 ** which case the trigger setting is not reported back. 2312 ** 2313 ** <p>Originally this option disabled all triggers. ^(However, since 2314 ** SQLite version 3.35.0, TEMP triggers are still allowed even if 2315 ** this option is off. So, in other words, this option now only disables 2316 ** triggers in the main database schema or in the schemas of [ATTACH]-ed 2317 ** databases.)^ </dd> 2318 ** 2319 ** [[SQLITE_DBCONFIG_ENABLE_VIEW]] 2320 ** <dt>SQLITE_DBCONFIG_ENABLE_VIEW</dt> 2321 ** <dd> ^This option is used to enable or disable [CREATE VIEW | views]. 2322 ** There must be two additional arguments. 2323 ** The first argument is an integer which is 0 to disable views, 2324 ** positive to enable views or negative to leave the setting unchanged. 2325 ** The second parameter is a pointer to an integer into which 2326 ** is written 0 or 1 to indicate whether views are disabled or enabled 2327 ** following this call. The second parameter may be a NULL pointer, in 2328 ** which case the view setting is not reported back. 2329 ** 2330 ** <p>Originally this option disabled all views. ^(However, since 2331 ** SQLite version 3.35.0, TEMP views are still allowed even if 2332 ** this option is off. So, in other words, this option now only disables 2333 ** views in the main database schema or in the schemas of ATTACH-ed 2334 ** databases.)^ </dd> 2335 ** 2336 ** [[SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER]] 2337 ** <dt>SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER</dt> 2338 ** <dd> ^This option is used to enable or disable the 2339 ** [fts3_tokenizer()] function which is part of the 2340 ** [FTS3] full-text search engine extension. 2341 ** There must be two additional arguments. 2342 ** The first argument is an integer which is 0 to disable fts3_tokenizer() or 2343 ** positive to enable fts3_tokenizer() or negative to leave the setting 2344 ** unchanged. 2345 ** The second parameter is a pointer to an integer into which 2346 ** is written 0 or 1 to indicate whether fts3_tokenizer is disabled or enabled 2347 ** following this call. The second parameter may be a NULL pointer, in 2348 ** which case the new setting is not reported back. </dd> 2349 ** 2350 ** [[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION]] 2351 ** <dt>SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION</dt> 2352 ** <dd> ^This option is used to enable or disable the [sqlite3_load_extension()] 2353 ** interface independently of the [load_extension()] SQL function. 2354 ** The [sqlite3_enable_load_extension()] API enables or disables both the 2355 ** C-API [sqlite3_load_extension()] and the SQL function [load_extension()]. 2356 ** There must be two additional arguments. 2357 ** When the first argument to this interface is 1, then only the C-API is 2358 ** enabled and the SQL function remains disabled. If the first argument to 2359 ** this interface is 0, then both the C-API and the SQL function are disabled. 2360 ** If the first argument is -1, then no changes are made to state of either the 2361 ** C-API or the SQL function. 2362 ** The second parameter is a pointer to an integer into which 2363 ** is written 0 or 1 to indicate whether [sqlite3_load_extension()] interface 2364 ** is disabled or enabled following this call. The second parameter may 2365 ** be a NULL pointer, in which case the new setting is not reported back. 2366 ** </dd> 2367 ** 2368 ** [[SQLITE_DBCONFIG_MAINDBNAME]] <dt>SQLITE_DBCONFIG_MAINDBNAME</dt> 2369 ** <dd> ^This option is used to change the name of the "main" database 2370 ** schema. This option does not follow the 2371 ** [DBCONFIG arguments|usual SQLITE_DBCONFIG argument format]. 2372 ** This option takes exactly one additional argument so that the 2373 ** [sqlite3_db_config()] call has a total of three parameters. The 2374 ** extra argument must be a pointer to a constant UTF8 string which 2375 ** will become the new schema name in place of "main". ^SQLite does 2376 ** not make a copy of the new main schema name string, so the application 2377 ** must ensure that the argument passed into SQLITE_DBCONFIG MAINDBNAME 2378 ** is unchanged until after the database connection closes. 2379 ** </dd> 2380 ** 2381 ** [[SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE]] 2382 ** <dt>SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE</dt> 2383 ** <dd> Usually, when a database in [WAL mode] is closed or detached from a 2384 ** database handle, SQLite checks if if there are other connections to the 2385 ** same database, and if there are no other database connection (if the 2386 ** connection being closed is the last open connection to the database), 2387 ** then SQLite performs a [checkpoint] before closing the connection and 2388 ** deletes the WAL file. The SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE option can 2389 ** be used to override that behavior. The first argument passed to this 2390 ** operation (the third parameter to [sqlite3_db_config()]) is an integer 2391 ** which is positive to disable checkpoints-on-close, or zero (the default) 2392 ** to enable them, and negative to leave the setting unchanged. 2393 ** The second argument (the fourth parameter) is a pointer to an integer 2394 ** into which is written 0 or 1 to indicate whether checkpoints-on-close 2395 ** have been disabled - 0 if they are not disabled, 1 if they are. 2396 ** </dd> 2397 ** 2398 ** [[SQLITE_DBCONFIG_ENABLE_QPSG]] <dt>SQLITE_DBCONFIG_ENABLE_QPSG</dt> 2399 ** <dd>^(The SQLITE_DBCONFIG_ENABLE_QPSG option activates or deactivates 2400 ** the [query planner stability guarantee] (QPSG). When the QPSG is active, 2401 ** a single SQL query statement will always use the same algorithm regardless 2402 ** of values of [bound parameters].)^ The QPSG disables some query optimizations 2403 ** that look at the values of bound parameters, which can make some queries 2404 ** slower. But the QPSG has the advantage of more predictable behavior. With 2405 ** the QPSG active, SQLite will always use the same query plan in the field as 2406 ** was used during testing in the lab. 2407 ** The first argument to this setting is an integer which is 0 to disable 2408 ** the QPSG, positive to enable QPSG, or negative to leave the setting 2409 ** unchanged. The second parameter is a pointer to an integer into which 2410 ** is written 0 or 1 to indicate whether the QPSG is disabled or enabled 2411 ** following this call. 2412 ** </dd> 2413 ** 2414 ** [[SQLITE_DBCONFIG_TRIGGER_EQP]] <dt>SQLITE_DBCONFIG_TRIGGER_EQP</dt> 2415 ** <dd> By default, the output of EXPLAIN QUERY PLAN commands does not 2416 ** include output for any operations performed by trigger programs. This 2417 ** option is used to set or clear (the default) a flag that governs this 2418 ** behavior. The first parameter passed to this operation is an integer - 2419 ** positive to enable output for trigger programs, or zero to disable it, 2420 ** or negative to leave the setting unchanged. 2421 ** The second parameter is a pointer to an integer into which is written 2422 ** 0 or 1 to indicate whether output-for-triggers has been disabled - 0 if 2423 ** it is not disabled, 1 if it is. 2424 ** </dd> 2425 ** 2426 ** [[SQLITE_DBCONFIG_RESET_DATABASE]] <dt>SQLITE_DBCONFIG_RESET_DATABASE</dt> 2427 ** <dd> Set the SQLITE_DBCONFIG_RESET_DATABASE flag and then run 2428 ** [VACUUM] in order to reset a database back to an empty database 2429 ** with no schema and no content. The following process works even for 2430 ** a badly corrupted database file: 2431 ** <ol> 2432 ** <li> If the database connection is newly opened, make sure it has read the 2433 ** database schema by preparing then discarding some query against the 2434 ** database, or calling sqlite3_table_column_metadata(), ignoring any 2435 ** errors. This step is only necessary if the application desires to keep 2436 ** the database in WAL mode after the reset if it was in WAL mode before 2437 ** the reset. 2438 ** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 1, 0); 2439 ** <li> [sqlite3_exec](db, "[VACUUM]", 0, 0, 0); 2440 ** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 0, 0); 2441 ** </ol> 2442 ** Because resetting a database is destructive and irreversible, the 2443 ** process requires the use of this obscure API and multiple steps to 2444 ** help ensure that it does not happen by accident. Because this 2445 ** feature must be capable of resetting corrupt databases, and 2446 ** shutting down virtual tables may require access to that corrupt 2447 ** storage, the library must abandon any installed virtual tables 2448 ** without calling their xDestroy() methods. 2449 ** 2450 ** [[SQLITE_DBCONFIG_DEFENSIVE]] <dt>SQLITE_DBCONFIG_DEFENSIVE</dt> 2451 ** <dd>The SQLITE_DBCONFIG_DEFENSIVE option activates or deactivates the 2452 ** "defensive" flag for a database connection. When the defensive 2453 ** flag is enabled, language features that allow ordinary SQL to 2454 ** deliberately corrupt the database file are disabled. The disabled 2455 ** features include but are not limited to the following: 2456 ** <ul> 2457 ** <li> The [PRAGMA writable_schema=ON] statement. 2458 ** <li> The [PRAGMA journal_mode=OFF] statement. 2459 ** <li> The [PRAGMA schema_version=N] statement. 2460 ** <li> Writes to the [sqlite_dbpage] virtual table. 2461 ** <li> Direct writes to [shadow tables]. 2462 ** </ul> 2463 ** </dd> 2464 ** 2465 ** [[SQLITE_DBCONFIG_WRITABLE_SCHEMA]] <dt>SQLITE_DBCONFIG_WRITABLE_SCHEMA</dt> 2466 ** <dd>The SQLITE_DBCONFIG_WRITABLE_SCHEMA option activates or deactivates the 2467 ** "writable_schema" flag. This has the same effect and is logically equivalent 2468 ** to setting [PRAGMA writable_schema=ON] or [PRAGMA writable_schema=OFF]. 2469 ** The first argument to this setting is an integer which is 0 to disable 2470 ** the writable_schema, positive to enable writable_schema, or negative to 2471 ** leave the setting unchanged. The second parameter is a pointer to an 2472 ** integer into which is written 0 or 1 to indicate whether the writable_schema 2473 ** is enabled or disabled following this call. 2474 ** </dd> 2475 ** 2476 ** [[SQLITE_DBCONFIG_LEGACY_ALTER_TABLE]] 2477 ** <dt>SQLITE_DBCONFIG_LEGACY_ALTER_TABLE</dt> 2478 ** <dd>The SQLITE_DBCONFIG_LEGACY_ALTER_TABLE option activates or deactivates 2479 ** the legacy behavior of the [ALTER TABLE RENAME] command such it 2480 ** behaves as it did prior to [version 3.24.0] (2018-06-04). See the 2481 ** "Compatibility Notice" on the [ALTER TABLE RENAME documentation] for 2482 ** additional information. This feature can also be turned on and off 2483 ** using the [PRAGMA legacy_alter_table] statement. 2484 ** </dd> 2485 ** 2486 ** [[SQLITE_DBCONFIG_DQS_DML]] 2487 ** <dt>SQLITE_DBCONFIG_DQS_DML</dt> 2488 ** <dd>The SQLITE_DBCONFIG_DQS_DML option activates or deactivates 2489 ** the legacy [double-quoted string literal] misfeature for DML statements 2490 ** only, that is DELETE, INSERT, SELECT, and UPDATE statements. The 2491 ** default value of this setting is determined by the [-DSQLITE_DQS] 2492 ** compile-time option. 2493 ** </dd> 2494 ** 2495 ** [[SQLITE_DBCONFIG_DQS_DDL]] 2496 ** <dt>SQLITE_DBCONFIG_DQS_DDL</dt> 2497 ** <dd>The SQLITE_DBCONFIG_DQS option activates or deactivates 2498 ** the legacy [double-quoted string literal] misfeature for DDL statements, 2499 ** such as CREATE TABLE and CREATE INDEX. The 2500 ** default value of this setting is determined by the [-DSQLITE_DQS] 2501 ** compile-time option. 2502 ** </dd> 2503 ** 2504 ** [[SQLITE_DBCONFIG_TRUSTED_SCHEMA]] 2505 ** <dt>SQLITE_DBCONFIG_TRUSTED_SCHEMA</dt> 2506 ** <dd>The SQLITE_DBCONFIG_TRUSTED_SCHEMA option tells SQLite to 2507 ** assume that database schemas are untainted by malicious content. 2508 ** When the SQLITE_DBCONFIG_TRUSTED_SCHEMA option is disabled, SQLite 2509 ** takes additional defensive steps to protect the application from harm 2510 ** including: 2511 ** <ul> 2512 ** <li> Prohibit the use of SQL functions inside triggers, views, 2513 ** CHECK constraints, DEFAULT clauses, expression indexes, 2514 ** partial indexes, or generated columns 2515 ** unless those functions are tagged with [SQLITE_INNOCUOUS]. 2516 ** <li> Prohibit the use of virtual tables inside of triggers or views 2517 ** unless those virtual tables are tagged with [SQLITE_VTAB_INNOCUOUS]. 2518 ** </ul> 2519 ** This setting defaults to "on" for legacy compatibility, however 2520 ** all applications are advised to turn it off if possible. This setting 2521 ** can also be controlled using the [PRAGMA trusted_schema] statement. 2522 ** </dd> 2523 ** 2524 ** [[SQLITE_DBCONFIG_LEGACY_FILE_FORMAT]] 2525 ** <dt>SQLITE_DBCONFIG_LEGACY_FILE_FORMAT</dt> 2526 ** <dd>The SQLITE_DBCONFIG_LEGACY_FILE_FORMAT option activates or deactivates 2527 ** the legacy file format flag. When activated, this flag causes all newly 2528 ** created database file to have a schema format version number (the 4-byte 2529 ** integer found at offset 44 into the database header) of 1. This in turn 2530 ** means that the resulting database file will be readable and writable by 2531 ** any SQLite version back to 3.0.0 ([dateof:3.0.0]). Without this setting, 2532 ** newly created databases are generally not understandable by SQLite versions 2533 ** prior to 3.3.0 ([dateof:3.3.0]). As these words are written, there 2534 ** is now scarcely any need to generate database files that are compatible 2535 ** all the way back to version 3.0.0, and so this setting is of little 2536 ** practical use, but is provided so that SQLite can continue to claim the 2537 ** ability to generate new database files that are compatible with version 2538 ** 3.0.0. 2539 ** <p>Note that when the SQLITE_DBCONFIG_LEGACY_FILE_FORMAT setting is on, 2540 ** the [VACUUM] command will fail with an obscure error when attempting to 2541 ** process a table with generated columns and a descending index. This is 2542 ** not considered a bug since SQLite versions 3.3.0 and earlier do not support 2543 ** either generated columns or descending indexes. 2544 ** </dd> 2545 ** 2546 ** [[SQLITE_DBCONFIG_STMT_SCANSTATUS]] 2547 ** <dt>SQLITE_DBCONFIG_STMT_SCANSTATUS</dt> 2548 ** <dd>The SQLITE_DBCONFIG_STMT_SCANSTATUS option is only useful in 2549 ** SQLITE_ENABLE_STMT_SCANSTATUS builds. In this case, it sets or clears 2550 ** a flag that enables collection of the sqlite3_stmt_scanstatus_v2() 2551 ** statistics. For statistics to be collected, the flag must be set on 2552 ** the database handle both when the SQL statement is prepared and when it 2553 ** is stepped. The flag is set (collection of statistics is enabled) 2554 ** by default. <p>This option takes two arguments: an integer and a pointer to 2555 ** an integer.. The first argument is 1, 0, or -1 to enable, disable, or 2556 ** leave unchanged the statement scanstatus option. If the second argument 2557 ** is not NULL, then the value of the statement scanstatus setting after 2558 ** processing the first argument is written into the integer that the second 2559 ** argument points to. 2560 ** </dd> 2561 ** 2562 ** [[SQLITE_DBCONFIG_REVERSE_SCANORDER]] 2563 ** <dt>SQLITE_DBCONFIG_REVERSE_SCANORDER</dt> 2564 ** <dd>The SQLITE_DBCONFIG_REVERSE_SCANORDER option changes the default order 2565 ** in which tables and indexes are scanned so that the scans start at the end 2566 ** and work toward the beginning rather than starting at the beginning and 2567 ** working toward the end. Setting SQLITE_DBCONFIG_REVERSE_SCANORDER is the 2568 ** same as setting [PRAGMA reverse_unordered_selects]. <p>This option takes 2569 ** two arguments which are an integer and a pointer to an integer. The first 2570 ** argument is 1, 0, or -1 to enable, disable, or leave unchanged the 2571 ** reverse scan order flag, respectively. If the second argument is not NULL, 2572 ** then 0 or 1 is written into the integer that the second argument points to 2573 ** depending on if the reverse scan order flag is set after processing the 2574 ** first argument. 2575 ** </dd> 2576 ** 2577 ** [[SQLITE_DBCONFIG_ENABLE_ATTACH_CREATE]] 2578 ** <dt>SQLITE_DBCONFIG_ENABLE_ATTACH_CREATE</dt> 2579 ** <dd>The SQLITE_DBCONFIG_ENABLE_ATTACH_CREATE option enables or disables 2580 ** the ability of the [ATTACH DATABASE] SQL command to create a new database 2581 ** file if the database filed named in the ATTACH command does not already 2582 ** exist. This ability of ATTACH to create a new database is enabled by 2583 ** default. Applications can disable or reenable the ability for ATTACH to 2584 ** create new database files using this DBCONFIG option.<p> 2585 ** This option takes two arguments which are an integer and a pointer 2586 ** to an integer. The first argument is 1, 0, or -1 to enable, disable, or 2587 ** leave unchanged the attach-create flag, respectively. If the second 2588 ** argument is not NULL, then 0 or 1 is written into the integer that the 2589 ** second argument points to depending on if the attach-create flag is set 2590 ** after processing the first argument. 2591 ** </dd> 2592 ** 2593 ** [[SQLITE_DBCONFIG_ENABLE_ATTACH_WRITE]] 2594 ** <dt>SQLITE_DBCONFIG_ENABLE_ATTACH_WRITE</dt> 2595 ** <dd>The SQLITE_DBCONFIG_ENABLE_ATTACH_WRITE option enables or disables the 2596 ** ability of the [ATTACH DATABASE] SQL command to open a database for writing. 2597 ** This capability is enabled by default. Applications can disable or 2598 ** reenable this capability using the current DBCONFIG option. If the 2599 ** the this capability is disabled, the [ATTACH] command will still work, 2600 ** but the database will be opened read-only. If this option is disabled, 2601 ** then the ability to create a new database using [ATTACH] is also disabled, 2602 ** regardless of the value of the [SQLITE_DBCONFIG_ENABLE_ATTACH_CREATE] 2603 ** option.<p> 2604 ** This option takes two arguments which are an integer and a pointer 2605 ** to an integer. The first argument is 1, 0, or -1 to enable, disable, or 2606 ** leave unchanged the ability to ATTACH another database for writing, 2607 ** respectively. If the second argument is not NULL, then 0 or 1 is written 2608 ** into the integer to which the second argument points, depending on whether 2609 ** the ability to ATTACH a read/write database is enabled or disabled 2610 ** after processing the first argument. 2611 ** </dd> 2612 ** 2613 ** [[SQLITE_DBCONFIG_ENABLE_COMMENTS]] 2614 ** <dt>SQLITE_DBCONFIG_ENABLE_COMMENTS</dt> 2615 ** <dd>The SQLITE_DBCONFIG_ENABLE_COMMENTS option enables or disables the 2616 ** ability to include comments in SQL text. Comments are enabled by default. 2617 ** An application can disable or reenable comments in SQL text using this 2618 ** DBCONFIG option.<p> 2619 ** This option takes two arguments which are an integer and a pointer 2620 ** to an integer. The first argument is 1, 0, or -1 to enable, disable, or 2621 ** leave unchanged the ability to use comments in SQL text, 2622 ** respectively. If the second argument is not NULL, then 0 or 1 is written 2623 ** into the integer that the second argument points to depending on if 2624 ** comments are allowed in SQL text after processing the first argument. 2625 ** </dd> 2626 ** 2627 ** </dl> 2628 ** 2629 ** [[DBCONFIG arguments]] <h3>Arguments To SQLITE_DBCONFIG Options</h3> 2630 ** 2631 ** <p>Most of the SQLITE_DBCONFIG options take two arguments, so that the 2632 ** overall call to [sqlite3_db_config()] has a total of four parameters. 2633 ** The first argument (the third parameter to sqlite3_db_config()) is a integer. 2634 ** The second argument is a pointer to an integer. If the first argument is 1, 2635 ** then the option becomes enabled. If the first integer argument is 0, then the 2636 ** option is disabled. If the first argument is -1, then the option setting 2637 ** is unchanged. The second argument, the pointer to an integer, may be NULL. 2638 ** If the second argument is not NULL, then a value of 0 or 1 is written into 2639 ** the integer to which the second argument points, depending on whether the 2640 ** setting is disabled or enabled after applying any changes specified by 2641 ** the first argument. 2642 ** 2643 ** <p>While most SQLITE_DBCONFIG options use the argument format 2644 ** described in the previous paragraph, the [SQLITE_DBCONFIG_MAINDBNAME] 2645 ** and [SQLITE_DBCONFIG_LOOKASIDE] options are different. See the 2646 ** documentation of those exceptional options for details. 2647 */ 2648 #define SQLITE_DBCONFIG_MAINDBNAME 1000 /* const char* */ 2649 #define SQLITE_DBCONFIG_LOOKASIDE 1001 /* void* int int */ 2650 #define SQLITE_DBCONFIG_ENABLE_FKEY 1002 /* int int* */ 2651 #define SQLITE_DBCONFIG_ENABLE_TRIGGER 1003 /* int int* */ 2652 #define SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER 1004 /* int int* */ 2653 #define SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION 1005 /* int int* */ 2654 #define SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE 1006 /* int int* */ 2655 #define SQLITE_DBCONFIG_ENABLE_QPSG 1007 /* int int* */ 2656 #define SQLITE_DBCONFIG_TRIGGER_EQP 1008 /* int int* */ 2657 #define SQLITE_DBCONFIG_RESET_DATABASE 1009 /* int int* */ 2658 #define SQLITE_DBCONFIG_DEFENSIVE 1010 /* int int* */ 2659 #define SQLITE_DBCONFIG_WRITABLE_SCHEMA 1011 /* int int* */ 2660 #define SQLITE_DBCONFIG_LEGACY_ALTER_TABLE 1012 /* int int* */ 2661 #define SQLITE_DBCONFIG_DQS_DML 1013 /* int int* */ 2662 #define SQLITE_DBCONFIG_DQS_DDL 1014 /* int int* */ 2663 #define SQLITE_DBCONFIG_ENABLE_VIEW 1015 /* int int* */ 2664 #define SQLITE_DBCONFIG_LEGACY_FILE_FORMAT 1016 /* int int* */ 2665 #define SQLITE_DBCONFIG_TRUSTED_SCHEMA 1017 /* int int* */ 2666 #define SQLITE_DBCONFIG_STMT_SCANSTATUS 1018 /* int int* */ 2667 #define SQLITE_DBCONFIG_REVERSE_SCANORDER 1019 /* int int* */ 2668 #define SQLITE_DBCONFIG_ENABLE_ATTACH_CREATE 1020 /* int int* */ 2669 #define SQLITE_DBCONFIG_ENABLE_ATTACH_WRITE 1021 /* int int* */ 2670 #define SQLITE_DBCONFIG_ENABLE_COMMENTS 1022 /* int int* */ 2671 #define SQLITE_DBCONFIG_MAX 1022 /* Largest DBCONFIG */ 2672 2673 /* 2674 ** CAPI3REF: Enable Or Disable Extended Result Codes 2675 ** METHOD: sqlite3 2676 ** 2677 ** ^The sqlite3_extended_result_codes() routine enables or disables the 2678 ** [extended result codes] feature of SQLite. ^The extended result 2679 ** codes are disabled by default for historical compatibility. 2680 */ 2681 SQLITE_API int sqlite3_extended_result_codes(sqlite3*, int onoff); 2682 2683 /* 2684 ** CAPI3REF: Last Insert Rowid 2685 ** METHOD: sqlite3 2686 ** 2687 ** ^Each entry in most SQLite tables (except for [WITHOUT ROWID] tables) 2688 ** has a unique 64-bit signed 2689 ** integer key called the [ROWID | "rowid"]. ^The rowid is always available 2690 ** as an undeclared column named ROWID, OID, or _ROWID_ as long as those 2691 ** names are not also used by explicitly declared columns. ^If 2692 ** the table has a column of type [INTEGER PRIMARY KEY] then that column 2693 ** is another alias for the rowid. 2694 ** 2695 ** ^The sqlite3_last_insert_rowid(D) interface usually returns the [rowid] of 2696 ** the most recent successful [INSERT] into a rowid table or [virtual table] 2697 ** on database connection D. ^Inserts into [WITHOUT ROWID] tables are not 2698 ** recorded. ^If no successful [INSERT]s into rowid tables have ever occurred 2699 ** on the database connection D, then sqlite3_last_insert_rowid(D) returns 2700 ** zero. 2701 ** 2702 ** As well as being set automatically as rows are inserted into database 2703 ** tables, the value returned by this function may be set explicitly by 2704 ** [sqlite3_set_last_insert_rowid()] 2705 ** 2706 ** Some virtual table implementations may INSERT rows into rowid tables as 2707 ** part of committing a transaction (e.g. to flush data accumulated in memory 2708 ** to disk). In this case subsequent calls to this function return the rowid 2709 ** associated with these internal INSERT operations, which leads to 2710 ** unintuitive results. Virtual table implementations that do write to rowid 2711 ** tables in this way can avoid this problem by restoring the original 2712 ** rowid value using [sqlite3_set_last_insert_rowid()] before returning 2713 ** control to the user. 2714 ** 2715 ** ^(If an [INSERT] occurs within a trigger then this routine will 2716 ** return the [rowid] of the inserted row as long as the trigger is 2717 ** running. Once the trigger program ends, the value returned 2718 ** by this routine reverts to what it was before the trigger was fired.)^ 2719 ** 2720 ** ^An [INSERT] that fails due to a constraint violation is not a 2721 ** successful [INSERT] and does not change the value returned by this 2722 ** routine. ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK, 2723 ** and INSERT OR ABORT make no changes to the return value of this 2724 ** routine when their insertion fails. ^(When INSERT OR REPLACE 2725 ** encounters a constraint violation, it does not fail. The 2726 ** INSERT continues to completion after deleting rows that caused 2727 ** the constraint problem so INSERT OR REPLACE will always change 2728 ** the return value of this interface.)^ 2729 ** 2730 ** ^For the purposes of this routine, an [INSERT] is considered to 2731 ** be successful even if it is subsequently rolled back. 2732 ** 2733 ** This function is accessible to SQL statements via the 2734 ** [last_insert_rowid() SQL function]. 2735 ** 2736 ** If a separate thread performs a new [INSERT] on the same 2737 ** database connection while the [sqlite3_last_insert_rowid()] 2738 ** function is running and thus changes the last insert [rowid], 2739 ** then the value returned by [sqlite3_last_insert_rowid()] is 2740 ** unpredictable and might not equal either the old or the new 2741 ** last insert [rowid]. 2742 */ 2743 SQLITE_API sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*); 2744 2745 /* 2746 ** CAPI3REF: Set the Last Insert Rowid value. 2747 ** METHOD: sqlite3 2748 ** 2749 ** The sqlite3_set_last_insert_rowid(D, R) method allows the application to 2750 ** set the value returned by calling sqlite3_last_insert_rowid(D) to R 2751 ** without inserting a row into the database. 2752 */ 2753 SQLITE_API void sqlite3_set_last_insert_rowid(sqlite3*,sqlite3_int64); 2754 2755 /* 2756 ** CAPI3REF: Count The Number Of Rows Modified 2757 ** METHOD: sqlite3 2758 ** 2759 ** ^These functions return the number of rows modified, inserted or 2760 ** deleted by the most recently completed INSERT, UPDATE or DELETE 2761 ** statement on the database connection specified by the only parameter. 2762 ** The two functions are identical except for the type of the return value 2763 ** and that if the number of rows modified by the most recent INSERT, UPDATE, 2764 ** or DELETE is greater than the maximum value supported by type "int", then 2765 ** the return value of sqlite3_changes() is undefined. ^Executing any other 2766 ** type of SQL statement does not modify the value returned by these functions. 2767 ** For the purposes of this interface, a CREATE TABLE AS SELECT statement 2768 ** does not count as an INSERT, UPDATE or DELETE statement and hence the rows 2769 ** added to the new table by the CREATE TABLE AS SELECT statement are not 2770 ** counted. 2771 ** 2772 ** ^Only changes made directly by the INSERT, UPDATE or DELETE statement are 2773 ** considered - auxiliary changes caused by [CREATE TRIGGER | triggers], 2774 ** [foreign key actions] or [REPLACE] constraint resolution are not counted. 2775 ** 2776 ** Changes to a view that are intercepted by 2777 ** [INSTEAD OF trigger | INSTEAD OF triggers] are not counted. ^The value 2778 ** returned by sqlite3_changes() immediately after an INSERT, UPDATE or 2779 ** DELETE statement run on a view is always zero. Only changes made to real 2780 ** tables are counted. 2781 ** 2782 ** Things are more complicated if the sqlite3_changes() function is 2783 ** executed while a trigger program is running. This may happen if the 2784 ** program uses the [changes() SQL function], or if some other callback 2785 ** function invokes sqlite3_changes() directly. Essentially: 2786 ** 2787 ** <ul> 2788 ** <li> ^(Before entering a trigger program the value returned by 2789 ** sqlite3_changes() function is saved. After the trigger program 2790 ** has finished, the original value is restored.)^ 2791 ** 2792 ** <li> ^(Within a trigger program each INSERT, UPDATE and DELETE 2793 ** statement sets the value returned by sqlite3_changes() 2794 ** upon completion as normal. Of course, this value will not include 2795 ** any changes performed by sub-triggers, as the sqlite3_changes() 2796 ** value will be saved and restored after each sub-trigger has run.)^ 2797 ** </ul> 2798 ** 2799 ** ^This means that if the changes() SQL function (or similar) is used 2800 ** by the first INSERT, UPDATE or DELETE statement within a trigger, it 2801 ** returns the value as set when the calling statement began executing. 2802 ** ^If it is used by the second or subsequent such statement within a trigger 2803 ** program, the value returned reflects the number of rows modified by the 2804 ** previous INSERT, UPDATE or DELETE statement within the same trigger. 2805 ** 2806 ** If a separate thread makes changes on the same database connection 2807 ** while [sqlite3_changes()] is running then the value returned 2808 ** is unpredictable and not meaningful. 2809 ** 2810 ** See also: 2811 ** <ul> 2812 ** <li> the [sqlite3_total_changes()] interface 2813 ** <li> the [count_changes pragma] 2814 ** <li> the [changes() SQL function] 2815 ** <li> the [data_version pragma] 2816 ** </ul> 2817 */ 2818 SQLITE_API int sqlite3_changes(sqlite3*); 2819 SQLITE_API sqlite3_int64 sqlite3_changes64(sqlite3*); 2820 2821 /* 2822 ** CAPI3REF: Total Number Of Rows Modified 2823 ** METHOD: sqlite3 2824 ** 2825 ** ^These functions return the total number of rows inserted, modified or 2826 ** deleted by all [INSERT], [UPDATE] or [DELETE] statements completed 2827 ** since the database connection was opened, including those executed as 2828 ** part of trigger programs. The two functions are identical except for the 2829 ** type of the return value and that if the number of rows modified by the 2830 ** connection exceeds the maximum value supported by type "int", then 2831 ** the return value of sqlite3_total_changes() is undefined. ^Executing 2832 ** any other type of SQL statement does not affect the value returned by 2833 ** sqlite3_total_changes(). 2834 ** 2835 ** ^Changes made as part of [foreign key actions] are included in the 2836 ** count, but those made as part of REPLACE constraint resolution are 2837 ** not. ^Changes to a view that are intercepted by INSTEAD OF triggers 2838 ** are not counted. 2839 ** 2840 ** The [sqlite3_total_changes(D)] interface only reports the number 2841 ** of rows that changed due to SQL statement run against database 2842 ** connection D. Any changes by other database connections are ignored. 2843 ** To detect changes against a database file from other database 2844 ** connections use the [PRAGMA data_version] command or the 2845 ** [SQLITE_FCNTL_DATA_VERSION] [file control]. 2846 ** 2847 ** If a separate thread makes changes on the same database connection 2848 ** while [sqlite3_total_changes()] is running then the value 2849 ** returned is unpredictable and not meaningful. 2850 ** 2851 ** See also: 2852 ** <ul> 2853 ** <li> the [sqlite3_changes()] interface 2854 ** <li> the [count_changes pragma] 2855 ** <li> the [changes() SQL function] 2856 ** <li> the [data_version pragma] 2857 ** <li> the [SQLITE_FCNTL_DATA_VERSION] [file control] 2858 ** </ul> 2859 */ 2860 SQLITE_API int sqlite3_total_changes(sqlite3*); 2861 SQLITE_API sqlite3_int64 sqlite3_total_changes64(sqlite3*); 2862 2863 /* 2864 ** CAPI3REF: Interrupt A Long-Running Query 2865 ** METHOD: sqlite3 2866 ** 2867 ** ^This function causes any pending database operation to abort and 2868 ** return at its earliest opportunity. This routine is typically 2869 ** called in response to a user action such as pressing "Cancel" 2870 ** or Ctrl-C where the user wants a long query operation to halt 2871 ** immediately. 2872 ** 2873 ** ^It is safe to call this routine from a thread different from the 2874 ** thread that is currently running the database operation. But it 2875 ** is not safe to call this routine with a [database connection] that 2876 ** is closed or might close before sqlite3_interrupt() returns. 2877 ** 2878 ** ^If an SQL operation is very nearly finished at the time when 2879 ** sqlite3_interrupt() is called, then it might not have an opportunity 2880 ** to be interrupted and might continue to completion. 2881 ** 2882 ** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT]. 2883 ** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE 2884 ** that is inside an explicit transaction, then the entire transaction 2885 ** will be rolled back automatically. 2886 ** 2887 ** ^The sqlite3_interrupt(D) call is in effect until all currently running 2888 ** SQL statements on [database connection] D complete. ^Any new SQL statements 2889 ** that are started after the sqlite3_interrupt() call and before the 2890 ** running statement count reaches zero are interrupted as if they had been 2891 ** running prior to the sqlite3_interrupt() call. ^New SQL statements 2892 ** that are started after the running statement count reaches zero are 2893 ** not effected by the sqlite3_interrupt(). 2894 ** ^A call to sqlite3_interrupt(D) that occurs when there are no running 2895 ** SQL statements is a no-op and has no effect on SQL statements 2896 ** that are started after the sqlite3_interrupt() call returns. 2897 ** 2898 ** ^The [sqlite3_is_interrupted(D)] interface can be used to determine whether 2899 ** or not an interrupt is currently in effect for [database connection] D. 2900 ** It returns 1 if an interrupt is currently in effect, or 0 otherwise. 2901 */ 2902 SQLITE_API void sqlite3_interrupt(sqlite3*); 2903 SQLITE_API int sqlite3_is_interrupted(sqlite3*); 2904 2905 /* 2906 ** CAPI3REF: Determine If An SQL Statement Is Complete 2907 ** 2908 ** These routines are useful during command-line input to determine if the 2909 ** currently entered text seems to form a complete SQL statement or 2910 ** if additional input is needed before sending the text into 2911 ** SQLite for parsing. ^These routines return 1 if the input string 2912 ** appears to be a complete SQL statement. ^A statement is judged to be 2913 ** complete if it ends with a semicolon token and is not a prefix of a 2914 ** well-formed CREATE TRIGGER statement. ^Semicolons that are embedded within 2915 ** string literals or quoted identifier names or comments are not 2916 ** independent tokens (they are part of the token in which they are 2917 ** embedded) and thus do not count as a statement terminator. ^Whitespace 2918 ** and comments that follow the final semicolon are ignored. 2919 ** 2920 ** ^These routines return 0 if the statement is incomplete. ^If a 2921 ** memory allocation fails, then SQLITE_NOMEM is returned. 2922 ** 2923 ** ^These routines do not parse the SQL statements thus 2924 ** will not detect syntactically incorrect SQL. 2925 ** 2926 ** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior 2927 ** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked 2928 ** automatically by sqlite3_complete16(). If that initialization fails, 2929 ** then the return value from sqlite3_complete16() will be non-zero 2930 ** regardless of whether or not the input SQL is complete.)^ 2931 ** 2932 ** The input to [sqlite3_complete()] must be a zero-terminated 2933 ** UTF-8 string. 2934 ** 2935 ** The input to [sqlite3_complete16()] must be a zero-terminated 2936 ** UTF-16 string in native byte order. 2937 */ 2938 SQLITE_API int sqlite3_complete(const char *sql); 2939 SQLITE_API int sqlite3_complete16(const void *sql); 2940 2941 /* 2942 ** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors 2943 ** KEYWORDS: {busy-handler callback} {busy handler} 2944 ** METHOD: sqlite3 2945 ** 2946 ** ^The sqlite3_busy_handler(D,X,P) routine sets a callback function X 2947 ** that might be invoked with argument P whenever 2948 ** an attempt is made to access a database table associated with 2949 ** [database connection] D when another thread 2950 ** or process has the table locked. 2951 ** The sqlite3_busy_handler() interface is used to implement 2952 ** [sqlite3_busy_timeout()] and [PRAGMA busy_timeout]. 2953 ** 2954 ** ^If the busy callback is NULL, then [SQLITE_BUSY] 2955 ** is returned immediately upon encountering the lock. ^If the busy callback 2956 ** is not NULL, then the callback might be invoked with two arguments. 2957 ** 2958 ** ^The first argument to the busy handler is a copy of the void* pointer which 2959 ** is the third argument to sqlite3_busy_handler(). ^The second argument to 2960 ** the busy handler callback is the number of times that the busy handler has 2961 ** been invoked previously for the same locking event. ^If the 2962 ** busy callback returns 0, then no additional attempts are made to 2963 ** access the database and [SQLITE_BUSY] is returned 2964 ** to the application. 2965 ** ^If the callback returns non-zero, then another attempt 2966 ** is made to access the database and the cycle repeats. 2967 ** 2968 ** The presence of a busy handler does not guarantee that it will be invoked 2969 ** when there is lock contention. ^If SQLite determines that invoking the busy 2970 ** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY] 2971 ** to the application instead of invoking the 2972 ** busy handler. 2973 ** Consider a scenario where one process is holding a read lock that 2974 ** it is trying to promote to a reserved lock and 2975 ** a second process is holding a reserved lock that it is trying 2976 ** to promote to an exclusive lock. The first process cannot proceed 2977 ** because it is blocked by the second and the second process cannot 2978 ** proceed because it is blocked by the first. If both processes 2979 ** invoke the busy handlers, neither will make any progress. Therefore, 2980 ** SQLite returns [SQLITE_BUSY] for the first process, hoping that this 2981 ** will induce the first process to release its read lock and allow 2982 ** the second process to proceed. 2983 ** 2984 ** ^The default busy callback is NULL. 2985 ** 2986 ** ^(There can only be a single busy handler defined for each 2987 ** [database connection]. Setting a new busy handler clears any 2988 ** previously set handler.)^ ^Note that calling [sqlite3_busy_timeout()] 2989 ** or evaluating [PRAGMA busy_timeout=N] will change the 2990 ** busy handler and thus clear any previously set busy handler. 2991 ** 2992 ** The busy callback should not take any actions which modify the 2993 ** database connection that invoked the busy handler. In other words, 2994 ** the busy handler is not reentrant. Any such actions 2995 ** result in undefined behavior. 2996 ** 2997 ** A busy handler must not close the database connection 2998 ** or [prepared statement] that invoked the busy handler. 2999 */ 3000 SQLITE_API int sqlite3_busy_handler(sqlite3*,int(*)(void*,int),void*); 3001 3002 /* 3003 ** CAPI3REF: Set A Busy Timeout 3004 ** METHOD: sqlite3 3005 ** 3006 ** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps 3007 ** for a specified amount of time when a table is locked. ^The handler 3008 ** will sleep multiple times until at least "ms" milliseconds of sleeping 3009 ** have accumulated. ^After at least "ms" milliseconds of sleeping, 3010 ** the handler returns 0 which causes [sqlite3_step()] to return 3011 ** [SQLITE_BUSY]. 3012 ** 3013 ** ^Calling this routine with an argument less than or equal to zero 3014 ** turns off all busy handlers. 3015 ** 3016 ** ^(There can only be a single busy handler for a particular 3017 ** [database connection] at any given moment. If another busy handler 3018 ** was defined (using [sqlite3_busy_handler()]) prior to calling 3019 ** this routine, that other busy handler is cleared.)^ 3020 ** 3021 ** See also: [PRAGMA busy_timeout] 3022 */ 3023 SQLITE_API int sqlite3_busy_timeout(sqlite3*, int ms); 3024 3025 /* 3026 ** CAPI3REF: Set the Setlk Timeout 3027 ** METHOD: sqlite3 3028 ** 3029 ** This routine is only useful in SQLITE_ENABLE_SETLK_TIMEOUT builds. If 3030 ** the VFS supports blocking locks, it sets the timeout in ms used by 3031 ** eligible locks taken on wal mode databases by the specified database 3032 ** handle. In non-SQLITE_ENABLE_SETLK_TIMEOUT builds, or if the VFS does 3033 ** not support blocking locks, this function is a no-op. 3034 ** 3035 ** Passing 0 to this function disables blocking locks altogether. Passing 3036 ** -1 to this function requests that the VFS blocks for a long time - 3037 ** indefinitely if possible. The results of passing any other negative value 3038 ** are undefined. 3039 ** 3040 ** Internally, each SQLite database handle store two timeout values - the 3041 ** busy-timeout (used for rollback mode databases, or if the VFS does not 3042 ** support blocking locks) and the setlk-timeout (used for blocking locks 3043 ** on wal-mode databases). The sqlite3_busy_timeout() method sets both 3044 ** values, this function sets only the setlk-timeout value. Therefore, 3045 ** to configure separate busy-timeout and setlk-timeout values for a single 3046 ** database handle, call sqlite3_busy_timeout() followed by this function. 3047 ** 3048 ** Whenever the number of connections to a wal mode database falls from 3049 ** 1 to 0, the last connection takes an exclusive lock on the database, 3050 ** then checkpoints and deletes the wal file. While it is doing this, any 3051 ** new connection that tries to read from the database fails with an 3052 ** SQLITE_BUSY error. Or, if the SQLITE_SETLK_BLOCK_ON_CONNECT flag is 3053 ** passed to this API, the new connection blocks until the exclusive lock 3054 ** has been released. 3055 */ 3056 SQLITE_API int sqlite3_setlk_timeout(sqlite3*, int ms, int flags); 3057 3058 /* 3059 ** CAPI3REF: Flags for sqlite3_setlk_timeout() 3060 */ 3061 #define SQLITE_SETLK_BLOCK_ON_CONNECT 0x01 3062 3063 /* 3064 ** CAPI3REF: Convenience Routines For Running Queries 3065 ** METHOD: sqlite3 3066 ** 3067 ** This is a legacy interface that is preserved for backwards compatibility. 3068 ** Use of this interface is not recommended. 3069 ** 3070 ** Definition: A <b>result table</b> is memory data structure created by the 3071 ** [sqlite3_get_table()] interface. A result table records the 3072 ** complete query results from one or more queries. 3073 ** 3074 ** The table conceptually has a number of rows and columns. But 3075 ** these numbers are not part of the result table itself. These 3076 ** numbers are obtained separately. Let N be the number of rows 3077 ** and M be the number of columns. 3078 ** 3079 ** A result table is an array of pointers to zero-terminated UTF-8 strings. 3080 ** There are (N+1)*M elements in the array. The first M pointers point 3081 ** to zero-terminated strings that contain the names of the columns. 3082 ** The remaining entries all point to query results. NULL values result 3083 ** in NULL pointers. All other values are in their UTF-8 zero-terminated 3084 ** string representation as returned by [sqlite3_column_text()]. 3085 ** 3086 ** A result table might consist of one or more memory allocations. 3087 ** It is not safe to pass a result table directly to [sqlite3_free()]. 3088 ** A result table should be deallocated using [sqlite3_free_table()]. 3089 ** 3090 ** ^(As an example of the result table format, suppose a query result 3091 ** is as follows: 3092 ** 3093 ** <blockquote><pre> 3094 ** Name | Age 3095 ** ----------------------- 3096 ** Alice | 43 3097 ** Bob | 28 3098 ** Cindy | 21 3099 ** </pre></blockquote> 3100 ** 3101 ** There are two columns (M==2) and three rows (N==3). Thus the 3102 ** result table has 8 entries. Suppose the result table is stored 3103 ** in an array named azResult. Then azResult holds this content: 3104 ** 3105 ** <blockquote><pre> 3106 ** azResult[0] = "Name"; 3107 ** azResult[1] = "Age"; 3108 ** azResult[2] = "Alice"; 3109 ** azResult[3] = "43"; 3110 ** azResult[4] = "Bob"; 3111 ** azResult[5] = "28"; 3112 ** azResult[6] = "Cindy"; 3113 ** azResult[7] = "21"; 3114 ** </pre></blockquote>)^ 3115 ** 3116 ** ^The sqlite3_get_table() function evaluates one or more 3117 ** semicolon-separated SQL statements in the zero-terminated UTF-8 3118 ** string of its 2nd parameter and returns a result table to the 3119 ** pointer given in its 3rd parameter. 3120 ** 3121 ** After the application has finished with the result from sqlite3_get_table(), 3122 ** it must pass the result table pointer to sqlite3_free_table() in order to 3123 ** release the memory that was malloced. Because of the way the 3124 ** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling 3125 ** function must not try to call [sqlite3_free()] directly. Only 3126 ** [sqlite3_free_table()] is able to release the memory properly and safely. 3127 ** 3128 ** The sqlite3_get_table() interface is implemented as a wrapper around 3129 ** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access 3130 ** to any internal data structures of SQLite. It uses only the public 3131 ** interface defined here. As a consequence, errors that occur in the 3132 ** wrapper layer outside of the internal [sqlite3_exec()] call are not 3133 ** reflected in subsequent calls to [sqlite3_errcode()] or 3134 ** [sqlite3_errmsg()]. 3135 */ 3136 SQLITE_API int sqlite3_get_table( 3137 sqlite3 *db, /* An open database */ 3138 const char *zSql, /* SQL to be evaluated */ 3139 char ***pazResult, /* Results of the query */ 3140 int *pnRow, /* Number of result rows written here */ 3141 int *pnColumn, /* Number of result columns written here */ 3142 char **pzErrmsg /* Error msg written here */ 3143 ); 3144 SQLITE_API void sqlite3_free_table(char **result); 3145 3146 /* 3147 ** CAPI3REF: Formatted String Printing Functions 3148 ** 3149 ** These routines are work-alikes of the "printf()" family of functions 3150 ** from the standard C library. 3151 ** These routines understand most of the common formatting options from 3152 ** the standard library printf() 3153 ** plus some additional non-standard formats ([%q], [%Q], [%w], and [%z]). 3154 ** See the [built-in printf()] documentation for details. 3155 ** 3156 ** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their 3157 ** results into memory obtained from [sqlite3_malloc64()]. 3158 ** The strings returned by these two routines should be 3159 ** released by [sqlite3_free()]. ^Both routines return a 3160 ** NULL pointer if [sqlite3_malloc64()] is unable to allocate enough 3161 ** memory to hold the resulting string. 3162 ** 3163 ** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from 3164 ** the standard C library. The result is written into the 3165 ** buffer supplied as the second parameter whose size is given by 3166 ** the first parameter. Note that the order of the 3167 ** first two parameters is reversed from snprintf().)^ This is an 3168 ** historical accident that cannot be fixed without breaking 3169 ** backwards compatibility. ^(Note also that sqlite3_snprintf() 3170 ** returns a pointer to its buffer instead of the number of 3171 ** characters actually written into the buffer.)^ We admit that 3172 ** the number of characters written would be a more useful return 3173 ** value but we cannot change the implementation of sqlite3_snprintf() 3174 ** now without breaking compatibility. 3175 ** 3176 ** ^As long as the buffer size is greater than zero, sqlite3_snprintf() 3177 ** guarantees that the buffer is always zero-terminated. ^The first 3178 ** parameter "n" is the total size of the buffer, including space for 3179 ** the zero terminator. So the longest string that can be completely 3180 ** written will be n-1 characters. 3181 ** 3182 ** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf(). 3183 ** 3184 ** See also: [built-in printf()], [printf() SQL function] 3185 */ 3186 SQLITE_API char *sqlite3_mprintf(const char*,...); 3187 SQLITE_API char *sqlite3_vmprintf(const char*, va_list); 3188 SQLITE_API char *sqlite3_snprintf(int,char*,const char*, ...); 3189 SQLITE_API char *sqlite3_vsnprintf(int,char*,const char*, va_list); 3190 3191 /* 3192 ** CAPI3REF: Memory Allocation Subsystem 3193 ** 3194 ** The SQLite core uses these three routines for all of its own 3195 ** internal memory allocation needs. "Core" in the previous sentence 3196 ** does not include operating-system specific [VFS] implementation. The 3197 ** Windows VFS uses native malloc() and free() for some operations. 3198 ** 3199 ** ^The sqlite3_malloc() routine returns a pointer to a block 3200 ** of memory at least N bytes in length, where N is the parameter. 3201 ** ^If sqlite3_malloc() is unable to obtain sufficient free 3202 ** memory, it returns a NULL pointer. ^If the parameter N to 3203 ** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns 3204 ** a NULL pointer. 3205 ** 3206 ** ^The sqlite3_malloc64(N) routine works just like 3207 ** sqlite3_malloc(N) except that N is an unsigned 64-bit integer instead 3208 ** of a signed 32-bit integer. 3209 ** 3210 ** ^Calling sqlite3_free() with a pointer previously returned 3211 ** by sqlite3_malloc() or sqlite3_realloc() releases that memory so 3212 ** that it might be reused. ^The sqlite3_free() routine is 3213 ** a no-op if is called with a NULL pointer. Passing a NULL pointer 3214 ** to sqlite3_free() is harmless. After being freed, memory 3215 ** should neither be read nor written. Even reading previously freed 3216 ** memory might result in a segmentation fault or other severe error. 3217 ** Memory corruption, a segmentation fault, or other severe error 3218 ** might result if sqlite3_free() is called with a non-NULL pointer that 3219 ** was not obtained from sqlite3_malloc() or sqlite3_realloc(). 3220 ** 3221 ** ^The sqlite3_realloc(X,N) interface attempts to resize a 3222 ** prior memory allocation X to be at least N bytes. 3223 ** ^If the X parameter to sqlite3_realloc(X,N) 3224 ** is a NULL pointer then its behavior is identical to calling 3225 ** sqlite3_malloc(N). 3226 ** ^If the N parameter to sqlite3_realloc(X,N) is zero or 3227 ** negative then the behavior is exactly the same as calling 3228 ** sqlite3_free(X). 3229 ** ^sqlite3_realloc(X,N) returns a pointer to a memory allocation 3230 ** of at least N bytes in size or NULL if insufficient memory is available. 3231 ** ^If M is the size of the prior allocation, then min(N,M) bytes 3232 ** of the prior allocation are copied into the beginning of buffer returned 3233 ** by sqlite3_realloc(X,N) and the prior allocation is freed. 3234 ** ^If sqlite3_realloc(X,N) returns NULL and N is positive, then the 3235 ** prior allocation is not freed. 3236 ** 3237 ** ^The sqlite3_realloc64(X,N) interfaces works the same as 3238 ** sqlite3_realloc(X,N) except that N is a 64-bit unsigned integer instead 3239 ** of a 32-bit signed integer. 3240 ** 3241 ** ^If X is a memory allocation previously obtained from sqlite3_malloc(), 3242 ** sqlite3_malloc64(), sqlite3_realloc(), or sqlite3_realloc64(), then 3243 ** sqlite3_msize(X) returns the size of that memory allocation in bytes. 3244 ** ^The value returned by sqlite3_msize(X) might be larger than the number 3245 ** of bytes requested when X was allocated. ^If X is a NULL pointer then 3246 ** sqlite3_msize(X) returns zero. If X points to something that is not 3247 ** the beginning of memory allocation, or if it points to a formerly 3248 ** valid memory allocation that has now been freed, then the behavior 3249 ** of sqlite3_msize(X) is undefined and possibly harmful. 3250 ** 3251 ** ^The memory returned by sqlite3_malloc(), sqlite3_realloc(), 3252 ** sqlite3_malloc64(), and sqlite3_realloc64() 3253 ** is always aligned to at least an 8 byte boundary, or to a 3254 ** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time 3255 ** option is used. 3256 ** 3257 ** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()] 3258 ** must be either NULL or else pointers obtained from a prior 3259 ** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have 3260 ** not yet been released. 3261 ** 3262 ** The application must not read or write any part of 3263 ** a block of memory after it has been released using 3264 ** [sqlite3_free()] or [sqlite3_realloc()]. 3265 */ 3266 SQLITE_API void *sqlite3_malloc(int); 3267 SQLITE_API void *sqlite3_malloc64(sqlite3_uint64); 3268 SQLITE_API void *sqlite3_realloc(void*, int); 3269 SQLITE_API void *sqlite3_realloc64(void*, sqlite3_uint64); 3270 SQLITE_API void sqlite3_free(void*); 3271 SQLITE_API sqlite3_uint64 sqlite3_msize(void*); 3272 3273 /* 3274 ** CAPI3REF: Memory Allocator Statistics 3275 ** 3276 ** SQLite provides these two interfaces for reporting on the status 3277 ** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()] 3278 ** routines, which form the built-in memory allocation subsystem. 3279 ** 3280 ** ^The [sqlite3_memory_used()] routine returns the number of bytes 3281 ** of memory currently outstanding (malloced but not freed). 3282 ** ^The [sqlite3_memory_highwater()] routine returns the maximum 3283 ** value of [sqlite3_memory_used()] since the high-water mark 3284 ** was last reset. ^The values returned by [sqlite3_memory_used()] and 3285 ** [sqlite3_memory_highwater()] include any overhead 3286 ** added by SQLite in its implementation of [sqlite3_malloc()], 3287 ** but not overhead added by the any underlying system library 3288 ** routines that [sqlite3_malloc()] may call. 3289 ** 3290 ** ^The memory high-water mark is reset to the current value of 3291 ** [sqlite3_memory_used()] if and only if the parameter to 3292 ** [sqlite3_memory_highwater()] is true. ^The value returned 3293 ** by [sqlite3_memory_highwater(1)] is the high-water mark 3294 ** prior to the reset. 3295 */ 3296 SQLITE_API sqlite3_int64 sqlite3_memory_used(void); 3297 SQLITE_API sqlite3_int64 sqlite3_memory_highwater(int resetFlag); 3298 3299 /* 3300 ** CAPI3REF: Pseudo-Random Number Generator 3301 ** 3302 ** SQLite contains a high-quality pseudo-random number generator (PRNG) used to 3303 ** select random [ROWID | ROWIDs] when inserting new records into a table that 3304 ** already uses the largest possible [ROWID]. The PRNG is also used for 3305 ** the built-in random() and randomblob() SQL functions. This interface allows 3306 ** applications to access the same PRNG for other purposes. 3307 ** 3308 ** ^A call to this routine stores N bytes of randomness into buffer P. 3309 ** ^The P parameter can be a NULL pointer. 3310 ** 3311 ** ^If this routine has not been previously called or if the previous 3312 ** call had N less than one or a NULL pointer for P, then the PRNG is 3313 ** seeded using randomness obtained from the xRandomness method of 3314 ** the default [sqlite3_vfs] object. 3315 ** ^If the previous call to this routine had an N of 1 or more and a 3316 ** non-NULL P then the pseudo-randomness is generated 3317 ** internally and without recourse to the [sqlite3_vfs] xRandomness 3318 ** method. 3319 */ 3320 SQLITE_API void sqlite3_randomness(int N, void *P); 3321 3322 /* 3323 ** CAPI3REF: Compile-Time Authorization Callbacks 3324 ** METHOD: sqlite3 3325 ** KEYWORDS: {authorizer callback} 3326 ** 3327 ** ^This routine registers an authorizer callback with a particular 3328 ** [database connection], supplied in the first argument. 3329 ** ^The authorizer callback is invoked as SQL statements are being compiled 3330 ** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()], 3331 ** [sqlite3_prepare_v3()], [sqlite3_prepare16()], [sqlite3_prepare16_v2()], 3332 ** and [sqlite3_prepare16_v3()]. ^At various 3333 ** points during the compilation process, as logic is being created 3334 ** to perform various actions, the authorizer callback is invoked to 3335 ** see if those actions are allowed. ^The authorizer callback should 3336 ** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the 3337 ** specific action but allow the SQL statement to continue to be 3338 ** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be 3339 ** rejected with an error. ^If the authorizer callback returns 3340 ** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY] 3341 ** then the [sqlite3_prepare_v2()] or equivalent call that triggered 3342 ** the authorizer will fail with an error message. 3343 ** 3344 ** When the callback returns [SQLITE_OK], that means the operation 3345 ** requested is ok. ^When the callback returns [SQLITE_DENY], the 3346 ** [sqlite3_prepare_v2()] or equivalent call that triggered the 3347 ** authorizer will fail with an error message explaining that 3348 ** access is denied. 3349 ** 3350 ** ^The first parameter to the authorizer callback is a copy of the third 3351 ** parameter to the sqlite3_set_authorizer() interface. ^The second parameter 3352 ** to the callback is an integer [SQLITE_COPY | action code] that specifies 3353 ** the particular action to be authorized. ^The third through sixth parameters 3354 ** to the callback are either NULL pointers or zero-terminated strings 3355 ** that contain additional details about the action to be authorized. 3356 ** Applications must always be prepared to encounter a NULL pointer in any 3357 ** of the third through the sixth parameters of the authorization callback. 3358 ** 3359 ** ^If the action code is [SQLITE_READ] 3360 ** and the callback returns [SQLITE_IGNORE] then the 3361 ** [prepared statement] statement is constructed to substitute 3362 ** a NULL value in place of the table column that would have 3363 ** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE] 3364 ** return can be used to deny an untrusted user access to individual 3365 ** columns of a table. 3366 ** ^When a table is referenced by a [SELECT] but no column values are 3367 ** extracted from that table (for example in a query like 3368 ** "SELECT count(*) FROM tab") then the [SQLITE_READ] authorizer callback 3369 ** is invoked once for that table with a column name that is an empty string. 3370 ** ^If the action code is [SQLITE_DELETE] and the callback returns 3371 ** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the 3372 ** [truncate optimization] is disabled and all rows are deleted individually. 3373 ** 3374 ** An authorizer is used when [sqlite3_prepare | preparing] 3375 ** SQL statements from an untrusted source, to ensure that the SQL statements 3376 ** do not try to access data they are not allowed to see, or that they do not 3377 ** try to execute malicious statements that damage the database. For 3378 ** example, an application may allow a user to enter arbitrary 3379 ** SQL queries for evaluation by a database. But the application does 3380 ** not want the user to be able to make arbitrary changes to the 3381 ** database. An authorizer could then be put in place while the 3382 ** user-entered SQL is being [sqlite3_prepare | prepared] that 3383 ** disallows everything except [SELECT] statements. 3384 ** 3385 ** Applications that need to process SQL from untrusted sources 3386 ** might also consider lowering resource limits using [sqlite3_limit()] 3387 ** and limiting database size using the [max_page_count] [PRAGMA] 3388 ** in addition to using an authorizer. 3389 ** 3390 ** ^(Only a single authorizer can be in place on a database connection 3391 ** at a time. Each call to sqlite3_set_authorizer overrides the 3392 ** previous call.)^ ^Disable the authorizer by installing a NULL callback. 3393 ** The authorizer is disabled by default. 3394 ** 3395 ** The authorizer callback must not do anything that will modify 3396 ** the database connection that invoked the authorizer callback. 3397 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 3398 ** database connections for the meaning of "modify" in this paragraph. 3399 ** 3400 ** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the 3401 ** statement might be re-prepared during [sqlite3_step()] due to a 3402 ** schema change. Hence, the application should ensure that the 3403 ** correct authorizer callback remains in place during the [sqlite3_step()]. 3404 ** 3405 ** ^Note that the authorizer callback is invoked only during 3406 ** [sqlite3_prepare()] or its variants. Authorization is not 3407 ** performed during statement evaluation in [sqlite3_step()], unless 3408 ** as stated in the previous paragraph, sqlite3_step() invokes 3409 ** sqlite3_prepare_v2() to reprepare a statement after a schema change. 3410 */ 3411 SQLITE_API int sqlite3_set_authorizer( 3412 sqlite3*, 3413 int (*xAuth)(void*,int,const char*,const char*,const char*,const char*), 3414 void *pUserData 3415 ); 3416 3417 /* 3418 ** CAPI3REF: Authorizer Return Codes 3419 ** 3420 ** The [sqlite3_set_authorizer | authorizer callback function] must 3421 ** return either [SQLITE_OK] or one of these two constants in order 3422 ** to signal SQLite whether or not the action is permitted. See the 3423 ** [sqlite3_set_authorizer | authorizer documentation] for additional 3424 ** information. 3425 ** 3426 ** Note that SQLITE_IGNORE is also used as a [conflict resolution mode] 3427 ** returned from the [sqlite3_vtab_on_conflict()] interface. 3428 */ 3429 #define SQLITE_DENY 1 /* Abort the SQL statement with an error */ 3430 #define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */ 3431 3432 /* 3433 ** CAPI3REF: Authorizer Action Codes 3434 ** 3435 ** The [sqlite3_set_authorizer()] interface registers a callback function 3436 ** that is invoked to authorize certain SQL statement actions. The 3437 ** second parameter to the callback is an integer code that specifies 3438 ** what action is being authorized. These are the integer action codes that 3439 ** the authorizer callback may be passed. 3440 ** 3441 ** These action code values signify what kind of operation is to be 3442 ** authorized. The 3rd and 4th parameters to the authorization 3443 ** callback function will be parameters or NULL depending on which of these 3444 ** codes is used as the second parameter. ^(The 5th parameter to the 3445 ** authorizer callback is the name of the database ("main", "temp", 3446 ** etc.) if applicable.)^ ^The 6th parameter to the authorizer callback 3447 ** is the name of the inner-most trigger or view that is responsible for 3448 ** the access attempt or NULL if this access attempt is directly from 3449 ** top-level SQL code. 3450 */ 3451 /******************************************* 3rd ************ 4th ***********/ 3452 #define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */ 3453 #define SQLITE_CREATE_TABLE 2 /* Table Name NULL */ 3454 #define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */ 3455 #define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */ 3456 #define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */ 3457 #define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */ 3458 #define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */ 3459 #define SQLITE_CREATE_VIEW 8 /* View Name NULL */ 3460 #define SQLITE_DELETE 9 /* Table Name NULL */ 3461 #define SQLITE_DROP_INDEX 10 /* Index Name Table Name */ 3462 #define SQLITE_DROP_TABLE 11 /* Table Name NULL */ 3463 #define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */ 3464 #define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */ 3465 #define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */ 3466 #define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */ 3467 #define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */ 3468 #define SQLITE_DROP_VIEW 17 /* View Name NULL */ 3469 #define SQLITE_INSERT 18 /* Table Name NULL */ 3470 #define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */ 3471 #define SQLITE_READ 20 /* Table Name Column Name */ 3472 #define SQLITE_SELECT 21 /* NULL NULL */ 3473 #define SQLITE_TRANSACTION 22 /* Operation NULL */ 3474 #define SQLITE_UPDATE 23 /* Table Name Column Name */ 3475 #define SQLITE_ATTACH 24 /* Filename NULL */ 3476 #define SQLITE_DETACH 25 /* Database Name NULL */ 3477 #define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */ 3478 #define SQLITE_REINDEX 27 /* Index Name NULL */ 3479 #define SQLITE_ANALYZE 28 /* Table Name NULL */ 3480 #define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */ 3481 #define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */ 3482 #define SQLITE_FUNCTION 31 /* NULL Function Name */ 3483 #define SQLITE_SAVEPOINT 32 /* Operation Savepoint Name */ 3484 #define SQLITE_COPY 0 /* No longer used */ 3485 #define SQLITE_RECURSIVE 33 /* NULL NULL */ 3486 3487 /* 3488 ** CAPI3REF: Deprecated Tracing And Profiling Functions 3489 ** DEPRECATED 3490 ** 3491 ** These routines are deprecated. Use the [sqlite3_trace_v2()] interface 3492 ** instead of the routines described here. 3493 ** 3494 ** These routines register callback functions that can be used for 3495 ** tracing and profiling the execution of SQL statements. 3496 ** 3497 ** ^The callback function registered by sqlite3_trace() is invoked at 3498 ** various times when an SQL statement is being run by [sqlite3_step()]. 3499 ** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the 3500 ** SQL statement text as the statement first begins executing. 3501 ** ^(Additional sqlite3_trace() callbacks might occur 3502 ** as each triggered subprogram is entered. The callbacks for triggers 3503 ** contain a UTF-8 SQL comment that identifies the trigger.)^ 3504 ** 3505 ** The [SQLITE_TRACE_SIZE_LIMIT] compile-time option can be used to limit 3506 ** the length of [bound parameter] expansion in the output of sqlite3_trace(). 3507 ** 3508 ** ^The callback function registered by sqlite3_profile() is invoked 3509 ** as each SQL statement finishes. ^The profile callback contains 3510 ** the original statement text and an estimate of wall-clock time 3511 ** of how long that statement took to run. ^The profile callback 3512 ** time is in units of nanoseconds, however the current implementation 3513 ** is only capable of millisecond resolution so the six least significant 3514 ** digits in the time are meaningless. Future versions of SQLite 3515 ** might provide greater resolution on the profiler callback. Invoking 3516 ** either [sqlite3_trace()] or [sqlite3_trace_v2()] will cancel the 3517 ** profile callback. 3518 */ 3519 SQLITE_API SQLITE_DEPRECATED void *sqlite3_trace(sqlite3*, 3520 void(*xTrace)(void*,const char*), void*); 3521 SQLITE_API SQLITE_DEPRECATED void *sqlite3_profile(sqlite3*, 3522 void(*xProfile)(void*,const char*,sqlite3_uint64), void*); 3523 3524 /* 3525 ** CAPI3REF: SQL Trace Event Codes 3526 ** KEYWORDS: SQLITE_TRACE 3527 ** 3528 ** These constants identify classes of events that can be monitored 3529 ** using the [sqlite3_trace_v2()] tracing logic. The M argument 3530 ** to [sqlite3_trace_v2(D,M,X,P)] is an OR-ed combination of one or more of 3531 ** the following constants. ^The first argument to the trace callback 3532 ** is one of the following constants. 3533 ** 3534 ** New tracing constants may be added in future releases. 3535 ** 3536 ** ^A trace callback has four arguments: xCallback(T,C,P,X). 3537 ** ^The T argument is one of the integer type codes above. 3538 ** ^The C argument is a copy of the context pointer passed in as the 3539 ** fourth argument to [sqlite3_trace_v2()]. 3540 ** The P and X arguments are pointers whose meanings depend on T. 3541 ** 3542 ** <dl> 3543 ** [[SQLITE_TRACE_STMT]] <dt>SQLITE_TRACE_STMT</dt> 3544 ** <dd>^An SQLITE_TRACE_STMT callback is invoked when a prepared statement 3545 ** first begins running and possibly at other times during the 3546 ** execution of the prepared statement, such as at the start of each 3547 ** trigger subprogram. ^The P argument is a pointer to the 3548 ** [prepared statement]. ^The X argument is a pointer to a string which 3549 ** is the unexpanded SQL text of the prepared statement or an SQL comment 3550 ** that indicates the invocation of a trigger. ^The callback can compute 3551 ** the same text that would have been returned by the legacy [sqlite3_trace()] 3552 ** interface by using the X argument when X begins with "--" and invoking 3553 ** [sqlite3_expanded_sql(P)] otherwise. 3554 ** 3555 ** [[SQLITE_TRACE_PROFILE]] <dt>SQLITE_TRACE_PROFILE</dt> 3556 ** <dd>^An SQLITE_TRACE_PROFILE callback provides approximately the same 3557 ** information as is provided by the [sqlite3_profile()] callback. 3558 ** ^The P argument is a pointer to the [prepared statement] and the 3559 ** X argument points to a 64-bit integer which is approximately 3560 ** the number of nanoseconds that the prepared statement took to run. 3561 ** ^The SQLITE_TRACE_PROFILE callback is invoked when the statement finishes. 3562 ** 3563 ** [[SQLITE_TRACE_ROW]] <dt>SQLITE_TRACE_ROW</dt> 3564 ** <dd>^An SQLITE_TRACE_ROW callback is invoked whenever a prepared 3565 ** statement generates a single row of result. 3566 ** ^The P argument is a pointer to the [prepared statement] and the 3567 ** X argument is unused. 3568 ** 3569 ** [[SQLITE_TRACE_CLOSE]] <dt>SQLITE_TRACE_CLOSE</dt> 3570 ** <dd>^An SQLITE_TRACE_CLOSE callback is invoked when a database 3571 ** connection closes. 3572 ** ^The P argument is a pointer to the [database connection] object 3573 ** and the X argument is unused. 3574 ** </dl> 3575 */ 3576 #define SQLITE_TRACE_STMT 0x01 3577 #define SQLITE_TRACE_PROFILE 0x02 3578 #define SQLITE_TRACE_ROW 0x04 3579 #define SQLITE_TRACE_CLOSE 0x08 3580 3581 /* 3582 ** CAPI3REF: SQL Trace Hook 3583 ** METHOD: sqlite3 3584 ** 3585 ** ^The sqlite3_trace_v2(D,M,X,P) interface registers a trace callback 3586 ** function X against [database connection] D, using property mask M 3587 ** and context pointer P. ^If the X callback is 3588 ** NULL or if the M mask is zero, then tracing is disabled. The 3589 ** M argument should be the bitwise OR-ed combination of 3590 ** zero or more [SQLITE_TRACE] constants. 3591 ** 3592 ** ^Each call to either sqlite3_trace(D,X,P) or sqlite3_trace_v2(D,M,X,P) 3593 ** overrides (cancels) all prior calls to sqlite3_trace(D,X,P) or 3594 ** sqlite3_trace_v2(D,M,X,P) for the [database connection] D. Each 3595 ** database connection may have at most one trace callback. 3596 ** 3597 ** ^The X callback is invoked whenever any of the events identified by 3598 ** mask M occur. ^The integer return value from the callback is currently 3599 ** ignored, though this may change in future releases. Callback 3600 ** implementations should return zero to ensure future compatibility. 3601 ** 3602 ** ^A trace callback is invoked with four arguments: callback(T,C,P,X). 3603 ** ^The T argument is one of the [SQLITE_TRACE] 3604 ** constants to indicate why the callback was invoked. 3605 ** ^The C argument is a copy of the context pointer. 3606 ** The P and X arguments are pointers whose meanings depend on T. 3607 ** 3608 ** The sqlite3_trace_v2() interface is intended to replace the legacy 3609 ** interfaces [sqlite3_trace()] and [sqlite3_profile()], both of which 3610 ** are deprecated. 3611 */ 3612 SQLITE_API int sqlite3_trace_v2( 3613 sqlite3*, 3614 unsigned uMask, 3615 int(*xCallback)(unsigned,void*,void*,void*), 3616 void *pCtx 3617 ); 3618 3619 /* 3620 ** CAPI3REF: Query Progress Callbacks 3621 ** METHOD: sqlite3 3622 ** 3623 ** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback 3624 ** function X to be invoked periodically during long running calls to 3625 ** [sqlite3_step()] and [sqlite3_prepare()] and similar for 3626 ** database connection D. An example use for this 3627 ** interface is to keep a GUI updated during a large query. 3628 ** 3629 ** ^The parameter P is passed through as the only parameter to the 3630 ** callback function X. ^The parameter N is the approximate number of 3631 ** [virtual machine instructions] that are evaluated between successive 3632 ** invocations of the callback X. ^If N is less than one then the progress 3633 ** handler is disabled. 3634 ** 3635 ** ^Only a single progress handler may be defined at one time per 3636 ** [database connection]; setting a new progress handler cancels the 3637 ** old one. ^Setting parameter X to NULL disables the progress handler. 3638 ** ^The progress handler is also disabled by setting N to a value less 3639 ** than 1. 3640 ** 3641 ** ^If the progress callback returns non-zero, the operation is 3642 ** interrupted. This feature can be used to implement a 3643 ** "Cancel" button on a GUI progress dialog box. 3644 ** 3645 ** The progress handler callback must not do anything that will modify 3646 ** the database connection that invoked the progress handler. 3647 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 3648 ** database connections for the meaning of "modify" in this paragraph. 3649 ** 3650 ** The progress handler callback would originally only be invoked from the 3651 ** bytecode engine. It still might be invoked during [sqlite3_prepare()] 3652 ** and similar because those routines might force a reparse of the schema 3653 ** which involves running the bytecode engine. However, beginning with 3654 ** SQLite version 3.41.0, the progress handler callback might also be 3655 ** invoked directly from [sqlite3_prepare()] while analyzing and generating 3656 ** code for complex queries. 3657 */ 3658 SQLITE_API void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*); 3659 3660 /* 3661 ** CAPI3REF: Opening A New Database Connection 3662 ** CONSTRUCTOR: sqlite3 3663 ** 3664 ** ^These routines open an SQLite database file as specified by the 3665 ** filename argument. ^The filename argument is interpreted as UTF-8 for 3666 ** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte 3667 ** order for sqlite3_open16(). ^(A [database connection] handle is usually 3668 ** returned in *ppDb, even if an error occurs. The only exception is that 3669 ** if SQLite is unable to allocate memory to hold the [sqlite3] object, 3670 ** a NULL will be written into *ppDb instead of a pointer to the [sqlite3] 3671 ** object.)^ ^(If the database is opened (and/or created) successfully, then 3672 ** [SQLITE_OK] is returned. Otherwise an [error code] is returned.)^ ^The 3673 ** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain 3674 ** an English language description of the error following a failure of any 3675 ** of the sqlite3_open() routines. 3676 ** 3677 ** ^The default encoding will be UTF-8 for databases created using 3678 ** sqlite3_open() or sqlite3_open_v2(). ^The default encoding for databases 3679 ** created using sqlite3_open16() will be UTF-16 in the native byte order. 3680 ** 3681 ** Whether or not an error occurs when it is opened, resources 3682 ** associated with the [database connection] handle should be released by 3683 ** passing it to [sqlite3_close()] when it is no longer required. 3684 ** 3685 ** The sqlite3_open_v2() interface works like sqlite3_open() 3686 ** except that it accepts two additional parameters for additional control 3687 ** over the new database connection. ^(The flags parameter to 3688 ** sqlite3_open_v2() must include, at a minimum, one of the following 3689 ** three flag combinations:)^ 3690 ** 3691 ** <dl> 3692 ** ^(<dt>[SQLITE_OPEN_READONLY]</dt> 3693 ** <dd>The database is opened in read-only mode. If the database does 3694 ** not already exist, an error is returned.</dd>)^ 3695 ** 3696 ** ^(<dt>[SQLITE_OPEN_READWRITE]</dt> 3697 ** <dd>The database is opened for reading and writing if possible, or 3698 ** reading only if the file is write protected by the operating 3699 ** system. In either case the database must already exist, otherwise 3700 ** an error is returned. For historical reasons, if opening in 3701 ** read-write mode fails due to OS-level permissions, an attempt is 3702 ** made to open it in read-only mode. [sqlite3_db_readonly()] can be 3703 ** used to determine whether the database is actually 3704 ** read-write.</dd>)^ 3705 ** 3706 ** ^(<dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt> 3707 ** <dd>The database is opened for reading and writing, and is created if 3708 ** it does not already exist. This is the behavior that is always used for 3709 ** sqlite3_open() and sqlite3_open16().</dd>)^ 3710 ** </dl> 3711 ** 3712 ** In addition to the required flags, the following optional flags are 3713 ** also supported: 3714 ** 3715 ** <dl> 3716 ** ^(<dt>[SQLITE_OPEN_URI]</dt> 3717 ** <dd>The filename can be interpreted as a URI if this flag is set.</dd>)^ 3718 ** 3719 ** ^(<dt>[SQLITE_OPEN_MEMORY]</dt> 3720 ** <dd>The database will be opened as an in-memory database. The database 3721 ** is named by the "filename" argument for the purposes of cache-sharing, 3722 ** if shared cache mode is enabled, but the "filename" is otherwise ignored. 3723 ** </dd>)^ 3724 ** 3725 ** ^(<dt>[SQLITE_OPEN_NOMUTEX]</dt> 3726 ** <dd>The new database connection will use the "multi-thread" 3727 ** [threading mode].)^ This means that separate threads are allowed 3728 ** to use SQLite at the same time, as long as each thread is using 3729 ** a different [database connection]. 3730 ** 3731 ** ^(<dt>[SQLITE_OPEN_FULLMUTEX]</dt> 3732 ** <dd>The new database connection will use the "serialized" 3733 ** [threading mode].)^ This means the multiple threads can safely 3734 ** attempt to use the same database connection at the same time. 3735 ** (Mutexes will block any actual concurrency, but in this mode 3736 ** there is no harm in trying.) 3737 ** 3738 ** ^(<dt>[SQLITE_OPEN_SHAREDCACHE]</dt> 3739 ** <dd>The database is opened [shared cache] enabled, overriding 3740 ** the default shared cache setting provided by 3741 ** [sqlite3_enable_shared_cache()].)^ 3742 ** The [use of shared cache mode is discouraged] and hence shared cache 3743 ** capabilities may be omitted from many builds of SQLite. In such cases, 3744 ** this option is a no-op. 3745 ** 3746 ** ^(<dt>[SQLITE_OPEN_PRIVATECACHE]</dt> 3747 ** <dd>The database is opened [shared cache] disabled, overriding 3748 ** the default shared cache setting provided by 3749 ** [sqlite3_enable_shared_cache()].)^ 3750 ** 3751 ** [[OPEN_EXRESCODE]] ^(<dt>[SQLITE_OPEN_EXRESCODE]</dt> 3752 ** <dd>The database connection comes up in "extended result code mode". 3753 ** In other words, the database behaves as if 3754 ** [sqlite3_extended_result_codes(db,1)] were called on the database 3755 ** connection as soon as the connection is created. In addition to setting 3756 ** the extended result code mode, this flag also causes [sqlite3_open_v2()] 3757 ** to return an extended result code.</dd> 3758 ** 3759 ** [[OPEN_NOFOLLOW]] ^(<dt>[SQLITE_OPEN_NOFOLLOW]</dt> 3760 ** <dd>The database filename is not allowed to contain a symbolic link</dd> 3761 ** </dl>)^ 3762 ** 3763 ** If the 3rd parameter to sqlite3_open_v2() is not one of the 3764 ** required combinations shown above optionally combined with other 3765 ** [SQLITE_OPEN_READONLY | SQLITE_OPEN_* bits] 3766 ** then the behavior is undefined. Historic versions of SQLite 3767 ** have silently ignored surplus bits in the flags parameter to 3768 ** sqlite3_open_v2(), however that behavior might not be carried through 3769 ** into future versions of SQLite and so applications should not rely 3770 ** upon it. Note in particular that the SQLITE_OPEN_EXCLUSIVE flag is a no-op 3771 ** for sqlite3_open_v2(). The SQLITE_OPEN_EXCLUSIVE does *not* cause 3772 ** the open to fail if the database already exists. The SQLITE_OPEN_EXCLUSIVE 3773 ** flag is intended for use by the [sqlite3_vfs|VFS interface] only, and not 3774 ** by sqlite3_open_v2(). 3775 ** 3776 ** ^The fourth parameter to sqlite3_open_v2() is the name of the 3777 ** [sqlite3_vfs] object that defines the operating system interface that 3778 ** the new database connection should use. ^If the fourth parameter is 3779 ** a NULL pointer then the default [sqlite3_vfs] object is used. 3780 ** 3781 ** ^If the filename is ":memory:", then a private, temporary in-memory database 3782 ** is created for the connection. ^This in-memory database will vanish when 3783 ** the database connection is closed. Future versions of SQLite might 3784 ** make use of additional special filenames that begin with the ":" character. 3785 ** It is recommended that when a database filename actually does begin with 3786 ** a ":" character you should prefix the filename with a pathname such as 3787 ** "./" to avoid ambiguity. 3788 ** 3789 ** ^If the filename is an empty string, then a private, temporary 3790 ** on-disk database will be created. ^This private database will be 3791 ** automatically deleted as soon as the database connection is closed. 3792 ** 3793 ** [[URI filenames in sqlite3_open()]] <h3>URI Filenames</h3> 3794 ** 3795 ** ^If [URI filename] interpretation is enabled, and the filename argument 3796 ** begins with "file:", then the filename is interpreted as a URI. ^URI 3797 ** filename interpretation is enabled if the [SQLITE_OPEN_URI] flag is 3798 ** set in the third argument to sqlite3_open_v2(), or if it has 3799 ** been enabled globally using the [SQLITE_CONFIG_URI] option with the 3800 ** [sqlite3_config()] method or by the [SQLITE_USE_URI] compile-time option. 3801 ** URI filename interpretation is turned off 3802 ** by default, but future releases of SQLite might enable URI filename 3803 ** interpretation by default. See "[URI filenames]" for additional 3804 ** information. 3805 ** 3806 ** URI filenames are parsed according to RFC 3986. ^If the URI contains an 3807 ** authority, then it must be either an empty string or the string 3808 ** "localhost". ^If the authority is not an empty string or "localhost", an 3809 ** error is returned to the caller. ^The fragment component of a URI, if 3810 ** present, is ignored. 3811 ** 3812 ** ^SQLite uses the path component of the URI as the name of the disk file 3813 ** which contains the database. ^If the path begins with a '/' character, 3814 ** then it is interpreted as an absolute path. ^If the path does not begin 3815 ** with a '/' (meaning that the authority section is omitted from the URI) 3816 ** then the path is interpreted as a relative path. 3817 ** ^(On windows, the first component of an absolute path 3818 ** is a drive specification (e.g. "C:").)^ 3819 ** 3820 ** [[core URI query parameters]] 3821 ** The query component of a URI may contain parameters that are interpreted 3822 ** either by SQLite itself, or by a [VFS | custom VFS implementation]. 3823 ** SQLite and its built-in [VFSes] interpret the 3824 ** following query parameters: 3825 ** 3826 ** <ul> 3827 ** <li> <b>vfs</b>: ^The "vfs" parameter may be used to specify the name of 3828 ** a VFS object that provides the operating system interface that should 3829 ** be used to access the database file on disk. ^If this option is set to 3830 ** an empty string the default VFS object is used. ^Specifying an unknown 3831 ** VFS is an error. ^If sqlite3_open_v2() is used and the vfs option is 3832 ** present, then the VFS specified by the option takes precedence over 3833 ** the value passed as the fourth parameter to sqlite3_open_v2(). 3834 ** 3835 ** <li> <b>mode</b>: ^(The mode parameter may be set to either "ro", "rw", 3836 ** "rwc", or "memory". Attempting to set it to any other value is 3837 ** an error)^. 3838 ** ^If "ro" is specified, then the database is opened for read-only 3839 ** access, just as if the [SQLITE_OPEN_READONLY] flag had been set in the 3840 ** third argument to sqlite3_open_v2(). ^If the mode option is set to 3841 ** "rw", then the database is opened for read-write (but not create) 3842 ** access, as if SQLITE_OPEN_READWRITE (but not SQLITE_OPEN_CREATE) had 3843 ** been set. ^Value "rwc" is equivalent to setting both 3844 ** SQLITE_OPEN_READWRITE and SQLITE_OPEN_CREATE. ^If the mode option is 3845 ** set to "memory" then a pure [in-memory database] that never reads 3846 ** or writes from disk is used. ^It is an error to specify a value for 3847 ** the mode parameter that is less restrictive than that specified by 3848 ** the flags passed in the third parameter to sqlite3_open_v2(). 3849 ** 3850 ** <li> <b>cache</b>: ^The cache parameter may be set to either "shared" or 3851 ** "private". ^Setting it to "shared" is equivalent to setting the 3852 ** SQLITE_OPEN_SHAREDCACHE bit in the flags argument passed to 3853 ** sqlite3_open_v2(). ^Setting the cache parameter to "private" is 3854 ** equivalent to setting the SQLITE_OPEN_PRIVATECACHE bit. 3855 ** ^If sqlite3_open_v2() is used and the "cache" parameter is present in 3856 ** a URI filename, its value overrides any behavior requested by setting 3857 ** SQLITE_OPEN_PRIVATECACHE or SQLITE_OPEN_SHAREDCACHE flag. 3858 ** 3859 ** <li> <b>psow</b>: ^The psow parameter indicates whether or not the 3860 ** [powersafe overwrite] property does or does not apply to the 3861 ** storage media on which the database file resides. 3862 ** 3863 ** <li> <b>nolock</b>: ^The nolock parameter is a boolean query parameter 3864 ** which if set disables file locking in rollback journal modes. This 3865 ** is useful for accessing a database on a filesystem that does not 3866 ** support locking. Caution: Database corruption might result if two 3867 ** or more processes write to the same database and any one of those 3868 ** processes uses nolock=1. 3869 ** 3870 ** <li> <b>immutable</b>: ^The immutable parameter is a boolean query 3871 ** parameter that indicates that the database file is stored on 3872 ** read-only media. ^When immutable is set, SQLite assumes that the 3873 ** database file cannot be changed, even by a process with higher 3874 ** privilege, and so the database is opened read-only and all locking 3875 ** and change detection is disabled. Caution: Setting the immutable 3876 ** property on a database file that does in fact change can result 3877 ** in incorrect query results and/or [SQLITE_CORRUPT] errors. 3878 ** See also: [SQLITE_IOCAP_IMMUTABLE]. 3879 ** 3880 ** </ul> 3881 ** 3882 ** ^Specifying an unknown parameter in the query component of a URI is not an 3883 ** error. Future versions of SQLite might understand additional query 3884 ** parameters. See "[query parameters with special meaning to SQLite]" for 3885 ** additional information. 3886 ** 3887 ** [[URI filename examples]] <h3>URI filename examples</h3> 3888 ** 3889 ** <table border="1" align=center cellpadding=5> 3890 ** <tr><th> URI filenames <th> Results 3891 ** <tr><td> file:data.db <td> 3892 ** Open the file "data.db" in the current directory. 3893 ** <tr><td> file:/home/fred/data.db<br> 3894 ** file:///home/fred/data.db <br> 3895 ** file://localhost/home/fred/data.db <br> <td> 3896 ** Open the database file "/home/fred/data.db". 3897 ** <tr><td> file://darkstar/home/fred/data.db <td> 3898 ** An error. "darkstar" is not a recognized authority. 3899 ** <tr><td style="white-space:nowrap"> 3900 ** file:///C:/Documents%20and%20Settings/fred/Desktop/data.db 3901 ** <td> Windows only: Open the file "data.db" on fred's desktop on drive 3902 ** C:. Note that the %20 escaping in this example is not strictly 3903 ** necessary - space characters can be used literally 3904 ** in URI filenames. 3905 ** <tr><td> file:data.db?mode=ro&cache=private <td> 3906 ** Open file "data.db" in the current directory for read-only access. 3907 ** Regardless of whether or not shared-cache mode is enabled by 3908 ** default, use a private cache. 3909 ** <tr><td> file:/home/fred/data.db?vfs=unix-dotfile <td> 3910 ** Open file "/home/fred/data.db". Use the special VFS "unix-dotfile" 3911 ** that uses dot-files in place of posix advisory locking. 3912 ** <tr><td> file:data.db?mode=readonly <td> 3913 ** An error. "readonly" is not a valid option for the "mode" parameter. 3914 ** Use "ro" instead: "file:data.db?mode=ro". 3915 ** </table> 3916 ** 3917 ** ^URI hexadecimal escape sequences (%HH) are supported within the path and 3918 ** query components of a URI. A hexadecimal escape sequence consists of a 3919 ** percent sign - "%" - followed by exactly two hexadecimal digits 3920 ** specifying an octet value. ^Before the path or query components of a 3921 ** URI filename are interpreted, they are encoded using UTF-8 and all 3922 ** hexadecimal escape sequences replaced by a single byte containing the 3923 ** corresponding octet. If this process generates an invalid UTF-8 encoding, 3924 ** the results are undefined. 3925 ** 3926 ** <b>Note to Windows users:</b> The encoding used for the filename argument 3927 ** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever 3928 ** codepage is currently defined. Filenames containing international 3929 ** characters must be converted to UTF-8 prior to passing them into 3930 ** sqlite3_open() or sqlite3_open_v2(). 3931 ** 3932 ** <b>Note to Windows Runtime users:</b> The temporary directory must be set 3933 ** prior to calling sqlite3_open() or sqlite3_open_v2(). Otherwise, various 3934 ** features that require the use of temporary files may fail. 3935 ** 3936 ** See also: [sqlite3_temp_directory] 3937 */ 3938 SQLITE_API int sqlite3_open( 3939 const char *filename, /* Database filename (UTF-8) */ 3940 sqlite3 **ppDb /* OUT: SQLite db handle */ 3941 ); 3942 SQLITE_API int sqlite3_open16( 3943 const void *filename, /* Database filename (UTF-16) */ 3944 sqlite3 **ppDb /* OUT: SQLite db handle */ 3945 ); 3946 SQLITE_API int sqlite3_open_v2( 3947 const char *filename, /* Database filename (UTF-8) */ 3948 sqlite3 **ppDb, /* OUT: SQLite db handle */ 3949 int flags, /* Flags */ 3950 const char *zVfs /* Name of VFS module to use */ 3951 ); 3952 3953 /* 3954 ** CAPI3REF: Obtain Values For URI Parameters 3955 ** 3956 ** These are utility routines, useful to [VFS|custom VFS implementations], 3957 ** that check if a database file was a URI that contained a specific query 3958 ** parameter, and if so obtains the value of that query parameter. 3959 ** 3960 ** The first parameter to these interfaces (hereafter referred to 3961 ** as F) must be one of: 3962 ** <ul> 3963 ** <li> A database filename pointer created by the SQLite core and 3964 ** passed into the xOpen() method of a VFS implementation, or 3965 ** <li> A filename obtained from [sqlite3_db_filename()], or 3966 ** <li> A new filename constructed using [sqlite3_create_filename()]. 3967 ** </ul> 3968 ** If the F parameter is not one of the above, then the behavior is 3969 ** undefined and probably undesirable. Older versions of SQLite were 3970 ** more tolerant of invalid F parameters than newer versions. 3971 ** 3972 ** If F is a suitable filename (as described in the previous paragraph) 3973 ** and if P is the name of the query parameter, then 3974 ** sqlite3_uri_parameter(F,P) returns the value of the P 3975 ** parameter if it exists or a NULL pointer if P does not appear as a 3976 ** query parameter on F. If P is a query parameter of F and it 3977 ** has no explicit value, then sqlite3_uri_parameter(F,P) returns 3978 ** a pointer to an empty string. 3979 ** 3980 ** The sqlite3_uri_boolean(F,P,B) routine assumes that P is a boolean 3981 ** parameter and returns true (1) or false (0) according to the value 3982 ** of P. The sqlite3_uri_boolean(F,P,B) routine returns true (1) if the 3983 ** value of query parameter P is one of "yes", "true", or "on" in any 3984 ** case or if the value begins with a non-zero number. The 3985 ** sqlite3_uri_boolean(F,P,B) routines returns false (0) if the value of 3986 ** query parameter P is one of "no", "false", or "off" in any case or 3987 ** if the value begins with a numeric zero. If P is not a query 3988 ** parameter on F or if the value of P does not match any of the 3989 ** above, then sqlite3_uri_boolean(F,P,B) returns (B!=0). 3990 ** 3991 ** The sqlite3_uri_int64(F,P,D) routine converts the value of P into a 3992 ** 64-bit signed integer and returns that integer, or D if P does not 3993 ** exist. If the value of P is something other than an integer, then 3994 ** zero is returned. 3995 ** 3996 ** The sqlite3_uri_key(F,N) returns a pointer to the name (not 3997 ** the value) of the N-th query parameter for filename F, or a NULL 3998 ** pointer if N is less than zero or greater than the number of query 3999 ** parameters minus 1. The N value is zero-based so N should be 0 to obtain 4000 ** the name of the first query parameter, 1 for the second parameter, and 4001 ** so forth. 4002 ** 4003 ** If F is a NULL pointer, then sqlite3_uri_parameter(F,P) returns NULL and 4004 ** sqlite3_uri_boolean(F,P,B) returns B. If F is not a NULL pointer and 4005 ** is not a database file pathname pointer that the SQLite core passed 4006 ** into the xOpen VFS method, then the behavior of this routine is undefined 4007 ** and probably undesirable. 4008 ** 4009 ** Beginning with SQLite [version 3.31.0] ([dateof:3.31.0]) the input F 4010 ** parameter can also be the name of a rollback journal file or WAL file 4011 ** in addition to the main database file. Prior to version 3.31.0, these 4012 ** routines would only work if F was the name of the main database file. 4013 ** When the F parameter is the name of the rollback journal or WAL file, 4014 ** it has access to all the same query parameters as were found on the 4015 ** main database file. 4016 ** 4017 ** See the [URI filename] documentation for additional information. 4018 */ 4019 SQLITE_API const char *sqlite3_uri_parameter(sqlite3_filename z, const char *zParam); 4020 SQLITE_API int sqlite3_uri_boolean(sqlite3_filename z, const char *zParam, int bDefault); 4021 SQLITE_API sqlite3_int64 sqlite3_uri_int64(sqlite3_filename, const char*, sqlite3_int64); 4022 SQLITE_API const char *sqlite3_uri_key(sqlite3_filename z, int N); 4023 4024 /* 4025 ** CAPI3REF: Translate filenames 4026 ** 4027 ** These routines are available to [VFS|custom VFS implementations] for 4028 ** translating filenames between the main database file, the journal file, 4029 ** and the WAL file. 4030 ** 4031 ** If F is the name of an sqlite database file, journal file, or WAL file 4032 ** passed by the SQLite core into the VFS, then sqlite3_filename_database(F) 4033 ** returns the name of the corresponding database file. 4034 ** 4035 ** If F is the name of an sqlite database file, journal file, or WAL file 4036 ** passed by the SQLite core into the VFS, or if F is a database filename 4037 ** obtained from [sqlite3_db_filename()], then sqlite3_filename_journal(F) 4038 ** returns the name of the corresponding rollback journal file. 4039 ** 4040 ** If F is the name of an sqlite database file, journal file, or WAL file 4041 ** that was passed by the SQLite core into the VFS, or if F is a database 4042 ** filename obtained from [sqlite3_db_filename()], then 4043 ** sqlite3_filename_wal(F) returns the name of the corresponding 4044 ** WAL file. 4045 ** 4046 ** In all of the above, if F is not the name of a database, journal or WAL 4047 ** filename passed into the VFS from the SQLite core and F is not the 4048 ** return value from [sqlite3_db_filename()], then the result is 4049 ** undefined and is likely a memory access violation. 4050 */ 4051 SQLITE_API const char *sqlite3_filename_database(sqlite3_filename); 4052 SQLITE_API const char *sqlite3_filename_journal(sqlite3_filename); 4053 SQLITE_API const char *sqlite3_filename_wal(sqlite3_filename); 4054 4055 /* 4056 ** CAPI3REF: Database File Corresponding To A Journal 4057 ** 4058 ** ^If X is the name of a rollback or WAL-mode journal file that is 4059 ** passed into the xOpen method of [sqlite3_vfs], then 4060 ** sqlite3_database_file_object(X) returns a pointer to the [sqlite3_file] 4061 ** object that represents the main database file. 4062 ** 4063 ** This routine is intended for use in custom [VFS] implementations 4064 ** only. It is not a general-purpose interface. 4065 ** The argument sqlite3_file_object(X) must be a filename pointer that 4066 ** has been passed into [sqlite3_vfs].xOpen method where the 4067 ** flags parameter to xOpen contains one of the bits 4068 ** [SQLITE_OPEN_MAIN_JOURNAL] or [SQLITE_OPEN_WAL]. Any other use 4069 ** of this routine results in undefined and probably undesirable 4070 ** behavior. 4071 */ 4072 SQLITE_API sqlite3_file *sqlite3_database_file_object(const char*); 4073 4074 /* 4075 ** CAPI3REF: Create and Destroy VFS Filenames 4076 ** 4077 ** These interfaces are provided for use by [VFS shim] implementations and 4078 ** are not useful outside of that context. 4079 ** 4080 ** The sqlite3_create_filename(D,J,W,N,P) allocates memory to hold a version of 4081 ** database filename D with corresponding journal file J and WAL file W and 4082 ** an array P of N URI Key/Value pairs. The result from 4083 ** sqlite3_create_filename(D,J,W,N,P) is a pointer to a database filename that 4084 ** is safe to pass to routines like: 4085 ** <ul> 4086 ** <li> [sqlite3_uri_parameter()], 4087 ** <li> [sqlite3_uri_boolean()], 4088 ** <li> [sqlite3_uri_int64()], 4089 ** <li> [sqlite3_uri_key()], 4090 ** <li> [sqlite3_filename_database()], 4091 ** <li> [sqlite3_filename_journal()], or 4092 ** <li> [sqlite3_filename_wal()]. 4093 ** </ul> 4094 ** If a memory allocation error occurs, sqlite3_create_filename() might 4095 ** return a NULL pointer. The memory obtained from sqlite3_create_filename(X) 4096 ** must be released by a corresponding call to sqlite3_free_filename(Y). 4097 ** 4098 ** The P parameter in sqlite3_create_filename(D,J,W,N,P) should be an array 4099 ** of 2*N pointers to strings. Each pair of pointers in this array corresponds 4100 ** to a key and value for a query parameter. The P parameter may be a NULL 4101 ** pointer if N is zero. None of the 2*N pointers in the P array may be 4102 ** NULL pointers and key pointers should not be empty strings. 4103 ** None of the D, J, or W parameters to sqlite3_create_filename(D,J,W,N,P) may 4104 ** be NULL pointers, though they can be empty strings. 4105 ** 4106 ** The sqlite3_free_filename(Y) routine releases a memory allocation 4107 ** previously obtained from sqlite3_create_filename(). Invoking 4108 ** sqlite3_free_filename(Y) where Y is a NULL pointer is a harmless no-op. 4109 ** 4110 ** If the Y parameter to sqlite3_free_filename(Y) is anything other 4111 ** than a NULL pointer or a pointer previously acquired from 4112 ** sqlite3_create_filename(), then bad things such as heap 4113 ** corruption or segfaults may occur. The value Y should not be 4114 ** used again after sqlite3_free_filename(Y) has been called. This means 4115 ** that if the [sqlite3_vfs.xOpen()] method of a VFS has been called using Y, 4116 ** then the corresponding [sqlite3_module.xClose() method should also be 4117 ** invoked prior to calling sqlite3_free_filename(Y). 4118 */ 4119 SQLITE_API sqlite3_filename sqlite3_create_filename( 4120 const char *zDatabase, 4121 const char *zJournal, 4122 const char *zWal, 4123 int nParam, 4124 const char **azParam 4125 ); 4126 SQLITE_API void sqlite3_free_filename(sqlite3_filename); 4127 4128 /* 4129 ** CAPI3REF: Error Codes And Messages 4130 ** METHOD: sqlite3 4131 ** 4132 ** ^If the most recent sqlite3_* API call associated with 4133 ** [database connection] D failed, then the sqlite3_errcode(D) interface 4134 ** returns the numeric [result code] or [extended result code] for that 4135 ** API call. 4136 ** ^The sqlite3_extended_errcode() 4137 ** interface is the same except that it always returns the 4138 ** [extended result code] even when extended result codes are 4139 ** disabled. 4140 ** 4141 ** The values returned by sqlite3_errcode() and/or 4142 ** sqlite3_extended_errcode() might change with each API call. 4143 ** Except, there are some interfaces that are guaranteed to never 4144 ** change the value of the error code. The error-code preserving 4145 ** interfaces include the following: 4146 ** 4147 ** <ul> 4148 ** <li> sqlite3_errcode() 4149 ** <li> sqlite3_extended_errcode() 4150 ** <li> sqlite3_errmsg() 4151 ** <li> sqlite3_errmsg16() 4152 ** <li> sqlite3_error_offset() 4153 ** </ul> 4154 ** 4155 ** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language 4156 ** text that describes the error, as either UTF-8 or UTF-16 respectively, 4157 ** or NULL if no error message is available. 4158 ** (See how SQLite handles [invalid UTF] for exceptions to this rule.) 4159 ** ^(Memory to hold the error message string is managed internally. 4160 ** The application does not need to worry about freeing the result. 4161 ** However, the error string might be overwritten or deallocated by 4162 ** subsequent calls to other SQLite interface functions.)^ 4163 ** 4164 ** ^The sqlite3_errstr(E) interface returns the English-language text 4165 ** that describes the [result code] E, as UTF-8, or NULL if E is not an 4166 ** result code for which a text error message is available. 4167 ** ^(Memory to hold the error message string is managed internally 4168 ** and must not be freed by the application)^. 4169 ** 4170 ** ^If the most recent error references a specific token in the input 4171 ** SQL, the sqlite3_error_offset() interface returns the byte offset 4172 ** of the start of that token. ^The byte offset returned by 4173 ** sqlite3_error_offset() assumes that the input SQL is UTF8. 4174 ** ^If the most recent error does not reference a specific token in the input 4175 ** SQL, then the sqlite3_error_offset() function returns -1. 4176 ** 4177 ** When the serialized [threading mode] is in use, it might be the 4178 ** case that a second error occurs on a separate thread in between 4179 ** the time of the first error and the call to these interfaces. 4180 ** When that happens, the second error will be reported since these 4181 ** interfaces always report the most recent result. To avoid 4182 ** this, each thread can obtain exclusive use of the [database connection] D 4183 ** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning 4184 ** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after 4185 ** all calls to the interfaces listed here are completed. 4186 ** 4187 ** If an interface fails with SQLITE_MISUSE, that means the interface 4188 ** was invoked incorrectly by the application. In that case, the 4189 ** error code and message may or may not be set. 4190 */ 4191 SQLITE_API int sqlite3_errcode(sqlite3 *db); 4192 SQLITE_API int sqlite3_extended_errcode(sqlite3 *db); 4193 SQLITE_API const char *sqlite3_errmsg(sqlite3*); 4194 SQLITE_API const void *sqlite3_errmsg16(sqlite3*); 4195 SQLITE_API const char *sqlite3_errstr(int); 4196 SQLITE_API int sqlite3_error_offset(sqlite3 *db); 4197 4198 /* 4199 ** CAPI3REF: Prepared Statement Object 4200 ** KEYWORDS: {prepared statement} {prepared statements} 4201 ** 4202 ** An instance of this object represents a single SQL statement that 4203 ** has been compiled into binary form and is ready to be evaluated. 4204 ** 4205 ** Think of each SQL statement as a separate computer program. The 4206 ** original SQL text is source code. A prepared statement object 4207 ** is the compiled object code. All SQL must be converted into a 4208 ** prepared statement before it can be run. 4209 ** 4210 ** The life-cycle of a prepared statement object usually goes like this: 4211 ** 4212 ** <ol> 4213 ** <li> Create the prepared statement object using [sqlite3_prepare_v2()]. 4214 ** <li> Bind values to [parameters] using the sqlite3_bind_*() 4215 ** interfaces. 4216 ** <li> Run the SQL by calling [sqlite3_step()] one or more times. 4217 ** <li> Reset the prepared statement using [sqlite3_reset()] then go back 4218 ** to step 2. Do this zero or more times. 4219 ** <li> Destroy the object using [sqlite3_finalize()]. 4220 ** </ol> 4221 */ 4222 typedef struct sqlite3_stmt sqlite3_stmt; 4223 4224 /* 4225 ** CAPI3REF: Run-time Limits 4226 ** METHOD: sqlite3 4227 ** 4228 ** ^(This interface allows the size of various constructs to be limited 4229 ** on a connection by connection basis. The first parameter is the 4230 ** [database connection] whose limit is to be set or queried. The 4231 ** second parameter is one of the [limit categories] that define a 4232 ** class of constructs to be size limited. The third parameter is the 4233 ** new limit for that construct.)^ 4234 ** 4235 ** ^If the new limit is a negative number, the limit is unchanged. 4236 ** ^(For each limit category SQLITE_LIMIT_<i>NAME</i> there is a 4237 ** [limits | hard upper bound] 4238 ** set at compile-time by a C preprocessor macro called 4239 ** [limits | SQLITE_MAX_<i>NAME</i>]. 4240 ** (The "_LIMIT_" in the name is changed to "_MAX_".))^ 4241 ** ^Attempts to increase a limit above its hard upper bound are 4242 ** silently truncated to the hard upper bound. 4243 ** 4244 ** ^Regardless of whether or not the limit was changed, the 4245 ** [sqlite3_limit()] interface returns the prior value of the limit. 4246 ** ^Hence, to find the current value of a limit without changing it, 4247 ** simply invoke this interface with the third parameter set to -1. 4248 ** 4249 ** Run-time limits are intended for use in applications that manage 4250 ** both their own internal database and also databases that are controlled 4251 ** by untrusted external sources. An example application might be a 4252 ** web browser that has its own databases for storing history and 4253 ** separate databases controlled by JavaScript applications downloaded 4254 ** off the Internet. The internal databases can be given the 4255 ** large, default limits. Databases managed by external sources can 4256 ** be given much smaller limits designed to prevent a denial of service 4257 ** attack. Developers might also want to use the [sqlite3_set_authorizer()] 4258 ** interface to further control untrusted SQL. The size of the database 4259 ** created by an untrusted script can be contained using the 4260 ** [max_page_count] [PRAGMA]. 4261 ** 4262 ** New run-time limit categories may be added in future releases. 4263 */ 4264 SQLITE_API int sqlite3_limit(sqlite3*, int id, int newVal); 4265 4266 /* 4267 ** CAPI3REF: Run-Time Limit Categories 4268 ** KEYWORDS: {limit category} {*limit categories} 4269 ** 4270 ** These constants define various performance limits 4271 ** that can be lowered at run-time using [sqlite3_limit()]. 4272 ** The synopsis of the meanings of the various limits is shown below. 4273 ** Additional information is available at [limits | Limits in SQLite]. 4274 ** 4275 ** <dl> 4276 ** [[SQLITE_LIMIT_LENGTH]] ^(<dt>SQLITE_LIMIT_LENGTH</dt> 4277 ** <dd>The maximum size of any string or BLOB or table row, in bytes.<dd>)^ 4278 ** 4279 ** [[SQLITE_LIMIT_SQL_LENGTH]] ^(<dt>SQLITE_LIMIT_SQL_LENGTH</dt> 4280 ** <dd>The maximum length of an SQL statement, in bytes.</dd>)^ 4281 ** 4282 ** [[SQLITE_LIMIT_COLUMN]] ^(<dt>SQLITE_LIMIT_COLUMN</dt> 4283 ** <dd>The maximum number of columns in a table definition or in the 4284 ** result set of a [SELECT] or the maximum number of columns in an index 4285 ** or in an ORDER BY or GROUP BY clause.</dd>)^ 4286 ** 4287 ** [[SQLITE_LIMIT_EXPR_DEPTH]] ^(<dt>SQLITE_LIMIT_EXPR_DEPTH</dt> 4288 ** <dd>The maximum depth of the parse tree on any expression.</dd>)^ 4289 ** 4290 ** [[SQLITE_LIMIT_COMPOUND_SELECT]] ^(<dt>SQLITE_LIMIT_COMPOUND_SELECT</dt> 4291 ** <dd>The maximum number of terms in a compound SELECT statement.</dd>)^ 4292 ** 4293 ** [[SQLITE_LIMIT_VDBE_OP]] ^(<dt>SQLITE_LIMIT_VDBE_OP</dt> 4294 ** <dd>The maximum number of instructions in a virtual machine program 4295 ** used to implement an SQL statement. If [sqlite3_prepare_v2()] or 4296 ** the equivalent tries to allocate space for more than this many opcodes 4297 ** in a single prepared statement, an SQLITE_NOMEM error is returned.</dd>)^ 4298 ** 4299 ** [[SQLITE_LIMIT_FUNCTION_ARG]] ^(<dt>SQLITE_LIMIT_FUNCTION_ARG</dt> 4300 ** <dd>The maximum number of arguments on a function.</dd>)^ 4301 ** 4302 ** [[SQLITE_LIMIT_ATTACHED]] ^(<dt>SQLITE_LIMIT_ATTACHED</dt> 4303 ** <dd>The maximum number of [ATTACH | attached databases].)^</dd> 4304 ** 4305 ** [[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]] 4306 ** ^(<dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt> 4307 ** <dd>The maximum length of the pattern argument to the [LIKE] or 4308 ** [GLOB] operators.</dd>)^ 4309 ** 4310 ** [[SQLITE_LIMIT_VARIABLE_NUMBER]] 4311 ** ^(<dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt> 4312 ** <dd>The maximum index number of any [parameter] in an SQL statement.)^ 4313 ** 4314 ** [[SQLITE_LIMIT_TRIGGER_DEPTH]] ^(<dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt> 4315 ** <dd>The maximum depth of recursion for triggers.</dd>)^ 4316 ** 4317 ** [[SQLITE_LIMIT_WORKER_THREADS]] ^(<dt>SQLITE_LIMIT_WORKER_THREADS</dt> 4318 ** <dd>The maximum number of auxiliary worker threads that a single 4319 ** [prepared statement] may start.</dd>)^ 4320 ** </dl> 4321 */ 4322 #define SQLITE_LIMIT_LENGTH 0 4323 #define SQLITE_LIMIT_SQL_LENGTH 1 4324 #define SQLITE_LIMIT_COLUMN 2 4325 #define SQLITE_LIMIT_EXPR_DEPTH 3 4326 #define SQLITE_LIMIT_COMPOUND_SELECT 4 4327 #define SQLITE_LIMIT_VDBE_OP 5 4328 #define SQLITE_LIMIT_FUNCTION_ARG 6 4329 #define SQLITE_LIMIT_ATTACHED 7 4330 #define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8 4331 #define SQLITE_LIMIT_VARIABLE_NUMBER 9 4332 #define SQLITE_LIMIT_TRIGGER_DEPTH 10 4333 #define SQLITE_LIMIT_WORKER_THREADS 11 4334 4335 /* 4336 ** CAPI3REF: Prepare Flags 4337 ** 4338 ** These constants define various flags that can be passed into 4339 ** "prepFlags" parameter of the [sqlite3_prepare_v3()] and 4340 ** [sqlite3_prepare16_v3()] interfaces. 4341 ** 4342 ** New flags may be added in future releases of SQLite. 4343 ** 4344 ** <dl> 4345 ** [[SQLITE_PREPARE_PERSISTENT]] ^(<dt>SQLITE_PREPARE_PERSISTENT</dt> 4346 ** <dd>The SQLITE_PREPARE_PERSISTENT flag is a hint to the query planner 4347 ** that the prepared statement will be retained for a long time and 4348 ** probably reused many times.)^ ^Without this flag, [sqlite3_prepare_v3()] 4349 ** and [sqlite3_prepare16_v3()] assume that the prepared statement will 4350 ** be used just once or at most a few times and then destroyed using 4351 ** [sqlite3_finalize()] relatively soon. The current implementation acts 4352 ** on this hint by avoiding the use of [lookaside memory] so as not to 4353 ** deplete the limited store of lookaside memory. Future versions of 4354 ** SQLite may act on this hint differently. 4355 ** 4356 ** [[SQLITE_PREPARE_NORMALIZE]] <dt>SQLITE_PREPARE_NORMALIZE</dt> 4357 ** <dd>The SQLITE_PREPARE_NORMALIZE flag is a no-op. This flag used 4358 ** to be required for any prepared statement that wanted to use the 4359 ** [sqlite3_normalized_sql()] interface. However, the 4360 ** [sqlite3_normalized_sql()] interface is now available to all 4361 ** prepared statements, regardless of whether or not they use this 4362 ** flag. 4363 ** 4364 ** [[SQLITE_PREPARE_NO_VTAB]] <dt>SQLITE_PREPARE_NO_VTAB</dt> 4365 ** <dd>The SQLITE_PREPARE_NO_VTAB flag causes the SQL compiler 4366 ** to return an error (error code SQLITE_ERROR) if the statement uses 4367 ** any virtual tables. 4368 ** 4369 ** [[SQLITE_PREPARE_DONT_LOG]] <dt>SQLITE_PREPARE_DONT_LOG</dt> 4370 ** <dd>The SQLITE_PREPARE_DONT_LOG flag prevents SQL compiler 4371 ** errors from being sent to the error log defined by 4372 ** [SQLITE_CONFIG_LOG]. This can be used, for example, to do test 4373 ** compiles to see if some SQL syntax is well-formed, without generating 4374 ** messages on the global error log when it is not. If the test compile 4375 ** fails, the sqlite3_prepare_v3() call returns the same error indications 4376 ** with or without this flag; it just omits the call to [sqlite3_log()] that 4377 ** logs the error. 4378 ** </dl> 4379 */ 4380 #define SQLITE_PREPARE_PERSISTENT 0x01 4381 #define SQLITE_PREPARE_NORMALIZE 0x02 4382 #define SQLITE_PREPARE_NO_VTAB 0x04 4383 #define SQLITE_PREPARE_DONT_LOG 0x10 4384 4385 /* 4386 ** CAPI3REF: Compiling An SQL Statement 4387 ** KEYWORDS: {SQL statement compiler} 4388 ** METHOD: sqlite3 4389 ** CONSTRUCTOR: sqlite3_stmt 4390 ** 4391 ** To execute an SQL statement, it must first be compiled into a byte-code 4392 ** program using one of these routines. Or, in other words, these routines 4393 ** are constructors for the [prepared statement] object. 4394 ** 4395 ** The preferred routine to use is [sqlite3_prepare_v2()]. The 4396 ** [sqlite3_prepare()] interface is legacy and should be avoided. 4397 ** [sqlite3_prepare_v3()] has an extra "prepFlags" option that is used 4398 ** for special purposes. 4399 ** 4400 ** The use of the UTF-8 interfaces is preferred, as SQLite currently 4401 ** does all parsing using UTF-8. The UTF-16 interfaces are provided 4402 ** as a convenience. The UTF-16 interfaces work by converting the 4403 ** input text into UTF-8, then invoking the corresponding UTF-8 interface. 4404 ** 4405 ** The first argument, "db", is a [database connection] obtained from a 4406 ** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or 4407 ** [sqlite3_open16()]. The database connection must not have been closed. 4408 ** 4409 ** The second argument, "zSql", is the statement to be compiled, encoded 4410 ** as either UTF-8 or UTF-16. The sqlite3_prepare(), sqlite3_prepare_v2(), 4411 ** and sqlite3_prepare_v3() 4412 ** interfaces use UTF-8, and sqlite3_prepare16(), sqlite3_prepare16_v2(), 4413 ** and sqlite3_prepare16_v3() use UTF-16. 4414 ** 4415 ** ^If the nByte argument is negative, then zSql is read up to the 4416 ** first zero terminator. ^If nByte is positive, then it is the maximum 4417 ** number of bytes read from zSql. When nByte is positive, zSql is read 4418 ** up to the first zero terminator or until the nByte bytes have been read, 4419 ** whichever comes first. ^If nByte is zero, then no prepared 4420 ** statement is generated. 4421 ** If the caller knows that the supplied string is nul-terminated, then 4422 ** there is a small performance advantage to passing an nByte parameter that 4423 ** is the number of bytes in the input string <i>including</i> 4424 ** the nul-terminator. 4425 ** Note that nByte measure the length of the input in bytes, not 4426 ** characters, even for the UTF-16 interfaces. 4427 ** 4428 ** ^If pzTail is not NULL then *pzTail is made to point to the first byte 4429 ** past the end of the first SQL statement in zSql. These routines only 4430 ** compile the first statement in zSql, so *pzTail is left pointing to 4431 ** what remains uncompiled. 4432 ** 4433 ** ^*ppStmt is left pointing to a compiled [prepared statement] that can be 4434 ** executed using [sqlite3_step()]. ^If there is an error, *ppStmt is set 4435 ** to NULL. ^If the input text contains no SQL (if the input is an empty 4436 ** string or a comment) then *ppStmt is set to NULL. 4437 ** The calling procedure is responsible for deleting the compiled 4438 ** SQL statement using [sqlite3_finalize()] after it has finished with it. 4439 ** ppStmt may not be NULL. 4440 ** 4441 ** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK]; 4442 ** otherwise an [error code] is returned. 4443 ** 4444 ** The sqlite3_prepare_v2(), sqlite3_prepare_v3(), sqlite3_prepare16_v2(), 4445 ** and sqlite3_prepare16_v3() interfaces are recommended for all new programs. 4446 ** The older interfaces (sqlite3_prepare() and sqlite3_prepare16()) 4447 ** are retained for backwards compatibility, but their use is discouraged. 4448 ** ^In the "vX" interfaces, the prepared statement 4449 ** that is returned (the [sqlite3_stmt] object) contains a copy of the 4450 ** original SQL text. This causes the [sqlite3_step()] interface to 4451 ** behave differently in three ways: 4452 ** 4453 ** <ol> 4454 ** <li> 4455 ** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it 4456 ** always used to do, [sqlite3_step()] will automatically recompile the SQL 4457 ** statement and try to run it again. As many as [SQLITE_MAX_SCHEMA_RETRY] 4458 ** retries will occur before sqlite3_step() gives up and returns an error. 4459 ** </li> 4460 ** 4461 ** <li> 4462 ** ^When an error occurs, [sqlite3_step()] will return one of the detailed 4463 ** [error codes] or [extended error codes]. ^The legacy behavior was that 4464 ** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code 4465 ** and the application would have to make a second call to [sqlite3_reset()] 4466 ** in order to find the underlying cause of the problem. With the "v2" prepare 4467 ** interfaces, the underlying reason for the error is returned immediately. 4468 ** </li> 4469 ** 4470 ** <li> 4471 ** ^If the specific value bound to a [parameter | host parameter] in the 4472 ** WHERE clause might influence the choice of query plan for a statement, 4473 ** then the statement will be automatically recompiled, as if there had been 4474 ** a schema change, on the first [sqlite3_step()] call following any change 4475 ** to the [sqlite3_bind_text | bindings] of that [parameter]. 4476 ** ^The specific value of a WHERE-clause [parameter] might influence the 4477 ** choice of query plan if the parameter is the left-hand side of a [LIKE] 4478 ** or [GLOB] operator or if the parameter is compared to an indexed column 4479 ** and the [SQLITE_ENABLE_STAT4] compile-time option is enabled. 4480 ** </li> 4481 ** </ol> 4482 ** 4483 ** <p>^sqlite3_prepare_v3() differs from sqlite3_prepare_v2() only in having 4484 ** the extra prepFlags parameter, which is a bit array consisting of zero or 4485 ** more of the [SQLITE_PREPARE_PERSISTENT|SQLITE_PREPARE_*] flags. ^The 4486 ** sqlite3_prepare_v2() interface works exactly the same as 4487 ** sqlite3_prepare_v3() with a zero prepFlags parameter. 4488 */ 4489 SQLITE_API int sqlite3_prepare( 4490 sqlite3 *db, /* Database handle */ 4491 const char *zSql, /* SQL statement, UTF-8 encoded */ 4492 int nByte, /* Maximum length of zSql in bytes. */ 4493 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 4494 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 4495 ); 4496 SQLITE_API int sqlite3_prepare_v2( 4497 sqlite3 *db, /* Database handle */ 4498 const char *zSql, /* SQL statement, UTF-8 encoded */ 4499 int nByte, /* Maximum length of zSql in bytes. */ 4500 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 4501 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 4502 ); 4503 SQLITE_API int sqlite3_prepare_v3( 4504 sqlite3 *db, /* Database handle */ 4505 const char *zSql, /* SQL statement, UTF-8 encoded */ 4506 int nByte, /* Maximum length of zSql in bytes. */ 4507 unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */ 4508 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 4509 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 4510 ); 4511 SQLITE_API int sqlite3_prepare16( 4512 sqlite3 *db, /* Database handle */ 4513 const void *zSql, /* SQL statement, UTF-16 encoded */ 4514 int nByte, /* Maximum length of zSql in bytes. */ 4515 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 4516 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 4517 ); 4518 SQLITE_API int sqlite3_prepare16_v2( 4519 sqlite3 *db, /* Database handle */ 4520 const void *zSql, /* SQL statement, UTF-16 encoded */ 4521 int nByte, /* Maximum length of zSql in bytes. */ 4522 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 4523 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 4524 ); 4525 SQLITE_API int sqlite3_prepare16_v3( 4526 sqlite3 *db, /* Database handle */ 4527 const void *zSql, /* SQL statement, UTF-16 encoded */ 4528 int nByte, /* Maximum length of zSql in bytes. */ 4529 unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */ 4530 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 4531 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 4532 ); 4533 4534 /* 4535 ** CAPI3REF: Retrieving Statement SQL 4536 ** METHOD: sqlite3_stmt 4537 ** 4538 ** ^The sqlite3_sql(P) interface returns a pointer to a copy of the UTF-8 4539 ** SQL text used to create [prepared statement] P if P was 4540 ** created by [sqlite3_prepare_v2()], [sqlite3_prepare_v3()], 4541 ** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()]. 4542 ** ^The sqlite3_expanded_sql(P) interface returns a pointer to a UTF-8 4543 ** string containing the SQL text of prepared statement P with 4544 ** [bound parameters] expanded. 4545 ** ^The sqlite3_normalized_sql(P) interface returns a pointer to a UTF-8 4546 ** string containing the normalized SQL text of prepared statement P. The 4547 ** semantics used to normalize a SQL statement are unspecified and subject 4548 ** to change. At a minimum, literal values will be replaced with suitable 4549 ** placeholders. 4550 ** 4551 ** ^(For example, if a prepared statement is created using the SQL 4552 ** text "SELECT $abc,:xyz" and if parameter $abc is bound to integer 2345 4553 ** and parameter :xyz is unbound, then sqlite3_sql() will return 4554 ** the original string, "SELECT $abc,:xyz" but sqlite3_expanded_sql() 4555 ** will return "SELECT 2345,NULL".)^ 4556 ** 4557 ** ^The sqlite3_expanded_sql() interface returns NULL if insufficient memory 4558 ** is available to hold the result, or if the result would exceed the 4559 ** the maximum string length determined by the [SQLITE_LIMIT_LENGTH]. 4560 ** 4561 ** ^The [SQLITE_TRACE_SIZE_LIMIT] compile-time option limits the size of 4562 ** bound parameter expansions. ^The [SQLITE_OMIT_TRACE] compile-time 4563 ** option causes sqlite3_expanded_sql() to always return NULL. 4564 ** 4565 ** ^The strings returned by sqlite3_sql(P) and sqlite3_normalized_sql(P) 4566 ** are managed by SQLite and are automatically freed when the prepared 4567 ** statement is finalized. 4568 ** ^The string returned by sqlite3_expanded_sql(P), on the other hand, 4569 ** is obtained from [sqlite3_malloc()] and must be freed by the application 4570 ** by passing it to [sqlite3_free()]. 4571 ** 4572 ** ^The sqlite3_normalized_sql() interface is only available if 4573 ** the [SQLITE_ENABLE_NORMALIZE] compile-time option is defined. 4574 */ 4575 SQLITE_API const char *sqlite3_sql(sqlite3_stmt *pStmt); 4576 SQLITE_API char *sqlite3_expanded_sql(sqlite3_stmt *pStmt); 4577 #ifdef SQLITE_ENABLE_NORMALIZE 4578 SQLITE_API const char *sqlite3_normalized_sql(sqlite3_stmt *pStmt); 4579 #endif 4580 4581 /* 4582 ** CAPI3REF: Determine If An SQL Statement Writes The Database 4583 ** METHOD: sqlite3_stmt 4584 ** 4585 ** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if 4586 ** and only if the [prepared statement] X makes no direct changes to 4587 ** the content of the database file. 4588 ** 4589 ** Note that [application-defined SQL functions] or 4590 ** [virtual tables] might change the database indirectly as a side effect. 4591 ** ^(For example, if an application defines a function "eval()" that 4592 ** calls [sqlite3_exec()], then the following SQL statement would 4593 ** change the database file through side-effects: 4594 ** 4595 ** <blockquote><pre> 4596 ** SELECT eval('DELETE FROM t1') FROM t2; 4597 ** </pre></blockquote> 4598 ** 4599 ** But because the [SELECT] statement does not change the database file 4600 ** directly, sqlite3_stmt_readonly() would still return true.)^ 4601 ** 4602 ** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK], 4603 ** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true, 4604 ** since the statements themselves do not actually modify the database but 4605 ** rather they control the timing of when other statements modify the 4606 ** database. ^The [ATTACH] and [DETACH] statements also cause 4607 ** sqlite3_stmt_readonly() to return true since, while those statements 4608 ** change the configuration of a database connection, they do not make 4609 ** changes to the content of the database files on disk. 4610 ** ^The sqlite3_stmt_readonly() interface returns true for [BEGIN] since 4611 ** [BEGIN] merely sets internal flags, but the [BEGIN|BEGIN IMMEDIATE] and 4612 ** [BEGIN|BEGIN EXCLUSIVE] commands do touch the database and so 4613 ** sqlite3_stmt_readonly() returns false for those commands. 4614 ** 4615 ** ^This routine returns false if there is any possibility that the 4616 ** statement might change the database file. ^A false return does 4617 ** not guarantee that the statement will change the database file. 4618 ** ^For example, an UPDATE statement might have a WHERE clause that 4619 ** makes it a no-op, but the sqlite3_stmt_readonly() result would still 4620 ** be false. ^Similarly, a CREATE TABLE IF NOT EXISTS statement is a 4621 ** read-only no-op if the table already exists, but 4622 ** sqlite3_stmt_readonly() still returns false for such a statement. 4623 ** 4624 ** ^If prepared statement X is an [EXPLAIN] or [EXPLAIN QUERY PLAN] 4625 ** statement, then sqlite3_stmt_readonly(X) returns the same value as 4626 ** if the EXPLAIN or EXPLAIN QUERY PLAN prefix were omitted. 4627 */ 4628 SQLITE_API int sqlite3_stmt_readonly(sqlite3_stmt *pStmt); 4629 4630 /* 4631 ** CAPI3REF: Query The EXPLAIN Setting For A Prepared Statement 4632 ** METHOD: sqlite3_stmt 4633 ** 4634 ** ^The sqlite3_stmt_isexplain(S) interface returns 1 if the 4635 ** prepared statement S is an EXPLAIN statement, or 2 if the 4636 ** statement S is an EXPLAIN QUERY PLAN. 4637 ** ^The sqlite3_stmt_isexplain(S) interface returns 0 if S is 4638 ** an ordinary statement or a NULL pointer. 4639 */ 4640 SQLITE_API int sqlite3_stmt_isexplain(sqlite3_stmt *pStmt); 4641 4642 /* 4643 ** CAPI3REF: Change The EXPLAIN Setting For A Prepared Statement 4644 ** METHOD: sqlite3_stmt 4645 ** 4646 ** The sqlite3_stmt_explain(S,E) interface changes the EXPLAIN 4647 ** setting for [prepared statement] S. If E is zero, then S becomes 4648 ** a normal prepared statement. If E is 1, then S behaves as if 4649 ** its SQL text began with "[EXPLAIN]". If E is 2, then S behaves as if 4650 ** its SQL text began with "[EXPLAIN QUERY PLAN]". 4651 ** 4652 ** Calling sqlite3_stmt_explain(S,E) might cause S to be reprepared. 4653 ** SQLite tries to avoid a reprepare, but a reprepare might be necessary 4654 ** on the first transition into EXPLAIN or EXPLAIN QUERY PLAN mode. 4655 ** 4656 ** Because of the potential need to reprepare, a call to 4657 ** sqlite3_stmt_explain(S,E) will fail with SQLITE_ERROR if S cannot be 4658 ** reprepared because it was created using [sqlite3_prepare()] instead of 4659 ** the newer [sqlite3_prepare_v2()] or [sqlite3_prepare_v3()] interfaces and 4660 ** hence has no saved SQL text with which to reprepare. 4661 ** 4662 ** Changing the explain setting for a prepared statement does not change 4663 ** the original SQL text for the statement. Hence, if the SQL text originally 4664 ** began with EXPLAIN or EXPLAIN QUERY PLAN, but sqlite3_stmt_explain(S,0) 4665 ** is called to convert the statement into an ordinary statement, the EXPLAIN 4666 ** or EXPLAIN QUERY PLAN keywords will still appear in the sqlite3_sql(S) 4667 ** output, even though the statement now acts like a normal SQL statement. 4668 ** 4669 ** This routine returns SQLITE_OK if the explain mode is successfully 4670 ** changed, or an error code if the explain mode could not be changed. 4671 ** The explain mode cannot be changed while a statement is active. 4672 ** Hence, it is good practice to call [sqlite3_reset(S)] 4673 ** immediately prior to calling sqlite3_stmt_explain(S,E). 4674 */ 4675 SQLITE_API int sqlite3_stmt_explain(sqlite3_stmt *pStmt, int eMode); 4676 4677 /* 4678 ** CAPI3REF: Determine If A Prepared Statement Has Been Reset 4679 ** METHOD: sqlite3_stmt 4680 ** 4681 ** ^The sqlite3_stmt_busy(S) interface returns true (non-zero) if the 4682 ** [prepared statement] S has been stepped at least once using 4683 ** [sqlite3_step(S)] but has neither run to completion (returned 4684 ** [SQLITE_DONE] from [sqlite3_step(S)]) nor 4685 ** been reset using [sqlite3_reset(S)]. ^The sqlite3_stmt_busy(S) 4686 ** interface returns false if S is a NULL pointer. If S is not a 4687 ** NULL pointer and is not a pointer to a valid [prepared statement] 4688 ** object, then the behavior is undefined and probably undesirable. 4689 ** 4690 ** This interface can be used in combination [sqlite3_next_stmt()] 4691 ** to locate all prepared statements associated with a database 4692 ** connection that are in need of being reset. This can be used, 4693 ** for example, in diagnostic routines to search for prepared 4694 ** statements that are holding a transaction open. 4695 */ 4696 SQLITE_API int sqlite3_stmt_busy(sqlite3_stmt*); 4697 4698 /* 4699 ** CAPI3REF: Dynamically Typed Value Object 4700 ** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value} 4701 ** 4702 ** SQLite uses the sqlite3_value object to represent all values 4703 ** that can be stored in a database table. SQLite uses dynamic typing 4704 ** for the values it stores. ^Values stored in sqlite3_value objects 4705 ** can be integers, floating point values, strings, BLOBs, or NULL. 4706 ** 4707 ** An sqlite3_value object may be either "protected" or "unprotected". 4708 ** Some interfaces require a protected sqlite3_value. Other interfaces 4709 ** will accept either a protected or an unprotected sqlite3_value. 4710 ** Every interface that accepts sqlite3_value arguments specifies 4711 ** whether or not it requires a protected sqlite3_value. The 4712 ** [sqlite3_value_dup()] interface can be used to construct a new 4713 ** protected sqlite3_value from an unprotected sqlite3_value. 4714 ** 4715 ** The terms "protected" and "unprotected" refer to whether or not 4716 ** a mutex is held. An internal mutex is held for a protected 4717 ** sqlite3_value object but no mutex is held for an unprotected 4718 ** sqlite3_value object. If SQLite is compiled to be single-threaded 4719 ** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0) 4720 ** or if SQLite is run in one of reduced mutex modes 4721 ** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD] 4722 ** then there is no distinction between protected and unprotected 4723 ** sqlite3_value objects and they can be used interchangeably. However, 4724 ** for maximum code portability it is recommended that applications 4725 ** still make the distinction between protected and unprotected 4726 ** sqlite3_value objects even when not strictly required. 4727 ** 4728 ** ^The sqlite3_value objects that are passed as parameters into the 4729 ** implementation of [application-defined SQL functions] are protected. 4730 ** ^The sqlite3_value objects returned by [sqlite3_vtab_rhs_value()] 4731 ** are protected. 4732 ** ^The sqlite3_value object returned by 4733 ** [sqlite3_column_value()] is unprotected. 4734 ** Unprotected sqlite3_value objects may only be used as arguments 4735 ** to [sqlite3_result_value()], [sqlite3_bind_value()], and 4736 ** [sqlite3_value_dup()]. 4737 ** The [sqlite3_value_blob | sqlite3_value_type()] family of 4738 ** interfaces require protected sqlite3_value objects. 4739 */ 4740 typedef struct sqlite3_value sqlite3_value; 4741 4742 /* 4743 ** CAPI3REF: SQL Function Context Object 4744 ** 4745 ** The context in which an SQL function executes is stored in an 4746 ** sqlite3_context object. ^A pointer to an sqlite3_context object 4747 ** is always first parameter to [application-defined SQL functions]. 4748 ** The application-defined SQL function implementation will pass this 4749 ** pointer through into calls to [sqlite3_result_int | sqlite3_result()], 4750 ** [sqlite3_aggregate_context()], [sqlite3_user_data()], 4751 ** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()], 4752 ** and/or [sqlite3_set_auxdata()]. 4753 */ 4754 typedef struct sqlite3_context sqlite3_context; 4755 4756 /* 4757 ** CAPI3REF: Binding Values To Prepared Statements 4758 ** KEYWORDS: {host parameter} {host parameters} {host parameter name} 4759 ** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding} 4760 ** METHOD: sqlite3_stmt 4761 ** 4762 ** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants, 4763 ** literals may be replaced by a [parameter] that matches one of the following 4764 ** templates: 4765 ** 4766 ** <ul> 4767 ** <li> ? 4768 ** <li> ?NNN 4769 ** <li> :VVV 4770 ** <li> @VVV 4771 ** <li> $VVV 4772 ** </ul> 4773 ** 4774 ** In the templates above, NNN represents an integer literal, 4775 ** and VVV represents an alphanumeric identifier.)^ ^The values of these 4776 ** parameters (also called "host parameter names" or "SQL parameters") 4777 ** can be set using the sqlite3_bind_*() routines defined here. 4778 ** 4779 ** ^The first argument to the sqlite3_bind_*() routines is always 4780 ** a pointer to the [sqlite3_stmt] object returned from 4781 ** [sqlite3_prepare_v2()] or its variants. 4782 ** 4783 ** ^The second argument is the index of the SQL parameter to be set. 4784 ** ^The leftmost SQL parameter has an index of 1. ^When the same named 4785 ** SQL parameter is used more than once, second and subsequent 4786 ** occurrences have the same index as the first occurrence. 4787 ** ^The index for named parameters can be looked up using the 4788 ** [sqlite3_bind_parameter_index()] API if desired. ^The index 4789 ** for "?NNN" parameters is the value of NNN. 4790 ** ^The NNN value must be between 1 and the [sqlite3_limit()] 4791 ** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 32766). 4792 ** 4793 ** ^The third argument is the value to bind to the parameter. 4794 ** ^If the third parameter to sqlite3_bind_text() or sqlite3_bind_text16() 4795 ** or sqlite3_bind_blob() is a NULL pointer then the fourth parameter 4796 ** is ignored and the end result is the same as sqlite3_bind_null(). 4797 ** ^If the third parameter to sqlite3_bind_text() is not NULL, then 4798 ** it should be a pointer to well-formed UTF8 text. 4799 ** ^If the third parameter to sqlite3_bind_text16() is not NULL, then 4800 ** it should be a pointer to well-formed UTF16 text. 4801 ** ^If the third parameter to sqlite3_bind_text64() is not NULL, then 4802 ** it should be a pointer to a well-formed unicode string that is 4803 ** either UTF8 if the sixth parameter is SQLITE_UTF8, or UTF16 4804 ** otherwise. 4805 ** 4806 ** [[byte-order determination rules]] ^The byte-order of 4807 ** UTF16 input text is determined by the byte-order mark (BOM, U+FEFF) 4808 ** found in the first character, which is removed, or in the absence of a BOM 4809 ** the byte order is the native byte order of the host 4810 ** machine for sqlite3_bind_text16() or the byte order specified in 4811 ** the 6th parameter for sqlite3_bind_text64().)^ 4812 ** ^If UTF16 input text contains invalid unicode 4813 ** characters, then SQLite might change those invalid characters 4814 ** into the unicode replacement character: U+FFFD. 4815 ** 4816 ** ^(In those routines that have a fourth argument, its value is the 4817 ** number of bytes in the parameter. To be clear: the value is the 4818 ** number of <u>bytes</u> in the value, not the number of characters.)^ 4819 ** ^If the fourth parameter to sqlite3_bind_text() or sqlite3_bind_text16() 4820 ** is negative, then the length of the string is 4821 ** the number of bytes up to the first zero terminator. 4822 ** If the fourth parameter to sqlite3_bind_blob() is negative, then 4823 ** the behavior is undefined. 4824 ** If a non-negative fourth parameter is provided to sqlite3_bind_text() 4825 ** or sqlite3_bind_text16() or sqlite3_bind_text64() then 4826 ** that parameter must be the byte offset 4827 ** where the NUL terminator would occur assuming the string were NUL 4828 ** terminated. If any NUL characters occur at byte offsets less than 4829 ** the value of the fourth parameter then the resulting string value will 4830 ** contain embedded NULs. The result of expressions involving strings 4831 ** with embedded NULs is undefined. 4832 ** 4833 ** ^The fifth argument to the BLOB and string binding interfaces controls 4834 ** or indicates the lifetime of the object referenced by the third parameter. 4835 ** These three options exist: 4836 ** ^ (1) A destructor to dispose of the BLOB or string after SQLite has finished 4837 ** with it may be passed. ^It is called to dispose of the BLOB or string even 4838 ** if the call to the bind API fails, except the destructor is not called if 4839 ** the third parameter is a NULL pointer or the fourth parameter is negative. 4840 ** ^ (2) The special constant, [SQLITE_STATIC], may be passed to indicate that 4841 ** the application remains responsible for disposing of the object. ^In this 4842 ** case, the object and the provided pointer to it must remain valid until 4843 ** either the prepared statement is finalized or the same SQL parameter is 4844 ** bound to something else, whichever occurs sooner. 4845 ** ^ (3) The constant, [SQLITE_TRANSIENT], may be passed to indicate that the 4846 ** object is to be copied prior to the return from sqlite3_bind_*(). ^The 4847 ** object and pointer to it must remain valid until then. ^SQLite will then 4848 ** manage the lifetime of its private copy. 4849 ** 4850 ** ^The sixth argument to sqlite3_bind_text64() must be one of 4851 ** [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE] 4852 ** to specify the encoding of the text in the third parameter. If 4853 ** the sixth argument to sqlite3_bind_text64() is not one of the 4854 ** allowed values shown above, or if the text encoding is different 4855 ** from the encoding specified by the sixth parameter, then the behavior 4856 ** is undefined. 4857 ** 4858 ** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that 4859 ** is filled with zeroes. ^A zeroblob uses a fixed amount of memory 4860 ** (just an integer to hold its size) while it is being processed. 4861 ** Zeroblobs are intended to serve as placeholders for BLOBs whose 4862 ** content is later written using 4863 ** [sqlite3_blob_open | incremental BLOB I/O] routines. 4864 ** ^A negative value for the zeroblob results in a zero-length BLOB. 4865 ** 4866 ** ^The sqlite3_bind_pointer(S,I,P,T,D) routine causes the I-th parameter in 4867 ** [prepared statement] S to have an SQL value of NULL, but to also be 4868 ** associated with the pointer P of type T. ^D is either a NULL pointer or 4869 ** a pointer to a destructor function for P. ^SQLite will invoke the 4870 ** destructor D with a single argument of P when it is finished using 4871 ** P. The T parameter should be a static string, preferably a string 4872 ** literal. The sqlite3_bind_pointer() routine is part of the 4873 ** [pointer passing interface] added for SQLite 3.20.0. 4874 ** 4875 ** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer 4876 ** for the [prepared statement] or with a prepared statement for which 4877 ** [sqlite3_step()] has been called more recently than [sqlite3_reset()], 4878 ** then the call will return [SQLITE_MISUSE]. If any sqlite3_bind_() 4879 ** routine is passed a [prepared statement] that has been finalized, the 4880 ** result is undefined and probably harmful. 4881 ** 4882 ** ^Bindings are not cleared by the [sqlite3_reset()] routine. 4883 ** ^Unbound parameters are interpreted as NULL. 4884 ** 4885 ** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an 4886 ** [error code] if anything goes wrong. 4887 ** ^[SQLITE_TOOBIG] might be returned if the size of a string or BLOB 4888 ** exceeds limits imposed by [sqlite3_limit]([SQLITE_LIMIT_LENGTH]) or 4889 ** [SQLITE_MAX_LENGTH]. 4890 ** ^[SQLITE_RANGE] is returned if the parameter 4891 ** index is out of range. ^[SQLITE_NOMEM] is returned if malloc() fails. 4892 ** 4893 ** See also: [sqlite3_bind_parameter_count()], 4894 ** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()]. 4895 */ 4896 SQLITE_API int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*)); 4897 SQLITE_API int sqlite3_bind_blob64(sqlite3_stmt*, int, const void*, sqlite3_uint64, 4898 void(*)(void*)); 4899 SQLITE_API int sqlite3_bind_double(sqlite3_stmt*, int, double); 4900 SQLITE_API int sqlite3_bind_int(sqlite3_stmt*, int, int); 4901 SQLITE_API int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64); 4902 SQLITE_API int sqlite3_bind_null(sqlite3_stmt*, int); 4903 SQLITE_API int sqlite3_bind_text(sqlite3_stmt*,int,const char*,int,void(*)(void*)); 4904 SQLITE_API int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*)); 4905 SQLITE_API int sqlite3_bind_text64(sqlite3_stmt*, int, const char*, sqlite3_uint64, 4906 void(*)(void*), unsigned char encoding); 4907 SQLITE_API int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*); 4908 SQLITE_API int sqlite3_bind_pointer(sqlite3_stmt*, int, void*, const char*,void(*)(void*)); 4909 SQLITE_API int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n); 4910 SQLITE_API int sqlite3_bind_zeroblob64(sqlite3_stmt*, int, sqlite3_uint64); 4911 4912 /* 4913 ** CAPI3REF: Number Of SQL Parameters 4914 ** METHOD: sqlite3_stmt 4915 ** 4916 ** ^This routine can be used to find the number of [SQL parameters] 4917 ** in a [prepared statement]. SQL parameters are tokens of the 4918 ** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as 4919 ** placeholders for values that are [sqlite3_bind_blob | bound] 4920 ** to the parameters at a later time. 4921 ** 4922 ** ^(This routine actually returns the index of the largest (rightmost) 4923 ** parameter. For all forms except ?NNN, this will correspond to the 4924 ** number of unique parameters. If parameters of the ?NNN form are used, 4925 ** there may be gaps in the list.)^ 4926 ** 4927 ** See also: [sqlite3_bind_blob|sqlite3_bind()], 4928 ** [sqlite3_bind_parameter_name()], and 4929 ** [sqlite3_bind_parameter_index()]. 4930 */ 4931 SQLITE_API int sqlite3_bind_parameter_count(sqlite3_stmt*); 4932 4933 /* 4934 ** CAPI3REF: Name Of A Host Parameter 4935 ** METHOD: sqlite3_stmt 4936 ** 4937 ** ^The sqlite3_bind_parameter_name(P,N) interface returns 4938 ** the name of the N-th [SQL parameter] in the [prepared statement] P. 4939 ** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA" 4940 ** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA" 4941 ** respectively. 4942 ** In other words, the initial ":" or "$" or "@" or "?" 4943 ** is included as part of the name.)^ 4944 ** ^Parameters of the form "?" without a following integer have no name 4945 ** and are referred to as "nameless" or "anonymous parameters". 4946 ** 4947 ** ^The first host parameter has an index of 1, not 0. 4948 ** 4949 ** ^If the value N is out of range or if the N-th parameter is 4950 ** nameless, then NULL is returned. ^The returned string is 4951 ** always in UTF-8 encoding even if the named parameter was 4952 ** originally specified as UTF-16 in [sqlite3_prepare16()], 4953 ** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()]. 4954 ** 4955 ** See also: [sqlite3_bind_blob|sqlite3_bind()], 4956 ** [sqlite3_bind_parameter_count()], and 4957 ** [sqlite3_bind_parameter_index()]. 4958 */ 4959 SQLITE_API const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int); 4960 4961 /* 4962 ** CAPI3REF: Index Of A Parameter With A Given Name 4963 ** METHOD: sqlite3_stmt 4964 ** 4965 ** ^Return the index of an SQL parameter given its name. ^The 4966 ** index value returned is suitable for use as the second 4967 ** parameter to [sqlite3_bind_blob|sqlite3_bind()]. ^A zero 4968 ** is returned if no matching parameter is found. ^The parameter 4969 ** name must be given in UTF-8 even if the original statement 4970 ** was prepared from UTF-16 text using [sqlite3_prepare16_v2()] or 4971 ** [sqlite3_prepare16_v3()]. 4972 ** 4973 ** See also: [sqlite3_bind_blob|sqlite3_bind()], 4974 ** [sqlite3_bind_parameter_count()], and 4975 ** [sqlite3_bind_parameter_name()]. 4976 */ 4977 SQLITE_API int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName); 4978 4979 /* 4980 ** CAPI3REF: Reset All Bindings On A Prepared Statement 4981 ** METHOD: sqlite3_stmt 4982 ** 4983 ** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset 4984 ** the [sqlite3_bind_blob | bindings] on a [prepared statement]. 4985 ** ^Use this routine to reset all host parameters to NULL. 4986 */ 4987 SQLITE_API int sqlite3_clear_bindings(sqlite3_stmt*); 4988 4989 /* 4990 ** CAPI3REF: Number Of Columns In A Result Set 4991 ** METHOD: sqlite3_stmt 4992 ** 4993 ** ^Return the number of columns in the result set returned by the 4994 ** [prepared statement]. ^If this routine returns 0, that means the 4995 ** [prepared statement] returns no data (for example an [UPDATE]). 4996 ** ^However, just because this routine returns a positive number does not 4997 ** mean that one or more rows of data will be returned. ^A SELECT statement 4998 ** will always have a positive sqlite3_column_count() but depending on the 4999 ** WHERE clause constraints and the table content, it might return no rows. 5000 ** 5001 ** See also: [sqlite3_data_count()] 5002 */ 5003 SQLITE_API int sqlite3_column_count(sqlite3_stmt *pStmt); 5004 5005 /* 5006 ** CAPI3REF: Column Names In A Result Set 5007 ** METHOD: sqlite3_stmt 5008 ** 5009 ** ^These routines return the name assigned to a particular column 5010 ** in the result set of a [SELECT] statement. ^The sqlite3_column_name() 5011 ** interface returns a pointer to a zero-terminated UTF-8 string 5012 ** and sqlite3_column_name16() returns a pointer to a zero-terminated 5013 ** UTF-16 string. ^The first parameter is the [prepared statement] 5014 ** that implements the [SELECT] statement. ^The second parameter is the 5015 ** column number. ^The leftmost column is number 0. 5016 ** 5017 ** ^The returned string pointer is valid until either the [prepared statement] 5018 ** is destroyed by [sqlite3_finalize()] or until the statement is automatically 5019 ** reprepared by the first call to [sqlite3_step()] for a particular run 5020 ** or until the next call to 5021 ** sqlite3_column_name() or sqlite3_column_name16() on the same column. 5022 ** 5023 ** ^If sqlite3_malloc() fails during the processing of either routine 5024 ** (for example during a conversion from UTF-8 to UTF-16) then a 5025 ** NULL pointer is returned. 5026 ** 5027 ** ^The name of a result column is the value of the "AS" clause for 5028 ** that column, if there is an AS clause. If there is no AS clause 5029 ** then the name of the column is unspecified and may change from 5030 ** one release of SQLite to the next. 5031 */ 5032 SQLITE_API const char *sqlite3_column_name(sqlite3_stmt*, int N); 5033 SQLITE_API const void *sqlite3_column_name16(sqlite3_stmt*, int N); 5034 5035 /* 5036 ** CAPI3REF: Source Of Data In A Query Result 5037 ** METHOD: sqlite3_stmt 5038 ** 5039 ** ^These routines provide a means to determine the database, table, and 5040 ** table column that is the origin of a particular result column in a 5041 ** [SELECT] statement. 5042 ** ^The name of the database or table or column can be returned as 5043 ** either a UTF-8 or UTF-16 string. ^The _database_ routines return 5044 ** the database name, the _table_ routines return the table name, and 5045 ** the origin_ routines return the column name. 5046 ** ^The returned string is valid until the [prepared statement] is destroyed 5047 ** using [sqlite3_finalize()] or until the statement is automatically 5048 ** reprepared by the first call to [sqlite3_step()] for a particular run 5049 ** or until the same information is requested 5050 ** again in a different encoding. 5051 ** 5052 ** ^The names returned are the original un-aliased names of the 5053 ** database, table, and column. 5054 ** 5055 ** ^The first argument to these interfaces is a [prepared statement]. 5056 ** ^These functions return information about the Nth result column returned by 5057 ** the statement, where N is the second function argument. 5058 ** ^The left-most column is column 0 for these routines. 5059 ** 5060 ** ^If the Nth column returned by the statement is an expression or 5061 ** subquery and is not a column value, then all of these functions return 5062 ** NULL. ^These routines might also return NULL if a memory allocation error 5063 ** occurs. ^Otherwise, they return the name of the attached database, table, 5064 ** or column that query result column was extracted from. 5065 ** 5066 ** ^As with all other SQLite APIs, those whose names end with "16" return 5067 ** UTF-16 encoded strings and the other functions return UTF-8. 5068 ** 5069 ** ^These APIs are only available if the library was compiled with the 5070 ** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol. 5071 ** 5072 ** If two or more threads call one or more 5073 ** [sqlite3_column_database_name | column metadata interfaces] 5074 ** for the same [prepared statement] and result column 5075 ** at the same time then the results are undefined. 5076 */ 5077 SQLITE_API const char *sqlite3_column_database_name(sqlite3_stmt*,int); 5078 SQLITE_API const void *sqlite3_column_database_name16(sqlite3_stmt*,int); 5079 SQLITE_API const char *sqlite3_column_table_name(sqlite3_stmt*,int); 5080 SQLITE_API const void *sqlite3_column_table_name16(sqlite3_stmt*,int); 5081 SQLITE_API const char *sqlite3_column_origin_name(sqlite3_stmt*,int); 5082 SQLITE_API const void *sqlite3_column_origin_name16(sqlite3_stmt*,int); 5083 5084 /* 5085 ** CAPI3REF: Declared Datatype Of A Query Result 5086 ** METHOD: sqlite3_stmt 5087 ** 5088 ** ^(The first parameter is a [prepared statement]. 5089 ** If this statement is a [SELECT] statement and the Nth column of the 5090 ** returned result set of that [SELECT] is a table column (not an 5091 ** expression or subquery) then the declared type of the table 5092 ** column is returned.)^ ^If the Nth column of the result set is an 5093 ** expression or subquery, then a NULL pointer is returned. 5094 ** ^The returned string is always UTF-8 encoded. 5095 ** 5096 ** ^(For example, given the database schema: 5097 ** 5098 ** CREATE TABLE t1(c1 VARIANT); 5099 ** 5100 ** and the following statement to be compiled: 5101 ** 5102 ** SELECT c1 + 1, c1 FROM t1; 5103 ** 5104 ** this routine would return the string "VARIANT" for the second result 5105 ** column (i==1), and a NULL pointer for the first result column (i==0).)^ 5106 ** 5107 ** ^SQLite uses dynamic run-time typing. ^So just because a column 5108 ** is declared to contain a particular type does not mean that the 5109 ** data stored in that column is of the declared type. SQLite is 5110 ** strongly typed, but the typing is dynamic not static. ^Type 5111 ** is associated with individual values, not with the containers 5112 ** used to hold those values. 5113 */ 5114 SQLITE_API const char *sqlite3_column_decltype(sqlite3_stmt*,int); 5115 SQLITE_API const void *sqlite3_column_decltype16(sqlite3_stmt*,int); 5116 5117 /* 5118 ** CAPI3REF: Evaluate An SQL Statement 5119 ** METHOD: sqlite3_stmt 5120 ** 5121 ** After a [prepared statement] has been prepared using any of 5122 ** [sqlite3_prepare_v2()], [sqlite3_prepare_v3()], [sqlite3_prepare16_v2()], 5123 ** or [sqlite3_prepare16_v3()] or one of the legacy 5124 ** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function 5125 ** must be called one or more times to evaluate the statement. 5126 ** 5127 ** The details of the behavior of the sqlite3_step() interface depend 5128 ** on whether the statement was prepared using the newer "vX" interfaces 5129 ** [sqlite3_prepare_v3()], [sqlite3_prepare_v2()], [sqlite3_prepare16_v3()], 5130 ** [sqlite3_prepare16_v2()] or the older legacy 5131 ** interfaces [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the 5132 ** new "vX" interface is recommended for new applications but the legacy 5133 ** interface will continue to be supported. 5134 ** 5135 ** ^In the legacy interface, the return value will be either [SQLITE_BUSY], 5136 ** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE]. 5137 ** ^With the "v2" interface, any of the other [result codes] or 5138 ** [extended result codes] might be returned as well. 5139 ** 5140 ** ^[SQLITE_BUSY] means that the database engine was unable to acquire the 5141 ** database locks it needs to do its job. ^If the statement is a [COMMIT] 5142 ** or occurs outside of an explicit transaction, then you can retry the 5143 ** statement. If the statement is not a [COMMIT] and occurs within an 5144 ** explicit transaction then you should rollback the transaction before 5145 ** continuing. 5146 ** 5147 ** ^[SQLITE_DONE] means that the statement has finished executing 5148 ** successfully. sqlite3_step() should not be called again on this virtual 5149 ** machine without first calling [sqlite3_reset()] to reset the virtual 5150 ** machine back to its initial state. 5151 ** 5152 ** ^If the SQL statement being executed returns any data, then [SQLITE_ROW] 5153 ** is returned each time a new row of data is ready for processing by the 5154 ** caller. The values may be accessed using the [column access functions]. 5155 ** sqlite3_step() is called again to retrieve the next row of data. 5156 ** 5157 ** ^[SQLITE_ERROR] means that a run-time error (such as a constraint 5158 ** violation) has occurred. sqlite3_step() should not be called again on 5159 ** the VM. More information may be found by calling [sqlite3_errmsg()]. 5160 ** ^With the legacy interface, a more specific error code (for example, 5161 ** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth) 5162 ** can be obtained by calling [sqlite3_reset()] on the 5163 ** [prepared statement]. ^In the "v2" interface, 5164 ** the more specific error code is returned directly by sqlite3_step(). 5165 ** 5166 ** [SQLITE_MISUSE] means that the this routine was called inappropriately. 5167 ** Perhaps it was called on a [prepared statement] that has 5168 ** already been [sqlite3_finalize | finalized] or on one that had 5169 ** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could 5170 ** be the case that the same database connection is being used by two or 5171 ** more threads at the same moment in time. 5172 ** 5173 ** For all versions of SQLite up to and including 3.6.23.1, a call to 5174 ** [sqlite3_reset()] was required after sqlite3_step() returned anything 5175 ** other than [SQLITE_ROW] before any subsequent invocation of 5176 ** sqlite3_step(). Failure to reset the prepared statement using 5177 ** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from 5178 ** sqlite3_step(). But after [version 3.6.23.1] ([dateof:3.6.23.1]), 5179 ** sqlite3_step() began 5180 ** calling [sqlite3_reset()] automatically in this circumstance rather 5181 ** than returning [SQLITE_MISUSE]. This is not considered a compatibility 5182 ** break because any application that ever receives an SQLITE_MISUSE error 5183 ** is broken by definition. The [SQLITE_OMIT_AUTORESET] compile-time option 5184 ** can be used to restore the legacy behavior. 5185 ** 5186 ** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step() 5187 ** API always returns a generic error code, [SQLITE_ERROR], following any 5188 ** error other than [SQLITE_BUSY] and [SQLITE_MISUSE]. You must call 5189 ** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the 5190 ** specific [error codes] that better describes the error. 5191 ** We admit that this is a goofy design. The problem has been fixed 5192 ** with the "v2" interface. If you prepare all of your SQL statements 5193 ** using [sqlite3_prepare_v3()] or [sqlite3_prepare_v2()] 5194 ** or [sqlite3_prepare16_v2()] or [sqlite3_prepare16_v3()] instead 5195 ** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces, 5196 ** then the more specific [error codes] are returned directly 5197 ** by sqlite3_step(). The use of the "vX" interfaces is recommended. 5198 */ 5199 SQLITE_API int sqlite3_step(sqlite3_stmt*); 5200 5201 /* 5202 ** CAPI3REF: Number of columns in a result set 5203 ** METHOD: sqlite3_stmt 5204 ** 5205 ** ^The sqlite3_data_count(P) interface returns the number of columns in the 5206 ** current row of the result set of [prepared statement] P. 5207 ** ^If prepared statement P does not have results ready to return 5208 ** (via calls to the [sqlite3_column_int | sqlite3_column()] family of 5209 ** interfaces) then sqlite3_data_count(P) returns 0. 5210 ** ^The sqlite3_data_count(P) routine also returns 0 if P is a NULL pointer. 5211 ** ^The sqlite3_data_count(P) routine returns 0 if the previous call to 5212 ** [sqlite3_step](P) returned [SQLITE_DONE]. ^The sqlite3_data_count(P) 5213 ** will return non-zero if previous call to [sqlite3_step](P) returned 5214 ** [SQLITE_ROW], except in the case of the [PRAGMA incremental_vacuum] 5215 ** where it always returns zero since each step of that multi-step 5216 ** pragma returns 0 columns of data. 5217 ** 5218 ** See also: [sqlite3_column_count()] 5219 */ 5220 SQLITE_API int sqlite3_data_count(sqlite3_stmt *pStmt); 5221 5222 /* 5223 ** CAPI3REF: Fundamental Datatypes 5224 ** KEYWORDS: SQLITE_TEXT 5225 ** 5226 ** ^(Every value in SQLite has one of five fundamental datatypes: 5227 ** 5228 ** <ul> 5229 ** <li> 64-bit signed integer 5230 ** <li> 64-bit IEEE floating point number 5231 ** <li> string 5232 ** <li> BLOB 5233 ** <li> NULL 5234 ** </ul>)^ 5235 ** 5236 ** These constants are codes for each of those types. 5237 ** 5238 ** Note that the SQLITE_TEXT constant was also used in SQLite version 2 5239 ** for a completely different meaning. Software that links against both 5240 ** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not 5241 ** SQLITE_TEXT. 5242 */ 5243 #define SQLITE_INTEGER 1 5244 #define SQLITE_FLOAT 2 5245 #define SQLITE_BLOB 4 5246 #define SQLITE_NULL 5 5247 #ifdef SQLITE_TEXT 5248 # undef SQLITE_TEXT 5249 #else 5250 # define SQLITE_TEXT 3 5251 #endif 5252 #define SQLITE3_TEXT 3 5253 5254 /* 5255 ** CAPI3REF: Result Values From A Query 5256 ** KEYWORDS: {column access functions} 5257 ** METHOD: sqlite3_stmt 5258 ** 5259 ** <b>Summary:</b> 5260 ** <blockquote><table border=0 cellpadding=0 cellspacing=0> 5261 ** <tr><td><b>sqlite3_column_blob</b><td>→<td>BLOB result 5262 ** <tr><td><b>sqlite3_column_double</b><td>→<td>REAL result 5263 ** <tr><td><b>sqlite3_column_int</b><td>→<td>32-bit INTEGER result 5264 ** <tr><td><b>sqlite3_column_int64</b><td>→<td>64-bit INTEGER result 5265 ** <tr><td><b>sqlite3_column_text</b><td>→<td>UTF-8 TEXT result 5266 ** <tr><td><b>sqlite3_column_text16</b><td>→<td>UTF-16 TEXT result 5267 ** <tr><td><b>sqlite3_column_value</b><td>→<td>The result as an 5268 ** [sqlite3_value|unprotected sqlite3_value] object. 5269 ** <tr><td> <td> <td> 5270 ** <tr><td><b>sqlite3_column_bytes</b><td>→<td>Size of a BLOB 5271 ** or a UTF-8 TEXT result in bytes 5272 ** <tr><td><b>sqlite3_column_bytes16 </b> 5273 ** <td>→ <td>Size of UTF-16 5274 ** TEXT in bytes 5275 ** <tr><td><b>sqlite3_column_type</b><td>→<td>Default 5276 ** datatype of the result 5277 ** </table></blockquote> 5278 ** 5279 ** <b>Details:</b> 5280 ** 5281 ** ^These routines return information about a single column of the current 5282 ** result row of a query. ^In every case the first argument is a pointer 5283 ** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*] 5284 ** that was returned from [sqlite3_prepare_v2()] or one of its variants) 5285 ** and the second argument is the index of the column for which information 5286 ** should be returned. ^The leftmost column of the result set has the index 0. 5287 ** ^The number of columns in the result can be determined using 5288 ** [sqlite3_column_count()]. 5289 ** 5290 ** If the SQL statement does not currently point to a valid row, or if the 5291 ** column index is out of range, the result is undefined. 5292 ** These routines may only be called when the most recent call to 5293 ** [sqlite3_step()] has returned [SQLITE_ROW] and neither 5294 ** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently. 5295 ** If any of these routines are called after [sqlite3_reset()] or 5296 ** [sqlite3_finalize()] or after [sqlite3_step()] has returned 5297 ** something other than [SQLITE_ROW], the results are undefined. 5298 ** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()] 5299 ** are called from a different thread while any of these routines 5300 ** are pending, then the results are undefined. 5301 ** 5302 ** The first six interfaces (_blob, _double, _int, _int64, _text, and _text16) 5303 ** each return the value of a result column in a specific data format. If 5304 ** the result column is not initially in the requested format (for example, 5305 ** if the query returns an integer but the sqlite3_column_text() interface 5306 ** is used to extract the value) then an automatic type conversion is performed. 5307 ** 5308 ** ^The sqlite3_column_type() routine returns the 5309 ** [SQLITE_INTEGER | datatype code] for the initial data type 5310 ** of the result column. ^The returned value is one of [SQLITE_INTEGER], 5311 ** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL]. 5312 ** The return value of sqlite3_column_type() can be used to decide which 5313 ** of the first six interface should be used to extract the column value. 5314 ** The value returned by sqlite3_column_type() is only meaningful if no 5315 ** automatic type conversions have occurred for the value in question. 5316 ** After a type conversion, the result of calling sqlite3_column_type() 5317 ** is undefined, though harmless. Future 5318 ** versions of SQLite may change the behavior of sqlite3_column_type() 5319 ** following a type conversion. 5320 ** 5321 ** If the result is a BLOB or a TEXT string, then the sqlite3_column_bytes() 5322 ** or sqlite3_column_bytes16() interfaces can be used to determine the size 5323 ** of that BLOB or string. 5324 ** 5325 ** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes() 5326 ** routine returns the number of bytes in that BLOB or string. 5327 ** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts 5328 ** the string to UTF-8 and then returns the number of bytes. 5329 ** ^If the result is a numeric value then sqlite3_column_bytes() uses 5330 ** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns 5331 ** the number of bytes in that string. 5332 ** ^If the result is NULL, then sqlite3_column_bytes() returns zero. 5333 ** 5334 ** ^If the result is a BLOB or UTF-16 string then the sqlite3_column_bytes16() 5335 ** routine returns the number of bytes in that BLOB or string. 5336 ** ^If the result is a UTF-8 string, then sqlite3_column_bytes16() converts 5337 ** the string to UTF-16 and then returns the number of bytes. 5338 ** ^If the result is a numeric value then sqlite3_column_bytes16() uses 5339 ** [sqlite3_snprintf()] to convert that value to a UTF-16 string and returns 5340 ** the number of bytes in that string. 5341 ** ^If the result is NULL, then sqlite3_column_bytes16() returns zero. 5342 ** 5343 ** ^The values returned by [sqlite3_column_bytes()] and 5344 ** [sqlite3_column_bytes16()] do not include the zero terminators at the end 5345 ** of the string. ^For clarity: the values returned by 5346 ** [sqlite3_column_bytes()] and [sqlite3_column_bytes16()] are the number of 5347 ** bytes in the string, not the number of characters. 5348 ** 5349 ** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(), 5350 ** even empty strings, are always zero-terminated. ^The return 5351 ** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer. 5352 ** 5353 ** ^Strings returned by sqlite3_column_text16() always have the endianness 5354 ** which is native to the platform, regardless of the text encoding set 5355 ** for the database. 5356 ** 5357 ** <b>Warning:</b> ^The object returned by [sqlite3_column_value()] is an 5358 ** [unprotected sqlite3_value] object. In a multithreaded environment, 5359 ** an unprotected sqlite3_value object may only be used safely with 5360 ** [sqlite3_bind_value()] and [sqlite3_result_value()]. 5361 ** If the [unprotected sqlite3_value] object returned by 5362 ** [sqlite3_column_value()] is used in any other way, including calls 5363 ** to routines like [sqlite3_value_int()], [sqlite3_value_text()], 5364 ** or [sqlite3_value_bytes()], the behavior is not threadsafe. 5365 ** Hence, the sqlite3_column_value() interface 5366 ** is normally only useful within the implementation of 5367 ** [application-defined SQL functions] or [virtual tables], not within 5368 ** top-level application code. 5369 ** 5370 ** These routines may attempt to convert the datatype of the result. 5371 ** ^For example, if the internal representation is FLOAT and a text result 5372 ** is requested, [sqlite3_snprintf()] is used internally to perform the 5373 ** conversion automatically. ^(The following table details the conversions 5374 ** that are applied: 5375 ** 5376 ** <blockquote> 5377 ** <table border="1"> 5378 ** <tr><th> Internal<br>Type <th> Requested<br>Type <th> Conversion 5379 ** 5380 ** <tr><td> NULL <td> INTEGER <td> Result is 0 5381 ** <tr><td> NULL <td> FLOAT <td> Result is 0.0 5382 ** <tr><td> NULL <td> TEXT <td> Result is a NULL pointer 5383 ** <tr><td> NULL <td> BLOB <td> Result is a NULL pointer 5384 ** <tr><td> INTEGER <td> FLOAT <td> Convert from integer to float 5385 ** <tr><td> INTEGER <td> TEXT <td> ASCII rendering of the integer 5386 ** <tr><td> INTEGER <td> BLOB <td> Same as INTEGER->TEXT 5387 ** <tr><td> FLOAT <td> INTEGER <td> [CAST] to INTEGER 5388 ** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float 5389 ** <tr><td> FLOAT <td> BLOB <td> [CAST] to BLOB 5390 ** <tr><td> TEXT <td> INTEGER <td> [CAST] to INTEGER 5391 ** <tr><td> TEXT <td> FLOAT <td> [CAST] to REAL 5392 ** <tr><td> TEXT <td> BLOB <td> No change 5393 ** <tr><td> BLOB <td> INTEGER <td> [CAST] to INTEGER 5394 ** <tr><td> BLOB <td> FLOAT <td> [CAST] to REAL 5395 ** <tr><td> BLOB <td> TEXT <td> [CAST] to TEXT, ensure zero terminator 5396 ** </table> 5397 ** </blockquote>)^ 5398 ** 5399 ** Note that when type conversions occur, pointers returned by prior 5400 ** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or 5401 ** sqlite3_column_text16() may be invalidated. 5402 ** Type conversions and pointer invalidations might occur 5403 ** in the following cases: 5404 ** 5405 ** <ul> 5406 ** <li> The initial content is a BLOB and sqlite3_column_text() or 5407 ** sqlite3_column_text16() is called. A zero-terminator might 5408 ** need to be added to the string.</li> 5409 ** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or 5410 ** sqlite3_column_text16() is called. The content must be converted 5411 ** to UTF-16.</li> 5412 ** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or 5413 ** sqlite3_column_text() is called. The content must be converted 5414 ** to UTF-8.</li> 5415 ** </ul> 5416 ** 5417 ** ^Conversions between UTF-16be and UTF-16le are always done in place and do 5418 ** not invalidate a prior pointer, though of course the content of the buffer 5419 ** that the prior pointer references will have been modified. Other kinds 5420 ** of conversion are done in place when it is possible, but sometimes they 5421 ** are not possible and in those cases prior pointers are invalidated. 5422 ** 5423 ** The safest policy is to invoke these routines 5424 ** in one of the following ways: 5425 ** 5426 ** <ul> 5427 ** <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li> 5428 ** <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li> 5429 ** <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li> 5430 ** </ul> 5431 ** 5432 ** In other words, you should call sqlite3_column_text(), 5433 ** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result 5434 ** into the desired format, then invoke sqlite3_column_bytes() or 5435 ** sqlite3_column_bytes16() to find the size of the result. Do not mix calls 5436 ** to sqlite3_column_text() or sqlite3_column_blob() with calls to 5437 ** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16() 5438 ** with calls to sqlite3_column_bytes(). 5439 ** 5440 ** ^The pointers returned are valid until a type conversion occurs as 5441 ** described above, or until [sqlite3_step()] or [sqlite3_reset()] or 5442 ** [sqlite3_finalize()] is called. ^The memory space used to hold strings 5443 ** and BLOBs is freed automatically. Do not pass the pointers returned 5444 ** from [sqlite3_column_blob()], [sqlite3_column_text()], etc. into 5445 ** [sqlite3_free()]. 5446 ** 5447 ** As long as the input parameters are correct, these routines will only 5448 ** fail if an out-of-memory error occurs during a format conversion. 5449 ** Only the following subset of interfaces are subject to out-of-memory 5450 ** errors: 5451 ** 5452 ** <ul> 5453 ** <li> sqlite3_column_blob() 5454 ** <li> sqlite3_column_text() 5455 ** <li> sqlite3_column_text16() 5456 ** <li> sqlite3_column_bytes() 5457 ** <li> sqlite3_column_bytes16() 5458 ** </ul> 5459 ** 5460 ** If an out-of-memory error occurs, then the return value from these 5461 ** routines is the same as if the column had contained an SQL NULL value. 5462 ** Valid SQL NULL returns can be distinguished from out-of-memory errors 5463 ** by invoking the [sqlite3_errcode()] immediately after the suspect 5464 ** return value is obtained and before any 5465 ** other SQLite interface is called on the same [database connection]. 5466 */ 5467 SQLITE_API const void *sqlite3_column_blob(sqlite3_stmt*, int iCol); 5468 SQLITE_API double sqlite3_column_double(sqlite3_stmt*, int iCol); 5469 SQLITE_API int sqlite3_column_int(sqlite3_stmt*, int iCol); 5470 SQLITE_API sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol); 5471 SQLITE_API const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol); 5472 SQLITE_API const void *sqlite3_column_text16(sqlite3_stmt*, int iCol); 5473 SQLITE_API sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol); 5474 SQLITE_API int sqlite3_column_bytes(sqlite3_stmt*, int iCol); 5475 SQLITE_API int sqlite3_column_bytes16(sqlite3_stmt*, int iCol); 5476 SQLITE_API int sqlite3_column_type(sqlite3_stmt*, int iCol); 5477 5478 /* 5479 ** CAPI3REF: Destroy A Prepared Statement Object 5480 ** DESTRUCTOR: sqlite3_stmt 5481 ** 5482 ** ^The sqlite3_finalize() function is called to delete a [prepared statement]. 5483 ** ^If the most recent evaluation of the statement encountered no errors 5484 ** or if the statement is never been evaluated, then sqlite3_finalize() returns 5485 ** SQLITE_OK. ^If the most recent evaluation of statement S failed, then 5486 ** sqlite3_finalize(S) returns the appropriate [error code] or 5487 ** [extended error code]. 5488 ** 5489 ** ^The sqlite3_finalize(S) routine can be called at any point during 5490 ** the life cycle of [prepared statement] S: 5491 ** before statement S is ever evaluated, after 5492 ** one or more calls to [sqlite3_reset()], or after any call 5493 ** to [sqlite3_step()] regardless of whether or not the statement has 5494 ** completed execution. 5495 ** 5496 ** ^Invoking sqlite3_finalize() on a NULL pointer is a harmless no-op. 5497 ** 5498 ** The application must finalize every [prepared statement] in order to avoid 5499 ** resource leaks. It is a grievous error for the application to try to use 5500 ** a prepared statement after it has been finalized. Any use of a prepared 5501 ** statement after it has been finalized can result in undefined and 5502 ** undesirable behavior such as segfaults and heap corruption. 5503 */ 5504 SQLITE_API int sqlite3_finalize(sqlite3_stmt *pStmt); 5505 5506 /* 5507 ** CAPI3REF: Reset A Prepared Statement Object 5508 ** METHOD: sqlite3_stmt 5509 ** 5510 ** The sqlite3_reset() function is called to reset a [prepared statement] 5511 ** object back to its initial state, ready to be re-executed. 5512 ** ^Any SQL statement variables that had values bound to them using 5513 ** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values. 5514 ** Use [sqlite3_clear_bindings()] to reset the bindings. 5515 ** 5516 ** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S 5517 ** back to the beginning of its program. 5518 ** 5519 ** ^The return code from [sqlite3_reset(S)] indicates whether or not 5520 ** the previous evaluation of prepared statement S completed successfully. 5521 ** ^If [sqlite3_step(S)] has never before been called on S or if 5522 ** [sqlite3_step(S)] has not been called since the previous call 5523 ** to [sqlite3_reset(S)], then [sqlite3_reset(S)] will return 5524 ** [SQLITE_OK]. 5525 ** 5526 ** ^If the most recent call to [sqlite3_step(S)] for the 5527 ** [prepared statement] S indicated an error, then 5528 ** [sqlite3_reset(S)] returns an appropriate [error code]. 5529 ** ^The [sqlite3_reset(S)] interface might also return an [error code] 5530 ** if there were no prior errors but the process of resetting 5531 ** the prepared statement caused a new error. ^For example, if an 5532 ** [INSERT] statement with a [RETURNING] clause is only stepped one time, 5533 ** that one call to [sqlite3_step(S)] might return SQLITE_ROW but 5534 ** the overall statement might still fail and the [sqlite3_reset(S)] call 5535 ** might return SQLITE_BUSY if locking constraints prevent the 5536 ** database change from committing. Therefore, it is important that 5537 ** applications check the return code from [sqlite3_reset(S)] even if 5538 ** no prior call to [sqlite3_step(S)] indicated a problem. 5539 ** 5540 ** ^The [sqlite3_reset(S)] interface does not change the values 5541 ** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S. 5542 */ 5543 SQLITE_API int sqlite3_reset(sqlite3_stmt *pStmt); 5544 5545 5546 /* 5547 ** CAPI3REF: Create Or Redefine SQL Functions 5548 ** KEYWORDS: {function creation routines} 5549 ** METHOD: sqlite3 5550 ** 5551 ** ^These functions (collectively known as "function creation routines") 5552 ** are used to add SQL functions or aggregates or to redefine the behavior 5553 ** of existing SQL functions or aggregates. The only differences between 5554 ** the three "sqlite3_create_function*" routines are the text encoding 5555 ** expected for the second parameter (the name of the function being 5556 ** created) and the presence or absence of a destructor callback for 5557 ** the application data pointer. Function sqlite3_create_window_function() 5558 ** is similar, but allows the user to supply the extra callback functions 5559 ** needed by [aggregate window functions]. 5560 ** 5561 ** ^The first parameter is the [database connection] to which the SQL 5562 ** function is to be added. ^If an application uses more than one database 5563 ** connection then application-defined SQL functions must be added 5564 ** to each database connection separately. 5565 ** 5566 ** ^The second parameter is the name of the SQL function to be created or 5567 ** redefined. ^The length of the name is limited to 255 bytes in a UTF-8 5568 ** representation, exclusive of the zero-terminator. ^Note that the name 5569 ** length limit is in UTF-8 bytes, not characters nor UTF-16 bytes. 5570 ** ^Any attempt to create a function with a longer name 5571 ** will result in [SQLITE_MISUSE] being returned. 5572 ** 5573 ** ^The third parameter (nArg) 5574 ** is the number of arguments that the SQL function or 5575 ** aggregate takes. ^If this parameter is -1, then the SQL function or 5576 ** aggregate may take any number of arguments between 0 and the limit 5577 ** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]). If the third 5578 ** parameter is less than -1 or greater than 127 then the behavior is 5579 ** undefined. 5580 ** 5581 ** ^The fourth parameter, eTextRep, specifies what 5582 ** [SQLITE_UTF8 | text encoding] this SQL function prefers for 5583 ** its parameters. The application should set this parameter to 5584 ** [SQLITE_UTF16LE] if the function implementation invokes 5585 ** [sqlite3_value_text16le()] on an input, or [SQLITE_UTF16BE] if the 5586 ** implementation invokes [sqlite3_value_text16be()] on an input, or 5587 ** [SQLITE_UTF16] if [sqlite3_value_text16()] is used, or [SQLITE_UTF8] 5588 ** otherwise. ^The same SQL function may be registered multiple times using 5589 ** different preferred text encodings, with different implementations for 5590 ** each encoding. 5591 ** ^When multiple implementations of the same function are available, SQLite 5592 ** will pick the one that involves the least amount of data conversion. 5593 ** 5594 ** ^The fourth parameter may optionally be ORed with [SQLITE_DETERMINISTIC] 5595 ** to signal that the function will always return the same result given 5596 ** the same inputs within a single SQL statement. Most SQL functions are 5597 ** deterministic. The built-in [random()] SQL function is an example of a 5598 ** function that is not deterministic. The SQLite query planner is able to 5599 ** perform additional optimizations on deterministic functions, so use 5600 ** of the [SQLITE_DETERMINISTIC] flag is recommended where possible. 5601 ** 5602 ** ^The fourth parameter may also optionally include the [SQLITE_DIRECTONLY] 5603 ** flag, which if present prevents the function from being invoked from 5604 ** within VIEWs, TRIGGERs, CHECK constraints, generated column expressions, 5605 ** index expressions, or the WHERE clause of partial indexes. 5606 ** 5607 ** For best security, the [SQLITE_DIRECTONLY] flag is recommended for 5608 ** all application-defined SQL functions that do not need to be 5609 ** used inside of triggers, views, CHECK constraints, or other elements of 5610 ** the database schema. This flag is especially recommended for SQL 5611 ** functions that have side effects or reveal internal application state. 5612 ** Without this flag, an attacker might be able to modify the schema of 5613 ** a database file to include invocations of the function with parameters 5614 ** chosen by the attacker, which the application will then execute when 5615 ** the database file is opened and read. 5616 ** 5617 ** ^(The fifth parameter is an arbitrary pointer. The implementation of the 5618 ** function can gain access to this pointer using [sqlite3_user_data()].)^ 5619 ** 5620 ** ^The sixth, seventh and eighth parameters passed to the three 5621 ** "sqlite3_create_function*" functions, xFunc, xStep and xFinal, are 5622 ** pointers to C-language functions that implement the SQL function or 5623 ** aggregate. ^A scalar SQL function requires an implementation of the xFunc 5624 ** callback only; NULL pointers must be passed as the xStep and xFinal 5625 ** parameters. ^An aggregate SQL function requires an implementation of xStep 5626 ** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing 5627 ** SQL function or aggregate, pass NULL pointers for all three function 5628 ** callbacks. 5629 ** 5630 ** ^The sixth, seventh, eighth and ninth parameters (xStep, xFinal, xValue 5631 ** and xInverse) passed to sqlite3_create_window_function are pointers to 5632 ** C-language callbacks that implement the new function. xStep and xFinal 5633 ** must both be non-NULL. xValue and xInverse may either both be NULL, in 5634 ** which case a regular aggregate function is created, or must both be 5635 ** non-NULL, in which case the new function may be used as either an aggregate 5636 ** or aggregate window function. More details regarding the implementation 5637 ** of aggregate window functions are 5638 ** [user-defined window functions|available here]. 5639 ** 5640 ** ^(If the final parameter to sqlite3_create_function_v2() or 5641 ** sqlite3_create_window_function() is not NULL, then it is the destructor for 5642 ** the application data pointer. The destructor is invoked when the function 5643 ** is deleted, either by being overloaded or when the database connection 5644 ** closes.)^ ^The destructor is also invoked if the call to 5645 ** sqlite3_create_function_v2() fails. ^When the destructor callback is 5646 ** invoked, it is passed a single argument which is a copy of the application 5647 ** data pointer which was the fifth parameter to sqlite3_create_function_v2(). 5648 ** 5649 ** ^It is permitted to register multiple implementations of the same 5650 ** functions with the same name but with either differing numbers of 5651 ** arguments or differing preferred text encodings. ^SQLite will use 5652 ** the implementation that most closely matches the way in which the 5653 ** SQL function is used. ^A function implementation with a non-negative 5654 ** nArg parameter is a better match than a function implementation with 5655 ** a negative nArg. ^A function where the preferred text encoding 5656 ** matches the database encoding is a better 5657 ** match than a function where the encoding is different. 5658 ** ^A function where the encoding difference is between UTF16le and UTF16be 5659 ** is a closer match than a function where the encoding difference is 5660 ** between UTF8 and UTF16. 5661 ** 5662 ** ^Built-in functions may be overloaded by new application-defined functions. 5663 ** 5664 ** ^An application-defined function is permitted to call other 5665 ** SQLite interfaces. However, such calls must not 5666 ** close the database connection nor finalize or reset the prepared 5667 ** statement in which the function is running. 5668 */ 5669 SQLITE_API int sqlite3_create_function( 5670 sqlite3 *db, 5671 const char *zFunctionName, 5672 int nArg, 5673 int eTextRep, 5674 void *pApp, 5675 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 5676 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 5677 void (*xFinal)(sqlite3_context*) 5678 ); 5679 SQLITE_API int sqlite3_create_function16( 5680 sqlite3 *db, 5681 const void *zFunctionName, 5682 int nArg, 5683 int eTextRep, 5684 void *pApp, 5685 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 5686 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 5687 void (*xFinal)(sqlite3_context*) 5688 ); 5689 SQLITE_API int sqlite3_create_function_v2( 5690 sqlite3 *db, 5691 const char *zFunctionName, 5692 int nArg, 5693 int eTextRep, 5694 void *pApp, 5695 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 5696 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 5697 void (*xFinal)(sqlite3_context*), 5698 void(*xDestroy)(void*) 5699 ); 5700 SQLITE_API int sqlite3_create_window_function( 5701 sqlite3 *db, 5702 const char *zFunctionName, 5703 int nArg, 5704 int eTextRep, 5705 void *pApp, 5706 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 5707 void (*xFinal)(sqlite3_context*), 5708 void (*xValue)(sqlite3_context*), 5709 void (*xInverse)(sqlite3_context*,int,sqlite3_value**), 5710 void(*xDestroy)(void*) 5711 ); 5712 5713 /* 5714 ** CAPI3REF: Text Encodings 5715 ** 5716 ** These constant define integer codes that represent the various 5717 ** text encodings supported by SQLite. 5718 */ 5719 #define SQLITE_UTF8 1 /* IMP: R-37514-35566 */ 5720 #define SQLITE_UTF16LE 2 /* IMP: R-03371-37637 */ 5721 #define SQLITE_UTF16BE 3 /* IMP: R-51971-34154 */ 5722 #define SQLITE_UTF16 4 /* Use native byte order */ 5723 #define SQLITE_ANY 5 /* Deprecated */ 5724 #define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */ 5725 5726 /* 5727 ** CAPI3REF: Function Flags 5728 ** 5729 ** These constants may be ORed together with the 5730 ** [SQLITE_UTF8 | preferred text encoding] as the fourth argument 5731 ** to [sqlite3_create_function()], [sqlite3_create_function16()], or 5732 ** [sqlite3_create_function_v2()]. 5733 ** 5734 ** <dl> 5735 ** [[SQLITE_DETERMINISTIC]] <dt>SQLITE_DETERMINISTIC</dt><dd> 5736 ** The SQLITE_DETERMINISTIC flag means that the new function always gives 5737 ** the same output when the input parameters are the same. 5738 ** The [abs|abs() function] is deterministic, for example, but 5739 ** [randomblob|randomblob()] is not. Functions must 5740 ** be deterministic in order to be used in certain contexts such as 5741 ** with the WHERE clause of [partial indexes] or in [generated columns]. 5742 ** SQLite might also optimize deterministic functions by factoring them 5743 ** out of inner loops. 5744 ** </dd> 5745 ** 5746 ** [[SQLITE_DIRECTONLY]] <dt>SQLITE_DIRECTONLY</dt><dd> 5747 ** The SQLITE_DIRECTONLY flag means that the function may only be invoked 5748 ** from top-level SQL, and cannot be used in VIEWs or TRIGGERs nor in 5749 ** schema structures such as [CHECK constraints], [DEFAULT clauses], 5750 ** [expression indexes], [partial indexes], or [generated columns]. 5751 ** <p> 5752 ** The SQLITE_DIRECTONLY flag is recommended for any 5753 ** [application-defined SQL function] 5754 ** that has side-effects or that could potentially leak sensitive information. 5755 ** This will prevent attacks in which an application is tricked 5756 ** into using a database file that has had its schema surreptitiously 5757 ** modified to invoke the application-defined function in ways that are 5758 ** harmful. 5759 ** <p> 5760 ** Some people say it is good practice to set SQLITE_DIRECTONLY on all 5761 ** [application-defined SQL functions], regardless of whether or not they 5762 ** are security sensitive, as doing so prevents those functions from being used 5763 ** inside of the database schema, and thus ensures that the database 5764 ** can be inspected and modified using generic tools (such as the [CLI]) 5765 ** that do not have access to the application-defined functions. 5766 ** </dd> 5767 ** 5768 ** [[SQLITE_INNOCUOUS]] <dt>SQLITE_INNOCUOUS</dt><dd> 5769 ** The SQLITE_INNOCUOUS flag means that the function is unlikely 5770 ** to cause problems even if misused. An innocuous function should have 5771 ** no side effects and should not depend on any values other than its 5772 ** input parameters. The [abs|abs() function] is an example of an 5773 ** innocuous function. 5774 ** The [load_extension() SQL function] is not innocuous because of its 5775 ** side effects. 5776 ** <p> SQLITE_INNOCUOUS is similar to SQLITE_DETERMINISTIC, but is not 5777 ** exactly the same. The [random|random() function] is an example of a 5778 ** function that is innocuous but not deterministic. 5779 ** <p>Some heightened security settings 5780 ** ([SQLITE_DBCONFIG_TRUSTED_SCHEMA] and [PRAGMA trusted_schema=OFF]) 5781 ** disable the use of SQL functions inside views and triggers and in 5782 ** schema structures such as [CHECK constraints], [DEFAULT clauses], 5783 ** [expression indexes], [partial indexes], and [generated columns] unless 5784 ** the function is tagged with SQLITE_INNOCUOUS. Most built-in functions 5785 ** are innocuous. Developers are advised to avoid using the 5786 ** SQLITE_INNOCUOUS flag for application-defined functions unless the 5787 ** function has been carefully audited and found to be free of potentially 5788 ** security-adverse side-effects and information-leaks. 5789 ** </dd> 5790 ** 5791 ** [[SQLITE_SUBTYPE]] <dt>SQLITE_SUBTYPE</dt><dd> 5792 ** The SQLITE_SUBTYPE flag indicates to SQLite that a function might call 5793 ** [sqlite3_value_subtype()] to inspect the sub-types of its arguments. 5794 ** This flag instructs SQLite to omit some corner-case optimizations that 5795 ** might disrupt the operation of the [sqlite3_value_subtype()] function, 5796 ** causing it to return zero rather than the correct subtype(). 5797 ** All SQL functions that invoke [sqlite3_value_subtype()] should have this 5798 ** property. If the SQLITE_SUBTYPE property is omitted, then the return 5799 ** value from [sqlite3_value_subtype()] might sometimes be zero even though 5800 ** a non-zero subtype was specified by the function argument expression. 5801 ** 5802 ** [[SQLITE_RESULT_SUBTYPE]] <dt>SQLITE_RESULT_SUBTYPE</dt><dd> 5803 ** The SQLITE_RESULT_SUBTYPE flag indicates to SQLite that a function might call 5804 ** [sqlite3_result_subtype()] to cause a sub-type to be associated with its 5805 ** result. 5806 ** Every function that invokes [sqlite3_result_subtype()] should have this 5807 ** property. If it does not, then the call to [sqlite3_result_subtype()] 5808 ** might become a no-op if the function is used as term in an 5809 ** [expression index]. On the other hand, SQL functions that never invoke 5810 ** [sqlite3_result_subtype()] should avoid setting this property, as the 5811 ** purpose of this property is to disable certain optimizations that are 5812 ** incompatible with subtypes. 5813 ** 5814 ** [[SQLITE_SELFORDER1]] <dt>SQLITE_SELFORDER1</dt><dd> 5815 ** The SQLITE_SELFORDER1 flag indicates that the function is an aggregate 5816 ** that internally orders the values provided to the first argument. The 5817 ** ordered-set aggregate SQL notation with a single ORDER BY term can be 5818 ** used to invoke this function. If the ordered-set aggregate notation is 5819 ** used on a function that lacks this flag, then an error is raised. Note 5820 ** that the ordered-set aggregate syntax is only available if SQLite is 5821 ** built using the -DSQLITE_ENABLE_ORDERED_SET_AGGREGATES compile-time option. 5822 ** </dd> 5823 ** </dl> 5824 */ 5825 #define SQLITE_DETERMINISTIC 0x000000800 5826 #define SQLITE_DIRECTONLY 0x000080000 5827 #define SQLITE_SUBTYPE 0x000100000 5828 #define SQLITE_INNOCUOUS 0x000200000 5829 #define SQLITE_RESULT_SUBTYPE 0x001000000 5830 #define SQLITE_SELFORDER1 0x002000000 5831 5832 /* 5833 ** CAPI3REF: Deprecated Functions 5834 ** DEPRECATED 5835 ** 5836 ** These functions are [deprecated]. In order to maintain 5837 ** backwards compatibility with older code, these functions continue 5838 ** to be supported. However, new applications should avoid 5839 ** the use of these functions. To encourage programmers to avoid 5840 ** these functions, we will not explain what they do. 5841 */ 5842 #ifndef SQLITE_OMIT_DEPRECATED 5843 SQLITE_API SQLITE_DEPRECATED int sqlite3_aggregate_count(sqlite3_context*); 5844 SQLITE_API SQLITE_DEPRECATED int sqlite3_expired(sqlite3_stmt*); 5845 SQLITE_API SQLITE_DEPRECATED int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*); 5846 SQLITE_API SQLITE_DEPRECATED int sqlite3_global_recover(void); 5847 SQLITE_API SQLITE_DEPRECATED void sqlite3_thread_cleanup(void); 5848 SQLITE_API SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int), 5849 void*,sqlite3_int64); 5850 #endif 5851 5852 /* 5853 ** CAPI3REF: Obtaining SQL Values 5854 ** METHOD: sqlite3_value 5855 ** 5856 ** <b>Summary:</b> 5857 ** <blockquote><table border=0 cellpadding=0 cellspacing=0> 5858 ** <tr><td><b>sqlite3_value_blob</b><td>→<td>BLOB value 5859 ** <tr><td><b>sqlite3_value_double</b><td>→<td>REAL value 5860 ** <tr><td><b>sqlite3_value_int</b><td>→<td>32-bit INTEGER value 5861 ** <tr><td><b>sqlite3_value_int64</b><td>→<td>64-bit INTEGER value 5862 ** <tr><td><b>sqlite3_value_pointer</b><td>→<td>Pointer value 5863 ** <tr><td><b>sqlite3_value_text</b><td>→<td>UTF-8 TEXT value 5864 ** <tr><td><b>sqlite3_value_text16</b><td>→<td>UTF-16 TEXT value in 5865 ** the native byteorder 5866 ** <tr><td><b>sqlite3_value_text16be</b><td>→<td>UTF-16be TEXT value 5867 ** <tr><td><b>sqlite3_value_text16le</b><td>→<td>UTF-16le TEXT value 5868 ** <tr><td> <td> <td> 5869 ** <tr><td><b>sqlite3_value_bytes</b><td>→<td>Size of a BLOB 5870 ** or a UTF-8 TEXT in bytes 5871 ** <tr><td><b>sqlite3_value_bytes16 </b> 5872 ** <td>→ <td>Size of UTF-16 5873 ** TEXT in bytes 5874 ** <tr><td><b>sqlite3_value_type</b><td>→<td>Default 5875 ** datatype of the value 5876 ** <tr><td><b>sqlite3_value_numeric_type </b> 5877 ** <td>→ <td>Best numeric datatype of the value 5878 ** <tr><td><b>sqlite3_value_nochange </b> 5879 ** <td>→ <td>True if the column is unchanged in an UPDATE 5880 ** against a virtual table. 5881 ** <tr><td><b>sqlite3_value_frombind </b> 5882 ** <td>→ <td>True if value originated from a [bound parameter] 5883 ** </table></blockquote> 5884 ** 5885 ** <b>Details:</b> 5886 ** 5887 ** These routines extract type, size, and content information from 5888 ** [protected sqlite3_value] objects. Protected sqlite3_value objects 5889 ** are used to pass parameter information into the functions that 5890 ** implement [application-defined SQL functions] and [virtual tables]. 5891 ** 5892 ** These routines work only with [protected sqlite3_value] objects. 5893 ** Any attempt to use these routines on an [unprotected sqlite3_value] 5894 ** is not threadsafe. 5895 ** 5896 ** ^These routines work just like the corresponding [column access functions] 5897 ** except that these routines take a single [protected sqlite3_value] object 5898 ** pointer instead of a [sqlite3_stmt*] pointer and an integer column number. 5899 ** 5900 ** ^The sqlite3_value_text16() interface extracts a UTF-16 string 5901 ** in the native byte-order of the host machine. ^The 5902 ** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces 5903 ** extract UTF-16 strings as big-endian and little-endian respectively. 5904 ** 5905 ** ^If [sqlite3_value] object V was initialized 5906 ** using [sqlite3_bind_pointer(S,I,P,X,D)] or [sqlite3_result_pointer(C,P,X,D)] 5907 ** and if X and Y are strings that compare equal according to strcmp(X,Y), 5908 ** then sqlite3_value_pointer(V,Y) will return the pointer P. ^Otherwise, 5909 ** sqlite3_value_pointer(V,Y) returns a NULL. The sqlite3_bind_pointer() 5910 ** routine is part of the [pointer passing interface] added for SQLite 3.20.0. 5911 ** 5912 ** ^(The sqlite3_value_type(V) interface returns the 5913 ** [SQLITE_INTEGER | datatype code] for the initial datatype of the 5914 ** [sqlite3_value] object V. The returned value is one of [SQLITE_INTEGER], 5915 ** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL].)^ 5916 ** Other interfaces might change the datatype for an sqlite3_value object. 5917 ** For example, if the datatype is initially SQLITE_INTEGER and 5918 ** sqlite3_value_text(V) is called to extract a text value for that 5919 ** integer, then subsequent calls to sqlite3_value_type(V) might return 5920 ** SQLITE_TEXT. Whether or not a persistent internal datatype conversion 5921 ** occurs is undefined and may change from one release of SQLite to the next. 5922 ** 5923 ** ^(The sqlite3_value_numeric_type() interface attempts to apply 5924 ** numeric affinity to the value. This means that an attempt is 5925 ** made to convert the value to an integer or floating point. If 5926 ** such a conversion is possible without loss of information (in other 5927 ** words, if the value is a string that looks like a number) 5928 ** then the conversion is performed. Otherwise no conversion occurs. 5929 ** The [SQLITE_INTEGER | datatype] after conversion is returned.)^ 5930 ** 5931 ** ^Within the [xUpdate] method of a [virtual table], the 5932 ** sqlite3_value_nochange(X) interface returns true if and only if 5933 ** the column corresponding to X is unchanged by the UPDATE operation 5934 ** that the xUpdate method call was invoked to implement and if 5935 ** and the prior [xColumn] method call that was invoked to extracted 5936 ** the value for that column returned without setting a result (probably 5937 ** because it queried [sqlite3_vtab_nochange()] and found that the column 5938 ** was unchanging). ^Within an [xUpdate] method, any value for which 5939 ** sqlite3_value_nochange(X) is true will in all other respects appear 5940 ** to be a NULL value. If sqlite3_value_nochange(X) is invoked anywhere other 5941 ** than within an [xUpdate] method call for an UPDATE statement, then 5942 ** the return value is arbitrary and meaningless. 5943 ** 5944 ** ^The sqlite3_value_frombind(X) interface returns non-zero if the 5945 ** value X originated from one of the [sqlite3_bind_int|sqlite3_bind()] 5946 ** interfaces. ^If X comes from an SQL literal value, or a table column, 5947 ** or an expression, then sqlite3_value_frombind(X) returns zero. 5948 ** 5949 ** Please pay particular attention to the fact that the pointer returned 5950 ** from [sqlite3_value_blob()], [sqlite3_value_text()], or 5951 ** [sqlite3_value_text16()] can be invalidated by a subsequent call to 5952 ** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()], 5953 ** or [sqlite3_value_text16()]. 5954 ** 5955 ** These routines must be called from the same thread as 5956 ** the SQL function that supplied the [sqlite3_value*] parameters. 5957 ** 5958 ** As long as the input parameter is correct, these routines can only 5959 ** fail if an out-of-memory error occurs during a format conversion. 5960 ** Only the following subset of interfaces are subject to out-of-memory 5961 ** errors: 5962 ** 5963 ** <ul> 5964 ** <li> sqlite3_value_blob() 5965 ** <li> sqlite3_value_text() 5966 ** <li> sqlite3_value_text16() 5967 ** <li> sqlite3_value_text16le() 5968 ** <li> sqlite3_value_text16be() 5969 ** <li> sqlite3_value_bytes() 5970 ** <li> sqlite3_value_bytes16() 5971 ** </ul> 5972 ** 5973 ** If an out-of-memory error occurs, then the return value from these 5974 ** routines is the same as if the column had contained an SQL NULL value. 5975 ** Valid SQL NULL returns can be distinguished from out-of-memory errors 5976 ** by invoking the [sqlite3_errcode()] immediately after the suspect 5977 ** return value is obtained and before any 5978 ** other SQLite interface is called on the same [database connection]. 5979 */ 5980 SQLITE_API const void *sqlite3_value_blob(sqlite3_value*); 5981 SQLITE_API double sqlite3_value_double(sqlite3_value*); 5982 SQLITE_API int sqlite3_value_int(sqlite3_value*); 5983 SQLITE_API sqlite3_int64 sqlite3_value_int64(sqlite3_value*); 5984 SQLITE_API void *sqlite3_value_pointer(sqlite3_value*, const char*); 5985 SQLITE_API const unsigned char *sqlite3_value_text(sqlite3_value*); 5986 SQLITE_API const void *sqlite3_value_text16(sqlite3_value*); 5987 SQLITE_API const void *sqlite3_value_text16le(sqlite3_value*); 5988 SQLITE_API const void *sqlite3_value_text16be(sqlite3_value*); 5989 SQLITE_API int sqlite3_value_bytes(sqlite3_value*); 5990 SQLITE_API int sqlite3_value_bytes16(sqlite3_value*); 5991 SQLITE_API int sqlite3_value_type(sqlite3_value*); 5992 SQLITE_API int sqlite3_value_numeric_type(sqlite3_value*); 5993 SQLITE_API int sqlite3_value_nochange(sqlite3_value*); 5994 SQLITE_API int sqlite3_value_frombind(sqlite3_value*); 5995 5996 /* 5997 ** CAPI3REF: Report the internal text encoding state of an sqlite3_value object 5998 ** METHOD: sqlite3_value 5999 ** 6000 ** ^(The sqlite3_value_encoding(X) interface returns one of [SQLITE_UTF8], 6001 ** [SQLITE_UTF16BE], or [SQLITE_UTF16LE] according to the current text encoding 6002 ** of the value X, assuming that X has type TEXT.)^ If sqlite3_value_type(X) 6003 ** returns something other than SQLITE_TEXT, then the return value from 6004 ** sqlite3_value_encoding(X) is meaningless. ^Calls to 6005 ** [sqlite3_value_text(X)], [sqlite3_value_text16(X)], [sqlite3_value_text16be(X)], 6006 ** [sqlite3_value_text16le(X)], [sqlite3_value_bytes(X)], or 6007 ** [sqlite3_value_bytes16(X)] might change the encoding of the value X and 6008 ** thus change the return from subsequent calls to sqlite3_value_encoding(X). 6009 ** 6010 ** This routine is intended for used by applications that test and validate 6011 ** the SQLite implementation. This routine is inquiring about the opaque 6012 ** internal state of an [sqlite3_value] object. Ordinary applications should 6013 ** not need to know what the internal state of an sqlite3_value object is and 6014 ** hence should not need to use this interface. 6015 */ 6016 SQLITE_API int sqlite3_value_encoding(sqlite3_value*); 6017 6018 /* 6019 ** CAPI3REF: Finding The Subtype Of SQL Values 6020 ** METHOD: sqlite3_value 6021 ** 6022 ** The sqlite3_value_subtype(V) function returns the subtype for 6023 ** an [application-defined SQL function] argument V. The subtype 6024 ** information can be used to pass a limited amount of context from 6025 ** one SQL function to another. Use the [sqlite3_result_subtype()] 6026 ** routine to set the subtype for the return value of an SQL function. 6027 ** 6028 ** Every [application-defined SQL function] that invokes this interface 6029 ** should include the [SQLITE_SUBTYPE] property in the text 6030 ** encoding argument when the function is [sqlite3_create_function|registered]. 6031 ** If the [SQLITE_SUBTYPE] property is omitted, then sqlite3_value_subtype() 6032 ** might return zero instead of the upstream subtype in some corner cases. 6033 */ 6034 SQLITE_API unsigned int sqlite3_value_subtype(sqlite3_value*); 6035 6036 /* 6037 ** CAPI3REF: Copy And Free SQL Values 6038 ** METHOD: sqlite3_value 6039 ** 6040 ** ^The sqlite3_value_dup(V) interface makes a copy of the [sqlite3_value] 6041 ** object V and returns a pointer to that copy. ^The [sqlite3_value] returned 6042 ** is a [protected sqlite3_value] object even if the input is not. 6043 ** ^The sqlite3_value_dup(V) interface returns NULL if V is NULL or if a 6044 ** memory allocation fails. ^If V is a [pointer value], then the result 6045 ** of sqlite3_value_dup(V) is a NULL value. 6046 ** 6047 ** ^The sqlite3_value_free(V) interface frees an [sqlite3_value] object 6048 ** previously obtained from [sqlite3_value_dup()]. ^If V is a NULL pointer 6049 ** then sqlite3_value_free(V) is a harmless no-op. 6050 */ 6051 SQLITE_API sqlite3_value *sqlite3_value_dup(const sqlite3_value*); 6052 SQLITE_API void sqlite3_value_free(sqlite3_value*); 6053 6054 /* 6055 ** CAPI3REF: Obtain Aggregate Function Context 6056 ** METHOD: sqlite3_context 6057 ** 6058 ** Implementations of aggregate SQL functions use this 6059 ** routine to allocate memory for storing their state. 6060 ** 6061 ** ^The first time the sqlite3_aggregate_context(C,N) routine is called 6062 ** for a particular aggregate function, SQLite allocates 6063 ** N bytes of memory, zeroes out that memory, and returns a pointer 6064 ** to the new memory. ^On second and subsequent calls to 6065 ** sqlite3_aggregate_context() for the same aggregate function instance, 6066 ** the same buffer is returned. Sqlite3_aggregate_context() is normally 6067 ** called once for each invocation of the xStep callback and then one 6068 ** last time when the xFinal callback is invoked. ^(When no rows match 6069 ** an aggregate query, the xStep() callback of the aggregate function 6070 ** implementation is never called and xFinal() is called exactly once. 6071 ** In those cases, sqlite3_aggregate_context() might be called for the 6072 ** first time from within xFinal().)^ 6073 ** 6074 ** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer 6075 ** when first called if N is less than or equal to zero or if a memory 6076 ** allocation error occurs. 6077 ** 6078 ** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is 6079 ** determined by the N parameter on the first successful call. Changing the 6080 ** value of N in any subsequent call to sqlite3_aggregate_context() within 6081 ** the same aggregate function instance will not resize the memory 6082 ** allocation.)^ Within the xFinal callback, it is customary to set 6083 ** N=0 in calls to sqlite3_aggregate_context(C,N) so that no 6084 ** pointless memory allocations occur. 6085 ** 6086 ** ^SQLite automatically frees the memory allocated by 6087 ** sqlite3_aggregate_context() when the aggregate query concludes. 6088 ** 6089 ** The first parameter must be a copy of the 6090 ** [sqlite3_context | SQL function context] that is the first parameter 6091 ** to the xStep or xFinal callback routine that implements the aggregate 6092 ** function. 6093 ** 6094 ** This routine must be called from the same thread in which 6095 ** the aggregate SQL function is running. 6096 */ 6097 SQLITE_API void *sqlite3_aggregate_context(sqlite3_context*, int nBytes); 6098 6099 /* 6100 ** CAPI3REF: User Data For Functions 6101 ** METHOD: sqlite3_context 6102 ** 6103 ** ^The sqlite3_user_data() interface returns a copy of 6104 ** the pointer that was the pUserData parameter (the 5th parameter) 6105 ** of the [sqlite3_create_function()] 6106 ** and [sqlite3_create_function16()] routines that originally 6107 ** registered the application defined function. 6108 ** 6109 ** This routine must be called from the same thread in which 6110 ** the application-defined function is running. 6111 */ 6112 SQLITE_API void *sqlite3_user_data(sqlite3_context*); 6113 6114 /* 6115 ** CAPI3REF: Database Connection For Functions 6116 ** METHOD: sqlite3_context 6117 ** 6118 ** ^The sqlite3_context_db_handle() interface returns a copy of 6119 ** the pointer to the [database connection] (the 1st parameter) 6120 ** of the [sqlite3_create_function()] 6121 ** and [sqlite3_create_function16()] routines that originally 6122 ** registered the application defined function. 6123 */ 6124 SQLITE_API sqlite3 *sqlite3_context_db_handle(sqlite3_context*); 6125 6126 /* 6127 ** CAPI3REF: Function Auxiliary Data 6128 ** METHOD: sqlite3_context 6129 ** 6130 ** These functions may be used by (non-aggregate) SQL functions to 6131 ** associate auxiliary data with argument values. If the same argument 6132 ** value is passed to multiple invocations of the same SQL function during 6133 ** query execution, under some circumstances the associated auxiliary data 6134 ** might be preserved. An example of where this might be useful is in a 6135 ** regular-expression matching function. The compiled version of the regular 6136 ** expression can be stored as auxiliary data associated with the pattern string. 6137 ** Then as long as the pattern string remains the same, 6138 ** the compiled regular expression can be reused on multiple 6139 ** invocations of the same function. 6140 ** 6141 ** ^The sqlite3_get_auxdata(C,N) interface returns a pointer to the auxiliary data 6142 ** associated by the sqlite3_set_auxdata(C,N,P,X) function with the Nth argument 6143 ** value to the application-defined function. ^N is zero for the left-most 6144 ** function argument. ^If there is no auxiliary data 6145 ** associated with the function argument, the sqlite3_get_auxdata(C,N) interface 6146 ** returns a NULL pointer. 6147 ** 6148 ** ^The sqlite3_set_auxdata(C,N,P,X) interface saves P as auxiliary data for the 6149 ** N-th argument of the application-defined function. ^Subsequent 6150 ** calls to sqlite3_get_auxdata(C,N) return P from the most recent 6151 ** sqlite3_set_auxdata(C,N,P,X) call if the auxiliary data is still valid or 6152 ** NULL if the auxiliary data has been discarded. 6153 ** ^After each call to sqlite3_set_auxdata(C,N,P,X) where X is not NULL, 6154 ** SQLite will invoke the destructor function X with parameter P exactly 6155 ** once, when the auxiliary data is discarded. 6156 ** SQLite is free to discard the auxiliary data at any time, including: <ul> 6157 ** <li> ^(when the corresponding function parameter changes)^, or 6158 ** <li> ^(when [sqlite3_reset()] or [sqlite3_finalize()] is called for the 6159 ** SQL statement)^, or 6160 ** <li> ^(when sqlite3_set_auxdata() is invoked again on the same 6161 ** parameter)^, or 6162 ** <li> ^(during the original sqlite3_set_auxdata() call when a memory 6163 ** allocation error occurs.)^ 6164 ** <li> ^(during the original sqlite3_set_auxdata() call if the function 6165 ** is evaluated during query planning instead of during query execution, 6166 ** as sometimes happens with [SQLITE_ENABLE_STAT4].)^ </ul> 6167 ** 6168 ** Note the last two bullets in particular. The destructor X in 6169 ** sqlite3_set_auxdata(C,N,P,X) might be called immediately, before the 6170 ** sqlite3_set_auxdata() interface even returns. Hence sqlite3_set_auxdata() 6171 ** should be called near the end of the function implementation and the 6172 ** function implementation should not make any use of P after 6173 ** sqlite3_set_auxdata() has been called. Furthermore, a call to 6174 ** sqlite3_get_auxdata() that occurs immediately after a corresponding call 6175 ** to sqlite3_set_auxdata() might still return NULL if an out-of-memory 6176 ** condition occurred during the sqlite3_set_auxdata() call or if the 6177 ** function is being evaluated during query planning rather than during 6178 ** query execution. 6179 ** 6180 ** ^(In practice, auxiliary data is preserved between function calls for 6181 ** function parameters that are compile-time constants, including literal 6182 ** values and [parameters] and expressions composed from the same.)^ 6183 ** 6184 ** The value of the N parameter to these interfaces should be non-negative. 6185 ** Future enhancements may make use of negative N values to define new 6186 ** kinds of function caching behavior. 6187 ** 6188 ** These routines must be called from the same thread in which 6189 ** the SQL function is running. 6190 ** 6191 ** See also: [sqlite3_get_clientdata()] and [sqlite3_set_clientdata()]. 6192 */ 6193 SQLITE_API void *sqlite3_get_auxdata(sqlite3_context*, int N); 6194 SQLITE_API void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*)); 6195 6196 /* 6197 ** CAPI3REF: Database Connection Client Data 6198 ** METHOD: sqlite3 6199 ** 6200 ** These functions are used to associate one or more named pointers 6201 ** with a [database connection]. 6202 ** A call to sqlite3_set_clientdata(D,N,P,X) causes the pointer P 6203 ** to be attached to [database connection] D using name N. Subsequent 6204 ** calls to sqlite3_get_clientdata(D,N) will return a copy of pointer P 6205 ** or a NULL pointer if there were no prior calls to 6206 ** sqlite3_set_clientdata() with the same values of D and N. 6207 ** Names are compared using strcmp() and are thus case sensitive. 6208 ** 6209 ** If P and X are both non-NULL, then the destructor X is invoked with 6210 ** argument P on the first of the following occurrences: 6211 ** <ul> 6212 ** <li> An out-of-memory error occurs during the call to 6213 ** sqlite3_set_clientdata() which attempts to register pointer P. 6214 ** <li> A subsequent call to sqlite3_set_clientdata(D,N,P,X) is made 6215 ** with the same D and N parameters. 6216 ** <li> The database connection closes. SQLite does not make any guarantees 6217 ** about the order in which destructors are called, only that all 6218 ** destructors will be called exactly once at some point during the 6219 ** database connection closing process. 6220 ** </ul> 6221 ** 6222 ** SQLite does not do anything with client data other than invoke 6223 ** destructors on the client data at the appropriate time. The intended 6224 ** use for client data is to provide a mechanism for wrapper libraries 6225 ** to store additional information about an SQLite database connection. 6226 ** 6227 ** There is no limit (other than available memory) on the number of different 6228 ** client data pointers (with different names) that can be attached to a 6229 ** single database connection. However, the implementation is optimized 6230 ** for the case of having only one or two different client data names. 6231 ** Applications and wrapper libraries are discouraged from using more than 6232 ** one client data name each. 6233 ** 6234 ** There is no way to enumerate the client data pointers 6235 ** associated with a database connection. The N parameter can be thought 6236 ** of as a secret key such that only code that knows the secret key is able 6237 ** to access the associated data. 6238 ** 6239 ** Security Warning: These interfaces should not be exposed in scripting 6240 ** languages or in other circumstances where it might be possible for an 6241 ** attacker to invoke them. Any agent that can invoke these interfaces 6242 ** can probably also take control of the process. 6243 ** 6244 ** Database connection client data is only available for SQLite 6245 ** version 3.44.0 ([dateof:3.44.0]) and later. 6246 ** 6247 ** See also: [sqlite3_set_auxdata()] and [sqlite3_get_auxdata()]. 6248 */ 6249 SQLITE_API void *sqlite3_get_clientdata(sqlite3*,const char*); 6250 SQLITE_API int sqlite3_set_clientdata(sqlite3*, const char*, void*, void(*)(void*)); 6251 6252 /* 6253 ** CAPI3REF: Constants Defining Special Destructor Behavior 6254 ** 6255 ** These are special values for the destructor that is passed in as the 6256 ** final argument to routines like [sqlite3_result_blob()]. ^If the destructor 6257 ** argument is SQLITE_STATIC, it means that the content pointer is constant 6258 ** and will never change. It does not need to be destroyed. ^The 6259 ** SQLITE_TRANSIENT value means that the content will likely change in 6260 ** the near future and that SQLite should make its own private copy of 6261 ** the content before returning. 6262 ** 6263 ** The typedef is necessary to work around problems in certain 6264 ** C++ compilers. 6265 */ 6266 typedef void (*sqlite3_destructor_type)(void*); 6267 #define SQLITE_STATIC ((sqlite3_destructor_type)0) 6268 #define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1) 6269 6270 /* 6271 ** CAPI3REF: Setting The Result Of An SQL Function 6272 ** METHOD: sqlite3_context 6273 ** 6274 ** These routines are used by the xFunc or xFinal callbacks that 6275 ** implement SQL functions and aggregates. See 6276 ** [sqlite3_create_function()] and [sqlite3_create_function16()] 6277 ** for additional information. 6278 ** 6279 ** These functions work very much like the [parameter binding] family of 6280 ** functions used to bind values to host parameters in prepared statements. 6281 ** Refer to the [SQL parameter] documentation for additional information. 6282 ** 6283 ** ^The sqlite3_result_blob() interface sets the result from 6284 ** an application-defined function to be the BLOB whose content is pointed 6285 ** to by the second parameter and which is N bytes long where N is the 6286 ** third parameter. 6287 ** 6288 ** ^The sqlite3_result_zeroblob(C,N) and sqlite3_result_zeroblob64(C,N) 6289 ** interfaces set the result of the application-defined function to be 6290 ** a BLOB containing all zero bytes and N bytes in size. 6291 ** 6292 ** ^The sqlite3_result_double() interface sets the result from 6293 ** an application-defined function to be a floating point value specified 6294 ** by its 2nd argument. 6295 ** 6296 ** ^The sqlite3_result_error() and sqlite3_result_error16() functions 6297 ** cause the implemented SQL function to throw an exception. 6298 ** ^SQLite uses the string pointed to by the 6299 ** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16() 6300 ** as the text of an error message. ^SQLite interprets the error 6301 ** message string from sqlite3_result_error() as UTF-8. ^SQLite 6302 ** interprets the string from sqlite3_result_error16() as UTF-16 using 6303 ** the same [byte-order determination rules] as [sqlite3_bind_text16()]. 6304 ** ^If the third parameter to sqlite3_result_error() 6305 ** or sqlite3_result_error16() is negative then SQLite takes as the error 6306 ** message all text up through the first zero character. 6307 ** ^If the third parameter to sqlite3_result_error() or 6308 ** sqlite3_result_error16() is non-negative then SQLite takes that many 6309 ** bytes (not characters) from the 2nd parameter as the error message. 6310 ** ^The sqlite3_result_error() and sqlite3_result_error16() 6311 ** routines make a private copy of the error message text before 6312 ** they return. Hence, the calling function can deallocate or 6313 ** modify the text after they return without harm. 6314 ** ^The sqlite3_result_error_code() function changes the error code 6315 ** returned by SQLite as a result of an error in a function. ^By default, 6316 ** the error code is SQLITE_ERROR. ^A subsequent call to sqlite3_result_error() 6317 ** or sqlite3_result_error16() resets the error code to SQLITE_ERROR. 6318 ** 6319 ** ^The sqlite3_result_error_toobig() interface causes SQLite to throw an 6320 ** error indicating that a string or BLOB is too long to represent. 6321 ** 6322 ** ^The sqlite3_result_error_nomem() interface causes SQLite to throw an 6323 ** error indicating that a memory allocation failed. 6324 ** 6325 ** ^The sqlite3_result_int() interface sets the return value 6326 ** of the application-defined function to be the 32-bit signed integer 6327 ** value given in the 2nd argument. 6328 ** ^The sqlite3_result_int64() interface sets the return value 6329 ** of the application-defined function to be the 64-bit signed integer 6330 ** value given in the 2nd argument. 6331 ** 6332 ** ^The sqlite3_result_null() interface sets the return value 6333 ** of the application-defined function to be NULL. 6334 ** 6335 ** ^The sqlite3_result_text(), sqlite3_result_text16(), 6336 ** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces 6337 ** set the return value of the application-defined function to be 6338 ** a text string which is represented as UTF-8, UTF-16 native byte order, 6339 ** UTF-16 little endian, or UTF-16 big endian, respectively. 6340 ** ^The sqlite3_result_text64() interface sets the return value of an 6341 ** application-defined function to be a text string in an encoding 6342 ** specified by the fifth (and last) parameter, which must be one 6343 ** of [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE]. 6344 ** ^SQLite takes the text result from the application from 6345 ** the 2nd parameter of the sqlite3_result_text* interfaces. 6346 ** ^If the 3rd parameter to any of the sqlite3_result_text* interfaces 6347 ** other than sqlite3_result_text64() is negative, then SQLite computes 6348 ** the string length itself by searching the 2nd parameter for the first 6349 ** zero character. 6350 ** ^If the 3rd parameter to the sqlite3_result_text* interfaces 6351 ** is non-negative, then as many bytes (not characters) of the text 6352 ** pointed to by the 2nd parameter are taken as the application-defined 6353 ** function result. If the 3rd parameter is non-negative, then it 6354 ** must be the byte offset into the string where the NUL terminator would 6355 ** appear if the string were NUL terminated. If any NUL characters occur 6356 ** in the string at a byte offset that is less than the value of the 3rd 6357 ** parameter, then the resulting string will contain embedded NULs and the 6358 ** result of expressions operating on strings with embedded NULs is undefined. 6359 ** ^If the 4th parameter to the sqlite3_result_text* interfaces 6360 ** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that 6361 ** function as the destructor on the text or BLOB result when it has 6362 ** finished using that result. 6363 ** ^If the 4th parameter to the sqlite3_result_text* interfaces or to 6364 ** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite 6365 ** assumes that the text or BLOB result is in constant space and does not 6366 ** copy the content of the parameter nor call a destructor on the content 6367 ** when it has finished using that result. 6368 ** ^If the 4th parameter to the sqlite3_result_text* interfaces 6369 ** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT 6370 ** then SQLite makes a copy of the result into space obtained 6371 ** from [sqlite3_malloc()] before it returns. 6372 ** 6373 ** ^For the sqlite3_result_text16(), sqlite3_result_text16le(), and 6374 ** sqlite3_result_text16be() routines, and for sqlite3_result_text64() 6375 ** when the encoding is not UTF8, if the input UTF16 begins with a 6376 ** byte-order mark (BOM, U+FEFF) then the BOM is removed from the 6377 ** string and the rest of the string is interpreted according to the 6378 ** byte-order specified by the BOM. ^The byte-order specified by 6379 ** the BOM at the beginning of the text overrides the byte-order 6380 ** specified by the interface procedure. ^So, for example, if 6381 ** sqlite3_result_text16le() is invoked with text that begins 6382 ** with bytes 0xfe, 0xff (a big-endian byte-order mark) then the 6383 ** first two bytes of input are skipped and the remaining input 6384 ** is interpreted as UTF16BE text. 6385 ** 6386 ** ^For UTF16 input text to the sqlite3_result_text16(), 6387 ** sqlite3_result_text16be(), sqlite3_result_text16le(), and 6388 ** sqlite3_result_text64() routines, if the text contains invalid 6389 ** UTF16 characters, the invalid characters might be converted 6390 ** into the unicode replacement character, U+FFFD. 6391 ** 6392 ** ^The sqlite3_result_value() interface sets the result of 6393 ** the application-defined function to be a copy of the 6394 ** [unprotected sqlite3_value] object specified by the 2nd parameter. ^The 6395 ** sqlite3_result_value() interface makes a copy of the [sqlite3_value] 6396 ** so that the [sqlite3_value] specified in the parameter may change or 6397 ** be deallocated after sqlite3_result_value() returns without harm. 6398 ** ^A [protected sqlite3_value] object may always be used where an 6399 ** [unprotected sqlite3_value] object is required, so either 6400 ** kind of [sqlite3_value] object can be used with this interface. 6401 ** 6402 ** ^The sqlite3_result_pointer(C,P,T,D) interface sets the result to an 6403 ** SQL NULL value, just like [sqlite3_result_null(C)], except that it 6404 ** also associates the host-language pointer P or type T with that 6405 ** NULL value such that the pointer can be retrieved within an 6406 ** [application-defined SQL function] using [sqlite3_value_pointer()]. 6407 ** ^If the D parameter is not NULL, then it is a pointer to a destructor 6408 ** for the P parameter. ^SQLite invokes D with P as its only argument 6409 ** when SQLite is finished with P. The T parameter should be a static 6410 ** string and preferably a string literal. The sqlite3_result_pointer() 6411 ** routine is part of the [pointer passing interface] added for SQLite 3.20.0. 6412 ** 6413 ** If these routines are called from within a different thread 6414 ** than the one containing the application-defined function that received 6415 ** the [sqlite3_context] pointer, the results are undefined. 6416 */ 6417 SQLITE_API void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*)); 6418 SQLITE_API void sqlite3_result_blob64(sqlite3_context*,const void*, 6419 sqlite3_uint64,void(*)(void*)); 6420 SQLITE_API void sqlite3_result_double(sqlite3_context*, double); 6421 SQLITE_API void sqlite3_result_error(sqlite3_context*, const char*, int); 6422 SQLITE_API void sqlite3_result_error16(sqlite3_context*, const void*, int); 6423 SQLITE_API void sqlite3_result_error_toobig(sqlite3_context*); 6424 SQLITE_API void sqlite3_result_error_nomem(sqlite3_context*); 6425 SQLITE_API void sqlite3_result_error_code(sqlite3_context*, int); 6426 SQLITE_API void sqlite3_result_int(sqlite3_context*, int); 6427 SQLITE_API void sqlite3_result_int64(sqlite3_context*, sqlite3_int64); 6428 SQLITE_API void sqlite3_result_null(sqlite3_context*); 6429 SQLITE_API void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*)); 6430 SQLITE_API void sqlite3_result_text64(sqlite3_context*, const char*,sqlite3_uint64, 6431 void(*)(void*), unsigned char encoding); 6432 SQLITE_API void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*)); 6433 SQLITE_API void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*)); 6434 SQLITE_API void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*)); 6435 SQLITE_API void sqlite3_result_value(sqlite3_context*, sqlite3_value*); 6436 SQLITE_API void sqlite3_result_pointer(sqlite3_context*, void*,const char*,void(*)(void*)); 6437 SQLITE_API void sqlite3_result_zeroblob(sqlite3_context*, int n); 6438 SQLITE_API int sqlite3_result_zeroblob64(sqlite3_context*, sqlite3_uint64 n); 6439 6440 6441 /* 6442 ** CAPI3REF: Setting The Subtype Of An SQL Function 6443 ** METHOD: sqlite3_context 6444 ** 6445 ** The sqlite3_result_subtype(C,T) function causes the subtype of 6446 ** the result from the [application-defined SQL function] with 6447 ** [sqlite3_context] C to be the value T. Only the lower 8 bits 6448 ** of the subtype T are preserved in current versions of SQLite; 6449 ** higher order bits are discarded. 6450 ** The number of subtype bytes preserved by SQLite might increase 6451 ** in future releases of SQLite. 6452 ** 6453 ** Every [application-defined SQL function] that invokes this interface 6454 ** should include the [SQLITE_RESULT_SUBTYPE] property in its 6455 ** text encoding argument when the SQL function is 6456 ** [sqlite3_create_function|registered]. If the [SQLITE_RESULT_SUBTYPE] 6457 ** property is omitted from the function that invokes sqlite3_result_subtype(), 6458 ** then in some cases the sqlite3_result_subtype() might fail to set 6459 ** the result subtype. 6460 ** 6461 ** If SQLite is compiled with -DSQLITE_STRICT_SUBTYPE=1, then any 6462 ** SQL function that invokes the sqlite3_result_subtype() interface 6463 ** and that does not have the SQLITE_RESULT_SUBTYPE property will raise 6464 ** an error. Future versions of SQLite might enable -DSQLITE_STRICT_SUBTYPE=1 6465 ** by default. 6466 */ 6467 SQLITE_API void sqlite3_result_subtype(sqlite3_context*,unsigned int); 6468 6469 /* 6470 ** CAPI3REF: Define New Collating Sequences 6471 ** METHOD: sqlite3 6472 ** 6473 ** ^These functions add, remove, or modify a [collation] associated 6474 ** with the [database connection] specified as the first argument. 6475 ** 6476 ** ^The name of the collation is a UTF-8 string 6477 ** for sqlite3_create_collation() and sqlite3_create_collation_v2() 6478 ** and a UTF-16 string in native byte order for sqlite3_create_collation16(). 6479 ** ^Collation names that compare equal according to [sqlite3_strnicmp()] are 6480 ** considered to be the same name. 6481 ** 6482 ** ^(The third argument (eTextRep) must be one of the constants: 6483 ** <ul> 6484 ** <li> [SQLITE_UTF8], 6485 ** <li> [SQLITE_UTF16LE], 6486 ** <li> [SQLITE_UTF16BE], 6487 ** <li> [SQLITE_UTF16], or 6488 ** <li> [SQLITE_UTF16_ALIGNED]. 6489 ** </ul>)^ 6490 ** ^The eTextRep argument determines the encoding of strings passed 6491 ** to the collating function callback, xCompare. 6492 ** ^The [SQLITE_UTF16] and [SQLITE_UTF16_ALIGNED] values for eTextRep 6493 ** force strings to be UTF16 with native byte order. 6494 ** ^The [SQLITE_UTF16_ALIGNED] value for eTextRep forces strings to begin 6495 ** on an even byte address. 6496 ** 6497 ** ^The fourth argument, pArg, is an application data pointer that is passed 6498 ** through as the first argument to the collating function callback. 6499 ** 6500 ** ^The fifth argument, xCompare, is a pointer to the collating function. 6501 ** ^Multiple collating functions can be registered using the same name but 6502 ** with different eTextRep parameters and SQLite will use whichever 6503 ** function requires the least amount of data transformation. 6504 ** ^If the xCompare argument is NULL then the collating function is 6505 ** deleted. ^When all collating functions having the same name are deleted, 6506 ** that collation is no longer usable. 6507 ** 6508 ** ^The collating function callback is invoked with a copy of the pArg 6509 ** application data pointer and with two strings in the encoding specified 6510 ** by the eTextRep argument. The two integer parameters to the collating 6511 ** function callback are the length of the two strings, in bytes. The collating 6512 ** function must return an integer that is negative, zero, or positive 6513 ** if the first string is less than, equal to, or greater than the second, 6514 ** respectively. A collating function must always return the same answer 6515 ** given the same inputs. If two or more collating functions are registered 6516 ** to the same collation name (using different eTextRep values) then all 6517 ** must give an equivalent answer when invoked with equivalent strings. 6518 ** The collating function must obey the following properties for all 6519 ** strings A, B, and C: 6520 ** 6521 ** <ol> 6522 ** <li> If A==B then B==A. 6523 ** <li> If A==B and B==C then A==C. 6524 ** <li> If A<B THEN B>A. 6525 ** <li> If A<B and B<C then A<C. 6526 ** </ol> 6527 ** 6528 ** If a collating function fails any of the above constraints and that 6529 ** collating function is registered and used, then the behavior of SQLite 6530 ** is undefined. 6531 ** 6532 ** ^The sqlite3_create_collation_v2() works like sqlite3_create_collation() 6533 ** with the addition that the xDestroy callback is invoked on pArg when 6534 ** the collating function is deleted. 6535 ** ^Collating functions are deleted when they are overridden by later 6536 ** calls to the collation creation functions or when the 6537 ** [database connection] is closed using [sqlite3_close()]. 6538 ** 6539 ** ^The xDestroy callback is <u>not</u> called if the 6540 ** sqlite3_create_collation_v2() function fails. Applications that invoke 6541 ** sqlite3_create_collation_v2() with a non-NULL xDestroy argument should 6542 ** check the return code and dispose of the application data pointer 6543 ** themselves rather than expecting SQLite to deal with it for them. 6544 ** This is different from every other SQLite interface. The inconsistency 6545 ** is unfortunate but cannot be changed without breaking backwards 6546 ** compatibility. 6547 ** 6548 ** See also: [sqlite3_collation_needed()] and [sqlite3_collation_needed16()]. 6549 */ 6550 SQLITE_API int sqlite3_create_collation( 6551 sqlite3*, 6552 const char *zName, 6553 int eTextRep, 6554 void *pArg, 6555 int(*xCompare)(void*,int,const void*,int,const void*) 6556 ); 6557 SQLITE_API int sqlite3_create_collation_v2( 6558 sqlite3*, 6559 const char *zName, 6560 int eTextRep, 6561 void *pArg, 6562 int(*xCompare)(void*,int,const void*,int,const void*), 6563 void(*xDestroy)(void*) 6564 ); 6565 SQLITE_API int sqlite3_create_collation16( 6566 sqlite3*, 6567 const void *zName, 6568 int eTextRep, 6569 void *pArg, 6570 int(*xCompare)(void*,int,const void*,int,const void*) 6571 ); 6572 6573 /* 6574 ** CAPI3REF: Collation Needed Callbacks 6575 ** METHOD: sqlite3 6576 ** 6577 ** ^To avoid having to register all collation sequences before a database 6578 ** can be used, a single callback function may be registered with the 6579 ** [database connection] to be invoked whenever an undefined collation 6580 ** sequence is required. 6581 ** 6582 ** ^If the function is registered using the sqlite3_collation_needed() API, 6583 ** then it is passed the names of undefined collation sequences as strings 6584 ** encoded in UTF-8. ^If sqlite3_collation_needed16() is used, 6585 ** the names are passed as UTF-16 in machine native byte order. 6586 ** ^A call to either function replaces the existing collation-needed callback. 6587 ** 6588 ** ^(When the callback is invoked, the first argument passed is a copy 6589 ** of the second argument to sqlite3_collation_needed() or 6590 ** sqlite3_collation_needed16(). The second argument is the database 6591 ** connection. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE], 6592 ** or [SQLITE_UTF16LE], indicating the most desirable form of the collation 6593 ** sequence function required. The fourth parameter is the name of the 6594 ** required collation sequence.)^ 6595 ** 6596 ** The callback function should register the desired collation using 6597 ** [sqlite3_create_collation()], [sqlite3_create_collation16()], or 6598 ** [sqlite3_create_collation_v2()]. 6599 */ 6600 SQLITE_API int sqlite3_collation_needed( 6601 sqlite3*, 6602 void*, 6603 void(*)(void*,sqlite3*,int eTextRep,const char*) 6604 ); 6605 SQLITE_API int sqlite3_collation_needed16( 6606 sqlite3*, 6607 void*, 6608 void(*)(void*,sqlite3*,int eTextRep,const void*) 6609 ); 6610 6611 #ifdef SQLITE_ENABLE_CEROD 6612 /* 6613 ** Specify the activation key for a CEROD database. Unless 6614 ** activated, none of the CEROD routines will work. 6615 */ 6616 SQLITE_API void sqlite3_activate_cerod( 6617 const char *zPassPhrase /* Activation phrase */ 6618 ); 6619 #endif 6620 6621 /* 6622 ** CAPI3REF: Suspend Execution For A Short Time 6623 ** 6624 ** The sqlite3_sleep() function causes the current thread to suspend execution 6625 ** for at least a number of milliseconds specified in its parameter. 6626 ** 6627 ** If the operating system does not support sleep requests with 6628 ** millisecond time resolution, then the time will be rounded up to 6629 ** the nearest second. The number of milliseconds of sleep actually 6630 ** requested from the operating system is returned. 6631 ** 6632 ** ^SQLite implements this interface by calling the xSleep() 6633 ** method of the default [sqlite3_vfs] object. If the xSleep() method 6634 ** of the default VFS is not implemented correctly, or not implemented at 6635 ** all, then the behavior of sqlite3_sleep() may deviate from the description 6636 ** in the previous paragraphs. 6637 ** 6638 ** If a negative argument is passed to sqlite3_sleep() the results vary by 6639 ** VFS and operating system. Some system treat a negative argument as an 6640 ** instruction to sleep forever. Others understand it to mean do not sleep 6641 ** at all. ^In SQLite version 3.42.0 and later, a negative 6642 ** argument passed into sqlite3_sleep() is changed to zero before it is relayed 6643 ** down into the xSleep method of the VFS. 6644 */ 6645 SQLITE_API int sqlite3_sleep(int); 6646 6647 /* 6648 ** CAPI3REF: Name Of The Folder Holding Temporary Files 6649 ** 6650 ** ^(If this global variable is made to point to a string which is 6651 ** the name of a folder (a.k.a. directory), then all temporary files 6652 ** created by SQLite when using a built-in [sqlite3_vfs | VFS] 6653 ** will be placed in that directory.)^ ^If this variable 6654 ** is a NULL pointer, then SQLite performs a search for an appropriate 6655 ** temporary file directory. 6656 ** 6657 ** Applications are strongly discouraged from using this global variable. 6658 ** It is required to set a temporary folder on Windows Runtime (WinRT). 6659 ** But for all other platforms, it is highly recommended that applications 6660 ** neither read nor write this variable. This global variable is a relic 6661 ** that exists for backwards compatibility of legacy applications and should 6662 ** be avoided in new projects. 6663 ** 6664 ** It is not safe to read or modify this variable in more than one 6665 ** thread at a time. It is not safe to read or modify this variable 6666 ** if a [database connection] is being used at the same time in a separate 6667 ** thread. 6668 ** It is intended that this variable be set once 6669 ** as part of process initialization and before any SQLite interface 6670 ** routines have been called and that this variable remain unchanged 6671 ** thereafter. 6672 ** 6673 ** ^The [temp_store_directory pragma] may modify this variable and cause 6674 ** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 6675 ** the [temp_store_directory pragma] always assumes that any string 6676 ** that this variable points to is held in memory obtained from 6677 ** [sqlite3_malloc] and the pragma may attempt to free that memory 6678 ** using [sqlite3_free]. 6679 ** Hence, if this variable is modified directly, either it should be 6680 ** made NULL or made to point to memory obtained from [sqlite3_malloc] 6681 ** or else the use of the [temp_store_directory pragma] should be avoided. 6682 ** Except when requested by the [temp_store_directory pragma], SQLite 6683 ** does not free the memory that sqlite3_temp_directory points to. If 6684 ** the application wants that memory to be freed, it must do 6685 ** so itself, taking care to only do so after all [database connection] 6686 ** objects have been destroyed. 6687 ** 6688 ** <b>Note to Windows Runtime users:</b> The temporary directory must be set 6689 ** prior to calling [sqlite3_open] or [sqlite3_open_v2]. Otherwise, various 6690 ** features that require the use of temporary files may fail. Here is an 6691 ** example of how to do this using C++ with the Windows Runtime: 6692 ** 6693 ** <blockquote><pre> 6694 ** LPCWSTR zPath = Windows::Storage::ApplicationData::Current-> 6695 ** TemporaryFolder->Path->Data(); 6696 ** char zPathBuf[MAX_PATH + 1]; 6697 ** memset(zPathBuf, 0, sizeof(zPathBuf)); 6698 ** WideCharToMultiByte(CP_UTF8, 0, zPath, -1, zPathBuf, sizeof(zPathBuf), 6699 ** NULL, NULL); 6700 ** sqlite3_temp_directory = sqlite3_mprintf("%s", zPathBuf); 6701 ** </pre></blockquote> 6702 */ 6703 SQLITE_API SQLITE_EXTERN char *sqlite3_temp_directory; 6704 6705 /* 6706 ** CAPI3REF: Name Of The Folder Holding Database Files 6707 ** 6708 ** ^(If this global variable is made to point to a string which is 6709 ** the name of a folder (a.k.a. directory), then all database files 6710 ** specified with a relative pathname and created or accessed by 6711 ** SQLite when using a built-in windows [sqlite3_vfs | VFS] will be assumed 6712 ** to be relative to that directory.)^ ^If this variable is a NULL 6713 ** pointer, then SQLite assumes that all database files specified 6714 ** with a relative pathname are relative to the current directory 6715 ** for the process. Only the windows VFS makes use of this global 6716 ** variable; it is ignored by the unix VFS. 6717 ** 6718 ** Changing the value of this variable while a database connection is 6719 ** open can result in a corrupt database. 6720 ** 6721 ** It is not safe to read or modify this variable in more than one 6722 ** thread at a time. It is not safe to read or modify this variable 6723 ** if a [database connection] is being used at the same time in a separate 6724 ** thread. 6725 ** It is intended that this variable be set once 6726 ** as part of process initialization and before any SQLite interface 6727 ** routines have been called and that this variable remain unchanged 6728 ** thereafter. 6729 ** 6730 ** ^The [data_store_directory pragma] may modify this variable and cause 6731 ** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 6732 ** the [data_store_directory pragma] always assumes that any string 6733 ** that this variable points to is held in memory obtained from 6734 ** [sqlite3_malloc] and the pragma may attempt to free that memory 6735 ** using [sqlite3_free]. 6736 ** Hence, if this variable is modified directly, either it should be 6737 ** made NULL or made to point to memory obtained from [sqlite3_malloc] 6738 ** or else the use of the [data_store_directory pragma] should be avoided. 6739 */ 6740 SQLITE_API SQLITE_EXTERN char *sqlite3_data_directory; 6741 6742 /* 6743 ** CAPI3REF: Win32 Specific Interface 6744 ** 6745 ** These interfaces are available only on Windows. The 6746 ** [sqlite3_win32_set_directory] interface is used to set the value associated 6747 ** with the [sqlite3_temp_directory] or [sqlite3_data_directory] variable, to 6748 ** zValue, depending on the value of the type parameter. The zValue parameter 6749 ** should be NULL to cause the previous value to be freed via [sqlite3_free]; 6750 ** a non-NULL value will be copied into memory obtained from [sqlite3_malloc] 6751 ** prior to being used. The [sqlite3_win32_set_directory] interface returns 6752 ** [SQLITE_OK] to indicate success, [SQLITE_ERROR] if the type is unsupported, 6753 ** or [SQLITE_NOMEM] if memory could not be allocated. The value of the 6754 ** [sqlite3_data_directory] variable is intended to act as a replacement for 6755 ** the current directory on the sub-platforms of Win32 where that concept is 6756 ** not present, e.g. WinRT and UWP. The [sqlite3_win32_set_directory8] and 6757 ** [sqlite3_win32_set_directory16] interfaces behave exactly the same as the 6758 ** sqlite3_win32_set_directory interface except the string parameter must be 6759 ** UTF-8 or UTF-16, respectively. 6760 */ 6761 SQLITE_API int sqlite3_win32_set_directory( 6762 unsigned long type, /* Identifier for directory being set or reset */ 6763 void *zValue /* New value for directory being set or reset */ 6764 ); 6765 SQLITE_API int sqlite3_win32_set_directory8(unsigned long type, const char *zValue); 6766 SQLITE_API int sqlite3_win32_set_directory16(unsigned long type, const void *zValue); 6767 6768 /* 6769 ** CAPI3REF: Win32 Directory Types 6770 ** 6771 ** These macros are only available on Windows. They define the allowed values 6772 ** for the type argument to the [sqlite3_win32_set_directory] interface. 6773 */ 6774 #define SQLITE_WIN32_DATA_DIRECTORY_TYPE 1 6775 #define SQLITE_WIN32_TEMP_DIRECTORY_TYPE 2 6776 6777 /* 6778 ** CAPI3REF: Test For Auto-Commit Mode 6779 ** KEYWORDS: {autocommit mode} 6780 ** METHOD: sqlite3 6781 ** 6782 ** ^The sqlite3_get_autocommit() interface returns non-zero or 6783 ** zero if the given database connection is or is not in autocommit mode, 6784 ** respectively. ^Autocommit mode is on by default. 6785 ** ^Autocommit mode is disabled by a [BEGIN] statement. 6786 ** ^Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK]. 6787 ** 6788 ** If certain kinds of errors occur on a statement within a multi-statement 6789 ** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR], 6790 ** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the 6791 ** transaction might be rolled back automatically. The only way to 6792 ** find out whether SQLite automatically rolled back the transaction after 6793 ** an error is to use this function. 6794 ** 6795 ** If another thread changes the autocommit status of the database 6796 ** connection while this routine is running, then the return value 6797 ** is undefined. 6798 */ 6799 SQLITE_API int sqlite3_get_autocommit(sqlite3*); 6800 6801 /* 6802 ** CAPI3REF: Find The Database Handle Of A Prepared Statement 6803 ** METHOD: sqlite3_stmt 6804 ** 6805 ** ^The sqlite3_db_handle interface returns the [database connection] handle 6806 ** to which a [prepared statement] belongs. ^The [database connection] 6807 ** returned by sqlite3_db_handle is the same [database connection] 6808 ** that was the first argument 6809 ** to the [sqlite3_prepare_v2()] call (or its variants) that was used to 6810 ** create the statement in the first place. 6811 */ 6812 SQLITE_API sqlite3 *sqlite3_db_handle(sqlite3_stmt*); 6813 6814 /* 6815 ** CAPI3REF: Return The Schema Name For A Database Connection 6816 ** METHOD: sqlite3 6817 ** 6818 ** ^The sqlite3_db_name(D,N) interface returns a pointer to the schema name 6819 ** for the N-th database on database connection D, or a NULL pointer if N is 6820 ** out of range. An N value of 0 means the main database file. An N of 1 is 6821 ** the "temp" schema. Larger values of N correspond to various ATTACH-ed 6822 ** databases. 6823 ** 6824 ** Space to hold the string that is returned by sqlite3_db_name() is managed 6825 ** by SQLite itself. The string might be deallocated by any operation that 6826 ** changes the schema, including [ATTACH] or [DETACH] or calls to 6827 ** [sqlite3_serialize()] or [sqlite3_deserialize()], even operations that 6828 ** occur on a different thread. Applications that need to 6829 ** remember the string long-term should make their own copy. Applications that 6830 ** are accessing the same database connection simultaneously on multiple 6831 ** threads should mutex-protect calls to this API and should make their own 6832 ** private copy of the result prior to releasing the mutex. 6833 */ 6834 SQLITE_API const char *sqlite3_db_name(sqlite3 *db, int N); 6835 6836 /* 6837 ** CAPI3REF: Return The Filename For A Database Connection 6838 ** METHOD: sqlite3 6839 ** 6840 ** ^The sqlite3_db_filename(D,N) interface returns a pointer to the filename 6841 ** associated with database N of connection D. 6842 ** ^If there is no attached database N on the database 6843 ** connection D, or if database N is a temporary or in-memory database, then 6844 ** this function will return either a NULL pointer or an empty string. 6845 ** 6846 ** ^The string value returned by this routine is owned and managed by 6847 ** the database connection. ^The value will be valid until the database N 6848 ** is [DETACH]-ed or until the database connection closes. 6849 ** 6850 ** ^The filename returned by this function is the output of the 6851 ** xFullPathname method of the [VFS]. ^In other words, the filename 6852 ** will be an absolute pathname, even if the filename used 6853 ** to open the database originally was a URI or relative pathname. 6854 ** 6855 ** If the filename pointer returned by this routine is not NULL, then it 6856 ** can be used as the filename input parameter to these routines: 6857 ** <ul> 6858 ** <li> [sqlite3_uri_parameter()] 6859 ** <li> [sqlite3_uri_boolean()] 6860 ** <li> [sqlite3_uri_int64()] 6861 ** <li> [sqlite3_filename_database()] 6862 ** <li> [sqlite3_filename_journal()] 6863 ** <li> [sqlite3_filename_wal()] 6864 ** </ul> 6865 */ 6866 SQLITE_API sqlite3_filename sqlite3_db_filename(sqlite3 *db, const char *zDbName); 6867 6868 /* 6869 ** CAPI3REF: Determine if a database is read-only 6870 ** METHOD: sqlite3 6871 ** 6872 ** ^The sqlite3_db_readonly(D,N) interface returns 1 if the database N 6873 ** of connection D is read-only, 0 if it is read/write, or -1 if N is not 6874 ** the name of a database on connection D. 6875 */ 6876 SQLITE_API int sqlite3_db_readonly(sqlite3 *db, const char *zDbName); 6877 6878 /* 6879 ** CAPI3REF: Determine the transaction state of a database 6880 ** METHOD: sqlite3 6881 ** 6882 ** ^The sqlite3_txn_state(D,S) interface returns the current 6883 ** [transaction state] of schema S in database connection D. ^If S is NULL, 6884 ** then the highest transaction state of any schema on database connection D 6885 ** is returned. Transaction states are (in order of lowest to highest): 6886 ** <ol> 6887 ** <li value="0"> SQLITE_TXN_NONE 6888 ** <li value="1"> SQLITE_TXN_READ 6889 ** <li value="2"> SQLITE_TXN_WRITE 6890 ** </ol> 6891 ** ^If the S argument to sqlite3_txn_state(D,S) is not the name of 6892 ** a valid schema, then -1 is returned. 6893 */ 6894 SQLITE_API int sqlite3_txn_state(sqlite3*,const char *zSchema); 6895 6896 /* 6897 ** CAPI3REF: Allowed return values from sqlite3_txn_state() 6898 ** KEYWORDS: {transaction state} 6899 ** 6900 ** These constants define the current transaction state of a database file. 6901 ** ^The [sqlite3_txn_state(D,S)] interface returns one of these 6902 ** constants in order to describe the transaction state of schema S 6903 ** in [database connection] D. 6904 ** 6905 ** <dl> 6906 ** [[SQLITE_TXN_NONE]] <dt>SQLITE_TXN_NONE</dt> 6907 ** <dd>The SQLITE_TXN_NONE state means that no transaction is currently 6908 ** pending.</dd> 6909 ** 6910 ** [[SQLITE_TXN_READ]] <dt>SQLITE_TXN_READ</dt> 6911 ** <dd>The SQLITE_TXN_READ state means that the database is currently 6912 ** in a read transaction. Content has been read from the database file 6913 ** but nothing in the database file has changed. The transaction state 6914 ** will be advanced to SQLITE_TXN_WRITE if any changes occur and there are 6915 ** no other conflicting concurrent write transactions. The transaction 6916 ** state will revert to SQLITE_TXN_NONE following a [ROLLBACK] or 6917 ** [COMMIT].</dd> 6918 ** 6919 ** [[SQLITE_TXN_WRITE]] <dt>SQLITE_TXN_WRITE</dt> 6920 ** <dd>The SQLITE_TXN_WRITE state means that the database is currently 6921 ** in a write transaction. Content has been written to the database file 6922 ** but has not yet committed. The transaction state will change to 6923 ** SQLITE_TXN_NONE at the next [ROLLBACK] or [COMMIT].</dd> 6924 */ 6925 #define SQLITE_TXN_NONE 0 6926 #define SQLITE_TXN_READ 1 6927 #define SQLITE_TXN_WRITE 2 6928 6929 /* 6930 ** CAPI3REF: Find the next prepared statement 6931 ** METHOD: sqlite3 6932 ** 6933 ** ^This interface returns a pointer to the next [prepared statement] after 6934 ** pStmt associated with the [database connection] pDb. ^If pStmt is NULL 6935 ** then this interface returns a pointer to the first prepared statement 6936 ** associated with the database connection pDb. ^If no prepared statement 6937 ** satisfies the conditions of this routine, it returns NULL. 6938 ** 6939 ** The [database connection] pointer D in a call to 6940 ** [sqlite3_next_stmt(D,S)] must refer to an open database 6941 ** connection and in particular must not be a NULL pointer. 6942 */ 6943 SQLITE_API sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt); 6944 6945 /* 6946 ** CAPI3REF: Commit And Rollback Notification Callbacks 6947 ** METHOD: sqlite3 6948 ** 6949 ** ^The sqlite3_commit_hook() interface registers a callback 6950 ** function to be invoked whenever a transaction is [COMMIT | committed]. 6951 ** ^Any callback set by a previous call to sqlite3_commit_hook() 6952 ** for the same database connection is overridden. 6953 ** ^The sqlite3_rollback_hook() interface registers a callback 6954 ** function to be invoked whenever a transaction is [ROLLBACK | rolled back]. 6955 ** ^Any callback set by a previous call to sqlite3_rollback_hook() 6956 ** for the same database connection is overridden. 6957 ** ^The pArg argument is passed through to the callback. 6958 ** ^If the callback on a commit hook function returns non-zero, 6959 ** then the commit is converted into a rollback. 6960 ** 6961 ** ^The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions 6962 ** return the P argument from the previous call of the same function 6963 ** on the same [database connection] D, or NULL for 6964 ** the first call for each function on D. 6965 ** 6966 ** The commit and rollback hook callbacks are not reentrant. 6967 ** The callback implementation must not do anything that will modify 6968 ** the database connection that invoked the callback. Any actions 6969 ** to modify the database connection must be deferred until after the 6970 ** completion of the [sqlite3_step()] call that triggered the commit 6971 ** or rollback hook in the first place. 6972 ** Note that running any other SQL statements, including SELECT statements, 6973 ** or merely calling [sqlite3_prepare_v2()] and [sqlite3_step()] will modify 6974 ** the database connections for the meaning of "modify" in this paragraph. 6975 ** 6976 ** ^Registering a NULL function disables the callback. 6977 ** 6978 ** ^When the commit hook callback routine returns zero, the [COMMIT] 6979 ** operation is allowed to continue normally. ^If the commit hook 6980 ** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK]. 6981 ** ^The rollback hook is invoked on a rollback that results from a commit 6982 ** hook returning non-zero, just as it would be with any other rollback. 6983 ** 6984 ** ^For the purposes of this API, a transaction is said to have been 6985 ** rolled back if an explicit "ROLLBACK" statement is executed, or 6986 ** an error or constraint causes an implicit rollback to occur. 6987 ** ^The rollback callback is not invoked if a transaction is 6988 ** automatically rolled back because the database connection is closed. 6989 ** 6990 ** See also the [sqlite3_update_hook()] interface. 6991 */ 6992 SQLITE_API void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*); 6993 SQLITE_API void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*); 6994 6995 /* 6996 ** CAPI3REF: Autovacuum Compaction Amount Callback 6997 ** METHOD: sqlite3 6998 ** 6999 ** ^The sqlite3_autovacuum_pages(D,C,P,X) interface registers a callback 7000 ** function C that is invoked prior to each autovacuum of the database 7001 ** file. ^The callback is passed a copy of the generic data pointer (P), 7002 ** the schema-name of the attached database that is being autovacuumed, 7003 ** the size of the database file in pages, the number of free pages, 7004 ** and the number of bytes per page, respectively. The callback should 7005 ** return the number of free pages that should be removed by the 7006 ** autovacuum. ^If the callback returns zero, then no autovacuum happens. 7007 ** ^If the value returned is greater than or equal to the number of 7008 ** free pages, then a complete autovacuum happens. 7009 ** 7010 ** <p>^If there are multiple ATTACH-ed database files that are being 7011 ** modified as part of a transaction commit, then the autovacuum pages 7012 ** callback is invoked separately for each file. 7013 ** 7014 ** <p><b>The callback is not reentrant.</b> The callback function should 7015 ** not attempt to invoke any other SQLite interface. If it does, bad 7016 ** things may happen, including segmentation faults and corrupt database 7017 ** files. The callback function should be a simple function that 7018 ** does some arithmetic on its input parameters and returns a result. 7019 ** 7020 ** ^The X parameter to sqlite3_autovacuum_pages(D,C,P,X) is an optional 7021 ** destructor for the P parameter. ^If X is not NULL, then X(P) is 7022 ** invoked whenever the database connection closes or when the callback 7023 ** is overwritten by another invocation of sqlite3_autovacuum_pages(). 7024 ** 7025 ** <p>^There is only one autovacuum pages callback per database connection. 7026 ** ^Each call to the sqlite3_autovacuum_pages() interface overrides all 7027 ** previous invocations for that database connection. ^If the callback 7028 ** argument (C) to sqlite3_autovacuum_pages(D,C,P,X) is a NULL pointer, 7029 ** then the autovacuum steps callback is canceled. The return value 7030 ** from sqlite3_autovacuum_pages() is normally SQLITE_OK, but might 7031 ** be some other error code if something goes wrong. The current 7032 ** implementation will only return SQLITE_OK or SQLITE_MISUSE, but other 7033 ** return codes might be added in future releases. 7034 ** 7035 ** <p>If no autovacuum pages callback is specified (the usual case) or 7036 ** a NULL pointer is provided for the callback, 7037 ** then the default behavior is to vacuum all free pages. So, in other 7038 ** words, the default behavior is the same as if the callback function 7039 ** were something like this: 7040 ** 7041 ** <blockquote><pre> 7042 ** unsigned int demonstration_autovac_pages_callback( 7043 ** void *pClientData, 7044 ** const char *zSchema, 7045 ** unsigned int nDbPage, 7046 ** unsigned int nFreePage, 7047 ** unsigned int nBytePerPage 7048 ** ){ 7049 ** return nFreePage; 7050 ** } 7051 ** </pre></blockquote> 7052 */ 7053 SQLITE_API int sqlite3_autovacuum_pages( 7054 sqlite3 *db, 7055 unsigned int(*)(void*,const char*,unsigned int,unsigned int,unsigned int), 7056 void*, 7057 void(*)(void*) 7058 ); 7059 7060 7061 /* 7062 ** CAPI3REF: Data Change Notification Callbacks 7063 ** METHOD: sqlite3 7064 ** 7065 ** ^The sqlite3_update_hook() interface registers a callback function 7066 ** with the [database connection] identified by the first argument 7067 ** to be invoked whenever a row is updated, inserted or deleted in 7068 ** a [rowid table]. 7069 ** ^Any callback set by a previous call to this function 7070 ** for the same database connection is overridden. 7071 ** 7072 ** ^The second argument is a pointer to the function to invoke when a 7073 ** row is updated, inserted or deleted in a rowid table. 7074 ** ^The update hook is disabled by invoking sqlite3_update_hook() 7075 ** with a NULL pointer as the second parameter. 7076 ** ^The first argument to the callback is a copy of the third argument 7077 ** to sqlite3_update_hook(). 7078 ** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE], 7079 ** or [SQLITE_UPDATE], depending on the operation that caused the callback 7080 ** to be invoked. 7081 ** ^The third and fourth arguments to the callback contain pointers to the 7082 ** database and table name containing the affected row. 7083 ** ^The final callback parameter is the [rowid] of the row. 7084 ** ^In the case of an update, this is the [rowid] after the update takes place. 7085 ** 7086 ** ^(The update hook is not invoked when internal system tables are 7087 ** modified (i.e. sqlite_sequence).)^ 7088 ** ^The update hook is not invoked when [WITHOUT ROWID] tables are modified. 7089 ** 7090 ** ^In the current implementation, the update hook 7091 ** is not invoked when conflicting rows are deleted because of an 7092 ** [ON CONFLICT | ON CONFLICT REPLACE] clause. ^Nor is the update hook 7093 ** invoked when rows are deleted using the [truncate optimization]. 7094 ** The exceptions defined in this paragraph might change in a future 7095 ** release of SQLite. 7096 ** 7097 ** Whether the update hook is invoked before or after the 7098 ** corresponding change is currently unspecified and may differ 7099 ** depending on the type of change. Do not rely on the order of the 7100 ** hook call with regards to the final result of the operation which 7101 ** triggers the hook. 7102 ** 7103 ** The update hook implementation must not do anything that will modify 7104 ** the database connection that invoked the update hook. Any actions 7105 ** to modify the database connection must be deferred until after the 7106 ** completion of the [sqlite3_step()] call that triggered the update hook. 7107 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 7108 ** database connections for the meaning of "modify" in this paragraph. 7109 ** 7110 ** ^The sqlite3_update_hook(D,C,P) function 7111 ** returns the P argument from the previous call 7112 ** on the same [database connection] D, or NULL for 7113 ** the first call on D. 7114 ** 7115 ** See also the [sqlite3_commit_hook()], [sqlite3_rollback_hook()], 7116 ** and [sqlite3_preupdate_hook()] interfaces. 7117 */ 7118 SQLITE_API void *sqlite3_update_hook( 7119 sqlite3*, 7120 void(*)(void *,int ,char const *,char const *,sqlite3_int64), 7121 void* 7122 ); 7123 7124 /* 7125 ** CAPI3REF: Enable Or Disable Shared Pager Cache 7126 ** 7127 ** ^(This routine enables or disables the sharing of the database cache 7128 ** and schema data structures between [database connection | connections] 7129 ** to the same database. Sharing is enabled if the argument is true 7130 ** and disabled if the argument is false.)^ 7131 ** 7132 ** This interface is omitted if SQLite is compiled with 7133 ** [-DSQLITE_OMIT_SHARED_CACHE]. The [-DSQLITE_OMIT_SHARED_CACHE] 7134 ** compile-time option is recommended because the 7135 ** [use of shared cache mode is discouraged]. 7136 ** 7137 ** ^Cache sharing is enabled and disabled for an entire process. 7138 ** This is a change as of SQLite [version 3.5.0] ([dateof:3.5.0]). 7139 ** In prior versions of SQLite, 7140 ** sharing was enabled or disabled for each thread separately. 7141 ** 7142 ** ^(The cache sharing mode set by this interface effects all subsequent 7143 ** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()]. 7144 ** Existing database connections continue to use the sharing mode 7145 ** that was in effect at the time they were opened.)^ 7146 ** 7147 ** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled 7148 ** successfully. An [error code] is returned otherwise.)^ 7149 ** 7150 ** ^Shared cache is disabled by default. It is recommended that it stay 7151 ** that way. In other words, do not use this routine. This interface 7152 ** continues to be provided for historical compatibility, but its use is 7153 ** discouraged. Any use of shared cache is discouraged. If shared cache 7154 ** must be used, it is recommended that shared cache only be enabled for 7155 ** individual database connections using the [sqlite3_open_v2()] interface 7156 ** with the [SQLITE_OPEN_SHAREDCACHE] flag. 7157 ** 7158 ** Note: This method is disabled on MacOS X 10.7 and iOS version 5.0 7159 ** and will always return SQLITE_MISUSE. On those systems, 7160 ** shared cache mode should be enabled per-database connection via 7161 ** [sqlite3_open_v2()] with [SQLITE_OPEN_SHAREDCACHE]. 7162 ** 7163 ** This interface is threadsafe on processors where writing a 7164 ** 32-bit integer is atomic. 7165 ** 7166 ** See Also: [SQLite Shared-Cache Mode] 7167 */ 7168 SQLITE_API int sqlite3_enable_shared_cache(int); 7169 7170 /* 7171 ** CAPI3REF: Attempt To Free Heap Memory 7172 ** 7173 ** ^The sqlite3_release_memory() interface attempts to free N bytes 7174 ** of heap memory by deallocating non-essential memory allocations 7175 ** held by the database library. Memory used to cache database 7176 ** pages to improve performance is an example of non-essential memory. 7177 ** ^sqlite3_release_memory() returns the number of bytes actually freed, 7178 ** which might be more or less than the amount requested. 7179 ** ^The sqlite3_release_memory() routine is a no-op returning zero 7180 ** if SQLite is not compiled with [SQLITE_ENABLE_MEMORY_MANAGEMENT]. 7181 ** 7182 ** See also: [sqlite3_db_release_memory()] 7183 */ 7184 SQLITE_API int sqlite3_release_memory(int); 7185 7186 /* 7187 ** CAPI3REF: Free Memory Used By A Database Connection 7188 ** METHOD: sqlite3 7189 ** 7190 ** ^The sqlite3_db_release_memory(D) interface attempts to free as much heap 7191 ** memory as possible from database connection D. Unlike the 7192 ** [sqlite3_release_memory()] interface, this interface is in effect even 7193 ** when the [SQLITE_ENABLE_MEMORY_MANAGEMENT] compile-time option is 7194 ** omitted. 7195 ** 7196 ** See also: [sqlite3_release_memory()] 7197 */ 7198 SQLITE_API int sqlite3_db_release_memory(sqlite3*); 7199 7200 /* 7201 ** CAPI3REF: Impose A Limit On Heap Size 7202 ** 7203 ** These interfaces impose limits on the amount of heap memory that will be 7204 ** used by all database connections within a single process. 7205 ** 7206 ** ^The sqlite3_soft_heap_limit64() interface sets and/or queries the 7207 ** soft limit on the amount of heap memory that may be allocated by SQLite. 7208 ** ^SQLite strives to keep heap memory utilization below the soft heap 7209 ** limit by reducing the number of pages held in the page cache 7210 ** as heap memory usages approaches the limit. 7211 ** ^The soft heap limit is "soft" because even though SQLite strives to stay 7212 ** below the limit, it will exceed the limit rather than generate 7213 ** an [SQLITE_NOMEM] error. In other words, the soft heap limit 7214 ** is advisory only. 7215 ** 7216 ** ^The sqlite3_hard_heap_limit64(N) interface sets a hard upper bound of 7217 ** N bytes on the amount of memory that will be allocated. ^The 7218 ** sqlite3_hard_heap_limit64(N) interface is similar to 7219 ** sqlite3_soft_heap_limit64(N) except that memory allocations will fail 7220 ** when the hard heap limit is reached. 7221 ** 7222 ** ^The return value from both sqlite3_soft_heap_limit64() and 7223 ** sqlite3_hard_heap_limit64() is the size of 7224 ** the heap limit prior to the call, or negative in the case of an 7225 ** error. ^If the argument N is negative 7226 ** then no change is made to the heap limit. Hence, the current 7227 ** size of heap limits can be determined by invoking 7228 ** sqlite3_soft_heap_limit64(-1) or sqlite3_hard_heap_limit(-1). 7229 ** 7230 ** ^Setting the heap limits to zero disables the heap limiter mechanism. 7231 ** 7232 ** ^The soft heap limit may not be greater than the hard heap limit. 7233 ** ^If the hard heap limit is enabled and if sqlite3_soft_heap_limit(N) 7234 ** is invoked with a value of N that is greater than the hard heap limit, 7235 ** the soft heap limit is set to the value of the hard heap limit. 7236 ** ^The soft heap limit is automatically enabled whenever the hard heap 7237 ** limit is enabled. ^When sqlite3_hard_heap_limit64(N) is invoked and 7238 ** the soft heap limit is outside the range of 1..N, then the soft heap 7239 ** limit is set to N. ^Invoking sqlite3_soft_heap_limit64(0) when the 7240 ** hard heap limit is enabled makes the soft heap limit equal to the 7241 ** hard heap limit. 7242 ** 7243 ** The memory allocation limits can also be adjusted using 7244 ** [PRAGMA soft_heap_limit] and [PRAGMA hard_heap_limit]. 7245 ** 7246 ** ^(The heap limits are not enforced in the current implementation 7247 ** if one or more of following conditions are true: 7248 ** 7249 ** <ul> 7250 ** <li> The limit value is set to zero. 7251 ** <li> Memory accounting is disabled using a combination of the 7252 ** [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],...) start-time option and 7253 ** the [SQLITE_DEFAULT_MEMSTATUS] compile-time option. 7254 ** <li> An alternative page cache implementation is specified using 7255 ** [sqlite3_config]([SQLITE_CONFIG_PCACHE2],...). 7256 ** <li> The page cache allocates from its own memory pool supplied 7257 ** by [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],...) rather than 7258 ** from the heap. 7259 ** </ul>)^ 7260 ** 7261 ** The circumstances under which SQLite will enforce the heap limits may 7262 ** change in future releases of SQLite. 7263 */ 7264 SQLITE_API sqlite3_int64 sqlite3_soft_heap_limit64(sqlite3_int64 N); 7265 SQLITE_API sqlite3_int64 sqlite3_hard_heap_limit64(sqlite3_int64 N); 7266 7267 /* 7268 ** CAPI3REF: Deprecated Soft Heap Limit Interface 7269 ** DEPRECATED 7270 ** 7271 ** This is a deprecated version of the [sqlite3_soft_heap_limit64()] 7272 ** interface. This routine is provided for historical compatibility 7273 ** only. All new applications should use the 7274 ** [sqlite3_soft_heap_limit64()] interface rather than this one. 7275 */ 7276 SQLITE_API SQLITE_DEPRECATED void sqlite3_soft_heap_limit(int N); 7277 7278 7279 /* 7280 ** CAPI3REF: Extract Metadata About A Column Of A Table 7281 ** METHOD: sqlite3 7282 ** 7283 ** ^(The sqlite3_table_column_metadata(X,D,T,C,....) routine returns 7284 ** information about column C of table T in database D 7285 ** on [database connection] X.)^ ^The sqlite3_table_column_metadata() 7286 ** interface returns SQLITE_OK and fills in the non-NULL pointers in 7287 ** the final five arguments with appropriate values if the specified 7288 ** column exists. ^The sqlite3_table_column_metadata() interface returns 7289 ** SQLITE_ERROR if the specified column does not exist. 7290 ** ^If the column-name parameter to sqlite3_table_column_metadata() is a 7291 ** NULL pointer, then this routine simply checks for the existence of the 7292 ** table and returns SQLITE_OK if the table exists and SQLITE_ERROR if it 7293 ** does not. If the table name parameter T in a call to 7294 ** sqlite3_table_column_metadata(X,D,T,C,...) is NULL then the result is 7295 ** undefined behavior. 7296 ** 7297 ** ^The column is identified by the second, third and fourth parameters to 7298 ** this function. ^(The second parameter is either the name of the database 7299 ** (i.e. "main", "temp", or an attached database) containing the specified 7300 ** table or NULL.)^ ^If it is NULL, then all attached databases are searched 7301 ** for the table using the same algorithm used by the database engine to 7302 ** resolve unqualified table references. 7303 ** 7304 ** ^The third and fourth parameters to this function are the table and column 7305 ** name of the desired column, respectively. 7306 ** 7307 ** ^Metadata is returned by writing to the memory locations passed as the 5th 7308 ** and subsequent parameters to this function. ^Any of these arguments may be 7309 ** NULL, in which case the corresponding element of metadata is omitted. 7310 ** 7311 ** ^(<blockquote> 7312 ** <table border="1"> 7313 ** <tr><th> Parameter <th> Output<br>Type <th> Description 7314 ** 7315 ** <tr><td> 5th <td> const char* <td> Data type 7316 ** <tr><td> 6th <td> const char* <td> Name of default collation sequence 7317 ** <tr><td> 7th <td> int <td> True if column has a NOT NULL constraint 7318 ** <tr><td> 8th <td> int <td> True if column is part of the PRIMARY KEY 7319 ** <tr><td> 9th <td> int <td> True if column is [AUTOINCREMENT] 7320 ** </table> 7321 ** </blockquote>)^ 7322 ** 7323 ** ^The memory pointed to by the character pointers returned for the 7324 ** declaration type and collation sequence is valid until the next 7325 ** call to any SQLite API function. 7326 ** 7327 ** ^If the specified table is actually a view, an [error code] is returned. 7328 ** 7329 ** ^If the specified column is "rowid", "oid" or "_rowid_" and the table 7330 ** is not a [WITHOUT ROWID] table and an 7331 ** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output 7332 ** parameters are set for the explicitly declared column. ^(If there is no 7333 ** [INTEGER PRIMARY KEY] column, then the outputs 7334 ** for the [rowid] are set as follows: 7335 ** 7336 ** <pre> 7337 ** data type: "INTEGER" 7338 ** collation sequence: "BINARY" 7339 ** not null: 0 7340 ** primary key: 1 7341 ** auto increment: 0 7342 ** </pre>)^ 7343 ** 7344 ** ^This function causes all database schemas to be read from disk and 7345 ** parsed, if that has not already been done, and returns an error if 7346 ** any errors are encountered while loading the schema. 7347 */ 7348 SQLITE_API int sqlite3_table_column_metadata( 7349 sqlite3 *db, /* Connection handle */ 7350 const char *zDbName, /* Database name or NULL */ 7351 const char *zTableName, /* Table name */ 7352 const char *zColumnName, /* Column name */ 7353 char const **pzDataType, /* OUTPUT: Declared data type */ 7354 char const **pzCollSeq, /* OUTPUT: Collation sequence name */ 7355 int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */ 7356 int *pPrimaryKey, /* OUTPUT: True if column part of PK */ 7357 int *pAutoinc /* OUTPUT: True if column is auto-increment */ 7358 ); 7359 7360 /* 7361 ** CAPI3REF: Load An Extension 7362 ** METHOD: sqlite3 7363 ** 7364 ** ^This interface loads an SQLite extension library from the named file. 7365 ** 7366 ** ^The sqlite3_load_extension() interface attempts to load an 7367 ** [SQLite extension] library contained in the file zFile. If 7368 ** the file cannot be loaded directly, attempts are made to load 7369 ** with various operating-system specific extensions added. 7370 ** So for example, if "samplelib" cannot be loaded, then names like 7371 ** "samplelib.so" or "samplelib.dylib" or "samplelib.dll" might 7372 ** be tried also. 7373 ** 7374 ** ^The entry point is zProc. 7375 ** ^(zProc may be 0, in which case SQLite will try to come up with an 7376 ** entry point name on its own. It first tries "sqlite3_extension_init". 7377 ** If that does not work, it constructs a name "sqlite3_X_init" where 7378 ** X consists of the lower-case equivalent of all ASCII alphabetic 7379 ** characters in the filename from the last "/" to the first following 7380 ** "." and omitting any initial "lib".)^ 7381 ** ^The sqlite3_load_extension() interface returns 7382 ** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong. 7383 ** ^If an error occurs and pzErrMsg is not 0, then the 7384 ** [sqlite3_load_extension()] interface shall attempt to 7385 ** fill *pzErrMsg with error message text stored in memory 7386 ** obtained from [sqlite3_malloc()]. The calling function 7387 ** should free this memory by calling [sqlite3_free()]. 7388 ** 7389 ** ^Extension loading must be enabled using 7390 ** [sqlite3_enable_load_extension()] or 7391 ** [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],1,NULL) 7392 ** prior to calling this API, 7393 ** otherwise an error will be returned. 7394 ** 7395 ** <b>Security warning:</b> It is recommended that the 7396 ** [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method be used to enable only this 7397 ** interface. The use of the [sqlite3_enable_load_extension()] interface 7398 ** should be avoided. This will keep the SQL function [load_extension()] 7399 ** disabled and prevent SQL injections from giving attackers 7400 ** access to extension loading capabilities. 7401 ** 7402 ** See also the [load_extension() SQL function]. 7403 */ 7404 SQLITE_API int sqlite3_load_extension( 7405 sqlite3 *db, /* Load the extension into this database connection */ 7406 const char *zFile, /* Name of the shared library containing extension */ 7407 const char *zProc, /* Entry point. Derived from zFile if 0 */ 7408 char **pzErrMsg /* Put error message here if not 0 */ 7409 ); 7410 7411 /* 7412 ** CAPI3REF: Enable Or Disable Extension Loading 7413 ** METHOD: sqlite3 7414 ** 7415 ** ^So as not to open security holes in older applications that are 7416 ** unprepared to deal with [extension loading], and as a means of disabling 7417 ** [extension loading] while evaluating user-entered SQL, the following API 7418 ** is provided to turn the [sqlite3_load_extension()] mechanism on and off. 7419 ** 7420 ** ^Extension loading is off by default. 7421 ** ^Call the sqlite3_enable_load_extension() routine with onoff==1 7422 ** to turn extension loading on and call it with onoff==0 to turn 7423 ** it back off again. 7424 ** 7425 ** ^This interface enables or disables both the C-API 7426 ** [sqlite3_load_extension()] and the SQL function [load_extension()]. 7427 ** ^(Use [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],..) 7428 ** to enable or disable only the C-API.)^ 7429 ** 7430 ** <b>Security warning:</b> It is recommended that extension loading 7431 ** be enabled using the [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method 7432 ** rather than this interface, so the [load_extension()] SQL function 7433 ** remains disabled. This will prevent SQL injections from giving attackers 7434 ** access to extension loading capabilities. 7435 */ 7436 SQLITE_API int sqlite3_enable_load_extension(sqlite3 *db, int onoff); 7437 7438 /* 7439 ** CAPI3REF: Automatically Load Statically Linked Extensions 7440 ** 7441 ** ^This interface causes the xEntryPoint() function to be invoked for 7442 ** each new [database connection] that is created. The idea here is that 7443 ** xEntryPoint() is the entry point for a statically linked [SQLite extension] 7444 ** that is to be automatically loaded into all new database connections. 7445 ** 7446 ** ^(Even though the function prototype shows that xEntryPoint() takes 7447 ** no arguments and returns void, SQLite invokes xEntryPoint() with three 7448 ** arguments and expects an integer result as if the signature of the 7449 ** entry point were as follows: 7450 ** 7451 ** <blockquote><pre> 7452 ** int xEntryPoint( 7453 ** sqlite3 *db, 7454 ** const char **pzErrMsg, 7455 ** const struct sqlite3_api_routines *pThunk 7456 ** ); 7457 ** </pre></blockquote>)^ 7458 ** 7459 ** If the xEntryPoint routine encounters an error, it should make *pzErrMsg 7460 ** point to an appropriate error message (obtained from [sqlite3_mprintf()]) 7461 ** and return an appropriate [error code]. ^SQLite ensures that *pzErrMsg 7462 ** is NULL before calling the xEntryPoint(). ^SQLite will invoke 7463 ** [sqlite3_free()] on *pzErrMsg after xEntryPoint() returns. ^If any 7464 ** xEntryPoint() returns an error, the [sqlite3_open()], [sqlite3_open16()], 7465 ** or [sqlite3_open_v2()] call that provoked the xEntryPoint() will fail. 7466 ** 7467 ** ^Calling sqlite3_auto_extension(X) with an entry point X that is already 7468 ** on the list of automatic extensions is a harmless no-op. ^No entry point 7469 ** will be called more than once for each database connection that is opened. 7470 ** 7471 ** See also: [sqlite3_reset_auto_extension()] 7472 ** and [sqlite3_cancel_auto_extension()] 7473 */ 7474 SQLITE_API int sqlite3_auto_extension(void(*xEntryPoint)(void)); 7475 7476 /* 7477 ** CAPI3REF: Cancel Automatic Extension Loading 7478 ** 7479 ** ^The [sqlite3_cancel_auto_extension(X)] interface unregisters the 7480 ** initialization routine X that was registered using a prior call to 7481 ** [sqlite3_auto_extension(X)]. ^The [sqlite3_cancel_auto_extension(X)] 7482 ** routine returns 1 if initialization routine X was successfully 7483 ** unregistered and it returns 0 if X was not on the list of initialization 7484 ** routines. 7485 */ 7486 SQLITE_API int sqlite3_cancel_auto_extension(void(*xEntryPoint)(void)); 7487 7488 /* 7489 ** CAPI3REF: Reset Automatic Extension Loading 7490 ** 7491 ** ^This interface disables all automatic extensions previously 7492 ** registered using [sqlite3_auto_extension()]. 7493 */ 7494 SQLITE_API void sqlite3_reset_auto_extension(void); 7495 7496 /* 7497 ** Structures used by the virtual table interface 7498 */ 7499 typedef struct sqlite3_vtab sqlite3_vtab; 7500 typedef struct sqlite3_index_info sqlite3_index_info; 7501 typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor; 7502 typedef struct sqlite3_module sqlite3_module; 7503 7504 /* 7505 ** CAPI3REF: Virtual Table Object 7506 ** KEYWORDS: sqlite3_module {virtual table module} 7507 ** 7508 ** This structure, sometimes called a "virtual table module", 7509 ** defines the implementation of a [virtual table]. 7510 ** This structure consists mostly of methods for the module. 7511 ** 7512 ** ^A virtual table module is created by filling in a persistent 7513 ** instance of this structure and passing a pointer to that instance 7514 ** to [sqlite3_create_module()] or [sqlite3_create_module_v2()]. 7515 ** ^The registration remains valid until it is replaced by a different 7516 ** module or until the [database connection] closes. The content 7517 ** of this structure must not change while it is registered with 7518 ** any database connection. 7519 */ 7520 struct sqlite3_module { 7521 int iVersion; 7522 int (*xCreate)(sqlite3*, void *pAux, 7523 int argc, const char *const*argv, 7524 sqlite3_vtab **ppVTab, char**); 7525 int (*xConnect)(sqlite3*, void *pAux, 7526 int argc, const char *const*argv, 7527 sqlite3_vtab **ppVTab, char**); 7528 int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*); 7529 int (*xDisconnect)(sqlite3_vtab *pVTab); 7530 int (*xDestroy)(sqlite3_vtab *pVTab); 7531 int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor); 7532 int (*xClose)(sqlite3_vtab_cursor*); 7533 int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr, 7534 int argc, sqlite3_value **argv); 7535 int (*xNext)(sqlite3_vtab_cursor*); 7536 int (*xEof)(sqlite3_vtab_cursor*); 7537 int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int); 7538 int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid); 7539 int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *); 7540 int (*xBegin)(sqlite3_vtab *pVTab); 7541 int (*xSync)(sqlite3_vtab *pVTab); 7542 int (*xCommit)(sqlite3_vtab *pVTab); 7543 int (*xRollback)(sqlite3_vtab *pVTab); 7544 int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName, 7545 void (**pxFunc)(sqlite3_context*,int,sqlite3_value**), 7546 void **ppArg); 7547 int (*xRename)(sqlite3_vtab *pVtab, const char *zNew); 7548 /* The methods above are in version 1 of the sqlite_module object. Those 7549 ** below are for version 2 and greater. */ 7550 int (*xSavepoint)(sqlite3_vtab *pVTab, int); 7551 int (*xRelease)(sqlite3_vtab *pVTab, int); 7552 int (*xRollbackTo)(sqlite3_vtab *pVTab, int); 7553 /* The methods above are in versions 1 and 2 of the sqlite_module object. 7554 ** Those below are for version 3 and greater. */ 7555 int (*xShadowName)(const char*); 7556 /* The methods above are in versions 1 through 3 of the sqlite_module object. 7557 ** Those below are for version 4 and greater. */ 7558 int (*xIntegrity)(sqlite3_vtab *pVTab, const char *zSchema, 7559 const char *zTabName, int mFlags, char **pzErr); 7560 }; 7561 7562 /* 7563 ** CAPI3REF: Virtual Table Indexing Information 7564 ** KEYWORDS: sqlite3_index_info 7565 ** 7566 ** The sqlite3_index_info structure and its substructures is used as part 7567 ** of the [virtual table] interface to 7568 ** pass information into and receive the reply from the [xBestIndex] 7569 ** method of a [virtual table module]. The fields under **Inputs** are the 7570 ** inputs to xBestIndex and are read-only. xBestIndex inserts its 7571 ** results into the **Outputs** fields. 7572 ** 7573 ** ^(The aConstraint[] array records WHERE clause constraints of the form: 7574 ** 7575 ** <blockquote>column OP expr</blockquote> 7576 ** 7577 ** where OP is =, <, <=, >, or >=.)^ ^(The particular operator is 7578 ** stored in aConstraint[].op using one of the 7579 ** [SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_ values].)^ 7580 ** ^(The index of the column is stored in 7581 ** aConstraint[].iColumn.)^ ^(aConstraint[].usable is TRUE if the 7582 ** expr on the right-hand side can be evaluated (and thus the constraint 7583 ** is usable) and false if it cannot.)^ 7584 ** 7585 ** ^The optimizer automatically inverts terms of the form "expr OP column" 7586 ** and makes other simplifications to the WHERE clause in an attempt to 7587 ** get as many WHERE clause terms into the form shown above as possible. 7588 ** ^The aConstraint[] array only reports WHERE clause terms that are 7589 ** relevant to the particular virtual table being queried. 7590 ** 7591 ** ^Information about the ORDER BY clause is stored in aOrderBy[]. 7592 ** ^Each term of aOrderBy records a column of the ORDER BY clause. 7593 ** 7594 ** The colUsed field indicates which columns of the virtual table may be 7595 ** required by the current scan. Virtual table columns are numbered from 7596 ** zero in the order in which they appear within the CREATE TABLE statement 7597 ** passed to sqlite3_declare_vtab(). For the first 63 columns (columns 0-62), 7598 ** the corresponding bit is set within the colUsed mask if the column may be 7599 ** required by SQLite. If the table has at least 64 columns and any column 7600 ** to the right of the first 63 is required, then bit 63 of colUsed is also 7601 ** set. In other words, column iCol may be required if the expression 7602 ** (colUsed & ((sqlite3_uint64)1 << (iCol>=63 ? 63 : iCol))) evaluates to 7603 ** non-zero. 7604 ** 7605 ** The [xBestIndex] method must fill aConstraintUsage[] with information 7606 ** about what parameters to pass to xFilter. ^If argvIndex>0 then 7607 ** the right-hand side of the corresponding aConstraint[] is evaluated 7608 ** and becomes the argvIndex-th entry in argv. ^(If aConstraintUsage[].omit 7609 ** is true, then the constraint is assumed to be fully handled by the 7610 ** virtual table and might not be checked again by the byte code.)^ ^(The 7611 ** aConstraintUsage[].omit flag is an optimization hint. When the omit flag 7612 ** is left in its default setting of false, the constraint will always be 7613 ** checked separately in byte code. If the omit flag is changed to true, then 7614 ** the constraint may or may not be checked in byte code. In other words, 7615 ** when the omit flag is true there is no guarantee that the constraint will 7616 ** not be checked again using byte code.)^ 7617 ** 7618 ** ^The idxNum and idxStr values are recorded and passed into the 7619 ** [xFilter] method. 7620 ** ^[sqlite3_free()] is used to free idxStr if and only if 7621 ** needToFreeIdxStr is true. 7622 ** 7623 ** ^The orderByConsumed means that output from [xFilter]/[xNext] will occur in 7624 ** the correct order to satisfy the ORDER BY clause so that no separate 7625 ** sorting step is required. 7626 ** 7627 ** ^The estimatedCost value is an estimate of the cost of a particular 7628 ** strategy. A cost of N indicates that the cost of the strategy is similar 7629 ** to a linear scan of an SQLite table with N rows. A cost of log(N) 7630 ** indicates that the expense of the operation is similar to that of a 7631 ** binary search on a unique indexed field of an SQLite table with N rows. 7632 ** 7633 ** ^The estimatedRows value is an estimate of the number of rows that 7634 ** will be returned by the strategy. 7635 ** 7636 ** The xBestIndex method may optionally populate the idxFlags field with a 7637 ** mask of SQLITE_INDEX_SCAN_* flags. One such flag is 7638 ** [SQLITE_INDEX_SCAN_HEX], which if set causes the [EXPLAIN QUERY PLAN] 7639 ** output to show the idxNum as hex instead of as decimal. Another flag is 7640 ** SQLITE_INDEX_SCAN_UNIQUE, which if set indicates that the query plan will 7641 ** return at most one row. 7642 ** 7643 ** Additionally, if xBestIndex sets the SQLITE_INDEX_SCAN_UNIQUE flag, then 7644 ** SQLite also assumes that if a call to the xUpdate() method is made as 7645 ** part of the same statement to delete or update a virtual table row and the 7646 ** implementation returns SQLITE_CONSTRAINT, then there is no need to rollback 7647 ** any database changes. In other words, if the xUpdate() returns 7648 ** SQLITE_CONSTRAINT, the database contents must be exactly as they were 7649 ** before xUpdate was called. By contrast, if SQLITE_INDEX_SCAN_UNIQUE is not 7650 ** set and xUpdate returns SQLITE_CONSTRAINT, any database changes made by 7651 ** the xUpdate method are automatically rolled back by SQLite. 7652 ** 7653 ** IMPORTANT: The estimatedRows field was added to the sqlite3_index_info 7654 ** structure for SQLite [version 3.8.2] ([dateof:3.8.2]). 7655 ** If a virtual table extension is 7656 ** used with an SQLite version earlier than 3.8.2, the results of attempting 7657 ** to read or write the estimatedRows field are undefined (but are likely 7658 ** to include crashing the application). The estimatedRows field should 7659 ** therefore only be used if [sqlite3_libversion_number()] returns a 7660 ** value greater than or equal to 3008002. Similarly, the idxFlags field 7661 ** was added for [version 3.9.0] ([dateof:3.9.0]). 7662 ** It may therefore only be used if 7663 ** sqlite3_libversion_number() returns a value greater than or equal to 7664 ** 3009000. 7665 */ 7666 struct sqlite3_index_info { 7667 /* Inputs */ 7668 int nConstraint; /* Number of entries in aConstraint */ 7669 struct sqlite3_index_constraint { 7670 int iColumn; /* Column constrained. -1 for ROWID */ 7671 unsigned char op; /* Constraint operator */ 7672 unsigned char usable; /* True if this constraint is usable */ 7673 int iTermOffset; /* Used internally - xBestIndex should ignore */ 7674 } *aConstraint; /* Table of WHERE clause constraints */ 7675 int nOrderBy; /* Number of terms in the ORDER BY clause */ 7676 struct sqlite3_index_orderby { 7677 int iColumn; /* Column number */ 7678 unsigned char desc; /* True for DESC. False for ASC. */ 7679 } *aOrderBy; /* The ORDER BY clause */ 7680 /* Outputs */ 7681 struct sqlite3_index_constraint_usage { 7682 int argvIndex; /* if >0, constraint is part of argv to xFilter */ 7683 unsigned char omit; /* Do not code a test for this constraint */ 7684 } *aConstraintUsage; 7685 int idxNum; /* Number used to identify the index */ 7686 char *idxStr; /* String, possibly obtained from sqlite3_malloc */ 7687 int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */ 7688 int orderByConsumed; /* True if output is already ordered */ 7689 double estimatedCost; /* Estimated cost of using this index */ 7690 /* Fields below are only available in SQLite 3.8.2 and later */ 7691 sqlite3_int64 estimatedRows; /* Estimated number of rows returned */ 7692 /* Fields below are only available in SQLite 3.9.0 and later */ 7693 int idxFlags; /* Mask of SQLITE_INDEX_SCAN_* flags */ 7694 /* Fields below are only available in SQLite 3.10.0 and later */ 7695 sqlite3_uint64 colUsed; /* Input: Mask of columns used by statement */ 7696 }; 7697 7698 /* 7699 ** CAPI3REF: Virtual Table Scan Flags 7700 ** 7701 ** Virtual table implementations are allowed to set the 7702 ** [sqlite3_index_info].idxFlags field to some combination of 7703 ** these bits. 7704 */ 7705 #define SQLITE_INDEX_SCAN_UNIQUE 0x00000001 /* Scan visits at most 1 row */ 7706 #define SQLITE_INDEX_SCAN_HEX 0x00000002 /* Display idxNum as hex */ 7707 /* in EXPLAIN QUERY PLAN */ 7708 7709 /* 7710 ** CAPI3REF: Virtual Table Constraint Operator Codes 7711 ** 7712 ** These macros define the allowed values for the 7713 ** [sqlite3_index_info].aConstraint[].op field. Each value represents 7714 ** an operator that is part of a constraint term in the WHERE clause of 7715 ** a query that uses a [virtual table]. 7716 ** 7717 ** ^The left-hand operand of the operator is given by the corresponding 7718 ** aConstraint[].iColumn field. ^An iColumn of -1 indicates the left-hand 7719 ** operand is the rowid. 7720 ** The SQLITE_INDEX_CONSTRAINT_LIMIT and SQLITE_INDEX_CONSTRAINT_OFFSET 7721 ** operators have no left-hand operand, and so for those operators the 7722 ** corresponding aConstraint[].iColumn is meaningless and should not be 7723 ** used. 7724 ** 7725 ** All operator values from SQLITE_INDEX_CONSTRAINT_FUNCTION through 7726 ** value 255 are reserved to represent functions that are overloaded 7727 ** by the [xFindFunction|xFindFunction method] of the virtual table 7728 ** implementation. 7729 ** 7730 ** The right-hand operands for each constraint might be accessible using 7731 ** the [sqlite3_vtab_rhs_value()] interface. Usually the right-hand 7732 ** operand is only available if it appears as a single constant literal 7733 ** in the input SQL. If the right-hand operand is another column or an 7734 ** expression (even a constant expression) or a parameter, then the 7735 ** sqlite3_vtab_rhs_value() probably will not be able to extract it. 7736 ** ^The SQLITE_INDEX_CONSTRAINT_ISNULL and 7737 ** SQLITE_INDEX_CONSTRAINT_ISNOTNULL operators have no right-hand operand 7738 ** and hence calls to sqlite3_vtab_rhs_value() for those operators will 7739 ** always return SQLITE_NOTFOUND. 7740 ** 7741 ** The collating sequence to be used for comparison can be found using 7742 ** the [sqlite3_vtab_collation()] interface. For most real-world virtual 7743 ** tables, the collating sequence of constraints does not matter (for example 7744 ** because the constraints are numeric) and so the sqlite3_vtab_collation() 7745 ** interface is not commonly needed. 7746 */ 7747 #define SQLITE_INDEX_CONSTRAINT_EQ 2 7748 #define SQLITE_INDEX_CONSTRAINT_GT 4 7749 #define SQLITE_INDEX_CONSTRAINT_LE 8 7750 #define SQLITE_INDEX_CONSTRAINT_LT 16 7751 #define SQLITE_INDEX_CONSTRAINT_GE 32 7752 #define SQLITE_INDEX_CONSTRAINT_MATCH 64 7753 #define SQLITE_INDEX_CONSTRAINT_LIKE 65 7754 #define SQLITE_INDEX_CONSTRAINT_GLOB 66 7755 #define SQLITE_INDEX_CONSTRAINT_REGEXP 67 7756 #define SQLITE_INDEX_CONSTRAINT_NE 68 7757 #define SQLITE_INDEX_CONSTRAINT_ISNOT 69 7758 #define SQLITE_INDEX_CONSTRAINT_ISNOTNULL 70 7759 #define SQLITE_INDEX_CONSTRAINT_ISNULL 71 7760 #define SQLITE_INDEX_CONSTRAINT_IS 72 7761 #define SQLITE_INDEX_CONSTRAINT_LIMIT 73 7762 #define SQLITE_INDEX_CONSTRAINT_OFFSET 74 7763 #define SQLITE_INDEX_CONSTRAINT_FUNCTION 150 7764 7765 /* 7766 ** CAPI3REF: Register A Virtual Table Implementation 7767 ** METHOD: sqlite3 7768 ** 7769 ** ^These routines are used to register a new [virtual table module] name. 7770 ** ^Module names must be registered before 7771 ** creating a new [virtual table] using the module and before using a 7772 ** preexisting [virtual table] for the module. 7773 ** 7774 ** ^The module name is registered on the [database connection] specified 7775 ** by the first parameter. ^The name of the module is given by the 7776 ** second parameter. ^The third parameter is a pointer to 7777 ** the implementation of the [virtual table module]. ^The fourth 7778 ** parameter is an arbitrary client data pointer that is passed through 7779 ** into the [xCreate] and [xConnect] methods of the virtual table module 7780 ** when a new virtual table is being created or reinitialized. 7781 ** 7782 ** ^The sqlite3_create_module_v2() interface has a fifth parameter which 7783 ** is a pointer to a destructor for the pClientData. ^SQLite will 7784 ** invoke the destructor function (if it is not NULL) when SQLite 7785 ** no longer needs the pClientData pointer. ^The destructor will also 7786 ** be invoked if the call to sqlite3_create_module_v2() fails. 7787 ** ^The sqlite3_create_module() 7788 ** interface is equivalent to sqlite3_create_module_v2() with a NULL 7789 ** destructor. 7790 ** 7791 ** ^If the third parameter (the pointer to the sqlite3_module object) is 7792 ** NULL then no new module is created and any existing modules with the 7793 ** same name are dropped. 7794 ** 7795 ** See also: [sqlite3_drop_modules()] 7796 */ 7797 SQLITE_API int sqlite3_create_module( 7798 sqlite3 *db, /* SQLite connection to register module with */ 7799 const char *zName, /* Name of the module */ 7800 const sqlite3_module *p, /* Methods for the module */ 7801 void *pClientData /* Client data for xCreate/xConnect */ 7802 ); 7803 SQLITE_API int sqlite3_create_module_v2( 7804 sqlite3 *db, /* SQLite connection to register module with */ 7805 const char *zName, /* Name of the module */ 7806 const sqlite3_module *p, /* Methods for the module */ 7807 void *pClientData, /* Client data for xCreate/xConnect */ 7808 void(*xDestroy)(void*) /* Module destructor function */ 7809 ); 7810 7811 /* 7812 ** CAPI3REF: Remove Unnecessary Virtual Table Implementations 7813 ** METHOD: sqlite3 7814 ** 7815 ** ^The sqlite3_drop_modules(D,L) interface removes all virtual 7816 ** table modules from database connection D except those named on list L. 7817 ** The L parameter must be either NULL or a pointer to an array of pointers 7818 ** to strings where the array is terminated by a single NULL pointer. 7819 ** ^If the L parameter is NULL, then all virtual table modules are removed. 7820 ** 7821 ** See also: [sqlite3_create_module()] 7822 */ 7823 SQLITE_API int sqlite3_drop_modules( 7824 sqlite3 *db, /* Remove modules from this connection */ 7825 const char **azKeep /* Except, do not remove the ones named here */ 7826 ); 7827 7828 /* 7829 ** CAPI3REF: Virtual Table Instance Object 7830 ** KEYWORDS: sqlite3_vtab 7831 ** 7832 ** Every [virtual table module] implementation uses a subclass 7833 ** of this object to describe a particular instance 7834 ** of the [virtual table]. Each subclass will 7835 ** be tailored to the specific needs of the module implementation. 7836 ** The purpose of this superclass is to define certain fields that are 7837 ** common to all module implementations. 7838 ** 7839 ** ^Virtual tables methods can set an error message by assigning a 7840 ** string obtained from [sqlite3_mprintf()] to zErrMsg. The method should 7841 ** take care that any prior string is freed by a call to [sqlite3_free()] 7842 ** prior to assigning a new string to zErrMsg. ^After the error message 7843 ** is delivered up to the client application, the string will be automatically 7844 ** freed by sqlite3_free() and the zErrMsg field will be zeroed. 7845 */ 7846 struct sqlite3_vtab { 7847 const sqlite3_module *pModule; /* The module for this virtual table */ 7848 int nRef; /* Number of open cursors */ 7849 char *zErrMsg; /* Error message from sqlite3_mprintf() */ 7850 /* Virtual table implementations will typically add additional fields */ 7851 }; 7852 7853 /* 7854 ** CAPI3REF: Virtual Table Cursor Object 7855 ** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor} 7856 ** 7857 ** Every [virtual table module] implementation uses a subclass of the 7858 ** following structure to describe cursors that point into the 7859 ** [virtual table] and are used 7860 ** to loop through the virtual table. Cursors are created using the 7861 ** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed 7862 ** by the [sqlite3_module.xClose | xClose] method. Cursors are used 7863 ** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods 7864 ** of the module. Each module implementation will define 7865 ** the content of a cursor structure to suit its own needs. 7866 ** 7867 ** This superclass exists in order to define fields of the cursor that 7868 ** are common to all implementations. 7869 */ 7870 struct sqlite3_vtab_cursor { 7871 sqlite3_vtab *pVtab; /* Virtual table of this cursor */ 7872 /* Virtual table implementations will typically add additional fields */ 7873 }; 7874 7875 /* 7876 ** CAPI3REF: Declare The Schema Of A Virtual Table 7877 ** 7878 ** ^The [xCreate] and [xConnect] methods of a 7879 ** [virtual table module] call this interface 7880 ** to declare the format (the names and datatypes of the columns) of 7881 ** the virtual tables they implement. 7882 */ 7883 SQLITE_API int sqlite3_declare_vtab(sqlite3*, const char *zSQL); 7884 7885 /* 7886 ** CAPI3REF: Overload A Function For A Virtual Table 7887 ** METHOD: sqlite3 7888 ** 7889 ** ^(Virtual tables can provide alternative implementations of functions 7890 ** using the [xFindFunction] method of the [virtual table module]. 7891 ** But global versions of those functions 7892 ** must exist in order to be overloaded.)^ 7893 ** 7894 ** ^(This API makes sure a global version of a function with a particular 7895 ** name and number of parameters exists. If no such function exists 7896 ** before this API is called, a new function is created.)^ ^The implementation 7897 ** of the new function always causes an exception to be thrown. So 7898 ** the new function is not good for anything by itself. Its only 7899 ** purpose is to be a placeholder function that can be overloaded 7900 ** by a [virtual table]. 7901 */ 7902 SQLITE_API int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg); 7903 7904 /* 7905 ** CAPI3REF: A Handle To An Open BLOB 7906 ** KEYWORDS: {BLOB handle} {BLOB handles} 7907 ** 7908 ** An instance of this object represents an open BLOB on which 7909 ** [sqlite3_blob_open | incremental BLOB I/O] can be performed. 7910 ** ^Objects of this type are created by [sqlite3_blob_open()] 7911 ** and destroyed by [sqlite3_blob_close()]. 7912 ** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces 7913 ** can be used to read or write small subsections of the BLOB. 7914 ** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes. 7915 */ 7916 typedef struct sqlite3_blob sqlite3_blob; 7917 7918 /* 7919 ** CAPI3REF: Open A BLOB For Incremental I/O 7920 ** METHOD: sqlite3 7921 ** CONSTRUCTOR: sqlite3_blob 7922 ** 7923 ** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located 7924 ** in row iRow, column zColumn, table zTable in database zDb; 7925 ** in other words, the same BLOB that would be selected by: 7926 ** 7927 ** <pre> 7928 ** SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow; 7929 ** </pre>)^ 7930 ** 7931 ** ^(Parameter zDb is not the filename that contains the database, but 7932 ** rather the symbolic name of the database. For attached databases, this is 7933 ** the name that appears after the AS keyword in the [ATTACH] statement. 7934 ** For the main database file, the database name is "main". For TEMP 7935 ** tables, the database name is "temp".)^ 7936 ** 7937 ** ^If the flags parameter is non-zero, then the BLOB is opened for read 7938 ** and write access. ^If the flags parameter is zero, the BLOB is opened for 7939 ** read-only access. 7940 ** 7941 ** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is stored 7942 ** in *ppBlob. Otherwise an [error code] is returned and, unless the error 7943 ** code is SQLITE_MISUSE, *ppBlob is set to NULL.)^ ^This means that, provided 7944 ** the API is not misused, it is always safe to call [sqlite3_blob_close()] 7945 ** on *ppBlob after this function returns. 7946 ** 7947 ** This function fails with SQLITE_ERROR if any of the following are true: 7948 ** <ul> 7949 ** <li> ^(Database zDb does not exist)^, 7950 ** <li> ^(Table zTable does not exist within database zDb)^, 7951 ** <li> ^(Table zTable is a WITHOUT ROWID table)^, 7952 ** <li> ^(Column zColumn does not exist)^, 7953 ** <li> ^(Row iRow is not present in the table)^, 7954 ** <li> ^(The specified column of row iRow contains a value that is not 7955 ** a TEXT or BLOB value)^, 7956 ** <li> ^(Column zColumn is part of an index, PRIMARY KEY or UNIQUE 7957 ** constraint and the blob is being opened for read/write access)^, 7958 ** <li> ^([foreign key constraints | Foreign key constraints] are enabled, 7959 ** column zColumn is part of a [child key] definition and the blob is 7960 ** being opened for read/write access)^. 7961 ** </ul> 7962 ** 7963 ** ^Unless it returns SQLITE_MISUSE, this function sets the 7964 ** [database connection] error code and message accessible via 7965 ** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions. 7966 ** 7967 ** A BLOB referenced by sqlite3_blob_open() may be read using the 7968 ** [sqlite3_blob_read()] interface and modified by using 7969 ** [sqlite3_blob_write()]. The [BLOB handle] can be moved to a 7970 ** different row of the same table using the [sqlite3_blob_reopen()] 7971 ** interface. However, the column, table, or database of a [BLOB handle] 7972 ** cannot be changed after the [BLOB handle] is opened. 7973 ** 7974 ** ^(If the row that a BLOB handle points to is modified by an 7975 ** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects 7976 ** then the BLOB handle is marked as "expired". 7977 ** This is true if any column of the row is changed, even a column 7978 ** other than the one the BLOB handle is open on.)^ 7979 ** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for 7980 ** an expired BLOB handle fail with a return code of [SQLITE_ABORT]. 7981 ** ^(Changes written into a BLOB prior to the BLOB expiring are not 7982 ** rolled back by the expiration of the BLOB. Such changes will eventually 7983 ** commit if the transaction continues to completion.)^ 7984 ** 7985 ** ^Use the [sqlite3_blob_bytes()] interface to determine the size of 7986 ** the opened blob. ^The size of a blob may not be changed by this 7987 ** interface. Use the [UPDATE] SQL command to change the size of a 7988 ** blob. 7989 ** 7990 ** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces 7991 ** and the built-in [zeroblob] SQL function may be used to create a 7992 ** zero-filled blob to read or write using the incremental-blob interface. 7993 ** 7994 ** To avoid a resource leak, every open [BLOB handle] should eventually 7995 ** be released by a call to [sqlite3_blob_close()]. 7996 ** 7997 ** See also: [sqlite3_blob_close()], 7998 ** [sqlite3_blob_reopen()], [sqlite3_blob_read()], 7999 ** [sqlite3_blob_bytes()], [sqlite3_blob_write()]. 8000 */ 8001 SQLITE_API int sqlite3_blob_open( 8002 sqlite3*, 8003 const char *zDb, 8004 const char *zTable, 8005 const char *zColumn, 8006 sqlite3_int64 iRow, 8007 int flags, 8008 sqlite3_blob **ppBlob 8009 ); 8010 8011 /* 8012 ** CAPI3REF: Move a BLOB Handle to a New Row 8013 ** METHOD: sqlite3_blob 8014 ** 8015 ** ^This function is used to move an existing [BLOB handle] so that it points 8016 ** to a different row of the same database table. ^The new row is identified 8017 ** by the rowid value passed as the second argument. Only the row can be 8018 ** changed. ^The database, table and column on which the blob handle is open 8019 ** remain the same. Moving an existing [BLOB handle] to a new row is 8020 ** faster than closing the existing handle and opening a new one. 8021 ** 8022 ** ^(The new row must meet the same criteria as for [sqlite3_blob_open()] - 8023 ** it must exist and there must be either a blob or text value stored in 8024 ** the nominated column.)^ ^If the new row is not present in the table, or if 8025 ** it does not contain a blob or text value, or if another error occurs, an 8026 ** SQLite error code is returned and the blob handle is considered aborted. 8027 ** ^All subsequent calls to [sqlite3_blob_read()], [sqlite3_blob_write()] or 8028 ** [sqlite3_blob_reopen()] on an aborted blob handle immediately return 8029 ** SQLITE_ABORT. ^Calling [sqlite3_blob_bytes()] on an aborted blob handle 8030 ** always returns zero. 8031 ** 8032 ** ^This function sets the database handle error code and message. 8033 */ 8034 SQLITE_API int sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64); 8035 8036 /* 8037 ** CAPI3REF: Close A BLOB Handle 8038 ** DESTRUCTOR: sqlite3_blob 8039 ** 8040 ** ^This function closes an open [BLOB handle]. ^(The BLOB handle is closed 8041 ** unconditionally. Even if this routine returns an error code, the 8042 ** handle is still closed.)^ 8043 ** 8044 ** ^If the blob handle being closed was opened for read-write access, and if 8045 ** the database is in auto-commit mode and there are no other open read-write 8046 ** blob handles or active write statements, the current transaction is 8047 ** committed. ^If an error occurs while committing the transaction, an error 8048 ** code is returned and the transaction rolled back. 8049 ** 8050 ** Calling this function with an argument that is not a NULL pointer or an 8051 ** open blob handle results in undefined behavior. ^Calling this routine 8052 ** with a null pointer (such as would be returned by a failed call to 8053 ** [sqlite3_blob_open()]) is a harmless no-op. ^Otherwise, if this function 8054 ** is passed a valid open blob handle, the values returned by the 8055 ** sqlite3_errcode() and sqlite3_errmsg() functions are set before returning. 8056 */ 8057 SQLITE_API int sqlite3_blob_close(sqlite3_blob *); 8058 8059 /* 8060 ** CAPI3REF: Return The Size Of An Open BLOB 8061 ** METHOD: sqlite3_blob 8062 ** 8063 ** ^Returns the size in bytes of the BLOB accessible via the 8064 ** successfully opened [BLOB handle] in its only argument. ^The 8065 ** incremental blob I/O routines can only read or overwrite existing 8066 ** blob content; they cannot change the size of a blob. 8067 ** 8068 ** This routine only works on a [BLOB handle] which has been created 8069 ** by a prior successful call to [sqlite3_blob_open()] and which has not 8070 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in 8071 ** to this routine results in undefined and probably undesirable behavior. 8072 */ 8073 SQLITE_API int sqlite3_blob_bytes(sqlite3_blob *); 8074 8075 /* 8076 ** CAPI3REF: Read Data From A BLOB Incrementally 8077 ** METHOD: sqlite3_blob 8078 ** 8079 ** ^(This function is used to read data from an open [BLOB handle] into a 8080 ** caller-supplied buffer. N bytes of data are copied into buffer Z 8081 ** from the open BLOB, starting at offset iOffset.)^ 8082 ** 8083 ** ^If offset iOffset is less than N bytes from the end of the BLOB, 8084 ** [SQLITE_ERROR] is returned and no data is read. ^If N or iOffset is 8085 ** less than zero, [SQLITE_ERROR] is returned and no data is read. 8086 ** ^The size of the blob (and hence the maximum value of N+iOffset) 8087 ** can be determined using the [sqlite3_blob_bytes()] interface. 8088 ** 8089 ** ^An attempt to read from an expired [BLOB handle] fails with an 8090 ** error code of [SQLITE_ABORT]. 8091 ** 8092 ** ^(On success, sqlite3_blob_read() returns SQLITE_OK. 8093 ** Otherwise, an [error code] or an [extended error code] is returned.)^ 8094 ** 8095 ** This routine only works on a [BLOB handle] which has been created 8096 ** by a prior successful call to [sqlite3_blob_open()] and which has not 8097 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in 8098 ** to this routine results in undefined and probably undesirable behavior. 8099 ** 8100 ** See also: [sqlite3_blob_write()]. 8101 */ 8102 SQLITE_API int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset); 8103 8104 /* 8105 ** CAPI3REF: Write Data Into A BLOB Incrementally 8106 ** METHOD: sqlite3_blob 8107 ** 8108 ** ^(This function is used to write data into an open [BLOB handle] from a 8109 ** caller-supplied buffer. N bytes of data are copied from the buffer Z 8110 ** into the open BLOB, starting at offset iOffset.)^ 8111 ** 8112 ** ^(On success, sqlite3_blob_write() returns SQLITE_OK. 8113 ** Otherwise, an [error code] or an [extended error code] is returned.)^ 8114 ** ^Unless SQLITE_MISUSE is returned, this function sets the 8115 ** [database connection] error code and message accessible via 8116 ** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions. 8117 ** 8118 ** ^If the [BLOB handle] passed as the first argument was not opened for 8119 ** writing (the flags parameter to [sqlite3_blob_open()] was zero), 8120 ** this function returns [SQLITE_READONLY]. 8121 ** 8122 ** This function may only modify the contents of the BLOB; it is 8123 ** not possible to increase the size of a BLOB using this API. 8124 ** ^If offset iOffset is less than N bytes from the end of the BLOB, 8125 ** [SQLITE_ERROR] is returned and no data is written. The size of the 8126 ** BLOB (and hence the maximum value of N+iOffset) can be determined 8127 ** using the [sqlite3_blob_bytes()] interface. ^If N or iOffset are less 8128 ** than zero [SQLITE_ERROR] is returned and no data is written. 8129 ** 8130 ** ^An attempt to write to an expired [BLOB handle] fails with an 8131 ** error code of [SQLITE_ABORT]. ^Writes to the BLOB that occurred 8132 ** before the [BLOB handle] expired are not rolled back by the 8133 ** expiration of the handle, though of course those changes might 8134 ** have been overwritten by the statement that expired the BLOB handle 8135 ** or by other independent statements. 8136 ** 8137 ** This routine only works on a [BLOB handle] which has been created 8138 ** by a prior successful call to [sqlite3_blob_open()] and which has not 8139 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in 8140 ** to this routine results in undefined and probably undesirable behavior. 8141 ** 8142 ** See also: [sqlite3_blob_read()]. 8143 */ 8144 SQLITE_API int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset); 8145 8146 /* 8147 ** CAPI3REF: Virtual File System Objects 8148 ** 8149 ** A virtual filesystem (VFS) is an [sqlite3_vfs] object 8150 ** that SQLite uses to interact 8151 ** with the underlying operating system. Most SQLite builds come with a 8152 ** single default VFS that is appropriate for the host computer. 8153 ** New VFSes can be registered and existing VFSes can be unregistered. 8154 ** The following interfaces are provided. 8155 ** 8156 ** ^The sqlite3_vfs_find() interface returns a pointer to a VFS given its name. 8157 ** ^Names are case sensitive. 8158 ** ^Names are zero-terminated UTF-8 strings. 8159 ** ^If there is no match, a NULL pointer is returned. 8160 ** ^If zVfsName is NULL then the default VFS is returned. 8161 ** 8162 ** ^New VFSes are registered with sqlite3_vfs_register(). 8163 ** ^Each new VFS becomes the default VFS if the makeDflt flag is set. 8164 ** ^The same VFS can be registered multiple times without injury. 8165 ** ^To make an existing VFS into the default VFS, register it again 8166 ** with the makeDflt flag set. If two different VFSes with the 8167 ** same name are registered, the behavior is undefined. If a 8168 ** VFS is registered with a name that is NULL or an empty string, 8169 ** then the behavior is undefined. 8170 ** 8171 ** ^Unregister a VFS with the sqlite3_vfs_unregister() interface. 8172 ** ^(If the default VFS is unregistered, another VFS is chosen as 8173 ** the default. The choice for the new VFS is arbitrary.)^ 8174 */ 8175 SQLITE_API sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName); 8176 SQLITE_API int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt); 8177 SQLITE_API int sqlite3_vfs_unregister(sqlite3_vfs*); 8178 8179 /* 8180 ** CAPI3REF: Mutexes 8181 ** 8182 ** The SQLite core uses these routines for thread 8183 ** synchronization. Though they are intended for internal 8184 ** use by SQLite, code that links against SQLite is 8185 ** permitted to use any of these routines. 8186 ** 8187 ** The SQLite source code contains multiple implementations 8188 ** of these mutex routines. An appropriate implementation 8189 ** is selected automatically at compile-time. The following 8190 ** implementations are available in the SQLite core: 8191 ** 8192 ** <ul> 8193 ** <li> SQLITE_MUTEX_PTHREADS 8194 ** <li> SQLITE_MUTEX_W32 8195 ** <li> SQLITE_MUTEX_NOOP 8196 ** </ul> 8197 ** 8198 ** The SQLITE_MUTEX_NOOP implementation is a set of routines 8199 ** that does no real locking and is appropriate for use in 8200 ** a single-threaded application. The SQLITE_MUTEX_PTHREADS and 8201 ** SQLITE_MUTEX_W32 implementations are appropriate for use on Unix 8202 ** and Windows. 8203 ** 8204 ** If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor 8205 ** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex 8206 ** implementation is included with the library. In this case the 8207 ** application must supply a custom mutex implementation using the 8208 ** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function 8209 ** before calling sqlite3_initialize() or any other public sqlite3_ 8210 ** function that calls sqlite3_initialize(). 8211 ** 8212 ** ^The sqlite3_mutex_alloc() routine allocates a new 8213 ** mutex and returns a pointer to it. ^The sqlite3_mutex_alloc() 8214 ** routine returns NULL if it is unable to allocate the requested 8215 ** mutex. The argument to sqlite3_mutex_alloc() must be one of these 8216 ** integer constants: 8217 ** 8218 ** <ul> 8219 ** <li> SQLITE_MUTEX_FAST 8220 ** <li> SQLITE_MUTEX_RECURSIVE 8221 ** <li> SQLITE_MUTEX_STATIC_MAIN 8222 ** <li> SQLITE_MUTEX_STATIC_MEM 8223 ** <li> SQLITE_MUTEX_STATIC_OPEN 8224 ** <li> SQLITE_MUTEX_STATIC_PRNG 8225 ** <li> SQLITE_MUTEX_STATIC_LRU 8226 ** <li> SQLITE_MUTEX_STATIC_PMEM 8227 ** <li> SQLITE_MUTEX_STATIC_APP1 8228 ** <li> SQLITE_MUTEX_STATIC_APP2 8229 ** <li> SQLITE_MUTEX_STATIC_APP3 8230 ** <li> SQLITE_MUTEX_STATIC_VFS1 8231 ** <li> SQLITE_MUTEX_STATIC_VFS2 8232 ** <li> SQLITE_MUTEX_STATIC_VFS3 8233 ** </ul> 8234 ** 8235 ** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) 8236 ** cause sqlite3_mutex_alloc() to create 8237 ** a new mutex. ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE 8238 ** is used but not necessarily so when SQLITE_MUTEX_FAST is used. 8239 ** The mutex implementation does not need to make a distinction 8240 ** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does 8241 ** not want to. SQLite will only request a recursive mutex in 8242 ** cases where it really needs one. If a faster non-recursive mutex 8243 ** implementation is available on the host platform, the mutex subsystem 8244 ** might return such a mutex in response to SQLITE_MUTEX_FAST. 8245 ** 8246 ** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other 8247 ** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return 8248 ** a pointer to a static preexisting mutex. ^Nine static mutexes are 8249 ** used by the current version of SQLite. Future versions of SQLite 8250 ** may add additional static mutexes. Static mutexes are for internal 8251 ** use by SQLite only. Applications that use SQLite mutexes should 8252 ** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or 8253 ** SQLITE_MUTEX_RECURSIVE. 8254 ** 8255 ** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST 8256 ** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc() 8257 ** returns a different mutex on every call. ^For the static 8258 ** mutex types, the same mutex is returned on every call that has 8259 ** the same type number. 8260 ** 8261 ** ^The sqlite3_mutex_free() routine deallocates a previously 8262 ** allocated dynamic mutex. Attempting to deallocate a static 8263 ** mutex results in undefined behavior. 8264 ** 8265 ** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt 8266 ** to enter a mutex. ^If another thread is already within the mutex, 8267 ** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return 8268 ** SQLITE_BUSY. ^The sqlite3_mutex_try() interface returns [SQLITE_OK] 8269 ** upon successful entry. ^(Mutexes created using 8270 ** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread. 8271 ** In such cases, the 8272 ** mutex must be exited an equal number of times before another thread 8273 ** can enter.)^ If the same thread tries to enter any mutex other 8274 ** than an SQLITE_MUTEX_RECURSIVE more than once, the behavior is undefined. 8275 ** 8276 ** ^(Some systems (for example, Windows 95) do not support the operation 8277 ** implemented by sqlite3_mutex_try(). On those systems, sqlite3_mutex_try() 8278 ** will always return SQLITE_BUSY. In most cases the SQLite core only uses 8279 ** sqlite3_mutex_try() as an optimization, so this is acceptable 8280 ** behavior. The exceptions are unix builds that set the 8281 ** SQLITE_ENABLE_SETLK_TIMEOUT build option. In that case a working 8282 ** sqlite3_mutex_try() is required.)^ 8283 ** 8284 ** ^The sqlite3_mutex_leave() routine exits a mutex that was 8285 ** previously entered by the same thread. The behavior 8286 ** is undefined if the mutex is not currently entered by the 8287 ** calling thread or is not currently allocated. 8288 ** 8289 ** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), 8290 ** sqlite3_mutex_leave(), or sqlite3_mutex_free() is a NULL pointer, 8291 ** then any of the four routines behaves as a no-op. 8292 ** 8293 ** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()]. 8294 */ 8295 SQLITE_API sqlite3_mutex *sqlite3_mutex_alloc(int); 8296 SQLITE_API void sqlite3_mutex_free(sqlite3_mutex*); 8297 SQLITE_API void sqlite3_mutex_enter(sqlite3_mutex*); 8298 SQLITE_API int sqlite3_mutex_try(sqlite3_mutex*); 8299 SQLITE_API void sqlite3_mutex_leave(sqlite3_mutex*); 8300 8301 /* 8302 ** CAPI3REF: Mutex Methods Object 8303 ** 8304 ** An instance of this structure defines the low-level routines 8305 ** used to allocate and use mutexes. 8306 ** 8307 ** Usually, the default mutex implementations provided by SQLite are 8308 ** sufficient, however the application has the option of substituting a custom 8309 ** implementation for specialized deployments or systems for which SQLite 8310 ** does not provide a suitable implementation. In this case, the application 8311 ** creates and populates an instance of this structure to pass 8312 ** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option. 8313 ** Additionally, an instance of this structure can be used as an 8314 ** output variable when querying the system for the current mutex 8315 ** implementation, using the [SQLITE_CONFIG_GETMUTEX] option. 8316 ** 8317 ** ^The xMutexInit method defined by this structure is invoked as 8318 ** part of system initialization by the sqlite3_initialize() function. 8319 ** ^The xMutexInit routine is called by SQLite exactly once for each 8320 ** effective call to [sqlite3_initialize()]. 8321 ** 8322 ** ^The xMutexEnd method defined by this structure is invoked as 8323 ** part of system shutdown by the sqlite3_shutdown() function. The 8324 ** implementation of this method is expected to release all outstanding 8325 ** resources obtained by the mutex methods implementation, especially 8326 ** those obtained by the xMutexInit method. ^The xMutexEnd() 8327 ** interface is invoked exactly once for each call to [sqlite3_shutdown()]. 8328 ** 8329 ** ^(The remaining seven methods defined by this structure (xMutexAlloc, 8330 ** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and 8331 ** xMutexNotheld) implement the following interfaces (respectively): 8332 ** 8333 ** <ul> 8334 ** <li> [sqlite3_mutex_alloc()] </li> 8335 ** <li> [sqlite3_mutex_free()] </li> 8336 ** <li> [sqlite3_mutex_enter()] </li> 8337 ** <li> [sqlite3_mutex_try()] </li> 8338 ** <li> [sqlite3_mutex_leave()] </li> 8339 ** <li> [sqlite3_mutex_held()] </li> 8340 ** <li> [sqlite3_mutex_notheld()] </li> 8341 ** </ul>)^ 8342 ** 8343 ** The only difference is that the public sqlite3_XXX functions enumerated 8344 ** above silently ignore any invocations that pass a NULL pointer instead 8345 ** of a valid mutex handle. The implementations of the methods defined 8346 ** by this structure are not required to handle this case. The results 8347 ** of passing a NULL pointer instead of a valid mutex handle are undefined 8348 ** (i.e. it is acceptable to provide an implementation that segfaults if 8349 ** it is passed a NULL pointer). 8350 ** 8351 ** The xMutexInit() method must be threadsafe. It must be harmless to 8352 ** invoke xMutexInit() multiple times within the same process and without 8353 ** intervening calls to xMutexEnd(). Second and subsequent calls to 8354 ** xMutexInit() must be no-ops. 8355 ** 8356 ** xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()] 8357 ** and its associates). Similarly, xMutexAlloc() must not use SQLite memory 8358 ** allocation for a static mutex. ^However xMutexAlloc() may use SQLite 8359 ** memory allocation for a fast or recursive mutex. 8360 ** 8361 ** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is 8362 ** called, but only if the prior call to xMutexInit returned SQLITE_OK. 8363 ** If xMutexInit fails in any way, it is expected to clean up after itself 8364 ** prior to returning. 8365 */ 8366 typedef struct sqlite3_mutex_methods sqlite3_mutex_methods; 8367 struct sqlite3_mutex_methods { 8368 int (*xMutexInit)(void); 8369 int (*xMutexEnd)(void); 8370 sqlite3_mutex *(*xMutexAlloc)(int); 8371 void (*xMutexFree)(sqlite3_mutex *); 8372 void (*xMutexEnter)(sqlite3_mutex *); 8373 int (*xMutexTry)(sqlite3_mutex *); 8374 void (*xMutexLeave)(sqlite3_mutex *); 8375 int (*xMutexHeld)(sqlite3_mutex *); 8376 int (*xMutexNotheld)(sqlite3_mutex *); 8377 }; 8378 8379 /* 8380 ** CAPI3REF: Mutex Verification Routines 8381 ** 8382 ** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines 8383 ** are intended for use inside assert() statements. The SQLite core 8384 ** never uses these routines except inside an assert() and applications 8385 ** are advised to follow the lead of the core. The SQLite core only 8386 ** provides implementations for these routines when it is compiled 8387 ** with the SQLITE_DEBUG flag. External mutex implementations 8388 ** are only required to provide these routines if SQLITE_DEBUG is 8389 ** defined and if NDEBUG is not defined. 8390 ** 8391 ** These routines should return true if the mutex in their argument 8392 ** is held or not held, respectively, by the calling thread. 8393 ** 8394 ** The implementation is not required to provide versions of these 8395 ** routines that actually work. If the implementation does not provide working 8396 ** versions of these routines, it should at least provide stubs that always 8397 ** return true so that one does not get spurious assertion failures. 8398 ** 8399 ** If the argument to sqlite3_mutex_held() is a NULL pointer then 8400 ** the routine should return 1. This seems counter-intuitive since 8401 ** clearly the mutex cannot be held if it does not exist. But 8402 ** the reason the mutex does not exist is because the build is not 8403 ** using mutexes. And we do not want the assert() containing the 8404 ** call to sqlite3_mutex_held() to fail, so a non-zero return is 8405 ** the appropriate thing to do. The sqlite3_mutex_notheld() 8406 ** interface should also return 1 when given a NULL pointer. 8407 */ 8408 #ifndef NDEBUG 8409 SQLITE_API int sqlite3_mutex_held(sqlite3_mutex*); 8410 SQLITE_API int sqlite3_mutex_notheld(sqlite3_mutex*); 8411 #endif 8412 8413 /* 8414 ** CAPI3REF: Mutex Types 8415 ** 8416 ** The [sqlite3_mutex_alloc()] interface takes a single argument 8417 ** which is one of these integer constants. 8418 ** 8419 ** The set of static mutexes may change from one SQLite release to the 8420 ** next. Applications that override the built-in mutex logic must be 8421 ** prepared to accommodate additional static mutexes. 8422 */ 8423 #define SQLITE_MUTEX_FAST 0 8424 #define SQLITE_MUTEX_RECURSIVE 1 8425 #define SQLITE_MUTEX_STATIC_MAIN 2 8426 #define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */ 8427 #define SQLITE_MUTEX_STATIC_MEM2 4 /* NOT USED */ 8428 #define SQLITE_MUTEX_STATIC_OPEN 4 /* sqlite3BtreeOpen() */ 8429 #define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_randomness() */ 8430 #define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */ 8431 #define SQLITE_MUTEX_STATIC_LRU2 7 /* NOT USED */ 8432 #define SQLITE_MUTEX_STATIC_PMEM 7 /* sqlite3PageMalloc() */ 8433 #define SQLITE_MUTEX_STATIC_APP1 8 /* For use by application */ 8434 #define SQLITE_MUTEX_STATIC_APP2 9 /* For use by application */ 8435 #define SQLITE_MUTEX_STATIC_APP3 10 /* For use by application */ 8436 #define SQLITE_MUTEX_STATIC_VFS1 11 /* For use by built-in VFS */ 8437 #define SQLITE_MUTEX_STATIC_VFS2 12 /* For use by extension VFS */ 8438 #define SQLITE_MUTEX_STATIC_VFS3 13 /* For use by application VFS */ 8439 8440 /* Legacy compatibility: */ 8441 #define SQLITE_MUTEX_STATIC_MASTER 2 8442 8443 8444 /* 8445 ** CAPI3REF: Retrieve the mutex for a database connection 8446 ** METHOD: sqlite3 8447 ** 8448 ** ^This interface returns a pointer to the [sqlite3_mutex] object that 8449 ** serializes access to the [database connection] given in the argument 8450 ** when the [threading mode] is Serialized. 8451 ** ^If the [threading mode] is Single-thread or Multi-thread then this 8452 ** routine returns a NULL pointer. 8453 */ 8454 SQLITE_API sqlite3_mutex *sqlite3_db_mutex(sqlite3*); 8455 8456 /* 8457 ** CAPI3REF: Low-Level Control Of Database Files 8458 ** METHOD: sqlite3 8459 ** KEYWORDS: {file control} 8460 ** 8461 ** ^The [sqlite3_file_control()] interface makes a direct call to the 8462 ** xFileControl method for the [sqlite3_io_methods] object associated 8463 ** with a particular database identified by the second argument. ^The 8464 ** name of the database is "main" for the main database or "temp" for the 8465 ** TEMP database, or the name that appears after the AS keyword for 8466 ** databases that are added using the [ATTACH] SQL command. 8467 ** ^A NULL pointer can be used in place of "main" to refer to the 8468 ** main database file. 8469 ** ^The third and fourth parameters to this routine 8470 ** are passed directly through to the second and third parameters of 8471 ** the xFileControl method. ^The return value of the xFileControl 8472 ** method becomes the return value of this routine. 8473 ** 8474 ** A few opcodes for [sqlite3_file_control()] are handled directly 8475 ** by the SQLite core and never invoke the 8476 ** sqlite3_io_methods.xFileControl method. 8477 ** ^The [SQLITE_FCNTL_FILE_POINTER] value for the op parameter causes 8478 ** a pointer to the underlying [sqlite3_file] object to be written into 8479 ** the space pointed to by the 4th parameter. The 8480 ** [SQLITE_FCNTL_JOURNAL_POINTER] works similarly except that it returns 8481 ** the [sqlite3_file] object associated with the journal file instead of 8482 ** the main database. The [SQLITE_FCNTL_VFS_POINTER] opcode returns 8483 ** a pointer to the underlying [sqlite3_vfs] object for the file. 8484 ** The [SQLITE_FCNTL_DATA_VERSION] returns the data version counter 8485 ** from the pager. 8486 ** 8487 ** ^If the second parameter (zDbName) does not match the name of any 8488 ** open database file, then SQLITE_ERROR is returned. ^This error 8489 ** code is not remembered and will not be recalled by [sqlite3_errcode()] 8490 ** or [sqlite3_errmsg()]. The underlying xFileControl method might 8491 ** also return SQLITE_ERROR. There is no way to distinguish between 8492 ** an incorrect zDbName and an SQLITE_ERROR return from the underlying 8493 ** xFileControl method. 8494 ** 8495 ** See also: [file control opcodes] 8496 */ 8497 SQLITE_API int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*); 8498 8499 /* 8500 ** CAPI3REF: Testing Interface 8501 ** 8502 ** ^The sqlite3_test_control() interface is used to read out internal 8503 ** state of SQLite and to inject faults into SQLite for testing 8504 ** purposes. ^The first parameter is an operation code that determines 8505 ** the number, meaning, and operation of all subsequent parameters. 8506 ** 8507 ** This interface is not for use by applications. It exists solely 8508 ** for verifying the correct operation of the SQLite library. Depending 8509 ** on how the SQLite library is compiled, this interface might not exist. 8510 ** 8511 ** The details of the operation codes, their meanings, the parameters 8512 ** they take, and what they do are all subject to change without notice. 8513 ** Unlike most of the SQLite API, this function is not guaranteed to 8514 ** operate consistently from one release to the next. 8515 */ 8516 SQLITE_API int sqlite3_test_control(int op, ...); 8517 8518 /* 8519 ** CAPI3REF: Testing Interface Operation Codes 8520 ** 8521 ** These constants are the valid operation code parameters used 8522 ** as the first argument to [sqlite3_test_control()]. 8523 ** 8524 ** These parameters and their meanings are subject to change 8525 ** without notice. These values are for testing purposes only. 8526 ** Applications should not use any of these parameters or the 8527 ** [sqlite3_test_control()] interface. 8528 */ 8529 #define SQLITE_TESTCTRL_FIRST 5 8530 #define SQLITE_TESTCTRL_PRNG_SAVE 5 8531 #define SQLITE_TESTCTRL_PRNG_RESTORE 6 8532 #define SQLITE_TESTCTRL_PRNG_RESET 7 /* NOT USED */ 8533 #define SQLITE_TESTCTRL_FK_NO_ACTION 7 8534 #define SQLITE_TESTCTRL_BITVEC_TEST 8 8535 #define SQLITE_TESTCTRL_FAULT_INSTALL 9 8536 #define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS 10 8537 #define SQLITE_TESTCTRL_PENDING_BYTE 11 8538 #define SQLITE_TESTCTRL_ASSERT 12 8539 #define SQLITE_TESTCTRL_ALWAYS 13 8540 #define SQLITE_TESTCTRL_RESERVE 14 /* NOT USED */ 8541 #define SQLITE_TESTCTRL_JSON_SELFCHECK 14 8542 #define SQLITE_TESTCTRL_OPTIMIZATIONS 15 8543 #define SQLITE_TESTCTRL_ISKEYWORD 16 /* NOT USED */ 8544 #define SQLITE_TESTCTRL_GETOPT 16 8545 #define SQLITE_TESTCTRL_SCRATCHMALLOC 17 /* NOT USED */ 8546 #define SQLITE_TESTCTRL_INTERNAL_FUNCTIONS 17 8547 #define SQLITE_TESTCTRL_LOCALTIME_FAULT 18 8548 #define SQLITE_TESTCTRL_EXPLAIN_STMT 19 /* NOT USED */ 8549 #define SQLITE_TESTCTRL_ONCE_RESET_THRESHOLD 19 8550 #define SQLITE_TESTCTRL_NEVER_CORRUPT 20 8551 #define SQLITE_TESTCTRL_VDBE_COVERAGE 21 8552 #define SQLITE_TESTCTRL_BYTEORDER 22 8553 #define SQLITE_TESTCTRL_ISINIT 23 8554 #define SQLITE_TESTCTRL_SORTER_MMAP 24 8555 #define SQLITE_TESTCTRL_IMPOSTER 25 8556 #define SQLITE_TESTCTRL_PARSER_COVERAGE 26 8557 #define SQLITE_TESTCTRL_RESULT_INTREAL 27 8558 #define SQLITE_TESTCTRL_PRNG_SEED 28 8559 #define SQLITE_TESTCTRL_EXTRA_SCHEMA_CHECKS 29 8560 #define SQLITE_TESTCTRL_SEEK_COUNT 30 8561 #define SQLITE_TESTCTRL_TRACEFLAGS 31 8562 #define SQLITE_TESTCTRL_TUNE 32 8563 #define SQLITE_TESTCTRL_LOGEST 33 8564 #define SQLITE_TESTCTRL_USELONGDOUBLE 34 /* NOT USED */ 8565 #define SQLITE_TESTCTRL_LAST 34 /* Largest TESTCTRL */ 8566 8567 /* 8568 ** CAPI3REF: SQL Keyword Checking 8569 ** 8570 ** These routines provide access to the set of SQL language keywords 8571 ** recognized by SQLite. Applications can use these routines to determine 8572 ** whether or not a specific identifier needs to be escaped (for example, 8573 ** by enclosing in double-quotes) so as not to confuse the parser. 8574 ** 8575 ** The sqlite3_keyword_count() interface returns the number of distinct 8576 ** keywords understood by SQLite. 8577 ** 8578 ** The sqlite3_keyword_name(N,Z,L) interface finds the 0-based N-th keyword and 8579 ** makes *Z point to that keyword expressed as UTF8 and writes the number 8580 ** of bytes in the keyword into *L. The string that *Z points to is not 8581 ** zero-terminated. The sqlite3_keyword_name(N,Z,L) routine returns 8582 ** SQLITE_OK if N is within bounds and SQLITE_ERROR if not. If either Z 8583 ** or L are NULL or invalid pointers then calls to 8584 ** sqlite3_keyword_name(N,Z,L) result in undefined behavior. 8585 ** 8586 ** The sqlite3_keyword_check(Z,L) interface checks to see whether or not 8587 ** the L-byte UTF8 identifier that Z points to is a keyword, returning non-zero 8588 ** if it is and zero if not. 8589 ** 8590 ** The parser used by SQLite is forgiving. It is often possible to use 8591 ** a keyword as an identifier as long as such use does not result in a 8592 ** parsing ambiguity. For example, the statement 8593 ** "CREATE TABLE BEGIN(REPLACE,PRAGMA,END);" is accepted by SQLite, and 8594 ** creates a new table named "BEGIN" with three columns named 8595 ** "REPLACE", "PRAGMA", and "END". Nevertheless, best practice is to avoid 8596 ** using keywords as identifiers. Common techniques used to avoid keyword 8597 ** name collisions include: 8598 ** <ul> 8599 ** <li> Put all identifier names inside double-quotes. This is the official 8600 ** SQL way to escape identifier names. 8601 ** <li> Put identifier names inside [...]. This is not standard SQL, 8602 ** but it is what SQL Server does and so lots of programmers use this 8603 ** technique. 8604 ** <li> Begin every identifier with the letter "Z" as no SQL keywords start 8605 ** with "Z". 8606 ** <li> Include a digit somewhere in every identifier name. 8607 ** </ul> 8608 ** 8609 ** Note that the number of keywords understood by SQLite can depend on 8610 ** compile-time options. For example, "VACUUM" is not a keyword if 8611 ** SQLite is compiled with the [-DSQLITE_OMIT_VACUUM] option. Also, 8612 ** new keywords may be added to future releases of SQLite. 8613 */ 8614 SQLITE_API int sqlite3_keyword_count(void); 8615 SQLITE_API int sqlite3_keyword_name(int,const char**,int*); 8616 SQLITE_API int sqlite3_keyword_check(const char*,int); 8617 8618 /* 8619 ** CAPI3REF: Dynamic String Object 8620 ** KEYWORDS: {dynamic string} 8621 ** 8622 ** An instance of the sqlite3_str object contains a dynamically-sized 8623 ** string under construction. 8624 ** 8625 ** The lifecycle of an sqlite3_str object is as follows: 8626 ** <ol> 8627 ** <li> ^The sqlite3_str object is created using [sqlite3_str_new()]. 8628 ** <li> ^Text is appended to the sqlite3_str object using various 8629 ** methods, such as [sqlite3_str_appendf()]. 8630 ** <li> ^The sqlite3_str object is destroyed and the string it created 8631 ** is returned using the [sqlite3_str_finish()] interface. 8632 ** </ol> 8633 */ 8634 typedef struct sqlite3_str sqlite3_str; 8635 8636 /* 8637 ** CAPI3REF: Create A New Dynamic String Object 8638 ** CONSTRUCTOR: sqlite3_str 8639 ** 8640 ** ^The [sqlite3_str_new(D)] interface allocates and initializes 8641 ** a new [sqlite3_str] object. To avoid memory leaks, the object returned by 8642 ** [sqlite3_str_new()] must be freed by a subsequent call to 8643 ** [sqlite3_str_finish(X)]. 8644 ** 8645 ** ^The [sqlite3_str_new(D)] interface always returns a pointer to a 8646 ** valid [sqlite3_str] object, though in the event of an out-of-memory 8647 ** error the returned object might be a special singleton that will 8648 ** silently reject new text, always return SQLITE_NOMEM from 8649 ** [sqlite3_str_errcode()], always return 0 for 8650 ** [sqlite3_str_length()], and always return NULL from 8651 ** [sqlite3_str_finish(X)]. It is always safe to use the value 8652 ** returned by [sqlite3_str_new(D)] as the sqlite3_str parameter 8653 ** to any of the other [sqlite3_str] methods. 8654 ** 8655 ** The D parameter to [sqlite3_str_new(D)] may be NULL. If the 8656 ** D parameter in [sqlite3_str_new(D)] is not NULL, then the maximum 8657 ** length of the string contained in the [sqlite3_str] object will be 8658 ** the value set for [sqlite3_limit](D,[SQLITE_LIMIT_LENGTH]) instead 8659 ** of [SQLITE_MAX_LENGTH]. 8660 */ 8661 SQLITE_API sqlite3_str *sqlite3_str_new(sqlite3*); 8662 8663 /* 8664 ** CAPI3REF: Finalize A Dynamic String 8665 ** DESTRUCTOR: sqlite3_str 8666 ** 8667 ** ^The [sqlite3_str_finish(X)] interface destroys the sqlite3_str object X 8668 ** and returns a pointer to a memory buffer obtained from [sqlite3_malloc64()] 8669 ** that contains the constructed string. The calling application should 8670 ** pass the returned value to [sqlite3_free()] to avoid a memory leak. 8671 ** ^The [sqlite3_str_finish(X)] interface may return a NULL pointer if any 8672 ** errors were encountered during construction of the string. ^The 8673 ** [sqlite3_str_finish(X)] interface will also return a NULL pointer if the 8674 ** string in [sqlite3_str] object X is zero bytes long. 8675 */ 8676 SQLITE_API char *sqlite3_str_finish(sqlite3_str*); 8677 8678 /* 8679 ** CAPI3REF: Add Content To A Dynamic String 8680 ** METHOD: sqlite3_str 8681 ** 8682 ** These interfaces add content to an sqlite3_str object previously obtained 8683 ** from [sqlite3_str_new()]. 8684 ** 8685 ** ^The [sqlite3_str_appendf(X,F,...)] and 8686 ** [sqlite3_str_vappendf(X,F,V)] interfaces uses the [built-in printf] 8687 ** functionality of SQLite to append formatted text onto the end of 8688 ** [sqlite3_str] object X. 8689 ** 8690 ** ^The [sqlite3_str_append(X,S,N)] method appends exactly N bytes from string S 8691 ** onto the end of the [sqlite3_str] object X. N must be non-negative. 8692 ** S must contain at least N non-zero bytes of content. To append a 8693 ** zero-terminated string in its entirety, use the [sqlite3_str_appendall()] 8694 ** method instead. 8695 ** 8696 ** ^The [sqlite3_str_appendall(X,S)] method appends the complete content of 8697 ** zero-terminated string S onto the end of [sqlite3_str] object X. 8698 ** 8699 ** ^The [sqlite3_str_appendchar(X,N,C)] method appends N copies of the 8700 ** single-byte character C onto the end of [sqlite3_str] object X. 8701 ** ^This method can be used, for example, to add whitespace indentation. 8702 ** 8703 ** ^The [sqlite3_str_reset(X)] method resets the string under construction 8704 ** inside [sqlite3_str] object X back to zero bytes in length. 8705 ** 8706 ** These methods do not return a result code. ^If an error occurs, that fact 8707 ** is recorded in the [sqlite3_str] object and can be recovered by a 8708 ** subsequent call to [sqlite3_str_errcode(X)]. 8709 */ 8710 SQLITE_API void sqlite3_str_appendf(sqlite3_str*, const char *zFormat, ...); 8711 SQLITE_API void sqlite3_str_vappendf(sqlite3_str*, const char *zFormat, va_list); 8712 SQLITE_API void sqlite3_str_append(sqlite3_str*, const char *zIn, int N); 8713 SQLITE_API void sqlite3_str_appendall(sqlite3_str*, const char *zIn); 8714 SQLITE_API void sqlite3_str_appendchar(sqlite3_str*, int N, char C); 8715 SQLITE_API void sqlite3_str_reset(sqlite3_str*); 8716 8717 /* 8718 ** CAPI3REF: Status Of A Dynamic String 8719 ** METHOD: sqlite3_str 8720 ** 8721 ** These interfaces return the current status of an [sqlite3_str] object. 8722 ** 8723 ** ^If any prior errors have occurred while constructing the dynamic string 8724 ** in sqlite3_str X, then the [sqlite3_str_errcode(X)] method will return 8725 ** an appropriate error code. ^The [sqlite3_str_errcode(X)] method returns 8726 ** [SQLITE_NOMEM] following any out-of-memory error, or 8727 ** [SQLITE_TOOBIG] if the size of the dynamic string exceeds 8728 ** [SQLITE_MAX_LENGTH], or [SQLITE_OK] if there have been no errors. 8729 ** 8730 ** ^The [sqlite3_str_length(X)] method returns the current length, in bytes, 8731 ** of the dynamic string under construction in [sqlite3_str] object X. 8732 ** ^The length returned by [sqlite3_str_length(X)] does not include the 8733 ** zero-termination byte. 8734 ** 8735 ** ^The [sqlite3_str_value(X)] method returns a pointer to the current 8736 ** content of the dynamic string under construction in X. The value 8737 ** returned by [sqlite3_str_value(X)] is managed by the sqlite3_str object X 8738 ** and might be freed or altered by any subsequent method on the same 8739 ** [sqlite3_str] object. Applications must not use the pointer returned by 8740 ** [sqlite3_str_value(X)] after any subsequent method call on the same 8741 ** object. ^Applications may change the content of the string returned 8742 ** by [sqlite3_str_value(X)] as long as they do not write into any bytes 8743 ** outside the range of 0 to [sqlite3_str_length(X)] and do not read or 8744 ** write any byte after any subsequent sqlite3_str method call. 8745 */ 8746 SQLITE_API int sqlite3_str_errcode(sqlite3_str*); 8747 SQLITE_API int sqlite3_str_length(sqlite3_str*); 8748 SQLITE_API char *sqlite3_str_value(sqlite3_str*); 8749 8750 /* 8751 ** CAPI3REF: SQLite Runtime Status 8752 ** 8753 ** ^These interfaces are used to retrieve runtime status information 8754 ** about the performance of SQLite, and optionally to reset various 8755 ** highwater marks. ^The first argument is an integer code for 8756 ** the specific parameter to measure. ^(Recognized integer codes 8757 ** are of the form [status parameters | SQLITE_STATUS_...].)^ 8758 ** ^The current value of the parameter is returned into *pCurrent. 8759 ** ^The highest recorded value is returned in *pHighwater. ^If the 8760 ** resetFlag is true, then the highest record value is reset after 8761 ** *pHighwater is written. ^(Some parameters do not record the highest 8762 ** value. For those parameters 8763 ** nothing is written into *pHighwater and the resetFlag is ignored.)^ 8764 ** ^(Other parameters record only the highwater mark and not the current 8765 ** value. For these latter parameters nothing is written into *pCurrent.)^ 8766 ** 8767 ** ^The sqlite3_status() and sqlite3_status64() routines return 8768 ** SQLITE_OK on success and a non-zero [error code] on failure. 8769 ** 8770 ** If either the current value or the highwater mark is too large to 8771 ** be represented by a 32-bit integer, then the values returned by 8772 ** sqlite3_status() are undefined. 8773 ** 8774 ** See also: [sqlite3_db_status()] 8775 */ 8776 SQLITE_API int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag); 8777 SQLITE_API int sqlite3_status64( 8778 int op, 8779 sqlite3_int64 *pCurrent, 8780 sqlite3_int64 *pHighwater, 8781 int resetFlag 8782 ); 8783 8784 8785 /* 8786 ** CAPI3REF: Status Parameters 8787 ** KEYWORDS: {status parameters} 8788 ** 8789 ** These integer constants designate various run-time status parameters 8790 ** that can be returned by [sqlite3_status()]. 8791 ** 8792 ** <dl> 8793 ** [[SQLITE_STATUS_MEMORY_USED]] ^(<dt>SQLITE_STATUS_MEMORY_USED</dt> 8794 ** <dd>This parameter is the current amount of memory checked out 8795 ** using [sqlite3_malloc()], either directly or indirectly. The 8796 ** figure includes calls made to [sqlite3_malloc()] by the application 8797 ** and internal memory usage by the SQLite library. Auxiliary page-cache 8798 ** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in 8799 ** this parameter. The amount returned is the sum of the allocation 8800 ** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>)^ 8801 ** 8802 ** [[SQLITE_STATUS_MALLOC_SIZE]] ^(<dt>SQLITE_STATUS_MALLOC_SIZE</dt> 8803 ** <dd>This parameter records the largest memory allocation request 8804 ** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their 8805 ** internal equivalents). Only the value returned in the 8806 ** *pHighwater parameter to [sqlite3_status()] is of interest. 8807 ** The value written into the *pCurrent parameter is undefined.</dd>)^ 8808 ** 8809 ** [[SQLITE_STATUS_MALLOC_COUNT]] ^(<dt>SQLITE_STATUS_MALLOC_COUNT</dt> 8810 ** <dd>This parameter records the number of separate memory allocations 8811 ** currently checked out.</dd>)^ 8812 ** 8813 ** [[SQLITE_STATUS_PAGECACHE_USED]] ^(<dt>SQLITE_STATUS_PAGECACHE_USED</dt> 8814 ** <dd>This parameter returns the number of pages used out of the 8815 ** [pagecache memory allocator] that was configured using 8816 ** [SQLITE_CONFIG_PAGECACHE]. The 8817 ** value returned is in pages, not in bytes.</dd>)^ 8818 ** 8819 ** [[SQLITE_STATUS_PAGECACHE_OVERFLOW]] 8820 ** ^(<dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt> 8821 ** <dd>This parameter returns the number of bytes of page cache 8822 ** allocation which could not be satisfied by the [SQLITE_CONFIG_PAGECACHE] 8823 ** buffer and where forced to overflow to [sqlite3_malloc()]. The 8824 ** returned value includes allocations that overflowed because they 8825 ** were too large (they were larger than the "sz" parameter to 8826 ** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because 8827 ** no space was left in the page cache.</dd>)^ 8828 ** 8829 ** [[SQLITE_STATUS_PAGECACHE_SIZE]] ^(<dt>SQLITE_STATUS_PAGECACHE_SIZE</dt> 8830 ** <dd>This parameter records the largest memory allocation request 8831 ** handed to the [pagecache memory allocator]. Only the value returned in the 8832 ** *pHighwater parameter to [sqlite3_status()] is of interest. 8833 ** The value written into the *pCurrent parameter is undefined.</dd>)^ 8834 ** 8835 ** [[SQLITE_STATUS_SCRATCH_USED]] <dt>SQLITE_STATUS_SCRATCH_USED</dt> 8836 ** <dd>No longer used.</dd> 8837 ** 8838 ** [[SQLITE_STATUS_SCRATCH_OVERFLOW]] ^(<dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt> 8839 ** <dd>No longer used.</dd> 8840 ** 8841 ** [[SQLITE_STATUS_SCRATCH_SIZE]] <dt>SQLITE_STATUS_SCRATCH_SIZE</dt> 8842 ** <dd>No longer used.</dd> 8843 ** 8844 ** [[SQLITE_STATUS_PARSER_STACK]] ^(<dt>SQLITE_STATUS_PARSER_STACK</dt> 8845 ** <dd>The *pHighwater parameter records the deepest parser stack. 8846 ** The *pCurrent value is undefined. The *pHighwater value is only 8847 ** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>)^ 8848 ** </dl> 8849 ** 8850 ** New status parameters may be added from time to time. 8851 */ 8852 #define SQLITE_STATUS_MEMORY_USED 0 8853 #define SQLITE_STATUS_PAGECACHE_USED 1 8854 #define SQLITE_STATUS_PAGECACHE_OVERFLOW 2 8855 #define SQLITE_STATUS_SCRATCH_USED 3 /* NOT USED */ 8856 #define SQLITE_STATUS_SCRATCH_OVERFLOW 4 /* NOT USED */ 8857 #define SQLITE_STATUS_MALLOC_SIZE 5 8858 #define SQLITE_STATUS_PARSER_STACK 6 8859 #define SQLITE_STATUS_PAGECACHE_SIZE 7 8860 #define SQLITE_STATUS_SCRATCH_SIZE 8 /* NOT USED */ 8861 #define SQLITE_STATUS_MALLOC_COUNT 9 8862 8863 /* 8864 ** CAPI3REF: Database Connection Status 8865 ** METHOD: sqlite3 8866 ** 8867 ** ^This interface is used to retrieve runtime status information 8868 ** about a single [database connection]. ^The first argument is the 8869 ** database connection object to be interrogated. ^The second argument 8870 ** is an integer constant, taken from the set of 8871 ** [SQLITE_DBSTATUS options], that 8872 ** determines the parameter to interrogate. The set of 8873 ** [SQLITE_DBSTATUS options] is likely 8874 ** to grow in future releases of SQLite. 8875 ** 8876 ** ^The current value of the requested parameter is written into *pCur 8877 ** and the highest instantaneous value is written into *pHiwtr. ^If 8878 ** the resetFlg is true, then the highest instantaneous value is 8879 ** reset back down to the current value. 8880 ** 8881 ** ^The sqlite3_db_status() routine returns SQLITE_OK on success and a 8882 ** non-zero [error code] on failure. 8883 ** 8884 ** See also: [sqlite3_status()] and [sqlite3_stmt_status()]. 8885 */ 8886 SQLITE_API int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg); 8887 8888 /* 8889 ** CAPI3REF: Status Parameters for database connections 8890 ** KEYWORDS: {SQLITE_DBSTATUS options} 8891 ** 8892 ** These constants are the available integer "verbs" that can be passed as 8893 ** the second argument to the [sqlite3_db_status()] interface. 8894 ** 8895 ** New verbs may be added in future releases of SQLite. Existing verbs 8896 ** might be discontinued. Applications should check the return code from 8897 ** [sqlite3_db_status()] to make sure that the call worked. 8898 ** The [sqlite3_db_status()] interface will return a non-zero error code 8899 ** if a discontinued or unsupported verb is invoked. 8900 ** 8901 ** <dl> 8902 ** [[SQLITE_DBSTATUS_LOOKASIDE_USED]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt> 8903 ** <dd>This parameter returns the number of lookaside memory slots currently 8904 ** checked out.</dd>)^ 8905 ** 8906 ** [[SQLITE_DBSTATUS_LOOKASIDE_HIT]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_HIT</dt> 8907 ** <dd>This parameter returns the number of malloc attempts that were 8908 ** satisfied using lookaside memory. Only the high-water value is meaningful; 8909 ** the current value is always zero.</dd>)^ 8910 ** 8911 ** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE]] 8912 ** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE</dt> 8913 ** <dd>This parameter returns the number of malloc attempts that might have 8914 ** been satisfied using lookaside memory but failed due to the amount of 8915 ** memory requested being larger than the lookaside slot size. 8916 ** Only the high-water value is meaningful; 8917 ** the current value is always zero.</dd>)^ 8918 ** 8919 ** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL]] 8920 ** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL</dt> 8921 ** <dd>This parameter returns the number of malloc attempts that might have 8922 ** been satisfied using lookaside memory but failed due to all lookaside 8923 ** memory already being in use. 8924 ** Only the high-water value is meaningful; 8925 ** the current value is always zero.</dd>)^ 8926 ** 8927 ** [[SQLITE_DBSTATUS_CACHE_USED]] ^(<dt>SQLITE_DBSTATUS_CACHE_USED</dt> 8928 ** <dd>This parameter returns the approximate number of bytes of heap 8929 ** memory used by all pager caches associated with the database connection.)^ 8930 ** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0. 8931 ** </dd> 8932 ** 8933 ** [[SQLITE_DBSTATUS_CACHE_USED_SHARED]] 8934 ** ^(<dt>SQLITE_DBSTATUS_CACHE_USED_SHARED</dt> 8935 ** <dd>This parameter is similar to DBSTATUS_CACHE_USED, except that if a 8936 ** pager cache is shared between two or more connections the bytes of heap 8937 ** memory used by that pager cache is divided evenly between the attached 8938 ** connections.)^ In other words, if none of the pager caches associated 8939 ** with the database connection are shared, this request returns the same 8940 ** value as DBSTATUS_CACHE_USED. Or, if one or more of the pager caches are 8941 ** shared, the value returned by this call will be smaller than that returned 8942 ** by DBSTATUS_CACHE_USED. ^The highwater mark associated with 8943 ** SQLITE_DBSTATUS_CACHE_USED_SHARED is always 0.</dd> 8944 ** 8945 ** [[SQLITE_DBSTATUS_SCHEMA_USED]] ^(<dt>SQLITE_DBSTATUS_SCHEMA_USED</dt> 8946 ** <dd>This parameter returns the approximate number of bytes of heap 8947 ** memory used to store the schema for all databases associated 8948 ** with the connection - main, temp, and any [ATTACH]-ed databases.)^ 8949 ** ^The full amount of memory used by the schemas is reported, even if the 8950 ** schema memory is shared with other database connections due to 8951 ** [shared cache mode] being enabled. 8952 ** ^The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0. 8953 ** </dd> 8954 ** 8955 ** [[SQLITE_DBSTATUS_STMT_USED]] ^(<dt>SQLITE_DBSTATUS_STMT_USED</dt> 8956 ** <dd>This parameter returns the approximate number of bytes of heap 8957 ** and lookaside memory used by all prepared statements associated with 8958 ** the database connection.)^ 8959 ** ^The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0. 8960 ** </dd> 8961 ** 8962 ** [[SQLITE_DBSTATUS_CACHE_HIT]] ^(<dt>SQLITE_DBSTATUS_CACHE_HIT</dt> 8963 ** <dd>This parameter returns the number of pager cache hits that have 8964 ** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_HIT 8965 ** is always 0. 8966 ** </dd> 8967 ** 8968 ** [[SQLITE_DBSTATUS_CACHE_MISS]] ^(<dt>SQLITE_DBSTATUS_CACHE_MISS</dt> 8969 ** <dd>This parameter returns the number of pager cache misses that have 8970 ** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_MISS 8971 ** is always 0. 8972 ** </dd> 8973 ** 8974 ** [[SQLITE_DBSTATUS_CACHE_WRITE]] ^(<dt>SQLITE_DBSTATUS_CACHE_WRITE</dt> 8975 ** <dd>This parameter returns the number of dirty cache entries that have 8976 ** been written to disk. Specifically, the number of pages written to the 8977 ** wal file in wal mode databases, or the number of pages written to the 8978 ** database file in rollback mode databases. Any pages written as part of 8979 ** transaction rollback or database recovery operations are not included. 8980 ** If an IO or other error occurs while writing a page to disk, the effect 8981 ** on subsequent SQLITE_DBSTATUS_CACHE_WRITE requests is undefined.)^ ^The 8982 ** highwater mark associated with SQLITE_DBSTATUS_CACHE_WRITE is always 0. 8983 ** </dd> 8984 ** 8985 ** [[SQLITE_DBSTATUS_CACHE_SPILL]] ^(<dt>SQLITE_DBSTATUS_CACHE_SPILL</dt> 8986 ** <dd>This parameter returns the number of dirty cache entries that have 8987 ** been written to disk in the middle of a transaction due to the page 8988 ** cache overflowing. Transactions are more efficient if they are written 8989 ** to disk all at once. When pages spill mid-transaction, that introduces 8990 ** additional overhead. This parameter can be used to help identify 8991 ** inefficiencies that can be resolved by increasing the cache size. 8992 ** </dd> 8993 ** 8994 ** [[SQLITE_DBSTATUS_DEFERRED_FKS]] ^(<dt>SQLITE_DBSTATUS_DEFERRED_FKS</dt> 8995 ** <dd>This parameter returns zero for the current value if and only if 8996 ** all foreign key constraints (deferred or immediate) have been 8997 ** resolved.)^ ^The highwater mark is always 0. 8998 ** </dd> 8999 ** </dl> 9000 */ 9001 #define SQLITE_DBSTATUS_LOOKASIDE_USED 0 9002 #define SQLITE_DBSTATUS_CACHE_USED 1 9003 #define SQLITE_DBSTATUS_SCHEMA_USED 2 9004 #define SQLITE_DBSTATUS_STMT_USED 3 9005 #define SQLITE_DBSTATUS_LOOKASIDE_HIT 4 9006 #define SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE 5 9007 #define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL 6 9008 #define SQLITE_DBSTATUS_CACHE_HIT 7 9009 #define SQLITE_DBSTATUS_CACHE_MISS 8 9010 #define SQLITE_DBSTATUS_CACHE_WRITE 9 9011 #define SQLITE_DBSTATUS_DEFERRED_FKS 10 9012 #define SQLITE_DBSTATUS_CACHE_USED_SHARED 11 9013 #define SQLITE_DBSTATUS_CACHE_SPILL 12 9014 #define SQLITE_DBSTATUS_MAX 12 /* Largest defined DBSTATUS */ 9015 9016 9017 /* 9018 ** CAPI3REF: Prepared Statement Status 9019 ** METHOD: sqlite3_stmt 9020 ** 9021 ** ^(Each prepared statement maintains various 9022 ** [SQLITE_STMTSTATUS counters] that measure the number 9023 ** of times it has performed specific operations.)^ These counters can 9024 ** be used to monitor the performance characteristics of the prepared 9025 ** statements. For example, if the number of table steps greatly exceeds 9026 ** the number of table searches or result rows, that would tend to indicate 9027 ** that the prepared statement is using a full table scan rather than 9028 ** an index. 9029 ** 9030 ** ^(This interface is used to retrieve and reset counter values from 9031 ** a [prepared statement]. The first argument is the prepared statement 9032 ** object to be interrogated. The second argument 9033 ** is an integer code for a specific [SQLITE_STMTSTATUS counter] 9034 ** to be interrogated.)^ 9035 ** ^The current value of the requested counter is returned. 9036 ** ^If the resetFlg is true, then the counter is reset to zero after this 9037 ** interface call returns. 9038 ** 9039 ** See also: [sqlite3_status()] and [sqlite3_db_status()]. 9040 */ 9041 SQLITE_API int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg); 9042 9043 /* 9044 ** CAPI3REF: Status Parameters for prepared statements 9045 ** KEYWORDS: {SQLITE_STMTSTATUS counter} {SQLITE_STMTSTATUS counters} 9046 ** 9047 ** These preprocessor macros define integer codes that name counter 9048 ** values associated with the [sqlite3_stmt_status()] interface. 9049 ** The meanings of the various counters are as follows: 9050 ** 9051 ** <dl> 9052 ** [[SQLITE_STMTSTATUS_FULLSCAN_STEP]] <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt> 9053 ** <dd>^This is the number of times that SQLite has stepped forward in 9054 ** a table as part of a full table scan. Large numbers for this counter 9055 ** may indicate opportunities for performance improvement through 9056 ** careful use of indices.</dd> 9057 ** 9058 ** [[SQLITE_STMTSTATUS_SORT]] <dt>SQLITE_STMTSTATUS_SORT</dt> 9059 ** <dd>^This is the number of sort operations that have occurred. 9060 ** A non-zero value in this counter may indicate an opportunity to 9061 ** improvement performance through careful use of indices.</dd> 9062 ** 9063 ** [[SQLITE_STMTSTATUS_AUTOINDEX]] <dt>SQLITE_STMTSTATUS_AUTOINDEX</dt> 9064 ** <dd>^This is the number of rows inserted into transient indices that 9065 ** were created automatically in order to help joins run faster. 9066 ** A non-zero value in this counter may indicate an opportunity to 9067 ** improvement performance by adding permanent indices that do not 9068 ** need to be reinitialized each time the statement is run.</dd> 9069 ** 9070 ** [[SQLITE_STMTSTATUS_VM_STEP]] <dt>SQLITE_STMTSTATUS_VM_STEP</dt> 9071 ** <dd>^This is the number of virtual machine operations executed 9072 ** by the prepared statement if that number is less than or equal 9073 ** to 2147483647. The number of virtual machine operations can be 9074 ** used as a proxy for the total work done by the prepared statement. 9075 ** If the number of virtual machine operations exceeds 2147483647 9076 ** then the value returned by this statement status code is undefined. 9077 ** 9078 ** [[SQLITE_STMTSTATUS_REPREPARE]] <dt>SQLITE_STMTSTATUS_REPREPARE</dt> 9079 ** <dd>^This is the number of times that the prepare statement has been 9080 ** automatically regenerated due to schema changes or changes to 9081 ** [bound parameters] that might affect the query plan. 9082 ** 9083 ** [[SQLITE_STMTSTATUS_RUN]] <dt>SQLITE_STMTSTATUS_RUN</dt> 9084 ** <dd>^This is the number of times that the prepared statement has 9085 ** been run. A single "run" for the purposes of this counter is one 9086 ** or more calls to [sqlite3_step()] followed by a call to [sqlite3_reset()]. 9087 ** The counter is incremented on the first [sqlite3_step()] call of each 9088 ** cycle. 9089 ** 9090 ** [[SQLITE_STMTSTATUS_FILTER_MISS]] 9091 ** [[SQLITE_STMTSTATUS_FILTER HIT]] 9092 ** <dt>SQLITE_STMTSTATUS_FILTER_HIT<br> 9093 ** SQLITE_STMTSTATUS_FILTER_MISS</dt> 9094 ** <dd>^SQLITE_STMTSTATUS_FILTER_HIT is the number of times that a join 9095 ** step was bypassed because a Bloom filter returned not-found. The 9096 ** corresponding SQLITE_STMTSTATUS_FILTER_MISS value is the number of 9097 ** times that the Bloom filter returned a find, and thus the join step 9098 ** had to be processed as normal. 9099 ** 9100 ** [[SQLITE_STMTSTATUS_MEMUSED]] <dt>SQLITE_STMTSTATUS_MEMUSED</dt> 9101 ** <dd>^This is the approximate number of bytes of heap memory 9102 ** used to store the prepared statement. ^This value is not actually 9103 ** a counter, and so the resetFlg parameter to sqlite3_stmt_status() 9104 ** is ignored when the opcode is SQLITE_STMTSTATUS_MEMUSED. 9105 ** </dd> 9106 ** </dl> 9107 */ 9108 #define SQLITE_STMTSTATUS_FULLSCAN_STEP 1 9109 #define SQLITE_STMTSTATUS_SORT 2 9110 #define SQLITE_STMTSTATUS_AUTOINDEX 3 9111 #define SQLITE_STMTSTATUS_VM_STEP 4 9112 #define SQLITE_STMTSTATUS_REPREPARE 5 9113 #define SQLITE_STMTSTATUS_RUN 6 9114 #define SQLITE_STMTSTATUS_FILTER_MISS 7 9115 #define SQLITE_STMTSTATUS_FILTER_HIT 8 9116 #define SQLITE_STMTSTATUS_MEMUSED 99 9117 9118 /* 9119 ** CAPI3REF: Custom Page Cache Object 9120 ** 9121 ** The sqlite3_pcache type is opaque. It is implemented by 9122 ** the pluggable module. The SQLite core has no knowledge of 9123 ** its size or internal structure and never deals with the 9124 ** sqlite3_pcache object except by holding and passing pointers 9125 ** to the object. 9126 ** 9127 ** See [sqlite3_pcache_methods2] for additional information. 9128 */ 9129 typedef struct sqlite3_pcache sqlite3_pcache; 9130 9131 /* 9132 ** CAPI3REF: Custom Page Cache Object 9133 ** 9134 ** The sqlite3_pcache_page object represents a single page in the 9135 ** page cache. The page cache will allocate instances of this 9136 ** object. Various methods of the page cache use pointers to instances 9137 ** of this object as parameters or as their return value. 9138 ** 9139 ** See [sqlite3_pcache_methods2] for additional information. 9140 */ 9141 typedef struct sqlite3_pcache_page sqlite3_pcache_page; 9142 struct sqlite3_pcache_page { 9143 void *pBuf; /* The content of the page */ 9144 void *pExtra; /* Extra information associated with the page */ 9145 }; 9146 9147 /* 9148 ** CAPI3REF: Application Defined Page Cache. 9149 ** KEYWORDS: {page cache} 9150 ** 9151 ** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE2], ...) interface can 9152 ** register an alternative page cache implementation by passing in an 9153 ** instance of the sqlite3_pcache_methods2 structure.)^ 9154 ** In many applications, most of the heap memory allocated by 9155 ** SQLite is used for the page cache. 9156 ** By implementing a 9157 ** custom page cache using this API, an application can better control 9158 ** the amount of memory consumed by SQLite, the way in which 9159 ** that memory is allocated and released, and the policies used to 9160 ** determine exactly which parts of a database file are cached and for 9161 ** how long. 9162 ** 9163 ** The alternative page cache mechanism is an 9164 ** extreme measure that is only needed by the most demanding applications. 9165 ** The built-in page cache is recommended for most uses. 9166 ** 9167 ** ^(The contents of the sqlite3_pcache_methods2 structure are copied to an 9168 ** internal buffer by SQLite within the call to [sqlite3_config]. Hence 9169 ** the application may discard the parameter after the call to 9170 ** [sqlite3_config()] returns.)^ 9171 ** 9172 ** [[the xInit() page cache method]] 9173 ** ^(The xInit() method is called once for each effective 9174 ** call to [sqlite3_initialize()])^ 9175 ** (usually only once during the lifetime of the process). ^(The xInit() 9176 ** method is passed a copy of the sqlite3_pcache_methods2.pArg value.)^ 9177 ** The intent of the xInit() method is to set up global data structures 9178 ** required by the custom page cache implementation. 9179 ** ^(If the xInit() method is NULL, then the 9180 ** built-in default page cache is used instead of the application defined 9181 ** page cache.)^ 9182 ** 9183 ** [[the xShutdown() page cache method]] 9184 ** ^The xShutdown() method is called by [sqlite3_shutdown()]. 9185 ** It can be used to clean up 9186 ** any outstanding resources before process shutdown, if required. 9187 ** ^The xShutdown() method may be NULL. 9188 ** 9189 ** ^SQLite automatically serializes calls to the xInit method, 9190 ** so the xInit method need not be threadsafe. ^The 9191 ** xShutdown method is only called from [sqlite3_shutdown()] so it does 9192 ** not need to be threadsafe either. All other methods must be threadsafe 9193 ** in multithreaded applications. 9194 ** 9195 ** ^SQLite will never invoke xInit() more than once without an intervening 9196 ** call to xShutdown(). 9197 ** 9198 ** [[the xCreate() page cache methods]] 9199 ** ^SQLite invokes the xCreate() method to construct a new cache instance. 9200 ** SQLite will typically create one cache instance for each open database file, 9201 ** though this is not guaranteed. ^The 9202 ** first parameter, szPage, is the size in bytes of the pages that must 9203 ** be allocated by the cache. ^szPage will always a power of two. ^The 9204 ** second parameter szExtra is a number of bytes of extra storage 9205 ** associated with each page cache entry. ^The szExtra parameter will 9206 ** a number less than 250. SQLite will use the 9207 ** extra szExtra bytes on each page to store metadata about the underlying 9208 ** database page on disk. The value passed into szExtra depends 9209 ** on the SQLite version, the target platform, and how SQLite was compiled. 9210 ** ^The third argument to xCreate(), bPurgeable, is true if the cache being 9211 ** created will be used to cache database pages of a file stored on disk, or 9212 ** false if it is used for an in-memory database. The cache implementation 9213 ** does not have to do anything special based with the value of bPurgeable; 9214 ** it is purely advisory. ^On a cache where bPurgeable is false, SQLite will 9215 ** never invoke xUnpin() except to deliberately delete a page. 9216 ** ^In other words, calls to xUnpin() on a cache with bPurgeable set to 9217 ** false will always have the "discard" flag set to true. 9218 ** ^Hence, a cache created with bPurgeable false will 9219 ** never contain any unpinned pages. 9220 ** 9221 ** [[the xCachesize() page cache method]] 9222 ** ^(The xCachesize() method may be called at any time by SQLite to set the 9223 ** suggested maximum cache-size (number of pages stored by) the cache 9224 ** instance passed as the first argument. This is the value configured using 9225 ** the SQLite "[PRAGMA cache_size]" command.)^ As with the bPurgeable 9226 ** parameter, the implementation is not required to do anything with this 9227 ** value; it is advisory only. 9228 ** 9229 ** [[the xPagecount() page cache methods]] 9230 ** The xPagecount() method must return the number of pages currently 9231 ** stored in the cache, both pinned and unpinned. 9232 ** 9233 ** [[the xFetch() page cache methods]] 9234 ** The xFetch() method locates a page in the cache and returns a pointer to 9235 ** an sqlite3_pcache_page object associated with that page, or a NULL pointer. 9236 ** The pBuf element of the returned sqlite3_pcache_page object will be a 9237 ** pointer to a buffer of szPage bytes used to store the content of a 9238 ** single database page. The pExtra element of sqlite3_pcache_page will be 9239 ** a pointer to the szExtra bytes of extra storage that SQLite has requested 9240 ** for each entry in the page cache. 9241 ** 9242 ** The page to be fetched is determined by the key. ^The minimum key value 9243 ** is 1. After it has been retrieved using xFetch, the page is considered 9244 ** to be "pinned". 9245 ** 9246 ** If the requested page is already in the page cache, then the page cache 9247 ** implementation must return a pointer to the page buffer with its content 9248 ** intact. If the requested page is not already in the cache, then the 9249 ** cache implementation should use the value of the createFlag 9250 ** parameter to help it determined what action to take: 9251 ** 9252 ** <table border=1 width=85% align=center> 9253 ** <tr><th> createFlag <th> Behavior when page is not already in cache 9254 ** <tr><td> 0 <td> Do not allocate a new page. Return NULL. 9255 ** <tr><td> 1 <td> Allocate a new page if it easy and convenient to do so. 9256 ** Otherwise return NULL. 9257 ** <tr><td> 2 <td> Make every effort to allocate a new page. Only return 9258 ** NULL if allocating a new page is effectively impossible. 9259 ** </table> 9260 ** 9261 ** ^(SQLite will normally invoke xFetch() with a createFlag of 0 or 1. SQLite 9262 ** will only use a createFlag of 2 after a prior call with a createFlag of 1 9263 ** failed.)^ In between the xFetch() calls, SQLite may 9264 ** attempt to unpin one or more cache pages by spilling the content of 9265 ** pinned pages to disk and synching the operating system disk cache. 9266 ** 9267 ** [[the xUnpin() page cache method]] 9268 ** ^xUnpin() is called by SQLite with a pointer to a currently pinned page 9269 ** as its second argument. If the third parameter, discard, is non-zero, 9270 ** then the page must be evicted from the cache. 9271 ** ^If the discard parameter is 9272 ** zero, then the page may be discarded or retained at the discretion of 9273 ** page cache implementation. ^The page cache implementation 9274 ** may choose to evict unpinned pages at any time. 9275 ** 9276 ** The cache must not perform any reference counting. A single 9277 ** call to xUnpin() unpins the page regardless of the number of prior calls 9278 ** to xFetch(). 9279 ** 9280 ** [[the xRekey() page cache methods]] 9281 ** The xRekey() method is used to change the key value associated with the 9282 ** page passed as the second argument. If the cache 9283 ** previously contains an entry associated with newKey, it must be 9284 ** discarded. ^Any prior cache entry associated with newKey is guaranteed not 9285 ** to be pinned. 9286 ** 9287 ** When SQLite calls the xTruncate() method, the cache must discard all 9288 ** existing cache entries with page numbers (keys) greater than or equal 9289 ** to the value of the iLimit parameter passed to xTruncate(). If any 9290 ** of these pages are pinned, they are implicitly unpinned, meaning that 9291 ** they can be safely discarded. 9292 ** 9293 ** [[the xDestroy() page cache method]] 9294 ** ^The xDestroy() method is used to delete a cache allocated by xCreate(). 9295 ** All resources associated with the specified cache should be freed. ^After 9296 ** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*] 9297 ** handle invalid, and will not use it with any other sqlite3_pcache_methods2 9298 ** functions. 9299 ** 9300 ** [[the xShrink() page cache method]] 9301 ** ^SQLite invokes the xShrink() method when it wants the page cache to 9302 ** free up as much of heap memory as possible. The page cache implementation 9303 ** is not obligated to free any memory, but well-behaved implementations should 9304 ** do their best. 9305 */ 9306 typedef struct sqlite3_pcache_methods2 sqlite3_pcache_methods2; 9307 struct sqlite3_pcache_methods2 { 9308 int iVersion; 9309 void *pArg; 9310 int (*xInit)(void*); 9311 void (*xShutdown)(void*); 9312 sqlite3_pcache *(*xCreate)(int szPage, int szExtra, int bPurgeable); 9313 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 9314 int (*xPagecount)(sqlite3_pcache*); 9315 sqlite3_pcache_page *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 9316 void (*xUnpin)(sqlite3_pcache*, sqlite3_pcache_page*, int discard); 9317 void (*xRekey)(sqlite3_pcache*, sqlite3_pcache_page*, 9318 unsigned oldKey, unsigned newKey); 9319 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 9320 void (*xDestroy)(sqlite3_pcache*); 9321 void (*xShrink)(sqlite3_pcache*); 9322 }; 9323 9324 /* 9325 ** This is the obsolete pcache_methods object that has now been replaced 9326 ** by sqlite3_pcache_methods2. This object is not used by SQLite. It is 9327 ** retained in the header file for backwards compatibility only. 9328 */ 9329 typedef struct sqlite3_pcache_methods sqlite3_pcache_methods; 9330 struct sqlite3_pcache_methods { 9331 void *pArg; 9332 int (*xInit)(void*); 9333 void (*xShutdown)(void*); 9334 sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable); 9335 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 9336 int (*xPagecount)(sqlite3_pcache*); 9337 void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 9338 void (*xUnpin)(sqlite3_pcache*, void*, int discard); 9339 void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey); 9340 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 9341 void (*xDestroy)(sqlite3_pcache*); 9342 }; 9343 9344 9345 /* 9346 ** CAPI3REF: Online Backup Object 9347 ** 9348 ** The sqlite3_backup object records state information about an ongoing 9349 ** online backup operation. ^The sqlite3_backup object is created by 9350 ** a call to [sqlite3_backup_init()] and is destroyed by a call to 9351 ** [sqlite3_backup_finish()]. 9352 ** 9353 ** See Also: [Using the SQLite Online Backup API] 9354 */ 9355 typedef struct sqlite3_backup sqlite3_backup; 9356 9357 /* 9358 ** CAPI3REF: Online Backup API. 9359 ** 9360 ** The backup API copies the content of one database into another. 9361 ** It is useful either for creating backups of databases or 9362 ** for copying in-memory databases to or from persistent files. 9363 ** 9364 ** See Also: [Using the SQLite Online Backup API] 9365 ** 9366 ** ^SQLite holds a write transaction open on the destination database file 9367 ** for the duration of the backup operation. 9368 ** ^The source database is read-locked only while it is being read; 9369 ** it is not locked continuously for the entire backup operation. 9370 ** ^Thus, the backup may be performed on a live source database without 9371 ** preventing other database connections from 9372 ** reading or writing to the source database while the backup is underway. 9373 ** 9374 ** ^(To perform a backup operation: 9375 ** <ol> 9376 ** <li><b>sqlite3_backup_init()</b> is called once to initialize the 9377 ** backup, 9378 ** <li><b>sqlite3_backup_step()</b> is called one or more times to transfer 9379 ** the data between the two databases, and finally 9380 ** <li><b>sqlite3_backup_finish()</b> is called to release all resources 9381 ** associated with the backup operation. 9382 ** </ol>)^ 9383 ** There should be exactly one call to sqlite3_backup_finish() for each 9384 ** successful call to sqlite3_backup_init(). 9385 ** 9386 ** [[sqlite3_backup_init()]] <b>sqlite3_backup_init()</b> 9387 ** 9388 ** ^The D and N arguments to sqlite3_backup_init(D,N,S,M) are the 9389 ** [database connection] associated with the destination database 9390 ** and the database name, respectively. 9391 ** ^The database name is "main" for the main database, "temp" for the 9392 ** temporary database, or the name specified after the AS keyword in 9393 ** an [ATTACH] statement for an attached database. 9394 ** ^The S and M arguments passed to 9395 ** sqlite3_backup_init(D,N,S,M) identify the [database connection] 9396 ** and database name of the source database, respectively. 9397 ** ^The source and destination [database connections] (parameters S and D) 9398 ** must be different or else sqlite3_backup_init(D,N,S,M) will fail with 9399 ** an error. 9400 ** 9401 ** ^A call to sqlite3_backup_init() will fail, returning NULL, if 9402 ** there is already a read or read-write transaction open on the 9403 ** destination database. 9404 ** 9405 ** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is 9406 ** returned and an error code and error message are stored in the 9407 ** destination [database connection] D. 9408 ** ^The error code and message for the failed call to sqlite3_backup_init() 9409 ** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or 9410 ** [sqlite3_errmsg16()] functions. 9411 ** ^A successful call to sqlite3_backup_init() returns a pointer to an 9412 ** [sqlite3_backup] object. 9413 ** ^The [sqlite3_backup] object may be used with the sqlite3_backup_step() and 9414 ** sqlite3_backup_finish() functions to perform the specified backup 9415 ** operation. 9416 ** 9417 ** [[sqlite3_backup_step()]] <b>sqlite3_backup_step()</b> 9418 ** 9419 ** ^Function sqlite3_backup_step(B,N) will copy up to N pages between 9420 ** the source and destination databases specified by [sqlite3_backup] object B. 9421 ** ^If N is negative, all remaining source pages are copied. 9422 ** ^If sqlite3_backup_step(B,N) successfully copies N pages and there 9423 ** are still more pages to be copied, then the function returns [SQLITE_OK]. 9424 ** ^If sqlite3_backup_step(B,N) successfully finishes copying all pages 9425 ** from source to destination, then it returns [SQLITE_DONE]. 9426 ** ^If an error occurs while running sqlite3_backup_step(B,N), 9427 ** then an [error code] is returned. ^As well as [SQLITE_OK] and 9428 ** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY], 9429 ** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an 9430 ** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code. 9431 ** 9432 ** ^(The sqlite3_backup_step() might return [SQLITE_READONLY] if 9433 ** <ol> 9434 ** <li> the destination database was opened read-only, or 9435 ** <li> the destination database is using write-ahead-log journaling 9436 ** and the destination and source page sizes differ, or 9437 ** <li> the destination database is an in-memory database and the 9438 ** destination and source page sizes differ. 9439 ** </ol>)^ 9440 ** 9441 ** ^If sqlite3_backup_step() cannot obtain a required file-system lock, then 9442 ** the [sqlite3_busy_handler | busy-handler function] 9443 ** is invoked (if one is specified). ^If the 9444 ** busy-handler returns non-zero before the lock is available, then 9445 ** [SQLITE_BUSY] is returned to the caller. ^In this case the call to 9446 ** sqlite3_backup_step() can be retried later. ^If the source 9447 ** [database connection] 9448 ** is being used to write to the source database when sqlite3_backup_step() 9449 ** is called, then [SQLITE_LOCKED] is returned immediately. ^Again, in this 9450 ** case the call to sqlite3_backup_step() can be retried later on. ^(If 9451 ** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or 9452 ** [SQLITE_READONLY] is returned, then 9453 ** there is no point in retrying the call to sqlite3_backup_step(). These 9454 ** errors are considered fatal.)^ The application must accept 9455 ** that the backup operation has failed and pass the backup operation handle 9456 ** to the sqlite3_backup_finish() to release associated resources. 9457 ** 9458 ** ^The first call to sqlite3_backup_step() obtains an exclusive lock 9459 ** on the destination file. ^The exclusive lock is not released until either 9460 ** sqlite3_backup_finish() is called or the backup operation is complete 9461 ** and sqlite3_backup_step() returns [SQLITE_DONE]. ^Every call to 9462 ** sqlite3_backup_step() obtains a [shared lock] on the source database that 9463 ** lasts for the duration of the sqlite3_backup_step() call. 9464 ** ^Because the source database is not locked between calls to 9465 ** sqlite3_backup_step(), the source database may be modified mid-way 9466 ** through the backup process. ^If the source database is modified by an 9467 ** external process or via a database connection other than the one being 9468 ** used by the backup operation, then the backup will be automatically 9469 ** restarted by the next call to sqlite3_backup_step(). ^If the source 9470 ** database is modified by using the same database connection as is used 9471 ** by the backup operation, then the backup database is automatically 9472 ** updated at the same time. 9473 ** 9474 ** [[sqlite3_backup_finish()]] <b>sqlite3_backup_finish()</b> 9475 ** 9476 ** When sqlite3_backup_step() has returned [SQLITE_DONE], or when the 9477 ** application wishes to abandon the backup operation, the application 9478 ** should destroy the [sqlite3_backup] by passing it to sqlite3_backup_finish(). 9479 ** ^The sqlite3_backup_finish() interfaces releases all 9480 ** resources associated with the [sqlite3_backup] object. 9481 ** ^If sqlite3_backup_step() has not yet returned [SQLITE_DONE], then any 9482 ** active write-transaction on the destination database is rolled back. 9483 ** The [sqlite3_backup] object is invalid 9484 ** and may not be used following a call to sqlite3_backup_finish(). 9485 ** 9486 ** ^The value returned by sqlite3_backup_finish is [SQLITE_OK] if no 9487 ** sqlite3_backup_step() errors occurred, regardless of whether or not 9488 ** sqlite3_backup_step() completed. 9489 ** ^If an out-of-memory condition or IO error occurred during any prior 9490 ** sqlite3_backup_step() call on the same [sqlite3_backup] object, then 9491 ** sqlite3_backup_finish() returns the corresponding [error code]. 9492 ** 9493 ** ^A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step() 9494 ** is not a permanent error and does not affect the return value of 9495 ** sqlite3_backup_finish(). 9496 ** 9497 ** [[sqlite3_backup_remaining()]] [[sqlite3_backup_pagecount()]] 9498 ** <b>sqlite3_backup_remaining() and sqlite3_backup_pagecount()</b> 9499 ** 9500 ** ^The sqlite3_backup_remaining() routine returns the number of pages still 9501 ** to be backed up at the conclusion of the most recent sqlite3_backup_step(). 9502 ** ^The sqlite3_backup_pagecount() routine returns the total number of pages 9503 ** in the source database at the conclusion of the most recent 9504 ** sqlite3_backup_step(). 9505 ** ^(The values returned by these functions are only updated by 9506 ** sqlite3_backup_step(). If the source database is modified in a way that 9507 ** changes the size of the source database or the number of pages remaining, 9508 ** those changes are not reflected in the output of sqlite3_backup_pagecount() 9509 ** and sqlite3_backup_remaining() until after the next 9510 ** sqlite3_backup_step().)^ 9511 ** 9512 ** <b>Concurrent Usage of Database Handles</b> 9513 ** 9514 ** ^The source [database connection] may be used by the application for other 9515 ** purposes while a backup operation is underway or being initialized. 9516 ** ^If SQLite is compiled and configured to support threadsafe database 9517 ** connections, then the source database connection may be used concurrently 9518 ** from within other threads. 9519 ** 9520 ** However, the application must guarantee that the destination 9521 ** [database connection] is not passed to any other API (by any thread) after 9522 ** sqlite3_backup_init() is called and before the corresponding call to 9523 ** sqlite3_backup_finish(). SQLite does not currently check to see 9524 ** if the application incorrectly accesses the destination [database connection] 9525 ** and so no error code is reported, but the operations may malfunction 9526 ** nevertheless. Use of the destination database connection while a 9527 ** backup is in progress might also cause a mutex deadlock. 9528 ** 9529 ** If running in [shared cache mode], the application must 9530 ** guarantee that the shared cache used by the destination database 9531 ** is not accessed while the backup is running. In practice this means 9532 ** that the application must guarantee that the disk file being 9533 ** backed up to is not accessed by any connection within the process, 9534 ** not just the specific connection that was passed to sqlite3_backup_init(). 9535 ** 9536 ** The [sqlite3_backup] object itself is partially threadsafe. Multiple 9537 ** threads may safely make multiple concurrent calls to sqlite3_backup_step(). 9538 ** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount() 9539 ** APIs are not strictly speaking threadsafe. If they are invoked at the 9540 ** same time as another thread is invoking sqlite3_backup_step() it is 9541 ** possible that they return invalid values. 9542 ** 9543 ** <b>Alternatives To Using The Backup API</b> 9544 ** 9545 ** Other techniques for safely creating a consistent backup of an SQLite 9546 ** database include: 9547 ** 9548 ** <ul> 9549 ** <li> The [VACUUM INTO] command. 9550 ** <li> The [sqlite3_rsync] utility program. 9551 ** </ul> 9552 */ 9553 SQLITE_API sqlite3_backup *sqlite3_backup_init( 9554 sqlite3 *pDest, /* Destination database handle */ 9555 const char *zDestName, /* Destination database name */ 9556 sqlite3 *pSource, /* Source database handle */ 9557 const char *zSourceName /* Source database name */ 9558 ); 9559 SQLITE_API int sqlite3_backup_step(sqlite3_backup *p, int nPage); 9560 SQLITE_API int sqlite3_backup_finish(sqlite3_backup *p); 9561 SQLITE_API int sqlite3_backup_remaining(sqlite3_backup *p); 9562 SQLITE_API int sqlite3_backup_pagecount(sqlite3_backup *p); 9563 9564 /* 9565 ** CAPI3REF: Unlock Notification 9566 ** METHOD: sqlite3 9567 ** 9568 ** ^When running in shared-cache mode, a database operation may fail with 9569 ** an [SQLITE_LOCKED] error if the required locks on the shared-cache or 9570 ** individual tables within the shared-cache cannot be obtained. See 9571 ** [SQLite Shared-Cache Mode] for a description of shared-cache locking. 9572 ** ^This API may be used to register a callback that SQLite will invoke 9573 ** when the connection currently holding the required lock relinquishes it. 9574 ** ^This API is only available if the library was compiled with the 9575 ** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined. 9576 ** 9577 ** See Also: [Using the SQLite Unlock Notification Feature]. 9578 ** 9579 ** ^Shared-cache locks are released when a database connection concludes 9580 ** its current transaction, either by committing it or rolling it back. 9581 ** 9582 ** ^When a connection (known as the blocked connection) fails to obtain a 9583 ** shared-cache lock and SQLITE_LOCKED is returned to the caller, the 9584 ** identity of the database connection (the blocking connection) that 9585 ** has locked the required resource is stored internally. ^After an 9586 ** application receives an SQLITE_LOCKED error, it may call the 9587 ** sqlite3_unlock_notify() method with the blocked connection handle as 9588 ** the first argument to register for a callback that will be invoked 9589 ** when the blocking connections current transaction is concluded. ^The 9590 ** callback is invoked from within the [sqlite3_step] or [sqlite3_close] 9591 ** call that concludes the blocking connection's transaction. 9592 ** 9593 ** ^(If sqlite3_unlock_notify() is called in a multi-threaded application, 9594 ** there is a chance that the blocking connection will have already 9595 ** concluded its transaction by the time sqlite3_unlock_notify() is invoked. 9596 ** If this happens, then the specified callback is invoked immediately, 9597 ** from within the call to sqlite3_unlock_notify().)^ 9598 ** 9599 ** ^If the blocked connection is attempting to obtain a write-lock on a 9600 ** shared-cache table, and more than one other connection currently holds 9601 ** a read-lock on the same table, then SQLite arbitrarily selects one of 9602 ** the other connections to use as the blocking connection. 9603 ** 9604 ** ^(There may be at most one unlock-notify callback registered by a 9605 ** blocked connection. If sqlite3_unlock_notify() is called when the 9606 ** blocked connection already has a registered unlock-notify callback, 9607 ** then the new callback replaces the old.)^ ^If sqlite3_unlock_notify() is 9608 ** called with a NULL pointer as its second argument, then any existing 9609 ** unlock-notify callback is canceled. ^The blocked connections 9610 ** unlock-notify callback may also be canceled by closing the blocked 9611 ** connection using [sqlite3_close()]. 9612 ** 9613 ** The unlock-notify callback is not reentrant. If an application invokes 9614 ** any sqlite3_xxx API functions from within an unlock-notify callback, a 9615 ** crash or deadlock may be the result. 9616 ** 9617 ** ^Unless deadlock is detected (see below), sqlite3_unlock_notify() always 9618 ** returns SQLITE_OK. 9619 ** 9620 ** <b>Callback Invocation Details</b> 9621 ** 9622 ** When an unlock-notify callback is registered, the application provides a 9623 ** single void* pointer that is passed to the callback when it is invoked. 9624 ** However, the signature of the callback function allows SQLite to pass 9625 ** it an array of void* context pointers. The first argument passed to 9626 ** an unlock-notify callback is a pointer to an array of void* pointers, 9627 ** and the second is the number of entries in the array. 9628 ** 9629 ** When a blocking connection's transaction is concluded, there may be 9630 ** more than one blocked connection that has registered for an unlock-notify 9631 ** callback. ^If two or more such blocked connections have specified the 9632 ** same callback function, then instead of invoking the callback function 9633 ** multiple times, it is invoked once with the set of void* context pointers 9634 ** specified by the blocked connections bundled together into an array. 9635 ** This gives the application an opportunity to prioritize any actions 9636 ** related to the set of unblocked database connections. 9637 ** 9638 ** <b>Deadlock Detection</b> 9639 ** 9640 ** Assuming that after registering for an unlock-notify callback a 9641 ** database waits for the callback to be issued before taking any further 9642 ** action (a reasonable assumption), then using this API may cause the 9643 ** application to deadlock. For example, if connection X is waiting for 9644 ** connection Y's transaction to be concluded, and similarly connection 9645 ** Y is waiting on connection X's transaction, then neither connection 9646 ** will proceed and the system may remain deadlocked indefinitely. 9647 ** 9648 ** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock 9649 ** detection. ^If a given call to sqlite3_unlock_notify() would put the 9650 ** system in a deadlocked state, then SQLITE_LOCKED is returned and no 9651 ** unlock-notify callback is registered. The system is said to be in 9652 ** a deadlocked state if connection A has registered for an unlock-notify 9653 ** callback on the conclusion of connection B's transaction, and connection 9654 ** B has itself registered for an unlock-notify callback when connection 9655 ** A's transaction is concluded. ^Indirect deadlock is also detected, so 9656 ** the system is also considered to be deadlocked if connection B has 9657 ** registered for an unlock-notify callback on the conclusion of connection 9658 ** C's transaction, where connection C is waiting on connection A. ^Any 9659 ** number of levels of indirection are allowed. 9660 ** 9661 ** <b>The "DROP TABLE" Exception</b> 9662 ** 9663 ** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost 9664 ** always appropriate to call sqlite3_unlock_notify(). There is however, 9665 ** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement, 9666 ** SQLite checks if there are any currently executing SELECT statements 9667 ** that belong to the same connection. If there are, SQLITE_LOCKED is 9668 ** returned. In this case there is no "blocking connection", so invoking 9669 ** sqlite3_unlock_notify() results in the unlock-notify callback being 9670 ** invoked immediately. If the application then re-attempts the "DROP TABLE" 9671 ** or "DROP INDEX" query, an infinite loop might be the result. 9672 ** 9673 ** One way around this problem is to check the extended error code returned 9674 ** by an sqlite3_step() call. ^(If there is a blocking connection, then the 9675 ** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in 9676 ** the special "DROP TABLE/INDEX" case, the extended error code is just 9677 ** SQLITE_LOCKED.)^ 9678 */ 9679 SQLITE_API int sqlite3_unlock_notify( 9680 sqlite3 *pBlocked, /* Waiting connection */ 9681 void (*xNotify)(void **apArg, int nArg), /* Callback function to invoke */ 9682 void *pNotifyArg /* Argument to pass to xNotify */ 9683 ); 9684 9685 9686 /* 9687 ** CAPI3REF: String Comparison 9688 ** 9689 ** ^The [sqlite3_stricmp()] and [sqlite3_strnicmp()] APIs allow applications 9690 ** and extensions to compare the contents of two buffers containing UTF-8 9691 ** strings in a case-independent fashion, using the same definition of "case 9692 ** independence" that SQLite uses internally when comparing identifiers. 9693 */ 9694 SQLITE_API int sqlite3_stricmp(const char *, const char *); 9695 SQLITE_API int sqlite3_strnicmp(const char *, const char *, int); 9696 9697 /* 9698 ** CAPI3REF: String Globbing 9699 * 9700 ** ^The [sqlite3_strglob(P,X)] interface returns zero if and only if 9701 ** string X matches the [GLOB] pattern P. 9702 ** ^The definition of [GLOB] pattern matching used in 9703 ** [sqlite3_strglob(P,X)] is the same as for the "X GLOB P" operator in the 9704 ** SQL dialect understood by SQLite. ^The [sqlite3_strglob(P,X)] function 9705 ** is case sensitive. 9706 ** 9707 ** Note that this routine returns zero on a match and non-zero if the strings 9708 ** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()]. 9709 ** 9710 ** See also: [sqlite3_strlike()]. 9711 */ 9712 SQLITE_API int sqlite3_strglob(const char *zGlob, const char *zStr); 9713 9714 /* 9715 ** CAPI3REF: String LIKE Matching 9716 * 9717 ** ^The [sqlite3_strlike(P,X,E)] interface returns zero if and only if 9718 ** string X matches the [LIKE] pattern P with escape character E. 9719 ** ^The definition of [LIKE] pattern matching used in 9720 ** [sqlite3_strlike(P,X,E)] is the same as for the "X LIKE P ESCAPE E" 9721 ** operator in the SQL dialect understood by SQLite. ^For "X LIKE P" without 9722 ** the ESCAPE clause, set the E parameter of [sqlite3_strlike(P,X,E)] to 0. 9723 ** ^As with the LIKE operator, the [sqlite3_strlike(P,X,E)] function is case 9724 ** insensitive - equivalent upper and lower case ASCII characters match 9725 ** one another. 9726 ** 9727 ** ^The [sqlite3_strlike(P,X,E)] function matches Unicode characters, though 9728 ** only ASCII characters are case folded. 9729 ** 9730 ** Note that this routine returns zero on a match and non-zero if the strings 9731 ** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()]. 9732 ** 9733 ** See also: [sqlite3_strglob()]. 9734 */ 9735 SQLITE_API int sqlite3_strlike(const char *zGlob, const char *zStr, unsigned int cEsc); 9736 9737 /* 9738 ** CAPI3REF: Error Logging Interface 9739 ** 9740 ** ^The [sqlite3_log()] interface writes a message into the [error log] 9741 ** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()]. 9742 ** ^If logging is enabled, the zFormat string and subsequent arguments are 9743 ** used with [sqlite3_snprintf()] to generate the final output string. 9744 ** 9745 ** The sqlite3_log() interface is intended for use by extensions such as 9746 ** virtual tables, collating functions, and SQL functions. While there is 9747 ** nothing to prevent an application from calling sqlite3_log(), doing so 9748 ** is considered bad form. 9749 ** 9750 ** The zFormat string must not be NULL. 9751 ** 9752 ** To avoid deadlocks and other threading problems, the sqlite3_log() routine 9753 ** will not use dynamically allocated memory. The log message is stored in 9754 ** a fixed-length buffer on the stack. If the log message is longer than 9755 ** a few hundred characters, it will be truncated to the length of the 9756 ** buffer. 9757 */ 9758 SQLITE_API void sqlite3_log(int iErrCode, const char *zFormat, ...); 9759 9760 /* 9761 ** CAPI3REF: Write-Ahead Log Commit Hook 9762 ** METHOD: sqlite3 9763 ** 9764 ** ^The [sqlite3_wal_hook()] function is used to register a callback that 9765 ** is invoked each time data is committed to a database in wal mode. 9766 ** 9767 ** ^(The callback is invoked by SQLite after the commit has taken place and 9768 ** the associated write-lock on the database released)^, so the implementation 9769 ** may read, write or [checkpoint] the database as required. 9770 ** 9771 ** ^The first parameter passed to the callback function when it is invoked 9772 ** is a copy of the third parameter passed to sqlite3_wal_hook() when 9773 ** registering the callback. ^The second is a copy of the database handle. 9774 ** ^The third parameter is the name of the database that was written to - 9775 ** either "main" or the name of an [ATTACH]-ed database. ^The fourth parameter 9776 ** is the number of pages currently in the write-ahead log file, 9777 ** including those that were just committed. 9778 ** 9779 ** The callback function should normally return [SQLITE_OK]. ^If an error 9780 ** code is returned, that error will propagate back up through the 9781 ** SQLite code base to cause the statement that provoked the callback 9782 ** to report an error, though the commit will have still occurred. If the 9783 ** callback returns [SQLITE_ROW] or [SQLITE_DONE], or if it returns a value 9784 ** that does not correspond to any valid SQLite error code, the results 9785 ** are undefined. 9786 ** 9787 ** A single database handle may have at most a single write-ahead log callback 9788 ** registered at one time. ^Calling [sqlite3_wal_hook()] replaces any 9789 ** previously registered write-ahead log callback. ^The return value is 9790 ** a copy of the third parameter from the previous call, if any, or 0. 9791 ** ^Note that the [sqlite3_wal_autocheckpoint()] interface and the 9792 ** [wal_autocheckpoint pragma] both invoke [sqlite3_wal_hook()] and will 9793 ** overwrite any prior [sqlite3_wal_hook()] settings. 9794 */ 9795 SQLITE_API void *sqlite3_wal_hook( 9796 sqlite3*, 9797 int(*)(void *,sqlite3*,const char*,int), 9798 void* 9799 ); 9800 9801 /* 9802 ** CAPI3REF: Configure an auto-checkpoint 9803 ** METHOD: sqlite3 9804 ** 9805 ** ^The [sqlite3_wal_autocheckpoint(D,N)] is a wrapper around 9806 ** [sqlite3_wal_hook()] that causes any database on [database connection] D 9807 ** to automatically [checkpoint] 9808 ** after committing a transaction if there are N or 9809 ** more frames in the [write-ahead log] file. ^Passing zero or 9810 ** a negative value as the nFrame parameter disables automatic 9811 ** checkpoints entirely. 9812 ** 9813 ** ^The callback registered by this function replaces any existing callback 9814 ** registered using [sqlite3_wal_hook()]. ^Likewise, registering a callback 9815 ** using [sqlite3_wal_hook()] disables the automatic checkpoint mechanism 9816 ** configured by this function. 9817 ** 9818 ** ^The [wal_autocheckpoint pragma] can be used to invoke this interface 9819 ** from SQL. 9820 ** 9821 ** ^Checkpoints initiated by this mechanism are 9822 ** [sqlite3_wal_checkpoint_v2|PASSIVE]. 9823 ** 9824 ** ^Every new [database connection] defaults to having the auto-checkpoint 9825 ** enabled with a threshold of 1000 or [SQLITE_DEFAULT_WAL_AUTOCHECKPOINT] 9826 ** pages. The use of this interface 9827 ** is only necessary if the default setting is found to be suboptimal 9828 ** for a particular application. 9829 */ 9830 SQLITE_API int sqlite3_wal_autocheckpoint(sqlite3 *db, int N); 9831 9832 /* 9833 ** CAPI3REF: Checkpoint a database 9834 ** METHOD: sqlite3 9835 ** 9836 ** ^(The sqlite3_wal_checkpoint(D,X) is equivalent to 9837 ** [sqlite3_wal_checkpoint_v2](D,X,[SQLITE_CHECKPOINT_PASSIVE],0,0).)^ 9838 ** 9839 ** In brief, sqlite3_wal_checkpoint(D,X) causes the content in the 9840 ** [write-ahead log] for database X on [database connection] D to be 9841 ** transferred into the database file and for the write-ahead log to 9842 ** be reset. See the [checkpointing] documentation for addition 9843 ** information. 9844 ** 9845 ** This interface used to be the only way to cause a checkpoint to 9846 ** occur. But then the newer and more powerful [sqlite3_wal_checkpoint_v2()] 9847 ** interface was added. This interface is retained for backwards 9848 ** compatibility and as a convenience for applications that need to manually 9849 ** start a callback but which do not need the full power (and corresponding 9850 ** complication) of [sqlite3_wal_checkpoint_v2()]. 9851 */ 9852 SQLITE_API int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb); 9853 9854 /* 9855 ** CAPI3REF: Checkpoint a database 9856 ** METHOD: sqlite3 9857 ** 9858 ** ^(The sqlite3_wal_checkpoint_v2(D,X,M,L,C) interface runs a checkpoint 9859 ** operation on database X of [database connection] D in mode M. Status 9860 ** information is written back into integers pointed to by L and C.)^ 9861 ** ^(The M parameter must be a valid [checkpoint mode]:)^ 9862 ** 9863 ** <dl> 9864 ** <dt>SQLITE_CHECKPOINT_PASSIVE<dd> 9865 ** ^Checkpoint as many frames as possible without waiting for any database 9866 ** readers or writers to finish, then sync the database file if all frames 9867 ** in the log were checkpointed. ^The [busy-handler callback] 9868 ** is never invoked in the SQLITE_CHECKPOINT_PASSIVE mode. 9869 ** ^On the other hand, passive mode might leave the checkpoint unfinished 9870 ** if there are concurrent readers or writers. 9871 ** 9872 ** <dt>SQLITE_CHECKPOINT_FULL<dd> 9873 ** ^This mode blocks (it invokes the 9874 ** [sqlite3_busy_handler|busy-handler callback]) until there is no 9875 ** database writer and all readers are reading from the most recent database 9876 ** snapshot. ^It then checkpoints all frames in the log file and syncs the 9877 ** database file. ^This mode blocks new database writers while it is pending, 9878 ** but new database readers are allowed to continue unimpeded. 9879 ** 9880 ** <dt>SQLITE_CHECKPOINT_RESTART<dd> 9881 ** ^This mode works the same way as SQLITE_CHECKPOINT_FULL with the addition 9882 ** that after checkpointing the log file it blocks (calls the 9883 ** [busy-handler callback]) 9884 ** until all readers are reading from the database file only. ^This ensures 9885 ** that the next writer will restart the log file from the beginning. 9886 ** ^Like SQLITE_CHECKPOINT_FULL, this mode blocks new 9887 ** database writer attempts while it is pending, but does not impede readers. 9888 ** 9889 ** <dt>SQLITE_CHECKPOINT_TRUNCATE<dd> 9890 ** ^This mode works the same way as SQLITE_CHECKPOINT_RESTART with the 9891 ** addition that it also truncates the log file to zero bytes just prior 9892 ** to a successful return. 9893 ** </dl> 9894 ** 9895 ** ^If pnLog is not NULL, then *pnLog is set to the total number of frames in 9896 ** the log file or to -1 if the checkpoint could not run because 9897 ** of an error or because the database is not in [WAL mode]. ^If pnCkpt is not 9898 ** NULL,then *pnCkpt is set to the total number of checkpointed frames in the 9899 ** log file (including any that were already checkpointed before the function 9900 ** was called) or to -1 if the checkpoint could not run due to an error or 9901 ** because the database is not in WAL mode. ^Note that upon successful 9902 ** completion of an SQLITE_CHECKPOINT_TRUNCATE, the log file will have been 9903 ** truncated to zero bytes and so both *pnLog and *pnCkpt will be set to zero. 9904 ** 9905 ** ^All calls obtain an exclusive "checkpoint" lock on the database file. ^If 9906 ** any other process is running a checkpoint operation at the same time, the 9907 ** lock cannot be obtained and SQLITE_BUSY is returned. ^Even if there is a 9908 ** busy-handler configured, it will not be invoked in this case. 9909 ** 9910 ** ^The SQLITE_CHECKPOINT_FULL, RESTART and TRUNCATE modes also obtain the 9911 ** exclusive "writer" lock on the database file. ^If the writer lock cannot be 9912 ** obtained immediately, and a busy-handler is configured, it is invoked and 9913 ** the writer lock retried until either the busy-handler returns 0 or the lock 9914 ** is successfully obtained. ^The busy-handler is also invoked while waiting for 9915 ** database readers as described above. ^If the busy-handler returns 0 before 9916 ** the writer lock is obtained or while waiting for database readers, the 9917 ** checkpoint operation proceeds from that point in the same way as 9918 ** SQLITE_CHECKPOINT_PASSIVE - checkpointing as many frames as possible 9919 ** without blocking any further. ^SQLITE_BUSY is returned in this case. 9920 ** 9921 ** ^If parameter zDb is NULL or points to a zero length string, then the 9922 ** specified operation is attempted on all WAL databases [attached] to 9923 ** [database connection] db. In this case the 9924 ** values written to output parameters *pnLog and *pnCkpt are undefined. ^If 9925 ** an SQLITE_BUSY error is encountered when processing one or more of the 9926 ** attached WAL databases, the operation is still attempted on any remaining 9927 ** attached databases and SQLITE_BUSY is returned at the end. ^If any other 9928 ** error occurs while processing an attached database, processing is abandoned 9929 ** and the error code is returned to the caller immediately. ^If no error 9930 ** (SQLITE_BUSY or otherwise) is encountered while processing the attached 9931 ** databases, SQLITE_OK is returned. 9932 ** 9933 ** ^If database zDb is the name of an attached database that is not in WAL 9934 ** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. ^If 9935 ** zDb is not NULL (or a zero length string) and is not the name of any 9936 ** attached database, SQLITE_ERROR is returned to the caller. 9937 ** 9938 ** ^Unless it returns SQLITE_MISUSE, 9939 ** the sqlite3_wal_checkpoint_v2() interface 9940 ** sets the error information that is queried by 9941 ** [sqlite3_errcode()] and [sqlite3_errmsg()]. 9942 ** 9943 ** ^The [PRAGMA wal_checkpoint] command can be used to invoke this interface 9944 ** from SQL. 9945 */ 9946 SQLITE_API int sqlite3_wal_checkpoint_v2( 9947 sqlite3 *db, /* Database handle */ 9948 const char *zDb, /* Name of attached database (or NULL) */ 9949 int eMode, /* SQLITE_CHECKPOINT_* value */ 9950 int *pnLog, /* OUT: Size of WAL log in frames */ 9951 int *pnCkpt /* OUT: Total number of frames checkpointed */ 9952 ); 9953 9954 /* 9955 ** CAPI3REF: Checkpoint Mode Values 9956 ** KEYWORDS: {checkpoint mode} 9957 ** 9958 ** These constants define all valid values for the "checkpoint mode" passed 9959 ** as the third parameter to the [sqlite3_wal_checkpoint_v2()] interface. 9960 ** See the [sqlite3_wal_checkpoint_v2()] documentation for details on the 9961 ** meaning of each of these checkpoint modes. 9962 */ 9963 #define SQLITE_CHECKPOINT_PASSIVE 0 /* Do as much as possible w/o blocking */ 9964 #define SQLITE_CHECKPOINT_FULL 1 /* Wait for writers, then checkpoint */ 9965 #define SQLITE_CHECKPOINT_RESTART 2 /* Like FULL but wait for readers */ 9966 #define SQLITE_CHECKPOINT_TRUNCATE 3 /* Like RESTART but also truncate WAL */ 9967 9968 /* 9969 ** CAPI3REF: Virtual Table Interface Configuration 9970 ** 9971 ** This function may be called by either the [xConnect] or [xCreate] method 9972 ** of a [virtual table] implementation to configure 9973 ** various facets of the virtual table interface. 9974 ** 9975 ** If this interface is invoked outside the context of an xConnect or 9976 ** xCreate virtual table method then the behavior is undefined. 9977 ** 9978 ** In the call sqlite3_vtab_config(D,C,...) the D parameter is the 9979 ** [database connection] in which the virtual table is being created and 9980 ** which is passed in as the first argument to the [xConnect] or [xCreate] 9981 ** method that is invoking sqlite3_vtab_config(). The C parameter is one 9982 ** of the [virtual table configuration options]. The presence and meaning 9983 ** of parameters after C depend on which [virtual table configuration option] 9984 ** is used. 9985 */ 9986 SQLITE_API int sqlite3_vtab_config(sqlite3*, int op, ...); 9987 9988 /* 9989 ** CAPI3REF: Virtual Table Configuration Options 9990 ** KEYWORDS: {virtual table configuration options} 9991 ** KEYWORDS: {virtual table configuration option} 9992 ** 9993 ** These macros define the various options to the 9994 ** [sqlite3_vtab_config()] interface that [virtual table] implementations 9995 ** can use to customize and optimize their behavior. 9996 ** 9997 ** <dl> 9998 ** [[SQLITE_VTAB_CONSTRAINT_SUPPORT]] 9999 ** <dt>SQLITE_VTAB_CONSTRAINT_SUPPORT</dt> 10000 ** <dd>Calls of the form 10001 ** [sqlite3_vtab_config](db,SQLITE_VTAB_CONSTRAINT_SUPPORT,X) are supported, 10002 ** where X is an integer. If X is zero, then the [virtual table] whose 10003 ** [xCreate] or [xConnect] method invoked [sqlite3_vtab_config()] does not 10004 ** support constraints. In this configuration (which is the default) if 10005 ** a call to the [xUpdate] method returns [SQLITE_CONSTRAINT], then the entire 10006 ** statement is rolled back as if [ON CONFLICT | OR ABORT] had been 10007 ** specified as part of the users SQL statement, regardless of the actual 10008 ** ON CONFLICT mode specified. 10009 ** 10010 ** If X is non-zero, then the virtual table implementation guarantees 10011 ** that if [xUpdate] returns [SQLITE_CONSTRAINT], it will do so before 10012 ** any modifications to internal or persistent data structures have been made. 10013 ** If the [ON CONFLICT] mode is ABORT, FAIL, IGNORE or ROLLBACK, SQLite 10014 ** is able to roll back a statement or database transaction, and abandon 10015 ** or continue processing the current SQL statement as appropriate. 10016 ** If the ON CONFLICT mode is REPLACE and the [xUpdate] method returns 10017 ** [SQLITE_CONSTRAINT], SQLite handles this as if the ON CONFLICT mode 10018 ** had been ABORT. 10019 ** 10020 ** Virtual table implementations that are required to handle OR REPLACE 10021 ** must do so within the [xUpdate] method. If a call to the 10022 ** [sqlite3_vtab_on_conflict()] function indicates that the current ON 10023 ** CONFLICT policy is REPLACE, the virtual table implementation should 10024 ** silently replace the appropriate rows within the xUpdate callback and 10025 ** return SQLITE_OK. Or, if this is not possible, it may return 10026 ** SQLITE_CONSTRAINT, in which case SQLite falls back to OR ABORT 10027 ** constraint handling. 10028 ** </dd> 10029 ** 10030 ** [[SQLITE_VTAB_DIRECTONLY]]<dt>SQLITE_VTAB_DIRECTONLY</dt> 10031 ** <dd>Calls of the form 10032 ** [sqlite3_vtab_config](db,SQLITE_VTAB_DIRECTONLY) from within the 10033 ** the [xConnect] or [xCreate] methods of a [virtual table] implementation 10034 ** prohibits that virtual table from being used from within triggers and 10035 ** views. 10036 ** </dd> 10037 ** 10038 ** [[SQLITE_VTAB_INNOCUOUS]]<dt>SQLITE_VTAB_INNOCUOUS</dt> 10039 ** <dd>Calls of the form 10040 ** [sqlite3_vtab_config](db,SQLITE_VTAB_INNOCUOUS) from within the 10041 ** the [xConnect] or [xCreate] methods of a [virtual table] implementation 10042 ** identify that virtual table as being safe to use from within triggers 10043 ** and views. Conceptually, the SQLITE_VTAB_INNOCUOUS tag means that the 10044 ** virtual table can do no serious harm even if it is controlled by a 10045 ** malicious hacker. Developers should avoid setting the SQLITE_VTAB_INNOCUOUS 10046 ** flag unless absolutely necessary. 10047 ** </dd> 10048 ** 10049 ** [[SQLITE_VTAB_USES_ALL_SCHEMAS]]<dt>SQLITE_VTAB_USES_ALL_SCHEMAS</dt> 10050 ** <dd>Calls of the form 10051 ** [sqlite3_vtab_config](db,SQLITE_VTAB_USES_ALL_SCHEMA) from within the 10052 ** the [xConnect] or [xCreate] methods of a [virtual table] implementation 10053 ** instruct the query planner to begin at least a read transaction on 10054 ** all schemas ("main", "temp", and any ATTACH-ed databases) whenever the 10055 ** virtual table is used. 10056 ** </dd> 10057 ** </dl> 10058 */ 10059 #define SQLITE_VTAB_CONSTRAINT_SUPPORT 1 10060 #define SQLITE_VTAB_INNOCUOUS 2 10061 #define SQLITE_VTAB_DIRECTONLY 3 10062 #define SQLITE_VTAB_USES_ALL_SCHEMAS 4 10063 10064 /* 10065 ** CAPI3REF: Determine The Virtual Table Conflict Policy 10066 ** 10067 ** This function may only be called from within a call to the [xUpdate] method 10068 ** of a [virtual table] implementation for an INSERT or UPDATE operation. ^The 10069 ** value returned is one of [SQLITE_ROLLBACK], [SQLITE_IGNORE], [SQLITE_FAIL], 10070 ** [SQLITE_ABORT], or [SQLITE_REPLACE], according to the [ON CONFLICT] mode 10071 ** of the SQL statement that triggered the call to the [xUpdate] method of the 10072 ** [virtual table]. 10073 */ 10074 SQLITE_API int sqlite3_vtab_on_conflict(sqlite3 *); 10075 10076 /* 10077 ** CAPI3REF: Determine If Virtual Table Column Access Is For UPDATE 10078 ** 10079 ** If the sqlite3_vtab_nochange(X) routine is called within the [xColumn] 10080 ** method of a [virtual table], then it might return true if the 10081 ** column is being fetched as part of an UPDATE operation during which the 10082 ** column value will not change. The virtual table implementation can use 10083 ** this hint as permission to substitute a return value that is less 10084 ** expensive to compute and that the corresponding 10085 ** [xUpdate] method understands as a "no-change" value. 10086 ** 10087 ** If the [xColumn] method calls sqlite3_vtab_nochange() and finds that 10088 ** the column is not changed by the UPDATE statement, then the xColumn 10089 ** method can optionally return without setting a result, without calling 10090 ** any of the [sqlite3_result_int|sqlite3_result_xxxxx() interfaces]. 10091 ** In that case, [sqlite3_value_nochange(X)] will return true for the 10092 ** same column in the [xUpdate] method. 10093 ** 10094 ** The sqlite3_vtab_nochange() routine is an optimization. Virtual table 10095 ** implementations should continue to give a correct answer even if the 10096 ** sqlite3_vtab_nochange() interface were to always return false. In the 10097 ** current implementation, the sqlite3_vtab_nochange() interface does always 10098 ** returns false for the enhanced [UPDATE FROM] statement. 10099 */ 10100 SQLITE_API int sqlite3_vtab_nochange(sqlite3_context*); 10101 10102 /* 10103 ** CAPI3REF: Determine The Collation For a Virtual Table Constraint 10104 ** METHOD: sqlite3_index_info 10105 ** 10106 ** This function may only be called from within a call to the [xBestIndex] 10107 ** method of a [virtual table]. This function returns a pointer to a string 10108 ** that is the name of the appropriate collation sequence to use for text 10109 ** comparisons on the constraint identified by its arguments. 10110 ** 10111 ** The first argument must be the pointer to the [sqlite3_index_info] object 10112 ** that is the first parameter to the xBestIndex() method. The second argument 10113 ** must be an index into the aConstraint[] array belonging to the 10114 ** sqlite3_index_info structure passed to xBestIndex. 10115 ** 10116 ** Important: 10117 ** The first parameter must be the same pointer that is passed into the 10118 ** xBestMethod() method. The first parameter may not be a pointer to a 10119 ** different [sqlite3_index_info] object, even an exact copy. 10120 ** 10121 ** The return value is computed as follows: 10122 ** 10123 ** <ol> 10124 ** <li><p> If the constraint comes from a WHERE clause expression that contains 10125 ** a [COLLATE operator], then the name of the collation specified by 10126 ** that COLLATE operator is returned. 10127 ** <li><p> If there is no COLLATE operator, but the column that is the subject 10128 ** of the constraint specifies an alternative collating sequence via 10129 ** a [COLLATE clause] on the column definition within the CREATE TABLE 10130 ** statement that was passed into [sqlite3_declare_vtab()], then the 10131 ** name of that alternative collating sequence is returned. 10132 ** <li><p> Otherwise, "BINARY" is returned. 10133 ** </ol> 10134 */ 10135 SQLITE_API const char *sqlite3_vtab_collation(sqlite3_index_info*,int); 10136 10137 /* 10138 ** CAPI3REF: Determine if a virtual table query is DISTINCT 10139 ** METHOD: sqlite3_index_info 10140 ** 10141 ** This API may only be used from within an [xBestIndex|xBestIndex method] 10142 ** of a [virtual table] implementation. The result of calling this 10143 ** interface from outside of xBestIndex() is undefined and probably harmful. 10144 ** 10145 ** ^The sqlite3_vtab_distinct() interface returns an integer between 0 and 10146 ** 3. The integer returned by sqlite3_vtab_distinct() 10147 ** gives the virtual table additional information about how the query 10148 ** planner wants the output to be ordered. As long as the virtual table 10149 ** can meet the ordering requirements of the query planner, it may set 10150 ** the "orderByConsumed" flag. 10151 ** 10152 ** <ol><li value="0"><p> 10153 ** ^If the sqlite3_vtab_distinct() interface returns 0, that means 10154 ** that the query planner needs the virtual table to return all rows in the 10155 ** sort order defined by the "nOrderBy" and "aOrderBy" fields of the 10156 ** [sqlite3_index_info] object. This is the default expectation. If the 10157 ** virtual table outputs all rows in sorted order, then it is always safe for 10158 ** the xBestIndex method to set the "orderByConsumed" flag, regardless of 10159 ** the return value from sqlite3_vtab_distinct(). 10160 ** <li value="1"><p> 10161 ** ^(If the sqlite3_vtab_distinct() interface returns 1, that means 10162 ** that the query planner does not need the rows to be returned in sorted order 10163 ** as long as all rows with the same values in all columns identified by the 10164 ** "aOrderBy" field are adjacent.)^ This mode is used when the query planner 10165 ** is doing a GROUP BY. 10166 ** <li value="2"><p> 10167 ** ^(If the sqlite3_vtab_distinct() interface returns 2, that means 10168 ** that the query planner does not need the rows returned in any particular 10169 ** order, as long as rows with the same values in all columns identified 10170 ** by "aOrderBy" are adjacent.)^ ^(Furthermore, when two or more rows 10171 ** contain the same values for all columns identified by "colUsed", all but 10172 ** one such row may optionally be omitted from the result.)^ 10173 ** The virtual table is not required to omit rows that are duplicates 10174 ** over the "colUsed" columns, but if the virtual table can do that without 10175 ** too much extra effort, it could potentially help the query to run faster. 10176 ** This mode is used for a DISTINCT query. 10177 ** <li value="3"><p> 10178 ** ^(If the sqlite3_vtab_distinct() interface returns 3, that means the 10179 ** virtual table must return rows in the order defined by "aOrderBy" as 10180 ** if the sqlite3_vtab_distinct() interface had returned 0. However if 10181 ** two or more rows in the result have the same values for all columns 10182 ** identified by "colUsed", then all but one such row may optionally be 10183 ** omitted.)^ Like when the return value is 2, the virtual table 10184 ** is not required to omit rows that are duplicates over the "colUsed" 10185 ** columns, but if the virtual table can do that without 10186 ** too much extra effort, it could potentially help the query to run faster. 10187 ** This mode is used for queries 10188 ** that have both DISTINCT and ORDER BY clauses. 10189 ** </ol> 10190 ** 10191 ** <p>The following table summarizes the conditions under which the 10192 ** virtual table is allowed to set the "orderByConsumed" flag based on 10193 ** the value returned by sqlite3_vtab_distinct(). This table is a 10194 ** restatement of the previous four paragraphs: 10195 ** 10196 ** <table border=1 cellspacing=0 cellpadding=10 width="90%"> 10197 ** <tr> 10198 ** <td valign="top">sqlite3_vtab_distinct() return value 10199 ** <td valign="top">Rows are returned in aOrderBy order 10200 ** <td valign="top">Rows with the same value in all aOrderBy columns are adjacent 10201 ** <td valign="top">Duplicates over all colUsed columns may be omitted 10202 ** <tr><td>0<td>yes<td>yes<td>no 10203 ** <tr><td>1<td>no<td>yes<td>no 10204 ** <tr><td>2<td>no<td>yes<td>yes 10205 ** <tr><td>3<td>yes<td>yes<td>yes 10206 ** </table> 10207 ** 10208 ** ^For the purposes of comparing virtual table output values to see if the 10209 ** values are same value for sorting purposes, two NULL values are considered 10210 ** to be the same. In other words, the comparison operator is "IS" 10211 ** (or "IS NOT DISTINCT FROM") and not "==". 10212 ** 10213 ** If a virtual table implementation is unable to meet the requirements 10214 ** specified above, then it must not set the "orderByConsumed" flag in the 10215 ** [sqlite3_index_info] object or an incorrect answer may result. 10216 ** 10217 ** ^A virtual table implementation is always free to return rows in any order 10218 ** it wants, as long as the "orderByConsumed" flag is not set. ^When the 10219 ** the "orderByConsumed" flag is unset, the query planner will add extra 10220 ** [bytecode] to ensure that the final results returned by the SQL query are 10221 ** ordered correctly. The use of the "orderByConsumed" flag and the 10222 ** sqlite3_vtab_distinct() interface is merely an optimization. ^Careful 10223 ** use of the sqlite3_vtab_distinct() interface and the "orderByConsumed" 10224 ** flag might help queries against a virtual table to run faster. Being 10225 ** overly aggressive and setting the "orderByConsumed" flag when it is not 10226 ** valid to do so, on the other hand, might cause SQLite to return incorrect 10227 ** results. 10228 */ 10229 SQLITE_API int sqlite3_vtab_distinct(sqlite3_index_info*); 10230 10231 /* 10232 ** CAPI3REF: Identify and handle IN constraints in xBestIndex 10233 ** 10234 ** This interface may only be used from within an 10235 ** [xBestIndex|xBestIndex() method] of a [virtual table] implementation. 10236 ** The result of invoking this interface from any other context is 10237 ** undefined and probably harmful. 10238 ** 10239 ** ^(A constraint on a virtual table of the form 10240 ** "[IN operator|column IN (...)]" is 10241 ** communicated to the xBestIndex method as a 10242 ** [SQLITE_INDEX_CONSTRAINT_EQ] constraint.)^ If xBestIndex wants to use 10243 ** this constraint, it must set the corresponding 10244 ** aConstraintUsage[].argvIndex to a positive integer. ^(Then, under 10245 ** the usual mode of handling IN operators, SQLite generates [bytecode] 10246 ** that invokes the [xFilter|xFilter() method] once for each value 10247 ** on the right-hand side of the IN operator.)^ Thus the virtual table 10248 ** only sees a single value from the right-hand side of the IN operator 10249 ** at a time. 10250 ** 10251 ** In some cases, however, it would be advantageous for the virtual 10252 ** table to see all values on the right-hand of the IN operator all at 10253 ** once. The sqlite3_vtab_in() interfaces facilitates this in two ways: 10254 ** 10255 ** <ol> 10256 ** <li><p> 10257 ** ^A call to sqlite3_vtab_in(P,N,-1) will return true (non-zero) 10258 ** if and only if the [sqlite3_index_info|P->aConstraint][N] constraint 10259 ** is an [IN operator] that can be processed all at once. ^In other words, 10260 ** sqlite3_vtab_in() with -1 in the third argument is a mechanism 10261 ** by which the virtual table can ask SQLite if all-at-once processing 10262 ** of the IN operator is even possible. 10263 ** 10264 ** <li><p> 10265 ** ^A call to sqlite3_vtab_in(P,N,F) with F==1 or F==0 indicates 10266 ** to SQLite that the virtual table does or does not want to process 10267 ** the IN operator all-at-once, respectively. ^Thus when the third 10268 ** parameter (F) is non-negative, this interface is the mechanism by 10269 ** which the virtual table tells SQLite how it wants to process the 10270 ** IN operator. 10271 ** </ol> 10272 ** 10273 ** ^The sqlite3_vtab_in(P,N,F) interface can be invoked multiple times 10274 ** within the same xBestIndex method call. ^For any given P,N pair, 10275 ** the return value from sqlite3_vtab_in(P,N,F) will always be the same 10276 ** within the same xBestIndex call. ^If the interface returns true 10277 ** (non-zero), that means that the constraint is an IN operator 10278 ** that can be processed all-at-once. ^If the constraint is not an IN 10279 ** operator or cannot be processed all-at-once, then the interface returns 10280 ** false. 10281 ** 10282 ** ^(All-at-once processing of the IN operator is selected if both of the 10283 ** following conditions are met: 10284 ** 10285 ** <ol> 10286 ** <li><p> The P->aConstraintUsage[N].argvIndex value is set to a positive 10287 ** integer. This is how the virtual table tells SQLite that it wants to 10288 ** use the N-th constraint. 10289 ** 10290 ** <li><p> The last call to sqlite3_vtab_in(P,N,F) for which F was 10291 ** non-negative had F>=1. 10292 ** </ol>)^ 10293 ** 10294 ** ^If either or both of the conditions above are false, then SQLite uses 10295 ** the traditional one-at-a-time processing strategy for the IN constraint. 10296 ** ^If both conditions are true, then the argvIndex-th parameter to the 10297 ** xFilter method will be an [sqlite3_value] that appears to be NULL, 10298 ** but which can be passed to [sqlite3_vtab_in_first()] and 10299 ** [sqlite3_vtab_in_next()] to find all values on the right-hand side 10300 ** of the IN constraint. 10301 */ 10302 SQLITE_API int sqlite3_vtab_in(sqlite3_index_info*, int iCons, int bHandle); 10303 10304 /* 10305 ** CAPI3REF: Find all elements on the right-hand side of an IN constraint. 10306 ** 10307 ** These interfaces are only useful from within the 10308 ** [xFilter|xFilter() method] of a [virtual table] implementation. 10309 ** The result of invoking these interfaces from any other context 10310 ** is undefined and probably harmful. 10311 ** 10312 ** The X parameter in a call to sqlite3_vtab_in_first(X,P) or 10313 ** sqlite3_vtab_in_next(X,P) should be one of the parameters to the 10314 ** xFilter method which invokes these routines, and specifically 10315 ** a parameter that was previously selected for all-at-once IN constraint 10316 ** processing use the [sqlite3_vtab_in()] interface in the 10317 ** [xBestIndex|xBestIndex method]. ^(If the X parameter is not 10318 ** an xFilter argument that was selected for all-at-once IN constraint 10319 ** processing, then these routines return [SQLITE_ERROR].)^ 10320 ** 10321 ** ^(Use these routines to access all values on the right-hand side 10322 ** of the IN constraint using code like the following: 10323 ** 10324 ** <blockquote><pre> 10325 ** for(rc=sqlite3_vtab_in_first(pList, &pVal); 10326 ** rc==SQLITE_OK && pVal; 10327 ** rc=sqlite3_vtab_in_next(pList, &pVal) 10328 ** ){ 10329 ** // do something with pVal 10330 ** } 10331 ** if( rc!=SQLITE_OK ){ 10332 ** // an error has occurred 10333 ** } 10334 ** </pre></blockquote>)^ 10335 ** 10336 ** ^On success, the sqlite3_vtab_in_first(X,P) and sqlite3_vtab_in_next(X,P) 10337 ** routines return SQLITE_OK and set *P to point to the first or next value 10338 ** on the RHS of the IN constraint. ^If there are no more values on the 10339 ** right hand side of the IN constraint, then *P is set to NULL and these 10340 ** routines return [SQLITE_DONE]. ^The return value might be 10341 ** some other value, such as SQLITE_NOMEM, in the event of a malfunction. 10342 ** 10343 ** The *ppOut values returned by these routines are only valid until the 10344 ** next call to either of these routines or until the end of the xFilter 10345 ** method from which these routines were called. If the virtual table 10346 ** implementation needs to retain the *ppOut values for longer, it must make 10347 ** copies. The *ppOut values are [protected sqlite3_value|protected]. 10348 */ 10349 SQLITE_API int sqlite3_vtab_in_first(sqlite3_value *pVal, sqlite3_value **ppOut); 10350 SQLITE_API int sqlite3_vtab_in_next(sqlite3_value *pVal, sqlite3_value **ppOut); 10351 10352 /* 10353 ** CAPI3REF: Constraint values in xBestIndex() 10354 ** METHOD: sqlite3_index_info 10355 ** 10356 ** This API may only be used from within the [xBestIndex|xBestIndex method] 10357 ** of a [virtual table] implementation. The result of calling this interface 10358 ** from outside of an xBestIndex method are undefined and probably harmful. 10359 ** 10360 ** ^When the sqlite3_vtab_rhs_value(P,J,V) interface is invoked from within 10361 ** the [xBestIndex] method of a [virtual table] implementation, with P being 10362 ** a copy of the [sqlite3_index_info] object pointer passed into xBestIndex and 10363 ** J being a 0-based index into P->aConstraint[], then this routine 10364 ** attempts to set *V to the value of the right-hand operand of 10365 ** that constraint if the right-hand operand is known. ^If the 10366 ** right-hand operand is not known, then *V is set to a NULL pointer. 10367 ** ^The sqlite3_vtab_rhs_value(P,J,V) interface returns SQLITE_OK if 10368 ** and only if *V is set to a value. ^The sqlite3_vtab_rhs_value(P,J,V) 10369 ** inteface returns SQLITE_NOTFOUND if the right-hand side of the J-th 10370 ** constraint is not available. ^The sqlite3_vtab_rhs_value() interface 10371 ** can return an result code other than SQLITE_OK or SQLITE_NOTFOUND if 10372 ** something goes wrong. 10373 ** 10374 ** The sqlite3_vtab_rhs_value() interface is usually only successful if 10375 ** the right-hand operand of a constraint is a literal value in the original 10376 ** SQL statement. If the right-hand operand is an expression or a reference 10377 ** to some other column or a [host parameter], then sqlite3_vtab_rhs_value() 10378 ** will probably return [SQLITE_NOTFOUND]. 10379 ** 10380 ** ^(Some constraints, such as [SQLITE_INDEX_CONSTRAINT_ISNULL] and 10381 ** [SQLITE_INDEX_CONSTRAINT_ISNOTNULL], have no right-hand operand. For such 10382 ** constraints, sqlite3_vtab_rhs_value() always returns SQLITE_NOTFOUND.)^ 10383 ** 10384 ** ^The [sqlite3_value] object returned in *V is a protected sqlite3_value 10385 ** and remains valid for the duration of the xBestIndex method call. 10386 ** ^When xBestIndex returns, the sqlite3_value object returned by 10387 ** sqlite3_vtab_rhs_value() is automatically deallocated. 10388 ** 10389 ** The "_rhs_" in the name of this routine is an abbreviation for 10390 ** "Right-Hand Side". 10391 */ 10392 SQLITE_API int sqlite3_vtab_rhs_value(sqlite3_index_info*, int, sqlite3_value **ppVal); 10393 10394 /* 10395 ** CAPI3REF: Conflict resolution modes 10396 ** KEYWORDS: {conflict resolution mode} 10397 ** 10398 ** These constants are returned by [sqlite3_vtab_on_conflict()] to 10399 ** inform a [virtual table] implementation what the [ON CONFLICT] mode 10400 ** is for the SQL statement being evaluated. 10401 ** 10402 ** Note that the [SQLITE_IGNORE] constant is also used as a potential 10403 ** return value from the [sqlite3_set_authorizer()] callback and that 10404 ** [SQLITE_ABORT] is also a [result code]. 10405 */ 10406 #define SQLITE_ROLLBACK 1 10407 /* #define SQLITE_IGNORE 2 // Also used by sqlite3_authorizer() callback */ 10408 #define SQLITE_FAIL 3 10409 /* #define SQLITE_ABORT 4 // Also an error code */ 10410 #define SQLITE_REPLACE 5 10411 10412 /* 10413 ** CAPI3REF: Prepared Statement Scan Status Opcodes 10414 ** KEYWORDS: {scanstatus options} 10415 ** 10416 ** The following constants can be used for the T parameter to the 10417 ** [sqlite3_stmt_scanstatus(S,X,T,V)] interface. Each constant designates a 10418 ** different metric for sqlite3_stmt_scanstatus() to return. 10419 ** 10420 ** When the value returned to V is a string, space to hold that string is 10421 ** managed by the prepared statement S and will be automatically freed when 10422 ** S is finalized. 10423 ** 10424 ** Not all values are available for all query elements. When a value is 10425 ** not available, the output variable is set to -1 if the value is numeric, 10426 ** or to NULL if it is a string (SQLITE_SCANSTAT_NAME). 10427 ** 10428 ** <dl> 10429 ** [[SQLITE_SCANSTAT_NLOOP]] <dt>SQLITE_SCANSTAT_NLOOP</dt> 10430 ** <dd>^The [sqlite3_int64] variable pointed to by the V parameter will be 10431 ** set to the total number of times that the X-th loop has run.</dd> 10432 ** 10433 ** [[SQLITE_SCANSTAT_NVISIT]] <dt>SQLITE_SCANSTAT_NVISIT</dt> 10434 ** <dd>^The [sqlite3_int64] variable pointed to by the V parameter will be set 10435 ** to the total number of rows examined by all iterations of the X-th loop.</dd> 10436 ** 10437 ** [[SQLITE_SCANSTAT_EST]] <dt>SQLITE_SCANSTAT_EST</dt> 10438 ** <dd>^The "double" variable pointed to by the V parameter will be set to the 10439 ** query planner's estimate for the average number of rows output from each 10440 ** iteration of the X-th loop. If the query planner's estimates was accurate, 10441 ** then this value will approximate the quotient NVISIT/NLOOP and the 10442 ** product of this value for all prior loops with the same SELECTID will 10443 ** be the NLOOP value for the current loop. 10444 ** 10445 ** [[SQLITE_SCANSTAT_NAME]] <dt>SQLITE_SCANSTAT_NAME</dt> 10446 ** <dd>^The "const char *" variable pointed to by the V parameter will be set 10447 ** to a zero-terminated UTF-8 string containing the name of the index or table 10448 ** used for the X-th loop. 10449 ** 10450 ** [[SQLITE_SCANSTAT_EXPLAIN]] <dt>SQLITE_SCANSTAT_EXPLAIN</dt> 10451 ** <dd>^The "const char *" variable pointed to by the V parameter will be set 10452 ** to a zero-terminated UTF-8 string containing the [EXPLAIN QUERY PLAN] 10453 ** description for the X-th loop. 10454 ** 10455 ** [[SQLITE_SCANSTAT_SELECTID]] <dt>SQLITE_SCANSTAT_SELECTID</dt> 10456 ** <dd>^The "int" variable pointed to by the V parameter will be set to the 10457 ** id for the X-th query plan element. The id value is unique within the 10458 ** statement. The select-id is the same value as is output in the first 10459 ** column of an [EXPLAIN QUERY PLAN] query. 10460 ** 10461 ** [[SQLITE_SCANSTAT_PARENTID]] <dt>SQLITE_SCANSTAT_PARENTID</dt> 10462 ** <dd>The "int" variable pointed to by the V parameter will be set to the 10463 ** the id of the parent of the current query element, if applicable, or 10464 ** to zero if the query element has no parent. This is the same value as 10465 ** returned in the second column of an [EXPLAIN QUERY PLAN] query. 10466 ** 10467 ** [[SQLITE_SCANSTAT_NCYCLE]] <dt>SQLITE_SCANSTAT_NCYCLE</dt> 10468 ** <dd>The sqlite3_int64 output value is set to the number of cycles, 10469 ** according to the processor time-stamp counter, that elapsed while the 10470 ** query element was being processed. This value is not available for 10471 ** all query elements - if it is unavailable the output variable is 10472 ** set to -1. 10473 ** </dl> 10474 */ 10475 #define SQLITE_SCANSTAT_NLOOP 0 10476 #define SQLITE_SCANSTAT_NVISIT 1 10477 #define SQLITE_SCANSTAT_EST 2 10478 #define SQLITE_SCANSTAT_NAME 3 10479 #define SQLITE_SCANSTAT_EXPLAIN 4 10480 #define SQLITE_SCANSTAT_SELECTID 5 10481 #define SQLITE_SCANSTAT_PARENTID 6 10482 #define SQLITE_SCANSTAT_NCYCLE 7 10483 10484 /* 10485 ** CAPI3REF: Prepared Statement Scan Status 10486 ** METHOD: sqlite3_stmt 10487 ** 10488 ** These interfaces return information about the predicted and measured 10489 ** performance for pStmt. Advanced applications can use this 10490 ** interface to compare the predicted and the measured performance and 10491 ** issue warnings and/or rerun [ANALYZE] if discrepancies are found. 10492 ** 10493 ** Since this interface is expected to be rarely used, it is only 10494 ** available if SQLite is compiled using the [SQLITE_ENABLE_STMT_SCANSTATUS] 10495 ** compile-time option. 10496 ** 10497 ** The "iScanStatusOp" parameter determines which status information to return. 10498 ** The "iScanStatusOp" must be one of the [scanstatus options] or the behavior 10499 ** of this interface is undefined. ^The requested measurement is written into 10500 ** a variable pointed to by the "pOut" parameter. 10501 ** 10502 ** The "flags" parameter must be passed a mask of flags. At present only 10503 ** one flag is defined - SQLITE_SCANSTAT_COMPLEX. If SQLITE_SCANSTAT_COMPLEX 10504 ** is specified, then status information is available for all elements 10505 ** of a query plan that are reported by "EXPLAIN QUERY PLAN" output. If 10506 ** SQLITE_SCANSTAT_COMPLEX is not specified, then only query plan elements 10507 ** that correspond to query loops (the "SCAN..." and "SEARCH..." elements of 10508 ** the EXPLAIN QUERY PLAN output) are available. Invoking API 10509 ** sqlite3_stmt_scanstatus() is equivalent to calling 10510 ** sqlite3_stmt_scanstatus_v2() with a zeroed flags parameter. 10511 ** 10512 ** Parameter "idx" identifies the specific query element to retrieve statistics 10513 ** for. Query elements are numbered starting from zero. A value of -1 may be 10514 ** to query for statistics regarding the entire query. ^If idx is out of range 10515 ** - less than -1 or greater than or equal to the total number of query 10516 ** elements used to implement the statement - a non-zero value is returned and 10517 ** the variable that pOut points to is unchanged. 10518 ** 10519 ** See also: [sqlite3_stmt_scanstatus_reset()] 10520 */ 10521 SQLITE_API int sqlite3_stmt_scanstatus( 10522 sqlite3_stmt *pStmt, /* Prepared statement for which info desired */ 10523 int idx, /* Index of loop to report on */ 10524 int iScanStatusOp, /* Information desired. SQLITE_SCANSTAT_* */ 10525 void *pOut /* Result written here */ 10526 ); 10527 SQLITE_API int sqlite3_stmt_scanstatus_v2( 10528 sqlite3_stmt *pStmt, /* Prepared statement for which info desired */ 10529 int idx, /* Index of loop to report on */ 10530 int iScanStatusOp, /* Information desired. SQLITE_SCANSTAT_* */ 10531 int flags, /* Mask of flags defined below */ 10532 void *pOut /* Result written here */ 10533 ); 10534 10535 /* 10536 ** CAPI3REF: Prepared Statement Scan Status 10537 ** KEYWORDS: {scan status flags} 10538 */ 10539 #define SQLITE_SCANSTAT_COMPLEX 0x0001 10540 10541 /* 10542 ** CAPI3REF: Zero Scan-Status Counters 10543 ** METHOD: sqlite3_stmt 10544 ** 10545 ** ^Zero all [sqlite3_stmt_scanstatus()] related event counters. 10546 ** 10547 ** This API is only available if the library is built with pre-processor 10548 ** symbol [SQLITE_ENABLE_STMT_SCANSTATUS] defined. 10549 */ 10550 SQLITE_API void sqlite3_stmt_scanstatus_reset(sqlite3_stmt*); 10551 10552 /* 10553 ** CAPI3REF: Flush caches to disk mid-transaction 10554 ** METHOD: sqlite3 10555 ** 10556 ** ^If a write-transaction is open on [database connection] D when the 10557 ** [sqlite3_db_cacheflush(D)] interface is invoked, any dirty 10558 ** pages in the pager-cache that are not currently in use are written out 10559 ** to disk. A dirty page may be in use if a database cursor created by an 10560 ** active SQL statement is reading from it, or if it is page 1 of a database 10561 ** file (page 1 is always "in use"). ^The [sqlite3_db_cacheflush(D)] 10562 ** interface flushes caches for all schemas - "main", "temp", and 10563 ** any [attached] databases. 10564 ** 10565 ** ^If this function needs to obtain extra database locks before dirty pages 10566 ** can be flushed to disk, it does so. ^If those locks cannot be obtained 10567 ** immediately and there is a busy-handler callback configured, it is invoked 10568 ** in the usual manner. ^If the required lock still cannot be obtained, then 10569 ** the database is skipped and an attempt made to flush any dirty pages 10570 ** belonging to the next (if any) database. ^If any databases are skipped 10571 ** because locks cannot be obtained, but no other error occurs, this 10572 ** function returns SQLITE_BUSY. 10573 ** 10574 ** ^If any other error occurs while flushing dirty pages to disk (for 10575 ** example an IO error or out-of-memory condition), then processing is 10576 ** abandoned and an SQLite [error code] is returned to the caller immediately. 10577 ** 10578 ** ^Otherwise, if no error occurs, [sqlite3_db_cacheflush()] returns SQLITE_OK. 10579 ** 10580 ** ^This function does not set the database handle error code or message 10581 ** returned by the [sqlite3_errcode()] and [sqlite3_errmsg()] functions. 10582 */ 10583 SQLITE_API int sqlite3_db_cacheflush(sqlite3*); 10584 10585 /* 10586 ** CAPI3REF: The pre-update hook. 10587 ** METHOD: sqlite3 10588 ** 10589 ** ^These interfaces are only available if SQLite is compiled using the 10590 ** [SQLITE_ENABLE_PREUPDATE_HOOK] compile-time option. 10591 ** 10592 ** ^The [sqlite3_preupdate_hook()] interface registers a callback function 10593 ** that is invoked prior to each [INSERT], [UPDATE], and [DELETE] operation 10594 ** on a database table. 10595 ** ^At most one preupdate hook may be registered at a time on a single 10596 ** [database connection]; each call to [sqlite3_preupdate_hook()] overrides 10597 ** the previous setting. 10598 ** ^The preupdate hook is disabled by invoking [sqlite3_preupdate_hook()] 10599 ** with a NULL pointer as the second parameter. 10600 ** ^The third parameter to [sqlite3_preupdate_hook()] is passed through as 10601 ** the first parameter to callbacks. 10602 ** 10603 ** ^The preupdate hook only fires for changes to real database tables; the 10604 ** preupdate hook is not invoked for changes to [virtual tables] or to 10605 ** system tables like sqlite_sequence or sqlite_stat1. 10606 ** 10607 ** ^The second parameter to the preupdate callback is a pointer to 10608 ** the [database connection] that registered the preupdate hook. 10609 ** ^The third parameter to the preupdate callback is one of the constants 10610 ** [SQLITE_INSERT], [SQLITE_DELETE], or [SQLITE_UPDATE] to identify the 10611 ** kind of update operation that is about to occur. 10612 ** ^(The fourth parameter to the preupdate callback is the name of the 10613 ** database within the database connection that is being modified. This 10614 ** will be "main" for the main database or "temp" for TEMP tables or 10615 ** the name given after the AS keyword in the [ATTACH] statement for attached 10616 ** databases.)^ 10617 ** ^The fifth parameter to the preupdate callback is the name of the 10618 ** table that is being modified. 10619 ** 10620 ** For an UPDATE or DELETE operation on a [rowid table], the sixth 10621 ** parameter passed to the preupdate callback is the initial [rowid] of the 10622 ** row being modified or deleted. For an INSERT operation on a rowid table, 10623 ** or any operation on a WITHOUT ROWID table, the value of the sixth 10624 ** parameter is undefined. For an INSERT or UPDATE on a rowid table the 10625 ** seventh parameter is the final rowid value of the row being inserted 10626 ** or updated. The value of the seventh parameter passed to the callback 10627 ** function is not defined for operations on WITHOUT ROWID tables, or for 10628 ** DELETE operations on rowid tables. 10629 ** 10630 ** ^The sqlite3_preupdate_hook(D,C,P) function returns the P argument from 10631 ** the previous call on the same [database connection] D, or NULL for 10632 ** the first call on D. 10633 ** 10634 ** The [sqlite3_preupdate_old()], [sqlite3_preupdate_new()], 10635 ** [sqlite3_preupdate_count()], and [sqlite3_preupdate_depth()] interfaces 10636 ** provide additional information about a preupdate event. These routines 10637 ** may only be called from within a preupdate callback. Invoking any of 10638 ** these routines from outside of a preupdate callback or with a 10639 ** [database connection] pointer that is different from the one supplied 10640 ** to the preupdate callback results in undefined and probably undesirable 10641 ** behavior. 10642 ** 10643 ** ^The [sqlite3_preupdate_count(D)] interface returns the number of columns 10644 ** in the row that is being inserted, updated, or deleted. 10645 ** 10646 ** ^The [sqlite3_preupdate_old(D,N,P)] interface writes into P a pointer to 10647 ** a [protected sqlite3_value] that contains the value of the Nth column of 10648 ** the table row before it is updated. The N parameter must be between 0 10649 ** and one less than the number of columns or the behavior will be 10650 ** undefined. This must only be used within SQLITE_UPDATE and SQLITE_DELETE 10651 ** preupdate callbacks; if it is used by an SQLITE_INSERT callback then the 10652 ** behavior is undefined. The [sqlite3_value] that P points to 10653 ** will be destroyed when the preupdate callback returns. 10654 ** 10655 ** ^The [sqlite3_preupdate_new(D,N,P)] interface writes into P a pointer to 10656 ** a [protected sqlite3_value] that contains the value of the Nth column of 10657 ** the table row after it is updated. The N parameter must be between 0 10658 ** and one less than the number of columns or the behavior will be 10659 ** undefined. This must only be used within SQLITE_INSERT and SQLITE_UPDATE 10660 ** preupdate callbacks; if it is used by an SQLITE_DELETE callback then the 10661 ** behavior is undefined. The [sqlite3_value] that P points to 10662 ** will be destroyed when the preupdate callback returns. 10663 ** 10664 ** ^The [sqlite3_preupdate_depth(D)] interface returns 0 if the preupdate 10665 ** callback was invoked as a result of a direct insert, update, or delete 10666 ** operation; or 1 for inserts, updates, or deletes invoked by top-level 10667 ** triggers; or 2 for changes resulting from triggers called by top-level 10668 ** triggers; and so forth. 10669 ** 10670 ** When the [sqlite3_blob_write()] API is used to update a blob column, 10671 ** the pre-update hook is invoked with SQLITE_DELETE. This is because the 10672 ** in this case the new values are not available. In this case, when a 10673 ** callback made with op==SQLITE_DELETE is actually a write using the 10674 ** sqlite3_blob_write() API, the [sqlite3_preupdate_blobwrite()] returns 10675 ** the index of the column being written. In other cases, where the 10676 ** pre-update hook is being invoked for some other reason, including a 10677 ** regular DELETE, sqlite3_preupdate_blobwrite() returns -1. 10678 ** 10679 ** See also: [sqlite3_update_hook()] 10680 */ 10681 #if defined(SQLITE_ENABLE_PREUPDATE_HOOK) 10682 SQLITE_API void *sqlite3_preupdate_hook( 10683 sqlite3 *db, 10684 void(*xPreUpdate)( 10685 void *pCtx, /* Copy of third arg to preupdate_hook() */ 10686 sqlite3 *db, /* Database handle */ 10687 int op, /* SQLITE_UPDATE, DELETE or INSERT */ 10688 char const *zDb, /* Database name */ 10689 char const *zName, /* Table name */ 10690 sqlite3_int64 iKey1, /* Rowid of row about to be deleted/updated */ 10691 sqlite3_int64 iKey2 /* New rowid value (for a rowid UPDATE) */ 10692 ), 10693 void* 10694 ); 10695 SQLITE_API int sqlite3_preupdate_old(sqlite3 *, int, sqlite3_value **); 10696 SQLITE_API int sqlite3_preupdate_count(sqlite3 *); 10697 SQLITE_API int sqlite3_preupdate_depth(sqlite3 *); 10698 SQLITE_API int sqlite3_preupdate_new(sqlite3 *, int, sqlite3_value **); 10699 SQLITE_API int sqlite3_preupdate_blobwrite(sqlite3 *); 10700 #endif 10701 10702 /* 10703 ** CAPI3REF: Low-level system error code 10704 ** METHOD: sqlite3 10705 ** 10706 ** ^Attempt to return the underlying operating system error code or error 10707 ** number that caused the most recent I/O error or failure to open a file. 10708 ** The return value is OS-dependent. For example, on unix systems, after 10709 ** [sqlite3_open_v2()] returns [SQLITE_CANTOPEN], this interface could be 10710 ** called to get back the underlying "errno" that caused the problem, such 10711 ** as ENOSPC, EAUTH, EISDIR, and so forth. 10712 */ 10713 SQLITE_API int sqlite3_system_errno(sqlite3*); 10714 10715 /* 10716 ** CAPI3REF: Database Snapshot 10717 ** KEYWORDS: {snapshot} {sqlite3_snapshot} 10718 ** 10719 ** An instance of the snapshot object records the state of a [WAL mode] 10720 ** database for some specific point in history. 10721 ** 10722 ** In [WAL mode], multiple [database connections] that are open on the 10723 ** same database file can each be reading a different historical version 10724 ** of the database file. When a [database connection] begins a read 10725 ** transaction, that connection sees an unchanging copy of the database 10726 ** as it existed for the point in time when the transaction first started. 10727 ** Subsequent changes to the database from other connections are not seen 10728 ** by the reader until a new read transaction is started. 10729 ** 10730 ** The sqlite3_snapshot object records state information about an historical 10731 ** version of the database file so that it is possible to later open a new read 10732 ** transaction that sees that historical version of the database rather than 10733 ** the most recent version. 10734 */ 10735 typedef struct sqlite3_snapshot { 10736 unsigned char hidden[48]; 10737 } sqlite3_snapshot; 10738 10739 /* 10740 ** CAPI3REF: Record A Database Snapshot 10741 ** CONSTRUCTOR: sqlite3_snapshot 10742 ** 10743 ** ^The [sqlite3_snapshot_get(D,S,P)] interface attempts to make a 10744 ** new [sqlite3_snapshot] object that records the current state of 10745 ** schema S in database connection D. ^On success, the 10746 ** [sqlite3_snapshot_get(D,S,P)] interface writes a pointer to the newly 10747 ** created [sqlite3_snapshot] object into *P and returns SQLITE_OK. 10748 ** If there is not already a read-transaction open on schema S when 10749 ** this function is called, one is opened automatically. 10750 ** 10751 ** If a read-transaction is opened by this function, then it is guaranteed 10752 ** that the returned snapshot object may not be invalidated by a database 10753 ** writer or checkpointer until after the read-transaction is closed. This 10754 ** is not guaranteed if a read-transaction is already open when this 10755 ** function is called. In that case, any subsequent write or checkpoint 10756 ** operation on the database may invalidate the returned snapshot handle, 10757 ** even while the read-transaction remains open. 10758 ** 10759 ** The following must be true for this function to succeed. If any of 10760 ** the following statements are false when sqlite3_snapshot_get() is 10761 ** called, SQLITE_ERROR is returned. The final value of *P is undefined 10762 ** in this case. 10763 ** 10764 ** <ul> 10765 ** <li> The database handle must not be in [autocommit mode]. 10766 ** 10767 ** <li> Schema S of [database connection] D must be a [WAL mode] database. 10768 ** 10769 ** <li> There must not be a write transaction open on schema S of database 10770 ** connection D. 10771 ** 10772 ** <li> One or more transactions must have been written to the current wal 10773 ** file since it was created on disk (by any connection). This means 10774 ** that a snapshot cannot be taken on a wal mode database with no wal 10775 ** file immediately after it is first opened. At least one transaction 10776 ** must be written to it first. 10777 ** </ul> 10778 ** 10779 ** This function may also return SQLITE_NOMEM. If it is called with the 10780 ** database handle in autocommit mode but fails for some other reason, 10781 ** whether or not a read transaction is opened on schema S is undefined. 10782 ** 10783 ** The [sqlite3_snapshot] object returned from a successful call to 10784 ** [sqlite3_snapshot_get()] must be freed using [sqlite3_snapshot_free()] 10785 ** to avoid a memory leak. 10786 ** 10787 ** The [sqlite3_snapshot_get()] interface is only available when the 10788 ** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used. 10789 */ 10790 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_get( 10791 sqlite3 *db, 10792 const char *zSchema, 10793 sqlite3_snapshot **ppSnapshot 10794 ); 10795 10796 /* 10797 ** CAPI3REF: Start a read transaction on an historical snapshot 10798 ** METHOD: sqlite3_snapshot 10799 ** 10800 ** ^The [sqlite3_snapshot_open(D,S,P)] interface either starts a new read 10801 ** transaction or upgrades an existing one for schema S of 10802 ** [database connection] D such that the read transaction refers to 10803 ** historical [snapshot] P, rather than the most recent change to the 10804 ** database. ^The [sqlite3_snapshot_open()] interface returns SQLITE_OK 10805 ** on success or an appropriate [error code] if it fails. 10806 ** 10807 ** ^In order to succeed, the database connection must not be in 10808 ** [autocommit mode] when [sqlite3_snapshot_open(D,S,P)] is called. If there 10809 ** is already a read transaction open on schema S, then the database handle 10810 ** must have no active statements (SELECT statements that have been passed 10811 ** to sqlite3_step() but not sqlite3_reset() or sqlite3_finalize()). 10812 ** SQLITE_ERROR is returned if either of these conditions is violated, or 10813 ** if schema S does not exist, or if the snapshot object is invalid. 10814 ** 10815 ** ^A call to sqlite3_snapshot_open() will fail to open if the specified 10816 ** snapshot has been overwritten by a [checkpoint]. In this case 10817 ** SQLITE_ERROR_SNAPSHOT is returned. 10818 ** 10819 ** If there is already a read transaction open when this function is 10820 ** invoked, then the same read transaction remains open (on the same 10821 ** database snapshot) if SQLITE_ERROR, SQLITE_BUSY or SQLITE_ERROR_SNAPSHOT 10822 ** is returned. If another error code - for example SQLITE_PROTOCOL or an 10823 ** SQLITE_IOERR error code - is returned, then the final state of the 10824 ** read transaction is undefined. If SQLITE_OK is returned, then the 10825 ** read transaction is now open on database snapshot P. 10826 ** 10827 ** ^(A call to [sqlite3_snapshot_open(D,S,P)] will fail if the 10828 ** database connection D does not know that the database file for 10829 ** schema S is in [WAL mode]. A database connection might not know 10830 ** that the database file is in [WAL mode] if there has been no prior 10831 ** I/O on that database connection, or if the database entered [WAL mode] 10832 ** after the most recent I/O on the database connection.)^ 10833 ** (Hint: Run "[PRAGMA application_id]" against a newly opened 10834 ** database connection in order to make it ready to use snapshots.) 10835 ** 10836 ** The [sqlite3_snapshot_open()] interface is only available when the 10837 ** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used. 10838 */ 10839 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_open( 10840 sqlite3 *db, 10841 const char *zSchema, 10842 sqlite3_snapshot *pSnapshot 10843 ); 10844 10845 /* 10846 ** CAPI3REF: Destroy a snapshot 10847 ** DESTRUCTOR: sqlite3_snapshot 10848 ** 10849 ** ^The [sqlite3_snapshot_free(P)] interface destroys [sqlite3_snapshot] P. 10850 ** The application must eventually free every [sqlite3_snapshot] object 10851 ** using this routine to avoid a memory leak. 10852 ** 10853 ** The [sqlite3_snapshot_free()] interface is only available when the 10854 ** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used. 10855 */ 10856 SQLITE_API SQLITE_EXPERIMENTAL void sqlite3_snapshot_free(sqlite3_snapshot*); 10857 10858 /* 10859 ** CAPI3REF: Compare the ages of two snapshot handles. 10860 ** METHOD: sqlite3_snapshot 10861 ** 10862 ** The sqlite3_snapshot_cmp(P1, P2) interface is used to compare the ages 10863 ** of two valid snapshot handles. 10864 ** 10865 ** If the two snapshot handles are not associated with the same database 10866 ** file, the result of the comparison is undefined. 10867 ** 10868 ** Additionally, the result of the comparison is only valid if both of the 10869 ** snapshot handles were obtained by calling sqlite3_snapshot_get() since the 10870 ** last time the wal file was deleted. The wal file is deleted when the 10871 ** database is changed back to rollback mode or when the number of database 10872 ** clients drops to zero. If either snapshot handle was obtained before the 10873 ** wal file was last deleted, the value returned by this function 10874 ** is undefined. 10875 ** 10876 ** Otherwise, this API returns a negative value if P1 refers to an older 10877 ** snapshot than P2, zero if the two handles refer to the same database 10878 ** snapshot, and a positive value if P1 is a newer snapshot than P2. 10879 ** 10880 ** This interface is only available if SQLite is compiled with the 10881 ** [SQLITE_ENABLE_SNAPSHOT] option. 10882 */ 10883 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_cmp( 10884 sqlite3_snapshot *p1, 10885 sqlite3_snapshot *p2 10886 ); 10887 10888 /* 10889 ** CAPI3REF: Recover snapshots from a wal file 10890 ** METHOD: sqlite3_snapshot 10891 ** 10892 ** If a [WAL file] remains on disk after all database connections close 10893 ** (either through the use of the [SQLITE_FCNTL_PERSIST_WAL] [file control] 10894 ** or because the last process to have the database opened exited without 10895 ** calling [sqlite3_close()]) and a new connection is subsequently opened 10896 ** on that database and [WAL file], the [sqlite3_snapshot_open()] interface 10897 ** will only be able to open the last transaction added to the WAL file 10898 ** even though the WAL file contains other valid transactions. 10899 ** 10900 ** This function attempts to scan the WAL file associated with database zDb 10901 ** of database handle db and make all valid snapshots available to 10902 ** sqlite3_snapshot_open(). It is an error if there is already a read 10903 ** transaction open on the database, or if the database is not a WAL mode 10904 ** database. 10905 ** 10906 ** SQLITE_OK is returned if successful, or an SQLite error code otherwise. 10907 ** 10908 ** This interface is only available if SQLite is compiled with the 10909 ** [SQLITE_ENABLE_SNAPSHOT] option. 10910 */ 10911 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_recover(sqlite3 *db, const char *zDb); 10912 10913 /* 10914 ** CAPI3REF: Serialize a database 10915 ** 10916 ** The sqlite3_serialize(D,S,P,F) interface returns a pointer to 10917 ** memory that is a serialization of the S database on 10918 ** [database connection] D. If S is a NULL pointer, the main database is used. 10919 ** If P is not a NULL pointer, then the size of the database in bytes 10920 ** is written into *P. 10921 ** 10922 ** For an ordinary on-disk database file, the serialization is just a 10923 ** copy of the disk file. For an in-memory database or a "TEMP" database, 10924 ** the serialization is the same sequence of bytes which would be written 10925 ** to disk if that database where backed up to disk. 10926 ** 10927 ** The usual case is that sqlite3_serialize() copies the serialization of 10928 ** the database into memory obtained from [sqlite3_malloc64()] and returns 10929 ** a pointer to that memory. The caller is responsible for freeing the 10930 ** returned value to avoid a memory leak. However, if the F argument 10931 ** contains the SQLITE_SERIALIZE_NOCOPY bit, then no memory allocations 10932 ** are made, and the sqlite3_serialize() function will return a pointer 10933 ** to the contiguous memory representation of the database that SQLite 10934 ** is currently using for that database, or NULL if the no such contiguous 10935 ** memory representation of the database exists. A contiguous memory 10936 ** representation of the database will usually only exist if there has 10937 ** been a prior call to [sqlite3_deserialize(D,S,...)] with the same 10938 ** values of D and S. 10939 ** The size of the database is written into *P even if the 10940 ** SQLITE_SERIALIZE_NOCOPY bit is set but no contiguous copy 10941 ** of the database exists. 10942 ** 10943 ** After the call, if the SQLITE_SERIALIZE_NOCOPY bit had been set, 10944 ** the returned buffer content will remain accessible and unchanged 10945 ** until either the next write operation on the connection or when 10946 ** the connection is closed, and applications must not modify the 10947 ** buffer. If the bit had been clear, the returned buffer will not 10948 ** be accessed by SQLite after the call. 10949 ** 10950 ** A call to sqlite3_serialize(D,S,P,F) might return NULL even if the 10951 ** SQLITE_SERIALIZE_NOCOPY bit is omitted from argument F if a memory 10952 ** allocation error occurs. 10953 ** 10954 ** This interface is omitted if SQLite is compiled with the 10955 ** [SQLITE_OMIT_DESERIALIZE] option. 10956 */ 10957 SQLITE_API unsigned char *sqlite3_serialize( 10958 sqlite3 *db, /* The database connection */ 10959 const char *zSchema, /* Which DB to serialize. ex: "main", "temp", ... */ 10960 sqlite3_int64 *piSize, /* Write size of the DB here, if not NULL */ 10961 unsigned int mFlags /* Zero or more SQLITE_SERIALIZE_* flags */ 10962 ); 10963 10964 /* 10965 ** CAPI3REF: Flags for sqlite3_serialize 10966 ** 10967 ** Zero or more of the following constants can be OR-ed together for 10968 ** the F argument to [sqlite3_serialize(D,S,P,F)]. 10969 ** 10970 ** SQLITE_SERIALIZE_NOCOPY means that [sqlite3_serialize()] will return 10971 ** a pointer to contiguous in-memory database that it is currently using, 10972 ** without making a copy of the database. If SQLite is not currently using 10973 ** a contiguous in-memory database, then this option causes 10974 ** [sqlite3_serialize()] to return a NULL pointer. SQLite will only be 10975 ** using a contiguous in-memory database if it has been initialized by a 10976 ** prior call to [sqlite3_deserialize()]. 10977 */ 10978 #define SQLITE_SERIALIZE_NOCOPY 0x001 /* Do no memory allocations */ 10979 10980 /* 10981 ** CAPI3REF: Deserialize a database 10982 ** 10983 ** The sqlite3_deserialize(D,S,P,N,M,F) interface causes the 10984 ** [database connection] D to disconnect from database S and then 10985 ** reopen S as an in-memory database based on the serialization contained 10986 ** in P. The serialized database P is N bytes in size. M is the size of 10987 ** the buffer P, which might be larger than N. If M is larger than N, and 10988 ** the SQLITE_DESERIALIZE_READONLY bit is not set in F, then SQLite is 10989 ** permitted to add content to the in-memory database as long as the total 10990 ** size does not exceed M bytes. 10991 ** 10992 ** If the SQLITE_DESERIALIZE_FREEONCLOSE bit is set in F, then SQLite will 10993 ** invoke sqlite3_free() on the serialization buffer when the database 10994 ** connection closes. If the SQLITE_DESERIALIZE_RESIZEABLE bit is set, then 10995 ** SQLite will try to increase the buffer size using sqlite3_realloc64() 10996 ** if writes on the database cause it to grow larger than M bytes. 10997 ** 10998 ** Applications must not modify the buffer P or invalidate it before 10999 ** the database connection D is closed. 11000 ** 11001 ** The sqlite3_deserialize() interface will fail with SQLITE_BUSY if the 11002 ** database is currently in a read transaction or is involved in a backup 11003 ** operation. 11004 ** 11005 ** It is not possible to deserialized into the TEMP database. If the 11006 ** S argument to sqlite3_deserialize(D,S,P,N,M,F) is "temp" then the 11007 ** function returns SQLITE_ERROR. 11008 ** 11009 ** The deserialized database should not be in [WAL mode]. If the database 11010 ** is in WAL mode, then any attempt to use the database file will result 11011 ** in an [SQLITE_CANTOPEN] error. The application can set the 11012 ** [file format version numbers] (bytes 18 and 19) of the input database P 11013 ** to 0x01 prior to invoking sqlite3_deserialize(D,S,P,N,M,F) to force the 11014 ** database file into rollback mode and work around this limitation. 11015 ** 11016 ** If sqlite3_deserialize(D,S,P,N,M,F) fails for any reason and if the 11017 ** SQLITE_DESERIALIZE_FREEONCLOSE bit is set in argument F, then 11018 ** [sqlite3_free()] is invoked on argument P prior to returning. 11019 ** 11020 ** This interface is omitted if SQLite is compiled with the 11021 ** [SQLITE_OMIT_DESERIALIZE] option. 11022 */ 11023 SQLITE_API int sqlite3_deserialize( 11024 sqlite3 *db, /* The database connection */ 11025 const char *zSchema, /* Which DB to reopen with the deserialization */ 11026 unsigned char *pData, /* The serialized database content */ 11027 sqlite3_int64 szDb, /* Number bytes in the deserialization */ 11028 sqlite3_int64 szBuf, /* Total size of buffer pData[] */ 11029 unsigned mFlags /* Zero or more SQLITE_DESERIALIZE_* flags */ 11030 ); 11031 11032 /* 11033 ** CAPI3REF: Flags for sqlite3_deserialize() 11034 ** 11035 ** The following are allowed values for 6th argument (the F argument) to 11036 ** the [sqlite3_deserialize(D,S,P,N,M,F)] interface. 11037 ** 11038 ** The SQLITE_DESERIALIZE_FREEONCLOSE means that the database serialization 11039 ** in the P argument is held in memory obtained from [sqlite3_malloc64()] 11040 ** and that SQLite should take ownership of this memory and automatically 11041 ** free it when it has finished using it. Without this flag, the caller 11042 ** is responsible for freeing any dynamically allocated memory. 11043 ** 11044 ** The SQLITE_DESERIALIZE_RESIZEABLE flag means that SQLite is allowed to 11045 ** grow the size of the database using calls to [sqlite3_realloc64()]. This 11046 ** flag should only be used if SQLITE_DESERIALIZE_FREEONCLOSE is also used. 11047 ** Without this flag, the deserialized database cannot increase in size beyond 11048 ** the number of bytes specified by the M parameter. 11049 ** 11050 ** The SQLITE_DESERIALIZE_READONLY flag means that the deserialized database 11051 ** should be treated as read-only. 11052 */ 11053 #define SQLITE_DESERIALIZE_FREEONCLOSE 1 /* Call sqlite3_free() on close */ 11054 #define SQLITE_DESERIALIZE_RESIZEABLE 2 /* Resize using sqlite3_realloc64() */ 11055 #define SQLITE_DESERIALIZE_READONLY 4 /* Database is read-only */ 11056 11057 /* 11058 ** Undo the hack that converts floating point types to integer for 11059 ** builds on processors without floating point support. 11060 */ 11061 #ifdef SQLITE_OMIT_FLOATING_POINT 11062 # undef double 11063 #endif 11064 11065 #if defined(__wasi__) 11066 # undef SQLITE_WASI 11067 # define SQLITE_WASI 1 11068 # ifndef SQLITE_OMIT_LOAD_EXTENSION 11069 # define SQLITE_OMIT_LOAD_EXTENSION 11070 # endif 11071 # ifndef SQLITE_THREADSAFE 11072 # define SQLITE_THREADSAFE 0 11073 # endif 11074 #endif 11075 11076 #ifdef __cplusplus 11077 } /* End of the 'extern "C"' block */ 11078 #endif 11079 /* #endif for SQLITE3_H will be added by mksqlite3.tcl */ 11080 11081 /******** Begin file sqlite3rtree.h *********/ 11082 /* 11083 ** 2010 August 30 11084 ** 11085 ** The author disclaims copyright to this source code. In place of 11086 ** a legal notice, here is a blessing: 11087 ** 11088 ** May you do good and not evil. 11089 ** May you find forgiveness for yourself and forgive others. 11090 ** May you share freely, never taking more than you give. 11091 ** 11092 ************************************************************************* 11093 */ 11094 11095 #ifndef _SQLITE3RTREE_H_ 11096 #define _SQLITE3RTREE_H_ 11097 11098 11099 #ifdef __cplusplus 11100 extern "C" { 11101 #endif 11102 11103 typedef struct sqlite3_rtree_geometry sqlite3_rtree_geometry; 11104 typedef struct sqlite3_rtree_query_info sqlite3_rtree_query_info; 11105 11106 /* The double-precision datatype used by RTree depends on the 11107 ** SQLITE_RTREE_INT_ONLY compile-time option. 11108 */ 11109 #ifdef SQLITE_RTREE_INT_ONLY 11110 typedef sqlite3_int64 sqlite3_rtree_dbl; 11111 #else 11112 typedef double sqlite3_rtree_dbl; 11113 #endif 11114 11115 /* 11116 ** Register a geometry callback named zGeom that can be used as part of an 11117 ** R-Tree geometry query as follows: 11118 ** 11119 ** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zGeom(... params ...) 11120 */ 11121 SQLITE_API int sqlite3_rtree_geometry_callback( 11122 sqlite3 *db, 11123 const char *zGeom, 11124 int (*xGeom)(sqlite3_rtree_geometry*, int, sqlite3_rtree_dbl*,int*), 11125 void *pContext 11126 ); 11127 11128 11129 /* 11130 ** A pointer to a structure of the following type is passed as the first 11131 ** argument to callbacks registered using rtree_geometry_callback(). 11132 */ 11133 struct sqlite3_rtree_geometry { 11134 void *pContext; /* Copy of pContext passed to s_r_g_c() */ 11135 int nParam; /* Size of array aParam[] */ 11136 sqlite3_rtree_dbl *aParam; /* Parameters passed to SQL geom function */ 11137 void *pUser; /* Callback implementation user data */ 11138 void (*xDelUser)(void *); /* Called by SQLite to clean up pUser */ 11139 }; 11140 11141 /* 11142 ** Register a 2nd-generation geometry callback named zScore that can be 11143 ** used as part of an R-Tree geometry query as follows: 11144 ** 11145 ** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zQueryFunc(... params ...) 11146 */ 11147 SQLITE_API int sqlite3_rtree_query_callback( 11148 sqlite3 *db, 11149 const char *zQueryFunc, 11150 int (*xQueryFunc)(sqlite3_rtree_query_info*), 11151 void *pContext, 11152 void (*xDestructor)(void*) 11153 ); 11154 11155 11156 /* 11157 ** A pointer to a structure of the following type is passed as the 11158 ** argument to scored geometry callback registered using 11159 ** sqlite3_rtree_query_callback(). 11160 ** 11161 ** Note that the first 5 fields of this structure are identical to 11162 ** sqlite3_rtree_geometry. This structure is a subclass of 11163 ** sqlite3_rtree_geometry. 11164 */ 11165 struct sqlite3_rtree_query_info { 11166 void *pContext; /* pContext from when function registered */ 11167 int nParam; /* Number of function parameters */ 11168 sqlite3_rtree_dbl *aParam; /* value of function parameters */ 11169 void *pUser; /* callback can use this, if desired */ 11170 void (*xDelUser)(void*); /* function to free pUser */ 11171 sqlite3_rtree_dbl *aCoord; /* Coordinates of node or entry to check */ 11172 unsigned int *anQueue; /* Number of pending entries in the queue */ 11173 int nCoord; /* Number of coordinates */ 11174 int iLevel; /* Level of current node or entry */ 11175 int mxLevel; /* The largest iLevel value in the tree */ 11176 sqlite3_int64 iRowid; /* Rowid for current entry */ 11177 sqlite3_rtree_dbl rParentScore; /* Score of parent node */ 11178 int eParentWithin; /* Visibility of parent node */ 11179 int eWithin; /* OUT: Visibility */ 11180 sqlite3_rtree_dbl rScore; /* OUT: Write the score here */ 11181 /* The following fields are only available in 3.8.11 and later */ 11182 sqlite3_value **apSqlParam; /* Original SQL values of parameters */ 11183 }; 11184 11185 /* 11186 ** Allowed values for sqlite3_rtree_query.eWithin and .eParentWithin. 11187 */ 11188 #define NOT_WITHIN 0 /* Object completely outside of query region */ 11189 #define PARTLY_WITHIN 1 /* Object partially overlaps query region */ 11190 #define FULLY_WITHIN 2 /* Object fully contained within query region */ 11191 11192 11193 #ifdef __cplusplus 11194 } /* end of the 'extern "C"' block */ 11195 #endif 11196 11197 #endif /* ifndef _SQLITE3RTREE_H_ */ 11198 11199 /******** End of sqlite3rtree.h *********/ 11200 /******** Begin file sqlite3session.h *********/ 11201 11202 #if !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION) 11203 #define __SQLITESESSION_H_ 1 11204 11205 /* 11206 ** Make sure we can call this stuff from C++. 11207 */ 11208 #ifdef __cplusplus 11209 extern "C" { 11210 #endif 11211 11212 11213 /* 11214 ** CAPI3REF: Session Object Handle 11215 ** 11216 ** An instance of this object is a [session] that can be used to 11217 ** record changes to a database. 11218 */ 11219 typedef struct sqlite3_session sqlite3_session; 11220 11221 /* 11222 ** CAPI3REF: Changeset Iterator Handle 11223 ** 11224 ** An instance of this object acts as a cursor for iterating 11225 ** over the elements of a [changeset] or [patchset]. 11226 */ 11227 typedef struct sqlite3_changeset_iter sqlite3_changeset_iter; 11228 11229 /* 11230 ** CAPI3REF: Create A New Session Object 11231 ** CONSTRUCTOR: sqlite3_session 11232 ** 11233 ** Create a new session object attached to database handle db. If successful, 11234 ** a pointer to the new object is written to *ppSession and SQLITE_OK is 11235 ** returned. If an error occurs, *ppSession is set to NULL and an SQLite 11236 ** error code (e.g. SQLITE_NOMEM) is returned. 11237 ** 11238 ** It is possible to create multiple session objects attached to a single 11239 ** database handle. 11240 ** 11241 ** Session objects created using this function should be deleted using the 11242 ** [sqlite3session_delete()] function before the database handle that they 11243 ** are attached to is itself closed. If the database handle is closed before 11244 ** the session object is deleted, then the results of calling any session 11245 ** module function, including [sqlite3session_delete()] on the session object 11246 ** are undefined. 11247 ** 11248 ** Because the session module uses the [sqlite3_preupdate_hook()] API, it 11249 ** is not possible for an application to register a pre-update hook on a 11250 ** database handle that has one or more session objects attached. Nor is 11251 ** it possible to create a session object attached to a database handle for 11252 ** which a pre-update hook is already defined. The results of attempting 11253 ** either of these things are undefined. 11254 ** 11255 ** The session object will be used to create changesets for tables in 11256 ** database zDb, where zDb is either "main", or "temp", or the name of an 11257 ** attached database. It is not an error if database zDb is not attached 11258 ** to the database when the session object is created. 11259 */ 11260 SQLITE_API int sqlite3session_create( 11261 sqlite3 *db, /* Database handle */ 11262 const char *zDb, /* Name of db (e.g. "main") */ 11263 sqlite3_session **ppSession /* OUT: New session object */ 11264 ); 11265 11266 /* 11267 ** CAPI3REF: Delete A Session Object 11268 ** DESTRUCTOR: sqlite3_session 11269 ** 11270 ** Delete a session object previously allocated using 11271 ** [sqlite3session_create()]. Once a session object has been deleted, the 11272 ** results of attempting to use pSession with any other session module 11273 ** function are undefined. 11274 ** 11275 ** Session objects must be deleted before the database handle to which they 11276 ** are attached is closed. Refer to the documentation for 11277 ** [sqlite3session_create()] for details. 11278 */ 11279 SQLITE_API void sqlite3session_delete(sqlite3_session *pSession); 11280 11281 /* 11282 ** CAPI3REF: Configure a Session Object 11283 ** METHOD: sqlite3_session 11284 ** 11285 ** This method is used to configure a session object after it has been 11286 ** created. At present the only valid values for the second parameter are 11287 ** [SQLITE_SESSION_OBJCONFIG_SIZE] and [SQLITE_SESSION_OBJCONFIG_ROWID]. 11288 ** 11289 */ 11290 SQLITE_API int sqlite3session_object_config(sqlite3_session*, int op, void *pArg); 11291 11292 /* 11293 ** CAPI3REF: Options for sqlite3session_object_config 11294 ** 11295 ** The following values may passed as the the 2nd parameter to 11296 ** sqlite3session_object_config(). 11297 ** 11298 ** <dt>SQLITE_SESSION_OBJCONFIG_SIZE <dd> 11299 ** This option is used to set, clear or query the flag that enables 11300 ** the [sqlite3session_changeset_size()] API. Because it imposes some 11301 ** computational overhead, this API is disabled by default. Argument 11302 ** pArg must point to a value of type (int). If the value is initially 11303 ** 0, then the sqlite3session_changeset_size() API is disabled. If it 11304 ** is greater than 0, then the same API is enabled. Or, if the initial 11305 ** value is less than zero, no change is made. In all cases the (int) 11306 ** variable is set to 1 if the sqlite3session_changeset_size() API is 11307 ** enabled following the current call, or 0 otherwise. 11308 ** 11309 ** It is an error (SQLITE_MISUSE) to attempt to modify this setting after 11310 ** the first table has been attached to the session object. 11311 ** 11312 ** <dt>SQLITE_SESSION_OBJCONFIG_ROWID <dd> 11313 ** This option is used to set, clear or query the flag that enables 11314 ** collection of data for tables with no explicit PRIMARY KEY. 11315 ** 11316 ** Normally, tables with no explicit PRIMARY KEY are simply ignored 11317 ** by the sessions module. However, if this flag is set, it behaves 11318 ** as if such tables have a column "_rowid_ INTEGER PRIMARY KEY" inserted 11319 ** as their leftmost columns. 11320 ** 11321 ** It is an error (SQLITE_MISUSE) to attempt to modify this setting after 11322 ** the first table has been attached to the session object. 11323 */ 11324 #define SQLITE_SESSION_OBJCONFIG_SIZE 1 11325 #define SQLITE_SESSION_OBJCONFIG_ROWID 2 11326 11327 /* 11328 ** CAPI3REF: Enable Or Disable A Session Object 11329 ** METHOD: sqlite3_session 11330 ** 11331 ** Enable or disable the recording of changes by a session object. When 11332 ** enabled, a session object records changes made to the database. When 11333 ** disabled - it does not. A newly created session object is enabled. 11334 ** Refer to the documentation for [sqlite3session_changeset()] for further 11335 ** details regarding how enabling and disabling a session object affects 11336 ** the eventual changesets. 11337 ** 11338 ** Passing zero to this function disables the session. Passing a value 11339 ** greater than zero enables it. Passing a value less than zero is a 11340 ** no-op, and may be used to query the current state of the session. 11341 ** 11342 ** The return value indicates the final state of the session object: 0 if 11343 ** the session is disabled, or 1 if it is enabled. 11344 */ 11345 SQLITE_API int sqlite3session_enable(sqlite3_session *pSession, int bEnable); 11346 11347 /* 11348 ** CAPI3REF: Set Or Clear the Indirect Change Flag 11349 ** METHOD: sqlite3_session 11350 ** 11351 ** Each change recorded by a session object is marked as either direct or 11352 ** indirect. A change is marked as indirect if either: 11353 ** 11354 ** <ul> 11355 ** <li> The session object "indirect" flag is set when the change is 11356 ** made, or 11357 ** <li> The change is made by an SQL trigger or foreign key action 11358 ** instead of directly as a result of a users SQL statement. 11359 ** </ul> 11360 ** 11361 ** If a single row is affected by more than one operation within a session, 11362 ** then the change is considered indirect if all operations meet the criteria 11363 ** for an indirect change above, or direct otherwise. 11364 ** 11365 ** This function is used to set, clear or query the session object indirect 11366 ** flag. If the second argument passed to this function is zero, then the 11367 ** indirect flag is cleared. If it is greater than zero, the indirect flag 11368 ** is set. Passing a value less than zero does not modify the current value 11369 ** of the indirect flag, and may be used to query the current state of the 11370 ** indirect flag for the specified session object. 11371 ** 11372 ** The return value indicates the final state of the indirect flag: 0 if 11373 ** it is clear, or 1 if it is set. 11374 */ 11375 SQLITE_API int sqlite3session_indirect(sqlite3_session *pSession, int bIndirect); 11376 11377 /* 11378 ** CAPI3REF: Attach A Table To A Session Object 11379 ** METHOD: sqlite3_session 11380 ** 11381 ** If argument zTab is not NULL, then it is the name of a table to attach 11382 ** to the session object passed as the first argument. All subsequent changes 11383 ** made to the table while the session object is enabled will be recorded. See 11384 ** documentation for [sqlite3session_changeset()] for further details. 11385 ** 11386 ** Or, if argument zTab is NULL, then changes are recorded for all tables 11387 ** in the database. If additional tables are added to the database (by 11388 ** executing "CREATE TABLE" statements) after this call is made, changes for 11389 ** the new tables are also recorded. 11390 ** 11391 ** Changes can only be recorded for tables that have a PRIMARY KEY explicitly 11392 ** defined as part of their CREATE TABLE statement. It does not matter if the 11393 ** PRIMARY KEY is an "INTEGER PRIMARY KEY" (rowid alias) or not. The PRIMARY 11394 ** KEY may consist of a single column, or may be a composite key. 11395 ** 11396 ** It is not an error if the named table does not exist in the database. Nor 11397 ** is it an error if the named table does not have a PRIMARY KEY. However, 11398 ** no changes will be recorded in either of these scenarios. 11399 ** 11400 ** Changes are not recorded for individual rows that have NULL values stored 11401 ** in one or more of their PRIMARY KEY columns. 11402 ** 11403 ** SQLITE_OK is returned if the call completes without error. Or, if an error 11404 ** occurs, an SQLite error code (e.g. SQLITE_NOMEM) is returned. 11405 ** 11406 ** <h3>Special sqlite_stat1 Handling</h3> 11407 ** 11408 ** As of SQLite version 3.22.0, the "sqlite_stat1" table is an exception to 11409 ** some of the rules above. In SQLite, the schema of sqlite_stat1 is: 11410 ** <pre> 11411 ** CREATE TABLE sqlite_stat1(tbl,idx,stat) 11412 ** </pre> 11413 ** 11414 ** Even though sqlite_stat1 does not have a PRIMARY KEY, changes are 11415 ** recorded for it as if the PRIMARY KEY is (tbl,idx). Additionally, changes 11416 ** are recorded for rows for which (idx IS NULL) is true. However, for such 11417 ** rows a zero-length blob (SQL value X'') is stored in the changeset or 11418 ** patchset instead of a NULL value. This allows such changesets to be 11419 ** manipulated by legacy implementations of sqlite3changeset_invert(), 11420 ** concat() and similar. 11421 ** 11422 ** The sqlite3changeset_apply() function automatically converts the 11423 ** zero-length blob back to a NULL value when updating the sqlite_stat1 11424 ** table. However, if the application calls sqlite3changeset_new(), 11425 ** sqlite3changeset_old() or sqlite3changeset_conflict on a changeset 11426 ** iterator directly (including on a changeset iterator passed to a 11427 ** conflict-handler callback) then the X'' value is returned. The application 11428 ** must translate X'' to NULL itself if required. 11429 ** 11430 ** Legacy (older than 3.22.0) versions of the sessions module cannot capture 11431 ** changes made to the sqlite_stat1 table. Legacy versions of the 11432 ** sqlite3changeset_apply() function silently ignore any modifications to the 11433 ** sqlite_stat1 table that are part of a changeset or patchset. 11434 */ 11435 SQLITE_API int sqlite3session_attach( 11436 sqlite3_session *pSession, /* Session object */ 11437 const char *zTab /* Table name */ 11438 ); 11439 11440 /* 11441 ** CAPI3REF: Set a table filter on a Session Object. 11442 ** METHOD: sqlite3_session 11443 ** 11444 ** The second argument (xFilter) is the "filter callback". For changes to rows 11445 ** in tables that are not attached to the Session object, the filter is called 11446 ** to determine whether changes to the table's rows should be tracked or not. 11447 ** If xFilter returns 0, changes are not tracked. Note that once a table is 11448 ** attached, xFilter will not be called again. 11449 */ 11450 SQLITE_API void sqlite3session_table_filter( 11451 sqlite3_session *pSession, /* Session object */ 11452 int(*xFilter)( 11453 void *pCtx, /* Copy of third arg to _filter_table() */ 11454 const char *zTab /* Table name */ 11455 ), 11456 void *pCtx /* First argument passed to xFilter */ 11457 ); 11458 11459 /* 11460 ** CAPI3REF: Generate A Changeset From A Session Object 11461 ** METHOD: sqlite3_session 11462 ** 11463 ** Obtain a changeset containing changes to the tables attached to the 11464 ** session object passed as the first argument. If successful, 11465 ** set *ppChangeset to point to a buffer containing the changeset 11466 ** and *pnChangeset to the size of the changeset in bytes before returning 11467 ** SQLITE_OK. If an error occurs, set both *ppChangeset and *pnChangeset to 11468 ** zero and return an SQLite error code. 11469 ** 11470 ** A changeset consists of zero or more INSERT, UPDATE and/or DELETE changes, 11471 ** each representing a change to a single row of an attached table. An INSERT 11472 ** change contains the values of each field of a new database row. A DELETE 11473 ** contains the original values of each field of a deleted database row. An 11474 ** UPDATE change contains the original values of each field of an updated 11475 ** database row along with the updated values for each updated non-primary-key 11476 ** column. It is not possible for an UPDATE change to represent a change that 11477 ** modifies the values of primary key columns. If such a change is made, it 11478 ** is represented in a changeset as a DELETE followed by an INSERT. 11479 ** 11480 ** Changes are not recorded for rows that have NULL values stored in one or 11481 ** more of their PRIMARY KEY columns. If such a row is inserted or deleted, 11482 ** no corresponding change is present in the changesets returned by this 11483 ** function. If an existing row with one or more NULL values stored in 11484 ** PRIMARY KEY columns is updated so that all PRIMARY KEY columns are non-NULL, 11485 ** only an INSERT is appears in the changeset. Similarly, if an existing row 11486 ** with non-NULL PRIMARY KEY values is updated so that one or more of its 11487 ** PRIMARY KEY columns are set to NULL, the resulting changeset contains a 11488 ** DELETE change only. 11489 ** 11490 ** The contents of a changeset may be traversed using an iterator created 11491 ** using the [sqlite3changeset_start()] API. A changeset may be applied to 11492 ** a database with a compatible schema using the [sqlite3changeset_apply()] 11493 ** API. 11494 ** 11495 ** Within a changeset generated by this function, all changes related to a 11496 ** single table are grouped together. In other words, when iterating through 11497 ** a changeset or when applying a changeset to a database, all changes related 11498 ** to a single table are processed before moving on to the next table. Tables 11499 ** are sorted in the same order in which they were attached (or auto-attached) 11500 ** to the sqlite3_session object. The order in which the changes related to 11501 ** a single table are stored is undefined. 11502 ** 11503 ** Following a successful call to this function, it is the responsibility of 11504 ** the caller to eventually free the buffer that *ppChangeset points to using 11505 ** [sqlite3_free()]. 11506 ** 11507 ** <h3>Changeset Generation</h3> 11508 ** 11509 ** Once a table has been attached to a session object, the session object 11510 ** records the primary key values of all new rows inserted into the table. 11511 ** It also records the original primary key and other column values of any 11512 ** deleted or updated rows. For each unique primary key value, data is only 11513 ** recorded once - the first time a row with said primary key is inserted, 11514 ** updated or deleted in the lifetime of the session. 11515 ** 11516 ** There is one exception to the previous paragraph: when a row is inserted, 11517 ** updated or deleted, if one or more of its primary key columns contain a 11518 ** NULL value, no record of the change is made. 11519 ** 11520 ** The session object therefore accumulates two types of records - those 11521 ** that consist of primary key values only (created when the user inserts 11522 ** a new record) and those that consist of the primary key values and the 11523 ** original values of other table columns (created when the users deletes 11524 ** or updates a record). 11525 ** 11526 ** When this function is called, the requested changeset is created using 11527 ** both the accumulated records and the current contents of the database 11528 ** file. Specifically: 11529 ** 11530 ** <ul> 11531 ** <li> For each record generated by an insert, the database is queried 11532 ** for a row with a matching primary key. If one is found, an INSERT 11533 ** change is added to the changeset. If no such row is found, no change 11534 ** is added to the changeset. 11535 ** 11536 ** <li> For each record generated by an update or delete, the database is 11537 ** queried for a row with a matching primary key. If such a row is 11538 ** found and one or more of the non-primary key fields have been 11539 ** modified from their original values, an UPDATE change is added to 11540 ** the changeset. Or, if no such row is found in the table, a DELETE 11541 ** change is added to the changeset. If there is a row with a matching 11542 ** primary key in the database, but all fields contain their original 11543 ** values, no change is added to the changeset. 11544 ** </ul> 11545 ** 11546 ** This means, amongst other things, that if a row is inserted and then later 11547 ** deleted while a session object is active, neither the insert nor the delete 11548 ** will be present in the changeset. Or if a row is deleted and then later a 11549 ** row with the same primary key values inserted while a session object is 11550 ** active, the resulting changeset will contain an UPDATE change instead of 11551 ** a DELETE and an INSERT. 11552 ** 11553 ** When a session object is disabled (see the [sqlite3session_enable()] API), 11554 ** it does not accumulate records when rows are inserted, updated or deleted. 11555 ** This may appear to have some counter-intuitive effects if a single row 11556 ** is written to more than once during a session. For example, if a row 11557 ** is inserted while a session object is enabled, then later deleted while 11558 ** the same session object is disabled, no INSERT record will appear in the 11559 ** changeset, even though the delete took place while the session was disabled. 11560 ** Or, if one field of a row is updated while a session is enabled, and 11561 ** then another field of the same row is updated while the session is disabled, 11562 ** the resulting changeset will contain an UPDATE change that updates both 11563 ** fields. 11564 */ 11565 SQLITE_API int sqlite3session_changeset( 11566 sqlite3_session *pSession, /* Session object */ 11567 int *pnChangeset, /* OUT: Size of buffer at *ppChangeset */ 11568 void **ppChangeset /* OUT: Buffer containing changeset */ 11569 ); 11570 11571 /* 11572 ** CAPI3REF: Return An Upper-limit For The Size Of The Changeset 11573 ** METHOD: sqlite3_session 11574 ** 11575 ** By default, this function always returns 0. For it to return 11576 ** a useful result, the sqlite3_session object must have been configured 11577 ** to enable this API using sqlite3session_object_config() with the 11578 ** SQLITE_SESSION_OBJCONFIG_SIZE verb. 11579 ** 11580 ** When enabled, this function returns an upper limit, in bytes, for the size 11581 ** of the changeset that might be produced if sqlite3session_changeset() were 11582 ** called. The final changeset size might be equal to or smaller than the 11583 ** size in bytes returned by this function. 11584 */ 11585 SQLITE_API sqlite3_int64 sqlite3session_changeset_size(sqlite3_session *pSession); 11586 11587 /* 11588 ** CAPI3REF: Load The Difference Between Tables Into A Session 11589 ** METHOD: sqlite3_session 11590 ** 11591 ** If it is not already attached to the session object passed as the first 11592 ** argument, this function attaches table zTbl in the same manner as the 11593 ** [sqlite3session_attach()] function. If zTbl does not exist, or if it 11594 ** does not have a primary key, this function is a no-op (but does not return 11595 ** an error). 11596 ** 11597 ** Argument zFromDb must be the name of a database ("main", "temp" etc.) 11598 ** attached to the same database handle as the session object that contains 11599 ** a table compatible with the table attached to the session by this function. 11600 ** A table is considered compatible if it: 11601 ** 11602 ** <ul> 11603 ** <li> Has the same name, 11604 ** <li> Has the same set of columns declared in the same order, and 11605 ** <li> Has the same PRIMARY KEY definition. 11606 ** </ul> 11607 ** 11608 ** If the tables are not compatible, SQLITE_SCHEMA is returned. If the tables 11609 ** are compatible but do not have any PRIMARY KEY columns, it is not an error 11610 ** but no changes are added to the session object. As with other session 11611 ** APIs, tables without PRIMARY KEYs are simply ignored. 11612 ** 11613 ** This function adds a set of changes to the session object that could be 11614 ** used to update the table in database zFrom (call this the "from-table") 11615 ** so that its content is the same as the table attached to the session 11616 ** object (call this the "to-table"). Specifically: 11617 ** 11618 ** <ul> 11619 ** <li> For each row (primary key) that exists in the to-table but not in 11620 ** the from-table, an INSERT record is added to the session object. 11621 ** 11622 ** <li> For each row (primary key) that exists in the to-table but not in 11623 ** the from-table, a DELETE record is added to the session object. 11624 ** 11625 ** <li> For each row (primary key) that exists in both tables, but features 11626 ** different non-PK values in each, an UPDATE record is added to the 11627 ** session. 11628 ** </ul> 11629 ** 11630 ** To clarify, if this function is called and then a changeset constructed 11631 ** using [sqlite3session_changeset()], then after applying that changeset to 11632 ** database zFrom the contents of the two compatible tables would be 11633 ** identical. 11634 ** 11635 ** Unless the call to this function is a no-op as described above, it is an 11636 ** error if database zFrom does not exist or does not contain the required 11637 ** compatible table. 11638 ** 11639 ** If the operation is successful, SQLITE_OK is returned. Otherwise, an SQLite 11640 ** error code. In this case, if argument pzErrMsg is not NULL, *pzErrMsg 11641 ** may be set to point to a buffer containing an English language error 11642 ** message. It is the responsibility of the caller to free this buffer using 11643 ** sqlite3_free(). 11644 */ 11645 SQLITE_API int sqlite3session_diff( 11646 sqlite3_session *pSession, 11647 const char *zFromDb, 11648 const char *zTbl, 11649 char **pzErrMsg 11650 ); 11651 11652 11653 /* 11654 ** CAPI3REF: Generate A Patchset From A Session Object 11655 ** METHOD: sqlite3_session 11656 ** 11657 ** The differences between a patchset and a changeset are that: 11658 ** 11659 ** <ul> 11660 ** <li> DELETE records consist of the primary key fields only. The 11661 ** original values of other fields are omitted. 11662 ** <li> The original values of any modified fields are omitted from 11663 ** UPDATE records. 11664 ** </ul> 11665 ** 11666 ** A patchset blob may be used with up to date versions of all 11667 ** sqlite3changeset_xxx API functions except for sqlite3changeset_invert(), 11668 ** which returns SQLITE_CORRUPT if it is passed a patchset. Similarly, 11669 ** attempting to use a patchset blob with old versions of the 11670 ** sqlite3changeset_xxx APIs also provokes an SQLITE_CORRUPT error. 11671 ** 11672 ** Because the non-primary key "old.*" fields are omitted, no 11673 ** SQLITE_CHANGESET_DATA conflicts can be detected or reported if a patchset 11674 ** is passed to the sqlite3changeset_apply() API. Other conflict types work 11675 ** in the same way as for changesets. 11676 ** 11677 ** Changes within a patchset are ordered in the same way as for changesets 11678 ** generated by the sqlite3session_changeset() function (i.e. all changes for 11679 ** a single table are grouped together, tables appear in the order in which 11680 ** they were attached to the session object). 11681 */ 11682 SQLITE_API int sqlite3session_patchset( 11683 sqlite3_session *pSession, /* Session object */ 11684 int *pnPatchset, /* OUT: Size of buffer at *ppPatchset */ 11685 void **ppPatchset /* OUT: Buffer containing patchset */ 11686 ); 11687 11688 /* 11689 ** CAPI3REF: Test if a changeset has recorded any changes. 11690 ** 11691 ** Return non-zero if no changes to attached tables have been recorded by 11692 ** the session object passed as the first argument. Otherwise, if one or 11693 ** more changes have been recorded, return zero. 11694 ** 11695 ** Even if this function returns zero, it is possible that calling 11696 ** [sqlite3session_changeset()] on the session handle may still return a 11697 ** changeset that contains no changes. This can happen when a row in 11698 ** an attached table is modified and then later on the original values 11699 ** are restored. However, if this function returns non-zero, then it is 11700 ** guaranteed that a call to sqlite3session_changeset() will return a 11701 ** changeset containing zero changes. 11702 */ 11703 SQLITE_API int sqlite3session_isempty(sqlite3_session *pSession); 11704 11705 /* 11706 ** CAPI3REF: Query for the amount of heap memory used by a session object. 11707 ** 11708 ** This API returns the total amount of heap memory in bytes currently 11709 ** used by the session object passed as the only argument. 11710 */ 11711 SQLITE_API sqlite3_int64 sqlite3session_memory_used(sqlite3_session *pSession); 11712 11713 /* 11714 ** CAPI3REF: Create An Iterator To Traverse A Changeset 11715 ** CONSTRUCTOR: sqlite3_changeset_iter 11716 ** 11717 ** Create an iterator used to iterate through the contents of a changeset. 11718 ** If successful, *pp is set to point to the iterator handle and SQLITE_OK 11719 ** is returned. Otherwise, if an error occurs, *pp is set to zero and an 11720 ** SQLite error code is returned. 11721 ** 11722 ** The following functions can be used to advance and query a changeset 11723 ** iterator created by this function: 11724 ** 11725 ** <ul> 11726 ** <li> [sqlite3changeset_next()] 11727 ** <li> [sqlite3changeset_op()] 11728 ** <li> [sqlite3changeset_new()] 11729 ** <li> [sqlite3changeset_old()] 11730 ** </ul> 11731 ** 11732 ** It is the responsibility of the caller to eventually destroy the iterator 11733 ** by passing it to [sqlite3changeset_finalize()]. The buffer containing the 11734 ** changeset (pChangeset) must remain valid until after the iterator is 11735 ** destroyed. 11736 ** 11737 ** Assuming the changeset blob was created by one of the 11738 ** [sqlite3session_changeset()], [sqlite3changeset_concat()] or 11739 ** [sqlite3changeset_invert()] functions, all changes within the changeset 11740 ** that apply to a single table are grouped together. This means that when 11741 ** an application iterates through a changeset using an iterator created by 11742 ** this function, all changes that relate to a single table are visited 11743 ** consecutively. There is no chance that the iterator will visit a change 11744 ** the applies to table X, then one for table Y, and then later on visit 11745 ** another change for table X. 11746 ** 11747 ** The behavior of sqlite3changeset_start_v2() and its streaming equivalent 11748 ** may be modified by passing a combination of 11749 ** [SQLITE_CHANGESETSTART_INVERT | supported flags] as the 4th parameter. 11750 ** 11751 ** Note that the sqlite3changeset_start_v2() API is still <b>experimental</b> 11752 ** and therefore subject to change. 11753 */ 11754 SQLITE_API int sqlite3changeset_start( 11755 sqlite3_changeset_iter **pp, /* OUT: New changeset iterator handle */ 11756 int nChangeset, /* Size of changeset blob in bytes */ 11757 void *pChangeset /* Pointer to blob containing changeset */ 11758 ); 11759 SQLITE_API int sqlite3changeset_start_v2( 11760 sqlite3_changeset_iter **pp, /* OUT: New changeset iterator handle */ 11761 int nChangeset, /* Size of changeset blob in bytes */ 11762 void *pChangeset, /* Pointer to blob containing changeset */ 11763 int flags /* SESSION_CHANGESETSTART_* flags */ 11764 ); 11765 11766 /* 11767 ** CAPI3REF: Flags for sqlite3changeset_start_v2 11768 ** 11769 ** The following flags may passed via the 4th parameter to 11770 ** [sqlite3changeset_start_v2] and [sqlite3changeset_start_v2_strm]: 11771 ** 11772 ** <dt>SQLITE_CHANGESETSTART_INVERT <dd> 11773 ** Invert the changeset while iterating through it. This is equivalent to 11774 ** inverting a changeset using sqlite3changeset_invert() before applying it. 11775 ** It is an error to specify this flag with a patchset. 11776 */ 11777 #define SQLITE_CHANGESETSTART_INVERT 0x0002 11778 11779 11780 /* 11781 ** CAPI3REF: Advance A Changeset Iterator 11782 ** METHOD: sqlite3_changeset_iter 11783 ** 11784 ** This function may only be used with iterators created by the function 11785 ** [sqlite3changeset_start()]. If it is called on an iterator passed to 11786 ** a conflict-handler callback by [sqlite3changeset_apply()], SQLITE_MISUSE 11787 ** is returned and the call has no effect. 11788 ** 11789 ** Immediately after an iterator is created by sqlite3changeset_start(), it 11790 ** does not point to any change in the changeset. Assuming the changeset 11791 ** is not empty, the first call to this function advances the iterator to 11792 ** point to the first change in the changeset. Each subsequent call advances 11793 ** the iterator to point to the next change in the changeset (if any). If 11794 ** no error occurs and the iterator points to a valid change after a call 11795 ** to sqlite3changeset_next() has advanced it, SQLITE_ROW is returned. 11796 ** Otherwise, if all changes in the changeset have already been visited, 11797 ** SQLITE_DONE is returned. 11798 ** 11799 ** If an error occurs, an SQLite error code is returned. Possible error 11800 ** codes include SQLITE_CORRUPT (if the changeset buffer is corrupt) or 11801 ** SQLITE_NOMEM. 11802 */ 11803 SQLITE_API int sqlite3changeset_next(sqlite3_changeset_iter *pIter); 11804 11805 /* 11806 ** CAPI3REF: Obtain The Current Operation From A Changeset Iterator 11807 ** METHOD: sqlite3_changeset_iter 11808 ** 11809 ** The pIter argument passed to this function may either be an iterator 11810 ** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator 11811 ** created by [sqlite3changeset_start()]. In the latter case, the most recent 11812 ** call to [sqlite3changeset_next()] must have returned [SQLITE_ROW]. If this 11813 ** is not the case, this function returns [SQLITE_MISUSE]. 11814 ** 11815 ** Arguments pOp, pnCol and pzTab may not be NULL. Upon return, three 11816 ** outputs are set through these pointers: 11817 ** 11818 ** *pOp is set to one of [SQLITE_INSERT], [SQLITE_DELETE] or [SQLITE_UPDATE], 11819 ** depending on the type of change that the iterator currently points to; 11820 ** 11821 ** *pnCol is set to the number of columns in the table affected by the change; and 11822 ** 11823 ** *pzTab is set to point to a nul-terminated utf-8 encoded string containing 11824 ** the name of the table affected by the current change. The buffer remains 11825 ** valid until either sqlite3changeset_next() is called on the iterator 11826 ** or until the conflict-handler function returns. 11827 ** 11828 ** If pbIndirect is not NULL, then *pbIndirect is set to true (1) if the change 11829 ** is an indirect change, or false (0) otherwise. See the documentation for 11830 ** [sqlite3session_indirect()] for a description of direct and indirect 11831 ** changes. 11832 ** 11833 ** If no error occurs, SQLITE_OK is returned. If an error does occur, an 11834 ** SQLite error code is returned. The values of the output variables may not 11835 ** be trusted in this case. 11836 */ 11837 SQLITE_API int sqlite3changeset_op( 11838 sqlite3_changeset_iter *pIter, /* Iterator object */ 11839 const char **pzTab, /* OUT: Pointer to table name */ 11840 int *pnCol, /* OUT: Number of columns in table */ 11841 int *pOp, /* OUT: SQLITE_INSERT, DELETE or UPDATE */ 11842 int *pbIndirect /* OUT: True for an 'indirect' change */ 11843 ); 11844 11845 /* 11846 ** CAPI3REF: Obtain The Primary Key Definition Of A Table 11847 ** METHOD: sqlite3_changeset_iter 11848 ** 11849 ** For each modified table, a changeset includes the following: 11850 ** 11851 ** <ul> 11852 ** <li> The number of columns in the table, and 11853 ** <li> Which of those columns make up the tables PRIMARY KEY. 11854 ** </ul> 11855 ** 11856 ** This function is used to find which columns comprise the PRIMARY KEY of 11857 ** the table modified by the change that iterator pIter currently points to. 11858 ** If successful, *pabPK is set to point to an array of nCol entries, where 11859 ** nCol is the number of columns in the table. Elements of *pabPK are set to 11860 ** 0x01 if the corresponding column is part of the tables primary key, or 11861 ** 0x00 if it is not. 11862 ** 11863 ** If argument pnCol is not NULL, then *pnCol is set to the number of columns 11864 ** in the table. 11865 ** 11866 ** If this function is called when the iterator does not point to a valid 11867 ** entry, SQLITE_MISUSE is returned and the output variables zeroed. Otherwise, 11868 ** SQLITE_OK is returned and the output variables populated as described 11869 ** above. 11870 */ 11871 SQLITE_API int sqlite3changeset_pk( 11872 sqlite3_changeset_iter *pIter, /* Iterator object */ 11873 unsigned char **pabPK, /* OUT: Array of boolean - true for PK cols */ 11874 int *pnCol /* OUT: Number of entries in output array */ 11875 ); 11876 11877 /* 11878 ** CAPI3REF: Obtain old.* Values From A Changeset Iterator 11879 ** METHOD: sqlite3_changeset_iter 11880 ** 11881 ** The pIter argument passed to this function may either be an iterator 11882 ** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator 11883 ** created by [sqlite3changeset_start()]. In the latter case, the most recent 11884 ** call to [sqlite3changeset_next()] must have returned SQLITE_ROW. 11885 ** Furthermore, it may only be called if the type of change that the iterator 11886 ** currently points to is either [SQLITE_DELETE] or [SQLITE_UPDATE]. Otherwise, 11887 ** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL. 11888 ** 11889 ** Argument iVal must be greater than or equal to 0, and less than the number 11890 ** of columns in the table affected by the current change. Otherwise, 11891 ** [SQLITE_RANGE] is returned and *ppValue is set to NULL. 11892 ** 11893 ** If successful, this function sets *ppValue to point to a protected 11894 ** sqlite3_value object containing the iVal'th value from the vector of 11895 ** original row values stored as part of the UPDATE or DELETE change and 11896 ** returns SQLITE_OK. The name of the function comes from the fact that this 11897 ** is similar to the "old.*" columns available to update or delete triggers. 11898 ** 11899 ** If some other error occurs (e.g. an OOM condition), an SQLite error code 11900 ** is returned and *ppValue is set to NULL. 11901 */ 11902 SQLITE_API int sqlite3changeset_old( 11903 sqlite3_changeset_iter *pIter, /* Changeset iterator */ 11904 int iVal, /* Column number */ 11905 sqlite3_value **ppValue /* OUT: Old value (or NULL pointer) */ 11906 ); 11907 11908 /* 11909 ** CAPI3REF: Obtain new.* Values From A Changeset Iterator 11910 ** METHOD: sqlite3_changeset_iter 11911 ** 11912 ** The pIter argument passed to this function may either be an iterator 11913 ** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator 11914 ** created by [sqlite3changeset_start()]. In the latter case, the most recent 11915 ** call to [sqlite3changeset_next()] must have returned SQLITE_ROW. 11916 ** Furthermore, it may only be called if the type of change that the iterator 11917 ** currently points to is either [SQLITE_UPDATE] or [SQLITE_INSERT]. Otherwise, 11918 ** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL. 11919 ** 11920 ** Argument iVal must be greater than or equal to 0, and less than the number 11921 ** of columns in the table affected by the current change. Otherwise, 11922 ** [SQLITE_RANGE] is returned and *ppValue is set to NULL. 11923 ** 11924 ** If successful, this function sets *ppValue to point to a protected 11925 ** sqlite3_value object containing the iVal'th value from the vector of 11926 ** new row values stored as part of the UPDATE or INSERT change and 11927 ** returns SQLITE_OK. If the change is an UPDATE and does not include 11928 ** a new value for the requested column, *ppValue is set to NULL and 11929 ** SQLITE_OK returned. The name of the function comes from the fact that 11930 ** this is similar to the "new.*" columns available to update or delete 11931 ** triggers. 11932 ** 11933 ** If some other error occurs (e.g. an OOM condition), an SQLite error code 11934 ** is returned and *ppValue is set to NULL. 11935 */ 11936 SQLITE_API int sqlite3changeset_new( 11937 sqlite3_changeset_iter *pIter, /* Changeset iterator */ 11938 int iVal, /* Column number */ 11939 sqlite3_value **ppValue /* OUT: New value (or NULL pointer) */ 11940 ); 11941 11942 /* 11943 ** CAPI3REF: Obtain Conflicting Row Values From A Changeset Iterator 11944 ** METHOD: sqlite3_changeset_iter 11945 ** 11946 ** This function should only be used with iterator objects passed to a 11947 ** conflict-handler callback by [sqlite3changeset_apply()] with either 11948 ** [SQLITE_CHANGESET_DATA] or [SQLITE_CHANGESET_CONFLICT]. If this function 11949 ** is called on any other iterator, [SQLITE_MISUSE] is returned and *ppValue 11950 ** is set to NULL. 11951 ** 11952 ** Argument iVal must be greater than or equal to 0, and less than the number 11953 ** of columns in the table affected by the current change. Otherwise, 11954 ** [SQLITE_RANGE] is returned and *ppValue is set to NULL. 11955 ** 11956 ** If successful, this function sets *ppValue to point to a protected 11957 ** sqlite3_value object containing the iVal'th value from the 11958 ** "conflicting row" associated with the current conflict-handler callback 11959 ** and returns SQLITE_OK. 11960 ** 11961 ** If some other error occurs (e.g. an OOM condition), an SQLite error code 11962 ** is returned and *ppValue is set to NULL. 11963 */ 11964 SQLITE_API int sqlite3changeset_conflict( 11965 sqlite3_changeset_iter *pIter, /* Changeset iterator */ 11966 int iVal, /* Column number */ 11967 sqlite3_value **ppValue /* OUT: Value from conflicting row */ 11968 ); 11969 11970 /* 11971 ** CAPI3REF: Determine The Number Of Foreign Key Constraint Violations 11972 ** METHOD: sqlite3_changeset_iter 11973 ** 11974 ** This function may only be called with an iterator passed to an 11975 ** SQLITE_CHANGESET_FOREIGN_KEY conflict handler callback. In this case 11976 ** it sets the output variable to the total number of known foreign key 11977 ** violations in the destination database and returns SQLITE_OK. 11978 ** 11979 ** In all other cases this function returns SQLITE_MISUSE. 11980 */ 11981 SQLITE_API int sqlite3changeset_fk_conflicts( 11982 sqlite3_changeset_iter *pIter, /* Changeset iterator */ 11983 int *pnOut /* OUT: Number of FK violations */ 11984 ); 11985 11986 11987 /* 11988 ** CAPI3REF: Finalize A Changeset Iterator 11989 ** METHOD: sqlite3_changeset_iter 11990 ** 11991 ** This function is used to finalize an iterator allocated with 11992 ** [sqlite3changeset_start()]. 11993 ** 11994 ** This function should only be called on iterators created using the 11995 ** [sqlite3changeset_start()] function. If an application calls this 11996 ** function with an iterator passed to a conflict-handler by 11997 ** [sqlite3changeset_apply()], [SQLITE_MISUSE] is immediately returned and the 11998 ** call has no effect. 11999 ** 12000 ** If an error was encountered within a call to an sqlite3changeset_xxx() 12001 ** function (for example an [SQLITE_CORRUPT] in [sqlite3changeset_next()] or an 12002 ** [SQLITE_NOMEM] in [sqlite3changeset_new()]) then an error code corresponding 12003 ** to that error is returned by this function. Otherwise, SQLITE_OK is 12004 ** returned. This is to allow the following pattern (pseudo-code): 12005 ** 12006 ** <pre> 12007 ** sqlite3changeset_start(); 12008 ** while( SQLITE_ROW==sqlite3changeset_next() ){ 12009 ** // Do something with change. 12010 ** } 12011 ** rc = sqlite3changeset_finalize(); 12012 ** if( rc!=SQLITE_OK ){ 12013 ** // An error has occurred 12014 ** } 12015 ** </pre> 12016 */ 12017 SQLITE_API int sqlite3changeset_finalize(sqlite3_changeset_iter *pIter); 12018 12019 /* 12020 ** CAPI3REF: Invert A Changeset 12021 ** 12022 ** This function is used to "invert" a changeset object. Applying an inverted 12023 ** changeset to a database reverses the effects of applying the uninverted 12024 ** changeset. Specifically: 12025 ** 12026 ** <ul> 12027 ** <li> Each DELETE change is changed to an INSERT, and 12028 ** <li> Each INSERT change is changed to a DELETE, and 12029 ** <li> For each UPDATE change, the old.* and new.* values are exchanged. 12030 ** </ul> 12031 ** 12032 ** This function does not change the order in which changes appear within 12033 ** the changeset. It merely reverses the sense of each individual change. 12034 ** 12035 ** If successful, a pointer to a buffer containing the inverted changeset 12036 ** is stored in *ppOut, the size of the same buffer is stored in *pnOut, and 12037 ** SQLITE_OK is returned. If an error occurs, both *pnOut and *ppOut are 12038 ** zeroed and an SQLite error code returned. 12039 ** 12040 ** It is the responsibility of the caller to eventually call sqlite3_free() 12041 ** on the *ppOut pointer to free the buffer allocation following a successful 12042 ** call to this function. 12043 ** 12044 ** WARNING/TODO: This function currently assumes that the input is a valid 12045 ** changeset. If it is not, the results are undefined. 12046 */ 12047 SQLITE_API int sqlite3changeset_invert( 12048 int nIn, const void *pIn, /* Input changeset */ 12049 int *pnOut, void **ppOut /* OUT: Inverse of input */ 12050 ); 12051 12052 /* 12053 ** CAPI3REF: Concatenate Two Changeset Objects 12054 ** 12055 ** This function is used to concatenate two changesets, A and B, into a 12056 ** single changeset. The result is a changeset equivalent to applying 12057 ** changeset A followed by changeset B. 12058 ** 12059 ** This function combines the two input changesets using an 12060 ** sqlite3_changegroup object. Calling it produces similar results as the 12061 ** following code fragment: 12062 ** 12063 ** <pre> 12064 ** sqlite3_changegroup *pGrp; 12065 ** rc = sqlite3_changegroup_new(&pGrp); 12066 ** if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nA, pA); 12067 ** if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nB, pB); 12068 ** if( rc==SQLITE_OK ){ 12069 ** rc = sqlite3changegroup_output(pGrp, pnOut, ppOut); 12070 ** }else{ 12071 ** *ppOut = 0; 12072 ** *pnOut = 0; 12073 ** } 12074 ** </pre> 12075 ** 12076 ** Refer to the sqlite3_changegroup documentation below for details. 12077 */ 12078 SQLITE_API int sqlite3changeset_concat( 12079 int nA, /* Number of bytes in buffer pA */ 12080 void *pA, /* Pointer to buffer containing changeset A */ 12081 int nB, /* Number of bytes in buffer pB */ 12082 void *pB, /* Pointer to buffer containing changeset B */ 12083 int *pnOut, /* OUT: Number of bytes in output changeset */ 12084 void **ppOut /* OUT: Buffer containing output changeset */ 12085 ); 12086 12087 /* 12088 ** CAPI3REF: Changegroup Handle 12089 ** 12090 ** A changegroup is an object used to combine two or more 12091 ** [changesets] or [patchsets] 12092 */ 12093 typedef struct sqlite3_changegroup sqlite3_changegroup; 12094 12095 /* 12096 ** CAPI3REF: Create A New Changegroup Object 12097 ** CONSTRUCTOR: sqlite3_changegroup 12098 ** 12099 ** An sqlite3_changegroup object is used to combine two or more changesets 12100 ** (or patchsets) into a single changeset (or patchset). A single changegroup 12101 ** object may combine changesets or patchsets, but not both. The output is 12102 ** always in the same format as the input. 12103 ** 12104 ** If successful, this function returns SQLITE_OK and populates (*pp) with 12105 ** a pointer to a new sqlite3_changegroup object before returning. The caller 12106 ** should eventually free the returned object using a call to 12107 ** sqlite3changegroup_delete(). If an error occurs, an SQLite error code 12108 ** (i.e. SQLITE_NOMEM) is returned and *pp is set to NULL. 12109 ** 12110 ** The usual usage pattern for an sqlite3_changegroup object is as follows: 12111 ** 12112 ** <ul> 12113 ** <li> It is created using a call to sqlite3changegroup_new(). 12114 ** 12115 ** <li> Zero or more changesets (or patchsets) are added to the object 12116 ** by calling sqlite3changegroup_add(). 12117 ** 12118 ** <li> The result of combining all input changesets together is obtained 12119 ** by the application via a call to sqlite3changegroup_output(). 12120 ** 12121 ** <li> The object is deleted using a call to sqlite3changegroup_delete(). 12122 ** </ul> 12123 ** 12124 ** Any number of calls to add() and output() may be made between the calls to 12125 ** new() and delete(), and in any order. 12126 ** 12127 ** As well as the regular sqlite3changegroup_add() and 12128 ** sqlite3changegroup_output() functions, also available are the streaming 12129 ** versions sqlite3changegroup_add_strm() and sqlite3changegroup_output_strm(). 12130 */ 12131 SQLITE_API int sqlite3changegroup_new(sqlite3_changegroup **pp); 12132 12133 /* 12134 ** CAPI3REF: Add a Schema to a Changegroup 12135 ** METHOD: sqlite3_changegroup_schema 12136 ** 12137 ** This method may be used to optionally enforce the rule that the changesets 12138 ** added to the changegroup handle must match the schema of database zDb 12139 ** ("main", "temp", or the name of an attached database). If 12140 ** sqlite3changegroup_add() is called to add a changeset that is not compatible 12141 ** with the configured schema, SQLITE_SCHEMA is returned and the changegroup 12142 ** object is left in an undefined state. 12143 ** 12144 ** A changeset schema is considered compatible with the database schema in 12145 ** the same way as for sqlite3changeset_apply(). Specifically, for each 12146 ** table in the changeset, there exists a database table with: 12147 ** 12148 ** <ul> 12149 ** <li> The name identified by the changeset, and 12150 ** <li> at least as many columns as recorded in the changeset, and 12151 ** <li> the primary key columns in the same position as recorded in 12152 ** the changeset. 12153 ** </ul> 12154 ** 12155 ** The output of the changegroup object always has the same schema as the 12156 ** database nominated using this function. In cases where changesets passed 12157 ** to sqlite3changegroup_add() have fewer columns than the corresponding table 12158 ** in the database schema, these are filled in using the default column 12159 ** values from the database schema. This makes it possible to combined 12160 ** changesets that have different numbers of columns for a single table 12161 ** within a changegroup, provided that they are otherwise compatible. 12162 */ 12163 SQLITE_API int sqlite3changegroup_schema(sqlite3_changegroup*, sqlite3*, const char *zDb); 12164 12165 /* 12166 ** CAPI3REF: Add A Changeset To A Changegroup 12167 ** METHOD: sqlite3_changegroup 12168 ** 12169 ** Add all changes within the changeset (or patchset) in buffer pData (size 12170 ** nData bytes) to the changegroup. 12171 ** 12172 ** If the buffer contains a patchset, then all prior calls to this function 12173 ** on the same changegroup object must also have specified patchsets. Or, if 12174 ** the buffer contains a changeset, so must have the earlier calls to this 12175 ** function. Otherwise, SQLITE_ERROR is returned and no changes are added 12176 ** to the changegroup. 12177 ** 12178 ** Rows within the changeset and changegroup are identified by the values in 12179 ** their PRIMARY KEY columns. A change in the changeset is considered to 12180 ** apply to the same row as a change already present in the changegroup if 12181 ** the two rows have the same primary key. 12182 ** 12183 ** Changes to rows that do not already appear in the changegroup are 12184 ** simply copied into it. Or, if both the new changeset and the changegroup 12185 ** contain changes that apply to a single row, the final contents of the 12186 ** changegroup depends on the type of each change, as follows: 12187 ** 12188 ** <table border=1 style="margin-left:8ex;margin-right:8ex"> 12189 ** <tr><th style="white-space:pre">Existing Change </th> 12190 ** <th style="white-space:pre">New Change </th> 12191 ** <th>Output Change 12192 ** <tr><td>INSERT <td>INSERT <td> 12193 ** The new change is ignored. This case does not occur if the new 12194 ** changeset was recorded immediately after the changesets already 12195 ** added to the changegroup. 12196 ** <tr><td>INSERT <td>UPDATE <td> 12197 ** The INSERT change remains in the changegroup. The values in the 12198 ** INSERT change are modified as if the row was inserted by the 12199 ** existing change and then updated according to the new change. 12200 ** <tr><td>INSERT <td>DELETE <td> 12201 ** The existing INSERT is removed from the changegroup. The DELETE is 12202 ** not added. 12203 ** <tr><td>UPDATE <td>INSERT <td> 12204 ** The new change is ignored. This case does not occur if the new 12205 ** changeset was recorded immediately after the changesets already 12206 ** added to the changegroup. 12207 ** <tr><td>UPDATE <td>UPDATE <td> 12208 ** The existing UPDATE remains within the changegroup. It is amended 12209 ** so that the accompanying values are as if the row was updated once 12210 ** by the existing change and then again by the new change. 12211 ** <tr><td>UPDATE <td>DELETE <td> 12212 ** The existing UPDATE is replaced by the new DELETE within the 12213 ** changegroup. 12214 ** <tr><td>DELETE <td>INSERT <td> 12215 ** If one or more of the column values in the row inserted by the 12216 ** new change differ from those in the row deleted by the existing 12217 ** change, the existing DELETE is replaced by an UPDATE within the 12218 ** changegroup. Otherwise, if the inserted row is exactly the same 12219 ** as the deleted row, the existing DELETE is simply discarded. 12220 ** <tr><td>DELETE <td>UPDATE <td> 12221 ** The new change is ignored. This case does not occur if the new 12222 ** changeset was recorded immediately after the changesets already 12223 ** added to the changegroup. 12224 ** <tr><td>DELETE <td>DELETE <td> 12225 ** The new change is ignored. This case does not occur if the new 12226 ** changeset was recorded immediately after the changesets already 12227 ** added to the changegroup. 12228 ** </table> 12229 ** 12230 ** If the new changeset contains changes to a table that is already present 12231 ** in the changegroup, then the number of columns and the position of the 12232 ** primary key columns for the table must be consistent. If this is not the 12233 ** case, this function fails with SQLITE_SCHEMA. Except, if the changegroup 12234 ** object has been configured with a database schema using the 12235 ** sqlite3changegroup_schema() API, then it is possible to combine changesets 12236 ** with different numbers of columns for a single table, provided that 12237 ** they are otherwise compatible. 12238 ** 12239 ** If the input changeset appears to be corrupt and the corruption is 12240 ** detected, SQLITE_CORRUPT is returned. Or, if an out-of-memory condition 12241 ** occurs during processing, this function returns SQLITE_NOMEM. 12242 ** 12243 ** In all cases, if an error occurs the state of the final contents of the 12244 ** changegroup is undefined. If no error occurs, SQLITE_OK is returned. 12245 */ 12246 SQLITE_API int sqlite3changegroup_add(sqlite3_changegroup*, int nData, void *pData); 12247 12248 /* 12249 ** CAPI3REF: Add A Single Change To A Changegroup 12250 ** METHOD: sqlite3_changegroup 12251 ** 12252 ** This function adds the single change currently indicated by the iterator 12253 ** passed as the second argument to the changegroup object. The rules for 12254 ** adding the change are just as described for [sqlite3changegroup_add()]. 12255 ** 12256 ** If the change is successfully added to the changegroup, SQLITE_OK is 12257 ** returned. Otherwise, an SQLite error code is returned. 12258 ** 12259 ** The iterator must point to a valid entry when this function is called. 12260 ** If it does not, SQLITE_ERROR is returned and no change is added to the 12261 ** changegroup. Additionally, the iterator must not have been opened with 12262 ** the SQLITE_CHANGESETAPPLY_INVERT flag. In this case SQLITE_ERROR is also 12263 ** returned. 12264 */ 12265 SQLITE_API int sqlite3changegroup_add_change( 12266 sqlite3_changegroup*, 12267 sqlite3_changeset_iter* 12268 ); 12269 12270 12271 12272 /* 12273 ** CAPI3REF: Obtain A Composite Changeset From A Changegroup 12274 ** METHOD: sqlite3_changegroup 12275 ** 12276 ** Obtain a buffer containing a changeset (or patchset) representing the 12277 ** current contents of the changegroup. If the inputs to the changegroup 12278 ** were themselves changesets, the output is a changeset. Or, if the 12279 ** inputs were patchsets, the output is also a patchset. 12280 ** 12281 ** As with the output of the sqlite3session_changeset() and 12282 ** sqlite3session_patchset() functions, all changes related to a single 12283 ** table are grouped together in the output of this function. Tables appear 12284 ** in the same order as for the very first changeset added to the changegroup. 12285 ** If the second or subsequent changesets added to the changegroup contain 12286 ** changes for tables that do not appear in the first changeset, they are 12287 ** appended onto the end of the output changeset, again in the order in 12288 ** which they are first encountered. 12289 ** 12290 ** If an error occurs, an SQLite error code is returned and the output 12291 ** variables (*pnData) and (*ppData) are set to 0. Otherwise, SQLITE_OK 12292 ** is returned and the output variables are set to the size of and a 12293 ** pointer to the output buffer, respectively. In this case it is the 12294 ** responsibility of the caller to eventually free the buffer using a 12295 ** call to sqlite3_free(). 12296 */ 12297 SQLITE_API int sqlite3changegroup_output( 12298 sqlite3_changegroup*, 12299 int *pnData, /* OUT: Size of output buffer in bytes */ 12300 void **ppData /* OUT: Pointer to output buffer */ 12301 ); 12302 12303 /* 12304 ** CAPI3REF: Delete A Changegroup Object 12305 ** DESTRUCTOR: sqlite3_changegroup 12306 */ 12307 SQLITE_API void sqlite3changegroup_delete(sqlite3_changegroup*); 12308 12309 /* 12310 ** CAPI3REF: Apply A Changeset To A Database 12311 ** 12312 ** Apply a changeset or patchset to a database. These functions attempt to 12313 ** update the "main" database attached to handle db with the changes found in 12314 ** the changeset passed via the second and third arguments. 12315 ** 12316 ** The fourth argument (xFilter) passed to these functions is the "filter 12317 ** callback". If it is not NULL, then for each table affected by at least one 12318 ** change in the changeset, the filter callback is invoked with 12319 ** the table name as the second argument, and a copy of the context pointer 12320 ** passed as the sixth argument as the first. If the "filter callback" 12321 ** returns zero, then no attempt is made to apply any changes to the table. 12322 ** Otherwise, if the return value is non-zero or the xFilter argument to 12323 ** is NULL, all changes related to the table are attempted. 12324 ** 12325 ** For each table that is not excluded by the filter callback, this function 12326 ** tests that the target database contains a compatible table. A table is 12327 ** considered compatible if all of the following are true: 12328 ** 12329 ** <ul> 12330 ** <li> The table has the same name as the name recorded in the 12331 ** changeset, and 12332 ** <li> The table has at least as many columns as recorded in the 12333 ** changeset, and 12334 ** <li> The table has primary key columns in the same position as 12335 ** recorded in the changeset. 12336 ** </ul> 12337 ** 12338 ** If there is no compatible table, it is not an error, but none of the 12339 ** changes associated with the table are applied. A warning message is issued 12340 ** via the sqlite3_log() mechanism with the error code SQLITE_SCHEMA. At most 12341 ** one such warning is issued for each table in the changeset. 12342 ** 12343 ** For each change for which there is a compatible table, an attempt is made 12344 ** to modify the table contents according to the UPDATE, INSERT or DELETE 12345 ** change. If a change cannot be applied cleanly, the conflict handler 12346 ** function passed as the fifth argument to sqlite3changeset_apply() may be 12347 ** invoked. A description of exactly when the conflict handler is invoked for 12348 ** each type of change is below. 12349 ** 12350 ** Unlike the xFilter argument, xConflict may not be passed NULL. The results 12351 ** of passing anything other than a valid function pointer as the xConflict 12352 ** argument are undefined. 12353 ** 12354 ** Each time the conflict handler function is invoked, it must return one 12355 ** of [SQLITE_CHANGESET_OMIT], [SQLITE_CHANGESET_ABORT] or 12356 ** [SQLITE_CHANGESET_REPLACE]. SQLITE_CHANGESET_REPLACE may only be returned 12357 ** if the second argument passed to the conflict handler is either 12358 ** SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If the conflict-handler 12359 ** returns an illegal value, any changes already made are rolled back and 12360 ** the call to sqlite3changeset_apply() returns SQLITE_MISUSE. Different 12361 ** actions are taken by sqlite3changeset_apply() depending on the value 12362 ** returned by each invocation of the conflict-handler function. Refer to 12363 ** the documentation for the three 12364 ** [SQLITE_CHANGESET_OMIT|available return values] for details. 12365 ** 12366 ** <dl> 12367 ** <dt>DELETE Changes<dd> 12368 ** For each DELETE change, the function checks if the target database 12369 ** contains a row with the same primary key value (or values) as the 12370 ** original row values stored in the changeset. If it does, and the values 12371 ** stored in all non-primary key columns also match the values stored in 12372 ** the changeset the row is deleted from the target database. 12373 ** 12374 ** If a row with matching primary key values is found, but one or more of 12375 ** the non-primary key fields contains a value different from the original 12376 ** row value stored in the changeset, the conflict-handler function is 12377 ** invoked with [SQLITE_CHANGESET_DATA] as the second argument. If the 12378 ** database table has more columns than are recorded in the changeset, 12379 ** only the values of those non-primary key fields are compared against 12380 ** the current database contents - any trailing database table columns 12381 ** are ignored. 12382 ** 12383 ** If no row with matching primary key values is found in the database, 12384 ** the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND] 12385 ** passed as the second argument. 12386 ** 12387 ** If the DELETE operation is attempted, but SQLite returns SQLITE_CONSTRAINT 12388 ** (which can only happen if a foreign key constraint is violated), the 12389 ** conflict-handler function is invoked with [SQLITE_CHANGESET_CONSTRAINT] 12390 ** passed as the second argument. This includes the case where the DELETE 12391 ** operation is attempted because an earlier call to the conflict handler 12392 ** function returned [SQLITE_CHANGESET_REPLACE]. 12393 ** 12394 ** <dt>INSERT Changes<dd> 12395 ** For each INSERT change, an attempt is made to insert the new row into 12396 ** the database. If the changeset row contains fewer fields than the 12397 ** database table, the trailing fields are populated with their default 12398 ** values. 12399 ** 12400 ** If the attempt to insert the row fails because the database already 12401 ** contains a row with the same primary key values, the conflict handler 12402 ** function is invoked with the second argument set to 12403 ** [SQLITE_CHANGESET_CONFLICT]. 12404 ** 12405 ** If the attempt to insert the row fails because of some other constraint 12406 ** violation (e.g. NOT NULL or UNIQUE), the conflict handler function is 12407 ** invoked with the second argument set to [SQLITE_CHANGESET_CONSTRAINT]. 12408 ** This includes the case where the INSERT operation is re-attempted because 12409 ** an earlier call to the conflict handler function returned 12410 ** [SQLITE_CHANGESET_REPLACE]. 12411 ** 12412 ** <dt>UPDATE Changes<dd> 12413 ** For each UPDATE change, the function checks if the target database 12414 ** contains a row with the same primary key value (or values) as the 12415 ** original row values stored in the changeset. If it does, and the values 12416 ** stored in all modified non-primary key columns also match the values 12417 ** stored in the changeset the row is updated within the target database. 12418 ** 12419 ** If a row with matching primary key values is found, but one or more of 12420 ** the modified non-primary key fields contains a value different from an 12421 ** original row value stored in the changeset, the conflict-handler function 12422 ** is invoked with [SQLITE_CHANGESET_DATA] as the second argument. Since 12423 ** UPDATE changes only contain values for non-primary key fields that are 12424 ** to be modified, only those fields need to match the original values to 12425 ** avoid the SQLITE_CHANGESET_DATA conflict-handler callback. 12426 ** 12427 ** If no row with matching primary key values is found in the database, 12428 ** the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND] 12429 ** passed as the second argument. 12430 ** 12431 ** If the UPDATE operation is attempted, but SQLite returns 12432 ** SQLITE_CONSTRAINT, the conflict-handler function is invoked with 12433 ** [SQLITE_CHANGESET_CONSTRAINT] passed as the second argument. 12434 ** This includes the case where the UPDATE operation is attempted after 12435 ** an earlier call to the conflict handler function returned 12436 ** [SQLITE_CHANGESET_REPLACE]. 12437 ** </dl> 12438 ** 12439 ** It is safe to execute SQL statements, including those that write to the 12440 ** table that the callback related to, from within the xConflict callback. 12441 ** This can be used to further customize the application's conflict 12442 ** resolution strategy. 12443 ** 12444 ** All changes made by these functions are enclosed in a savepoint transaction. 12445 ** If any other error (aside from a constraint failure when attempting to 12446 ** write to the target database) occurs, then the savepoint transaction is 12447 ** rolled back, restoring the target database to its original state, and an 12448 ** SQLite error code returned. 12449 ** 12450 ** If the output parameters (ppRebase) and (pnRebase) are non-NULL and 12451 ** the input is a changeset (not a patchset), then sqlite3changeset_apply_v2() 12452 ** may set (*ppRebase) to point to a "rebase" that may be used with the 12453 ** sqlite3_rebaser APIs buffer before returning. In this case (*pnRebase) 12454 ** is set to the size of the buffer in bytes. It is the responsibility of the 12455 ** caller to eventually free any such buffer using sqlite3_free(). The buffer 12456 ** is only allocated and populated if one or more conflicts were encountered 12457 ** while applying the patchset. See comments surrounding the sqlite3_rebaser 12458 ** APIs for further details. 12459 ** 12460 ** The behavior of sqlite3changeset_apply_v2() and its streaming equivalent 12461 ** may be modified by passing a combination of 12462 ** [SQLITE_CHANGESETAPPLY_NOSAVEPOINT | supported flags] as the 9th parameter. 12463 ** 12464 ** Note that the sqlite3changeset_apply_v2() API is still <b>experimental</b> 12465 ** and therefore subject to change. 12466 */ 12467 SQLITE_API int sqlite3changeset_apply( 12468 sqlite3 *db, /* Apply change to "main" db of this handle */ 12469 int nChangeset, /* Size of changeset in bytes */ 12470 void *pChangeset, /* Changeset blob */ 12471 int(*xFilter)( 12472 void *pCtx, /* Copy of sixth arg to _apply() */ 12473 const char *zTab /* Table name */ 12474 ), 12475 int(*xConflict)( 12476 void *pCtx, /* Copy of sixth arg to _apply() */ 12477 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */ 12478 sqlite3_changeset_iter *p /* Handle describing change and conflict */ 12479 ), 12480 void *pCtx /* First argument passed to xConflict */ 12481 ); 12482 SQLITE_API int sqlite3changeset_apply_v2( 12483 sqlite3 *db, /* Apply change to "main" db of this handle */ 12484 int nChangeset, /* Size of changeset in bytes */ 12485 void *pChangeset, /* Changeset blob */ 12486 int(*xFilter)( 12487 void *pCtx, /* Copy of sixth arg to _apply() */ 12488 const char *zTab /* Table name */ 12489 ), 12490 int(*xConflict)( 12491 void *pCtx, /* Copy of sixth arg to _apply() */ 12492 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */ 12493 sqlite3_changeset_iter *p /* Handle describing change and conflict */ 12494 ), 12495 void *pCtx, /* First argument passed to xConflict */ 12496 void **ppRebase, int *pnRebase, /* OUT: Rebase data */ 12497 int flags /* SESSION_CHANGESETAPPLY_* flags */ 12498 ); 12499 12500 /* 12501 ** CAPI3REF: Flags for sqlite3changeset_apply_v2 12502 ** 12503 ** The following flags may passed via the 9th parameter to 12504 ** [sqlite3changeset_apply_v2] and [sqlite3changeset_apply_v2_strm]: 12505 ** 12506 ** <dl> 12507 ** <dt>SQLITE_CHANGESETAPPLY_NOSAVEPOINT <dd> 12508 ** Usually, the sessions module encloses all operations performed by 12509 ** a single call to apply_v2() or apply_v2_strm() in a [SAVEPOINT]. The 12510 ** SAVEPOINT is committed if the changeset or patchset is successfully 12511 ** applied, or rolled back if an error occurs. Specifying this flag 12512 ** causes the sessions module to omit this savepoint. In this case, if the 12513 ** caller has an open transaction or savepoint when apply_v2() is called, 12514 ** it may revert the partially applied changeset by rolling it back. 12515 ** 12516 ** <dt>SQLITE_CHANGESETAPPLY_INVERT <dd> 12517 ** Invert the changeset before applying it. This is equivalent to inverting 12518 ** a changeset using sqlite3changeset_invert() before applying it. It is 12519 ** an error to specify this flag with a patchset. 12520 ** 12521 ** <dt>SQLITE_CHANGESETAPPLY_IGNORENOOP <dd> 12522 ** Do not invoke the conflict handler callback for any changes that 12523 ** would not actually modify the database even if they were applied. 12524 ** Specifically, this means that the conflict handler is not invoked 12525 ** for: 12526 ** <ul> 12527 ** <li>a delete change if the row being deleted cannot be found, 12528 ** <li>an update change if the modified fields are already set to 12529 ** their new values in the conflicting row, or 12530 ** <li>an insert change if all fields of the conflicting row match 12531 ** the row being inserted. 12532 ** </ul> 12533 ** 12534 ** <dt>SQLITE_CHANGESETAPPLY_FKNOACTION <dd> 12535 ** If this flag it set, then all foreign key constraints in the target 12536 ** database behave as if they were declared with "ON UPDATE NO ACTION ON 12537 ** DELETE NO ACTION", even if they are actually CASCADE, RESTRICT, SET NULL 12538 ** or SET DEFAULT. 12539 */ 12540 #define SQLITE_CHANGESETAPPLY_NOSAVEPOINT 0x0001 12541 #define SQLITE_CHANGESETAPPLY_INVERT 0x0002 12542 #define SQLITE_CHANGESETAPPLY_IGNORENOOP 0x0004 12543 #define SQLITE_CHANGESETAPPLY_FKNOACTION 0x0008 12544 12545 /* 12546 ** CAPI3REF: Constants Passed To The Conflict Handler 12547 ** 12548 ** Values that may be passed as the second argument to a conflict-handler. 12549 ** 12550 ** <dl> 12551 ** <dt>SQLITE_CHANGESET_DATA<dd> 12552 ** The conflict handler is invoked with CHANGESET_DATA as the second argument 12553 ** when processing a DELETE or UPDATE change if a row with the required 12554 ** PRIMARY KEY fields is present in the database, but one or more other 12555 ** (non primary-key) fields modified by the update do not contain the 12556 ** expected "before" values. 12557 ** 12558 ** The conflicting row, in this case, is the database row with the matching 12559 ** primary key. 12560 ** 12561 ** <dt>SQLITE_CHANGESET_NOTFOUND<dd> 12562 ** The conflict handler is invoked with CHANGESET_NOTFOUND as the second 12563 ** argument when processing a DELETE or UPDATE change if a row with the 12564 ** required PRIMARY KEY fields is not present in the database. 12565 ** 12566 ** There is no conflicting row in this case. The results of invoking the 12567 ** sqlite3changeset_conflict() API are undefined. 12568 ** 12569 ** <dt>SQLITE_CHANGESET_CONFLICT<dd> 12570 ** CHANGESET_CONFLICT is passed as the second argument to the conflict 12571 ** handler while processing an INSERT change if the operation would result 12572 ** in duplicate primary key values. 12573 ** 12574 ** The conflicting row in this case is the database row with the matching 12575 ** primary key. 12576 ** 12577 ** <dt>SQLITE_CHANGESET_FOREIGN_KEY<dd> 12578 ** If foreign key handling is enabled, and applying a changeset leaves the 12579 ** database in a state containing foreign key violations, the conflict 12580 ** handler is invoked with CHANGESET_FOREIGN_KEY as the second argument 12581 ** exactly once before the changeset is committed. If the conflict handler 12582 ** returns CHANGESET_OMIT, the changes, including those that caused the 12583 ** foreign key constraint violation, are committed. Or, if it returns 12584 ** CHANGESET_ABORT, the changeset is rolled back. 12585 ** 12586 ** No current or conflicting row information is provided. The only function 12587 ** it is possible to call on the supplied sqlite3_changeset_iter handle 12588 ** is sqlite3changeset_fk_conflicts(). 12589 ** 12590 ** <dt>SQLITE_CHANGESET_CONSTRAINT<dd> 12591 ** If any other constraint violation occurs while applying a change (i.e. 12592 ** a UNIQUE, CHECK or NOT NULL constraint), the conflict handler is 12593 ** invoked with CHANGESET_CONSTRAINT as the second argument. 12594 ** 12595 ** There is no conflicting row in this case. The results of invoking the 12596 ** sqlite3changeset_conflict() API are undefined. 12597 ** 12598 ** </dl> 12599 */ 12600 #define SQLITE_CHANGESET_DATA 1 12601 #define SQLITE_CHANGESET_NOTFOUND 2 12602 #define SQLITE_CHANGESET_CONFLICT 3 12603 #define SQLITE_CHANGESET_CONSTRAINT 4 12604 #define SQLITE_CHANGESET_FOREIGN_KEY 5 12605 12606 /* 12607 ** CAPI3REF: Constants Returned By The Conflict Handler 12608 ** 12609 ** A conflict handler callback must return one of the following three values. 12610 ** 12611 ** <dl> 12612 ** <dt>SQLITE_CHANGESET_OMIT<dd> 12613 ** If a conflict handler returns this value no special action is taken. The 12614 ** change that caused the conflict is not applied. The session module 12615 ** continues to the next change in the changeset. 12616 ** 12617 ** <dt>SQLITE_CHANGESET_REPLACE<dd> 12618 ** This value may only be returned if the second argument to the conflict 12619 ** handler was SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If this 12620 ** is not the case, any changes applied so far are rolled back and the 12621 ** call to sqlite3changeset_apply() returns SQLITE_MISUSE. 12622 ** 12623 ** If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_DATA conflict 12624 ** handler, then the conflicting row is either updated or deleted, depending 12625 ** on the type of change. 12626 ** 12627 ** If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_CONFLICT conflict 12628 ** handler, then the conflicting row is removed from the database and a 12629 ** second attempt to apply the change is made. If this second attempt fails, 12630 ** the original row is restored to the database before continuing. 12631 ** 12632 ** <dt>SQLITE_CHANGESET_ABORT<dd> 12633 ** If this value is returned, any changes applied so far are rolled back 12634 ** and the call to sqlite3changeset_apply() returns SQLITE_ABORT. 12635 ** </dl> 12636 */ 12637 #define SQLITE_CHANGESET_OMIT 0 12638 #define SQLITE_CHANGESET_REPLACE 1 12639 #define SQLITE_CHANGESET_ABORT 2 12640 12641 /* 12642 ** CAPI3REF: Rebasing changesets 12643 ** EXPERIMENTAL 12644 ** 12645 ** Suppose there is a site hosting a database in state S0. And that 12646 ** modifications are made that move that database to state S1 and a 12647 ** changeset recorded (the "local" changeset). Then, a changeset based 12648 ** on S0 is received from another site (the "remote" changeset) and 12649 ** applied to the database. The database is then in state 12650 ** (S1+"remote"), where the exact state depends on any conflict 12651 ** resolution decisions (OMIT or REPLACE) made while applying "remote". 12652 ** Rebasing a changeset is to update it to take those conflict 12653 ** resolution decisions into account, so that the same conflicts 12654 ** do not have to be resolved elsewhere in the network. 12655 ** 12656 ** For example, if both the local and remote changesets contain an 12657 ** INSERT of the same key on "CREATE TABLE t1(a PRIMARY KEY, b)": 12658 ** 12659 ** local: INSERT INTO t1 VALUES(1, 'v1'); 12660 ** remote: INSERT INTO t1 VALUES(1, 'v2'); 12661 ** 12662 ** and the conflict resolution is REPLACE, then the INSERT change is 12663 ** removed from the local changeset (it was overridden). Or, if the 12664 ** conflict resolution was "OMIT", then the local changeset is modified 12665 ** to instead contain: 12666 ** 12667 ** UPDATE t1 SET b = 'v2' WHERE a=1; 12668 ** 12669 ** Changes within the local changeset are rebased as follows: 12670 ** 12671 ** <dl> 12672 ** <dt>Local INSERT<dd> 12673 ** This may only conflict with a remote INSERT. If the conflict 12674 ** resolution was OMIT, then add an UPDATE change to the rebased 12675 ** changeset. Or, if the conflict resolution was REPLACE, add 12676 ** nothing to the rebased changeset. 12677 ** 12678 ** <dt>Local DELETE<dd> 12679 ** This may conflict with a remote UPDATE or DELETE. In both cases the 12680 ** only possible resolution is OMIT. If the remote operation was a 12681 ** DELETE, then add no change to the rebased changeset. If the remote 12682 ** operation was an UPDATE, then the old.* fields of change are updated 12683 ** to reflect the new.* values in the UPDATE. 12684 ** 12685 ** <dt>Local UPDATE<dd> 12686 ** This may conflict with a remote UPDATE or DELETE. If it conflicts 12687 ** with a DELETE, and the conflict resolution was OMIT, then the update 12688 ** is changed into an INSERT. Any undefined values in the new.* record 12689 ** from the update change are filled in using the old.* values from 12690 ** the conflicting DELETE. Or, if the conflict resolution was REPLACE, 12691 ** the UPDATE change is simply omitted from the rebased changeset. 12692 ** 12693 ** If conflict is with a remote UPDATE and the resolution is OMIT, then 12694 ** the old.* values are rebased using the new.* values in the remote 12695 ** change. Or, if the resolution is REPLACE, then the change is copied 12696 ** into the rebased changeset with updates to columns also updated by 12697 ** the conflicting remote UPDATE removed. If this means no columns would 12698 ** be updated, the change is omitted. 12699 ** </dl> 12700 ** 12701 ** A local change may be rebased against multiple remote changes 12702 ** simultaneously. If a single key is modified by multiple remote 12703 ** changesets, they are combined as follows before the local changeset 12704 ** is rebased: 12705 ** 12706 ** <ul> 12707 ** <li> If there has been one or more REPLACE resolutions on a 12708 ** key, it is rebased according to a REPLACE. 12709 ** 12710 ** <li> If there have been no REPLACE resolutions on a key, then 12711 ** the local changeset is rebased according to the most recent 12712 ** of the OMIT resolutions. 12713 ** </ul> 12714 ** 12715 ** Note that conflict resolutions from multiple remote changesets are 12716 ** combined on a per-field basis, not per-row. This means that in the 12717 ** case of multiple remote UPDATE operations, some fields of a single 12718 ** local change may be rebased for REPLACE while others are rebased for 12719 ** OMIT. 12720 ** 12721 ** In order to rebase a local changeset, the remote changeset must first 12722 ** be applied to the local database using sqlite3changeset_apply_v2() and 12723 ** the buffer of rebase information captured. Then: 12724 ** 12725 ** <ol> 12726 ** <li> An sqlite3_rebaser object is created by calling 12727 ** sqlite3rebaser_create(). 12728 ** <li> The new object is configured with the rebase buffer obtained from 12729 ** sqlite3changeset_apply_v2() by calling sqlite3rebaser_configure(). 12730 ** If the local changeset is to be rebased against multiple remote 12731 ** changesets, then sqlite3rebaser_configure() should be called 12732 ** multiple times, in the same order that the multiple 12733 ** sqlite3changeset_apply_v2() calls were made. 12734 ** <li> Each local changeset is rebased by calling sqlite3rebaser_rebase(). 12735 ** <li> The sqlite3_rebaser object is deleted by calling 12736 ** sqlite3rebaser_delete(). 12737 ** </ol> 12738 */ 12739 typedef struct sqlite3_rebaser sqlite3_rebaser; 12740 12741 /* 12742 ** CAPI3REF: Create a changeset rebaser object. 12743 ** EXPERIMENTAL 12744 ** 12745 ** Allocate a new changeset rebaser object. If successful, set (*ppNew) to 12746 ** point to the new object and return SQLITE_OK. Otherwise, if an error 12747 ** occurs, return an SQLite error code (e.g. SQLITE_NOMEM) and set (*ppNew) 12748 ** to NULL. 12749 */ 12750 SQLITE_API int sqlite3rebaser_create(sqlite3_rebaser **ppNew); 12751 12752 /* 12753 ** CAPI3REF: Configure a changeset rebaser object. 12754 ** EXPERIMENTAL 12755 ** 12756 ** Configure the changeset rebaser object to rebase changesets according 12757 ** to the conflict resolutions described by buffer pRebase (size nRebase 12758 ** bytes), which must have been obtained from a previous call to 12759 ** sqlite3changeset_apply_v2(). 12760 */ 12761 SQLITE_API int sqlite3rebaser_configure( 12762 sqlite3_rebaser*, 12763 int nRebase, const void *pRebase 12764 ); 12765 12766 /* 12767 ** CAPI3REF: Rebase a changeset 12768 ** EXPERIMENTAL 12769 ** 12770 ** Argument pIn must point to a buffer containing a changeset nIn bytes 12771 ** in size. This function allocates and populates a buffer with a copy 12772 ** of the changeset rebased according to the configuration of the 12773 ** rebaser object passed as the first argument. If successful, (*ppOut) 12774 ** is set to point to the new buffer containing the rebased changeset and 12775 ** (*pnOut) to its size in bytes and SQLITE_OK returned. It is the 12776 ** responsibility of the caller to eventually free the new buffer using 12777 ** sqlite3_free(). Otherwise, if an error occurs, (*ppOut) and (*pnOut) 12778 ** are set to zero and an SQLite error code returned. 12779 */ 12780 SQLITE_API int sqlite3rebaser_rebase( 12781 sqlite3_rebaser*, 12782 int nIn, const void *pIn, 12783 int *pnOut, void **ppOut 12784 ); 12785 12786 /* 12787 ** CAPI3REF: Delete a changeset rebaser object. 12788 ** EXPERIMENTAL 12789 ** 12790 ** Delete the changeset rebaser object and all associated resources. There 12791 ** should be one call to this function for each successful invocation 12792 ** of sqlite3rebaser_create(). 12793 */ 12794 SQLITE_API void sqlite3rebaser_delete(sqlite3_rebaser *p); 12795 12796 /* 12797 ** CAPI3REF: Streaming Versions of API functions. 12798 ** 12799 ** The six streaming API xxx_strm() functions serve similar purposes to the 12800 ** corresponding non-streaming API functions: 12801 ** 12802 ** <table border=1 style="margin-left:8ex;margin-right:8ex"> 12803 ** <tr><th>Streaming function<th>Non-streaming equivalent</th> 12804 ** <tr><td>sqlite3changeset_apply_strm<td>[sqlite3changeset_apply] 12805 ** <tr><td>sqlite3changeset_apply_strm_v2<td>[sqlite3changeset_apply_v2] 12806 ** <tr><td>sqlite3changeset_concat_strm<td>[sqlite3changeset_concat] 12807 ** <tr><td>sqlite3changeset_invert_strm<td>[sqlite3changeset_invert] 12808 ** <tr><td>sqlite3changeset_start_strm<td>[sqlite3changeset_start] 12809 ** <tr><td>sqlite3session_changeset_strm<td>[sqlite3session_changeset] 12810 ** <tr><td>sqlite3session_patchset_strm<td>[sqlite3session_patchset] 12811 ** </table> 12812 ** 12813 ** Non-streaming functions that accept changesets (or patchsets) as input 12814 ** require that the entire changeset be stored in a single buffer in memory. 12815 ** Similarly, those that return a changeset or patchset do so by returning 12816 ** a pointer to a single large buffer allocated using sqlite3_malloc(). 12817 ** Normally this is convenient. However, if an application running in a 12818 ** low-memory environment is required to handle very large changesets, the 12819 ** large contiguous memory allocations required can become onerous. 12820 ** 12821 ** In order to avoid this problem, instead of a single large buffer, input 12822 ** is passed to a streaming API functions by way of a callback function that 12823 ** the sessions module invokes to incrementally request input data as it is 12824 ** required. In all cases, a pair of API function parameters such as 12825 ** 12826 ** <pre> 12827 ** int nChangeset, 12828 ** void *pChangeset, 12829 ** </pre> 12830 ** 12831 ** Is replaced by: 12832 ** 12833 ** <pre> 12834 ** int (*xInput)(void *pIn, void *pData, int *pnData), 12835 ** void *pIn, 12836 ** </pre> 12837 ** 12838 ** Each time the xInput callback is invoked by the sessions module, the first 12839 ** argument passed is a copy of the supplied pIn context pointer. The second 12840 ** argument, pData, points to a buffer (*pnData) bytes in size. Assuming no 12841 ** error occurs the xInput method should copy up to (*pnData) bytes of data 12842 ** into the buffer and set (*pnData) to the actual number of bytes copied 12843 ** before returning SQLITE_OK. If the input is completely exhausted, (*pnData) 12844 ** should be set to zero to indicate this. Or, if an error occurs, an SQLite 12845 ** error code should be returned. In all cases, if an xInput callback returns 12846 ** an error, all processing is abandoned and the streaming API function 12847 ** returns a copy of the error code to the caller. 12848 ** 12849 ** In the case of sqlite3changeset_start_strm(), the xInput callback may be 12850 ** invoked by the sessions module at any point during the lifetime of the 12851 ** iterator. If such an xInput callback returns an error, the iterator enters 12852 ** an error state, whereby all subsequent calls to iterator functions 12853 ** immediately fail with the same error code as returned by xInput. 12854 ** 12855 ** Similarly, streaming API functions that return changesets (or patchsets) 12856 ** return them in chunks by way of a callback function instead of via a 12857 ** pointer to a single large buffer. In this case, a pair of parameters such 12858 ** as: 12859 ** 12860 ** <pre> 12861 ** int *pnChangeset, 12862 ** void **ppChangeset, 12863 ** </pre> 12864 ** 12865 ** Is replaced by: 12866 ** 12867 ** <pre> 12868 ** int (*xOutput)(void *pOut, const void *pData, int nData), 12869 ** void *pOut 12870 ** </pre> 12871 ** 12872 ** The xOutput callback is invoked zero or more times to return data to 12873 ** the application. The first parameter passed to each call is a copy of the 12874 ** pOut pointer supplied by the application. The second parameter, pData, 12875 ** points to a buffer nData bytes in size containing the chunk of output 12876 ** data being returned. If the xOutput callback successfully processes the 12877 ** supplied data, it should return SQLITE_OK to indicate success. Otherwise, 12878 ** it should return some other SQLite error code. In this case processing 12879 ** is immediately abandoned and the streaming API function returns a copy 12880 ** of the xOutput error code to the application. 12881 ** 12882 ** The sessions module never invokes an xOutput callback with the third 12883 ** parameter set to a value less than or equal to zero. Other than this, 12884 ** no guarantees are made as to the size of the chunks of data returned. 12885 */ 12886 SQLITE_API int sqlite3changeset_apply_strm( 12887 sqlite3 *db, /* Apply change to "main" db of this handle */ 12888 int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */ 12889 void *pIn, /* First arg for xInput */ 12890 int(*xFilter)( 12891 void *pCtx, /* Copy of sixth arg to _apply() */ 12892 const char *zTab /* Table name */ 12893 ), 12894 int(*xConflict)( 12895 void *pCtx, /* Copy of sixth arg to _apply() */ 12896 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */ 12897 sqlite3_changeset_iter *p /* Handle describing change and conflict */ 12898 ), 12899 void *pCtx /* First argument passed to xConflict */ 12900 ); 12901 SQLITE_API int sqlite3changeset_apply_v2_strm( 12902 sqlite3 *db, /* Apply change to "main" db of this handle */ 12903 int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */ 12904 void *pIn, /* First arg for xInput */ 12905 int(*xFilter)( 12906 void *pCtx, /* Copy of sixth arg to _apply() */ 12907 const char *zTab /* Table name */ 12908 ), 12909 int(*xConflict)( 12910 void *pCtx, /* Copy of sixth arg to _apply() */ 12911 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */ 12912 sqlite3_changeset_iter *p /* Handle describing change and conflict */ 12913 ), 12914 void *pCtx, /* First argument passed to xConflict */ 12915 void **ppRebase, int *pnRebase, 12916 int flags 12917 ); 12918 SQLITE_API int sqlite3changeset_concat_strm( 12919 int (*xInputA)(void *pIn, void *pData, int *pnData), 12920 void *pInA, 12921 int (*xInputB)(void *pIn, void *pData, int *pnData), 12922 void *pInB, 12923 int (*xOutput)(void *pOut, const void *pData, int nData), 12924 void *pOut 12925 ); 12926 SQLITE_API int sqlite3changeset_invert_strm( 12927 int (*xInput)(void *pIn, void *pData, int *pnData), 12928 void *pIn, 12929 int (*xOutput)(void *pOut, const void *pData, int nData), 12930 void *pOut 12931 ); 12932 SQLITE_API int sqlite3changeset_start_strm( 12933 sqlite3_changeset_iter **pp, 12934 int (*xInput)(void *pIn, void *pData, int *pnData), 12935 void *pIn 12936 ); 12937 SQLITE_API int sqlite3changeset_start_v2_strm( 12938 sqlite3_changeset_iter **pp, 12939 int (*xInput)(void *pIn, void *pData, int *pnData), 12940 void *pIn, 12941 int flags 12942 ); 12943 SQLITE_API int sqlite3session_changeset_strm( 12944 sqlite3_session *pSession, 12945 int (*xOutput)(void *pOut, const void *pData, int nData), 12946 void *pOut 12947 ); 12948 SQLITE_API int sqlite3session_patchset_strm( 12949 sqlite3_session *pSession, 12950 int (*xOutput)(void *pOut, const void *pData, int nData), 12951 void *pOut 12952 ); 12953 SQLITE_API int sqlite3changegroup_add_strm(sqlite3_changegroup*, 12954 int (*xInput)(void *pIn, void *pData, int *pnData), 12955 void *pIn 12956 ); 12957 SQLITE_API int sqlite3changegroup_output_strm(sqlite3_changegroup*, 12958 int (*xOutput)(void *pOut, const void *pData, int nData), 12959 void *pOut 12960 ); 12961 SQLITE_API int sqlite3rebaser_rebase_strm( 12962 sqlite3_rebaser *pRebaser, 12963 int (*xInput)(void *pIn, void *pData, int *pnData), 12964 void *pIn, 12965 int (*xOutput)(void *pOut, const void *pData, int nData), 12966 void *pOut 12967 ); 12968 12969 /* 12970 ** CAPI3REF: Configure global parameters 12971 ** 12972 ** The sqlite3session_config() interface is used to make global configuration 12973 ** changes to the sessions module in order to tune it to the specific needs 12974 ** of the application. 12975 ** 12976 ** The sqlite3session_config() interface is not threadsafe. If it is invoked 12977 ** while any other thread is inside any other sessions method then the 12978 ** results are undefined. Furthermore, if it is invoked after any sessions 12979 ** related objects have been created, the results are also undefined. 12980 ** 12981 ** The first argument to the sqlite3session_config() function must be one 12982 ** of the SQLITE_SESSION_CONFIG_XXX constants defined below. The 12983 ** interpretation of the (void*) value passed as the second parameter and 12984 ** the effect of calling this function depends on the value of the first 12985 ** parameter. 12986 ** 12987 ** <dl> 12988 ** <dt>SQLITE_SESSION_CONFIG_STRMSIZE<dd> 12989 ** By default, the sessions module streaming interfaces attempt to input 12990 ** and output data in approximately 1 KiB chunks. This operand may be used 12991 ** to set and query the value of this configuration setting. The pointer 12992 ** passed as the second argument must point to a value of type (int). 12993 ** If this value is greater than 0, it is used as the new streaming data 12994 ** chunk size for both input and output. Before returning, the (int) value 12995 ** pointed to by pArg is set to the final value of the streaming interface 12996 ** chunk size. 12997 ** </dl> 12998 ** 12999 ** This function returns SQLITE_OK if successful, or an SQLite error code 13000 ** otherwise. 13001 */ 13002 SQLITE_API int sqlite3session_config(int op, void *pArg); 13003 13004 /* 13005 ** CAPI3REF: Values for sqlite3session_config(). 13006 */ 13007 #define SQLITE_SESSION_CONFIG_STRMSIZE 1 13008 13009 /* 13010 ** Make sure we can call this stuff from C++. 13011 */ 13012 #ifdef __cplusplus 13013 } 13014 #endif 13015 13016 #endif /* !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION) */ 13017 13018 /******** End of sqlite3session.h *********/ 13019 /******** Begin file fts5.h *********/ 13020 /* 13021 ** 2014 May 31 13022 ** 13023 ** The author disclaims copyright to this source code. In place of 13024 ** a legal notice, here is a blessing: 13025 ** 13026 ** May you do good and not evil. 13027 ** May you find forgiveness for yourself and forgive others. 13028 ** May you share freely, never taking more than you give. 13029 ** 13030 ****************************************************************************** 13031 ** 13032 ** Interfaces to extend FTS5. Using the interfaces defined in this file, 13033 ** FTS5 may be extended with: 13034 ** 13035 ** * custom tokenizers, and 13036 ** * custom auxiliary functions. 13037 */ 13038 13039 13040 #ifndef _FTS5_H 13041 #define _FTS5_H 13042 13043 13044 #ifdef __cplusplus 13045 extern "C" { 13046 #endif 13047 13048 /************************************************************************* 13049 ** CUSTOM AUXILIARY FUNCTIONS 13050 ** 13051 ** Virtual table implementations may overload SQL functions by implementing 13052 ** the sqlite3_module.xFindFunction() method. 13053 */ 13054 13055 typedef struct Fts5ExtensionApi Fts5ExtensionApi; 13056 typedef struct Fts5Context Fts5Context; 13057 typedef struct Fts5PhraseIter Fts5PhraseIter; 13058 13059 typedef void (*fts5_extension_function)( 13060 const Fts5ExtensionApi *pApi, /* API offered by current FTS version */ 13061 Fts5Context *pFts, /* First arg to pass to pApi functions */ 13062 sqlite3_context *pCtx, /* Context for returning result/error */ 13063 int nVal, /* Number of values in apVal[] array */ 13064 sqlite3_value **apVal /* Array of trailing arguments */ 13065 ); 13066 13067 struct Fts5PhraseIter { 13068 const unsigned char *a; 13069 const unsigned char *b; 13070 }; 13071 13072 /* 13073 ** EXTENSION API FUNCTIONS 13074 ** 13075 ** xUserData(pFts): 13076 ** Return a copy of the pUserData pointer passed to the xCreateFunction() 13077 ** API when the extension function was registered. 13078 ** 13079 ** xColumnTotalSize(pFts, iCol, pnToken): 13080 ** If parameter iCol is less than zero, set output variable *pnToken 13081 ** to the total number of tokens in the FTS5 table. Or, if iCol is 13082 ** non-negative but less than the number of columns in the table, return 13083 ** the total number of tokens in column iCol, considering all rows in 13084 ** the FTS5 table. 13085 ** 13086 ** If parameter iCol is greater than or equal to the number of columns 13087 ** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g. 13088 ** an OOM condition or IO error), an appropriate SQLite error code is 13089 ** returned. 13090 ** 13091 ** xColumnCount(pFts): 13092 ** Return the number of columns in the table. 13093 ** 13094 ** xColumnSize(pFts, iCol, pnToken): 13095 ** If parameter iCol is less than zero, set output variable *pnToken 13096 ** to the total number of tokens in the current row. Or, if iCol is 13097 ** non-negative but less than the number of columns in the table, set 13098 ** *pnToken to the number of tokens in column iCol of the current row. 13099 ** 13100 ** If parameter iCol is greater than or equal to the number of columns 13101 ** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g. 13102 ** an OOM condition or IO error), an appropriate SQLite error code is 13103 ** returned. 13104 ** 13105 ** This function may be quite inefficient if used with an FTS5 table 13106 ** created with the "columnsize=0" option. 13107 ** 13108 ** xColumnText: 13109 ** If parameter iCol is less than zero, or greater than or equal to the 13110 ** number of columns in the table, SQLITE_RANGE is returned. 13111 ** 13112 ** Otherwise, this function attempts to retrieve the text of column iCol of 13113 ** the current document. If successful, (*pz) is set to point to a buffer 13114 ** containing the text in utf-8 encoding, (*pn) is set to the size in bytes 13115 ** (not characters) of the buffer and SQLITE_OK is returned. Otherwise, 13116 ** if an error occurs, an SQLite error code is returned and the final values 13117 ** of (*pz) and (*pn) are undefined. 13118 ** 13119 ** xPhraseCount: 13120 ** Returns the number of phrases in the current query expression. 13121 ** 13122 ** xPhraseSize: 13123 ** If parameter iCol is less than zero, or greater than or equal to the 13124 ** number of phrases in the current query, as returned by xPhraseCount, 13125 ** 0 is returned. Otherwise, this function returns the number of tokens in 13126 ** phrase iPhrase of the query. Phrases are numbered starting from zero. 13127 ** 13128 ** xInstCount: 13129 ** Set *pnInst to the total number of occurrences of all phrases within 13130 ** the query within the current row. Return SQLITE_OK if successful, or 13131 ** an error code (i.e. SQLITE_NOMEM) if an error occurs. 13132 ** 13133 ** This API can be quite slow if used with an FTS5 table created with the 13134 ** "detail=none" or "detail=column" option. If the FTS5 table is created 13135 ** with either "detail=none" or "detail=column" and "content=" option 13136 ** (i.e. if it is a contentless table), then this API always returns 0. 13137 ** 13138 ** xInst: 13139 ** Query for the details of phrase match iIdx within the current row. 13140 ** Phrase matches are numbered starting from zero, so the iIdx argument 13141 ** should be greater than or equal to zero and smaller than the value 13142 ** output by xInstCount(). If iIdx is less than zero or greater than 13143 ** or equal to the value returned by xInstCount(), SQLITE_RANGE is returned. 13144 ** 13145 ** Otherwise, output parameter *piPhrase is set to the phrase number, *piCol 13146 ** to the column in which it occurs and *piOff the token offset of the 13147 ** first token of the phrase. SQLITE_OK is returned if successful, or an 13148 ** error code (i.e. SQLITE_NOMEM) if an error occurs. 13149 ** 13150 ** This API can be quite slow if used with an FTS5 table created with the 13151 ** "detail=none" or "detail=column" option. 13152 ** 13153 ** xRowid: 13154 ** Returns the rowid of the current row. 13155 ** 13156 ** xTokenize: 13157 ** Tokenize text using the tokenizer belonging to the FTS5 table. 13158 ** 13159 ** xQueryPhrase(pFts5, iPhrase, pUserData, xCallback): 13160 ** This API function is used to query the FTS table for phrase iPhrase 13161 ** of the current query. Specifically, a query equivalent to: 13162 ** 13163 ** ... FROM ftstable WHERE ftstable MATCH $p ORDER BY rowid 13164 ** 13165 ** with $p set to a phrase equivalent to the phrase iPhrase of the 13166 ** current query is executed. Any column filter that applies to 13167 ** phrase iPhrase of the current query is included in $p. For each 13168 ** row visited, the callback function passed as the fourth argument 13169 ** is invoked. The context and API objects passed to the callback 13170 ** function may be used to access the properties of each matched row. 13171 ** Invoking Api.xUserData() returns a copy of the pointer passed as 13172 ** the third argument to pUserData. 13173 ** 13174 ** If parameter iPhrase is less than zero, or greater than or equal to 13175 ** the number of phrases in the query, as returned by xPhraseCount(), 13176 ** this function returns SQLITE_RANGE. 13177 ** 13178 ** If the callback function returns any value other than SQLITE_OK, the 13179 ** query is abandoned and the xQueryPhrase function returns immediately. 13180 ** If the returned value is SQLITE_DONE, xQueryPhrase returns SQLITE_OK. 13181 ** Otherwise, the error code is propagated upwards. 13182 ** 13183 ** If the query runs to completion without incident, SQLITE_OK is returned. 13184 ** Or, if some error occurs before the query completes or is aborted by 13185 ** the callback, an SQLite error code is returned. 13186 ** 13187 ** 13188 ** xSetAuxdata(pFts5, pAux, xDelete) 13189 ** 13190 ** Save the pointer passed as the second argument as the extension function's 13191 ** "auxiliary data". The pointer may then be retrieved by the current or any 13192 ** future invocation of the same fts5 extension function made as part of 13193 ** the same MATCH query using the xGetAuxdata() API. 13194 ** 13195 ** Each extension function is allocated a single auxiliary data slot for 13196 ** each FTS query (MATCH expression). If the extension function is invoked 13197 ** more than once for a single FTS query, then all invocations share a 13198 ** single auxiliary data context. 13199 ** 13200 ** If there is already an auxiliary data pointer when this function is 13201 ** invoked, then it is replaced by the new pointer. If an xDelete callback 13202 ** was specified along with the original pointer, it is invoked at this 13203 ** point. 13204 ** 13205 ** The xDelete callback, if one is specified, is also invoked on the 13206 ** auxiliary data pointer after the FTS5 query has finished. 13207 ** 13208 ** If an error (e.g. an OOM condition) occurs within this function, 13209 ** the auxiliary data is set to NULL and an error code returned. If the 13210 ** xDelete parameter was not NULL, it is invoked on the auxiliary data 13211 ** pointer before returning. 13212 ** 13213 ** 13214 ** xGetAuxdata(pFts5, bClear) 13215 ** 13216 ** Returns the current auxiliary data pointer for the fts5 extension 13217 ** function. See the xSetAuxdata() method for details. 13218 ** 13219 ** If the bClear argument is non-zero, then the auxiliary data is cleared 13220 ** (set to NULL) before this function returns. In this case the xDelete, 13221 ** if any, is not invoked. 13222 ** 13223 ** 13224 ** xRowCount(pFts5, pnRow) 13225 ** 13226 ** This function is used to retrieve the total number of rows in the table. 13227 ** In other words, the same value that would be returned by: 13228 ** 13229 ** SELECT count(*) FROM ftstable; 13230 ** 13231 ** xPhraseFirst() 13232 ** This function is used, along with type Fts5PhraseIter and the xPhraseNext 13233 ** method, to iterate through all instances of a single query phrase within 13234 ** the current row. This is the same information as is accessible via the 13235 ** xInstCount/xInst APIs. While the xInstCount/xInst APIs are more convenient 13236 ** to use, this API may be faster under some circumstances. To iterate 13237 ** through instances of phrase iPhrase, use the following code: 13238 ** 13239 ** Fts5PhraseIter iter; 13240 ** int iCol, iOff; 13241 ** for(pApi->xPhraseFirst(pFts, iPhrase, &iter, &iCol, &iOff); 13242 ** iCol>=0; 13243 ** pApi->xPhraseNext(pFts, &iter, &iCol, &iOff) 13244 ** ){ 13245 ** // An instance of phrase iPhrase at offset iOff of column iCol 13246 ** } 13247 ** 13248 ** The Fts5PhraseIter structure is defined above. Applications should not 13249 ** modify this structure directly - it should only be used as shown above 13250 ** with the xPhraseFirst() and xPhraseNext() API methods (and by 13251 ** xPhraseFirstColumn() and xPhraseNextColumn() as illustrated below). 13252 ** 13253 ** This API can be quite slow if used with an FTS5 table created with the 13254 ** "detail=none" or "detail=column" option. If the FTS5 table is created 13255 ** with either "detail=none" or "detail=column" and "content=" option 13256 ** (i.e. if it is a contentless table), then this API always iterates 13257 ** through an empty set (all calls to xPhraseFirst() set iCol to -1). 13258 ** 13259 ** In all cases, matches are visited in (column ASC, offset ASC) order. 13260 ** i.e. all those in column 0, sorted by offset, followed by those in 13261 ** column 1, etc. 13262 ** 13263 ** xPhraseNext() 13264 ** See xPhraseFirst above. 13265 ** 13266 ** xPhraseFirstColumn() 13267 ** This function and xPhraseNextColumn() are similar to the xPhraseFirst() 13268 ** and xPhraseNext() APIs described above. The difference is that instead 13269 ** of iterating through all instances of a phrase in the current row, these 13270 ** APIs are used to iterate through the set of columns in the current row 13271 ** that contain one or more instances of a specified phrase. For example: 13272 ** 13273 ** Fts5PhraseIter iter; 13274 ** int iCol; 13275 ** for(pApi->xPhraseFirstColumn(pFts, iPhrase, &iter, &iCol); 13276 ** iCol>=0; 13277 ** pApi->xPhraseNextColumn(pFts, &iter, &iCol) 13278 ** ){ 13279 ** // Column iCol contains at least one instance of phrase iPhrase 13280 ** } 13281 ** 13282 ** This API can be quite slow if used with an FTS5 table created with the 13283 ** "detail=none" option. If the FTS5 table is created with either 13284 ** "detail=none" "content=" option (i.e. if it is a contentless table), 13285 ** then this API always iterates through an empty set (all calls to 13286 ** xPhraseFirstColumn() set iCol to -1). 13287 ** 13288 ** The information accessed using this API and its companion 13289 ** xPhraseFirstColumn() may also be obtained using xPhraseFirst/xPhraseNext 13290 ** (or xInst/xInstCount). The chief advantage of this API is that it is 13291 ** significantly more efficient than those alternatives when used with 13292 ** "detail=column" tables. 13293 ** 13294 ** xPhraseNextColumn() 13295 ** See xPhraseFirstColumn above. 13296 ** 13297 ** xQueryToken(pFts5, iPhrase, iToken, ppToken, pnToken) 13298 ** This is used to access token iToken of phrase iPhrase of the current 13299 ** query. Before returning, output parameter *ppToken is set to point 13300 ** to a buffer containing the requested token, and *pnToken to the 13301 ** size of this buffer in bytes. 13302 ** 13303 ** If iPhrase or iToken are less than zero, or if iPhrase is greater than 13304 ** or equal to the number of phrases in the query as reported by 13305 ** xPhraseCount(), or if iToken is equal to or greater than the number of 13306 ** tokens in the phrase, SQLITE_RANGE is returned and *ppToken and *pnToken 13307 are both zeroed. 13308 ** 13309 ** The output text is not a copy of the query text that specified the 13310 ** token. It is the output of the tokenizer module. For tokendata=1 13311 ** tables, this includes any embedded 0x00 and trailing data. 13312 ** 13313 ** xInstToken(pFts5, iIdx, iToken, ppToken, pnToken) 13314 ** This is used to access token iToken of phrase hit iIdx within the 13315 ** current row. If iIdx is less than zero or greater than or equal to the 13316 ** value returned by xInstCount(), SQLITE_RANGE is returned. Otherwise, 13317 ** output variable (*ppToken) is set to point to a buffer containing the 13318 ** matching document token, and (*pnToken) to the size of that buffer in 13319 ** bytes. 13320 ** 13321 ** The output text is not a copy of the document text that was tokenized. 13322 ** It is the output of the tokenizer module. For tokendata=1 tables, this 13323 ** includes any embedded 0x00 and trailing data. 13324 ** 13325 ** This API may be slow in some cases if the token identified by parameters 13326 ** iIdx and iToken matched a prefix token in the query. In most cases, the 13327 ** first call to this API for each prefix token in the query is forced 13328 ** to scan the portion of the full-text index that matches the prefix 13329 ** token to collect the extra data required by this API. If the prefix 13330 ** token matches a large number of token instances in the document set, 13331 ** this may be a performance problem. 13332 ** 13333 ** If the user knows in advance that a query may use this API for a 13334 ** prefix token, FTS5 may be configured to collect all required data as part 13335 ** of the initial querying of the full-text index, avoiding the second scan 13336 ** entirely. This also causes prefix queries that do not use this API to 13337 ** run more slowly and use more memory. FTS5 may be configured in this way 13338 ** either on a per-table basis using the [FTS5 insttoken | 'insttoken'] 13339 ** option, or on a per-query basis using the 13340 ** [fts5_insttoken | fts5_insttoken()] user function. 13341 ** 13342 ** This API can be quite slow if used with an FTS5 table created with the 13343 ** "detail=none" or "detail=column" option. 13344 ** 13345 ** xColumnLocale(pFts5, iIdx, pzLocale, pnLocale) 13346 ** If parameter iCol is less than zero, or greater than or equal to the 13347 ** number of columns in the table, SQLITE_RANGE is returned. 13348 ** 13349 ** Otherwise, this function attempts to retrieve the locale associated 13350 ** with column iCol of the current row. Usually, there is no associated 13351 ** locale, and output parameters (*pzLocale) and (*pnLocale) are set 13352 ** to NULL and 0, respectively. However, if the fts5_locale() function 13353 ** was used to associate a locale with the value when it was inserted 13354 ** into the fts5 table, then (*pzLocale) is set to point to a nul-terminated 13355 ** buffer containing the name of the locale in utf-8 encoding. (*pnLocale) 13356 ** is set to the size in bytes of the buffer, not including the 13357 ** nul-terminator. 13358 ** 13359 ** If successful, SQLITE_OK is returned. Or, if an error occurs, an 13360 ** SQLite error code is returned. The final value of the output parameters 13361 ** is undefined in this case. 13362 ** 13363 ** xTokenize_v2: 13364 ** Tokenize text using the tokenizer belonging to the FTS5 table. This 13365 ** API is the same as the xTokenize() API, except that it allows a tokenizer 13366 ** locale to be specified. 13367 */ 13368 struct Fts5ExtensionApi { 13369 int iVersion; /* Currently always set to 4 */ 13370 13371 void *(*xUserData)(Fts5Context*); 13372 13373 int (*xColumnCount)(Fts5Context*); 13374 int (*xRowCount)(Fts5Context*, sqlite3_int64 *pnRow); 13375 int (*xColumnTotalSize)(Fts5Context*, int iCol, sqlite3_int64 *pnToken); 13376 13377 int (*xTokenize)(Fts5Context*, 13378 const char *pText, int nText, /* Text to tokenize */ 13379 void *pCtx, /* Context passed to xToken() */ 13380 int (*xToken)(void*, int, const char*, int, int, int) /* Callback */ 13381 ); 13382 13383 int (*xPhraseCount)(Fts5Context*); 13384 int (*xPhraseSize)(Fts5Context*, int iPhrase); 13385 13386 int (*xInstCount)(Fts5Context*, int *pnInst); 13387 int (*xInst)(Fts5Context*, int iIdx, int *piPhrase, int *piCol, int *piOff); 13388 13389 sqlite3_int64 (*xRowid)(Fts5Context*); 13390 int (*xColumnText)(Fts5Context*, int iCol, const char **pz, int *pn); 13391 int (*xColumnSize)(Fts5Context*, int iCol, int *pnToken); 13392 13393 int (*xQueryPhrase)(Fts5Context*, int iPhrase, void *pUserData, 13394 int(*)(const Fts5ExtensionApi*,Fts5Context*,void*) 13395 ); 13396 int (*xSetAuxdata)(Fts5Context*, void *pAux, void(*xDelete)(void*)); 13397 void *(*xGetAuxdata)(Fts5Context*, int bClear); 13398 13399 int (*xPhraseFirst)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*, int*); 13400 void (*xPhraseNext)(Fts5Context*, Fts5PhraseIter*, int *piCol, int *piOff); 13401 13402 int (*xPhraseFirstColumn)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*); 13403 void (*xPhraseNextColumn)(Fts5Context*, Fts5PhraseIter*, int *piCol); 13404 13405 /* Below this point are iVersion>=3 only */ 13406 int (*xQueryToken)(Fts5Context*, 13407 int iPhrase, int iToken, 13408 const char **ppToken, int *pnToken 13409 ); 13410 int (*xInstToken)(Fts5Context*, int iIdx, int iToken, const char**, int*); 13411 13412 /* Below this point are iVersion>=4 only */ 13413 int (*xColumnLocale)(Fts5Context*, int iCol, const char **pz, int *pn); 13414 int (*xTokenize_v2)(Fts5Context*, 13415 const char *pText, int nText, /* Text to tokenize */ 13416 const char *pLocale, int nLocale, /* Locale to pass to tokenizer */ 13417 void *pCtx, /* Context passed to xToken() */ 13418 int (*xToken)(void*, int, const char*, int, int, int) /* Callback */ 13419 ); 13420 }; 13421 13422 /* 13423 ** CUSTOM AUXILIARY FUNCTIONS 13424 *************************************************************************/ 13425 13426 /************************************************************************* 13427 ** CUSTOM TOKENIZERS 13428 ** 13429 ** Applications may also register custom tokenizer types. A tokenizer 13430 ** is registered by providing fts5 with a populated instance of the 13431 ** following structure. All structure methods must be defined, setting 13432 ** any member of the fts5_tokenizer struct to NULL leads to undefined 13433 ** behaviour. The structure methods are expected to function as follows: 13434 ** 13435 ** xCreate: 13436 ** This function is used to allocate and initialize a tokenizer instance. 13437 ** A tokenizer instance is required to actually tokenize text. 13438 ** 13439 ** The first argument passed to this function is a copy of the (void*) 13440 ** pointer provided by the application when the fts5_tokenizer_v2 object 13441 ** was registered with FTS5 (the third argument to xCreateTokenizer()). 13442 ** The second and third arguments are an array of nul-terminated strings 13443 ** containing the tokenizer arguments, if any, specified following the 13444 ** tokenizer name as part of the CREATE VIRTUAL TABLE statement used 13445 ** to create the FTS5 table. 13446 ** 13447 ** The final argument is an output variable. If successful, (*ppOut) 13448 ** should be set to point to the new tokenizer handle and SQLITE_OK 13449 ** returned. If an error occurs, some value other than SQLITE_OK should 13450 ** be returned. In this case, fts5 assumes that the final value of *ppOut 13451 ** is undefined. 13452 ** 13453 ** xDelete: 13454 ** This function is invoked to delete a tokenizer handle previously 13455 ** allocated using xCreate(). Fts5 guarantees that this function will 13456 ** be invoked exactly once for each successful call to xCreate(). 13457 ** 13458 ** xTokenize: 13459 ** This function is expected to tokenize the nText byte string indicated 13460 ** by argument pText. pText may or may not be nul-terminated. The first 13461 ** argument passed to this function is a pointer to an Fts5Tokenizer object 13462 ** returned by an earlier call to xCreate(). 13463 ** 13464 ** The third argument indicates the reason that FTS5 is requesting 13465 ** tokenization of the supplied text. This is always one of the following 13466 ** four values: 13467 ** 13468 ** <ul><li> <b>FTS5_TOKENIZE_DOCUMENT</b> - A document is being inserted into 13469 ** or removed from the FTS table. The tokenizer is being invoked to 13470 ** determine the set of tokens to add to (or delete from) the 13471 ** FTS index. 13472 ** 13473 ** <li> <b>FTS5_TOKENIZE_QUERY</b> - A MATCH query is being executed 13474 ** against the FTS index. The tokenizer is being called to tokenize 13475 ** a bareword or quoted string specified as part of the query. 13476 ** 13477 ** <li> <b>(FTS5_TOKENIZE_QUERY | FTS5_TOKENIZE_PREFIX)</b> - Same as 13478 ** FTS5_TOKENIZE_QUERY, except that the bareword or quoted string is 13479 ** followed by a "*" character, indicating that the last token 13480 ** returned by the tokenizer will be treated as a token prefix. 13481 ** 13482 ** <li> <b>FTS5_TOKENIZE_AUX</b> - The tokenizer is being invoked to 13483 ** satisfy an fts5_api.xTokenize() request made by an auxiliary 13484 ** function. Or an fts5_api.xColumnSize() request made by the same 13485 ** on a columnsize=0 database. 13486 ** </ul> 13487 ** 13488 ** The sixth and seventh arguments passed to xTokenize() - pLocale and 13489 ** nLocale - are a pointer to a buffer containing the locale to use for 13490 ** tokenization (e.g. "en_US") and its size in bytes, respectively. The 13491 ** pLocale buffer is not nul-terminated. pLocale may be passed NULL (in 13492 ** which case nLocale is always 0) to indicate that the tokenizer should 13493 ** use its default locale. 13494 ** 13495 ** For each token in the input string, the supplied callback xToken() must 13496 ** be invoked. The first argument to it should be a copy of the pointer 13497 ** passed as the second argument to xTokenize(). The third and fourth 13498 ** arguments are a pointer to a buffer containing the token text, and the 13499 ** size of the token in bytes. The 4th and 5th arguments are the byte offsets 13500 ** of the first byte of and first byte immediately following the text from 13501 ** which the token is derived within the input. 13502 ** 13503 ** The second argument passed to the xToken() callback ("tflags") should 13504 ** normally be set to 0. The exception is if the tokenizer supports 13505 ** synonyms. In this case see the discussion below for details. 13506 ** 13507 ** FTS5 assumes the xToken() callback is invoked for each token in the 13508 ** order that they occur within the input text. 13509 ** 13510 ** If an xToken() callback returns any value other than SQLITE_OK, then 13511 ** the tokenization should be abandoned and the xTokenize() method should 13512 ** immediately return a copy of the xToken() return value. Or, if the 13513 ** input buffer is exhausted, xTokenize() should return SQLITE_OK. Finally, 13514 ** if an error occurs with the xTokenize() implementation itself, it 13515 ** may abandon the tokenization and return any error code other than 13516 ** SQLITE_OK or SQLITE_DONE. 13517 ** 13518 ** If the tokenizer is registered using an fts5_tokenizer_v2 object, 13519 ** then the xTokenize() method has two additional arguments - pLocale 13520 ** and nLocale. These specify the locale that the tokenizer should use 13521 ** for the current request. If pLocale and nLocale are both 0, then the 13522 ** tokenizer should use its default locale. Otherwise, pLocale points to 13523 ** an nLocale byte buffer containing the name of the locale to use as utf-8 13524 ** text. pLocale is not nul-terminated. 13525 ** 13526 ** FTS5_TOKENIZER 13527 ** 13528 ** There is also an fts5_tokenizer object. This is an older, deprecated, 13529 ** version of fts5_tokenizer_v2. It is similar except that: 13530 ** 13531 ** <ul> 13532 ** <li> There is no "iVersion" field, and 13533 ** <li> The xTokenize() method does not take a locale argument. 13534 ** </ul> 13535 ** 13536 ** Legacy fts5_tokenizer tokenizers must be registered using the 13537 ** legacy xCreateTokenizer() function, instead of xCreateTokenizer_v2(). 13538 ** 13539 ** Tokenizer implementations registered using either API may be retrieved 13540 ** using both xFindTokenizer() and xFindTokenizer_v2(). 13541 ** 13542 ** SYNONYM SUPPORT 13543 ** 13544 ** Custom tokenizers may also support synonyms. Consider a case in which a 13545 ** user wishes to query for a phrase such as "first place". Using the 13546 ** built-in tokenizers, the FTS5 query 'first + place' will match instances 13547 ** of "first place" within the document set, but not alternative forms 13548 ** such as "1st place". In some applications, it would be better to match 13549 ** all instances of "first place" or "1st place" regardless of which form 13550 ** the user specified in the MATCH query text. 13551 ** 13552 ** There are several ways to approach this in FTS5: 13553 ** 13554 ** <ol><li> By mapping all synonyms to a single token. In this case, using 13555 ** the above example, this means that the tokenizer returns the 13556 ** same token for inputs "first" and "1st". Say that token is in 13557 ** fact "first", so that when the user inserts the document "I won 13558 ** 1st place" entries are added to the index for tokens "i", "won", 13559 ** "first" and "place". If the user then queries for '1st + place', 13560 ** the tokenizer substitutes "first" for "1st" and the query works 13561 ** as expected. 13562 ** 13563 ** <li> By querying the index for all synonyms of each query term 13564 ** separately. In this case, when tokenizing query text, the 13565 ** tokenizer may provide multiple synonyms for a single term 13566 ** within the document. FTS5 then queries the index for each 13567 ** synonym individually. For example, faced with the query: 13568 ** 13569 ** <codeblock> 13570 ** ... MATCH 'first place'</codeblock> 13571 ** 13572 ** the tokenizer offers both "1st" and "first" as synonyms for the 13573 ** first token in the MATCH query and FTS5 effectively runs a query 13574 ** similar to: 13575 ** 13576 ** <codeblock> 13577 ** ... MATCH '(first OR 1st) place'</codeblock> 13578 ** 13579 ** except that, for the purposes of auxiliary functions, the query 13580 ** still appears to contain just two phrases - "(first OR 1st)" 13581 ** being treated as a single phrase. 13582 ** 13583 ** <li> By adding multiple synonyms for a single term to the FTS index. 13584 ** Using this method, when tokenizing document text, the tokenizer 13585 ** provides multiple synonyms for each token. So that when a 13586 ** document such as "I won first place" is tokenized, entries are 13587 ** added to the FTS index for "i", "won", "first", "1st" and 13588 ** "place". 13589 ** 13590 ** This way, even if the tokenizer does not provide synonyms 13591 ** when tokenizing query text (it should not - to do so would be 13592 ** inefficient), it doesn't matter if the user queries for 13593 ** 'first + place' or '1st + place', as there are entries in the 13594 ** FTS index corresponding to both forms of the first token. 13595 ** </ol> 13596 ** 13597 ** Whether it is parsing document or query text, any call to xToken that 13598 ** specifies a <i>tflags</i> argument with the FTS5_TOKEN_COLOCATED bit 13599 ** is considered to supply a synonym for the previous token. For example, 13600 ** when parsing the document "I won first place", a tokenizer that supports 13601 ** synonyms would call xToken() 5 times, as follows: 13602 ** 13603 ** <codeblock> 13604 ** xToken(pCtx, 0, "i", 1, 0, 1); 13605 ** xToken(pCtx, 0, "won", 3, 2, 5); 13606 ** xToken(pCtx, 0, "first", 5, 6, 11); 13607 ** xToken(pCtx, FTS5_TOKEN_COLOCATED, "1st", 3, 6, 11); 13608 ** xToken(pCtx, 0, "place", 5, 12, 17); 13609 **</codeblock> 13610 ** 13611 ** It is an error to specify the FTS5_TOKEN_COLOCATED flag the first time 13612 ** xToken() is called. Multiple synonyms may be specified for a single token 13613 ** by making multiple calls to xToken(FTS5_TOKEN_COLOCATED) in sequence. 13614 ** There is no limit to the number of synonyms that may be provided for a 13615 ** single token. 13616 ** 13617 ** In many cases, method (1) above is the best approach. It does not add 13618 ** extra data to the FTS index or require FTS5 to query for multiple terms, 13619 ** so it is efficient in terms of disk space and query speed. However, it 13620 ** does not support prefix queries very well. If, as suggested above, the 13621 ** token "first" is substituted for "1st" by the tokenizer, then the query: 13622 ** 13623 ** <codeblock> 13624 ** ... MATCH '1s*'</codeblock> 13625 ** 13626 ** will not match documents that contain the token "1st" (as the tokenizer 13627 ** will probably not map "1s" to any prefix of "first"). 13628 ** 13629 ** For full prefix support, method (3) may be preferred. In this case, 13630 ** because the index contains entries for both "first" and "1st", prefix 13631 ** queries such as 'fi*' or '1s*' will match correctly. However, because 13632 ** extra entries are added to the FTS index, this method uses more space 13633 ** within the database. 13634 ** 13635 ** Method (2) offers a midpoint between (1) and (3). Using this method, 13636 ** a query such as '1s*' will match documents that contain the literal 13637 ** token "1st", but not "first" (assuming the tokenizer is not able to 13638 ** provide synonyms for prefixes). However, a non-prefix query like '1st' 13639 ** will match against "1st" and "first". This method does not require 13640 ** extra disk space, as no extra entries are added to the FTS index. 13641 ** On the other hand, it may require more CPU cycles to run MATCH queries, 13642 ** as separate queries of the FTS index are required for each synonym. 13643 ** 13644 ** When using methods (2) or (3), it is important that the tokenizer only 13645 ** provide synonyms when tokenizing document text (method (3)) or query 13646 ** text (method (2)), not both. Doing so will not cause any errors, but is 13647 ** inefficient. 13648 */ 13649 typedef struct Fts5Tokenizer Fts5Tokenizer; 13650 typedef struct fts5_tokenizer_v2 fts5_tokenizer_v2; 13651 struct fts5_tokenizer_v2 { 13652 int iVersion; /* Currently always 2 */ 13653 13654 int (*xCreate)(void*, const char **azArg, int nArg, Fts5Tokenizer **ppOut); 13655 void (*xDelete)(Fts5Tokenizer*); 13656 int (*xTokenize)(Fts5Tokenizer*, 13657 void *pCtx, 13658 int flags, /* Mask of FTS5_TOKENIZE_* flags */ 13659 const char *pText, int nText, 13660 const char *pLocale, int nLocale, 13661 int (*xToken)( 13662 void *pCtx, /* Copy of 2nd argument to xTokenize() */ 13663 int tflags, /* Mask of FTS5_TOKEN_* flags */ 13664 const char *pToken, /* Pointer to buffer containing token */ 13665 int nToken, /* Size of token in bytes */ 13666 int iStart, /* Byte offset of token within input text */ 13667 int iEnd /* Byte offset of end of token within input text */ 13668 ) 13669 ); 13670 }; 13671 13672 /* 13673 ** New code should use the fts5_tokenizer_v2 type to define tokenizer 13674 ** implementations. The following type is included for legacy applications 13675 ** that still use it. 13676 */ 13677 typedef struct fts5_tokenizer fts5_tokenizer; 13678 struct fts5_tokenizer { 13679 int (*xCreate)(void*, const char **azArg, int nArg, Fts5Tokenizer **ppOut); 13680 void (*xDelete)(Fts5Tokenizer*); 13681 int (*xTokenize)(Fts5Tokenizer*, 13682 void *pCtx, 13683 int flags, /* Mask of FTS5_TOKENIZE_* flags */ 13684 const char *pText, int nText, 13685 int (*xToken)( 13686 void *pCtx, /* Copy of 2nd argument to xTokenize() */ 13687 int tflags, /* Mask of FTS5_TOKEN_* flags */ 13688 const char *pToken, /* Pointer to buffer containing token */ 13689 int nToken, /* Size of token in bytes */ 13690 int iStart, /* Byte offset of token within input text */ 13691 int iEnd /* Byte offset of end of token within input text */ 13692 ) 13693 ); 13694 }; 13695 13696 13697 /* Flags that may be passed as the third argument to xTokenize() */ 13698 #define FTS5_TOKENIZE_QUERY 0x0001 13699 #define FTS5_TOKENIZE_PREFIX 0x0002 13700 #define FTS5_TOKENIZE_DOCUMENT 0x0004 13701 #define FTS5_TOKENIZE_AUX 0x0008 13702 13703 /* Flags that may be passed by the tokenizer implementation back to FTS5 13704 ** as the third argument to the supplied xToken callback. */ 13705 #define FTS5_TOKEN_COLOCATED 0x0001 /* Same position as prev. token */ 13706 13707 /* 13708 ** END OF CUSTOM TOKENIZERS 13709 *************************************************************************/ 13710 13711 /************************************************************************* 13712 ** FTS5 EXTENSION REGISTRATION API 13713 */ 13714 typedef struct fts5_api fts5_api; 13715 struct fts5_api { 13716 int iVersion; /* Currently always set to 3 */ 13717 13718 /* Create a new tokenizer */ 13719 int (*xCreateTokenizer)( 13720 fts5_api *pApi, 13721 const char *zName, 13722 void *pUserData, 13723 fts5_tokenizer *pTokenizer, 13724 void (*xDestroy)(void*) 13725 ); 13726 13727 /* Find an existing tokenizer */ 13728 int (*xFindTokenizer)( 13729 fts5_api *pApi, 13730 const char *zName, 13731 void **ppUserData, 13732 fts5_tokenizer *pTokenizer 13733 ); 13734 13735 /* Create a new auxiliary function */ 13736 int (*xCreateFunction)( 13737 fts5_api *pApi, 13738 const char *zName, 13739 void *pUserData, 13740 fts5_extension_function xFunction, 13741 void (*xDestroy)(void*) 13742 ); 13743 13744 /* APIs below this point are only available if iVersion>=3 */ 13745 13746 /* Create a new tokenizer */ 13747 int (*xCreateTokenizer_v2)( 13748 fts5_api *pApi, 13749 const char *zName, 13750 void *pUserData, 13751 fts5_tokenizer_v2 *pTokenizer, 13752 void (*xDestroy)(void*) 13753 ); 13754 13755 /* Find an existing tokenizer */ 13756 int (*xFindTokenizer_v2)( 13757 fts5_api *pApi, 13758 const char *zName, 13759 void **ppUserData, 13760 fts5_tokenizer_v2 **ppTokenizer 13761 ); 13762 }; 13763 13764 /* 13765 ** END OF REGISTRATION API 13766 *************************************************************************/ 13767 13768 #ifdef __cplusplus 13769 } /* end of the 'extern "C"' block */ 13770 #endif 13771 13772 #endif /* _FTS5_H */ 13773 13774 /******** End of fts5.h *********/ 13775 #endif /* SQLITE3_H */ 13776