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://www.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 "3.42.0" 150 #define SQLITE_VERSION_NUMBER 3042000 151 #define SQLITE_SOURCE_ID "2023-05-16 12:36:15 831d0fb2836b71c9bc51067c49fee4b8f18047814f2ff22d817d25195cf350b0" 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 ** </ul> 424 */ 425 SQLITE_API int sqlite3_exec( 426 sqlite3*, /* An open database */ 427 const char *sql, /* SQL to be evaluated */ 428 int (*callback)(void*,int,char**,char**), /* Callback function */ 429 void *, /* 1st argument to callback */ 430 char **errmsg /* Error msg written here */ 431 ); 432 433 /* 434 ** CAPI3REF: Result Codes 435 ** KEYWORDS: {result code definitions} 436 ** 437 ** Many SQLite functions return an integer result code from the set shown 438 ** here in order to indicate success or failure. 439 ** 440 ** New error codes may be added in future versions of SQLite. 441 ** 442 ** See also: [extended result code definitions] 443 */ 444 #define SQLITE_OK 0 /* Successful result */ 445 /* beginning-of-error-codes */ 446 #define SQLITE_ERROR 1 /* Generic error */ 447 #define SQLITE_INTERNAL 2 /* Internal logic error in SQLite */ 448 #define SQLITE_PERM 3 /* Access permission denied */ 449 #define SQLITE_ABORT 4 /* Callback routine requested an abort */ 450 #define SQLITE_BUSY 5 /* The database file is locked */ 451 #define SQLITE_LOCKED 6 /* A table in the database is locked */ 452 #define SQLITE_NOMEM 7 /* A malloc() failed */ 453 #define SQLITE_READONLY 8 /* Attempt to write a readonly database */ 454 #define SQLITE_INTERRUPT 9 /* Operation terminated by sqlite3_interrupt()*/ 455 #define SQLITE_IOERR 10 /* Some kind of disk I/O error occurred */ 456 #define SQLITE_CORRUPT 11 /* The database disk image is malformed */ 457 #define SQLITE_NOTFOUND 12 /* Unknown opcode in sqlite3_file_control() */ 458 #define SQLITE_FULL 13 /* Insertion failed because database is full */ 459 #define SQLITE_CANTOPEN 14 /* Unable to open the database file */ 460 #define SQLITE_PROTOCOL 15 /* Database lock protocol error */ 461 #define SQLITE_EMPTY 16 /* Internal use only */ 462 #define SQLITE_SCHEMA 17 /* The database schema changed */ 463 #define SQLITE_TOOBIG 18 /* String or BLOB exceeds size limit */ 464 #define SQLITE_CONSTRAINT 19 /* Abort due to constraint violation */ 465 #define SQLITE_MISMATCH 20 /* Data type mismatch */ 466 #define SQLITE_MISUSE 21 /* Library used incorrectly */ 467 #define SQLITE_NOLFS 22 /* Uses OS features not supported on host */ 468 #define SQLITE_AUTH 23 /* Authorization denied */ 469 #define SQLITE_FORMAT 24 /* Not used */ 470 #define SQLITE_RANGE 25 /* 2nd parameter to sqlite3_bind out of range */ 471 #define SQLITE_NOTADB 26 /* File opened that is not a database file */ 472 #define SQLITE_NOTICE 27 /* Notifications from sqlite3_log() */ 473 #define SQLITE_WARNING 28 /* Warnings from sqlite3_log() */ 474 #define SQLITE_ROW 100 /* sqlite3_step() has another row ready */ 475 #define SQLITE_DONE 101 /* sqlite3_step() has finished executing */ 476 /* end-of-error-codes */ 477 478 /* 479 ** CAPI3REF: Extended Result Codes 480 ** KEYWORDS: {extended result code definitions} 481 ** 482 ** In its default configuration, SQLite API routines return one of 30 integer 483 ** [result codes]. However, experience has shown that many of 484 ** these result codes are too coarse-grained. They do not provide as 485 ** much information about problems as programmers might like. In an effort to 486 ** address this, newer versions of SQLite (version 3.3.8 [dateof:3.3.8] 487 ** and later) include 488 ** support for additional result codes that provide more detailed information 489 ** about errors. These [extended result codes] are enabled or disabled 490 ** on a per database connection basis using the 491 ** [sqlite3_extended_result_codes()] API. Or, the extended code for 492 ** the most recent error can be obtained using 493 ** [sqlite3_extended_errcode()]. 494 */ 495 #define SQLITE_ERROR_MISSING_COLLSEQ (SQLITE_ERROR | (1<<8)) 496 #define SQLITE_ERROR_RETRY (SQLITE_ERROR | (2<<8)) 497 #define SQLITE_ERROR_SNAPSHOT (SQLITE_ERROR | (3<<8)) 498 #define SQLITE_IOERR_READ (SQLITE_IOERR | (1<<8)) 499 #define SQLITE_IOERR_SHORT_READ (SQLITE_IOERR | (2<<8)) 500 #define SQLITE_IOERR_WRITE (SQLITE_IOERR | (3<<8)) 501 #define SQLITE_IOERR_FSYNC (SQLITE_IOERR | (4<<8)) 502 #define SQLITE_IOERR_DIR_FSYNC (SQLITE_IOERR | (5<<8)) 503 #define SQLITE_IOERR_TRUNCATE (SQLITE_IOERR | (6<<8)) 504 #define SQLITE_IOERR_FSTAT (SQLITE_IOERR | (7<<8)) 505 #define SQLITE_IOERR_UNLOCK (SQLITE_IOERR | (8<<8)) 506 #define SQLITE_IOERR_RDLOCK (SQLITE_IOERR | (9<<8)) 507 #define SQLITE_IOERR_DELETE (SQLITE_IOERR | (10<<8)) 508 #define SQLITE_IOERR_BLOCKED (SQLITE_IOERR | (11<<8)) 509 #define SQLITE_IOERR_NOMEM (SQLITE_IOERR | (12<<8)) 510 #define SQLITE_IOERR_ACCESS (SQLITE_IOERR | (13<<8)) 511 #define SQLITE_IOERR_CHECKRESERVEDLOCK (SQLITE_IOERR | (14<<8)) 512 #define SQLITE_IOERR_LOCK (SQLITE_IOERR | (15<<8)) 513 #define SQLITE_IOERR_CLOSE (SQLITE_IOERR | (16<<8)) 514 #define SQLITE_IOERR_DIR_CLOSE (SQLITE_IOERR | (17<<8)) 515 #define SQLITE_IOERR_SHMOPEN (SQLITE_IOERR | (18<<8)) 516 #define SQLITE_IOERR_SHMSIZE (SQLITE_IOERR | (19<<8)) 517 #define SQLITE_IOERR_SHMLOCK (SQLITE_IOERR | (20<<8)) 518 #define SQLITE_IOERR_SHMMAP (SQLITE_IOERR | (21<<8)) 519 #define SQLITE_IOERR_SEEK (SQLITE_IOERR | (22<<8)) 520 #define SQLITE_IOERR_DELETE_NOENT (SQLITE_IOERR | (23<<8)) 521 #define SQLITE_IOERR_MMAP (SQLITE_IOERR | (24<<8)) 522 #define SQLITE_IOERR_GETTEMPPATH (SQLITE_IOERR | (25<<8)) 523 #define SQLITE_IOERR_CONVPATH (SQLITE_IOERR | (26<<8)) 524 #define SQLITE_IOERR_VNODE (SQLITE_IOERR | (27<<8)) 525 #define SQLITE_IOERR_AUTH (SQLITE_IOERR | (28<<8)) 526 #define SQLITE_IOERR_BEGIN_ATOMIC (SQLITE_IOERR | (29<<8)) 527 #define SQLITE_IOERR_COMMIT_ATOMIC (SQLITE_IOERR | (30<<8)) 528 #define SQLITE_IOERR_ROLLBACK_ATOMIC (SQLITE_IOERR | (31<<8)) 529 #define SQLITE_IOERR_DATA (SQLITE_IOERR | (32<<8)) 530 #define SQLITE_IOERR_CORRUPTFS (SQLITE_IOERR | (33<<8)) 531 #define SQLITE_LOCKED_SHAREDCACHE (SQLITE_LOCKED | (1<<8)) 532 #define SQLITE_LOCKED_VTAB (SQLITE_LOCKED | (2<<8)) 533 #define SQLITE_BUSY_RECOVERY (SQLITE_BUSY | (1<<8)) 534 #define SQLITE_BUSY_SNAPSHOT (SQLITE_BUSY | (2<<8)) 535 #define SQLITE_BUSY_TIMEOUT (SQLITE_BUSY | (3<<8)) 536 #define SQLITE_CANTOPEN_NOTEMPDIR (SQLITE_CANTOPEN | (1<<8)) 537 #define SQLITE_CANTOPEN_ISDIR (SQLITE_CANTOPEN | (2<<8)) 538 #define SQLITE_CANTOPEN_FULLPATH (SQLITE_CANTOPEN | (3<<8)) 539 #define SQLITE_CANTOPEN_CONVPATH (SQLITE_CANTOPEN | (4<<8)) 540 #define SQLITE_CANTOPEN_DIRTYWAL (SQLITE_CANTOPEN | (5<<8)) /* Not Used */ 541 #define SQLITE_CANTOPEN_SYMLINK (SQLITE_CANTOPEN | (6<<8)) 542 #define SQLITE_CORRUPT_VTAB (SQLITE_CORRUPT | (1<<8)) 543 #define SQLITE_CORRUPT_SEQUENCE (SQLITE_CORRUPT | (2<<8)) 544 #define SQLITE_CORRUPT_INDEX (SQLITE_CORRUPT | (3<<8)) 545 #define SQLITE_READONLY_RECOVERY (SQLITE_READONLY | (1<<8)) 546 #define SQLITE_READONLY_CANTLOCK (SQLITE_READONLY | (2<<8)) 547 #define SQLITE_READONLY_ROLLBACK (SQLITE_READONLY | (3<<8)) 548 #define SQLITE_READONLY_DBMOVED (SQLITE_READONLY | (4<<8)) 549 #define SQLITE_READONLY_CANTINIT (SQLITE_READONLY | (5<<8)) 550 #define SQLITE_READONLY_DIRECTORY (SQLITE_READONLY | (6<<8)) 551 #define SQLITE_ABORT_ROLLBACK (SQLITE_ABORT | (2<<8)) 552 #define SQLITE_CONSTRAINT_CHECK (SQLITE_CONSTRAINT | (1<<8)) 553 #define SQLITE_CONSTRAINT_COMMITHOOK (SQLITE_CONSTRAINT | (2<<8)) 554 #define SQLITE_CONSTRAINT_FOREIGNKEY (SQLITE_CONSTRAINT | (3<<8)) 555 #define SQLITE_CONSTRAINT_FUNCTION (SQLITE_CONSTRAINT | (4<<8)) 556 #define SQLITE_CONSTRAINT_NOTNULL (SQLITE_CONSTRAINT | (5<<8)) 557 #define SQLITE_CONSTRAINT_PRIMARYKEY (SQLITE_CONSTRAINT | (6<<8)) 558 #define SQLITE_CONSTRAINT_TRIGGER (SQLITE_CONSTRAINT | (7<<8)) 559 #define SQLITE_CONSTRAINT_UNIQUE (SQLITE_CONSTRAINT | (8<<8)) 560 #define SQLITE_CONSTRAINT_VTAB (SQLITE_CONSTRAINT | (9<<8)) 561 #define SQLITE_CONSTRAINT_ROWID (SQLITE_CONSTRAINT |(10<<8)) 562 #define SQLITE_CONSTRAINT_PINNED (SQLITE_CONSTRAINT |(11<<8)) 563 #define SQLITE_CONSTRAINT_DATATYPE (SQLITE_CONSTRAINT |(12<<8)) 564 #define SQLITE_NOTICE_RECOVER_WAL (SQLITE_NOTICE | (1<<8)) 565 #define SQLITE_NOTICE_RECOVER_ROLLBACK (SQLITE_NOTICE | (2<<8)) 566 #define SQLITE_NOTICE_RBU (SQLITE_NOTICE | (3<<8)) 567 #define SQLITE_WARNING_AUTOINDEX (SQLITE_WARNING | (1<<8)) 568 #define SQLITE_AUTH_USER (SQLITE_AUTH | (1<<8)) 569 #define SQLITE_OK_LOAD_PERMANENTLY (SQLITE_OK | (1<<8)) 570 #define SQLITE_OK_SYMLINK (SQLITE_OK | (2<<8)) /* internal use only */ 571 572 /* 573 ** CAPI3REF: Flags For File Open Operations 574 ** 575 ** These bit values are intended for use in the 576 ** 3rd parameter to the [sqlite3_open_v2()] interface and 577 ** in the 4th parameter to the [sqlite3_vfs.xOpen] method. 578 ** 579 ** Only those flags marked as "Ok for sqlite3_open_v2()" may be 580 ** used as the third argument to the [sqlite3_open_v2()] interface. 581 ** The other flags have historically been ignored by sqlite3_open_v2(), 582 ** though future versions of SQLite might change so that an error is 583 ** raised if any of the disallowed bits are passed into sqlite3_open_v2(). 584 ** Applications should not depend on the historical behavior. 585 ** 586 ** Note in particular that passing the SQLITE_OPEN_EXCLUSIVE flag into 587 ** [sqlite3_open_v2()] does *not* cause the underlying database file 588 ** to be opened using O_EXCL. Passing SQLITE_OPEN_EXCLUSIVE into 589 ** [sqlite3_open_v2()] has historically be a no-op and might become an 590 ** error in future versions of SQLite. 591 */ 592 #define SQLITE_OPEN_READONLY 0x00000001 /* Ok for sqlite3_open_v2() */ 593 #define SQLITE_OPEN_READWRITE 0x00000002 /* Ok for sqlite3_open_v2() */ 594 #define SQLITE_OPEN_CREATE 0x00000004 /* Ok for sqlite3_open_v2() */ 595 #define SQLITE_OPEN_DELETEONCLOSE 0x00000008 /* VFS only */ 596 #define SQLITE_OPEN_EXCLUSIVE 0x00000010 /* VFS only */ 597 #define SQLITE_OPEN_AUTOPROXY 0x00000020 /* VFS only */ 598 #define SQLITE_OPEN_URI 0x00000040 /* Ok for sqlite3_open_v2() */ 599 #define SQLITE_OPEN_MEMORY 0x00000080 /* Ok for sqlite3_open_v2() */ 600 #define SQLITE_OPEN_MAIN_DB 0x00000100 /* VFS only */ 601 #define SQLITE_OPEN_TEMP_DB 0x00000200 /* VFS only */ 602 #define SQLITE_OPEN_TRANSIENT_DB 0x00000400 /* VFS only */ 603 #define SQLITE_OPEN_MAIN_JOURNAL 0x00000800 /* VFS only */ 604 #define SQLITE_OPEN_TEMP_JOURNAL 0x00001000 /* VFS only */ 605 #define SQLITE_OPEN_SUBJOURNAL 0x00002000 /* VFS only */ 606 #define SQLITE_OPEN_SUPER_JOURNAL 0x00004000 /* VFS only */ 607 #define SQLITE_OPEN_NOMUTEX 0x00008000 /* Ok for sqlite3_open_v2() */ 608 #define SQLITE_OPEN_FULLMUTEX 0x00010000 /* Ok for sqlite3_open_v2() */ 609 #define SQLITE_OPEN_SHAREDCACHE 0x00020000 /* Ok for sqlite3_open_v2() */ 610 #define SQLITE_OPEN_PRIVATECACHE 0x00040000 /* Ok for sqlite3_open_v2() */ 611 #define SQLITE_OPEN_WAL 0x00080000 /* VFS only */ 612 #define SQLITE_OPEN_NOFOLLOW 0x01000000 /* Ok for sqlite3_open_v2() */ 613 #define SQLITE_OPEN_EXRESCODE 0x02000000 /* Extended result codes */ 614 615 /* Reserved: 0x00F00000 */ 616 /* Legacy compatibility: */ 617 #define SQLITE_OPEN_MASTER_JOURNAL 0x00004000 /* VFS only */ 618 619 620 /* 621 ** CAPI3REF: Device Characteristics 622 ** 623 ** The xDeviceCharacteristics method of the [sqlite3_io_methods] 624 ** object returns an integer which is a vector of these 625 ** bit values expressing I/O characteristics of the mass storage 626 ** device that holds the file that the [sqlite3_io_methods] 627 ** refers to. 628 ** 629 ** The SQLITE_IOCAP_ATOMIC property means that all writes of 630 ** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 631 ** mean that writes of blocks that are nnn bytes in size and 632 ** are aligned to an address which is an integer multiple of 633 ** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 634 ** that when data is appended to a file, the data is appended 635 ** first then the size of the file is extended, never the other 636 ** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 637 ** information is written to disk in the same order as calls 638 ** to xWrite(). The SQLITE_IOCAP_POWERSAFE_OVERWRITE property means that 639 ** after reboot following a crash or power loss, the only bytes in a 640 ** file that were written at the application level might have changed 641 ** and that adjacent bytes, even bytes within the same sector are 642 ** guaranteed to be unchanged. The SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 643 ** flag indicates that a file cannot be deleted when open. The 644 ** SQLITE_IOCAP_IMMUTABLE flag indicates that the file is on 645 ** read-only media and cannot be changed even by processes with 646 ** elevated privileges. 647 ** 648 ** The SQLITE_IOCAP_BATCH_ATOMIC property means that the underlying 649 ** filesystem supports doing multiple write operations atomically when those 650 ** write operations are bracketed by [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] and 651 ** [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]. 652 */ 653 #define SQLITE_IOCAP_ATOMIC 0x00000001 654 #define SQLITE_IOCAP_ATOMIC512 0x00000002 655 #define SQLITE_IOCAP_ATOMIC1K 0x00000004 656 #define SQLITE_IOCAP_ATOMIC2K 0x00000008 657 #define SQLITE_IOCAP_ATOMIC4K 0x00000010 658 #define SQLITE_IOCAP_ATOMIC8K 0x00000020 659 #define SQLITE_IOCAP_ATOMIC16K 0x00000040 660 #define SQLITE_IOCAP_ATOMIC32K 0x00000080 661 #define SQLITE_IOCAP_ATOMIC64K 0x00000100 662 #define SQLITE_IOCAP_SAFE_APPEND 0x00000200 663 #define SQLITE_IOCAP_SEQUENTIAL 0x00000400 664 #define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 0x00000800 665 #define SQLITE_IOCAP_POWERSAFE_OVERWRITE 0x00001000 666 #define SQLITE_IOCAP_IMMUTABLE 0x00002000 667 #define SQLITE_IOCAP_BATCH_ATOMIC 0x00004000 668 669 /* 670 ** CAPI3REF: File Locking Levels 671 ** 672 ** SQLite uses one of these integer values as the second 673 ** argument to calls it makes to the xLock() and xUnlock() methods 674 ** of an [sqlite3_io_methods] object. These values are ordered from 675 ** lest restrictive to most restrictive. 676 ** 677 ** The argument to xLock() is always SHARED or higher. The argument to 678 ** xUnlock is either SHARED or NONE. 679 */ 680 #define SQLITE_LOCK_NONE 0 /* xUnlock() only */ 681 #define SQLITE_LOCK_SHARED 1 /* xLock() or xUnlock() */ 682 #define SQLITE_LOCK_RESERVED 2 /* xLock() only */ 683 #define SQLITE_LOCK_PENDING 3 /* xLock() only */ 684 #define SQLITE_LOCK_EXCLUSIVE 4 /* xLock() only */ 685 686 /* 687 ** CAPI3REF: Synchronization Type Flags 688 ** 689 ** When SQLite invokes the xSync() method of an 690 ** [sqlite3_io_methods] object it uses a combination of 691 ** these integer values as the second argument. 692 ** 693 ** When the SQLITE_SYNC_DATAONLY flag is used, it means that the 694 ** sync operation only needs to flush data to mass storage. Inode 695 ** information need not be flushed. If the lower four bits of the flag 696 ** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics. 697 ** If the lower four bits equal SQLITE_SYNC_FULL, that means 698 ** to use Mac OS X style fullsync instead of fsync(). 699 ** 700 ** Do not confuse the SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags 701 ** with the [PRAGMA synchronous]=NORMAL and [PRAGMA synchronous]=FULL 702 ** settings. The [synchronous pragma] determines when calls to the 703 ** xSync VFS method occur and applies uniformly across all platforms. 704 ** The SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags determine how 705 ** energetic or rigorous or forceful the sync operations are and 706 ** only make a difference on Mac OSX for the default SQLite code. 707 ** (Third-party VFS implementations might also make the distinction 708 ** between SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL, but among the 709 ** operating systems natively supported by SQLite, only Mac OSX 710 ** cares about the difference.) 711 */ 712 #define SQLITE_SYNC_NORMAL 0x00002 713 #define SQLITE_SYNC_FULL 0x00003 714 #define SQLITE_SYNC_DATAONLY 0x00010 715 716 /* 717 ** CAPI3REF: OS Interface Open File Handle 718 ** 719 ** An [sqlite3_file] object represents an open file in the 720 ** [sqlite3_vfs | OS interface layer]. Individual OS interface 721 ** implementations will 722 ** want to subclass this object by appending additional fields 723 ** for their own use. The pMethods entry is a pointer to an 724 ** [sqlite3_io_methods] object that defines methods for performing 725 ** I/O operations on the open file. 726 */ 727 typedef struct sqlite3_file sqlite3_file; 728 struct sqlite3_file { 729 const struct sqlite3_io_methods *pMethods; /* Methods for an open file */ 730 }; 731 732 /* 733 ** CAPI3REF: OS Interface File Virtual Methods Object 734 ** 735 ** Every file opened by the [sqlite3_vfs.xOpen] method populates an 736 ** [sqlite3_file] object (or, more commonly, a subclass of the 737 ** [sqlite3_file] object) with a pointer to an instance of this object. 738 ** This object defines the methods used to perform various operations 739 ** against the open file represented by the [sqlite3_file] object. 740 ** 741 ** If the [sqlite3_vfs.xOpen] method sets the sqlite3_file.pMethods element 742 ** to a non-NULL pointer, then the sqlite3_io_methods.xClose method 743 ** may be invoked even if the [sqlite3_vfs.xOpen] reported that it failed. The 744 ** only way to prevent a call to xClose following a failed [sqlite3_vfs.xOpen] 745 ** is for the [sqlite3_vfs.xOpen] to set the sqlite3_file.pMethods element 746 ** to NULL. 747 ** 748 ** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or 749 ** [SQLITE_SYNC_FULL]. The first choice is the normal fsync(). 750 ** The second choice is a Mac OS X style fullsync. The [SQLITE_SYNC_DATAONLY] 751 ** flag may be ORed in to indicate that only the data of the file 752 ** and not its inode needs to be synced. 753 ** 754 ** The integer values to xLock() and xUnlock() are one of 755 ** <ul> 756 ** <li> [SQLITE_LOCK_NONE], 757 ** <li> [SQLITE_LOCK_SHARED], 758 ** <li> [SQLITE_LOCK_RESERVED], 759 ** <li> [SQLITE_LOCK_PENDING], or 760 ** <li> [SQLITE_LOCK_EXCLUSIVE]. 761 ** </ul> 762 ** xLock() upgrades the database file lock. In other words, xLock() moves the 763 ** database file lock in the direction NONE toward EXCLUSIVE. The argument to 764 ** xLock() is always on of SHARED, RESERVED, PENDING, or EXCLUSIVE, never 765 ** SQLITE_LOCK_NONE. If the database file lock is already at or above the 766 ** requested lock, then the call to xLock() is a no-op. 767 ** xUnlock() downgrades the database file lock to either SHARED or NONE. 768 * If the lock is already at or below the requested lock state, then the call 769 ** to xUnlock() is a no-op. 770 ** The xCheckReservedLock() method checks whether any database connection, 771 ** either in this process or in some other process, is holding a RESERVED, 772 ** PENDING, or EXCLUSIVE lock on the file. It returns true 773 ** if such a lock exists and false otherwise. 774 ** 775 ** The xFileControl() method is a generic interface that allows custom 776 ** VFS implementations to directly control an open file using the 777 ** [sqlite3_file_control()] interface. The second "op" argument is an 778 ** integer opcode. The third argument is a generic pointer intended to 779 ** point to a structure that may contain arguments or space in which to 780 ** write return values. Potential uses for xFileControl() might be 781 ** functions to enable blocking locks with timeouts, to change the 782 ** locking strategy (for example to use dot-file locks), to inquire 783 ** about the status of a lock, or to break stale locks. The SQLite 784 ** core reserves all opcodes less than 100 for its own use. 785 ** A [file control opcodes | list of opcodes] less than 100 is available. 786 ** Applications that define a custom xFileControl method should use opcodes 787 ** greater than 100 to avoid conflicts. VFS implementations should 788 ** return [SQLITE_NOTFOUND] for file control opcodes that they do not 789 ** recognize. 790 ** 791 ** The xSectorSize() method returns the sector size of the 792 ** device that underlies the file. The sector size is the 793 ** minimum write that can be performed without disturbing 794 ** other bytes in the file. The xDeviceCharacteristics() 795 ** method returns a bit vector describing behaviors of the 796 ** underlying device: 797 ** 798 ** <ul> 799 ** <li> [SQLITE_IOCAP_ATOMIC] 800 ** <li> [SQLITE_IOCAP_ATOMIC512] 801 ** <li> [SQLITE_IOCAP_ATOMIC1K] 802 ** <li> [SQLITE_IOCAP_ATOMIC2K] 803 ** <li> [SQLITE_IOCAP_ATOMIC4K] 804 ** <li> [SQLITE_IOCAP_ATOMIC8K] 805 ** <li> [SQLITE_IOCAP_ATOMIC16K] 806 ** <li> [SQLITE_IOCAP_ATOMIC32K] 807 ** <li> [SQLITE_IOCAP_ATOMIC64K] 808 ** <li> [SQLITE_IOCAP_SAFE_APPEND] 809 ** <li> [SQLITE_IOCAP_SEQUENTIAL] 810 ** <li> [SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN] 811 ** <li> [SQLITE_IOCAP_POWERSAFE_OVERWRITE] 812 ** <li> [SQLITE_IOCAP_IMMUTABLE] 813 ** <li> [SQLITE_IOCAP_BATCH_ATOMIC] 814 ** </ul> 815 ** 816 ** The SQLITE_IOCAP_ATOMIC property means that all writes of 817 ** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 818 ** mean that writes of blocks that are nnn bytes in size and 819 ** are aligned to an address which is an integer multiple of 820 ** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 821 ** that when data is appended to a file, the data is appended 822 ** first then the size of the file is extended, never the other 823 ** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 824 ** information is written to disk in the same order as calls 825 ** to xWrite(). 826 ** 827 ** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill 828 ** in the unread portions of the buffer with zeros. A VFS that 829 ** fails to zero-fill short reads might seem to work. However, 830 ** failure to zero-fill short reads will eventually lead to 831 ** database corruption. 832 */ 833 typedef struct sqlite3_io_methods sqlite3_io_methods; 834 struct sqlite3_io_methods { 835 int iVersion; 836 int (*xClose)(sqlite3_file*); 837 int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst); 838 int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst); 839 int (*xTruncate)(sqlite3_file*, sqlite3_int64 size); 840 int (*xSync)(sqlite3_file*, int flags); 841 int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize); 842 int (*xLock)(sqlite3_file*, int); 843 int (*xUnlock)(sqlite3_file*, int); 844 int (*xCheckReservedLock)(sqlite3_file*, int *pResOut); 845 int (*xFileControl)(sqlite3_file*, int op, void *pArg); 846 int (*xSectorSize)(sqlite3_file*); 847 int (*xDeviceCharacteristics)(sqlite3_file*); 848 /* Methods above are valid for version 1 */ 849 int (*xShmMap)(sqlite3_file*, int iPg, int pgsz, int, void volatile**); 850 int (*xShmLock)(sqlite3_file*, int offset, int n, int flags); 851 void (*xShmBarrier)(sqlite3_file*); 852 int (*xShmUnmap)(sqlite3_file*, int deleteFlag); 853 /* Methods above are valid for version 2 */ 854 int (*xFetch)(sqlite3_file*, sqlite3_int64 iOfst, int iAmt, void **pp); 855 int (*xUnfetch)(sqlite3_file*, sqlite3_int64 iOfst, void *p); 856 /* Methods above are valid for version 3 */ 857 /* Additional methods may be added in future releases */ 858 }; 859 860 /* 861 ** CAPI3REF: Standard File Control Opcodes 862 ** KEYWORDS: {file control opcodes} {file control opcode} 863 ** 864 ** These integer constants are opcodes for the xFileControl method 865 ** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()] 866 ** interface. 867 ** 868 ** <ul> 869 ** <li>[[SQLITE_FCNTL_LOCKSTATE]] 870 ** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging. This 871 ** opcode causes the xFileControl method to write the current state of 872 ** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED], 873 ** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE]) 874 ** into an integer that the pArg argument points to. 875 ** This capability is only available if SQLite is compiled with [SQLITE_DEBUG]. 876 ** 877 ** <li>[[SQLITE_FCNTL_SIZE_HINT]] 878 ** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS 879 ** layer a hint of how large the database file will grow to be during the 880 ** current transaction. This hint is not guaranteed to be accurate but it 881 ** is often close. The underlying VFS might choose to preallocate database 882 ** file space based on this hint in order to help writes to the database 883 ** file run faster. 884 ** 885 ** <li>[[SQLITE_FCNTL_SIZE_LIMIT]] 886 ** The [SQLITE_FCNTL_SIZE_LIMIT] opcode is used by in-memory VFS that 887 ** implements [sqlite3_deserialize()] to set an upper bound on the size 888 ** of the in-memory database. The argument is a pointer to a [sqlite3_int64]. 889 ** If the integer pointed to is negative, then it is filled in with the 890 ** current limit. Otherwise the limit is set to the larger of the value 891 ** of the integer pointed to and the current database size. The integer 892 ** pointed to is set to the new limit. 893 ** 894 ** <li>[[SQLITE_FCNTL_CHUNK_SIZE]] 895 ** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS 896 ** extends and truncates the database file in chunks of a size specified 897 ** by the user. The fourth argument to [sqlite3_file_control()] should 898 ** point to an integer (type int) containing the new chunk-size to use 899 ** for the nominated database. Allocating database file space in large 900 ** chunks (say 1MB at a time), may reduce file-system fragmentation and 901 ** improve performance on some systems. 902 ** 903 ** <li>[[SQLITE_FCNTL_FILE_POINTER]] 904 ** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer 905 ** to the [sqlite3_file] object associated with a particular database 906 ** connection. See also [SQLITE_FCNTL_JOURNAL_POINTER]. 907 ** 908 ** <li>[[SQLITE_FCNTL_JOURNAL_POINTER]] 909 ** The [SQLITE_FCNTL_JOURNAL_POINTER] opcode is used to obtain a pointer 910 ** to the [sqlite3_file] object associated with the journal file (either 911 ** the [rollback journal] or the [write-ahead log]) for a particular database 912 ** connection. See also [SQLITE_FCNTL_FILE_POINTER]. 913 ** 914 ** <li>[[SQLITE_FCNTL_SYNC_OMITTED]] 915 ** No longer in use. 916 ** 917 ** <li>[[SQLITE_FCNTL_SYNC]] 918 ** The [SQLITE_FCNTL_SYNC] opcode is generated internally by SQLite and 919 ** sent to the VFS immediately before the xSync method is invoked on a 920 ** database file descriptor. Or, if the xSync method is not invoked 921 ** because the user has configured SQLite with 922 ** [PRAGMA synchronous | PRAGMA synchronous=OFF] it is invoked in place 923 ** of the xSync method. In most cases, the pointer argument passed with 924 ** this file-control is NULL. However, if the database file is being synced 925 ** as part of a multi-database commit, the argument points to a nul-terminated 926 ** string containing the transactions super-journal file name. VFSes that 927 ** do not need this signal should silently ignore this opcode. Applications 928 ** should not call [sqlite3_file_control()] with this opcode as doing so may 929 ** disrupt the operation of the specialized VFSes that do require it. 930 ** 931 ** <li>[[SQLITE_FCNTL_COMMIT_PHASETWO]] 932 ** The [SQLITE_FCNTL_COMMIT_PHASETWO] opcode is generated internally by SQLite 933 ** and sent to the VFS after a transaction has been committed immediately 934 ** but before the database is unlocked. VFSes that do not need this signal 935 ** should silently ignore this opcode. Applications should not call 936 ** [sqlite3_file_control()] with this opcode as doing so may disrupt the 937 ** operation of the specialized VFSes that do require it. 938 ** 939 ** <li>[[SQLITE_FCNTL_WIN32_AV_RETRY]] 940 ** ^The [SQLITE_FCNTL_WIN32_AV_RETRY] opcode is used to configure automatic 941 ** retry counts and intervals for certain disk I/O operations for the 942 ** windows [VFS] in order to provide robustness in the presence of 943 ** anti-virus programs. By default, the windows VFS will retry file read, 944 ** file write, and file delete operations up to 10 times, with a delay 945 ** of 25 milliseconds before the first retry and with the delay increasing 946 ** by an additional 25 milliseconds with each subsequent retry. This 947 ** opcode allows these two values (10 retries and 25 milliseconds of delay) 948 ** to be adjusted. The values are changed for all database connections 949 ** within the same process. The argument is a pointer to an array of two 950 ** integers where the first integer is the new retry count and the second 951 ** integer is the delay. If either integer is negative, then the setting 952 ** is not changed but instead the prior value of that setting is written 953 ** into the array entry, allowing the current retry settings to be 954 ** interrogated. The zDbName parameter is ignored. 955 ** 956 ** <li>[[SQLITE_FCNTL_PERSIST_WAL]] 957 ** ^The [SQLITE_FCNTL_PERSIST_WAL] opcode is used to set or query the 958 ** persistent [WAL | Write Ahead Log] setting. By default, the auxiliary 959 ** write ahead log ([WAL file]) and shared memory 960 ** files used for transaction control 961 ** are automatically deleted when the latest connection to the database 962 ** closes. Setting persistent WAL mode causes those files to persist after 963 ** close. Persisting the files is useful when other processes that do not 964 ** have write permission on the directory containing the database file want 965 ** to read the database file, as the WAL and shared memory files must exist 966 ** in order for the database to be readable. The fourth parameter to 967 ** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 968 ** That integer is 0 to disable persistent WAL mode or 1 to enable persistent 969 ** WAL mode. If the integer is -1, then it is overwritten with the current 970 ** WAL persistence setting. 971 ** 972 ** <li>[[SQLITE_FCNTL_POWERSAFE_OVERWRITE]] 973 ** ^The [SQLITE_FCNTL_POWERSAFE_OVERWRITE] opcode is used to set or query the 974 ** persistent "powersafe-overwrite" or "PSOW" setting. The PSOW setting 975 ** determines the [SQLITE_IOCAP_POWERSAFE_OVERWRITE] bit of the 976 ** xDeviceCharacteristics methods. The fourth parameter to 977 ** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 978 ** That integer is 0 to disable zero-damage mode or 1 to enable zero-damage 979 ** mode. If the integer is -1, then it is overwritten with the current 980 ** zero-damage mode setting. 981 ** 982 ** <li>[[SQLITE_FCNTL_OVERWRITE]] 983 ** ^The [SQLITE_FCNTL_OVERWRITE] opcode is invoked by SQLite after opening 984 ** a write transaction to indicate that, unless it is rolled back for some 985 ** reason, the entire database file will be overwritten by the current 986 ** transaction. This is used by VACUUM operations. 987 ** 988 ** <li>[[SQLITE_FCNTL_VFSNAME]] 989 ** ^The [SQLITE_FCNTL_VFSNAME] opcode can be used to obtain the names of 990 ** all [VFSes] in the VFS stack. The names are of all VFS shims and the 991 ** final bottom-level VFS are written into memory obtained from 992 ** [sqlite3_malloc()] and the result is stored in the char* variable 993 ** that the fourth parameter of [sqlite3_file_control()] points to. 994 ** The caller is responsible for freeing the memory when done. As with 995 ** all file-control actions, there is no guarantee that this will actually 996 ** do anything. Callers should initialize the char* variable to a NULL 997 ** pointer in case this file-control is not implemented. This file-control 998 ** is intended for diagnostic use only. 999 ** 1000 ** <li>[[SQLITE_FCNTL_VFS_POINTER]] 1001 ** ^The [SQLITE_FCNTL_VFS_POINTER] opcode finds a pointer to the top-level 1002 ** [VFSes] currently in use. ^(The argument X in 1003 ** sqlite3_file_control(db,SQLITE_FCNTL_VFS_POINTER,X) must be 1004 ** of type "[sqlite3_vfs] **". This opcodes will set *X 1005 ** to a pointer to the top-level VFS.)^ 1006 ** ^When there are multiple VFS shims in the stack, this opcode finds the 1007 ** upper-most shim only. 1008 ** 1009 ** <li>[[SQLITE_FCNTL_PRAGMA]] 1010 ** ^Whenever a [PRAGMA] statement is parsed, an [SQLITE_FCNTL_PRAGMA] 1011 ** file control is sent to the open [sqlite3_file] object corresponding 1012 ** to the database file to which the pragma statement refers. ^The argument 1013 ** to the [SQLITE_FCNTL_PRAGMA] file control is an array of 1014 ** pointers to strings (char**) in which the second element of the array 1015 ** is the name of the pragma and the third element is the argument to the 1016 ** pragma or NULL if the pragma has no argument. ^The handler for an 1017 ** [SQLITE_FCNTL_PRAGMA] file control can optionally make the first element 1018 ** of the char** argument point to a string obtained from [sqlite3_mprintf()] 1019 ** or the equivalent and that string will become the result of the pragma or 1020 ** the error message if the pragma fails. ^If the 1021 ** [SQLITE_FCNTL_PRAGMA] file control returns [SQLITE_NOTFOUND], then normal 1022 ** [PRAGMA] processing continues. ^If the [SQLITE_FCNTL_PRAGMA] 1023 ** file control returns [SQLITE_OK], then the parser assumes that the 1024 ** VFS has handled the PRAGMA itself and the parser generates a no-op 1025 ** prepared statement if result string is NULL, or that returns a copy 1026 ** of the result string if the string is non-NULL. 1027 ** ^If the [SQLITE_FCNTL_PRAGMA] file control returns 1028 ** any result code other than [SQLITE_OK] or [SQLITE_NOTFOUND], that means 1029 ** that the VFS encountered an error while handling the [PRAGMA] and the 1030 ** compilation of the PRAGMA fails with an error. ^The [SQLITE_FCNTL_PRAGMA] 1031 ** file control occurs at the beginning of pragma statement analysis and so 1032 ** it is able to override built-in [PRAGMA] statements. 1033 ** 1034 ** <li>[[SQLITE_FCNTL_BUSYHANDLER]] 1035 ** ^The [SQLITE_FCNTL_BUSYHANDLER] 1036 ** file-control may be invoked by SQLite on the database file handle 1037 ** shortly after it is opened in order to provide a custom VFS with access 1038 ** to the connection's busy-handler callback. The argument is of type (void**) 1039 ** - an array of two (void *) values. The first (void *) actually points 1040 ** to a function of type (int (*)(void *)). In order to invoke the connection's 1041 ** busy-handler, this function should be invoked with the second (void *) in 1042 ** the array as the only argument. If it returns non-zero, then the operation 1043 ** should be retried. If it returns zero, the custom VFS should abandon the 1044 ** current operation. 1045 ** 1046 ** <li>[[SQLITE_FCNTL_TEMPFILENAME]] 1047 ** ^Applications can invoke the [SQLITE_FCNTL_TEMPFILENAME] file-control 1048 ** to have SQLite generate a 1049 ** temporary filename using the same algorithm that is followed to generate 1050 ** temporary filenames for TEMP tables and other internal uses. The 1051 ** argument should be a char** which will be filled with the filename 1052 ** written into memory obtained from [sqlite3_malloc()]. The caller should 1053 ** invoke [sqlite3_free()] on the result to avoid a memory leak. 1054 ** 1055 ** <li>[[SQLITE_FCNTL_MMAP_SIZE]] 1056 ** The [SQLITE_FCNTL_MMAP_SIZE] file control is used to query or set the 1057 ** maximum number of bytes that will be used for memory-mapped I/O. 1058 ** The argument is a pointer to a value of type sqlite3_int64 that 1059 ** is an advisory maximum number of bytes in the file to memory map. The 1060 ** pointer is overwritten with the old value. The limit is not changed if 1061 ** the value originally pointed to is negative, and so the current limit 1062 ** can be queried by passing in a pointer to a negative number. This 1063 ** file-control is used internally to implement [PRAGMA mmap_size]. 1064 ** 1065 ** <li>[[SQLITE_FCNTL_TRACE]] 1066 ** The [SQLITE_FCNTL_TRACE] file control provides advisory information 1067 ** to the VFS about what the higher layers of the SQLite stack are doing. 1068 ** This file control is used by some VFS activity tracing [shims]. 1069 ** The argument is a zero-terminated string. Higher layers in the 1070 ** SQLite stack may generate instances of this file control if 1071 ** the [SQLITE_USE_FCNTL_TRACE] compile-time option is enabled. 1072 ** 1073 ** <li>[[SQLITE_FCNTL_HAS_MOVED]] 1074 ** The [SQLITE_FCNTL_HAS_MOVED] file control interprets its argument as a 1075 ** pointer to an integer and it writes a boolean into that integer depending 1076 ** on whether or not the file has been renamed, moved, or deleted since it 1077 ** was first opened. 1078 ** 1079 ** <li>[[SQLITE_FCNTL_WIN32_GET_HANDLE]] 1080 ** The [SQLITE_FCNTL_WIN32_GET_HANDLE] opcode can be used to obtain the 1081 ** underlying native file handle associated with a file handle. This file 1082 ** control interprets its argument as a pointer to a native file handle and 1083 ** writes the resulting value there. 1084 ** 1085 ** <li>[[SQLITE_FCNTL_WIN32_SET_HANDLE]] 1086 ** The [SQLITE_FCNTL_WIN32_SET_HANDLE] opcode is used for debugging. This 1087 ** opcode causes the xFileControl method to swap the file handle with the one 1088 ** pointed to by the pArg argument. This capability is used during testing 1089 ** and only needs to be supported when SQLITE_TEST is defined. 1090 ** 1091 ** <li>[[SQLITE_FCNTL_WAL_BLOCK]] 1092 ** The [SQLITE_FCNTL_WAL_BLOCK] is a signal to the VFS layer that it might 1093 ** be advantageous to block on the next WAL lock if the lock is not immediately 1094 ** available. The WAL subsystem issues this signal during rare 1095 ** circumstances in order to fix a problem with priority inversion. 1096 ** Applications should <em>not</em> use this file-control. 1097 ** 1098 ** <li>[[SQLITE_FCNTL_ZIPVFS]] 1099 ** The [SQLITE_FCNTL_ZIPVFS] opcode is implemented by zipvfs only. All other 1100 ** VFS should return SQLITE_NOTFOUND for this opcode. 1101 ** 1102 ** <li>[[SQLITE_FCNTL_RBU]] 1103 ** The [SQLITE_FCNTL_RBU] opcode is implemented by the special VFS used by 1104 ** the RBU extension only. All other VFS should return SQLITE_NOTFOUND for 1105 ** this opcode. 1106 ** 1107 ** <li>[[SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]] 1108 ** If the [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] opcode returns SQLITE_OK, then 1109 ** the file descriptor is placed in "batch write mode", which 1110 ** means all subsequent write operations will be deferred and done 1111 ** atomically at the next [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]. Systems 1112 ** that do not support batch atomic writes will return SQLITE_NOTFOUND. 1113 ** ^Following a successful SQLITE_FCNTL_BEGIN_ATOMIC_WRITE and prior to 1114 ** the closing [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] or 1115 ** [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE], SQLite will make 1116 ** no VFS interface calls on the same [sqlite3_file] file descriptor 1117 ** except for calls to the xWrite method and the xFileControl method 1118 ** with [SQLITE_FCNTL_SIZE_HINT]. 1119 ** 1120 ** <li>[[SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]] 1121 ** The [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] opcode causes all write 1122 ** operations since the previous successful call to 1123 ** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be performed atomically. 1124 ** This file control returns [SQLITE_OK] if and only if the writes were 1125 ** all performed successfully and have been committed to persistent storage. 1126 ** ^Regardless of whether or not it is successful, this file control takes 1127 ** the file descriptor out of batch write mode so that all subsequent 1128 ** write operations are independent. 1129 ** ^SQLite will never invoke SQLITE_FCNTL_COMMIT_ATOMIC_WRITE without 1130 ** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]. 1131 ** 1132 ** <li>[[SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE]] 1133 ** The [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE] opcode causes all write 1134 ** operations since the previous successful call to 1135 ** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be rolled back. 1136 ** ^This file control takes the file descriptor out of batch write mode 1137 ** so that all subsequent write operations are independent. 1138 ** ^SQLite will never invoke SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE without 1139 ** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]. 1140 ** 1141 ** <li>[[SQLITE_FCNTL_LOCK_TIMEOUT]] 1142 ** The [SQLITE_FCNTL_LOCK_TIMEOUT] opcode is used to configure a VFS 1143 ** to block for up to M milliseconds before failing when attempting to 1144 ** obtain a file lock using the xLock or xShmLock methods of the VFS. 1145 ** The parameter is a pointer to a 32-bit signed integer that contains 1146 ** the value that M is to be set to. Before returning, the 32-bit signed 1147 ** integer is overwritten with the previous value of M. 1148 ** 1149 ** <li>[[SQLITE_FCNTL_DATA_VERSION]] 1150 ** The [SQLITE_FCNTL_DATA_VERSION] opcode is used to detect changes to 1151 ** a database file. The argument is a pointer to a 32-bit unsigned integer. 1152 ** The "data version" for the pager is written into the pointer. The 1153 ** "data version" changes whenever any change occurs to the corresponding 1154 ** database file, either through SQL statements on the same database 1155 ** connection or through transactions committed by separate database 1156 ** connections possibly in other processes. The [sqlite3_total_changes()] 1157 ** interface can be used to find if any database on the connection has changed, 1158 ** but that interface responds to changes on TEMP as well as MAIN and does 1159 ** not provide a mechanism to detect changes to MAIN only. Also, the 1160 ** [sqlite3_total_changes()] interface responds to internal changes only and 1161 ** omits changes made by other database connections. The 1162 ** [PRAGMA data_version] command provides a mechanism to detect changes to 1163 ** a single attached database that occur due to other database connections, 1164 ** but omits changes implemented by the database connection on which it is 1165 ** called. This file control is the only mechanism to detect changes that 1166 ** happen either internally or externally and that are associated with 1167 ** a particular attached database. 1168 ** 1169 ** <li>[[SQLITE_FCNTL_CKPT_START]] 1170 ** The [SQLITE_FCNTL_CKPT_START] opcode is invoked from within a checkpoint 1171 ** in wal mode before the client starts to copy pages from the wal 1172 ** file to the database file. 1173 ** 1174 ** <li>[[SQLITE_FCNTL_CKPT_DONE]] 1175 ** The [SQLITE_FCNTL_CKPT_DONE] opcode is invoked from within a checkpoint 1176 ** in wal mode after the client has finished copying pages from the wal 1177 ** file to the database file, but before the *-shm file is updated to 1178 ** record the fact that the pages have been checkpointed. 1179 ** 1180 ** <li>[[SQLITE_FCNTL_EXTERNAL_READER]] 1181 ** The EXPERIMENTAL [SQLITE_FCNTL_EXTERNAL_READER] opcode is used to detect 1182 ** whether or not there is a database client in another process with a wal-mode 1183 ** transaction open on the database or not. It is only available on unix.The 1184 ** (void*) argument passed with this file-control should be a pointer to a 1185 ** value of type (int). The integer value is set to 1 if the database is a wal 1186 ** mode database and there exists at least one client in another process that 1187 ** currently has an SQL transaction open on the database. It is set to 0 if 1188 ** the database is not a wal-mode db, or if there is no such connection in any 1189 ** other process. This opcode cannot be used to detect transactions opened 1190 ** by clients within the current process, only within other processes. 1191 ** 1192 ** <li>[[SQLITE_FCNTL_CKSM_FILE]] 1193 ** The [SQLITE_FCNTL_CKSM_FILE] opcode is for use interally by the 1194 ** [checksum VFS shim] only. 1195 ** 1196 ** <li>[[SQLITE_FCNTL_RESET_CACHE]] 1197 ** If there is currently no transaction open on the database, and the 1198 ** database is not a temp db, then the [SQLITE_FCNTL_RESET_CACHE] file-control 1199 ** purges the contents of the in-memory page cache. If there is an open 1200 ** transaction, or if the db is a temp-db, this opcode is a no-op, not an error. 1201 ** </ul> 1202 */ 1203 #define SQLITE_FCNTL_LOCKSTATE 1 1204 #define SQLITE_FCNTL_GET_LOCKPROXYFILE 2 1205 #define SQLITE_FCNTL_SET_LOCKPROXYFILE 3 1206 #define SQLITE_FCNTL_LAST_ERRNO 4 1207 #define SQLITE_FCNTL_SIZE_HINT 5 1208 #define SQLITE_FCNTL_CHUNK_SIZE 6 1209 #define SQLITE_FCNTL_FILE_POINTER 7 1210 #define SQLITE_FCNTL_SYNC_OMITTED 8 1211 #define SQLITE_FCNTL_WIN32_AV_RETRY 9 1212 #define SQLITE_FCNTL_PERSIST_WAL 10 1213 #define SQLITE_FCNTL_OVERWRITE 11 1214 #define SQLITE_FCNTL_VFSNAME 12 1215 #define SQLITE_FCNTL_POWERSAFE_OVERWRITE 13 1216 #define SQLITE_FCNTL_PRAGMA 14 1217 #define SQLITE_FCNTL_BUSYHANDLER 15 1218 #define SQLITE_FCNTL_TEMPFILENAME 16 1219 #define SQLITE_FCNTL_MMAP_SIZE 18 1220 #define SQLITE_FCNTL_TRACE 19 1221 #define SQLITE_FCNTL_HAS_MOVED 20 1222 #define SQLITE_FCNTL_SYNC 21 1223 #define SQLITE_FCNTL_COMMIT_PHASETWO 22 1224 #define SQLITE_FCNTL_WIN32_SET_HANDLE 23 1225 #define SQLITE_FCNTL_WAL_BLOCK 24 1226 #define SQLITE_FCNTL_ZIPVFS 25 1227 #define SQLITE_FCNTL_RBU 26 1228 #define SQLITE_FCNTL_VFS_POINTER 27 1229 #define SQLITE_FCNTL_JOURNAL_POINTER 28 1230 #define SQLITE_FCNTL_WIN32_GET_HANDLE 29 1231 #define SQLITE_FCNTL_PDB 30 1232 #define SQLITE_FCNTL_BEGIN_ATOMIC_WRITE 31 1233 #define SQLITE_FCNTL_COMMIT_ATOMIC_WRITE 32 1234 #define SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE 33 1235 #define SQLITE_FCNTL_LOCK_TIMEOUT 34 1236 #define SQLITE_FCNTL_DATA_VERSION 35 1237 #define SQLITE_FCNTL_SIZE_LIMIT 36 1238 #define SQLITE_FCNTL_CKPT_DONE 37 1239 #define SQLITE_FCNTL_RESERVE_BYTES 38 1240 #define SQLITE_FCNTL_CKPT_START 39 1241 #define SQLITE_FCNTL_EXTERNAL_READER 40 1242 #define SQLITE_FCNTL_CKSM_FILE 41 1243 #define SQLITE_FCNTL_RESET_CACHE 42 1244 1245 /* deprecated names */ 1246 #define SQLITE_GET_LOCKPROXYFILE SQLITE_FCNTL_GET_LOCKPROXYFILE 1247 #define SQLITE_SET_LOCKPROXYFILE SQLITE_FCNTL_SET_LOCKPROXYFILE 1248 #define SQLITE_LAST_ERRNO SQLITE_FCNTL_LAST_ERRNO 1249 1250 1251 /* 1252 ** CAPI3REF: Mutex Handle 1253 ** 1254 ** The mutex module within SQLite defines [sqlite3_mutex] to be an 1255 ** abstract type for a mutex object. The SQLite core never looks 1256 ** at the internal representation of an [sqlite3_mutex]. It only 1257 ** deals with pointers to the [sqlite3_mutex] object. 1258 ** 1259 ** Mutexes are created using [sqlite3_mutex_alloc()]. 1260 */ 1261 typedef struct sqlite3_mutex sqlite3_mutex; 1262 1263 /* 1264 ** CAPI3REF: Loadable Extension Thunk 1265 ** 1266 ** A pointer to the opaque sqlite3_api_routines structure is passed as 1267 ** the third parameter to entry points of [loadable extensions]. This 1268 ** structure must be typedefed in order to work around compiler warnings 1269 ** on some platforms. 1270 */ 1271 typedef struct sqlite3_api_routines sqlite3_api_routines; 1272 1273 /* 1274 ** CAPI3REF: File Name 1275 ** 1276 ** Type [sqlite3_filename] is used by SQLite to pass filenames to the 1277 ** xOpen method of a [VFS]. It may be cast to (const char*) and treated 1278 ** as a normal, nul-terminated, UTF-8 buffer containing the filename, but 1279 ** may also be passed to special APIs such as: 1280 ** 1281 ** <ul> 1282 ** <li> sqlite3_filename_database() 1283 ** <li> sqlite3_filename_journal() 1284 ** <li> sqlite3_filename_wal() 1285 ** <li> sqlite3_uri_parameter() 1286 ** <li> sqlite3_uri_boolean() 1287 ** <li> sqlite3_uri_int64() 1288 ** <li> sqlite3_uri_key() 1289 ** </ul> 1290 */ 1291 typedef const char *sqlite3_filename; 1292 1293 /* 1294 ** CAPI3REF: OS Interface Object 1295 ** 1296 ** An instance of the sqlite3_vfs object defines the interface between 1297 ** the SQLite core and the underlying operating system. The "vfs" 1298 ** in the name of the object stands for "virtual file system". See 1299 ** the [VFS | VFS documentation] for further information. 1300 ** 1301 ** The VFS interface is sometimes extended by adding new methods onto 1302 ** the end. Each time such an extension occurs, the iVersion field 1303 ** is incremented. The iVersion value started out as 1 in 1304 ** SQLite [version 3.5.0] on [dateof:3.5.0], then increased to 2 1305 ** with SQLite [version 3.7.0] on [dateof:3.7.0], and then increased 1306 ** to 3 with SQLite [version 3.7.6] on [dateof:3.7.6]. Additional fields 1307 ** may be appended to the sqlite3_vfs object and the iVersion value 1308 ** may increase again in future versions of SQLite. 1309 ** Note that due to an oversight, the structure 1310 ** of the sqlite3_vfs object changed in the transition from 1311 ** SQLite [version 3.5.9] to [version 3.6.0] on [dateof:3.6.0] 1312 ** and yet the iVersion field was not increased. 1313 ** 1314 ** The szOsFile field is the size of the subclassed [sqlite3_file] 1315 ** structure used by this VFS. mxPathname is the maximum length of 1316 ** a pathname in this VFS. 1317 ** 1318 ** Registered sqlite3_vfs objects are kept on a linked list formed by 1319 ** the pNext pointer. The [sqlite3_vfs_register()] 1320 ** and [sqlite3_vfs_unregister()] interfaces manage this list 1321 ** in a thread-safe way. The [sqlite3_vfs_find()] interface 1322 ** searches the list. Neither the application code nor the VFS 1323 ** implementation should use the pNext pointer. 1324 ** 1325 ** The pNext field is the only field in the sqlite3_vfs 1326 ** structure that SQLite will ever modify. SQLite will only access 1327 ** or modify this field while holding a particular static mutex. 1328 ** The application should never modify anything within the sqlite3_vfs 1329 ** object once the object has been registered. 1330 ** 1331 ** The zName field holds the name of the VFS module. The name must 1332 ** be unique across all VFS modules. 1333 ** 1334 ** [[sqlite3_vfs.xOpen]] 1335 ** ^SQLite guarantees that the zFilename parameter to xOpen 1336 ** is either a NULL pointer or string obtained 1337 ** from xFullPathname() with an optional suffix added. 1338 ** ^If a suffix is added to the zFilename parameter, it will 1339 ** consist of a single "-" character followed by no more than 1340 ** 11 alphanumeric and/or "-" characters. 1341 ** ^SQLite further guarantees that 1342 ** the string will be valid and unchanged until xClose() is 1343 ** called. Because of the previous sentence, 1344 ** the [sqlite3_file] can safely store a pointer to the 1345 ** filename if it needs to remember the filename for some reason. 1346 ** If the zFilename parameter to xOpen is a NULL pointer then xOpen 1347 ** must invent its own temporary name for the file. ^Whenever the 1348 ** xFilename parameter is NULL it will also be the case that the 1349 ** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE]. 1350 ** 1351 ** The flags argument to xOpen() includes all bits set in 1352 ** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()] 1353 ** or [sqlite3_open16()] is used, then flags includes at least 1354 ** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]. 1355 ** If xOpen() opens a file read-only then it sets *pOutFlags to 1356 ** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be set. 1357 ** 1358 ** ^(SQLite will also add one of the following flags to the xOpen() 1359 ** call, depending on the object being opened: 1360 ** 1361 ** <ul> 1362 ** <li> [SQLITE_OPEN_MAIN_DB] 1363 ** <li> [SQLITE_OPEN_MAIN_JOURNAL] 1364 ** <li> [SQLITE_OPEN_TEMP_DB] 1365 ** <li> [SQLITE_OPEN_TEMP_JOURNAL] 1366 ** <li> [SQLITE_OPEN_TRANSIENT_DB] 1367 ** <li> [SQLITE_OPEN_SUBJOURNAL] 1368 ** <li> [SQLITE_OPEN_SUPER_JOURNAL] 1369 ** <li> [SQLITE_OPEN_WAL] 1370 ** </ul>)^ 1371 ** 1372 ** The file I/O implementation can use the object type flags to 1373 ** change the way it deals with files. For example, an application 1374 ** that does not care about crash recovery or rollback might make 1375 ** the open of a journal file a no-op. Writes to this journal would 1376 ** also be no-ops, and any attempt to read the journal would return 1377 ** SQLITE_IOERR. Or the implementation might recognize that a database 1378 ** file will be doing page-aligned sector reads and writes in a random 1379 ** order and set up its I/O subsystem accordingly. 1380 ** 1381 ** SQLite might also add one of the following flags to the xOpen method: 1382 ** 1383 ** <ul> 1384 ** <li> [SQLITE_OPEN_DELETEONCLOSE] 1385 ** <li> [SQLITE_OPEN_EXCLUSIVE] 1386 ** </ul> 1387 ** 1388 ** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be 1389 ** deleted when it is closed. ^The [SQLITE_OPEN_DELETEONCLOSE] 1390 ** will be set for TEMP databases and their journals, transient 1391 ** databases, and subjournals. 1392 ** 1393 ** ^The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction 1394 ** with the [SQLITE_OPEN_CREATE] flag, which are both directly 1395 ** analogous to the O_EXCL and O_CREAT flags of the POSIX open() 1396 ** API. The SQLITE_OPEN_EXCLUSIVE flag, when paired with the 1397 ** SQLITE_OPEN_CREATE, is used to indicate that file should always 1398 ** be created, and that it is an error if it already exists. 1399 ** It is <i>not</i> used to indicate the file should be opened 1400 ** for exclusive access. 1401 ** 1402 ** ^At least szOsFile bytes of memory are allocated by SQLite 1403 ** to hold the [sqlite3_file] structure passed as the third 1404 ** argument to xOpen. The xOpen method does not have to 1405 ** allocate the structure; it should just fill it in. Note that 1406 ** the xOpen method must set the sqlite3_file.pMethods to either 1407 ** a valid [sqlite3_io_methods] object or to NULL. xOpen must do 1408 ** this even if the open fails. SQLite expects that the sqlite3_file.pMethods 1409 ** element will be valid after xOpen returns regardless of the success 1410 ** or failure of the xOpen call. 1411 ** 1412 ** [[sqlite3_vfs.xAccess]] 1413 ** ^The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS] 1414 ** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to 1415 ** test whether a file is readable and writable, or [SQLITE_ACCESS_READ] 1416 ** to test whether a file is at least readable. The SQLITE_ACCESS_READ 1417 ** flag is never actually used and is not implemented in the built-in 1418 ** VFSes of SQLite. The file is named by the second argument and can be a 1419 ** directory. The xAccess method returns [SQLITE_OK] on success or some 1420 ** non-zero error code if there is an I/O error or if the name of 1421 ** the file given in the second argument is illegal. If SQLITE_OK 1422 ** is returned, then non-zero or zero is written into *pResOut to indicate 1423 ** whether or not the file is accessible. 1424 ** 1425 ** ^SQLite will always allocate at least mxPathname+1 bytes for the 1426 ** output buffer xFullPathname. The exact size of the output buffer 1427 ** is also passed as a parameter to both methods. If the output buffer 1428 ** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is 1429 ** handled as a fatal error by SQLite, vfs implementations should endeavor 1430 ** to prevent this by setting mxPathname to a sufficiently large value. 1431 ** 1432 ** The xRandomness(), xSleep(), xCurrentTime(), and xCurrentTimeInt64() 1433 ** interfaces are not strictly a part of the filesystem, but they are 1434 ** included in the VFS structure for completeness. 1435 ** The xRandomness() function attempts to return nBytes bytes 1436 ** of good-quality randomness into zOut. The return value is 1437 ** the actual number of bytes of randomness obtained. 1438 ** The xSleep() method causes the calling thread to sleep for at 1439 ** least the number of microseconds given. ^The xCurrentTime() 1440 ** method returns a Julian Day Number for the current date and time as 1441 ** a floating point value. 1442 ** ^The xCurrentTimeInt64() method returns, as an integer, the Julian 1443 ** Day Number multiplied by 86400000 (the number of milliseconds in 1444 ** a 24-hour day). 1445 ** ^SQLite will use the xCurrentTimeInt64() method to get the current 1446 ** date and time if that method is available (if iVersion is 2 or 1447 ** greater and the function pointer is not NULL) and will fall back 1448 ** to xCurrentTime() if xCurrentTimeInt64() is unavailable. 1449 ** 1450 ** ^The xSetSystemCall(), xGetSystemCall(), and xNestSystemCall() interfaces 1451 ** are not used by the SQLite core. These optional interfaces are provided 1452 ** by some VFSes to facilitate testing of the VFS code. By overriding 1453 ** system calls with functions under its control, a test program can 1454 ** simulate faults and error conditions that would otherwise be difficult 1455 ** or impossible to induce. The set of system calls that can be overridden 1456 ** varies from one VFS to another, and from one version of the same VFS to the 1457 ** next. Applications that use these interfaces must be prepared for any 1458 ** or all of these interfaces to be NULL or for their behavior to change 1459 ** from one release to the next. Applications must not attempt to access 1460 ** any of these methods if the iVersion of the VFS is less than 3. 1461 */ 1462 typedef struct sqlite3_vfs sqlite3_vfs; 1463 typedef void (*sqlite3_syscall_ptr)(void); 1464 struct sqlite3_vfs { 1465 int iVersion; /* Structure version number (currently 3) */ 1466 int szOsFile; /* Size of subclassed sqlite3_file */ 1467 int mxPathname; /* Maximum file pathname length */ 1468 sqlite3_vfs *pNext; /* Next registered VFS */ 1469 const char *zName; /* Name of this virtual file system */ 1470 void *pAppData; /* Pointer to application-specific data */ 1471 int (*xOpen)(sqlite3_vfs*, sqlite3_filename zName, sqlite3_file*, 1472 int flags, int *pOutFlags); 1473 int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir); 1474 int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut); 1475 int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut); 1476 void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename); 1477 void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg); 1478 void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void); 1479 void (*xDlClose)(sqlite3_vfs*, void*); 1480 int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut); 1481 int (*xSleep)(sqlite3_vfs*, int microseconds); 1482 int (*xCurrentTime)(sqlite3_vfs*, double*); 1483 int (*xGetLastError)(sqlite3_vfs*, int, char *); 1484 /* 1485 ** The methods above are in version 1 of the sqlite_vfs object 1486 ** definition. Those that follow are added in version 2 or later 1487 */ 1488 int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*); 1489 /* 1490 ** The methods above are in versions 1 and 2 of the sqlite_vfs object. 1491 ** Those below are for version 3 and greater. 1492 */ 1493 int (*xSetSystemCall)(sqlite3_vfs*, const char *zName, sqlite3_syscall_ptr); 1494 sqlite3_syscall_ptr (*xGetSystemCall)(sqlite3_vfs*, const char *zName); 1495 const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName); 1496 /* 1497 ** The methods above are in versions 1 through 3 of the sqlite_vfs object. 1498 ** New fields may be appended in future versions. The iVersion 1499 ** value will increment whenever this happens. 1500 */ 1501 }; 1502 1503 /* 1504 ** CAPI3REF: Flags for the xAccess VFS method 1505 ** 1506 ** These integer constants can be used as the third parameter to 1507 ** the xAccess method of an [sqlite3_vfs] object. They determine 1508 ** what kind of permissions the xAccess method is looking for. 1509 ** With SQLITE_ACCESS_EXISTS, the xAccess method 1510 ** simply checks whether the file exists. 1511 ** With SQLITE_ACCESS_READWRITE, the xAccess method 1512 ** checks whether the named directory is both readable and writable 1513 ** (in other words, if files can be added, removed, and renamed within 1514 ** the directory). 1515 ** The SQLITE_ACCESS_READWRITE constant is currently used only by the 1516 ** [temp_store_directory pragma], though this could change in a future 1517 ** release of SQLite. 1518 ** With SQLITE_ACCESS_READ, the xAccess method 1519 ** checks whether the file is readable. The SQLITE_ACCESS_READ constant is 1520 ** currently unused, though it might be used in a future release of 1521 ** SQLite. 1522 */ 1523 #define SQLITE_ACCESS_EXISTS 0 1524 #define SQLITE_ACCESS_READWRITE 1 /* Used by PRAGMA temp_store_directory */ 1525 #define SQLITE_ACCESS_READ 2 /* Unused */ 1526 1527 /* 1528 ** CAPI3REF: Flags for the xShmLock VFS method 1529 ** 1530 ** These integer constants define the various locking operations 1531 ** allowed by the xShmLock method of [sqlite3_io_methods]. The 1532 ** following are the only legal combinations of flags to the 1533 ** xShmLock method: 1534 ** 1535 ** <ul> 1536 ** <li> SQLITE_SHM_LOCK | SQLITE_SHM_SHARED 1537 ** <li> SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE 1538 ** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED 1539 ** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE 1540 ** </ul> 1541 ** 1542 ** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as 1543 ** was given on the corresponding lock. 1544 ** 1545 ** The xShmLock method can transition between unlocked and SHARED or 1546 ** between unlocked and EXCLUSIVE. It cannot transition between SHARED 1547 ** and EXCLUSIVE. 1548 */ 1549 #define SQLITE_SHM_UNLOCK 1 1550 #define SQLITE_SHM_LOCK 2 1551 #define SQLITE_SHM_SHARED 4 1552 #define SQLITE_SHM_EXCLUSIVE 8 1553 1554 /* 1555 ** CAPI3REF: Maximum xShmLock index 1556 ** 1557 ** The xShmLock method on [sqlite3_io_methods] may use values 1558 ** between 0 and this upper bound as its "offset" argument. 1559 ** The SQLite core will never attempt to acquire or release a 1560 ** lock outside of this range 1561 */ 1562 #define SQLITE_SHM_NLOCK 8 1563 1564 1565 /* 1566 ** CAPI3REF: Initialize The SQLite Library 1567 ** 1568 ** ^The sqlite3_initialize() routine initializes the 1569 ** SQLite library. ^The sqlite3_shutdown() routine 1570 ** deallocates any resources that were allocated by sqlite3_initialize(). 1571 ** These routines are designed to aid in process initialization and 1572 ** shutdown on embedded systems. Workstation applications using 1573 ** SQLite normally do not need to invoke either of these routines. 1574 ** 1575 ** A call to sqlite3_initialize() is an "effective" call if it is 1576 ** the first time sqlite3_initialize() is invoked during the lifetime of 1577 ** the process, or if it is the first time sqlite3_initialize() is invoked 1578 ** following a call to sqlite3_shutdown(). ^(Only an effective call 1579 ** of sqlite3_initialize() does any initialization. All other calls 1580 ** are harmless no-ops.)^ 1581 ** 1582 ** A call to sqlite3_shutdown() is an "effective" call if it is the first 1583 ** call to sqlite3_shutdown() since the last sqlite3_initialize(). ^(Only 1584 ** an effective call to sqlite3_shutdown() does any deinitialization. 1585 ** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^ 1586 ** 1587 ** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown() 1588 ** is not. The sqlite3_shutdown() interface must only be called from a 1589 ** single thread. All open [database connections] must be closed and all 1590 ** other SQLite resources must be deallocated prior to invoking 1591 ** sqlite3_shutdown(). 1592 ** 1593 ** Among other things, ^sqlite3_initialize() will invoke 1594 ** sqlite3_os_init(). Similarly, ^sqlite3_shutdown() 1595 ** will invoke sqlite3_os_end(). 1596 ** 1597 ** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success. 1598 ** ^If for some reason, sqlite3_initialize() is unable to initialize 1599 ** the library (perhaps it is unable to allocate a needed resource such 1600 ** as a mutex) it returns an [error code] other than [SQLITE_OK]. 1601 ** 1602 ** ^The sqlite3_initialize() routine is called internally by many other 1603 ** SQLite interfaces so that an application usually does not need to 1604 ** invoke sqlite3_initialize() directly. For example, [sqlite3_open()] 1605 ** calls sqlite3_initialize() so the SQLite library will be automatically 1606 ** initialized when [sqlite3_open()] is called if it has not be initialized 1607 ** already. ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT] 1608 ** compile-time option, then the automatic calls to sqlite3_initialize() 1609 ** are omitted and the application must call sqlite3_initialize() directly 1610 ** prior to using any other SQLite interface. For maximum portability, 1611 ** it is recommended that applications always invoke sqlite3_initialize() 1612 ** directly prior to using any other SQLite interface. Future releases 1613 ** of SQLite may require this. In other words, the behavior exhibited 1614 ** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the 1615 ** default behavior in some future release of SQLite. 1616 ** 1617 ** The sqlite3_os_init() routine does operating-system specific 1618 ** initialization of the SQLite library. The sqlite3_os_end() 1619 ** routine undoes the effect of sqlite3_os_init(). Typical tasks 1620 ** performed by these routines include allocation or deallocation 1621 ** of static resources, initialization of global variables, 1622 ** setting up a default [sqlite3_vfs] module, or setting up 1623 ** a default configuration using [sqlite3_config()]. 1624 ** 1625 ** The application should never invoke either sqlite3_os_init() 1626 ** or sqlite3_os_end() directly. The application should only invoke 1627 ** sqlite3_initialize() and sqlite3_shutdown(). The sqlite3_os_init() 1628 ** interface is called automatically by sqlite3_initialize() and 1629 ** sqlite3_os_end() is called by sqlite3_shutdown(). Appropriate 1630 ** implementations for sqlite3_os_init() and sqlite3_os_end() 1631 ** are built into SQLite when it is compiled for Unix, Windows, or OS/2. 1632 ** When [custom builds | built for other platforms] 1633 ** (using the [SQLITE_OS_OTHER=1] compile-time 1634 ** option) the application must supply a suitable implementation for 1635 ** sqlite3_os_init() and sqlite3_os_end(). An application-supplied 1636 ** implementation of sqlite3_os_init() or sqlite3_os_end() 1637 ** must return [SQLITE_OK] on success and some other [error code] upon 1638 ** failure. 1639 */ 1640 SQLITE_API int sqlite3_initialize(void); 1641 SQLITE_API int sqlite3_shutdown(void); 1642 SQLITE_API int sqlite3_os_init(void); 1643 SQLITE_API int sqlite3_os_end(void); 1644 1645 /* 1646 ** CAPI3REF: Configuring The SQLite Library 1647 ** 1648 ** The sqlite3_config() interface is used to make global configuration 1649 ** changes to SQLite in order to tune SQLite to the specific needs of 1650 ** the application. The default configuration is recommended for most 1651 ** applications and so this routine is usually not necessary. It is 1652 ** provided to support rare applications with unusual needs. 1653 ** 1654 ** <b>The sqlite3_config() interface is not threadsafe. The application 1655 ** must ensure that no other SQLite interfaces are invoked by other 1656 ** threads while sqlite3_config() is running.</b> 1657 ** 1658 ** The first argument to sqlite3_config() is an integer 1659 ** [configuration option] that determines 1660 ** what property of SQLite is to be configured. Subsequent arguments 1661 ** vary depending on the [configuration option] 1662 ** in the first argument. 1663 ** 1664 ** For most configuration options, the sqlite3_config() interface 1665 ** may only be invoked prior to library initialization using 1666 ** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()]. 1667 ** The exceptional configuration options that may be invoked at any time 1668 ** are called "anytime configuration options". 1669 ** ^If sqlite3_config() is called after [sqlite3_initialize()] and before 1670 ** [sqlite3_shutdown()] with a first argument that is not an anytime 1671 ** configuration option, then the sqlite3_config() call will return SQLITE_MISUSE. 1672 ** Note, however, that ^sqlite3_config() can be called as part of the 1673 ** implementation of an application-defined [sqlite3_os_init()]. 1674 ** 1675 ** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK]. 1676 ** ^If the option is unknown or SQLite is unable to set the option 1677 ** then this routine returns a non-zero [error code]. 1678 */ 1679 SQLITE_API int sqlite3_config(int, ...); 1680 1681 /* 1682 ** CAPI3REF: Configure database connections 1683 ** METHOD: sqlite3 1684 ** 1685 ** The sqlite3_db_config() interface is used to make configuration 1686 ** changes to a [database connection]. The interface is similar to 1687 ** [sqlite3_config()] except that the changes apply to a single 1688 ** [database connection] (specified in the first argument). 1689 ** 1690 ** The second argument to sqlite3_db_config(D,V,...) is the 1691 ** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code 1692 ** that indicates what aspect of the [database connection] is being configured. 1693 ** Subsequent arguments vary depending on the configuration verb. 1694 ** 1695 ** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if 1696 ** the call is considered successful. 1697 */ 1698 SQLITE_API int sqlite3_db_config(sqlite3*, int op, ...); 1699 1700 /* 1701 ** CAPI3REF: Memory Allocation Routines 1702 ** 1703 ** An instance of this object defines the interface between SQLite 1704 ** and low-level memory allocation routines. 1705 ** 1706 ** This object is used in only one place in the SQLite interface. 1707 ** A pointer to an instance of this object is the argument to 1708 ** [sqlite3_config()] when the configuration option is 1709 ** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC]. 1710 ** By creating an instance of this object 1711 ** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC]) 1712 ** during configuration, an application can specify an alternative 1713 ** memory allocation subsystem for SQLite to use for all of its 1714 ** dynamic memory needs. 1715 ** 1716 ** Note that SQLite comes with several [built-in memory allocators] 1717 ** that are perfectly adequate for the overwhelming majority of applications 1718 ** and that this object is only useful to a tiny minority of applications 1719 ** with specialized memory allocation requirements. This object is 1720 ** also used during testing of SQLite in order to specify an alternative 1721 ** memory allocator that simulates memory out-of-memory conditions in 1722 ** order to verify that SQLite recovers gracefully from such 1723 ** conditions. 1724 ** 1725 ** The xMalloc, xRealloc, and xFree methods must work like the 1726 ** malloc(), realloc() and free() functions from the standard C library. 1727 ** ^SQLite guarantees that the second argument to 1728 ** xRealloc is always a value returned by a prior call to xRoundup. 1729 ** 1730 ** xSize should return the allocated size of a memory allocation 1731 ** previously obtained from xMalloc or xRealloc. The allocated size 1732 ** is always at least as big as the requested size but may be larger. 1733 ** 1734 ** The xRoundup method returns what would be the allocated size of 1735 ** a memory allocation given a particular requested size. Most memory 1736 ** allocators round up memory allocations at least to the next multiple 1737 ** of 8. Some allocators round up to a larger multiple or to a power of 2. 1738 ** Every memory allocation request coming in through [sqlite3_malloc()] 1739 ** or [sqlite3_realloc()] first calls xRoundup. If xRoundup returns 0, 1740 ** that causes the corresponding memory allocation to fail. 1741 ** 1742 ** The xInit method initializes the memory allocator. For example, 1743 ** it might allocate any required mutexes or initialize internal data 1744 ** structures. The xShutdown method is invoked (indirectly) by 1745 ** [sqlite3_shutdown()] and should deallocate any resources acquired 1746 ** by xInit. The pAppData pointer is used as the only parameter to 1747 ** xInit and xShutdown. 1748 ** 1749 ** SQLite holds the [SQLITE_MUTEX_STATIC_MAIN] mutex when it invokes 1750 ** the xInit method, so the xInit method need not be threadsafe. The 1751 ** xShutdown method is only called from [sqlite3_shutdown()] so it does 1752 ** not need to be threadsafe either. For all other methods, SQLite 1753 ** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the 1754 ** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which 1755 ** it is by default) and so the methods are automatically serialized. 1756 ** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other 1757 ** methods must be threadsafe or else make their own arrangements for 1758 ** serialization. 1759 ** 1760 ** SQLite will never invoke xInit() more than once without an intervening 1761 ** call to xShutdown(). 1762 */ 1763 typedef struct sqlite3_mem_methods sqlite3_mem_methods; 1764 struct sqlite3_mem_methods { 1765 void *(*xMalloc)(int); /* Memory allocation function */ 1766 void (*xFree)(void*); /* Free a prior allocation */ 1767 void *(*xRealloc)(void*,int); /* Resize an allocation */ 1768 int (*xSize)(void*); /* Return the size of an allocation */ 1769 int (*xRoundup)(int); /* Round up request size to allocation size */ 1770 int (*xInit)(void*); /* Initialize the memory allocator */ 1771 void (*xShutdown)(void*); /* Deinitialize the memory allocator */ 1772 void *pAppData; /* Argument to xInit() and xShutdown() */ 1773 }; 1774 1775 /* 1776 ** CAPI3REF: Configuration Options 1777 ** KEYWORDS: {configuration option} 1778 ** 1779 ** These constants are the available integer configuration options that 1780 ** can be passed as the first argument to the [sqlite3_config()] interface. 1781 ** 1782 ** Most of the configuration options for sqlite3_config() 1783 ** will only work if invoked prior to [sqlite3_initialize()] or after 1784 ** [sqlite3_shutdown()]. The few exceptions to this rule are called 1785 ** "anytime configuration options". 1786 ** ^Calling [sqlite3_config()] with a first argument that is not an 1787 ** anytime configuration option in between calls to [sqlite3_initialize()] and 1788 ** [sqlite3_shutdown()] is a no-op that returns SQLITE_MISUSE. 1789 ** 1790 ** The set of anytime configuration options can change (by insertions 1791 ** and/or deletions) from one release of SQLite to the next. 1792 ** As of SQLite version 3.42.0, the complete set of anytime configuration 1793 ** options is: 1794 ** <ul> 1795 ** <li> SQLITE_CONFIG_LOG 1796 ** <li> SQLITE_CONFIG_PCACHE_HDRSZ 1797 ** </ul> 1798 ** 1799 ** New configuration options may be added in future releases of SQLite. 1800 ** Existing configuration options might be discontinued. Applications 1801 ** should check the return code from [sqlite3_config()] to make sure that 1802 ** the call worked. The [sqlite3_config()] interface will return a 1803 ** non-zero [error code] if a discontinued or unsupported configuration option 1804 ** is invoked. 1805 ** 1806 ** <dl> 1807 ** [[SQLITE_CONFIG_SINGLETHREAD]] <dt>SQLITE_CONFIG_SINGLETHREAD</dt> 1808 ** <dd>There are no arguments to this option. ^This option sets the 1809 ** [threading mode] to Single-thread. In other words, it disables 1810 ** all mutexing and puts SQLite into a mode where it can only be used 1811 ** by a single thread. ^If SQLite is compiled with 1812 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1813 ** it is not possible to change the [threading mode] from its default 1814 ** value of Single-thread and so [sqlite3_config()] will return 1815 ** [SQLITE_ERROR] if called with the SQLITE_CONFIG_SINGLETHREAD 1816 ** configuration option.</dd> 1817 ** 1818 ** [[SQLITE_CONFIG_MULTITHREAD]] <dt>SQLITE_CONFIG_MULTITHREAD</dt> 1819 ** <dd>There are no arguments to this option. ^This option sets the 1820 ** [threading mode] to Multi-thread. In other words, it disables 1821 ** mutexing on [database connection] and [prepared statement] objects. 1822 ** The application is responsible for serializing access to 1823 ** [database connections] and [prepared statements]. But other mutexes 1824 ** are enabled so that SQLite will be safe to use in a multi-threaded 1825 ** environment as long as no two threads attempt to use the same 1826 ** [database connection] at the same time. ^If SQLite is compiled with 1827 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1828 ** it is not possible to set the Multi-thread [threading mode] and 1829 ** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1830 ** SQLITE_CONFIG_MULTITHREAD configuration option.</dd> 1831 ** 1832 ** [[SQLITE_CONFIG_SERIALIZED]] <dt>SQLITE_CONFIG_SERIALIZED</dt> 1833 ** <dd>There are no arguments to this option. ^This option sets the 1834 ** [threading mode] to Serialized. In other words, this option enables 1835 ** all mutexes including the recursive 1836 ** mutexes on [database connection] and [prepared statement] objects. 1837 ** In this mode (which is the default when SQLite is compiled with 1838 ** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access 1839 ** to [database connections] and [prepared statements] so that the 1840 ** application is free to use the same [database connection] or the 1841 ** same [prepared statement] in different threads at the same time. 1842 ** ^If SQLite is compiled with 1843 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1844 ** it is not possible to set the Serialized [threading mode] and 1845 ** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1846 ** SQLITE_CONFIG_SERIALIZED configuration option.</dd> 1847 ** 1848 ** [[SQLITE_CONFIG_MALLOC]] <dt>SQLITE_CONFIG_MALLOC</dt> 1849 ** <dd> ^(The SQLITE_CONFIG_MALLOC option takes a single argument which is 1850 ** a pointer to an instance of the [sqlite3_mem_methods] structure. 1851 ** The argument specifies 1852 ** alternative low-level memory allocation routines to be used in place of 1853 ** the memory allocation routines built into SQLite.)^ ^SQLite makes 1854 ** its own private copy of the content of the [sqlite3_mem_methods] structure 1855 ** before the [sqlite3_config()] call returns.</dd> 1856 ** 1857 ** [[SQLITE_CONFIG_GETMALLOC]] <dt>SQLITE_CONFIG_GETMALLOC</dt> 1858 ** <dd> ^(The SQLITE_CONFIG_GETMALLOC option takes a single argument which 1859 ** is a pointer to an instance of the [sqlite3_mem_methods] structure. 1860 ** The [sqlite3_mem_methods] 1861 ** structure is filled with the currently defined memory allocation routines.)^ 1862 ** This option can be used to overload the default memory allocation 1863 ** routines with a wrapper that simulations memory allocation failure or 1864 ** tracks memory usage, for example. </dd> 1865 ** 1866 ** [[SQLITE_CONFIG_SMALL_MALLOC]] <dt>SQLITE_CONFIG_SMALL_MALLOC</dt> 1867 ** <dd> ^The SQLITE_CONFIG_SMALL_MALLOC option takes single argument of 1868 ** type int, interpreted as a boolean, which if true provides a hint to 1869 ** SQLite that it should avoid large memory allocations if possible. 1870 ** SQLite will run faster if it is free to make large memory allocations, 1871 ** but some application might prefer to run slower in exchange for 1872 ** guarantees about memory fragmentation that are possible if large 1873 ** allocations are avoided. This hint is normally off. 1874 ** </dd> 1875 ** 1876 ** [[SQLITE_CONFIG_MEMSTATUS]] <dt>SQLITE_CONFIG_MEMSTATUS</dt> 1877 ** <dd> ^The SQLITE_CONFIG_MEMSTATUS option takes single argument of type int, 1878 ** interpreted as a boolean, which enables or disables the collection of 1879 ** memory allocation statistics. ^(When memory allocation statistics are 1880 ** disabled, the following SQLite interfaces become non-operational: 1881 ** <ul> 1882 ** <li> [sqlite3_hard_heap_limit64()] 1883 ** <li> [sqlite3_memory_used()] 1884 ** <li> [sqlite3_memory_highwater()] 1885 ** <li> [sqlite3_soft_heap_limit64()] 1886 ** <li> [sqlite3_status64()] 1887 ** </ul>)^ 1888 ** ^Memory allocation statistics are enabled by default unless SQLite is 1889 ** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory 1890 ** allocation statistics are disabled by default. 1891 ** </dd> 1892 ** 1893 ** [[SQLITE_CONFIG_SCRATCH]] <dt>SQLITE_CONFIG_SCRATCH</dt> 1894 ** <dd> The SQLITE_CONFIG_SCRATCH option is no longer used. 1895 ** </dd> 1896 ** 1897 ** [[SQLITE_CONFIG_PAGECACHE]] <dt>SQLITE_CONFIG_PAGECACHE</dt> 1898 ** <dd> ^The SQLITE_CONFIG_PAGECACHE option specifies a memory pool 1899 ** that SQLite can use for the database page cache with the default page 1900 ** cache implementation. 1901 ** This configuration option is a no-op if an application-defined page 1902 ** cache implementation is loaded using the [SQLITE_CONFIG_PCACHE2]. 1903 ** ^There are three arguments to SQLITE_CONFIG_PAGECACHE: A pointer to 1904 ** 8-byte aligned memory (pMem), the size of each page cache line (sz), 1905 ** and the number of cache lines (N). 1906 ** The sz argument should be the size of the largest database page 1907 ** (a power of two between 512 and 65536) plus some extra bytes for each 1908 ** page header. ^The number of extra bytes needed by the page header 1909 ** can be determined using [SQLITE_CONFIG_PCACHE_HDRSZ]. 1910 ** ^It is harmless, apart from the wasted memory, 1911 ** for the sz parameter to be larger than necessary. The pMem 1912 ** argument must be either a NULL pointer or a pointer to an 8-byte 1913 ** aligned block of memory of at least sz*N bytes, otherwise 1914 ** subsequent behavior is undefined. 1915 ** ^When pMem is not NULL, SQLite will strive to use the memory provided 1916 ** to satisfy page cache needs, falling back to [sqlite3_malloc()] if 1917 ** a page cache line is larger than sz bytes or if all of the pMem buffer 1918 ** is exhausted. 1919 ** ^If pMem is NULL and N is non-zero, then each database connection 1920 ** does an initial bulk allocation for page cache memory 1921 ** from [sqlite3_malloc()] sufficient for N cache lines if N is positive or 1922 ** of -1024*N bytes if N is negative, . ^If additional 1923 ** page cache memory is needed beyond what is provided by the initial 1924 ** allocation, then SQLite goes to [sqlite3_malloc()] separately for each 1925 ** additional cache line. </dd> 1926 ** 1927 ** [[SQLITE_CONFIG_HEAP]] <dt>SQLITE_CONFIG_HEAP</dt> 1928 ** <dd> ^The SQLITE_CONFIG_HEAP option specifies a static memory buffer 1929 ** that SQLite will use for all of its dynamic memory allocation needs 1930 ** beyond those provided for by [SQLITE_CONFIG_PAGECACHE]. 1931 ** ^The SQLITE_CONFIG_HEAP option is only available if SQLite is compiled 1932 ** with either [SQLITE_ENABLE_MEMSYS3] or [SQLITE_ENABLE_MEMSYS5] and returns 1933 ** [SQLITE_ERROR] if invoked otherwise. 1934 ** ^There are three arguments to SQLITE_CONFIG_HEAP: 1935 ** An 8-byte aligned pointer to the memory, 1936 ** the number of bytes in the memory buffer, and the minimum allocation size. 1937 ** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts 1938 ** to using its default memory allocator (the system malloc() implementation), 1939 ** undoing any prior invocation of [SQLITE_CONFIG_MALLOC]. ^If the 1940 ** memory pointer is not NULL then the alternative memory 1941 ** allocator is engaged to handle all of SQLites memory allocation needs. 1942 ** The first pointer (the memory pointer) must be aligned to an 8-byte 1943 ** boundary or subsequent behavior of SQLite will be undefined. 1944 ** The minimum allocation size is capped at 2**12. Reasonable values 1945 ** for the minimum allocation size are 2**5 through 2**8.</dd> 1946 ** 1947 ** [[SQLITE_CONFIG_MUTEX]] <dt>SQLITE_CONFIG_MUTEX</dt> 1948 ** <dd> ^(The SQLITE_CONFIG_MUTEX option takes a single argument which is a 1949 ** pointer to an instance of the [sqlite3_mutex_methods] structure. 1950 ** The argument specifies alternative low-level mutex routines to be used 1951 ** in place the mutex routines built into SQLite.)^ ^SQLite makes a copy of 1952 ** the content of the [sqlite3_mutex_methods] structure before the call to 1953 ** [sqlite3_config()] returns. ^If SQLite is compiled with 1954 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1955 ** the entire mutexing subsystem is omitted from the build and hence calls to 1956 ** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will 1957 ** return [SQLITE_ERROR].</dd> 1958 ** 1959 ** [[SQLITE_CONFIG_GETMUTEX]] <dt>SQLITE_CONFIG_GETMUTEX</dt> 1960 ** <dd> ^(The SQLITE_CONFIG_GETMUTEX option takes a single argument which 1961 ** is a pointer to an instance of the [sqlite3_mutex_methods] structure. The 1962 ** [sqlite3_mutex_methods] 1963 ** structure is filled with the currently defined mutex routines.)^ 1964 ** This option can be used to overload the default mutex allocation 1965 ** routines with a wrapper used to track mutex usage for performance 1966 ** profiling or testing, for example. ^If SQLite is compiled with 1967 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1968 ** the entire mutexing subsystem is omitted from the build and hence calls to 1969 ** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will 1970 ** return [SQLITE_ERROR].</dd> 1971 ** 1972 ** [[SQLITE_CONFIG_LOOKASIDE]] <dt>SQLITE_CONFIG_LOOKASIDE</dt> 1973 ** <dd> ^(The SQLITE_CONFIG_LOOKASIDE option takes two arguments that determine 1974 ** the default size of lookaside memory on each [database connection]. 1975 ** The first argument is the 1976 ** size of each lookaside buffer slot and the second is the number of 1977 ** slots allocated to each database connection.)^ ^(SQLITE_CONFIG_LOOKASIDE 1978 ** sets the <i>default</i> lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE] 1979 ** option to [sqlite3_db_config()] can be used to change the lookaside 1980 ** configuration on individual connections.)^ </dd> 1981 ** 1982 ** [[SQLITE_CONFIG_PCACHE2]] <dt>SQLITE_CONFIG_PCACHE2</dt> 1983 ** <dd> ^(The SQLITE_CONFIG_PCACHE2 option takes a single argument which is 1984 ** a pointer to an [sqlite3_pcache_methods2] object. This object specifies 1985 ** the interface to a custom page cache implementation.)^ 1986 ** ^SQLite makes a copy of the [sqlite3_pcache_methods2] object.</dd> 1987 ** 1988 ** [[SQLITE_CONFIG_GETPCACHE2]] <dt>SQLITE_CONFIG_GETPCACHE2</dt> 1989 ** <dd> ^(The SQLITE_CONFIG_GETPCACHE2 option takes a single argument which 1990 ** is a pointer to an [sqlite3_pcache_methods2] object. SQLite copies of 1991 ** the current page cache implementation into that object.)^ </dd> 1992 ** 1993 ** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt> 1994 ** <dd> The SQLITE_CONFIG_LOG option is used to configure the SQLite 1995 ** global [error log]. 1996 ** (^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a 1997 ** function with a call signature of void(*)(void*,int,const char*), 1998 ** and a pointer to void. ^If the function pointer is not NULL, it is 1999 ** invoked by [sqlite3_log()] to process each logging event. ^If the 2000 ** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op. 2001 ** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is 2002 ** passed through as the first parameter to the application-defined logger 2003 ** function whenever that function is invoked. ^The second parameter to 2004 ** the logger function is a copy of the first parameter to the corresponding 2005 ** [sqlite3_log()] call and is intended to be a [result code] or an 2006 ** [extended result code]. ^The third parameter passed to the logger is 2007 ** log message after formatting via [sqlite3_snprintf()]. 2008 ** The SQLite logging interface is not reentrant; the logger function 2009 ** supplied by the application must not invoke any SQLite interface. 2010 ** In a multi-threaded application, the application-defined logger 2011 ** function must be threadsafe. </dd> 2012 ** 2013 ** [[SQLITE_CONFIG_URI]] <dt>SQLITE_CONFIG_URI 2014 ** <dd>^(The SQLITE_CONFIG_URI option takes a single argument of type int. 2015 ** If non-zero, then URI handling is globally enabled. If the parameter is zero, 2016 ** then URI handling is globally disabled.)^ ^If URI handling is globally 2017 ** enabled, all filenames passed to [sqlite3_open()], [sqlite3_open_v2()], 2018 ** [sqlite3_open16()] or 2019 ** specified as part of [ATTACH] commands are interpreted as URIs, regardless 2020 ** of whether or not the [SQLITE_OPEN_URI] flag is set when the database 2021 ** connection is opened. ^If it is globally disabled, filenames are 2022 ** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the 2023 ** database connection is opened. ^(By default, URI handling is globally 2024 ** disabled. The default value may be changed by compiling with the 2025 ** [SQLITE_USE_URI] symbol defined.)^ 2026 ** 2027 ** [[SQLITE_CONFIG_COVERING_INDEX_SCAN]] <dt>SQLITE_CONFIG_COVERING_INDEX_SCAN 2028 ** <dd>^The SQLITE_CONFIG_COVERING_INDEX_SCAN option takes a single integer 2029 ** argument which is interpreted as a boolean in order to enable or disable 2030 ** the use of covering indices for full table scans in the query optimizer. 2031 ** ^The default setting is determined 2032 ** by the [SQLITE_ALLOW_COVERING_INDEX_SCAN] compile-time option, or is "on" 2033 ** if that compile-time option is omitted. 2034 ** The ability to disable the use of covering indices for full table scans 2035 ** is because some incorrectly coded legacy applications might malfunction 2036 ** when the optimization is enabled. Providing the ability to 2037 ** disable the optimization allows the older, buggy application code to work 2038 ** without change even with newer versions of SQLite. 2039 ** 2040 ** [[SQLITE_CONFIG_PCACHE]] [[SQLITE_CONFIG_GETPCACHE]] 2041 ** <dt>SQLITE_CONFIG_PCACHE and SQLITE_CONFIG_GETPCACHE 2042 ** <dd> These options are obsolete and should not be used by new code. 2043 ** They are retained for backwards compatibility but are now no-ops. 2044 ** </dd> 2045 ** 2046 ** [[SQLITE_CONFIG_SQLLOG]] 2047 ** <dt>SQLITE_CONFIG_SQLLOG 2048 ** <dd>This option is only available if sqlite is compiled with the 2049 ** [SQLITE_ENABLE_SQLLOG] pre-processor macro defined. The first argument should 2050 ** be a pointer to a function of type void(*)(void*,sqlite3*,const char*, int). 2051 ** The second should be of type (void*). The callback is invoked by the library 2052 ** in three separate circumstances, identified by the value passed as the 2053 ** fourth parameter. If the fourth parameter is 0, then the database connection 2054 ** passed as the second argument has just been opened. The third argument 2055 ** points to a buffer containing the name of the main database file. If the 2056 ** fourth parameter is 1, then the SQL statement that the third parameter 2057 ** points to has just been executed. Or, if the fourth parameter is 2, then 2058 ** the connection being passed as the second parameter is being closed. The 2059 ** third parameter is passed NULL In this case. An example of using this 2060 ** configuration option can be seen in the "test_sqllog.c" source file in 2061 ** the canonical SQLite source tree.</dd> 2062 ** 2063 ** [[SQLITE_CONFIG_MMAP_SIZE]] 2064 ** <dt>SQLITE_CONFIG_MMAP_SIZE 2065 ** <dd>^SQLITE_CONFIG_MMAP_SIZE takes two 64-bit integer (sqlite3_int64) values 2066 ** that are the default mmap size limit (the default setting for 2067 ** [PRAGMA mmap_size]) and the maximum allowed mmap size limit. 2068 ** ^The default setting can be overridden by each database connection using 2069 ** either the [PRAGMA mmap_size] command, or by using the 2070 ** [SQLITE_FCNTL_MMAP_SIZE] file control. ^(The maximum allowed mmap size 2071 ** will be silently truncated if necessary so that it does not exceed the 2072 ** compile-time maximum mmap size set by the 2073 ** [SQLITE_MAX_MMAP_SIZE] compile-time option.)^ 2074 ** ^If either argument to this option is negative, then that argument is 2075 ** changed to its compile-time default. 2076 ** 2077 ** [[SQLITE_CONFIG_WIN32_HEAPSIZE]] 2078 ** <dt>SQLITE_CONFIG_WIN32_HEAPSIZE 2079 ** <dd>^The SQLITE_CONFIG_WIN32_HEAPSIZE option is only available if SQLite is 2080 ** compiled for Windows with the [SQLITE_WIN32_MALLOC] pre-processor macro 2081 ** defined. ^SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit unsigned integer value 2082 ** that specifies the maximum size of the created heap. 2083 ** 2084 ** [[SQLITE_CONFIG_PCACHE_HDRSZ]] 2085 ** <dt>SQLITE_CONFIG_PCACHE_HDRSZ 2086 ** <dd>^The SQLITE_CONFIG_PCACHE_HDRSZ option takes a single parameter which 2087 ** is a pointer to an integer and writes into that integer the number of extra 2088 ** bytes per page required for each page in [SQLITE_CONFIG_PAGECACHE]. 2089 ** The amount of extra space required can change depending on the compiler, 2090 ** target platform, and SQLite version. 2091 ** 2092 ** [[SQLITE_CONFIG_PMASZ]] 2093 ** <dt>SQLITE_CONFIG_PMASZ 2094 ** <dd>^The SQLITE_CONFIG_PMASZ option takes a single parameter which 2095 ** is an unsigned integer and sets the "Minimum PMA Size" for the multithreaded 2096 ** sorter to that integer. The default minimum PMA Size is set by the 2097 ** [SQLITE_SORTER_PMASZ] compile-time option. New threads are launched 2098 ** to help with sort operations when multithreaded sorting 2099 ** is enabled (using the [PRAGMA threads] command) and the amount of content 2100 ** to be sorted exceeds the page size times the minimum of the 2101 ** [PRAGMA cache_size] setting and this value. 2102 ** 2103 ** [[SQLITE_CONFIG_STMTJRNL_SPILL]] 2104 ** <dt>SQLITE_CONFIG_STMTJRNL_SPILL 2105 ** <dd>^The SQLITE_CONFIG_STMTJRNL_SPILL option takes a single parameter which 2106 ** becomes the [statement journal] spill-to-disk threshold. 2107 ** [Statement journals] are held in memory until their size (in bytes) 2108 ** exceeds this threshold, at which point they are written to disk. 2109 ** Or if the threshold is -1, statement journals are always held 2110 ** exclusively in memory. 2111 ** Since many statement journals never become large, setting the spill 2112 ** threshold to a value such as 64KiB can greatly reduce the amount of 2113 ** I/O required to support statement rollback. 2114 ** The default value for this setting is controlled by the 2115 ** [SQLITE_STMTJRNL_SPILL] compile-time option. 2116 ** 2117 ** [[SQLITE_CONFIG_SORTERREF_SIZE]] 2118 ** <dt>SQLITE_CONFIG_SORTERREF_SIZE 2119 ** <dd>The SQLITE_CONFIG_SORTERREF_SIZE option accepts a single parameter 2120 ** of type (int) - the new value of the sorter-reference size threshold. 2121 ** Usually, when SQLite uses an external sort to order records according 2122 ** to an ORDER BY clause, all fields required by the caller are present in the 2123 ** sorted records. However, if SQLite determines based on the declared type 2124 ** of a table column that its values are likely to be very large - larger 2125 ** than the configured sorter-reference size threshold - then a reference 2126 ** is stored in each sorted record and the required column values loaded 2127 ** from the database as records are returned in sorted order. The default 2128 ** value for this option is to never use this optimization. Specifying a 2129 ** negative value for this option restores the default behaviour. 2130 ** This option is only available if SQLite is compiled with the 2131 ** [SQLITE_ENABLE_SORTER_REFERENCES] compile-time option. 2132 ** 2133 ** [[SQLITE_CONFIG_MEMDB_MAXSIZE]] 2134 ** <dt>SQLITE_CONFIG_MEMDB_MAXSIZE 2135 ** <dd>The SQLITE_CONFIG_MEMDB_MAXSIZE option accepts a single parameter 2136 ** [sqlite3_int64] parameter which is the default maximum size for an in-memory 2137 ** database created using [sqlite3_deserialize()]. This default maximum 2138 ** size can be adjusted up or down for individual databases using the 2139 ** [SQLITE_FCNTL_SIZE_LIMIT] [sqlite3_file_control|file-control]. If this 2140 ** configuration setting is never used, then the default maximum is determined 2141 ** by the [SQLITE_MEMDB_DEFAULT_MAXSIZE] compile-time option. If that 2142 ** compile-time option is not set, then the default maximum is 1073741824. 2143 ** </dl> 2144 */ 2145 #define SQLITE_CONFIG_SINGLETHREAD 1 /* nil */ 2146 #define SQLITE_CONFIG_MULTITHREAD 2 /* nil */ 2147 #define SQLITE_CONFIG_SERIALIZED 3 /* nil */ 2148 #define SQLITE_CONFIG_MALLOC 4 /* sqlite3_mem_methods* */ 2149 #define SQLITE_CONFIG_GETMALLOC 5 /* sqlite3_mem_methods* */ 2150 #define SQLITE_CONFIG_SCRATCH 6 /* No longer used */ 2151 #define SQLITE_CONFIG_PAGECACHE 7 /* void*, int sz, int N */ 2152 #define SQLITE_CONFIG_HEAP 8 /* void*, int nByte, int min */ 2153 #define SQLITE_CONFIG_MEMSTATUS 9 /* boolean */ 2154 #define SQLITE_CONFIG_MUTEX 10 /* sqlite3_mutex_methods* */ 2155 #define SQLITE_CONFIG_GETMUTEX 11 /* sqlite3_mutex_methods* */ 2156 /* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */ 2157 #define SQLITE_CONFIG_LOOKASIDE 13 /* int int */ 2158 #define SQLITE_CONFIG_PCACHE 14 /* no-op */ 2159 #define SQLITE_CONFIG_GETPCACHE 15 /* no-op */ 2160 #define SQLITE_CONFIG_LOG 16 /* xFunc, void* */ 2161 #define SQLITE_CONFIG_URI 17 /* int */ 2162 #define SQLITE_CONFIG_PCACHE2 18 /* sqlite3_pcache_methods2* */ 2163 #define SQLITE_CONFIG_GETPCACHE2 19 /* sqlite3_pcache_methods2* */ 2164 #define SQLITE_CONFIG_COVERING_INDEX_SCAN 20 /* int */ 2165 #define SQLITE_CONFIG_SQLLOG 21 /* xSqllog, void* */ 2166 #define SQLITE_CONFIG_MMAP_SIZE 22 /* sqlite3_int64, sqlite3_int64 */ 2167 #define SQLITE_CONFIG_WIN32_HEAPSIZE 23 /* int nByte */ 2168 #define SQLITE_CONFIG_PCACHE_HDRSZ 24 /* int *psz */ 2169 #define SQLITE_CONFIG_PMASZ 25 /* unsigned int szPma */ 2170 #define SQLITE_CONFIG_STMTJRNL_SPILL 26 /* int nByte */ 2171 #define SQLITE_CONFIG_SMALL_MALLOC 27 /* boolean */ 2172 #define SQLITE_CONFIG_SORTERREF_SIZE 28 /* int nByte */ 2173 #define SQLITE_CONFIG_MEMDB_MAXSIZE 29 /* sqlite3_int64 */ 2174 2175 /* 2176 ** CAPI3REF: Database Connection Configuration Options 2177 ** 2178 ** These constants are the available integer configuration options that 2179 ** can be passed as the second argument to the [sqlite3_db_config()] interface. 2180 ** 2181 ** New configuration options may be added in future releases of SQLite. 2182 ** Existing configuration options might be discontinued. Applications 2183 ** should check the return code from [sqlite3_db_config()] to make sure that 2184 ** the call worked. ^The [sqlite3_db_config()] interface will return a 2185 ** non-zero [error code] if a discontinued or unsupported configuration option 2186 ** is invoked. 2187 ** 2188 ** <dl> 2189 ** [[SQLITE_DBCONFIG_LOOKASIDE]] 2190 ** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt> 2191 ** <dd> ^This option takes three additional arguments that determine the 2192 ** [lookaside memory allocator] configuration for the [database connection]. 2193 ** ^The first argument (the third parameter to [sqlite3_db_config()] is a 2194 ** pointer to a memory buffer to use for lookaside memory. 2195 ** ^The first argument after the SQLITE_DBCONFIG_LOOKASIDE verb 2196 ** may be NULL in which case SQLite will allocate the 2197 ** lookaside buffer itself using [sqlite3_malloc()]. ^The second argument is the 2198 ** size of each lookaside buffer slot. ^The third argument is the number of 2199 ** slots. The size of the buffer in the first argument must be greater than 2200 ** or equal to the product of the second and third arguments. The buffer 2201 ** must be aligned to an 8-byte boundary. ^If the second argument to 2202 ** SQLITE_DBCONFIG_LOOKASIDE is not a multiple of 8, it is internally 2203 ** rounded down to the next smaller multiple of 8. ^(The lookaside memory 2204 ** configuration for a database connection can only be changed when that 2205 ** connection is not currently using lookaside memory, or in other words 2206 ** when the "current value" returned by 2207 ** [sqlite3_db_status](D,[SQLITE_DBSTATUS_LOOKASIDE_USED],...) is zero. 2208 ** Any attempt to change the lookaside memory configuration when lookaside 2209 ** memory is in use leaves the configuration unchanged and returns 2210 ** [SQLITE_BUSY].)^</dd> 2211 ** 2212 ** [[SQLITE_DBCONFIG_ENABLE_FKEY]] 2213 ** <dt>SQLITE_DBCONFIG_ENABLE_FKEY</dt> 2214 ** <dd> ^This option is used to enable or disable the enforcement of 2215 ** [foreign key constraints]. There should be two additional arguments. 2216 ** The first argument is an integer which is 0 to disable FK enforcement, 2217 ** positive to enable FK enforcement or negative to leave FK enforcement 2218 ** unchanged. The second parameter is a pointer to an integer into which 2219 ** is written 0 or 1 to indicate whether FK enforcement is off or on 2220 ** following this call. The second parameter may be a NULL pointer, in 2221 ** which case the FK enforcement setting is not reported back. </dd> 2222 ** 2223 ** [[SQLITE_DBCONFIG_ENABLE_TRIGGER]] 2224 ** <dt>SQLITE_DBCONFIG_ENABLE_TRIGGER</dt> 2225 ** <dd> ^This option is used to enable or disable [CREATE TRIGGER | triggers]. 2226 ** There should be two additional arguments. 2227 ** The first argument is an integer which is 0 to disable triggers, 2228 ** positive to enable triggers or negative to leave the setting unchanged. 2229 ** The second parameter is a pointer to an integer into which 2230 ** is written 0 or 1 to indicate whether triggers are disabled or enabled 2231 ** following this call. The second parameter may be a NULL pointer, in 2232 ** which case the trigger setting is not reported back. 2233 ** 2234 ** <p>Originally this option disabled all triggers. ^(However, since 2235 ** SQLite version 3.35.0, TEMP triggers are still allowed even if 2236 ** this option is off. So, in other words, this option now only disables 2237 ** triggers in the main database schema or in the schemas of ATTACH-ed 2238 ** databases.)^ </dd> 2239 ** 2240 ** [[SQLITE_DBCONFIG_ENABLE_VIEW]] 2241 ** <dt>SQLITE_DBCONFIG_ENABLE_VIEW</dt> 2242 ** <dd> ^This option is used to enable or disable [CREATE VIEW | views]. 2243 ** There should be two additional arguments. 2244 ** The first argument is an integer which is 0 to disable views, 2245 ** positive to enable views or negative to leave the setting unchanged. 2246 ** The second parameter is a pointer to an integer into which 2247 ** is written 0 or 1 to indicate whether views are disabled or enabled 2248 ** following this call. The second parameter may be a NULL pointer, in 2249 ** which case the view setting is not reported back. 2250 ** 2251 ** <p>Originally this option disabled all views. ^(However, since 2252 ** SQLite version 3.35.0, TEMP views are still allowed even if 2253 ** this option is off. So, in other words, this option now only disables 2254 ** views in the main database schema or in the schemas of ATTACH-ed 2255 ** databases.)^ </dd> 2256 ** 2257 ** [[SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER]] 2258 ** <dt>SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER</dt> 2259 ** <dd> ^This option is used to enable or disable the 2260 ** [fts3_tokenizer()] function which is part of the 2261 ** [FTS3] full-text search engine extension. 2262 ** There should be two additional arguments. 2263 ** The first argument is an integer which is 0 to disable fts3_tokenizer() or 2264 ** positive to enable fts3_tokenizer() or negative to leave the setting 2265 ** unchanged. 2266 ** The second parameter is a pointer to an integer into which 2267 ** is written 0 or 1 to indicate whether fts3_tokenizer is disabled or enabled 2268 ** following this call. The second parameter may be a NULL pointer, in 2269 ** which case the new setting is not reported back. </dd> 2270 ** 2271 ** [[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION]] 2272 ** <dt>SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION</dt> 2273 ** <dd> ^This option is used to enable or disable the [sqlite3_load_extension()] 2274 ** interface independently of the [load_extension()] SQL function. 2275 ** The [sqlite3_enable_load_extension()] API enables or disables both the 2276 ** C-API [sqlite3_load_extension()] and the SQL function [load_extension()]. 2277 ** There should be two additional arguments. 2278 ** When the first argument to this interface is 1, then only the C-API is 2279 ** enabled and the SQL function remains disabled. If the first argument to 2280 ** this interface is 0, then both the C-API and the SQL function are disabled. 2281 ** If the first argument is -1, then no changes are made to state of either the 2282 ** C-API or the SQL function. 2283 ** The second parameter is a pointer to an integer into which 2284 ** is written 0 or 1 to indicate whether [sqlite3_load_extension()] interface 2285 ** is disabled or enabled following this call. The second parameter may 2286 ** be a NULL pointer, in which case the new setting is not reported back. 2287 ** </dd> 2288 ** 2289 ** [[SQLITE_DBCONFIG_MAINDBNAME]] <dt>SQLITE_DBCONFIG_MAINDBNAME</dt> 2290 ** <dd> ^This option is used to change the name of the "main" database 2291 ** schema. ^The sole argument is a pointer to a constant UTF8 string 2292 ** which will become the new schema name in place of "main". ^SQLite 2293 ** does not make a copy of the new main schema name string, so the application 2294 ** must ensure that the argument passed into this DBCONFIG option is unchanged 2295 ** until after the database connection closes. 2296 ** </dd> 2297 ** 2298 ** [[SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE]] 2299 ** <dt>SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE</dt> 2300 ** <dd> Usually, when a database in wal mode is closed or detached from a 2301 ** database handle, SQLite checks if this will mean that there are now no 2302 ** connections at all to the database. If so, it performs a checkpoint 2303 ** operation before closing the connection. This option may be used to 2304 ** override this behaviour. The first parameter passed to this operation 2305 ** is an integer - positive to disable checkpoints-on-close, or zero (the 2306 ** default) to enable them, and negative to leave the setting unchanged. 2307 ** The second parameter is a pointer to an integer 2308 ** into which is written 0 or 1 to indicate whether checkpoints-on-close 2309 ** have been disabled - 0 if they are not disabled, 1 if they are. 2310 ** </dd> 2311 ** 2312 ** [[SQLITE_DBCONFIG_ENABLE_QPSG]] <dt>SQLITE_DBCONFIG_ENABLE_QPSG</dt> 2313 ** <dd>^(The SQLITE_DBCONFIG_ENABLE_QPSG option activates or deactivates 2314 ** the [query planner stability guarantee] (QPSG). When the QPSG is active, 2315 ** a single SQL query statement will always use the same algorithm regardless 2316 ** of values of [bound parameters].)^ The QPSG disables some query optimizations 2317 ** that look at the values of bound parameters, which can make some queries 2318 ** slower. But the QPSG has the advantage of more predictable behavior. With 2319 ** the QPSG active, SQLite will always use the same query plan in the field as 2320 ** was used during testing in the lab. 2321 ** The first argument to this setting is an integer which is 0 to disable 2322 ** the QPSG, positive to enable QPSG, or negative to leave the setting 2323 ** unchanged. The second parameter is a pointer to an integer into which 2324 ** is written 0 or 1 to indicate whether the QPSG is disabled or enabled 2325 ** following this call. 2326 ** </dd> 2327 ** 2328 ** [[SQLITE_DBCONFIG_TRIGGER_EQP]] <dt>SQLITE_DBCONFIG_TRIGGER_EQP</dt> 2329 ** <dd> By default, the output of EXPLAIN QUERY PLAN commands does not 2330 ** include output for any operations performed by trigger programs. This 2331 ** option is used to set or clear (the default) a flag that governs this 2332 ** behavior. The first parameter passed to this operation is an integer - 2333 ** positive to enable output for trigger programs, or zero to disable it, 2334 ** or negative to leave the setting unchanged. 2335 ** The second parameter is a pointer to an integer into which is written 2336 ** 0 or 1 to indicate whether output-for-triggers has been disabled - 0 if 2337 ** it is not disabled, 1 if it is. 2338 ** </dd> 2339 ** 2340 ** [[SQLITE_DBCONFIG_RESET_DATABASE]] <dt>SQLITE_DBCONFIG_RESET_DATABASE</dt> 2341 ** <dd> Set the SQLITE_DBCONFIG_RESET_DATABASE flag and then run 2342 ** [VACUUM] in order to reset a database back to an empty database 2343 ** with no schema and no content. The following process works even for 2344 ** a badly corrupted database file: 2345 ** <ol> 2346 ** <li> If the database connection is newly opened, make sure it has read the 2347 ** database schema by preparing then discarding some query against the 2348 ** database, or calling sqlite3_table_column_metadata(), ignoring any 2349 ** errors. This step is only necessary if the application desires to keep 2350 ** the database in WAL mode after the reset if it was in WAL mode before 2351 ** the reset. 2352 ** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 1, 0); 2353 ** <li> [sqlite3_exec](db, "[VACUUM]", 0, 0, 0); 2354 ** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 0, 0); 2355 ** </ol> 2356 ** Because resetting a database is destructive and irreversible, the 2357 ** process requires the use of this obscure API and multiple steps to 2358 ** help ensure that it does not happen by accident. Because this 2359 ** feature must be capable of resetting corrupt databases, and 2360 ** shutting down virtual tables may require access to that corrupt 2361 ** storage, the library must abandon any installed virtual tables 2362 ** without calling their xDestroy() methods. 2363 ** 2364 ** [[SQLITE_DBCONFIG_DEFENSIVE]] <dt>SQLITE_DBCONFIG_DEFENSIVE</dt> 2365 ** <dd>The SQLITE_DBCONFIG_DEFENSIVE option activates or deactivates the 2366 ** "defensive" flag for a database connection. When the defensive 2367 ** flag is enabled, language features that allow ordinary SQL to 2368 ** deliberately corrupt the database file are disabled. The disabled 2369 ** features include but are not limited to the following: 2370 ** <ul> 2371 ** <li> The [PRAGMA writable_schema=ON] statement. 2372 ** <li> The [PRAGMA journal_mode=OFF] statement. 2373 ** <li> The [PRAGMA schema_version=N] statement. 2374 ** <li> Writes to the [sqlite_dbpage] virtual table. 2375 ** <li> Direct writes to [shadow tables]. 2376 ** </ul> 2377 ** </dd> 2378 ** 2379 ** [[SQLITE_DBCONFIG_WRITABLE_SCHEMA]] <dt>SQLITE_DBCONFIG_WRITABLE_SCHEMA</dt> 2380 ** <dd>The SQLITE_DBCONFIG_WRITABLE_SCHEMA option activates or deactivates the 2381 ** "writable_schema" flag. This has the same effect and is logically equivalent 2382 ** to setting [PRAGMA writable_schema=ON] or [PRAGMA writable_schema=OFF]. 2383 ** The first argument to this setting is an integer which is 0 to disable 2384 ** the writable_schema, positive to enable writable_schema, or negative to 2385 ** leave the setting unchanged. The second parameter is a pointer to an 2386 ** integer into which is written 0 or 1 to indicate whether the writable_schema 2387 ** is enabled or disabled following this call. 2388 ** </dd> 2389 ** 2390 ** [[SQLITE_DBCONFIG_LEGACY_ALTER_TABLE]] 2391 ** <dt>SQLITE_DBCONFIG_LEGACY_ALTER_TABLE</dt> 2392 ** <dd>The SQLITE_DBCONFIG_LEGACY_ALTER_TABLE option activates or deactivates 2393 ** the legacy behavior of the [ALTER TABLE RENAME] command such it 2394 ** behaves as it did prior to [version 3.24.0] (2018-06-04). See the 2395 ** "Compatibility Notice" on the [ALTER TABLE RENAME documentation] for 2396 ** additional information. This feature can also be turned on and off 2397 ** using the [PRAGMA legacy_alter_table] statement. 2398 ** </dd> 2399 ** 2400 ** [[SQLITE_DBCONFIG_DQS_DML]] 2401 ** <dt>SQLITE_DBCONFIG_DQS_DML</dt> 2402 ** <dd>The SQLITE_DBCONFIG_DQS_DML option activates or deactivates 2403 ** the legacy [double-quoted string literal] misfeature for DML statements 2404 ** only, that is DELETE, INSERT, SELECT, and UPDATE statements. The 2405 ** default value of this setting is determined by the [-DSQLITE_DQS] 2406 ** compile-time option. 2407 ** </dd> 2408 ** 2409 ** [[SQLITE_DBCONFIG_DQS_DDL]] 2410 ** <dt>SQLITE_DBCONFIG_DQS_DDL</dt> 2411 ** <dd>The SQLITE_DBCONFIG_DQS option activates or deactivates 2412 ** the legacy [double-quoted string literal] misfeature for DDL statements, 2413 ** such as CREATE TABLE and CREATE INDEX. The 2414 ** default value of this setting is determined by the [-DSQLITE_DQS] 2415 ** compile-time option. 2416 ** </dd> 2417 ** 2418 ** [[SQLITE_DBCONFIG_TRUSTED_SCHEMA]] 2419 ** <dt>SQLITE_DBCONFIG_TRUSTED_SCHEMA</dt> 2420 ** <dd>The SQLITE_DBCONFIG_TRUSTED_SCHEMA option tells SQLite to 2421 ** assume that database schemas are untainted by malicious content. 2422 ** When the SQLITE_DBCONFIG_TRUSTED_SCHEMA option is disabled, SQLite 2423 ** takes additional defensive steps to protect the application from harm 2424 ** including: 2425 ** <ul> 2426 ** <li> Prohibit the use of SQL functions inside triggers, views, 2427 ** CHECK constraints, DEFAULT clauses, expression indexes, 2428 ** partial indexes, or generated columns 2429 ** unless those functions are tagged with [SQLITE_INNOCUOUS]. 2430 ** <li> Prohibit the use of virtual tables inside of triggers or views 2431 ** unless those virtual tables are tagged with [SQLITE_VTAB_INNOCUOUS]. 2432 ** </ul> 2433 ** This setting defaults to "on" for legacy compatibility, however 2434 ** all applications are advised to turn it off if possible. This setting 2435 ** can also be controlled using the [PRAGMA trusted_schema] statement. 2436 ** </dd> 2437 ** 2438 ** [[SQLITE_DBCONFIG_LEGACY_FILE_FORMAT]] 2439 ** <dt>SQLITE_DBCONFIG_LEGACY_FILE_FORMAT</dt> 2440 ** <dd>The SQLITE_DBCONFIG_LEGACY_FILE_FORMAT option activates or deactivates 2441 ** the legacy file format flag. When activated, this flag causes all newly 2442 ** created database file to have a schema format version number (the 4-byte 2443 ** integer found at offset 44 into the database header) of 1. This in turn 2444 ** means that the resulting database file will be readable and writable by 2445 ** any SQLite version back to 3.0.0 ([dateof:3.0.0]). Without this setting, 2446 ** newly created databases are generally not understandable by SQLite versions 2447 ** prior to 3.3.0 ([dateof:3.3.0]). As these words are written, there 2448 ** is now scarcely any need to generate database files that are compatible 2449 ** all the way back to version 3.0.0, and so this setting is of little 2450 ** practical use, but is provided so that SQLite can continue to claim the 2451 ** ability to generate new database files that are compatible with version 2452 ** 3.0.0. 2453 ** <p>Note that when the SQLITE_DBCONFIG_LEGACY_FILE_FORMAT setting is on, 2454 ** the [VACUUM] command will fail with an obscure error when attempting to 2455 ** process a table with generated columns and a descending index. This is 2456 ** not considered a bug since SQLite versions 3.3.0 and earlier do not support 2457 ** either generated columns or decending indexes. 2458 ** </dd> 2459 ** 2460 ** [[SQLITE_DBCONFIG_STMT_SCANSTATUS]] 2461 ** <dt>SQLITE_DBCONFIG_STMT_SCANSTATUS</dt> 2462 ** <dd>The SQLITE_DBCONFIG_STMT_SCANSTATUS option is only useful in 2463 ** SQLITE_ENABLE_STMT_SCANSTATUS builds. In this case, it sets or clears 2464 ** a flag that enables collection of the sqlite3_stmt_scanstatus_v2() 2465 ** statistics. For statistics to be collected, the flag must be set on 2466 ** the database handle both when the SQL statement is prepared and when it 2467 ** is stepped. The flag is set (collection of statistics is enabled) 2468 ** by default. This option takes two arguments: an integer and a pointer to 2469 ** an integer.. The first argument is 1, 0, or -1 to enable, disable, or 2470 ** leave unchanged the statement scanstatus option. If the second argument 2471 ** is not NULL, then the value of the statement scanstatus setting after 2472 ** processing the first argument is written into the integer that the second 2473 ** argument points to. 2474 ** </dd> 2475 ** 2476 ** [[SQLITE_DBCONFIG_REVERSE_SCANORDER]] 2477 ** <dt>SQLITE_DBCONFIG_REVERSE_SCANORDER</dt> 2478 ** <dd>The SQLITE_DBCONFIG_REVERSE_SCANORDER option changes the default order 2479 ** in which tables and indexes are scanned so that the scans start at the end 2480 ** and work toward the beginning rather than starting at the beginning and 2481 ** working toward the end. Setting SQLITE_DBCONFIG_REVERSE_SCANORDER is the 2482 ** same as setting [PRAGMA reverse_unordered_selects]. This option takes 2483 ** two arguments which are an integer and a pointer to an integer. The first 2484 ** argument is 1, 0, or -1 to enable, disable, or leave unchanged the 2485 ** reverse scan order flag, respectively. If the second argument is not NULL, 2486 ** then 0 or 1 is written into the integer that the second argument points to 2487 ** depending on if the reverse scan order flag is set after processing the 2488 ** first argument. 2489 ** </dd> 2490 ** 2491 ** </dl> 2492 */ 2493 #define SQLITE_DBCONFIG_MAINDBNAME 1000 /* const char* */ 2494 #define SQLITE_DBCONFIG_LOOKASIDE 1001 /* void* int int */ 2495 #define SQLITE_DBCONFIG_ENABLE_FKEY 1002 /* int int* */ 2496 #define SQLITE_DBCONFIG_ENABLE_TRIGGER 1003 /* int int* */ 2497 #define SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER 1004 /* int int* */ 2498 #define SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION 1005 /* int int* */ 2499 #define SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE 1006 /* int int* */ 2500 #define SQLITE_DBCONFIG_ENABLE_QPSG 1007 /* int int* */ 2501 #define SQLITE_DBCONFIG_TRIGGER_EQP 1008 /* int int* */ 2502 #define SQLITE_DBCONFIG_RESET_DATABASE 1009 /* int int* */ 2503 #define SQLITE_DBCONFIG_DEFENSIVE 1010 /* int int* */ 2504 #define SQLITE_DBCONFIG_WRITABLE_SCHEMA 1011 /* int int* */ 2505 #define SQLITE_DBCONFIG_LEGACY_ALTER_TABLE 1012 /* int int* */ 2506 #define SQLITE_DBCONFIG_DQS_DML 1013 /* int int* */ 2507 #define SQLITE_DBCONFIG_DQS_DDL 1014 /* int int* */ 2508 #define SQLITE_DBCONFIG_ENABLE_VIEW 1015 /* int int* */ 2509 #define SQLITE_DBCONFIG_LEGACY_FILE_FORMAT 1016 /* int int* */ 2510 #define SQLITE_DBCONFIG_TRUSTED_SCHEMA 1017 /* int int* */ 2511 #define SQLITE_DBCONFIG_STMT_SCANSTATUS 1018 /* int int* */ 2512 #define SQLITE_DBCONFIG_REVERSE_SCANORDER 1019 /* int int* */ 2513 #define SQLITE_DBCONFIG_MAX 1019 /* Largest DBCONFIG */ 2514 2515 /* 2516 ** CAPI3REF: Enable Or Disable Extended Result Codes 2517 ** METHOD: sqlite3 2518 ** 2519 ** ^The sqlite3_extended_result_codes() routine enables or disables the 2520 ** [extended result codes] feature of SQLite. ^The extended result 2521 ** codes are disabled by default for historical compatibility. 2522 */ 2523 SQLITE_API int sqlite3_extended_result_codes(sqlite3*, int onoff); 2524 2525 /* 2526 ** CAPI3REF: Last Insert Rowid 2527 ** METHOD: sqlite3 2528 ** 2529 ** ^Each entry in most SQLite tables (except for [WITHOUT ROWID] tables) 2530 ** has a unique 64-bit signed 2531 ** integer key called the [ROWID | "rowid"]. ^The rowid is always available 2532 ** as an undeclared column named ROWID, OID, or _ROWID_ as long as those 2533 ** names are not also used by explicitly declared columns. ^If 2534 ** the table has a column of type [INTEGER PRIMARY KEY] then that column 2535 ** is another alias for the rowid. 2536 ** 2537 ** ^The sqlite3_last_insert_rowid(D) interface usually returns the [rowid] of 2538 ** the most recent successful [INSERT] into a rowid table or [virtual table] 2539 ** on database connection D. ^Inserts into [WITHOUT ROWID] tables are not 2540 ** recorded. ^If no successful [INSERT]s into rowid tables have ever occurred 2541 ** on the database connection D, then sqlite3_last_insert_rowid(D) returns 2542 ** zero. 2543 ** 2544 ** As well as being set automatically as rows are inserted into database 2545 ** tables, the value returned by this function may be set explicitly by 2546 ** [sqlite3_set_last_insert_rowid()] 2547 ** 2548 ** Some virtual table implementations may INSERT rows into rowid tables as 2549 ** part of committing a transaction (e.g. to flush data accumulated in memory 2550 ** to disk). In this case subsequent calls to this function return the rowid 2551 ** associated with these internal INSERT operations, which leads to 2552 ** unintuitive results. Virtual table implementations that do write to rowid 2553 ** tables in this way can avoid this problem by restoring the original 2554 ** rowid value using [sqlite3_set_last_insert_rowid()] before returning 2555 ** control to the user. 2556 ** 2557 ** ^(If an [INSERT] occurs within a trigger then this routine will 2558 ** return the [rowid] of the inserted row as long as the trigger is 2559 ** running. Once the trigger program ends, the value returned 2560 ** by this routine reverts to what it was before the trigger was fired.)^ 2561 ** 2562 ** ^An [INSERT] that fails due to a constraint violation is not a 2563 ** successful [INSERT] and does not change the value returned by this 2564 ** routine. ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK, 2565 ** and INSERT OR ABORT make no changes to the return value of this 2566 ** routine when their insertion fails. ^(When INSERT OR REPLACE 2567 ** encounters a constraint violation, it does not fail. The 2568 ** INSERT continues to completion after deleting rows that caused 2569 ** the constraint problem so INSERT OR REPLACE will always change 2570 ** the return value of this interface.)^ 2571 ** 2572 ** ^For the purposes of this routine, an [INSERT] is considered to 2573 ** be successful even if it is subsequently rolled back. 2574 ** 2575 ** This function is accessible to SQL statements via the 2576 ** [last_insert_rowid() SQL function]. 2577 ** 2578 ** If a separate thread performs a new [INSERT] on the same 2579 ** database connection while the [sqlite3_last_insert_rowid()] 2580 ** function is running and thus changes the last insert [rowid], 2581 ** then the value returned by [sqlite3_last_insert_rowid()] is 2582 ** unpredictable and might not equal either the old or the new 2583 ** last insert [rowid]. 2584 */ 2585 SQLITE_API sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*); 2586 2587 /* 2588 ** CAPI3REF: Set the Last Insert Rowid value. 2589 ** METHOD: sqlite3 2590 ** 2591 ** The sqlite3_set_last_insert_rowid(D, R) method allows the application to 2592 ** set the value returned by calling sqlite3_last_insert_rowid(D) to R 2593 ** without inserting a row into the database. 2594 */ 2595 SQLITE_API void sqlite3_set_last_insert_rowid(sqlite3*,sqlite3_int64); 2596 2597 /* 2598 ** CAPI3REF: Count The Number Of Rows Modified 2599 ** METHOD: sqlite3 2600 ** 2601 ** ^These functions return the number of rows modified, inserted or 2602 ** deleted by the most recently completed INSERT, UPDATE or DELETE 2603 ** statement on the database connection specified by the only parameter. 2604 ** The two functions are identical except for the type of the return value 2605 ** and that if the number of rows modified by the most recent INSERT, UPDATE 2606 ** or DELETE is greater than the maximum value supported by type "int", then 2607 ** the return value of sqlite3_changes() is undefined. ^Executing any other 2608 ** type of SQL statement does not modify the value returned by these functions. 2609 ** 2610 ** ^Only changes made directly by the INSERT, UPDATE or DELETE statement are 2611 ** considered - auxiliary changes caused by [CREATE TRIGGER | triggers], 2612 ** [foreign key actions] or [REPLACE] constraint resolution are not counted. 2613 ** 2614 ** Changes to a view that are intercepted by 2615 ** [INSTEAD OF trigger | INSTEAD OF triggers] are not counted. ^The value 2616 ** returned by sqlite3_changes() immediately after an INSERT, UPDATE or 2617 ** DELETE statement run on a view is always zero. Only changes made to real 2618 ** tables are counted. 2619 ** 2620 ** Things are more complicated if the sqlite3_changes() function is 2621 ** executed while a trigger program is running. This may happen if the 2622 ** program uses the [changes() SQL function], or if some other callback 2623 ** function invokes sqlite3_changes() directly. Essentially: 2624 ** 2625 ** <ul> 2626 ** <li> ^(Before entering a trigger program the value returned by 2627 ** sqlite3_changes() function is saved. After the trigger program 2628 ** has finished, the original value is restored.)^ 2629 ** 2630 ** <li> ^(Within a trigger program each INSERT, UPDATE and DELETE 2631 ** statement sets the value returned by sqlite3_changes() 2632 ** upon completion as normal. Of course, this value will not include 2633 ** any changes performed by sub-triggers, as the sqlite3_changes() 2634 ** value will be saved and restored after each sub-trigger has run.)^ 2635 ** </ul> 2636 ** 2637 ** ^This means that if the changes() SQL function (or similar) is used 2638 ** by the first INSERT, UPDATE or DELETE statement within a trigger, it 2639 ** returns the value as set when the calling statement began executing. 2640 ** ^If it is used by the second or subsequent such statement within a trigger 2641 ** program, the value returned reflects the number of rows modified by the 2642 ** previous INSERT, UPDATE or DELETE statement within the same trigger. 2643 ** 2644 ** If a separate thread makes changes on the same database connection 2645 ** while [sqlite3_changes()] is running then the value returned 2646 ** is unpredictable and not meaningful. 2647 ** 2648 ** See also: 2649 ** <ul> 2650 ** <li> the [sqlite3_total_changes()] interface 2651 ** <li> the [count_changes pragma] 2652 ** <li> the [changes() SQL function] 2653 ** <li> the [data_version pragma] 2654 ** </ul> 2655 */ 2656 SQLITE_API int sqlite3_changes(sqlite3*); 2657 SQLITE_API sqlite3_int64 sqlite3_changes64(sqlite3*); 2658 2659 /* 2660 ** CAPI3REF: Total Number Of Rows Modified 2661 ** METHOD: sqlite3 2662 ** 2663 ** ^These functions return the total number of rows inserted, modified or 2664 ** deleted by all [INSERT], [UPDATE] or [DELETE] statements completed 2665 ** since the database connection was opened, including those executed as 2666 ** part of trigger programs. The two functions are identical except for the 2667 ** type of the return value and that if the number of rows modified by the 2668 ** connection exceeds the maximum value supported by type "int", then 2669 ** the return value of sqlite3_total_changes() is undefined. ^Executing 2670 ** any other type of SQL statement does not affect the value returned by 2671 ** sqlite3_total_changes(). 2672 ** 2673 ** ^Changes made as part of [foreign key actions] are included in the 2674 ** count, but those made as part of REPLACE constraint resolution are 2675 ** not. ^Changes to a view that are intercepted by INSTEAD OF triggers 2676 ** are not counted. 2677 ** 2678 ** The [sqlite3_total_changes(D)] interface only reports the number 2679 ** of rows that changed due to SQL statement run against database 2680 ** connection D. Any changes by other database connections are ignored. 2681 ** To detect changes against a database file from other database 2682 ** connections use the [PRAGMA data_version] command or the 2683 ** [SQLITE_FCNTL_DATA_VERSION] [file control]. 2684 ** 2685 ** If a separate thread makes changes on the same database connection 2686 ** while [sqlite3_total_changes()] is running then the value 2687 ** returned is unpredictable and not meaningful. 2688 ** 2689 ** See also: 2690 ** <ul> 2691 ** <li> the [sqlite3_changes()] interface 2692 ** <li> the [count_changes pragma] 2693 ** <li> the [changes() SQL function] 2694 ** <li> the [data_version pragma] 2695 ** <li> the [SQLITE_FCNTL_DATA_VERSION] [file control] 2696 ** </ul> 2697 */ 2698 SQLITE_API int sqlite3_total_changes(sqlite3*); 2699 SQLITE_API sqlite3_int64 sqlite3_total_changes64(sqlite3*); 2700 2701 /* 2702 ** CAPI3REF: Interrupt A Long-Running Query 2703 ** METHOD: sqlite3 2704 ** 2705 ** ^This function causes any pending database operation to abort and 2706 ** return at its earliest opportunity. This routine is typically 2707 ** called in response to a user action such as pressing "Cancel" 2708 ** or Ctrl-C where the user wants a long query operation to halt 2709 ** immediately. 2710 ** 2711 ** ^It is safe to call this routine from a thread different from the 2712 ** thread that is currently running the database operation. But it 2713 ** is not safe to call this routine with a [database connection] that 2714 ** is closed or might close before sqlite3_interrupt() returns. 2715 ** 2716 ** ^If an SQL operation is very nearly finished at the time when 2717 ** sqlite3_interrupt() is called, then it might not have an opportunity 2718 ** to be interrupted and might continue to completion. 2719 ** 2720 ** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT]. 2721 ** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE 2722 ** that is inside an explicit transaction, then the entire transaction 2723 ** will be rolled back automatically. 2724 ** 2725 ** ^The sqlite3_interrupt(D) call is in effect until all currently running 2726 ** SQL statements on [database connection] D complete. ^Any new SQL statements 2727 ** that are started after the sqlite3_interrupt() call and before the 2728 ** running statement count reaches zero are interrupted as if they had been 2729 ** running prior to the sqlite3_interrupt() call. ^New SQL statements 2730 ** that are started after the running statement count reaches zero are 2731 ** not effected by the sqlite3_interrupt(). 2732 ** ^A call to sqlite3_interrupt(D) that occurs when there are no running 2733 ** SQL statements is a no-op and has no effect on SQL statements 2734 ** that are started after the sqlite3_interrupt() call returns. 2735 ** 2736 ** ^The [sqlite3_is_interrupted(D)] interface can be used to determine whether 2737 ** or not an interrupt is currently in effect for [database connection] D. 2738 */ 2739 SQLITE_API void sqlite3_interrupt(sqlite3*); 2740 SQLITE_API int sqlite3_is_interrupted(sqlite3*); 2741 2742 /* 2743 ** CAPI3REF: Determine If An SQL Statement Is Complete 2744 ** 2745 ** These routines are useful during command-line input to determine if the 2746 ** currently entered text seems to form a complete SQL statement or 2747 ** if additional input is needed before sending the text into 2748 ** SQLite for parsing. ^These routines return 1 if the input string 2749 ** appears to be a complete SQL statement. ^A statement is judged to be 2750 ** complete if it ends with a semicolon token and is not a prefix of a 2751 ** well-formed CREATE TRIGGER statement. ^Semicolons that are embedded within 2752 ** string literals or quoted identifier names or comments are not 2753 ** independent tokens (they are part of the token in which they are 2754 ** embedded) and thus do not count as a statement terminator. ^Whitespace 2755 ** and comments that follow the final semicolon are ignored. 2756 ** 2757 ** ^These routines return 0 if the statement is incomplete. ^If a 2758 ** memory allocation fails, then SQLITE_NOMEM is returned. 2759 ** 2760 ** ^These routines do not parse the SQL statements thus 2761 ** will not detect syntactically incorrect SQL. 2762 ** 2763 ** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior 2764 ** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked 2765 ** automatically by sqlite3_complete16(). If that initialization fails, 2766 ** then the return value from sqlite3_complete16() will be non-zero 2767 ** regardless of whether or not the input SQL is complete.)^ 2768 ** 2769 ** The input to [sqlite3_complete()] must be a zero-terminated 2770 ** UTF-8 string. 2771 ** 2772 ** The input to [sqlite3_complete16()] must be a zero-terminated 2773 ** UTF-16 string in native byte order. 2774 */ 2775 SQLITE_API int sqlite3_complete(const char *sql); 2776 SQLITE_API int sqlite3_complete16(const void *sql); 2777 2778 /* 2779 ** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors 2780 ** KEYWORDS: {busy-handler callback} {busy handler} 2781 ** METHOD: sqlite3 2782 ** 2783 ** ^The sqlite3_busy_handler(D,X,P) routine sets a callback function X 2784 ** that might be invoked with argument P whenever 2785 ** an attempt is made to access a database table associated with 2786 ** [database connection] D when another thread 2787 ** or process has the table locked. 2788 ** The sqlite3_busy_handler() interface is used to implement 2789 ** [sqlite3_busy_timeout()] and [PRAGMA busy_timeout]. 2790 ** 2791 ** ^If the busy callback is NULL, then [SQLITE_BUSY] 2792 ** is returned immediately upon encountering the lock. ^If the busy callback 2793 ** is not NULL, then the callback might be invoked with two arguments. 2794 ** 2795 ** ^The first argument to the busy handler is a copy of the void* pointer which 2796 ** is the third argument to sqlite3_busy_handler(). ^The second argument to 2797 ** the busy handler callback is the number of times that the busy handler has 2798 ** been invoked previously for the same locking event. ^If the 2799 ** busy callback returns 0, then no additional attempts are made to 2800 ** access the database and [SQLITE_BUSY] is returned 2801 ** to the application. 2802 ** ^If the callback returns non-zero, then another attempt 2803 ** is made to access the database and the cycle repeats. 2804 ** 2805 ** The presence of a busy handler does not guarantee that it will be invoked 2806 ** when there is lock contention. ^If SQLite determines that invoking the busy 2807 ** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY] 2808 ** to the application instead of invoking the 2809 ** busy handler. 2810 ** Consider a scenario where one process is holding a read lock that 2811 ** it is trying to promote to a reserved lock and 2812 ** a second process is holding a reserved lock that it is trying 2813 ** to promote to an exclusive lock. The first process cannot proceed 2814 ** because it is blocked by the second and the second process cannot 2815 ** proceed because it is blocked by the first. If both processes 2816 ** invoke the busy handlers, neither will make any progress. Therefore, 2817 ** SQLite returns [SQLITE_BUSY] for the first process, hoping that this 2818 ** will induce the first process to release its read lock and allow 2819 ** the second process to proceed. 2820 ** 2821 ** ^The default busy callback is NULL. 2822 ** 2823 ** ^(There can only be a single busy handler defined for each 2824 ** [database connection]. Setting a new busy handler clears any 2825 ** previously set handler.)^ ^Note that calling [sqlite3_busy_timeout()] 2826 ** or evaluating [PRAGMA busy_timeout=N] will change the 2827 ** busy handler and thus clear any previously set busy handler. 2828 ** 2829 ** The busy callback should not take any actions which modify the 2830 ** database connection that invoked the busy handler. In other words, 2831 ** the busy handler is not reentrant. Any such actions 2832 ** result in undefined behavior. 2833 ** 2834 ** A busy handler must not close the database connection 2835 ** or [prepared statement] that invoked the busy handler. 2836 */ 2837 SQLITE_API int sqlite3_busy_handler(sqlite3*,int(*)(void*,int),void*); 2838 2839 /* 2840 ** CAPI3REF: Set A Busy Timeout 2841 ** METHOD: sqlite3 2842 ** 2843 ** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps 2844 ** for a specified amount of time when a table is locked. ^The handler 2845 ** will sleep multiple times until at least "ms" milliseconds of sleeping 2846 ** have accumulated. ^After at least "ms" milliseconds of sleeping, 2847 ** the handler returns 0 which causes [sqlite3_step()] to return 2848 ** [SQLITE_BUSY]. 2849 ** 2850 ** ^Calling this routine with an argument less than or equal to zero 2851 ** turns off all busy handlers. 2852 ** 2853 ** ^(There can only be a single busy handler for a particular 2854 ** [database connection] at any given moment. If another busy handler 2855 ** was defined (using [sqlite3_busy_handler()]) prior to calling 2856 ** this routine, that other busy handler is cleared.)^ 2857 ** 2858 ** See also: [PRAGMA busy_timeout] 2859 */ 2860 SQLITE_API int sqlite3_busy_timeout(sqlite3*, int ms); 2861 2862 /* 2863 ** CAPI3REF: Convenience Routines For Running Queries 2864 ** METHOD: sqlite3 2865 ** 2866 ** This is a legacy interface that is preserved for backwards compatibility. 2867 ** Use of this interface is not recommended. 2868 ** 2869 ** Definition: A <b>result table</b> is memory data structure created by the 2870 ** [sqlite3_get_table()] interface. A result table records the 2871 ** complete query results from one or more queries. 2872 ** 2873 ** The table conceptually has a number of rows and columns. But 2874 ** these numbers are not part of the result table itself. These 2875 ** numbers are obtained separately. Let N be the number of rows 2876 ** and M be the number of columns. 2877 ** 2878 ** A result table is an array of pointers to zero-terminated UTF-8 strings. 2879 ** There are (N+1)*M elements in the array. The first M pointers point 2880 ** to zero-terminated strings that contain the names of the columns. 2881 ** The remaining entries all point to query results. NULL values result 2882 ** in NULL pointers. All other values are in their UTF-8 zero-terminated 2883 ** string representation as returned by [sqlite3_column_text()]. 2884 ** 2885 ** A result table might consist of one or more memory allocations. 2886 ** It is not safe to pass a result table directly to [sqlite3_free()]. 2887 ** A result table should be deallocated using [sqlite3_free_table()]. 2888 ** 2889 ** ^(As an example of the result table format, suppose a query result 2890 ** is as follows: 2891 ** 2892 ** <blockquote><pre> 2893 ** Name | Age 2894 ** ----------------------- 2895 ** Alice | 43 2896 ** Bob | 28 2897 ** Cindy | 21 2898 ** </pre></blockquote> 2899 ** 2900 ** There are two columns (M==2) and three rows (N==3). Thus the 2901 ** result table has 8 entries. Suppose the result table is stored 2902 ** in an array named azResult. Then azResult holds this content: 2903 ** 2904 ** <blockquote><pre> 2905 ** azResult[0] = "Name"; 2906 ** azResult[1] = "Age"; 2907 ** azResult[2] = "Alice"; 2908 ** azResult[3] = "43"; 2909 ** azResult[4] = "Bob"; 2910 ** azResult[5] = "28"; 2911 ** azResult[6] = "Cindy"; 2912 ** azResult[7] = "21"; 2913 ** </pre></blockquote>)^ 2914 ** 2915 ** ^The sqlite3_get_table() function evaluates one or more 2916 ** semicolon-separated SQL statements in the zero-terminated UTF-8 2917 ** string of its 2nd parameter and returns a result table to the 2918 ** pointer given in its 3rd parameter. 2919 ** 2920 ** After the application has finished with the result from sqlite3_get_table(), 2921 ** it must pass the result table pointer to sqlite3_free_table() in order to 2922 ** release the memory that was malloced. Because of the way the 2923 ** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling 2924 ** function must not try to call [sqlite3_free()] directly. Only 2925 ** [sqlite3_free_table()] is able to release the memory properly and safely. 2926 ** 2927 ** The sqlite3_get_table() interface is implemented as a wrapper around 2928 ** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access 2929 ** to any internal data structures of SQLite. It uses only the public 2930 ** interface defined here. As a consequence, errors that occur in the 2931 ** wrapper layer outside of the internal [sqlite3_exec()] call are not 2932 ** reflected in subsequent calls to [sqlite3_errcode()] or 2933 ** [sqlite3_errmsg()]. 2934 */ 2935 SQLITE_API int sqlite3_get_table( 2936 sqlite3 *db, /* An open database */ 2937 const char *zSql, /* SQL to be evaluated */ 2938 char ***pazResult, /* Results of the query */ 2939 int *pnRow, /* Number of result rows written here */ 2940 int *pnColumn, /* Number of result columns written here */ 2941 char **pzErrmsg /* Error msg written here */ 2942 ); 2943 SQLITE_API void sqlite3_free_table(char **result); 2944 2945 /* 2946 ** CAPI3REF: Formatted String Printing Functions 2947 ** 2948 ** These routines are work-alikes of the "printf()" family of functions 2949 ** from the standard C library. 2950 ** These routines understand most of the common formatting options from 2951 ** the standard library printf() 2952 ** plus some additional non-standard formats ([%q], [%Q], [%w], and [%z]). 2953 ** See the [built-in printf()] documentation for details. 2954 ** 2955 ** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their 2956 ** results into memory obtained from [sqlite3_malloc64()]. 2957 ** The strings returned by these two routines should be 2958 ** released by [sqlite3_free()]. ^Both routines return a 2959 ** NULL pointer if [sqlite3_malloc64()] is unable to allocate enough 2960 ** memory to hold the resulting string. 2961 ** 2962 ** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from 2963 ** the standard C library. The result is written into the 2964 ** buffer supplied as the second parameter whose size is given by 2965 ** the first parameter. Note that the order of the 2966 ** first two parameters is reversed from snprintf().)^ This is an 2967 ** historical accident that cannot be fixed without breaking 2968 ** backwards compatibility. ^(Note also that sqlite3_snprintf() 2969 ** returns a pointer to its buffer instead of the number of 2970 ** characters actually written into the buffer.)^ We admit that 2971 ** the number of characters written would be a more useful return 2972 ** value but we cannot change the implementation of sqlite3_snprintf() 2973 ** now without breaking compatibility. 2974 ** 2975 ** ^As long as the buffer size is greater than zero, sqlite3_snprintf() 2976 ** guarantees that the buffer is always zero-terminated. ^The first 2977 ** parameter "n" is the total size of the buffer, including space for 2978 ** the zero terminator. So the longest string that can be completely 2979 ** written will be n-1 characters. 2980 ** 2981 ** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf(). 2982 ** 2983 ** See also: [built-in printf()], [printf() SQL function] 2984 */ 2985 SQLITE_API char *sqlite3_mprintf(const char*,...); 2986 SQLITE_API char *sqlite3_vmprintf(const char*, va_list); 2987 SQLITE_API char *sqlite3_snprintf(int,char*,const char*, ...); 2988 SQLITE_API char *sqlite3_vsnprintf(int,char*,const char*, va_list); 2989 2990 /* 2991 ** CAPI3REF: Memory Allocation Subsystem 2992 ** 2993 ** The SQLite core uses these three routines for all of its own 2994 ** internal memory allocation needs. "Core" in the previous sentence 2995 ** does not include operating-system specific [VFS] implementation. The 2996 ** Windows VFS uses native malloc() and free() for some operations. 2997 ** 2998 ** ^The sqlite3_malloc() routine returns a pointer to a block 2999 ** of memory at least N bytes in length, where N is the parameter. 3000 ** ^If sqlite3_malloc() is unable to obtain sufficient free 3001 ** memory, it returns a NULL pointer. ^If the parameter N to 3002 ** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns 3003 ** a NULL pointer. 3004 ** 3005 ** ^The sqlite3_malloc64(N) routine works just like 3006 ** sqlite3_malloc(N) except that N is an unsigned 64-bit integer instead 3007 ** of a signed 32-bit integer. 3008 ** 3009 ** ^Calling sqlite3_free() with a pointer previously returned 3010 ** by sqlite3_malloc() or sqlite3_realloc() releases that memory so 3011 ** that it might be reused. ^The sqlite3_free() routine is 3012 ** a no-op if is called with a NULL pointer. Passing a NULL pointer 3013 ** to sqlite3_free() is harmless. After being freed, memory 3014 ** should neither be read nor written. Even reading previously freed 3015 ** memory might result in a segmentation fault or other severe error. 3016 ** Memory corruption, a segmentation fault, or other severe error 3017 ** might result if sqlite3_free() is called with a non-NULL pointer that 3018 ** was not obtained from sqlite3_malloc() or sqlite3_realloc(). 3019 ** 3020 ** ^The sqlite3_realloc(X,N) interface attempts to resize a 3021 ** prior memory allocation X to be at least N bytes. 3022 ** ^If the X parameter to sqlite3_realloc(X,N) 3023 ** is a NULL pointer then its behavior is identical to calling 3024 ** sqlite3_malloc(N). 3025 ** ^If the N parameter to sqlite3_realloc(X,N) is zero or 3026 ** negative then the behavior is exactly the same as calling 3027 ** sqlite3_free(X). 3028 ** ^sqlite3_realloc(X,N) returns a pointer to a memory allocation 3029 ** of at least N bytes in size or NULL if insufficient memory is available. 3030 ** ^If M is the size of the prior allocation, then min(N,M) bytes 3031 ** of the prior allocation are copied into the beginning of buffer returned 3032 ** by sqlite3_realloc(X,N) and the prior allocation is freed. 3033 ** ^If sqlite3_realloc(X,N) returns NULL and N is positive, then the 3034 ** prior allocation is not freed. 3035 ** 3036 ** ^The sqlite3_realloc64(X,N) interfaces works the same as 3037 ** sqlite3_realloc(X,N) except that N is a 64-bit unsigned integer instead 3038 ** of a 32-bit signed integer. 3039 ** 3040 ** ^If X is a memory allocation previously obtained from sqlite3_malloc(), 3041 ** sqlite3_malloc64(), sqlite3_realloc(), or sqlite3_realloc64(), then 3042 ** sqlite3_msize(X) returns the size of that memory allocation in bytes. 3043 ** ^The value returned by sqlite3_msize(X) might be larger than the number 3044 ** of bytes requested when X was allocated. ^If X is a NULL pointer then 3045 ** sqlite3_msize(X) returns zero. If X points to something that is not 3046 ** the beginning of memory allocation, or if it points to a formerly 3047 ** valid memory allocation that has now been freed, then the behavior 3048 ** of sqlite3_msize(X) is undefined and possibly harmful. 3049 ** 3050 ** ^The memory returned by sqlite3_malloc(), sqlite3_realloc(), 3051 ** sqlite3_malloc64(), and sqlite3_realloc64() 3052 ** is always aligned to at least an 8 byte boundary, or to a 3053 ** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time 3054 ** option is used. 3055 ** 3056 ** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()] 3057 ** must be either NULL or else pointers obtained from a prior 3058 ** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have 3059 ** not yet been released. 3060 ** 3061 ** The application must not read or write any part of 3062 ** a block of memory after it has been released using 3063 ** [sqlite3_free()] or [sqlite3_realloc()]. 3064 */ 3065 SQLITE_API void *sqlite3_malloc(int); 3066 SQLITE_API void *sqlite3_malloc64(sqlite3_uint64); 3067 SQLITE_API void *sqlite3_realloc(void*, int); 3068 SQLITE_API void *sqlite3_realloc64(void*, sqlite3_uint64); 3069 SQLITE_API void sqlite3_free(void*); 3070 SQLITE_API sqlite3_uint64 sqlite3_msize(void*); 3071 3072 /* 3073 ** CAPI3REF: Memory Allocator Statistics 3074 ** 3075 ** SQLite provides these two interfaces for reporting on the status 3076 ** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()] 3077 ** routines, which form the built-in memory allocation subsystem. 3078 ** 3079 ** ^The [sqlite3_memory_used()] routine returns the number of bytes 3080 ** of memory currently outstanding (malloced but not freed). 3081 ** ^The [sqlite3_memory_highwater()] routine returns the maximum 3082 ** value of [sqlite3_memory_used()] since the high-water mark 3083 ** was last reset. ^The values returned by [sqlite3_memory_used()] and 3084 ** [sqlite3_memory_highwater()] include any overhead 3085 ** added by SQLite in its implementation of [sqlite3_malloc()], 3086 ** but not overhead added by the any underlying system library 3087 ** routines that [sqlite3_malloc()] may call. 3088 ** 3089 ** ^The memory high-water mark is reset to the current value of 3090 ** [sqlite3_memory_used()] if and only if the parameter to 3091 ** [sqlite3_memory_highwater()] is true. ^The value returned 3092 ** by [sqlite3_memory_highwater(1)] is the high-water mark 3093 ** prior to the reset. 3094 */ 3095 SQLITE_API sqlite3_int64 sqlite3_memory_used(void); 3096 SQLITE_API sqlite3_int64 sqlite3_memory_highwater(int resetFlag); 3097 3098 /* 3099 ** CAPI3REF: Pseudo-Random Number Generator 3100 ** 3101 ** SQLite contains a high-quality pseudo-random number generator (PRNG) used to 3102 ** select random [ROWID | ROWIDs] when inserting new records into a table that 3103 ** already uses the largest possible [ROWID]. The PRNG is also used for 3104 ** the built-in random() and randomblob() SQL functions. This interface allows 3105 ** applications to access the same PRNG for other purposes. 3106 ** 3107 ** ^A call to this routine stores N bytes of randomness into buffer P. 3108 ** ^The P parameter can be a NULL pointer. 3109 ** 3110 ** ^If this routine has not been previously called or if the previous 3111 ** call had N less than one or a NULL pointer for P, then the PRNG is 3112 ** seeded using randomness obtained from the xRandomness method of 3113 ** the default [sqlite3_vfs] object. 3114 ** ^If the previous call to this routine had an N of 1 or more and a 3115 ** non-NULL P then the pseudo-randomness is generated 3116 ** internally and without recourse to the [sqlite3_vfs] xRandomness 3117 ** method. 3118 */ 3119 SQLITE_API void sqlite3_randomness(int N, void *P); 3120 3121 /* 3122 ** CAPI3REF: Compile-Time Authorization Callbacks 3123 ** METHOD: sqlite3 3124 ** KEYWORDS: {authorizer callback} 3125 ** 3126 ** ^This routine registers an authorizer callback with a particular 3127 ** [database connection], supplied in the first argument. 3128 ** ^The authorizer callback is invoked as SQL statements are being compiled 3129 ** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()], 3130 ** [sqlite3_prepare_v3()], [sqlite3_prepare16()], [sqlite3_prepare16_v2()], 3131 ** and [sqlite3_prepare16_v3()]. ^At various 3132 ** points during the compilation process, as logic is being created 3133 ** to perform various actions, the authorizer callback is invoked to 3134 ** see if those actions are allowed. ^The authorizer callback should 3135 ** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the 3136 ** specific action but allow the SQL statement to continue to be 3137 ** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be 3138 ** rejected with an error. ^If the authorizer callback returns 3139 ** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY] 3140 ** then the [sqlite3_prepare_v2()] or equivalent call that triggered 3141 ** the authorizer will fail with an error message. 3142 ** 3143 ** When the callback returns [SQLITE_OK], that means the operation 3144 ** requested is ok. ^When the callback returns [SQLITE_DENY], the 3145 ** [sqlite3_prepare_v2()] or equivalent call that triggered the 3146 ** authorizer will fail with an error message explaining that 3147 ** access is denied. 3148 ** 3149 ** ^The first parameter to the authorizer callback is a copy of the third 3150 ** parameter to the sqlite3_set_authorizer() interface. ^The second parameter 3151 ** to the callback is an integer [SQLITE_COPY | action code] that specifies 3152 ** the particular action to be authorized. ^The third through sixth parameters 3153 ** to the callback are either NULL pointers or zero-terminated strings 3154 ** that contain additional details about the action to be authorized. 3155 ** Applications must always be prepared to encounter a NULL pointer in any 3156 ** of the third through the sixth parameters of the authorization callback. 3157 ** 3158 ** ^If the action code is [SQLITE_READ] 3159 ** and the callback returns [SQLITE_IGNORE] then the 3160 ** [prepared statement] statement is constructed to substitute 3161 ** a NULL value in place of the table column that would have 3162 ** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE] 3163 ** return can be used to deny an untrusted user access to individual 3164 ** columns of a table. 3165 ** ^When a table is referenced by a [SELECT] but no column values are 3166 ** extracted from that table (for example in a query like 3167 ** "SELECT count(*) FROM tab") then the [SQLITE_READ] authorizer callback 3168 ** is invoked once for that table with a column name that is an empty string. 3169 ** ^If the action code is [SQLITE_DELETE] and the callback returns 3170 ** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the 3171 ** [truncate optimization] is disabled and all rows are deleted individually. 3172 ** 3173 ** An authorizer is used when [sqlite3_prepare | preparing] 3174 ** SQL statements from an untrusted source, to ensure that the SQL statements 3175 ** do not try to access data they are not allowed to see, or that they do not 3176 ** try to execute malicious statements that damage the database. For 3177 ** example, an application may allow a user to enter arbitrary 3178 ** SQL queries for evaluation by a database. But the application does 3179 ** not want the user to be able to make arbitrary changes to the 3180 ** database. An authorizer could then be put in place while the 3181 ** user-entered SQL is being [sqlite3_prepare | prepared] that 3182 ** disallows everything except [SELECT] statements. 3183 ** 3184 ** Applications that need to process SQL from untrusted sources 3185 ** might also consider lowering resource limits using [sqlite3_limit()] 3186 ** and limiting database size using the [max_page_count] [PRAGMA] 3187 ** in addition to using an authorizer. 3188 ** 3189 ** ^(Only a single authorizer can be in place on a database connection 3190 ** at a time. Each call to sqlite3_set_authorizer overrides the 3191 ** previous call.)^ ^Disable the authorizer by installing a NULL callback. 3192 ** The authorizer is disabled by default. 3193 ** 3194 ** The authorizer callback must not do anything that will modify 3195 ** the database connection that invoked the authorizer callback. 3196 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 3197 ** database connections for the meaning of "modify" in this paragraph. 3198 ** 3199 ** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the 3200 ** statement might be re-prepared during [sqlite3_step()] due to a 3201 ** schema change. Hence, the application should ensure that the 3202 ** correct authorizer callback remains in place during the [sqlite3_step()]. 3203 ** 3204 ** ^Note that the authorizer callback is invoked only during 3205 ** [sqlite3_prepare()] or its variants. Authorization is not 3206 ** performed during statement evaluation in [sqlite3_step()], unless 3207 ** as stated in the previous paragraph, sqlite3_step() invokes 3208 ** sqlite3_prepare_v2() to reprepare a statement after a schema change. 3209 */ 3210 SQLITE_API int sqlite3_set_authorizer( 3211 sqlite3*, 3212 int (*xAuth)(void*,int,const char*,const char*,const char*,const char*), 3213 void *pUserData 3214 ); 3215 3216 /* 3217 ** CAPI3REF: Authorizer Return Codes 3218 ** 3219 ** The [sqlite3_set_authorizer | authorizer callback function] must 3220 ** return either [SQLITE_OK] or one of these two constants in order 3221 ** to signal SQLite whether or not the action is permitted. See the 3222 ** [sqlite3_set_authorizer | authorizer documentation] for additional 3223 ** information. 3224 ** 3225 ** Note that SQLITE_IGNORE is also used as a [conflict resolution mode] 3226 ** returned from the [sqlite3_vtab_on_conflict()] interface. 3227 */ 3228 #define SQLITE_DENY 1 /* Abort the SQL statement with an error */ 3229 #define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */ 3230 3231 /* 3232 ** CAPI3REF: Authorizer Action Codes 3233 ** 3234 ** The [sqlite3_set_authorizer()] interface registers a callback function 3235 ** that is invoked to authorize certain SQL statement actions. The 3236 ** second parameter to the callback is an integer code that specifies 3237 ** what action is being authorized. These are the integer action codes that 3238 ** the authorizer callback may be passed. 3239 ** 3240 ** These action code values signify what kind of operation is to be 3241 ** authorized. The 3rd and 4th parameters to the authorization 3242 ** callback function will be parameters or NULL depending on which of these 3243 ** codes is used as the second parameter. ^(The 5th parameter to the 3244 ** authorizer callback is the name of the database ("main", "temp", 3245 ** etc.) if applicable.)^ ^The 6th parameter to the authorizer callback 3246 ** is the name of the inner-most trigger or view that is responsible for 3247 ** the access attempt or NULL if this access attempt is directly from 3248 ** top-level SQL code. 3249 */ 3250 /******************************************* 3rd ************ 4th ***********/ 3251 #define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */ 3252 #define SQLITE_CREATE_TABLE 2 /* Table Name NULL */ 3253 #define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */ 3254 #define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */ 3255 #define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */ 3256 #define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */ 3257 #define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */ 3258 #define SQLITE_CREATE_VIEW 8 /* View Name NULL */ 3259 #define SQLITE_DELETE 9 /* Table Name NULL */ 3260 #define SQLITE_DROP_INDEX 10 /* Index Name Table Name */ 3261 #define SQLITE_DROP_TABLE 11 /* Table Name NULL */ 3262 #define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */ 3263 #define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */ 3264 #define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */ 3265 #define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */ 3266 #define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */ 3267 #define SQLITE_DROP_VIEW 17 /* View Name NULL */ 3268 #define SQLITE_INSERT 18 /* Table Name NULL */ 3269 #define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */ 3270 #define SQLITE_READ 20 /* Table Name Column Name */ 3271 #define SQLITE_SELECT 21 /* NULL NULL */ 3272 #define SQLITE_TRANSACTION 22 /* Operation NULL */ 3273 #define SQLITE_UPDATE 23 /* Table Name Column Name */ 3274 #define SQLITE_ATTACH 24 /* Filename NULL */ 3275 #define SQLITE_DETACH 25 /* Database Name NULL */ 3276 #define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */ 3277 #define SQLITE_REINDEX 27 /* Index Name NULL */ 3278 #define SQLITE_ANALYZE 28 /* Table Name NULL */ 3279 #define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */ 3280 #define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */ 3281 #define SQLITE_FUNCTION 31 /* NULL Function Name */ 3282 #define SQLITE_SAVEPOINT 32 /* Operation Savepoint Name */ 3283 #define SQLITE_COPY 0 /* No longer used */ 3284 #define SQLITE_RECURSIVE 33 /* NULL NULL */ 3285 3286 /* 3287 ** CAPI3REF: Tracing And Profiling Functions 3288 ** METHOD: sqlite3 3289 ** 3290 ** These routines are deprecated. Use the [sqlite3_trace_v2()] interface 3291 ** instead of the routines described here. 3292 ** 3293 ** These routines register callback functions that can be used for 3294 ** tracing and profiling the execution of SQL statements. 3295 ** 3296 ** ^The callback function registered by sqlite3_trace() is invoked at 3297 ** various times when an SQL statement is being run by [sqlite3_step()]. 3298 ** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the 3299 ** SQL statement text as the statement first begins executing. 3300 ** ^(Additional sqlite3_trace() callbacks might occur 3301 ** as each triggered subprogram is entered. The callbacks for triggers 3302 ** contain a UTF-8 SQL comment that identifies the trigger.)^ 3303 ** 3304 ** The [SQLITE_TRACE_SIZE_LIMIT] compile-time option can be used to limit 3305 ** the length of [bound parameter] expansion in the output of sqlite3_trace(). 3306 ** 3307 ** ^The callback function registered by sqlite3_profile() is invoked 3308 ** as each SQL statement finishes. ^The profile callback contains 3309 ** the original statement text and an estimate of wall-clock time 3310 ** of how long that statement took to run. ^The profile callback 3311 ** time is in units of nanoseconds, however the current implementation 3312 ** is only capable of millisecond resolution so the six least significant 3313 ** digits in the time are meaningless. Future versions of SQLite 3314 ** might provide greater resolution on the profiler callback. Invoking 3315 ** either [sqlite3_trace()] or [sqlite3_trace_v2()] will cancel the 3316 ** profile callback. 3317 */ 3318 SQLITE_API SQLITE_DEPRECATED void *sqlite3_trace(sqlite3*, 3319 void(*xTrace)(void*,const char*), void*); 3320 SQLITE_API SQLITE_DEPRECATED void *sqlite3_profile(sqlite3*, 3321 void(*xProfile)(void*,const char*,sqlite3_uint64), void*); 3322 3323 /* 3324 ** CAPI3REF: SQL Trace Event Codes 3325 ** KEYWORDS: SQLITE_TRACE 3326 ** 3327 ** These constants identify classes of events that can be monitored 3328 ** using the [sqlite3_trace_v2()] tracing logic. The M argument 3329 ** to [sqlite3_trace_v2(D,M,X,P)] is an OR-ed combination of one or more of 3330 ** the following constants. ^The first argument to the trace callback 3331 ** is one of the following constants. 3332 ** 3333 ** New tracing constants may be added in future releases. 3334 ** 3335 ** ^A trace callback has four arguments: xCallback(T,C,P,X). 3336 ** ^The T argument is one of the integer type codes above. 3337 ** ^The C argument is a copy of the context pointer passed in as the 3338 ** fourth argument to [sqlite3_trace_v2()]. 3339 ** The P and X arguments are pointers whose meanings depend on T. 3340 ** 3341 ** <dl> 3342 ** [[SQLITE_TRACE_STMT]] <dt>SQLITE_TRACE_STMT</dt> 3343 ** <dd>^An SQLITE_TRACE_STMT callback is invoked when a prepared statement 3344 ** first begins running and possibly at other times during the 3345 ** execution of the prepared statement, such as at the start of each 3346 ** trigger subprogram. ^The P argument is a pointer to the 3347 ** [prepared statement]. ^The X argument is a pointer to a string which 3348 ** is the unexpanded SQL text of the prepared statement or an SQL comment 3349 ** that indicates the invocation of a trigger. ^The callback can compute 3350 ** the same text that would have been returned by the legacy [sqlite3_trace()] 3351 ** interface by using the X argument when X begins with "--" and invoking 3352 ** [sqlite3_expanded_sql(P)] otherwise. 3353 ** 3354 ** [[SQLITE_TRACE_PROFILE]] <dt>SQLITE_TRACE_PROFILE</dt> 3355 ** <dd>^An SQLITE_TRACE_PROFILE callback provides approximately the same 3356 ** information as is provided by the [sqlite3_profile()] callback. 3357 ** ^The P argument is a pointer to the [prepared statement] and the 3358 ** X argument points to a 64-bit integer which is approximately 3359 ** the number of nanoseconds that the prepared statement took to run. 3360 ** ^The SQLITE_TRACE_PROFILE callback is invoked when the statement finishes. 3361 ** 3362 ** [[SQLITE_TRACE_ROW]] <dt>SQLITE_TRACE_ROW</dt> 3363 ** <dd>^An SQLITE_TRACE_ROW callback is invoked whenever a prepared 3364 ** statement generates a single row of result. 3365 ** ^The P argument is a pointer to the [prepared statement] and the 3366 ** X argument is unused. 3367 ** 3368 ** [[SQLITE_TRACE_CLOSE]] <dt>SQLITE_TRACE_CLOSE</dt> 3369 ** <dd>^An SQLITE_TRACE_CLOSE callback is invoked when a database 3370 ** connection closes. 3371 ** ^The P argument is a pointer to the [database connection] object 3372 ** and the X argument is unused. 3373 ** </dl> 3374 */ 3375 #define SQLITE_TRACE_STMT 0x01 3376 #define SQLITE_TRACE_PROFILE 0x02 3377 #define SQLITE_TRACE_ROW 0x04 3378 #define SQLITE_TRACE_CLOSE 0x08 3379 3380 /* 3381 ** CAPI3REF: SQL Trace Hook 3382 ** METHOD: sqlite3 3383 ** 3384 ** ^The sqlite3_trace_v2(D,M,X,P) interface registers a trace callback 3385 ** function X against [database connection] D, using property mask M 3386 ** and context pointer P. ^If the X callback is 3387 ** NULL or if the M mask is zero, then tracing is disabled. The 3388 ** M argument should be the bitwise OR-ed combination of 3389 ** zero or more [SQLITE_TRACE] constants. 3390 ** 3391 ** ^Each call to either sqlite3_trace() or sqlite3_trace_v2() overrides 3392 ** (cancels) any prior calls to sqlite3_trace() or sqlite3_trace_v2(). 3393 ** 3394 ** ^The X callback is invoked whenever any of the events identified by 3395 ** mask M occur. ^The integer return value from the callback is currently 3396 ** ignored, though this may change in future releases. Callback 3397 ** implementations should return zero to ensure future compatibility. 3398 ** 3399 ** ^A trace callback is invoked with four arguments: callback(T,C,P,X). 3400 ** ^The T argument is one of the [SQLITE_TRACE] 3401 ** constants to indicate why the callback was invoked. 3402 ** ^The C argument is a copy of the context pointer. 3403 ** The P and X arguments are pointers whose meanings depend on T. 3404 ** 3405 ** The sqlite3_trace_v2() interface is intended to replace the legacy 3406 ** interfaces [sqlite3_trace()] and [sqlite3_profile()], both of which 3407 ** are deprecated. 3408 */ 3409 SQLITE_API int sqlite3_trace_v2( 3410 sqlite3*, 3411 unsigned uMask, 3412 int(*xCallback)(unsigned,void*,void*,void*), 3413 void *pCtx 3414 ); 3415 3416 /* 3417 ** CAPI3REF: Query Progress Callbacks 3418 ** METHOD: sqlite3 3419 ** 3420 ** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback 3421 ** function X to be invoked periodically during long running calls to 3422 ** [sqlite3_step()] and [sqlite3_prepare()] and similar for 3423 ** database connection D. An example use for this 3424 ** interface is to keep a GUI updated during a large query. 3425 ** 3426 ** ^The parameter P is passed through as the only parameter to the 3427 ** callback function X. ^The parameter N is the approximate number of 3428 ** [virtual machine instructions] that are evaluated between successive 3429 ** invocations of the callback X. ^If N is less than one then the progress 3430 ** handler is disabled. 3431 ** 3432 ** ^Only a single progress handler may be defined at one time per 3433 ** [database connection]; setting a new progress handler cancels the 3434 ** old one. ^Setting parameter X to NULL disables the progress handler. 3435 ** ^The progress handler is also disabled by setting N to a value less 3436 ** than 1. 3437 ** 3438 ** ^If the progress callback returns non-zero, the operation is 3439 ** interrupted. This feature can be used to implement a 3440 ** "Cancel" button on a GUI progress dialog box. 3441 ** 3442 ** The progress handler callback must not do anything that will modify 3443 ** the database connection that invoked the progress handler. 3444 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 3445 ** database connections for the meaning of "modify" in this paragraph. 3446 ** 3447 ** The progress handler callback would originally only be invoked from the 3448 ** bytecode engine. It still might be invoked during [sqlite3_prepare()] 3449 ** and similar because those routines might force a reparse of the schema 3450 ** which involves running the bytecode engine. However, beginning with 3451 ** SQLite version 3.41.0, the progress handler callback might also be 3452 ** invoked directly from [sqlite3_prepare()] while analyzing and generating 3453 ** code for complex queries. 3454 */ 3455 SQLITE_API void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*); 3456 3457 /* 3458 ** CAPI3REF: Opening A New Database Connection 3459 ** CONSTRUCTOR: sqlite3 3460 ** 3461 ** ^These routines open an SQLite database file as specified by the 3462 ** filename argument. ^The filename argument is interpreted as UTF-8 for 3463 ** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte 3464 ** order for sqlite3_open16(). ^(A [database connection] handle is usually 3465 ** returned in *ppDb, even if an error occurs. The only exception is that 3466 ** if SQLite is unable to allocate memory to hold the [sqlite3] object, 3467 ** a NULL will be written into *ppDb instead of a pointer to the [sqlite3] 3468 ** object.)^ ^(If the database is opened (and/or created) successfully, then 3469 ** [SQLITE_OK] is returned. Otherwise an [error code] is returned.)^ ^The 3470 ** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain 3471 ** an English language description of the error following a failure of any 3472 ** of the sqlite3_open() routines. 3473 ** 3474 ** ^The default encoding will be UTF-8 for databases created using 3475 ** sqlite3_open() or sqlite3_open_v2(). ^The default encoding for databases 3476 ** created using sqlite3_open16() will be UTF-16 in the native byte order. 3477 ** 3478 ** Whether or not an error occurs when it is opened, resources 3479 ** associated with the [database connection] handle should be released by 3480 ** passing it to [sqlite3_close()] when it is no longer required. 3481 ** 3482 ** The sqlite3_open_v2() interface works like sqlite3_open() 3483 ** except that it accepts two additional parameters for additional control 3484 ** over the new database connection. ^(The flags parameter to 3485 ** sqlite3_open_v2() must include, at a minimum, one of the following 3486 ** three flag combinations:)^ 3487 ** 3488 ** <dl> 3489 ** ^(<dt>[SQLITE_OPEN_READONLY]</dt> 3490 ** <dd>The database is opened in read-only mode. If the database does 3491 ** not already exist, an error is returned.</dd>)^ 3492 ** 3493 ** ^(<dt>[SQLITE_OPEN_READWRITE]</dt> 3494 ** <dd>The database is opened for reading and writing if possible, or 3495 ** reading only if the file is write protected by the operating 3496 ** system. In either case the database must already exist, otherwise 3497 ** an error is returned. For historical reasons, if opening in 3498 ** read-write mode fails due to OS-level permissions, an attempt is 3499 ** made to open it in read-only mode. [sqlite3_db_readonly()] can be 3500 ** used to determine whether the database is actually 3501 ** read-write.</dd>)^ 3502 ** 3503 ** ^(<dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt> 3504 ** <dd>The database is opened for reading and writing, and is created if 3505 ** it does not already exist. This is the behavior that is always used for 3506 ** sqlite3_open() and sqlite3_open16().</dd>)^ 3507 ** </dl> 3508 ** 3509 ** In addition to the required flags, the following optional flags are 3510 ** also supported: 3511 ** 3512 ** <dl> 3513 ** ^(<dt>[SQLITE_OPEN_URI]</dt> 3514 ** <dd>The filename can be interpreted as a URI if this flag is set.</dd>)^ 3515 ** 3516 ** ^(<dt>[SQLITE_OPEN_MEMORY]</dt> 3517 ** <dd>The database will be opened as an in-memory database. The database 3518 ** is named by the "filename" argument for the purposes of cache-sharing, 3519 ** if shared cache mode is enabled, but the "filename" is otherwise ignored. 3520 ** </dd>)^ 3521 ** 3522 ** ^(<dt>[SQLITE_OPEN_NOMUTEX]</dt> 3523 ** <dd>The new database connection will use the "multi-thread" 3524 ** [threading mode].)^ This means that separate threads are allowed 3525 ** to use SQLite at the same time, as long as each thread is using 3526 ** a different [database connection]. 3527 ** 3528 ** ^(<dt>[SQLITE_OPEN_FULLMUTEX]</dt> 3529 ** <dd>The new database connection will use the "serialized" 3530 ** [threading mode].)^ This means the multiple threads can safely 3531 ** attempt to use the same database connection at the same time. 3532 ** (Mutexes will block any actual concurrency, but in this mode 3533 ** there is no harm in trying.) 3534 ** 3535 ** ^(<dt>[SQLITE_OPEN_SHAREDCACHE]</dt> 3536 ** <dd>The database is opened [shared cache] enabled, overriding 3537 ** the default shared cache setting provided by 3538 ** [sqlite3_enable_shared_cache()].)^ 3539 ** The [use of shared cache mode is discouraged] and hence shared cache 3540 ** capabilities may be omitted from many builds of SQLite. In such cases, 3541 ** this option is a no-op. 3542 ** 3543 ** ^(<dt>[SQLITE_OPEN_PRIVATECACHE]</dt> 3544 ** <dd>The database is opened [shared cache] disabled, overriding 3545 ** the default shared cache setting provided by 3546 ** [sqlite3_enable_shared_cache()].)^ 3547 ** 3548 ** [[OPEN_EXRESCODE]] ^(<dt>[SQLITE_OPEN_EXRESCODE]</dt> 3549 ** <dd>The database connection comes up in "extended result code mode". 3550 ** In other words, the database behaves has if 3551 ** [sqlite3_extended_result_codes(db,1)] where called on the database 3552 ** connection as soon as the connection is created. In addition to setting 3553 ** the extended result code mode, this flag also causes [sqlite3_open_v2()] 3554 ** to return an extended result code.</dd> 3555 ** 3556 ** [[OPEN_NOFOLLOW]] ^(<dt>[SQLITE_OPEN_NOFOLLOW]</dt> 3557 ** <dd>The database filename is not allowed to contain a symbolic link</dd> 3558 ** </dl>)^ 3559 ** 3560 ** If the 3rd parameter to sqlite3_open_v2() is not one of the 3561 ** required combinations shown above optionally combined with other 3562 ** [SQLITE_OPEN_READONLY | SQLITE_OPEN_* bits] 3563 ** then the behavior is undefined. Historic versions of SQLite 3564 ** have silently ignored surplus bits in the flags parameter to 3565 ** sqlite3_open_v2(), however that behavior might not be carried through 3566 ** into future versions of SQLite and so applications should not rely 3567 ** upon it. Note in particular that the SQLITE_OPEN_EXCLUSIVE flag is a no-op 3568 ** for sqlite3_open_v2(). The SQLITE_OPEN_EXCLUSIVE does *not* cause 3569 ** the open to fail if the database already exists. The SQLITE_OPEN_EXCLUSIVE 3570 ** flag is intended for use by the [sqlite3_vfs|VFS interface] only, and not 3571 ** by sqlite3_open_v2(). 3572 ** 3573 ** ^The fourth parameter to sqlite3_open_v2() is the name of the 3574 ** [sqlite3_vfs] object that defines the operating system interface that 3575 ** the new database connection should use. ^If the fourth parameter is 3576 ** a NULL pointer then the default [sqlite3_vfs] object is used. 3577 ** 3578 ** ^If the filename is ":memory:", then a private, temporary in-memory database 3579 ** is created for the connection. ^This in-memory database will vanish when 3580 ** the database connection is closed. Future versions of SQLite might 3581 ** make use of additional special filenames that begin with the ":" character. 3582 ** It is recommended that when a database filename actually does begin with 3583 ** a ":" character you should prefix the filename with a pathname such as 3584 ** "./" to avoid ambiguity. 3585 ** 3586 ** ^If the filename is an empty string, then a private, temporary 3587 ** on-disk database will be created. ^This private database will be 3588 ** automatically deleted as soon as the database connection is closed. 3589 ** 3590 ** [[URI filenames in sqlite3_open()]] <h3>URI Filenames</h3> 3591 ** 3592 ** ^If [URI filename] interpretation is enabled, and the filename argument 3593 ** begins with "file:", then the filename is interpreted as a URI. ^URI 3594 ** filename interpretation is enabled if the [SQLITE_OPEN_URI] flag is 3595 ** set in the third argument to sqlite3_open_v2(), or if it has 3596 ** been enabled globally using the [SQLITE_CONFIG_URI] option with the 3597 ** [sqlite3_config()] method or by the [SQLITE_USE_URI] compile-time option. 3598 ** URI filename interpretation is turned off 3599 ** by default, but future releases of SQLite might enable URI filename 3600 ** interpretation by default. See "[URI filenames]" for additional 3601 ** information. 3602 ** 3603 ** URI filenames are parsed according to RFC 3986. ^If the URI contains an 3604 ** authority, then it must be either an empty string or the string 3605 ** "localhost". ^If the authority is not an empty string or "localhost", an 3606 ** error is returned to the caller. ^The fragment component of a URI, if 3607 ** present, is ignored. 3608 ** 3609 ** ^SQLite uses the path component of the URI as the name of the disk file 3610 ** which contains the database. ^If the path begins with a '/' character, 3611 ** then it is interpreted as an absolute path. ^If the path does not begin 3612 ** with a '/' (meaning that the authority section is omitted from the URI) 3613 ** then the path is interpreted as a relative path. 3614 ** ^(On windows, the first component of an absolute path 3615 ** is a drive specification (e.g. "C:").)^ 3616 ** 3617 ** [[core URI query parameters]] 3618 ** The query component of a URI may contain parameters that are interpreted 3619 ** either by SQLite itself, or by a [VFS | custom VFS implementation]. 3620 ** SQLite and its built-in [VFSes] interpret the 3621 ** following query parameters: 3622 ** 3623 ** <ul> 3624 ** <li> <b>vfs</b>: ^The "vfs" parameter may be used to specify the name of 3625 ** a VFS object that provides the operating system interface that should 3626 ** be used to access the database file on disk. ^If this option is set to 3627 ** an empty string the default VFS object is used. ^Specifying an unknown 3628 ** VFS is an error. ^If sqlite3_open_v2() is used and the vfs option is 3629 ** present, then the VFS specified by the option takes precedence over 3630 ** the value passed as the fourth parameter to sqlite3_open_v2(). 3631 ** 3632 ** <li> <b>mode</b>: ^(The mode parameter may be set to either "ro", "rw", 3633 ** "rwc", or "memory". Attempting to set it to any other value is 3634 ** an error)^. 3635 ** ^If "ro" is specified, then the database is opened for read-only 3636 ** access, just as if the [SQLITE_OPEN_READONLY] flag had been set in the 3637 ** third argument to sqlite3_open_v2(). ^If the mode option is set to 3638 ** "rw", then the database is opened for read-write (but not create) 3639 ** access, as if SQLITE_OPEN_READWRITE (but not SQLITE_OPEN_CREATE) had 3640 ** been set. ^Value "rwc" is equivalent to setting both 3641 ** SQLITE_OPEN_READWRITE and SQLITE_OPEN_CREATE. ^If the mode option is 3642 ** set to "memory" then a pure [in-memory database] that never reads 3643 ** or writes from disk is used. ^It is an error to specify a value for 3644 ** the mode parameter that is less restrictive than that specified by 3645 ** the flags passed in the third parameter to sqlite3_open_v2(). 3646 ** 3647 ** <li> <b>cache</b>: ^The cache parameter may be set to either "shared" or 3648 ** "private". ^Setting it to "shared" is equivalent to setting the 3649 ** SQLITE_OPEN_SHAREDCACHE bit in the flags argument passed to 3650 ** sqlite3_open_v2(). ^Setting the cache parameter to "private" is 3651 ** equivalent to setting the SQLITE_OPEN_PRIVATECACHE bit. 3652 ** ^If sqlite3_open_v2() is used and the "cache" parameter is present in 3653 ** a URI filename, its value overrides any behavior requested by setting 3654 ** SQLITE_OPEN_PRIVATECACHE or SQLITE_OPEN_SHAREDCACHE flag. 3655 ** 3656 ** <li> <b>psow</b>: ^The psow parameter indicates whether or not the 3657 ** [powersafe overwrite] property does or does not apply to the 3658 ** storage media on which the database file resides. 3659 ** 3660 ** <li> <b>nolock</b>: ^The nolock parameter is a boolean query parameter 3661 ** which if set disables file locking in rollback journal modes. This 3662 ** is useful for accessing a database on a filesystem that does not 3663 ** support locking. Caution: Database corruption might result if two 3664 ** or more processes write to the same database and any one of those 3665 ** processes uses nolock=1. 3666 ** 3667 ** <li> <b>immutable</b>: ^The immutable parameter is a boolean query 3668 ** parameter that indicates that the database file is stored on 3669 ** read-only media. ^When immutable is set, SQLite assumes that the 3670 ** database file cannot be changed, even by a process with higher 3671 ** privilege, and so the database is opened read-only and all locking 3672 ** and change detection is disabled. Caution: Setting the immutable 3673 ** property on a database file that does in fact change can result 3674 ** in incorrect query results and/or [SQLITE_CORRUPT] errors. 3675 ** See also: [SQLITE_IOCAP_IMMUTABLE]. 3676 ** 3677 ** </ul> 3678 ** 3679 ** ^Specifying an unknown parameter in the query component of a URI is not an 3680 ** error. Future versions of SQLite might understand additional query 3681 ** parameters. See "[query parameters with special meaning to SQLite]" for 3682 ** additional information. 3683 ** 3684 ** [[URI filename examples]] <h3>URI filename examples</h3> 3685 ** 3686 ** <table border="1" align=center cellpadding=5> 3687 ** <tr><th> URI filenames <th> Results 3688 ** <tr><td> file:data.db <td> 3689 ** Open the file "data.db" in the current directory. 3690 ** <tr><td> file:/home/fred/data.db<br> 3691 ** file:///home/fred/data.db <br> 3692 ** file://localhost/home/fred/data.db <br> <td> 3693 ** Open the database file "/home/fred/data.db". 3694 ** <tr><td> file://darkstar/home/fred/data.db <td> 3695 ** An error. "darkstar" is not a recognized authority. 3696 ** <tr><td style="white-space:nowrap"> 3697 ** file:///C:/Documents%20and%20Settings/fred/Desktop/data.db 3698 ** <td> Windows only: Open the file "data.db" on fred's desktop on drive 3699 ** C:. Note that the %20 escaping in this example is not strictly 3700 ** necessary - space characters can be used literally 3701 ** in URI filenames. 3702 ** <tr><td> file:data.db?mode=ro&cache=private <td> 3703 ** Open file "data.db" in the current directory for read-only access. 3704 ** Regardless of whether or not shared-cache mode is enabled by 3705 ** default, use a private cache. 3706 ** <tr><td> file:/home/fred/data.db?vfs=unix-dotfile <td> 3707 ** Open file "/home/fred/data.db". Use the special VFS "unix-dotfile" 3708 ** that uses dot-files in place of posix advisory locking. 3709 ** <tr><td> file:data.db?mode=readonly <td> 3710 ** An error. "readonly" is not a valid option for the "mode" parameter. 3711 ** Use "ro" instead: "file:data.db?mode=ro". 3712 ** </table> 3713 ** 3714 ** ^URI hexadecimal escape sequences (%HH) are supported within the path and 3715 ** query components of a URI. A hexadecimal escape sequence consists of a 3716 ** percent sign - "%" - followed by exactly two hexadecimal digits 3717 ** specifying an octet value. ^Before the path or query components of a 3718 ** URI filename are interpreted, they are encoded using UTF-8 and all 3719 ** hexadecimal escape sequences replaced by a single byte containing the 3720 ** corresponding octet. If this process generates an invalid UTF-8 encoding, 3721 ** the results are undefined. 3722 ** 3723 ** <b>Note to Windows users:</b> The encoding used for the filename argument 3724 ** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever 3725 ** codepage is currently defined. Filenames containing international 3726 ** characters must be converted to UTF-8 prior to passing them into 3727 ** sqlite3_open() or sqlite3_open_v2(). 3728 ** 3729 ** <b>Note to Windows Runtime users:</b> The temporary directory must be set 3730 ** prior to calling sqlite3_open() or sqlite3_open_v2(). Otherwise, various 3731 ** features that require the use of temporary files may fail. 3732 ** 3733 ** See also: [sqlite3_temp_directory] 3734 */ 3735 SQLITE_API int sqlite3_open( 3736 const char *filename, /* Database filename (UTF-8) */ 3737 sqlite3 **ppDb /* OUT: SQLite db handle */ 3738 ); 3739 SQLITE_API int sqlite3_open16( 3740 const void *filename, /* Database filename (UTF-16) */ 3741 sqlite3 **ppDb /* OUT: SQLite db handle */ 3742 ); 3743 SQLITE_API int sqlite3_open_v2( 3744 const char *filename, /* Database filename (UTF-8) */ 3745 sqlite3 **ppDb, /* OUT: SQLite db handle */ 3746 int flags, /* Flags */ 3747 const char *zVfs /* Name of VFS module to use */ 3748 ); 3749 3750 /* 3751 ** CAPI3REF: Obtain Values For URI Parameters 3752 ** 3753 ** These are utility routines, useful to [VFS|custom VFS implementations], 3754 ** that check if a database file was a URI that contained a specific query 3755 ** parameter, and if so obtains the value of that query parameter. 3756 ** 3757 ** The first parameter to these interfaces (hereafter referred to 3758 ** as F) must be one of: 3759 ** <ul> 3760 ** <li> A database filename pointer created by the SQLite core and 3761 ** passed into the xOpen() method of a VFS implemention, or 3762 ** <li> A filename obtained from [sqlite3_db_filename()], or 3763 ** <li> A new filename constructed using [sqlite3_create_filename()]. 3764 ** </ul> 3765 ** If the F parameter is not one of the above, then the behavior is 3766 ** undefined and probably undesirable. Older versions of SQLite were 3767 ** more tolerant of invalid F parameters than newer versions. 3768 ** 3769 ** If F is a suitable filename (as described in the previous paragraph) 3770 ** and if P is the name of the query parameter, then 3771 ** sqlite3_uri_parameter(F,P) returns the value of the P 3772 ** parameter if it exists or a NULL pointer if P does not appear as a 3773 ** query parameter on F. If P is a query parameter of F and it 3774 ** has no explicit value, then sqlite3_uri_parameter(F,P) returns 3775 ** a pointer to an empty string. 3776 ** 3777 ** The sqlite3_uri_boolean(F,P,B) routine assumes that P is a boolean 3778 ** parameter and returns true (1) or false (0) according to the value 3779 ** of P. The sqlite3_uri_boolean(F,P,B) routine returns true (1) if the 3780 ** value of query parameter P is one of "yes", "true", or "on" in any 3781 ** case or if the value begins with a non-zero number. The 3782 ** sqlite3_uri_boolean(F,P,B) routines returns false (0) if the value of 3783 ** query parameter P is one of "no", "false", or "off" in any case or 3784 ** if the value begins with a numeric zero. If P is not a query 3785 ** parameter on F or if the value of P does not match any of the 3786 ** above, then sqlite3_uri_boolean(F,P,B) returns (B!=0). 3787 ** 3788 ** The sqlite3_uri_int64(F,P,D) routine converts the value of P into a 3789 ** 64-bit signed integer and returns that integer, or D if P does not 3790 ** exist. If the value of P is something other than an integer, then 3791 ** zero is returned. 3792 ** 3793 ** The sqlite3_uri_key(F,N) returns a pointer to the name (not 3794 ** the value) of the N-th query parameter for filename F, or a NULL 3795 ** pointer if N is less than zero or greater than the number of query 3796 ** parameters minus 1. The N value is zero-based so N should be 0 to obtain 3797 ** the name of the first query parameter, 1 for the second parameter, and 3798 ** so forth. 3799 ** 3800 ** If F is a NULL pointer, then sqlite3_uri_parameter(F,P) returns NULL and 3801 ** sqlite3_uri_boolean(F,P,B) returns B. If F is not a NULL pointer and 3802 ** is not a database file pathname pointer that the SQLite core passed 3803 ** into the xOpen VFS method, then the behavior of this routine is undefined 3804 ** and probably undesirable. 3805 ** 3806 ** Beginning with SQLite [version 3.31.0] ([dateof:3.31.0]) the input F 3807 ** parameter can also be the name of a rollback journal file or WAL file 3808 ** in addition to the main database file. Prior to version 3.31.0, these 3809 ** routines would only work if F was the name of the main database file. 3810 ** When the F parameter is the name of the rollback journal or WAL file, 3811 ** it has access to all the same query parameters as were found on the 3812 ** main database file. 3813 ** 3814 ** See the [URI filename] documentation for additional information. 3815 */ 3816 SQLITE_API const char *sqlite3_uri_parameter(sqlite3_filename z, const char *zParam); 3817 SQLITE_API int sqlite3_uri_boolean(sqlite3_filename z, const char *zParam, int bDefault); 3818 SQLITE_API sqlite3_int64 sqlite3_uri_int64(sqlite3_filename, const char*, sqlite3_int64); 3819 SQLITE_API const char *sqlite3_uri_key(sqlite3_filename z, int N); 3820 3821 /* 3822 ** CAPI3REF: Translate filenames 3823 ** 3824 ** These routines are available to [VFS|custom VFS implementations] for 3825 ** translating filenames between the main database file, the journal file, 3826 ** and the WAL file. 3827 ** 3828 ** If F is the name of an sqlite database file, journal file, or WAL file 3829 ** passed by the SQLite core into the VFS, then sqlite3_filename_database(F) 3830 ** returns the name of the corresponding database file. 3831 ** 3832 ** If F is the name of an sqlite database file, journal file, or WAL file 3833 ** passed by the SQLite core into the VFS, or if F is a database filename 3834 ** obtained from [sqlite3_db_filename()], then sqlite3_filename_journal(F) 3835 ** returns the name of the corresponding rollback journal file. 3836 ** 3837 ** If F is the name of an sqlite database file, journal file, or WAL file 3838 ** that was passed by the SQLite core into the VFS, or if F is a database 3839 ** filename obtained from [sqlite3_db_filename()], then 3840 ** sqlite3_filename_wal(F) returns the name of the corresponding 3841 ** WAL file. 3842 ** 3843 ** In all of the above, if F is not the name of a database, journal or WAL 3844 ** filename passed into the VFS from the SQLite core and F is not the 3845 ** return value from [sqlite3_db_filename()], then the result is 3846 ** undefined and is likely a memory access violation. 3847 */ 3848 SQLITE_API const char *sqlite3_filename_database(sqlite3_filename); 3849 SQLITE_API const char *sqlite3_filename_journal(sqlite3_filename); 3850 SQLITE_API const char *sqlite3_filename_wal(sqlite3_filename); 3851 3852 /* 3853 ** CAPI3REF: Database File Corresponding To A Journal 3854 ** 3855 ** ^If X is the name of a rollback or WAL-mode journal file that is 3856 ** passed into the xOpen method of [sqlite3_vfs], then 3857 ** sqlite3_database_file_object(X) returns a pointer to the [sqlite3_file] 3858 ** object that represents the main database file. 3859 ** 3860 ** This routine is intended for use in custom [VFS] implementations 3861 ** only. It is not a general-purpose interface. 3862 ** The argument sqlite3_file_object(X) must be a filename pointer that 3863 ** has been passed into [sqlite3_vfs].xOpen method where the 3864 ** flags parameter to xOpen contains one of the bits 3865 ** [SQLITE_OPEN_MAIN_JOURNAL] or [SQLITE_OPEN_WAL]. Any other use 3866 ** of this routine results in undefined and probably undesirable 3867 ** behavior. 3868 */ 3869 SQLITE_API sqlite3_file *sqlite3_database_file_object(const char*); 3870 3871 /* 3872 ** CAPI3REF: Create and Destroy VFS Filenames 3873 ** 3874 ** These interfces are provided for use by [VFS shim] implementations and 3875 ** are not useful outside of that context. 3876 ** 3877 ** The sqlite3_create_filename(D,J,W,N,P) allocates memory to hold a version of 3878 ** database filename D with corresponding journal file J and WAL file W and 3879 ** with N URI parameters key/values pairs in the array P. The result from 3880 ** sqlite3_create_filename(D,J,W,N,P) is a pointer to a database filename that 3881 ** is safe to pass to routines like: 3882 ** <ul> 3883 ** <li> [sqlite3_uri_parameter()], 3884 ** <li> [sqlite3_uri_boolean()], 3885 ** <li> [sqlite3_uri_int64()], 3886 ** <li> [sqlite3_uri_key()], 3887 ** <li> [sqlite3_filename_database()], 3888 ** <li> [sqlite3_filename_journal()], or 3889 ** <li> [sqlite3_filename_wal()]. 3890 ** </ul> 3891 ** If a memory allocation error occurs, sqlite3_create_filename() might 3892 ** return a NULL pointer. The memory obtained from sqlite3_create_filename(X) 3893 ** must be released by a corresponding call to sqlite3_free_filename(Y). 3894 ** 3895 ** The P parameter in sqlite3_create_filename(D,J,W,N,P) should be an array 3896 ** of 2*N pointers to strings. Each pair of pointers in this array corresponds 3897 ** to a key and value for a query parameter. The P parameter may be a NULL 3898 ** pointer if N is zero. None of the 2*N pointers in the P array may be 3899 ** NULL pointers and key pointers should not be empty strings. 3900 ** None of the D, J, or W parameters to sqlite3_create_filename(D,J,W,N,P) may 3901 ** be NULL pointers, though they can be empty strings. 3902 ** 3903 ** The sqlite3_free_filename(Y) routine releases a memory allocation 3904 ** previously obtained from sqlite3_create_filename(). Invoking 3905 ** sqlite3_free_filename(Y) where Y is a NULL pointer is a harmless no-op. 3906 ** 3907 ** If the Y parameter to sqlite3_free_filename(Y) is anything other 3908 ** than a NULL pointer or a pointer previously acquired from 3909 ** sqlite3_create_filename(), then bad things such as heap 3910 ** corruption or segfaults may occur. The value Y should not be 3911 ** used again after sqlite3_free_filename(Y) has been called. This means 3912 ** that if the [sqlite3_vfs.xOpen()] method of a VFS has been called using Y, 3913 ** then the corresponding [sqlite3_module.xClose() method should also be 3914 ** invoked prior to calling sqlite3_free_filename(Y). 3915 */ 3916 SQLITE_API sqlite3_filename sqlite3_create_filename( 3917 const char *zDatabase, 3918 const char *zJournal, 3919 const char *zWal, 3920 int nParam, 3921 const char **azParam 3922 ); 3923 SQLITE_API void sqlite3_free_filename(sqlite3_filename); 3924 3925 /* 3926 ** CAPI3REF: Error Codes And Messages 3927 ** METHOD: sqlite3 3928 ** 3929 ** ^If the most recent sqlite3_* API call associated with 3930 ** [database connection] D failed, then the sqlite3_errcode(D) interface 3931 ** returns the numeric [result code] or [extended result code] for that 3932 ** API call. 3933 ** ^The sqlite3_extended_errcode() 3934 ** interface is the same except that it always returns the 3935 ** [extended result code] even when extended result codes are 3936 ** disabled. 3937 ** 3938 ** The values returned by sqlite3_errcode() and/or 3939 ** sqlite3_extended_errcode() might change with each API call. 3940 ** Except, there are some interfaces that are guaranteed to never 3941 ** change the value of the error code. The error-code preserving 3942 ** interfaces include the following: 3943 ** 3944 ** <ul> 3945 ** <li> sqlite3_errcode() 3946 ** <li> sqlite3_extended_errcode() 3947 ** <li> sqlite3_errmsg() 3948 ** <li> sqlite3_errmsg16() 3949 ** <li> sqlite3_error_offset() 3950 ** </ul> 3951 ** 3952 ** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language 3953 ** text that describes the error, as either UTF-8 or UTF-16 respectively. 3954 ** ^(Memory to hold the error message string is managed internally. 3955 ** The application does not need to worry about freeing the result. 3956 ** However, the error string might be overwritten or deallocated by 3957 ** subsequent calls to other SQLite interface functions.)^ 3958 ** 3959 ** ^The sqlite3_errstr() interface returns the English-language text 3960 ** that describes the [result code], as UTF-8. 3961 ** ^(Memory to hold the error message string is managed internally 3962 ** and must not be freed by the application)^. 3963 ** 3964 ** ^If the most recent error references a specific token in the input 3965 ** SQL, the sqlite3_error_offset() interface returns the byte offset 3966 ** of the start of that token. ^The byte offset returned by 3967 ** sqlite3_error_offset() assumes that the input SQL is UTF8. 3968 ** ^If the most recent error does not reference a specific token in the input 3969 ** SQL, then the sqlite3_error_offset() function returns -1. 3970 ** 3971 ** When the serialized [threading mode] is in use, it might be the 3972 ** case that a second error occurs on a separate thread in between 3973 ** the time of the first error and the call to these interfaces. 3974 ** When that happens, the second error will be reported since these 3975 ** interfaces always report the most recent result. To avoid 3976 ** this, each thread can obtain exclusive use of the [database connection] D 3977 ** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning 3978 ** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after 3979 ** all calls to the interfaces listed here are completed. 3980 ** 3981 ** If an interface fails with SQLITE_MISUSE, that means the interface 3982 ** was invoked incorrectly by the application. In that case, the 3983 ** error code and message may or may not be set. 3984 */ 3985 SQLITE_API int sqlite3_errcode(sqlite3 *db); 3986 SQLITE_API int sqlite3_extended_errcode(sqlite3 *db); 3987 SQLITE_API const char *sqlite3_errmsg(sqlite3*); 3988 SQLITE_API const void *sqlite3_errmsg16(sqlite3*); 3989 SQLITE_API const char *sqlite3_errstr(int); 3990 SQLITE_API int sqlite3_error_offset(sqlite3 *db); 3991 3992 /* 3993 ** CAPI3REF: Prepared Statement Object 3994 ** KEYWORDS: {prepared statement} {prepared statements} 3995 ** 3996 ** An instance of this object represents a single SQL statement that 3997 ** has been compiled into binary form and is ready to be evaluated. 3998 ** 3999 ** Think of each SQL statement as a separate computer program. The 4000 ** original SQL text is source code. A prepared statement object 4001 ** is the compiled object code. All SQL must be converted into a 4002 ** prepared statement before it can be run. 4003 ** 4004 ** The life-cycle of a prepared statement object usually goes like this: 4005 ** 4006 ** <ol> 4007 ** <li> Create the prepared statement object using [sqlite3_prepare_v2()]. 4008 ** <li> Bind values to [parameters] using the sqlite3_bind_*() 4009 ** interfaces. 4010 ** <li> Run the SQL by calling [sqlite3_step()] one or more times. 4011 ** <li> Reset the prepared statement using [sqlite3_reset()] then go back 4012 ** to step 2. Do this zero or more times. 4013 ** <li> Destroy the object using [sqlite3_finalize()]. 4014 ** </ol> 4015 */ 4016 typedef struct sqlite3_stmt sqlite3_stmt; 4017 4018 /* 4019 ** CAPI3REF: Run-time Limits 4020 ** METHOD: sqlite3 4021 ** 4022 ** ^(This interface allows the size of various constructs to be limited 4023 ** on a connection by connection basis. The first parameter is the 4024 ** [database connection] whose limit is to be set or queried. The 4025 ** second parameter is one of the [limit categories] that define a 4026 ** class of constructs to be size limited. The third parameter is the 4027 ** new limit for that construct.)^ 4028 ** 4029 ** ^If the new limit is a negative number, the limit is unchanged. 4030 ** ^(For each limit category SQLITE_LIMIT_<i>NAME</i> there is a 4031 ** [limits | hard upper bound] 4032 ** set at compile-time by a C preprocessor macro called 4033 ** [limits | SQLITE_MAX_<i>NAME</i>]. 4034 ** (The "_LIMIT_" in the name is changed to "_MAX_".))^ 4035 ** ^Attempts to increase a limit above its hard upper bound are 4036 ** silently truncated to the hard upper bound. 4037 ** 4038 ** ^Regardless of whether or not the limit was changed, the 4039 ** [sqlite3_limit()] interface returns the prior value of the limit. 4040 ** ^Hence, to find the current value of a limit without changing it, 4041 ** simply invoke this interface with the third parameter set to -1. 4042 ** 4043 ** Run-time limits are intended for use in applications that manage 4044 ** both their own internal database and also databases that are controlled 4045 ** by untrusted external sources. An example application might be a 4046 ** web browser that has its own databases for storing history and 4047 ** separate databases controlled by JavaScript applications downloaded 4048 ** off the Internet. The internal databases can be given the 4049 ** large, default limits. Databases managed by external sources can 4050 ** be given much smaller limits designed to prevent a denial of service 4051 ** attack. Developers might also want to use the [sqlite3_set_authorizer()] 4052 ** interface to further control untrusted SQL. The size of the database 4053 ** created by an untrusted script can be contained using the 4054 ** [max_page_count] [PRAGMA]. 4055 ** 4056 ** New run-time limit categories may be added in future releases. 4057 */ 4058 SQLITE_API int sqlite3_limit(sqlite3*, int id, int newVal); 4059 4060 /* 4061 ** CAPI3REF: Run-Time Limit Categories 4062 ** KEYWORDS: {limit category} {*limit categories} 4063 ** 4064 ** These constants define various performance limits 4065 ** that can be lowered at run-time using [sqlite3_limit()]. 4066 ** The synopsis of the meanings of the various limits is shown below. 4067 ** Additional information is available at [limits | Limits in SQLite]. 4068 ** 4069 ** <dl> 4070 ** [[SQLITE_LIMIT_LENGTH]] ^(<dt>SQLITE_LIMIT_LENGTH</dt> 4071 ** <dd>The maximum size of any string or BLOB or table row, in bytes.<dd>)^ 4072 ** 4073 ** [[SQLITE_LIMIT_SQL_LENGTH]] ^(<dt>SQLITE_LIMIT_SQL_LENGTH</dt> 4074 ** <dd>The maximum length of an SQL statement, in bytes.</dd>)^ 4075 ** 4076 ** [[SQLITE_LIMIT_COLUMN]] ^(<dt>SQLITE_LIMIT_COLUMN</dt> 4077 ** <dd>The maximum number of columns in a table definition or in the 4078 ** result set of a [SELECT] or the maximum number of columns in an index 4079 ** or in an ORDER BY or GROUP BY clause.</dd>)^ 4080 ** 4081 ** [[SQLITE_LIMIT_EXPR_DEPTH]] ^(<dt>SQLITE_LIMIT_EXPR_DEPTH</dt> 4082 ** <dd>The maximum depth of the parse tree on any expression.</dd>)^ 4083 ** 4084 ** [[SQLITE_LIMIT_COMPOUND_SELECT]] ^(<dt>SQLITE_LIMIT_COMPOUND_SELECT</dt> 4085 ** <dd>The maximum number of terms in a compound SELECT statement.</dd>)^ 4086 ** 4087 ** [[SQLITE_LIMIT_VDBE_OP]] ^(<dt>SQLITE_LIMIT_VDBE_OP</dt> 4088 ** <dd>The maximum number of instructions in a virtual machine program 4089 ** used to implement an SQL statement. If [sqlite3_prepare_v2()] or 4090 ** the equivalent tries to allocate space for more than this many opcodes 4091 ** in a single prepared statement, an SQLITE_NOMEM error is returned.</dd>)^ 4092 ** 4093 ** [[SQLITE_LIMIT_FUNCTION_ARG]] ^(<dt>SQLITE_LIMIT_FUNCTION_ARG</dt> 4094 ** <dd>The maximum number of arguments on a function.</dd>)^ 4095 ** 4096 ** [[SQLITE_LIMIT_ATTACHED]] ^(<dt>SQLITE_LIMIT_ATTACHED</dt> 4097 ** <dd>The maximum number of [ATTACH | attached databases].)^</dd> 4098 ** 4099 ** [[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]] 4100 ** ^(<dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt> 4101 ** <dd>The maximum length of the pattern argument to the [LIKE] or 4102 ** [GLOB] operators.</dd>)^ 4103 ** 4104 ** [[SQLITE_LIMIT_VARIABLE_NUMBER]] 4105 ** ^(<dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt> 4106 ** <dd>The maximum index number of any [parameter] in an SQL statement.)^ 4107 ** 4108 ** [[SQLITE_LIMIT_TRIGGER_DEPTH]] ^(<dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt> 4109 ** <dd>The maximum depth of recursion for triggers.</dd>)^ 4110 ** 4111 ** [[SQLITE_LIMIT_WORKER_THREADS]] ^(<dt>SQLITE_LIMIT_WORKER_THREADS</dt> 4112 ** <dd>The maximum number of auxiliary worker threads that a single 4113 ** [prepared statement] may start.</dd>)^ 4114 ** </dl> 4115 */ 4116 #define SQLITE_LIMIT_LENGTH 0 4117 #define SQLITE_LIMIT_SQL_LENGTH 1 4118 #define SQLITE_LIMIT_COLUMN 2 4119 #define SQLITE_LIMIT_EXPR_DEPTH 3 4120 #define SQLITE_LIMIT_COMPOUND_SELECT 4 4121 #define SQLITE_LIMIT_VDBE_OP 5 4122 #define SQLITE_LIMIT_FUNCTION_ARG 6 4123 #define SQLITE_LIMIT_ATTACHED 7 4124 #define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8 4125 #define SQLITE_LIMIT_VARIABLE_NUMBER 9 4126 #define SQLITE_LIMIT_TRIGGER_DEPTH 10 4127 #define SQLITE_LIMIT_WORKER_THREADS 11 4128 4129 /* 4130 ** CAPI3REF: Prepare Flags 4131 ** 4132 ** These constants define various flags that can be passed into 4133 ** "prepFlags" parameter of the [sqlite3_prepare_v3()] and 4134 ** [sqlite3_prepare16_v3()] interfaces. 4135 ** 4136 ** New flags may be added in future releases of SQLite. 4137 ** 4138 ** <dl> 4139 ** [[SQLITE_PREPARE_PERSISTENT]] ^(<dt>SQLITE_PREPARE_PERSISTENT</dt> 4140 ** <dd>The SQLITE_PREPARE_PERSISTENT flag is a hint to the query planner 4141 ** that the prepared statement will be retained for a long time and 4142 ** probably reused many times.)^ ^Without this flag, [sqlite3_prepare_v3()] 4143 ** and [sqlite3_prepare16_v3()] assume that the prepared statement will 4144 ** be used just once or at most a few times and then destroyed using 4145 ** [sqlite3_finalize()] relatively soon. The current implementation acts 4146 ** on this hint by avoiding the use of [lookaside memory] so as not to 4147 ** deplete the limited store of lookaside memory. Future versions of 4148 ** SQLite may act on this hint differently. 4149 ** 4150 ** [[SQLITE_PREPARE_NORMALIZE]] <dt>SQLITE_PREPARE_NORMALIZE</dt> 4151 ** <dd>The SQLITE_PREPARE_NORMALIZE flag is a no-op. This flag used 4152 ** to be required for any prepared statement that wanted to use the 4153 ** [sqlite3_normalized_sql()] interface. However, the 4154 ** [sqlite3_normalized_sql()] interface is now available to all 4155 ** prepared statements, regardless of whether or not they use this 4156 ** flag. 4157 ** 4158 ** [[SQLITE_PREPARE_NO_VTAB]] <dt>SQLITE_PREPARE_NO_VTAB</dt> 4159 ** <dd>The SQLITE_PREPARE_NO_VTAB flag causes the SQL compiler 4160 ** to return an error (error code SQLITE_ERROR) if the statement uses 4161 ** any virtual tables. 4162 ** </dl> 4163 */ 4164 #define SQLITE_PREPARE_PERSISTENT 0x01 4165 #define SQLITE_PREPARE_NORMALIZE 0x02 4166 #define SQLITE_PREPARE_NO_VTAB 0x04 4167 4168 /* 4169 ** CAPI3REF: Compiling An SQL Statement 4170 ** KEYWORDS: {SQL statement compiler} 4171 ** METHOD: sqlite3 4172 ** CONSTRUCTOR: sqlite3_stmt 4173 ** 4174 ** To execute an SQL statement, it must first be compiled into a byte-code 4175 ** program using one of these routines. Or, in other words, these routines 4176 ** are constructors for the [prepared statement] object. 4177 ** 4178 ** The preferred routine to use is [sqlite3_prepare_v2()]. The 4179 ** [sqlite3_prepare()] interface is legacy and should be avoided. 4180 ** [sqlite3_prepare_v3()] has an extra "prepFlags" option that is used 4181 ** for special purposes. 4182 ** 4183 ** The use of the UTF-8 interfaces is preferred, as SQLite currently 4184 ** does all parsing using UTF-8. The UTF-16 interfaces are provided 4185 ** as a convenience. The UTF-16 interfaces work by converting the 4186 ** input text into UTF-8, then invoking the corresponding UTF-8 interface. 4187 ** 4188 ** The first argument, "db", is a [database connection] obtained from a 4189 ** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or 4190 ** [sqlite3_open16()]. The database connection must not have been closed. 4191 ** 4192 ** The second argument, "zSql", is the statement to be compiled, encoded 4193 ** as either UTF-8 or UTF-16. The sqlite3_prepare(), sqlite3_prepare_v2(), 4194 ** and sqlite3_prepare_v3() 4195 ** interfaces use UTF-8, and sqlite3_prepare16(), sqlite3_prepare16_v2(), 4196 ** and sqlite3_prepare16_v3() use UTF-16. 4197 ** 4198 ** ^If the nByte argument is negative, then zSql is read up to the 4199 ** first zero terminator. ^If nByte is positive, then it is the 4200 ** number of bytes read from zSql. ^If nByte is zero, then no prepared 4201 ** statement is generated. 4202 ** If the caller knows that the supplied string is nul-terminated, then 4203 ** there is a small performance advantage to passing an nByte parameter that 4204 ** is the number of bytes in the input string <i>including</i> 4205 ** the nul-terminator. 4206 ** 4207 ** ^If pzTail is not NULL then *pzTail is made to point to the first byte 4208 ** past the end of the first SQL statement in zSql. These routines only 4209 ** compile the first statement in zSql, so *pzTail is left pointing to 4210 ** what remains uncompiled. 4211 ** 4212 ** ^*ppStmt is left pointing to a compiled [prepared statement] that can be 4213 ** executed using [sqlite3_step()]. ^If there is an error, *ppStmt is set 4214 ** to NULL. ^If the input text contains no SQL (if the input is an empty 4215 ** string or a comment) then *ppStmt is set to NULL. 4216 ** The calling procedure is responsible for deleting the compiled 4217 ** SQL statement using [sqlite3_finalize()] after it has finished with it. 4218 ** ppStmt may not be NULL. 4219 ** 4220 ** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK]; 4221 ** otherwise an [error code] is returned. 4222 ** 4223 ** The sqlite3_prepare_v2(), sqlite3_prepare_v3(), sqlite3_prepare16_v2(), 4224 ** and sqlite3_prepare16_v3() interfaces are recommended for all new programs. 4225 ** The older interfaces (sqlite3_prepare() and sqlite3_prepare16()) 4226 ** are retained for backwards compatibility, but their use is discouraged. 4227 ** ^In the "vX" interfaces, the prepared statement 4228 ** that is returned (the [sqlite3_stmt] object) contains a copy of the 4229 ** original SQL text. This causes the [sqlite3_step()] interface to 4230 ** behave differently in three ways: 4231 ** 4232 ** <ol> 4233 ** <li> 4234 ** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it 4235 ** always used to do, [sqlite3_step()] will automatically recompile the SQL 4236 ** statement and try to run it again. As many as [SQLITE_MAX_SCHEMA_RETRY] 4237 ** retries will occur before sqlite3_step() gives up and returns an error. 4238 ** </li> 4239 ** 4240 ** <li> 4241 ** ^When an error occurs, [sqlite3_step()] will return one of the detailed 4242 ** [error codes] or [extended error codes]. ^The legacy behavior was that 4243 ** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code 4244 ** and the application would have to make a second call to [sqlite3_reset()] 4245 ** in order to find the underlying cause of the problem. With the "v2" prepare 4246 ** interfaces, the underlying reason for the error is returned immediately. 4247 ** </li> 4248 ** 4249 ** <li> 4250 ** ^If the specific value bound to a [parameter | host parameter] in the 4251 ** WHERE clause might influence the choice of query plan for a statement, 4252 ** then the statement will be automatically recompiled, as if there had been 4253 ** a schema change, on the first [sqlite3_step()] call following any change 4254 ** to the [sqlite3_bind_text | bindings] of that [parameter]. 4255 ** ^The specific value of a WHERE-clause [parameter] might influence the 4256 ** choice of query plan if the parameter is the left-hand side of a [LIKE] 4257 ** or [GLOB] operator or if the parameter is compared to an indexed column 4258 ** and the [SQLITE_ENABLE_STAT4] compile-time option is enabled. 4259 ** </li> 4260 ** </ol> 4261 ** 4262 ** <p>^sqlite3_prepare_v3() differs from sqlite3_prepare_v2() only in having 4263 ** the extra prepFlags parameter, which is a bit array consisting of zero or 4264 ** more of the [SQLITE_PREPARE_PERSISTENT|SQLITE_PREPARE_*] flags. ^The 4265 ** sqlite3_prepare_v2() interface works exactly the same as 4266 ** sqlite3_prepare_v3() with a zero prepFlags parameter. 4267 */ 4268 SQLITE_API int sqlite3_prepare( 4269 sqlite3 *db, /* Database handle */ 4270 const char *zSql, /* SQL statement, UTF-8 encoded */ 4271 int nByte, /* Maximum length of zSql in bytes. */ 4272 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 4273 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 4274 ); 4275 SQLITE_API int sqlite3_prepare_v2( 4276 sqlite3 *db, /* Database handle */ 4277 const char *zSql, /* SQL statement, UTF-8 encoded */ 4278 int nByte, /* Maximum length of zSql in bytes. */ 4279 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 4280 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 4281 ); 4282 SQLITE_API int sqlite3_prepare_v3( 4283 sqlite3 *db, /* Database handle */ 4284 const char *zSql, /* SQL statement, UTF-8 encoded */ 4285 int nByte, /* Maximum length of zSql in bytes. */ 4286 unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */ 4287 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 4288 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 4289 ); 4290 SQLITE_API int sqlite3_prepare16( 4291 sqlite3 *db, /* Database handle */ 4292 const void *zSql, /* SQL statement, UTF-16 encoded */ 4293 int nByte, /* Maximum length of zSql in bytes. */ 4294 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 4295 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 4296 ); 4297 SQLITE_API int sqlite3_prepare16_v2( 4298 sqlite3 *db, /* Database handle */ 4299 const void *zSql, /* SQL statement, UTF-16 encoded */ 4300 int nByte, /* Maximum length of zSql in bytes. */ 4301 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 4302 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 4303 ); 4304 SQLITE_API int sqlite3_prepare16_v3( 4305 sqlite3 *db, /* Database handle */ 4306 const void *zSql, /* SQL statement, UTF-16 encoded */ 4307 int nByte, /* Maximum length of zSql in bytes. */ 4308 unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */ 4309 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 4310 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 4311 ); 4312 4313 /* 4314 ** CAPI3REF: Retrieving Statement SQL 4315 ** METHOD: sqlite3_stmt 4316 ** 4317 ** ^The sqlite3_sql(P) interface returns a pointer to a copy of the UTF-8 4318 ** SQL text used to create [prepared statement] P if P was 4319 ** created by [sqlite3_prepare_v2()], [sqlite3_prepare_v3()], 4320 ** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()]. 4321 ** ^The sqlite3_expanded_sql(P) interface returns a pointer to a UTF-8 4322 ** string containing the SQL text of prepared statement P with 4323 ** [bound parameters] expanded. 4324 ** ^The sqlite3_normalized_sql(P) interface returns a pointer to a UTF-8 4325 ** string containing the normalized SQL text of prepared statement P. The 4326 ** semantics used to normalize a SQL statement are unspecified and subject 4327 ** to change. At a minimum, literal values will be replaced with suitable 4328 ** placeholders. 4329 ** 4330 ** ^(For example, if a prepared statement is created using the SQL 4331 ** text "SELECT $abc,:xyz" and if parameter $abc is bound to integer 2345 4332 ** and parameter :xyz is unbound, then sqlite3_sql() will return 4333 ** the original string, "SELECT $abc,:xyz" but sqlite3_expanded_sql() 4334 ** will return "SELECT 2345,NULL".)^ 4335 ** 4336 ** ^The sqlite3_expanded_sql() interface returns NULL if insufficient memory 4337 ** is available to hold the result, or if the result would exceed the 4338 ** the maximum string length determined by the [SQLITE_LIMIT_LENGTH]. 4339 ** 4340 ** ^The [SQLITE_TRACE_SIZE_LIMIT] compile-time option limits the size of 4341 ** bound parameter expansions. ^The [SQLITE_OMIT_TRACE] compile-time 4342 ** option causes sqlite3_expanded_sql() to always return NULL. 4343 ** 4344 ** ^The strings returned by sqlite3_sql(P) and sqlite3_normalized_sql(P) 4345 ** are managed by SQLite and are automatically freed when the prepared 4346 ** statement is finalized. 4347 ** ^The string returned by sqlite3_expanded_sql(P), on the other hand, 4348 ** is obtained from [sqlite3_malloc()] and must be freed by the application 4349 ** by passing it to [sqlite3_free()]. 4350 ** 4351 ** ^The sqlite3_normalized_sql() interface is only available if 4352 ** the [SQLITE_ENABLE_NORMALIZE] compile-time option is defined. 4353 */ 4354 SQLITE_API const char *sqlite3_sql(sqlite3_stmt *pStmt); 4355 SQLITE_API char *sqlite3_expanded_sql(sqlite3_stmt *pStmt); 4356 #ifdef SQLITE_ENABLE_NORMALIZE 4357 SQLITE_API const char *sqlite3_normalized_sql(sqlite3_stmt *pStmt); 4358 #endif 4359 4360 /* 4361 ** CAPI3REF: Determine If An SQL Statement Writes The Database 4362 ** METHOD: sqlite3_stmt 4363 ** 4364 ** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if 4365 ** and only if the [prepared statement] X makes no direct changes to 4366 ** the content of the database file. 4367 ** 4368 ** Note that [application-defined SQL functions] or 4369 ** [virtual tables] might change the database indirectly as a side effect. 4370 ** ^(For example, if an application defines a function "eval()" that 4371 ** calls [sqlite3_exec()], then the following SQL statement would 4372 ** change the database file through side-effects: 4373 ** 4374 ** <blockquote><pre> 4375 ** SELECT eval('DELETE FROM t1') FROM t2; 4376 ** </pre></blockquote> 4377 ** 4378 ** But because the [SELECT] statement does not change the database file 4379 ** directly, sqlite3_stmt_readonly() would still return true.)^ 4380 ** 4381 ** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK], 4382 ** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true, 4383 ** since the statements themselves do not actually modify the database but 4384 ** rather they control the timing of when other statements modify the 4385 ** database. ^The [ATTACH] and [DETACH] statements also cause 4386 ** sqlite3_stmt_readonly() to return true since, while those statements 4387 ** change the configuration of a database connection, they do not make 4388 ** changes to the content of the database files on disk. 4389 ** ^The sqlite3_stmt_readonly() interface returns true for [BEGIN] since 4390 ** [BEGIN] merely sets internal flags, but the [BEGIN|BEGIN IMMEDIATE] and 4391 ** [BEGIN|BEGIN EXCLUSIVE] commands do touch the database and so 4392 ** sqlite3_stmt_readonly() returns false for those commands. 4393 ** 4394 ** ^This routine returns false if there is any possibility that the 4395 ** statement might change the database file. ^A false return does 4396 ** not guarantee that the statement will change the database file. 4397 ** ^For example, an UPDATE statement might have a WHERE clause that 4398 ** makes it a no-op, but the sqlite3_stmt_readonly() result would still 4399 ** be false. ^Similarly, a CREATE TABLE IF NOT EXISTS statement is a 4400 ** read-only no-op if the table already exists, but 4401 ** sqlite3_stmt_readonly() still returns false for such a statement. 4402 ** 4403 ** ^If prepared statement X is an [EXPLAIN] or [EXPLAIN QUERY PLAN] 4404 ** statement, then sqlite3_stmt_readonly(X) returns the same value as 4405 ** if the EXPLAIN or EXPLAIN QUERY PLAN prefix were omitted. 4406 */ 4407 SQLITE_API int sqlite3_stmt_readonly(sqlite3_stmt *pStmt); 4408 4409 /* 4410 ** CAPI3REF: Query The EXPLAIN Setting For A Prepared Statement 4411 ** METHOD: sqlite3_stmt 4412 ** 4413 ** ^The sqlite3_stmt_isexplain(S) interface returns 1 if the 4414 ** prepared statement S is an EXPLAIN statement, or 2 if the 4415 ** statement S is an EXPLAIN QUERY PLAN. 4416 ** ^The sqlite3_stmt_isexplain(S) interface returns 0 if S is 4417 ** an ordinary statement or a NULL pointer. 4418 */ 4419 SQLITE_API int sqlite3_stmt_isexplain(sqlite3_stmt *pStmt); 4420 4421 /* 4422 ** CAPI3REF: Determine If A Prepared Statement Has Been Reset 4423 ** METHOD: sqlite3_stmt 4424 ** 4425 ** ^The sqlite3_stmt_busy(S) interface returns true (non-zero) if the 4426 ** [prepared statement] S has been stepped at least once using 4427 ** [sqlite3_step(S)] but has neither run to completion (returned 4428 ** [SQLITE_DONE] from [sqlite3_step(S)]) nor 4429 ** been reset using [sqlite3_reset(S)]. ^The sqlite3_stmt_busy(S) 4430 ** interface returns false if S is a NULL pointer. If S is not a 4431 ** NULL pointer and is not a pointer to a valid [prepared statement] 4432 ** object, then the behavior is undefined and probably undesirable. 4433 ** 4434 ** This interface can be used in combination [sqlite3_next_stmt()] 4435 ** to locate all prepared statements associated with a database 4436 ** connection that are in need of being reset. This can be used, 4437 ** for example, in diagnostic routines to search for prepared 4438 ** statements that are holding a transaction open. 4439 */ 4440 SQLITE_API int sqlite3_stmt_busy(sqlite3_stmt*); 4441 4442 /* 4443 ** CAPI3REF: Dynamically Typed Value Object 4444 ** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value} 4445 ** 4446 ** SQLite uses the sqlite3_value object to represent all values 4447 ** that can be stored in a database table. SQLite uses dynamic typing 4448 ** for the values it stores. ^Values stored in sqlite3_value objects 4449 ** can be integers, floating point values, strings, BLOBs, or NULL. 4450 ** 4451 ** An sqlite3_value object may be either "protected" or "unprotected". 4452 ** Some interfaces require a protected sqlite3_value. Other interfaces 4453 ** will accept either a protected or an unprotected sqlite3_value. 4454 ** Every interface that accepts sqlite3_value arguments specifies 4455 ** whether or not it requires a protected sqlite3_value. The 4456 ** [sqlite3_value_dup()] interface can be used to construct a new 4457 ** protected sqlite3_value from an unprotected sqlite3_value. 4458 ** 4459 ** The terms "protected" and "unprotected" refer to whether or not 4460 ** a mutex is held. An internal mutex is held for a protected 4461 ** sqlite3_value object but no mutex is held for an unprotected 4462 ** sqlite3_value object. If SQLite is compiled to be single-threaded 4463 ** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0) 4464 ** or if SQLite is run in one of reduced mutex modes 4465 ** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD] 4466 ** then there is no distinction between protected and unprotected 4467 ** sqlite3_value objects and they can be used interchangeably. However, 4468 ** for maximum code portability it is recommended that applications 4469 ** still make the distinction between protected and unprotected 4470 ** sqlite3_value objects even when not strictly required. 4471 ** 4472 ** ^The sqlite3_value objects that are passed as parameters into the 4473 ** implementation of [application-defined SQL functions] are protected. 4474 ** ^The sqlite3_value objects returned by [sqlite3_vtab_rhs_value()] 4475 ** are protected. 4476 ** ^The sqlite3_value object returned by 4477 ** [sqlite3_column_value()] is unprotected. 4478 ** Unprotected sqlite3_value objects may only be used as arguments 4479 ** to [sqlite3_result_value()], [sqlite3_bind_value()], and 4480 ** [sqlite3_value_dup()]. 4481 ** The [sqlite3_value_blob | sqlite3_value_type()] family of 4482 ** interfaces require protected sqlite3_value objects. 4483 */ 4484 typedef struct sqlite3_value sqlite3_value; 4485 4486 /* 4487 ** CAPI3REF: SQL Function Context Object 4488 ** 4489 ** The context in which an SQL function executes is stored in an 4490 ** sqlite3_context object. ^A pointer to an sqlite3_context object 4491 ** is always first parameter to [application-defined SQL functions]. 4492 ** The application-defined SQL function implementation will pass this 4493 ** pointer through into calls to [sqlite3_result_int | sqlite3_result()], 4494 ** [sqlite3_aggregate_context()], [sqlite3_user_data()], 4495 ** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()], 4496 ** and/or [sqlite3_set_auxdata()]. 4497 */ 4498 typedef struct sqlite3_context sqlite3_context; 4499 4500 /* 4501 ** CAPI3REF: Binding Values To Prepared Statements 4502 ** KEYWORDS: {host parameter} {host parameters} {host parameter name} 4503 ** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding} 4504 ** METHOD: sqlite3_stmt 4505 ** 4506 ** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants, 4507 ** literals may be replaced by a [parameter] that matches one of following 4508 ** templates: 4509 ** 4510 ** <ul> 4511 ** <li> ? 4512 ** <li> ?NNN 4513 ** <li> :VVV 4514 ** <li> @VVV 4515 ** <li> $VVV 4516 ** </ul> 4517 ** 4518 ** In the templates above, NNN represents an integer literal, 4519 ** and VVV represents an alphanumeric identifier.)^ ^The values of these 4520 ** parameters (also called "host parameter names" or "SQL parameters") 4521 ** can be set using the sqlite3_bind_*() routines defined here. 4522 ** 4523 ** ^The first argument to the sqlite3_bind_*() routines is always 4524 ** a pointer to the [sqlite3_stmt] object returned from 4525 ** [sqlite3_prepare_v2()] or its variants. 4526 ** 4527 ** ^The second argument is the index of the SQL parameter to be set. 4528 ** ^The leftmost SQL parameter has an index of 1. ^When the same named 4529 ** SQL parameter is used more than once, second and subsequent 4530 ** occurrences have the same index as the first occurrence. 4531 ** ^The index for named parameters can be looked up using the 4532 ** [sqlite3_bind_parameter_index()] API if desired. ^The index 4533 ** for "?NNN" parameters is the value of NNN. 4534 ** ^The NNN value must be between 1 and the [sqlite3_limit()] 4535 ** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 32766). 4536 ** 4537 ** ^The third argument is the value to bind to the parameter. 4538 ** ^If the third parameter to sqlite3_bind_text() or sqlite3_bind_text16() 4539 ** or sqlite3_bind_blob() is a NULL pointer then the fourth parameter 4540 ** is ignored and the end result is the same as sqlite3_bind_null(). 4541 ** ^If the third parameter to sqlite3_bind_text() is not NULL, then 4542 ** it should be a pointer to well-formed UTF8 text. 4543 ** ^If the third parameter to sqlite3_bind_text16() is not NULL, then 4544 ** it should be a pointer to well-formed UTF16 text. 4545 ** ^If the third parameter to sqlite3_bind_text64() is not NULL, then 4546 ** it should be a pointer to a well-formed unicode string that is 4547 ** either UTF8 if the sixth parameter is SQLITE_UTF8, or UTF16 4548 ** otherwise. 4549 ** 4550 ** [[byte-order determination rules]] ^The byte-order of 4551 ** UTF16 input text is determined by the byte-order mark (BOM, U+FEFF) 4552 ** found in first character, which is removed, or in the absence of a BOM 4553 ** the byte order is the native byte order of the host 4554 ** machine for sqlite3_bind_text16() or the byte order specified in 4555 ** the 6th parameter for sqlite3_bind_text64().)^ 4556 ** ^If UTF16 input text contains invalid unicode 4557 ** characters, then SQLite might change those invalid characters 4558 ** into the unicode replacement character: U+FFFD. 4559 ** 4560 ** ^(In those routines that have a fourth argument, its value is the 4561 ** number of bytes in the parameter. To be clear: the value is the 4562 ** number of <u>bytes</u> in the value, not the number of characters.)^ 4563 ** ^If the fourth parameter to sqlite3_bind_text() or sqlite3_bind_text16() 4564 ** is negative, then the length of the string is 4565 ** the number of bytes up to the first zero terminator. 4566 ** If the fourth parameter to sqlite3_bind_blob() is negative, then 4567 ** the behavior is undefined. 4568 ** If a non-negative fourth parameter is provided to sqlite3_bind_text() 4569 ** or sqlite3_bind_text16() or sqlite3_bind_text64() then 4570 ** that parameter must be the byte offset 4571 ** where the NUL terminator would occur assuming the string were NUL 4572 ** terminated. If any NUL characters occurs at byte offsets less than 4573 ** the value of the fourth parameter then the resulting string value will 4574 ** contain embedded NULs. The result of expressions involving strings 4575 ** with embedded NULs is undefined. 4576 ** 4577 ** ^The fifth argument to the BLOB and string binding interfaces controls 4578 ** or indicates the lifetime of the object referenced by the third parameter. 4579 ** These three options exist: 4580 ** ^ (1) A destructor to dispose of the BLOB or string after SQLite has finished 4581 ** with it may be passed. ^It is called to dispose of the BLOB or string even 4582 ** if the call to the bind API fails, except the destructor is not called if 4583 ** the third parameter is a NULL pointer or the fourth parameter is negative. 4584 ** ^ (2) The special constant, [SQLITE_STATIC], may be passsed to indicate that 4585 ** the application remains responsible for disposing of the object. ^In this 4586 ** case, the object and the provided pointer to it must remain valid until 4587 ** either the prepared statement is finalized or the same SQL parameter is 4588 ** bound to something else, whichever occurs sooner. 4589 ** ^ (3) The constant, [SQLITE_TRANSIENT], may be passed to indicate that the 4590 ** object is to be copied prior to the return from sqlite3_bind_*(). ^The 4591 ** object and pointer to it must remain valid until then. ^SQLite will then 4592 ** manage the lifetime of its private copy. 4593 ** 4594 ** ^The sixth argument to sqlite3_bind_text64() must be one of 4595 ** [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE] 4596 ** to specify the encoding of the text in the third parameter. If 4597 ** the sixth argument to sqlite3_bind_text64() is not one of the 4598 ** allowed values shown above, or if the text encoding is different 4599 ** from the encoding specified by the sixth parameter, then the behavior 4600 ** is undefined. 4601 ** 4602 ** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that 4603 ** is filled with zeroes. ^A zeroblob uses a fixed amount of memory 4604 ** (just an integer to hold its size) while it is being processed. 4605 ** Zeroblobs are intended to serve as placeholders for BLOBs whose 4606 ** content is later written using 4607 ** [sqlite3_blob_open | incremental BLOB I/O] routines. 4608 ** ^A negative value for the zeroblob results in a zero-length BLOB. 4609 ** 4610 ** ^The sqlite3_bind_pointer(S,I,P,T,D) routine causes the I-th parameter in 4611 ** [prepared statement] S to have an SQL value of NULL, but to also be 4612 ** associated with the pointer P of type T. ^D is either a NULL pointer or 4613 ** a pointer to a destructor function for P. ^SQLite will invoke the 4614 ** destructor D with a single argument of P when it is finished using 4615 ** P. The T parameter should be a static string, preferably a string 4616 ** literal. The sqlite3_bind_pointer() routine is part of the 4617 ** [pointer passing interface] added for SQLite 3.20.0. 4618 ** 4619 ** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer 4620 ** for the [prepared statement] or with a prepared statement for which 4621 ** [sqlite3_step()] has been called more recently than [sqlite3_reset()], 4622 ** then the call will return [SQLITE_MISUSE]. If any sqlite3_bind_() 4623 ** routine is passed a [prepared statement] that has been finalized, the 4624 ** result is undefined and probably harmful. 4625 ** 4626 ** ^Bindings are not cleared by the [sqlite3_reset()] routine. 4627 ** ^Unbound parameters are interpreted as NULL. 4628 ** 4629 ** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an 4630 ** [error code] if anything goes wrong. 4631 ** ^[SQLITE_TOOBIG] might be returned if the size of a string or BLOB 4632 ** exceeds limits imposed by [sqlite3_limit]([SQLITE_LIMIT_LENGTH]) or 4633 ** [SQLITE_MAX_LENGTH]. 4634 ** ^[SQLITE_RANGE] is returned if the parameter 4635 ** index is out of range. ^[SQLITE_NOMEM] is returned if malloc() fails. 4636 ** 4637 ** See also: [sqlite3_bind_parameter_count()], 4638 ** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()]. 4639 */ 4640 SQLITE_API int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*)); 4641 SQLITE_API int sqlite3_bind_blob64(sqlite3_stmt*, int, const void*, sqlite3_uint64, 4642 void(*)(void*)); 4643 SQLITE_API int sqlite3_bind_double(sqlite3_stmt*, int, double); 4644 SQLITE_API int sqlite3_bind_int(sqlite3_stmt*, int, int); 4645 SQLITE_API int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64); 4646 SQLITE_API int sqlite3_bind_null(sqlite3_stmt*, int); 4647 SQLITE_API int sqlite3_bind_text(sqlite3_stmt*,int,const char*,int,void(*)(void*)); 4648 SQLITE_API int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*)); 4649 SQLITE_API int sqlite3_bind_text64(sqlite3_stmt*, int, const char*, sqlite3_uint64, 4650 void(*)(void*), unsigned char encoding); 4651 SQLITE_API int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*); 4652 SQLITE_API int sqlite3_bind_pointer(sqlite3_stmt*, int, void*, const char*,void(*)(void*)); 4653 SQLITE_API int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n); 4654 SQLITE_API int sqlite3_bind_zeroblob64(sqlite3_stmt*, int, sqlite3_uint64); 4655 4656 /* 4657 ** CAPI3REF: Number Of SQL Parameters 4658 ** METHOD: sqlite3_stmt 4659 ** 4660 ** ^This routine can be used to find the number of [SQL parameters] 4661 ** in a [prepared statement]. SQL parameters are tokens of the 4662 ** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as 4663 ** placeholders for values that are [sqlite3_bind_blob | bound] 4664 ** to the parameters at a later time. 4665 ** 4666 ** ^(This routine actually returns the index of the largest (rightmost) 4667 ** parameter. For all forms except ?NNN, this will correspond to the 4668 ** number of unique parameters. If parameters of the ?NNN form are used, 4669 ** there may be gaps in the list.)^ 4670 ** 4671 ** See also: [sqlite3_bind_blob|sqlite3_bind()], 4672 ** [sqlite3_bind_parameter_name()], and 4673 ** [sqlite3_bind_parameter_index()]. 4674 */ 4675 SQLITE_API int sqlite3_bind_parameter_count(sqlite3_stmt*); 4676 4677 /* 4678 ** CAPI3REF: Name Of A Host Parameter 4679 ** METHOD: sqlite3_stmt 4680 ** 4681 ** ^The sqlite3_bind_parameter_name(P,N) interface returns 4682 ** the name of the N-th [SQL parameter] in the [prepared statement] P. 4683 ** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA" 4684 ** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA" 4685 ** respectively. 4686 ** In other words, the initial ":" or "$" or "@" or "?" 4687 ** is included as part of the name.)^ 4688 ** ^Parameters of the form "?" without a following integer have no name 4689 ** and are referred to as "nameless" or "anonymous parameters". 4690 ** 4691 ** ^The first host parameter has an index of 1, not 0. 4692 ** 4693 ** ^If the value N is out of range or if the N-th parameter is 4694 ** nameless, then NULL is returned. ^The returned string is 4695 ** always in UTF-8 encoding even if the named parameter was 4696 ** originally specified as UTF-16 in [sqlite3_prepare16()], 4697 ** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()]. 4698 ** 4699 ** See also: [sqlite3_bind_blob|sqlite3_bind()], 4700 ** [sqlite3_bind_parameter_count()], and 4701 ** [sqlite3_bind_parameter_index()]. 4702 */ 4703 SQLITE_API const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int); 4704 4705 /* 4706 ** CAPI3REF: Index Of A Parameter With A Given Name 4707 ** METHOD: sqlite3_stmt 4708 ** 4709 ** ^Return the index of an SQL parameter given its name. ^The 4710 ** index value returned is suitable for use as the second 4711 ** parameter to [sqlite3_bind_blob|sqlite3_bind()]. ^A zero 4712 ** is returned if no matching parameter is found. ^The parameter 4713 ** name must be given in UTF-8 even if the original statement 4714 ** was prepared from UTF-16 text using [sqlite3_prepare16_v2()] or 4715 ** [sqlite3_prepare16_v3()]. 4716 ** 4717 ** See also: [sqlite3_bind_blob|sqlite3_bind()], 4718 ** [sqlite3_bind_parameter_count()], and 4719 ** [sqlite3_bind_parameter_name()]. 4720 */ 4721 SQLITE_API int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName); 4722 4723 /* 4724 ** CAPI3REF: Reset All Bindings On A Prepared Statement 4725 ** METHOD: sqlite3_stmt 4726 ** 4727 ** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset 4728 ** the [sqlite3_bind_blob | bindings] on a [prepared statement]. 4729 ** ^Use this routine to reset all host parameters to NULL. 4730 */ 4731 SQLITE_API int sqlite3_clear_bindings(sqlite3_stmt*); 4732 4733 /* 4734 ** CAPI3REF: Number Of Columns In A Result Set 4735 ** METHOD: sqlite3_stmt 4736 ** 4737 ** ^Return the number of columns in the result set returned by the 4738 ** [prepared statement]. ^If this routine returns 0, that means the 4739 ** [prepared statement] returns no data (for example an [UPDATE]). 4740 ** ^However, just because this routine returns a positive number does not 4741 ** mean that one or more rows of data will be returned. ^A SELECT statement 4742 ** will always have a positive sqlite3_column_count() but depending on the 4743 ** WHERE clause constraints and the table content, it might return no rows. 4744 ** 4745 ** See also: [sqlite3_data_count()] 4746 */ 4747 SQLITE_API int sqlite3_column_count(sqlite3_stmt *pStmt); 4748 4749 /* 4750 ** CAPI3REF: Column Names In A Result Set 4751 ** METHOD: sqlite3_stmt 4752 ** 4753 ** ^These routines return the name assigned to a particular column 4754 ** in the result set of a [SELECT] statement. ^The sqlite3_column_name() 4755 ** interface returns a pointer to a zero-terminated UTF-8 string 4756 ** and sqlite3_column_name16() returns a pointer to a zero-terminated 4757 ** UTF-16 string. ^The first parameter is the [prepared statement] 4758 ** that implements the [SELECT] statement. ^The second parameter is the 4759 ** column number. ^The leftmost column is number 0. 4760 ** 4761 ** ^The returned string pointer is valid until either the [prepared statement] 4762 ** is destroyed by [sqlite3_finalize()] or until the statement is automatically 4763 ** reprepared by the first call to [sqlite3_step()] for a particular run 4764 ** or until the next call to 4765 ** sqlite3_column_name() or sqlite3_column_name16() on the same column. 4766 ** 4767 ** ^If sqlite3_malloc() fails during the processing of either routine 4768 ** (for example during a conversion from UTF-8 to UTF-16) then a 4769 ** NULL pointer is returned. 4770 ** 4771 ** ^The name of a result column is the value of the "AS" clause for 4772 ** that column, if there is an AS clause. If there is no AS clause 4773 ** then the name of the column is unspecified and may change from 4774 ** one release of SQLite to the next. 4775 */ 4776 SQLITE_API const char *sqlite3_column_name(sqlite3_stmt*, int N); 4777 SQLITE_API const void *sqlite3_column_name16(sqlite3_stmt*, int N); 4778 4779 /* 4780 ** CAPI3REF: Source Of Data In A Query Result 4781 ** METHOD: sqlite3_stmt 4782 ** 4783 ** ^These routines provide a means to determine the database, table, and 4784 ** table column that is the origin of a particular result column in 4785 ** [SELECT] statement. 4786 ** ^The name of the database or table or column can be returned as 4787 ** either a UTF-8 or UTF-16 string. ^The _database_ routines return 4788 ** the database name, the _table_ routines return the table name, and 4789 ** the origin_ routines return the column name. 4790 ** ^The returned string is valid until the [prepared statement] is destroyed 4791 ** using [sqlite3_finalize()] or until the statement is automatically 4792 ** reprepared by the first call to [sqlite3_step()] for a particular run 4793 ** or until the same information is requested 4794 ** again in a different encoding. 4795 ** 4796 ** ^The names returned are the original un-aliased names of the 4797 ** database, table, and column. 4798 ** 4799 ** ^The first argument to these interfaces is a [prepared statement]. 4800 ** ^These functions return information about the Nth result column returned by 4801 ** the statement, where N is the second function argument. 4802 ** ^The left-most column is column 0 for these routines. 4803 ** 4804 ** ^If the Nth column returned by the statement is an expression or 4805 ** subquery and is not a column value, then all of these functions return 4806 ** NULL. ^These routines might also return NULL if a memory allocation error 4807 ** occurs. ^Otherwise, they return the name of the attached database, table, 4808 ** or column that query result column was extracted from. 4809 ** 4810 ** ^As with all other SQLite APIs, those whose names end with "16" return 4811 ** UTF-16 encoded strings and the other functions return UTF-8. 4812 ** 4813 ** ^These APIs are only available if the library was compiled with the 4814 ** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol. 4815 ** 4816 ** If two or more threads call one or more 4817 ** [sqlite3_column_database_name | column metadata interfaces] 4818 ** for the same [prepared statement] and result column 4819 ** at the same time then the results are undefined. 4820 */ 4821 SQLITE_API const char *sqlite3_column_database_name(sqlite3_stmt*,int); 4822 SQLITE_API const void *sqlite3_column_database_name16(sqlite3_stmt*,int); 4823 SQLITE_API const char *sqlite3_column_table_name(sqlite3_stmt*,int); 4824 SQLITE_API const void *sqlite3_column_table_name16(sqlite3_stmt*,int); 4825 SQLITE_API const char *sqlite3_column_origin_name(sqlite3_stmt*,int); 4826 SQLITE_API const void *sqlite3_column_origin_name16(sqlite3_stmt*,int); 4827 4828 /* 4829 ** CAPI3REF: Declared Datatype Of A Query Result 4830 ** METHOD: sqlite3_stmt 4831 ** 4832 ** ^(The first parameter is a [prepared statement]. 4833 ** If this statement is a [SELECT] statement and the Nth column of the 4834 ** returned result set of that [SELECT] is a table column (not an 4835 ** expression or subquery) then the declared type of the table 4836 ** column is returned.)^ ^If the Nth column of the result set is an 4837 ** expression or subquery, then a NULL pointer is returned. 4838 ** ^The returned string is always UTF-8 encoded. 4839 ** 4840 ** ^(For example, given the database schema: 4841 ** 4842 ** CREATE TABLE t1(c1 VARIANT); 4843 ** 4844 ** and the following statement to be compiled: 4845 ** 4846 ** SELECT c1 + 1, c1 FROM t1; 4847 ** 4848 ** this routine would return the string "VARIANT" for the second result 4849 ** column (i==1), and a NULL pointer for the first result column (i==0).)^ 4850 ** 4851 ** ^SQLite uses dynamic run-time typing. ^So just because a column 4852 ** is declared to contain a particular type does not mean that the 4853 ** data stored in that column is of the declared type. SQLite is 4854 ** strongly typed, but the typing is dynamic not static. ^Type 4855 ** is associated with individual values, not with the containers 4856 ** used to hold those values. 4857 */ 4858 SQLITE_API const char *sqlite3_column_decltype(sqlite3_stmt*,int); 4859 SQLITE_API const void *sqlite3_column_decltype16(sqlite3_stmt*,int); 4860 4861 /* 4862 ** CAPI3REF: Evaluate An SQL Statement 4863 ** METHOD: sqlite3_stmt 4864 ** 4865 ** After a [prepared statement] has been prepared using any of 4866 ** [sqlite3_prepare_v2()], [sqlite3_prepare_v3()], [sqlite3_prepare16_v2()], 4867 ** or [sqlite3_prepare16_v3()] or one of the legacy 4868 ** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function 4869 ** must be called one or more times to evaluate the statement. 4870 ** 4871 ** The details of the behavior of the sqlite3_step() interface depend 4872 ** on whether the statement was prepared using the newer "vX" interfaces 4873 ** [sqlite3_prepare_v3()], [sqlite3_prepare_v2()], [sqlite3_prepare16_v3()], 4874 ** [sqlite3_prepare16_v2()] or the older legacy 4875 ** interfaces [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the 4876 ** new "vX" interface is recommended for new applications but the legacy 4877 ** interface will continue to be supported. 4878 ** 4879 ** ^In the legacy interface, the return value will be either [SQLITE_BUSY], 4880 ** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE]. 4881 ** ^With the "v2" interface, any of the other [result codes] or 4882 ** [extended result codes] might be returned as well. 4883 ** 4884 ** ^[SQLITE_BUSY] means that the database engine was unable to acquire the 4885 ** database locks it needs to do its job. ^If the statement is a [COMMIT] 4886 ** or occurs outside of an explicit transaction, then you can retry the 4887 ** statement. If the statement is not a [COMMIT] and occurs within an 4888 ** explicit transaction then you should rollback the transaction before 4889 ** continuing. 4890 ** 4891 ** ^[SQLITE_DONE] means that the statement has finished executing 4892 ** successfully. sqlite3_step() should not be called again on this virtual 4893 ** machine without first calling [sqlite3_reset()] to reset the virtual 4894 ** machine back to its initial state. 4895 ** 4896 ** ^If the SQL statement being executed returns any data, then [SQLITE_ROW] 4897 ** is returned each time a new row of data is ready for processing by the 4898 ** caller. The values may be accessed using the [column access functions]. 4899 ** sqlite3_step() is called again to retrieve the next row of data. 4900 ** 4901 ** ^[SQLITE_ERROR] means that a run-time error (such as a constraint 4902 ** violation) has occurred. sqlite3_step() should not be called again on 4903 ** the VM. More information may be found by calling [sqlite3_errmsg()]. 4904 ** ^With the legacy interface, a more specific error code (for example, 4905 ** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth) 4906 ** can be obtained by calling [sqlite3_reset()] on the 4907 ** [prepared statement]. ^In the "v2" interface, 4908 ** the more specific error code is returned directly by sqlite3_step(). 4909 ** 4910 ** [SQLITE_MISUSE] means that the this routine was called inappropriately. 4911 ** Perhaps it was called on a [prepared statement] that has 4912 ** already been [sqlite3_finalize | finalized] or on one that had 4913 ** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could 4914 ** be the case that the same database connection is being used by two or 4915 ** more threads at the same moment in time. 4916 ** 4917 ** For all versions of SQLite up to and including 3.6.23.1, a call to 4918 ** [sqlite3_reset()] was required after sqlite3_step() returned anything 4919 ** other than [SQLITE_ROW] before any subsequent invocation of 4920 ** sqlite3_step(). Failure to reset the prepared statement using 4921 ** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from 4922 ** sqlite3_step(). But after [version 3.6.23.1] ([dateof:3.6.23.1], 4923 ** sqlite3_step() began 4924 ** calling [sqlite3_reset()] automatically in this circumstance rather 4925 ** than returning [SQLITE_MISUSE]. This is not considered a compatibility 4926 ** break because any application that ever receives an SQLITE_MISUSE error 4927 ** is broken by definition. The [SQLITE_OMIT_AUTORESET] compile-time option 4928 ** can be used to restore the legacy behavior. 4929 ** 4930 ** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step() 4931 ** API always returns a generic error code, [SQLITE_ERROR], following any 4932 ** error other than [SQLITE_BUSY] and [SQLITE_MISUSE]. You must call 4933 ** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the 4934 ** specific [error codes] that better describes the error. 4935 ** We admit that this is a goofy design. The problem has been fixed 4936 ** with the "v2" interface. If you prepare all of your SQL statements 4937 ** using [sqlite3_prepare_v3()] or [sqlite3_prepare_v2()] 4938 ** or [sqlite3_prepare16_v2()] or [sqlite3_prepare16_v3()] instead 4939 ** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces, 4940 ** then the more specific [error codes] are returned directly 4941 ** by sqlite3_step(). The use of the "vX" interfaces is recommended. 4942 */ 4943 SQLITE_API int sqlite3_step(sqlite3_stmt*); 4944 4945 /* 4946 ** CAPI3REF: Number of columns in a result set 4947 ** METHOD: sqlite3_stmt 4948 ** 4949 ** ^The sqlite3_data_count(P) interface returns the number of columns in the 4950 ** current row of the result set of [prepared statement] P. 4951 ** ^If prepared statement P does not have results ready to return 4952 ** (via calls to the [sqlite3_column_int | sqlite3_column()] family of 4953 ** interfaces) then sqlite3_data_count(P) returns 0. 4954 ** ^The sqlite3_data_count(P) routine also returns 0 if P is a NULL pointer. 4955 ** ^The sqlite3_data_count(P) routine returns 0 if the previous call to 4956 ** [sqlite3_step](P) returned [SQLITE_DONE]. ^The sqlite3_data_count(P) 4957 ** will return non-zero if previous call to [sqlite3_step](P) returned 4958 ** [SQLITE_ROW], except in the case of the [PRAGMA incremental_vacuum] 4959 ** where it always returns zero since each step of that multi-step 4960 ** pragma returns 0 columns of data. 4961 ** 4962 ** See also: [sqlite3_column_count()] 4963 */ 4964 SQLITE_API int sqlite3_data_count(sqlite3_stmt *pStmt); 4965 4966 /* 4967 ** CAPI3REF: Fundamental Datatypes 4968 ** KEYWORDS: SQLITE_TEXT 4969 ** 4970 ** ^(Every value in SQLite has one of five fundamental datatypes: 4971 ** 4972 ** <ul> 4973 ** <li> 64-bit signed integer 4974 ** <li> 64-bit IEEE floating point number 4975 ** <li> string 4976 ** <li> BLOB 4977 ** <li> NULL 4978 ** </ul>)^ 4979 ** 4980 ** These constants are codes for each of those types. 4981 ** 4982 ** Note that the SQLITE_TEXT constant was also used in SQLite version 2 4983 ** for a completely different meaning. Software that links against both 4984 ** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not 4985 ** SQLITE_TEXT. 4986 */ 4987 #define SQLITE_INTEGER 1 4988 #define SQLITE_FLOAT 2 4989 #define SQLITE_BLOB 4 4990 #define SQLITE_NULL 5 4991 #ifdef SQLITE_TEXT 4992 # undef SQLITE_TEXT 4993 #else 4994 # define SQLITE_TEXT 3 4995 #endif 4996 #define SQLITE3_TEXT 3 4997 4998 /* 4999 ** CAPI3REF: Result Values From A Query 5000 ** KEYWORDS: {column access functions} 5001 ** METHOD: sqlite3_stmt 5002 ** 5003 ** <b>Summary:</b> 5004 ** <blockquote><table border=0 cellpadding=0 cellspacing=0> 5005 ** <tr><td><b>sqlite3_column_blob</b><td>→<td>BLOB result 5006 ** <tr><td><b>sqlite3_column_double</b><td>→<td>REAL result 5007 ** <tr><td><b>sqlite3_column_int</b><td>→<td>32-bit INTEGER result 5008 ** <tr><td><b>sqlite3_column_int64</b><td>→<td>64-bit INTEGER result 5009 ** <tr><td><b>sqlite3_column_text</b><td>→<td>UTF-8 TEXT result 5010 ** <tr><td><b>sqlite3_column_text16</b><td>→<td>UTF-16 TEXT result 5011 ** <tr><td><b>sqlite3_column_value</b><td>→<td>The result as an 5012 ** [sqlite3_value|unprotected sqlite3_value] object. 5013 ** <tr><td> <td> <td> 5014 ** <tr><td><b>sqlite3_column_bytes</b><td>→<td>Size of a BLOB 5015 ** or a UTF-8 TEXT result in bytes 5016 ** <tr><td><b>sqlite3_column_bytes16 </b> 5017 ** <td>→ <td>Size of UTF-16 5018 ** TEXT in bytes 5019 ** <tr><td><b>sqlite3_column_type</b><td>→<td>Default 5020 ** datatype of the result 5021 ** </table></blockquote> 5022 ** 5023 ** <b>Details:</b> 5024 ** 5025 ** ^These routines return information about a single column of the current 5026 ** result row of a query. ^In every case the first argument is a pointer 5027 ** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*] 5028 ** that was returned from [sqlite3_prepare_v2()] or one of its variants) 5029 ** and the second argument is the index of the column for which information 5030 ** should be returned. ^The leftmost column of the result set has the index 0. 5031 ** ^The number of columns in the result can be determined using 5032 ** [sqlite3_column_count()]. 5033 ** 5034 ** If the SQL statement does not currently point to a valid row, or if the 5035 ** column index is out of range, the result is undefined. 5036 ** These routines may only be called when the most recent call to 5037 ** [sqlite3_step()] has returned [SQLITE_ROW] and neither 5038 ** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently. 5039 ** If any of these routines are called after [sqlite3_reset()] or 5040 ** [sqlite3_finalize()] or after [sqlite3_step()] has returned 5041 ** something other than [SQLITE_ROW], the results are undefined. 5042 ** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()] 5043 ** are called from a different thread while any of these routines 5044 ** are pending, then the results are undefined. 5045 ** 5046 ** The first six interfaces (_blob, _double, _int, _int64, _text, and _text16) 5047 ** each return the value of a result column in a specific data format. If 5048 ** the result column is not initially in the requested format (for example, 5049 ** if the query returns an integer but the sqlite3_column_text() interface 5050 ** is used to extract the value) then an automatic type conversion is performed. 5051 ** 5052 ** ^The sqlite3_column_type() routine returns the 5053 ** [SQLITE_INTEGER | datatype code] for the initial data type 5054 ** of the result column. ^The returned value is one of [SQLITE_INTEGER], 5055 ** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL]. 5056 ** The return value of sqlite3_column_type() can be used to decide which 5057 ** of the first six interface should be used to extract the column value. 5058 ** The value returned by sqlite3_column_type() is only meaningful if no 5059 ** automatic type conversions have occurred for the value in question. 5060 ** After a type conversion, the result of calling sqlite3_column_type() 5061 ** is undefined, though harmless. Future 5062 ** versions of SQLite may change the behavior of sqlite3_column_type() 5063 ** following a type conversion. 5064 ** 5065 ** If the result is a BLOB or a TEXT string, then the sqlite3_column_bytes() 5066 ** or sqlite3_column_bytes16() interfaces can be used to determine the size 5067 ** of that BLOB or string. 5068 ** 5069 ** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes() 5070 ** routine returns the number of bytes in that BLOB or string. 5071 ** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts 5072 ** the string to UTF-8 and then returns the number of bytes. 5073 ** ^If the result is a numeric value then sqlite3_column_bytes() uses 5074 ** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns 5075 ** the number of bytes in that string. 5076 ** ^If the result is NULL, then sqlite3_column_bytes() returns zero. 5077 ** 5078 ** ^If the result is a BLOB or UTF-16 string then the sqlite3_column_bytes16() 5079 ** routine returns the number of bytes in that BLOB or string. 5080 ** ^If the result is a UTF-8 string, then sqlite3_column_bytes16() converts 5081 ** the string to UTF-16 and then returns the number of bytes. 5082 ** ^If the result is a numeric value then sqlite3_column_bytes16() uses 5083 ** [sqlite3_snprintf()] to convert that value to a UTF-16 string and returns 5084 ** the number of bytes in that string. 5085 ** ^If the result is NULL, then sqlite3_column_bytes16() returns zero. 5086 ** 5087 ** ^The values returned by [sqlite3_column_bytes()] and 5088 ** [sqlite3_column_bytes16()] do not include the zero terminators at the end 5089 ** of the string. ^For clarity: the values returned by 5090 ** [sqlite3_column_bytes()] and [sqlite3_column_bytes16()] are the number of 5091 ** bytes in the string, not the number of characters. 5092 ** 5093 ** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(), 5094 ** even empty strings, are always zero-terminated. ^The return 5095 ** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer. 5096 ** 5097 ** ^Strings returned by sqlite3_column_text16() always have the endianness 5098 ** which is native to the platform, regardless of the text encoding set 5099 ** for the database. 5100 ** 5101 ** <b>Warning:</b> ^The object returned by [sqlite3_column_value()] is an 5102 ** [unprotected sqlite3_value] object. In a multithreaded environment, 5103 ** an unprotected sqlite3_value object may only be used safely with 5104 ** [sqlite3_bind_value()] and [sqlite3_result_value()]. 5105 ** If the [unprotected sqlite3_value] object returned by 5106 ** [sqlite3_column_value()] is used in any other way, including calls 5107 ** to routines like [sqlite3_value_int()], [sqlite3_value_text()], 5108 ** or [sqlite3_value_bytes()], the behavior is not threadsafe. 5109 ** Hence, the sqlite3_column_value() interface 5110 ** is normally only useful within the implementation of 5111 ** [application-defined SQL functions] or [virtual tables], not within 5112 ** top-level application code. 5113 ** 5114 ** These routines may attempt to convert the datatype of the result. 5115 ** ^For example, if the internal representation is FLOAT and a text result 5116 ** is requested, [sqlite3_snprintf()] is used internally to perform the 5117 ** conversion automatically. ^(The following table details the conversions 5118 ** that are applied: 5119 ** 5120 ** <blockquote> 5121 ** <table border="1"> 5122 ** <tr><th> Internal<br>Type <th> Requested<br>Type <th> Conversion 5123 ** 5124 ** <tr><td> NULL <td> INTEGER <td> Result is 0 5125 ** <tr><td> NULL <td> FLOAT <td> Result is 0.0 5126 ** <tr><td> NULL <td> TEXT <td> Result is a NULL pointer 5127 ** <tr><td> NULL <td> BLOB <td> Result is a NULL pointer 5128 ** <tr><td> INTEGER <td> FLOAT <td> Convert from integer to float 5129 ** <tr><td> INTEGER <td> TEXT <td> ASCII rendering of the integer 5130 ** <tr><td> INTEGER <td> BLOB <td> Same as INTEGER->TEXT 5131 ** <tr><td> FLOAT <td> INTEGER <td> [CAST] to INTEGER 5132 ** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float 5133 ** <tr><td> FLOAT <td> BLOB <td> [CAST] to BLOB 5134 ** <tr><td> TEXT <td> INTEGER <td> [CAST] to INTEGER 5135 ** <tr><td> TEXT <td> FLOAT <td> [CAST] to REAL 5136 ** <tr><td> TEXT <td> BLOB <td> No change 5137 ** <tr><td> BLOB <td> INTEGER <td> [CAST] to INTEGER 5138 ** <tr><td> BLOB <td> FLOAT <td> [CAST] to REAL 5139 ** <tr><td> BLOB <td> TEXT <td> [CAST] to TEXT, ensure zero terminator 5140 ** </table> 5141 ** </blockquote>)^ 5142 ** 5143 ** Note that when type conversions occur, pointers returned by prior 5144 ** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or 5145 ** sqlite3_column_text16() may be invalidated. 5146 ** Type conversions and pointer invalidations might occur 5147 ** in the following cases: 5148 ** 5149 ** <ul> 5150 ** <li> The initial content is a BLOB and sqlite3_column_text() or 5151 ** sqlite3_column_text16() is called. A zero-terminator might 5152 ** need to be added to the string.</li> 5153 ** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or 5154 ** sqlite3_column_text16() is called. The content must be converted 5155 ** to UTF-16.</li> 5156 ** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or 5157 ** sqlite3_column_text() is called. The content must be converted 5158 ** to UTF-8.</li> 5159 ** </ul> 5160 ** 5161 ** ^Conversions between UTF-16be and UTF-16le are always done in place and do 5162 ** not invalidate a prior pointer, though of course the content of the buffer 5163 ** that the prior pointer references will have been modified. Other kinds 5164 ** of conversion are done in place when it is possible, but sometimes they 5165 ** are not possible and in those cases prior pointers are invalidated. 5166 ** 5167 ** The safest policy is to invoke these routines 5168 ** in one of the following ways: 5169 ** 5170 ** <ul> 5171 ** <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li> 5172 ** <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li> 5173 ** <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li> 5174 ** </ul> 5175 ** 5176 ** In other words, you should call sqlite3_column_text(), 5177 ** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result 5178 ** into the desired format, then invoke sqlite3_column_bytes() or 5179 ** sqlite3_column_bytes16() to find the size of the result. Do not mix calls 5180 ** to sqlite3_column_text() or sqlite3_column_blob() with calls to 5181 ** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16() 5182 ** with calls to sqlite3_column_bytes(). 5183 ** 5184 ** ^The pointers returned are valid until a type conversion occurs as 5185 ** described above, or until [sqlite3_step()] or [sqlite3_reset()] or 5186 ** [sqlite3_finalize()] is called. ^The memory space used to hold strings 5187 ** and BLOBs is freed automatically. Do not pass the pointers returned 5188 ** from [sqlite3_column_blob()], [sqlite3_column_text()], etc. into 5189 ** [sqlite3_free()]. 5190 ** 5191 ** As long as the input parameters are correct, these routines will only 5192 ** fail if an out-of-memory error occurs during a format conversion. 5193 ** Only the following subset of interfaces are subject to out-of-memory 5194 ** errors: 5195 ** 5196 ** <ul> 5197 ** <li> sqlite3_column_blob() 5198 ** <li> sqlite3_column_text() 5199 ** <li> sqlite3_column_text16() 5200 ** <li> sqlite3_column_bytes() 5201 ** <li> sqlite3_column_bytes16() 5202 ** </ul> 5203 ** 5204 ** If an out-of-memory error occurs, then the return value from these 5205 ** routines is the same as if the column had contained an SQL NULL value. 5206 ** Valid SQL NULL returns can be distinguished from out-of-memory errors 5207 ** by invoking the [sqlite3_errcode()] immediately after the suspect 5208 ** return value is obtained and before any 5209 ** other SQLite interface is called on the same [database connection]. 5210 */ 5211 SQLITE_API const void *sqlite3_column_blob(sqlite3_stmt*, int iCol); 5212 SQLITE_API double sqlite3_column_double(sqlite3_stmt*, int iCol); 5213 SQLITE_API int sqlite3_column_int(sqlite3_stmt*, int iCol); 5214 SQLITE_API sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol); 5215 SQLITE_API const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol); 5216 SQLITE_API const void *sqlite3_column_text16(sqlite3_stmt*, int iCol); 5217 SQLITE_API sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol); 5218 SQLITE_API int sqlite3_column_bytes(sqlite3_stmt*, int iCol); 5219 SQLITE_API int sqlite3_column_bytes16(sqlite3_stmt*, int iCol); 5220 SQLITE_API int sqlite3_column_type(sqlite3_stmt*, int iCol); 5221 5222 /* 5223 ** CAPI3REF: Destroy A Prepared Statement Object 5224 ** DESTRUCTOR: sqlite3_stmt 5225 ** 5226 ** ^The sqlite3_finalize() function is called to delete a [prepared statement]. 5227 ** ^If the most recent evaluation of the statement encountered no errors 5228 ** or if the statement is never been evaluated, then sqlite3_finalize() returns 5229 ** SQLITE_OK. ^If the most recent evaluation of statement S failed, then 5230 ** sqlite3_finalize(S) returns the appropriate [error code] or 5231 ** [extended error code]. 5232 ** 5233 ** ^The sqlite3_finalize(S) routine can be called at any point during 5234 ** the life cycle of [prepared statement] S: 5235 ** before statement S is ever evaluated, after 5236 ** one or more calls to [sqlite3_reset()], or after any call 5237 ** to [sqlite3_step()] regardless of whether or not the statement has 5238 ** completed execution. 5239 ** 5240 ** ^Invoking sqlite3_finalize() on a NULL pointer is a harmless no-op. 5241 ** 5242 ** The application must finalize every [prepared statement] in order to avoid 5243 ** resource leaks. It is a grievous error for the application to try to use 5244 ** a prepared statement after it has been finalized. Any use of a prepared 5245 ** statement after it has been finalized can result in undefined and 5246 ** undesirable behavior such as segfaults and heap corruption. 5247 */ 5248 SQLITE_API int sqlite3_finalize(sqlite3_stmt *pStmt); 5249 5250 /* 5251 ** CAPI3REF: Reset A Prepared Statement Object 5252 ** METHOD: sqlite3_stmt 5253 ** 5254 ** The sqlite3_reset() function is called to reset a [prepared statement] 5255 ** object back to its initial state, ready to be re-executed. 5256 ** ^Any SQL statement variables that had values bound to them using 5257 ** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values. 5258 ** Use [sqlite3_clear_bindings()] to reset the bindings. 5259 ** 5260 ** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S 5261 ** back to the beginning of its program. 5262 ** 5263 ** ^If the most recent call to [sqlite3_step(S)] for the 5264 ** [prepared statement] S returned [SQLITE_ROW] or [SQLITE_DONE], 5265 ** or if [sqlite3_step(S)] has never before been called on S, 5266 ** then [sqlite3_reset(S)] returns [SQLITE_OK]. 5267 ** 5268 ** ^If the most recent call to [sqlite3_step(S)] for the 5269 ** [prepared statement] S indicated an error, then 5270 ** [sqlite3_reset(S)] returns an appropriate [error code]. 5271 ** 5272 ** ^The [sqlite3_reset(S)] interface does not change the values 5273 ** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S. 5274 */ 5275 SQLITE_API int sqlite3_reset(sqlite3_stmt *pStmt); 5276 5277 /* 5278 ** CAPI3REF: Create Or Redefine SQL Functions 5279 ** KEYWORDS: {function creation routines} 5280 ** METHOD: sqlite3 5281 ** 5282 ** ^These functions (collectively known as "function creation routines") 5283 ** are used to add SQL functions or aggregates or to redefine the behavior 5284 ** of existing SQL functions or aggregates. The only differences between 5285 ** the three "sqlite3_create_function*" routines are the text encoding 5286 ** expected for the second parameter (the name of the function being 5287 ** created) and the presence or absence of a destructor callback for 5288 ** the application data pointer. Function sqlite3_create_window_function() 5289 ** is similar, but allows the user to supply the extra callback functions 5290 ** needed by [aggregate window functions]. 5291 ** 5292 ** ^The first parameter is the [database connection] to which the SQL 5293 ** function is to be added. ^If an application uses more than one database 5294 ** connection then application-defined SQL functions must be added 5295 ** to each database connection separately. 5296 ** 5297 ** ^The second parameter is the name of the SQL function to be created or 5298 ** redefined. ^The length of the name is limited to 255 bytes in a UTF-8 5299 ** representation, exclusive of the zero-terminator. ^Note that the name 5300 ** length limit is in UTF-8 bytes, not characters nor UTF-16 bytes. 5301 ** ^Any attempt to create a function with a longer name 5302 ** will result in [SQLITE_MISUSE] being returned. 5303 ** 5304 ** ^The third parameter (nArg) 5305 ** is the number of arguments that the SQL function or 5306 ** aggregate takes. ^If this parameter is -1, then the SQL function or 5307 ** aggregate may take any number of arguments between 0 and the limit 5308 ** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]). If the third 5309 ** parameter is less than -1 or greater than 127 then the behavior is 5310 ** undefined. 5311 ** 5312 ** ^The fourth parameter, eTextRep, specifies what 5313 ** [SQLITE_UTF8 | text encoding] this SQL function prefers for 5314 ** its parameters. The application should set this parameter to 5315 ** [SQLITE_UTF16LE] if the function implementation invokes 5316 ** [sqlite3_value_text16le()] on an input, or [SQLITE_UTF16BE] if the 5317 ** implementation invokes [sqlite3_value_text16be()] on an input, or 5318 ** [SQLITE_UTF16] if [sqlite3_value_text16()] is used, or [SQLITE_UTF8] 5319 ** otherwise. ^The same SQL function may be registered multiple times using 5320 ** different preferred text encodings, with different implementations for 5321 ** each encoding. 5322 ** ^When multiple implementations of the same function are available, SQLite 5323 ** will pick the one that involves the least amount of data conversion. 5324 ** 5325 ** ^The fourth parameter may optionally be ORed with [SQLITE_DETERMINISTIC] 5326 ** to signal that the function will always return the same result given 5327 ** the same inputs within a single SQL statement. Most SQL functions are 5328 ** deterministic. The built-in [random()] SQL function is an example of a 5329 ** function that is not deterministic. The SQLite query planner is able to 5330 ** perform additional optimizations on deterministic functions, so use 5331 ** of the [SQLITE_DETERMINISTIC] flag is recommended where possible. 5332 ** 5333 ** ^The fourth parameter may also optionally include the [SQLITE_DIRECTONLY] 5334 ** flag, which if present prevents the function from being invoked from 5335 ** within VIEWs, TRIGGERs, CHECK constraints, generated column expressions, 5336 ** index expressions, or the WHERE clause of partial indexes. 5337 ** 5338 ** For best security, the [SQLITE_DIRECTONLY] flag is recommended for 5339 ** all application-defined SQL functions that do not need to be 5340 ** used inside of triggers, view, CHECK constraints, or other elements of 5341 ** the database schema. This flags is especially recommended for SQL 5342 ** functions that have side effects or reveal internal application state. 5343 ** Without this flag, an attacker might be able to modify the schema of 5344 ** a database file to include invocations of the function with parameters 5345 ** chosen by the attacker, which the application will then execute when 5346 ** the database file is opened and read. 5347 ** 5348 ** ^(The fifth parameter is an arbitrary pointer. The implementation of the 5349 ** function can gain access to this pointer using [sqlite3_user_data()].)^ 5350 ** 5351 ** ^The sixth, seventh and eighth parameters passed to the three 5352 ** "sqlite3_create_function*" functions, xFunc, xStep and xFinal, are 5353 ** pointers to C-language functions that implement the SQL function or 5354 ** aggregate. ^A scalar SQL function requires an implementation of the xFunc 5355 ** callback only; NULL pointers must be passed as the xStep and xFinal 5356 ** parameters. ^An aggregate SQL function requires an implementation of xStep 5357 ** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing 5358 ** SQL function or aggregate, pass NULL pointers for all three function 5359 ** callbacks. 5360 ** 5361 ** ^The sixth, seventh, eighth and ninth parameters (xStep, xFinal, xValue 5362 ** and xInverse) passed to sqlite3_create_window_function are pointers to 5363 ** C-language callbacks that implement the new function. xStep and xFinal 5364 ** must both be non-NULL. xValue and xInverse may either both be NULL, in 5365 ** which case a regular aggregate function is created, or must both be 5366 ** non-NULL, in which case the new function may be used as either an aggregate 5367 ** or aggregate window function. More details regarding the implementation 5368 ** of aggregate window functions are 5369 ** [user-defined window functions|available here]. 5370 ** 5371 ** ^(If the final parameter to sqlite3_create_function_v2() or 5372 ** sqlite3_create_window_function() is not NULL, then it is destructor for 5373 ** the application data pointer. The destructor is invoked when the function 5374 ** is deleted, either by being overloaded or when the database connection 5375 ** closes.)^ ^The destructor is also invoked if the call to 5376 ** sqlite3_create_function_v2() fails. ^When the destructor callback is 5377 ** invoked, it is passed a single argument which is a copy of the application 5378 ** data pointer which was the fifth parameter to sqlite3_create_function_v2(). 5379 ** 5380 ** ^It is permitted to register multiple implementations of the same 5381 ** functions with the same name but with either differing numbers of 5382 ** arguments or differing preferred text encodings. ^SQLite will use 5383 ** the implementation that most closely matches the way in which the 5384 ** SQL function is used. ^A function implementation with a non-negative 5385 ** nArg parameter is a better match than a function implementation with 5386 ** a negative nArg. ^A function where the preferred text encoding 5387 ** matches the database encoding is a better 5388 ** match than a function where the encoding is different. 5389 ** ^A function where the encoding difference is between UTF16le and UTF16be 5390 ** is a closer match than a function where the encoding difference is 5391 ** between UTF8 and UTF16. 5392 ** 5393 ** ^Built-in functions may be overloaded by new application-defined functions. 5394 ** 5395 ** ^An application-defined function is permitted to call other 5396 ** SQLite interfaces. However, such calls must not 5397 ** close the database connection nor finalize or reset the prepared 5398 ** statement in which the function is running. 5399 */ 5400 SQLITE_API int sqlite3_create_function( 5401 sqlite3 *db, 5402 const char *zFunctionName, 5403 int nArg, 5404 int eTextRep, 5405 void *pApp, 5406 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 5407 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 5408 void (*xFinal)(sqlite3_context*) 5409 ); 5410 SQLITE_API int sqlite3_create_function16( 5411 sqlite3 *db, 5412 const void *zFunctionName, 5413 int nArg, 5414 int eTextRep, 5415 void *pApp, 5416 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 5417 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 5418 void (*xFinal)(sqlite3_context*) 5419 ); 5420 SQLITE_API int sqlite3_create_function_v2( 5421 sqlite3 *db, 5422 const char *zFunctionName, 5423 int nArg, 5424 int eTextRep, 5425 void *pApp, 5426 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 5427 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 5428 void (*xFinal)(sqlite3_context*), 5429 void(*xDestroy)(void*) 5430 ); 5431 SQLITE_API int sqlite3_create_window_function( 5432 sqlite3 *db, 5433 const char *zFunctionName, 5434 int nArg, 5435 int eTextRep, 5436 void *pApp, 5437 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 5438 void (*xFinal)(sqlite3_context*), 5439 void (*xValue)(sqlite3_context*), 5440 void (*xInverse)(sqlite3_context*,int,sqlite3_value**), 5441 void(*xDestroy)(void*) 5442 ); 5443 5444 /* 5445 ** CAPI3REF: Text Encodings 5446 ** 5447 ** These constant define integer codes that represent the various 5448 ** text encodings supported by SQLite. 5449 */ 5450 #define SQLITE_UTF8 1 /* IMP: R-37514-35566 */ 5451 #define SQLITE_UTF16LE 2 /* IMP: R-03371-37637 */ 5452 #define SQLITE_UTF16BE 3 /* IMP: R-51971-34154 */ 5453 #define SQLITE_UTF16 4 /* Use native byte order */ 5454 #define SQLITE_ANY 5 /* Deprecated */ 5455 #define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */ 5456 5457 /* 5458 ** CAPI3REF: Function Flags 5459 ** 5460 ** These constants may be ORed together with the 5461 ** [SQLITE_UTF8 | preferred text encoding] as the fourth argument 5462 ** to [sqlite3_create_function()], [sqlite3_create_function16()], or 5463 ** [sqlite3_create_function_v2()]. 5464 ** 5465 ** <dl> 5466 ** [[SQLITE_DETERMINISTIC]] <dt>SQLITE_DETERMINISTIC</dt><dd> 5467 ** The SQLITE_DETERMINISTIC flag means that the new function always gives 5468 ** the same output when the input parameters are the same. 5469 ** The [abs|abs() function] is deterministic, for example, but 5470 ** [randomblob|randomblob()] is not. Functions must 5471 ** be deterministic in order to be used in certain contexts such as 5472 ** with the WHERE clause of [partial indexes] or in [generated columns]. 5473 ** SQLite might also optimize deterministic functions by factoring them 5474 ** out of inner loops. 5475 ** </dd> 5476 ** 5477 ** [[SQLITE_DIRECTONLY]] <dt>SQLITE_DIRECTONLY</dt><dd> 5478 ** The SQLITE_DIRECTONLY flag means that the function may only be invoked 5479 ** from top-level SQL, and cannot be used in VIEWs or TRIGGERs nor in 5480 ** schema structures such as [CHECK constraints], [DEFAULT clauses], 5481 ** [expression indexes], [partial indexes], or [generated columns]. 5482 ** <p> 5483 ** The SQLITE_DIRECTONLY flag is recommended for any 5484 ** [application-defined SQL function] 5485 ** that has side-effects or that could potentially leak sensitive information. 5486 ** This will prevent attacks in which an application is tricked 5487 ** into using a database file that has had its schema surreptiously 5488 ** modified to invoke the application-defined function in ways that are 5489 ** harmful. 5490 ** <p> 5491 ** Some people say it is good practice to set SQLITE_DIRECTONLY on all 5492 ** [application-defined SQL functions], regardless of whether or not they 5493 ** are security sensitive, as doing so prevents those functions from being used 5494 ** inside of the database schema, and thus ensures that the database 5495 ** can be inspected and modified using generic tools (such as the [CLI]) 5496 ** that do not have access to the application-defined functions. 5497 ** </dd> 5498 ** 5499 ** [[SQLITE_INNOCUOUS]] <dt>SQLITE_INNOCUOUS</dt><dd> 5500 ** The SQLITE_INNOCUOUS flag means that the function is unlikely 5501 ** to cause problems even if misused. An innocuous function should have 5502 ** no side effects and should not depend on any values other than its 5503 ** input parameters. The [abs|abs() function] is an example of an 5504 ** innocuous function. 5505 ** The [load_extension() SQL function] is not innocuous because of its 5506 ** side effects. 5507 ** <p> SQLITE_INNOCUOUS is similar to SQLITE_DETERMINISTIC, but is not 5508 ** exactly the same. The [random|random() function] is an example of a 5509 ** function that is innocuous but not deterministic. 5510 ** <p>Some heightened security settings 5511 ** ([SQLITE_DBCONFIG_TRUSTED_SCHEMA] and [PRAGMA trusted_schema=OFF]) 5512 ** disable the use of SQL functions inside views and triggers and in 5513 ** schema structures such as [CHECK constraints], [DEFAULT clauses], 5514 ** [expression indexes], [partial indexes], and [generated columns] unless 5515 ** the function is tagged with SQLITE_INNOCUOUS. Most built-in functions 5516 ** are innocuous. Developers are advised to avoid using the 5517 ** SQLITE_INNOCUOUS flag for application-defined functions unless the 5518 ** function has been carefully audited and found to be free of potentially 5519 ** security-adverse side-effects and information-leaks. 5520 ** </dd> 5521 ** 5522 ** [[SQLITE_SUBTYPE]] <dt>SQLITE_SUBTYPE</dt><dd> 5523 ** The SQLITE_SUBTYPE flag indicates to SQLite that a function may call 5524 ** [sqlite3_value_subtype()] to inspect the sub-types of its arguments. 5525 ** Specifying this flag makes no difference for scalar or aggregate user 5526 ** functions. However, if it is not specified for a user-defined window 5527 ** function, then any sub-types belonging to arguments passed to the window 5528 ** function may be discarded before the window function is called (i.e. 5529 ** sqlite3_value_subtype() will always return 0). 5530 ** </dd> 5531 ** </dl> 5532 */ 5533 #define SQLITE_DETERMINISTIC 0x000000800 5534 #define SQLITE_DIRECTONLY 0x000080000 5535 #define SQLITE_SUBTYPE 0x000100000 5536 #define SQLITE_INNOCUOUS 0x000200000 5537 5538 /* 5539 ** CAPI3REF: Deprecated Functions 5540 ** DEPRECATED 5541 ** 5542 ** These functions are [deprecated]. In order to maintain 5543 ** backwards compatibility with older code, these functions continue 5544 ** to be supported. However, new applications should avoid 5545 ** the use of these functions. To encourage programmers to avoid 5546 ** these functions, we will not explain what they do. 5547 */ 5548 #ifndef SQLITE_OMIT_DEPRECATED 5549 SQLITE_API SQLITE_DEPRECATED int sqlite3_aggregate_count(sqlite3_context*); 5550 SQLITE_API SQLITE_DEPRECATED int sqlite3_expired(sqlite3_stmt*); 5551 SQLITE_API SQLITE_DEPRECATED int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*); 5552 SQLITE_API SQLITE_DEPRECATED int sqlite3_global_recover(void); 5553 SQLITE_API SQLITE_DEPRECATED void sqlite3_thread_cleanup(void); 5554 SQLITE_API SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int), 5555 void*,sqlite3_int64); 5556 #endif 5557 5558 /* 5559 ** CAPI3REF: Obtaining SQL Values 5560 ** METHOD: sqlite3_value 5561 ** 5562 ** <b>Summary:</b> 5563 ** <blockquote><table border=0 cellpadding=0 cellspacing=0> 5564 ** <tr><td><b>sqlite3_value_blob</b><td>→<td>BLOB value 5565 ** <tr><td><b>sqlite3_value_double</b><td>→<td>REAL value 5566 ** <tr><td><b>sqlite3_value_int</b><td>→<td>32-bit INTEGER value 5567 ** <tr><td><b>sqlite3_value_int64</b><td>→<td>64-bit INTEGER value 5568 ** <tr><td><b>sqlite3_value_pointer</b><td>→<td>Pointer value 5569 ** <tr><td><b>sqlite3_value_text</b><td>→<td>UTF-8 TEXT value 5570 ** <tr><td><b>sqlite3_value_text16</b><td>→<td>UTF-16 TEXT value in 5571 ** the native byteorder 5572 ** <tr><td><b>sqlite3_value_text16be</b><td>→<td>UTF-16be TEXT value 5573 ** <tr><td><b>sqlite3_value_text16le</b><td>→<td>UTF-16le TEXT value 5574 ** <tr><td> <td> <td> 5575 ** <tr><td><b>sqlite3_value_bytes</b><td>→<td>Size of a BLOB 5576 ** or a UTF-8 TEXT in bytes 5577 ** <tr><td><b>sqlite3_value_bytes16 </b> 5578 ** <td>→ <td>Size of UTF-16 5579 ** TEXT in bytes 5580 ** <tr><td><b>sqlite3_value_type</b><td>→<td>Default 5581 ** datatype of the value 5582 ** <tr><td><b>sqlite3_value_numeric_type </b> 5583 ** <td>→ <td>Best numeric datatype of the value 5584 ** <tr><td><b>sqlite3_value_nochange </b> 5585 ** <td>→ <td>True if the column is unchanged in an UPDATE 5586 ** against a virtual table. 5587 ** <tr><td><b>sqlite3_value_frombind </b> 5588 ** <td>→ <td>True if value originated from a [bound parameter] 5589 ** </table></blockquote> 5590 ** 5591 ** <b>Details:</b> 5592 ** 5593 ** These routines extract type, size, and content information from 5594 ** [protected sqlite3_value] objects. Protected sqlite3_value objects 5595 ** are used to pass parameter information into the functions that 5596 ** implement [application-defined SQL functions] and [virtual tables]. 5597 ** 5598 ** These routines work only with [protected sqlite3_value] objects. 5599 ** Any attempt to use these routines on an [unprotected sqlite3_value] 5600 ** is not threadsafe. 5601 ** 5602 ** ^These routines work just like the corresponding [column access functions] 5603 ** except that these routines take a single [protected sqlite3_value] object 5604 ** pointer instead of a [sqlite3_stmt*] pointer and an integer column number. 5605 ** 5606 ** ^The sqlite3_value_text16() interface extracts a UTF-16 string 5607 ** in the native byte-order of the host machine. ^The 5608 ** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces 5609 ** extract UTF-16 strings as big-endian and little-endian respectively. 5610 ** 5611 ** ^If [sqlite3_value] object V was initialized 5612 ** using [sqlite3_bind_pointer(S,I,P,X,D)] or [sqlite3_result_pointer(C,P,X,D)] 5613 ** and if X and Y are strings that compare equal according to strcmp(X,Y), 5614 ** then sqlite3_value_pointer(V,Y) will return the pointer P. ^Otherwise, 5615 ** sqlite3_value_pointer(V,Y) returns a NULL. The sqlite3_bind_pointer() 5616 ** routine is part of the [pointer passing interface] added for SQLite 3.20.0. 5617 ** 5618 ** ^(The sqlite3_value_type(V) interface returns the 5619 ** [SQLITE_INTEGER | datatype code] for the initial datatype of the 5620 ** [sqlite3_value] object V. The returned value is one of [SQLITE_INTEGER], 5621 ** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL].)^ 5622 ** Other interfaces might change the datatype for an sqlite3_value object. 5623 ** For example, if the datatype is initially SQLITE_INTEGER and 5624 ** sqlite3_value_text(V) is called to extract a text value for that 5625 ** integer, then subsequent calls to sqlite3_value_type(V) might return 5626 ** SQLITE_TEXT. Whether or not a persistent internal datatype conversion 5627 ** occurs is undefined and may change from one release of SQLite to the next. 5628 ** 5629 ** ^(The sqlite3_value_numeric_type() interface attempts to apply 5630 ** numeric affinity to the value. This means that an attempt is 5631 ** made to convert the value to an integer or floating point. If 5632 ** such a conversion is possible without loss of information (in other 5633 ** words, if the value is a string that looks like a number) 5634 ** then the conversion is performed. Otherwise no conversion occurs. 5635 ** The [SQLITE_INTEGER | datatype] after conversion is returned.)^ 5636 ** 5637 ** ^Within the [xUpdate] method of a [virtual table], the 5638 ** sqlite3_value_nochange(X) interface returns true if and only if 5639 ** the column corresponding to X is unchanged by the UPDATE operation 5640 ** that the xUpdate method call was invoked to implement and if 5641 ** and the prior [xColumn] method call that was invoked to extracted 5642 ** the value for that column returned without setting a result (probably 5643 ** because it queried [sqlite3_vtab_nochange()] and found that the column 5644 ** was unchanging). ^Within an [xUpdate] method, any value for which 5645 ** sqlite3_value_nochange(X) is true will in all other respects appear 5646 ** to be a NULL value. If sqlite3_value_nochange(X) is invoked anywhere other 5647 ** than within an [xUpdate] method call for an UPDATE statement, then 5648 ** the return value is arbitrary and meaningless. 5649 ** 5650 ** ^The sqlite3_value_frombind(X) interface returns non-zero if the 5651 ** value X originated from one of the [sqlite3_bind_int|sqlite3_bind()] 5652 ** interfaces. ^If X comes from an SQL literal value, or a table column, 5653 ** or an expression, then sqlite3_value_frombind(X) returns zero. 5654 ** 5655 ** Please pay particular attention to the fact that the pointer returned 5656 ** from [sqlite3_value_blob()], [sqlite3_value_text()], or 5657 ** [sqlite3_value_text16()] can be invalidated by a subsequent call to 5658 ** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()], 5659 ** or [sqlite3_value_text16()]. 5660 ** 5661 ** These routines must be called from the same thread as 5662 ** the SQL function that supplied the [sqlite3_value*] parameters. 5663 ** 5664 ** As long as the input parameter is correct, these routines can only 5665 ** fail if an out-of-memory error occurs during a format conversion. 5666 ** Only the following subset of interfaces are subject to out-of-memory 5667 ** errors: 5668 ** 5669 ** <ul> 5670 ** <li> sqlite3_value_blob() 5671 ** <li> sqlite3_value_text() 5672 ** <li> sqlite3_value_text16() 5673 ** <li> sqlite3_value_text16le() 5674 ** <li> sqlite3_value_text16be() 5675 ** <li> sqlite3_value_bytes() 5676 ** <li> sqlite3_value_bytes16() 5677 ** </ul> 5678 ** 5679 ** If an out-of-memory error occurs, then the return value from these 5680 ** routines is the same as if the column had contained an SQL NULL value. 5681 ** Valid SQL NULL returns can be distinguished from out-of-memory errors 5682 ** by invoking the [sqlite3_errcode()] immediately after the suspect 5683 ** return value is obtained and before any 5684 ** other SQLite interface is called on the same [database connection]. 5685 */ 5686 SQLITE_API const void *sqlite3_value_blob(sqlite3_value*); 5687 SQLITE_API double sqlite3_value_double(sqlite3_value*); 5688 SQLITE_API int sqlite3_value_int(sqlite3_value*); 5689 SQLITE_API sqlite3_int64 sqlite3_value_int64(sqlite3_value*); 5690 SQLITE_API void *sqlite3_value_pointer(sqlite3_value*, const char*); 5691 SQLITE_API const unsigned char *sqlite3_value_text(sqlite3_value*); 5692 SQLITE_API const void *sqlite3_value_text16(sqlite3_value*); 5693 SQLITE_API const void *sqlite3_value_text16le(sqlite3_value*); 5694 SQLITE_API const void *sqlite3_value_text16be(sqlite3_value*); 5695 SQLITE_API int sqlite3_value_bytes(sqlite3_value*); 5696 SQLITE_API int sqlite3_value_bytes16(sqlite3_value*); 5697 SQLITE_API int sqlite3_value_type(sqlite3_value*); 5698 SQLITE_API int sqlite3_value_numeric_type(sqlite3_value*); 5699 SQLITE_API int sqlite3_value_nochange(sqlite3_value*); 5700 SQLITE_API int sqlite3_value_frombind(sqlite3_value*); 5701 5702 /* 5703 ** CAPI3REF: Report the internal text encoding state of an sqlite3_value object 5704 ** METHOD: sqlite3_value 5705 ** 5706 ** ^(The sqlite3_value_encoding(X) interface returns one of [SQLITE_UTF8], 5707 ** [SQLITE_UTF16BE], or [SQLITE_UTF16LE] according to the current text encoding 5708 ** of the value X, assuming that X has type TEXT.)^ If sqlite3_value_type(X) 5709 ** returns something other than SQLITE_TEXT, then the return value from 5710 ** sqlite3_value_encoding(X) is meaningless. ^Calls to 5711 ** [sqlite3_value_text(X)], [sqlite3_value_text16(X)], [sqlite3_value_text16be(X)], 5712 ** [sqlite3_value_text16le(X)], [sqlite3_value_bytes(X)], or 5713 ** [sqlite3_value_bytes16(X)] might change the encoding of the value X and 5714 ** thus change the return from subsequent calls to sqlite3_value_encoding(X). 5715 ** 5716 ** This routine is intended for used by applications that test and validate 5717 ** the SQLite implementation. This routine is inquiring about the opaque 5718 ** internal state of an [sqlite3_value] object. Ordinary applications should 5719 ** not need to know what the internal state of an sqlite3_value object is and 5720 ** hence should not need to use this interface. 5721 */ 5722 SQLITE_API int sqlite3_value_encoding(sqlite3_value*); 5723 5724 /* 5725 ** CAPI3REF: Finding The Subtype Of SQL Values 5726 ** METHOD: sqlite3_value 5727 ** 5728 ** The sqlite3_value_subtype(V) function returns the subtype for 5729 ** an [application-defined SQL function] argument V. The subtype 5730 ** information can be used to pass a limited amount of context from 5731 ** one SQL function to another. Use the [sqlite3_result_subtype()] 5732 ** routine to set the subtype for the return value of an SQL function. 5733 */ 5734 SQLITE_API unsigned int sqlite3_value_subtype(sqlite3_value*); 5735 5736 /* 5737 ** CAPI3REF: Copy And Free SQL Values 5738 ** METHOD: sqlite3_value 5739 ** 5740 ** ^The sqlite3_value_dup(V) interface makes a copy of the [sqlite3_value] 5741 ** object D and returns a pointer to that copy. ^The [sqlite3_value] returned 5742 ** is a [protected sqlite3_value] object even if the input is not. 5743 ** ^The sqlite3_value_dup(V) interface returns NULL if V is NULL or if a 5744 ** memory allocation fails. ^If V is a [pointer value], then the result 5745 ** of sqlite3_value_dup(V) is a NULL value. 5746 ** 5747 ** ^The sqlite3_value_free(V) interface frees an [sqlite3_value] object 5748 ** previously obtained from [sqlite3_value_dup()]. ^If V is a NULL pointer 5749 ** then sqlite3_value_free(V) is a harmless no-op. 5750 */ 5751 SQLITE_API sqlite3_value *sqlite3_value_dup(const sqlite3_value*); 5752 SQLITE_API void sqlite3_value_free(sqlite3_value*); 5753 5754 /* 5755 ** CAPI3REF: Obtain Aggregate Function Context 5756 ** METHOD: sqlite3_context 5757 ** 5758 ** Implementations of aggregate SQL functions use this 5759 ** routine to allocate memory for storing their state. 5760 ** 5761 ** ^The first time the sqlite3_aggregate_context(C,N) routine is called 5762 ** for a particular aggregate function, SQLite allocates 5763 ** N bytes of memory, zeroes out that memory, and returns a pointer 5764 ** to the new memory. ^On second and subsequent calls to 5765 ** sqlite3_aggregate_context() for the same aggregate function instance, 5766 ** the same buffer is returned. Sqlite3_aggregate_context() is normally 5767 ** called once for each invocation of the xStep callback and then one 5768 ** last time when the xFinal callback is invoked. ^(When no rows match 5769 ** an aggregate query, the xStep() callback of the aggregate function 5770 ** implementation is never called and xFinal() is called exactly once. 5771 ** In those cases, sqlite3_aggregate_context() might be called for the 5772 ** first time from within xFinal().)^ 5773 ** 5774 ** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer 5775 ** when first called if N is less than or equal to zero or if a memory 5776 ** allocation error occurs. 5777 ** 5778 ** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is 5779 ** determined by the N parameter on first successful call. Changing the 5780 ** value of N in any subsequent call to sqlite3_aggregate_context() within 5781 ** the same aggregate function instance will not resize the memory 5782 ** allocation.)^ Within the xFinal callback, it is customary to set 5783 ** N=0 in calls to sqlite3_aggregate_context(C,N) so that no 5784 ** pointless memory allocations occur. 5785 ** 5786 ** ^SQLite automatically frees the memory allocated by 5787 ** sqlite3_aggregate_context() when the aggregate query concludes. 5788 ** 5789 ** The first parameter must be a copy of the 5790 ** [sqlite3_context | SQL function context] that is the first parameter 5791 ** to the xStep or xFinal callback routine that implements the aggregate 5792 ** function. 5793 ** 5794 ** This routine must be called from the same thread in which 5795 ** the aggregate SQL function is running. 5796 */ 5797 SQLITE_API void *sqlite3_aggregate_context(sqlite3_context*, int nBytes); 5798 5799 /* 5800 ** CAPI3REF: User Data For Functions 5801 ** METHOD: sqlite3_context 5802 ** 5803 ** ^The sqlite3_user_data() interface returns a copy of 5804 ** the pointer that was the pUserData parameter (the 5th parameter) 5805 ** of the [sqlite3_create_function()] 5806 ** and [sqlite3_create_function16()] routines that originally 5807 ** registered the application defined function. 5808 ** 5809 ** This routine must be called from the same thread in which 5810 ** the application-defined function is running. 5811 */ 5812 SQLITE_API void *sqlite3_user_data(sqlite3_context*); 5813 5814 /* 5815 ** CAPI3REF: Database Connection For Functions 5816 ** METHOD: sqlite3_context 5817 ** 5818 ** ^The sqlite3_context_db_handle() interface returns a copy of 5819 ** the pointer to the [database connection] (the 1st parameter) 5820 ** of the [sqlite3_create_function()] 5821 ** and [sqlite3_create_function16()] routines that originally 5822 ** registered the application defined function. 5823 */ 5824 SQLITE_API sqlite3 *sqlite3_context_db_handle(sqlite3_context*); 5825 5826 /* 5827 ** CAPI3REF: Function Auxiliary Data 5828 ** METHOD: sqlite3_context 5829 ** 5830 ** These functions may be used by (non-aggregate) SQL functions to 5831 ** associate metadata with argument values. If the same value is passed to 5832 ** multiple invocations of the same SQL function during query execution, under 5833 ** some circumstances the associated metadata may be preserved. An example 5834 ** of where this might be useful is in a regular-expression matching 5835 ** function. The compiled version of the regular expression can be stored as 5836 ** metadata associated with the pattern string. 5837 ** Then as long as the pattern string remains the same, 5838 ** the compiled regular expression can be reused on multiple 5839 ** invocations of the same function. 5840 ** 5841 ** ^The sqlite3_get_auxdata(C,N) interface returns a pointer to the metadata 5842 ** associated by the sqlite3_set_auxdata(C,N,P,X) function with the Nth argument 5843 ** value to the application-defined function. ^N is zero for the left-most 5844 ** function argument. ^If there is no metadata 5845 ** associated with the function argument, the sqlite3_get_auxdata(C,N) interface 5846 ** returns a NULL pointer. 5847 ** 5848 ** ^The sqlite3_set_auxdata(C,N,P,X) interface saves P as metadata for the N-th 5849 ** argument of the application-defined function. ^Subsequent 5850 ** calls to sqlite3_get_auxdata(C,N) return P from the most recent 5851 ** sqlite3_set_auxdata(C,N,P,X) call if the metadata is still valid or 5852 ** NULL if the metadata has been discarded. 5853 ** ^After each call to sqlite3_set_auxdata(C,N,P,X) where X is not NULL, 5854 ** SQLite will invoke the destructor function X with parameter P exactly 5855 ** once, when the metadata is discarded. 5856 ** SQLite is free to discard the metadata at any time, including: <ul> 5857 ** <li> ^(when the corresponding function parameter changes)^, or 5858 ** <li> ^(when [sqlite3_reset()] or [sqlite3_finalize()] is called for the 5859 ** SQL statement)^, or 5860 ** <li> ^(when sqlite3_set_auxdata() is invoked again on the same 5861 ** parameter)^, or 5862 ** <li> ^(during the original sqlite3_set_auxdata() call when a memory 5863 ** allocation error occurs.)^ </ul> 5864 ** 5865 ** Note the last bullet in particular. The destructor X in 5866 ** sqlite3_set_auxdata(C,N,P,X) might be called immediately, before the 5867 ** sqlite3_set_auxdata() interface even returns. Hence sqlite3_set_auxdata() 5868 ** should be called near the end of the function implementation and the 5869 ** function implementation should not make any use of P after 5870 ** sqlite3_set_auxdata() has been called. 5871 ** 5872 ** ^(In practice, metadata is preserved between function calls for 5873 ** function parameters that are compile-time constants, including literal 5874 ** values and [parameters] and expressions composed from the same.)^ 5875 ** 5876 ** The value of the N parameter to these interfaces should be non-negative. 5877 ** Future enhancements may make use of negative N values to define new 5878 ** kinds of function caching behavior. 5879 ** 5880 ** These routines must be called from the same thread in which 5881 ** the SQL function is running. 5882 */ 5883 SQLITE_API void *sqlite3_get_auxdata(sqlite3_context*, int N); 5884 SQLITE_API void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*)); 5885 5886 5887 /* 5888 ** CAPI3REF: Constants Defining Special Destructor Behavior 5889 ** 5890 ** These are special values for the destructor that is passed in as the 5891 ** final argument to routines like [sqlite3_result_blob()]. ^If the destructor 5892 ** argument is SQLITE_STATIC, it means that the content pointer is constant 5893 ** and will never change. It does not need to be destroyed. ^The 5894 ** SQLITE_TRANSIENT value means that the content will likely change in 5895 ** the near future and that SQLite should make its own private copy of 5896 ** the content before returning. 5897 ** 5898 ** The typedef is necessary to work around problems in certain 5899 ** C++ compilers. 5900 */ 5901 typedef void (*sqlite3_destructor_type)(void*); 5902 #define SQLITE_STATIC ((sqlite3_destructor_type)0) 5903 #define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1) 5904 5905 /* 5906 ** CAPI3REF: Setting The Result Of An SQL Function 5907 ** METHOD: sqlite3_context 5908 ** 5909 ** These routines are used by the xFunc or xFinal callbacks that 5910 ** implement SQL functions and aggregates. See 5911 ** [sqlite3_create_function()] and [sqlite3_create_function16()] 5912 ** for additional information. 5913 ** 5914 ** These functions work very much like the [parameter binding] family of 5915 ** functions used to bind values to host parameters in prepared statements. 5916 ** Refer to the [SQL parameter] documentation for additional information. 5917 ** 5918 ** ^The sqlite3_result_blob() interface sets the result from 5919 ** an application-defined function to be the BLOB whose content is pointed 5920 ** to by the second parameter and which is N bytes long where N is the 5921 ** third parameter. 5922 ** 5923 ** ^The sqlite3_result_zeroblob(C,N) and sqlite3_result_zeroblob64(C,N) 5924 ** interfaces set the result of the application-defined function to be 5925 ** a BLOB containing all zero bytes and N bytes in size. 5926 ** 5927 ** ^The sqlite3_result_double() interface sets the result from 5928 ** an application-defined function to be a floating point value specified 5929 ** by its 2nd argument. 5930 ** 5931 ** ^The sqlite3_result_error() and sqlite3_result_error16() functions 5932 ** cause the implemented SQL function to throw an exception. 5933 ** ^SQLite uses the string pointed to by the 5934 ** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16() 5935 ** as the text of an error message. ^SQLite interprets the error 5936 ** message string from sqlite3_result_error() as UTF-8. ^SQLite 5937 ** interprets the string from sqlite3_result_error16() as UTF-16 using 5938 ** the same [byte-order determination rules] as [sqlite3_bind_text16()]. 5939 ** ^If the third parameter to sqlite3_result_error() 5940 ** or sqlite3_result_error16() is negative then SQLite takes as the error 5941 ** message all text up through the first zero character. 5942 ** ^If the third parameter to sqlite3_result_error() or 5943 ** sqlite3_result_error16() is non-negative then SQLite takes that many 5944 ** bytes (not characters) from the 2nd parameter as the error message. 5945 ** ^The sqlite3_result_error() and sqlite3_result_error16() 5946 ** routines make a private copy of the error message text before 5947 ** they return. Hence, the calling function can deallocate or 5948 ** modify the text after they return without harm. 5949 ** ^The sqlite3_result_error_code() function changes the error code 5950 ** returned by SQLite as a result of an error in a function. ^By default, 5951 ** the error code is SQLITE_ERROR. ^A subsequent call to sqlite3_result_error() 5952 ** or sqlite3_result_error16() resets the error code to SQLITE_ERROR. 5953 ** 5954 ** ^The sqlite3_result_error_toobig() interface causes SQLite to throw an 5955 ** error indicating that a string or BLOB is too long to represent. 5956 ** 5957 ** ^The sqlite3_result_error_nomem() interface causes SQLite to throw an 5958 ** error indicating that a memory allocation failed. 5959 ** 5960 ** ^The sqlite3_result_int() interface sets the return value 5961 ** of the application-defined function to be the 32-bit signed integer 5962 ** value given in the 2nd argument. 5963 ** ^The sqlite3_result_int64() interface sets the return value 5964 ** of the application-defined function to be the 64-bit signed integer 5965 ** value given in the 2nd argument. 5966 ** 5967 ** ^The sqlite3_result_null() interface sets the return value 5968 ** of the application-defined function to be NULL. 5969 ** 5970 ** ^The sqlite3_result_text(), sqlite3_result_text16(), 5971 ** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces 5972 ** set the return value of the application-defined function to be 5973 ** a text string which is represented as UTF-8, UTF-16 native byte order, 5974 ** UTF-16 little endian, or UTF-16 big endian, respectively. 5975 ** ^The sqlite3_result_text64() interface sets the return value of an 5976 ** application-defined function to be a text string in an encoding 5977 ** specified by the fifth (and last) parameter, which must be one 5978 ** of [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE]. 5979 ** ^SQLite takes the text result from the application from 5980 ** the 2nd parameter of the sqlite3_result_text* interfaces. 5981 ** ^If the 3rd parameter to any of the sqlite3_result_text* interfaces 5982 ** other than sqlite3_result_text64() is negative, then SQLite computes 5983 ** the string length itself by searching the 2nd parameter for the first 5984 ** zero character. 5985 ** ^If the 3rd parameter to the sqlite3_result_text* interfaces 5986 ** is non-negative, then as many bytes (not characters) of the text 5987 ** pointed to by the 2nd parameter are taken as the application-defined 5988 ** function result. If the 3rd parameter is non-negative, then it 5989 ** must be the byte offset into the string where the NUL terminator would 5990 ** appear if the string where NUL terminated. If any NUL characters occur 5991 ** in the string at a byte offset that is less than the value of the 3rd 5992 ** parameter, then the resulting string will contain embedded NULs and the 5993 ** result of expressions operating on strings with embedded NULs is undefined. 5994 ** ^If the 4th parameter to the sqlite3_result_text* interfaces 5995 ** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that 5996 ** function as the destructor on the text or BLOB result when it has 5997 ** finished using that result. 5998 ** ^If the 4th parameter to the sqlite3_result_text* interfaces or to 5999 ** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite 6000 ** assumes that the text or BLOB result is in constant space and does not 6001 ** copy the content of the parameter nor call a destructor on the content 6002 ** when it has finished using that result. 6003 ** ^If the 4th parameter to the sqlite3_result_text* interfaces 6004 ** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT 6005 ** then SQLite makes a copy of the result into space obtained 6006 ** from [sqlite3_malloc()] before it returns. 6007 ** 6008 ** ^For the sqlite3_result_text16(), sqlite3_result_text16le(), and 6009 ** sqlite3_result_text16be() routines, and for sqlite3_result_text64() 6010 ** when the encoding is not UTF8, if the input UTF16 begins with a 6011 ** byte-order mark (BOM, U+FEFF) then the BOM is removed from the 6012 ** string and the rest of the string is interpreted according to the 6013 ** byte-order specified by the BOM. ^The byte-order specified by 6014 ** the BOM at the beginning of the text overrides the byte-order 6015 ** specified by the interface procedure. ^So, for example, if 6016 ** sqlite3_result_text16le() is invoked with text that begins 6017 ** with bytes 0xfe, 0xff (a big-endian byte-order mark) then the 6018 ** first two bytes of input are skipped and the remaining input 6019 ** is interpreted as UTF16BE text. 6020 ** 6021 ** ^For UTF16 input text to the sqlite3_result_text16(), 6022 ** sqlite3_result_text16be(), sqlite3_result_text16le(), and 6023 ** sqlite3_result_text64() routines, if the text contains invalid 6024 ** UTF16 characters, the invalid characters might be converted 6025 ** into the unicode replacement character, U+FFFD. 6026 ** 6027 ** ^The sqlite3_result_value() interface sets the result of 6028 ** the application-defined function to be a copy of the 6029 ** [unprotected sqlite3_value] object specified by the 2nd parameter. ^The 6030 ** sqlite3_result_value() interface makes a copy of the [sqlite3_value] 6031 ** so that the [sqlite3_value] specified in the parameter may change or 6032 ** be deallocated after sqlite3_result_value() returns without harm. 6033 ** ^A [protected sqlite3_value] object may always be used where an 6034 ** [unprotected sqlite3_value] object is required, so either 6035 ** kind of [sqlite3_value] object can be used with this interface. 6036 ** 6037 ** ^The sqlite3_result_pointer(C,P,T,D) interface sets the result to an 6038 ** SQL NULL value, just like [sqlite3_result_null(C)], except that it 6039 ** also associates the host-language pointer P or type T with that 6040 ** NULL value such that the pointer can be retrieved within an 6041 ** [application-defined SQL function] using [sqlite3_value_pointer()]. 6042 ** ^If the D parameter is not NULL, then it is a pointer to a destructor 6043 ** for the P parameter. ^SQLite invokes D with P as its only argument 6044 ** when SQLite is finished with P. The T parameter should be a static 6045 ** string and preferably a string literal. The sqlite3_result_pointer() 6046 ** routine is part of the [pointer passing interface] added for SQLite 3.20.0. 6047 ** 6048 ** If these routines are called from within the different thread 6049 ** than the one containing the application-defined function that received 6050 ** the [sqlite3_context] pointer, the results are undefined. 6051 */ 6052 SQLITE_API void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*)); 6053 SQLITE_API void sqlite3_result_blob64(sqlite3_context*,const void*, 6054 sqlite3_uint64,void(*)(void*)); 6055 SQLITE_API void sqlite3_result_double(sqlite3_context*, double); 6056 SQLITE_API void sqlite3_result_error(sqlite3_context*, const char*, int); 6057 SQLITE_API void sqlite3_result_error16(sqlite3_context*, const void*, int); 6058 SQLITE_API void sqlite3_result_error_toobig(sqlite3_context*); 6059 SQLITE_API void sqlite3_result_error_nomem(sqlite3_context*); 6060 SQLITE_API void sqlite3_result_error_code(sqlite3_context*, int); 6061 SQLITE_API void sqlite3_result_int(sqlite3_context*, int); 6062 SQLITE_API void sqlite3_result_int64(sqlite3_context*, sqlite3_int64); 6063 SQLITE_API void sqlite3_result_null(sqlite3_context*); 6064 SQLITE_API void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*)); 6065 SQLITE_API void sqlite3_result_text64(sqlite3_context*, const char*,sqlite3_uint64, 6066 void(*)(void*), unsigned char encoding); 6067 SQLITE_API void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*)); 6068 SQLITE_API void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*)); 6069 SQLITE_API void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*)); 6070 SQLITE_API void sqlite3_result_value(sqlite3_context*, sqlite3_value*); 6071 SQLITE_API void sqlite3_result_pointer(sqlite3_context*, void*,const char*,void(*)(void*)); 6072 SQLITE_API void sqlite3_result_zeroblob(sqlite3_context*, int n); 6073 SQLITE_API int sqlite3_result_zeroblob64(sqlite3_context*, sqlite3_uint64 n); 6074 6075 6076 /* 6077 ** CAPI3REF: Setting The Subtype Of An SQL Function 6078 ** METHOD: sqlite3_context 6079 ** 6080 ** The sqlite3_result_subtype(C,T) function causes the subtype of 6081 ** the result from the [application-defined SQL function] with 6082 ** [sqlite3_context] C to be the value T. Only the lower 8 bits 6083 ** of the subtype T are preserved in current versions of SQLite; 6084 ** higher order bits are discarded. 6085 ** The number of subtype bytes preserved by SQLite might increase 6086 ** in future releases of SQLite. 6087 */ 6088 SQLITE_API void sqlite3_result_subtype(sqlite3_context*,unsigned int); 6089 6090 /* 6091 ** CAPI3REF: Define New Collating Sequences 6092 ** METHOD: sqlite3 6093 ** 6094 ** ^These functions add, remove, or modify a [collation] associated 6095 ** with the [database connection] specified as the first argument. 6096 ** 6097 ** ^The name of the collation is a UTF-8 string 6098 ** for sqlite3_create_collation() and sqlite3_create_collation_v2() 6099 ** and a UTF-16 string in native byte order for sqlite3_create_collation16(). 6100 ** ^Collation names that compare equal according to [sqlite3_strnicmp()] are 6101 ** considered to be the same name. 6102 ** 6103 ** ^(The third argument (eTextRep) must be one of the constants: 6104 ** <ul> 6105 ** <li> [SQLITE_UTF8], 6106 ** <li> [SQLITE_UTF16LE], 6107 ** <li> [SQLITE_UTF16BE], 6108 ** <li> [SQLITE_UTF16], or 6109 ** <li> [SQLITE_UTF16_ALIGNED]. 6110 ** </ul>)^ 6111 ** ^The eTextRep argument determines the encoding of strings passed 6112 ** to the collating function callback, xCompare. 6113 ** ^The [SQLITE_UTF16] and [SQLITE_UTF16_ALIGNED] values for eTextRep 6114 ** force strings to be UTF16 with native byte order. 6115 ** ^The [SQLITE_UTF16_ALIGNED] value for eTextRep forces strings to begin 6116 ** on an even byte address. 6117 ** 6118 ** ^The fourth argument, pArg, is an application data pointer that is passed 6119 ** through as the first argument to the collating function callback. 6120 ** 6121 ** ^The fifth argument, xCompare, is a pointer to the collating function. 6122 ** ^Multiple collating functions can be registered using the same name but 6123 ** with different eTextRep parameters and SQLite will use whichever 6124 ** function requires the least amount of data transformation. 6125 ** ^If the xCompare argument is NULL then the collating function is 6126 ** deleted. ^When all collating functions having the same name are deleted, 6127 ** that collation is no longer usable. 6128 ** 6129 ** ^The collating function callback is invoked with a copy of the pArg 6130 ** application data pointer and with two strings in the encoding specified 6131 ** by the eTextRep argument. The two integer parameters to the collating 6132 ** function callback are the length of the two strings, in bytes. The collating 6133 ** function must return an integer that is negative, zero, or positive 6134 ** if the first string is less than, equal to, or greater than the second, 6135 ** respectively. A collating function must always return the same answer 6136 ** given the same inputs. If two or more collating functions are registered 6137 ** to the same collation name (using different eTextRep values) then all 6138 ** must give an equivalent answer when invoked with equivalent strings. 6139 ** The collating function must obey the following properties for all 6140 ** strings A, B, and C: 6141 ** 6142 ** <ol> 6143 ** <li> If A==B then B==A. 6144 ** <li> If A==B and B==C then A==C. 6145 ** <li> If A<B THEN B>A. 6146 ** <li> If A<B and B<C then A<C. 6147 ** </ol> 6148 ** 6149 ** If a collating function fails any of the above constraints and that 6150 ** collating function is registered and used, then the behavior of SQLite 6151 ** is undefined. 6152 ** 6153 ** ^The sqlite3_create_collation_v2() works like sqlite3_create_collation() 6154 ** with the addition that the xDestroy callback is invoked on pArg when 6155 ** the collating function is deleted. 6156 ** ^Collating functions are deleted when they are overridden by later 6157 ** calls to the collation creation functions or when the 6158 ** [database connection] is closed using [sqlite3_close()]. 6159 ** 6160 ** ^The xDestroy callback is <u>not</u> called if the 6161 ** sqlite3_create_collation_v2() function fails. Applications that invoke 6162 ** sqlite3_create_collation_v2() with a non-NULL xDestroy argument should 6163 ** check the return code and dispose of the application data pointer 6164 ** themselves rather than expecting SQLite to deal with it for them. 6165 ** This is different from every other SQLite interface. The inconsistency 6166 ** is unfortunate but cannot be changed without breaking backwards 6167 ** compatibility. 6168 ** 6169 ** See also: [sqlite3_collation_needed()] and [sqlite3_collation_needed16()]. 6170 */ 6171 SQLITE_API int sqlite3_create_collation( 6172 sqlite3*, 6173 const char *zName, 6174 int eTextRep, 6175 void *pArg, 6176 int(*xCompare)(void*,int,const void*,int,const void*) 6177 ); 6178 SQLITE_API int sqlite3_create_collation_v2( 6179 sqlite3*, 6180 const char *zName, 6181 int eTextRep, 6182 void *pArg, 6183 int(*xCompare)(void*,int,const void*,int,const void*), 6184 void(*xDestroy)(void*) 6185 ); 6186 SQLITE_API int sqlite3_create_collation16( 6187 sqlite3*, 6188 const void *zName, 6189 int eTextRep, 6190 void *pArg, 6191 int(*xCompare)(void*,int,const void*,int,const void*) 6192 ); 6193 6194 /* 6195 ** CAPI3REF: Collation Needed Callbacks 6196 ** METHOD: sqlite3 6197 ** 6198 ** ^To avoid having to register all collation sequences before a database 6199 ** can be used, a single callback function may be registered with the 6200 ** [database connection] to be invoked whenever an undefined collation 6201 ** sequence is required. 6202 ** 6203 ** ^If the function is registered using the sqlite3_collation_needed() API, 6204 ** then it is passed the names of undefined collation sequences as strings 6205 ** encoded in UTF-8. ^If sqlite3_collation_needed16() is used, 6206 ** the names are passed as UTF-16 in machine native byte order. 6207 ** ^A call to either function replaces the existing collation-needed callback. 6208 ** 6209 ** ^(When the callback is invoked, the first argument passed is a copy 6210 ** of the second argument to sqlite3_collation_needed() or 6211 ** sqlite3_collation_needed16(). The second argument is the database 6212 ** connection. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE], 6213 ** or [SQLITE_UTF16LE], indicating the most desirable form of the collation 6214 ** sequence function required. The fourth parameter is the name of the 6215 ** required collation sequence.)^ 6216 ** 6217 ** The callback function should register the desired collation using 6218 ** [sqlite3_create_collation()], [sqlite3_create_collation16()], or 6219 ** [sqlite3_create_collation_v2()]. 6220 */ 6221 SQLITE_API int sqlite3_collation_needed( 6222 sqlite3*, 6223 void*, 6224 void(*)(void*,sqlite3*,int eTextRep,const char*) 6225 ); 6226 SQLITE_API int sqlite3_collation_needed16( 6227 sqlite3*, 6228 void*, 6229 void(*)(void*,sqlite3*,int eTextRep,const void*) 6230 ); 6231 6232 #ifdef SQLITE_ENABLE_CEROD 6233 /* 6234 ** Specify the activation key for a CEROD database. Unless 6235 ** activated, none of the CEROD routines will work. 6236 */ 6237 SQLITE_API void sqlite3_activate_cerod( 6238 const char *zPassPhrase /* Activation phrase */ 6239 ); 6240 #endif 6241 6242 /* 6243 ** CAPI3REF: Suspend Execution For A Short Time 6244 ** 6245 ** The sqlite3_sleep() function causes the current thread to suspend execution 6246 ** for at least a number of milliseconds specified in its parameter. 6247 ** 6248 ** If the operating system does not support sleep requests with 6249 ** millisecond time resolution, then the time will be rounded up to 6250 ** the nearest second. The number of milliseconds of sleep actually 6251 ** requested from the operating system is returned. 6252 ** 6253 ** ^SQLite implements this interface by calling the xSleep() 6254 ** method of the default [sqlite3_vfs] object. If the xSleep() method 6255 ** of the default VFS is not implemented correctly, or not implemented at 6256 ** all, then the behavior of sqlite3_sleep() may deviate from the description 6257 ** in the previous paragraphs. 6258 ** 6259 ** If a negative argument is passed to sqlite3_sleep() the results vary by 6260 ** VFS and operating system. Some system treat a negative argument as an 6261 ** instruction to sleep forever. Others understand it to mean do not sleep 6262 ** at all. ^In SQLite version 3.42.0 and later, a negative 6263 ** argument passed into sqlite3_sleep() is changed to zero before it is relayed 6264 ** down into the xSleep method of the VFS. 6265 */ 6266 SQLITE_API int sqlite3_sleep(int); 6267 6268 /* 6269 ** CAPI3REF: Name Of The Folder Holding Temporary Files 6270 ** 6271 ** ^(If this global variable is made to point to a string which is 6272 ** the name of a folder (a.k.a. directory), then all temporary files 6273 ** created by SQLite when using a built-in [sqlite3_vfs | VFS] 6274 ** will be placed in that directory.)^ ^If this variable 6275 ** is a NULL pointer, then SQLite performs a search for an appropriate 6276 ** temporary file directory. 6277 ** 6278 ** Applications are strongly discouraged from using this global variable. 6279 ** It is required to set a temporary folder on Windows Runtime (WinRT). 6280 ** But for all other platforms, it is highly recommended that applications 6281 ** neither read nor write this variable. This global variable is a relic 6282 ** that exists for backwards compatibility of legacy applications and should 6283 ** be avoided in new projects. 6284 ** 6285 ** It is not safe to read or modify this variable in more than one 6286 ** thread at a time. It is not safe to read or modify this variable 6287 ** if a [database connection] is being used at the same time in a separate 6288 ** thread. 6289 ** It is intended that this variable be set once 6290 ** as part of process initialization and before any SQLite interface 6291 ** routines have been called and that this variable remain unchanged 6292 ** thereafter. 6293 ** 6294 ** ^The [temp_store_directory pragma] may modify this variable and cause 6295 ** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 6296 ** the [temp_store_directory pragma] always assumes that any string 6297 ** that this variable points to is held in memory obtained from 6298 ** [sqlite3_malloc] and the pragma may attempt to free that memory 6299 ** using [sqlite3_free]. 6300 ** Hence, if this variable is modified directly, either it should be 6301 ** made NULL or made to point to memory obtained from [sqlite3_malloc] 6302 ** or else the use of the [temp_store_directory pragma] should be avoided. 6303 ** Except when requested by the [temp_store_directory pragma], SQLite 6304 ** does not free the memory that sqlite3_temp_directory points to. If 6305 ** the application wants that memory to be freed, it must do 6306 ** so itself, taking care to only do so after all [database connection] 6307 ** objects have been destroyed. 6308 ** 6309 ** <b>Note to Windows Runtime users:</b> The temporary directory must be set 6310 ** prior to calling [sqlite3_open] or [sqlite3_open_v2]. Otherwise, various 6311 ** features that require the use of temporary files may fail. Here is an 6312 ** example of how to do this using C++ with the Windows Runtime: 6313 ** 6314 ** <blockquote><pre> 6315 ** LPCWSTR zPath = Windows::Storage::ApplicationData::Current-> 6316 ** TemporaryFolder->Path->Data(); 6317 ** char zPathBuf[MAX_PATH + 1]; 6318 ** memset(zPathBuf, 0, sizeof(zPathBuf)); 6319 ** WideCharToMultiByte(CP_UTF8, 0, zPath, -1, zPathBuf, sizeof(zPathBuf), 6320 ** NULL, NULL); 6321 ** sqlite3_temp_directory = sqlite3_mprintf("%s", zPathBuf); 6322 ** </pre></blockquote> 6323 */ 6324 SQLITE_API SQLITE_EXTERN char *sqlite3_temp_directory; 6325 6326 /* 6327 ** CAPI3REF: Name Of The Folder Holding Database Files 6328 ** 6329 ** ^(If this global variable is made to point to a string which is 6330 ** the name of a folder (a.k.a. directory), then all database files 6331 ** specified with a relative pathname and created or accessed by 6332 ** SQLite when using a built-in windows [sqlite3_vfs | VFS] will be assumed 6333 ** to be relative to that directory.)^ ^If this variable is a NULL 6334 ** pointer, then SQLite assumes that all database files specified 6335 ** with a relative pathname are relative to the current directory 6336 ** for the process. Only the windows VFS makes use of this global 6337 ** variable; it is ignored by the unix VFS. 6338 ** 6339 ** Changing the value of this variable while a database connection is 6340 ** open can result in a corrupt database. 6341 ** 6342 ** It is not safe to read or modify this variable in more than one 6343 ** thread at a time. It is not safe to read or modify this variable 6344 ** if a [database connection] is being used at the same time in a separate 6345 ** thread. 6346 ** It is intended that this variable be set once 6347 ** as part of process initialization and before any SQLite interface 6348 ** routines have been called and that this variable remain unchanged 6349 ** thereafter. 6350 ** 6351 ** ^The [data_store_directory pragma] may modify this variable and cause 6352 ** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 6353 ** the [data_store_directory pragma] always assumes that any string 6354 ** that this variable points to is held in memory obtained from 6355 ** [sqlite3_malloc] and the pragma may attempt to free that memory 6356 ** using [sqlite3_free]. 6357 ** Hence, if this variable is modified directly, either it should be 6358 ** made NULL or made to point to memory obtained from [sqlite3_malloc] 6359 ** or else the use of the [data_store_directory pragma] should be avoided. 6360 */ 6361 SQLITE_API SQLITE_EXTERN char *sqlite3_data_directory; 6362 6363 /* 6364 ** CAPI3REF: Win32 Specific Interface 6365 ** 6366 ** These interfaces are available only on Windows. The 6367 ** [sqlite3_win32_set_directory] interface is used to set the value associated 6368 ** with the [sqlite3_temp_directory] or [sqlite3_data_directory] variable, to 6369 ** zValue, depending on the value of the type parameter. The zValue parameter 6370 ** should be NULL to cause the previous value to be freed via [sqlite3_free]; 6371 ** a non-NULL value will be copied into memory obtained from [sqlite3_malloc] 6372 ** prior to being used. The [sqlite3_win32_set_directory] interface returns 6373 ** [SQLITE_OK] to indicate success, [SQLITE_ERROR] if the type is unsupported, 6374 ** or [SQLITE_NOMEM] if memory could not be allocated. The value of the 6375 ** [sqlite3_data_directory] variable is intended to act as a replacement for 6376 ** the current directory on the sub-platforms of Win32 where that concept is 6377 ** not present, e.g. WinRT and UWP. The [sqlite3_win32_set_directory8] and 6378 ** [sqlite3_win32_set_directory16] interfaces behave exactly the same as the 6379 ** sqlite3_win32_set_directory interface except the string parameter must be 6380 ** UTF-8 or UTF-16, respectively. 6381 */ 6382 SQLITE_API int sqlite3_win32_set_directory( 6383 unsigned long type, /* Identifier for directory being set or reset */ 6384 void *zValue /* New value for directory being set or reset */ 6385 ); 6386 SQLITE_API int sqlite3_win32_set_directory8(unsigned long type, const char *zValue); 6387 SQLITE_API int sqlite3_win32_set_directory16(unsigned long type, const void *zValue); 6388 6389 /* 6390 ** CAPI3REF: Win32 Directory Types 6391 ** 6392 ** These macros are only available on Windows. They define the allowed values 6393 ** for the type argument to the [sqlite3_win32_set_directory] interface. 6394 */ 6395 #define SQLITE_WIN32_DATA_DIRECTORY_TYPE 1 6396 #define SQLITE_WIN32_TEMP_DIRECTORY_TYPE 2 6397 6398 /* 6399 ** CAPI3REF: Test For Auto-Commit Mode 6400 ** KEYWORDS: {autocommit mode} 6401 ** METHOD: sqlite3 6402 ** 6403 ** ^The sqlite3_get_autocommit() interface returns non-zero or 6404 ** zero if the given database connection is or is not in autocommit mode, 6405 ** respectively. ^Autocommit mode is on by default. 6406 ** ^Autocommit mode is disabled by a [BEGIN] statement. 6407 ** ^Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK]. 6408 ** 6409 ** If certain kinds of errors occur on a statement within a multi-statement 6410 ** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR], 6411 ** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the 6412 ** transaction might be rolled back automatically. The only way to 6413 ** find out whether SQLite automatically rolled back the transaction after 6414 ** an error is to use this function. 6415 ** 6416 ** If another thread changes the autocommit status of the database 6417 ** connection while this routine is running, then the return value 6418 ** is undefined. 6419 */ 6420 SQLITE_API int sqlite3_get_autocommit(sqlite3*); 6421 6422 /* 6423 ** CAPI3REF: Find The Database Handle Of A Prepared Statement 6424 ** METHOD: sqlite3_stmt 6425 ** 6426 ** ^The sqlite3_db_handle interface returns the [database connection] handle 6427 ** to which a [prepared statement] belongs. ^The [database connection] 6428 ** returned by sqlite3_db_handle is the same [database connection] 6429 ** that was the first argument 6430 ** to the [sqlite3_prepare_v2()] call (or its variants) that was used to 6431 ** create the statement in the first place. 6432 */ 6433 SQLITE_API sqlite3 *sqlite3_db_handle(sqlite3_stmt*); 6434 6435 /* 6436 ** CAPI3REF: Return The Schema Name For A Database Connection 6437 ** METHOD: sqlite3 6438 ** 6439 ** ^The sqlite3_db_name(D,N) interface returns a pointer to the schema name 6440 ** for the N-th database on database connection D, or a NULL pointer of N is 6441 ** out of range. An N value of 0 means the main database file. An N of 1 is 6442 ** the "temp" schema. Larger values of N correspond to various ATTACH-ed 6443 ** databases. 6444 ** 6445 ** Space to hold the string that is returned by sqlite3_db_name() is managed 6446 ** by SQLite itself. The string might be deallocated by any operation that 6447 ** changes the schema, including [ATTACH] or [DETACH] or calls to 6448 ** [sqlite3_serialize()] or [sqlite3_deserialize()], even operations that 6449 ** occur on a different thread. Applications that need to 6450 ** remember the string long-term should make their own copy. Applications that 6451 ** are accessing the same database connection simultaneously on multiple 6452 ** threads should mutex-protect calls to this API and should make their own 6453 ** private copy of the result prior to releasing the mutex. 6454 */ 6455 SQLITE_API const char *sqlite3_db_name(sqlite3 *db, int N); 6456 6457 /* 6458 ** CAPI3REF: Return The Filename For A Database Connection 6459 ** METHOD: sqlite3 6460 ** 6461 ** ^The sqlite3_db_filename(D,N) interface returns a pointer to the filename 6462 ** associated with database N of connection D. 6463 ** ^If there is no attached database N on the database 6464 ** connection D, or if database N is a temporary or in-memory database, then 6465 ** this function will return either a NULL pointer or an empty string. 6466 ** 6467 ** ^The string value returned by this routine is owned and managed by 6468 ** the database connection. ^The value will be valid until the database N 6469 ** is [DETACH]-ed or until the database connection closes. 6470 ** 6471 ** ^The filename returned by this function is the output of the 6472 ** xFullPathname method of the [VFS]. ^In other words, the filename 6473 ** will be an absolute pathname, even if the filename used 6474 ** to open the database originally was a URI or relative pathname. 6475 ** 6476 ** If the filename pointer returned by this routine is not NULL, then it 6477 ** can be used as the filename input parameter to these routines: 6478 ** <ul> 6479 ** <li> [sqlite3_uri_parameter()] 6480 ** <li> [sqlite3_uri_boolean()] 6481 ** <li> [sqlite3_uri_int64()] 6482 ** <li> [sqlite3_filename_database()] 6483 ** <li> [sqlite3_filename_journal()] 6484 ** <li> [sqlite3_filename_wal()] 6485 ** </ul> 6486 */ 6487 SQLITE_API sqlite3_filename sqlite3_db_filename(sqlite3 *db, const char *zDbName); 6488 6489 /* 6490 ** CAPI3REF: Determine if a database is read-only 6491 ** METHOD: sqlite3 6492 ** 6493 ** ^The sqlite3_db_readonly(D,N) interface returns 1 if the database N 6494 ** of connection D is read-only, 0 if it is read/write, or -1 if N is not 6495 ** the name of a database on connection D. 6496 */ 6497 SQLITE_API int sqlite3_db_readonly(sqlite3 *db, const char *zDbName); 6498 6499 /* 6500 ** CAPI3REF: Determine the transaction state of a database 6501 ** METHOD: sqlite3 6502 ** 6503 ** ^The sqlite3_txn_state(D,S) interface returns the current 6504 ** [transaction state] of schema S in database connection D. ^If S is NULL, 6505 ** then the highest transaction state of any schema on database connection D 6506 ** is returned. Transaction states are (in order of lowest to highest): 6507 ** <ol> 6508 ** <li value="0"> SQLITE_TXN_NONE 6509 ** <li value="1"> SQLITE_TXN_READ 6510 ** <li value="2"> SQLITE_TXN_WRITE 6511 ** </ol> 6512 ** ^If the S argument to sqlite3_txn_state(D,S) is not the name of 6513 ** a valid schema, then -1 is returned. 6514 */ 6515 SQLITE_API int sqlite3_txn_state(sqlite3*,const char *zSchema); 6516 6517 /* 6518 ** CAPI3REF: Allowed return values from [sqlite3_txn_state()] 6519 ** KEYWORDS: {transaction state} 6520 ** 6521 ** These constants define the current transaction state of a database file. 6522 ** ^The [sqlite3_txn_state(D,S)] interface returns one of these 6523 ** constants in order to describe the transaction state of schema S 6524 ** in [database connection] D. 6525 ** 6526 ** <dl> 6527 ** [[SQLITE_TXN_NONE]] <dt>SQLITE_TXN_NONE</dt> 6528 ** <dd>The SQLITE_TXN_NONE state means that no transaction is currently 6529 ** pending.</dd> 6530 ** 6531 ** [[SQLITE_TXN_READ]] <dt>SQLITE_TXN_READ</dt> 6532 ** <dd>The SQLITE_TXN_READ state means that the database is currently 6533 ** in a read transaction. Content has been read from the database file 6534 ** but nothing in the database file has changed. The transaction state 6535 ** will advanced to SQLITE_TXN_WRITE if any changes occur and there are 6536 ** no other conflicting concurrent write transactions. The transaction 6537 ** state will revert to SQLITE_TXN_NONE following a [ROLLBACK] or 6538 ** [COMMIT].</dd> 6539 ** 6540 ** [[SQLITE_TXN_WRITE]] <dt>SQLITE_TXN_WRITE</dt> 6541 ** <dd>The SQLITE_TXN_WRITE state means that the database is currently 6542 ** in a write transaction. Content has been written to the database file 6543 ** but has not yet committed. The transaction state will change to 6544 ** to SQLITE_TXN_NONE at the next [ROLLBACK] or [COMMIT].</dd> 6545 */ 6546 #define SQLITE_TXN_NONE 0 6547 #define SQLITE_TXN_READ 1 6548 #define SQLITE_TXN_WRITE 2 6549 6550 /* 6551 ** CAPI3REF: Find the next prepared statement 6552 ** METHOD: sqlite3 6553 ** 6554 ** ^This interface returns a pointer to the next [prepared statement] after 6555 ** pStmt associated with the [database connection] pDb. ^If pStmt is NULL 6556 ** then this interface returns a pointer to the first prepared statement 6557 ** associated with the database connection pDb. ^If no prepared statement 6558 ** satisfies the conditions of this routine, it returns NULL. 6559 ** 6560 ** The [database connection] pointer D in a call to 6561 ** [sqlite3_next_stmt(D,S)] must refer to an open database 6562 ** connection and in particular must not be a NULL pointer. 6563 */ 6564 SQLITE_API sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt); 6565 6566 /* 6567 ** CAPI3REF: Commit And Rollback Notification Callbacks 6568 ** METHOD: sqlite3 6569 ** 6570 ** ^The sqlite3_commit_hook() interface registers a callback 6571 ** function to be invoked whenever a transaction is [COMMIT | committed]. 6572 ** ^Any callback set by a previous call to sqlite3_commit_hook() 6573 ** for the same database connection is overridden. 6574 ** ^The sqlite3_rollback_hook() interface registers a callback 6575 ** function to be invoked whenever a transaction is [ROLLBACK | rolled back]. 6576 ** ^Any callback set by a previous call to sqlite3_rollback_hook() 6577 ** for the same database connection is overridden. 6578 ** ^The pArg argument is passed through to the callback. 6579 ** ^If the callback on a commit hook function returns non-zero, 6580 ** then the commit is converted into a rollback. 6581 ** 6582 ** ^The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions 6583 ** return the P argument from the previous call of the same function 6584 ** on the same [database connection] D, or NULL for 6585 ** the first call for each function on D. 6586 ** 6587 ** The commit and rollback hook callbacks are not reentrant. 6588 ** The callback implementation must not do anything that will modify 6589 ** the database connection that invoked the callback. Any actions 6590 ** to modify the database connection must be deferred until after the 6591 ** completion of the [sqlite3_step()] call that triggered the commit 6592 ** or rollback hook in the first place. 6593 ** Note that running any other SQL statements, including SELECT statements, 6594 ** or merely calling [sqlite3_prepare_v2()] and [sqlite3_step()] will modify 6595 ** the database connections for the meaning of "modify" in this paragraph. 6596 ** 6597 ** ^Registering a NULL function disables the callback. 6598 ** 6599 ** ^When the commit hook callback routine returns zero, the [COMMIT] 6600 ** operation is allowed to continue normally. ^If the commit hook 6601 ** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK]. 6602 ** ^The rollback hook is invoked on a rollback that results from a commit 6603 ** hook returning non-zero, just as it would be with any other rollback. 6604 ** 6605 ** ^For the purposes of this API, a transaction is said to have been 6606 ** rolled back if an explicit "ROLLBACK" statement is executed, or 6607 ** an error or constraint causes an implicit rollback to occur. 6608 ** ^The rollback callback is not invoked if a transaction is 6609 ** automatically rolled back because the database connection is closed. 6610 ** 6611 ** See also the [sqlite3_update_hook()] interface. 6612 */ 6613 SQLITE_API void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*); 6614 SQLITE_API void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*); 6615 6616 /* 6617 ** CAPI3REF: Autovacuum Compaction Amount Callback 6618 ** METHOD: sqlite3 6619 ** 6620 ** ^The sqlite3_autovacuum_pages(D,C,P,X) interface registers a callback 6621 ** function C that is invoked prior to each autovacuum of the database 6622 ** file. ^The callback is passed a copy of the generic data pointer (P), 6623 ** the schema-name of the attached database that is being autovacuumed, 6624 ** the size of the database file in pages, the number of free pages, 6625 ** and the number of bytes per page, respectively. The callback should 6626 ** return the number of free pages that should be removed by the 6627 ** autovacuum. ^If the callback returns zero, then no autovacuum happens. 6628 ** ^If the value returned is greater than or equal to the number of 6629 ** free pages, then a complete autovacuum happens. 6630 ** 6631 ** <p>^If there are multiple ATTACH-ed database files that are being 6632 ** modified as part of a transaction commit, then the autovacuum pages 6633 ** callback is invoked separately for each file. 6634 ** 6635 ** <p><b>The callback is not reentrant.</b> The callback function should 6636 ** not attempt to invoke any other SQLite interface. If it does, bad 6637 ** things may happen, including segmentation faults and corrupt database 6638 ** files. The callback function should be a simple function that 6639 ** does some arithmetic on its input parameters and returns a result. 6640 ** 6641 ** ^The X parameter to sqlite3_autovacuum_pages(D,C,P,X) is an optional 6642 ** destructor for the P parameter. ^If X is not NULL, then X(P) is 6643 ** invoked whenever the database connection closes or when the callback 6644 ** is overwritten by another invocation of sqlite3_autovacuum_pages(). 6645 ** 6646 ** <p>^There is only one autovacuum pages callback per database connection. 6647 ** ^Each call to the sqlite3_autovacuum_pages() interface overrides all 6648 ** previous invocations for that database connection. ^If the callback 6649 ** argument (C) to sqlite3_autovacuum_pages(D,C,P,X) is a NULL pointer, 6650 ** then the autovacuum steps callback is cancelled. The return value 6651 ** from sqlite3_autovacuum_pages() is normally SQLITE_OK, but might 6652 ** be some other error code if something goes wrong. The current 6653 ** implementation will only return SQLITE_OK or SQLITE_MISUSE, but other 6654 ** return codes might be added in future releases. 6655 ** 6656 ** <p>If no autovacuum pages callback is specified (the usual case) or 6657 ** a NULL pointer is provided for the callback, 6658 ** then the default behavior is to vacuum all free pages. So, in other 6659 ** words, the default behavior is the same as if the callback function 6660 ** were something like this: 6661 ** 6662 ** <blockquote><pre> 6663 ** unsigned int demonstration_autovac_pages_callback( 6664 ** void *pClientData, 6665 ** const char *zSchema, 6666 ** unsigned int nDbPage, 6667 ** unsigned int nFreePage, 6668 ** unsigned int nBytePerPage 6669 ** ){ 6670 ** return nFreePage; 6671 ** } 6672 ** </pre></blockquote> 6673 */ 6674 SQLITE_API int sqlite3_autovacuum_pages( 6675 sqlite3 *db, 6676 unsigned int(*)(void*,const char*,unsigned int,unsigned int,unsigned int), 6677 void*, 6678 void(*)(void*) 6679 ); 6680 6681 6682 /* 6683 ** CAPI3REF: Data Change Notification Callbacks 6684 ** METHOD: sqlite3 6685 ** 6686 ** ^The sqlite3_update_hook() interface registers a callback function 6687 ** with the [database connection] identified by the first argument 6688 ** to be invoked whenever a row is updated, inserted or deleted in 6689 ** a [rowid table]. 6690 ** ^Any callback set by a previous call to this function 6691 ** for the same database connection is overridden. 6692 ** 6693 ** ^The second argument is a pointer to the function to invoke when a 6694 ** row is updated, inserted or deleted in a rowid table. 6695 ** ^The first argument to the callback is a copy of the third argument 6696 ** to sqlite3_update_hook(). 6697 ** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE], 6698 ** or [SQLITE_UPDATE], depending on the operation that caused the callback 6699 ** to be invoked. 6700 ** ^The third and fourth arguments to the callback contain pointers to the 6701 ** database and table name containing the affected row. 6702 ** ^The final callback parameter is the [rowid] of the row. 6703 ** ^In the case of an update, this is the [rowid] after the update takes place. 6704 ** 6705 ** ^(The update hook is not invoked when internal system tables are 6706 ** modified (i.e. sqlite_sequence).)^ 6707 ** ^The update hook is not invoked when [WITHOUT ROWID] tables are modified. 6708 ** 6709 ** ^In the current implementation, the update hook 6710 ** is not invoked when conflicting rows are deleted because of an 6711 ** [ON CONFLICT | ON CONFLICT REPLACE] clause. ^Nor is the update hook 6712 ** invoked when rows are deleted using the [truncate optimization]. 6713 ** The exceptions defined in this paragraph might change in a future 6714 ** release of SQLite. 6715 ** 6716 ** The update hook implementation must not do anything that will modify 6717 ** the database connection that invoked the update hook. Any actions 6718 ** to modify the database connection must be deferred until after the 6719 ** completion of the [sqlite3_step()] call that triggered the update hook. 6720 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 6721 ** database connections for the meaning of "modify" in this paragraph. 6722 ** 6723 ** ^The sqlite3_update_hook(D,C,P) function 6724 ** returns the P argument from the previous call 6725 ** on the same [database connection] D, or NULL for 6726 ** the first call on D. 6727 ** 6728 ** See also the [sqlite3_commit_hook()], [sqlite3_rollback_hook()], 6729 ** and [sqlite3_preupdate_hook()] interfaces. 6730 */ 6731 SQLITE_API void *sqlite3_update_hook( 6732 sqlite3*, 6733 void(*)(void *,int ,char const *,char const *,sqlite3_int64), 6734 void* 6735 ); 6736 6737 /* 6738 ** CAPI3REF: Enable Or Disable Shared Pager Cache 6739 ** 6740 ** ^(This routine enables or disables the sharing of the database cache 6741 ** and schema data structures between [database connection | connections] 6742 ** to the same database. Sharing is enabled if the argument is true 6743 ** and disabled if the argument is false.)^ 6744 ** 6745 ** This interface is omitted if SQLite is compiled with 6746 ** [-DSQLITE_OMIT_SHARED_CACHE]. The [-DSQLITE_OMIT_SHARED_CACHE] 6747 ** compile-time option is recommended because the 6748 ** [use of shared cache mode is discouraged]. 6749 ** 6750 ** ^Cache sharing is enabled and disabled for an entire process. 6751 ** This is a change as of SQLite [version 3.5.0] ([dateof:3.5.0]). 6752 ** In prior versions of SQLite, 6753 ** sharing was enabled or disabled for each thread separately. 6754 ** 6755 ** ^(The cache sharing mode set by this interface effects all subsequent 6756 ** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()]. 6757 ** Existing database connections continue to use the sharing mode 6758 ** that was in effect at the time they were opened.)^ 6759 ** 6760 ** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled 6761 ** successfully. An [error code] is returned otherwise.)^ 6762 ** 6763 ** ^Shared cache is disabled by default. It is recommended that it stay 6764 ** that way. In other words, do not use this routine. This interface 6765 ** continues to be provided for historical compatibility, but its use is 6766 ** discouraged. Any use of shared cache is discouraged. If shared cache 6767 ** must be used, it is recommended that shared cache only be enabled for 6768 ** individual database connections using the [sqlite3_open_v2()] interface 6769 ** with the [SQLITE_OPEN_SHAREDCACHE] flag. 6770 ** 6771 ** Note: This method is disabled on MacOS X 10.7 and iOS version 5.0 6772 ** and will always return SQLITE_MISUSE. On those systems, 6773 ** shared cache mode should be enabled per-database connection via 6774 ** [sqlite3_open_v2()] with [SQLITE_OPEN_SHAREDCACHE]. 6775 ** 6776 ** This interface is threadsafe on processors where writing a 6777 ** 32-bit integer is atomic. 6778 ** 6779 ** See Also: [SQLite Shared-Cache Mode] 6780 */ 6781 SQLITE_API int sqlite3_enable_shared_cache(int); 6782 6783 /* 6784 ** CAPI3REF: Attempt To Free Heap Memory 6785 ** 6786 ** ^The sqlite3_release_memory() interface attempts to free N bytes 6787 ** of heap memory by deallocating non-essential memory allocations 6788 ** held by the database library. Memory used to cache database 6789 ** pages to improve performance is an example of non-essential memory. 6790 ** ^sqlite3_release_memory() returns the number of bytes actually freed, 6791 ** which might be more or less than the amount requested. 6792 ** ^The sqlite3_release_memory() routine is a no-op returning zero 6793 ** if SQLite is not compiled with [SQLITE_ENABLE_MEMORY_MANAGEMENT]. 6794 ** 6795 ** See also: [sqlite3_db_release_memory()] 6796 */ 6797 SQLITE_API int sqlite3_release_memory(int); 6798 6799 /* 6800 ** CAPI3REF: Free Memory Used By A Database Connection 6801 ** METHOD: sqlite3 6802 ** 6803 ** ^The sqlite3_db_release_memory(D) interface attempts to free as much heap 6804 ** memory as possible from database connection D. Unlike the 6805 ** [sqlite3_release_memory()] interface, this interface is in effect even 6806 ** when the [SQLITE_ENABLE_MEMORY_MANAGEMENT] compile-time option is 6807 ** omitted. 6808 ** 6809 ** See also: [sqlite3_release_memory()] 6810 */ 6811 SQLITE_API int sqlite3_db_release_memory(sqlite3*); 6812 6813 /* 6814 ** CAPI3REF: Impose A Limit On Heap Size 6815 ** 6816 ** These interfaces impose limits on the amount of heap memory that will be 6817 ** by all database connections within a single process. 6818 ** 6819 ** ^The sqlite3_soft_heap_limit64() interface sets and/or queries the 6820 ** soft limit on the amount of heap memory that may be allocated by SQLite. 6821 ** ^SQLite strives to keep heap memory utilization below the soft heap 6822 ** limit by reducing the number of pages held in the page cache 6823 ** as heap memory usages approaches the limit. 6824 ** ^The soft heap limit is "soft" because even though SQLite strives to stay 6825 ** below the limit, it will exceed the limit rather than generate 6826 ** an [SQLITE_NOMEM] error. In other words, the soft heap limit 6827 ** is advisory only. 6828 ** 6829 ** ^The sqlite3_hard_heap_limit64(N) interface sets a hard upper bound of 6830 ** N bytes on the amount of memory that will be allocated. ^The 6831 ** sqlite3_hard_heap_limit64(N) interface is similar to 6832 ** sqlite3_soft_heap_limit64(N) except that memory allocations will fail 6833 ** when the hard heap limit is reached. 6834 ** 6835 ** ^The return value from both sqlite3_soft_heap_limit64() and 6836 ** sqlite3_hard_heap_limit64() is the size of 6837 ** the heap limit prior to the call, or negative in the case of an 6838 ** error. ^If the argument N is negative 6839 ** then no change is made to the heap limit. Hence, the current 6840 ** size of heap limits can be determined by invoking 6841 ** sqlite3_soft_heap_limit64(-1) or sqlite3_hard_heap_limit(-1). 6842 ** 6843 ** ^Setting the heap limits to zero disables the heap limiter mechanism. 6844 ** 6845 ** ^The soft heap limit may not be greater than the hard heap limit. 6846 ** ^If the hard heap limit is enabled and if sqlite3_soft_heap_limit(N) 6847 ** is invoked with a value of N that is greater than the hard heap limit, 6848 ** the soft heap limit is set to the value of the hard heap limit. 6849 ** ^The soft heap limit is automatically enabled whenever the hard heap 6850 ** limit is enabled. ^When sqlite3_hard_heap_limit64(N) is invoked and 6851 ** the soft heap limit is outside the range of 1..N, then the soft heap 6852 ** limit is set to N. ^Invoking sqlite3_soft_heap_limit64(0) when the 6853 ** hard heap limit is enabled makes the soft heap limit equal to the 6854 ** hard heap limit. 6855 ** 6856 ** The memory allocation limits can also be adjusted using 6857 ** [PRAGMA soft_heap_limit] and [PRAGMA hard_heap_limit]. 6858 ** 6859 ** ^(The heap limits are not enforced in the current implementation 6860 ** if one or more of following conditions are true: 6861 ** 6862 ** <ul> 6863 ** <li> The limit value is set to zero. 6864 ** <li> Memory accounting is disabled using a combination of the 6865 ** [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],...) start-time option and 6866 ** the [SQLITE_DEFAULT_MEMSTATUS] compile-time option. 6867 ** <li> An alternative page cache implementation is specified using 6868 ** [sqlite3_config]([SQLITE_CONFIG_PCACHE2],...). 6869 ** <li> The page cache allocates from its own memory pool supplied 6870 ** by [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],...) rather than 6871 ** from the heap. 6872 ** </ul>)^ 6873 ** 6874 ** The circumstances under which SQLite will enforce the heap limits may 6875 ** changes in future releases of SQLite. 6876 */ 6877 SQLITE_API sqlite3_int64 sqlite3_soft_heap_limit64(sqlite3_int64 N); 6878 SQLITE_API sqlite3_int64 sqlite3_hard_heap_limit64(sqlite3_int64 N); 6879 6880 /* 6881 ** CAPI3REF: Deprecated Soft Heap Limit Interface 6882 ** DEPRECATED 6883 ** 6884 ** This is a deprecated version of the [sqlite3_soft_heap_limit64()] 6885 ** interface. This routine is provided for historical compatibility 6886 ** only. All new applications should use the 6887 ** [sqlite3_soft_heap_limit64()] interface rather than this one. 6888 */ 6889 SQLITE_API SQLITE_DEPRECATED void sqlite3_soft_heap_limit(int N); 6890 6891 6892 /* 6893 ** CAPI3REF: Extract Metadata About A Column Of A Table 6894 ** METHOD: sqlite3 6895 ** 6896 ** ^(The sqlite3_table_column_metadata(X,D,T,C,....) routine returns 6897 ** information about column C of table T in database D 6898 ** on [database connection] X.)^ ^The sqlite3_table_column_metadata() 6899 ** interface returns SQLITE_OK and fills in the non-NULL pointers in 6900 ** the final five arguments with appropriate values if the specified 6901 ** column exists. ^The sqlite3_table_column_metadata() interface returns 6902 ** SQLITE_ERROR if the specified column does not exist. 6903 ** ^If the column-name parameter to sqlite3_table_column_metadata() is a 6904 ** NULL pointer, then this routine simply checks for the existence of the 6905 ** table and returns SQLITE_OK if the table exists and SQLITE_ERROR if it 6906 ** does not. If the table name parameter T in a call to 6907 ** sqlite3_table_column_metadata(X,D,T,C,...) is NULL then the result is 6908 ** undefined behavior. 6909 ** 6910 ** ^The column is identified by the second, third and fourth parameters to 6911 ** this function. ^(The second parameter is either the name of the database 6912 ** (i.e. "main", "temp", or an attached database) containing the specified 6913 ** table or NULL.)^ ^If it is NULL, then all attached databases are searched 6914 ** for the table using the same algorithm used by the database engine to 6915 ** resolve unqualified table references. 6916 ** 6917 ** ^The third and fourth parameters to this function are the table and column 6918 ** name of the desired column, respectively. 6919 ** 6920 ** ^Metadata is returned by writing to the memory locations passed as the 5th 6921 ** and subsequent parameters to this function. ^Any of these arguments may be 6922 ** NULL, in which case the corresponding element of metadata is omitted. 6923 ** 6924 ** ^(<blockquote> 6925 ** <table border="1"> 6926 ** <tr><th> Parameter <th> Output<br>Type <th> Description 6927 ** 6928 ** <tr><td> 5th <td> const char* <td> Data type 6929 ** <tr><td> 6th <td> const char* <td> Name of default collation sequence 6930 ** <tr><td> 7th <td> int <td> True if column has a NOT NULL constraint 6931 ** <tr><td> 8th <td> int <td> True if column is part of the PRIMARY KEY 6932 ** <tr><td> 9th <td> int <td> True if column is [AUTOINCREMENT] 6933 ** </table> 6934 ** </blockquote>)^ 6935 ** 6936 ** ^The memory pointed to by the character pointers returned for the 6937 ** declaration type and collation sequence is valid until the next 6938 ** call to any SQLite API function. 6939 ** 6940 ** ^If the specified table is actually a view, an [error code] is returned. 6941 ** 6942 ** ^If the specified column is "rowid", "oid" or "_rowid_" and the table 6943 ** is not a [WITHOUT ROWID] table and an 6944 ** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output 6945 ** parameters are set for the explicitly declared column. ^(If there is no 6946 ** [INTEGER PRIMARY KEY] column, then the outputs 6947 ** for the [rowid] are set as follows: 6948 ** 6949 ** <pre> 6950 ** data type: "INTEGER" 6951 ** collation sequence: "BINARY" 6952 ** not null: 0 6953 ** primary key: 1 6954 ** auto increment: 0 6955 ** </pre>)^ 6956 ** 6957 ** ^This function causes all database schemas to be read from disk and 6958 ** parsed, if that has not already been done, and returns an error if 6959 ** any errors are encountered while loading the schema. 6960 */ 6961 SQLITE_API int sqlite3_table_column_metadata( 6962 sqlite3 *db, /* Connection handle */ 6963 const char *zDbName, /* Database name or NULL */ 6964 const char *zTableName, /* Table name */ 6965 const char *zColumnName, /* Column name */ 6966 char const **pzDataType, /* OUTPUT: Declared data type */ 6967 char const **pzCollSeq, /* OUTPUT: Collation sequence name */ 6968 int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */ 6969 int *pPrimaryKey, /* OUTPUT: True if column part of PK */ 6970 int *pAutoinc /* OUTPUT: True if column is auto-increment */ 6971 ); 6972 6973 /* 6974 ** CAPI3REF: Load An Extension 6975 ** METHOD: sqlite3 6976 ** 6977 ** ^This interface loads an SQLite extension library from the named file. 6978 ** 6979 ** ^The sqlite3_load_extension() interface attempts to load an 6980 ** [SQLite extension] library contained in the file zFile. If 6981 ** the file cannot be loaded directly, attempts are made to load 6982 ** with various operating-system specific extensions added. 6983 ** So for example, if "samplelib" cannot be loaded, then names like 6984 ** "samplelib.so" or "samplelib.dylib" or "samplelib.dll" might 6985 ** be tried also. 6986 ** 6987 ** ^The entry point is zProc. 6988 ** ^(zProc may be 0, in which case SQLite will try to come up with an 6989 ** entry point name on its own. It first tries "sqlite3_extension_init". 6990 ** If that does not work, it constructs a name "sqlite3_X_init" where the 6991 ** X is consists of the lower-case equivalent of all ASCII alphabetic 6992 ** characters in the filename from the last "/" to the first following 6993 ** "." and omitting any initial "lib".)^ 6994 ** ^The sqlite3_load_extension() interface returns 6995 ** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong. 6996 ** ^If an error occurs and pzErrMsg is not 0, then the 6997 ** [sqlite3_load_extension()] interface shall attempt to 6998 ** fill *pzErrMsg with error message text stored in memory 6999 ** obtained from [sqlite3_malloc()]. The calling function 7000 ** should free this memory by calling [sqlite3_free()]. 7001 ** 7002 ** ^Extension loading must be enabled using 7003 ** [sqlite3_enable_load_extension()] or 7004 ** [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],1,NULL) 7005 ** prior to calling this API, 7006 ** otherwise an error will be returned. 7007 ** 7008 ** <b>Security warning:</b> It is recommended that the 7009 ** [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method be used to enable only this 7010 ** interface. The use of the [sqlite3_enable_load_extension()] interface 7011 ** should be avoided. This will keep the SQL function [load_extension()] 7012 ** disabled and prevent SQL injections from giving attackers 7013 ** access to extension loading capabilities. 7014 ** 7015 ** See also the [load_extension() SQL function]. 7016 */ 7017 SQLITE_API int sqlite3_load_extension( 7018 sqlite3 *db, /* Load the extension into this database connection */ 7019 const char *zFile, /* Name of the shared library containing extension */ 7020 const char *zProc, /* Entry point. Derived from zFile if 0 */ 7021 char **pzErrMsg /* Put error message here if not 0 */ 7022 ); 7023 7024 /* 7025 ** CAPI3REF: Enable Or Disable Extension Loading 7026 ** METHOD: sqlite3 7027 ** 7028 ** ^So as not to open security holes in older applications that are 7029 ** unprepared to deal with [extension loading], and as a means of disabling 7030 ** [extension loading] while evaluating user-entered SQL, the following API 7031 ** is provided to turn the [sqlite3_load_extension()] mechanism on and off. 7032 ** 7033 ** ^Extension loading is off by default. 7034 ** ^Call the sqlite3_enable_load_extension() routine with onoff==1 7035 ** to turn extension loading on and call it with onoff==0 to turn 7036 ** it back off again. 7037 ** 7038 ** ^This interface enables or disables both the C-API 7039 ** [sqlite3_load_extension()] and the SQL function [load_extension()]. 7040 ** ^(Use [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],..) 7041 ** to enable or disable only the C-API.)^ 7042 ** 7043 ** <b>Security warning:</b> It is recommended that extension loading 7044 ** be enabled using the [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method 7045 ** rather than this interface, so the [load_extension()] SQL function 7046 ** remains disabled. This will prevent SQL injections from giving attackers 7047 ** access to extension loading capabilities. 7048 */ 7049 SQLITE_API int sqlite3_enable_load_extension(sqlite3 *db, int onoff); 7050 7051 /* 7052 ** CAPI3REF: Automatically Load Statically Linked Extensions 7053 ** 7054 ** ^This interface causes the xEntryPoint() function to be invoked for 7055 ** each new [database connection] that is created. The idea here is that 7056 ** xEntryPoint() is the entry point for a statically linked [SQLite extension] 7057 ** that is to be automatically loaded into all new database connections. 7058 ** 7059 ** ^(Even though the function prototype shows that xEntryPoint() takes 7060 ** no arguments and returns void, SQLite invokes xEntryPoint() with three 7061 ** arguments and expects an integer result as if the signature of the 7062 ** entry point where as follows: 7063 ** 7064 ** <blockquote><pre> 7065 ** int xEntryPoint( 7066 ** sqlite3 *db, 7067 ** const char **pzErrMsg, 7068 ** const struct sqlite3_api_routines *pThunk 7069 ** ); 7070 ** </pre></blockquote>)^ 7071 ** 7072 ** If the xEntryPoint routine encounters an error, it should make *pzErrMsg 7073 ** point to an appropriate error message (obtained from [sqlite3_mprintf()]) 7074 ** and return an appropriate [error code]. ^SQLite ensures that *pzErrMsg 7075 ** is NULL before calling the xEntryPoint(). ^SQLite will invoke 7076 ** [sqlite3_free()] on *pzErrMsg after xEntryPoint() returns. ^If any 7077 ** xEntryPoint() returns an error, the [sqlite3_open()], [sqlite3_open16()], 7078 ** or [sqlite3_open_v2()] call that provoked the xEntryPoint() will fail. 7079 ** 7080 ** ^Calling sqlite3_auto_extension(X) with an entry point X that is already 7081 ** on the list of automatic extensions is a harmless no-op. ^No entry point 7082 ** will be called more than once for each database connection that is opened. 7083 ** 7084 ** See also: [sqlite3_reset_auto_extension()] 7085 ** and [sqlite3_cancel_auto_extension()] 7086 */ 7087 SQLITE_API int sqlite3_auto_extension(void(*xEntryPoint)(void)); 7088 7089 /* 7090 ** CAPI3REF: Cancel Automatic Extension Loading 7091 ** 7092 ** ^The [sqlite3_cancel_auto_extension(X)] interface unregisters the 7093 ** initialization routine X that was registered using a prior call to 7094 ** [sqlite3_auto_extension(X)]. ^The [sqlite3_cancel_auto_extension(X)] 7095 ** routine returns 1 if initialization routine X was successfully 7096 ** unregistered and it returns 0 if X was not on the list of initialization 7097 ** routines. 7098 */ 7099 SQLITE_API int sqlite3_cancel_auto_extension(void(*xEntryPoint)(void)); 7100 7101 /* 7102 ** CAPI3REF: Reset Automatic Extension Loading 7103 ** 7104 ** ^This interface disables all automatic extensions previously 7105 ** registered using [sqlite3_auto_extension()]. 7106 */ 7107 SQLITE_API void sqlite3_reset_auto_extension(void); 7108 7109 /* 7110 ** Structures used by the virtual table interface 7111 */ 7112 typedef struct sqlite3_vtab sqlite3_vtab; 7113 typedef struct sqlite3_index_info sqlite3_index_info; 7114 typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor; 7115 typedef struct sqlite3_module sqlite3_module; 7116 7117 /* 7118 ** CAPI3REF: Virtual Table Object 7119 ** KEYWORDS: sqlite3_module {virtual table module} 7120 ** 7121 ** This structure, sometimes called a "virtual table module", 7122 ** defines the implementation of a [virtual table]. 7123 ** This structure consists mostly of methods for the module. 7124 ** 7125 ** ^A virtual table module is created by filling in a persistent 7126 ** instance of this structure and passing a pointer to that instance 7127 ** to [sqlite3_create_module()] or [sqlite3_create_module_v2()]. 7128 ** ^The registration remains valid until it is replaced by a different 7129 ** module or until the [database connection] closes. The content 7130 ** of this structure must not change while it is registered with 7131 ** any database connection. 7132 */ 7133 struct sqlite3_module { 7134 int iVersion; 7135 int (*xCreate)(sqlite3*, void *pAux, 7136 int argc, const char *const*argv, 7137 sqlite3_vtab **ppVTab, char**); 7138 int (*xConnect)(sqlite3*, void *pAux, 7139 int argc, const char *const*argv, 7140 sqlite3_vtab **ppVTab, char**); 7141 int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*); 7142 int (*xDisconnect)(sqlite3_vtab *pVTab); 7143 int (*xDestroy)(sqlite3_vtab *pVTab); 7144 int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor); 7145 int (*xClose)(sqlite3_vtab_cursor*); 7146 int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr, 7147 int argc, sqlite3_value **argv); 7148 int (*xNext)(sqlite3_vtab_cursor*); 7149 int (*xEof)(sqlite3_vtab_cursor*); 7150 int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int); 7151 int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid); 7152 int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *); 7153 int (*xBegin)(sqlite3_vtab *pVTab); 7154 int (*xSync)(sqlite3_vtab *pVTab); 7155 int (*xCommit)(sqlite3_vtab *pVTab); 7156 int (*xRollback)(sqlite3_vtab *pVTab); 7157 int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName, 7158 void (**pxFunc)(sqlite3_context*,int,sqlite3_value**), 7159 void **ppArg); 7160 int (*xRename)(sqlite3_vtab *pVtab, const char *zNew); 7161 /* The methods above are in version 1 of the sqlite_module object. Those 7162 ** below are for version 2 and greater. */ 7163 int (*xSavepoint)(sqlite3_vtab *pVTab, int); 7164 int (*xRelease)(sqlite3_vtab *pVTab, int); 7165 int (*xRollbackTo)(sqlite3_vtab *pVTab, int); 7166 /* The methods above are in versions 1 and 2 of the sqlite_module object. 7167 ** Those below are for version 3 and greater. */ 7168 int (*xShadowName)(const char*); 7169 }; 7170 7171 /* 7172 ** CAPI3REF: Virtual Table Indexing Information 7173 ** KEYWORDS: sqlite3_index_info 7174 ** 7175 ** The sqlite3_index_info structure and its substructures is used as part 7176 ** of the [virtual table] interface to 7177 ** pass information into and receive the reply from the [xBestIndex] 7178 ** method of a [virtual table module]. The fields under **Inputs** are the 7179 ** inputs to xBestIndex and are read-only. xBestIndex inserts its 7180 ** results into the **Outputs** fields. 7181 ** 7182 ** ^(The aConstraint[] array records WHERE clause constraints of the form: 7183 ** 7184 ** <blockquote>column OP expr</blockquote> 7185 ** 7186 ** where OP is =, <, <=, >, or >=.)^ ^(The particular operator is 7187 ** stored in aConstraint[].op using one of the 7188 ** [SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_ values].)^ 7189 ** ^(The index of the column is stored in 7190 ** aConstraint[].iColumn.)^ ^(aConstraint[].usable is TRUE if the 7191 ** expr on the right-hand side can be evaluated (and thus the constraint 7192 ** is usable) and false if it cannot.)^ 7193 ** 7194 ** ^The optimizer automatically inverts terms of the form "expr OP column" 7195 ** and makes other simplifications to the WHERE clause in an attempt to 7196 ** get as many WHERE clause terms into the form shown above as possible. 7197 ** ^The aConstraint[] array only reports WHERE clause terms that are 7198 ** relevant to the particular virtual table being queried. 7199 ** 7200 ** ^Information about the ORDER BY clause is stored in aOrderBy[]. 7201 ** ^Each term of aOrderBy records a column of the ORDER BY clause. 7202 ** 7203 ** The colUsed field indicates which columns of the virtual table may be 7204 ** required by the current scan. Virtual table columns are numbered from 7205 ** zero in the order in which they appear within the CREATE TABLE statement 7206 ** passed to sqlite3_declare_vtab(). For the first 63 columns (columns 0-62), 7207 ** the corresponding bit is set within the colUsed mask if the column may be 7208 ** required by SQLite. If the table has at least 64 columns and any column 7209 ** to the right of the first 63 is required, then bit 63 of colUsed is also 7210 ** set. In other words, column iCol may be required if the expression 7211 ** (colUsed & ((sqlite3_uint64)1 << (iCol>=63 ? 63 : iCol))) evaluates to 7212 ** non-zero. 7213 ** 7214 ** The [xBestIndex] method must fill aConstraintUsage[] with information 7215 ** about what parameters to pass to xFilter. ^If argvIndex>0 then 7216 ** the right-hand side of the corresponding aConstraint[] is evaluated 7217 ** and becomes the argvIndex-th entry in argv. ^(If aConstraintUsage[].omit 7218 ** is true, then the constraint is assumed to be fully handled by the 7219 ** virtual table and might not be checked again by the byte code.)^ ^(The 7220 ** aConstraintUsage[].omit flag is an optimization hint. When the omit flag 7221 ** is left in its default setting of false, the constraint will always be 7222 ** checked separately in byte code. If the omit flag is change to true, then 7223 ** the constraint may or may not be checked in byte code. In other words, 7224 ** when the omit flag is true there is no guarantee that the constraint will 7225 ** not be checked again using byte code.)^ 7226 ** 7227 ** ^The idxNum and idxStr values are recorded and passed into the 7228 ** [xFilter] method. 7229 ** ^[sqlite3_free()] is used to free idxStr if and only if 7230 ** needToFreeIdxStr is true. 7231 ** 7232 ** ^The orderByConsumed means that output from [xFilter]/[xNext] will occur in 7233 ** the correct order to satisfy the ORDER BY clause so that no separate 7234 ** sorting step is required. 7235 ** 7236 ** ^The estimatedCost value is an estimate of the cost of a particular 7237 ** strategy. A cost of N indicates that the cost of the strategy is similar 7238 ** to a linear scan of an SQLite table with N rows. A cost of log(N) 7239 ** indicates that the expense of the operation is similar to that of a 7240 ** binary search on a unique indexed field of an SQLite table with N rows. 7241 ** 7242 ** ^The estimatedRows value is an estimate of the number of rows that 7243 ** will be returned by the strategy. 7244 ** 7245 ** The xBestIndex method may optionally populate the idxFlags field with a 7246 ** mask of SQLITE_INDEX_SCAN_* flags. Currently there is only one such flag - 7247 ** SQLITE_INDEX_SCAN_UNIQUE. If the xBestIndex method sets this flag, SQLite 7248 ** assumes that the strategy may visit at most one row. 7249 ** 7250 ** Additionally, if xBestIndex sets the SQLITE_INDEX_SCAN_UNIQUE flag, then 7251 ** SQLite also assumes that if a call to the xUpdate() method is made as 7252 ** part of the same statement to delete or update a virtual table row and the 7253 ** implementation returns SQLITE_CONSTRAINT, then there is no need to rollback 7254 ** any database changes. In other words, if the xUpdate() returns 7255 ** SQLITE_CONSTRAINT, the database contents must be exactly as they were 7256 ** before xUpdate was called. By contrast, if SQLITE_INDEX_SCAN_UNIQUE is not 7257 ** set and xUpdate returns SQLITE_CONSTRAINT, any database changes made by 7258 ** the xUpdate method are automatically rolled back by SQLite. 7259 ** 7260 ** IMPORTANT: The estimatedRows field was added to the sqlite3_index_info 7261 ** structure for SQLite [version 3.8.2] ([dateof:3.8.2]). 7262 ** If a virtual table extension is 7263 ** used with an SQLite version earlier than 3.8.2, the results of attempting 7264 ** to read or write the estimatedRows field are undefined (but are likely 7265 ** to include crashing the application). The estimatedRows field should 7266 ** therefore only be used if [sqlite3_libversion_number()] returns a 7267 ** value greater than or equal to 3008002. Similarly, the idxFlags field 7268 ** was added for [version 3.9.0] ([dateof:3.9.0]). 7269 ** It may therefore only be used if 7270 ** sqlite3_libversion_number() returns a value greater than or equal to 7271 ** 3009000. 7272 */ 7273 struct sqlite3_index_info { 7274 /* Inputs */ 7275 int nConstraint; /* Number of entries in aConstraint */ 7276 struct sqlite3_index_constraint { 7277 int iColumn; /* Column constrained. -1 for ROWID */ 7278 unsigned char op; /* Constraint operator */ 7279 unsigned char usable; /* True if this constraint is usable */ 7280 int iTermOffset; /* Used internally - xBestIndex should ignore */ 7281 } *aConstraint; /* Table of WHERE clause constraints */ 7282 int nOrderBy; /* Number of terms in the ORDER BY clause */ 7283 struct sqlite3_index_orderby { 7284 int iColumn; /* Column number */ 7285 unsigned char desc; /* True for DESC. False for ASC. */ 7286 } *aOrderBy; /* The ORDER BY clause */ 7287 /* Outputs */ 7288 struct sqlite3_index_constraint_usage { 7289 int argvIndex; /* if >0, constraint is part of argv to xFilter */ 7290 unsigned char omit; /* Do not code a test for this constraint */ 7291 } *aConstraintUsage; 7292 int idxNum; /* Number used to identify the index */ 7293 char *idxStr; /* String, possibly obtained from sqlite3_malloc */ 7294 int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */ 7295 int orderByConsumed; /* True if output is already ordered */ 7296 double estimatedCost; /* Estimated cost of using this index */ 7297 /* Fields below are only available in SQLite 3.8.2 and later */ 7298 sqlite3_int64 estimatedRows; /* Estimated number of rows returned */ 7299 /* Fields below are only available in SQLite 3.9.0 and later */ 7300 int idxFlags; /* Mask of SQLITE_INDEX_SCAN_* flags */ 7301 /* Fields below are only available in SQLite 3.10.0 and later */ 7302 sqlite3_uint64 colUsed; /* Input: Mask of columns used by statement */ 7303 }; 7304 7305 /* 7306 ** CAPI3REF: Virtual Table Scan Flags 7307 ** 7308 ** Virtual table implementations are allowed to set the 7309 ** [sqlite3_index_info].idxFlags field to some combination of 7310 ** these bits. 7311 */ 7312 #define SQLITE_INDEX_SCAN_UNIQUE 1 /* Scan visits at most 1 row */ 7313 7314 /* 7315 ** CAPI3REF: Virtual Table Constraint Operator Codes 7316 ** 7317 ** These macros define the allowed values for the 7318 ** [sqlite3_index_info].aConstraint[].op field. Each value represents 7319 ** an operator that is part of a constraint term in the WHERE clause of 7320 ** a query that uses a [virtual table]. 7321 ** 7322 ** ^The left-hand operand of the operator is given by the corresponding 7323 ** aConstraint[].iColumn field. ^An iColumn of -1 indicates the left-hand 7324 ** operand is the rowid. 7325 ** The SQLITE_INDEX_CONSTRAINT_LIMIT and SQLITE_INDEX_CONSTRAINT_OFFSET 7326 ** operators have no left-hand operand, and so for those operators the 7327 ** corresponding aConstraint[].iColumn is meaningless and should not be 7328 ** used. 7329 ** 7330 ** All operator values from SQLITE_INDEX_CONSTRAINT_FUNCTION through 7331 ** value 255 are reserved to represent functions that are overloaded 7332 ** by the [xFindFunction|xFindFunction method] of the virtual table 7333 ** implementation. 7334 ** 7335 ** The right-hand operands for each constraint might be accessible using 7336 ** the [sqlite3_vtab_rhs_value()] interface. Usually the right-hand 7337 ** operand is only available if it appears as a single constant literal 7338 ** in the input SQL. If the right-hand operand is another column or an 7339 ** expression (even a constant expression) or a parameter, then the 7340 ** sqlite3_vtab_rhs_value() probably will not be able to extract it. 7341 ** ^The SQLITE_INDEX_CONSTRAINT_ISNULL and 7342 ** SQLITE_INDEX_CONSTRAINT_ISNOTNULL operators have no right-hand operand 7343 ** and hence calls to sqlite3_vtab_rhs_value() for those operators will 7344 ** always return SQLITE_NOTFOUND. 7345 ** 7346 ** The collating sequence to be used for comparison can be found using 7347 ** the [sqlite3_vtab_collation()] interface. For most real-world virtual 7348 ** tables, the collating sequence of constraints does not matter (for example 7349 ** because the constraints are numeric) and so the sqlite3_vtab_collation() 7350 ** interface is not commonly needed. 7351 */ 7352 #define SQLITE_INDEX_CONSTRAINT_EQ 2 7353 #define SQLITE_INDEX_CONSTRAINT_GT 4 7354 #define SQLITE_INDEX_CONSTRAINT_LE 8 7355 #define SQLITE_INDEX_CONSTRAINT_LT 16 7356 #define SQLITE_INDEX_CONSTRAINT_GE 32 7357 #define SQLITE_INDEX_CONSTRAINT_MATCH 64 7358 #define SQLITE_INDEX_CONSTRAINT_LIKE 65 7359 #define SQLITE_INDEX_CONSTRAINT_GLOB 66 7360 #define SQLITE_INDEX_CONSTRAINT_REGEXP 67 7361 #define SQLITE_INDEX_CONSTRAINT_NE 68 7362 #define SQLITE_INDEX_CONSTRAINT_ISNOT 69 7363 #define SQLITE_INDEX_CONSTRAINT_ISNOTNULL 70 7364 #define SQLITE_INDEX_CONSTRAINT_ISNULL 71 7365 #define SQLITE_INDEX_CONSTRAINT_IS 72 7366 #define SQLITE_INDEX_CONSTRAINT_LIMIT 73 7367 #define SQLITE_INDEX_CONSTRAINT_OFFSET 74 7368 #define SQLITE_INDEX_CONSTRAINT_FUNCTION 150 7369 7370 /* 7371 ** CAPI3REF: Register A Virtual Table Implementation 7372 ** METHOD: sqlite3 7373 ** 7374 ** ^These routines are used to register a new [virtual table module] name. 7375 ** ^Module names must be registered before 7376 ** creating a new [virtual table] using the module and before using a 7377 ** preexisting [virtual table] for the module. 7378 ** 7379 ** ^The module name is registered on the [database connection] specified 7380 ** by the first parameter. ^The name of the module is given by the 7381 ** second parameter. ^The third parameter is a pointer to 7382 ** the implementation of the [virtual table module]. ^The fourth 7383 ** parameter is an arbitrary client data pointer that is passed through 7384 ** into the [xCreate] and [xConnect] methods of the virtual table module 7385 ** when a new virtual table is be being created or reinitialized. 7386 ** 7387 ** ^The sqlite3_create_module_v2() interface has a fifth parameter which 7388 ** is a pointer to a destructor for the pClientData. ^SQLite will 7389 ** invoke the destructor function (if it is not NULL) when SQLite 7390 ** no longer needs the pClientData pointer. ^The destructor will also 7391 ** be invoked if the call to sqlite3_create_module_v2() fails. 7392 ** ^The sqlite3_create_module() 7393 ** interface is equivalent to sqlite3_create_module_v2() with a NULL 7394 ** destructor. 7395 ** 7396 ** ^If the third parameter (the pointer to the sqlite3_module object) is 7397 ** NULL then no new module is created and any existing modules with the 7398 ** same name are dropped. 7399 ** 7400 ** See also: [sqlite3_drop_modules()] 7401 */ 7402 SQLITE_API int sqlite3_create_module( 7403 sqlite3 *db, /* SQLite connection to register module with */ 7404 const char *zName, /* Name of the module */ 7405 const sqlite3_module *p, /* Methods for the module */ 7406 void *pClientData /* Client data for xCreate/xConnect */ 7407 ); 7408 SQLITE_API int sqlite3_create_module_v2( 7409 sqlite3 *db, /* SQLite connection to register module with */ 7410 const char *zName, /* Name of the module */ 7411 const sqlite3_module *p, /* Methods for the module */ 7412 void *pClientData, /* Client data for xCreate/xConnect */ 7413 void(*xDestroy)(void*) /* Module destructor function */ 7414 ); 7415 7416 /* 7417 ** CAPI3REF: Remove Unnecessary Virtual Table Implementations 7418 ** METHOD: sqlite3 7419 ** 7420 ** ^The sqlite3_drop_modules(D,L) interface removes all virtual 7421 ** table modules from database connection D except those named on list L. 7422 ** The L parameter must be either NULL or a pointer to an array of pointers 7423 ** to strings where the array is terminated by a single NULL pointer. 7424 ** ^If the L parameter is NULL, then all virtual table modules are removed. 7425 ** 7426 ** See also: [sqlite3_create_module()] 7427 */ 7428 SQLITE_API int sqlite3_drop_modules( 7429 sqlite3 *db, /* Remove modules from this connection */ 7430 const char **azKeep /* Except, do not remove the ones named here */ 7431 ); 7432 7433 /* 7434 ** CAPI3REF: Virtual Table Instance Object 7435 ** KEYWORDS: sqlite3_vtab 7436 ** 7437 ** Every [virtual table module] implementation uses a subclass 7438 ** of this object to describe a particular instance 7439 ** of the [virtual table]. Each subclass will 7440 ** be tailored to the specific needs of the module implementation. 7441 ** The purpose of this superclass is to define certain fields that are 7442 ** common to all module implementations. 7443 ** 7444 ** ^Virtual tables methods can set an error message by assigning a 7445 ** string obtained from [sqlite3_mprintf()] to zErrMsg. The method should 7446 ** take care that any prior string is freed by a call to [sqlite3_free()] 7447 ** prior to assigning a new string to zErrMsg. ^After the error message 7448 ** is delivered up to the client application, the string will be automatically 7449 ** freed by sqlite3_free() and the zErrMsg field will be zeroed. 7450 */ 7451 struct sqlite3_vtab { 7452 const sqlite3_module *pModule; /* The module for this virtual table */ 7453 int nRef; /* Number of open cursors */ 7454 char *zErrMsg; /* Error message from sqlite3_mprintf() */ 7455 /* Virtual table implementations will typically add additional fields */ 7456 }; 7457 7458 /* 7459 ** CAPI3REF: Virtual Table Cursor Object 7460 ** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor} 7461 ** 7462 ** Every [virtual table module] implementation uses a subclass of the 7463 ** following structure to describe cursors that point into the 7464 ** [virtual table] and are used 7465 ** to loop through the virtual table. Cursors are created using the 7466 ** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed 7467 ** by the [sqlite3_module.xClose | xClose] method. Cursors are used 7468 ** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods 7469 ** of the module. Each module implementation will define 7470 ** the content of a cursor structure to suit its own needs. 7471 ** 7472 ** This superclass exists in order to define fields of the cursor that 7473 ** are common to all implementations. 7474 */ 7475 struct sqlite3_vtab_cursor { 7476 sqlite3_vtab *pVtab; /* Virtual table of this cursor */ 7477 /* Virtual table implementations will typically add additional fields */ 7478 }; 7479 7480 /* 7481 ** CAPI3REF: Declare The Schema Of A Virtual Table 7482 ** 7483 ** ^The [xCreate] and [xConnect] methods of a 7484 ** [virtual table module] call this interface 7485 ** to declare the format (the names and datatypes of the columns) of 7486 ** the virtual tables they implement. 7487 */ 7488 SQLITE_API int sqlite3_declare_vtab(sqlite3*, const char *zSQL); 7489 7490 /* 7491 ** CAPI3REF: Overload A Function For A Virtual Table 7492 ** METHOD: sqlite3 7493 ** 7494 ** ^(Virtual tables can provide alternative implementations of functions 7495 ** using the [xFindFunction] method of the [virtual table module]. 7496 ** But global versions of those functions 7497 ** must exist in order to be overloaded.)^ 7498 ** 7499 ** ^(This API makes sure a global version of a function with a particular 7500 ** name and number of parameters exists. If no such function exists 7501 ** before this API is called, a new function is created.)^ ^The implementation 7502 ** of the new function always causes an exception to be thrown. So 7503 ** the new function is not good for anything by itself. Its only 7504 ** purpose is to be a placeholder function that can be overloaded 7505 ** by a [virtual table]. 7506 */ 7507 SQLITE_API int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg); 7508 7509 /* 7510 ** CAPI3REF: A Handle To An Open BLOB 7511 ** KEYWORDS: {BLOB handle} {BLOB handles} 7512 ** 7513 ** An instance of this object represents an open BLOB on which 7514 ** [sqlite3_blob_open | incremental BLOB I/O] can be performed. 7515 ** ^Objects of this type are created by [sqlite3_blob_open()] 7516 ** and destroyed by [sqlite3_blob_close()]. 7517 ** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces 7518 ** can be used to read or write small subsections of the BLOB. 7519 ** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes. 7520 */ 7521 typedef struct sqlite3_blob sqlite3_blob; 7522 7523 /* 7524 ** CAPI3REF: Open A BLOB For Incremental I/O 7525 ** METHOD: sqlite3 7526 ** CONSTRUCTOR: sqlite3_blob 7527 ** 7528 ** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located 7529 ** in row iRow, column zColumn, table zTable in database zDb; 7530 ** in other words, the same BLOB that would be selected by: 7531 ** 7532 ** <pre> 7533 ** SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow; 7534 ** </pre>)^ 7535 ** 7536 ** ^(Parameter zDb is not the filename that contains the database, but 7537 ** rather the symbolic name of the database. For attached databases, this is 7538 ** the name that appears after the AS keyword in the [ATTACH] statement. 7539 ** For the main database file, the database name is "main". For TEMP 7540 ** tables, the database name is "temp".)^ 7541 ** 7542 ** ^If the flags parameter is non-zero, then the BLOB is opened for read 7543 ** and write access. ^If the flags parameter is zero, the BLOB is opened for 7544 ** read-only access. 7545 ** 7546 ** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is stored 7547 ** in *ppBlob. Otherwise an [error code] is returned and, unless the error 7548 ** code is SQLITE_MISUSE, *ppBlob is set to NULL.)^ ^This means that, provided 7549 ** the API is not misused, it is always safe to call [sqlite3_blob_close()] 7550 ** on *ppBlob after this function it returns. 7551 ** 7552 ** This function fails with SQLITE_ERROR if any of the following are true: 7553 ** <ul> 7554 ** <li> ^(Database zDb does not exist)^, 7555 ** <li> ^(Table zTable does not exist within database zDb)^, 7556 ** <li> ^(Table zTable is a WITHOUT ROWID table)^, 7557 ** <li> ^(Column zColumn does not exist)^, 7558 ** <li> ^(Row iRow is not present in the table)^, 7559 ** <li> ^(The specified column of row iRow contains a value that is not 7560 ** a TEXT or BLOB value)^, 7561 ** <li> ^(Column zColumn is part of an index, PRIMARY KEY or UNIQUE 7562 ** constraint and the blob is being opened for read/write access)^, 7563 ** <li> ^([foreign key constraints | Foreign key constraints] are enabled, 7564 ** column zColumn is part of a [child key] definition and the blob is 7565 ** being opened for read/write access)^. 7566 ** </ul> 7567 ** 7568 ** ^Unless it returns SQLITE_MISUSE, this function sets the 7569 ** [database connection] error code and message accessible via 7570 ** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions. 7571 ** 7572 ** A BLOB referenced by sqlite3_blob_open() may be read using the 7573 ** [sqlite3_blob_read()] interface and modified by using 7574 ** [sqlite3_blob_write()]. The [BLOB handle] can be moved to a 7575 ** different row of the same table using the [sqlite3_blob_reopen()] 7576 ** interface. However, the column, table, or database of a [BLOB handle] 7577 ** cannot be changed after the [BLOB handle] is opened. 7578 ** 7579 ** ^(If the row that a BLOB handle points to is modified by an 7580 ** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects 7581 ** then the BLOB handle is marked as "expired". 7582 ** This is true if any column of the row is changed, even a column 7583 ** other than the one the BLOB handle is open on.)^ 7584 ** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for 7585 ** an expired BLOB handle fail with a return code of [SQLITE_ABORT]. 7586 ** ^(Changes written into a BLOB prior to the BLOB expiring are not 7587 ** rolled back by the expiration of the BLOB. Such changes will eventually 7588 ** commit if the transaction continues to completion.)^ 7589 ** 7590 ** ^Use the [sqlite3_blob_bytes()] interface to determine the size of 7591 ** the opened blob. ^The size of a blob may not be changed by this 7592 ** interface. Use the [UPDATE] SQL command to change the size of a 7593 ** blob. 7594 ** 7595 ** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces 7596 ** and the built-in [zeroblob] SQL function may be used to create a 7597 ** zero-filled blob to read or write using the incremental-blob interface. 7598 ** 7599 ** To avoid a resource leak, every open [BLOB handle] should eventually 7600 ** be released by a call to [sqlite3_blob_close()]. 7601 ** 7602 ** See also: [sqlite3_blob_close()], 7603 ** [sqlite3_blob_reopen()], [sqlite3_blob_read()], 7604 ** [sqlite3_blob_bytes()], [sqlite3_blob_write()]. 7605 */ 7606 SQLITE_API int sqlite3_blob_open( 7607 sqlite3*, 7608 const char *zDb, 7609 const char *zTable, 7610 const char *zColumn, 7611 sqlite3_int64 iRow, 7612 int flags, 7613 sqlite3_blob **ppBlob 7614 ); 7615 7616 /* 7617 ** CAPI3REF: Move a BLOB Handle to a New Row 7618 ** METHOD: sqlite3_blob 7619 ** 7620 ** ^This function is used to move an existing [BLOB handle] so that it points 7621 ** to a different row of the same database table. ^The new row is identified 7622 ** by the rowid value passed as the second argument. Only the row can be 7623 ** changed. ^The database, table and column on which the blob handle is open 7624 ** remain the same. Moving an existing [BLOB handle] to a new row is 7625 ** faster than closing the existing handle and opening a new one. 7626 ** 7627 ** ^(The new row must meet the same criteria as for [sqlite3_blob_open()] - 7628 ** it must exist and there must be either a blob or text value stored in 7629 ** the nominated column.)^ ^If the new row is not present in the table, or if 7630 ** it does not contain a blob or text value, or if another error occurs, an 7631 ** SQLite error code is returned and the blob handle is considered aborted. 7632 ** ^All subsequent calls to [sqlite3_blob_read()], [sqlite3_blob_write()] or 7633 ** [sqlite3_blob_reopen()] on an aborted blob handle immediately return 7634 ** SQLITE_ABORT. ^Calling [sqlite3_blob_bytes()] on an aborted blob handle 7635 ** always returns zero. 7636 ** 7637 ** ^This function sets the database handle error code and message. 7638 */ 7639 SQLITE_API int sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64); 7640 7641 /* 7642 ** CAPI3REF: Close A BLOB Handle 7643 ** DESTRUCTOR: sqlite3_blob 7644 ** 7645 ** ^This function closes an open [BLOB handle]. ^(The BLOB handle is closed 7646 ** unconditionally. Even if this routine returns an error code, the 7647 ** handle is still closed.)^ 7648 ** 7649 ** ^If the blob handle being closed was opened for read-write access, and if 7650 ** the database is in auto-commit mode and there are no other open read-write 7651 ** blob handles or active write statements, the current transaction is 7652 ** committed. ^If an error occurs while committing the transaction, an error 7653 ** code is returned and the transaction rolled back. 7654 ** 7655 ** Calling this function with an argument that is not a NULL pointer or an 7656 ** open blob handle results in undefined behaviour. ^Calling this routine 7657 ** with a null pointer (such as would be returned by a failed call to 7658 ** [sqlite3_blob_open()]) is a harmless no-op. ^Otherwise, if this function 7659 ** is passed a valid open blob handle, the values returned by the 7660 ** sqlite3_errcode() and sqlite3_errmsg() functions are set before returning. 7661 */ 7662 SQLITE_API int sqlite3_blob_close(sqlite3_blob *); 7663 7664 /* 7665 ** CAPI3REF: Return The Size Of An Open BLOB 7666 ** METHOD: sqlite3_blob 7667 ** 7668 ** ^Returns the size in bytes of the BLOB accessible via the 7669 ** successfully opened [BLOB handle] in its only argument. ^The 7670 ** incremental blob I/O routines can only read or overwriting existing 7671 ** blob content; they cannot change the size of a blob. 7672 ** 7673 ** This routine only works on a [BLOB handle] which has been created 7674 ** by a prior successful call to [sqlite3_blob_open()] and which has not 7675 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in 7676 ** to this routine results in undefined and probably undesirable behavior. 7677 */ 7678 SQLITE_API int sqlite3_blob_bytes(sqlite3_blob *); 7679 7680 /* 7681 ** CAPI3REF: Read Data From A BLOB Incrementally 7682 ** METHOD: sqlite3_blob 7683 ** 7684 ** ^(This function is used to read data from an open [BLOB handle] into a 7685 ** caller-supplied buffer. N bytes of data are copied into buffer Z 7686 ** from the open BLOB, starting at offset iOffset.)^ 7687 ** 7688 ** ^If offset iOffset is less than N bytes from the end of the BLOB, 7689 ** [SQLITE_ERROR] is returned and no data is read. ^If N or iOffset is 7690 ** less than zero, [SQLITE_ERROR] is returned and no data is read. 7691 ** ^The size of the blob (and hence the maximum value of N+iOffset) 7692 ** can be determined using the [sqlite3_blob_bytes()] interface. 7693 ** 7694 ** ^An attempt to read from an expired [BLOB handle] fails with an 7695 ** error code of [SQLITE_ABORT]. 7696 ** 7697 ** ^(On success, sqlite3_blob_read() returns SQLITE_OK. 7698 ** Otherwise, an [error code] or an [extended error code] is returned.)^ 7699 ** 7700 ** This routine only works on a [BLOB handle] which has been created 7701 ** by a prior successful call to [sqlite3_blob_open()] and which has not 7702 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in 7703 ** to this routine results in undefined and probably undesirable behavior. 7704 ** 7705 ** See also: [sqlite3_blob_write()]. 7706 */ 7707 SQLITE_API int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset); 7708 7709 /* 7710 ** CAPI3REF: Write Data Into A BLOB Incrementally 7711 ** METHOD: sqlite3_blob 7712 ** 7713 ** ^(This function is used to write data into an open [BLOB handle] from a 7714 ** caller-supplied buffer. N bytes of data are copied from the buffer Z 7715 ** into the open BLOB, starting at offset iOffset.)^ 7716 ** 7717 ** ^(On success, sqlite3_blob_write() returns SQLITE_OK. 7718 ** Otherwise, an [error code] or an [extended error code] is returned.)^ 7719 ** ^Unless SQLITE_MISUSE is returned, this function sets the 7720 ** [database connection] error code and message accessible via 7721 ** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions. 7722 ** 7723 ** ^If the [BLOB handle] passed as the first argument was not opened for 7724 ** writing (the flags parameter to [sqlite3_blob_open()] was zero), 7725 ** this function returns [SQLITE_READONLY]. 7726 ** 7727 ** This function may only modify the contents of the BLOB; it is 7728 ** not possible to increase the size of a BLOB using this API. 7729 ** ^If offset iOffset is less than N bytes from the end of the BLOB, 7730 ** [SQLITE_ERROR] is returned and no data is written. The size of the 7731 ** BLOB (and hence the maximum value of N+iOffset) can be determined 7732 ** using the [sqlite3_blob_bytes()] interface. ^If N or iOffset are less 7733 ** than zero [SQLITE_ERROR] is returned and no data is written. 7734 ** 7735 ** ^An attempt to write to an expired [BLOB handle] fails with an 7736 ** error code of [SQLITE_ABORT]. ^Writes to the BLOB that occurred 7737 ** before the [BLOB handle] expired are not rolled back by the 7738 ** expiration of the handle, though of course those changes might 7739 ** have been overwritten by the statement that expired the BLOB handle 7740 ** or by other independent statements. 7741 ** 7742 ** This routine only works on a [BLOB handle] which has been created 7743 ** by a prior successful call to [sqlite3_blob_open()] and which has not 7744 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in 7745 ** to this routine results in undefined and probably undesirable behavior. 7746 ** 7747 ** See also: [sqlite3_blob_read()]. 7748 */ 7749 SQLITE_API int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset); 7750 7751 /* 7752 ** CAPI3REF: Virtual File System Objects 7753 ** 7754 ** A virtual filesystem (VFS) is an [sqlite3_vfs] object 7755 ** that SQLite uses to interact 7756 ** with the underlying operating system. Most SQLite builds come with a 7757 ** single default VFS that is appropriate for the host computer. 7758 ** New VFSes can be registered and existing VFSes can be unregistered. 7759 ** The following interfaces are provided. 7760 ** 7761 ** ^The sqlite3_vfs_find() interface returns a pointer to a VFS given its name. 7762 ** ^Names are case sensitive. 7763 ** ^Names are zero-terminated UTF-8 strings. 7764 ** ^If there is no match, a NULL pointer is returned. 7765 ** ^If zVfsName is NULL then the default VFS is returned. 7766 ** 7767 ** ^New VFSes are registered with sqlite3_vfs_register(). 7768 ** ^Each new VFS becomes the default VFS if the makeDflt flag is set. 7769 ** ^The same VFS can be registered multiple times without injury. 7770 ** ^To make an existing VFS into the default VFS, register it again 7771 ** with the makeDflt flag set. If two different VFSes with the 7772 ** same name are registered, the behavior is undefined. If a 7773 ** VFS is registered with a name that is NULL or an empty string, 7774 ** then the behavior is undefined. 7775 ** 7776 ** ^Unregister a VFS with the sqlite3_vfs_unregister() interface. 7777 ** ^(If the default VFS is unregistered, another VFS is chosen as 7778 ** the default. The choice for the new VFS is arbitrary.)^ 7779 */ 7780 SQLITE_API sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName); 7781 SQLITE_API int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt); 7782 SQLITE_API int sqlite3_vfs_unregister(sqlite3_vfs*); 7783 7784 /* 7785 ** CAPI3REF: Mutexes 7786 ** 7787 ** The SQLite core uses these routines for thread 7788 ** synchronization. Though they are intended for internal 7789 ** use by SQLite, code that links against SQLite is 7790 ** permitted to use any of these routines. 7791 ** 7792 ** The SQLite source code contains multiple implementations 7793 ** of these mutex routines. An appropriate implementation 7794 ** is selected automatically at compile-time. The following 7795 ** implementations are available in the SQLite core: 7796 ** 7797 ** <ul> 7798 ** <li> SQLITE_MUTEX_PTHREADS 7799 ** <li> SQLITE_MUTEX_W32 7800 ** <li> SQLITE_MUTEX_NOOP 7801 ** </ul> 7802 ** 7803 ** The SQLITE_MUTEX_NOOP implementation is a set of routines 7804 ** that does no real locking and is appropriate for use in 7805 ** a single-threaded application. The SQLITE_MUTEX_PTHREADS and 7806 ** SQLITE_MUTEX_W32 implementations are appropriate for use on Unix 7807 ** and Windows. 7808 ** 7809 ** If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor 7810 ** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex 7811 ** implementation is included with the library. In this case the 7812 ** application must supply a custom mutex implementation using the 7813 ** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function 7814 ** before calling sqlite3_initialize() or any other public sqlite3_ 7815 ** function that calls sqlite3_initialize(). 7816 ** 7817 ** ^The sqlite3_mutex_alloc() routine allocates a new 7818 ** mutex and returns a pointer to it. ^The sqlite3_mutex_alloc() 7819 ** routine returns NULL if it is unable to allocate the requested 7820 ** mutex. The argument to sqlite3_mutex_alloc() must one of these 7821 ** integer constants: 7822 ** 7823 ** <ul> 7824 ** <li> SQLITE_MUTEX_FAST 7825 ** <li> SQLITE_MUTEX_RECURSIVE 7826 ** <li> SQLITE_MUTEX_STATIC_MAIN 7827 ** <li> SQLITE_MUTEX_STATIC_MEM 7828 ** <li> SQLITE_MUTEX_STATIC_OPEN 7829 ** <li> SQLITE_MUTEX_STATIC_PRNG 7830 ** <li> SQLITE_MUTEX_STATIC_LRU 7831 ** <li> SQLITE_MUTEX_STATIC_PMEM 7832 ** <li> SQLITE_MUTEX_STATIC_APP1 7833 ** <li> SQLITE_MUTEX_STATIC_APP2 7834 ** <li> SQLITE_MUTEX_STATIC_APP3 7835 ** <li> SQLITE_MUTEX_STATIC_VFS1 7836 ** <li> SQLITE_MUTEX_STATIC_VFS2 7837 ** <li> SQLITE_MUTEX_STATIC_VFS3 7838 ** </ul> 7839 ** 7840 ** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) 7841 ** cause sqlite3_mutex_alloc() to create 7842 ** a new mutex. ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE 7843 ** is used but not necessarily so when SQLITE_MUTEX_FAST is used. 7844 ** The mutex implementation does not need to make a distinction 7845 ** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does 7846 ** not want to. SQLite will only request a recursive mutex in 7847 ** cases where it really needs one. If a faster non-recursive mutex 7848 ** implementation is available on the host platform, the mutex subsystem 7849 ** might return such a mutex in response to SQLITE_MUTEX_FAST. 7850 ** 7851 ** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other 7852 ** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return 7853 ** a pointer to a static preexisting mutex. ^Nine static mutexes are 7854 ** used by the current version of SQLite. Future versions of SQLite 7855 ** may add additional static mutexes. Static mutexes are for internal 7856 ** use by SQLite only. Applications that use SQLite mutexes should 7857 ** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or 7858 ** SQLITE_MUTEX_RECURSIVE. 7859 ** 7860 ** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST 7861 ** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc() 7862 ** returns a different mutex on every call. ^For the static 7863 ** mutex types, the same mutex is returned on every call that has 7864 ** the same type number. 7865 ** 7866 ** ^The sqlite3_mutex_free() routine deallocates a previously 7867 ** allocated dynamic mutex. Attempting to deallocate a static 7868 ** mutex results in undefined behavior. 7869 ** 7870 ** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt 7871 ** to enter a mutex. ^If another thread is already within the mutex, 7872 ** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return 7873 ** SQLITE_BUSY. ^The sqlite3_mutex_try() interface returns [SQLITE_OK] 7874 ** upon successful entry. ^(Mutexes created using 7875 ** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread. 7876 ** In such cases, the 7877 ** mutex must be exited an equal number of times before another thread 7878 ** can enter.)^ If the same thread tries to enter any mutex other 7879 ** than an SQLITE_MUTEX_RECURSIVE more than once, the behavior is undefined. 7880 ** 7881 ** ^(Some systems (for example, Windows 95) do not support the operation 7882 ** implemented by sqlite3_mutex_try(). On those systems, sqlite3_mutex_try() 7883 ** will always return SQLITE_BUSY. The SQLite core only ever uses 7884 ** sqlite3_mutex_try() as an optimization so this is acceptable 7885 ** behavior.)^ 7886 ** 7887 ** ^The sqlite3_mutex_leave() routine exits a mutex that was 7888 ** previously entered by the same thread. The behavior 7889 ** is undefined if the mutex is not currently entered by the 7890 ** calling thread or is not currently allocated. 7891 ** 7892 ** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), 7893 ** sqlite3_mutex_leave(), or sqlite3_mutex_free() is a NULL pointer, 7894 ** then any of the four routines behaves as a no-op. 7895 ** 7896 ** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()]. 7897 */ 7898 SQLITE_API sqlite3_mutex *sqlite3_mutex_alloc(int); 7899 SQLITE_API void sqlite3_mutex_free(sqlite3_mutex*); 7900 SQLITE_API void sqlite3_mutex_enter(sqlite3_mutex*); 7901 SQLITE_API int sqlite3_mutex_try(sqlite3_mutex*); 7902 SQLITE_API void sqlite3_mutex_leave(sqlite3_mutex*); 7903 7904 /* 7905 ** CAPI3REF: Mutex Methods Object 7906 ** 7907 ** An instance of this structure defines the low-level routines 7908 ** used to allocate and use mutexes. 7909 ** 7910 ** Usually, the default mutex implementations provided by SQLite are 7911 ** sufficient, however the application has the option of substituting a custom 7912 ** implementation for specialized deployments or systems for which SQLite 7913 ** does not provide a suitable implementation. In this case, the application 7914 ** creates and populates an instance of this structure to pass 7915 ** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option. 7916 ** Additionally, an instance of this structure can be used as an 7917 ** output variable when querying the system for the current mutex 7918 ** implementation, using the [SQLITE_CONFIG_GETMUTEX] option. 7919 ** 7920 ** ^The xMutexInit method defined by this structure is invoked as 7921 ** part of system initialization by the sqlite3_initialize() function. 7922 ** ^The xMutexInit routine is called by SQLite exactly once for each 7923 ** effective call to [sqlite3_initialize()]. 7924 ** 7925 ** ^The xMutexEnd method defined by this structure is invoked as 7926 ** part of system shutdown by the sqlite3_shutdown() function. The 7927 ** implementation of this method is expected to release all outstanding 7928 ** resources obtained by the mutex methods implementation, especially 7929 ** those obtained by the xMutexInit method. ^The xMutexEnd() 7930 ** interface is invoked exactly once for each call to [sqlite3_shutdown()]. 7931 ** 7932 ** ^(The remaining seven methods defined by this structure (xMutexAlloc, 7933 ** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and 7934 ** xMutexNotheld) implement the following interfaces (respectively): 7935 ** 7936 ** <ul> 7937 ** <li> [sqlite3_mutex_alloc()] </li> 7938 ** <li> [sqlite3_mutex_free()] </li> 7939 ** <li> [sqlite3_mutex_enter()] </li> 7940 ** <li> [sqlite3_mutex_try()] </li> 7941 ** <li> [sqlite3_mutex_leave()] </li> 7942 ** <li> [sqlite3_mutex_held()] </li> 7943 ** <li> [sqlite3_mutex_notheld()] </li> 7944 ** </ul>)^ 7945 ** 7946 ** The only difference is that the public sqlite3_XXX functions enumerated 7947 ** above silently ignore any invocations that pass a NULL pointer instead 7948 ** of a valid mutex handle. The implementations of the methods defined 7949 ** by this structure are not required to handle this case. The results 7950 ** of passing a NULL pointer instead of a valid mutex handle are undefined 7951 ** (i.e. it is acceptable to provide an implementation that segfaults if 7952 ** it is passed a NULL pointer). 7953 ** 7954 ** The xMutexInit() method must be threadsafe. It must be harmless to 7955 ** invoke xMutexInit() multiple times within the same process and without 7956 ** intervening calls to xMutexEnd(). Second and subsequent calls to 7957 ** xMutexInit() must be no-ops. 7958 ** 7959 ** xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()] 7960 ** and its associates). Similarly, xMutexAlloc() must not use SQLite memory 7961 ** allocation for a static mutex. ^However xMutexAlloc() may use SQLite 7962 ** memory allocation for a fast or recursive mutex. 7963 ** 7964 ** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is 7965 ** called, but only if the prior call to xMutexInit returned SQLITE_OK. 7966 ** If xMutexInit fails in any way, it is expected to clean up after itself 7967 ** prior to returning. 7968 */ 7969 typedef struct sqlite3_mutex_methods sqlite3_mutex_methods; 7970 struct sqlite3_mutex_methods { 7971 int (*xMutexInit)(void); 7972 int (*xMutexEnd)(void); 7973 sqlite3_mutex *(*xMutexAlloc)(int); 7974 void (*xMutexFree)(sqlite3_mutex *); 7975 void (*xMutexEnter)(sqlite3_mutex *); 7976 int (*xMutexTry)(sqlite3_mutex *); 7977 void (*xMutexLeave)(sqlite3_mutex *); 7978 int (*xMutexHeld)(sqlite3_mutex *); 7979 int (*xMutexNotheld)(sqlite3_mutex *); 7980 }; 7981 7982 /* 7983 ** CAPI3REF: Mutex Verification Routines 7984 ** 7985 ** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines 7986 ** are intended for use inside assert() statements. The SQLite core 7987 ** never uses these routines except inside an assert() and applications 7988 ** are advised to follow the lead of the core. The SQLite core only 7989 ** provides implementations for these routines when it is compiled 7990 ** with the SQLITE_DEBUG flag. External mutex implementations 7991 ** are only required to provide these routines if SQLITE_DEBUG is 7992 ** defined and if NDEBUG is not defined. 7993 ** 7994 ** These routines should return true if the mutex in their argument 7995 ** is held or not held, respectively, by the calling thread. 7996 ** 7997 ** The implementation is not required to provide versions of these 7998 ** routines that actually work. If the implementation does not provide working 7999 ** versions of these routines, it should at least provide stubs that always 8000 ** return true so that one does not get spurious assertion failures. 8001 ** 8002 ** If the argument to sqlite3_mutex_held() is a NULL pointer then 8003 ** the routine should return 1. This seems counter-intuitive since 8004 ** clearly the mutex cannot be held if it does not exist. But 8005 ** the reason the mutex does not exist is because the build is not 8006 ** using mutexes. And we do not want the assert() containing the 8007 ** call to sqlite3_mutex_held() to fail, so a non-zero return is 8008 ** the appropriate thing to do. The sqlite3_mutex_notheld() 8009 ** interface should also return 1 when given a NULL pointer. 8010 */ 8011 #ifndef NDEBUG 8012 SQLITE_API int sqlite3_mutex_held(sqlite3_mutex*); 8013 SQLITE_API int sqlite3_mutex_notheld(sqlite3_mutex*); 8014 #endif 8015 8016 /* 8017 ** CAPI3REF: Mutex Types 8018 ** 8019 ** The [sqlite3_mutex_alloc()] interface takes a single argument 8020 ** which is one of these integer constants. 8021 ** 8022 ** The set of static mutexes may change from one SQLite release to the 8023 ** next. Applications that override the built-in mutex logic must be 8024 ** prepared to accommodate additional static mutexes. 8025 */ 8026 #define SQLITE_MUTEX_FAST 0 8027 #define SQLITE_MUTEX_RECURSIVE 1 8028 #define SQLITE_MUTEX_STATIC_MAIN 2 8029 #define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */ 8030 #define SQLITE_MUTEX_STATIC_MEM2 4 /* NOT USED */ 8031 #define SQLITE_MUTEX_STATIC_OPEN 4 /* sqlite3BtreeOpen() */ 8032 #define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_randomness() */ 8033 #define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */ 8034 #define SQLITE_MUTEX_STATIC_LRU2 7 /* NOT USED */ 8035 #define SQLITE_MUTEX_STATIC_PMEM 7 /* sqlite3PageMalloc() */ 8036 #define SQLITE_MUTEX_STATIC_APP1 8 /* For use by application */ 8037 #define SQLITE_MUTEX_STATIC_APP2 9 /* For use by application */ 8038 #define SQLITE_MUTEX_STATIC_APP3 10 /* For use by application */ 8039 #define SQLITE_MUTEX_STATIC_VFS1 11 /* For use by built-in VFS */ 8040 #define SQLITE_MUTEX_STATIC_VFS2 12 /* For use by extension VFS */ 8041 #define SQLITE_MUTEX_STATIC_VFS3 13 /* For use by application VFS */ 8042 8043 /* Legacy compatibility: */ 8044 #define SQLITE_MUTEX_STATIC_MASTER 2 8045 8046 8047 /* 8048 ** CAPI3REF: Retrieve the mutex for a database connection 8049 ** METHOD: sqlite3 8050 ** 8051 ** ^This interface returns a pointer the [sqlite3_mutex] object that 8052 ** serializes access to the [database connection] given in the argument 8053 ** when the [threading mode] is Serialized. 8054 ** ^If the [threading mode] is Single-thread or Multi-thread then this 8055 ** routine returns a NULL pointer. 8056 */ 8057 SQLITE_API sqlite3_mutex *sqlite3_db_mutex(sqlite3*); 8058 8059 /* 8060 ** CAPI3REF: Low-Level Control Of Database Files 8061 ** METHOD: sqlite3 8062 ** KEYWORDS: {file control} 8063 ** 8064 ** ^The [sqlite3_file_control()] interface makes a direct call to the 8065 ** xFileControl method for the [sqlite3_io_methods] object associated 8066 ** with a particular database identified by the second argument. ^The 8067 ** name of the database is "main" for the main database or "temp" for the 8068 ** TEMP database, or the name that appears after the AS keyword for 8069 ** databases that are added using the [ATTACH] SQL command. 8070 ** ^A NULL pointer can be used in place of "main" to refer to the 8071 ** main database file. 8072 ** ^The third and fourth parameters to this routine 8073 ** are passed directly through to the second and third parameters of 8074 ** the xFileControl method. ^The return value of the xFileControl 8075 ** method becomes the return value of this routine. 8076 ** 8077 ** A few opcodes for [sqlite3_file_control()] are handled directly 8078 ** by the SQLite core and never invoke the 8079 ** sqlite3_io_methods.xFileControl method. 8080 ** ^The [SQLITE_FCNTL_FILE_POINTER] value for the op parameter causes 8081 ** a pointer to the underlying [sqlite3_file] object to be written into 8082 ** the space pointed to by the 4th parameter. The 8083 ** [SQLITE_FCNTL_JOURNAL_POINTER] works similarly except that it returns 8084 ** the [sqlite3_file] object associated with the journal file instead of 8085 ** the main database. The [SQLITE_FCNTL_VFS_POINTER] opcode returns 8086 ** a pointer to the underlying [sqlite3_vfs] object for the file. 8087 ** The [SQLITE_FCNTL_DATA_VERSION] returns the data version counter 8088 ** from the pager. 8089 ** 8090 ** ^If the second parameter (zDbName) does not match the name of any 8091 ** open database file, then SQLITE_ERROR is returned. ^This error 8092 ** code is not remembered and will not be recalled by [sqlite3_errcode()] 8093 ** or [sqlite3_errmsg()]. The underlying xFileControl method might 8094 ** also return SQLITE_ERROR. There is no way to distinguish between 8095 ** an incorrect zDbName and an SQLITE_ERROR return from the underlying 8096 ** xFileControl method. 8097 ** 8098 ** See also: [file control opcodes] 8099 */ 8100 SQLITE_API int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*); 8101 8102 /* 8103 ** CAPI3REF: Testing Interface 8104 ** 8105 ** ^The sqlite3_test_control() interface is used to read out internal 8106 ** state of SQLite and to inject faults into SQLite for testing 8107 ** purposes. ^The first parameter is an operation code that determines 8108 ** the number, meaning, and operation of all subsequent parameters. 8109 ** 8110 ** This interface is not for use by applications. It exists solely 8111 ** for verifying the correct operation of the SQLite library. Depending 8112 ** on how the SQLite library is compiled, this interface might not exist. 8113 ** 8114 ** The details of the operation codes, their meanings, the parameters 8115 ** they take, and what they do are all subject to change without notice. 8116 ** Unlike most of the SQLite API, this function is not guaranteed to 8117 ** operate consistently from one release to the next. 8118 */ 8119 SQLITE_API int sqlite3_test_control(int op, ...); 8120 8121 /* 8122 ** CAPI3REF: Testing Interface Operation Codes 8123 ** 8124 ** These constants are the valid operation code parameters used 8125 ** as the first argument to [sqlite3_test_control()]. 8126 ** 8127 ** These parameters and their meanings are subject to change 8128 ** without notice. These values are for testing purposes only. 8129 ** Applications should not use any of these parameters or the 8130 ** [sqlite3_test_control()] interface. 8131 */ 8132 #define SQLITE_TESTCTRL_FIRST 5 8133 #define SQLITE_TESTCTRL_PRNG_SAVE 5 8134 #define SQLITE_TESTCTRL_PRNG_RESTORE 6 8135 #define SQLITE_TESTCTRL_PRNG_RESET 7 /* NOT USED */ 8136 #define SQLITE_TESTCTRL_BITVEC_TEST 8 8137 #define SQLITE_TESTCTRL_FAULT_INSTALL 9 8138 #define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS 10 8139 #define SQLITE_TESTCTRL_PENDING_BYTE 11 8140 #define SQLITE_TESTCTRL_ASSERT 12 8141 #define SQLITE_TESTCTRL_ALWAYS 13 8142 #define SQLITE_TESTCTRL_RESERVE 14 /* NOT USED */ 8143 #define SQLITE_TESTCTRL_OPTIMIZATIONS 15 8144 #define SQLITE_TESTCTRL_ISKEYWORD 16 /* NOT USED */ 8145 #define SQLITE_TESTCTRL_SCRATCHMALLOC 17 /* NOT USED */ 8146 #define SQLITE_TESTCTRL_INTERNAL_FUNCTIONS 17 8147 #define SQLITE_TESTCTRL_LOCALTIME_FAULT 18 8148 #define SQLITE_TESTCTRL_EXPLAIN_STMT 19 /* NOT USED */ 8149 #define SQLITE_TESTCTRL_ONCE_RESET_THRESHOLD 19 8150 #define SQLITE_TESTCTRL_NEVER_CORRUPT 20 8151 #define SQLITE_TESTCTRL_VDBE_COVERAGE 21 8152 #define SQLITE_TESTCTRL_BYTEORDER 22 8153 #define SQLITE_TESTCTRL_ISINIT 23 8154 #define SQLITE_TESTCTRL_SORTER_MMAP 24 8155 #define SQLITE_TESTCTRL_IMPOSTER 25 8156 #define SQLITE_TESTCTRL_PARSER_COVERAGE 26 8157 #define SQLITE_TESTCTRL_RESULT_INTREAL 27 8158 #define SQLITE_TESTCTRL_PRNG_SEED 28 8159 #define SQLITE_TESTCTRL_EXTRA_SCHEMA_CHECKS 29 8160 #define SQLITE_TESTCTRL_SEEK_COUNT 30 8161 #define SQLITE_TESTCTRL_TRACEFLAGS 31 8162 #define SQLITE_TESTCTRL_TUNE 32 8163 #define SQLITE_TESTCTRL_LOGEST 33 8164 #define SQLITE_TESTCTRL_LAST 33 /* Largest TESTCTRL */ 8165 8166 /* 8167 ** CAPI3REF: SQL Keyword Checking 8168 ** 8169 ** These routines provide access to the set of SQL language keywords 8170 ** recognized by SQLite. Applications can uses these routines to determine 8171 ** whether or not a specific identifier needs to be escaped (for example, 8172 ** by enclosing in double-quotes) so as not to confuse the parser. 8173 ** 8174 ** The sqlite3_keyword_count() interface returns the number of distinct 8175 ** keywords understood by SQLite. 8176 ** 8177 ** The sqlite3_keyword_name(N,Z,L) interface finds the N-th keyword and 8178 ** makes *Z point to that keyword expressed as UTF8 and writes the number 8179 ** of bytes in the keyword into *L. The string that *Z points to is not 8180 ** zero-terminated. The sqlite3_keyword_name(N,Z,L) routine returns 8181 ** SQLITE_OK if N is within bounds and SQLITE_ERROR if not. If either Z 8182 ** or L are NULL or invalid pointers then calls to 8183 ** sqlite3_keyword_name(N,Z,L) result in undefined behavior. 8184 ** 8185 ** The sqlite3_keyword_check(Z,L) interface checks to see whether or not 8186 ** the L-byte UTF8 identifier that Z points to is a keyword, returning non-zero 8187 ** if it is and zero if not. 8188 ** 8189 ** The parser used by SQLite is forgiving. It is often possible to use 8190 ** a keyword as an identifier as long as such use does not result in a 8191 ** parsing ambiguity. For example, the statement 8192 ** "CREATE TABLE BEGIN(REPLACE,PRAGMA,END);" is accepted by SQLite, and 8193 ** creates a new table named "BEGIN" with three columns named 8194 ** "REPLACE", "PRAGMA", and "END". Nevertheless, best practice is to avoid 8195 ** using keywords as identifiers. Common techniques used to avoid keyword 8196 ** name collisions include: 8197 ** <ul> 8198 ** <li> Put all identifier names inside double-quotes. This is the official 8199 ** SQL way to escape identifier names. 8200 ** <li> Put identifier names inside [...]. This is not standard SQL, 8201 ** but it is what SQL Server does and so lots of programmers use this 8202 ** technique. 8203 ** <li> Begin every identifier with the letter "Z" as no SQL keywords start 8204 ** with "Z". 8205 ** <li> Include a digit somewhere in every identifier name. 8206 ** </ul> 8207 ** 8208 ** Note that the number of keywords understood by SQLite can depend on 8209 ** compile-time options. For example, "VACUUM" is not a keyword if 8210 ** SQLite is compiled with the [-DSQLITE_OMIT_VACUUM] option. Also, 8211 ** new keywords may be added to future releases of SQLite. 8212 */ 8213 SQLITE_API int sqlite3_keyword_count(void); 8214 SQLITE_API int sqlite3_keyword_name(int,const char**,int*); 8215 SQLITE_API int sqlite3_keyword_check(const char*,int); 8216 8217 /* 8218 ** CAPI3REF: Dynamic String Object 8219 ** KEYWORDS: {dynamic string} 8220 ** 8221 ** An instance of the sqlite3_str object contains a dynamically-sized 8222 ** string under construction. 8223 ** 8224 ** The lifecycle of an sqlite3_str object is as follows: 8225 ** <ol> 8226 ** <li> ^The sqlite3_str object is created using [sqlite3_str_new()]. 8227 ** <li> ^Text is appended to the sqlite3_str object using various 8228 ** methods, such as [sqlite3_str_appendf()]. 8229 ** <li> ^The sqlite3_str object is destroyed and the string it created 8230 ** is returned using the [sqlite3_str_finish()] interface. 8231 ** </ol> 8232 */ 8233 typedef struct sqlite3_str sqlite3_str; 8234 8235 /* 8236 ** CAPI3REF: Create A New Dynamic String Object 8237 ** CONSTRUCTOR: sqlite3_str 8238 ** 8239 ** ^The [sqlite3_str_new(D)] interface allocates and initializes 8240 ** a new [sqlite3_str] object. To avoid memory leaks, the object returned by 8241 ** [sqlite3_str_new()] must be freed by a subsequent call to 8242 ** [sqlite3_str_finish(X)]. 8243 ** 8244 ** ^The [sqlite3_str_new(D)] interface always returns a pointer to a 8245 ** valid [sqlite3_str] object, though in the event of an out-of-memory 8246 ** error the returned object might be a special singleton that will 8247 ** silently reject new text, always return SQLITE_NOMEM from 8248 ** [sqlite3_str_errcode()], always return 0 for 8249 ** [sqlite3_str_length()], and always return NULL from 8250 ** [sqlite3_str_finish(X)]. It is always safe to use the value 8251 ** returned by [sqlite3_str_new(D)] as the sqlite3_str parameter 8252 ** to any of the other [sqlite3_str] methods. 8253 ** 8254 ** The D parameter to [sqlite3_str_new(D)] may be NULL. If the 8255 ** D parameter in [sqlite3_str_new(D)] is not NULL, then the maximum 8256 ** length of the string contained in the [sqlite3_str] object will be 8257 ** the value set for [sqlite3_limit](D,[SQLITE_LIMIT_LENGTH]) instead 8258 ** of [SQLITE_MAX_LENGTH]. 8259 */ 8260 SQLITE_API sqlite3_str *sqlite3_str_new(sqlite3*); 8261 8262 /* 8263 ** CAPI3REF: Finalize A Dynamic String 8264 ** DESTRUCTOR: sqlite3_str 8265 ** 8266 ** ^The [sqlite3_str_finish(X)] interface destroys the sqlite3_str object X 8267 ** and returns a pointer to a memory buffer obtained from [sqlite3_malloc64()] 8268 ** that contains the constructed string. The calling application should 8269 ** pass the returned value to [sqlite3_free()] to avoid a memory leak. 8270 ** ^The [sqlite3_str_finish(X)] interface may return a NULL pointer if any 8271 ** errors were encountered during construction of the string. ^The 8272 ** [sqlite3_str_finish(X)] interface will also return a NULL pointer if the 8273 ** string in [sqlite3_str] object X is zero bytes long. 8274 */ 8275 SQLITE_API char *sqlite3_str_finish(sqlite3_str*); 8276 8277 /* 8278 ** CAPI3REF: Add Content To A Dynamic String 8279 ** METHOD: sqlite3_str 8280 ** 8281 ** These interfaces add content to an sqlite3_str object previously obtained 8282 ** from [sqlite3_str_new()]. 8283 ** 8284 ** ^The [sqlite3_str_appendf(X,F,...)] and 8285 ** [sqlite3_str_vappendf(X,F,V)] interfaces uses the [built-in printf] 8286 ** functionality of SQLite to append formatted text onto the end of 8287 ** [sqlite3_str] object X. 8288 ** 8289 ** ^The [sqlite3_str_append(X,S,N)] method appends exactly N bytes from string S 8290 ** onto the end of the [sqlite3_str] object X. N must be non-negative. 8291 ** S must contain at least N non-zero bytes of content. To append a 8292 ** zero-terminated string in its entirety, use the [sqlite3_str_appendall()] 8293 ** method instead. 8294 ** 8295 ** ^The [sqlite3_str_appendall(X,S)] method appends the complete content of 8296 ** zero-terminated string S onto the end of [sqlite3_str] object X. 8297 ** 8298 ** ^The [sqlite3_str_appendchar(X,N,C)] method appends N copies of the 8299 ** single-byte character C onto the end of [sqlite3_str] object X. 8300 ** ^This method can be used, for example, to add whitespace indentation. 8301 ** 8302 ** ^The [sqlite3_str_reset(X)] method resets the string under construction 8303 ** inside [sqlite3_str] object X back to zero bytes in length. 8304 ** 8305 ** These methods do not return a result code. ^If an error occurs, that fact 8306 ** is recorded in the [sqlite3_str] object and can be recovered by a 8307 ** subsequent call to [sqlite3_str_errcode(X)]. 8308 */ 8309 SQLITE_API void sqlite3_str_appendf(sqlite3_str*, const char *zFormat, ...); 8310 SQLITE_API void sqlite3_str_vappendf(sqlite3_str*, const char *zFormat, va_list); 8311 SQLITE_API void sqlite3_str_append(sqlite3_str*, const char *zIn, int N); 8312 SQLITE_API void sqlite3_str_appendall(sqlite3_str*, const char *zIn); 8313 SQLITE_API void sqlite3_str_appendchar(sqlite3_str*, int N, char C); 8314 SQLITE_API void sqlite3_str_reset(sqlite3_str*); 8315 8316 /* 8317 ** CAPI3REF: Status Of A Dynamic String 8318 ** METHOD: sqlite3_str 8319 ** 8320 ** These interfaces return the current status of an [sqlite3_str] object. 8321 ** 8322 ** ^If any prior errors have occurred while constructing the dynamic string 8323 ** in sqlite3_str X, then the [sqlite3_str_errcode(X)] method will return 8324 ** an appropriate error code. ^The [sqlite3_str_errcode(X)] method returns 8325 ** [SQLITE_NOMEM] following any out-of-memory error, or 8326 ** [SQLITE_TOOBIG] if the size of the dynamic string exceeds 8327 ** [SQLITE_MAX_LENGTH], or [SQLITE_OK] if there have been no errors. 8328 ** 8329 ** ^The [sqlite3_str_length(X)] method returns the current length, in bytes, 8330 ** of the dynamic string under construction in [sqlite3_str] object X. 8331 ** ^The length returned by [sqlite3_str_length(X)] does not include the 8332 ** zero-termination byte. 8333 ** 8334 ** ^The [sqlite3_str_value(X)] method returns a pointer to the current 8335 ** content of the dynamic string under construction in X. The value 8336 ** returned by [sqlite3_str_value(X)] is managed by the sqlite3_str object X 8337 ** and might be freed or altered by any subsequent method on the same 8338 ** [sqlite3_str] object. Applications must not used the pointer returned 8339 ** [sqlite3_str_value(X)] after any subsequent method call on the same 8340 ** object. ^Applications may change the content of the string returned 8341 ** by [sqlite3_str_value(X)] as long as they do not write into any bytes 8342 ** outside the range of 0 to [sqlite3_str_length(X)] and do not read or 8343 ** write any byte after any subsequent sqlite3_str method call. 8344 */ 8345 SQLITE_API int sqlite3_str_errcode(sqlite3_str*); 8346 SQLITE_API int sqlite3_str_length(sqlite3_str*); 8347 SQLITE_API char *sqlite3_str_value(sqlite3_str*); 8348 8349 /* 8350 ** CAPI3REF: SQLite Runtime Status 8351 ** 8352 ** ^These interfaces are used to retrieve runtime status information 8353 ** about the performance of SQLite, and optionally to reset various 8354 ** highwater marks. ^The first argument is an integer code for 8355 ** the specific parameter to measure. ^(Recognized integer codes 8356 ** are of the form [status parameters | SQLITE_STATUS_...].)^ 8357 ** ^The current value of the parameter is returned into *pCurrent. 8358 ** ^The highest recorded value is returned in *pHighwater. ^If the 8359 ** resetFlag is true, then the highest record value is reset after 8360 ** *pHighwater is written. ^(Some parameters do not record the highest 8361 ** value. For those parameters 8362 ** nothing is written into *pHighwater and the resetFlag is ignored.)^ 8363 ** ^(Other parameters record only the highwater mark and not the current 8364 ** value. For these latter parameters nothing is written into *pCurrent.)^ 8365 ** 8366 ** ^The sqlite3_status() and sqlite3_status64() routines return 8367 ** SQLITE_OK on success and a non-zero [error code] on failure. 8368 ** 8369 ** If either the current value or the highwater mark is too large to 8370 ** be represented by a 32-bit integer, then the values returned by 8371 ** sqlite3_status() are undefined. 8372 ** 8373 ** See also: [sqlite3_db_status()] 8374 */ 8375 SQLITE_API int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag); 8376 SQLITE_API int sqlite3_status64( 8377 int op, 8378 sqlite3_int64 *pCurrent, 8379 sqlite3_int64 *pHighwater, 8380 int resetFlag 8381 ); 8382 8383 8384 /* 8385 ** CAPI3REF: Status Parameters 8386 ** KEYWORDS: {status parameters} 8387 ** 8388 ** These integer constants designate various run-time status parameters 8389 ** that can be returned by [sqlite3_status()]. 8390 ** 8391 ** <dl> 8392 ** [[SQLITE_STATUS_MEMORY_USED]] ^(<dt>SQLITE_STATUS_MEMORY_USED</dt> 8393 ** <dd>This parameter is the current amount of memory checked out 8394 ** using [sqlite3_malloc()], either directly or indirectly. The 8395 ** figure includes calls made to [sqlite3_malloc()] by the application 8396 ** and internal memory usage by the SQLite library. Auxiliary page-cache 8397 ** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in 8398 ** this parameter. The amount returned is the sum of the allocation 8399 ** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>)^ 8400 ** 8401 ** [[SQLITE_STATUS_MALLOC_SIZE]] ^(<dt>SQLITE_STATUS_MALLOC_SIZE</dt> 8402 ** <dd>This parameter records the largest memory allocation request 8403 ** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their 8404 ** internal equivalents). Only the value returned in the 8405 ** *pHighwater parameter to [sqlite3_status()] is of interest. 8406 ** The value written into the *pCurrent parameter is undefined.</dd>)^ 8407 ** 8408 ** [[SQLITE_STATUS_MALLOC_COUNT]] ^(<dt>SQLITE_STATUS_MALLOC_COUNT</dt> 8409 ** <dd>This parameter records the number of separate memory allocations 8410 ** currently checked out.</dd>)^ 8411 ** 8412 ** [[SQLITE_STATUS_PAGECACHE_USED]] ^(<dt>SQLITE_STATUS_PAGECACHE_USED</dt> 8413 ** <dd>This parameter returns the number of pages used out of the 8414 ** [pagecache memory allocator] that was configured using 8415 ** [SQLITE_CONFIG_PAGECACHE]. The 8416 ** value returned is in pages, not in bytes.</dd>)^ 8417 ** 8418 ** [[SQLITE_STATUS_PAGECACHE_OVERFLOW]] 8419 ** ^(<dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt> 8420 ** <dd>This parameter returns the number of bytes of page cache 8421 ** allocation which could not be satisfied by the [SQLITE_CONFIG_PAGECACHE] 8422 ** buffer and where forced to overflow to [sqlite3_malloc()]. The 8423 ** returned value includes allocations that overflowed because they 8424 ** where too large (they were larger than the "sz" parameter to 8425 ** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because 8426 ** no space was left in the page cache.</dd>)^ 8427 ** 8428 ** [[SQLITE_STATUS_PAGECACHE_SIZE]] ^(<dt>SQLITE_STATUS_PAGECACHE_SIZE</dt> 8429 ** <dd>This parameter records the largest memory allocation request 8430 ** handed to the [pagecache memory allocator]. Only the value returned in the 8431 ** *pHighwater parameter to [sqlite3_status()] is of interest. 8432 ** The value written into the *pCurrent parameter is undefined.</dd>)^ 8433 ** 8434 ** [[SQLITE_STATUS_SCRATCH_USED]] <dt>SQLITE_STATUS_SCRATCH_USED</dt> 8435 ** <dd>No longer used.</dd> 8436 ** 8437 ** [[SQLITE_STATUS_SCRATCH_OVERFLOW]] ^(<dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt> 8438 ** <dd>No longer used.</dd> 8439 ** 8440 ** [[SQLITE_STATUS_SCRATCH_SIZE]] <dt>SQLITE_STATUS_SCRATCH_SIZE</dt> 8441 ** <dd>No longer used.</dd> 8442 ** 8443 ** [[SQLITE_STATUS_PARSER_STACK]] ^(<dt>SQLITE_STATUS_PARSER_STACK</dt> 8444 ** <dd>The *pHighwater parameter records the deepest parser stack. 8445 ** The *pCurrent value is undefined. The *pHighwater value is only 8446 ** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>)^ 8447 ** </dl> 8448 ** 8449 ** New status parameters may be added from time to time. 8450 */ 8451 #define SQLITE_STATUS_MEMORY_USED 0 8452 #define SQLITE_STATUS_PAGECACHE_USED 1 8453 #define SQLITE_STATUS_PAGECACHE_OVERFLOW 2 8454 #define SQLITE_STATUS_SCRATCH_USED 3 /* NOT USED */ 8455 #define SQLITE_STATUS_SCRATCH_OVERFLOW 4 /* NOT USED */ 8456 #define SQLITE_STATUS_MALLOC_SIZE 5 8457 #define SQLITE_STATUS_PARSER_STACK 6 8458 #define SQLITE_STATUS_PAGECACHE_SIZE 7 8459 #define SQLITE_STATUS_SCRATCH_SIZE 8 /* NOT USED */ 8460 #define SQLITE_STATUS_MALLOC_COUNT 9 8461 8462 /* 8463 ** CAPI3REF: Database Connection Status 8464 ** METHOD: sqlite3 8465 ** 8466 ** ^This interface is used to retrieve runtime status information 8467 ** about a single [database connection]. ^The first argument is the 8468 ** database connection object to be interrogated. ^The second argument 8469 ** is an integer constant, taken from the set of 8470 ** [SQLITE_DBSTATUS options], that 8471 ** determines the parameter to interrogate. The set of 8472 ** [SQLITE_DBSTATUS options] is likely 8473 ** to grow in future releases of SQLite. 8474 ** 8475 ** ^The current value of the requested parameter is written into *pCur 8476 ** and the highest instantaneous value is written into *pHiwtr. ^If 8477 ** the resetFlg is true, then the highest instantaneous value is 8478 ** reset back down to the current value. 8479 ** 8480 ** ^The sqlite3_db_status() routine returns SQLITE_OK on success and a 8481 ** non-zero [error code] on failure. 8482 ** 8483 ** See also: [sqlite3_status()] and [sqlite3_stmt_status()]. 8484 */ 8485 SQLITE_API int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg); 8486 8487 /* 8488 ** CAPI3REF: Status Parameters for database connections 8489 ** KEYWORDS: {SQLITE_DBSTATUS options} 8490 ** 8491 ** These constants are the available integer "verbs" that can be passed as 8492 ** the second argument to the [sqlite3_db_status()] interface. 8493 ** 8494 ** New verbs may be added in future releases of SQLite. Existing verbs 8495 ** might be discontinued. Applications should check the return code from 8496 ** [sqlite3_db_status()] to make sure that the call worked. 8497 ** The [sqlite3_db_status()] interface will return a non-zero error code 8498 ** if a discontinued or unsupported verb is invoked. 8499 ** 8500 ** <dl> 8501 ** [[SQLITE_DBSTATUS_LOOKASIDE_USED]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt> 8502 ** <dd>This parameter returns the number of lookaside memory slots currently 8503 ** checked out.</dd>)^ 8504 ** 8505 ** [[SQLITE_DBSTATUS_LOOKASIDE_HIT]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_HIT</dt> 8506 ** <dd>This parameter returns the number of malloc attempts that were 8507 ** satisfied using lookaside memory. Only the high-water value is meaningful; 8508 ** the current value is always zero.)^ 8509 ** 8510 ** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE]] 8511 ** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE</dt> 8512 ** <dd>This parameter returns the number malloc attempts that might have 8513 ** been satisfied using lookaside memory but failed due to the amount of 8514 ** memory requested being larger than the lookaside slot size. 8515 ** Only the high-water value is meaningful; 8516 ** the current value is always zero.)^ 8517 ** 8518 ** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL]] 8519 ** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL</dt> 8520 ** <dd>This parameter returns the number malloc attempts that might have 8521 ** been satisfied using lookaside memory but failed due to all lookaside 8522 ** memory already being in use. 8523 ** Only the high-water value is meaningful; 8524 ** the current value is always zero.)^ 8525 ** 8526 ** [[SQLITE_DBSTATUS_CACHE_USED]] ^(<dt>SQLITE_DBSTATUS_CACHE_USED</dt> 8527 ** <dd>This parameter returns the approximate number of bytes of heap 8528 ** memory used by all pager caches associated with the database connection.)^ 8529 ** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0. 8530 ** 8531 ** [[SQLITE_DBSTATUS_CACHE_USED_SHARED]] 8532 ** ^(<dt>SQLITE_DBSTATUS_CACHE_USED_SHARED</dt> 8533 ** <dd>This parameter is similar to DBSTATUS_CACHE_USED, except that if a 8534 ** pager cache is shared between two or more connections the bytes of heap 8535 ** memory used by that pager cache is divided evenly between the attached 8536 ** connections.)^ In other words, if none of the pager caches associated 8537 ** with the database connection are shared, this request returns the same 8538 ** value as DBSTATUS_CACHE_USED. Or, if one or more or the pager caches are 8539 ** shared, the value returned by this call will be smaller than that returned 8540 ** by DBSTATUS_CACHE_USED. ^The highwater mark associated with 8541 ** SQLITE_DBSTATUS_CACHE_USED_SHARED is always 0. 8542 ** 8543 ** [[SQLITE_DBSTATUS_SCHEMA_USED]] ^(<dt>SQLITE_DBSTATUS_SCHEMA_USED</dt> 8544 ** <dd>This parameter returns the approximate number of bytes of heap 8545 ** memory used to store the schema for all databases associated 8546 ** with the connection - main, temp, and any [ATTACH]-ed databases.)^ 8547 ** ^The full amount of memory used by the schemas is reported, even if the 8548 ** schema memory is shared with other database connections due to 8549 ** [shared cache mode] being enabled. 8550 ** ^The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0. 8551 ** 8552 ** [[SQLITE_DBSTATUS_STMT_USED]] ^(<dt>SQLITE_DBSTATUS_STMT_USED</dt> 8553 ** <dd>This parameter returns the approximate number of bytes of heap 8554 ** and lookaside memory used by all prepared statements associated with 8555 ** the database connection.)^ 8556 ** ^The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0. 8557 ** </dd> 8558 ** 8559 ** [[SQLITE_DBSTATUS_CACHE_HIT]] ^(<dt>SQLITE_DBSTATUS_CACHE_HIT</dt> 8560 ** <dd>This parameter returns the number of pager cache hits that have 8561 ** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_HIT 8562 ** is always 0. 8563 ** </dd> 8564 ** 8565 ** [[SQLITE_DBSTATUS_CACHE_MISS]] ^(<dt>SQLITE_DBSTATUS_CACHE_MISS</dt> 8566 ** <dd>This parameter returns the number of pager cache misses that have 8567 ** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_MISS 8568 ** is always 0. 8569 ** </dd> 8570 ** 8571 ** [[SQLITE_DBSTATUS_CACHE_WRITE]] ^(<dt>SQLITE_DBSTATUS_CACHE_WRITE</dt> 8572 ** <dd>This parameter returns the number of dirty cache entries that have 8573 ** been written to disk. Specifically, the number of pages written to the 8574 ** wal file in wal mode databases, or the number of pages written to the 8575 ** database file in rollback mode databases. Any pages written as part of 8576 ** transaction rollback or database recovery operations are not included. 8577 ** If an IO or other error occurs while writing a page to disk, the effect 8578 ** on subsequent SQLITE_DBSTATUS_CACHE_WRITE requests is undefined.)^ ^The 8579 ** highwater mark associated with SQLITE_DBSTATUS_CACHE_WRITE is always 0. 8580 ** </dd> 8581 ** 8582 ** [[SQLITE_DBSTATUS_CACHE_SPILL]] ^(<dt>SQLITE_DBSTATUS_CACHE_SPILL</dt> 8583 ** <dd>This parameter returns the number of dirty cache entries that have 8584 ** been written to disk in the middle of a transaction due to the page 8585 ** cache overflowing. Transactions are more efficient if they are written 8586 ** to disk all at once. When pages spill mid-transaction, that introduces 8587 ** additional overhead. This parameter can be used help identify 8588 ** inefficiencies that can be resolved by increasing the cache size. 8589 ** </dd> 8590 ** 8591 ** [[SQLITE_DBSTATUS_DEFERRED_FKS]] ^(<dt>SQLITE_DBSTATUS_DEFERRED_FKS</dt> 8592 ** <dd>This parameter returns zero for the current value if and only if 8593 ** all foreign key constraints (deferred or immediate) have been 8594 ** resolved.)^ ^The highwater mark is always 0. 8595 ** </dd> 8596 ** </dl> 8597 */ 8598 #define SQLITE_DBSTATUS_LOOKASIDE_USED 0 8599 #define SQLITE_DBSTATUS_CACHE_USED 1 8600 #define SQLITE_DBSTATUS_SCHEMA_USED 2 8601 #define SQLITE_DBSTATUS_STMT_USED 3 8602 #define SQLITE_DBSTATUS_LOOKASIDE_HIT 4 8603 #define SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE 5 8604 #define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL 6 8605 #define SQLITE_DBSTATUS_CACHE_HIT 7 8606 #define SQLITE_DBSTATUS_CACHE_MISS 8 8607 #define SQLITE_DBSTATUS_CACHE_WRITE 9 8608 #define SQLITE_DBSTATUS_DEFERRED_FKS 10 8609 #define SQLITE_DBSTATUS_CACHE_USED_SHARED 11 8610 #define SQLITE_DBSTATUS_CACHE_SPILL 12 8611 #define SQLITE_DBSTATUS_MAX 12 /* Largest defined DBSTATUS */ 8612 8613 8614 /* 8615 ** CAPI3REF: Prepared Statement Status 8616 ** METHOD: sqlite3_stmt 8617 ** 8618 ** ^(Each prepared statement maintains various 8619 ** [SQLITE_STMTSTATUS counters] that measure the number 8620 ** of times it has performed specific operations.)^ These counters can 8621 ** be used to monitor the performance characteristics of the prepared 8622 ** statements. For example, if the number of table steps greatly exceeds 8623 ** the number of table searches or result rows, that would tend to indicate 8624 ** that the prepared statement is using a full table scan rather than 8625 ** an index. 8626 ** 8627 ** ^(This interface is used to retrieve and reset counter values from 8628 ** a [prepared statement]. The first argument is the prepared statement 8629 ** object to be interrogated. The second argument 8630 ** is an integer code for a specific [SQLITE_STMTSTATUS counter] 8631 ** to be interrogated.)^ 8632 ** ^The current value of the requested counter is returned. 8633 ** ^If the resetFlg is true, then the counter is reset to zero after this 8634 ** interface call returns. 8635 ** 8636 ** See also: [sqlite3_status()] and [sqlite3_db_status()]. 8637 */ 8638 SQLITE_API int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg); 8639 8640 /* 8641 ** CAPI3REF: Status Parameters for prepared statements 8642 ** KEYWORDS: {SQLITE_STMTSTATUS counter} {SQLITE_STMTSTATUS counters} 8643 ** 8644 ** These preprocessor macros define integer codes that name counter 8645 ** values associated with the [sqlite3_stmt_status()] interface. 8646 ** The meanings of the various counters are as follows: 8647 ** 8648 ** <dl> 8649 ** [[SQLITE_STMTSTATUS_FULLSCAN_STEP]] <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt> 8650 ** <dd>^This is the number of times that SQLite has stepped forward in 8651 ** a table as part of a full table scan. Large numbers for this counter 8652 ** may indicate opportunities for performance improvement through 8653 ** careful use of indices.</dd> 8654 ** 8655 ** [[SQLITE_STMTSTATUS_SORT]] <dt>SQLITE_STMTSTATUS_SORT</dt> 8656 ** <dd>^This is the number of sort operations that have occurred. 8657 ** A non-zero value in this counter may indicate an opportunity to 8658 ** improvement performance through careful use of indices.</dd> 8659 ** 8660 ** [[SQLITE_STMTSTATUS_AUTOINDEX]] <dt>SQLITE_STMTSTATUS_AUTOINDEX</dt> 8661 ** <dd>^This is the number of rows inserted into transient indices that 8662 ** were created automatically in order to help joins run faster. 8663 ** A non-zero value in this counter may indicate an opportunity to 8664 ** improvement performance by adding permanent indices that do not 8665 ** need to be reinitialized each time the statement is run.</dd> 8666 ** 8667 ** [[SQLITE_STMTSTATUS_VM_STEP]] <dt>SQLITE_STMTSTATUS_VM_STEP</dt> 8668 ** <dd>^This is the number of virtual machine operations executed 8669 ** by the prepared statement if that number is less than or equal 8670 ** to 2147483647. The number of virtual machine operations can be 8671 ** used as a proxy for the total work done by the prepared statement. 8672 ** If the number of virtual machine operations exceeds 2147483647 8673 ** then the value returned by this statement status code is undefined. 8674 ** 8675 ** [[SQLITE_STMTSTATUS_REPREPARE]] <dt>SQLITE_STMTSTATUS_REPREPARE</dt> 8676 ** <dd>^This is the number of times that the prepare statement has been 8677 ** automatically regenerated due to schema changes or changes to 8678 ** [bound parameters] that might affect the query plan. 8679 ** 8680 ** [[SQLITE_STMTSTATUS_RUN]] <dt>SQLITE_STMTSTATUS_RUN</dt> 8681 ** <dd>^This is the number of times that the prepared statement has 8682 ** been run. A single "run" for the purposes of this counter is one 8683 ** or more calls to [sqlite3_step()] followed by a call to [sqlite3_reset()]. 8684 ** The counter is incremented on the first [sqlite3_step()] call of each 8685 ** cycle. 8686 ** 8687 ** [[SQLITE_STMTSTATUS_FILTER_MISS]] 8688 ** [[SQLITE_STMTSTATUS_FILTER HIT]] 8689 ** <dt>SQLITE_STMTSTATUS_FILTER_HIT<br> 8690 ** SQLITE_STMTSTATUS_FILTER_MISS</dt> 8691 ** <dd>^SQLITE_STMTSTATUS_FILTER_HIT is the number of times that a join 8692 ** step was bypassed because a Bloom filter returned not-found. The 8693 ** corresponding SQLITE_STMTSTATUS_FILTER_MISS value is the number of 8694 ** times that the Bloom filter returned a find, and thus the join step 8695 ** had to be processed as normal. 8696 ** 8697 ** [[SQLITE_STMTSTATUS_MEMUSED]] <dt>SQLITE_STMTSTATUS_MEMUSED</dt> 8698 ** <dd>^This is the approximate number of bytes of heap memory 8699 ** used to store the prepared statement. ^This value is not actually 8700 ** a counter, and so the resetFlg parameter to sqlite3_stmt_status() 8701 ** is ignored when the opcode is SQLITE_STMTSTATUS_MEMUSED. 8702 ** </dd> 8703 ** </dl> 8704 */ 8705 #define SQLITE_STMTSTATUS_FULLSCAN_STEP 1 8706 #define SQLITE_STMTSTATUS_SORT 2 8707 #define SQLITE_STMTSTATUS_AUTOINDEX 3 8708 #define SQLITE_STMTSTATUS_VM_STEP 4 8709 #define SQLITE_STMTSTATUS_REPREPARE 5 8710 #define SQLITE_STMTSTATUS_RUN 6 8711 #define SQLITE_STMTSTATUS_FILTER_MISS 7 8712 #define SQLITE_STMTSTATUS_FILTER_HIT 8 8713 #define SQLITE_STMTSTATUS_MEMUSED 99 8714 8715 /* 8716 ** CAPI3REF: Custom Page Cache Object 8717 ** 8718 ** The sqlite3_pcache type is opaque. It is implemented by 8719 ** the pluggable module. The SQLite core has no knowledge of 8720 ** its size or internal structure and never deals with the 8721 ** sqlite3_pcache object except by holding and passing pointers 8722 ** to the object. 8723 ** 8724 ** See [sqlite3_pcache_methods2] for additional information. 8725 */ 8726 typedef struct sqlite3_pcache sqlite3_pcache; 8727 8728 /* 8729 ** CAPI3REF: Custom Page Cache Object 8730 ** 8731 ** The sqlite3_pcache_page object represents a single page in the 8732 ** page cache. The page cache will allocate instances of this 8733 ** object. Various methods of the page cache use pointers to instances 8734 ** of this object as parameters or as their return value. 8735 ** 8736 ** See [sqlite3_pcache_methods2] for additional information. 8737 */ 8738 typedef struct sqlite3_pcache_page sqlite3_pcache_page; 8739 struct sqlite3_pcache_page { 8740 void *pBuf; /* The content of the page */ 8741 void *pExtra; /* Extra information associated with the page */ 8742 }; 8743 8744 /* 8745 ** CAPI3REF: Application Defined Page Cache. 8746 ** KEYWORDS: {page cache} 8747 ** 8748 ** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE2], ...) interface can 8749 ** register an alternative page cache implementation by passing in an 8750 ** instance of the sqlite3_pcache_methods2 structure.)^ 8751 ** In many applications, most of the heap memory allocated by 8752 ** SQLite is used for the page cache. 8753 ** By implementing a 8754 ** custom page cache using this API, an application can better control 8755 ** the amount of memory consumed by SQLite, the way in which 8756 ** that memory is allocated and released, and the policies used to 8757 ** determine exactly which parts of a database file are cached and for 8758 ** how long. 8759 ** 8760 ** The alternative page cache mechanism is an 8761 ** extreme measure that is only needed by the most demanding applications. 8762 ** The built-in page cache is recommended for most uses. 8763 ** 8764 ** ^(The contents of the sqlite3_pcache_methods2 structure are copied to an 8765 ** internal buffer by SQLite within the call to [sqlite3_config]. Hence 8766 ** the application may discard the parameter after the call to 8767 ** [sqlite3_config()] returns.)^ 8768 ** 8769 ** [[the xInit() page cache method]] 8770 ** ^(The xInit() method is called once for each effective 8771 ** call to [sqlite3_initialize()])^ 8772 ** (usually only once during the lifetime of the process). ^(The xInit() 8773 ** method is passed a copy of the sqlite3_pcache_methods2.pArg value.)^ 8774 ** The intent of the xInit() method is to set up global data structures 8775 ** required by the custom page cache implementation. 8776 ** ^(If the xInit() method is NULL, then the 8777 ** built-in default page cache is used instead of the application defined 8778 ** page cache.)^ 8779 ** 8780 ** [[the xShutdown() page cache method]] 8781 ** ^The xShutdown() method is called by [sqlite3_shutdown()]. 8782 ** It can be used to clean up 8783 ** any outstanding resources before process shutdown, if required. 8784 ** ^The xShutdown() method may be NULL. 8785 ** 8786 ** ^SQLite automatically serializes calls to the xInit method, 8787 ** so the xInit method need not be threadsafe. ^The 8788 ** xShutdown method is only called from [sqlite3_shutdown()] so it does 8789 ** not need to be threadsafe either. All other methods must be threadsafe 8790 ** in multithreaded applications. 8791 ** 8792 ** ^SQLite will never invoke xInit() more than once without an intervening 8793 ** call to xShutdown(). 8794 ** 8795 ** [[the xCreate() page cache methods]] 8796 ** ^SQLite invokes the xCreate() method to construct a new cache instance. 8797 ** SQLite will typically create one cache instance for each open database file, 8798 ** though this is not guaranteed. ^The 8799 ** first parameter, szPage, is the size in bytes of the pages that must 8800 ** be allocated by the cache. ^szPage will always a power of two. ^The 8801 ** second parameter szExtra is a number of bytes of extra storage 8802 ** associated with each page cache entry. ^The szExtra parameter will 8803 ** a number less than 250. SQLite will use the 8804 ** extra szExtra bytes on each page to store metadata about the underlying 8805 ** database page on disk. The value passed into szExtra depends 8806 ** on the SQLite version, the target platform, and how SQLite was compiled. 8807 ** ^The third argument to xCreate(), bPurgeable, is true if the cache being 8808 ** created will be used to cache database pages of a file stored on disk, or 8809 ** false if it is used for an in-memory database. The cache implementation 8810 ** does not have to do anything special based with the value of bPurgeable; 8811 ** it is purely advisory. ^On a cache where bPurgeable is false, SQLite will 8812 ** never invoke xUnpin() except to deliberately delete a page. 8813 ** ^In other words, calls to xUnpin() on a cache with bPurgeable set to 8814 ** false will always have the "discard" flag set to true. 8815 ** ^Hence, a cache created with bPurgeable false will 8816 ** never contain any unpinned pages. 8817 ** 8818 ** [[the xCachesize() page cache method]] 8819 ** ^(The xCachesize() method may be called at any time by SQLite to set the 8820 ** suggested maximum cache-size (number of pages stored by) the cache 8821 ** instance passed as the first argument. This is the value configured using 8822 ** the SQLite "[PRAGMA cache_size]" command.)^ As with the bPurgeable 8823 ** parameter, the implementation is not required to do anything with this 8824 ** value; it is advisory only. 8825 ** 8826 ** [[the xPagecount() page cache methods]] 8827 ** The xPagecount() method must return the number of pages currently 8828 ** stored in the cache, both pinned and unpinned. 8829 ** 8830 ** [[the xFetch() page cache methods]] 8831 ** The xFetch() method locates a page in the cache and returns a pointer to 8832 ** an sqlite3_pcache_page object associated with that page, or a NULL pointer. 8833 ** The pBuf element of the returned sqlite3_pcache_page object will be a 8834 ** pointer to a buffer of szPage bytes used to store the content of a 8835 ** single database page. The pExtra element of sqlite3_pcache_page will be 8836 ** a pointer to the szExtra bytes of extra storage that SQLite has requested 8837 ** for each entry in the page cache. 8838 ** 8839 ** The page to be fetched is determined by the key. ^The minimum key value 8840 ** is 1. After it has been retrieved using xFetch, the page is considered 8841 ** to be "pinned". 8842 ** 8843 ** If the requested page is already in the page cache, then the page cache 8844 ** implementation must return a pointer to the page buffer with its content 8845 ** intact. If the requested page is not already in the cache, then the 8846 ** cache implementation should use the value of the createFlag 8847 ** parameter to help it determined what action to take: 8848 ** 8849 ** <table border=1 width=85% align=center> 8850 ** <tr><th> createFlag <th> Behavior when page is not already in cache 8851 ** <tr><td> 0 <td> Do not allocate a new page. Return NULL. 8852 ** <tr><td> 1 <td> Allocate a new page if it easy and convenient to do so. 8853 ** Otherwise return NULL. 8854 ** <tr><td> 2 <td> Make every effort to allocate a new page. Only return 8855 ** NULL if allocating a new page is effectively impossible. 8856 ** </table> 8857 ** 8858 ** ^(SQLite will normally invoke xFetch() with a createFlag of 0 or 1. SQLite 8859 ** will only use a createFlag of 2 after a prior call with a createFlag of 1 8860 ** failed.)^ In between the xFetch() calls, SQLite may 8861 ** attempt to unpin one or more cache pages by spilling the content of 8862 ** pinned pages to disk and synching the operating system disk cache. 8863 ** 8864 ** [[the xUnpin() page cache method]] 8865 ** ^xUnpin() is called by SQLite with a pointer to a currently pinned page 8866 ** as its second argument. If the third parameter, discard, is non-zero, 8867 ** then the page must be evicted from the cache. 8868 ** ^If the discard parameter is 8869 ** zero, then the page may be discarded or retained at the discretion of 8870 ** page cache implementation. ^The page cache implementation 8871 ** may choose to evict unpinned pages at any time. 8872 ** 8873 ** The cache must not perform any reference counting. A single 8874 ** call to xUnpin() unpins the page regardless of the number of prior calls 8875 ** to xFetch(). 8876 ** 8877 ** [[the xRekey() page cache methods]] 8878 ** The xRekey() method is used to change the key value associated with the 8879 ** page passed as the second argument. If the cache 8880 ** previously contains an entry associated with newKey, it must be 8881 ** discarded. ^Any prior cache entry associated with newKey is guaranteed not 8882 ** to be pinned. 8883 ** 8884 ** When SQLite calls the xTruncate() method, the cache must discard all 8885 ** existing cache entries with page numbers (keys) greater than or equal 8886 ** to the value of the iLimit parameter passed to xTruncate(). If any 8887 ** of these pages are pinned, they are implicitly unpinned, meaning that 8888 ** they can be safely discarded. 8889 ** 8890 ** [[the xDestroy() page cache method]] 8891 ** ^The xDestroy() method is used to delete a cache allocated by xCreate(). 8892 ** All resources associated with the specified cache should be freed. ^After 8893 ** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*] 8894 ** handle invalid, and will not use it with any other sqlite3_pcache_methods2 8895 ** functions. 8896 ** 8897 ** [[the xShrink() page cache method]] 8898 ** ^SQLite invokes the xShrink() method when it wants the page cache to 8899 ** free up as much of heap memory as possible. The page cache implementation 8900 ** is not obligated to free any memory, but well-behaved implementations should 8901 ** do their best. 8902 */ 8903 typedef struct sqlite3_pcache_methods2 sqlite3_pcache_methods2; 8904 struct sqlite3_pcache_methods2 { 8905 int iVersion; 8906 void *pArg; 8907 int (*xInit)(void*); 8908 void (*xShutdown)(void*); 8909 sqlite3_pcache *(*xCreate)(int szPage, int szExtra, int bPurgeable); 8910 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 8911 int (*xPagecount)(sqlite3_pcache*); 8912 sqlite3_pcache_page *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 8913 void (*xUnpin)(sqlite3_pcache*, sqlite3_pcache_page*, int discard); 8914 void (*xRekey)(sqlite3_pcache*, sqlite3_pcache_page*, 8915 unsigned oldKey, unsigned newKey); 8916 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 8917 void (*xDestroy)(sqlite3_pcache*); 8918 void (*xShrink)(sqlite3_pcache*); 8919 }; 8920 8921 /* 8922 ** This is the obsolete pcache_methods object that has now been replaced 8923 ** by sqlite3_pcache_methods2. This object is not used by SQLite. It is 8924 ** retained in the header file for backwards compatibility only. 8925 */ 8926 typedef struct sqlite3_pcache_methods sqlite3_pcache_methods; 8927 struct sqlite3_pcache_methods { 8928 void *pArg; 8929 int (*xInit)(void*); 8930 void (*xShutdown)(void*); 8931 sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable); 8932 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 8933 int (*xPagecount)(sqlite3_pcache*); 8934 void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 8935 void (*xUnpin)(sqlite3_pcache*, void*, int discard); 8936 void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey); 8937 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 8938 void (*xDestroy)(sqlite3_pcache*); 8939 }; 8940 8941 8942 /* 8943 ** CAPI3REF: Online Backup Object 8944 ** 8945 ** The sqlite3_backup object records state information about an ongoing 8946 ** online backup operation. ^The sqlite3_backup object is created by 8947 ** a call to [sqlite3_backup_init()] and is destroyed by a call to 8948 ** [sqlite3_backup_finish()]. 8949 ** 8950 ** See Also: [Using the SQLite Online Backup API] 8951 */ 8952 typedef struct sqlite3_backup sqlite3_backup; 8953 8954 /* 8955 ** CAPI3REF: Online Backup API. 8956 ** 8957 ** The backup API copies the content of one database into another. 8958 ** It is useful either for creating backups of databases or 8959 ** for copying in-memory databases to or from persistent files. 8960 ** 8961 ** See Also: [Using the SQLite Online Backup API] 8962 ** 8963 ** ^SQLite holds a write transaction open on the destination database file 8964 ** for the duration of the backup operation. 8965 ** ^The source database is read-locked only while it is being read; 8966 ** it is not locked continuously for the entire backup operation. 8967 ** ^Thus, the backup may be performed on a live source database without 8968 ** preventing other database connections from 8969 ** reading or writing to the source database while the backup is underway. 8970 ** 8971 ** ^(To perform a backup operation: 8972 ** <ol> 8973 ** <li><b>sqlite3_backup_init()</b> is called once to initialize the 8974 ** backup, 8975 ** <li><b>sqlite3_backup_step()</b> is called one or more times to transfer 8976 ** the data between the two databases, and finally 8977 ** <li><b>sqlite3_backup_finish()</b> is called to release all resources 8978 ** associated with the backup operation. 8979 ** </ol>)^ 8980 ** There should be exactly one call to sqlite3_backup_finish() for each 8981 ** successful call to sqlite3_backup_init(). 8982 ** 8983 ** [[sqlite3_backup_init()]] <b>sqlite3_backup_init()</b> 8984 ** 8985 ** ^The D and N arguments to sqlite3_backup_init(D,N,S,M) are the 8986 ** [database connection] associated with the destination database 8987 ** and the database name, respectively. 8988 ** ^The database name is "main" for the main database, "temp" for the 8989 ** temporary database, or the name specified after the AS keyword in 8990 ** an [ATTACH] statement for an attached database. 8991 ** ^The S and M arguments passed to 8992 ** sqlite3_backup_init(D,N,S,M) identify the [database connection] 8993 ** and database name of the source database, respectively. 8994 ** ^The source and destination [database connections] (parameters S and D) 8995 ** must be different or else sqlite3_backup_init(D,N,S,M) will fail with 8996 ** an error. 8997 ** 8998 ** ^A call to sqlite3_backup_init() will fail, returning NULL, if 8999 ** there is already a read or read-write transaction open on the 9000 ** destination database. 9001 ** 9002 ** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is 9003 ** returned and an error code and error message are stored in the 9004 ** destination [database connection] D. 9005 ** ^The error code and message for the failed call to sqlite3_backup_init() 9006 ** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or 9007 ** [sqlite3_errmsg16()] functions. 9008 ** ^A successful call to sqlite3_backup_init() returns a pointer to an 9009 ** [sqlite3_backup] object. 9010 ** ^The [sqlite3_backup] object may be used with the sqlite3_backup_step() and 9011 ** sqlite3_backup_finish() functions to perform the specified backup 9012 ** operation. 9013 ** 9014 ** [[sqlite3_backup_step()]] <b>sqlite3_backup_step()</b> 9015 ** 9016 ** ^Function sqlite3_backup_step(B,N) will copy up to N pages between 9017 ** the source and destination databases specified by [sqlite3_backup] object B. 9018 ** ^If N is negative, all remaining source pages are copied. 9019 ** ^If sqlite3_backup_step(B,N) successfully copies N pages and there 9020 ** are still more pages to be copied, then the function returns [SQLITE_OK]. 9021 ** ^If sqlite3_backup_step(B,N) successfully finishes copying all pages 9022 ** from source to destination, then it returns [SQLITE_DONE]. 9023 ** ^If an error occurs while running sqlite3_backup_step(B,N), 9024 ** then an [error code] is returned. ^As well as [SQLITE_OK] and 9025 ** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY], 9026 ** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an 9027 ** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code. 9028 ** 9029 ** ^(The sqlite3_backup_step() might return [SQLITE_READONLY] if 9030 ** <ol> 9031 ** <li> the destination database was opened read-only, or 9032 ** <li> the destination database is using write-ahead-log journaling 9033 ** and the destination and source page sizes differ, or 9034 ** <li> the destination database is an in-memory database and the 9035 ** destination and source page sizes differ. 9036 ** </ol>)^ 9037 ** 9038 ** ^If sqlite3_backup_step() cannot obtain a required file-system lock, then 9039 ** the [sqlite3_busy_handler | busy-handler function] 9040 ** is invoked (if one is specified). ^If the 9041 ** busy-handler returns non-zero before the lock is available, then 9042 ** [SQLITE_BUSY] is returned to the caller. ^In this case the call to 9043 ** sqlite3_backup_step() can be retried later. ^If the source 9044 ** [database connection] 9045 ** is being used to write to the source database when sqlite3_backup_step() 9046 ** is called, then [SQLITE_LOCKED] is returned immediately. ^Again, in this 9047 ** case the call to sqlite3_backup_step() can be retried later on. ^(If 9048 ** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or 9049 ** [SQLITE_READONLY] is returned, then 9050 ** there is no point in retrying the call to sqlite3_backup_step(). These 9051 ** errors are considered fatal.)^ The application must accept 9052 ** that the backup operation has failed and pass the backup operation handle 9053 ** to the sqlite3_backup_finish() to release associated resources. 9054 ** 9055 ** ^The first call to sqlite3_backup_step() obtains an exclusive lock 9056 ** on the destination file. ^The exclusive lock is not released until either 9057 ** sqlite3_backup_finish() is called or the backup operation is complete 9058 ** and sqlite3_backup_step() returns [SQLITE_DONE]. ^Every call to 9059 ** sqlite3_backup_step() obtains a [shared lock] on the source database that 9060 ** lasts for the duration of the sqlite3_backup_step() call. 9061 ** ^Because the source database is not locked between calls to 9062 ** sqlite3_backup_step(), the source database may be modified mid-way 9063 ** through the backup process. ^If the source database is modified by an 9064 ** external process or via a database connection other than the one being 9065 ** used by the backup operation, then the backup will be automatically 9066 ** restarted by the next call to sqlite3_backup_step(). ^If the source 9067 ** database is modified by the using the same database connection as is used 9068 ** by the backup operation, then the backup database is automatically 9069 ** updated at the same time. 9070 ** 9071 ** [[sqlite3_backup_finish()]] <b>sqlite3_backup_finish()</b> 9072 ** 9073 ** When sqlite3_backup_step() has returned [SQLITE_DONE], or when the 9074 ** application wishes to abandon the backup operation, the application 9075 ** should destroy the [sqlite3_backup] by passing it to sqlite3_backup_finish(). 9076 ** ^The sqlite3_backup_finish() interfaces releases all 9077 ** resources associated with the [sqlite3_backup] object. 9078 ** ^If sqlite3_backup_step() has not yet returned [SQLITE_DONE], then any 9079 ** active write-transaction on the destination database is rolled back. 9080 ** The [sqlite3_backup] object is invalid 9081 ** and may not be used following a call to sqlite3_backup_finish(). 9082 ** 9083 ** ^The value returned by sqlite3_backup_finish is [SQLITE_OK] if no 9084 ** sqlite3_backup_step() errors occurred, regardless or whether or not 9085 ** sqlite3_backup_step() completed. 9086 ** ^If an out-of-memory condition or IO error occurred during any prior 9087 ** sqlite3_backup_step() call on the same [sqlite3_backup] object, then 9088 ** sqlite3_backup_finish() returns the corresponding [error code]. 9089 ** 9090 ** ^A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step() 9091 ** is not a permanent error and does not affect the return value of 9092 ** sqlite3_backup_finish(). 9093 ** 9094 ** [[sqlite3_backup_remaining()]] [[sqlite3_backup_pagecount()]] 9095 ** <b>sqlite3_backup_remaining() and sqlite3_backup_pagecount()</b> 9096 ** 9097 ** ^The sqlite3_backup_remaining() routine returns the number of pages still 9098 ** to be backed up at the conclusion of the most recent sqlite3_backup_step(). 9099 ** ^The sqlite3_backup_pagecount() routine returns the total number of pages 9100 ** in the source database at the conclusion of the most recent 9101 ** sqlite3_backup_step(). 9102 ** ^(The values returned by these functions are only updated by 9103 ** sqlite3_backup_step(). If the source database is modified in a way that 9104 ** changes the size of the source database or the number of pages remaining, 9105 ** those changes are not reflected in the output of sqlite3_backup_pagecount() 9106 ** and sqlite3_backup_remaining() until after the next 9107 ** sqlite3_backup_step().)^ 9108 ** 9109 ** <b>Concurrent Usage of Database Handles</b> 9110 ** 9111 ** ^The source [database connection] may be used by the application for other 9112 ** purposes while a backup operation is underway or being initialized. 9113 ** ^If SQLite is compiled and configured to support threadsafe database 9114 ** connections, then the source database connection may be used concurrently 9115 ** from within other threads. 9116 ** 9117 ** However, the application must guarantee that the destination 9118 ** [database connection] is not passed to any other API (by any thread) after 9119 ** sqlite3_backup_init() is called and before the corresponding call to 9120 ** sqlite3_backup_finish(). SQLite does not currently check to see 9121 ** if the application incorrectly accesses the destination [database connection] 9122 ** and so no error code is reported, but the operations may malfunction 9123 ** nevertheless. Use of the destination database connection while a 9124 ** backup is in progress might also cause a mutex deadlock. 9125 ** 9126 ** If running in [shared cache mode], the application must 9127 ** guarantee that the shared cache used by the destination database 9128 ** is not accessed while the backup is running. In practice this means 9129 ** that the application must guarantee that the disk file being 9130 ** backed up to is not accessed by any connection within the process, 9131 ** not just the specific connection that was passed to sqlite3_backup_init(). 9132 ** 9133 ** The [sqlite3_backup] object itself is partially threadsafe. Multiple 9134 ** threads may safely make multiple concurrent calls to sqlite3_backup_step(). 9135 ** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount() 9136 ** APIs are not strictly speaking threadsafe. If they are invoked at the 9137 ** same time as another thread is invoking sqlite3_backup_step() it is 9138 ** possible that they return invalid values. 9139 */ 9140 SQLITE_API sqlite3_backup *sqlite3_backup_init( 9141 sqlite3 *pDest, /* Destination database handle */ 9142 const char *zDestName, /* Destination database name */ 9143 sqlite3 *pSource, /* Source database handle */ 9144 const char *zSourceName /* Source database name */ 9145 ); 9146 SQLITE_API int sqlite3_backup_step(sqlite3_backup *p, int nPage); 9147 SQLITE_API int sqlite3_backup_finish(sqlite3_backup *p); 9148 SQLITE_API int sqlite3_backup_remaining(sqlite3_backup *p); 9149 SQLITE_API int sqlite3_backup_pagecount(sqlite3_backup *p); 9150 9151 /* 9152 ** CAPI3REF: Unlock Notification 9153 ** METHOD: sqlite3 9154 ** 9155 ** ^When running in shared-cache mode, a database operation may fail with 9156 ** an [SQLITE_LOCKED] error if the required locks on the shared-cache or 9157 ** individual tables within the shared-cache cannot be obtained. See 9158 ** [SQLite Shared-Cache Mode] for a description of shared-cache locking. 9159 ** ^This API may be used to register a callback that SQLite will invoke 9160 ** when the connection currently holding the required lock relinquishes it. 9161 ** ^This API is only available if the library was compiled with the 9162 ** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined. 9163 ** 9164 ** See Also: [Using the SQLite Unlock Notification Feature]. 9165 ** 9166 ** ^Shared-cache locks are released when a database connection concludes 9167 ** its current transaction, either by committing it or rolling it back. 9168 ** 9169 ** ^When a connection (known as the blocked connection) fails to obtain a 9170 ** shared-cache lock and SQLITE_LOCKED is returned to the caller, the 9171 ** identity of the database connection (the blocking connection) that 9172 ** has locked the required resource is stored internally. ^After an 9173 ** application receives an SQLITE_LOCKED error, it may call the 9174 ** sqlite3_unlock_notify() method with the blocked connection handle as 9175 ** the first argument to register for a callback that will be invoked 9176 ** when the blocking connections current transaction is concluded. ^The 9177 ** callback is invoked from within the [sqlite3_step] or [sqlite3_close] 9178 ** call that concludes the blocking connection's transaction. 9179 ** 9180 ** ^(If sqlite3_unlock_notify() is called in a multi-threaded application, 9181 ** there is a chance that the blocking connection will have already 9182 ** concluded its transaction by the time sqlite3_unlock_notify() is invoked. 9183 ** If this happens, then the specified callback is invoked immediately, 9184 ** from within the call to sqlite3_unlock_notify().)^ 9185 ** 9186 ** ^If the blocked connection is attempting to obtain a write-lock on a 9187 ** shared-cache table, and more than one other connection currently holds 9188 ** a read-lock on the same table, then SQLite arbitrarily selects one of 9189 ** the other connections to use as the blocking connection. 9190 ** 9191 ** ^(There may be at most one unlock-notify callback registered by a 9192 ** blocked connection. If sqlite3_unlock_notify() is called when the 9193 ** blocked connection already has a registered unlock-notify callback, 9194 ** then the new callback replaces the old.)^ ^If sqlite3_unlock_notify() is 9195 ** called with a NULL pointer as its second argument, then any existing 9196 ** unlock-notify callback is canceled. ^The blocked connections 9197 ** unlock-notify callback may also be canceled by closing the blocked 9198 ** connection using [sqlite3_close()]. 9199 ** 9200 ** The unlock-notify callback is not reentrant. If an application invokes 9201 ** any sqlite3_xxx API functions from within an unlock-notify callback, a 9202 ** crash or deadlock may be the result. 9203 ** 9204 ** ^Unless deadlock is detected (see below), sqlite3_unlock_notify() always 9205 ** returns SQLITE_OK. 9206 ** 9207 ** <b>Callback Invocation Details</b> 9208 ** 9209 ** When an unlock-notify callback is registered, the application provides a 9210 ** single void* pointer that is passed to the callback when it is invoked. 9211 ** However, the signature of the callback function allows SQLite to pass 9212 ** it an array of void* context pointers. The first argument passed to 9213 ** an unlock-notify callback is a pointer to an array of void* pointers, 9214 ** and the second is the number of entries in the array. 9215 ** 9216 ** When a blocking connection's transaction is concluded, there may be 9217 ** more than one blocked connection that has registered for an unlock-notify 9218 ** callback. ^If two or more such blocked connections have specified the 9219 ** same callback function, then instead of invoking the callback function 9220 ** multiple times, it is invoked once with the set of void* context pointers 9221 ** specified by the blocked connections bundled together into an array. 9222 ** This gives the application an opportunity to prioritize any actions 9223 ** related to the set of unblocked database connections. 9224 ** 9225 ** <b>Deadlock Detection</b> 9226 ** 9227 ** Assuming that after registering for an unlock-notify callback a 9228 ** database waits for the callback to be issued before taking any further 9229 ** action (a reasonable assumption), then using this API may cause the 9230 ** application to deadlock. For example, if connection X is waiting for 9231 ** connection Y's transaction to be concluded, and similarly connection 9232 ** Y is waiting on connection X's transaction, then neither connection 9233 ** will proceed and the system may remain deadlocked indefinitely. 9234 ** 9235 ** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock 9236 ** detection. ^If a given call to sqlite3_unlock_notify() would put the 9237 ** system in a deadlocked state, then SQLITE_LOCKED is returned and no 9238 ** unlock-notify callback is registered. The system is said to be in 9239 ** a deadlocked state if connection A has registered for an unlock-notify 9240 ** callback on the conclusion of connection B's transaction, and connection 9241 ** B has itself registered for an unlock-notify callback when connection 9242 ** A's transaction is concluded. ^Indirect deadlock is also detected, so 9243 ** the system is also considered to be deadlocked if connection B has 9244 ** registered for an unlock-notify callback on the conclusion of connection 9245 ** C's transaction, where connection C is waiting on connection A. ^Any 9246 ** number of levels of indirection are allowed. 9247 ** 9248 ** <b>The "DROP TABLE" Exception</b> 9249 ** 9250 ** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost 9251 ** always appropriate to call sqlite3_unlock_notify(). There is however, 9252 ** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement, 9253 ** SQLite checks if there are any currently executing SELECT statements 9254 ** that belong to the same connection. If there are, SQLITE_LOCKED is 9255 ** returned. In this case there is no "blocking connection", so invoking 9256 ** sqlite3_unlock_notify() results in the unlock-notify callback being 9257 ** invoked immediately. If the application then re-attempts the "DROP TABLE" 9258 ** or "DROP INDEX" query, an infinite loop might be the result. 9259 ** 9260 ** One way around this problem is to check the extended error code returned 9261 ** by an sqlite3_step() call. ^(If there is a blocking connection, then the 9262 ** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in 9263 ** the special "DROP TABLE/INDEX" case, the extended error code is just 9264 ** SQLITE_LOCKED.)^ 9265 */ 9266 SQLITE_API int sqlite3_unlock_notify( 9267 sqlite3 *pBlocked, /* Waiting connection */ 9268 void (*xNotify)(void **apArg, int nArg), /* Callback function to invoke */ 9269 void *pNotifyArg /* Argument to pass to xNotify */ 9270 ); 9271 9272 9273 /* 9274 ** CAPI3REF: String Comparison 9275 ** 9276 ** ^The [sqlite3_stricmp()] and [sqlite3_strnicmp()] APIs allow applications 9277 ** and extensions to compare the contents of two buffers containing UTF-8 9278 ** strings in a case-independent fashion, using the same definition of "case 9279 ** independence" that SQLite uses internally when comparing identifiers. 9280 */ 9281 SQLITE_API int sqlite3_stricmp(const char *, const char *); 9282 SQLITE_API int sqlite3_strnicmp(const char *, const char *, int); 9283 9284 /* 9285 ** CAPI3REF: String Globbing 9286 * 9287 ** ^The [sqlite3_strglob(P,X)] interface returns zero if and only if 9288 ** string X matches the [GLOB] pattern P. 9289 ** ^The definition of [GLOB] pattern matching used in 9290 ** [sqlite3_strglob(P,X)] is the same as for the "X GLOB P" operator in the 9291 ** SQL dialect understood by SQLite. ^The [sqlite3_strglob(P,X)] function 9292 ** is case sensitive. 9293 ** 9294 ** Note that this routine returns zero on a match and non-zero if the strings 9295 ** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()]. 9296 ** 9297 ** See also: [sqlite3_strlike()]. 9298 */ 9299 SQLITE_API int sqlite3_strglob(const char *zGlob, const char *zStr); 9300 9301 /* 9302 ** CAPI3REF: String LIKE Matching 9303 * 9304 ** ^The [sqlite3_strlike(P,X,E)] interface returns zero if and only if 9305 ** string X matches the [LIKE] pattern P with escape character E. 9306 ** ^The definition of [LIKE] pattern matching used in 9307 ** [sqlite3_strlike(P,X,E)] is the same as for the "X LIKE P ESCAPE E" 9308 ** operator in the SQL dialect understood by SQLite. ^For "X LIKE P" without 9309 ** the ESCAPE clause, set the E parameter of [sqlite3_strlike(P,X,E)] to 0. 9310 ** ^As with the LIKE operator, the [sqlite3_strlike(P,X,E)] function is case 9311 ** insensitive - equivalent upper and lower case ASCII characters match 9312 ** one another. 9313 ** 9314 ** ^The [sqlite3_strlike(P,X,E)] function matches Unicode characters, though 9315 ** only ASCII characters are case folded. 9316 ** 9317 ** Note that this routine returns zero on a match and non-zero if the strings 9318 ** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()]. 9319 ** 9320 ** See also: [sqlite3_strglob()]. 9321 */ 9322 SQLITE_API int sqlite3_strlike(const char *zGlob, const char *zStr, unsigned int cEsc); 9323 9324 /* 9325 ** CAPI3REF: Error Logging Interface 9326 ** 9327 ** ^The [sqlite3_log()] interface writes a message into the [error log] 9328 ** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()]. 9329 ** ^If logging is enabled, the zFormat string and subsequent arguments are 9330 ** used with [sqlite3_snprintf()] to generate the final output string. 9331 ** 9332 ** The sqlite3_log() interface is intended for use by extensions such as 9333 ** virtual tables, collating functions, and SQL functions. While there is 9334 ** nothing to prevent an application from calling sqlite3_log(), doing so 9335 ** is considered bad form. 9336 ** 9337 ** The zFormat string must not be NULL. 9338 ** 9339 ** To avoid deadlocks and other threading problems, the sqlite3_log() routine 9340 ** will not use dynamically allocated memory. The log message is stored in 9341 ** a fixed-length buffer on the stack. If the log message is longer than 9342 ** a few hundred characters, it will be truncated to the length of the 9343 ** buffer. 9344 */ 9345 SQLITE_API void sqlite3_log(int iErrCode, const char *zFormat, ...); 9346 9347 /* 9348 ** CAPI3REF: Write-Ahead Log Commit Hook 9349 ** METHOD: sqlite3 9350 ** 9351 ** ^The [sqlite3_wal_hook()] function is used to register a callback that 9352 ** is invoked each time data is committed to a database in wal mode. 9353 ** 9354 ** ^(The callback is invoked by SQLite after the commit has taken place and 9355 ** the associated write-lock on the database released)^, so the implementation 9356 ** may read, write or [checkpoint] the database as required. 9357 ** 9358 ** ^The first parameter passed to the callback function when it is invoked 9359 ** is a copy of the third parameter passed to sqlite3_wal_hook() when 9360 ** registering the callback. ^The second is a copy of the database handle. 9361 ** ^The third parameter is the name of the database that was written to - 9362 ** either "main" or the name of an [ATTACH]-ed database. ^The fourth parameter 9363 ** is the number of pages currently in the write-ahead log file, 9364 ** including those that were just committed. 9365 ** 9366 ** The callback function should normally return [SQLITE_OK]. ^If an error 9367 ** code is returned, that error will propagate back up through the 9368 ** SQLite code base to cause the statement that provoked the callback 9369 ** to report an error, though the commit will have still occurred. If the 9370 ** callback returns [SQLITE_ROW] or [SQLITE_DONE], or if it returns a value 9371 ** that does not correspond to any valid SQLite error code, the results 9372 ** are undefined. 9373 ** 9374 ** A single database handle may have at most a single write-ahead log callback 9375 ** registered at one time. ^Calling [sqlite3_wal_hook()] replaces any 9376 ** previously registered write-ahead log callback. ^The return value is 9377 ** a copy of the third parameter from the previous call, if any, or 0. 9378 ** ^Note that the [sqlite3_wal_autocheckpoint()] interface and the 9379 ** [wal_autocheckpoint pragma] both invoke [sqlite3_wal_hook()] and will 9380 ** overwrite any prior [sqlite3_wal_hook()] settings. 9381 */ 9382 SQLITE_API void *sqlite3_wal_hook( 9383 sqlite3*, 9384 int(*)(void *,sqlite3*,const char*,int), 9385 void* 9386 ); 9387 9388 /* 9389 ** CAPI3REF: Configure an auto-checkpoint 9390 ** METHOD: sqlite3 9391 ** 9392 ** ^The [sqlite3_wal_autocheckpoint(D,N)] is a wrapper around 9393 ** [sqlite3_wal_hook()] that causes any database on [database connection] D 9394 ** to automatically [checkpoint] 9395 ** after committing a transaction if there are N or 9396 ** more frames in the [write-ahead log] file. ^Passing zero or 9397 ** a negative value as the nFrame parameter disables automatic 9398 ** checkpoints entirely. 9399 ** 9400 ** ^The callback registered by this function replaces any existing callback 9401 ** registered using [sqlite3_wal_hook()]. ^Likewise, registering a callback 9402 ** using [sqlite3_wal_hook()] disables the automatic checkpoint mechanism 9403 ** configured by this function. 9404 ** 9405 ** ^The [wal_autocheckpoint pragma] can be used to invoke this interface 9406 ** from SQL. 9407 ** 9408 ** ^Checkpoints initiated by this mechanism are 9409 ** [sqlite3_wal_checkpoint_v2|PASSIVE]. 9410 ** 9411 ** ^Every new [database connection] defaults to having the auto-checkpoint 9412 ** enabled with a threshold of 1000 or [SQLITE_DEFAULT_WAL_AUTOCHECKPOINT] 9413 ** pages. The use of this interface 9414 ** is only necessary if the default setting is found to be suboptimal 9415 ** for a particular application. 9416 */ 9417 SQLITE_API int sqlite3_wal_autocheckpoint(sqlite3 *db, int N); 9418 9419 /* 9420 ** CAPI3REF: Checkpoint a database 9421 ** METHOD: sqlite3 9422 ** 9423 ** ^(The sqlite3_wal_checkpoint(D,X) is equivalent to 9424 ** [sqlite3_wal_checkpoint_v2](D,X,[SQLITE_CHECKPOINT_PASSIVE],0,0).)^ 9425 ** 9426 ** In brief, sqlite3_wal_checkpoint(D,X) causes the content in the 9427 ** [write-ahead log] for database X on [database connection] D to be 9428 ** transferred into the database file and for the write-ahead log to 9429 ** be reset. See the [checkpointing] documentation for addition 9430 ** information. 9431 ** 9432 ** This interface used to be the only way to cause a checkpoint to 9433 ** occur. But then the newer and more powerful [sqlite3_wal_checkpoint_v2()] 9434 ** interface was added. This interface is retained for backwards 9435 ** compatibility and as a convenience for applications that need to manually 9436 ** start a callback but which do not need the full power (and corresponding 9437 ** complication) of [sqlite3_wal_checkpoint_v2()]. 9438 */ 9439 SQLITE_API int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb); 9440 9441 /* 9442 ** CAPI3REF: Checkpoint a database 9443 ** METHOD: sqlite3 9444 ** 9445 ** ^(The sqlite3_wal_checkpoint_v2(D,X,M,L,C) interface runs a checkpoint 9446 ** operation on database X of [database connection] D in mode M. Status 9447 ** information is written back into integers pointed to by L and C.)^ 9448 ** ^(The M parameter must be a valid [checkpoint mode]:)^ 9449 ** 9450 ** <dl> 9451 ** <dt>SQLITE_CHECKPOINT_PASSIVE<dd> 9452 ** ^Checkpoint as many frames as possible without waiting for any database 9453 ** readers or writers to finish, then sync the database file if all frames 9454 ** in the log were checkpointed. ^The [busy-handler callback] 9455 ** is never invoked in the SQLITE_CHECKPOINT_PASSIVE mode. 9456 ** ^On the other hand, passive mode might leave the checkpoint unfinished 9457 ** if there are concurrent readers or writers. 9458 ** 9459 ** <dt>SQLITE_CHECKPOINT_FULL<dd> 9460 ** ^This mode blocks (it invokes the 9461 ** [sqlite3_busy_handler|busy-handler callback]) until there is no 9462 ** database writer and all readers are reading from the most recent database 9463 ** snapshot. ^It then checkpoints all frames in the log file and syncs the 9464 ** database file. ^This mode blocks new database writers while it is pending, 9465 ** but new database readers are allowed to continue unimpeded. 9466 ** 9467 ** <dt>SQLITE_CHECKPOINT_RESTART<dd> 9468 ** ^This mode works the same way as SQLITE_CHECKPOINT_FULL with the addition 9469 ** that after checkpointing the log file it blocks (calls the 9470 ** [busy-handler callback]) 9471 ** until all readers are reading from the database file only. ^This ensures 9472 ** that the next writer will restart the log file from the beginning. 9473 ** ^Like SQLITE_CHECKPOINT_FULL, this mode blocks new 9474 ** database writer attempts while it is pending, but does not impede readers. 9475 ** 9476 ** <dt>SQLITE_CHECKPOINT_TRUNCATE<dd> 9477 ** ^This mode works the same way as SQLITE_CHECKPOINT_RESTART with the 9478 ** addition that it also truncates the log file to zero bytes just prior 9479 ** to a successful return. 9480 ** </dl> 9481 ** 9482 ** ^If pnLog is not NULL, then *pnLog is set to the total number of frames in 9483 ** the log file or to -1 if the checkpoint could not run because 9484 ** of an error or because the database is not in [WAL mode]. ^If pnCkpt is not 9485 ** NULL,then *pnCkpt is set to the total number of checkpointed frames in the 9486 ** log file (including any that were already checkpointed before the function 9487 ** was called) or to -1 if the checkpoint could not run due to an error or 9488 ** because the database is not in WAL mode. ^Note that upon successful 9489 ** completion of an SQLITE_CHECKPOINT_TRUNCATE, the log file will have been 9490 ** truncated to zero bytes and so both *pnLog and *pnCkpt will be set to zero. 9491 ** 9492 ** ^All calls obtain an exclusive "checkpoint" lock on the database file. ^If 9493 ** any other process is running a checkpoint operation at the same time, the 9494 ** lock cannot be obtained and SQLITE_BUSY is returned. ^Even if there is a 9495 ** busy-handler configured, it will not be invoked in this case. 9496 ** 9497 ** ^The SQLITE_CHECKPOINT_FULL, RESTART and TRUNCATE modes also obtain the 9498 ** exclusive "writer" lock on the database file. ^If the writer lock cannot be 9499 ** obtained immediately, and a busy-handler is configured, it is invoked and 9500 ** the writer lock retried until either the busy-handler returns 0 or the lock 9501 ** is successfully obtained. ^The busy-handler is also invoked while waiting for 9502 ** database readers as described above. ^If the busy-handler returns 0 before 9503 ** the writer lock is obtained or while waiting for database readers, the 9504 ** checkpoint operation proceeds from that point in the same way as 9505 ** SQLITE_CHECKPOINT_PASSIVE - checkpointing as many frames as possible 9506 ** without blocking any further. ^SQLITE_BUSY is returned in this case. 9507 ** 9508 ** ^If parameter zDb is NULL or points to a zero length string, then the 9509 ** specified operation is attempted on all WAL databases [attached] to 9510 ** [database connection] db. In this case the 9511 ** values written to output parameters *pnLog and *pnCkpt are undefined. ^If 9512 ** an SQLITE_BUSY error is encountered when processing one or more of the 9513 ** attached WAL databases, the operation is still attempted on any remaining 9514 ** attached databases and SQLITE_BUSY is returned at the end. ^If any other 9515 ** error occurs while processing an attached database, processing is abandoned 9516 ** and the error code is returned to the caller immediately. ^If no error 9517 ** (SQLITE_BUSY or otherwise) is encountered while processing the attached 9518 ** databases, SQLITE_OK is returned. 9519 ** 9520 ** ^If database zDb is the name of an attached database that is not in WAL 9521 ** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. ^If 9522 ** zDb is not NULL (or a zero length string) and is not the name of any 9523 ** attached database, SQLITE_ERROR is returned to the caller. 9524 ** 9525 ** ^Unless it returns SQLITE_MISUSE, 9526 ** the sqlite3_wal_checkpoint_v2() interface 9527 ** sets the error information that is queried by 9528 ** [sqlite3_errcode()] and [sqlite3_errmsg()]. 9529 ** 9530 ** ^The [PRAGMA wal_checkpoint] command can be used to invoke this interface 9531 ** from SQL. 9532 */ 9533 SQLITE_API int sqlite3_wal_checkpoint_v2( 9534 sqlite3 *db, /* Database handle */ 9535 const char *zDb, /* Name of attached database (or NULL) */ 9536 int eMode, /* SQLITE_CHECKPOINT_* value */ 9537 int *pnLog, /* OUT: Size of WAL log in frames */ 9538 int *pnCkpt /* OUT: Total number of frames checkpointed */ 9539 ); 9540 9541 /* 9542 ** CAPI3REF: Checkpoint Mode Values 9543 ** KEYWORDS: {checkpoint mode} 9544 ** 9545 ** These constants define all valid values for the "checkpoint mode" passed 9546 ** as the third parameter to the [sqlite3_wal_checkpoint_v2()] interface. 9547 ** See the [sqlite3_wal_checkpoint_v2()] documentation for details on the 9548 ** meaning of each of these checkpoint modes. 9549 */ 9550 #define SQLITE_CHECKPOINT_PASSIVE 0 /* Do as much as possible w/o blocking */ 9551 #define SQLITE_CHECKPOINT_FULL 1 /* Wait for writers, then checkpoint */ 9552 #define SQLITE_CHECKPOINT_RESTART 2 /* Like FULL but wait for readers */ 9553 #define SQLITE_CHECKPOINT_TRUNCATE 3 /* Like RESTART but also truncate WAL */ 9554 9555 /* 9556 ** CAPI3REF: Virtual Table Interface Configuration 9557 ** 9558 ** This function may be called by either the [xConnect] or [xCreate] method 9559 ** of a [virtual table] implementation to configure 9560 ** various facets of the virtual table interface. 9561 ** 9562 ** If this interface is invoked outside the context of an xConnect or 9563 ** xCreate virtual table method then the behavior is undefined. 9564 ** 9565 ** In the call sqlite3_vtab_config(D,C,...) the D parameter is the 9566 ** [database connection] in which the virtual table is being created and 9567 ** which is passed in as the first argument to the [xConnect] or [xCreate] 9568 ** method that is invoking sqlite3_vtab_config(). The C parameter is one 9569 ** of the [virtual table configuration options]. The presence and meaning 9570 ** of parameters after C depend on which [virtual table configuration option] 9571 ** is used. 9572 */ 9573 SQLITE_API int sqlite3_vtab_config(sqlite3*, int op, ...); 9574 9575 /* 9576 ** CAPI3REF: Virtual Table Configuration Options 9577 ** KEYWORDS: {virtual table configuration options} 9578 ** KEYWORDS: {virtual table configuration option} 9579 ** 9580 ** These macros define the various options to the 9581 ** [sqlite3_vtab_config()] interface that [virtual table] implementations 9582 ** can use to customize and optimize their behavior. 9583 ** 9584 ** <dl> 9585 ** [[SQLITE_VTAB_CONSTRAINT_SUPPORT]] 9586 ** <dt>SQLITE_VTAB_CONSTRAINT_SUPPORT</dt> 9587 ** <dd>Calls of the form 9588 ** [sqlite3_vtab_config](db,SQLITE_VTAB_CONSTRAINT_SUPPORT,X) are supported, 9589 ** where X is an integer. If X is zero, then the [virtual table] whose 9590 ** [xCreate] or [xConnect] method invoked [sqlite3_vtab_config()] does not 9591 ** support constraints. In this configuration (which is the default) if 9592 ** a call to the [xUpdate] method returns [SQLITE_CONSTRAINT], then the entire 9593 ** statement is rolled back as if [ON CONFLICT | OR ABORT] had been 9594 ** specified as part of the users SQL statement, regardless of the actual 9595 ** ON CONFLICT mode specified. 9596 ** 9597 ** If X is non-zero, then the virtual table implementation guarantees 9598 ** that if [xUpdate] returns [SQLITE_CONSTRAINT], it will do so before 9599 ** any modifications to internal or persistent data structures have been made. 9600 ** If the [ON CONFLICT] mode is ABORT, FAIL, IGNORE or ROLLBACK, SQLite 9601 ** is able to roll back a statement or database transaction, and abandon 9602 ** or continue processing the current SQL statement as appropriate. 9603 ** If the ON CONFLICT mode is REPLACE and the [xUpdate] method returns 9604 ** [SQLITE_CONSTRAINT], SQLite handles this as if the ON CONFLICT mode 9605 ** had been ABORT. 9606 ** 9607 ** Virtual table implementations that are required to handle OR REPLACE 9608 ** must do so within the [xUpdate] method. If a call to the 9609 ** [sqlite3_vtab_on_conflict()] function indicates that the current ON 9610 ** CONFLICT policy is REPLACE, the virtual table implementation should 9611 ** silently replace the appropriate rows within the xUpdate callback and 9612 ** return SQLITE_OK. Or, if this is not possible, it may return 9613 ** SQLITE_CONSTRAINT, in which case SQLite falls back to OR ABORT 9614 ** constraint handling. 9615 ** </dd> 9616 ** 9617 ** [[SQLITE_VTAB_DIRECTONLY]]<dt>SQLITE_VTAB_DIRECTONLY</dt> 9618 ** <dd>Calls of the form 9619 ** [sqlite3_vtab_config](db,SQLITE_VTAB_DIRECTONLY) from within the 9620 ** the [xConnect] or [xCreate] methods of a [virtual table] implmentation 9621 ** prohibits that virtual table from being used from within triggers and 9622 ** views. 9623 ** </dd> 9624 ** 9625 ** [[SQLITE_VTAB_INNOCUOUS]]<dt>SQLITE_VTAB_INNOCUOUS</dt> 9626 ** <dd>Calls of the form 9627 ** [sqlite3_vtab_config](db,SQLITE_VTAB_INNOCUOUS) from within the 9628 ** the [xConnect] or [xCreate] methods of a [virtual table] implementation 9629 ** identify that virtual table as being safe to use from within triggers 9630 ** and views. Conceptually, the SQLITE_VTAB_INNOCUOUS tag means that the 9631 ** virtual table can do no serious harm even if it is controlled by a 9632 ** malicious hacker. Developers should avoid setting the SQLITE_VTAB_INNOCUOUS 9633 ** flag unless absolutely necessary. 9634 ** </dd> 9635 ** 9636 ** [[SQLITE_VTAB_USES_ALL_SCHEMAS]]<dt>SQLITE_VTAB_USES_ALL_SCHEMAS</dt> 9637 ** <dd>Calls of the form 9638 ** [sqlite3_vtab_config](db,SQLITE_VTAB_USES_ALL_SCHEMA) from within the 9639 ** the [xConnect] or [xCreate] methods of a [virtual table] implementation 9640 ** instruct the query planner to begin at least a read transaction on 9641 ** all schemas ("main", "temp", and any ATTACH-ed databases) whenever the 9642 ** virtual table is used. 9643 ** </dd> 9644 ** </dl> 9645 */ 9646 #define SQLITE_VTAB_CONSTRAINT_SUPPORT 1 9647 #define SQLITE_VTAB_INNOCUOUS 2 9648 #define SQLITE_VTAB_DIRECTONLY 3 9649 #define SQLITE_VTAB_USES_ALL_SCHEMAS 4 9650 9651 /* 9652 ** CAPI3REF: Determine The Virtual Table Conflict Policy 9653 ** 9654 ** This function may only be called from within a call to the [xUpdate] method 9655 ** of a [virtual table] implementation for an INSERT or UPDATE operation. ^The 9656 ** value returned is one of [SQLITE_ROLLBACK], [SQLITE_IGNORE], [SQLITE_FAIL], 9657 ** [SQLITE_ABORT], or [SQLITE_REPLACE], according to the [ON CONFLICT] mode 9658 ** of the SQL statement that triggered the call to the [xUpdate] method of the 9659 ** [virtual table]. 9660 */ 9661 SQLITE_API int sqlite3_vtab_on_conflict(sqlite3 *); 9662 9663 /* 9664 ** CAPI3REF: Determine If Virtual Table Column Access Is For UPDATE 9665 ** 9666 ** If the sqlite3_vtab_nochange(X) routine is called within the [xColumn] 9667 ** method of a [virtual table], then it might return true if the 9668 ** column is being fetched as part of an UPDATE operation during which the 9669 ** column value will not change. The virtual table implementation can use 9670 ** this hint as permission to substitute a return value that is less 9671 ** expensive to compute and that the corresponding 9672 ** [xUpdate] method understands as a "no-change" value. 9673 ** 9674 ** If the [xColumn] method calls sqlite3_vtab_nochange() and finds that 9675 ** the column is not changed by the UPDATE statement, then the xColumn 9676 ** method can optionally return without setting a result, without calling 9677 ** any of the [sqlite3_result_int|sqlite3_result_xxxxx() interfaces]. 9678 ** In that case, [sqlite3_value_nochange(X)] will return true for the 9679 ** same column in the [xUpdate] method. 9680 ** 9681 ** The sqlite3_vtab_nochange() routine is an optimization. Virtual table 9682 ** implementations should continue to give a correct answer even if the 9683 ** sqlite3_vtab_nochange() interface were to always return false. In the 9684 ** current implementation, the sqlite3_vtab_nochange() interface does always 9685 ** returns false for the enhanced [UPDATE FROM] statement. 9686 */ 9687 SQLITE_API int sqlite3_vtab_nochange(sqlite3_context*); 9688 9689 /* 9690 ** CAPI3REF: Determine The Collation For a Virtual Table Constraint 9691 ** METHOD: sqlite3_index_info 9692 ** 9693 ** This function may only be called from within a call to the [xBestIndex] 9694 ** method of a [virtual table]. This function returns a pointer to a string 9695 ** that is the name of the appropriate collation sequence to use for text 9696 ** comparisons on the constraint identified by its arguments. 9697 ** 9698 ** The first argument must be the pointer to the [sqlite3_index_info] object 9699 ** that is the first parameter to the xBestIndex() method. The second argument 9700 ** must be an index into the aConstraint[] array belonging to the 9701 ** sqlite3_index_info structure passed to xBestIndex. 9702 ** 9703 ** Important: 9704 ** The first parameter must be the same pointer that is passed into the 9705 ** xBestMethod() method. The first parameter may not be a pointer to a 9706 ** different [sqlite3_index_info] object, even an exact copy. 9707 ** 9708 ** The return value is computed as follows: 9709 ** 9710 ** <ol> 9711 ** <li><p> If the constraint comes from a WHERE clause expression that contains 9712 ** a [COLLATE operator], then the name of the collation specified by 9713 ** that COLLATE operator is returned. 9714 ** <li><p> If there is no COLLATE operator, but the column that is the subject 9715 ** of the constraint specifies an alternative collating sequence via 9716 ** a [COLLATE clause] on the column definition within the CREATE TABLE 9717 ** statement that was passed into [sqlite3_declare_vtab()], then the 9718 ** name of that alternative collating sequence is returned. 9719 ** <li><p> Otherwise, "BINARY" is returned. 9720 ** </ol> 9721 */ 9722 SQLITE_API const char *sqlite3_vtab_collation(sqlite3_index_info*,int); 9723 9724 /* 9725 ** CAPI3REF: Determine if a virtual table query is DISTINCT 9726 ** METHOD: sqlite3_index_info 9727 ** 9728 ** This API may only be used from within an [xBestIndex|xBestIndex method] 9729 ** of a [virtual table] implementation. The result of calling this 9730 ** interface from outside of xBestIndex() is undefined and probably harmful. 9731 ** 9732 ** ^The sqlite3_vtab_distinct() interface returns an integer between 0 and 9733 ** 3. The integer returned by sqlite3_vtab_distinct() 9734 ** gives the virtual table additional information about how the query 9735 ** planner wants the output to be ordered. As long as the virtual table 9736 ** can meet the ordering requirements of the query planner, it may set 9737 ** the "orderByConsumed" flag. 9738 ** 9739 ** <ol><li value="0"><p> 9740 ** ^If the sqlite3_vtab_distinct() interface returns 0, that means 9741 ** that the query planner needs the virtual table to return all rows in the 9742 ** sort order defined by the "nOrderBy" and "aOrderBy" fields of the 9743 ** [sqlite3_index_info] object. This is the default expectation. If the 9744 ** virtual table outputs all rows in sorted order, then it is always safe for 9745 ** the xBestIndex method to set the "orderByConsumed" flag, regardless of 9746 ** the return value from sqlite3_vtab_distinct(). 9747 ** <li value="1"><p> 9748 ** ^(If the sqlite3_vtab_distinct() interface returns 1, that means 9749 ** that the query planner does not need the rows to be returned in sorted order 9750 ** as long as all rows with the same values in all columns identified by the 9751 ** "aOrderBy" field are adjacent.)^ This mode is used when the query planner 9752 ** is doing a GROUP BY. 9753 ** <li value="2"><p> 9754 ** ^(If the sqlite3_vtab_distinct() interface returns 2, that means 9755 ** that the query planner does not need the rows returned in any particular 9756 ** order, as long as rows with the same values in all "aOrderBy" columns 9757 ** are adjacent.)^ ^(Furthermore, only a single row for each particular 9758 ** combination of values in the columns identified by the "aOrderBy" field 9759 ** needs to be returned.)^ ^It is always ok for two or more rows with the same 9760 ** values in all "aOrderBy" columns to be returned, as long as all such rows 9761 ** are adjacent. ^The virtual table may, if it chooses, omit extra rows 9762 ** that have the same value for all columns identified by "aOrderBy". 9763 ** ^However omitting the extra rows is optional. 9764 ** This mode is used for a DISTINCT query. 9765 ** <li value="3"><p> 9766 ** ^(If the sqlite3_vtab_distinct() interface returns 3, that means 9767 ** that the query planner needs only distinct rows but it does need the 9768 ** rows to be sorted.)^ ^The virtual table implementation is free to omit 9769 ** rows that are identical in all aOrderBy columns, if it wants to, but 9770 ** it is not required to omit any rows. This mode is used for queries 9771 ** that have both DISTINCT and ORDER BY clauses. 9772 ** </ol> 9773 ** 9774 ** ^For the purposes of comparing virtual table output values to see if the 9775 ** values are same value for sorting purposes, two NULL values are considered 9776 ** to be the same. In other words, the comparison operator is "IS" 9777 ** (or "IS NOT DISTINCT FROM") and not "==". 9778 ** 9779 ** If a virtual table implementation is unable to meet the requirements 9780 ** specified above, then it must not set the "orderByConsumed" flag in the 9781 ** [sqlite3_index_info] object or an incorrect answer may result. 9782 ** 9783 ** ^A virtual table implementation is always free to return rows in any order 9784 ** it wants, as long as the "orderByConsumed" flag is not set. ^When the 9785 ** the "orderByConsumed" flag is unset, the query planner will add extra 9786 ** [bytecode] to ensure that the final results returned by the SQL query are 9787 ** ordered correctly. The use of the "orderByConsumed" flag and the 9788 ** sqlite3_vtab_distinct() interface is merely an optimization. ^Careful 9789 ** use of the sqlite3_vtab_distinct() interface and the "orderByConsumed" 9790 ** flag might help queries against a virtual table to run faster. Being 9791 ** overly aggressive and setting the "orderByConsumed" flag when it is not 9792 ** valid to do so, on the other hand, might cause SQLite to return incorrect 9793 ** results. 9794 */ 9795 SQLITE_API int sqlite3_vtab_distinct(sqlite3_index_info*); 9796 9797 /* 9798 ** CAPI3REF: Identify and handle IN constraints in xBestIndex 9799 ** 9800 ** This interface may only be used from within an 9801 ** [xBestIndex|xBestIndex() method] of a [virtual table] implementation. 9802 ** The result of invoking this interface from any other context is 9803 ** undefined and probably harmful. 9804 ** 9805 ** ^(A constraint on a virtual table of the form 9806 ** "[IN operator|column IN (...)]" is 9807 ** communicated to the xBestIndex method as a 9808 ** [SQLITE_INDEX_CONSTRAINT_EQ] constraint.)^ If xBestIndex wants to use 9809 ** this constraint, it must set the corresponding 9810 ** aConstraintUsage[].argvIndex to a postive integer. ^(Then, under 9811 ** the usual mode of handling IN operators, SQLite generates [bytecode] 9812 ** that invokes the [xFilter|xFilter() method] once for each value 9813 ** on the right-hand side of the IN operator.)^ Thus the virtual table 9814 ** only sees a single value from the right-hand side of the IN operator 9815 ** at a time. 9816 ** 9817 ** In some cases, however, it would be advantageous for the virtual 9818 ** table to see all values on the right-hand of the IN operator all at 9819 ** once. The sqlite3_vtab_in() interfaces facilitates this in two ways: 9820 ** 9821 ** <ol> 9822 ** <li><p> 9823 ** ^A call to sqlite3_vtab_in(P,N,-1) will return true (non-zero) 9824 ** if and only if the [sqlite3_index_info|P->aConstraint][N] constraint 9825 ** is an [IN operator] that can be processed all at once. ^In other words, 9826 ** sqlite3_vtab_in() with -1 in the third argument is a mechanism 9827 ** by which the virtual table can ask SQLite if all-at-once processing 9828 ** of the IN operator is even possible. 9829 ** 9830 ** <li><p> 9831 ** ^A call to sqlite3_vtab_in(P,N,F) with F==1 or F==0 indicates 9832 ** to SQLite that the virtual table does or does not want to process 9833 ** the IN operator all-at-once, respectively. ^Thus when the third 9834 ** parameter (F) is non-negative, this interface is the mechanism by 9835 ** which the virtual table tells SQLite how it wants to process the 9836 ** IN operator. 9837 ** </ol> 9838 ** 9839 ** ^The sqlite3_vtab_in(P,N,F) interface can be invoked multiple times 9840 ** within the same xBestIndex method call. ^For any given P,N pair, 9841 ** the return value from sqlite3_vtab_in(P,N,F) will always be the same 9842 ** within the same xBestIndex call. ^If the interface returns true 9843 ** (non-zero), that means that the constraint is an IN operator 9844 ** that can be processed all-at-once. ^If the constraint is not an IN 9845 ** operator or cannot be processed all-at-once, then the interface returns 9846 ** false. 9847 ** 9848 ** ^(All-at-once processing of the IN operator is selected if both of the 9849 ** following conditions are met: 9850 ** 9851 ** <ol> 9852 ** <li><p> The P->aConstraintUsage[N].argvIndex value is set to a positive 9853 ** integer. This is how the virtual table tells SQLite that it wants to 9854 ** use the N-th constraint. 9855 ** 9856 ** <li><p> The last call to sqlite3_vtab_in(P,N,F) for which F was 9857 ** non-negative had F>=1. 9858 ** </ol>)^ 9859 ** 9860 ** ^If either or both of the conditions above are false, then SQLite uses 9861 ** the traditional one-at-a-time processing strategy for the IN constraint. 9862 ** ^If both conditions are true, then the argvIndex-th parameter to the 9863 ** xFilter method will be an [sqlite3_value] that appears to be NULL, 9864 ** but which can be passed to [sqlite3_vtab_in_first()] and 9865 ** [sqlite3_vtab_in_next()] to find all values on the right-hand side 9866 ** of the IN constraint. 9867 */ 9868 SQLITE_API int sqlite3_vtab_in(sqlite3_index_info*, int iCons, int bHandle); 9869 9870 /* 9871 ** CAPI3REF: Find all elements on the right-hand side of an IN constraint. 9872 ** 9873 ** These interfaces are only useful from within the 9874 ** [xFilter|xFilter() method] of a [virtual table] implementation. 9875 ** The result of invoking these interfaces from any other context 9876 ** is undefined and probably harmful. 9877 ** 9878 ** The X parameter in a call to sqlite3_vtab_in_first(X,P) or 9879 ** sqlite3_vtab_in_next(X,P) should be one of the parameters to the 9880 ** xFilter method which invokes these routines, and specifically 9881 ** a parameter that was previously selected for all-at-once IN constraint 9882 ** processing use the [sqlite3_vtab_in()] interface in the 9883 ** [xBestIndex|xBestIndex method]. ^(If the X parameter is not 9884 ** an xFilter argument that was selected for all-at-once IN constraint 9885 ** processing, then these routines return [SQLITE_ERROR].)^ 9886 ** 9887 ** ^(Use these routines to access all values on the right-hand side 9888 ** of the IN constraint using code like the following: 9889 ** 9890 ** <blockquote><pre> 9891 ** for(rc=sqlite3_vtab_in_first(pList, &pVal); 9892 ** rc==SQLITE_OK && pVal; 9893 ** rc=sqlite3_vtab_in_next(pList, &pVal) 9894 ** ){ 9895 ** // do something with pVal 9896 ** } 9897 ** if( rc!=SQLITE_OK ){ 9898 ** // an error has occurred 9899 ** } 9900 ** </pre></blockquote>)^ 9901 ** 9902 ** ^On success, the sqlite3_vtab_in_first(X,P) and sqlite3_vtab_in_next(X,P) 9903 ** routines return SQLITE_OK and set *P to point to the first or next value 9904 ** on the RHS of the IN constraint. ^If there are no more values on the 9905 ** right hand side of the IN constraint, then *P is set to NULL and these 9906 ** routines return [SQLITE_DONE]. ^The return value might be 9907 ** some other value, such as SQLITE_NOMEM, in the event of a malfunction. 9908 ** 9909 ** The *ppOut values returned by these routines are only valid until the 9910 ** next call to either of these routines or until the end of the xFilter 9911 ** method from which these routines were called. If the virtual table 9912 ** implementation needs to retain the *ppOut values for longer, it must make 9913 ** copies. The *ppOut values are [protected sqlite3_value|protected]. 9914 */ 9915 SQLITE_API int sqlite3_vtab_in_first(sqlite3_value *pVal, sqlite3_value **ppOut); 9916 SQLITE_API int sqlite3_vtab_in_next(sqlite3_value *pVal, sqlite3_value **ppOut); 9917 9918 /* 9919 ** CAPI3REF: Constraint values in xBestIndex() 9920 ** METHOD: sqlite3_index_info 9921 ** 9922 ** This API may only be used from within the [xBestIndex|xBestIndex method] 9923 ** of a [virtual table] implementation. The result of calling this interface 9924 ** from outside of an xBestIndex method are undefined and probably harmful. 9925 ** 9926 ** ^When the sqlite3_vtab_rhs_value(P,J,V) interface is invoked from within 9927 ** the [xBestIndex] method of a [virtual table] implementation, with P being 9928 ** a copy of the [sqlite3_index_info] object pointer passed into xBestIndex and 9929 ** J being a 0-based index into P->aConstraint[], then this routine 9930 ** attempts to set *V to the value of the right-hand operand of 9931 ** that constraint if the right-hand operand is known. ^If the 9932 ** right-hand operand is not known, then *V is set to a NULL pointer. 9933 ** ^The sqlite3_vtab_rhs_value(P,J,V) interface returns SQLITE_OK if 9934 ** and only if *V is set to a value. ^The sqlite3_vtab_rhs_value(P,J,V) 9935 ** inteface returns SQLITE_NOTFOUND if the right-hand side of the J-th 9936 ** constraint is not available. ^The sqlite3_vtab_rhs_value() interface 9937 ** can return an result code other than SQLITE_OK or SQLITE_NOTFOUND if 9938 ** something goes wrong. 9939 ** 9940 ** The sqlite3_vtab_rhs_value() interface is usually only successful if 9941 ** the right-hand operand of a constraint is a literal value in the original 9942 ** SQL statement. If the right-hand operand is an expression or a reference 9943 ** to some other column or a [host parameter], then sqlite3_vtab_rhs_value() 9944 ** will probably return [SQLITE_NOTFOUND]. 9945 ** 9946 ** ^(Some constraints, such as [SQLITE_INDEX_CONSTRAINT_ISNULL] and 9947 ** [SQLITE_INDEX_CONSTRAINT_ISNOTNULL], have no right-hand operand. For such 9948 ** constraints, sqlite3_vtab_rhs_value() always returns SQLITE_NOTFOUND.)^ 9949 ** 9950 ** ^The [sqlite3_value] object returned in *V is a protected sqlite3_value 9951 ** and remains valid for the duration of the xBestIndex method call. 9952 ** ^When xBestIndex returns, the sqlite3_value object returned by 9953 ** sqlite3_vtab_rhs_value() is automatically deallocated. 9954 ** 9955 ** The "_rhs_" in the name of this routine is an abbreviation for 9956 ** "Right-Hand Side". 9957 */ 9958 SQLITE_API int sqlite3_vtab_rhs_value(sqlite3_index_info*, int, sqlite3_value **ppVal); 9959 9960 /* 9961 ** CAPI3REF: Conflict resolution modes 9962 ** KEYWORDS: {conflict resolution mode} 9963 ** 9964 ** These constants are returned by [sqlite3_vtab_on_conflict()] to 9965 ** inform a [virtual table] implementation what the [ON CONFLICT] mode 9966 ** is for the SQL statement being evaluated. 9967 ** 9968 ** Note that the [SQLITE_IGNORE] constant is also used as a potential 9969 ** return value from the [sqlite3_set_authorizer()] callback and that 9970 ** [SQLITE_ABORT] is also a [result code]. 9971 */ 9972 #define SQLITE_ROLLBACK 1 9973 /* #define SQLITE_IGNORE 2 // Also used by sqlite3_authorizer() callback */ 9974 #define SQLITE_FAIL 3 9975 /* #define SQLITE_ABORT 4 // Also an error code */ 9976 #define SQLITE_REPLACE 5 9977 9978 /* 9979 ** CAPI3REF: Prepared Statement Scan Status Opcodes 9980 ** KEYWORDS: {scanstatus options} 9981 ** 9982 ** The following constants can be used for the T parameter to the 9983 ** [sqlite3_stmt_scanstatus(S,X,T,V)] interface. Each constant designates a 9984 ** different metric for sqlite3_stmt_scanstatus() to return. 9985 ** 9986 ** When the value returned to V is a string, space to hold that string is 9987 ** managed by the prepared statement S and will be automatically freed when 9988 ** S is finalized. 9989 ** 9990 ** Not all values are available for all query elements. When a value is 9991 ** not available, the output variable is set to -1 if the value is numeric, 9992 ** or to NULL if it is a string (SQLITE_SCANSTAT_NAME). 9993 ** 9994 ** <dl> 9995 ** [[SQLITE_SCANSTAT_NLOOP]] <dt>SQLITE_SCANSTAT_NLOOP</dt> 9996 ** <dd>^The [sqlite3_int64] variable pointed to by the V parameter will be 9997 ** set to the total number of times that the X-th loop has run.</dd> 9998 ** 9999 ** [[SQLITE_SCANSTAT_NVISIT]] <dt>SQLITE_SCANSTAT_NVISIT</dt> 10000 ** <dd>^The [sqlite3_int64] variable pointed to by the V parameter will be set 10001 ** to the total number of rows examined by all iterations of the X-th loop.</dd> 10002 ** 10003 ** [[SQLITE_SCANSTAT_EST]] <dt>SQLITE_SCANSTAT_EST</dt> 10004 ** <dd>^The "double" variable pointed to by the V parameter will be set to the 10005 ** query planner's estimate for the average number of rows output from each 10006 ** iteration of the X-th loop. If the query planner's estimates was accurate, 10007 ** then this value will approximate the quotient NVISIT/NLOOP and the 10008 ** product of this value for all prior loops with the same SELECTID will 10009 ** be the NLOOP value for the current loop. 10010 ** 10011 ** [[SQLITE_SCANSTAT_NAME]] <dt>SQLITE_SCANSTAT_NAME</dt> 10012 ** <dd>^The "const char *" variable pointed to by the V parameter will be set 10013 ** to a zero-terminated UTF-8 string containing the name of the index or table 10014 ** used for the X-th loop. 10015 ** 10016 ** [[SQLITE_SCANSTAT_EXPLAIN]] <dt>SQLITE_SCANSTAT_EXPLAIN</dt> 10017 ** <dd>^The "const char *" variable pointed to by the V parameter will be set 10018 ** to a zero-terminated UTF-8 string containing the [EXPLAIN QUERY PLAN] 10019 ** description for the X-th loop. 10020 ** 10021 ** [[SQLITE_SCANSTAT_SELECTID]] <dt>SQLITE_SCANSTAT_SELECTID</dt> 10022 ** <dd>^The "int" variable pointed to by the V parameter will be set to the 10023 ** id for the X-th query plan element. The id value is unique within the 10024 ** statement. The select-id is the same value as is output in the first 10025 ** column of an [EXPLAIN QUERY PLAN] query. 10026 ** 10027 ** [[SQLITE_SCANSTAT_PARENTID]] <dt>SQLITE_SCANSTAT_PARENTID</dt> 10028 ** <dd>The "int" variable pointed to by the V parameter will be set to the 10029 ** the id of the parent of the current query element, if applicable, or 10030 ** to zero if the query element has no parent. This is the same value as 10031 ** returned in the second column of an [EXPLAIN QUERY PLAN] query. 10032 ** 10033 ** [[SQLITE_SCANSTAT_NCYCLE]] <dt>SQLITE_SCANSTAT_NCYCLE</dt> 10034 ** <dd>The sqlite3_int64 output value is set to the number of cycles, 10035 ** according to the processor time-stamp counter, that elapsed while the 10036 ** query element was being processed. This value is not available for 10037 ** all query elements - if it is unavailable the output variable is 10038 ** set to -1. 10039 ** </dl> 10040 */ 10041 #define SQLITE_SCANSTAT_NLOOP 0 10042 #define SQLITE_SCANSTAT_NVISIT 1 10043 #define SQLITE_SCANSTAT_EST 2 10044 #define SQLITE_SCANSTAT_NAME 3 10045 #define SQLITE_SCANSTAT_EXPLAIN 4 10046 #define SQLITE_SCANSTAT_SELECTID 5 10047 #define SQLITE_SCANSTAT_PARENTID 6 10048 #define SQLITE_SCANSTAT_NCYCLE 7 10049 10050 /* 10051 ** CAPI3REF: Prepared Statement Scan Status 10052 ** METHOD: sqlite3_stmt 10053 ** 10054 ** These interfaces return information about the predicted and measured 10055 ** performance for pStmt. Advanced applications can use this 10056 ** interface to compare the predicted and the measured performance and 10057 ** issue warnings and/or rerun [ANALYZE] if discrepancies are found. 10058 ** 10059 ** Since this interface is expected to be rarely used, it is only 10060 ** available if SQLite is compiled using the [SQLITE_ENABLE_STMT_SCANSTATUS] 10061 ** compile-time option. 10062 ** 10063 ** The "iScanStatusOp" parameter determines which status information to return. 10064 ** The "iScanStatusOp" must be one of the [scanstatus options] or the behavior 10065 ** of this interface is undefined. ^The requested measurement is written into 10066 ** a variable pointed to by the "pOut" parameter. 10067 ** 10068 ** The "flags" parameter must be passed a mask of flags. At present only 10069 ** one flag is defined - SQLITE_SCANSTAT_COMPLEX. If SQLITE_SCANSTAT_COMPLEX 10070 ** is specified, then status information is available for all elements 10071 ** of a query plan that are reported by "EXPLAIN QUERY PLAN" output. If 10072 ** SQLITE_SCANSTAT_COMPLEX is not specified, then only query plan elements 10073 ** that correspond to query loops (the "SCAN..." and "SEARCH..." elements of 10074 ** the EXPLAIN QUERY PLAN output) are available. Invoking API 10075 ** sqlite3_stmt_scanstatus() is equivalent to calling 10076 ** sqlite3_stmt_scanstatus_v2() with a zeroed flags parameter. 10077 ** 10078 ** Parameter "idx" identifies the specific query element to retrieve statistics 10079 ** for. Query elements are numbered starting from zero. A value of -1 may be 10080 ** to query for statistics regarding the entire query. ^If idx is out of range 10081 ** - less than -1 or greater than or equal to the total number of query 10082 ** elements used to implement the statement - a non-zero value is returned and 10083 ** the variable that pOut points to is unchanged. 10084 ** 10085 ** See also: [sqlite3_stmt_scanstatus_reset()] 10086 */ 10087 SQLITE_API int sqlite3_stmt_scanstatus( 10088 sqlite3_stmt *pStmt, /* Prepared statement for which info desired */ 10089 int idx, /* Index of loop to report on */ 10090 int iScanStatusOp, /* Information desired. SQLITE_SCANSTAT_* */ 10091 void *pOut /* Result written here */ 10092 ); 10093 SQLITE_API int sqlite3_stmt_scanstatus_v2( 10094 sqlite3_stmt *pStmt, /* Prepared statement for which info desired */ 10095 int idx, /* Index of loop to report on */ 10096 int iScanStatusOp, /* Information desired. SQLITE_SCANSTAT_* */ 10097 int flags, /* Mask of flags defined below */ 10098 void *pOut /* Result written here */ 10099 ); 10100 10101 /* 10102 ** CAPI3REF: Prepared Statement Scan Status 10103 ** KEYWORDS: {scan status flags} 10104 */ 10105 #define SQLITE_SCANSTAT_COMPLEX 0x0001 10106 10107 /* 10108 ** CAPI3REF: Zero Scan-Status Counters 10109 ** METHOD: sqlite3_stmt 10110 ** 10111 ** ^Zero all [sqlite3_stmt_scanstatus()] related event counters. 10112 ** 10113 ** This API is only available if the library is built with pre-processor 10114 ** symbol [SQLITE_ENABLE_STMT_SCANSTATUS] defined. 10115 */ 10116 SQLITE_API void sqlite3_stmt_scanstatus_reset(sqlite3_stmt*); 10117 10118 /* 10119 ** CAPI3REF: Flush caches to disk mid-transaction 10120 ** METHOD: sqlite3 10121 ** 10122 ** ^If a write-transaction is open on [database connection] D when the 10123 ** [sqlite3_db_cacheflush(D)] interface invoked, any dirty 10124 ** pages in the pager-cache that are not currently in use are written out 10125 ** to disk. A dirty page may be in use if a database cursor created by an 10126 ** active SQL statement is reading from it, or if it is page 1 of a database 10127 ** file (page 1 is always "in use"). ^The [sqlite3_db_cacheflush(D)] 10128 ** interface flushes caches for all schemas - "main", "temp", and 10129 ** any [attached] databases. 10130 ** 10131 ** ^If this function needs to obtain extra database locks before dirty pages 10132 ** can be flushed to disk, it does so. ^If those locks cannot be obtained 10133 ** immediately and there is a busy-handler callback configured, it is invoked 10134 ** in the usual manner. ^If the required lock still cannot be obtained, then 10135 ** the database is skipped and an attempt made to flush any dirty pages 10136 ** belonging to the next (if any) database. ^If any databases are skipped 10137 ** because locks cannot be obtained, but no other error occurs, this 10138 ** function returns SQLITE_BUSY. 10139 ** 10140 ** ^If any other error occurs while flushing dirty pages to disk (for 10141 ** example an IO error or out-of-memory condition), then processing is 10142 ** abandoned and an SQLite [error code] is returned to the caller immediately. 10143 ** 10144 ** ^Otherwise, if no error occurs, [sqlite3_db_cacheflush()] returns SQLITE_OK. 10145 ** 10146 ** ^This function does not set the database handle error code or message 10147 ** returned by the [sqlite3_errcode()] and [sqlite3_errmsg()] functions. 10148 */ 10149 SQLITE_API int sqlite3_db_cacheflush(sqlite3*); 10150 10151 /* 10152 ** CAPI3REF: The pre-update hook. 10153 ** METHOD: sqlite3 10154 ** 10155 ** ^These interfaces are only available if SQLite is compiled using the 10156 ** [SQLITE_ENABLE_PREUPDATE_HOOK] compile-time option. 10157 ** 10158 ** ^The [sqlite3_preupdate_hook()] interface registers a callback function 10159 ** that is invoked prior to each [INSERT], [UPDATE], and [DELETE] operation 10160 ** on a database table. 10161 ** ^At most one preupdate hook may be registered at a time on a single 10162 ** [database connection]; each call to [sqlite3_preupdate_hook()] overrides 10163 ** the previous setting. 10164 ** ^The preupdate hook is disabled by invoking [sqlite3_preupdate_hook()] 10165 ** with a NULL pointer as the second parameter. 10166 ** ^The third parameter to [sqlite3_preupdate_hook()] is passed through as 10167 ** the first parameter to callbacks. 10168 ** 10169 ** ^The preupdate hook only fires for changes to real database tables; the 10170 ** preupdate hook is not invoked for changes to [virtual tables] or to 10171 ** system tables like sqlite_sequence or sqlite_stat1. 10172 ** 10173 ** ^The second parameter to the preupdate callback is a pointer to 10174 ** the [database connection] that registered the preupdate hook. 10175 ** ^The third parameter to the preupdate callback is one of the constants 10176 ** [SQLITE_INSERT], [SQLITE_DELETE], or [SQLITE_UPDATE] to identify the 10177 ** kind of update operation that is about to occur. 10178 ** ^(The fourth parameter to the preupdate callback is the name of the 10179 ** database within the database connection that is being modified. This 10180 ** will be "main" for the main database or "temp" for TEMP tables or 10181 ** the name given after the AS keyword in the [ATTACH] statement for attached 10182 ** databases.)^ 10183 ** ^The fifth parameter to the preupdate callback is the name of the 10184 ** table that is being modified. 10185 ** 10186 ** For an UPDATE or DELETE operation on a [rowid table], the sixth 10187 ** parameter passed to the preupdate callback is the initial [rowid] of the 10188 ** row being modified or deleted. For an INSERT operation on a rowid table, 10189 ** or any operation on a WITHOUT ROWID table, the value of the sixth 10190 ** parameter is undefined. For an INSERT or UPDATE on a rowid table the 10191 ** seventh parameter is the final rowid value of the row being inserted 10192 ** or updated. The value of the seventh parameter passed to the callback 10193 ** function is not defined for operations on WITHOUT ROWID tables, or for 10194 ** DELETE operations on rowid tables. 10195 ** 10196 ** ^The sqlite3_preupdate_hook(D,C,P) function returns the P argument from 10197 ** the previous call on the same [database connection] D, or NULL for 10198 ** the first call on D. 10199 ** 10200 ** The [sqlite3_preupdate_old()], [sqlite3_preupdate_new()], 10201 ** [sqlite3_preupdate_count()], and [sqlite3_preupdate_depth()] interfaces 10202 ** provide additional information about a preupdate event. These routines 10203 ** may only be called from within a preupdate callback. Invoking any of 10204 ** these routines from outside of a preupdate callback or with a 10205 ** [database connection] pointer that is different from the one supplied 10206 ** to the preupdate callback results in undefined and probably undesirable 10207 ** behavior. 10208 ** 10209 ** ^The [sqlite3_preupdate_count(D)] interface returns the number of columns 10210 ** in the row that is being inserted, updated, or deleted. 10211 ** 10212 ** ^The [sqlite3_preupdate_old(D,N,P)] interface writes into P a pointer to 10213 ** a [protected sqlite3_value] that contains the value of the Nth column of 10214 ** the table row before it is updated. The N parameter must be between 0 10215 ** and one less than the number of columns or the behavior will be 10216 ** undefined. This must only be used within SQLITE_UPDATE and SQLITE_DELETE 10217 ** preupdate callbacks; if it is used by an SQLITE_INSERT callback then the 10218 ** behavior is undefined. The [sqlite3_value] that P points to 10219 ** will be destroyed when the preupdate callback returns. 10220 ** 10221 ** ^The [sqlite3_preupdate_new(D,N,P)] interface writes into P a pointer to 10222 ** a [protected sqlite3_value] that contains the value of the Nth column of 10223 ** the table row after it is updated. The N parameter must be between 0 10224 ** and one less than the number of columns or the behavior will be 10225 ** undefined. This must only be used within SQLITE_INSERT and SQLITE_UPDATE 10226 ** preupdate callbacks; if it is used by an SQLITE_DELETE callback then the 10227 ** behavior is undefined. The [sqlite3_value] that P points to 10228 ** will be destroyed when the preupdate callback returns. 10229 ** 10230 ** ^The [sqlite3_preupdate_depth(D)] interface returns 0 if the preupdate 10231 ** callback was invoked as a result of a direct insert, update, or delete 10232 ** operation; or 1 for inserts, updates, or deletes invoked by top-level 10233 ** triggers; or 2 for changes resulting from triggers called by top-level 10234 ** triggers; and so forth. 10235 ** 10236 ** When the [sqlite3_blob_write()] API is used to update a blob column, 10237 ** the pre-update hook is invoked with SQLITE_DELETE. This is because the 10238 ** in this case the new values are not available. In this case, when a 10239 ** callback made with op==SQLITE_DELETE is actuall a write using the 10240 ** sqlite3_blob_write() API, the [sqlite3_preupdate_blobwrite()] returns 10241 ** the index of the column being written. In other cases, where the 10242 ** pre-update hook is being invoked for some other reason, including a 10243 ** regular DELETE, sqlite3_preupdate_blobwrite() returns -1. 10244 ** 10245 ** See also: [sqlite3_update_hook()] 10246 */ 10247 #if defined(SQLITE_ENABLE_PREUPDATE_HOOK) 10248 SQLITE_API void *sqlite3_preupdate_hook( 10249 sqlite3 *db, 10250 void(*xPreUpdate)( 10251 void *pCtx, /* Copy of third arg to preupdate_hook() */ 10252 sqlite3 *db, /* Database handle */ 10253 int op, /* SQLITE_UPDATE, DELETE or INSERT */ 10254 char const *zDb, /* Database name */ 10255 char const *zName, /* Table name */ 10256 sqlite3_int64 iKey1, /* Rowid of row about to be deleted/updated */ 10257 sqlite3_int64 iKey2 /* New rowid value (for a rowid UPDATE) */ 10258 ), 10259 void* 10260 ); 10261 SQLITE_API int sqlite3_preupdate_old(sqlite3 *, int, sqlite3_value **); 10262 SQLITE_API int sqlite3_preupdate_count(sqlite3 *); 10263 SQLITE_API int sqlite3_preupdate_depth(sqlite3 *); 10264 SQLITE_API int sqlite3_preupdate_new(sqlite3 *, int, sqlite3_value **); 10265 SQLITE_API int sqlite3_preupdate_blobwrite(sqlite3 *); 10266 #endif 10267 10268 /* 10269 ** CAPI3REF: Low-level system error code 10270 ** METHOD: sqlite3 10271 ** 10272 ** ^Attempt to return the underlying operating system error code or error 10273 ** number that caused the most recent I/O error or failure to open a file. 10274 ** The return value is OS-dependent. For example, on unix systems, after 10275 ** [sqlite3_open_v2()] returns [SQLITE_CANTOPEN], this interface could be 10276 ** called to get back the underlying "errno" that caused the problem, such 10277 ** as ENOSPC, EAUTH, EISDIR, and so forth. 10278 */ 10279 SQLITE_API int sqlite3_system_errno(sqlite3*); 10280 10281 /* 10282 ** CAPI3REF: Database Snapshot 10283 ** KEYWORDS: {snapshot} {sqlite3_snapshot} 10284 ** 10285 ** An instance of the snapshot object records the state of a [WAL mode] 10286 ** database for some specific point in history. 10287 ** 10288 ** In [WAL mode], multiple [database connections] that are open on the 10289 ** same database file can each be reading a different historical version 10290 ** of the database file. When a [database connection] begins a read 10291 ** transaction, that connection sees an unchanging copy of the database 10292 ** as it existed for the point in time when the transaction first started. 10293 ** Subsequent changes to the database from other connections are not seen 10294 ** by the reader until a new read transaction is started. 10295 ** 10296 ** The sqlite3_snapshot object records state information about an historical 10297 ** version of the database file so that it is possible to later open a new read 10298 ** transaction that sees that historical version of the database rather than 10299 ** the most recent version. 10300 */ 10301 typedef struct sqlite3_snapshot { 10302 unsigned char hidden[48]; 10303 } sqlite3_snapshot; 10304 10305 /* 10306 ** CAPI3REF: Record A Database Snapshot 10307 ** CONSTRUCTOR: sqlite3_snapshot 10308 ** 10309 ** ^The [sqlite3_snapshot_get(D,S,P)] interface attempts to make a 10310 ** new [sqlite3_snapshot] object that records the current state of 10311 ** schema S in database connection D. ^On success, the 10312 ** [sqlite3_snapshot_get(D,S,P)] interface writes a pointer to the newly 10313 ** created [sqlite3_snapshot] object into *P and returns SQLITE_OK. 10314 ** If there is not already a read-transaction open on schema S when 10315 ** this function is called, one is opened automatically. 10316 ** 10317 ** The following must be true for this function to succeed. If any of 10318 ** the following statements are false when sqlite3_snapshot_get() is 10319 ** called, SQLITE_ERROR is returned. The final value of *P is undefined 10320 ** in this case. 10321 ** 10322 ** <ul> 10323 ** <li> The database handle must not be in [autocommit mode]. 10324 ** 10325 ** <li> Schema S of [database connection] D must be a [WAL mode] database. 10326 ** 10327 ** <li> There must not be a write transaction open on schema S of database 10328 ** connection D. 10329 ** 10330 ** <li> One or more transactions must have been written to the current wal 10331 ** file since it was created on disk (by any connection). This means 10332 ** that a snapshot cannot be taken on a wal mode database with no wal 10333 ** file immediately after it is first opened. At least one transaction 10334 ** must be written to it first. 10335 ** </ul> 10336 ** 10337 ** This function may also return SQLITE_NOMEM. If it is called with the 10338 ** database handle in autocommit mode but fails for some other reason, 10339 ** whether or not a read transaction is opened on schema S is undefined. 10340 ** 10341 ** The [sqlite3_snapshot] object returned from a successful call to 10342 ** [sqlite3_snapshot_get()] must be freed using [sqlite3_snapshot_free()] 10343 ** to avoid a memory leak. 10344 ** 10345 ** The [sqlite3_snapshot_get()] interface is only available when the 10346 ** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used. 10347 */ 10348 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_get( 10349 sqlite3 *db, 10350 const char *zSchema, 10351 sqlite3_snapshot **ppSnapshot 10352 ); 10353 10354 /* 10355 ** CAPI3REF: Start a read transaction on an historical snapshot 10356 ** METHOD: sqlite3_snapshot 10357 ** 10358 ** ^The [sqlite3_snapshot_open(D,S,P)] interface either starts a new read 10359 ** transaction or upgrades an existing one for schema S of 10360 ** [database connection] D such that the read transaction refers to 10361 ** historical [snapshot] P, rather than the most recent change to the 10362 ** database. ^The [sqlite3_snapshot_open()] interface returns SQLITE_OK 10363 ** on success or an appropriate [error code] if it fails. 10364 ** 10365 ** ^In order to succeed, the database connection must not be in 10366 ** [autocommit mode] when [sqlite3_snapshot_open(D,S,P)] is called. If there 10367 ** is already a read transaction open on schema S, then the database handle 10368 ** must have no active statements (SELECT statements that have been passed 10369 ** to sqlite3_step() but not sqlite3_reset() or sqlite3_finalize()). 10370 ** SQLITE_ERROR is returned if either of these conditions is violated, or 10371 ** if schema S does not exist, or if the snapshot object is invalid. 10372 ** 10373 ** ^A call to sqlite3_snapshot_open() will fail to open if the specified 10374 ** snapshot has been overwritten by a [checkpoint]. In this case 10375 ** SQLITE_ERROR_SNAPSHOT is returned. 10376 ** 10377 ** If there is already a read transaction open when this function is 10378 ** invoked, then the same read transaction remains open (on the same 10379 ** database snapshot) if SQLITE_ERROR, SQLITE_BUSY or SQLITE_ERROR_SNAPSHOT 10380 ** is returned. If another error code - for example SQLITE_PROTOCOL or an 10381 ** SQLITE_IOERR error code - is returned, then the final state of the 10382 ** read transaction is undefined. If SQLITE_OK is returned, then the 10383 ** read transaction is now open on database snapshot P. 10384 ** 10385 ** ^(A call to [sqlite3_snapshot_open(D,S,P)] will fail if the 10386 ** database connection D does not know that the database file for 10387 ** schema S is in [WAL mode]. A database connection might not know 10388 ** that the database file is in [WAL mode] if there has been no prior 10389 ** I/O on that database connection, or if the database entered [WAL mode] 10390 ** after the most recent I/O on the database connection.)^ 10391 ** (Hint: Run "[PRAGMA application_id]" against a newly opened 10392 ** database connection in order to make it ready to use snapshots.) 10393 ** 10394 ** The [sqlite3_snapshot_open()] interface is only available when the 10395 ** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used. 10396 */ 10397 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_open( 10398 sqlite3 *db, 10399 const char *zSchema, 10400 sqlite3_snapshot *pSnapshot 10401 ); 10402 10403 /* 10404 ** CAPI3REF: Destroy a snapshot 10405 ** DESTRUCTOR: sqlite3_snapshot 10406 ** 10407 ** ^The [sqlite3_snapshot_free(P)] interface destroys [sqlite3_snapshot] P. 10408 ** The application must eventually free every [sqlite3_snapshot] object 10409 ** using this routine to avoid a memory leak. 10410 ** 10411 ** The [sqlite3_snapshot_free()] interface is only available when the 10412 ** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used. 10413 */ 10414 SQLITE_API SQLITE_EXPERIMENTAL void sqlite3_snapshot_free(sqlite3_snapshot*); 10415 10416 /* 10417 ** CAPI3REF: Compare the ages of two snapshot handles. 10418 ** METHOD: sqlite3_snapshot 10419 ** 10420 ** The sqlite3_snapshot_cmp(P1, P2) interface is used to compare the ages 10421 ** of two valid snapshot handles. 10422 ** 10423 ** If the two snapshot handles are not associated with the same database 10424 ** file, the result of the comparison is undefined. 10425 ** 10426 ** Additionally, the result of the comparison is only valid if both of the 10427 ** snapshot handles were obtained by calling sqlite3_snapshot_get() since the 10428 ** last time the wal file was deleted. The wal file is deleted when the 10429 ** database is changed back to rollback mode or when the number of database 10430 ** clients drops to zero. If either snapshot handle was obtained before the 10431 ** wal file was last deleted, the value returned by this function 10432 ** is undefined. 10433 ** 10434 ** Otherwise, this API returns a negative value if P1 refers to an older 10435 ** snapshot than P2, zero if the two handles refer to the same database 10436 ** snapshot, and a positive value if P1 is a newer snapshot than P2. 10437 ** 10438 ** This interface is only available if SQLite is compiled with the 10439 ** [SQLITE_ENABLE_SNAPSHOT] option. 10440 */ 10441 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_cmp( 10442 sqlite3_snapshot *p1, 10443 sqlite3_snapshot *p2 10444 ); 10445 10446 /* 10447 ** CAPI3REF: Recover snapshots from a wal file 10448 ** METHOD: sqlite3_snapshot 10449 ** 10450 ** If a [WAL file] remains on disk after all database connections close 10451 ** (either through the use of the [SQLITE_FCNTL_PERSIST_WAL] [file control] 10452 ** or because the last process to have the database opened exited without 10453 ** calling [sqlite3_close()]) and a new connection is subsequently opened 10454 ** on that database and [WAL file], the [sqlite3_snapshot_open()] interface 10455 ** will only be able to open the last transaction added to the WAL file 10456 ** even though the WAL file contains other valid transactions. 10457 ** 10458 ** This function attempts to scan the WAL file associated with database zDb 10459 ** of database handle db and make all valid snapshots available to 10460 ** sqlite3_snapshot_open(). It is an error if there is already a read 10461 ** transaction open on the database, or if the database is not a WAL mode 10462 ** database. 10463 ** 10464 ** SQLITE_OK is returned if successful, or an SQLite error code otherwise. 10465 ** 10466 ** This interface is only available if SQLite is compiled with the 10467 ** [SQLITE_ENABLE_SNAPSHOT] option. 10468 */ 10469 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_recover(sqlite3 *db, const char *zDb); 10470 10471 /* 10472 ** CAPI3REF: Serialize a database 10473 ** 10474 ** The sqlite3_serialize(D,S,P,F) interface returns a pointer to memory 10475 ** that is a serialization of the S database on [database connection] D. 10476 ** If P is not a NULL pointer, then the size of the database in bytes 10477 ** is written into *P. 10478 ** 10479 ** For an ordinary on-disk database file, the serialization is just a 10480 ** copy of the disk file. For an in-memory database or a "TEMP" database, 10481 ** the serialization is the same sequence of bytes which would be written 10482 ** to disk if that database where backed up to disk. 10483 ** 10484 ** The usual case is that sqlite3_serialize() copies the serialization of 10485 ** the database into memory obtained from [sqlite3_malloc64()] and returns 10486 ** a pointer to that memory. The caller is responsible for freeing the 10487 ** returned value to avoid a memory leak. However, if the F argument 10488 ** contains the SQLITE_SERIALIZE_NOCOPY bit, then no memory allocations 10489 ** are made, and the sqlite3_serialize() function will return a pointer 10490 ** to the contiguous memory representation of the database that SQLite 10491 ** is currently using for that database, or NULL if the no such contiguous 10492 ** memory representation of the database exists. A contiguous memory 10493 ** representation of the database will usually only exist if there has 10494 ** been a prior call to [sqlite3_deserialize(D,S,...)] with the same 10495 ** values of D and S. 10496 ** The size of the database is written into *P even if the 10497 ** SQLITE_SERIALIZE_NOCOPY bit is set but no contiguous copy 10498 ** of the database exists. 10499 ** 10500 ** A call to sqlite3_serialize(D,S,P,F) might return NULL even if the 10501 ** SQLITE_SERIALIZE_NOCOPY bit is omitted from argument F if a memory 10502 ** allocation error occurs. 10503 ** 10504 ** This interface is omitted if SQLite is compiled with the 10505 ** [SQLITE_OMIT_DESERIALIZE] option. 10506 */ 10507 SQLITE_API unsigned char *sqlite3_serialize( 10508 sqlite3 *db, /* The database connection */ 10509 const char *zSchema, /* Which DB to serialize. ex: "main", "temp", ... */ 10510 sqlite3_int64 *piSize, /* Write size of the DB here, if not NULL */ 10511 unsigned int mFlags /* Zero or more SQLITE_SERIALIZE_* flags */ 10512 ); 10513 10514 /* 10515 ** CAPI3REF: Flags for sqlite3_serialize 10516 ** 10517 ** Zero or more of the following constants can be OR-ed together for 10518 ** the F argument to [sqlite3_serialize(D,S,P,F)]. 10519 ** 10520 ** SQLITE_SERIALIZE_NOCOPY means that [sqlite3_serialize()] will return 10521 ** a pointer to contiguous in-memory database that it is currently using, 10522 ** without making a copy of the database. If SQLite is not currently using 10523 ** a contiguous in-memory database, then this option causes 10524 ** [sqlite3_serialize()] to return a NULL pointer. SQLite will only be 10525 ** using a contiguous in-memory database if it has been initialized by a 10526 ** prior call to [sqlite3_deserialize()]. 10527 */ 10528 #define SQLITE_SERIALIZE_NOCOPY 0x001 /* Do no memory allocations */ 10529 10530 /* 10531 ** CAPI3REF: Deserialize a database 10532 ** 10533 ** The sqlite3_deserialize(D,S,P,N,M,F) interface causes the 10534 ** [database connection] D to disconnect from database S and then 10535 ** reopen S as an in-memory database based on the serialization contained 10536 ** in P. The serialized database P is N bytes in size. M is the size of 10537 ** the buffer P, which might be larger than N. If M is larger than N, and 10538 ** the SQLITE_DESERIALIZE_READONLY bit is not set in F, then SQLite is 10539 ** permitted to add content to the in-memory database as long as the total 10540 ** size does not exceed M bytes. 10541 ** 10542 ** If the SQLITE_DESERIALIZE_FREEONCLOSE bit is set in F, then SQLite will 10543 ** invoke sqlite3_free() on the serialization buffer when the database 10544 ** connection closes. If the SQLITE_DESERIALIZE_RESIZEABLE bit is set, then 10545 ** SQLite will try to increase the buffer size using sqlite3_realloc64() 10546 ** if writes on the database cause it to grow larger than M bytes. 10547 ** 10548 ** The sqlite3_deserialize() interface will fail with SQLITE_BUSY if the 10549 ** database is currently in a read transaction or is involved in a backup 10550 ** operation. 10551 ** 10552 ** It is not possible to deserialized into the TEMP database. If the 10553 ** S argument to sqlite3_deserialize(D,S,P,N,M,F) is "temp" then the 10554 ** function returns SQLITE_ERROR. 10555 ** 10556 ** If sqlite3_deserialize(D,S,P,N,M,F) fails for any reason and if the 10557 ** SQLITE_DESERIALIZE_FREEONCLOSE bit is set in argument F, then 10558 ** [sqlite3_free()] is invoked on argument P prior to returning. 10559 ** 10560 ** This interface is omitted if SQLite is compiled with the 10561 ** [SQLITE_OMIT_DESERIALIZE] option. 10562 */ 10563 SQLITE_API int sqlite3_deserialize( 10564 sqlite3 *db, /* The database connection */ 10565 const char *zSchema, /* Which DB to reopen with the deserialization */ 10566 unsigned char *pData, /* The serialized database content */ 10567 sqlite3_int64 szDb, /* Number bytes in the deserialization */ 10568 sqlite3_int64 szBuf, /* Total size of buffer pData[] */ 10569 unsigned mFlags /* Zero or more SQLITE_DESERIALIZE_* flags */ 10570 ); 10571 10572 /* 10573 ** CAPI3REF: Flags for sqlite3_deserialize() 10574 ** 10575 ** The following are allowed values for 6th argument (the F argument) to 10576 ** the [sqlite3_deserialize(D,S,P,N,M,F)] interface. 10577 ** 10578 ** The SQLITE_DESERIALIZE_FREEONCLOSE means that the database serialization 10579 ** in the P argument is held in memory obtained from [sqlite3_malloc64()] 10580 ** and that SQLite should take ownership of this memory and automatically 10581 ** free it when it has finished using it. Without this flag, the caller 10582 ** is responsible for freeing any dynamically allocated memory. 10583 ** 10584 ** The SQLITE_DESERIALIZE_RESIZEABLE flag means that SQLite is allowed to 10585 ** grow the size of the database using calls to [sqlite3_realloc64()]. This 10586 ** flag should only be used if SQLITE_DESERIALIZE_FREEONCLOSE is also used. 10587 ** Without this flag, the deserialized database cannot increase in size beyond 10588 ** the number of bytes specified by the M parameter. 10589 ** 10590 ** The SQLITE_DESERIALIZE_READONLY flag means that the deserialized database 10591 ** should be treated as read-only. 10592 */ 10593 #define SQLITE_DESERIALIZE_FREEONCLOSE 1 /* Call sqlite3_free() on close */ 10594 #define SQLITE_DESERIALIZE_RESIZEABLE 2 /* Resize using sqlite3_realloc64() */ 10595 #define SQLITE_DESERIALIZE_READONLY 4 /* Database is read-only */ 10596 10597 /* 10598 ** Undo the hack that converts floating point types to integer for 10599 ** builds on processors without floating point support. 10600 */ 10601 #ifdef SQLITE_OMIT_FLOATING_POINT 10602 # undef double 10603 #endif 10604 10605 #if defined(__wasi__) 10606 # undef SQLITE_WASI 10607 # define SQLITE_WASI 1 10608 # undef SQLITE_OMIT_WAL 10609 # define SQLITE_OMIT_WAL 1/* because it requires shared memory APIs */ 10610 # ifndef SQLITE_OMIT_LOAD_EXTENSION 10611 # define SQLITE_OMIT_LOAD_EXTENSION 10612 # endif 10613 # ifndef SQLITE_THREADSAFE 10614 # define SQLITE_THREADSAFE 0 10615 # endif 10616 #endif 10617 10618 #ifdef __cplusplus 10619 } /* End of the 'extern "C"' block */ 10620 #endif 10621 #endif /* SQLITE3_H */ 10622 10623 /******** Begin file sqlite3rtree.h *********/ 10624 /* 10625 ** 2010 August 30 10626 ** 10627 ** The author disclaims copyright to this source code. In place of 10628 ** a legal notice, here is a blessing: 10629 ** 10630 ** May you do good and not evil. 10631 ** May you find forgiveness for yourself and forgive others. 10632 ** May you share freely, never taking more than you give. 10633 ** 10634 ************************************************************************* 10635 */ 10636 10637 #ifndef _SQLITE3RTREE_H_ 10638 #define _SQLITE3RTREE_H_ 10639 10640 10641 #ifdef __cplusplus 10642 extern "C" { 10643 #endif 10644 10645 typedef struct sqlite3_rtree_geometry sqlite3_rtree_geometry; 10646 typedef struct sqlite3_rtree_query_info sqlite3_rtree_query_info; 10647 10648 /* The double-precision datatype used by RTree depends on the 10649 ** SQLITE_RTREE_INT_ONLY compile-time option. 10650 */ 10651 #ifdef SQLITE_RTREE_INT_ONLY 10652 typedef sqlite3_int64 sqlite3_rtree_dbl; 10653 #else 10654 typedef double sqlite3_rtree_dbl; 10655 #endif 10656 10657 /* 10658 ** Register a geometry callback named zGeom that can be used as part of an 10659 ** R-Tree geometry query as follows: 10660 ** 10661 ** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zGeom(... params ...) 10662 */ 10663 SQLITE_API int sqlite3_rtree_geometry_callback( 10664 sqlite3 *db, 10665 const char *zGeom, 10666 int (*xGeom)(sqlite3_rtree_geometry*, int, sqlite3_rtree_dbl*,int*), 10667 void *pContext 10668 ); 10669 10670 10671 /* 10672 ** A pointer to a structure of the following type is passed as the first 10673 ** argument to callbacks registered using rtree_geometry_callback(). 10674 */ 10675 struct sqlite3_rtree_geometry { 10676 void *pContext; /* Copy of pContext passed to s_r_g_c() */ 10677 int nParam; /* Size of array aParam[] */ 10678 sqlite3_rtree_dbl *aParam; /* Parameters passed to SQL geom function */ 10679 void *pUser; /* Callback implementation user data */ 10680 void (*xDelUser)(void *); /* Called by SQLite to clean up pUser */ 10681 }; 10682 10683 /* 10684 ** Register a 2nd-generation geometry callback named zScore that can be 10685 ** used as part of an R-Tree geometry query as follows: 10686 ** 10687 ** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zQueryFunc(... params ...) 10688 */ 10689 SQLITE_API int sqlite3_rtree_query_callback( 10690 sqlite3 *db, 10691 const char *zQueryFunc, 10692 int (*xQueryFunc)(sqlite3_rtree_query_info*), 10693 void *pContext, 10694 void (*xDestructor)(void*) 10695 ); 10696 10697 10698 /* 10699 ** A pointer to a structure of the following type is passed as the 10700 ** argument to scored geometry callback registered using 10701 ** sqlite3_rtree_query_callback(). 10702 ** 10703 ** Note that the first 5 fields of this structure are identical to 10704 ** sqlite3_rtree_geometry. This structure is a subclass of 10705 ** sqlite3_rtree_geometry. 10706 */ 10707 struct sqlite3_rtree_query_info { 10708 void *pContext; /* pContext from when function registered */ 10709 int nParam; /* Number of function parameters */ 10710 sqlite3_rtree_dbl *aParam; /* value of function parameters */ 10711 void *pUser; /* callback can use this, if desired */ 10712 void (*xDelUser)(void*); /* function to free pUser */ 10713 sqlite3_rtree_dbl *aCoord; /* Coordinates of node or entry to check */ 10714 unsigned int *anQueue; /* Number of pending entries in the queue */ 10715 int nCoord; /* Number of coordinates */ 10716 int iLevel; /* Level of current node or entry */ 10717 int mxLevel; /* The largest iLevel value in the tree */ 10718 sqlite3_int64 iRowid; /* Rowid for current entry */ 10719 sqlite3_rtree_dbl rParentScore; /* Score of parent node */ 10720 int eParentWithin; /* Visibility of parent node */ 10721 int eWithin; /* OUT: Visibility */ 10722 sqlite3_rtree_dbl rScore; /* OUT: Write the score here */ 10723 /* The following fields are only available in 3.8.11 and later */ 10724 sqlite3_value **apSqlParam; /* Original SQL values of parameters */ 10725 }; 10726 10727 /* 10728 ** Allowed values for sqlite3_rtree_query.eWithin and .eParentWithin. 10729 */ 10730 #define NOT_WITHIN 0 /* Object completely outside of query region */ 10731 #define PARTLY_WITHIN 1 /* Object partially overlaps query region */ 10732 #define FULLY_WITHIN 2 /* Object fully contained within query region */ 10733 10734 10735 #ifdef __cplusplus 10736 } /* end of the 'extern "C"' block */ 10737 #endif 10738 10739 #endif /* ifndef _SQLITE3RTREE_H_ */ 10740 10741 /******** End of sqlite3rtree.h *********/ 10742 /******** Begin file sqlite3session.h *********/ 10743 10744 #if !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION) 10745 #define __SQLITESESSION_H_ 1 10746 10747 /* 10748 ** Make sure we can call this stuff from C++. 10749 */ 10750 #ifdef __cplusplus 10751 extern "C" { 10752 #endif 10753 10754 10755 /* 10756 ** CAPI3REF: Session Object Handle 10757 ** 10758 ** An instance of this object is a [session] that can be used to 10759 ** record changes to a database. 10760 */ 10761 typedef struct sqlite3_session sqlite3_session; 10762 10763 /* 10764 ** CAPI3REF: Changeset Iterator Handle 10765 ** 10766 ** An instance of this object acts as a cursor for iterating 10767 ** over the elements of a [changeset] or [patchset]. 10768 */ 10769 typedef struct sqlite3_changeset_iter sqlite3_changeset_iter; 10770 10771 /* 10772 ** CAPI3REF: Create A New Session Object 10773 ** CONSTRUCTOR: sqlite3_session 10774 ** 10775 ** Create a new session object attached to database handle db. If successful, 10776 ** a pointer to the new object is written to *ppSession and SQLITE_OK is 10777 ** returned. If an error occurs, *ppSession is set to NULL and an SQLite 10778 ** error code (e.g. SQLITE_NOMEM) is returned. 10779 ** 10780 ** It is possible to create multiple session objects attached to a single 10781 ** database handle. 10782 ** 10783 ** Session objects created using this function should be deleted using the 10784 ** [sqlite3session_delete()] function before the database handle that they 10785 ** are attached to is itself closed. If the database handle is closed before 10786 ** the session object is deleted, then the results of calling any session 10787 ** module function, including [sqlite3session_delete()] on the session object 10788 ** are undefined. 10789 ** 10790 ** Because the session module uses the [sqlite3_preupdate_hook()] API, it 10791 ** is not possible for an application to register a pre-update hook on a 10792 ** database handle that has one or more session objects attached. Nor is 10793 ** it possible to create a session object attached to a database handle for 10794 ** which a pre-update hook is already defined. The results of attempting 10795 ** either of these things are undefined. 10796 ** 10797 ** The session object will be used to create changesets for tables in 10798 ** database zDb, where zDb is either "main", or "temp", or the name of an 10799 ** attached database. It is not an error if database zDb is not attached 10800 ** to the database when the session object is created. 10801 */ 10802 SQLITE_API int sqlite3session_create( 10803 sqlite3 *db, /* Database handle */ 10804 const char *zDb, /* Name of db (e.g. "main") */ 10805 sqlite3_session **ppSession /* OUT: New session object */ 10806 ); 10807 10808 /* 10809 ** CAPI3REF: Delete A Session Object 10810 ** DESTRUCTOR: sqlite3_session 10811 ** 10812 ** Delete a session object previously allocated using 10813 ** [sqlite3session_create()]. Once a session object has been deleted, the 10814 ** results of attempting to use pSession with any other session module 10815 ** function are undefined. 10816 ** 10817 ** Session objects must be deleted before the database handle to which they 10818 ** are attached is closed. Refer to the documentation for 10819 ** [sqlite3session_create()] for details. 10820 */ 10821 SQLITE_API void sqlite3session_delete(sqlite3_session *pSession); 10822 10823 /* 10824 ** CAPI3REF: Configure a Session Object 10825 ** METHOD: sqlite3_session 10826 ** 10827 ** This method is used to configure a session object after it has been 10828 ** created. At present the only valid values for the second parameter are 10829 ** [SQLITE_SESSION_OBJCONFIG_SIZE] and [SQLITE_SESSION_OBJCONFIG_ROWID]. 10830 ** 10831 */ 10832 SQLITE_API int sqlite3session_object_config(sqlite3_session*, int op, void *pArg); 10833 10834 /* 10835 ** CAPI3REF: Options for sqlite3session_object_config 10836 ** 10837 ** The following values may passed as the the 2nd parameter to 10838 ** sqlite3session_object_config(). 10839 ** 10840 ** <dt>SQLITE_SESSION_OBJCONFIG_SIZE <dd> 10841 ** This option is used to set, clear or query the flag that enables 10842 ** the [sqlite3session_changeset_size()] API. Because it imposes some 10843 ** computational overhead, this API is disabled by default. Argument 10844 ** pArg must point to a value of type (int). If the value is initially 10845 ** 0, then the sqlite3session_changeset_size() API is disabled. If it 10846 ** is greater than 0, then the same API is enabled. Or, if the initial 10847 ** value is less than zero, no change is made. In all cases the (int) 10848 ** variable is set to 1 if the sqlite3session_changeset_size() API is 10849 ** enabled following the current call, or 0 otherwise. 10850 ** 10851 ** It is an error (SQLITE_MISUSE) to attempt to modify this setting after 10852 ** the first table has been attached to the session object. 10853 ** 10854 ** <dt>SQLITE_SESSION_OBJCONFIG_ROWID <dd> 10855 ** This option is used to set, clear or query the flag that enables 10856 ** collection of data for tables with no explicit PRIMARY KEY. 10857 ** 10858 ** Normally, tables with no explicit PRIMARY KEY are simply ignored 10859 ** by the sessions module. However, if this flag is set, it behaves 10860 ** as if such tables have a column "_rowid_ INTEGER PRIMARY KEY" inserted 10861 ** as their leftmost columns. 10862 ** 10863 ** It is an error (SQLITE_MISUSE) to attempt to modify this setting after 10864 ** the first table has been attached to the session object. 10865 */ 10866 #define SQLITE_SESSION_OBJCONFIG_SIZE 1 10867 #define SQLITE_SESSION_OBJCONFIG_ROWID 2 10868 10869 /* 10870 ** CAPI3REF: Enable Or Disable A Session Object 10871 ** METHOD: sqlite3_session 10872 ** 10873 ** Enable or disable the recording of changes by a session object. When 10874 ** enabled, a session object records changes made to the database. When 10875 ** disabled - it does not. A newly created session object is enabled. 10876 ** Refer to the documentation for [sqlite3session_changeset()] for further 10877 ** details regarding how enabling and disabling a session object affects 10878 ** the eventual changesets. 10879 ** 10880 ** Passing zero to this function disables the session. Passing a value 10881 ** greater than zero enables it. Passing a value less than zero is a 10882 ** no-op, and may be used to query the current state of the session. 10883 ** 10884 ** The return value indicates the final state of the session object: 0 if 10885 ** the session is disabled, or 1 if it is enabled. 10886 */ 10887 SQLITE_API int sqlite3session_enable(sqlite3_session *pSession, int bEnable); 10888 10889 /* 10890 ** CAPI3REF: Set Or Clear the Indirect Change Flag 10891 ** METHOD: sqlite3_session 10892 ** 10893 ** Each change recorded by a session object is marked as either direct or 10894 ** indirect. A change is marked as indirect if either: 10895 ** 10896 ** <ul> 10897 ** <li> The session object "indirect" flag is set when the change is 10898 ** made, or 10899 ** <li> The change is made by an SQL trigger or foreign key action 10900 ** instead of directly as a result of a users SQL statement. 10901 ** </ul> 10902 ** 10903 ** If a single row is affected by more than one operation within a session, 10904 ** then the change is considered indirect if all operations meet the criteria 10905 ** for an indirect change above, or direct otherwise. 10906 ** 10907 ** This function is used to set, clear or query the session object indirect 10908 ** flag. If the second argument passed to this function is zero, then the 10909 ** indirect flag is cleared. If it is greater than zero, the indirect flag 10910 ** is set. Passing a value less than zero does not modify the current value 10911 ** of the indirect flag, and may be used to query the current state of the 10912 ** indirect flag for the specified session object. 10913 ** 10914 ** The return value indicates the final state of the indirect flag: 0 if 10915 ** it is clear, or 1 if it is set. 10916 */ 10917 SQLITE_API int sqlite3session_indirect(sqlite3_session *pSession, int bIndirect); 10918 10919 /* 10920 ** CAPI3REF: Attach A Table To A Session Object 10921 ** METHOD: sqlite3_session 10922 ** 10923 ** If argument zTab is not NULL, then it is the name of a table to attach 10924 ** to the session object passed as the first argument. All subsequent changes 10925 ** made to the table while the session object is enabled will be recorded. See 10926 ** documentation for [sqlite3session_changeset()] for further details. 10927 ** 10928 ** Or, if argument zTab is NULL, then changes are recorded for all tables 10929 ** in the database. If additional tables are added to the database (by 10930 ** executing "CREATE TABLE" statements) after this call is made, changes for 10931 ** the new tables are also recorded. 10932 ** 10933 ** Changes can only be recorded for tables that have a PRIMARY KEY explicitly 10934 ** defined as part of their CREATE TABLE statement. It does not matter if the 10935 ** PRIMARY KEY is an "INTEGER PRIMARY KEY" (rowid alias) or not. The PRIMARY 10936 ** KEY may consist of a single column, or may be a composite key. 10937 ** 10938 ** It is not an error if the named table does not exist in the database. Nor 10939 ** is it an error if the named table does not have a PRIMARY KEY. However, 10940 ** no changes will be recorded in either of these scenarios. 10941 ** 10942 ** Changes are not recorded for individual rows that have NULL values stored 10943 ** in one or more of their PRIMARY KEY columns. 10944 ** 10945 ** SQLITE_OK is returned if the call completes without error. Or, if an error 10946 ** occurs, an SQLite error code (e.g. SQLITE_NOMEM) is returned. 10947 ** 10948 ** <h3>Special sqlite_stat1 Handling</h3> 10949 ** 10950 ** As of SQLite version 3.22.0, the "sqlite_stat1" table is an exception to 10951 ** some of the rules above. In SQLite, the schema of sqlite_stat1 is: 10952 ** <pre> 10953 ** CREATE TABLE sqlite_stat1(tbl,idx,stat) 10954 ** </pre> 10955 ** 10956 ** Even though sqlite_stat1 does not have a PRIMARY KEY, changes are 10957 ** recorded for it as if the PRIMARY KEY is (tbl,idx). Additionally, changes 10958 ** are recorded for rows for which (idx IS NULL) is true. However, for such 10959 ** rows a zero-length blob (SQL value X'') is stored in the changeset or 10960 ** patchset instead of a NULL value. This allows such changesets to be 10961 ** manipulated by legacy implementations of sqlite3changeset_invert(), 10962 ** concat() and similar. 10963 ** 10964 ** The sqlite3changeset_apply() function automatically converts the 10965 ** zero-length blob back to a NULL value when updating the sqlite_stat1 10966 ** table. However, if the application calls sqlite3changeset_new(), 10967 ** sqlite3changeset_old() or sqlite3changeset_conflict on a changeset 10968 ** iterator directly (including on a changeset iterator passed to a 10969 ** conflict-handler callback) then the X'' value is returned. The application 10970 ** must translate X'' to NULL itself if required. 10971 ** 10972 ** Legacy (older than 3.22.0) versions of the sessions module cannot capture 10973 ** changes made to the sqlite_stat1 table. Legacy versions of the 10974 ** sqlite3changeset_apply() function silently ignore any modifications to the 10975 ** sqlite_stat1 table that are part of a changeset or patchset. 10976 */ 10977 SQLITE_API int sqlite3session_attach( 10978 sqlite3_session *pSession, /* Session object */ 10979 const char *zTab /* Table name */ 10980 ); 10981 10982 /* 10983 ** CAPI3REF: Set a table filter on a Session Object. 10984 ** METHOD: sqlite3_session 10985 ** 10986 ** The second argument (xFilter) is the "filter callback". For changes to rows 10987 ** in tables that are not attached to the Session object, the filter is called 10988 ** to determine whether changes to the table's rows should be tracked or not. 10989 ** If xFilter returns 0, changes are not tracked. Note that once a table is 10990 ** attached, xFilter will not be called again. 10991 */ 10992 SQLITE_API void sqlite3session_table_filter( 10993 sqlite3_session *pSession, /* Session object */ 10994 int(*xFilter)( 10995 void *pCtx, /* Copy of third arg to _filter_table() */ 10996 const char *zTab /* Table name */ 10997 ), 10998 void *pCtx /* First argument passed to xFilter */ 10999 ); 11000 11001 /* 11002 ** CAPI3REF: Generate A Changeset From A Session Object 11003 ** METHOD: sqlite3_session 11004 ** 11005 ** Obtain a changeset containing changes to the tables attached to the 11006 ** session object passed as the first argument. If successful, 11007 ** set *ppChangeset to point to a buffer containing the changeset 11008 ** and *pnChangeset to the size of the changeset in bytes before returning 11009 ** SQLITE_OK. If an error occurs, set both *ppChangeset and *pnChangeset to 11010 ** zero and return an SQLite error code. 11011 ** 11012 ** A changeset consists of zero or more INSERT, UPDATE and/or DELETE changes, 11013 ** each representing a change to a single row of an attached table. An INSERT 11014 ** change contains the values of each field of a new database row. A DELETE 11015 ** contains the original values of each field of a deleted database row. An 11016 ** UPDATE change contains the original values of each field of an updated 11017 ** database row along with the updated values for each updated non-primary-key 11018 ** column. It is not possible for an UPDATE change to represent a change that 11019 ** modifies the values of primary key columns. If such a change is made, it 11020 ** is represented in a changeset as a DELETE followed by an INSERT. 11021 ** 11022 ** Changes are not recorded for rows that have NULL values stored in one or 11023 ** more of their PRIMARY KEY columns. If such a row is inserted or deleted, 11024 ** no corresponding change is present in the changesets returned by this 11025 ** function. If an existing row with one or more NULL values stored in 11026 ** PRIMARY KEY columns is updated so that all PRIMARY KEY columns are non-NULL, 11027 ** only an INSERT is appears in the changeset. Similarly, if an existing row 11028 ** with non-NULL PRIMARY KEY values is updated so that one or more of its 11029 ** PRIMARY KEY columns are set to NULL, the resulting changeset contains a 11030 ** DELETE change only. 11031 ** 11032 ** The contents of a changeset may be traversed using an iterator created 11033 ** using the [sqlite3changeset_start()] API. A changeset may be applied to 11034 ** a database with a compatible schema using the [sqlite3changeset_apply()] 11035 ** API. 11036 ** 11037 ** Within a changeset generated by this function, all changes related to a 11038 ** single table are grouped together. In other words, when iterating through 11039 ** a changeset or when applying a changeset to a database, all changes related 11040 ** to a single table are processed before moving on to the next table. Tables 11041 ** are sorted in the same order in which they were attached (or auto-attached) 11042 ** to the sqlite3_session object. The order in which the changes related to 11043 ** a single table are stored is undefined. 11044 ** 11045 ** Following a successful call to this function, it is the responsibility of 11046 ** the caller to eventually free the buffer that *ppChangeset points to using 11047 ** [sqlite3_free()]. 11048 ** 11049 ** <h3>Changeset Generation</h3> 11050 ** 11051 ** Once a table has been attached to a session object, the session object 11052 ** records the primary key values of all new rows inserted into the table. 11053 ** It also records the original primary key and other column values of any 11054 ** deleted or updated rows. For each unique primary key value, data is only 11055 ** recorded once - the first time a row with said primary key is inserted, 11056 ** updated or deleted in the lifetime of the session. 11057 ** 11058 ** There is one exception to the previous paragraph: when a row is inserted, 11059 ** updated or deleted, if one or more of its primary key columns contain a 11060 ** NULL value, no record of the change is made. 11061 ** 11062 ** The session object therefore accumulates two types of records - those 11063 ** that consist of primary key values only (created when the user inserts 11064 ** a new record) and those that consist of the primary key values and the 11065 ** original values of other table columns (created when the users deletes 11066 ** or updates a record). 11067 ** 11068 ** When this function is called, the requested changeset is created using 11069 ** both the accumulated records and the current contents of the database 11070 ** file. Specifically: 11071 ** 11072 ** <ul> 11073 ** <li> For each record generated by an insert, the database is queried 11074 ** for a row with a matching primary key. If one is found, an INSERT 11075 ** change is added to the changeset. If no such row is found, no change 11076 ** is added to the changeset. 11077 ** 11078 ** <li> For each record generated by an update or delete, the database is 11079 ** queried for a row with a matching primary key. If such a row is 11080 ** found and one or more of the non-primary key fields have been 11081 ** modified from their original values, an UPDATE change is added to 11082 ** the changeset. Or, if no such row is found in the table, a DELETE 11083 ** change is added to the changeset. If there is a row with a matching 11084 ** primary key in the database, but all fields contain their original 11085 ** values, no change is added to the changeset. 11086 ** </ul> 11087 ** 11088 ** This means, amongst other things, that if a row is inserted and then later 11089 ** deleted while a session object is active, neither the insert nor the delete 11090 ** will be present in the changeset. Or if a row is deleted and then later a 11091 ** row with the same primary key values inserted while a session object is 11092 ** active, the resulting changeset will contain an UPDATE change instead of 11093 ** a DELETE and an INSERT. 11094 ** 11095 ** When a session object is disabled (see the [sqlite3session_enable()] API), 11096 ** it does not accumulate records when rows are inserted, updated or deleted. 11097 ** This may appear to have some counter-intuitive effects if a single row 11098 ** is written to more than once during a session. For example, if a row 11099 ** is inserted while a session object is enabled, then later deleted while 11100 ** the same session object is disabled, no INSERT record will appear in the 11101 ** changeset, even though the delete took place while the session was disabled. 11102 ** Or, if one field of a row is updated while a session is disabled, and 11103 ** another field of the same row is updated while the session is enabled, the 11104 ** resulting changeset will contain an UPDATE change that updates both fields. 11105 */ 11106 SQLITE_API int sqlite3session_changeset( 11107 sqlite3_session *pSession, /* Session object */ 11108 int *pnChangeset, /* OUT: Size of buffer at *ppChangeset */ 11109 void **ppChangeset /* OUT: Buffer containing changeset */ 11110 ); 11111 11112 /* 11113 ** CAPI3REF: Return An Upper-limit For The Size Of The Changeset 11114 ** METHOD: sqlite3_session 11115 ** 11116 ** By default, this function always returns 0. For it to return 11117 ** a useful result, the sqlite3_session object must have been configured 11118 ** to enable this API using sqlite3session_object_config() with the 11119 ** SQLITE_SESSION_OBJCONFIG_SIZE verb. 11120 ** 11121 ** When enabled, this function returns an upper limit, in bytes, for the size 11122 ** of the changeset that might be produced if sqlite3session_changeset() were 11123 ** called. The final changeset size might be equal to or smaller than the 11124 ** size in bytes returned by this function. 11125 */ 11126 SQLITE_API sqlite3_int64 sqlite3session_changeset_size(sqlite3_session *pSession); 11127 11128 /* 11129 ** CAPI3REF: Load The Difference Between Tables Into A Session 11130 ** METHOD: sqlite3_session 11131 ** 11132 ** If it is not already attached to the session object passed as the first 11133 ** argument, this function attaches table zTbl in the same manner as the 11134 ** [sqlite3session_attach()] function. If zTbl does not exist, or if it 11135 ** does not have a primary key, this function is a no-op (but does not return 11136 ** an error). 11137 ** 11138 ** Argument zFromDb must be the name of a database ("main", "temp" etc.) 11139 ** attached to the same database handle as the session object that contains 11140 ** a table compatible with the table attached to the session by this function. 11141 ** A table is considered compatible if it: 11142 ** 11143 ** <ul> 11144 ** <li> Has the same name, 11145 ** <li> Has the same set of columns declared in the same order, and 11146 ** <li> Has the same PRIMARY KEY definition. 11147 ** </ul> 11148 ** 11149 ** If the tables are not compatible, SQLITE_SCHEMA is returned. If the tables 11150 ** are compatible but do not have any PRIMARY KEY columns, it is not an error 11151 ** but no changes are added to the session object. As with other session 11152 ** APIs, tables without PRIMARY KEYs are simply ignored. 11153 ** 11154 ** This function adds a set of changes to the session object that could be 11155 ** used to update the table in database zFrom (call this the "from-table") 11156 ** so that its content is the same as the table attached to the session 11157 ** object (call this the "to-table"). Specifically: 11158 ** 11159 ** <ul> 11160 ** <li> For each row (primary key) that exists in the to-table but not in 11161 ** the from-table, an INSERT record is added to the session object. 11162 ** 11163 ** <li> For each row (primary key) that exists in the to-table but not in 11164 ** the from-table, a DELETE record is added to the session object. 11165 ** 11166 ** <li> For each row (primary key) that exists in both tables, but features 11167 ** different non-PK values in each, an UPDATE record is added to the 11168 ** session. 11169 ** </ul> 11170 ** 11171 ** To clarify, if this function is called and then a changeset constructed 11172 ** using [sqlite3session_changeset()], then after applying that changeset to 11173 ** database zFrom the contents of the two compatible tables would be 11174 ** identical. 11175 ** 11176 ** It an error if database zFrom does not exist or does not contain the 11177 ** required compatible table. 11178 ** 11179 ** If the operation is successful, SQLITE_OK is returned. Otherwise, an SQLite 11180 ** error code. In this case, if argument pzErrMsg is not NULL, *pzErrMsg 11181 ** may be set to point to a buffer containing an English language error 11182 ** message. It is the responsibility of the caller to free this buffer using 11183 ** sqlite3_free(). 11184 */ 11185 SQLITE_API int sqlite3session_diff( 11186 sqlite3_session *pSession, 11187 const char *zFromDb, 11188 const char *zTbl, 11189 char **pzErrMsg 11190 ); 11191 11192 11193 /* 11194 ** CAPI3REF: Generate A Patchset From A Session Object 11195 ** METHOD: sqlite3_session 11196 ** 11197 ** The differences between a patchset and a changeset are that: 11198 ** 11199 ** <ul> 11200 ** <li> DELETE records consist of the primary key fields only. The 11201 ** original values of other fields are omitted. 11202 ** <li> The original values of any modified fields are omitted from 11203 ** UPDATE records. 11204 ** </ul> 11205 ** 11206 ** A patchset blob may be used with up to date versions of all 11207 ** sqlite3changeset_xxx API functions except for sqlite3changeset_invert(), 11208 ** which returns SQLITE_CORRUPT if it is passed a patchset. Similarly, 11209 ** attempting to use a patchset blob with old versions of the 11210 ** sqlite3changeset_xxx APIs also provokes an SQLITE_CORRUPT error. 11211 ** 11212 ** Because the non-primary key "old.*" fields are omitted, no 11213 ** SQLITE_CHANGESET_DATA conflicts can be detected or reported if a patchset 11214 ** is passed to the sqlite3changeset_apply() API. Other conflict types work 11215 ** in the same way as for changesets. 11216 ** 11217 ** Changes within a patchset are ordered in the same way as for changesets 11218 ** generated by the sqlite3session_changeset() function (i.e. all changes for 11219 ** a single table are grouped together, tables appear in the order in which 11220 ** they were attached to the session object). 11221 */ 11222 SQLITE_API int sqlite3session_patchset( 11223 sqlite3_session *pSession, /* Session object */ 11224 int *pnPatchset, /* OUT: Size of buffer at *ppPatchset */ 11225 void **ppPatchset /* OUT: Buffer containing patchset */ 11226 ); 11227 11228 /* 11229 ** CAPI3REF: Test if a changeset has recorded any changes. 11230 ** 11231 ** Return non-zero if no changes to attached tables have been recorded by 11232 ** the session object passed as the first argument. Otherwise, if one or 11233 ** more changes have been recorded, return zero. 11234 ** 11235 ** Even if this function returns zero, it is possible that calling 11236 ** [sqlite3session_changeset()] on the session handle may still return a 11237 ** changeset that contains no changes. This can happen when a row in 11238 ** an attached table is modified and then later on the original values 11239 ** are restored. However, if this function returns non-zero, then it is 11240 ** guaranteed that a call to sqlite3session_changeset() will return a 11241 ** changeset containing zero changes. 11242 */ 11243 SQLITE_API int sqlite3session_isempty(sqlite3_session *pSession); 11244 11245 /* 11246 ** CAPI3REF: Query for the amount of heap memory used by a session object. 11247 ** 11248 ** This API returns the total amount of heap memory in bytes currently 11249 ** used by the session object passed as the only argument. 11250 */ 11251 SQLITE_API sqlite3_int64 sqlite3session_memory_used(sqlite3_session *pSession); 11252 11253 /* 11254 ** CAPI3REF: Create An Iterator To Traverse A Changeset 11255 ** CONSTRUCTOR: sqlite3_changeset_iter 11256 ** 11257 ** Create an iterator used to iterate through the contents of a changeset. 11258 ** If successful, *pp is set to point to the iterator handle and SQLITE_OK 11259 ** is returned. Otherwise, if an error occurs, *pp is set to zero and an 11260 ** SQLite error code is returned. 11261 ** 11262 ** The following functions can be used to advance and query a changeset 11263 ** iterator created by this function: 11264 ** 11265 ** <ul> 11266 ** <li> [sqlite3changeset_next()] 11267 ** <li> [sqlite3changeset_op()] 11268 ** <li> [sqlite3changeset_new()] 11269 ** <li> [sqlite3changeset_old()] 11270 ** </ul> 11271 ** 11272 ** It is the responsibility of the caller to eventually destroy the iterator 11273 ** by passing it to [sqlite3changeset_finalize()]. The buffer containing the 11274 ** changeset (pChangeset) must remain valid until after the iterator is 11275 ** destroyed. 11276 ** 11277 ** Assuming the changeset blob was created by one of the 11278 ** [sqlite3session_changeset()], [sqlite3changeset_concat()] or 11279 ** [sqlite3changeset_invert()] functions, all changes within the changeset 11280 ** that apply to a single table are grouped together. This means that when 11281 ** an application iterates through a changeset using an iterator created by 11282 ** this function, all changes that relate to a single table are visited 11283 ** consecutively. There is no chance that the iterator will visit a change 11284 ** the applies to table X, then one for table Y, and then later on visit 11285 ** another change for table X. 11286 ** 11287 ** The behavior of sqlite3changeset_start_v2() and its streaming equivalent 11288 ** may be modified by passing a combination of 11289 ** [SQLITE_CHANGESETSTART_INVERT | supported flags] as the 4th parameter. 11290 ** 11291 ** Note that the sqlite3changeset_start_v2() API is still <b>experimental</b> 11292 ** and therefore subject to change. 11293 */ 11294 SQLITE_API int sqlite3changeset_start( 11295 sqlite3_changeset_iter **pp, /* OUT: New changeset iterator handle */ 11296 int nChangeset, /* Size of changeset blob in bytes */ 11297 void *pChangeset /* Pointer to blob containing changeset */ 11298 ); 11299 SQLITE_API int sqlite3changeset_start_v2( 11300 sqlite3_changeset_iter **pp, /* OUT: New changeset iterator handle */ 11301 int nChangeset, /* Size of changeset blob in bytes */ 11302 void *pChangeset, /* Pointer to blob containing changeset */ 11303 int flags /* SESSION_CHANGESETSTART_* flags */ 11304 ); 11305 11306 /* 11307 ** CAPI3REF: Flags for sqlite3changeset_start_v2 11308 ** 11309 ** The following flags may passed via the 4th parameter to 11310 ** [sqlite3changeset_start_v2] and [sqlite3changeset_start_v2_strm]: 11311 ** 11312 ** <dt>SQLITE_CHANGESETAPPLY_INVERT <dd> 11313 ** Invert the changeset while iterating through it. This is equivalent to 11314 ** inverting a changeset using sqlite3changeset_invert() before applying it. 11315 ** It is an error to specify this flag with a patchset. 11316 */ 11317 #define SQLITE_CHANGESETSTART_INVERT 0x0002 11318 11319 11320 /* 11321 ** CAPI3REF: Advance A Changeset Iterator 11322 ** METHOD: sqlite3_changeset_iter 11323 ** 11324 ** This function may only be used with iterators created by the function 11325 ** [sqlite3changeset_start()]. If it is called on an iterator passed to 11326 ** a conflict-handler callback by [sqlite3changeset_apply()], SQLITE_MISUSE 11327 ** is returned and the call has no effect. 11328 ** 11329 ** Immediately after an iterator is created by sqlite3changeset_start(), it 11330 ** does not point to any change in the changeset. Assuming the changeset 11331 ** is not empty, the first call to this function advances the iterator to 11332 ** point to the first change in the changeset. Each subsequent call advances 11333 ** the iterator to point to the next change in the changeset (if any). If 11334 ** no error occurs and the iterator points to a valid change after a call 11335 ** to sqlite3changeset_next() has advanced it, SQLITE_ROW is returned. 11336 ** Otherwise, if all changes in the changeset have already been visited, 11337 ** SQLITE_DONE is returned. 11338 ** 11339 ** If an error occurs, an SQLite error code is returned. Possible error 11340 ** codes include SQLITE_CORRUPT (if the changeset buffer is corrupt) or 11341 ** SQLITE_NOMEM. 11342 */ 11343 SQLITE_API int sqlite3changeset_next(sqlite3_changeset_iter *pIter); 11344 11345 /* 11346 ** CAPI3REF: Obtain The Current Operation From A Changeset Iterator 11347 ** METHOD: sqlite3_changeset_iter 11348 ** 11349 ** The pIter argument passed to this function may either be an iterator 11350 ** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator 11351 ** created by [sqlite3changeset_start()]. In the latter case, the most recent 11352 ** call to [sqlite3changeset_next()] must have returned [SQLITE_ROW]. If this 11353 ** is not the case, this function returns [SQLITE_MISUSE]. 11354 ** 11355 ** Arguments pOp, pnCol and pzTab may not be NULL. Upon return, three 11356 ** outputs are set through these pointers: 11357 ** 11358 ** *pOp is set to one of [SQLITE_INSERT], [SQLITE_DELETE] or [SQLITE_UPDATE], 11359 ** depending on the type of change that the iterator currently points to; 11360 ** 11361 ** *pnCol is set to the number of columns in the table affected by the change; and 11362 ** 11363 ** *pzTab is set to point to a nul-terminated utf-8 encoded string containing 11364 ** the name of the table affected by the current change. The buffer remains 11365 ** valid until either sqlite3changeset_next() is called on the iterator 11366 ** or until the conflict-handler function returns. 11367 ** 11368 ** If pbIndirect is not NULL, then *pbIndirect is set to true (1) if the change 11369 ** is an indirect change, or false (0) otherwise. See the documentation for 11370 ** [sqlite3session_indirect()] for a description of direct and indirect 11371 ** changes. 11372 ** 11373 ** If no error occurs, SQLITE_OK is returned. If an error does occur, an 11374 ** SQLite error code is returned. The values of the output variables may not 11375 ** be trusted in this case. 11376 */ 11377 SQLITE_API int sqlite3changeset_op( 11378 sqlite3_changeset_iter *pIter, /* Iterator object */ 11379 const char **pzTab, /* OUT: Pointer to table name */ 11380 int *pnCol, /* OUT: Number of columns in table */ 11381 int *pOp, /* OUT: SQLITE_INSERT, DELETE or UPDATE */ 11382 int *pbIndirect /* OUT: True for an 'indirect' change */ 11383 ); 11384 11385 /* 11386 ** CAPI3REF: Obtain The Primary Key Definition Of A Table 11387 ** METHOD: sqlite3_changeset_iter 11388 ** 11389 ** For each modified table, a changeset includes the following: 11390 ** 11391 ** <ul> 11392 ** <li> The number of columns in the table, and 11393 ** <li> Which of those columns make up the tables PRIMARY KEY. 11394 ** </ul> 11395 ** 11396 ** This function is used to find which columns comprise the PRIMARY KEY of 11397 ** the table modified by the change that iterator pIter currently points to. 11398 ** If successful, *pabPK is set to point to an array of nCol entries, where 11399 ** nCol is the number of columns in the table. Elements of *pabPK are set to 11400 ** 0x01 if the corresponding column is part of the tables primary key, or 11401 ** 0x00 if it is not. 11402 ** 11403 ** If argument pnCol is not NULL, then *pnCol is set to the number of columns 11404 ** in the table. 11405 ** 11406 ** If this function is called when the iterator does not point to a valid 11407 ** entry, SQLITE_MISUSE is returned and the output variables zeroed. Otherwise, 11408 ** SQLITE_OK is returned and the output variables populated as described 11409 ** above. 11410 */ 11411 SQLITE_API int sqlite3changeset_pk( 11412 sqlite3_changeset_iter *pIter, /* Iterator object */ 11413 unsigned char **pabPK, /* OUT: Array of boolean - true for PK cols */ 11414 int *pnCol /* OUT: Number of entries in output array */ 11415 ); 11416 11417 /* 11418 ** CAPI3REF: Obtain old.* Values From A Changeset Iterator 11419 ** METHOD: sqlite3_changeset_iter 11420 ** 11421 ** The pIter argument passed to this function may either be an iterator 11422 ** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator 11423 ** created by [sqlite3changeset_start()]. In the latter case, the most recent 11424 ** call to [sqlite3changeset_next()] must have returned SQLITE_ROW. 11425 ** Furthermore, it may only be called if the type of change that the iterator 11426 ** currently points to is either [SQLITE_DELETE] or [SQLITE_UPDATE]. Otherwise, 11427 ** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL. 11428 ** 11429 ** Argument iVal must be greater than or equal to 0, and less than the number 11430 ** of columns in the table affected by the current change. Otherwise, 11431 ** [SQLITE_RANGE] is returned and *ppValue is set to NULL. 11432 ** 11433 ** If successful, this function sets *ppValue to point to a protected 11434 ** sqlite3_value object containing the iVal'th value from the vector of 11435 ** original row values stored as part of the UPDATE or DELETE change and 11436 ** returns SQLITE_OK. The name of the function comes from the fact that this 11437 ** is similar to the "old.*" columns available to update or delete triggers. 11438 ** 11439 ** If some other error occurs (e.g. an OOM condition), an SQLite error code 11440 ** is returned and *ppValue is set to NULL. 11441 */ 11442 SQLITE_API int sqlite3changeset_old( 11443 sqlite3_changeset_iter *pIter, /* Changeset iterator */ 11444 int iVal, /* Column number */ 11445 sqlite3_value **ppValue /* OUT: Old value (or NULL pointer) */ 11446 ); 11447 11448 /* 11449 ** CAPI3REF: Obtain new.* Values From A Changeset Iterator 11450 ** METHOD: sqlite3_changeset_iter 11451 ** 11452 ** The pIter argument passed to this function may either be an iterator 11453 ** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator 11454 ** created by [sqlite3changeset_start()]. In the latter case, the most recent 11455 ** call to [sqlite3changeset_next()] must have returned SQLITE_ROW. 11456 ** Furthermore, it may only be called if the type of change that the iterator 11457 ** currently points to is either [SQLITE_UPDATE] or [SQLITE_INSERT]. Otherwise, 11458 ** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL. 11459 ** 11460 ** Argument iVal must be greater than or equal to 0, and less than the number 11461 ** of columns in the table affected by the current change. Otherwise, 11462 ** [SQLITE_RANGE] is returned and *ppValue is set to NULL. 11463 ** 11464 ** If successful, this function sets *ppValue to point to a protected 11465 ** sqlite3_value object containing the iVal'th value from the vector of 11466 ** new row values stored as part of the UPDATE or INSERT change and 11467 ** returns SQLITE_OK. If the change is an UPDATE and does not include 11468 ** a new value for the requested column, *ppValue is set to NULL and 11469 ** SQLITE_OK returned. The name of the function comes from the fact that 11470 ** this is similar to the "new.*" columns available to update or delete 11471 ** triggers. 11472 ** 11473 ** If some other error occurs (e.g. an OOM condition), an SQLite error code 11474 ** is returned and *ppValue is set to NULL. 11475 */ 11476 SQLITE_API int sqlite3changeset_new( 11477 sqlite3_changeset_iter *pIter, /* Changeset iterator */ 11478 int iVal, /* Column number */ 11479 sqlite3_value **ppValue /* OUT: New value (or NULL pointer) */ 11480 ); 11481 11482 /* 11483 ** CAPI3REF: Obtain Conflicting Row Values From A Changeset Iterator 11484 ** METHOD: sqlite3_changeset_iter 11485 ** 11486 ** This function should only be used with iterator objects passed to a 11487 ** conflict-handler callback by [sqlite3changeset_apply()] with either 11488 ** [SQLITE_CHANGESET_DATA] or [SQLITE_CHANGESET_CONFLICT]. If this function 11489 ** is called on any other iterator, [SQLITE_MISUSE] is returned and *ppValue 11490 ** is set to NULL. 11491 ** 11492 ** Argument iVal must be greater than or equal to 0, and less than the number 11493 ** of columns in the table affected by the current change. Otherwise, 11494 ** [SQLITE_RANGE] is returned and *ppValue is set to NULL. 11495 ** 11496 ** If successful, this function sets *ppValue to point to a protected 11497 ** sqlite3_value object containing the iVal'th value from the 11498 ** "conflicting row" associated with the current conflict-handler callback 11499 ** and returns SQLITE_OK. 11500 ** 11501 ** If some other error occurs (e.g. an OOM condition), an SQLite error code 11502 ** is returned and *ppValue is set to NULL. 11503 */ 11504 SQLITE_API int sqlite3changeset_conflict( 11505 sqlite3_changeset_iter *pIter, /* Changeset iterator */ 11506 int iVal, /* Column number */ 11507 sqlite3_value **ppValue /* OUT: Value from conflicting row */ 11508 ); 11509 11510 /* 11511 ** CAPI3REF: Determine The Number Of Foreign Key Constraint Violations 11512 ** METHOD: sqlite3_changeset_iter 11513 ** 11514 ** This function may only be called with an iterator passed to an 11515 ** SQLITE_CHANGESET_FOREIGN_KEY conflict handler callback. In this case 11516 ** it sets the output variable to the total number of known foreign key 11517 ** violations in the destination database and returns SQLITE_OK. 11518 ** 11519 ** In all other cases this function returns SQLITE_MISUSE. 11520 */ 11521 SQLITE_API int sqlite3changeset_fk_conflicts( 11522 sqlite3_changeset_iter *pIter, /* Changeset iterator */ 11523 int *pnOut /* OUT: Number of FK violations */ 11524 ); 11525 11526 11527 /* 11528 ** CAPI3REF: Finalize A Changeset Iterator 11529 ** METHOD: sqlite3_changeset_iter 11530 ** 11531 ** This function is used to finalize an iterator allocated with 11532 ** [sqlite3changeset_start()]. 11533 ** 11534 ** This function should only be called on iterators created using the 11535 ** [sqlite3changeset_start()] function. If an application calls this 11536 ** function with an iterator passed to a conflict-handler by 11537 ** [sqlite3changeset_apply()], [SQLITE_MISUSE] is immediately returned and the 11538 ** call has no effect. 11539 ** 11540 ** If an error was encountered within a call to an sqlite3changeset_xxx() 11541 ** function (for example an [SQLITE_CORRUPT] in [sqlite3changeset_next()] or an 11542 ** [SQLITE_NOMEM] in [sqlite3changeset_new()]) then an error code corresponding 11543 ** to that error is returned by this function. Otherwise, SQLITE_OK is 11544 ** returned. This is to allow the following pattern (pseudo-code): 11545 ** 11546 ** <pre> 11547 ** sqlite3changeset_start(); 11548 ** while( SQLITE_ROW==sqlite3changeset_next() ){ 11549 ** // Do something with change. 11550 ** } 11551 ** rc = sqlite3changeset_finalize(); 11552 ** if( rc!=SQLITE_OK ){ 11553 ** // An error has occurred 11554 ** } 11555 ** </pre> 11556 */ 11557 SQLITE_API int sqlite3changeset_finalize(sqlite3_changeset_iter *pIter); 11558 11559 /* 11560 ** CAPI3REF: Invert A Changeset 11561 ** 11562 ** This function is used to "invert" a changeset object. Applying an inverted 11563 ** changeset to a database reverses the effects of applying the uninverted 11564 ** changeset. Specifically: 11565 ** 11566 ** <ul> 11567 ** <li> Each DELETE change is changed to an INSERT, and 11568 ** <li> Each INSERT change is changed to a DELETE, and 11569 ** <li> For each UPDATE change, the old.* and new.* values are exchanged. 11570 ** </ul> 11571 ** 11572 ** This function does not change the order in which changes appear within 11573 ** the changeset. It merely reverses the sense of each individual change. 11574 ** 11575 ** If successful, a pointer to a buffer containing the inverted changeset 11576 ** is stored in *ppOut, the size of the same buffer is stored in *pnOut, and 11577 ** SQLITE_OK is returned. If an error occurs, both *pnOut and *ppOut are 11578 ** zeroed and an SQLite error code returned. 11579 ** 11580 ** It is the responsibility of the caller to eventually call sqlite3_free() 11581 ** on the *ppOut pointer to free the buffer allocation following a successful 11582 ** call to this function. 11583 ** 11584 ** WARNING/TODO: This function currently assumes that the input is a valid 11585 ** changeset. If it is not, the results are undefined. 11586 */ 11587 SQLITE_API int sqlite3changeset_invert( 11588 int nIn, const void *pIn, /* Input changeset */ 11589 int *pnOut, void **ppOut /* OUT: Inverse of input */ 11590 ); 11591 11592 /* 11593 ** CAPI3REF: Concatenate Two Changeset Objects 11594 ** 11595 ** This function is used to concatenate two changesets, A and B, into a 11596 ** single changeset. The result is a changeset equivalent to applying 11597 ** changeset A followed by changeset B. 11598 ** 11599 ** This function combines the two input changesets using an 11600 ** sqlite3_changegroup object. Calling it produces similar results as the 11601 ** following code fragment: 11602 ** 11603 ** <pre> 11604 ** sqlite3_changegroup *pGrp; 11605 ** rc = sqlite3_changegroup_new(&pGrp); 11606 ** if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nA, pA); 11607 ** if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nB, pB); 11608 ** if( rc==SQLITE_OK ){ 11609 ** rc = sqlite3changegroup_output(pGrp, pnOut, ppOut); 11610 ** }else{ 11611 ** *ppOut = 0; 11612 ** *pnOut = 0; 11613 ** } 11614 ** </pre> 11615 ** 11616 ** Refer to the sqlite3_changegroup documentation below for details. 11617 */ 11618 SQLITE_API int sqlite3changeset_concat( 11619 int nA, /* Number of bytes in buffer pA */ 11620 void *pA, /* Pointer to buffer containing changeset A */ 11621 int nB, /* Number of bytes in buffer pB */ 11622 void *pB, /* Pointer to buffer containing changeset B */ 11623 int *pnOut, /* OUT: Number of bytes in output changeset */ 11624 void **ppOut /* OUT: Buffer containing output changeset */ 11625 ); 11626 11627 11628 /* 11629 ** CAPI3REF: Changegroup Handle 11630 ** 11631 ** A changegroup is an object used to combine two or more 11632 ** [changesets] or [patchsets] 11633 */ 11634 typedef struct sqlite3_changegroup sqlite3_changegroup; 11635 11636 /* 11637 ** CAPI3REF: Create A New Changegroup Object 11638 ** CONSTRUCTOR: sqlite3_changegroup 11639 ** 11640 ** An sqlite3_changegroup object is used to combine two or more changesets 11641 ** (or patchsets) into a single changeset (or patchset). A single changegroup 11642 ** object may combine changesets or patchsets, but not both. The output is 11643 ** always in the same format as the input. 11644 ** 11645 ** If successful, this function returns SQLITE_OK and populates (*pp) with 11646 ** a pointer to a new sqlite3_changegroup object before returning. The caller 11647 ** should eventually free the returned object using a call to 11648 ** sqlite3changegroup_delete(). If an error occurs, an SQLite error code 11649 ** (i.e. SQLITE_NOMEM) is returned and *pp is set to NULL. 11650 ** 11651 ** The usual usage pattern for an sqlite3_changegroup object is as follows: 11652 ** 11653 ** <ul> 11654 ** <li> It is created using a call to sqlite3changegroup_new(). 11655 ** 11656 ** <li> Zero or more changesets (or patchsets) are added to the object 11657 ** by calling sqlite3changegroup_add(). 11658 ** 11659 ** <li> The result of combining all input changesets together is obtained 11660 ** by the application via a call to sqlite3changegroup_output(). 11661 ** 11662 ** <li> The object is deleted using a call to sqlite3changegroup_delete(). 11663 ** </ul> 11664 ** 11665 ** Any number of calls to add() and output() may be made between the calls to 11666 ** new() and delete(), and in any order. 11667 ** 11668 ** As well as the regular sqlite3changegroup_add() and 11669 ** sqlite3changegroup_output() functions, also available are the streaming 11670 ** versions sqlite3changegroup_add_strm() and sqlite3changegroup_output_strm(). 11671 */ 11672 SQLITE_API int sqlite3changegroup_new(sqlite3_changegroup **pp); 11673 11674 /* 11675 ** CAPI3REF: Add A Changeset To A Changegroup 11676 ** METHOD: sqlite3_changegroup 11677 ** 11678 ** Add all changes within the changeset (or patchset) in buffer pData (size 11679 ** nData bytes) to the changegroup. 11680 ** 11681 ** If the buffer contains a patchset, then all prior calls to this function 11682 ** on the same changegroup object must also have specified patchsets. Or, if 11683 ** the buffer contains a changeset, so must have the earlier calls to this 11684 ** function. Otherwise, SQLITE_ERROR is returned and no changes are added 11685 ** to the changegroup. 11686 ** 11687 ** Rows within the changeset and changegroup are identified by the values in 11688 ** their PRIMARY KEY columns. A change in the changeset is considered to 11689 ** apply to the same row as a change already present in the changegroup if 11690 ** the two rows have the same primary key. 11691 ** 11692 ** Changes to rows that do not already appear in the changegroup are 11693 ** simply copied into it. Or, if both the new changeset and the changegroup 11694 ** contain changes that apply to a single row, the final contents of the 11695 ** changegroup depends on the type of each change, as follows: 11696 ** 11697 ** <table border=1 style="margin-left:8ex;margin-right:8ex"> 11698 ** <tr><th style="white-space:pre">Existing Change </th> 11699 ** <th style="white-space:pre">New Change </th> 11700 ** <th>Output Change 11701 ** <tr><td>INSERT <td>INSERT <td> 11702 ** The new change is ignored. This case does not occur if the new 11703 ** changeset was recorded immediately after the changesets already 11704 ** added to the changegroup. 11705 ** <tr><td>INSERT <td>UPDATE <td> 11706 ** The INSERT change remains in the changegroup. The values in the 11707 ** INSERT change are modified as if the row was inserted by the 11708 ** existing change and then updated according to the new change. 11709 ** <tr><td>INSERT <td>DELETE <td> 11710 ** The existing INSERT is removed from the changegroup. The DELETE is 11711 ** not added. 11712 ** <tr><td>UPDATE <td>INSERT <td> 11713 ** The new change is ignored. This case does not occur if the new 11714 ** changeset was recorded immediately after the changesets already 11715 ** added to the changegroup. 11716 ** <tr><td>UPDATE <td>UPDATE <td> 11717 ** The existing UPDATE remains within the changegroup. It is amended 11718 ** so that the accompanying values are as if the row was updated once 11719 ** by the existing change and then again by the new change. 11720 ** <tr><td>UPDATE <td>DELETE <td> 11721 ** The existing UPDATE is replaced by the new DELETE within the 11722 ** changegroup. 11723 ** <tr><td>DELETE <td>INSERT <td> 11724 ** If one or more of the column values in the row inserted by the 11725 ** new change differ from those in the row deleted by the existing 11726 ** change, the existing DELETE is replaced by an UPDATE within the 11727 ** changegroup. Otherwise, if the inserted row is exactly the same 11728 ** as the deleted row, the existing DELETE is simply discarded. 11729 ** <tr><td>DELETE <td>UPDATE <td> 11730 ** The new change is ignored. This case does not occur if the new 11731 ** changeset was recorded immediately after the changesets already 11732 ** added to the changegroup. 11733 ** <tr><td>DELETE <td>DELETE <td> 11734 ** The new change is ignored. This case does not occur if the new 11735 ** changeset was recorded immediately after the changesets already 11736 ** added to the changegroup. 11737 ** </table> 11738 ** 11739 ** If the new changeset contains changes to a table that is already present 11740 ** in the changegroup, then the number of columns and the position of the 11741 ** primary key columns for the table must be consistent. If this is not the 11742 ** case, this function fails with SQLITE_SCHEMA. If the input changeset 11743 ** appears to be corrupt and the corruption is detected, SQLITE_CORRUPT is 11744 ** returned. Or, if an out-of-memory condition occurs during processing, this 11745 ** function returns SQLITE_NOMEM. In all cases, if an error occurs the state 11746 ** of the final contents of the changegroup is undefined. 11747 ** 11748 ** If no error occurs, SQLITE_OK is returned. 11749 */ 11750 SQLITE_API int sqlite3changegroup_add(sqlite3_changegroup*, int nData, void *pData); 11751 11752 /* 11753 ** CAPI3REF: Obtain A Composite Changeset From A Changegroup 11754 ** METHOD: sqlite3_changegroup 11755 ** 11756 ** Obtain a buffer containing a changeset (or patchset) representing the 11757 ** current contents of the changegroup. If the inputs to the changegroup 11758 ** were themselves changesets, the output is a changeset. Or, if the 11759 ** inputs were patchsets, the output is also a patchset. 11760 ** 11761 ** As with the output of the sqlite3session_changeset() and 11762 ** sqlite3session_patchset() functions, all changes related to a single 11763 ** table are grouped together in the output of this function. Tables appear 11764 ** in the same order as for the very first changeset added to the changegroup. 11765 ** If the second or subsequent changesets added to the changegroup contain 11766 ** changes for tables that do not appear in the first changeset, they are 11767 ** appended onto the end of the output changeset, again in the order in 11768 ** which they are first encountered. 11769 ** 11770 ** If an error occurs, an SQLite error code is returned and the output 11771 ** variables (*pnData) and (*ppData) are set to 0. Otherwise, SQLITE_OK 11772 ** is returned and the output variables are set to the size of and a 11773 ** pointer to the output buffer, respectively. In this case it is the 11774 ** responsibility of the caller to eventually free the buffer using a 11775 ** call to sqlite3_free(). 11776 */ 11777 SQLITE_API int sqlite3changegroup_output( 11778 sqlite3_changegroup*, 11779 int *pnData, /* OUT: Size of output buffer in bytes */ 11780 void **ppData /* OUT: Pointer to output buffer */ 11781 ); 11782 11783 /* 11784 ** CAPI3REF: Delete A Changegroup Object 11785 ** DESTRUCTOR: sqlite3_changegroup 11786 */ 11787 SQLITE_API void sqlite3changegroup_delete(sqlite3_changegroup*); 11788 11789 /* 11790 ** CAPI3REF: Apply A Changeset To A Database 11791 ** 11792 ** Apply a changeset or patchset to a database. These functions attempt to 11793 ** update the "main" database attached to handle db with the changes found in 11794 ** the changeset passed via the second and third arguments. 11795 ** 11796 ** The fourth argument (xFilter) passed to these functions is the "filter 11797 ** callback". If it is not NULL, then for each table affected by at least one 11798 ** change in the changeset, the filter callback is invoked with 11799 ** the table name as the second argument, and a copy of the context pointer 11800 ** passed as the sixth argument as the first. If the "filter callback" 11801 ** returns zero, then no attempt is made to apply any changes to the table. 11802 ** Otherwise, if the return value is non-zero or the xFilter argument to 11803 ** is NULL, all changes related to the table are attempted. 11804 ** 11805 ** For each table that is not excluded by the filter callback, this function 11806 ** tests that the target database contains a compatible table. A table is 11807 ** considered compatible if all of the following are true: 11808 ** 11809 ** <ul> 11810 ** <li> The table has the same name as the name recorded in the 11811 ** changeset, and 11812 ** <li> The table has at least as many columns as recorded in the 11813 ** changeset, and 11814 ** <li> The table has primary key columns in the same position as 11815 ** recorded in the changeset. 11816 ** </ul> 11817 ** 11818 ** If there is no compatible table, it is not an error, but none of the 11819 ** changes associated with the table are applied. A warning message is issued 11820 ** via the sqlite3_log() mechanism with the error code SQLITE_SCHEMA. At most 11821 ** one such warning is issued for each table in the changeset. 11822 ** 11823 ** For each change for which there is a compatible table, an attempt is made 11824 ** to modify the table contents according to the UPDATE, INSERT or DELETE 11825 ** change. If a change cannot be applied cleanly, the conflict handler 11826 ** function passed as the fifth argument to sqlite3changeset_apply() may be 11827 ** invoked. A description of exactly when the conflict handler is invoked for 11828 ** each type of change is below. 11829 ** 11830 ** Unlike the xFilter argument, xConflict may not be passed NULL. The results 11831 ** of passing anything other than a valid function pointer as the xConflict 11832 ** argument are undefined. 11833 ** 11834 ** Each time the conflict handler function is invoked, it must return one 11835 ** of [SQLITE_CHANGESET_OMIT], [SQLITE_CHANGESET_ABORT] or 11836 ** [SQLITE_CHANGESET_REPLACE]. SQLITE_CHANGESET_REPLACE may only be returned 11837 ** if the second argument passed to the conflict handler is either 11838 ** SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If the conflict-handler 11839 ** returns an illegal value, any changes already made are rolled back and 11840 ** the call to sqlite3changeset_apply() returns SQLITE_MISUSE. Different 11841 ** actions are taken by sqlite3changeset_apply() depending on the value 11842 ** returned by each invocation of the conflict-handler function. Refer to 11843 ** the documentation for the three 11844 ** [SQLITE_CHANGESET_OMIT|available return values] for details. 11845 ** 11846 ** <dl> 11847 ** <dt>DELETE Changes<dd> 11848 ** For each DELETE change, the function checks if the target database 11849 ** contains a row with the same primary key value (or values) as the 11850 ** original row values stored in the changeset. If it does, and the values 11851 ** stored in all non-primary key columns also match the values stored in 11852 ** the changeset the row is deleted from the target database. 11853 ** 11854 ** If a row with matching primary key values is found, but one or more of 11855 ** the non-primary key fields contains a value different from the original 11856 ** row value stored in the changeset, the conflict-handler function is 11857 ** invoked with [SQLITE_CHANGESET_DATA] as the second argument. If the 11858 ** database table has more columns than are recorded in the changeset, 11859 ** only the values of those non-primary key fields are compared against 11860 ** the current database contents - any trailing database table columns 11861 ** are ignored. 11862 ** 11863 ** If no row with matching primary key values is found in the database, 11864 ** the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND] 11865 ** passed as the second argument. 11866 ** 11867 ** If the DELETE operation is attempted, but SQLite returns SQLITE_CONSTRAINT 11868 ** (which can only happen if a foreign key constraint is violated), the 11869 ** conflict-handler function is invoked with [SQLITE_CHANGESET_CONSTRAINT] 11870 ** passed as the second argument. This includes the case where the DELETE 11871 ** operation is attempted because an earlier call to the conflict handler 11872 ** function returned [SQLITE_CHANGESET_REPLACE]. 11873 ** 11874 ** <dt>INSERT Changes<dd> 11875 ** For each INSERT change, an attempt is made to insert the new row into 11876 ** the database. If the changeset row contains fewer fields than the 11877 ** database table, the trailing fields are populated with their default 11878 ** values. 11879 ** 11880 ** If the attempt to insert the row fails because the database already 11881 ** contains a row with the same primary key values, the conflict handler 11882 ** function is invoked with the second argument set to 11883 ** [SQLITE_CHANGESET_CONFLICT]. 11884 ** 11885 ** If the attempt to insert the row fails because of some other constraint 11886 ** violation (e.g. NOT NULL or UNIQUE), the conflict handler function is 11887 ** invoked with the second argument set to [SQLITE_CHANGESET_CONSTRAINT]. 11888 ** This includes the case where the INSERT operation is re-attempted because 11889 ** an earlier call to the conflict handler function returned 11890 ** [SQLITE_CHANGESET_REPLACE]. 11891 ** 11892 ** <dt>UPDATE Changes<dd> 11893 ** For each UPDATE change, the function checks if the target database 11894 ** contains a row with the same primary key value (or values) as the 11895 ** original row values stored in the changeset. If it does, and the values 11896 ** stored in all modified non-primary key columns also match the values 11897 ** stored in the changeset the row is updated within the target database. 11898 ** 11899 ** If a row with matching primary key values is found, but one or more of 11900 ** the modified non-primary key fields contains a value different from an 11901 ** original row value stored in the changeset, the conflict-handler function 11902 ** is invoked with [SQLITE_CHANGESET_DATA] as the second argument. Since 11903 ** UPDATE changes only contain values for non-primary key fields that are 11904 ** to be modified, only those fields need to match the original values to 11905 ** avoid the SQLITE_CHANGESET_DATA conflict-handler callback. 11906 ** 11907 ** If no row with matching primary key values is found in the database, 11908 ** the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND] 11909 ** passed as the second argument. 11910 ** 11911 ** If the UPDATE operation is attempted, but SQLite returns 11912 ** SQLITE_CONSTRAINT, the conflict-handler function is invoked with 11913 ** [SQLITE_CHANGESET_CONSTRAINT] passed as the second argument. 11914 ** This includes the case where the UPDATE operation is attempted after 11915 ** an earlier call to the conflict handler function returned 11916 ** [SQLITE_CHANGESET_REPLACE]. 11917 ** </dl> 11918 ** 11919 ** It is safe to execute SQL statements, including those that write to the 11920 ** table that the callback related to, from within the xConflict callback. 11921 ** This can be used to further customize the application's conflict 11922 ** resolution strategy. 11923 ** 11924 ** All changes made by these functions are enclosed in a savepoint transaction. 11925 ** If any other error (aside from a constraint failure when attempting to 11926 ** write to the target database) occurs, then the savepoint transaction is 11927 ** rolled back, restoring the target database to its original state, and an 11928 ** SQLite error code returned. 11929 ** 11930 ** If the output parameters (ppRebase) and (pnRebase) are non-NULL and 11931 ** the input is a changeset (not a patchset), then sqlite3changeset_apply_v2() 11932 ** may set (*ppRebase) to point to a "rebase" that may be used with the 11933 ** sqlite3_rebaser APIs buffer before returning. In this case (*pnRebase) 11934 ** is set to the size of the buffer in bytes. It is the responsibility of the 11935 ** caller to eventually free any such buffer using sqlite3_free(). The buffer 11936 ** is only allocated and populated if one or more conflicts were encountered 11937 ** while applying the patchset. See comments surrounding the sqlite3_rebaser 11938 ** APIs for further details. 11939 ** 11940 ** The behavior of sqlite3changeset_apply_v2() and its streaming equivalent 11941 ** may be modified by passing a combination of 11942 ** [SQLITE_CHANGESETAPPLY_NOSAVEPOINT | supported flags] as the 9th parameter. 11943 ** 11944 ** Note that the sqlite3changeset_apply_v2() API is still <b>experimental</b> 11945 ** and therefore subject to change. 11946 */ 11947 SQLITE_API int sqlite3changeset_apply( 11948 sqlite3 *db, /* Apply change to "main" db of this handle */ 11949 int nChangeset, /* Size of changeset in bytes */ 11950 void *pChangeset, /* Changeset blob */ 11951 int(*xFilter)( 11952 void *pCtx, /* Copy of sixth arg to _apply() */ 11953 const char *zTab /* Table name */ 11954 ), 11955 int(*xConflict)( 11956 void *pCtx, /* Copy of sixth arg to _apply() */ 11957 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */ 11958 sqlite3_changeset_iter *p /* Handle describing change and conflict */ 11959 ), 11960 void *pCtx /* First argument passed to xConflict */ 11961 ); 11962 SQLITE_API int sqlite3changeset_apply_v2( 11963 sqlite3 *db, /* Apply change to "main" db of this handle */ 11964 int nChangeset, /* Size of changeset in bytes */ 11965 void *pChangeset, /* Changeset blob */ 11966 int(*xFilter)( 11967 void *pCtx, /* Copy of sixth arg to _apply() */ 11968 const char *zTab /* Table name */ 11969 ), 11970 int(*xConflict)( 11971 void *pCtx, /* Copy of sixth arg to _apply() */ 11972 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */ 11973 sqlite3_changeset_iter *p /* Handle describing change and conflict */ 11974 ), 11975 void *pCtx, /* First argument passed to xConflict */ 11976 void **ppRebase, int *pnRebase, /* OUT: Rebase data */ 11977 int flags /* SESSION_CHANGESETAPPLY_* flags */ 11978 ); 11979 11980 /* 11981 ** CAPI3REF: Flags for sqlite3changeset_apply_v2 11982 ** 11983 ** The following flags may passed via the 9th parameter to 11984 ** [sqlite3changeset_apply_v2] and [sqlite3changeset_apply_v2_strm]: 11985 ** 11986 ** <dl> 11987 ** <dt>SQLITE_CHANGESETAPPLY_NOSAVEPOINT <dd> 11988 ** Usually, the sessions module encloses all operations performed by 11989 ** a single call to apply_v2() or apply_v2_strm() in a [SAVEPOINT]. The 11990 ** SAVEPOINT is committed if the changeset or patchset is successfully 11991 ** applied, or rolled back if an error occurs. Specifying this flag 11992 ** causes the sessions module to omit this savepoint. In this case, if the 11993 ** caller has an open transaction or savepoint when apply_v2() is called, 11994 ** it may revert the partially applied changeset by rolling it back. 11995 ** 11996 ** <dt>SQLITE_CHANGESETAPPLY_INVERT <dd> 11997 ** Invert the changeset before applying it. This is equivalent to inverting 11998 ** a changeset using sqlite3changeset_invert() before applying it. It is 11999 ** an error to specify this flag with a patchset. 12000 ** 12001 ** <dt>SQLITE_CHANGESETAPPLY_IGNORENOOP <dd> 12002 ** Do not invoke the conflict handler callback for any changes that 12003 ** would not actually modify the database even if they were applied. 12004 ** Specifically, this means that the conflict handler is not invoked 12005 ** for: 12006 ** <ul> 12007 ** <li>a delete change if the row being deleted cannot be found, 12008 ** <li>an update change if the modified fields are already set to 12009 ** their new values in the conflicting row, or 12010 ** <li>an insert change if all fields of the conflicting row match 12011 ** the row being inserted. 12012 ** </ul> 12013 */ 12014 #define SQLITE_CHANGESETAPPLY_NOSAVEPOINT 0x0001 12015 #define SQLITE_CHANGESETAPPLY_INVERT 0x0002 12016 #define SQLITE_CHANGESETAPPLY_IGNORENOOP 0x0004 12017 12018 /* 12019 ** CAPI3REF: Constants Passed To The Conflict Handler 12020 ** 12021 ** Values that may be passed as the second argument to a conflict-handler. 12022 ** 12023 ** <dl> 12024 ** <dt>SQLITE_CHANGESET_DATA<dd> 12025 ** The conflict handler is invoked with CHANGESET_DATA as the second argument 12026 ** when processing a DELETE or UPDATE change if a row with the required 12027 ** PRIMARY KEY fields is present in the database, but one or more other 12028 ** (non primary-key) fields modified by the update do not contain the 12029 ** expected "before" values. 12030 ** 12031 ** The conflicting row, in this case, is the database row with the matching 12032 ** primary key. 12033 ** 12034 ** <dt>SQLITE_CHANGESET_NOTFOUND<dd> 12035 ** The conflict handler is invoked with CHANGESET_NOTFOUND as the second 12036 ** argument when processing a DELETE or UPDATE change if a row with the 12037 ** required PRIMARY KEY fields is not present in the database. 12038 ** 12039 ** There is no conflicting row in this case. The results of invoking the 12040 ** sqlite3changeset_conflict() API are undefined. 12041 ** 12042 ** <dt>SQLITE_CHANGESET_CONFLICT<dd> 12043 ** CHANGESET_CONFLICT is passed as the second argument to the conflict 12044 ** handler while processing an INSERT change if the operation would result 12045 ** in duplicate primary key values. 12046 ** 12047 ** The conflicting row in this case is the database row with the matching 12048 ** primary key. 12049 ** 12050 ** <dt>SQLITE_CHANGESET_FOREIGN_KEY<dd> 12051 ** If foreign key handling is enabled, and applying a changeset leaves the 12052 ** database in a state containing foreign key violations, the conflict 12053 ** handler is invoked with CHANGESET_FOREIGN_KEY as the second argument 12054 ** exactly once before the changeset is committed. If the conflict handler 12055 ** returns CHANGESET_OMIT, the changes, including those that caused the 12056 ** foreign key constraint violation, are committed. Or, if it returns 12057 ** CHANGESET_ABORT, the changeset is rolled back. 12058 ** 12059 ** No current or conflicting row information is provided. The only function 12060 ** it is possible to call on the supplied sqlite3_changeset_iter handle 12061 ** is sqlite3changeset_fk_conflicts(). 12062 ** 12063 ** <dt>SQLITE_CHANGESET_CONSTRAINT<dd> 12064 ** If any other constraint violation occurs while applying a change (i.e. 12065 ** a UNIQUE, CHECK or NOT NULL constraint), the conflict handler is 12066 ** invoked with CHANGESET_CONSTRAINT as the second argument. 12067 ** 12068 ** There is no conflicting row in this case. The results of invoking the 12069 ** sqlite3changeset_conflict() API are undefined. 12070 ** 12071 ** </dl> 12072 */ 12073 #define SQLITE_CHANGESET_DATA 1 12074 #define SQLITE_CHANGESET_NOTFOUND 2 12075 #define SQLITE_CHANGESET_CONFLICT 3 12076 #define SQLITE_CHANGESET_CONSTRAINT 4 12077 #define SQLITE_CHANGESET_FOREIGN_KEY 5 12078 12079 /* 12080 ** CAPI3REF: Constants Returned By The Conflict Handler 12081 ** 12082 ** A conflict handler callback must return one of the following three values. 12083 ** 12084 ** <dl> 12085 ** <dt>SQLITE_CHANGESET_OMIT<dd> 12086 ** If a conflict handler returns this value no special action is taken. The 12087 ** change that caused the conflict is not applied. The session module 12088 ** continues to the next change in the changeset. 12089 ** 12090 ** <dt>SQLITE_CHANGESET_REPLACE<dd> 12091 ** This value may only be returned if the second argument to the conflict 12092 ** handler was SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If this 12093 ** is not the case, any changes applied so far are rolled back and the 12094 ** call to sqlite3changeset_apply() returns SQLITE_MISUSE. 12095 ** 12096 ** If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_DATA conflict 12097 ** handler, then the conflicting row is either updated or deleted, depending 12098 ** on the type of change. 12099 ** 12100 ** If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_CONFLICT conflict 12101 ** handler, then the conflicting row is removed from the database and a 12102 ** second attempt to apply the change is made. If this second attempt fails, 12103 ** the original row is restored to the database before continuing. 12104 ** 12105 ** <dt>SQLITE_CHANGESET_ABORT<dd> 12106 ** If this value is returned, any changes applied so far are rolled back 12107 ** and the call to sqlite3changeset_apply() returns SQLITE_ABORT. 12108 ** </dl> 12109 */ 12110 #define SQLITE_CHANGESET_OMIT 0 12111 #define SQLITE_CHANGESET_REPLACE 1 12112 #define SQLITE_CHANGESET_ABORT 2 12113 12114 /* 12115 ** CAPI3REF: Rebasing changesets 12116 ** EXPERIMENTAL 12117 ** 12118 ** Suppose there is a site hosting a database in state S0. And that 12119 ** modifications are made that move that database to state S1 and a 12120 ** changeset recorded (the "local" changeset). Then, a changeset based 12121 ** on S0 is received from another site (the "remote" changeset) and 12122 ** applied to the database. The database is then in state 12123 ** (S1+"remote"), where the exact state depends on any conflict 12124 ** resolution decisions (OMIT or REPLACE) made while applying "remote". 12125 ** Rebasing a changeset is to update it to take those conflict 12126 ** resolution decisions into account, so that the same conflicts 12127 ** do not have to be resolved elsewhere in the network. 12128 ** 12129 ** For example, if both the local and remote changesets contain an 12130 ** INSERT of the same key on "CREATE TABLE t1(a PRIMARY KEY, b)": 12131 ** 12132 ** local: INSERT INTO t1 VALUES(1, 'v1'); 12133 ** remote: INSERT INTO t1 VALUES(1, 'v2'); 12134 ** 12135 ** and the conflict resolution is REPLACE, then the INSERT change is 12136 ** removed from the local changeset (it was overridden). Or, if the 12137 ** conflict resolution was "OMIT", then the local changeset is modified 12138 ** to instead contain: 12139 ** 12140 ** UPDATE t1 SET b = 'v2' WHERE a=1; 12141 ** 12142 ** Changes within the local changeset are rebased as follows: 12143 ** 12144 ** <dl> 12145 ** <dt>Local INSERT<dd> 12146 ** This may only conflict with a remote INSERT. If the conflict 12147 ** resolution was OMIT, then add an UPDATE change to the rebased 12148 ** changeset. Or, if the conflict resolution was REPLACE, add 12149 ** nothing to the rebased changeset. 12150 ** 12151 ** <dt>Local DELETE<dd> 12152 ** This may conflict with a remote UPDATE or DELETE. In both cases the 12153 ** only possible resolution is OMIT. If the remote operation was a 12154 ** DELETE, then add no change to the rebased changeset. If the remote 12155 ** operation was an UPDATE, then the old.* fields of change are updated 12156 ** to reflect the new.* values in the UPDATE. 12157 ** 12158 ** <dt>Local UPDATE<dd> 12159 ** This may conflict with a remote UPDATE or DELETE. If it conflicts 12160 ** with a DELETE, and the conflict resolution was OMIT, then the update 12161 ** is changed into an INSERT. Any undefined values in the new.* record 12162 ** from the update change are filled in using the old.* values from 12163 ** the conflicting DELETE. Or, if the conflict resolution was REPLACE, 12164 ** the UPDATE change is simply omitted from the rebased changeset. 12165 ** 12166 ** If conflict is with a remote UPDATE and the resolution is OMIT, then 12167 ** the old.* values are rebased using the new.* values in the remote 12168 ** change. Or, if the resolution is REPLACE, then the change is copied 12169 ** into the rebased changeset with updates to columns also updated by 12170 ** the conflicting remote UPDATE removed. If this means no columns would 12171 ** be updated, the change is omitted. 12172 ** </dl> 12173 ** 12174 ** A local change may be rebased against multiple remote changes 12175 ** simultaneously. If a single key is modified by multiple remote 12176 ** changesets, they are combined as follows before the local changeset 12177 ** is rebased: 12178 ** 12179 ** <ul> 12180 ** <li> If there has been one or more REPLACE resolutions on a 12181 ** key, it is rebased according to a REPLACE. 12182 ** 12183 ** <li> If there have been no REPLACE resolutions on a key, then 12184 ** the local changeset is rebased according to the most recent 12185 ** of the OMIT resolutions. 12186 ** </ul> 12187 ** 12188 ** Note that conflict resolutions from multiple remote changesets are 12189 ** combined on a per-field basis, not per-row. This means that in the 12190 ** case of multiple remote UPDATE operations, some fields of a single 12191 ** local change may be rebased for REPLACE while others are rebased for 12192 ** OMIT. 12193 ** 12194 ** In order to rebase a local changeset, the remote changeset must first 12195 ** be applied to the local database using sqlite3changeset_apply_v2() and 12196 ** the buffer of rebase information captured. Then: 12197 ** 12198 ** <ol> 12199 ** <li> An sqlite3_rebaser object is created by calling 12200 ** sqlite3rebaser_create(). 12201 ** <li> The new object is configured with the rebase buffer obtained from 12202 ** sqlite3changeset_apply_v2() by calling sqlite3rebaser_configure(). 12203 ** If the local changeset is to be rebased against multiple remote 12204 ** changesets, then sqlite3rebaser_configure() should be called 12205 ** multiple times, in the same order that the multiple 12206 ** sqlite3changeset_apply_v2() calls were made. 12207 ** <li> Each local changeset is rebased by calling sqlite3rebaser_rebase(). 12208 ** <li> The sqlite3_rebaser object is deleted by calling 12209 ** sqlite3rebaser_delete(). 12210 ** </ol> 12211 */ 12212 typedef struct sqlite3_rebaser sqlite3_rebaser; 12213 12214 /* 12215 ** CAPI3REF: Create a changeset rebaser object. 12216 ** EXPERIMENTAL 12217 ** 12218 ** Allocate a new changeset rebaser object. If successful, set (*ppNew) to 12219 ** point to the new object and return SQLITE_OK. Otherwise, if an error 12220 ** occurs, return an SQLite error code (e.g. SQLITE_NOMEM) and set (*ppNew) 12221 ** to NULL. 12222 */ 12223 SQLITE_API int sqlite3rebaser_create(sqlite3_rebaser **ppNew); 12224 12225 /* 12226 ** CAPI3REF: Configure a changeset rebaser object. 12227 ** EXPERIMENTAL 12228 ** 12229 ** Configure the changeset rebaser object to rebase changesets according 12230 ** to the conflict resolutions described by buffer pRebase (size nRebase 12231 ** bytes), which must have been obtained from a previous call to 12232 ** sqlite3changeset_apply_v2(). 12233 */ 12234 SQLITE_API int sqlite3rebaser_configure( 12235 sqlite3_rebaser*, 12236 int nRebase, const void *pRebase 12237 ); 12238 12239 /* 12240 ** CAPI3REF: Rebase a changeset 12241 ** EXPERIMENTAL 12242 ** 12243 ** Argument pIn must point to a buffer containing a changeset nIn bytes 12244 ** in size. This function allocates and populates a buffer with a copy 12245 ** of the changeset rebased according to the configuration of the 12246 ** rebaser object passed as the first argument. If successful, (*ppOut) 12247 ** is set to point to the new buffer containing the rebased changeset and 12248 ** (*pnOut) to its size in bytes and SQLITE_OK returned. It is the 12249 ** responsibility of the caller to eventually free the new buffer using 12250 ** sqlite3_free(). Otherwise, if an error occurs, (*ppOut) and (*pnOut) 12251 ** are set to zero and an SQLite error code returned. 12252 */ 12253 SQLITE_API int sqlite3rebaser_rebase( 12254 sqlite3_rebaser*, 12255 int nIn, const void *pIn, 12256 int *pnOut, void **ppOut 12257 ); 12258 12259 /* 12260 ** CAPI3REF: Delete a changeset rebaser object. 12261 ** EXPERIMENTAL 12262 ** 12263 ** Delete the changeset rebaser object and all associated resources. There 12264 ** should be one call to this function for each successful invocation 12265 ** of sqlite3rebaser_create(). 12266 */ 12267 SQLITE_API void sqlite3rebaser_delete(sqlite3_rebaser *p); 12268 12269 /* 12270 ** CAPI3REF: Streaming Versions of API functions. 12271 ** 12272 ** The six streaming API xxx_strm() functions serve similar purposes to the 12273 ** corresponding non-streaming API functions: 12274 ** 12275 ** <table border=1 style="margin-left:8ex;margin-right:8ex"> 12276 ** <tr><th>Streaming function<th>Non-streaming equivalent</th> 12277 ** <tr><td>sqlite3changeset_apply_strm<td>[sqlite3changeset_apply] 12278 ** <tr><td>sqlite3changeset_apply_strm_v2<td>[sqlite3changeset_apply_v2] 12279 ** <tr><td>sqlite3changeset_concat_strm<td>[sqlite3changeset_concat] 12280 ** <tr><td>sqlite3changeset_invert_strm<td>[sqlite3changeset_invert] 12281 ** <tr><td>sqlite3changeset_start_strm<td>[sqlite3changeset_start] 12282 ** <tr><td>sqlite3session_changeset_strm<td>[sqlite3session_changeset] 12283 ** <tr><td>sqlite3session_patchset_strm<td>[sqlite3session_patchset] 12284 ** </table> 12285 ** 12286 ** Non-streaming functions that accept changesets (or patchsets) as input 12287 ** require that the entire changeset be stored in a single buffer in memory. 12288 ** Similarly, those that return a changeset or patchset do so by returning 12289 ** a pointer to a single large buffer allocated using sqlite3_malloc(). 12290 ** Normally this is convenient. However, if an application running in a 12291 ** low-memory environment is required to handle very large changesets, the 12292 ** large contiguous memory allocations required can become onerous. 12293 ** 12294 ** In order to avoid this problem, instead of a single large buffer, input 12295 ** is passed to a streaming API functions by way of a callback function that 12296 ** the sessions module invokes to incrementally request input data as it is 12297 ** required. In all cases, a pair of API function parameters such as 12298 ** 12299 ** <pre> 12300 ** int nChangeset, 12301 ** void *pChangeset, 12302 ** </pre> 12303 ** 12304 ** Is replaced by: 12305 ** 12306 ** <pre> 12307 ** int (*xInput)(void *pIn, void *pData, int *pnData), 12308 ** void *pIn, 12309 ** </pre> 12310 ** 12311 ** Each time the xInput callback is invoked by the sessions module, the first 12312 ** argument passed is a copy of the supplied pIn context pointer. The second 12313 ** argument, pData, points to a buffer (*pnData) bytes in size. Assuming no 12314 ** error occurs the xInput method should copy up to (*pnData) bytes of data 12315 ** into the buffer and set (*pnData) to the actual number of bytes copied 12316 ** before returning SQLITE_OK. If the input is completely exhausted, (*pnData) 12317 ** should be set to zero to indicate this. Or, if an error occurs, an SQLite 12318 ** error code should be returned. In all cases, if an xInput callback returns 12319 ** an error, all processing is abandoned and the streaming API function 12320 ** returns a copy of the error code to the caller. 12321 ** 12322 ** In the case of sqlite3changeset_start_strm(), the xInput callback may be 12323 ** invoked by the sessions module at any point during the lifetime of the 12324 ** iterator. If such an xInput callback returns an error, the iterator enters 12325 ** an error state, whereby all subsequent calls to iterator functions 12326 ** immediately fail with the same error code as returned by xInput. 12327 ** 12328 ** Similarly, streaming API functions that return changesets (or patchsets) 12329 ** return them in chunks by way of a callback function instead of via a 12330 ** pointer to a single large buffer. In this case, a pair of parameters such 12331 ** as: 12332 ** 12333 ** <pre> 12334 ** int *pnChangeset, 12335 ** void **ppChangeset, 12336 ** </pre> 12337 ** 12338 ** Is replaced by: 12339 ** 12340 ** <pre> 12341 ** int (*xOutput)(void *pOut, const void *pData, int nData), 12342 ** void *pOut 12343 ** </pre> 12344 ** 12345 ** The xOutput callback is invoked zero or more times to return data to 12346 ** the application. The first parameter passed to each call is a copy of the 12347 ** pOut pointer supplied by the application. The second parameter, pData, 12348 ** points to a buffer nData bytes in size containing the chunk of output 12349 ** data being returned. If the xOutput callback successfully processes the 12350 ** supplied data, it should return SQLITE_OK to indicate success. Otherwise, 12351 ** it should return some other SQLite error code. In this case processing 12352 ** is immediately abandoned and the streaming API function returns a copy 12353 ** of the xOutput error code to the application. 12354 ** 12355 ** The sessions module never invokes an xOutput callback with the third 12356 ** parameter set to a value less than or equal to zero. Other than this, 12357 ** no guarantees are made as to the size of the chunks of data returned. 12358 */ 12359 SQLITE_API int sqlite3changeset_apply_strm( 12360 sqlite3 *db, /* Apply change to "main" db of this handle */ 12361 int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */ 12362 void *pIn, /* First arg for xInput */ 12363 int(*xFilter)( 12364 void *pCtx, /* Copy of sixth arg to _apply() */ 12365 const char *zTab /* Table name */ 12366 ), 12367 int(*xConflict)( 12368 void *pCtx, /* Copy of sixth arg to _apply() */ 12369 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */ 12370 sqlite3_changeset_iter *p /* Handle describing change and conflict */ 12371 ), 12372 void *pCtx /* First argument passed to xConflict */ 12373 ); 12374 SQLITE_API int sqlite3changeset_apply_v2_strm( 12375 sqlite3 *db, /* Apply change to "main" db of this handle */ 12376 int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */ 12377 void *pIn, /* First arg for xInput */ 12378 int(*xFilter)( 12379 void *pCtx, /* Copy of sixth arg to _apply() */ 12380 const char *zTab /* Table name */ 12381 ), 12382 int(*xConflict)( 12383 void *pCtx, /* Copy of sixth arg to _apply() */ 12384 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */ 12385 sqlite3_changeset_iter *p /* Handle describing change and conflict */ 12386 ), 12387 void *pCtx, /* First argument passed to xConflict */ 12388 void **ppRebase, int *pnRebase, 12389 int flags 12390 ); 12391 SQLITE_API int sqlite3changeset_concat_strm( 12392 int (*xInputA)(void *pIn, void *pData, int *pnData), 12393 void *pInA, 12394 int (*xInputB)(void *pIn, void *pData, int *pnData), 12395 void *pInB, 12396 int (*xOutput)(void *pOut, const void *pData, int nData), 12397 void *pOut 12398 ); 12399 SQLITE_API int sqlite3changeset_invert_strm( 12400 int (*xInput)(void *pIn, void *pData, int *pnData), 12401 void *pIn, 12402 int (*xOutput)(void *pOut, const void *pData, int nData), 12403 void *pOut 12404 ); 12405 SQLITE_API int sqlite3changeset_start_strm( 12406 sqlite3_changeset_iter **pp, 12407 int (*xInput)(void *pIn, void *pData, int *pnData), 12408 void *pIn 12409 ); 12410 SQLITE_API int sqlite3changeset_start_v2_strm( 12411 sqlite3_changeset_iter **pp, 12412 int (*xInput)(void *pIn, void *pData, int *pnData), 12413 void *pIn, 12414 int flags 12415 ); 12416 SQLITE_API int sqlite3session_changeset_strm( 12417 sqlite3_session *pSession, 12418 int (*xOutput)(void *pOut, const void *pData, int nData), 12419 void *pOut 12420 ); 12421 SQLITE_API int sqlite3session_patchset_strm( 12422 sqlite3_session *pSession, 12423 int (*xOutput)(void *pOut, const void *pData, int nData), 12424 void *pOut 12425 ); 12426 SQLITE_API int sqlite3changegroup_add_strm(sqlite3_changegroup*, 12427 int (*xInput)(void *pIn, void *pData, int *pnData), 12428 void *pIn 12429 ); 12430 SQLITE_API int sqlite3changegroup_output_strm(sqlite3_changegroup*, 12431 int (*xOutput)(void *pOut, const void *pData, int nData), 12432 void *pOut 12433 ); 12434 SQLITE_API int sqlite3rebaser_rebase_strm( 12435 sqlite3_rebaser *pRebaser, 12436 int (*xInput)(void *pIn, void *pData, int *pnData), 12437 void *pIn, 12438 int (*xOutput)(void *pOut, const void *pData, int nData), 12439 void *pOut 12440 ); 12441 12442 /* 12443 ** CAPI3REF: Configure global parameters 12444 ** 12445 ** The sqlite3session_config() interface is used to make global configuration 12446 ** changes to the sessions module in order to tune it to the specific needs 12447 ** of the application. 12448 ** 12449 ** The sqlite3session_config() interface is not threadsafe. If it is invoked 12450 ** while any other thread is inside any other sessions method then the 12451 ** results are undefined. Furthermore, if it is invoked after any sessions 12452 ** related objects have been created, the results are also undefined. 12453 ** 12454 ** The first argument to the sqlite3session_config() function must be one 12455 ** of the SQLITE_SESSION_CONFIG_XXX constants defined below. The 12456 ** interpretation of the (void*) value passed as the second parameter and 12457 ** the effect of calling this function depends on the value of the first 12458 ** parameter. 12459 ** 12460 ** <dl> 12461 ** <dt>SQLITE_SESSION_CONFIG_STRMSIZE<dd> 12462 ** By default, the sessions module streaming interfaces attempt to input 12463 ** and output data in approximately 1 KiB chunks. This operand may be used 12464 ** to set and query the value of this configuration setting. The pointer 12465 ** passed as the second argument must point to a value of type (int). 12466 ** If this value is greater than 0, it is used as the new streaming data 12467 ** chunk size for both input and output. Before returning, the (int) value 12468 ** pointed to by pArg is set to the final value of the streaming interface 12469 ** chunk size. 12470 ** </dl> 12471 ** 12472 ** This function returns SQLITE_OK if successful, or an SQLite error code 12473 ** otherwise. 12474 */ 12475 SQLITE_API int sqlite3session_config(int op, void *pArg); 12476 12477 /* 12478 ** CAPI3REF: Values for sqlite3session_config(). 12479 */ 12480 #define SQLITE_SESSION_CONFIG_STRMSIZE 1 12481 12482 /* 12483 ** Make sure we can call this stuff from C++. 12484 */ 12485 #ifdef __cplusplus 12486 } 12487 #endif 12488 12489 #endif /* !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION) */ 12490 12491 /******** End of sqlite3session.h *********/ 12492 /******** Begin file fts5.h *********/ 12493 /* 12494 ** 2014 May 31 12495 ** 12496 ** The author disclaims copyright to this source code. In place of 12497 ** a legal notice, here is a blessing: 12498 ** 12499 ** May you do good and not evil. 12500 ** May you find forgiveness for yourself and forgive others. 12501 ** May you share freely, never taking more than you give. 12502 ** 12503 ****************************************************************************** 12504 ** 12505 ** Interfaces to extend FTS5. Using the interfaces defined in this file, 12506 ** FTS5 may be extended with: 12507 ** 12508 ** * custom tokenizers, and 12509 ** * custom auxiliary functions. 12510 */ 12511 12512 12513 #ifndef _FTS5_H 12514 #define _FTS5_H 12515 12516 12517 #ifdef __cplusplus 12518 extern "C" { 12519 #endif 12520 12521 /************************************************************************* 12522 ** CUSTOM AUXILIARY FUNCTIONS 12523 ** 12524 ** Virtual table implementations may overload SQL functions by implementing 12525 ** the sqlite3_module.xFindFunction() method. 12526 */ 12527 12528 typedef struct Fts5ExtensionApi Fts5ExtensionApi; 12529 typedef struct Fts5Context Fts5Context; 12530 typedef struct Fts5PhraseIter Fts5PhraseIter; 12531 12532 typedef void (*fts5_extension_function)( 12533 const Fts5ExtensionApi *pApi, /* API offered by current FTS version */ 12534 Fts5Context *pFts, /* First arg to pass to pApi functions */ 12535 sqlite3_context *pCtx, /* Context for returning result/error */ 12536 int nVal, /* Number of values in apVal[] array */ 12537 sqlite3_value **apVal /* Array of trailing arguments */ 12538 ); 12539 12540 struct Fts5PhraseIter { 12541 const unsigned char *a; 12542 const unsigned char *b; 12543 }; 12544 12545 /* 12546 ** EXTENSION API FUNCTIONS 12547 ** 12548 ** xUserData(pFts): 12549 ** Return a copy of the context pointer the extension function was 12550 ** registered with. 12551 ** 12552 ** xColumnTotalSize(pFts, iCol, pnToken): 12553 ** If parameter iCol is less than zero, set output variable *pnToken 12554 ** to the total number of tokens in the FTS5 table. Or, if iCol is 12555 ** non-negative but less than the number of columns in the table, return 12556 ** the total number of tokens in column iCol, considering all rows in 12557 ** the FTS5 table. 12558 ** 12559 ** If parameter iCol is greater than or equal to the number of columns 12560 ** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g. 12561 ** an OOM condition or IO error), an appropriate SQLite error code is 12562 ** returned. 12563 ** 12564 ** xColumnCount(pFts): 12565 ** Return the number of columns in the table. 12566 ** 12567 ** xColumnSize(pFts, iCol, pnToken): 12568 ** If parameter iCol is less than zero, set output variable *pnToken 12569 ** to the total number of tokens in the current row. Or, if iCol is 12570 ** non-negative but less than the number of columns in the table, set 12571 ** *pnToken to the number of tokens in column iCol of the current row. 12572 ** 12573 ** If parameter iCol is greater than or equal to the number of columns 12574 ** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g. 12575 ** an OOM condition or IO error), an appropriate SQLite error code is 12576 ** returned. 12577 ** 12578 ** This function may be quite inefficient if used with an FTS5 table 12579 ** created with the "columnsize=0" option. 12580 ** 12581 ** xColumnText: 12582 ** This function attempts to retrieve the text of column iCol of the 12583 ** current document. If successful, (*pz) is set to point to a buffer 12584 ** containing the text in utf-8 encoding, (*pn) is set to the size in bytes 12585 ** (not characters) of the buffer and SQLITE_OK is returned. Otherwise, 12586 ** if an error occurs, an SQLite error code is returned and the final values 12587 ** of (*pz) and (*pn) are undefined. 12588 ** 12589 ** xPhraseCount: 12590 ** Returns the number of phrases in the current query expression. 12591 ** 12592 ** xPhraseSize: 12593 ** Returns the number of tokens in phrase iPhrase of the query. Phrases 12594 ** are numbered starting from zero. 12595 ** 12596 ** xInstCount: 12597 ** Set *pnInst to the total number of occurrences of all phrases within 12598 ** the query within the current row. Return SQLITE_OK if successful, or 12599 ** an error code (i.e. SQLITE_NOMEM) if an error occurs. 12600 ** 12601 ** This API can be quite slow if used with an FTS5 table created with the 12602 ** "detail=none" or "detail=column" option. If the FTS5 table is created 12603 ** with either "detail=none" or "detail=column" and "content=" option 12604 ** (i.e. if it is a contentless table), then this API always returns 0. 12605 ** 12606 ** xInst: 12607 ** Query for the details of phrase match iIdx within the current row. 12608 ** Phrase matches are numbered starting from zero, so the iIdx argument 12609 ** should be greater than or equal to zero and smaller than the value 12610 ** output by xInstCount(). 12611 ** 12612 ** Usually, output parameter *piPhrase is set to the phrase number, *piCol 12613 ** to the column in which it occurs and *piOff the token offset of the 12614 ** first token of the phrase. Returns SQLITE_OK if successful, or an error 12615 ** code (i.e. SQLITE_NOMEM) if an error occurs. 12616 ** 12617 ** This API can be quite slow if used with an FTS5 table created with the 12618 ** "detail=none" or "detail=column" option. 12619 ** 12620 ** xRowid: 12621 ** Returns the rowid of the current row. 12622 ** 12623 ** xTokenize: 12624 ** Tokenize text using the tokenizer belonging to the FTS5 table. 12625 ** 12626 ** xQueryPhrase(pFts5, iPhrase, pUserData, xCallback): 12627 ** This API function is used to query the FTS table for phrase iPhrase 12628 ** of the current query. Specifically, a query equivalent to: 12629 ** 12630 ** ... FROM ftstable WHERE ftstable MATCH $p ORDER BY rowid 12631 ** 12632 ** with $p set to a phrase equivalent to the phrase iPhrase of the 12633 ** current query is executed. Any column filter that applies to 12634 ** phrase iPhrase of the current query is included in $p. For each 12635 ** row visited, the callback function passed as the fourth argument 12636 ** is invoked. The context and API objects passed to the callback 12637 ** function may be used to access the properties of each matched row. 12638 ** Invoking Api.xUserData() returns a copy of the pointer passed as 12639 ** the third argument to pUserData. 12640 ** 12641 ** If the callback function returns any value other than SQLITE_OK, the 12642 ** query is abandoned and the xQueryPhrase function returns immediately. 12643 ** If the returned value is SQLITE_DONE, xQueryPhrase returns SQLITE_OK. 12644 ** Otherwise, the error code is propagated upwards. 12645 ** 12646 ** If the query runs to completion without incident, SQLITE_OK is returned. 12647 ** Or, if some error occurs before the query completes or is aborted by 12648 ** the callback, an SQLite error code is returned. 12649 ** 12650 ** 12651 ** xSetAuxdata(pFts5, pAux, xDelete) 12652 ** 12653 ** Save the pointer passed as the second argument as the extension function's 12654 ** "auxiliary data". The pointer may then be retrieved by the current or any 12655 ** future invocation of the same fts5 extension function made as part of 12656 ** the same MATCH query using the xGetAuxdata() API. 12657 ** 12658 ** Each extension function is allocated a single auxiliary data slot for 12659 ** each FTS query (MATCH expression). If the extension function is invoked 12660 ** more than once for a single FTS query, then all invocations share a 12661 ** single auxiliary data context. 12662 ** 12663 ** If there is already an auxiliary data pointer when this function is 12664 ** invoked, then it is replaced by the new pointer. If an xDelete callback 12665 ** was specified along with the original pointer, it is invoked at this 12666 ** point. 12667 ** 12668 ** The xDelete callback, if one is specified, is also invoked on the 12669 ** auxiliary data pointer after the FTS5 query has finished. 12670 ** 12671 ** If an error (e.g. an OOM condition) occurs within this function, 12672 ** the auxiliary data is set to NULL and an error code returned. If the 12673 ** xDelete parameter was not NULL, it is invoked on the auxiliary data 12674 ** pointer before returning. 12675 ** 12676 ** 12677 ** xGetAuxdata(pFts5, bClear) 12678 ** 12679 ** Returns the current auxiliary data pointer for the fts5 extension 12680 ** function. See the xSetAuxdata() method for details. 12681 ** 12682 ** If the bClear argument is non-zero, then the auxiliary data is cleared 12683 ** (set to NULL) before this function returns. In this case the xDelete, 12684 ** if any, is not invoked. 12685 ** 12686 ** 12687 ** xRowCount(pFts5, pnRow) 12688 ** 12689 ** This function is used to retrieve the total number of rows in the table. 12690 ** In other words, the same value that would be returned by: 12691 ** 12692 ** SELECT count(*) FROM ftstable; 12693 ** 12694 ** xPhraseFirst() 12695 ** This function is used, along with type Fts5PhraseIter and the xPhraseNext 12696 ** method, to iterate through all instances of a single query phrase within 12697 ** the current row. This is the same information as is accessible via the 12698 ** xInstCount/xInst APIs. While the xInstCount/xInst APIs are more convenient 12699 ** to use, this API may be faster under some circumstances. To iterate 12700 ** through instances of phrase iPhrase, use the following code: 12701 ** 12702 ** Fts5PhraseIter iter; 12703 ** int iCol, iOff; 12704 ** for(pApi->xPhraseFirst(pFts, iPhrase, &iter, &iCol, &iOff); 12705 ** iCol>=0; 12706 ** pApi->xPhraseNext(pFts, &iter, &iCol, &iOff) 12707 ** ){ 12708 ** // An instance of phrase iPhrase at offset iOff of column iCol 12709 ** } 12710 ** 12711 ** The Fts5PhraseIter structure is defined above. Applications should not 12712 ** modify this structure directly - it should only be used as shown above 12713 ** with the xPhraseFirst() and xPhraseNext() API methods (and by 12714 ** xPhraseFirstColumn() and xPhraseNextColumn() as illustrated below). 12715 ** 12716 ** This API can be quite slow if used with an FTS5 table created with the 12717 ** "detail=none" or "detail=column" option. If the FTS5 table is created 12718 ** with either "detail=none" or "detail=column" and "content=" option 12719 ** (i.e. if it is a contentless table), then this API always iterates 12720 ** through an empty set (all calls to xPhraseFirst() set iCol to -1). 12721 ** 12722 ** xPhraseNext() 12723 ** See xPhraseFirst above. 12724 ** 12725 ** xPhraseFirstColumn() 12726 ** This function and xPhraseNextColumn() are similar to the xPhraseFirst() 12727 ** and xPhraseNext() APIs described above. The difference is that instead 12728 ** of iterating through all instances of a phrase in the current row, these 12729 ** APIs are used to iterate through the set of columns in the current row 12730 ** that contain one or more instances of a specified phrase. For example: 12731 ** 12732 ** Fts5PhraseIter iter; 12733 ** int iCol; 12734 ** for(pApi->xPhraseFirstColumn(pFts, iPhrase, &iter, &iCol); 12735 ** iCol>=0; 12736 ** pApi->xPhraseNextColumn(pFts, &iter, &iCol) 12737 ** ){ 12738 ** // Column iCol contains at least one instance of phrase iPhrase 12739 ** } 12740 ** 12741 ** This API can be quite slow if used with an FTS5 table created with the 12742 ** "detail=none" option. If the FTS5 table is created with either 12743 ** "detail=none" "content=" option (i.e. if it is a contentless table), 12744 ** then this API always iterates through an empty set (all calls to 12745 ** xPhraseFirstColumn() set iCol to -1). 12746 ** 12747 ** The information accessed using this API and its companion 12748 ** xPhraseFirstColumn() may also be obtained using xPhraseFirst/xPhraseNext 12749 ** (or xInst/xInstCount). The chief advantage of this API is that it is 12750 ** significantly more efficient than those alternatives when used with 12751 ** "detail=column" tables. 12752 ** 12753 ** xPhraseNextColumn() 12754 ** See xPhraseFirstColumn above. 12755 */ 12756 struct Fts5ExtensionApi { 12757 int iVersion; /* Currently always set to 3 */ 12758 12759 void *(*xUserData)(Fts5Context*); 12760 12761 int (*xColumnCount)(Fts5Context*); 12762 int (*xRowCount)(Fts5Context*, sqlite3_int64 *pnRow); 12763 int (*xColumnTotalSize)(Fts5Context*, int iCol, sqlite3_int64 *pnToken); 12764 12765 int (*xTokenize)(Fts5Context*, 12766 const char *pText, int nText, /* Text to tokenize */ 12767 void *pCtx, /* Context passed to xToken() */ 12768 int (*xToken)(void*, int, const char*, int, int, int) /* Callback */ 12769 ); 12770 12771 int (*xPhraseCount)(Fts5Context*); 12772 int (*xPhraseSize)(Fts5Context*, int iPhrase); 12773 12774 int (*xInstCount)(Fts5Context*, int *pnInst); 12775 int (*xInst)(Fts5Context*, int iIdx, int *piPhrase, int *piCol, int *piOff); 12776 12777 sqlite3_int64 (*xRowid)(Fts5Context*); 12778 int (*xColumnText)(Fts5Context*, int iCol, const char **pz, int *pn); 12779 int (*xColumnSize)(Fts5Context*, int iCol, int *pnToken); 12780 12781 int (*xQueryPhrase)(Fts5Context*, int iPhrase, void *pUserData, 12782 int(*)(const Fts5ExtensionApi*,Fts5Context*,void*) 12783 ); 12784 int (*xSetAuxdata)(Fts5Context*, void *pAux, void(*xDelete)(void*)); 12785 void *(*xGetAuxdata)(Fts5Context*, int bClear); 12786 12787 int (*xPhraseFirst)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*, int*); 12788 void (*xPhraseNext)(Fts5Context*, Fts5PhraseIter*, int *piCol, int *piOff); 12789 12790 int (*xPhraseFirstColumn)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*); 12791 void (*xPhraseNextColumn)(Fts5Context*, Fts5PhraseIter*, int *piCol); 12792 }; 12793 12794 /* 12795 ** CUSTOM AUXILIARY FUNCTIONS 12796 *************************************************************************/ 12797 12798 /************************************************************************* 12799 ** CUSTOM TOKENIZERS 12800 ** 12801 ** Applications may also register custom tokenizer types. A tokenizer 12802 ** is registered by providing fts5 with a populated instance of the 12803 ** following structure. All structure methods must be defined, setting 12804 ** any member of the fts5_tokenizer struct to NULL leads to undefined 12805 ** behaviour. The structure methods are expected to function as follows: 12806 ** 12807 ** xCreate: 12808 ** This function is used to allocate and initialize a tokenizer instance. 12809 ** A tokenizer instance is required to actually tokenize text. 12810 ** 12811 ** The first argument passed to this function is a copy of the (void*) 12812 ** pointer provided by the application when the fts5_tokenizer object 12813 ** was registered with FTS5 (the third argument to xCreateTokenizer()). 12814 ** The second and third arguments are an array of nul-terminated strings 12815 ** containing the tokenizer arguments, if any, specified following the 12816 ** tokenizer name as part of the CREATE VIRTUAL TABLE statement used 12817 ** to create the FTS5 table. 12818 ** 12819 ** The final argument is an output variable. If successful, (*ppOut) 12820 ** should be set to point to the new tokenizer handle and SQLITE_OK 12821 ** returned. If an error occurs, some value other than SQLITE_OK should 12822 ** be returned. In this case, fts5 assumes that the final value of *ppOut 12823 ** is undefined. 12824 ** 12825 ** xDelete: 12826 ** This function is invoked to delete a tokenizer handle previously 12827 ** allocated using xCreate(). Fts5 guarantees that this function will 12828 ** be invoked exactly once for each successful call to xCreate(). 12829 ** 12830 ** xTokenize: 12831 ** This function is expected to tokenize the nText byte string indicated 12832 ** by argument pText. pText may or may not be nul-terminated. The first 12833 ** argument passed to this function is a pointer to an Fts5Tokenizer object 12834 ** returned by an earlier call to xCreate(). 12835 ** 12836 ** The second argument indicates the reason that FTS5 is requesting 12837 ** tokenization of the supplied text. This is always one of the following 12838 ** four values: 12839 ** 12840 ** <ul><li> <b>FTS5_TOKENIZE_DOCUMENT</b> - A document is being inserted into 12841 ** or removed from the FTS table. The tokenizer is being invoked to 12842 ** determine the set of tokens to add to (or delete from) the 12843 ** FTS index. 12844 ** 12845 ** <li> <b>FTS5_TOKENIZE_QUERY</b> - A MATCH query is being executed 12846 ** against the FTS index. The tokenizer is being called to tokenize 12847 ** a bareword or quoted string specified as part of the query. 12848 ** 12849 ** <li> <b>(FTS5_TOKENIZE_QUERY | FTS5_TOKENIZE_PREFIX)</b> - Same as 12850 ** FTS5_TOKENIZE_QUERY, except that the bareword or quoted string is 12851 ** followed by a "*" character, indicating that the last token 12852 ** returned by the tokenizer will be treated as a token prefix. 12853 ** 12854 ** <li> <b>FTS5_TOKENIZE_AUX</b> - The tokenizer is being invoked to 12855 ** satisfy an fts5_api.xTokenize() request made by an auxiliary 12856 ** function. Or an fts5_api.xColumnSize() request made by the same 12857 ** on a columnsize=0 database. 12858 ** </ul> 12859 ** 12860 ** For each token in the input string, the supplied callback xToken() must 12861 ** be invoked. The first argument to it should be a copy of the pointer 12862 ** passed as the second argument to xTokenize(). The third and fourth 12863 ** arguments are a pointer to a buffer containing the token text, and the 12864 ** size of the token in bytes. The 4th and 5th arguments are the byte offsets 12865 ** of the first byte of and first byte immediately following the text from 12866 ** which the token is derived within the input. 12867 ** 12868 ** The second argument passed to the xToken() callback ("tflags") should 12869 ** normally be set to 0. The exception is if the tokenizer supports 12870 ** synonyms. In this case see the discussion below for details. 12871 ** 12872 ** FTS5 assumes the xToken() callback is invoked for each token in the 12873 ** order that they occur within the input text. 12874 ** 12875 ** If an xToken() callback returns any value other than SQLITE_OK, then 12876 ** the tokenization should be abandoned and the xTokenize() method should 12877 ** immediately return a copy of the xToken() return value. Or, if the 12878 ** input buffer is exhausted, xTokenize() should return SQLITE_OK. Finally, 12879 ** if an error occurs with the xTokenize() implementation itself, it 12880 ** may abandon the tokenization and return any error code other than 12881 ** SQLITE_OK or SQLITE_DONE. 12882 ** 12883 ** SYNONYM SUPPORT 12884 ** 12885 ** Custom tokenizers may also support synonyms. Consider a case in which a 12886 ** user wishes to query for a phrase such as "first place". Using the 12887 ** built-in tokenizers, the FTS5 query 'first + place' will match instances 12888 ** of "first place" within the document set, but not alternative forms 12889 ** such as "1st place". In some applications, it would be better to match 12890 ** all instances of "first place" or "1st place" regardless of which form 12891 ** the user specified in the MATCH query text. 12892 ** 12893 ** There are several ways to approach this in FTS5: 12894 ** 12895 ** <ol><li> By mapping all synonyms to a single token. In this case, using 12896 ** the above example, this means that the tokenizer returns the 12897 ** same token for inputs "first" and "1st". Say that token is in 12898 ** fact "first", so that when the user inserts the document "I won 12899 ** 1st place" entries are added to the index for tokens "i", "won", 12900 ** "first" and "place". If the user then queries for '1st + place', 12901 ** the tokenizer substitutes "first" for "1st" and the query works 12902 ** as expected. 12903 ** 12904 ** <li> By querying the index for all synonyms of each query term 12905 ** separately. In this case, when tokenizing query text, the 12906 ** tokenizer may provide multiple synonyms for a single term 12907 ** within the document. FTS5 then queries the index for each 12908 ** synonym individually. For example, faced with the query: 12909 ** 12910 ** <codeblock> 12911 ** ... MATCH 'first place'</codeblock> 12912 ** 12913 ** the tokenizer offers both "1st" and "first" as synonyms for the 12914 ** first token in the MATCH query and FTS5 effectively runs a query 12915 ** similar to: 12916 ** 12917 ** <codeblock> 12918 ** ... MATCH '(first OR 1st) place'</codeblock> 12919 ** 12920 ** except that, for the purposes of auxiliary functions, the query 12921 ** still appears to contain just two phrases - "(first OR 1st)" 12922 ** being treated as a single phrase. 12923 ** 12924 ** <li> By adding multiple synonyms for a single term to the FTS index. 12925 ** Using this method, when tokenizing document text, the tokenizer 12926 ** provides multiple synonyms for each token. So that when a 12927 ** document such as "I won first place" is tokenized, entries are 12928 ** added to the FTS index for "i", "won", "first", "1st" and 12929 ** "place". 12930 ** 12931 ** This way, even if the tokenizer does not provide synonyms 12932 ** when tokenizing query text (it should not - to do so would be 12933 ** inefficient), it doesn't matter if the user queries for 12934 ** 'first + place' or '1st + place', as there are entries in the 12935 ** FTS index corresponding to both forms of the first token. 12936 ** </ol> 12937 ** 12938 ** Whether it is parsing document or query text, any call to xToken that 12939 ** specifies a <i>tflags</i> argument with the FTS5_TOKEN_COLOCATED bit 12940 ** is considered to supply a synonym for the previous token. For example, 12941 ** when parsing the document "I won first place", a tokenizer that supports 12942 ** synonyms would call xToken() 5 times, as follows: 12943 ** 12944 ** <codeblock> 12945 ** xToken(pCtx, 0, "i", 1, 0, 1); 12946 ** xToken(pCtx, 0, "won", 3, 2, 5); 12947 ** xToken(pCtx, 0, "first", 5, 6, 11); 12948 ** xToken(pCtx, FTS5_TOKEN_COLOCATED, "1st", 3, 6, 11); 12949 ** xToken(pCtx, 0, "place", 5, 12, 17); 12950 **</codeblock> 12951 ** 12952 ** It is an error to specify the FTS5_TOKEN_COLOCATED flag the first time 12953 ** xToken() is called. Multiple synonyms may be specified for a single token 12954 ** by making multiple calls to xToken(FTS5_TOKEN_COLOCATED) in sequence. 12955 ** There is no limit to the number of synonyms that may be provided for a 12956 ** single token. 12957 ** 12958 ** In many cases, method (1) above is the best approach. It does not add 12959 ** extra data to the FTS index or require FTS5 to query for multiple terms, 12960 ** so it is efficient in terms of disk space and query speed. However, it 12961 ** does not support prefix queries very well. If, as suggested above, the 12962 ** token "first" is substituted for "1st" by the tokenizer, then the query: 12963 ** 12964 ** <codeblock> 12965 ** ... MATCH '1s*'</codeblock> 12966 ** 12967 ** will not match documents that contain the token "1st" (as the tokenizer 12968 ** will probably not map "1s" to any prefix of "first"). 12969 ** 12970 ** For full prefix support, method (3) may be preferred. In this case, 12971 ** because the index contains entries for both "first" and "1st", prefix 12972 ** queries such as 'fi*' or '1s*' will match correctly. However, because 12973 ** extra entries are added to the FTS index, this method uses more space 12974 ** within the database. 12975 ** 12976 ** Method (2) offers a midpoint between (1) and (3). Using this method, 12977 ** a query such as '1s*' will match documents that contain the literal 12978 ** token "1st", but not "first" (assuming the tokenizer is not able to 12979 ** provide synonyms for prefixes). However, a non-prefix query like '1st' 12980 ** will match against "1st" and "first". This method does not require 12981 ** extra disk space, as no extra entries are added to the FTS index. 12982 ** On the other hand, it may require more CPU cycles to run MATCH queries, 12983 ** as separate queries of the FTS index are required for each synonym. 12984 ** 12985 ** When using methods (2) or (3), it is important that the tokenizer only 12986 ** provide synonyms when tokenizing document text (method (2)) or query 12987 ** text (method (3)), not both. Doing so will not cause any errors, but is 12988 ** inefficient. 12989 */ 12990 typedef struct Fts5Tokenizer Fts5Tokenizer; 12991 typedef struct fts5_tokenizer fts5_tokenizer; 12992 struct fts5_tokenizer { 12993 int (*xCreate)(void*, const char **azArg, int nArg, Fts5Tokenizer **ppOut); 12994 void (*xDelete)(Fts5Tokenizer*); 12995 int (*xTokenize)(Fts5Tokenizer*, 12996 void *pCtx, 12997 int flags, /* Mask of FTS5_TOKENIZE_* flags */ 12998 const char *pText, int nText, 12999 int (*xToken)( 13000 void *pCtx, /* Copy of 2nd argument to xTokenize() */ 13001 int tflags, /* Mask of FTS5_TOKEN_* flags */ 13002 const char *pToken, /* Pointer to buffer containing token */ 13003 int nToken, /* Size of token in bytes */ 13004 int iStart, /* Byte offset of token within input text */ 13005 int iEnd /* Byte offset of end of token within input text */ 13006 ) 13007 ); 13008 }; 13009 13010 /* Flags that may be passed as the third argument to xTokenize() */ 13011 #define FTS5_TOKENIZE_QUERY 0x0001 13012 #define FTS5_TOKENIZE_PREFIX 0x0002 13013 #define FTS5_TOKENIZE_DOCUMENT 0x0004 13014 #define FTS5_TOKENIZE_AUX 0x0008 13015 13016 /* Flags that may be passed by the tokenizer implementation back to FTS5 13017 ** as the third argument to the supplied xToken callback. */ 13018 #define FTS5_TOKEN_COLOCATED 0x0001 /* Same position as prev. token */ 13019 13020 /* 13021 ** END OF CUSTOM TOKENIZERS 13022 *************************************************************************/ 13023 13024 /************************************************************************* 13025 ** FTS5 EXTENSION REGISTRATION API 13026 */ 13027 typedef struct fts5_api fts5_api; 13028 struct fts5_api { 13029 int iVersion; /* Currently always set to 2 */ 13030 13031 /* Create a new tokenizer */ 13032 int (*xCreateTokenizer)( 13033 fts5_api *pApi, 13034 const char *zName, 13035 void *pContext, 13036 fts5_tokenizer *pTokenizer, 13037 void (*xDestroy)(void*) 13038 ); 13039 13040 /* Find an existing tokenizer */ 13041 int (*xFindTokenizer)( 13042 fts5_api *pApi, 13043 const char *zName, 13044 void **ppContext, 13045 fts5_tokenizer *pTokenizer 13046 ); 13047 13048 /* Create a new auxiliary function */ 13049 int (*xCreateFunction)( 13050 fts5_api *pApi, 13051 const char *zName, 13052 void *pContext, 13053 fts5_extension_function xFunction, 13054 void (*xDestroy)(void*) 13055 ); 13056 }; 13057 13058 /* 13059 ** END OF REGISTRATION API 13060 *************************************************************************/ 13061 13062 #ifdef __cplusplus 13063 } /* end of the 'extern "C"' block */ 13064 #endif 13065 13066 #endif /* _FTS5_H */ 13067 13068 /******** End of fts5.h *********/ 13069