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 "3.44.0" 150 #define SQLITE_VERSION_NUMBER 3044000 151 #define SQLITE_SOURCE_ID "2023-11-01 11:23:50 17129ba1ff7f0daf37100ee82d507aef7827cf38de1866e2633096ae6ad81301" 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_IOERR_IN_PAGE (SQLITE_IOERR | (34<<8)) 532 #define SQLITE_LOCKED_SHAREDCACHE (SQLITE_LOCKED | (1<<8)) 533 #define SQLITE_LOCKED_VTAB (SQLITE_LOCKED | (2<<8)) 534 #define SQLITE_BUSY_RECOVERY (SQLITE_BUSY | (1<<8)) 535 #define SQLITE_BUSY_SNAPSHOT (SQLITE_BUSY | (2<<8)) 536 #define SQLITE_BUSY_TIMEOUT (SQLITE_BUSY | (3<<8)) 537 #define SQLITE_CANTOPEN_NOTEMPDIR (SQLITE_CANTOPEN | (1<<8)) 538 #define SQLITE_CANTOPEN_ISDIR (SQLITE_CANTOPEN | (2<<8)) 539 #define SQLITE_CANTOPEN_FULLPATH (SQLITE_CANTOPEN | (3<<8)) 540 #define SQLITE_CANTOPEN_CONVPATH (SQLITE_CANTOPEN | (4<<8)) 541 #define SQLITE_CANTOPEN_DIRTYWAL (SQLITE_CANTOPEN | (5<<8)) /* Not Used */ 542 #define SQLITE_CANTOPEN_SYMLINK (SQLITE_CANTOPEN | (6<<8)) 543 #define SQLITE_CORRUPT_VTAB (SQLITE_CORRUPT | (1<<8)) 544 #define SQLITE_CORRUPT_SEQUENCE (SQLITE_CORRUPT | (2<<8)) 545 #define SQLITE_CORRUPT_INDEX (SQLITE_CORRUPT | (3<<8)) 546 #define SQLITE_READONLY_RECOVERY (SQLITE_READONLY | (1<<8)) 547 #define SQLITE_READONLY_CANTLOCK (SQLITE_READONLY | (2<<8)) 548 #define SQLITE_READONLY_ROLLBACK (SQLITE_READONLY | (3<<8)) 549 #define SQLITE_READONLY_DBMOVED (SQLITE_READONLY | (4<<8)) 550 #define SQLITE_READONLY_CANTINIT (SQLITE_READONLY | (5<<8)) 551 #define SQLITE_READONLY_DIRECTORY (SQLITE_READONLY | (6<<8)) 552 #define SQLITE_ABORT_ROLLBACK (SQLITE_ABORT | (2<<8)) 553 #define SQLITE_CONSTRAINT_CHECK (SQLITE_CONSTRAINT | (1<<8)) 554 #define SQLITE_CONSTRAINT_COMMITHOOK (SQLITE_CONSTRAINT | (2<<8)) 555 #define SQLITE_CONSTRAINT_FOREIGNKEY (SQLITE_CONSTRAINT | (3<<8)) 556 #define SQLITE_CONSTRAINT_FUNCTION (SQLITE_CONSTRAINT | (4<<8)) 557 #define SQLITE_CONSTRAINT_NOTNULL (SQLITE_CONSTRAINT | (5<<8)) 558 #define SQLITE_CONSTRAINT_PRIMARYKEY (SQLITE_CONSTRAINT | (6<<8)) 559 #define SQLITE_CONSTRAINT_TRIGGER (SQLITE_CONSTRAINT | (7<<8)) 560 #define SQLITE_CONSTRAINT_UNIQUE (SQLITE_CONSTRAINT | (8<<8)) 561 #define SQLITE_CONSTRAINT_VTAB (SQLITE_CONSTRAINT | (9<<8)) 562 #define SQLITE_CONSTRAINT_ROWID (SQLITE_CONSTRAINT |(10<<8)) 563 #define SQLITE_CONSTRAINT_PINNED (SQLITE_CONSTRAINT |(11<<8)) 564 #define SQLITE_CONSTRAINT_DATATYPE (SQLITE_CONSTRAINT |(12<<8)) 565 #define SQLITE_NOTICE_RECOVER_WAL (SQLITE_NOTICE | (1<<8)) 566 #define SQLITE_NOTICE_RECOVER_ROLLBACK (SQLITE_NOTICE | (2<<8)) 567 #define SQLITE_NOTICE_RBU (SQLITE_NOTICE | (3<<8)) 568 #define SQLITE_WARNING_AUTOINDEX (SQLITE_WARNING | (1<<8)) 569 #define SQLITE_AUTH_USER (SQLITE_AUTH | (1<<8)) 570 #define SQLITE_OK_LOAD_PERMANENTLY (SQLITE_OK | (1<<8)) 571 #define SQLITE_OK_SYMLINK (SQLITE_OK | (2<<8)) /* internal use only */ 572 573 /* 574 ** CAPI3REF: Flags For File Open Operations 575 ** 576 ** These bit values are intended for use in the 577 ** 3rd parameter to the [sqlite3_open_v2()] interface and 578 ** in the 4th parameter to the [sqlite3_vfs.xOpen] method. 579 ** 580 ** Only those flags marked as "Ok for sqlite3_open_v2()" may be 581 ** used as the third argument to the [sqlite3_open_v2()] interface. 582 ** The other flags have historically been ignored by sqlite3_open_v2(), 583 ** though future versions of SQLite might change so that an error is 584 ** raised if any of the disallowed bits are passed into sqlite3_open_v2(). 585 ** Applications should not depend on the historical behavior. 586 ** 587 ** Note in particular that passing the SQLITE_OPEN_EXCLUSIVE flag into 588 ** [sqlite3_open_v2()] does *not* cause the underlying database file 589 ** to be opened using O_EXCL. Passing SQLITE_OPEN_EXCLUSIVE into 590 ** [sqlite3_open_v2()] has historically be a no-op and might become an 591 ** error in future versions of SQLite. 592 */ 593 #define SQLITE_OPEN_READONLY 0x00000001 /* Ok for sqlite3_open_v2() */ 594 #define SQLITE_OPEN_READWRITE 0x00000002 /* Ok for sqlite3_open_v2() */ 595 #define SQLITE_OPEN_CREATE 0x00000004 /* Ok for sqlite3_open_v2() */ 596 #define SQLITE_OPEN_DELETEONCLOSE 0x00000008 /* VFS only */ 597 #define SQLITE_OPEN_EXCLUSIVE 0x00000010 /* VFS only */ 598 #define SQLITE_OPEN_AUTOPROXY 0x00000020 /* VFS only */ 599 #define SQLITE_OPEN_URI 0x00000040 /* Ok for sqlite3_open_v2() */ 600 #define SQLITE_OPEN_MEMORY 0x00000080 /* Ok for sqlite3_open_v2() */ 601 #define SQLITE_OPEN_MAIN_DB 0x00000100 /* VFS only */ 602 #define SQLITE_OPEN_TEMP_DB 0x00000200 /* VFS only */ 603 #define SQLITE_OPEN_TRANSIENT_DB 0x00000400 /* VFS only */ 604 #define SQLITE_OPEN_MAIN_JOURNAL 0x00000800 /* VFS only */ 605 #define SQLITE_OPEN_TEMP_JOURNAL 0x00001000 /* VFS only */ 606 #define SQLITE_OPEN_SUBJOURNAL 0x00002000 /* VFS only */ 607 #define SQLITE_OPEN_SUPER_JOURNAL 0x00004000 /* VFS only */ 608 #define SQLITE_OPEN_NOMUTEX 0x00008000 /* Ok for sqlite3_open_v2() */ 609 #define SQLITE_OPEN_FULLMUTEX 0x00010000 /* Ok for sqlite3_open_v2() */ 610 #define SQLITE_OPEN_SHAREDCACHE 0x00020000 /* Ok for sqlite3_open_v2() */ 611 #define SQLITE_OPEN_PRIVATECACHE 0x00040000 /* Ok for sqlite3_open_v2() */ 612 #define SQLITE_OPEN_WAL 0x00080000 /* VFS only */ 613 #define SQLITE_OPEN_NOFOLLOW 0x01000000 /* Ok for sqlite3_open_v2() */ 614 #define SQLITE_OPEN_EXRESCODE 0x02000000 /* Extended result codes */ 615 616 /* Reserved: 0x00F00000 */ 617 /* Legacy compatibility: */ 618 #define SQLITE_OPEN_MASTER_JOURNAL 0x00004000 /* VFS only */ 619 620 621 /* 622 ** CAPI3REF: Device Characteristics 623 ** 624 ** The xDeviceCharacteristics method of the [sqlite3_io_methods] 625 ** object returns an integer which is a vector of these 626 ** bit values expressing I/O characteristics of the mass storage 627 ** device that holds the file that the [sqlite3_io_methods] 628 ** refers to. 629 ** 630 ** The SQLITE_IOCAP_ATOMIC property means that all writes of 631 ** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 632 ** mean that writes of blocks that are nnn bytes in size and 633 ** are aligned to an address which is an integer multiple of 634 ** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 635 ** that when data is appended to a file, the data is appended 636 ** first then the size of the file is extended, never the other 637 ** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 638 ** information is written to disk in the same order as calls 639 ** to xWrite(). The SQLITE_IOCAP_POWERSAFE_OVERWRITE property means that 640 ** after reboot following a crash or power loss, the only bytes in a 641 ** file that were written at the application level might have changed 642 ** and that adjacent bytes, even bytes within the same sector are 643 ** guaranteed to be unchanged. The SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 644 ** flag indicates that a file cannot be deleted when open. The 645 ** SQLITE_IOCAP_IMMUTABLE flag indicates that the file is on 646 ** read-only media and cannot be changed even by processes with 647 ** elevated privileges. 648 ** 649 ** The SQLITE_IOCAP_BATCH_ATOMIC property means that the underlying 650 ** filesystem supports doing multiple write operations atomically when those 651 ** write operations are bracketed by [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] and 652 ** [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]. 653 */ 654 #define SQLITE_IOCAP_ATOMIC 0x00000001 655 #define SQLITE_IOCAP_ATOMIC512 0x00000002 656 #define SQLITE_IOCAP_ATOMIC1K 0x00000004 657 #define SQLITE_IOCAP_ATOMIC2K 0x00000008 658 #define SQLITE_IOCAP_ATOMIC4K 0x00000010 659 #define SQLITE_IOCAP_ATOMIC8K 0x00000020 660 #define SQLITE_IOCAP_ATOMIC16K 0x00000040 661 #define SQLITE_IOCAP_ATOMIC32K 0x00000080 662 #define SQLITE_IOCAP_ATOMIC64K 0x00000100 663 #define SQLITE_IOCAP_SAFE_APPEND 0x00000200 664 #define SQLITE_IOCAP_SEQUENTIAL 0x00000400 665 #define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 0x00000800 666 #define SQLITE_IOCAP_POWERSAFE_OVERWRITE 0x00001000 667 #define SQLITE_IOCAP_IMMUTABLE 0x00002000 668 #define SQLITE_IOCAP_BATCH_ATOMIC 0x00004000 669 670 /* 671 ** CAPI3REF: File Locking Levels 672 ** 673 ** SQLite uses one of these integer values as the second 674 ** argument to calls it makes to the xLock() and xUnlock() methods 675 ** of an [sqlite3_io_methods] object. These values are ordered from 676 ** lest restrictive to most restrictive. 677 ** 678 ** The argument to xLock() is always SHARED or higher. The argument to 679 ** xUnlock is either SHARED or NONE. 680 */ 681 #define SQLITE_LOCK_NONE 0 /* xUnlock() only */ 682 #define SQLITE_LOCK_SHARED 1 /* xLock() or xUnlock() */ 683 #define SQLITE_LOCK_RESERVED 2 /* xLock() only */ 684 #define SQLITE_LOCK_PENDING 3 /* xLock() only */ 685 #define SQLITE_LOCK_EXCLUSIVE 4 /* xLock() only */ 686 687 /* 688 ** CAPI3REF: Synchronization Type Flags 689 ** 690 ** When SQLite invokes the xSync() method of an 691 ** [sqlite3_io_methods] object it uses a combination of 692 ** these integer values as the second argument. 693 ** 694 ** When the SQLITE_SYNC_DATAONLY flag is used, it means that the 695 ** sync operation only needs to flush data to mass storage. Inode 696 ** information need not be flushed. If the lower four bits of the flag 697 ** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics. 698 ** If the lower four bits equal SQLITE_SYNC_FULL, that means 699 ** to use Mac OS X style fullsync instead of fsync(). 700 ** 701 ** Do not confuse the SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags 702 ** with the [PRAGMA synchronous]=NORMAL and [PRAGMA synchronous]=FULL 703 ** settings. The [synchronous pragma] determines when calls to the 704 ** xSync VFS method occur and applies uniformly across all platforms. 705 ** The SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags determine how 706 ** energetic or rigorous or forceful the sync operations are and 707 ** only make a difference on Mac OSX for the default SQLite code. 708 ** (Third-party VFS implementations might also make the distinction 709 ** between SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL, but among the 710 ** operating systems natively supported by SQLite, only Mac OSX 711 ** cares about the difference.) 712 */ 713 #define SQLITE_SYNC_NORMAL 0x00002 714 #define SQLITE_SYNC_FULL 0x00003 715 #define SQLITE_SYNC_DATAONLY 0x00010 716 717 /* 718 ** CAPI3REF: OS Interface Open File Handle 719 ** 720 ** An [sqlite3_file] object represents an open file in the 721 ** [sqlite3_vfs | OS interface layer]. Individual OS interface 722 ** implementations will 723 ** want to subclass this object by appending additional fields 724 ** for their own use. The pMethods entry is a pointer to an 725 ** [sqlite3_io_methods] object that defines methods for performing 726 ** I/O operations on the open file. 727 */ 728 typedef struct sqlite3_file sqlite3_file; 729 struct sqlite3_file { 730 const struct sqlite3_io_methods *pMethods; /* Methods for an open file */ 731 }; 732 733 /* 734 ** CAPI3REF: OS Interface File Virtual Methods Object 735 ** 736 ** Every file opened by the [sqlite3_vfs.xOpen] method populates an 737 ** [sqlite3_file] object (or, more commonly, a subclass of the 738 ** [sqlite3_file] object) with a pointer to an instance of this object. 739 ** This object defines the methods used to perform various operations 740 ** against the open file represented by the [sqlite3_file] object. 741 ** 742 ** If the [sqlite3_vfs.xOpen] method sets the sqlite3_file.pMethods element 743 ** to a non-NULL pointer, then the sqlite3_io_methods.xClose method 744 ** may be invoked even if the [sqlite3_vfs.xOpen] reported that it failed. The 745 ** only way to prevent a call to xClose following a failed [sqlite3_vfs.xOpen] 746 ** is for the [sqlite3_vfs.xOpen] to set the sqlite3_file.pMethods element 747 ** to NULL. 748 ** 749 ** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or 750 ** [SQLITE_SYNC_FULL]. The first choice is the normal fsync(). 751 ** The second choice is a Mac OS X style fullsync. The [SQLITE_SYNC_DATAONLY] 752 ** flag may be ORed in to indicate that only the data of the file 753 ** and not its inode needs to be synced. 754 ** 755 ** The integer values to xLock() and xUnlock() are one of 756 ** <ul> 757 ** <li> [SQLITE_LOCK_NONE], 758 ** <li> [SQLITE_LOCK_SHARED], 759 ** <li> [SQLITE_LOCK_RESERVED], 760 ** <li> [SQLITE_LOCK_PENDING], or 761 ** <li> [SQLITE_LOCK_EXCLUSIVE]. 762 ** </ul> 763 ** xLock() upgrades the database file lock. In other words, xLock() moves the 764 ** database file lock in the direction NONE toward EXCLUSIVE. The argument to 765 ** xLock() is always on of SHARED, RESERVED, PENDING, or EXCLUSIVE, never 766 ** SQLITE_LOCK_NONE. If the database file lock is already at or above the 767 ** requested lock, then the call to xLock() is a no-op. 768 ** xUnlock() downgrades the database file lock to either SHARED or NONE. 769 * If the lock is already at or below the requested lock state, then the call 770 ** to xUnlock() is a no-op. 771 ** The xCheckReservedLock() method checks whether any database connection, 772 ** either in this process or in some other process, is holding a RESERVED, 773 ** PENDING, or EXCLUSIVE lock on the file. It returns true 774 ** if such a lock exists and false otherwise. 775 ** 776 ** The xFileControl() method is a generic interface that allows custom 777 ** VFS implementations to directly control an open file using the 778 ** [sqlite3_file_control()] interface. The second "op" argument is an 779 ** integer opcode. The third argument is a generic pointer intended to 780 ** point to a structure that may contain arguments or space in which to 781 ** write return values. Potential uses for xFileControl() might be 782 ** functions to enable blocking locks with timeouts, to change the 783 ** locking strategy (for example to use dot-file locks), to inquire 784 ** about the status of a lock, or to break stale locks. The SQLite 785 ** core reserves all opcodes less than 100 for its own use. 786 ** A [file control opcodes | list of opcodes] less than 100 is available. 787 ** Applications that define a custom xFileControl method should use opcodes 788 ** greater than 100 to avoid conflicts. VFS implementations should 789 ** return [SQLITE_NOTFOUND] for file control opcodes that they do not 790 ** recognize. 791 ** 792 ** The xSectorSize() method returns the sector size of the 793 ** device that underlies the file. The sector size is the 794 ** minimum write that can be performed without disturbing 795 ** other bytes in the file. The xDeviceCharacteristics() 796 ** method returns a bit vector describing behaviors of the 797 ** underlying device: 798 ** 799 ** <ul> 800 ** <li> [SQLITE_IOCAP_ATOMIC] 801 ** <li> [SQLITE_IOCAP_ATOMIC512] 802 ** <li> [SQLITE_IOCAP_ATOMIC1K] 803 ** <li> [SQLITE_IOCAP_ATOMIC2K] 804 ** <li> [SQLITE_IOCAP_ATOMIC4K] 805 ** <li> [SQLITE_IOCAP_ATOMIC8K] 806 ** <li> [SQLITE_IOCAP_ATOMIC16K] 807 ** <li> [SQLITE_IOCAP_ATOMIC32K] 808 ** <li> [SQLITE_IOCAP_ATOMIC64K] 809 ** <li> [SQLITE_IOCAP_SAFE_APPEND] 810 ** <li> [SQLITE_IOCAP_SEQUENTIAL] 811 ** <li> [SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN] 812 ** <li> [SQLITE_IOCAP_POWERSAFE_OVERWRITE] 813 ** <li> [SQLITE_IOCAP_IMMUTABLE] 814 ** <li> [SQLITE_IOCAP_BATCH_ATOMIC] 815 ** </ul> 816 ** 817 ** The SQLITE_IOCAP_ATOMIC property means that all writes of 818 ** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 819 ** mean that writes of blocks that are nnn bytes in size and 820 ** are aligned to an address which is an integer multiple of 821 ** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 822 ** that when data is appended to a file, the data is appended 823 ** first then the size of the file is extended, never the other 824 ** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 825 ** information is written to disk in the same order as calls 826 ** to xWrite(). 827 ** 828 ** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill 829 ** in the unread portions of the buffer with zeros. A VFS that 830 ** fails to zero-fill short reads might seem to work. However, 831 ** failure to zero-fill short reads will eventually lead to 832 ** database corruption. 833 */ 834 typedef struct sqlite3_io_methods sqlite3_io_methods; 835 struct sqlite3_io_methods { 836 int iVersion; 837 int (*xClose)(sqlite3_file*); 838 int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst); 839 int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst); 840 int (*xTruncate)(sqlite3_file*, sqlite3_int64 size); 841 int (*xSync)(sqlite3_file*, int flags); 842 int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize); 843 int (*xLock)(sqlite3_file*, int); 844 int (*xUnlock)(sqlite3_file*, int); 845 int (*xCheckReservedLock)(sqlite3_file*, int *pResOut); 846 int (*xFileControl)(sqlite3_file*, int op, void *pArg); 847 int (*xSectorSize)(sqlite3_file*); 848 int (*xDeviceCharacteristics)(sqlite3_file*); 849 /* Methods above are valid for version 1 */ 850 int (*xShmMap)(sqlite3_file*, int iPg, int pgsz, int, void volatile**); 851 int (*xShmLock)(sqlite3_file*, int offset, int n, int flags); 852 void (*xShmBarrier)(sqlite3_file*); 853 int (*xShmUnmap)(sqlite3_file*, int deleteFlag); 854 /* Methods above are valid for version 2 */ 855 int (*xFetch)(sqlite3_file*, sqlite3_int64 iOfst, int iAmt, void **pp); 856 int (*xUnfetch)(sqlite3_file*, sqlite3_int64 iOfst, void *p); 857 /* Methods above are valid for version 3 */ 858 /* Additional methods may be added in future releases */ 859 }; 860 861 /* 862 ** CAPI3REF: Standard File Control Opcodes 863 ** KEYWORDS: {file control opcodes} {file control opcode} 864 ** 865 ** These integer constants are opcodes for the xFileControl method 866 ** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()] 867 ** interface. 868 ** 869 ** <ul> 870 ** <li>[[SQLITE_FCNTL_LOCKSTATE]] 871 ** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging. This 872 ** opcode causes the xFileControl method to write the current state of 873 ** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED], 874 ** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE]) 875 ** into an integer that the pArg argument points to. 876 ** This capability is only available if SQLite is compiled with [SQLITE_DEBUG]. 877 ** 878 ** <li>[[SQLITE_FCNTL_SIZE_HINT]] 879 ** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS 880 ** layer a hint of how large the database file will grow to be during the 881 ** current transaction. This hint is not guaranteed to be accurate but it 882 ** is often close. The underlying VFS might choose to preallocate database 883 ** file space based on this hint in order to help writes to the database 884 ** file run faster. 885 ** 886 ** <li>[[SQLITE_FCNTL_SIZE_LIMIT]] 887 ** The [SQLITE_FCNTL_SIZE_LIMIT] opcode is used by in-memory VFS that 888 ** implements [sqlite3_deserialize()] to set an upper bound on the size 889 ** of the in-memory database. The argument is a pointer to a [sqlite3_int64]. 890 ** If the integer pointed to is negative, then it is filled in with the 891 ** current limit. Otherwise the limit is set to the larger of the value 892 ** of the integer pointed to and the current database size. The integer 893 ** pointed to is set to the new limit. 894 ** 895 ** <li>[[SQLITE_FCNTL_CHUNK_SIZE]] 896 ** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS 897 ** extends and truncates the database file in chunks of a size specified 898 ** by the user. The fourth argument to [sqlite3_file_control()] should 899 ** point to an integer (type int) containing the new chunk-size to use 900 ** for the nominated database. Allocating database file space in large 901 ** chunks (say 1MB at a time), may reduce file-system fragmentation and 902 ** improve performance on some systems. 903 ** 904 ** <li>[[SQLITE_FCNTL_FILE_POINTER]] 905 ** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer 906 ** to the [sqlite3_file] object associated with a particular database 907 ** connection. See also [SQLITE_FCNTL_JOURNAL_POINTER]. 908 ** 909 ** <li>[[SQLITE_FCNTL_JOURNAL_POINTER]] 910 ** The [SQLITE_FCNTL_JOURNAL_POINTER] opcode is used to obtain a pointer 911 ** to the [sqlite3_file] object associated with the journal file (either 912 ** the [rollback journal] or the [write-ahead log]) for a particular database 913 ** connection. See also [SQLITE_FCNTL_FILE_POINTER]. 914 ** 915 ** <li>[[SQLITE_FCNTL_SYNC_OMITTED]] 916 ** No longer in use. 917 ** 918 ** <li>[[SQLITE_FCNTL_SYNC]] 919 ** The [SQLITE_FCNTL_SYNC] opcode is generated internally by SQLite and 920 ** sent to the VFS immediately before the xSync method is invoked on a 921 ** database file descriptor. Or, if the xSync method is not invoked 922 ** because the user has configured SQLite with 923 ** [PRAGMA synchronous | PRAGMA synchronous=OFF] it is invoked in place 924 ** of the xSync method. In most cases, the pointer argument passed with 925 ** this file-control is NULL. However, if the database file is being synced 926 ** as part of a multi-database commit, the argument points to a nul-terminated 927 ** string containing the transactions super-journal file name. VFSes that 928 ** do not need this signal should silently ignore this opcode. Applications 929 ** should not call [sqlite3_file_control()] with this opcode as doing so may 930 ** disrupt the operation of the specialized VFSes that do require it. 931 ** 932 ** <li>[[SQLITE_FCNTL_COMMIT_PHASETWO]] 933 ** The [SQLITE_FCNTL_COMMIT_PHASETWO] opcode is generated internally by SQLite 934 ** and sent to the VFS after a transaction has been committed immediately 935 ** but before the database is unlocked. VFSes that do not need this signal 936 ** should silently ignore this opcode. Applications should not call 937 ** [sqlite3_file_control()] with this opcode as doing so may disrupt the 938 ** operation of the specialized VFSes that do require it. 939 ** 940 ** <li>[[SQLITE_FCNTL_WIN32_AV_RETRY]] 941 ** ^The [SQLITE_FCNTL_WIN32_AV_RETRY] opcode is used to configure automatic 942 ** retry counts and intervals for certain disk I/O operations for the 943 ** windows [VFS] in order to provide robustness in the presence of 944 ** anti-virus programs. By default, the windows VFS will retry file read, 945 ** file write, and file delete operations up to 10 times, with a delay 946 ** of 25 milliseconds before the first retry and with the delay increasing 947 ** by an additional 25 milliseconds with each subsequent retry. This 948 ** opcode allows these two values (10 retries and 25 milliseconds of delay) 949 ** to be adjusted. The values are changed for all database connections 950 ** within the same process. The argument is a pointer to an array of two 951 ** integers where the first integer is the new retry count and the second 952 ** integer is the delay. If either integer is negative, then the setting 953 ** is not changed but instead the prior value of that setting is written 954 ** into the array entry, allowing the current retry settings to be 955 ** interrogated. The zDbName parameter is ignored. 956 ** 957 ** <li>[[SQLITE_FCNTL_PERSIST_WAL]] 958 ** ^The [SQLITE_FCNTL_PERSIST_WAL] opcode is used to set or query the 959 ** persistent [WAL | Write Ahead Log] setting. By default, the auxiliary 960 ** write ahead log ([WAL file]) and shared memory 961 ** files used for transaction control 962 ** are automatically deleted when the latest connection to the database 963 ** closes. Setting persistent WAL mode causes those files to persist after 964 ** close. Persisting the files is useful when other processes that do not 965 ** have write permission on the directory containing the database file want 966 ** to read the database file, as the WAL and shared memory files must exist 967 ** in order for the database to be readable. The fourth parameter to 968 ** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 969 ** That integer is 0 to disable persistent WAL mode or 1 to enable persistent 970 ** WAL mode. If the integer is -1, then it is overwritten with the current 971 ** WAL persistence setting. 972 ** 973 ** <li>[[SQLITE_FCNTL_POWERSAFE_OVERWRITE]] 974 ** ^The [SQLITE_FCNTL_POWERSAFE_OVERWRITE] opcode is used to set or query the 975 ** persistent "powersafe-overwrite" or "PSOW" setting. The PSOW setting 976 ** determines the [SQLITE_IOCAP_POWERSAFE_OVERWRITE] bit of the 977 ** xDeviceCharacteristics methods. The fourth parameter to 978 ** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 979 ** That integer is 0 to disable zero-damage mode or 1 to enable zero-damage 980 ** mode. If the integer is -1, then it is overwritten with the current 981 ** zero-damage mode setting. 982 ** 983 ** <li>[[SQLITE_FCNTL_OVERWRITE]] 984 ** ^The [SQLITE_FCNTL_OVERWRITE] opcode is invoked by SQLite after opening 985 ** a write transaction to indicate that, unless it is rolled back for some 986 ** reason, the entire database file will be overwritten by the current 987 ** transaction. This is used by VACUUM operations. 988 ** 989 ** <li>[[SQLITE_FCNTL_VFSNAME]] 990 ** ^The [SQLITE_FCNTL_VFSNAME] opcode can be used to obtain the names of 991 ** all [VFSes] in the VFS stack. The names are of all VFS shims and the 992 ** final bottom-level VFS are written into memory obtained from 993 ** [sqlite3_malloc()] and the result is stored in the char* variable 994 ** that the fourth parameter of [sqlite3_file_control()] points to. 995 ** The caller is responsible for freeing the memory when done. As with 996 ** all file-control actions, there is no guarantee that this will actually 997 ** do anything. Callers should initialize the char* variable to a NULL 998 ** pointer in case this file-control is not implemented. This file-control 999 ** is intended for diagnostic use only. 1000 ** 1001 ** <li>[[SQLITE_FCNTL_VFS_POINTER]] 1002 ** ^The [SQLITE_FCNTL_VFS_POINTER] opcode finds a pointer to the top-level 1003 ** [VFSes] currently in use. ^(The argument X in 1004 ** sqlite3_file_control(db,SQLITE_FCNTL_VFS_POINTER,X) must be 1005 ** of type "[sqlite3_vfs] **". This opcodes will set *X 1006 ** to a pointer to the top-level VFS.)^ 1007 ** ^When there are multiple VFS shims in the stack, this opcode finds the 1008 ** upper-most shim only. 1009 ** 1010 ** <li>[[SQLITE_FCNTL_PRAGMA]] 1011 ** ^Whenever a [PRAGMA] statement is parsed, an [SQLITE_FCNTL_PRAGMA] 1012 ** file control is sent to the open [sqlite3_file] object corresponding 1013 ** to the database file to which the pragma statement refers. ^The argument 1014 ** to the [SQLITE_FCNTL_PRAGMA] file control is an array of 1015 ** pointers to strings (char**) in which the second element of the array 1016 ** is the name of the pragma and the third element is the argument to the 1017 ** pragma or NULL if the pragma has no argument. ^The handler for an 1018 ** [SQLITE_FCNTL_PRAGMA] file control can optionally make the first element 1019 ** of the char** argument point to a string obtained from [sqlite3_mprintf()] 1020 ** or the equivalent and that string will become the result of the pragma or 1021 ** the error message if the pragma fails. ^If the 1022 ** [SQLITE_FCNTL_PRAGMA] file control returns [SQLITE_NOTFOUND], then normal 1023 ** [PRAGMA] processing continues. ^If the [SQLITE_FCNTL_PRAGMA] 1024 ** file control returns [SQLITE_OK], then the parser assumes that the 1025 ** VFS has handled the PRAGMA itself and the parser generates a no-op 1026 ** prepared statement if result string is NULL, or that returns a copy 1027 ** of the result string if the string is non-NULL. 1028 ** ^If the [SQLITE_FCNTL_PRAGMA] file control returns 1029 ** any result code other than [SQLITE_OK] or [SQLITE_NOTFOUND], that means 1030 ** that the VFS encountered an error while handling the [PRAGMA] and the 1031 ** compilation of the PRAGMA fails with an error. ^The [SQLITE_FCNTL_PRAGMA] 1032 ** file control occurs at the beginning of pragma statement analysis and so 1033 ** it is able to override built-in [PRAGMA] statements. 1034 ** 1035 ** <li>[[SQLITE_FCNTL_BUSYHANDLER]] 1036 ** ^The [SQLITE_FCNTL_BUSYHANDLER] 1037 ** file-control may be invoked by SQLite on the database file handle 1038 ** shortly after it is opened in order to provide a custom VFS with access 1039 ** to the connection's busy-handler callback. The argument is of type (void**) 1040 ** - an array of two (void *) values. The first (void *) actually points 1041 ** to a function of type (int (*)(void *)). In order to invoke the connection's 1042 ** busy-handler, this function should be invoked with the second (void *) in 1043 ** the array as the only argument. If it returns non-zero, then the operation 1044 ** should be retried. If it returns zero, the custom VFS should abandon the 1045 ** current operation. 1046 ** 1047 ** <li>[[SQLITE_FCNTL_TEMPFILENAME]] 1048 ** ^Applications can invoke the [SQLITE_FCNTL_TEMPFILENAME] file-control 1049 ** to have SQLite generate a 1050 ** temporary filename using the same algorithm that is followed to generate 1051 ** temporary filenames for TEMP tables and other internal uses. The 1052 ** argument should be a char** which will be filled with the filename 1053 ** written into memory obtained from [sqlite3_malloc()]. The caller should 1054 ** invoke [sqlite3_free()] on the result to avoid a memory leak. 1055 ** 1056 ** <li>[[SQLITE_FCNTL_MMAP_SIZE]] 1057 ** The [SQLITE_FCNTL_MMAP_SIZE] file control is used to query or set the 1058 ** maximum number of bytes that will be used for memory-mapped I/O. 1059 ** The argument is a pointer to a value of type sqlite3_int64 that 1060 ** is an advisory maximum number of bytes in the file to memory map. The 1061 ** pointer is overwritten with the old value. The limit is not changed if 1062 ** the value originally pointed to is negative, and so the current limit 1063 ** can be queried by passing in a pointer to a negative number. This 1064 ** file-control is used internally to implement [PRAGMA mmap_size]. 1065 ** 1066 ** <li>[[SQLITE_FCNTL_TRACE]] 1067 ** The [SQLITE_FCNTL_TRACE] file control provides advisory information 1068 ** to the VFS about what the higher layers of the SQLite stack are doing. 1069 ** This file control is used by some VFS activity tracing [shims]. 1070 ** The argument is a zero-terminated string. Higher layers in the 1071 ** SQLite stack may generate instances of this file control if 1072 ** the [SQLITE_USE_FCNTL_TRACE] compile-time option is enabled. 1073 ** 1074 ** <li>[[SQLITE_FCNTL_HAS_MOVED]] 1075 ** The [SQLITE_FCNTL_HAS_MOVED] file control interprets its argument as a 1076 ** pointer to an integer and it writes a boolean into that integer depending 1077 ** on whether or not the file has been renamed, moved, or deleted since it 1078 ** was first opened. 1079 ** 1080 ** <li>[[SQLITE_FCNTL_WIN32_GET_HANDLE]] 1081 ** The [SQLITE_FCNTL_WIN32_GET_HANDLE] opcode can be used to obtain the 1082 ** underlying native file handle associated with a file handle. This file 1083 ** control interprets its argument as a pointer to a native file handle and 1084 ** writes the resulting value there. 1085 ** 1086 ** <li>[[SQLITE_FCNTL_WIN32_SET_HANDLE]] 1087 ** The [SQLITE_FCNTL_WIN32_SET_HANDLE] opcode is used for debugging. This 1088 ** opcode causes the xFileControl method to swap the file handle with the one 1089 ** pointed to by the pArg argument. This capability is used during testing 1090 ** and only needs to be supported when SQLITE_TEST is defined. 1091 ** 1092 ** <li>[[SQLITE_FCNTL_WAL_BLOCK]] 1093 ** The [SQLITE_FCNTL_WAL_BLOCK] is a signal to the VFS layer that it might 1094 ** be advantageous to block on the next WAL lock if the lock is not immediately 1095 ** available. The WAL subsystem issues this signal during rare 1096 ** circumstances in order to fix a problem with priority inversion. 1097 ** Applications should <em>not</em> use this file-control. 1098 ** 1099 ** <li>[[SQLITE_FCNTL_ZIPVFS]] 1100 ** The [SQLITE_FCNTL_ZIPVFS] opcode is implemented by zipvfs only. All other 1101 ** VFS should return SQLITE_NOTFOUND for this opcode. 1102 ** 1103 ** <li>[[SQLITE_FCNTL_RBU]] 1104 ** The [SQLITE_FCNTL_RBU] opcode is implemented by the special VFS used by 1105 ** the RBU extension only. All other VFS should return SQLITE_NOTFOUND for 1106 ** this opcode. 1107 ** 1108 ** <li>[[SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]] 1109 ** If the [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] opcode returns SQLITE_OK, then 1110 ** the file descriptor is placed in "batch write mode", which 1111 ** means all subsequent write operations will be deferred and done 1112 ** atomically at the next [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]. Systems 1113 ** that do not support batch atomic writes will return SQLITE_NOTFOUND. 1114 ** ^Following a successful SQLITE_FCNTL_BEGIN_ATOMIC_WRITE and prior to 1115 ** the closing [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] or 1116 ** [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE], SQLite will make 1117 ** no VFS interface calls on the same [sqlite3_file] file descriptor 1118 ** except for calls to the xWrite method and the xFileControl method 1119 ** with [SQLITE_FCNTL_SIZE_HINT]. 1120 ** 1121 ** <li>[[SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]] 1122 ** The [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] opcode causes all write 1123 ** operations since the previous successful call to 1124 ** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be performed atomically. 1125 ** This file control returns [SQLITE_OK] if and only if the writes were 1126 ** all performed successfully and have been committed to persistent storage. 1127 ** ^Regardless of whether or not it is successful, this file control takes 1128 ** the file descriptor out of batch write mode so that all subsequent 1129 ** write operations are independent. 1130 ** ^SQLite will never invoke SQLITE_FCNTL_COMMIT_ATOMIC_WRITE without 1131 ** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]. 1132 ** 1133 ** <li>[[SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE]] 1134 ** The [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE] opcode causes all write 1135 ** operations since the previous successful call to 1136 ** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be rolled back. 1137 ** ^This file control takes the file descriptor out of batch write mode 1138 ** so that all subsequent write operations are independent. 1139 ** ^SQLite will never invoke SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE without 1140 ** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]. 1141 ** 1142 ** <li>[[SQLITE_FCNTL_LOCK_TIMEOUT]] 1143 ** The [SQLITE_FCNTL_LOCK_TIMEOUT] opcode is used to configure a VFS 1144 ** to block for up to M milliseconds before failing when attempting to 1145 ** obtain a file lock using the xLock or xShmLock methods of the VFS. 1146 ** The parameter is a pointer to a 32-bit signed integer that contains 1147 ** the value that M is to be set to. Before returning, the 32-bit signed 1148 ** integer is overwritten with the previous value of M. 1149 ** 1150 ** <li>[[SQLITE_FCNTL_DATA_VERSION]] 1151 ** The [SQLITE_FCNTL_DATA_VERSION] opcode is used to detect changes to 1152 ** a database file. The argument is a pointer to a 32-bit unsigned integer. 1153 ** The "data version" for the pager is written into the pointer. The 1154 ** "data version" changes whenever any change occurs to the corresponding 1155 ** database file, either through SQL statements on the same database 1156 ** connection or through transactions committed by separate database 1157 ** connections possibly in other processes. The [sqlite3_total_changes()] 1158 ** interface can be used to find if any database on the connection has changed, 1159 ** but that interface responds to changes on TEMP as well as MAIN and does 1160 ** not provide a mechanism to detect changes to MAIN only. Also, the 1161 ** [sqlite3_total_changes()] interface responds to internal changes only and 1162 ** omits changes made by other database connections. The 1163 ** [PRAGMA data_version] command provides a mechanism to detect changes to 1164 ** a single attached database that occur due to other database connections, 1165 ** but omits changes implemented by the database connection on which it is 1166 ** called. This file control is the only mechanism to detect changes that 1167 ** happen either internally or externally and that are associated with 1168 ** a particular attached database. 1169 ** 1170 ** <li>[[SQLITE_FCNTL_CKPT_START]] 1171 ** The [SQLITE_FCNTL_CKPT_START] opcode is invoked from within a checkpoint 1172 ** in wal mode before the client starts to copy pages from the wal 1173 ** file to the database file. 1174 ** 1175 ** <li>[[SQLITE_FCNTL_CKPT_DONE]] 1176 ** The [SQLITE_FCNTL_CKPT_DONE] opcode is invoked from within a checkpoint 1177 ** in wal mode after the client has finished copying pages from the wal 1178 ** file to the database file, but before the *-shm file is updated to 1179 ** record the fact that the pages have been checkpointed. 1180 ** 1181 ** <li>[[SQLITE_FCNTL_EXTERNAL_READER]] 1182 ** The EXPERIMENTAL [SQLITE_FCNTL_EXTERNAL_READER] opcode is used to detect 1183 ** whether or not there is a database client in another process with a wal-mode 1184 ** transaction open on the database or not. It is only available on unix.The 1185 ** (void*) argument passed with this file-control should be a pointer to a 1186 ** value of type (int). The integer value is set to 1 if the database is a wal 1187 ** mode database and there exists at least one client in another process that 1188 ** currently has an SQL transaction open on the database. It is set to 0 if 1189 ** the database is not a wal-mode db, or if there is no such connection in any 1190 ** other process. This opcode cannot be used to detect transactions opened 1191 ** by clients within the current process, only within other processes. 1192 ** 1193 ** <li>[[SQLITE_FCNTL_CKSM_FILE]] 1194 ** The [SQLITE_FCNTL_CKSM_FILE] opcode is for use internally by the 1195 ** [checksum VFS shim] only. 1196 ** 1197 ** <li>[[SQLITE_FCNTL_RESET_CACHE]] 1198 ** If there is currently no transaction open on the database, and the 1199 ** database is not a temp db, then the [SQLITE_FCNTL_RESET_CACHE] file-control 1200 ** purges the contents of the in-memory page cache. If there is an open 1201 ** transaction, or if the db is a temp-db, this opcode is a no-op, not an error. 1202 ** </ul> 1203 */ 1204 #define SQLITE_FCNTL_LOCKSTATE 1 1205 #define SQLITE_FCNTL_GET_LOCKPROXYFILE 2 1206 #define SQLITE_FCNTL_SET_LOCKPROXYFILE 3 1207 #define SQLITE_FCNTL_LAST_ERRNO 4 1208 #define SQLITE_FCNTL_SIZE_HINT 5 1209 #define SQLITE_FCNTL_CHUNK_SIZE 6 1210 #define SQLITE_FCNTL_FILE_POINTER 7 1211 #define SQLITE_FCNTL_SYNC_OMITTED 8 1212 #define SQLITE_FCNTL_WIN32_AV_RETRY 9 1213 #define SQLITE_FCNTL_PERSIST_WAL 10 1214 #define SQLITE_FCNTL_OVERWRITE 11 1215 #define SQLITE_FCNTL_VFSNAME 12 1216 #define SQLITE_FCNTL_POWERSAFE_OVERWRITE 13 1217 #define SQLITE_FCNTL_PRAGMA 14 1218 #define SQLITE_FCNTL_BUSYHANDLER 15 1219 #define SQLITE_FCNTL_TEMPFILENAME 16 1220 #define SQLITE_FCNTL_MMAP_SIZE 18 1221 #define SQLITE_FCNTL_TRACE 19 1222 #define SQLITE_FCNTL_HAS_MOVED 20 1223 #define SQLITE_FCNTL_SYNC 21 1224 #define SQLITE_FCNTL_COMMIT_PHASETWO 22 1225 #define SQLITE_FCNTL_WIN32_SET_HANDLE 23 1226 #define SQLITE_FCNTL_WAL_BLOCK 24 1227 #define SQLITE_FCNTL_ZIPVFS 25 1228 #define SQLITE_FCNTL_RBU 26 1229 #define SQLITE_FCNTL_VFS_POINTER 27 1230 #define SQLITE_FCNTL_JOURNAL_POINTER 28 1231 #define SQLITE_FCNTL_WIN32_GET_HANDLE 29 1232 #define SQLITE_FCNTL_PDB 30 1233 #define SQLITE_FCNTL_BEGIN_ATOMIC_WRITE 31 1234 #define SQLITE_FCNTL_COMMIT_ATOMIC_WRITE 32 1235 #define SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE 33 1236 #define SQLITE_FCNTL_LOCK_TIMEOUT 34 1237 #define SQLITE_FCNTL_DATA_VERSION 35 1238 #define SQLITE_FCNTL_SIZE_LIMIT 36 1239 #define SQLITE_FCNTL_CKPT_DONE 37 1240 #define SQLITE_FCNTL_RESERVE_BYTES 38 1241 #define SQLITE_FCNTL_CKPT_START 39 1242 #define SQLITE_FCNTL_EXTERNAL_READER 40 1243 #define SQLITE_FCNTL_CKSM_FILE 41 1244 #define SQLITE_FCNTL_RESET_CACHE 42 1245 1246 /* deprecated names */ 1247 #define SQLITE_GET_LOCKPROXYFILE SQLITE_FCNTL_GET_LOCKPROXYFILE 1248 #define SQLITE_SET_LOCKPROXYFILE SQLITE_FCNTL_SET_LOCKPROXYFILE 1249 #define SQLITE_LAST_ERRNO SQLITE_FCNTL_LAST_ERRNO 1250 1251 1252 /* 1253 ** CAPI3REF: Mutex Handle 1254 ** 1255 ** The mutex module within SQLite defines [sqlite3_mutex] to be an 1256 ** abstract type for a mutex object. The SQLite core never looks 1257 ** at the internal representation of an [sqlite3_mutex]. It only 1258 ** deals with pointers to the [sqlite3_mutex] object. 1259 ** 1260 ** Mutexes are created using [sqlite3_mutex_alloc()]. 1261 */ 1262 typedef struct sqlite3_mutex sqlite3_mutex; 1263 1264 /* 1265 ** CAPI3REF: Loadable Extension Thunk 1266 ** 1267 ** A pointer to the opaque sqlite3_api_routines structure is passed as 1268 ** the third parameter to entry points of [loadable extensions]. This 1269 ** structure must be typedefed in order to work around compiler warnings 1270 ** on some platforms. 1271 */ 1272 typedef struct sqlite3_api_routines sqlite3_api_routines; 1273 1274 /* 1275 ** CAPI3REF: File Name 1276 ** 1277 ** Type [sqlite3_filename] is used by SQLite to pass filenames to the 1278 ** xOpen method of a [VFS]. It may be cast to (const char*) and treated 1279 ** as a normal, nul-terminated, UTF-8 buffer containing the filename, but 1280 ** may also be passed to special APIs such as: 1281 ** 1282 ** <ul> 1283 ** <li> sqlite3_filename_database() 1284 ** <li> sqlite3_filename_journal() 1285 ** <li> sqlite3_filename_wal() 1286 ** <li> sqlite3_uri_parameter() 1287 ** <li> sqlite3_uri_boolean() 1288 ** <li> sqlite3_uri_int64() 1289 ** <li> sqlite3_uri_key() 1290 ** </ul> 1291 */ 1292 typedef const char *sqlite3_filename; 1293 1294 /* 1295 ** CAPI3REF: OS Interface Object 1296 ** 1297 ** An instance of the sqlite3_vfs object defines the interface between 1298 ** the SQLite core and the underlying operating system. The "vfs" 1299 ** in the name of the object stands for "virtual file system". See 1300 ** the [VFS | VFS documentation] for further information. 1301 ** 1302 ** The VFS interface is sometimes extended by adding new methods onto 1303 ** the end. Each time such an extension occurs, the iVersion field 1304 ** is incremented. The iVersion value started out as 1 in 1305 ** SQLite [version 3.5.0] on [dateof:3.5.0], then increased to 2 1306 ** with SQLite [version 3.7.0] on [dateof:3.7.0], and then increased 1307 ** to 3 with SQLite [version 3.7.6] on [dateof:3.7.6]. Additional fields 1308 ** may be appended to the sqlite3_vfs object and the iVersion value 1309 ** may increase again in future versions of SQLite. 1310 ** Note that due to an oversight, the structure 1311 ** of the sqlite3_vfs object changed in the transition from 1312 ** SQLite [version 3.5.9] to [version 3.6.0] on [dateof:3.6.0] 1313 ** and yet the iVersion field was not increased. 1314 ** 1315 ** The szOsFile field is the size of the subclassed [sqlite3_file] 1316 ** structure used by this VFS. mxPathname is the maximum length of 1317 ** a pathname in this VFS. 1318 ** 1319 ** Registered sqlite3_vfs objects are kept on a linked list formed by 1320 ** the pNext pointer. The [sqlite3_vfs_register()] 1321 ** and [sqlite3_vfs_unregister()] interfaces manage this list 1322 ** in a thread-safe way. The [sqlite3_vfs_find()] interface 1323 ** searches the list. Neither the application code nor the VFS 1324 ** implementation should use the pNext pointer. 1325 ** 1326 ** The pNext field is the only field in the sqlite3_vfs 1327 ** structure that SQLite will ever modify. SQLite will only access 1328 ** or modify this field while holding a particular static mutex. 1329 ** The application should never modify anything within the sqlite3_vfs 1330 ** object once the object has been registered. 1331 ** 1332 ** The zName field holds the name of the VFS module. The name must 1333 ** be unique across all VFS modules. 1334 ** 1335 ** [[sqlite3_vfs.xOpen]] 1336 ** ^SQLite guarantees that the zFilename parameter to xOpen 1337 ** is either a NULL pointer or string obtained 1338 ** from xFullPathname() with an optional suffix added. 1339 ** ^If a suffix is added to the zFilename parameter, it will 1340 ** consist of a single "-" character followed by no more than 1341 ** 11 alphanumeric and/or "-" characters. 1342 ** ^SQLite further guarantees that 1343 ** the string will be valid and unchanged until xClose() is 1344 ** called. Because of the previous sentence, 1345 ** the [sqlite3_file] can safely store a pointer to the 1346 ** filename if it needs to remember the filename for some reason. 1347 ** If the zFilename parameter to xOpen is a NULL pointer then xOpen 1348 ** must invent its own temporary name for the file. ^Whenever the 1349 ** xFilename parameter is NULL it will also be the case that the 1350 ** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE]. 1351 ** 1352 ** The flags argument to xOpen() includes all bits set in 1353 ** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()] 1354 ** or [sqlite3_open16()] is used, then flags includes at least 1355 ** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]. 1356 ** If xOpen() opens a file read-only then it sets *pOutFlags to 1357 ** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be set. 1358 ** 1359 ** ^(SQLite will also add one of the following flags to the xOpen() 1360 ** call, depending on the object being opened: 1361 ** 1362 ** <ul> 1363 ** <li> [SQLITE_OPEN_MAIN_DB] 1364 ** <li> [SQLITE_OPEN_MAIN_JOURNAL] 1365 ** <li> [SQLITE_OPEN_TEMP_DB] 1366 ** <li> [SQLITE_OPEN_TEMP_JOURNAL] 1367 ** <li> [SQLITE_OPEN_TRANSIENT_DB] 1368 ** <li> [SQLITE_OPEN_SUBJOURNAL] 1369 ** <li> [SQLITE_OPEN_SUPER_JOURNAL] 1370 ** <li> [SQLITE_OPEN_WAL] 1371 ** </ul>)^ 1372 ** 1373 ** The file I/O implementation can use the object type flags to 1374 ** change the way it deals with files. For example, an application 1375 ** that does not care about crash recovery or rollback might make 1376 ** the open of a journal file a no-op. Writes to this journal would 1377 ** also be no-ops, and any attempt to read the journal would return 1378 ** SQLITE_IOERR. Or the implementation might recognize that a database 1379 ** file will be doing page-aligned sector reads and writes in a random 1380 ** order and set up its I/O subsystem accordingly. 1381 ** 1382 ** SQLite might also add one of the following flags to the xOpen method: 1383 ** 1384 ** <ul> 1385 ** <li> [SQLITE_OPEN_DELETEONCLOSE] 1386 ** <li> [SQLITE_OPEN_EXCLUSIVE] 1387 ** </ul> 1388 ** 1389 ** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be 1390 ** deleted when it is closed. ^The [SQLITE_OPEN_DELETEONCLOSE] 1391 ** will be set for TEMP databases and their journals, transient 1392 ** databases, and subjournals. 1393 ** 1394 ** ^The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction 1395 ** with the [SQLITE_OPEN_CREATE] flag, which are both directly 1396 ** analogous to the O_EXCL and O_CREAT flags of the POSIX open() 1397 ** API. The SQLITE_OPEN_EXCLUSIVE flag, when paired with the 1398 ** SQLITE_OPEN_CREATE, is used to indicate that file should always 1399 ** be created, and that it is an error if it already exists. 1400 ** It is <i>not</i> used to indicate the file should be opened 1401 ** for exclusive access. 1402 ** 1403 ** ^At least szOsFile bytes of memory are allocated by SQLite 1404 ** to hold the [sqlite3_file] structure passed as the third 1405 ** argument to xOpen. The xOpen method does not have to 1406 ** allocate the structure; it should just fill it in. Note that 1407 ** the xOpen method must set the sqlite3_file.pMethods to either 1408 ** a valid [sqlite3_io_methods] object or to NULL. xOpen must do 1409 ** this even if the open fails. SQLite expects that the sqlite3_file.pMethods 1410 ** element will be valid after xOpen returns regardless of the success 1411 ** or failure of the xOpen call. 1412 ** 1413 ** [[sqlite3_vfs.xAccess]] 1414 ** ^The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS] 1415 ** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to 1416 ** test whether a file is readable and writable, or [SQLITE_ACCESS_READ] 1417 ** to test whether a file is at least readable. The SQLITE_ACCESS_READ 1418 ** flag is never actually used and is not implemented in the built-in 1419 ** VFSes of SQLite. The file is named by the second argument and can be a 1420 ** directory. The xAccess method returns [SQLITE_OK] on success or some 1421 ** non-zero error code if there is an I/O error or if the name of 1422 ** the file given in the second argument is illegal. If SQLITE_OK 1423 ** is returned, then non-zero or zero is written into *pResOut to indicate 1424 ** whether or not the file is accessible. 1425 ** 1426 ** ^SQLite will always allocate at least mxPathname+1 bytes for the 1427 ** output buffer xFullPathname. The exact size of the output buffer 1428 ** is also passed as a parameter to both methods. If the output buffer 1429 ** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is 1430 ** handled as a fatal error by SQLite, vfs implementations should endeavor 1431 ** to prevent this by setting mxPathname to a sufficiently large value. 1432 ** 1433 ** The xRandomness(), xSleep(), xCurrentTime(), and xCurrentTimeInt64() 1434 ** interfaces are not strictly a part of the filesystem, but they are 1435 ** included in the VFS structure for completeness. 1436 ** The xRandomness() function attempts to return nBytes bytes 1437 ** of good-quality randomness into zOut. The return value is 1438 ** the actual number of bytes of randomness obtained. 1439 ** The xSleep() method causes the calling thread to sleep for at 1440 ** least the number of microseconds given. ^The xCurrentTime() 1441 ** method returns a Julian Day Number for the current date and time as 1442 ** a floating point value. 1443 ** ^The xCurrentTimeInt64() method returns, as an integer, the Julian 1444 ** Day Number multiplied by 86400000 (the number of milliseconds in 1445 ** a 24-hour day). 1446 ** ^SQLite will use the xCurrentTimeInt64() method to get the current 1447 ** date and time if that method is available (if iVersion is 2 or 1448 ** greater and the function pointer is not NULL) and will fall back 1449 ** to xCurrentTime() if xCurrentTimeInt64() is unavailable. 1450 ** 1451 ** ^The xSetSystemCall(), xGetSystemCall(), and xNestSystemCall() interfaces 1452 ** are not used by the SQLite core. These optional interfaces are provided 1453 ** by some VFSes to facilitate testing of the VFS code. By overriding 1454 ** system calls with functions under its control, a test program can 1455 ** simulate faults and error conditions that would otherwise be difficult 1456 ** or impossible to induce. The set of system calls that can be overridden 1457 ** varies from one VFS to another, and from one version of the same VFS to the 1458 ** next. Applications that use these interfaces must be prepared for any 1459 ** or all of these interfaces to be NULL or for their behavior to change 1460 ** from one release to the next. Applications must not attempt to access 1461 ** any of these methods if the iVersion of the VFS is less than 3. 1462 */ 1463 typedef struct sqlite3_vfs sqlite3_vfs; 1464 typedef void (*sqlite3_syscall_ptr)(void); 1465 struct sqlite3_vfs { 1466 int iVersion; /* Structure version number (currently 3) */ 1467 int szOsFile; /* Size of subclassed sqlite3_file */ 1468 int mxPathname; /* Maximum file pathname length */ 1469 sqlite3_vfs *pNext; /* Next registered VFS */ 1470 const char *zName; /* Name of this virtual file system */ 1471 void *pAppData; /* Pointer to application-specific data */ 1472 int (*xOpen)(sqlite3_vfs*, sqlite3_filename zName, sqlite3_file*, 1473 int flags, int *pOutFlags); 1474 int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir); 1475 int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut); 1476 int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut); 1477 void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename); 1478 void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg); 1479 void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void); 1480 void (*xDlClose)(sqlite3_vfs*, void*); 1481 int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut); 1482 int (*xSleep)(sqlite3_vfs*, int microseconds); 1483 int (*xCurrentTime)(sqlite3_vfs*, double*); 1484 int (*xGetLastError)(sqlite3_vfs*, int, char *); 1485 /* 1486 ** The methods above are in version 1 of the sqlite_vfs object 1487 ** definition. Those that follow are added in version 2 or later 1488 */ 1489 int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*); 1490 /* 1491 ** The methods above are in versions 1 and 2 of the sqlite_vfs object. 1492 ** Those below are for version 3 and greater. 1493 */ 1494 int (*xSetSystemCall)(sqlite3_vfs*, const char *zName, sqlite3_syscall_ptr); 1495 sqlite3_syscall_ptr (*xGetSystemCall)(sqlite3_vfs*, const char *zName); 1496 const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName); 1497 /* 1498 ** The methods above are in versions 1 through 3 of the sqlite_vfs object. 1499 ** New fields may be appended in future versions. The iVersion 1500 ** value will increment whenever this happens. 1501 */ 1502 }; 1503 1504 /* 1505 ** CAPI3REF: Flags for the xAccess VFS method 1506 ** 1507 ** These integer constants can be used as the third parameter to 1508 ** the xAccess method of an [sqlite3_vfs] object. They determine 1509 ** what kind of permissions the xAccess method is looking for. 1510 ** With SQLITE_ACCESS_EXISTS, the xAccess method 1511 ** simply checks whether the file exists. 1512 ** With SQLITE_ACCESS_READWRITE, the xAccess method 1513 ** checks whether the named directory is both readable and writable 1514 ** (in other words, if files can be added, removed, and renamed within 1515 ** the directory). 1516 ** The SQLITE_ACCESS_READWRITE constant is currently used only by the 1517 ** [temp_store_directory pragma], though this could change in a future 1518 ** release of SQLite. 1519 ** With SQLITE_ACCESS_READ, the xAccess method 1520 ** checks whether the file is readable. The SQLITE_ACCESS_READ constant is 1521 ** currently unused, though it might be used in a future release of 1522 ** SQLite. 1523 */ 1524 #define SQLITE_ACCESS_EXISTS 0 1525 #define SQLITE_ACCESS_READWRITE 1 /* Used by PRAGMA temp_store_directory */ 1526 #define SQLITE_ACCESS_READ 2 /* Unused */ 1527 1528 /* 1529 ** CAPI3REF: Flags for the xShmLock VFS method 1530 ** 1531 ** These integer constants define the various locking operations 1532 ** allowed by the xShmLock method of [sqlite3_io_methods]. The 1533 ** following are the only legal combinations of flags to the 1534 ** xShmLock method: 1535 ** 1536 ** <ul> 1537 ** <li> SQLITE_SHM_LOCK | SQLITE_SHM_SHARED 1538 ** <li> SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE 1539 ** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED 1540 ** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE 1541 ** </ul> 1542 ** 1543 ** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as 1544 ** was given on the corresponding lock. 1545 ** 1546 ** The xShmLock method can transition between unlocked and SHARED or 1547 ** between unlocked and EXCLUSIVE. It cannot transition between SHARED 1548 ** and EXCLUSIVE. 1549 */ 1550 #define SQLITE_SHM_UNLOCK 1 1551 #define SQLITE_SHM_LOCK 2 1552 #define SQLITE_SHM_SHARED 4 1553 #define SQLITE_SHM_EXCLUSIVE 8 1554 1555 /* 1556 ** CAPI3REF: Maximum xShmLock index 1557 ** 1558 ** The xShmLock method on [sqlite3_io_methods] may use values 1559 ** between 0 and this upper bound as its "offset" argument. 1560 ** The SQLite core will never attempt to acquire or release a 1561 ** lock outside of this range 1562 */ 1563 #define SQLITE_SHM_NLOCK 8 1564 1565 1566 /* 1567 ** CAPI3REF: Initialize The SQLite Library 1568 ** 1569 ** ^The sqlite3_initialize() routine initializes the 1570 ** SQLite library. ^The sqlite3_shutdown() routine 1571 ** deallocates any resources that were allocated by sqlite3_initialize(). 1572 ** These routines are designed to aid in process initialization and 1573 ** shutdown on embedded systems. Workstation applications using 1574 ** SQLite normally do not need to invoke either of these routines. 1575 ** 1576 ** A call to sqlite3_initialize() is an "effective" call if it is 1577 ** the first time sqlite3_initialize() is invoked during the lifetime of 1578 ** the process, or if it is the first time sqlite3_initialize() is invoked 1579 ** following a call to sqlite3_shutdown(). ^(Only an effective call 1580 ** of sqlite3_initialize() does any initialization. All other calls 1581 ** are harmless no-ops.)^ 1582 ** 1583 ** A call to sqlite3_shutdown() is an "effective" call if it is the first 1584 ** call to sqlite3_shutdown() since the last sqlite3_initialize(). ^(Only 1585 ** an effective call to sqlite3_shutdown() does any deinitialization. 1586 ** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^ 1587 ** 1588 ** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown() 1589 ** is not. The sqlite3_shutdown() interface must only be called from a 1590 ** single thread. All open [database connections] must be closed and all 1591 ** other SQLite resources must be deallocated prior to invoking 1592 ** sqlite3_shutdown(). 1593 ** 1594 ** Among other things, ^sqlite3_initialize() will invoke 1595 ** sqlite3_os_init(). Similarly, ^sqlite3_shutdown() 1596 ** will invoke sqlite3_os_end(). 1597 ** 1598 ** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success. 1599 ** ^If for some reason, sqlite3_initialize() is unable to initialize 1600 ** the library (perhaps it is unable to allocate a needed resource such 1601 ** as a mutex) it returns an [error code] other than [SQLITE_OK]. 1602 ** 1603 ** ^The sqlite3_initialize() routine is called internally by many other 1604 ** SQLite interfaces so that an application usually does not need to 1605 ** invoke sqlite3_initialize() directly. For example, [sqlite3_open()] 1606 ** calls sqlite3_initialize() so the SQLite library will be automatically 1607 ** initialized when [sqlite3_open()] is called if it has not be initialized 1608 ** already. ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT] 1609 ** compile-time option, then the automatic calls to sqlite3_initialize() 1610 ** are omitted and the application must call sqlite3_initialize() directly 1611 ** prior to using any other SQLite interface. For maximum portability, 1612 ** it is recommended that applications always invoke sqlite3_initialize() 1613 ** directly prior to using any other SQLite interface. Future releases 1614 ** of SQLite may require this. In other words, the behavior exhibited 1615 ** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the 1616 ** default behavior in some future release of SQLite. 1617 ** 1618 ** The sqlite3_os_init() routine does operating-system specific 1619 ** initialization of the SQLite library. The sqlite3_os_end() 1620 ** routine undoes the effect of sqlite3_os_init(). Typical tasks 1621 ** performed by these routines include allocation or deallocation 1622 ** of static resources, initialization of global variables, 1623 ** setting up a default [sqlite3_vfs] module, or setting up 1624 ** a default configuration using [sqlite3_config()]. 1625 ** 1626 ** The application should never invoke either sqlite3_os_init() 1627 ** or sqlite3_os_end() directly. The application should only invoke 1628 ** sqlite3_initialize() and sqlite3_shutdown(). The sqlite3_os_init() 1629 ** interface is called automatically by sqlite3_initialize() and 1630 ** sqlite3_os_end() is called by sqlite3_shutdown(). Appropriate 1631 ** implementations for sqlite3_os_init() and sqlite3_os_end() 1632 ** are built into SQLite when it is compiled for Unix, Windows, or OS/2. 1633 ** When [custom builds | built for other platforms] 1634 ** (using the [SQLITE_OS_OTHER=1] compile-time 1635 ** option) the application must supply a suitable implementation for 1636 ** sqlite3_os_init() and sqlite3_os_end(). An application-supplied 1637 ** implementation of sqlite3_os_init() or sqlite3_os_end() 1638 ** must return [SQLITE_OK] on success and some other [error code] upon 1639 ** failure. 1640 */ 1641 SQLITE_API int sqlite3_initialize(void); 1642 SQLITE_API int sqlite3_shutdown(void); 1643 SQLITE_API int sqlite3_os_init(void); 1644 SQLITE_API int sqlite3_os_end(void); 1645 1646 /* 1647 ** CAPI3REF: Configuring The SQLite Library 1648 ** 1649 ** The sqlite3_config() interface is used to make global configuration 1650 ** changes to SQLite in order to tune SQLite to the specific needs of 1651 ** the application. The default configuration is recommended for most 1652 ** applications and so this routine is usually not necessary. It is 1653 ** provided to support rare applications with unusual needs. 1654 ** 1655 ** <b>The sqlite3_config() interface is not threadsafe. The application 1656 ** must ensure that no other SQLite interfaces are invoked by other 1657 ** threads while sqlite3_config() is running.</b> 1658 ** 1659 ** The first argument to sqlite3_config() is an integer 1660 ** [configuration option] that determines 1661 ** what property of SQLite is to be configured. Subsequent arguments 1662 ** vary depending on the [configuration option] 1663 ** in the first argument. 1664 ** 1665 ** For most configuration options, the sqlite3_config() interface 1666 ** may only be invoked prior to library initialization using 1667 ** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()]. 1668 ** The exceptional configuration options that may be invoked at any time 1669 ** are called "anytime configuration options". 1670 ** ^If sqlite3_config() is called after [sqlite3_initialize()] and before 1671 ** [sqlite3_shutdown()] with a first argument that is not an anytime 1672 ** configuration option, then the sqlite3_config() call will return SQLITE_MISUSE. 1673 ** Note, however, that ^sqlite3_config() can be called as part of the 1674 ** implementation of an application-defined [sqlite3_os_init()]. 1675 ** 1676 ** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK]. 1677 ** ^If the option is unknown or SQLite is unable to set the option 1678 ** then this routine returns a non-zero [error code]. 1679 */ 1680 SQLITE_API int sqlite3_config(int, ...); 1681 1682 /* 1683 ** CAPI3REF: Configure database connections 1684 ** METHOD: sqlite3 1685 ** 1686 ** The sqlite3_db_config() interface is used to make configuration 1687 ** changes to a [database connection]. The interface is similar to 1688 ** [sqlite3_config()] except that the changes apply to a single 1689 ** [database connection] (specified in the first argument). 1690 ** 1691 ** The second argument to sqlite3_db_config(D,V,...) is the 1692 ** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code 1693 ** that indicates what aspect of the [database connection] is being configured. 1694 ** Subsequent arguments vary depending on the configuration verb. 1695 ** 1696 ** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if 1697 ** the call is considered successful. 1698 */ 1699 SQLITE_API int sqlite3_db_config(sqlite3*, int op, ...); 1700 1701 /* 1702 ** CAPI3REF: Memory Allocation Routines 1703 ** 1704 ** An instance of this object defines the interface between SQLite 1705 ** and low-level memory allocation routines. 1706 ** 1707 ** This object is used in only one place in the SQLite interface. 1708 ** A pointer to an instance of this object is the argument to 1709 ** [sqlite3_config()] when the configuration option is 1710 ** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC]. 1711 ** By creating an instance of this object 1712 ** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC]) 1713 ** during configuration, an application can specify an alternative 1714 ** memory allocation subsystem for SQLite to use for all of its 1715 ** dynamic memory needs. 1716 ** 1717 ** Note that SQLite comes with several [built-in memory allocators] 1718 ** that are perfectly adequate for the overwhelming majority of applications 1719 ** and that this object is only useful to a tiny minority of applications 1720 ** with specialized memory allocation requirements. This object is 1721 ** also used during testing of SQLite in order to specify an alternative 1722 ** memory allocator that simulates memory out-of-memory conditions in 1723 ** order to verify that SQLite recovers gracefully from such 1724 ** conditions. 1725 ** 1726 ** The xMalloc, xRealloc, and xFree methods must work like the 1727 ** malloc(), realloc() and free() functions from the standard C library. 1728 ** ^SQLite guarantees that the second argument to 1729 ** xRealloc is always a value returned by a prior call to xRoundup. 1730 ** 1731 ** xSize should return the allocated size of a memory allocation 1732 ** previously obtained from xMalloc or xRealloc. The allocated size 1733 ** is always at least as big as the requested size but may be larger. 1734 ** 1735 ** The xRoundup method returns what would be the allocated size of 1736 ** a memory allocation given a particular requested size. Most memory 1737 ** allocators round up memory allocations at least to the next multiple 1738 ** of 8. Some allocators round up to a larger multiple or to a power of 2. 1739 ** Every memory allocation request coming in through [sqlite3_malloc()] 1740 ** or [sqlite3_realloc()] first calls xRoundup. If xRoundup returns 0, 1741 ** that causes the corresponding memory allocation to fail. 1742 ** 1743 ** The xInit method initializes the memory allocator. For example, 1744 ** it might allocate any required mutexes or initialize internal data 1745 ** structures. The xShutdown method is invoked (indirectly) by 1746 ** [sqlite3_shutdown()] and should deallocate any resources acquired 1747 ** by xInit. The pAppData pointer is used as the only parameter to 1748 ** xInit and xShutdown. 1749 ** 1750 ** SQLite holds the [SQLITE_MUTEX_STATIC_MAIN] mutex when it invokes 1751 ** the xInit method, so the xInit method need not be threadsafe. The 1752 ** xShutdown method is only called from [sqlite3_shutdown()] so it does 1753 ** not need to be threadsafe either. For all other methods, SQLite 1754 ** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the 1755 ** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which 1756 ** it is by default) and so the methods are automatically serialized. 1757 ** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other 1758 ** methods must be threadsafe or else make their own arrangements for 1759 ** serialization. 1760 ** 1761 ** SQLite will never invoke xInit() more than once without an intervening 1762 ** call to xShutdown(). 1763 */ 1764 typedef struct sqlite3_mem_methods sqlite3_mem_methods; 1765 struct sqlite3_mem_methods { 1766 void *(*xMalloc)(int); /* Memory allocation function */ 1767 void (*xFree)(void*); /* Free a prior allocation */ 1768 void *(*xRealloc)(void*,int); /* Resize an allocation */ 1769 int (*xSize)(void*); /* Return the size of an allocation */ 1770 int (*xRoundup)(int); /* Round up request size to allocation size */ 1771 int (*xInit)(void*); /* Initialize the memory allocator */ 1772 void (*xShutdown)(void*); /* Deinitialize the memory allocator */ 1773 void *pAppData; /* Argument to xInit() and xShutdown() */ 1774 }; 1775 1776 /* 1777 ** CAPI3REF: Configuration Options 1778 ** KEYWORDS: {configuration option} 1779 ** 1780 ** These constants are the available integer configuration options that 1781 ** can be passed as the first argument to the [sqlite3_config()] interface. 1782 ** 1783 ** Most of the configuration options for sqlite3_config() 1784 ** will only work if invoked prior to [sqlite3_initialize()] or after 1785 ** [sqlite3_shutdown()]. The few exceptions to this rule are called 1786 ** "anytime configuration options". 1787 ** ^Calling [sqlite3_config()] with a first argument that is not an 1788 ** anytime configuration option in between calls to [sqlite3_initialize()] and 1789 ** [sqlite3_shutdown()] is a no-op that returns SQLITE_MISUSE. 1790 ** 1791 ** The set of anytime configuration options can change (by insertions 1792 ** and/or deletions) from one release of SQLite to the next. 1793 ** As of SQLite version 3.42.0, the complete set of anytime configuration 1794 ** options is: 1795 ** <ul> 1796 ** <li> SQLITE_CONFIG_LOG 1797 ** <li> SQLITE_CONFIG_PCACHE_HDRSZ 1798 ** </ul> 1799 ** 1800 ** New configuration options may be added in future releases of SQLite. 1801 ** Existing configuration options might be discontinued. Applications 1802 ** should check the return code from [sqlite3_config()] to make sure that 1803 ** the call worked. The [sqlite3_config()] interface will return a 1804 ** non-zero [error code] if a discontinued or unsupported configuration option 1805 ** is invoked. 1806 ** 1807 ** <dl> 1808 ** [[SQLITE_CONFIG_SINGLETHREAD]] <dt>SQLITE_CONFIG_SINGLETHREAD</dt> 1809 ** <dd>There are no arguments to this option. ^This option sets the 1810 ** [threading mode] to Single-thread. In other words, it disables 1811 ** all mutexing and puts SQLite into a mode where it can only be used 1812 ** by a single thread. ^If SQLite is compiled with 1813 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1814 ** it is not possible to change the [threading mode] from its default 1815 ** value of Single-thread and so [sqlite3_config()] will return 1816 ** [SQLITE_ERROR] if called with the SQLITE_CONFIG_SINGLETHREAD 1817 ** configuration option.</dd> 1818 ** 1819 ** [[SQLITE_CONFIG_MULTITHREAD]] <dt>SQLITE_CONFIG_MULTITHREAD</dt> 1820 ** <dd>There are no arguments to this option. ^This option sets the 1821 ** [threading mode] to Multi-thread. In other words, it disables 1822 ** mutexing on [database connection] and [prepared statement] objects. 1823 ** The application is responsible for serializing access to 1824 ** [database connections] and [prepared statements]. But other mutexes 1825 ** are enabled so that SQLite will be safe to use in a multi-threaded 1826 ** environment as long as no two threads attempt to use the same 1827 ** [database connection] at the same time. ^If SQLite is compiled with 1828 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1829 ** it is not possible to set the Multi-thread [threading mode] and 1830 ** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1831 ** SQLITE_CONFIG_MULTITHREAD configuration option.</dd> 1832 ** 1833 ** [[SQLITE_CONFIG_SERIALIZED]] <dt>SQLITE_CONFIG_SERIALIZED</dt> 1834 ** <dd>There are no arguments to this option. ^This option sets the 1835 ** [threading mode] to Serialized. In other words, this option enables 1836 ** all mutexes including the recursive 1837 ** mutexes on [database connection] and [prepared statement] objects. 1838 ** In this mode (which is the default when SQLite is compiled with 1839 ** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access 1840 ** to [database connections] and [prepared statements] so that the 1841 ** application is free to use the same [database connection] or the 1842 ** same [prepared statement] in different threads at the same time. 1843 ** ^If SQLite is compiled with 1844 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1845 ** it is not possible to set the Serialized [threading mode] and 1846 ** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1847 ** SQLITE_CONFIG_SERIALIZED configuration option.</dd> 1848 ** 1849 ** [[SQLITE_CONFIG_MALLOC]] <dt>SQLITE_CONFIG_MALLOC</dt> 1850 ** <dd> ^(The SQLITE_CONFIG_MALLOC option takes a single argument which is 1851 ** a pointer to an instance of the [sqlite3_mem_methods] structure. 1852 ** The argument specifies 1853 ** alternative low-level memory allocation routines to be used in place of 1854 ** the memory allocation routines built into SQLite.)^ ^SQLite makes 1855 ** its own private copy of the content of the [sqlite3_mem_methods] structure 1856 ** before the [sqlite3_config()] call returns.</dd> 1857 ** 1858 ** [[SQLITE_CONFIG_GETMALLOC]] <dt>SQLITE_CONFIG_GETMALLOC</dt> 1859 ** <dd> ^(The SQLITE_CONFIG_GETMALLOC option takes a single argument which 1860 ** is a pointer to an instance of the [sqlite3_mem_methods] structure. 1861 ** The [sqlite3_mem_methods] 1862 ** structure is filled with the currently defined memory allocation routines.)^ 1863 ** This option can be used to overload the default memory allocation 1864 ** routines with a wrapper that simulations memory allocation failure or 1865 ** tracks memory usage, for example. </dd> 1866 ** 1867 ** [[SQLITE_CONFIG_SMALL_MALLOC]] <dt>SQLITE_CONFIG_SMALL_MALLOC</dt> 1868 ** <dd> ^The SQLITE_CONFIG_SMALL_MALLOC option takes single argument of 1869 ** type int, interpreted as a boolean, which if true provides a hint to 1870 ** SQLite that it should avoid large memory allocations if possible. 1871 ** SQLite will run faster if it is free to make large memory allocations, 1872 ** but some application might prefer to run slower in exchange for 1873 ** guarantees about memory fragmentation that are possible if large 1874 ** allocations are avoided. This hint is normally off. 1875 ** </dd> 1876 ** 1877 ** [[SQLITE_CONFIG_MEMSTATUS]] <dt>SQLITE_CONFIG_MEMSTATUS</dt> 1878 ** <dd> ^The SQLITE_CONFIG_MEMSTATUS option takes single argument of type int, 1879 ** interpreted as a boolean, which enables or disables the collection of 1880 ** memory allocation statistics. ^(When memory allocation statistics are 1881 ** disabled, the following SQLite interfaces become non-operational: 1882 ** <ul> 1883 ** <li> [sqlite3_hard_heap_limit64()] 1884 ** <li> [sqlite3_memory_used()] 1885 ** <li> [sqlite3_memory_highwater()] 1886 ** <li> [sqlite3_soft_heap_limit64()] 1887 ** <li> [sqlite3_status64()] 1888 ** </ul>)^ 1889 ** ^Memory allocation statistics are enabled by default unless SQLite is 1890 ** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory 1891 ** allocation statistics are disabled by default. 1892 ** </dd> 1893 ** 1894 ** [[SQLITE_CONFIG_SCRATCH]] <dt>SQLITE_CONFIG_SCRATCH</dt> 1895 ** <dd> The SQLITE_CONFIG_SCRATCH option is no longer used. 1896 ** </dd> 1897 ** 1898 ** [[SQLITE_CONFIG_PAGECACHE]] <dt>SQLITE_CONFIG_PAGECACHE</dt> 1899 ** <dd> ^The SQLITE_CONFIG_PAGECACHE option specifies a memory pool 1900 ** that SQLite can use for the database page cache with the default page 1901 ** cache implementation. 1902 ** This configuration option is a no-op if an application-defined page 1903 ** cache implementation is loaded using the [SQLITE_CONFIG_PCACHE2]. 1904 ** ^There are three arguments to SQLITE_CONFIG_PAGECACHE: A pointer to 1905 ** 8-byte aligned memory (pMem), the size of each page cache line (sz), 1906 ** and the number of cache lines (N). 1907 ** The sz argument should be the size of the largest database page 1908 ** (a power of two between 512 and 65536) plus some extra bytes for each 1909 ** page header. ^The number of extra bytes needed by the page header 1910 ** can be determined using [SQLITE_CONFIG_PCACHE_HDRSZ]. 1911 ** ^It is harmless, apart from the wasted memory, 1912 ** for the sz parameter to be larger than necessary. The pMem 1913 ** argument must be either a NULL pointer or a pointer to an 8-byte 1914 ** aligned block of memory of at least sz*N bytes, otherwise 1915 ** subsequent behavior is undefined. 1916 ** ^When pMem is not NULL, SQLite will strive to use the memory provided 1917 ** to satisfy page cache needs, falling back to [sqlite3_malloc()] if 1918 ** a page cache line is larger than sz bytes or if all of the pMem buffer 1919 ** is exhausted. 1920 ** ^If pMem is NULL and N is non-zero, then each database connection 1921 ** does an initial bulk allocation for page cache memory 1922 ** from [sqlite3_malloc()] sufficient for N cache lines if N is positive or 1923 ** of -1024*N bytes if N is negative, . ^If additional 1924 ** page cache memory is needed beyond what is provided by the initial 1925 ** allocation, then SQLite goes to [sqlite3_malloc()] separately for each 1926 ** additional cache line. </dd> 1927 ** 1928 ** [[SQLITE_CONFIG_HEAP]] <dt>SQLITE_CONFIG_HEAP</dt> 1929 ** <dd> ^The SQLITE_CONFIG_HEAP option specifies a static memory buffer 1930 ** that SQLite will use for all of its dynamic memory allocation needs 1931 ** beyond those provided for by [SQLITE_CONFIG_PAGECACHE]. 1932 ** ^The SQLITE_CONFIG_HEAP option is only available if SQLite is compiled 1933 ** with either [SQLITE_ENABLE_MEMSYS3] or [SQLITE_ENABLE_MEMSYS5] and returns 1934 ** [SQLITE_ERROR] if invoked otherwise. 1935 ** ^There are three arguments to SQLITE_CONFIG_HEAP: 1936 ** An 8-byte aligned pointer to the memory, 1937 ** the number of bytes in the memory buffer, and the minimum allocation size. 1938 ** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts 1939 ** to using its default memory allocator (the system malloc() implementation), 1940 ** undoing any prior invocation of [SQLITE_CONFIG_MALLOC]. ^If the 1941 ** memory pointer is not NULL then the alternative memory 1942 ** allocator is engaged to handle all of SQLites memory allocation needs. 1943 ** The first pointer (the memory pointer) must be aligned to an 8-byte 1944 ** boundary or subsequent behavior of SQLite will be undefined. 1945 ** The minimum allocation size is capped at 2**12. Reasonable values 1946 ** for the minimum allocation size are 2**5 through 2**8.</dd> 1947 ** 1948 ** [[SQLITE_CONFIG_MUTEX]] <dt>SQLITE_CONFIG_MUTEX</dt> 1949 ** <dd> ^(The SQLITE_CONFIG_MUTEX option takes a single argument which is a 1950 ** pointer to an instance of the [sqlite3_mutex_methods] structure. 1951 ** The argument specifies alternative low-level mutex routines to be used 1952 ** in place the mutex routines built into SQLite.)^ ^SQLite makes a copy of 1953 ** the content of the [sqlite3_mutex_methods] structure before the call to 1954 ** [sqlite3_config()] returns. ^If SQLite is compiled with 1955 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1956 ** the entire mutexing subsystem is omitted from the build and hence calls to 1957 ** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will 1958 ** return [SQLITE_ERROR].</dd> 1959 ** 1960 ** [[SQLITE_CONFIG_GETMUTEX]] <dt>SQLITE_CONFIG_GETMUTEX</dt> 1961 ** <dd> ^(The SQLITE_CONFIG_GETMUTEX option takes a single argument which 1962 ** is a pointer to an instance of the [sqlite3_mutex_methods] structure. The 1963 ** [sqlite3_mutex_methods] 1964 ** structure is filled with the currently defined mutex routines.)^ 1965 ** This option can be used to overload the default mutex allocation 1966 ** routines with a wrapper used to track mutex usage for performance 1967 ** profiling or testing, for example. ^If SQLite is compiled with 1968 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1969 ** the entire mutexing subsystem is omitted from the build and hence calls to 1970 ** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will 1971 ** return [SQLITE_ERROR].</dd> 1972 ** 1973 ** [[SQLITE_CONFIG_LOOKASIDE]] <dt>SQLITE_CONFIG_LOOKASIDE</dt> 1974 ** <dd> ^(The SQLITE_CONFIG_LOOKASIDE option takes two arguments that determine 1975 ** the default size of lookaside memory on each [database connection]. 1976 ** The first argument is the 1977 ** size of each lookaside buffer slot and the second is the number of 1978 ** slots allocated to each database connection.)^ ^(SQLITE_CONFIG_LOOKASIDE 1979 ** sets the <i>default</i> lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE] 1980 ** option to [sqlite3_db_config()] can be used to change the lookaside 1981 ** configuration on individual connections.)^ </dd> 1982 ** 1983 ** [[SQLITE_CONFIG_PCACHE2]] <dt>SQLITE_CONFIG_PCACHE2</dt> 1984 ** <dd> ^(The SQLITE_CONFIG_PCACHE2 option takes a single argument which is 1985 ** a pointer to an [sqlite3_pcache_methods2] object. This object specifies 1986 ** the interface to a custom page cache implementation.)^ 1987 ** ^SQLite makes a copy of the [sqlite3_pcache_methods2] object.</dd> 1988 ** 1989 ** [[SQLITE_CONFIG_GETPCACHE2]] <dt>SQLITE_CONFIG_GETPCACHE2</dt> 1990 ** <dd> ^(The SQLITE_CONFIG_GETPCACHE2 option takes a single argument which 1991 ** is a pointer to an [sqlite3_pcache_methods2] object. SQLite copies of 1992 ** the current page cache implementation into that object.)^ </dd> 1993 ** 1994 ** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt> 1995 ** <dd> The SQLITE_CONFIG_LOG option is used to configure the SQLite 1996 ** global [error log]. 1997 ** (^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a 1998 ** function with a call signature of void(*)(void*,int,const char*), 1999 ** and a pointer to void. ^If the function pointer is not NULL, it is 2000 ** invoked by [sqlite3_log()] to process each logging event. ^If the 2001 ** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op. 2002 ** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is 2003 ** passed through as the first parameter to the application-defined logger 2004 ** function whenever that function is invoked. ^The second parameter to 2005 ** the logger function is a copy of the first parameter to the corresponding 2006 ** [sqlite3_log()] call and is intended to be a [result code] or an 2007 ** [extended result code]. ^The third parameter passed to the logger is 2008 ** log message after formatting via [sqlite3_snprintf()]. 2009 ** The SQLite logging interface is not reentrant; the logger function 2010 ** supplied by the application must not invoke any SQLite interface. 2011 ** In a multi-threaded application, the application-defined logger 2012 ** function must be threadsafe. </dd> 2013 ** 2014 ** [[SQLITE_CONFIG_URI]] <dt>SQLITE_CONFIG_URI 2015 ** <dd>^(The SQLITE_CONFIG_URI option takes a single argument of type int. 2016 ** If non-zero, then URI handling is globally enabled. If the parameter is zero, 2017 ** then URI handling is globally disabled.)^ ^If URI handling is globally 2018 ** enabled, all filenames passed to [sqlite3_open()], [sqlite3_open_v2()], 2019 ** [sqlite3_open16()] or 2020 ** specified as part of [ATTACH] commands are interpreted as URIs, regardless 2021 ** of whether or not the [SQLITE_OPEN_URI] flag is set when the database 2022 ** connection is opened. ^If it is globally disabled, filenames are 2023 ** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the 2024 ** database connection is opened. ^(By default, URI handling is globally 2025 ** disabled. The default value may be changed by compiling with the 2026 ** [SQLITE_USE_URI] symbol defined.)^ 2027 ** 2028 ** [[SQLITE_CONFIG_COVERING_INDEX_SCAN]] <dt>SQLITE_CONFIG_COVERING_INDEX_SCAN 2029 ** <dd>^The SQLITE_CONFIG_COVERING_INDEX_SCAN option takes a single integer 2030 ** argument which is interpreted as a boolean in order to enable or disable 2031 ** the use of covering indices for full table scans in the query optimizer. 2032 ** ^The default setting is determined 2033 ** by the [SQLITE_ALLOW_COVERING_INDEX_SCAN] compile-time option, or is "on" 2034 ** if that compile-time option is omitted. 2035 ** The ability to disable the use of covering indices for full table scans 2036 ** is because some incorrectly coded legacy applications might malfunction 2037 ** when the optimization is enabled. Providing the ability to 2038 ** disable the optimization allows the older, buggy application code to work 2039 ** without change even with newer versions of SQLite. 2040 ** 2041 ** [[SQLITE_CONFIG_PCACHE]] [[SQLITE_CONFIG_GETPCACHE]] 2042 ** <dt>SQLITE_CONFIG_PCACHE and SQLITE_CONFIG_GETPCACHE 2043 ** <dd> These options are obsolete and should not be used by new code. 2044 ** They are retained for backwards compatibility but are now no-ops. 2045 ** </dd> 2046 ** 2047 ** [[SQLITE_CONFIG_SQLLOG]] 2048 ** <dt>SQLITE_CONFIG_SQLLOG 2049 ** <dd>This option is only available if sqlite is compiled with the 2050 ** [SQLITE_ENABLE_SQLLOG] pre-processor macro defined. The first argument should 2051 ** be a pointer to a function of type void(*)(void*,sqlite3*,const char*, int). 2052 ** The second should be of type (void*). The callback is invoked by the library 2053 ** in three separate circumstances, identified by the value passed as the 2054 ** fourth parameter. If the fourth parameter is 0, then the database connection 2055 ** passed as the second argument has just been opened. The third argument 2056 ** points to a buffer containing the name of the main database file. If the 2057 ** fourth parameter is 1, then the SQL statement that the third parameter 2058 ** points to has just been executed. Or, if the fourth parameter is 2, then 2059 ** the connection being passed as the second parameter is being closed. The 2060 ** third parameter is passed NULL In this case. An example of using this 2061 ** configuration option can be seen in the "test_sqllog.c" source file in 2062 ** the canonical SQLite source tree.</dd> 2063 ** 2064 ** [[SQLITE_CONFIG_MMAP_SIZE]] 2065 ** <dt>SQLITE_CONFIG_MMAP_SIZE 2066 ** <dd>^SQLITE_CONFIG_MMAP_SIZE takes two 64-bit integer (sqlite3_int64) values 2067 ** that are the default mmap size limit (the default setting for 2068 ** [PRAGMA mmap_size]) and the maximum allowed mmap size limit. 2069 ** ^The default setting can be overridden by each database connection using 2070 ** either the [PRAGMA mmap_size] command, or by using the 2071 ** [SQLITE_FCNTL_MMAP_SIZE] file control. ^(The maximum allowed mmap size 2072 ** will be silently truncated if necessary so that it does not exceed the 2073 ** compile-time maximum mmap size set by the 2074 ** [SQLITE_MAX_MMAP_SIZE] compile-time option.)^ 2075 ** ^If either argument to this option is negative, then that argument is 2076 ** changed to its compile-time default. 2077 ** 2078 ** [[SQLITE_CONFIG_WIN32_HEAPSIZE]] 2079 ** <dt>SQLITE_CONFIG_WIN32_HEAPSIZE 2080 ** <dd>^The SQLITE_CONFIG_WIN32_HEAPSIZE option is only available if SQLite is 2081 ** compiled for Windows with the [SQLITE_WIN32_MALLOC] pre-processor macro 2082 ** defined. ^SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit unsigned integer value 2083 ** that specifies the maximum size of the created heap. 2084 ** 2085 ** [[SQLITE_CONFIG_PCACHE_HDRSZ]] 2086 ** <dt>SQLITE_CONFIG_PCACHE_HDRSZ 2087 ** <dd>^The SQLITE_CONFIG_PCACHE_HDRSZ option takes a single parameter which 2088 ** is a pointer to an integer and writes into that integer the number of extra 2089 ** bytes per page required for each page in [SQLITE_CONFIG_PAGECACHE]. 2090 ** The amount of extra space required can change depending on the compiler, 2091 ** target platform, and SQLite version. 2092 ** 2093 ** [[SQLITE_CONFIG_PMASZ]] 2094 ** <dt>SQLITE_CONFIG_PMASZ 2095 ** <dd>^The SQLITE_CONFIG_PMASZ option takes a single parameter which 2096 ** is an unsigned integer and sets the "Minimum PMA Size" for the multithreaded 2097 ** sorter to that integer. The default minimum PMA Size is set by the 2098 ** [SQLITE_SORTER_PMASZ] compile-time option. New threads are launched 2099 ** to help with sort operations when multithreaded sorting 2100 ** is enabled (using the [PRAGMA threads] command) and the amount of content 2101 ** to be sorted exceeds the page size times the minimum of the 2102 ** [PRAGMA cache_size] setting and this value. 2103 ** 2104 ** [[SQLITE_CONFIG_STMTJRNL_SPILL]] 2105 ** <dt>SQLITE_CONFIG_STMTJRNL_SPILL 2106 ** <dd>^The SQLITE_CONFIG_STMTJRNL_SPILL option takes a single parameter which 2107 ** becomes the [statement journal] spill-to-disk threshold. 2108 ** [Statement journals] are held in memory until their size (in bytes) 2109 ** exceeds this threshold, at which point they are written to disk. 2110 ** Or if the threshold is -1, statement journals are always held 2111 ** exclusively in memory. 2112 ** Since many statement journals never become large, setting the spill 2113 ** threshold to a value such as 64KiB can greatly reduce the amount of 2114 ** I/O required to support statement rollback. 2115 ** The default value for this setting is controlled by the 2116 ** [SQLITE_STMTJRNL_SPILL] compile-time option. 2117 ** 2118 ** [[SQLITE_CONFIG_SORTERREF_SIZE]] 2119 ** <dt>SQLITE_CONFIG_SORTERREF_SIZE 2120 ** <dd>The SQLITE_CONFIG_SORTERREF_SIZE option accepts a single parameter 2121 ** of type (int) - the new value of the sorter-reference size threshold. 2122 ** Usually, when SQLite uses an external sort to order records according 2123 ** to an ORDER BY clause, all fields required by the caller are present in the 2124 ** sorted records. However, if SQLite determines based on the declared type 2125 ** of a table column that its values are likely to be very large - larger 2126 ** than the configured sorter-reference size threshold - then a reference 2127 ** is stored in each sorted record and the required column values loaded 2128 ** from the database as records are returned in sorted order. The default 2129 ** value for this option is to never use this optimization. Specifying a 2130 ** negative value for this option restores the default behavior. 2131 ** This option is only available if SQLite is compiled with the 2132 ** [SQLITE_ENABLE_SORTER_REFERENCES] compile-time option. 2133 ** 2134 ** [[SQLITE_CONFIG_MEMDB_MAXSIZE]] 2135 ** <dt>SQLITE_CONFIG_MEMDB_MAXSIZE 2136 ** <dd>The SQLITE_CONFIG_MEMDB_MAXSIZE option accepts a single parameter 2137 ** [sqlite3_int64] parameter which is the default maximum size for an in-memory 2138 ** database created using [sqlite3_deserialize()]. This default maximum 2139 ** size can be adjusted up or down for individual databases using the 2140 ** [SQLITE_FCNTL_SIZE_LIMIT] [sqlite3_file_control|file-control]. If this 2141 ** configuration setting is never used, then the default maximum is determined 2142 ** by the [SQLITE_MEMDB_DEFAULT_MAXSIZE] compile-time option. If that 2143 ** compile-time option is not set, then the default maximum is 1073741824. 2144 ** </dl> 2145 */ 2146 #define SQLITE_CONFIG_SINGLETHREAD 1 /* nil */ 2147 #define SQLITE_CONFIG_MULTITHREAD 2 /* nil */ 2148 #define SQLITE_CONFIG_SERIALIZED 3 /* nil */ 2149 #define SQLITE_CONFIG_MALLOC 4 /* sqlite3_mem_methods* */ 2150 #define SQLITE_CONFIG_GETMALLOC 5 /* sqlite3_mem_methods* */ 2151 #define SQLITE_CONFIG_SCRATCH 6 /* No longer used */ 2152 #define SQLITE_CONFIG_PAGECACHE 7 /* void*, int sz, int N */ 2153 #define SQLITE_CONFIG_HEAP 8 /* void*, int nByte, int min */ 2154 #define SQLITE_CONFIG_MEMSTATUS 9 /* boolean */ 2155 #define SQLITE_CONFIG_MUTEX 10 /* sqlite3_mutex_methods* */ 2156 #define SQLITE_CONFIG_GETMUTEX 11 /* sqlite3_mutex_methods* */ 2157 /* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */ 2158 #define SQLITE_CONFIG_LOOKASIDE 13 /* int int */ 2159 #define SQLITE_CONFIG_PCACHE 14 /* no-op */ 2160 #define SQLITE_CONFIG_GETPCACHE 15 /* no-op */ 2161 #define SQLITE_CONFIG_LOG 16 /* xFunc, void* */ 2162 #define SQLITE_CONFIG_URI 17 /* int */ 2163 #define SQLITE_CONFIG_PCACHE2 18 /* sqlite3_pcache_methods2* */ 2164 #define SQLITE_CONFIG_GETPCACHE2 19 /* sqlite3_pcache_methods2* */ 2165 #define SQLITE_CONFIG_COVERING_INDEX_SCAN 20 /* int */ 2166 #define SQLITE_CONFIG_SQLLOG 21 /* xSqllog, void* */ 2167 #define SQLITE_CONFIG_MMAP_SIZE 22 /* sqlite3_int64, sqlite3_int64 */ 2168 #define SQLITE_CONFIG_WIN32_HEAPSIZE 23 /* int nByte */ 2169 #define SQLITE_CONFIG_PCACHE_HDRSZ 24 /* int *psz */ 2170 #define SQLITE_CONFIG_PMASZ 25 /* unsigned int szPma */ 2171 #define SQLITE_CONFIG_STMTJRNL_SPILL 26 /* int nByte */ 2172 #define SQLITE_CONFIG_SMALL_MALLOC 27 /* boolean */ 2173 #define SQLITE_CONFIG_SORTERREF_SIZE 28 /* int nByte */ 2174 #define SQLITE_CONFIG_MEMDB_MAXSIZE 29 /* sqlite3_int64 */ 2175 2176 /* 2177 ** CAPI3REF: Database Connection Configuration Options 2178 ** 2179 ** These constants are the available integer configuration options that 2180 ** can be passed as the second argument to the [sqlite3_db_config()] interface. 2181 ** 2182 ** New configuration options may be added in future releases of SQLite. 2183 ** Existing configuration options might be discontinued. Applications 2184 ** should check the return code from [sqlite3_db_config()] to make sure that 2185 ** the call worked. ^The [sqlite3_db_config()] interface will return a 2186 ** non-zero [error code] if a discontinued or unsupported configuration option 2187 ** is invoked. 2188 ** 2189 ** <dl> 2190 ** [[SQLITE_DBCONFIG_LOOKASIDE]] 2191 ** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt> 2192 ** <dd> ^This option takes three additional arguments that determine the 2193 ** [lookaside memory allocator] configuration for the [database connection]. 2194 ** ^The first argument (the third parameter to [sqlite3_db_config()] is a 2195 ** pointer to a memory buffer to use for lookaside memory. 2196 ** ^The first argument after the SQLITE_DBCONFIG_LOOKASIDE verb 2197 ** may be NULL in which case SQLite will allocate the 2198 ** lookaside buffer itself using [sqlite3_malloc()]. ^The second argument is the 2199 ** size of each lookaside buffer slot. ^The third argument is the number of 2200 ** slots. The size of the buffer in the first argument must be greater than 2201 ** or equal to the product of the second and third arguments. The buffer 2202 ** must be aligned to an 8-byte boundary. ^If the second argument to 2203 ** SQLITE_DBCONFIG_LOOKASIDE is not a multiple of 8, it is internally 2204 ** rounded down to the next smaller multiple of 8. ^(The lookaside memory 2205 ** configuration for a database connection can only be changed when that 2206 ** connection is not currently using lookaside memory, or in other words 2207 ** when the "current value" returned by 2208 ** [sqlite3_db_status](D,[SQLITE_DBSTATUS_LOOKASIDE_USED],...) is zero. 2209 ** Any attempt to change the lookaside memory configuration when lookaside 2210 ** memory is in use leaves the configuration unchanged and returns 2211 ** [SQLITE_BUSY].)^</dd> 2212 ** 2213 ** [[SQLITE_DBCONFIG_ENABLE_FKEY]] 2214 ** <dt>SQLITE_DBCONFIG_ENABLE_FKEY</dt> 2215 ** <dd> ^This option is used to enable or disable the enforcement of 2216 ** [foreign key constraints]. There should be two additional arguments. 2217 ** The first argument is an integer which is 0 to disable FK enforcement, 2218 ** positive to enable FK enforcement or negative to leave FK enforcement 2219 ** unchanged. The second parameter is a pointer to an integer into which 2220 ** is written 0 or 1 to indicate whether FK enforcement is off or on 2221 ** following this call. The second parameter may be a NULL pointer, in 2222 ** which case the FK enforcement setting is not reported back. </dd> 2223 ** 2224 ** [[SQLITE_DBCONFIG_ENABLE_TRIGGER]] 2225 ** <dt>SQLITE_DBCONFIG_ENABLE_TRIGGER</dt> 2226 ** <dd> ^This option is used to enable or disable [CREATE TRIGGER | triggers]. 2227 ** There should be two additional arguments. 2228 ** The first argument is an integer which is 0 to disable triggers, 2229 ** positive to enable triggers or negative to leave the setting unchanged. 2230 ** The second parameter is a pointer to an integer into which 2231 ** is written 0 or 1 to indicate whether triggers are disabled or enabled 2232 ** following this call. The second parameter may be a NULL pointer, in 2233 ** which case the trigger setting is not reported back. 2234 ** 2235 ** <p>Originally this option disabled all triggers. ^(However, since 2236 ** SQLite version 3.35.0, TEMP triggers are still allowed even if 2237 ** this option is off. So, in other words, this option now only disables 2238 ** triggers in the main database schema or in the schemas of ATTACH-ed 2239 ** databases.)^ </dd> 2240 ** 2241 ** [[SQLITE_DBCONFIG_ENABLE_VIEW]] 2242 ** <dt>SQLITE_DBCONFIG_ENABLE_VIEW</dt> 2243 ** <dd> ^This option is used to enable or disable [CREATE VIEW | views]. 2244 ** There should be two additional arguments. 2245 ** The first argument is an integer which is 0 to disable views, 2246 ** positive to enable views or negative to leave the setting unchanged. 2247 ** The second parameter is a pointer to an integer into which 2248 ** is written 0 or 1 to indicate whether views are disabled or enabled 2249 ** following this call. The second parameter may be a NULL pointer, in 2250 ** which case the view setting is not reported back. 2251 ** 2252 ** <p>Originally this option disabled all views. ^(However, since 2253 ** SQLite version 3.35.0, TEMP views are still allowed even if 2254 ** this option is off. So, in other words, this option now only disables 2255 ** views in the main database schema or in the schemas of ATTACH-ed 2256 ** databases.)^ </dd> 2257 ** 2258 ** [[SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER]] 2259 ** <dt>SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER</dt> 2260 ** <dd> ^This option is used to enable or disable the 2261 ** [fts3_tokenizer()] function which is part of the 2262 ** [FTS3] full-text search engine extension. 2263 ** There should be two additional arguments. 2264 ** The first argument is an integer which is 0 to disable fts3_tokenizer() or 2265 ** positive to enable fts3_tokenizer() or negative to leave the setting 2266 ** unchanged. 2267 ** The second parameter is a pointer to an integer into which 2268 ** is written 0 or 1 to indicate whether fts3_tokenizer is disabled or enabled 2269 ** following this call. The second parameter may be a NULL pointer, in 2270 ** which case the new setting is not reported back. </dd> 2271 ** 2272 ** [[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION]] 2273 ** <dt>SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION</dt> 2274 ** <dd> ^This option is used to enable or disable the [sqlite3_load_extension()] 2275 ** interface independently of the [load_extension()] SQL function. 2276 ** The [sqlite3_enable_load_extension()] API enables or disables both the 2277 ** C-API [sqlite3_load_extension()] and the SQL function [load_extension()]. 2278 ** There should be two additional arguments. 2279 ** When the first argument to this interface is 1, then only the C-API is 2280 ** enabled and the SQL function remains disabled. If the first argument to 2281 ** this interface is 0, then both the C-API and the SQL function are disabled. 2282 ** If the first argument is -1, then no changes are made to state of either the 2283 ** C-API or the SQL function. 2284 ** The second parameter is a pointer to an integer into which 2285 ** is written 0 or 1 to indicate whether [sqlite3_load_extension()] interface 2286 ** is disabled or enabled following this call. The second parameter may 2287 ** be a NULL pointer, in which case the new setting is not reported back. 2288 ** </dd> 2289 ** 2290 ** [[SQLITE_DBCONFIG_MAINDBNAME]] <dt>SQLITE_DBCONFIG_MAINDBNAME</dt> 2291 ** <dd> ^This option is used to change the name of the "main" database 2292 ** schema. ^The sole argument is a pointer to a constant UTF8 string 2293 ** which will become the new schema name in place of "main". ^SQLite 2294 ** does not make a copy of the new main schema name string, so the application 2295 ** must ensure that the argument passed into this DBCONFIG option is unchanged 2296 ** until after the database connection closes. 2297 ** </dd> 2298 ** 2299 ** [[SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE]] 2300 ** <dt>SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE</dt> 2301 ** <dd> Usually, when a database in wal mode is closed or detached from a 2302 ** database handle, SQLite checks if this will mean that there are now no 2303 ** connections at all to the database. If so, it performs a checkpoint 2304 ** operation before closing the connection. This option may be used to 2305 ** override this behavior. The first parameter passed to this operation 2306 ** is an integer - positive to disable checkpoints-on-close, or zero (the 2307 ** default) to enable them, and negative to leave the setting unchanged. 2308 ** The second parameter is a pointer to an integer 2309 ** into which is written 0 or 1 to indicate whether checkpoints-on-close 2310 ** have been disabled - 0 if they are not disabled, 1 if they are. 2311 ** </dd> 2312 ** 2313 ** [[SQLITE_DBCONFIG_ENABLE_QPSG]] <dt>SQLITE_DBCONFIG_ENABLE_QPSG</dt> 2314 ** <dd>^(The SQLITE_DBCONFIG_ENABLE_QPSG option activates or deactivates 2315 ** the [query planner stability guarantee] (QPSG). When the QPSG is active, 2316 ** a single SQL query statement will always use the same algorithm regardless 2317 ** of values of [bound parameters].)^ The QPSG disables some query optimizations 2318 ** that look at the values of bound parameters, which can make some queries 2319 ** slower. But the QPSG has the advantage of more predictable behavior. With 2320 ** the QPSG active, SQLite will always use the same query plan in the field as 2321 ** was used during testing in the lab. 2322 ** The first argument to this setting is an integer which is 0 to disable 2323 ** the QPSG, positive to enable QPSG, or negative to leave the setting 2324 ** unchanged. The second parameter is a pointer to an integer into which 2325 ** is written 0 or 1 to indicate whether the QPSG is disabled or enabled 2326 ** following this call. 2327 ** </dd> 2328 ** 2329 ** [[SQLITE_DBCONFIG_TRIGGER_EQP]] <dt>SQLITE_DBCONFIG_TRIGGER_EQP</dt> 2330 ** <dd> By default, the output of EXPLAIN QUERY PLAN commands does not 2331 ** include output for any operations performed by trigger programs. This 2332 ** option is used to set or clear (the default) a flag that governs this 2333 ** behavior. The first parameter passed to this operation is an integer - 2334 ** positive to enable output for trigger programs, or zero to disable it, 2335 ** or negative to leave the setting unchanged. 2336 ** The second parameter is a pointer to an integer into which is written 2337 ** 0 or 1 to indicate whether output-for-triggers has been disabled - 0 if 2338 ** it is not disabled, 1 if it is. 2339 ** </dd> 2340 ** 2341 ** [[SQLITE_DBCONFIG_RESET_DATABASE]] <dt>SQLITE_DBCONFIG_RESET_DATABASE</dt> 2342 ** <dd> Set the SQLITE_DBCONFIG_RESET_DATABASE flag and then run 2343 ** [VACUUM] in order to reset a database back to an empty database 2344 ** with no schema and no content. The following process works even for 2345 ** a badly corrupted database file: 2346 ** <ol> 2347 ** <li> If the database connection is newly opened, make sure it has read the 2348 ** database schema by preparing then discarding some query against the 2349 ** database, or calling sqlite3_table_column_metadata(), ignoring any 2350 ** errors. This step is only necessary if the application desires to keep 2351 ** the database in WAL mode after the reset if it was in WAL mode before 2352 ** the reset. 2353 ** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 1, 0); 2354 ** <li> [sqlite3_exec](db, "[VACUUM]", 0, 0, 0); 2355 ** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 0, 0); 2356 ** </ol> 2357 ** Because resetting a database is destructive and irreversible, the 2358 ** process requires the use of this obscure API and multiple steps to 2359 ** help ensure that it does not happen by accident. Because this 2360 ** feature must be capable of resetting corrupt databases, and 2361 ** shutting down virtual tables may require access to that corrupt 2362 ** storage, the library must abandon any installed virtual tables 2363 ** without calling their xDestroy() methods. 2364 ** 2365 ** [[SQLITE_DBCONFIG_DEFENSIVE]] <dt>SQLITE_DBCONFIG_DEFENSIVE</dt> 2366 ** <dd>The SQLITE_DBCONFIG_DEFENSIVE option activates or deactivates the 2367 ** "defensive" flag for a database connection. When the defensive 2368 ** flag is enabled, language features that allow ordinary SQL to 2369 ** deliberately corrupt the database file are disabled. The disabled 2370 ** features include but are not limited to the following: 2371 ** <ul> 2372 ** <li> The [PRAGMA writable_schema=ON] statement. 2373 ** <li> The [PRAGMA journal_mode=OFF] statement. 2374 ** <li> The [PRAGMA schema_version=N] statement. 2375 ** <li> Writes to the [sqlite_dbpage] virtual table. 2376 ** <li> Direct writes to [shadow tables]. 2377 ** </ul> 2378 ** </dd> 2379 ** 2380 ** [[SQLITE_DBCONFIG_WRITABLE_SCHEMA]] <dt>SQLITE_DBCONFIG_WRITABLE_SCHEMA</dt> 2381 ** <dd>The SQLITE_DBCONFIG_WRITABLE_SCHEMA option activates or deactivates the 2382 ** "writable_schema" flag. This has the same effect and is logically equivalent 2383 ** to setting [PRAGMA writable_schema=ON] or [PRAGMA writable_schema=OFF]. 2384 ** The first argument to this setting is an integer which is 0 to disable 2385 ** the writable_schema, positive to enable writable_schema, or negative to 2386 ** leave the setting unchanged. The second parameter is a pointer to an 2387 ** integer into which is written 0 or 1 to indicate whether the writable_schema 2388 ** is enabled or disabled following this call. 2389 ** </dd> 2390 ** 2391 ** [[SQLITE_DBCONFIG_LEGACY_ALTER_TABLE]] 2392 ** <dt>SQLITE_DBCONFIG_LEGACY_ALTER_TABLE</dt> 2393 ** <dd>The SQLITE_DBCONFIG_LEGACY_ALTER_TABLE option activates or deactivates 2394 ** the legacy behavior of the [ALTER TABLE RENAME] command such it 2395 ** behaves as it did prior to [version 3.24.0] (2018-06-04). See the 2396 ** "Compatibility Notice" on the [ALTER TABLE RENAME documentation] for 2397 ** additional information. This feature can also be turned on and off 2398 ** using the [PRAGMA legacy_alter_table] statement. 2399 ** </dd> 2400 ** 2401 ** [[SQLITE_DBCONFIG_DQS_DML]] 2402 ** <dt>SQLITE_DBCONFIG_DQS_DML</dt> 2403 ** <dd>The SQLITE_DBCONFIG_DQS_DML option activates or deactivates 2404 ** the legacy [double-quoted string literal] misfeature for DML statements 2405 ** only, that is DELETE, INSERT, SELECT, and UPDATE statements. The 2406 ** default value of this setting is determined by the [-DSQLITE_DQS] 2407 ** compile-time option. 2408 ** </dd> 2409 ** 2410 ** [[SQLITE_DBCONFIG_DQS_DDL]] 2411 ** <dt>SQLITE_DBCONFIG_DQS_DDL</dt> 2412 ** <dd>The SQLITE_DBCONFIG_DQS option activates or deactivates 2413 ** the legacy [double-quoted string literal] misfeature for DDL statements, 2414 ** such as CREATE TABLE and CREATE INDEX. The 2415 ** default value of this setting is determined by the [-DSQLITE_DQS] 2416 ** compile-time option. 2417 ** </dd> 2418 ** 2419 ** [[SQLITE_DBCONFIG_TRUSTED_SCHEMA]] 2420 ** <dt>SQLITE_DBCONFIG_TRUSTED_SCHEMA</dt> 2421 ** <dd>The SQLITE_DBCONFIG_TRUSTED_SCHEMA option tells SQLite to 2422 ** assume that database schemas are untainted by malicious content. 2423 ** When the SQLITE_DBCONFIG_TRUSTED_SCHEMA option is disabled, SQLite 2424 ** takes additional defensive steps to protect the application from harm 2425 ** including: 2426 ** <ul> 2427 ** <li> Prohibit the use of SQL functions inside triggers, views, 2428 ** CHECK constraints, DEFAULT clauses, expression indexes, 2429 ** partial indexes, or generated columns 2430 ** unless those functions are tagged with [SQLITE_INNOCUOUS]. 2431 ** <li> Prohibit the use of virtual tables inside of triggers or views 2432 ** unless those virtual tables are tagged with [SQLITE_VTAB_INNOCUOUS]. 2433 ** </ul> 2434 ** This setting defaults to "on" for legacy compatibility, however 2435 ** all applications are advised to turn it off if possible. This setting 2436 ** can also be controlled using the [PRAGMA trusted_schema] statement. 2437 ** </dd> 2438 ** 2439 ** [[SQLITE_DBCONFIG_LEGACY_FILE_FORMAT]] 2440 ** <dt>SQLITE_DBCONFIG_LEGACY_FILE_FORMAT</dt> 2441 ** <dd>The SQLITE_DBCONFIG_LEGACY_FILE_FORMAT option activates or deactivates 2442 ** the legacy file format flag. When activated, this flag causes all newly 2443 ** created database file to have a schema format version number (the 4-byte 2444 ** integer found at offset 44 into the database header) of 1. This in turn 2445 ** means that the resulting database file will be readable and writable by 2446 ** any SQLite version back to 3.0.0 ([dateof:3.0.0]). Without this setting, 2447 ** newly created databases are generally not understandable by SQLite versions 2448 ** prior to 3.3.0 ([dateof:3.3.0]). As these words are written, there 2449 ** is now scarcely any need to generate database files that are compatible 2450 ** all the way back to version 3.0.0, and so this setting is of little 2451 ** practical use, but is provided so that SQLite can continue to claim the 2452 ** ability to generate new database files that are compatible with version 2453 ** 3.0.0. 2454 ** <p>Note that when the SQLITE_DBCONFIG_LEGACY_FILE_FORMAT setting is on, 2455 ** the [VACUUM] command will fail with an obscure error when attempting to 2456 ** process a table with generated columns and a descending index. This is 2457 ** not considered a bug since SQLite versions 3.3.0 and earlier do not support 2458 ** either generated columns or descending indexes. 2459 ** </dd> 2460 ** 2461 ** [[SQLITE_DBCONFIG_STMT_SCANSTATUS]] 2462 ** <dt>SQLITE_DBCONFIG_STMT_SCANSTATUS</dt> 2463 ** <dd>The SQLITE_DBCONFIG_STMT_SCANSTATUS option is only useful in 2464 ** SQLITE_ENABLE_STMT_SCANSTATUS builds. In this case, it sets or clears 2465 ** a flag that enables collection of the sqlite3_stmt_scanstatus_v2() 2466 ** statistics. For statistics to be collected, the flag must be set on 2467 ** the database handle both when the SQL statement is prepared and when it 2468 ** is stepped. The flag is set (collection of statistics is enabled) 2469 ** by default. This option takes two arguments: an integer and a pointer to 2470 ** an integer.. The first argument is 1, 0, or -1 to enable, disable, or 2471 ** leave unchanged the statement scanstatus option. If the second argument 2472 ** is not NULL, then the value of the statement scanstatus setting after 2473 ** processing the first argument is written into the integer that the second 2474 ** argument points to. 2475 ** </dd> 2476 ** 2477 ** [[SQLITE_DBCONFIG_REVERSE_SCANORDER]] 2478 ** <dt>SQLITE_DBCONFIG_REVERSE_SCANORDER</dt> 2479 ** <dd>The SQLITE_DBCONFIG_REVERSE_SCANORDER option changes the default order 2480 ** in which tables and indexes are scanned so that the scans start at the end 2481 ** and work toward the beginning rather than starting at the beginning and 2482 ** working toward the end. Setting SQLITE_DBCONFIG_REVERSE_SCANORDER is the 2483 ** same as setting [PRAGMA reverse_unordered_selects]. This option takes 2484 ** two arguments which are an integer and a pointer to an integer. The first 2485 ** argument is 1, 0, or -1 to enable, disable, or leave unchanged the 2486 ** reverse scan order flag, respectively. If the second argument is not NULL, 2487 ** then 0 or 1 is written into the integer that the second argument points to 2488 ** depending on if the reverse scan order flag is set after processing the 2489 ** first argument. 2490 ** </dd> 2491 ** 2492 ** </dl> 2493 */ 2494 #define SQLITE_DBCONFIG_MAINDBNAME 1000 /* const char* */ 2495 #define SQLITE_DBCONFIG_LOOKASIDE 1001 /* void* int int */ 2496 #define SQLITE_DBCONFIG_ENABLE_FKEY 1002 /* int int* */ 2497 #define SQLITE_DBCONFIG_ENABLE_TRIGGER 1003 /* int int* */ 2498 #define SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER 1004 /* int int* */ 2499 #define SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION 1005 /* int int* */ 2500 #define SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE 1006 /* int int* */ 2501 #define SQLITE_DBCONFIG_ENABLE_QPSG 1007 /* int int* */ 2502 #define SQLITE_DBCONFIG_TRIGGER_EQP 1008 /* int int* */ 2503 #define SQLITE_DBCONFIG_RESET_DATABASE 1009 /* int int* */ 2504 #define SQLITE_DBCONFIG_DEFENSIVE 1010 /* int int* */ 2505 #define SQLITE_DBCONFIG_WRITABLE_SCHEMA 1011 /* int int* */ 2506 #define SQLITE_DBCONFIG_LEGACY_ALTER_TABLE 1012 /* int int* */ 2507 #define SQLITE_DBCONFIG_DQS_DML 1013 /* int int* */ 2508 #define SQLITE_DBCONFIG_DQS_DDL 1014 /* int int* */ 2509 #define SQLITE_DBCONFIG_ENABLE_VIEW 1015 /* int int* */ 2510 #define SQLITE_DBCONFIG_LEGACY_FILE_FORMAT 1016 /* int int* */ 2511 #define SQLITE_DBCONFIG_TRUSTED_SCHEMA 1017 /* int int* */ 2512 #define SQLITE_DBCONFIG_STMT_SCANSTATUS 1018 /* int int* */ 2513 #define SQLITE_DBCONFIG_REVERSE_SCANORDER 1019 /* int int* */ 2514 #define SQLITE_DBCONFIG_MAX 1019 /* Largest DBCONFIG */ 2515 2516 /* 2517 ** CAPI3REF: Enable Or Disable Extended Result Codes 2518 ** METHOD: sqlite3 2519 ** 2520 ** ^The sqlite3_extended_result_codes() routine enables or disables the 2521 ** [extended result codes] feature of SQLite. ^The extended result 2522 ** codes are disabled by default for historical compatibility. 2523 */ 2524 SQLITE_API int sqlite3_extended_result_codes(sqlite3*, int onoff); 2525 2526 /* 2527 ** CAPI3REF: Last Insert Rowid 2528 ** METHOD: sqlite3 2529 ** 2530 ** ^Each entry in most SQLite tables (except for [WITHOUT ROWID] tables) 2531 ** has a unique 64-bit signed 2532 ** integer key called the [ROWID | "rowid"]. ^The rowid is always available 2533 ** as an undeclared column named ROWID, OID, or _ROWID_ as long as those 2534 ** names are not also used by explicitly declared columns. ^If 2535 ** the table has a column of type [INTEGER PRIMARY KEY] then that column 2536 ** is another alias for the rowid. 2537 ** 2538 ** ^The sqlite3_last_insert_rowid(D) interface usually returns the [rowid] of 2539 ** the most recent successful [INSERT] into a rowid table or [virtual table] 2540 ** on database connection D. ^Inserts into [WITHOUT ROWID] tables are not 2541 ** recorded. ^If no successful [INSERT]s into rowid tables have ever occurred 2542 ** on the database connection D, then sqlite3_last_insert_rowid(D) returns 2543 ** zero. 2544 ** 2545 ** As well as being set automatically as rows are inserted into database 2546 ** tables, the value returned by this function may be set explicitly by 2547 ** [sqlite3_set_last_insert_rowid()] 2548 ** 2549 ** Some virtual table implementations may INSERT rows into rowid tables as 2550 ** part of committing a transaction (e.g. to flush data accumulated in memory 2551 ** to disk). In this case subsequent calls to this function return the rowid 2552 ** associated with these internal INSERT operations, which leads to 2553 ** unintuitive results. Virtual table implementations that do write to rowid 2554 ** tables in this way can avoid this problem by restoring the original 2555 ** rowid value using [sqlite3_set_last_insert_rowid()] before returning 2556 ** control to the user. 2557 ** 2558 ** ^(If an [INSERT] occurs within a trigger then this routine will 2559 ** return the [rowid] of the inserted row as long as the trigger is 2560 ** running. Once the trigger program ends, the value returned 2561 ** by this routine reverts to what it was before the trigger was fired.)^ 2562 ** 2563 ** ^An [INSERT] that fails due to a constraint violation is not a 2564 ** successful [INSERT] and does not change the value returned by this 2565 ** routine. ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK, 2566 ** and INSERT OR ABORT make no changes to the return value of this 2567 ** routine when their insertion fails. ^(When INSERT OR REPLACE 2568 ** encounters a constraint violation, it does not fail. The 2569 ** INSERT continues to completion after deleting rows that caused 2570 ** the constraint problem so INSERT OR REPLACE will always change 2571 ** the return value of this interface.)^ 2572 ** 2573 ** ^For the purposes of this routine, an [INSERT] is considered to 2574 ** be successful even if it is subsequently rolled back. 2575 ** 2576 ** This function is accessible to SQL statements via the 2577 ** [last_insert_rowid() SQL function]. 2578 ** 2579 ** If a separate thread performs a new [INSERT] on the same 2580 ** database connection while the [sqlite3_last_insert_rowid()] 2581 ** function is running and thus changes the last insert [rowid], 2582 ** then the value returned by [sqlite3_last_insert_rowid()] is 2583 ** unpredictable and might not equal either the old or the new 2584 ** last insert [rowid]. 2585 */ 2586 SQLITE_API sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*); 2587 2588 /* 2589 ** CAPI3REF: Set the Last Insert Rowid value. 2590 ** METHOD: sqlite3 2591 ** 2592 ** The sqlite3_set_last_insert_rowid(D, R) method allows the application to 2593 ** set the value returned by calling sqlite3_last_insert_rowid(D) to R 2594 ** without inserting a row into the database. 2595 */ 2596 SQLITE_API void sqlite3_set_last_insert_rowid(sqlite3*,sqlite3_int64); 2597 2598 /* 2599 ** CAPI3REF: Count The Number Of Rows Modified 2600 ** METHOD: sqlite3 2601 ** 2602 ** ^These functions return the number of rows modified, inserted or 2603 ** deleted by the most recently completed INSERT, UPDATE or DELETE 2604 ** statement on the database connection specified by the only parameter. 2605 ** The two functions are identical except for the type of the return value 2606 ** and that if the number of rows modified by the most recent INSERT, UPDATE 2607 ** or DELETE is greater than the maximum value supported by type "int", then 2608 ** the return value of sqlite3_changes() is undefined. ^Executing any other 2609 ** type of SQL statement does not modify the value returned by these functions. 2610 ** 2611 ** ^Only changes made directly by the INSERT, UPDATE or DELETE statement are 2612 ** considered - auxiliary changes caused by [CREATE TRIGGER | triggers], 2613 ** [foreign key actions] or [REPLACE] constraint resolution are not counted. 2614 ** 2615 ** Changes to a view that are intercepted by 2616 ** [INSTEAD OF trigger | INSTEAD OF triggers] are not counted. ^The value 2617 ** returned by sqlite3_changes() immediately after an INSERT, UPDATE or 2618 ** DELETE statement run on a view is always zero. Only changes made to real 2619 ** tables are counted. 2620 ** 2621 ** Things are more complicated if the sqlite3_changes() function is 2622 ** executed while a trigger program is running. This may happen if the 2623 ** program uses the [changes() SQL function], or if some other callback 2624 ** function invokes sqlite3_changes() directly. Essentially: 2625 ** 2626 ** <ul> 2627 ** <li> ^(Before entering a trigger program the value returned by 2628 ** sqlite3_changes() function is saved. After the trigger program 2629 ** has finished, the original value is restored.)^ 2630 ** 2631 ** <li> ^(Within a trigger program each INSERT, UPDATE and DELETE 2632 ** statement sets the value returned by sqlite3_changes() 2633 ** upon completion as normal. Of course, this value will not include 2634 ** any changes performed by sub-triggers, as the sqlite3_changes() 2635 ** value will be saved and restored after each sub-trigger has run.)^ 2636 ** </ul> 2637 ** 2638 ** ^This means that if the changes() SQL function (or similar) is used 2639 ** by the first INSERT, UPDATE or DELETE statement within a trigger, it 2640 ** returns the value as set when the calling statement began executing. 2641 ** ^If it is used by the second or subsequent such statement within a trigger 2642 ** program, the value returned reflects the number of rows modified by the 2643 ** previous INSERT, UPDATE or DELETE statement within the same trigger. 2644 ** 2645 ** If a separate thread makes changes on the same database connection 2646 ** while [sqlite3_changes()] is running then the value returned 2647 ** is unpredictable and not meaningful. 2648 ** 2649 ** See also: 2650 ** <ul> 2651 ** <li> the [sqlite3_total_changes()] interface 2652 ** <li> the [count_changes pragma] 2653 ** <li> the [changes() SQL function] 2654 ** <li> the [data_version pragma] 2655 ** </ul> 2656 */ 2657 SQLITE_API int sqlite3_changes(sqlite3*); 2658 SQLITE_API sqlite3_int64 sqlite3_changes64(sqlite3*); 2659 2660 /* 2661 ** CAPI3REF: Total Number Of Rows Modified 2662 ** METHOD: sqlite3 2663 ** 2664 ** ^These functions return the total number of rows inserted, modified or 2665 ** deleted by all [INSERT], [UPDATE] or [DELETE] statements completed 2666 ** since the database connection was opened, including those executed as 2667 ** part of trigger programs. The two functions are identical except for the 2668 ** type of the return value and that if the number of rows modified by the 2669 ** connection exceeds the maximum value supported by type "int", then 2670 ** the return value of sqlite3_total_changes() is undefined. ^Executing 2671 ** any other type of SQL statement does not affect the value returned by 2672 ** sqlite3_total_changes(). 2673 ** 2674 ** ^Changes made as part of [foreign key actions] are included in the 2675 ** count, but those made as part of REPLACE constraint resolution are 2676 ** not. ^Changes to a view that are intercepted by INSTEAD OF triggers 2677 ** are not counted. 2678 ** 2679 ** The [sqlite3_total_changes(D)] interface only reports the number 2680 ** of rows that changed due to SQL statement run against database 2681 ** connection D. Any changes by other database connections are ignored. 2682 ** To detect changes against a database file from other database 2683 ** connections use the [PRAGMA data_version] command or the 2684 ** [SQLITE_FCNTL_DATA_VERSION] [file control]. 2685 ** 2686 ** If a separate thread makes changes on the same database connection 2687 ** while [sqlite3_total_changes()] is running then the value 2688 ** returned is unpredictable and not meaningful. 2689 ** 2690 ** See also: 2691 ** <ul> 2692 ** <li> the [sqlite3_changes()] interface 2693 ** <li> the [count_changes pragma] 2694 ** <li> the [changes() SQL function] 2695 ** <li> the [data_version pragma] 2696 ** <li> the [SQLITE_FCNTL_DATA_VERSION] [file control] 2697 ** </ul> 2698 */ 2699 SQLITE_API int sqlite3_total_changes(sqlite3*); 2700 SQLITE_API sqlite3_int64 sqlite3_total_changes64(sqlite3*); 2701 2702 /* 2703 ** CAPI3REF: Interrupt A Long-Running Query 2704 ** METHOD: sqlite3 2705 ** 2706 ** ^This function causes any pending database operation to abort and 2707 ** return at its earliest opportunity. This routine is typically 2708 ** called in response to a user action such as pressing "Cancel" 2709 ** or Ctrl-C where the user wants a long query operation to halt 2710 ** immediately. 2711 ** 2712 ** ^It is safe to call this routine from a thread different from the 2713 ** thread that is currently running the database operation. But it 2714 ** is not safe to call this routine with a [database connection] that 2715 ** is closed or might close before sqlite3_interrupt() returns. 2716 ** 2717 ** ^If an SQL operation is very nearly finished at the time when 2718 ** sqlite3_interrupt() is called, then it might not have an opportunity 2719 ** to be interrupted and might continue to completion. 2720 ** 2721 ** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT]. 2722 ** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE 2723 ** that is inside an explicit transaction, then the entire transaction 2724 ** will be rolled back automatically. 2725 ** 2726 ** ^The sqlite3_interrupt(D) call is in effect until all currently running 2727 ** SQL statements on [database connection] D complete. ^Any new SQL statements 2728 ** that are started after the sqlite3_interrupt() call and before the 2729 ** running statement count reaches zero are interrupted as if they had been 2730 ** running prior to the sqlite3_interrupt() call. ^New SQL statements 2731 ** that are started after the running statement count reaches zero are 2732 ** not effected by the sqlite3_interrupt(). 2733 ** ^A call to sqlite3_interrupt(D) that occurs when there are no running 2734 ** SQL statements is a no-op and has no effect on SQL statements 2735 ** that are started after the sqlite3_interrupt() call returns. 2736 ** 2737 ** ^The [sqlite3_is_interrupted(D)] interface can be used to determine whether 2738 ** or not an interrupt is currently in effect for [database connection] D. 2739 ** It returns 1 if an interrupt is currently in effect, or 0 otherwise. 2740 */ 2741 SQLITE_API void sqlite3_interrupt(sqlite3*); 2742 SQLITE_API int sqlite3_is_interrupted(sqlite3*); 2743 2744 /* 2745 ** CAPI3REF: Determine If An SQL Statement Is Complete 2746 ** 2747 ** These routines are useful during command-line input to determine if the 2748 ** currently entered text seems to form a complete SQL statement or 2749 ** if additional input is needed before sending the text into 2750 ** SQLite for parsing. ^These routines return 1 if the input string 2751 ** appears to be a complete SQL statement. ^A statement is judged to be 2752 ** complete if it ends with a semicolon token and is not a prefix of a 2753 ** well-formed CREATE TRIGGER statement. ^Semicolons that are embedded within 2754 ** string literals or quoted identifier names or comments are not 2755 ** independent tokens (they are part of the token in which they are 2756 ** embedded) and thus do not count as a statement terminator. ^Whitespace 2757 ** and comments that follow the final semicolon are ignored. 2758 ** 2759 ** ^These routines return 0 if the statement is incomplete. ^If a 2760 ** memory allocation fails, then SQLITE_NOMEM is returned. 2761 ** 2762 ** ^These routines do not parse the SQL statements thus 2763 ** will not detect syntactically incorrect SQL. 2764 ** 2765 ** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior 2766 ** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked 2767 ** automatically by sqlite3_complete16(). If that initialization fails, 2768 ** then the return value from sqlite3_complete16() will be non-zero 2769 ** regardless of whether or not the input SQL is complete.)^ 2770 ** 2771 ** The input to [sqlite3_complete()] must be a zero-terminated 2772 ** UTF-8 string. 2773 ** 2774 ** The input to [sqlite3_complete16()] must be a zero-terminated 2775 ** UTF-16 string in native byte order. 2776 */ 2777 SQLITE_API int sqlite3_complete(const char *sql); 2778 SQLITE_API int sqlite3_complete16(const void *sql); 2779 2780 /* 2781 ** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors 2782 ** KEYWORDS: {busy-handler callback} {busy handler} 2783 ** METHOD: sqlite3 2784 ** 2785 ** ^The sqlite3_busy_handler(D,X,P) routine sets a callback function X 2786 ** that might be invoked with argument P whenever 2787 ** an attempt is made to access a database table associated with 2788 ** [database connection] D when another thread 2789 ** or process has the table locked. 2790 ** The sqlite3_busy_handler() interface is used to implement 2791 ** [sqlite3_busy_timeout()] and [PRAGMA busy_timeout]. 2792 ** 2793 ** ^If the busy callback is NULL, then [SQLITE_BUSY] 2794 ** is returned immediately upon encountering the lock. ^If the busy callback 2795 ** is not NULL, then the callback might be invoked with two arguments. 2796 ** 2797 ** ^The first argument to the busy handler is a copy of the void* pointer which 2798 ** is the third argument to sqlite3_busy_handler(). ^The second argument to 2799 ** the busy handler callback is the number of times that the busy handler has 2800 ** been invoked previously for the same locking event. ^If the 2801 ** busy callback returns 0, then no additional attempts are made to 2802 ** access the database and [SQLITE_BUSY] is returned 2803 ** to the application. 2804 ** ^If the callback returns non-zero, then another attempt 2805 ** is made to access the database and the cycle repeats. 2806 ** 2807 ** The presence of a busy handler does not guarantee that it will be invoked 2808 ** when there is lock contention. ^If SQLite determines that invoking the busy 2809 ** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY] 2810 ** to the application instead of invoking the 2811 ** busy handler. 2812 ** Consider a scenario where one process is holding a read lock that 2813 ** it is trying to promote to a reserved lock and 2814 ** a second process is holding a reserved lock that it is trying 2815 ** to promote to an exclusive lock. The first process cannot proceed 2816 ** because it is blocked by the second and the second process cannot 2817 ** proceed because it is blocked by the first. If both processes 2818 ** invoke the busy handlers, neither will make any progress. Therefore, 2819 ** SQLite returns [SQLITE_BUSY] for the first process, hoping that this 2820 ** will induce the first process to release its read lock and allow 2821 ** the second process to proceed. 2822 ** 2823 ** ^The default busy callback is NULL. 2824 ** 2825 ** ^(There can only be a single busy handler defined for each 2826 ** [database connection]. Setting a new busy handler clears any 2827 ** previously set handler.)^ ^Note that calling [sqlite3_busy_timeout()] 2828 ** or evaluating [PRAGMA busy_timeout=N] will change the 2829 ** busy handler and thus clear any previously set busy handler. 2830 ** 2831 ** The busy callback should not take any actions which modify the 2832 ** database connection that invoked the busy handler. In other words, 2833 ** the busy handler is not reentrant. Any such actions 2834 ** result in undefined behavior. 2835 ** 2836 ** A busy handler must not close the database connection 2837 ** or [prepared statement] that invoked the busy handler. 2838 */ 2839 SQLITE_API int sqlite3_busy_handler(sqlite3*,int(*)(void*,int),void*); 2840 2841 /* 2842 ** CAPI3REF: Set A Busy Timeout 2843 ** METHOD: sqlite3 2844 ** 2845 ** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps 2846 ** for a specified amount of time when a table is locked. ^The handler 2847 ** will sleep multiple times until at least "ms" milliseconds of sleeping 2848 ** have accumulated. ^After at least "ms" milliseconds of sleeping, 2849 ** the handler returns 0 which causes [sqlite3_step()] to return 2850 ** [SQLITE_BUSY]. 2851 ** 2852 ** ^Calling this routine with an argument less than or equal to zero 2853 ** turns off all busy handlers. 2854 ** 2855 ** ^(There can only be a single busy handler for a particular 2856 ** [database connection] at any given moment. If another busy handler 2857 ** was defined (using [sqlite3_busy_handler()]) prior to calling 2858 ** this routine, that other busy handler is cleared.)^ 2859 ** 2860 ** See also: [PRAGMA busy_timeout] 2861 */ 2862 SQLITE_API int sqlite3_busy_timeout(sqlite3*, int ms); 2863 2864 /* 2865 ** CAPI3REF: Convenience Routines For Running Queries 2866 ** METHOD: sqlite3 2867 ** 2868 ** This is a legacy interface that is preserved for backwards compatibility. 2869 ** Use of this interface is not recommended. 2870 ** 2871 ** Definition: A <b>result table</b> is memory data structure created by the 2872 ** [sqlite3_get_table()] interface. A result table records the 2873 ** complete query results from one or more queries. 2874 ** 2875 ** The table conceptually has a number of rows and columns. But 2876 ** these numbers are not part of the result table itself. These 2877 ** numbers are obtained separately. Let N be the number of rows 2878 ** and M be the number of columns. 2879 ** 2880 ** A result table is an array of pointers to zero-terminated UTF-8 strings. 2881 ** There are (N+1)*M elements in the array. The first M pointers point 2882 ** to zero-terminated strings that contain the names of the columns. 2883 ** The remaining entries all point to query results. NULL values result 2884 ** in NULL pointers. All other values are in their UTF-8 zero-terminated 2885 ** string representation as returned by [sqlite3_column_text()]. 2886 ** 2887 ** A result table might consist of one or more memory allocations. 2888 ** It is not safe to pass a result table directly to [sqlite3_free()]. 2889 ** A result table should be deallocated using [sqlite3_free_table()]. 2890 ** 2891 ** ^(As an example of the result table format, suppose a query result 2892 ** is as follows: 2893 ** 2894 ** <blockquote><pre> 2895 ** Name | Age 2896 ** ----------------------- 2897 ** Alice | 43 2898 ** Bob | 28 2899 ** Cindy | 21 2900 ** </pre></blockquote> 2901 ** 2902 ** There are two columns (M==2) and three rows (N==3). Thus the 2903 ** result table has 8 entries. Suppose the result table is stored 2904 ** in an array named azResult. Then azResult holds this content: 2905 ** 2906 ** <blockquote><pre> 2907 ** azResult[0] = "Name"; 2908 ** azResult[1] = "Age"; 2909 ** azResult[2] = "Alice"; 2910 ** azResult[3] = "43"; 2911 ** azResult[4] = "Bob"; 2912 ** azResult[5] = "28"; 2913 ** azResult[6] = "Cindy"; 2914 ** azResult[7] = "21"; 2915 ** </pre></blockquote>)^ 2916 ** 2917 ** ^The sqlite3_get_table() function evaluates one or more 2918 ** semicolon-separated SQL statements in the zero-terminated UTF-8 2919 ** string of its 2nd parameter and returns a result table to the 2920 ** pointer given in its 3rd parameter. 2921 ** 2922 ** After the application has finished with the result from sqlite3_get_table(), 2923 ** it must pass the result table pointer to sqlite3_free_table() in order to 2924 ** release the memory that was malloced. Because of the way the 2925 ** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling 2926 ** function must not try to call [sqlite3_free()] directly. Only 2927 ** [sqlite3_free_table()] is able to release the memory properly and safely. 2928 ** 2929 ** The sqlite3_get_table() interface is implemented as a wrapper around 2930 ** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access 2931 ** to any internal data structures of SQLite. It uses only the public 2932 ** interface defined here. As a consequence, errors that occur in the 2933 ** wrapper layer outside of the internal [sqlite3_exec()] call are not 2934 ** reflected in subsequent calls to [sqlite3_errcode()] or 2935 ** [sqlite3_errmsg()]. 2936 */ 2937 SQLITE_API int sqlite3_get_table( 2938 sqlite3 *db, /* An open database */ 2939 const char *zSql, /* SQL to be evaluated */ 2940 char ***pazResult, /* Results of the query */ 2941 int *pnRow, /* Number of result rows written here */ 2942 int *pnColumn, /* Number of result columns written here */ 2943 char **pzErrmsg /* Error msg written here */ 2944 ); 2945 SQLITE_API void sqlite3_free_table(char **result); 2946 2947 /* 2948 ** CAPI3REF: Formatted String Printing Functions 2949 ** 2950 ** These routines are work-alikes of the "printf()" family of functions 2951 ** from the standard C library. 2952 ** These routines understand most of the common formatting options from 2953 ** the standard library printf() 2954 ** plus some additional non-standard formats ([%q], [%Q], [%w], and [%z]). 2955 ** See the [built-in printf()] documentation for details. 2956 ** 2957 ** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their 2958 ** results into memory obtained from [sqlite3_malloc64()]. 2959 ** The strings returned by these two routines should be 2960 ** released by [sqlite3_free()]. ^Both routines return a 2961 ** NULL pointer if [sqlite3_malloc64()] is unable to allocate enough 2962 ** memory to hold the resulting string. 2963 ** 2964 ** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from 2965 ** the standard C library. The result is written into the 2966 ** buffer supplied as the second parameter whose size is given by 2967 ** the first parameter. Note that the order of the 2968 ** first two parameters is reversed from snprintf().)^ This is an 2969 ** historical accident that cannot be fixed without breaking 2970 ** backwards compatibility. ^(Note also that sqlite3_snprintf() 2971 ** returns a pointer to its buffer instead of the number of 2972 ** characters actually written into the buffer.)^ We admit that 2973 ** the number of characters written would be a more useful return 2974 ** value but we cannot change the implementation of sqlite3_snprintf() 2975 ** now without breaking compatibility. 2976 ** 2977 ** ^As long as the buffer size is greater than zero, sqlite3_snprintf() 2978 ** guarantees that the buffer is always zero-terminated. ^The first 2979 ** parameter "n" is the total size of the buffer, including space for 2980 ** the zero terminator. So the longest string that can be completely 2981 ** written will be n-1 characters. 2982 ** 2983 ** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf(). 2984 ** 2985 ** See also: [built-in printf()], [printf() SQL function] 2986 */ 2987 SQLITE_API char *sqlite3_mprintf(const char*,...); 2988 SQLITE_API char *sqlite3_vmprintf(const char*, va_list); 2989 SQLITE_API char *sqlite3_snprintf(int,char*,const char*, ...); 2990 SQLITE_API char *sqlite3_vsnprintf(int,char*,const char*, va_list); 2991 2992 /* 2993 ** CAPI3REF: Memory Allocation Subsystem 2994 ** 2995 ** The SQLite core uses these three routines for all of its own 2996 ** internal memory allocation needs. "Core" in the previous sentence 2997 ** does not include operating-system specific [VFS] implementation. The 2998 ** Windows VFS uses native malloc() and free() for some operations. 2999 ** 3000 ** ^The sqlite3_malloc() routine returns a pointer to a block 3001 ** of memory at least N bytes in length, where N is the parameter. 3002 ** ^If sqlite3_malloc() is unable to obtain sufficient free 3003 ** memory, it returns a NULL pointer. ^If the parameter N to 3004 ** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns 3005 ** a NULL pointer. 3006 ** 3007 ** ^The sqlite3_malloc64(N) routine works just like 3008 ** sqlite3_malloc(N) except that N is an unsigned 64-bit integer instead 3009 ** of a signed 32-bit integer. 3010 ** 3011 ** ^Calling sqlite3_free() with a pointer previously returned 3012 ** by sqlite3_malloc() or sqlite3_realloc() releases that memory so 3013 ** that it might be reused. ^The sqlite3_free() routine is 3014 ** a no-op if is called with a NULL pointer. Passing a NULL pointer 3015 ** to sqlite3_free() is harmless. After being freed, memory 3016 ** should neither be read nor written. Even reading previously freed 3017 ** memory might result in a segmentation fault or other severe error. 3018 ** Memory corruption, a segmentation fault, or other severe error 3019 ** might result if sqlite3_free() is called with a non-NULL pointer that 3020 ** was not obtained from sqlite3_malloc() or sqlite3_realloc(). 3021 ** 3022 ** ^The sqlite3_realloc(X,N) interface attempts to resize a 3023 ** prior memory allocation X to be at least N bytes. 3024 ** ^If the X parameter to sqlite3_realloc(X,N) 3025 ** is a NULL pointer then its behavior is identical to calling 3026 ** sqlite3_malloc(N). 3027 ** ^If the N parameter to sqlite3_realloc(X,N) is zero or 3028 ** negative then the behavior is exactly the same as calling 3029 ** sqlite3_free(X). 3030 ** ^sqlite3_realloc(X,N) returns a pointer to a memory allocation 3031 ** of at least N bytes in size or NULL if insufficient memory is available. 3032 ** ^If M is the size of the prior allocation, then min(N,M) bytes 3033 ** of the prior allocation are copied into the beginning of buffer returned 3034 ** by sqlite3_realloc(X,N) and the prior allocation is freed. 3035 ** ^If sqlite3_realloc(X,N) returns NULL and N is positive, then the 3036 ** prior allocation is not freed. 3037 ** 3038 ** ^The sqlite3_realloc64(X,N) interfaces works the same as 3039 ** sqlite3_realloc(X,N) except that N is a 64-bit unsigned integer instead 3040 ** of a 32-bit signed integer. 3041 ** 3042 ** ^If X is a memory allocation previously obtained from sqlite3_malloc(), 3043 ** sqlite3_malloc64(), sqlite3_realloc(), or sqlite3_realloc64(), then 3044 ** sqlite3_msize(X) returns the size of that memory allocation in bytes. 3045 ** ^The value returned by sqlite3_msize(X) might be larger than the number 3046 ** of bytes requested when X was allocated. ^If X is a NULL pointer then 3047 ** sqlite3_msize(X) returns zero. If X points to something that is not 3048 ** the beginning of memory allocation, or if it points to a formerly 3049 ** valid memory allocation that has now been freed, then the behavior 3050 ** of sqlite3_msize(X) is undefined and possibly harmful. 3051 ** 3052 ** ^The memory returned by sqlite3_malloc(), sqlite3_realloc(), 3053 ** sqlite3_malloc64(), and sqlite3_realloc64() 3054 ** is always aligned to at least an 8 byte boundary, or to a 3055 ** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time 3056 ** option is used. 3057 ** 3058 ** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()] 3059 ** must be either NULL or else pointers obtained from a prior 3060 ** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have 3061 ** not yet been released. 3062 ** 3063 ** The application must not read or write any part of 3064 ** a block of memory after it has been released using 3065 ** [sqlite3_free()] or [sqlite3_realloc()]. 3066 */ 3067 SQLITE_API void *sqlite3_malloc(int); 3068 SQLITE_API void *sqlite3_malloc64(sqlite3_uint64); 3069 SQLITE_API void *sqlite3_realloc(void*, int); 3070 SQLITE_API void *sqlite3_realloc64(void*, sqlite3_uint64); 3071 SQLITE_API void sqlite3_free(void*); 3072 SQLITE_API sqlite3_uint64 sqlite3_msize(void*); 3073 3074 /* 3075 ** CAPI3REF: Memory Allocator Statistics 3076 ** 3077 ** SQLite provides these two interfaces for reporting on the status 3078 ** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()] 3079 ** routines, which form the built-in memory allocation subsystem. 3080 ** 3081 ** ^The [sqlite3_memory_used()] routine returns the number of bytes 3082 ** of memory currently outstanding (malloced but not freed). 3083 ** ^The [sqlite3_memory_highwater()] routine returns the maximum 3084 ** value of [sqlite3_memory_used()] since the high-water mark 3085 ** was last reset. ^The values returned by [sqlite3_memory_used()] and 3086 ** [sqlite3_memory_highwater()] include any overhead 3087 ** added by SQLite in its implementation of [sqlite3_malloc()], 3088 ** but not overhead added by the any underlying system library 3089 ** routines that [sqlite3_malloc()] may call. 3090 ** 3091 ** ^The memory high-water mark is reset to the current value of 3092 ** [sqlite3_memory_used()] if and only if the parameter to 3093 ** [sqlite3_memory_highwater()] is true. ^The value returned 3094 ** by [sqlite3_memory_highwater(1)] is the high-water mark 3095 ** prior to the reset. 3096 */ 3097 SQLITE_API sqlite3_int64 sqlite3_memory_used(void); 3098 SQLITE_API sqlite3_int64 sqlite3_memory_highwater(int resetFlag); 3099 3100 /* 3101 ** CAPI3REF: Pseudo-Random Number Generator 3102 ** 3103 ** SQLite contains a high-quality pseudo-random number generator (PRNG) used to 3104 ** select random [ROWID | ROWIDs] when inserting new records into a table that 3105 ** already uses the largest possible [ROWID]. The PRNG is also used for 3106 ** the built-in random() and randomblob() SQL functions. This interface allows 3107 ** applications to access the same PRNG for other purposes. 3108 ** 3109 ** ^A call to this routine stores N bytes of randomness into buffer P. 3110 ** ^The P parameter can be a NULL pointer. 3111 ** 3112 ** ^If this routine has not been previously called or if the previous 3113 ** call had N less than one or a NULL pointer for P, then the PRNG is 3114 ** seeded using randomness obtained from the xRandomness method of 3115 ** the default [sqlite3_vfs] object. 3116 ** ^If the previous call to this routine had an N of 1 or more and a 3117 ** non-NULL P then the pseudo-randomness is generated 3118 ** internally and without recourse to the [sqlite3_vfs] xRandomness 3119 ** method. 3120 */ 3121 SQLITE_API void sqlite3_randomness(int N, void *P); 3122 3123 /* 3124 ** CAPI3REF: Compile-Time Authorization Callbacks 3125 ** METHOD: sqlite3 3126 ** KEYWORDS: {authorizer callback} 3127 ** 3128 ** ^This routine registers an authorizer callback with a particular 3129 ** [database connection], supplied in the first argument. 3130 ** ^The authorizer callback is invoked as SQL statements are being compiled 3131 ** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()], 3132 ** [sqlite3_prepare_v3()], [sqlite3_prepare16()], [sqlite3_prepare16_v2()], 3133 ** and [sqlite3_prepare16_v3()]. ^At various 3134 ** points during the compilation process, as logic is being created 3135 ** to perform various actions, the authorizer callback is invoked to 3136 ** see if those actions are allowed. ^The authorizer callback should 3137 ** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the 3138 ** specific action but allow the SQL statement to continue to be 3139 ** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be 3140 ** rejected with an error. ^If the authorizer callback returns 3141 ** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY] 3142 ** then the [sqlite3_prepare_v2()] or equivalent call that triggered 3143 ** the authorizer will fail with an error message. 3144 ** 3145 ** When the callback returns [SQLITE_OK], that means the operation 3146 ** requested is ok. ^When the callback returns [SQLITE_DENY], the 3147 ** [sqlite3_prepare_v2()] or equivalent call that triggered the 3148 ** authorizer will fail with an error message explaining that 3149 ** access is denied. 3150 ** 3151 ** ^The first parameter to the authorizer callback is a copy of the third 3152 ** parameter to the sqlite3_set_authorizer() interface. ^The second parameter 3153 ** to the callback is an integer [SQLITE_COPY | action code] that specifies 3154 ** the particular action to be authorized. ^The third through sixth parameters 3155 ** to the callback are either NULL pointers or zero-terminated strings 3156 ** that contain additional details about the action to be authorized. 3157 ** Applications must always be prepared to encounter a NULL pointer in any 3158 ** of the third through the sixth parameters of the authorization callback. 3159 ** 3160 ** ^If the action code is [SQLITE_READ] 3161 ** and the callback returns [SQLITE_IGNORE] then the 3162 ** [prepared statement] statement is constructed to substitute 3163 ** a NULL value in place of the table column that would have 3164 ** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE] 3165 ** return can be used to deny an untrusted user access to individual 3166 ** columns of a table. 3167 ** ^When a table is referenced by a [SELECT] but no column values are 3168 ** extracted from that table (for example in a query like 3169 ** "SELECT count(*) FROM tab") then the [SQLITE_READ] authorizer callback 3170 ** is invoked once for that table with a column name that is an empty string. 3171 ** ^If the action code is [SQLITE_DELETE] and the callback returns 3172 ** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the 3173 ** [truncate optimization] is disabled and all rows are deleted individually. 3174 ** 3175 ** An authorizer is used when [sqlite3_prepare | preparing] 3176 ** SQL statements from an untrusted source, to ensure that the SQL statements 3177 ** do not try to access data they are not allowed to see, or that they do not 3178 ** try to execute malicious statements that damage the database. For 3179 ** example, an application may allow a user to enter arbitrary 3180 ** SQL queries for evaluation by a database. But the application does 3181 ** not want the user to be able to make arbitrary changes to the 3182 ** database. An authorizer could then be put in place while the 3183 ** user-entered SQL is being [sqlite3_prepare | prepared] that 3184 ** disallows everything except [SELECT] statements. 3185 ** 3186 ** Applications that need to process SQL from untrusted sources 3187 ** might also consider lowering resource limits using [sqlite3_limit()] 3188 ** and limiting database size using the [max_page_count] [PRAGMA] 3189 ** in addition to using an authorizer. 3190 ** 3191 ** ^(Only a single authorizer can be in place on a database connection 3192 ** at a time. Each call to sqlite3_set_authorizer overrides the 3193 ** previous call.)^ ^Disable the authorizer by installing a NULL callback. 3194 ** The authorizer is disabled by default. 3195 ** 3196 ** The authorizer callback must not do anything that will modify 3197 ** the database connection that invoked the authorizer callback. 3198 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 3199 ** database connections for the meaning of "modify" in this paragraph. 3200 ** 3201 ** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the 3202 ** statement might be re-prepared during [sqlite3_step()] due to a 3203 ** schema change. Hence, the application should ensure that the 3204 ** correct authorizer callback remains in place during the [sqlite3_step()]. 3205 ** 3206 ** ^Note that the authorizer callback is invoked only during 3207 ** [sqlite3_prepare()] or its variants. Authorization is not 3208 ** performed during statement evaluation in [sqlite3_step()], unless 3209 ** as stated in the previous paragraph, sqlite3_step() invokes 3210 ** sqlite3_prepare_v2() to reprepare a statement after a schema change. 3211 */ 3212 SQLITE_API int sqlite3_set_authorizer( 3213 sqlite3*, 3214 int (*xAuth)(void*,int,const char*,const char*,const char*,const char*), 3215 void *pUserData 3216 ); 3217 3218 /* 3219 ** CAPI3REF: Authorizer Return Codes 3220 ** 3221 ** The [sqlite3_set_authorizer | authorizer callback function] must 3222 ** return either [SQLITE_OK] or one of these two constants in order 3223 ** to signal SQLite whether or not the action is permitted. See the 3224 ** [sqlite3_set_authorizer | authorizer documentation] for additional 3225 ** information. 3226 ** 3227 ** Note that SQLITE_IGNORE is also used as a [conflict resolution mode] 3228 ** returned from the [sqlite3_vtab_on_conflict()] interface. 3229 */ 3230 #define SQLITE_DENY 1 /* Abort the SQL statement with an error */ 3231 #define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */ 3232 3233 /* 3234 ** CAPI3REF: Authorizer Action Codes 3235 ** 3236 ** The [sqlite3_set_authorizer()] interface registers a callback function 3237 ** that is invoked to authorize certain SQL statement actions. The 3238 ** second parameter to the callback is an integer code that specifies 3239 ** what action is being authorized. These are the integer action codes that 3240 ** the authorizer callback may be passed. 3241 ** 3242 ** These action code values signify what kind of operation is to be 3243 ** authorized. The 3rd and 4th parameters to the authorization 3244 ** callback function will be parameters or NULL depending on which of these 3245 ** codes is used as the second parameter. ^(The 5th parameter to the 3246 ** authorizer callback is the name of the database ("main", "temp", 3247 ** etc.) if applicable.)^ ^The 6th parameter to the authorizer callback 3248 ** is the name of the inner-most trigger or view that is responsible for 3249 ** the access attempt or NULL if this access attempt is directly from 3250 ** top-level SQL code. 3251 */ 3252 /******************************************* 3rd ************ 4th ***********/ 3253 #define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */ 3254 #define SQLITE_CREATE_TABLE 2 /* Table Name NULL */ 3255 #define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */ 3256 #define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */ 3257 #define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */ 3258 #define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */ 3259 #define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */ 3260 #define SQLITE_CREATE_VIEW 8 /* View Name NULL */ 3261 #define SQLITE_DELETE 9 /* Table Name NULL */ 3262 #define SQLITE_DROP_INDEX 10 /* Index Name Table Name */ 3263 #define SQLITE_DROP_TABLE 11 /* Table Name NULL */ 3264 #define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */ 3265 #define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */ 3266 #define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */ 3267 #define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */ 3268 #define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */ 3269 #define SQLITE_DROP_VIEW 17 /* View Name NULL */ 3270 #define SQLITE_INSERT 18 /* Table Name NULL */ 3271 #define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */ 3272 #define SQLITE_READ 20 /* Table Name Column Name */ 3273 #define SQLITE_SELECT 21 /* NULL NULL */ 3274 #define SQLITE_TRANSACTION 22 /* Operation NULL */ 3275 #define SQLITE_UPDATE 23 /* Table Name Column Name */ 3276 #define SQLITE_ATTACH 24 /* Filename NULL */ 3277 #define SQLITE_DETACH 25 /* Database Name NULL */ 3278 #define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */ 3279 #define SQLITE_REINDEX 27 /* Index Name NULL */ 3280 #define SQLITE_ANALYZE 28 /* Table Name NULL */ 3281 #define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */ 3282 #define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */ 3283 #define SQLITE_FUNCTION 31 /* NULL Function Name */ 3284 #define SQLITE_SAVEPOINT 32 /* Operation Savepoint Name */ 3285 #define SQLITE_COPY 0 /* No longer used */ 3286 #define SQLITE_RECURSIVE 33 /* NULL NULL */ 3287 3288 /* 3289 ** CAPI3REF: Tracing And Profiling Functions 3290 ** METHOD: sqlite3 3291 ** 3292 ** These routines are deprecated. Use the [sqlite3_trace_v2()] interface 3293 ** instead of the routines described here. 3294 ** 3295 ** These routines register callback functions that can be used for 3296 ** tracing and profiling the execution of SQL statements. 3297 ** 3298 ** ^The callback function registered by sqlite3_trace() is invoked at 3299 ** various times when an SQL statement is being run by [sqlite3_step()]. 3300 ** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the 3301 ** SQL statement text as the statement first begins executing. 3302 ** ^(Additional sqlite3_trace() callbacks might occur 3303 ** as each triggered subprogram is entered. The callbacks for triggers 3304 ** contain a UTF-8 SQL comment that identifies the trigger.)^ 3305 ** 3306 ** The [SQLITE_TRACE_SIZE_LIMIT] compile-time option can be used to limit 3307 ** the length of [bound parameter] expansion in the output of sqlite3_trace(). 3308 ** 3309 ** ^The callback function registered by sqlite3_profile() is invoked 3310 ** as each SQL statement finishes. ^The profile callback contains 3311 ** the original statement text and an estimate of wall-clock time 3312 ** of how long that statement took to run. ^The profile callback 3313 ** time is in units of nanoseconds, however the current implementation 3314 ** is only capable of millisecond resolution so the six least significant 3315 ** digits in the time are meaningless. Future versions of SQLite 3316 ** might provide greater resolution on the profiler callback. Invoking 3317 ** either [sqlite3_trace()] or [sqlite3_trace_v2()] will cancel the 3318 ** profile callback. 3319 */ 3320 SQLITE_API SQLITE_DEPRECATED void *sqlite3_trace(sqlite3*, 3321 void(*xTrace)(void*,const char*), void*); 3322 SQLITE_API SQLITE_DEPRECATED void *sqlite3_profile(sqlite3*, 3323 void(*xProfile)(void*,const char*,sqlite3_uint64), void*); 3324 3325 /* 3326 ** CAPI3REF: SQL Trace Event Codes 3327 ** KEYWORDS: SQLITE_TRACE 3328 ** 3329 ** These constants identify classes of events that can be monitored 3330 ** using the [sqlite3_trace_v2()] tracing logic. The M argument 3331 ** to [sqlite3_trace_v2(D,M,X,P)] is an OR-ed combination of one or more of 3332 ** the following constants. ^The first argument to the trace callback 3333 ** is one of the following constants. 3334 ** 3335 ** New tracing constants may be added in future releases. 3336 ** 3337 ** ^A trace callback has four arguments: xCallback(T,C,P,X). 3338 ** ^The T argument is one of the integer type codes above. 3339 ** ^The C argument is a copy of the context pointer passed in as the 3340 ** fourth argument to [sqlite3_trace_v2()]. 3341 ** The P and X arguments are pointers whose meanings depend on T. 3342 ** 3343 ** <dl> 3344 ** [[SQLITE_TRACE_STMT]] <dt>SQLITE_TRACE_STMT</dt> 3345 ** <dd>^An SQLITE_TRACE_STMT callback is invoked when a prepared statement 3346 ** first begins running and possibly at other times during the 3347 ** execution of the prepared statement, such as at the start of each 3348 ** trigger subprogram. ^The P argument is a pointer to the 3349 ** [prepared statement]. ^The X argument is a pointer to a string which 3350 ** is the unexpanded SQL text of the prepared statement or an SQL comment 3351 ** that indicates the invocation of a trigger. ^The callback can compute 3352 ** the same text that would have been returned by the legacy [sqlite3_trace()] 3353 ** interface by using the X argument when X begins with "--" and invoking 3354 ** [sqlite3_expanded_sql(P)] otherwise. 3355 ** 3356 ** [[SQLITE_TRACE_PROFILE]] <dt>SQLITE_TRACE_PROFILE</dt> 3357 ** <dd>^An SQLITE_TRACE_PROFILE callback provides approximately the same 3358 ** information as is provided by the [sqlite3_profile()] callback. 3359 ** ^The P argument is a pointer to the [prepared statement] and the 3360 ** X argument points to a 64-bit integer which is approximately 3361 ** the number of nanoseconds that the prepared statement took to run. 3362 ** ^The SQLITE_TRACE_PROFILE callback is invoked when the statement finishes. 3363 ** 3364 ** [[SQLITE_TRACE_ROW]] <dt>SQLITE_TRACE_ROW</dt> 3365 ** <dd>^An SQLITE_TRACE_ROW callback is invoked whenever a prepared 3366 ** statement generates a single row of result. 3367 ** ^The P argument is a pointer to the [prepared statement] and the 3368 ** X argument is unused. 3369 ** 3370 ** [[SQLITE_TRACE_CLOSE]] <dt>SQLITE_TRACE_CLOSE</dt> 3371 ** <dd>^An SQLITE_TRACE_CLOSE callback is invoked when a database 3372 ** connection closes. 3373 ** ^The P argument is a pointer to the [database connection] object 3374 ** and the X argument is unused. 3375 ** </dl> 3376 */ 3377 #define SQLITE_TRACE_STMT 0x01 3378 #define SQLITE_TRACE_PROFILE 0x02 3379 #define SQLITE_TRACE_ROW 0x04 3380 #define SQLITE_TRACE_CLOSE 0x08 3381 3382 /* 3383 ** CAPI3REF: SQL Trace Hook 3384 ** METHOD: sqlite3 3385 ** 3386 ** ^The sqlite3_trace_v2(D,M,X,P) interface registers a trace callback 3387 ** function X against [database connection] D, using property mask M 3388 ** and context pointer P. ^If the X callback is 3389 ** NULL or if the M mask is zero, then tracing is disabled. The 3390 ** M argument should be the bitwise OR-ed combination of 3391 ** zero or more [SQLITE_TRACE] constants. 3392 ** 3393 ** ^Each call to either sqlite3_trace(D,X,P) or sqlite3_trace_v2(D,M,X,P) 3394 ** overrides (cancels) all prior calls to sqlite3_trace(D,X,P) or 3395 ** sqlite3_trace_v2(D,M,X,P) for the [database connection] D. Each 3396 ** database connection may have at most one trace callback. 3397 ** 3398 ** ^The X callback is invoked whenever any of the events identified by 3399 ** mask M occur. ^The integer return value from the callback is currently 3400 ** ignored, though this may change in future releases. Callback 3401 ** implementations should return zero to ensure future compatibility. 3402 ** 3403 ** ^A trace callback is invoked with four arguments: callback(T,C,P,X). 3404 ** ^The T argument is one of the [SQLITE_TRACE] 3405 ** constants to indicate why the callback was invoked. 3406 ** ^The C argument is a copy of the context pointer. 3407 ** The P and X arguments are pointers whose meanings depend on T. 3408 ** 3409 ** The sqlite3_trace_v2() interface is intended to replace the legacy 3410 ** interfaces [sqlite3_trace()] and [sqlite3_profile()], both of which 3411 ** are deprecated. 3412 */ 3413 SQLITE_API int sqlite3_trace_v2( 3414 sqlite3*, 3415 unsigned uMask, 3416 int(*xCallback)(unsigned,void*,void*,void*), 3417 void *pCtx 3418 ); 3419 3420 /* 3421 ** CAPI3REF: Query Progress Callbacks 3422 ** METHOD: sqlite3 3423 ** 3424 ** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback 3425 ** function X to be invoked periodically during long running calls to 3426 ** [sqlite3_step()] and [sqlite3_prepare()] and similar for 3427 ** database connection D. An example use for this 3428 ** interface is to keep a GUI updated during a large query. 3429 ** 3430 ** ^The parameter P is passed through as the only parameter to the 3431 ** callback function X. ^The parameter N is the approximate number of 3432 ** [virtual machine instructions] that are evaluated between successive 3433 ** invocations of the callback X. ^If N is less than one then the progress 3434 ** handler is disabled. 3435 ** 3436 ** ^Only a single progress handler may be defined at one time per 3437 ** [database connection]; setting a new progress handler cancels the 3438 ** old one. ^Setting parameter X to NULL disables the progress handler. 3439 ** ^The progress handler is also disabled by setting N to a value less 3440 ** than 1. 3441 ** 3442 ** ^If the progress callback returns non-zero, the operation is 3443 ** interrupted. This feature can be used to implement a 3444 ** "Cancel" button on a GUI progress dialog box. 3445 ** 3446 ** The progress handler callback must not do anything that will modify 3447 ** the database connection that invoked the progress handler. 3448 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 3449 ** database connections for the meaning of "modify" in this paragraph. 3450 ** 3451 ** The progress handler callback would originally only be invoked from the 3452 ** bytecode engine. It still might be invoked during [sqlite3_prepare()] 3453 ** and similar because those routines might force a reparse of the schema 3454 ** which involves running the bytecode engine. However, beginning with 3455 ** SQLite version 3.41.0, the progress handler callback might also be 3456 ** invoked directly from [sqlite3_prepare()] while analyzing and generating 3457 ** code for complex queries. 3458 */ 3459 SQLITE_API void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*); 3460 3461 /* 3462 ** CAPI3REF: Opening A New Database Connection 3463 ** CONSTRUCTOR: sqlite3 3464 ** 3465 ** ^These routines open an SQLite database file as specified by the 3466 ** filename argument. ^The filename argument is interpreted as UTF-8 for 3467 ** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte 3468 ** order for sqlite3_open16(). ^(A [database connection] handle is usually 3469 ** returned in *ppDb, even if an error occurs. The only exception is that 3470 ** if SQLite is unable to allocate memory to hold the [sqlite3] object, 3471 ** a NULL will be written into *ppDb instead of a pointer to the [sqlite3] 3472 ** object.)^ ^(If the database is opened (and/or created) successfully, then 3473 ** [SQLITE_OK] is returned. Otherwise an [error code] is returned.)^ ^The 3474 ** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain 3475 ** an English language description of the error following a failure of any 3476 ** of the sqlite3_open() routines. 3477 ** 3478 ** ^The default encoding will be UTF-8 for databases created using 3479 ** sqlite3_open() or sqlite3_open_v2(). ^The default encoding for databases 3480 ** created using sqlite3_open16() will be UTF-16 in the native byte order. 3481 ** 3482 ** Whether or not an error occurs when it is opened, resources 3483 ** associated with the [database connection] handle should be released by 3484 ** passing it to [sqlite3_close()] when it is no longer required. 3485 ** 3486 ** The sqlite3_open_v2() interface works like sqlite3_open() 3487 ** except that it accepts two additional parameters for additional control 3488 ** over the new database connection. ^(The flags parameter to 3489 ** sqlite3_open_v2() must include, at a minimum, one of the following 3490 ** three flag combinations:)^ 3491 ** 3492 ** <dl> 3493 ** ^(<dt>[SQLITE_OPEN_READONLY]</dt> 3494 ** <dd>The database is opened in read-only mode. If the database does 3495 ** not already exist, an error is returned.</dd>)^ 3496 ** 3497 ** ^(<dt>[SQLITE_OPEN_READWRITE]</dt> 3498 ** <dd>The database is opened for reading and writing if possible, or 3499 ** reading only if the file is write protected by the operating 3500 ** system. In either case the database must already exist, otherwise 3501 ** an error is returned. For historical reasons, if opening in 3502 ** read-write mode fails due to OS-level permissions, an attempt is 3503 ** made to open it in read-only mode. [sqlite3_db_readonly()] can be 3504 ** used to determine whether the database is actually 3505 ** read-write.</dd>)^ 3506 ** 3507 ** ^(<dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt> 3508 ** <dd>The database is opened for reading and writing, and is created if 3509 ** it does not already exist. This is the behavior that is always used for 3510 ** sqlite3_open() and sqlite3_open16().</dd>)^ 3511 ** </dl> 3512 ** 3513 ** In addition to the required flags, the following optional flags are 3514 ** also supported: 3515 ** 3516 ** <dl> 3517 ** ^(<dt>[SQLITE_OPEN_URI]</dt> 3518 ** <dd>The filename can be interpreted as a URI if this flag is set.</dd>)^ 3519 ** 3520 ** ^(<dt>[SQLITE_OPEN_MEMORY]</dt> 3521 ** <dd>The database will be opened as an in-memory database. The database 3522 ** is named by the "filename" argument for the purposes of cache-sharing, 3523 ** if shared cache mode is enabled, but the "filename" is otherwise ignored. 3524 ** </dd>)^ 3525 ** 3526 ** ^(<dt>[SQLITE_OPEN_NOMUTEX]</dt> 3527 ** <dd>The new database connection will use the "multi-thread" 3528 ** [threading mode].)^ This means that separate threads are allowed 3529 ** to use SQLite at the same time, as long as each thread is using 3530 ** a different [database connection]. 3531 ** 3532 ** ^(<dt>[SQLITE_OPEN_FULLMUTEX]</dt> 3533 ** <dd>The new database connection will use the "serialized" 3534 ** [threading mode].)^ This means the multiple threads can safely 3535 ** attempt to use the same database connection at the same time. 3536 ** (Mutexes will block any actual concurrency, but in this mode 3537 ** there is no harm in trying.) 3538 ** 3539 ** ^(<dt>[SQLITE_OPEN_SHAREDCACHE]</dt> 3540 ** <dd>The database is opened [shared cache] enabled, overriding 3541 ** the default shared cache setting provided by 3542 ** [sqlite3_enable_shared_cache()].)^ 3543 ** The [use of shared cache mode is discouraged] and hence shared cache 3544 ** capabilities may be omitted from many builds of SQLite. In such cases, 3545 ** this option is a no-op. 3546 ** 3547 ** ^(<dt>[SQLITE_OPEN_PRIVATECACHE]</dt> 3548 ** <dd>The database is opened [shared cache] disabled, overriding 3549 ** the default shared cache setting provided by 3550 ** [sqlite3_enable_shared_cache()].)^ 3551 ** 3552 ** [[OPEN_EXRESCODE]] ^(<dt>[SQLITE_OPEN_EXRESCODE]</dt> 3553 ** <dd>The database connection comes up in "extended result code mode". 3554 ** In other words, the database behaves has if 3555 ** [sqlite3_extended_result_codes(db,1)] where called on the database 3556 ** connection as soon as the connection is created. In addition to setting 3557 ** the extended result code mode, this flag also causes [sqlite3_open_v2()] 3558 ** to return an extended result code.</dd> 3559 ** 3560 ** [[OPEN_NOFOLLOW]] ^(<dt>[SQLITE_OPEN_NOFOLLOW]</dt> 3561 ** <dd>The database filename is not allowed to contain a symbolic link</dd> 3562 ** </dl>)^ 3563 ** 3564 ** If the 3rd parameter to sqlite3_open_v2() is not one of the 3565 ** required combinations shown above optionally combined with other 3566 ** [SQLITE_OPEN_READONLY | SQLITE_OPEN_* bits] 3567 ** then the behavior is undefined. Historic versions of SQLite 3568 ** have silently ignored surplus bits in the flags parameter to 3569 ** sqlite3_open_v2(), however that behavior might not be carried through 3570 ** into future versions of SQLite and so applications should not rely 3571 ** upon it. Note in particular that the SQLITE_OPEN_EXCLUSIVE flag is a no-op 3572 ** for sqlite3_open_v2(). The SQLITE_OPEN_EXCLUSIVE does *not* cause 3573 ** the open to fail if the database already exists. The SQLITE_OPEN_EXCLUSIVE 3574 ** flag is intended for use by the [sqlite3_vfs|VFS interface] only, and not 3575 ** by sqlite3_open_v2(). 3576 ** 3577 ** ^The fourth parameter to sqlite3_open_v2() is the name of the 3578 ** [sqlite3_vfs] object that defines the operating system interface that 3579 ** the new database connection should use. ^If the fourth parameter is 3580 ** a NULL pointer then the default [sqlite3_vfs] object is used. 3581 ** 3582 ** ^If the filename is ":memory:", then a private, temporary in-memory database 3583 ** is created for the connection. ^This in-memory database will vanish when 3584 ** the database connection is closed. Future versions of SQLite might 3585 ** make use of additional special filenames that begin with the ":" character. 3586 ** It is recommended that when a database filename actually does begin with 3587 ** a ":" character you should prefix the filename with a pathname such as 3588 ** "./" to avoid ambiguity. 3589 ** 3590 ** ^If the filename is an empty string, then a private, temporary 3591 ** on-disk database will be created. ^This private database will be 3592 ** automatically deleted as soon as the database connection is closed. 3593 ** 3594 ** [[URI filenames in sqlite3_open()]] <h3>URI Filenames</h3> 3595 ** 3596 ** ^If [URI filename] interpretation is enabled, and the filename argument 3597 ** begins with "file:", then the filename is interpreted as a URI. ^URI 3598 ** filename interpretation is enabled if the [SQLITE_OPEN_URI] flag is 3599 ** set in the third argument to sqlite3_open_v2(), or if it has 3600 ** been enabled globally using the [SQLITE_CONFIG_URI] option with the 3601 ** [sqlite3_config()] method or by the [SQLITE_USE_URI] compile-time option. 3602 ** URI filename interpretation is turned off 3603 ** by default, but future releases of SQLite might enable URI filename 3604 ** interpretation by default. See "[URI filenames]" for additional 3605 ** information. 3606 ** 3607 ** URI filenames are parsed according to RFC 3986. ^If the URI contains an 3608 ** authority, then it must be either an empty string or the string 3609 ** "localhost". ^If the authority is not an empty string or "localhost", an 3610 ** error is returned to the caller. ^The fragment component of a URI, if 3611 ** present, is ignored. 3612 ** 3613 ** ^SQLite uses the path component of the URI as the name of the disk file 3614 ** which contains the database. ^If the path begins with a '/' character, 3615 ** then it is interpreted as an absolute path. ^If the path does not begin 3616 ** with a '/' (meaning that the authority section is omitted from the URI) 3617 ** then the path is interpreted as a relative path. 3618 ** ^(On windows, the first component of an absolute path 3619 ** is a drive specification (e.g. "C:").)^ 3620 ** 3621 ** [[core URI query parameters]] 3622 ** The query component of a URI may contain parameters that are interpreted 3623 ** either by SQLite itself, or by a [VFS | custom VFS implementation]. 3624 ** SQLite and its built-in [VFSes] interpret the 3625 ** following query parameters: 3626 ** 3627 ** <ul> 3628 ** <li> <b>vfs</b>: ^The "vfs" parameter may be used to specify the name of 3629 ** a VFS object that provides the operating system interface that should 3630 ** be used to access the database file on disk. ^If this option is set to 3631 ** an empty string the default VFS object is used. ^Specifying an unknown 3632 ** VFS is an error. ^If sqlite3_open_v2() is used and the vfs option is 3633 ** present, then the VFS specified by the option takes precedence over 3634 ** the value passed as the fourth parameter to sqlite3_open_v2(). 3635 ** 3636 ** <li> <b>mode</b>: ^(The mode parameter may be set to either "ro", "rw", 3637 ** "rwc", or "memory". Attempting to set it to any other value is 3638 ** an error)^. 3639 ** ^If "ro" is specified, then the database is opened for read-only 3640 ** access, just as if the [SQLITE_OPEN_READONLY] flag had been set in the 3641 ** third argument to sqlite3_open_v2(). ^If the mode option is set to 3642 ** "rw", then the database is opened for read-write (but not create) 3643 ** access, as if SQLITE_OPEN_READWRITE (but not SQLITE_OPEN_CREATE) had 3644 ** been set. ^Value "rwc" is equivalent to setting both 3645 ** SQLITE_OPEN_READWRITE and SQLITE_OPEN_CREATE. ^If the mode option is 3646 ** set to "memory" then a pure [in-memory database] that never reads 3647 ** or writes from disk is used. ^It is an error to specify a value for 3648 ** the mode parameter that is less restrictive than that specified by 3649 ** the flags passed in the third parameter to sqlite3_open_v2(). 3650 ** 3651 ** <li> <b>cache</b>: ^The cache parameter may be set to either "shared" or 3652 ** "private". ^Setting it to "shared" is equivalent to setting the 3653 ** SQLITE_OPEN_SHAREDCACHE bit in the flags argument passed to 3654 ** sqlite3_open_v2(). ^Setting the cache parameter to "private" is 3655 ** equivalent to setting the SQLITE_OPEN_PRIVATECACHE bit. 3656 ** ^If sqlite3_open_v2() is used and the "cache" parameter is present in 3657 ** a URI filename, its value overrides any behavior requested by setting 3658 ** SQLITE_OPEN_PRIVATECACHE or SQLITE_OPEN_SHAREDCACHE flag. 3659 ** 3660 ** <li> <b>psow</b>: ^The psow parameter indicates whether or not the 3661 ** [powersafe overwrite] property does or does not apply to the 3662 ** storage media on which the database file resides. 3663 ** 3664 ** <li> <b>nolock</b>: ^The nolock parameter is a boolean query parameter 3665 ** which if set disables file locking in rollback journal modes. This 3666 ** is useful for accessing a database on a filesystem that does not 3667 ** support locking. Caution: Database corruption might result if two 3668 ** or more processes write to the same database and any one of those 3669 ** processes uses nolock=1. 3670 ** 3671 ** <li> <b>immutable</b>: ^The immutable parameter is a boolean query 3672 ** parameter that indicates that the database file is stored on 3673 ** read-only media. ^When immutable is set, SQLite assumes that the 3674 ** database file cannot be changed, even by a process with higher 3675 ** privilege, and so the database is opened read-only and all locking 3676 ** and change detection is disabled. Caution: Setting the immutable 3677 ** property on a database file that does in fact change can result 3678 ** in incorrect query results and/or [SQLITE_CORRUPT] errors. 3679 ** See also: [SQLITE_IOCAP_IMMUTABLE]. 3680 ** 3681 ** </ul> 3682 ** 3683 ** ^Specifying an unknown parameter in the query component of a URI is not an 3684 ** error. Future versions of SQLite might understand additional query 3685 ** parameters. See "[query parameters with special meaning to SQLite]" for 3686 ** additional information. 3687 ** 3688 ** [[URI filename examples]] <h3>URI filename examples</h3> 3689 ** 3690 ** <table border="1" align=center cellpadding=5> 3691 ** <tr><th> URI filenames <th> Results 3692 ** <tr><td> file:data.db <td> 3693 ** Open the file "data.db" in the current directory. 3694 ** <tr><td> file:/home/fred/data.db<br> 3695 ** file:///home/fred/data.db <br> 3696 ** file://localhost/home/fred/data.db <br> <td> 3697 ** Open the database file "/home/fred/data.db". 3698 ** <tr><td> file://darkstar/home/fred/data.db <td> 3699 ** An error. "darkstar" is not a recognized authority. 3700 ** <tr><td style="white-space:nowrap"> 3701 ** file:///C:/Documents%20and%20Settings/fred/Desktop/data.db 3702 ** <td> Windows only: Open the file "data.db" on fred's desktop on drive 3703 ** C:. Note that the %20 escaping in this example is not strictly 3704 ** necessary - space characters can be used literally 3705 ** in URI filenames. 3706 ** <tr><td> file:data.db?mode=ro&cache=private <td> 3707 ** Open file "data.db" in the current directory for read-only access. 3708 ** Regardless of whether or not shared-cache mode is enabled by 3709 ** default, use a private cache. 3710 ** <tr><td> file:/home/fred/data.db?vfs=unix-dotfile <td> 3711 ** Open file "/home/fred/data.db". Use the special VFS "unix-dotfile" 3712 ** that uses dot-files in place of posix advisory locking. 3713 ** <tr><td> file:data.db?mode=readonly <td> 3714 ** An error. "readonly" is not a valid option for the "mode" parameter. 3715 ** Use "ro" instead: "file:data.db?mode=ro". 3716 ** </table> 3717 ** 3718 ** ^URI hexadecimal escape sequences (%HH) are supported within the path and 3719 ** query components of a URI. A hexadecimal escape sequence consists of a 3720 ** percent sign - "%" - followed by exactly two hexadecimal digits 3721 ** specifying an octet value. ^Before the path or query components of a 3722 ** URI filename are interpreted, they are encoded using UTF-8 and all 3723 ** hexadecimal escape sequences replaced by a single byte containing the 3724 ** corresponding octet. If this process generates an invalid UTF-8 encoding, 3725 ** the results are undefined. 3726 ** 3727 ** <b>Note to Windows users:</b> The encoding used for the filename argument 3728 ** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever 3729 ** codepage is currently defined. Filenames containing international 3730 ** characters must be converted to UTF-8 prior to passing them into 3731 ** sqlite3_open() or sqlite3_open_v2(). 3732 ** 3733 ** <b>Note to Windows Runtime users:</b> The temporary directory must be set 3734 ** prior to calling sqlite3_open() or sqlite3_open_v2(). Otherwise, various 3735 ** features that require the use of temporary files may fail. 3736 ** 3737 ** See also: [sqlite3_temp_directory] 3738 */ 3739 SQLITE_API int sqlite3_open( 3740 const char *filename, /* Database filename (UTF-8) */ 3741 sqlite3 **ppDb /* OUT: SQLite db handle */ 3742 ); 3743 SQLITE_API int sqlite3_open16( 3744 const void *filename, /* Database filename (UTF-16) */ 3745 sqlite3 **ppDb /* OUT: SQLite db handle */ 3746 ); 3747 SQLITE_API int sqlite3_open_v2( 3748 const char *filename, /* Database filename (UTF-8) */ 3749 sqlite3 **ppDb, /* OUT: SQLite db handle */ 3750 int flags, /* Flags */ 3751 const char *zVfs /* Name of VFS module to use */ 3752 ); 3753 3754 /* 3755 ** CAPI3REF: Obtain Values For URI Parameters 3756 ** 3757 ** These are utility routines, useful to [VFS|custom VFS implementations], 3758 ** that check if a database file was a URI that contained a specific query 3759 ** parameter, and if so obtains the value of that query parameter. 3760 ** 3761 ** The first parameter to these interfaces (hereafter referred to 3762 ** as F) must be one of: 3763 ** <ul> 3764 ** <li> A database filename pointer created by the SQLite core and 3765 ** passed into the xOpen() method of a VFS implementation, or 3766 ** <li> A filename obtained from [sqlite3_db_filename()], or 3767 ** <li> A new filename constructed using [sqlite3_create_filename()]. 3768 ** </ul> 3769 ** If the F parameter is not one of the above, then the behavior is 3770 ** undefined and probably undesirable. Older versions of SQLite were 3771 ** more tolerant of invalid F parameters than newer versions. 3772 ** 3773 ** If F is a suitable filename (as described in the previous paragraph) 3774 ** and if P is the name of the query parameter, then 3775 ** sqlite3_uri_parameter(F,P) returns the value of the P 3776 ** parameter if it exists or a NULL pointer if P does not appear as a 3777 ** query parameter on F. If P is a query parameter of F and it 3778 ** has no explicit value, then sqlite3_uri_parameter(F,P) returns 3779 ** a pointer to an empty string. 3780 ** 3781 ** The sqlite3_uri_boolean(F,P,B) routine assumes that P is a boolean 3782 ** parameter and returns true (1) or false (0) according to the value 3783 ** of P. The sqlite3_uri_boolean(F,P,B) routine returns true (1) if the 3784 ** value of query parameter P is one of "yes", "true", or "on" in any 3785 ** case or if the value begins with a non-zero number. The 3786 ** sqlite3_uri_boolean(F,P,B) routines returns false (0) if the value of 3787 ** query parameter P is one of "no", "false", or "off" in any case or 3788 ** if the value begins with a numeric zero. If P is not a query 3789 ** parameter on F or if the value of P does not match any of the 3790 ** above, then sqlite3_uri_boolean(F,P,B) returns (B!=0). 3791 ** 3792 ** The sqlite3_uri_int64(F,P,D) routine converts the value of P into a 3793 ** 64-bit signed integer and returns that integer, or D if P does not 3794 ** exist. If the value of P is something other than an integer, then 3795 ** zero is returned. 3796 ** 3797 ** The sqlite3_uri_key(F,N) returns a pointer to the name (not 3798 ** the value) of the N-th query parameter for filename F, or a NULL 3799 ** pointer if N is less than zero or greater than the number of query 3800 ** parameters minus 1. The N value is zero-based so N should be 0 to obtain 3801 ** the name of the first query parameter, 1 for the second parameter, and 3802 ** so forth. 3803 ** 3804 ** If F is a NULL pointer, then sqlite3_uri_parameter(F,P) returns NULL and 3805 ** sqlite3_uri_boolean(F,P,B) returns B. If F is not a NULL pointer and 3806 ** is not a database file pathname pointer that the SQLite core passed 3807 ** into the xOpen VFS method, then the behavior of this routine is undefined 3808 ** and probably undesirable. 3809 ** 3810 ** Beginning with SQLite [version 3.31.0] ([dateof:3.31.0]) the input F 3811 ** parameter can also be the name of a rollback journal file or WAL file 3812 ** in addition to the main database file. Prior to version 3.31.0, these 3813 ** routines would only work if F was the name of the main database file. 3814 ** When the F parameter is the name of the rollback journal or WAL file, 3815 ** it has access to all the same query parameters as were found on the 3816 ** main database file. 3817 ** 3818 ** See the [URI filename] documentation for additional information. 3819 */ 3820 SQLITE_API const char *sqlite3_uri_parameter(sqlite3_filename z, const char *zParam); 3821 SQLITE_API int sqlite3_uri_boolean(sqlite3_filename z, const char *zParam, int bDefault); 3822 SQLITE_API sqlite3_int64 sqlite3_uri_int64(sqlite3_filename, const char*, sqlite3_int64); 3823 SQLITE_API const char *sqlite3_uri_key(sqlite3_filename z, int N); 3824 3825 /* 3826 ** CAPI3REF: Translate filenames 3827 ** 3828 ** These routines are available to [VFS|custom VFS implementations] for 3829 ** translating filenames between the main database file, the journal file, 3830 ** and the WAL 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, then sqlite3_filename_database(F) 3834 ** returns the name of the corresponding database file. 3835 ** 3836 ** If F is the name of an sqlite database file, journal file, or WAL file 3837 ** passed by the SQLite core into the VFS, or if F is a database filename 3838 ** obtained from [sqlite3_db_filename()], then sqlite3_filename_journal(F) 3839 ** returns the name of the corresponding rollback journal file. 3840 ** 3841 ** If F is the name of an sqlite database file, journal file, or WAL file 3842 ** that was passed by the SQLite core into the VFS, or if F is a database 3843 ** filename obtained from [sqlite3_db_filename()], then 3844 ** sqlite3_filename_wal(F) returns the name of the corresponding 3845 ** WAL file. 3846 ** 3847 ** In all of the above, if F is not the name of a database, journal or WAL 3848 ** filename passed into the VFS from the SQLite core and F is not the 3849 ** return value from [sqlite3_db_filename()], then the result is 3850 ** undefined and is likely a memory access violation. 3851 */ 3852 SQLITE_API const char *sqlite3_filename_database(sqlite3_filename); 3853 SQLITE_API const char *sqlite3_filename_journal(sqlite3_filename); 3854 SQLITE_API const char *sqlite3_filename_wal(sqlite3_filename); 3855 3856 /* 3857 ** CAPI3REF: Database File Corresponding To A Journal 3858 ** 3859 ** ^If X is the name of a rollback or WAL-mode journal file that is 3860 ** passed into the xOpen method of [sqlite3_vfs], then 3861 ** sqlite3_database_file_object(X) returns a pointer to the [sqlite3_file] 3862 ** object that represents the main database file. 3863 ** 3864 ** This routine is intended for use in custom [VFS] implementations 3865 ** only. It is not a general-purpose interface. 3866 ** The argument sqlite3_file_object(X) must be a filename pointer that 3867 ** has been passed into [sqlite3_vfs].xOpen method where the 3868 ** flags parameter to xOpen contains one of the bits 3869 ** [SQLITE_OPEN_MAIN_JOURNAL] or [SQLITE_OPEN_WAL]. Any other use 3870 ** of this routine results in undefined and probably undesirable 3871 ** behavior. 3872 */ 3873 SQLITE_API sqlite3_file *sqlite3_database_file_object(const char*); 3874 3875 /* 3876 ** CAPI3REF: Create and Destroy VFS Filenames 3877 ** 3878 ** These interfaces are provided for use by [VFS shim] implementations and 3879 ** are not useful outside of that context. 3880 ** 3881 ** The sqlite3_create_filename(D,J,W,N,P) allocates memory to hold a version of 3882 ** database filename D with corresponding journal file J and WAL file W and 3883 ** with N URI parameters key/values pairs in the array P. The result from 3884 ** sqlite3_create_filename(D,J,W,N,P) is a pointer to a database filename that 3885 ** is safe to pass to routines like: 3886 ** <ul> 3887 ** <li> [sqlite3_uri_parameter()], 3888 ** <li> [sqlite3_uri_boolean()], 3889 ** <li> [sqlite3_uri_int64()], 3890 ** <li> [sqlite3_uri_key()], 3891 ** <li> [sqlite3_filename_database()], 3892 ** <li> [sqlite3_filename_journal()], or 3893 ** <li> [sqlite3_filename_wal()]. 3894 ** </ul> 3895 ** If a memory allocation error occurs, sqlite3_create_filename() might 3896 ** return a NULL pointer. The memory obtained from sqlite3_create_filename(X) 3897 ** must be released by a corresponding call to sqlite3_free_filename(Y). 3898 ** 3899 ** The P parameter in sqlite3_create_filename(D,J,W,N,P) should be an array 3900 ** of 2*N pointers to strings. Each pair of pointers in this array corresponds 3901 ** to a key and value for a query parameter. The P parameter may be a NULL 3902 ** pointer if N is zero. None of the 2*N pointers in the P array may be 3903 ** NULL pointers and key pointers should not be empty strings. 3904 ** None of the D, J, or W parameters to sqlite3_create_filename(D,J,W,N,P) may 3905 ** be NULL pointers, though they can be empty strings. 3906 ** 3907 ** The sqlite3_free_filename(Y) routine releases a memory allocation 3908 ** previously obtained from sqlite3_create_filename(). Invoking 3909 ** sqlite3_free_filename(Y) where Y is a NULL pointer is a harmless no-op. 3910 ** 3911 ** If the Y parameter to sqlite3_free_filename(Y) is anything other 3912 ** than a NULL pointer or a pointer previously acquired from 3913 ** sqlite3_create_filename(), then bad things such as heap 3914 ** corruption or segfaults may occur. The value Y should not be 3915 ** used again after sqlite3_free_filename(Y) has been called. This means 3916 ** that if the [sqlite3_vfs.xOpen()] method of a VFS has been called using Y, 3917 ** then the corresponding [sqlite3_module.xClose() method should also be 3918 ** invoked prior to calling sqlite3_free_filename(Y). 3919 */ 3920 SQLITE_API sqlite3_filename sqlite3_create_filename( 3921 const char *zDatabase, 3922 const char *zJournal, 3923 const char *zWal, 3924 int nParam, 3925 const char **azParam 3926 ); 3927 SQLITE_API void sqlite3_free_filename(sqlite3_filename); 3928 3929 /* 3930 ** CAPI3REF: Error Codes And Messages 3931 ** METHOD: sqlite3 3932 ** 3933 ** ^If the most recent sqlite3_* API call associated with 3934 ** [database connection] D failed, then the sqlite3_errcode(D) interface 3935 ** returns the numeric [result code] or [extended result code] for that 3936 ** API call. 3937 ** ^The sqlite3_extended_errcode() 3938 ** interface is the same except that it always returns the 3939 ** [extended result code] even when extended result codes are 3940 ** disabled. 3941 ** 3942 ** The values returned by sqlite3_errcode() and/or 3943 ** sqlite3_extended_errcode() might change with each API call. 3944 ** Except, there are some interfaces that are guaranteed to never 3945 ** change the value of the error code. The error-code preserving 3946 ** interfaces include the following: 3947 ** 3948 ** <ul> 3949 ** <li> sqlite3_errcode() 3950 ** <li> sqlite3_extended_errcode() 3951 ** <li> sqlite3_errmsg() 3952 ** <li> sqlite3_errmsg16() 3953 ** <li> sqlite3_error_offset() 3954 ** </ul> 3955 ** 3956 ** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language 3957 ** text that describes the error, as either UTF-8 or UTF-16 respectively. 3958 ** (See how SQLite handles [invalid UTF] for exceptions to this rule.) 3959 ** ^(Memory to hold the error message string is managed internally. 3960 ** The application does not need to worry about freeing the result. 3961 ** However, the error string might be overwritten or deallocated by 3962 ** subsequent calls to other SQLite interface functions.)^ 3963 ** 3964 ** ^The sqlite3_errstr() interface returns the English-language text 3965 ** that describes the [result code], as UTF-8. 3966 ** ^(Memory to hold the error message string is managed internally 3967 ** and must not be freed by the application)^. 3968 ** 3969 ** ^If the most recent error references a specific token in the input 3970 ** SQL, the sqlite3_error_offset() interface returns the byte offset 3971 ** of the start of that token. ^The byte offset returned by 3972 ** sqlite3_error_offset() assumes that the input SQL is UTF8. 3973 ** ^If the most recent error does not reference a specific token in the input 3974 ** SQL, then the sqlite3_error_offset() function returns -1. 3975 ** 3976 ** When the serialized [threading mode] is in use, it might be the 3977 ** case that a second error occurs on a separate thread in between 3978 ** the time of the first error and the call to these interfaces. 3979 ** When that happens, the second error will be reported since these 3980 ** interfaces always report the most recent result. To avoid 3981 ** this, each thread can obtain exclusive use of the [database connection] D 3982 ** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning 3983 ** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after 3984 ** all calls to the interfaces listed here are completed. 3985 ** 3986 ** If an interface fails with SQLITE_MISUSE, that means the interface 3987 ** was invoked incorrectly by the application. In that case, the 3988 ** error code and message may or may not be set. 3989 */ 3990 SQLITE_API int sqlite3_errcode(sqlite3 *db); 3991 SQLITE_API int sqlite3_extended_errcode(sqlite3 *db); 3992 SQLITE_API const char *sqlite3_errmsg(sqlite3*); 3993 SQLITE_API const void *sqlite3_errmsg16(sqlite3*); 3994 SQLITE_API const char *sqlite3_errstr(int); 3995 SQLITE_API int sqlite3_error_offset(sqlite3 *db); 3996 3997 /* 3998 ** CAPI3REF: Prepared Statement Object 3999 ** KEYWORDS: {prepared statement} {prepared statements} 4000 ** 4001 ** An instance of this object represents a single SQL statement that 4002 ** has been compiled into binary form and is ready to be evaluated. 4003 ** 4004 ** Think of each SQL statement as a separate computer program. The 4005 ** original SQL text is source code. A prepared statement object 4006 ** is the compiled object code. All SQL must be converted into a 4007 ** prepared statement before it can be run. 4008 ** 4009 ** The life-cycle of a prepared statement object usually goes like this: 4010 ** 4011 ** <ol> 4012 ** <li> Create the prepared statement object using [sqlite3_prepare_v2()]. 4013 ** <li> Bind values to [parameters] using the sqlite3_bind_*() 4014 ** interfaces. 4015 ** <li> Run the SQL by calling [sqlite3_step()] one or more times. 4016 ** <li> Reset the prepared statement using [sqlite3_reset()] then go back 4017 ** to step 2. Do this zero or more times. 4018 ** <li> Destroy the object using [sqlite3_finalize()]. 4019 ** </ol> 4020 */ 4021 typedef struct sqlite3_stmt sqlite3_stmt; 4022 4023 /* 4024 ** CAPI3REF: Run-time Limits 4025 ** METHOD: sqlite3 4026 ** 4027 ** ^(This interface allows the size of various constructs to be limited 4028 ** on a connection by connection basis. The first parameter is the 4029 ** [database connection] whose limit is to be set or queried. The 4030 ** second parameter is one of the [limit categories] that define a 4031 ** class of constructs to be size limited. The third parameter is the 4032 ** new limit for that construct.)^ 4033 ** 4034 ** ^If the new limit is a negative number, the limit is unchanged. 4035 ** ^(For each limit category SQLITE_LIMIT_<i>NAME</i> there is a 4036 ** [limits | hard upper bound] 4037 ** set at compile-time by a C preprocessor macro called 4038 ** [limits | SQLITE_MAX_<i>NAME</i>]. 4039 ** (The "_LIMIT_" in the name is changed to "_MAX_".))^ 4040 ** ^Attempts to increase a limit above its hard upper bound are 4041 ** silently truncated to the hard upper bound. 4042 ** 4043 ** ^Regardless of whether or not the limit was changed, the 4044 ** [sqlite3_limit()] interface returns the prior value of the limit. 4045 ** ^Hence, to find the current value of a limit without changing it, 4046 ** simply invoke this interface with the third parameter set to -1. 4047 ** 4048 ** Run-time limits are intended for use in applications that manage 4049 ** both their own internal database and also databases that are controlled 4050 ** by untrusted external sources. An example application might be a 4051 ** web browser that has its own databases for storing history and 4052 ** separate databases controlled by JavaScript applications downloaded 4053 ** off the Internet. The internal databases can be given the 4054 ** large, default limits. Databases managed by external sources can 4055 ** be given much smaller limits designed to prevent a denial of service 4056 ** attack. Developers might also want to use the [sqlite3_set_authorizer()] 4057 ** interface to further control untrusted SQL. The size of the database 4058 ** created by an untrusted script can be contained using the 4059 ** [max_page_count] [PRAGMA]. 4060 ** 4061 ** New run-time limit categories may be added in future releases. 4062 */ 4063 SQLITE_API int sqlite3_limit(sqlite3*, int id, int newVal); 4064 4065 /* 4066 ** CAPI3REF: Run-Time Limit Categories 4067 ** KEYWORDS: {limit category} {*limit categories} 4068 ** 4069 ** These constants define various performance limits 4070 ** that can be lowered at run-time using [sqlite3_limit()]. 4071 ** The synopsis of the meanings of the various limits is shown below. 4072 ** Additional information is available at [limits | Limits in SQLite]. 4073 ** 4074 ** <dl> 4075 ** [[SQLITE_LIMIT_LENGTH]] ^(<dt>SQLITE_LIMIT_LENGTH</dt> 4076 ** <dd>The maximum size of any string or BLOB or table row, in bytes.<dd>)^ 4077 ** 4078 ** [[SQLITE_LIMIT_SQL_LENGTH]] ^(<dt>SQLITE_LIMIT_SQL_LENGTH</dt> 4079 ** <dd>The maximum length of an SQL statement, in bytes.</dd>)^ 4080 ** 4081 ** [[SQLITE_LIMIT_COLUMN]] ^(<dt>SQLITE_LIMIT_COLUMN</dt> 4082 ** <dd>The maximum number of columns in a table definition or in the 4083 ** result set of a [SELECT] or the maximum number of columns in an index 4084 ** or in an ORDER BY or GROUP BY clause.</dd>)^ 4085 ** 4086 ** [[SQLITE_LIMIT_EXPR_DEPTH]] ^(<dt>SQLITE_LIMIT_EXPR_DEPTH</dt> 4087 ** <dd>The maximum depth of the parse tree on any expression.</dd>)^ 4088 ** 4089 ** [[SQLITE_LIMIT_COMPOUND_SELECT]] ^(<dt>SQLITE_LIMIT_COMPOUND_SELECT</dt> 4090 ** <dd>The maximum number of terms in a compound SELECT statement.</dd>)^ 4091 ** 4092 ** [[SQLITE_LIMIT_VDBE_OP]] ^(<dt>SQLITE_LIMIT_VDBE_OP</dt> 4093 ** <dd>The maximum number of instructions in a virtual machine program 4094 ** used to implement an SQL statement. If [sqlite3_prepare_v2()] or 4095 ** the equivalent tries to allocate space for more than this many opcodes 4096 ** in a single prepared statement, an SQLITE_NOMEM error is returned.</dd>)^ 4097 ** 4098 ** [[SQLITE_LIMIT_FUNCTION_ARG]] ^(<dt>SQLITE_LIMIT_FUNCTION_ARG</dt> 4099 ** <dd>The maximum number of arguments on a function.</dd>)^ 4100 ** 4101 ** [[SQLITE_LIMIT_ATTACHED]] ^(<dt>SQLITE_LIMIT_ATTACHED</dt> 4102 ** <dd>The maximum number of [ATTACH | attached databases].)^</dd> 4103 ** 4104 ** [[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]] 4105 ** ^(<dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt> 4106 ** <dd>The maximum length of the pattern argument to the [LIKE] or 4107 ** [GLOB] operators.</dd>)^ 4108 ** 4109 ** [[SQLITE_LIMIT_VARIABLE_NUMBER]] 4110 ** ^(<dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt> 4111 ** <dd>The maximum index number of any [parameter] in an SQL statement.)^ 4112 ** 4113 ** [[SQLITE_LIMIT_TRIGGER_DEPTH]] ^(<dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt> 4114 ** <dd>The maximum depth of recursion for triggers.</dd>)^ 4115 ** 4116 ** [[SQLITE_LIMIT_WORKER_THREADS]] ^(<dt>SQLITE_LIMIT_WORKER_THREADS</dt> 4117 ** <dd>The maximum number of auxiliary worker threads that a single 4118 ** [prepared statement] may start.</dd>)^ 4119 ** </dl> 4120 */ 4121 #define SQLITE_LIMIT_LENGTH 0 4122 #define SQLITE_LIMIT_SQL_LENGTH 1 4123 #define SQLITE_LIMIT_COLUMN 2 4124 #define SQLITE_LIMIT_EXPR_DEPTH 3 4125 #define SQLITE_LIMIT_COMPOUND_SELECT 4 4126 #define SQLITE_LIMIT_VDBE_OP 5 4127 #define SQLITE_LIMIT_FUNCTION_ARG 6 4128 #define SQLITE_LIMIT_ATTACHED 7 4129 #define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8 4130 #define SQLITE_LIMIT_VARIABLE_NUMBER 9 4131 #define SQLITE_LIMIT_TRIGGER_DEPTH 10 4132 #define SQLITE_LIMIT_WORKER_THREADS 11 4133 4134 /* 4135 ** CAPI3REF: Prepare Flags 4136 ** 4137 ** These constants define various flags that can be passed into 4138 ** "prepFlags" parameter of the [sqlite3_prepare_v3()] and 4139 ** [sqlite3_prepare16_v3()] interfaces. 4140 ** 4141 ** New flags may be added in future releases of SQLite. 4142 ** 4143 ** <dl> 4144 ** [[SQLITE_PREPARE_PERSISTENT]] ^(<dt>SQLITE_PREPARE_PERSISTENT</dt> 4145 ** <dd>The SQLITE_PREPARE_PERSISTENT flag is a hint to the query planner 4146 ** that the prepared statement will be retained for a long time and 4147 ** probably reused many times.)^ ^Without this flag, [sqlite3_prepare_v3()] 4148 ** and [sqlite3_prepare16_v3()] assume that the prepared statement will 4149 ** be used just once or at most a few times and then destroyed using 4150 ** [sqlite3_finalize()] relatively soon. The current implementation acts 4151 ** on this hint by avoiding the use of [lookaside memory] so as not to 4152 ** deplete the limited store of lookaside memory. Future versions of 4153 ** SQLite may act on this hint differently. 4154 ** 4155 ** [[SQLITE_PREPARE_NORMALIZE]] <dt>SQLITE_PREPARE_NORMALIZE</dt> 4156 ** <dd>The SQLITE_PREPARE_NORMALIZE flag is a no-op. This flag used 4157 ** to be required for any prepared statement that wanted to use the 4158 ** [sqlite3_normalized_sql()] interface. However, the 4159 ** [sqlite3_normalized_sql()] interface is now available to all 4160 ** prepared statements, regardless of whether or not they use this 4161 ** flag. 4162 ** 4163 ** [[SQLITE_PREPARE_NO_VTAB]] <dt>SQLITE_PREPARE_NO_VTAB</dt> 4164 ** <dd>The SQLITE_PREPARE_NO_VTAB flag causes the SQL compiler 4165 ** to return an error (error code SQLITE_ERROR) if the statement uses 4166 ** any virtual tables. 4167 ** </dl> 4168 */ 4169 #define SQLITE_PREPARE_PERSISTENT 0x01 4170 #define SQLITE_PREPARE_NORMALIZE 0x02 4171 #define SQLITE_PREPARE_NO_VTAB 0x04 4172 4173 /* 4174 ** CAPI3REF: Compiling An SQL Statement 4175 ** KEYWORDS: {SQL statement compiler} 4176 ** METHOD: sqlite3 4177 ** CONSTRUCTOR: sqlite3_stmt 4178 ** 4179 ** To execute an SQL statement, it must first be compiled into a byte-code 4180 ** program using one of these routines. Or, in other words, these routines 4181 ** are constructors for the [prepared statement] object. 4182 ** 4183 ** The preferred routine to use is [sqlite3_prepare_v2()]. The 4184 ** [sqlite3_prepare()] interface is legacy and should be avoided. 4185 ** [sqlite3_prepare_v3()] has an extra "prepFlags" option that is used 4186 ** for special purposes. 4187 ** 4188 ** The use of the UTF-8 interfaces is preferred, as SQLite currently 4189 ** does all parsing using UTF-8. The UTF-16 interfaces are provided 4190 ** as a convenience. The UTF-16 interfaces work by converting the 4191 ** input text into UTF-8, then invoking the corresponding UTF-8 interface. 4192 ** 4193 ** The first argument, "db", is a [database connection] obtained from a 4194 ** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or 4195 ** [sqlite3_open16()]. The database connection must not have been closed. 4196 ** 4197 ** The second argument, "zSql", is the statement to be compiled, encoded 4198 ** as either UTF-8 or UTF-16. The sqlite3_prepare(), sqlite3_prepare_v2(), 4199 ** and sqlite3_prepare_v3() 4200 ** interfaces use UTF-8, and sqlite3_prepare16(), sqlite3_prepare16_v2(), 4201 ** and sqlite3_prepare16_v3() use UTF-16. 4202 ** 4203 ** ^If the nByte argument is negative, then zSql is read up to the 4204 ** first zero terminator. ^If nByte is positive, then it is the 4205 ** number of bytes read from zSql. ^If nByte is zero, then no prepared 4206 ** statement is generated. 4207 ** If the caller knows that the supplied string is nul-terminated, then 4208 ** there is a small performance advantage to passing an nByte parameter that 4209 ** is the number of bytes in the input string <i>including</i> 4210 ** the nul-terminator. 4211 ** 4212 ** ^If pzTail is not NULL then *pzTail is made to point to the first byte 4213 ** past the end of the first SQL statement in zSql. These routines only 4214 ** compile the first statement in zSql, so *pzTail is left pointing to 4215 ** what remains uncompiled. 4216 ** 4217 ** ^*ppStmt is left pointing to a compiled [prepared statement] that can be 4218 ** executed using [sqlite3_step()]. ^If there is an error, *ppStmt is set 4219 ** to NULL. ^If the input text contains no SQL (if the input is an empty 4220 ** string or a comment) then *ppStmt is set to NULL. 4221 ** The calling procedure is responsible for deleting the compiled 4222 ** SQL statement using [sqlite3_finalize()] after it has finished with it. 4223 ** ppStmt may not be NULL. 4224 ** 4225 ** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK]; 4226 ** otherwise an [error code] is returned. 4227 ** 4228 ** The sqlite3_prepare_v2(), sqlite3_prepare_v3(), sqlite3_prepare16_v2(), 4229 ** and sqlite3_prepare16_v3() interfaces are recommended for all new programs. 4230 ** The older interfaces (sqlite3_prepare() and sqlite3_prepare16()) 4231 ** are retained for backwards compatibility, but their use is discouraged. 4232 ** ^In the "vX" interfaces, the prepared statement 4233 ** that is returned (the [sqlite3_stmt] object) contains a copy of the 4234 ** original SQL text. This causes the [sqlite3_step()] interface to 4235 ** behave differently in three ways: 4236 ** 4237 ** <ol> 4238 ** <li> 4239 ** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it 4240 ** always used to do, [sqlite3_step()] will automatically recompile the SQL 4241 ** statement and try to run it again. As many as [SQLITE_MAX_SCHEMA_RETRY] 4242 ** retries will occur before sqlite3_step() gives up and returns an error. 4243 ** </li> 4244 ** 4245 ** <li> 4246 ** ^When an error occurs, [sqlite3_step()] will return one of the detailed 4247 ** [error codes] or [extended error codes]. ^The legacy behavior was that 4248 ** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code 4249 ** and the application would have to make a second call to [sqlite3_reset()] 4250 ** in order to find the underlying cause of the problem. With the "v2" prepare 4251 ** interfaces, the underlying reason for the error is returned immediately. 4252 ** </li> 4253 ** 4254 ** <li> 4255 ** ^If the specific value bound to a [parameter | host parameter] in the 4256 ** WHERE clause might influence the choice of query plan for a statement, 4257 ** then the statement will be automatically recompiled, as if there had been 4258 ** a schema change, on the first [sqlite3_step()] call following any change 4259 ** to the [sqlite3_bind_text | bindings] of that [parameter]. 4260 ** ^The specific value of a WHERE-clause [parameter] might influence the 4261 ** choice of query plan if the parameter is the left-hand side of a [LIKE] 4262 ** or [GLOB] operator or if the parameter is compared to an indexed column 4263 ** and the [SQLITE_ENABLE_STAT4] compile-time option is enabled. 4264 ** </li> 4265 ** </ol> 4266 ** 4267 ** <p>^sqlite3_prepare_v3() differs from sqlite3_prepare_v2() only in having 4268 ** the extra prepFlags parameter, which is a bit array consisting of zero or 4269 ** more of the [SQLITE_PREPARE_PERSISTENT|SQLITE_PREPARE_*] flags. ^The 4270 ** sqlite3_prepare_v2() interface works exactly the same as 4271 ** sqlite3_prepare_v3() with a zero prepFlags parameter. 4272 */ 4273 SQLITE_API int sqlite3_prepare( 4274 sqlite3 *db, /* Database handle */ 4275 const char *zSql, /* SQL statement, UTF-8 encoded */ 4276 int nByte, /* Maximum length of zSql in bytes. */ 4277 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 4278 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 4279 ); 4280 SQLITE_API int sqlite3_prepare_v2( 4281 sqlite3 *db, /* Database handle */ 4282 const char *zSql, /* SQL statement, UTF-8 encoded */ 4283 int nByte, /* Maximum length of zSql in bytes. */ 4284 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 4285 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 4286 ); 4287 SQLITE_API int sqlite3_prepare_v3( 4288 sqlite3 *db, /* Database handle */ 4289 const char *zSql, /* SQL statement, UTF-8 encoded */ 4290 int nByte, /* Maximum length of zSql in bytes. */ 4291 unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */ 4292 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 4293 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 4294 ); 4295 SQLITE_API int sqlite3_prepare16( 4296 sqlite3 *db, /* Database handle */ 4297 const void *zSql, /* SQL statement, UTF-16 encoded */ 4298 int nByte, /* Maximum length of zSql in bytes. */ 4299 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 4300 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 4301 ); 4302 SQLITE_API int sqlite3_prepare16_v2( 4303 sqlite3 *db, /* Database handle */ 4304 const void *zSql, /* SQL statement, UTF-16 encoded */ 4305 int nByte, /* Maximum length of zSql in bytes. */ 4306 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 4307 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 4308 ); 4309 SQLITE_API int sqlite3_prepare16_v3( 4310 sqlite3 *db, /* Database handle */ 4311 const void *zSql, /* SQL statement, UTF-16 encoded */ 4312 int nByte, /* Maximum length of zSql in bytes. */ 4313 unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */ 4314 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 4315 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 4316 ); 4317 4318 /* 4319 ** CAPI3REF: Retrieving Statement SQL 4320 ** METHOD: sqlite3_stmt 4321 ** 4322 ** ^The sqlite3_sql(P) interface returns a pointer to a copy of the UTF-8 4323 ** SQL text used to create [prepared statement] P if P was 4324 ** created by [sqlite3_prepare_v2()], [sqlite3_prepare_v3()], 4325 ** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()]. 4326 ** ^The sqlite3_expanded_sql(P) interface returns a pointer to a UTF-8 4327 ** string containing the SQL text of prepared statement P with 4328 ** [bound parameters] expanded. 4329 ** ^The sqlite3_normalized_sql(P) interface returns a pointer to a UTF-8 4330 ** string containing the normalized SQL text of prepared statement P. The 4331 ** semantics used to normalize a SQL statement are unspecified and subject 4332 ** to change. At a minimum, literal values will be replaced with suitable 4333 ** placeholders. 4334 ** 4335 ** ^(For example, if a prepared statement is created using the SQL 4336 ** text "SELECT $abc,:xyz" and if parameter $abc is bound to integer 2345 4337 ** and parameter :xyz is unbound, then sqlite3_sql() will return 4338 ** the original string, "SELECT $abc,:xyz" but sqlite3_expanded_sql() 4339 ** will return "SELECT 2345,NULL".)^ 4340 ** 4341 ** ^The sqlite3_expanded_sql() interface returns NULL if insufficient memory 4342 ** is available to hold the result, or if the result would exceed the 4343 ** the maximum string length determined by the [SQLITE_LIMIT_LENGTH]. 4344 ** 4345 ** ^The [SQLITE_TRACE_SIZE_LIMIT] compile-time option limits the size of 4346 ** bound parameter expansions. ^The [SQLITE_OMIT_TRACE] compile-time 4347 ** option causes sqlite3_expanded_sql() to always return NULL. 4348 ** 4349 ** ^The strings returned by sqlite3_sql(P) and sqlite3_normalized_sql(P) 4350 ** are managed by SQLite and are automatically freed when the prepared 4351 ** statement is finalized. 4352 ** ^The string returned by sqlite3_expanded_sql(P), on the other hand, 4353 ** is obtained from [sqlite3_malloc()] and must be freed by the application 4354 ** by passing it to [sqlite3_free()]. 4355 ** 4356 ** ^The sqlite3_normalized_sql() interface is only available if 4357 ** the [SQLITE_ENABLE_NORMALIZE] compile-time option is defined. 4358 */ 4359 SQLITE_API const char *sqlite3_sql(sqlite3_stmt *pStmt); 4360 SQLITE_API char *sqlite3_expanded_sql(sqlite3_stmt *pStmt); 4361 #ifdef SQLITE_ENABLE_NORMALIZE 4362 SQLITE_API const char *sqlite3_normalized_sql(sqlite3_stmt *pStmt); 4363 #endif 4364 4365 /* 4366 ** CAPI3REF: Determine If An SQL Statement Writes The Database 4367 ** METHOD: sqlite3_stmt 4368 ** 4369 ** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if 4370 ** and only if the [prepared statement] X makes no direct changes to 4371 ** the content of the database file. 4372 ** 4373 ** Note that [application-defined SQL functions] or 4374 ** [virtual tables] might change the database indirectly as a side effect. 4375 ** ^(For example, if an application defines a function "eval()" that 4376 ** calls [sqlite3_exec()], then the following SQL statement would 4377 ** change the database file through side-effects: 4378 ** 4379 ** <blockquote><pre> 4380 ** SELECT eval('DELETE FROM t1') FROM t2; 4381 ** </pre></blockquote> 4382 ** 4383 ** But because the [SELECT] statement does not change the database file 4384 ** directly, sqlite3_stmt_readonly() would still return true.)^ 4385 ** 4386 ** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK], 4387 ** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true, 4388 ** since the statements themselves do not actually modify the database but 4389 ** rather they control the timing of when other statements modify the 4390 ** database. ^The [ATTACH] and [DETACH] statements also cause 4391 ** sqlite3_stmt_readonly() to return true since, while those statements 4392 ** change the configuration of a database connection, they do not make 4393 ** changes to the content of the database files on disk. 4394 ** ^The sqlite3_stmt_readonly() interface returns true for [BEGIN] since 4395 ** [BEGIN] merely sets internal flags, but the [BEGIN|BEGIN IMMEDIATE] and 4396 ** [BEGIN|BEGIN EXCLUSIVE] commands do touch the database and so 4397 ** sqlite3_stmt_readonly() returns false for those commands. 4398 ** 4399 ** ^This routine returns false if there is any possibility that the 4400 ** statement might change the database file. ^A false return does 4401 ** not guarantee that the statement will change the database file. 4402 ** ^For example, an UPDATE statement might have a WHERE clause that 4403 ** makes it a no-op, but the sqlite3_stmt_readonly() result would still 4404 ** be false. ^Similarly, a CREATE TABLE IF NOT EXISTS statement is a 4405 ** read-only no-op if the table already exists, but 4406 ** sqlite3_stmt_readonly() still returns false for such a statement. 4407 ** 4408 ** ^If prepared statement X is an [EXPLAIN] or [EXPLAIN QUERY PLAN] 4409 ** statement, then sqlite3_stmt_readonly(X) returns the same value as 4410 ** if the EXPLAIN or EXPLAIN QUERY PLAN prefix were omitted. 4411 */ 4412 SQLITE_API int sqlite3_stmt_readonly(sqlite3_stmt *pStmt); 4413 4414 /* 4415 ** CAPI3REF: Query The EXPLAIN Setting For A Prepared Statement 4416 ** METHOD: sqlite3_stmt 4417 ** 4418 ** ^The sqlite3_stmt_isexplain(S) interface returns 1 if the 4419 ** prepared statement S is an EXPLAIN statement, or 2 if the 4420 ** statement S is an EXPLAIN QUERY PLAN. 4421 ** ^The sqlite3_stmt_isexplain(S) interface returns 0 if S is 4422 ** an ordinary statement or a NULL pointer. 4423 */ 4424 SQLITE_API int sqlite3_stmt_isexplain(sqlite3_stmt *pStmt); 4425 4426 /* 4427 ** CAPI3REF: Change The EXPLAIN Setting For A Prepared Statement 4428 ** METHOD: sqlite3_stmt 4429 ** 4430 ** The sqlite3_stmt_explain(S,E) interface changes the EXPLAIN 4431 ** setting for [prepared statement] S. If E is zero, then S becomes 4432 ** a normal prepared statement. If E is 1, then S behaves as if 4433 ** its SQL text began with "[EXPLAIN]". If E is 2, then S behaves as if 4434 ** its SQL text began with "[EXPLAIN QUERY PLAN]". 4435 ** 4436 ** Calling sqlite3_stmt_explain(S,E) might cause S to be reprepared. 4437 ** SQLite tries to avoid a reprepare, but a reprepare might be necessary 4438 ** on the first transition into EXPLAIN or EXPLAIN QUERY PLAN mode. 4439 ** 4440 ** Because of the potential need to reprepare, a call to 4441 ** sqlite3_stmt_explain(S,E) will fail with SQLITE_ERROR if S cannot be 4442 ** reprepared because it was created using [sqlite3_prepare()] instead of 4443 ** the newer [sqlite3_prepare_v2()] or [sqlite3_prepare_v3()] interfaces and 4444 ** hence has no saved SQL text with which to reprepare. 4445 ** 4446 ** Changing the explain setting for a prepared statement does not change 4447 ** the original SQL text for the statement. Hence, if the SQL text originally 4448 ** began with EXPLAIN or EXPLAIN QUERY PLAN, but sqlite3_stmt_explain(S,0) 4449 ** is called to convert the statement into an ordinary statement, the EXPLAIN 4450 ** or EXPLAIN QUERY PLAN keywords will still appear in the sqlite3_sql(S) 4451 ** output, even though the statement now acts like a normal SQL statement. 4452 ** 4453 ** This routine returns SQLITE_OK if the explain mode is successfully 4454 ** changed, or an error code if the explain mode could not be changed. 4455 ** The explain mode cannot be changed while a statement is active. 4456 ** Hence, it is good practice to call [sqlite3_reset(S)] 4457 ** immediately prior to calling sqlite3_stmt_explain(S,E). 4458 */ 4459 SQLITE_API int sqlite3_stmt_explain(sqlite3_stmt *pStmt, int eMode); 4460 4461 /* 4462 ** CAPI3REF: Determine If A Prepared Statement Has Been Reset 4463 ** METHOD: sqlite3_stmt 4464 ** 4465 ** ^The sqlite3_stmt_busy(S) interface returns true (non-zero) if the 4466 ** [prepared statement] S has been stepped at least once using 4467 ** [sqlite3_step(S)] but has neither run to completion (returned 4468 ** [SQLITE_DONE] from [sqlite3_step(S)]) nor 4469 ** been reset using [sqlite3_reset(S)]. ^The sqlite3_stmt_busy(S) 4470 ** interface returns false if S is a NULL pointer. If S is not a 4471 ** NULL pointer and is not a pointer to a valid [prepared statement] 4472 ** object, then the behavior is undefined and probably undesirable. 4473 ** 4474 ** This interface can be used in combination [sqlite3_next_stmt()] 4475 ** to locate all prepared statements associated with a database 4476 ** connection that are in need of being reset. This can be used, 4477 ** for example, in diagnostic routines to search for prepared 4478 ** statements that are holding a transaction open. 4479 */ 4480 SQLITE_API int sqlite3_stmt_busy(sqlite3_stmt*); 4481 4482 /* 4483 ** CAPI3REF: Dynamically Typed Value Object 4484 ** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value} 4485 ** 4486 ** SQLite uses the sqlite3_value object to represent all values 4487 ** that can be stored in a database table. SQLite uses dynamic typing 4488 ** for the values it stores. ^Values stored in sqlite3_value objects 4489 ** can be integers, floating point values, strings, BLOBs, or NULL. 4490 ** 4491 ** An sqlite3_value object may be either "protected" or "unprotected". 4492 ** Some interfaces require a protected sqlite3_value. Other interfaces 4493 ** will accept either a protected or an unprotected sqlite3_value. 4494 ** Every interface that accepts sqlite3_value arguments specifies 4495 ** whether or not it requires a protected sqlite3_value. The 4496 ** [sqlite3_value_dup()] interface can be used to construct a new 4497 ** protected sqlite3_value from an unprotected sqlite3_value. 4498 ** 4499 ** The terms "protected" and "unprotected" refer to whether or not 4500 ** a mutex is held. An internal mutex is held for a protected 4501 ** sqlite3_value object but no mutex is held for an unprotected 4502 ** sqlite3_value object. If SQLite is compiled to be single-threaded 4503 ** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0) 4504 ** or if SQLite is run in one of reduced mutex modes 4505 ** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD] 4506 ** then there is no distinction between protected and unprotected 4507 ** sqlite3_value objects and they can be used interchangeably. However, 4508 ** for maximum code portability it is recommended that applications 4509 ** still make the distinction between protected and unprotected 4510 ** sqlite3_value objects even when not strictly required. 4511 ** 4512 ** ^The sqlite3_value objects that are passed as parameters into the 4513 ** implementation of [application-defined SQL functions] are protected. 4514 ** ^The sqlite3_value objects returned by [sqlite3_vtab_rhs_value()] 4515 ** are protected. 4516 ** ^The sqlite3_value object returned by 4517 ** [sqlite3_column_value()] is unprotected. 4518 ** Unprotected sqlite3_value objects may only be used as arguments 4519 ** to [sqlite3_result_value()], [sqlite3_bind_value()], and 4520 ** [sqlite3_value_dup()]. 4521 ** The [sqlite3_value_blob | sqlite3_value_type()] family of 4522 ** interfaces require protected sqlite3_value objects. 4523 */ 4524 typedef struct sqlite3_value sqlite3_value; 4525 4526 /* 4527 ** CAPI3REF: SQL Function Context Object 4528 ** 4529 ** The context in which an SQL function executes is stored in an 4530 ** sqlite3_context object. ^A pointer to an sqlite3_context object 4531 ** is always first parameter to [application-defined SQL functions]. 4532 ** The application-defined SQL function implementation will pass this 4533 ** pointer through into calls to [sqlite3_result_int | sqlite3_result()], 4534 ** [sqlite3_aggregate_context()], [sqlite3_user_data()], 4535 ** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()], 4536 ** and/or [sqlite3_set_auxdata()]. 4537 */ 4538 typedef struct sqlite3_context sqlite3_context; 4539 4540 /* 4541 ** CAPI3REF: Binding Values To Prepared Statements 4542 ** KEYWORDS: {host parameter} {host parameters} {host parameter name} 4543 ** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding} 4544 ** METHOD: sqlite3_stmt 4545 ** 4546 ** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants, 4547 ** literals may be replaced by a [parameter] that matches one of following 4548 ** templates: 4549 ** 4550 ** <ul> 4551 ** <li> ? 4552 ** <li> ?NNN 4553 ** <li> :VVV 4554 ** <li> @VVV 4555 ** <li> $VVV 4556 ** </ul> 4557 ** 4558 ** In the templates above, NNN represents an integer literal, 4559 ** and VVV represents an alphanumeric identifier.)^ ^The values of these 4560 ** parameters (also called "host parameter names" or "SQL parameters") 4561 ** can be set using the sqlite3_bind_*() routines defined here. 4562 ** 4563 ** ^The first argument to the sqlite3_bind_*() routines is always 4564 ** a pointer to the [sqlite3_stmt] object returned from 4565 ** [sqlite3_prepare_v2()] or its variants. 4566 ** 4567 ** ^The second argument is the index of the SQL parameter to be set. 4568 ** ^The leftmost SQL parameter has an index of 1. ^When the same named 4569 ** SQL parameter is used more than once, second and subsequent 4570 ** occurrences have the same index as the first occurrence. 4571 ** ^The index for named parameters can be looked up using the 4572 ** [sqlite3_bind_parameter_index()] API if desired. ^The index 4573 ** for "?NNN" parameters is the value of NNN. 4574 ** ^The NNN value must be between 1 and the [sqlite3_limit()] 4575 ** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 32766). 4576 ** 4577 ** ^The third argument is the value to bind to the parameter. 4578 ** ^If the third parameter to sqlite3_bind_text() or sqlite3_bind_text16() 4579 ** or sqlite3_bind_blob() is a NULL pointer then the fourth parameter 4580 ** is ignored and the end result is the same as sqlite3_bind_null(). 4581 ** ^If the third parameter to sqlite3_bind_text() is not NULL, then 4582 ** it should be a pointer to well-formed UTF8 text. 4583 ** ^If the third parameter to sqlite3_bind_text16() is not NULL, then 4584 ** it should be a pointer to well-formed UTF16 text. 4585 ** ^If the third parameter to sqlite3_bind_text64() is not NULL, then 4586 ** it should be a pointer to a well-formed unicode string that is 4587 ** either UTF8 if the sixth parameter is SQLITE_UTF8, or UTF16 4588 ** otherwise. 4589 ** 4590 ** [[byte-order determination rules]] ^The byte-order of 4591 ** UTF16 input text is determined by the byte-order mark (BOM, U+FEFF) 4592 ** found in first character, which is removed, or in the absence of a BOM 4593 ** the byte order is the native byte order of the host 4594 ** machine for sqlite3_bind_text16() or the byte order specified in 4595 ** the 6th parameter for sqlite3_bind_text64().)^ 4596 ** ^If UTF16 input text contains invalid unicode 4597 ** characters, then SQLite might change those invalid characters 4598 ** into the unicode replacement character: U+FFFD. 4599 ** 4600 ** ^(In those routines that have a fourth argument, its value is the 4601 ** number of bytes in the parameter. To be clear: the value is the 4602 ** number of <u>bytes</u> in the value, not the number of characters.)^ 4603 ** ^If the fourth parameter to sqlite3_bind_text() or sqlite3_bind_text16() 4604 ** is negative, then the length of the string is 4605 ** the number of bytes up to the first zero terminator. 4606 ** If the fourth parameter to sqlite3_bind_blob() is negative, then 4607 ** the behavior is undefined. 4608 ** If a non-negative fourth parameter is provided to sqlite3_bind_text() 4609 ** or sqlite3_bind_text16() or sqlite3_bind_text64() then 4610 ** that parameter must be the byte offset 4611 ** where the NUL terminator would occur assuming the string were NUL 4612 ** terminated. If any NUL characters occurs at byte offsets less than 4613 ** the value of the fourth parameter then the resulting string value will 4614 ** contain embedded NULs. The result of expressions involving strings 4615 ** with embedded NULs is undefined. 4616 ** 4617 ** ^The fifth argument to the BLOB and string binding interfaces controls 4618 ** or indicates the lifetime of the object referenced by the third parameter. 4619 ** These three options exist: 4620 ** ^ (1) A destructor to dispose of the BLOB or string after SQLite has finished 4621 ** with it may be passed. ^It is called to dispose of the BLOB or string even 4622 ** if the call to the bind API fails, except the destructor is not called if 4623 ** the third parameter is a NULL pointer or the fourth parameter is negative. 4624 ** ^ (2) The special constant, [SQLITE_STATIC], may be passed to indicate that 4625 ** the application remains responsible for disposing of the object. ^In this 4626 ** case, the object and the provided pointer to it must remain valid until 4627 ** either the prepared statement is finalized or the same SQL parameter is 4628 ** bound to something else, whichever occurs sooner. 4629 ** ^ (3) The constant, [SQLITE_TRANSIENT], may be passed to indicate that the 4630 ** object is to be copied prior to the return from sqlite3_bind_*(). ^The 4631 ** object and pointer to it must remain valid until then. ^SQLite will then 4632 ** manage the lifetime of its private copy. 4633 ** 4634 ** ^The sixth argument to sqlite3_bind_text64() must be one of 4635 ** [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE] 4636 ** to specify the encoding of the text in the third parameter. If 4637 ** the sixth argument to sqlite3_bind_text64() is not one of the 4638 ** allowed values shown above, or if the text encoding is different 4639 ** from the encoding specified by the sixth parameter, then the behavior 4640 ** is undefined. 4641 ** 4642 ** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that 4643 ** is filled with zeroes. ^A zeroblob uses a fixed amount of memory 4644 ** (just an integer to hold its size) while it is being processed. 4645 ** Zeroblobs are intended to serve as placeholders for BLOBs whose 4646 ** content is later written using 4647 ** [sqlite3_blob_open | incremental BLOB I/O] routines. 4648 ** ^A negative value for the zeroblob results in a zero-length BLOB. 4649 ** 4650 ** ^The sqlite3_bind_pointer(S,I,P,T,D) routine causes the I-th parameter in 4651 ** [prepared statement] S to have an SQL value of NULL, but to also be 4652 ** associated with the pointer P of type T. ^D is either a NULL pointer or 4653 ** a pointer to a destructor function for P. ^SQLite will invoke the 4654 ** destructor D with a single argument of P when it is finished using 4655 ** P. The T parameter should be a static string, preferably a string 4656 ** literal. The sqlite3_bind_pointer() routine is part of the 4657 ** [pointer passing interface] added for SQLite 3.20.0. 4658 ** 4659 ** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer 4660 ** for the [prepared statement] or with a prepared statement for which 4661 ** [sqlite3_step()] has been called more recently than [sqlite3_reset()], 4662 ** then the call will return [SQLITE_MISUSE]. If any sqlite3_bind_() 4663 ** routine is passed a [prepared statement] that has been finalized, the 4664 ** result is undefined and probably harmful. 4665 ** 4666 ** ^Bindings are not cleared by the [sqlite3_reset()] routine. 4667 ** ^Unbound parameters are interpreted as NULL. 4668 ** 4669 ** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an 4670 ** [error code] if anything goes wrong. 4671 ** ^[SQLITE_TOOBIG] might be returned if the size of a string or BLOB 4672 ** exceeds limits imposed by [sqlite3_limit]([SQLITE_LIMIT_LENGTH]) or 4673 ** [SQLITE_MAX_LENGTH]. 4674 ** ^[SQLITE_RANGE] is returned if the parameter 4675 ** index is out of range. ^[SQLITE_NOMEM] is returned if malloc() fails. 4676 ** 4677 ** See also: [sqlite3_bind_parameter_count()], 4678 ** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()]. 4679 */ 4680 SQLITE_API int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*)); 4681 SQLITE_API int sqlite3_bind_blob64(sqlite3_stmt*, int, const void*, sqlite3_uint64, 4682 void(*)(void*)); 4683 SQLITE_API int sqlite3_bind_double(sqlite3_stmt*, int, double); 4684 SQLITE_API int sqlite3_bind_int(sqlite3_stmt*, int, int); 4685 SQLITE_API int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64); 4686 SQLITE_API int sqlite3_bind_null(sqlite3_stmt*, int); 4687 SQLITE_API int sqlite3_bind_text(sqlite3_stmt*,int,const char*,int,void(*)(void*)); 4688 SQLITE_API int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*)); 4689 SQLITE_API int sqlite3_bind_text64(sqlite3_stmt*, int, const char*, sqlite3_uint64, 4690 void(*)(void*), unsigned char encoding); 4691 SQLITE_API int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*); 4692 SQLITE_API int sqlite3_bind_pointer(sqlite3_stmt*, int, void*, const char*,void(*)(void*)); 4693 SQLITE_API int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n); 4694 SQLITE_API int sqlite3_bind_zeroblob64(sqlite3_stmt*, int, sqlite3_uint64); 4695 4696 /* 4697 ** CAPI3REF: Number Of SQL Parameters 4698 ** METHOD: sqlite3_stmt 4699 ** 4700 ** ^This routine can be used to find the number of [SQL parameters] 4701 ** in a [prepared statement]. SQL parameters are tokens of the 4702 ** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as 4703 ** placeholders for values that are [sqlite3_bind_blob | bound] 4704 ** to the parameters at a later time. 4705 ** 4706 ** ^(This routine actually returns the index of the largest (rightmost) 4707 ** parameter. For all forms except ?NNN, this will correspond to the 4708 ** number of unique parameters. If parameters of the ?NNN form are used, 4709 ** there may be gaps in the list.)^ 4710 ** 4711 ** See also: [sqlite3_bind_blob|sqlite3_bind()], 4712 ** [sqlite3_bind_parameter_name()], and 4713 ** [sqlite3_bind_parameter_index()]. 4714 */ 4715 SQLITE_API int sqlite3_bind_parameter_count(sqlite3_stmt*); 4716 4717 /* 4718 ** CAPI3REF: Name Of A Host Parameter 4719 ** METHOD: sqlite3_stmt 4720 ** 4721 ** ^The sqlite3_bind_parameter_name(P,N) interface returns 4722 ** the name of the N-th [SQL parameter] in the [prepared statement] P. 4723 ** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA" 4724 ** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA" 4725 ** respectively. 4726 ** In other words, the initial ":" or "$" or "@" or "?" 4727 ** is included as part of the name.)^ 4728 ** ^Parameters of the form "?" without a following integer have no name 4729 ** and are referred to as "nameless" or "anonymous parameters". 4730 ** 4731 ** ^The first host parameter has an index of 1, not 0. 4732 ** 4733 ** ^If the value N is out of range or if the N-th parameter is 4734 ** nameless, then NULL is returned. ^The returned string is 4735 ** always in UTF-8 encoding even if the named parameter was 4736 ** originally specified as UTF-16 in [sqlite3_prepare16()], 4737 ** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()]. 4738 ** 4739 ** See also: [sqlite3_bind_blob|sqlite3_bind()], 4740 ** [sqlite3_bind_parameter_count()], and 4741 ** [sqlite3_bind_parameter_index()]. 4742 */ 4743 SQLITE_API const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int); 4744 4745 /* 4746 ** CAPI3REF: Index Of A Parameter With A Given Name 4747 ** METHOD: sqlite3_stmt 4748 ** 4749 ** ^Return the index of an SQL parameter given its name. ^The 4750 ** index value returned is suitable for use as the second 4751 ** parameter to [sqlite3_bind_blob|sqlite3_bind()]. ^A zero 4752 ** is returned if no matching parameter is found. ^The parameter 4753 ** name must be given in UTF-8 even if the original statement 4754 ** was prepared from UTF-16 text using [sqlite3_prepare16_v2()] or 4755 ** [sqlite3_prepare16_v3()]. 4756 ** 4757 ** See also: [sqlite3_bind_blob|sqlite3_bind()], 4758 ** [sqlite3_bind_parameter_count()], and 4759 ** [sqlite3_bind_parameter_name()]. 4760 */ 4761 SQLITE_API int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName); 4762 4763 /* 4764 ** CAPI3REF: Reset All Bindings On A Prepared Statement 4765 ** METHOD: sqlite3_stmt 4766 ** 4767 ** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset 4768 ** the [sqlite3_bind_blob | bindings] on a [prepared statement]. 4769 ** ^Use this routine to reset all host parameters to NULL. 4770 */ 4771 SQLITE_API int sqlite3_clear_bindings(sqlite3_stmt*); 4772 4773 /* 4774 ** CAPI3REF: Number Of Columns In A Result Set 4775 ** METHOD: sqlite3_stmt 4776 ** 4777 ** ^Return the number of columns in the result set returned by the 4778 ** [prepared statement]. ^If this routine returns 0, that means the 4779 ** [prepared statement] returns no data (for example an [UPDATE]). 4780 ** ^However, just because this routine returns a positive number does not 4781 ** mean that one or more rows of data will be returned. ^A SELECT statement 4782 ** will always have a positive sqlite3_column_count() but depending on the 4783 ** WHERE clause constraints and the table content, it might return no rows. 4784 ** 4785 ** See also: [sqlite3_data_count()] 4786 */ 4787 SQLITE_API int sqlite3_column_count(sqlite3_stmt *pStmt); 4788 4789 /* 4790 ** CAPI3REF: Column Names In A Result Set 4791 ** METHOD: sqlite3_stmt 4792 ** 4793 ** ^These routines return the name assigned to a particular column 4794 ** in the result set of a [SELECT] statement. ^The sqlite3_column_name() 4795 ** interface returns a pointer to a zero-terminated UTF-8 string 4796 ** and sqlite3_column_name16() returns a pointer to a zero-terminated 4797 ** UTF-16 string. ^The first parameter is the [prepared statement] 4798 ** that implements the [SELECT] statement. ^The second parameter is the 4799 ** column number. ^The leftmost column is number 0. 4800 ** 4801 ** ^The returned string pointer is valid until either the [prepared statement] 4802 ** is destroyed by [sqlite3_finalize()] or until the statement is automatically 4803 ** reprepared by the first call to [sqlite3_step()] for a particular run 4804 ** or until the next call to 4805 ** sqlite3_column_name() or sqlite3_column_name16() on the same column. 4806 ** 4807 ** ^If sqlite3_malloc() fails during the processing of either routine 4808 ** (for example during a conversion from UTF-8 to UTF-16) then a 4809 ** NULL pointer is returned. 4810 ** 4811 ** ^The name of a result column is the value of the "AS" clause for 4812 ** that column, if there is an AS clause. If there is no AS clause 4813 ** then the name of the column is unspecified and may change from 4814 ** one release of SQLite to the next. 4815 */ 4816 SQLITE_API const char *sqlite3_column_name(sqlite3_stmt*, int N); 4817 SQLITE_API const void *sqlite3_column_name16(sqlite3_stmt*, int N); 4818 4819 /* 4820 ** CAPI3REF: Source Of Data In A Query Result 4821 ** METHOD: sqlite3_stmt 4822 ** 4823 ** ^These routines provide a means to determine the database, table, and 4824 ** table column that is the origin of a particular result column in 4825 ** [SELECT] statement. 4826 ** ^The name of the database or table or column can be returned as 4827 ** either a UTF-8 or UTF-16 string. ^The _database_ routines return 4828 ** the database name, the _table_ routines return the table name, and 4829 ** the origin_ routines return the column name. 4830 ** ^The returned string is valid until the [prepared statement] is destroyed 4831 ** using [sqlite3_finalize()] or until the statement is automatically 4832 ** reprepared by the first call to [sqlite3_step()] for a particular run 4833 ** or until the same information is requested 4834 ** again in a different encoding. 4835 ** 4836 ** ^The names returned are the original un-aliased names of the 4837 ** database, table, and column. 4838 ** 4839 ** ^The first argument to these interfaces is a [prepared statement]. 4840 ** ^These functions return information about the Nth result column returned by 4841 ** the statement, where N is the second function argument. 4842 ** ^The left-most column is column 0 for these routines. 4843 ** 4844 ** ^If the Nth column returned by the statement is an expression or 4845 ** subquery and is not a column value, then all of these functions return 4846 ** NULL. ^These routines might also return NULL if a memory allocation error 4847 ** occurs. ^Otherwise, they return the name of the attached database, table, 4848 ** or column that query result column was extracted from. 4849 ** 4850 ** ^As with all other SQLite APIs, those whose names end with "16" return 4851 ** UTF-16 encoded strings and the other functions return UTF-8. 4852 ** 4853 ** ^These APIs are only available if the library was compiled with the 4854 ** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol. 4855 ** 4856 ** If two or more threads call one or more 4857 ** [sqlite3_column_database_name | column metadata interfaces] 4858 ** for the same [prepared statement] and result column 4859 ** at the same time then the results are undefined. 4860 */ 4861 SQLITE_API const char *sqlite3_column_database_name(sqlite3_stmt*,int); 4862 SQLITE_API const void *sqlite3_column_database_name16(sqlite3_stmt*,int); 4863 SQLITE_API const char *sqlite3_column_table_name(sqlite3_stmt*,int); 4864 SQLITE_API const void *sqlite3_column_table_name16(sqlite3_stmt*,int); 4865 SQLITE_API const char *sqlite3_column_origin_name(sqlite3_stmt*,int); 4866 SQLITE_API const void *sqlite3_column_origin_name16(sqlite3_stmt*,int); 4867 4868 /* 4869 ** CAPI3REF: Declared Datatype Of A Query Result 4870 ** METHOD: sqlite3_stmt 4871 ** 4872 ** ^(The first parameter is a [prepared statement]. 4873 ** If this statement is a [SELECT] statement and the Nth column of the 4874 ** returned result set of that [SELECT] is a table column (not an 4875 ** expression or subquery) then the declared type of the table 4876 ** column is returned.)^ ^If the Nth column of the result set is an 4877 ** expression or subquery, then a NULL pointer is returned. 4878 ** ^The returned string is always UTF-8 encoded. 4879 ** 4880 ** ^(For example, given the database schema: 4881 ** 4882 ** CREATE TABLE t1(c1 VARIANT); 4883 ** 4884 ** and the following statement to be compiled: 4885 ** 4886 ** SELECT c1 + 1, c1 FROM t1; 4887 ** 4888 ** this routine would return the string "VARIANT" for the second result 4889 ** column (i==1), and a NULL pointer for the first result column (i==0).)^ 4890 ** 4891 ** ^SQLite uses dynamic run-time typing. ^So just because a column 4892 ** is declared to contain a particular type does not mean that the 4893 ** data stored in that column is of the declared type. SQLite is 4894 ** strongly typed, but the typing is dynamic not static. ^Type 4895 ** is associated with individual values, not with the containers 4896 ** used to hold those values. 4897 */ 4898 SQLITE_API const char *sqlite3_column_decltype(sqlite3_stmt*,int); 4899 SQLITE_API const void *sqlite3_column_decltype16(sqlite3_stmt*,int); 4900 4901 /* 4902 ** CAPI3REF: Evaluate An SQL Statement 4903 ** METHOD: sqlite3_stmt 4904 ** 4905 ** After a [prepared statement] has been prepared using any of 4906 ** [sqlite3_prepare_v2()], [sqlite3_prepare_v3()], [sqlite3_prepare16_v2()], 4907 ** or [sqlite3_prepare16_v3()] or one of the legacy 4908 ** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function 4909 ** must be called one or more times to evaluate the statement. 4910 ** 4911 ** The details of the behavior of the sqlite3_step() interface depend 4912 ** on whether the statement was prepared using the newer "vX" interfaces 4913 ** [sqlite3_prepare_v3()], [sqlite3_prepare_v2()], [sqlite3_prepare16_v3()], 4914 ** [sqlite3_prepare16_v2()] or the older legacy 4915 ** interfaces [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the 4916 ** new "vX" interface is recommended for new applications but the legacy 4917 ** interface will continue to be supported. 4918 ** 4919 ** ^In the legacy interface, the return value will be either [SQLITE_BUSY], 4920 ** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE]. 4921 ** ^With the "v2" interface, any of the other [result codes] or 4922 ** [extended result codes] might be returned as well. 4923 ** 4924 ** ^[SQLITE_BUSY] means that the database engine was unable to acquire the 4925 ** database locks it needs to do its job. ^If the statement is a [COMMIT] 4926 ** or occurs outside of an explicit transaction, then you can retry the 4927 ** statement. If the statement is not a [COMMIT] and occurs within an 4928 ** explicit transaction then you should rollback the transaction before 4929 ** continuing. 4930 ** 4931 ** ^[SQLITE_DONE] means that the statement has finished executing 4932 ** successfully. sqlite3_step() should not be called again on this virtual 4933 ** machine without first calling [sqlite3_reset()] to reset the virtual 4934 ** machine back to its initial state. 4935 ** 4936 ** ^If the SQL statement being executed returns any data, then [SQLITE_ROW] 4937 ** is returned each time a new row of data is ready for processing by the 4938 ** caller. The values may be accessed using the [column access functions]. 4939 ** sqlite3_step() is called again to retrieve the next row of data. 4940 ** 4941 ** ^[SQLITE_ERROR] means that a run-time error (such as a constraint 4942 ** violation) has occurred. sqlite3_step() should not be called again on 4943 ** the VM. More information may be found by calling [sqlite3_errmsg()]. 4944 ** ^With the legacy interface, a more specific error code (for example, 4945 ** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth) 4946 ** can be obtained by calling [sqlite3_reset()] on the 4947 ** [prepared statement]. ^In the "v2" interface, 4948 ** the more specific error code is returned directly by sqlite3_step(). 4949 ** 4950 ** [SQLITE_MISUSE] means that the this routine was called inappropriately. 4951 ** Perhaps it was called on a [prepared statement] that has 4952 ** already been [sqlite3_finalize | finalized] or on one that had 4953 ** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could 4954 ** be the case that the same database connection is being used by two or 4955 ** more threads at the same moment in time. 4956 ** 4957 ** For all versions of SQLite up to and including 3.6.23.1, a call to 4958 ** [sqlite3_reset()] was required after sqlite3_step() returned anything 4959 ** other than [SQLITE_ROW] before any subsequent invocation of 4960 ** sqlite3_step(). Failure to reset the prepared statement using 4961 ** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from 4962 ** sqlite3_step(). But after [version 3.6.23.1] ([dateof:3.6.23.1], 4963 ** sqlite3_step() began 4964 ** calling [sqlite3_reset()] automatically in this circumstance rather 4965 ** than returning [SQLITE_MISUSE]. This is not considered a compatibility 4966 ** break because any application that ever receives an SQLITE_MISUSE error 4967 ** is broken by definition. The [SQLITE_OMIT_AUTORESET] compile-time option 4968 ** can be used to restore the legacy behavior. 4969 ** 4970 ** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step() 4971 ** API always returns a generic error code, [SQLITE_ERROR], following any 4972 ** error other than [SQLITE_BUSY] and [SQLITE_MISUSE]. You must call 4973 ** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the 4974 ** specific [error codes] that better describes the error. 4975 ** We admit that this is a goofy design. The problem has been fixed 4976 ** with the "v2" interface. If you prepare all of your SQL statements 4977 ** using [sqlite3_prepare_v3()] or [sqlite3_prepare_v2()] 4978 ** or [sqlite3_prepare16_v2()] or [sqlite3_prepare16_v3()] instead 4979 ** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces, 4980 ** then the more specific [error codes] are returned directly 4981 ** by sqlite3_step(). The use of the "vX" interfaces is recommended. 4982 */ 4983 SQLITE_API int sqlite3_step(sqlite3_stmt*); 4984 4985 /* 4986 ** CAPI3REF: Number of columns in a result set 4987 ** METHOD: sqlite3_stmt 4988 ** 4989 ** ^The sqlite3_data_count(P) interface returns the number of columns in the 4990 ** current row of the result set of [prepared statement] P. 4991 ** ^If prepared statement P does not have results ready to return 4992 ** (via calls to the [sqlite3_column_int | sqlite3_column()] family of 4993 ** interfaces) then sqlite3_data_count(P) returns 0. 4994 ** ^The sqlite3_data_count(P) routine also returns 0 if P is a NULL pointer. 4995 ** ^The sqlite3_data_count(P) routine returns 0 if the previous call to 4996 ** [sqlite3_step](P) returned [SQLITE_DONE]. ^The sqlite3_data_count(P) 4997 ** will return non-zero if previous call to [sqlite3_step](P) returned 4998 ** [SQLITE_ROW], except in the case of the [PRAGMA incremental_vacuum] 4999 ** where it always returns zero since each step of that multi-step 5000 ** pragma returns 0 columns of data. 5001 ** 5002 ** See also: [sqlite3_column_count()] 5003 */ 5004 SQLITE_API int sqlite3_data_count(sqlite3_stmt *pStmt); 5005 5006 /* 5007 ** CAPI3REF: Fundamental Datatypes 5008 ** KEYWORDS: SQLITE_TEXT 5009 ** 5010 ** ^(Every value in SQLite has one of five fundamental datatypes: 5011 ** 5012 ** <ul> 5013 ** <li> 64-bit signed integer 5014 ** <li> 64-bit IEEE floating point number 5015 ** <li> string 5016 ** <li> BLOB 5017 ** <li> NULL 5018 ** </ul>)^ 5019 ** 5020 ** These constants are codes for each of those types. 5021 ** 5022 ** Note that the SQLITE_TEXT constant was also used in SQLite version 2 5023 ** for a completely different meaning. Software that links against both 5024 ** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not 5025 ** SQLITE_TEXT. 5026 */ 5027 #define SQLITE_INTEGER 1 5028 #define SQLITE_FLOAT 2 5029 #define SQLITE_BLOB 4 5030 #define SQLITE_NULL 5 5031 #ifdef SQLITE_TEXT 5032 # undef SQLITE_TEXT 5033 #else 5034 # define SQLITE_TEXT 3 5035 #endif 5036 #define SQLITE3_TEXT 3 5037 5038 /* 5039 ** CAPI3REF: Result Values From A Query 5040 ** KEYWORDS: {column access functions} 5041 ** METHOD: sqlite3_stmt 5042 ** 5043 ** <b>Summary:</b> 5044 ** <blockquote><table border=0 cellpadding=0 cellspacing=0> 5045 ** <tr><td><b>sqlite3_column_blob</b><td>→<td>BLOB result 5046 ** <tr><td><b>sqlite3_column_double</b><td>→<td>REAL result 5047 ** <tr><td><b>sqlite3_column_int</b><td>→<td>32-bit INTEGER result 5048 ** <tr><td><b>sqlite3_column_int64</b><td>→<td>64-bit INTEGER result 5049 ** <tr><td><b>sqlite3_column_text</b><td>→<td>UTF-8 TEXT result 5050 ** <tr><td><b>sqlite3_column_text16</b><td>→<td>UTF-16 TEXT result 5051 ** <tr><td><b>sqlite3_column_value</b><td>→<td>The result as an 5052 ** [sqlite3_value|unprotected sqlite3_value] object. 5053 ** <tr><td> <td> <td> 5054 ** <tr><td><b>sqlite3_column_bytes</b><td>→<td>Size of a BLOB 5055 ** or a UTF-8 TEXT result in bytes 5056 ** <tr><td><b>sqlite3_column_bytes16 </b> 5057 ** <td>→ <td>Size of UTF-16 5058 ** TEXT in bytes 5059 ** <tr><td><b>sqlite3_column_type</b><td>→<td>Default 5060 ** datatype of the result 5061 ** </table></blockquote> 5062 ** 5063 ** <b>Details:</b> 5064 ** 5065 ** ^These routines return information about a single column of the current 5066 ** result row of a query. ^In every case the first argument is a pointer 5067 ** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*] 5068 ** that was returned from [sqlite3_prepare_v2()] or one of its variants) 5069 ** and the second argument is the index of the column for which information 5070 ** should be returned. ^The leftmost column of the result set has the index 0. 5071 ** ^The number of columns in the result can be determined using 5072 ** [sqlite3_column_count()]. 5073 ** 5074 ** If the SQL statement does not currently point to a valid row, or if the 5075 ** column index is out of range, the result is undefined. 5076 ** These routines may only be called when the most recent call to 5077 ** [sqlite3_step()] has returned [SQLITE_ROW] and neither 5078 ** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently. 5079 ** If any of these routines are called after [sqlite3_reset()] or 5080 ** [sqlite3_finalize()] or after [sqlite3_step()] has returned 5081 ** something other than [SQLITE_ROW], the results are undefined. 5082 ** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()] 5083 ** are called from a different thread while any of these routines 5084 ** are pending, then the results are undefined. 5085 ** 5086 ** The first six interfaces (_blob, _double, _int, _int64, _text, and _text16) 5087 ** each return the value of a result column in a specific data format. If 5088 ** the result column is not initially in the requested format (for example, 5089 ** if the query returns an integer but the sqlite3_column_text() interface 5090 ** is used to extract the value) then an automatic type conversion is performed. 5091 ** 5092 ** ^The sqlite3_column_type() routine returns the 5093 ** [SQLITE_INTEGER | datatype code] for the initial data type 5094 ** of the result column. ^The returned value is one of [SQLITE_INTEGER], 5095 ** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL]. 5096 ** The return value of sqlite3_column_type() can be used to decide which 5097 ** of the first six interface should be used to extract the column value. 5098 ** The value returned by sqlite3_column_type() is only meaningful if no 5099 ** automatic type conversions have occurred for the value in question. 5100 ** After a type conversion, the result of calling sqlite3_column_type() 5101 ** is undefined, though harmless. Future 5102 ** versions of SQLite may change the behavior of sqlite3_column_type() 5103 ** following a type conversion. 5104 ** 5105 ** If the result is a BLOB or a TEXT string, then the sqlite3_column_bytes() 5106 ** or sqlite3_column_bytes16() interfaces can be used to determine the size 5107 ** of that BLOB or string. 5108 ** 5109 ** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes() 5110 ** routine returns the number of bytes in that BLOB or string. 5111 ** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts 5112 ** the string to UTF-8 and then returns the number of bytes. 5113 ** ^If the result is a numeric value then sqlite3_column_bytes() uses 5114 ** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns 5115 ** the number of bytes in that string. 5116 ** ^If the result is NULL, then sqlite3_column_bytes() returns zero. 5117 ** 5118 ** ^If the result is a BLOB or UTF-16 string then the sqlite3_column_bytes16() 5119 ** routine returns the number of bytes in that BLOB or string. 5120 ** ^If the result is a UTF-8 string, then sqlite3_column_bytes16() converts 5121 ** the string to UTF-16 and then returns the number of bytes. 5122 ** ^If the result is a numeric value then sqlite3_column_bytes16() uses 5123 ** [sqlite3_snprintf()] to convert that value to a UTF-16 string and returns 5124 ** the number of bytes in that string. 5125 ** ^If the result is NULL, then sqlite3_column_bytes16() returns zero. 5126 ** 5127 ** ^The values returned by [sqlite3_column_bytes()] and 5128 ** [sqlite3_column_bytes16()] do not include the zero terminators at the end 5129 ** of the string. ^For clarity: the values returned by 5130 ** [sqlite3_column_bytes()] and [sqlite3_column_bytes16()] are the number of 5131 ** bytes in the string, not the number of characters. 5132 ** 5133 ** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(), 5134 ** even empty strings, are always zero-terminated. ^The return 5135 ** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer. 5136 ** 5137 ** ^Strings returned by sqlite3_column_text16() always have the endianness 5138 ** which is native to the platform, regardless of the text encoding set 5139 ** for the database. 5140 ** 5141 ** <b>Warning:</b> ^The object returned by [sqlite3_column_value()] is an 5142 ** [unprotected sqlite3_value] object. In a multithreaded environment, 5143 ** an unprotected sqlite3_value object may only be used safely with 5144 ** [sqlite3_bind_value()] and [sqlite3_result_value()]. 5145 ** If the [unprotected sqlite3_value] object returned by 5146 ** [sqlite3_column_value()] is used in any other way, including calls 5147 ** to routines like [sqlite3_value_int()], [sqlite3_value_text()], 5148 ** or [sqlite3_value_bytes()], the behavior is not threadsafe. 5149 ** Hence, the sqlite3_column_value() interface 5150 ** is normally only useful within the implementation of 5151 ** [application-defined SQL functions] or [virtual tables], not within 5152 ** top-level application code. 5153 ** 5154 ** These routines may attempt to convert the datatype of the result. 5155 ** ^For example, if the internal representation is FLOAT and a text result 5156 ** is requested, [sqlite3_snprintf()] is used internally to perform the 5157 ** conversion automatically. ^(The following table details the conversions 5158 ** that are applied: 5159 ** 5160 ** <blockquote> 5161 ** <table border="1"> 5162 ** <tr><th> Internal<br>Type <th> Requested<br>Type <th> Conversion 5163 ** 5164 ** <tr><td> NULL <td> INTEGER <td> Result is 0 5165 ** <tr><td> NULL <td> FLOAT <td> Result is 0.0 5166 ** <tr><td> NULL <td> TEXT <td> Result is a NULL pointer 5167 ** <tr><td> NULL <td> BLOB <td> Result is a NULL pointer 5168 ** <tr><td> INTEGER <td> FLOAT <td> Convert from integer to float 5169 ** <tr><td> INTEGER <td> TEXT <td> ASCII rendering of the integer 5170 ** <tr><td> INTEGER <td> BLOB <td> Same as INTEGER->TEXT 5171 ** <tr><td> FLOAT <td> INTEGER <td> [CAST] to INTEGER 5172 ** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float 5173 ** <tr><td> FLOAT <td> BLOB <td> [CAST] to BLOB 5174 ** <tr><td> TEXT <td> INTEGER <td> [CAST] to INTEGER 5175 ** <tr><td> TEXT <td> FLOAT <td> [CAST] to REAL 5176 ** <tr><td> TEXT <td> BLOB <td> No change 5177 ** <tr><td> BLOB <td> INTEGER <td> [CAST] to INTEGER 5178 ** <tr><td> BLOB <td> FLOAT <td> [CAST] to REAL 5179 ** <tr><td> BLOB <td> TEXT <td> [CAST] to TEXT, ensure zero terminator 5180 ** </table> 5181 ** </blockquote>)^ 5182 ** 5183 ** Note that when type conversions occur, pointers returned by prior 5184 ** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or 5185 ** sqlite3_column_text16() may be invalidated. 5186 ** Type conversions and pointer invalidations might occur 5187 ** in the following cases: 5188 ** 5189 ** <ul> 5190 ** <li> The initial content is a BLOB and sqlite3_column_text() or 5191 ** sqlite3_column_text16() is called. A zero-terminator might 5192 ** need to be added to the string.</li> 5193 ** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or 5194 ** sqlite3_column_text16() is called. The content must be converted 5195 ** to UTF-16.</li> 5196 ** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or 5197 ** sqlite3_column_text() is called. The content must be converted 5198 ** to UTF-8.</li> 5199 ** </ul> 5200 ** 5201 ** ^Conversions between UTF-16be and UTF-16le are always done in place and do 5202 ** not invalidate a prior pointer, though of course the content of the buffer 5203 ** that the prior pointer references will have been modified. Other kinds 5204 ** of conversion are done in place when it is possible, but sometimes they 5205 ** are not possible and in those cases prior pointers are invalidated. 5206 ** 5207 ** The safest policy is to invoke these routines 5208 ** in one of the following ways: 5209 ** 5210 ** <ul> 5211 ** <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li> 5212 ** <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li> 5213 ** <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li> 5214 ** </ul> 5215 ** 5216 ** In other words, you should call sqlite3_column_text(), 5217 ** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result 5218 ** into the desired format, then invoke sqlite3_column_bytes() or 5219 ** sqlite3_column_bytes16() to find the size of the result. Do not mix calls 5220 ** to sqlite3_column_text() or sqlite3_column_blob() with calls to 5221 ** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16() 5222 ** with calls to sqlite3_column_bytes(). 5223 ** 5224 ** ^The pointers returned are valid until a type conversion occurs as 5225 ** described above, or until [sqlite3_step()] or [sqlite3_reset()] or 5226 ** [sqlite3_finalize()] is called. ^The memory space used to hold strings 5227 ** and BLOBs is freed automatically. Do not pass the pointers returned 5228 ** from [sqlite3_column_blob()], [sqlite3_column_text()], etc. into 5229 ** [sqlite3_free()]. 5230 ** 5231 ** As long as the input parameters are correct, these routines will only 5232 ** fail if an out-of-memory error occurs during a format conversion. 5233 ** Only the following subset of interfaces are subject to out-of-memory 5234 ** errors: 5235 ** 5236 ** <ul> 5237 ** <li> sqlite3_column_blob() 5238 ** <li> sqlite3_column_text() 5239 ** <li> sqlite3_column_text16() 5240 ** <li> sqlite3_column_bytes() 5241 ** <li> sqlite3_column_bytes16() 5242 ** </ul> 5243 ** 5244 ** If an out-of-memory error occurs, then the return value from these 5245 ** routines is the same as if the column had contained an SQL NULL value. 5246 ** Valid SQL NULL returns can be distinguished from out-of-memory errors 5247 ** by invoking the [sqlite3_errcode()] immediately after the suspect 5248 ** return value is obtained and before any 5249 ** other SQLite interface is called on the same [database connection]. 5250 */ 5251 SQLITE_API const void *sqlite3_column_blob(sqlite3_stmt*, int iCol); 5252 SQLITE_API double sqlite3_column_double(sqlite3_stmt*, int iCol); 5253 SQLITE_API int sqlite3_column_int(sqlite3_stmt*, int iCol); 5254 SQLITE_API sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol); 5255 SQLITE_API const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol); 5256 SQLITE_API const void *sqlite3_column_text16(sqlite3_stmt*, int iCol); 5257 SQLITE_API sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol); 5258 SQLITE_API int sqlite3_column_bytes(sqlite3_stmt*, int iCol); 5259 SQLITE_API int sqlite3_column_bytes16(sqlite3_stmt*, int iCol); 5260 SQLITE_API int sqlite3_column_type(sqlite3_stmt*, int iCol); 5261 5262 /* 5263 ** CAPI3REF: Destroy A Prepared Statement Object 5264 ** DESTRUCTOR: sqlite3_stmt 5265 ** 5266 ** ^The sqlite3_finalize() function is called to delete a [prepared statement]. 5267 ** ^If the most recent evaluation of the statement encountered no errors 5268 ** or if the statement is never been evaluated, then sqlite3_finalize() returns 5269 ** SQLITE_OK. ^If the most recent evaluation of statement S failed, then 5270 ** sqlite3_finalize(S) returns the appropriate [error code] or 5271 ** [extended error code]. 5272 ** 5273 ** ^The sqlite3_finalize(S) routine can be called at any point during 5274 ** the life cycle of [prepared statement] S: 5275 ** before statement S is ever evaluated, after 5276 ** one or more calls to [sqlite3_reset()], or after any call 5277 ** to [sqlite3_step()] regardless of whether or not the statement has 5278 ** completed execution. 5279 ** 5280 ** ^Invoking sqlite3_finalize() on a NULL pointer is a harmless no-op. 5281 ** 5282 ** The application must finalize every [prepared statement] in order to avoid 5283 ** resource leaks. It is a grievous error for the application to try to use 5284 ** a prepared statement after it has been finalized. Any use of a prepared 5285 ** statement after it has been finalized can result in undefined and 5286 ** undesirable behavior such as segfaults and heap corruption. 5287 */ 5288 SQLITE_API int sqlite3_finalize(sqlite3_stmt *pStmt); 5289 5290 /* 5291 ** CAPI3REF: Reset A Prepared Statement Object 5292 ** METHOD: sqlite3_stmt 5293 ** 5294 ** The sqlite3_reset() function is called to reset a [prepared statement] 5295 ** object back to its initial state, ready to be re-executed. 5296 ** ^Any SQL statement variables that had values bound to them using 5297 ** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values. 5298 ** Use [sqlite3_clear_bindings()] to reset the bindings. 5299 ** 5300 ** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S 5301 ** back to the beginning of its program. 5302 ** 5303 ** ^The return code from [sqlite3_reset(S)] indicates whether or not 5304 ** the previous evaluation of prepared statement S completed successfully. 5305 ** ^If [sqlite3_step(S)] has never before been called on S or if 5306 ** [sqlite3_step(S)] has not been called since the previous call 5307 ** to [sqlite3_reset(S)], then [sqlite3_reset(S)] will return 5308 ** [SQLITE_OK]. 5309 ** 5310 ** ^If the most recent call to [sqlite3_step(S)] for the 5311 ** [prepared statement] S indicated an error, then 5312 ** [sqlite3_reset(S)] returns an appropriate [error code]. 5313 ** ^The [sqlite3_reset(S)] interface might also return an [error code] 5314 ** if there were no prior errors but the process of resetting 5315 ** the prepared statement caused a new error. ^For example, if an 5316 ** [INSERT] statement with a [RETURNING] clause is only stepped one time, 5317 ** that one call to [sqlite3_step(S)] might return SQLITE_ROW but 5318 ** the overall statement might still fail and the [sqlite3_reset(S)] call 5319 ** might return SQLITE_BUSY if locking constraints prevent the 5320 ** database change from committing. Therefore, it is important that 5321 ** applications check the return code from [sqlite3_reset(S)] even if 5322 ** no prior call to [sqlite3_step(S)] indicated a problem. 5323 ** 5324 ** ^The [sqlite3_reset(S)] interface does not change the values 5325 ** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S. 5326 */ 5327 SQLITE_API int sqlite3_reset(sqlite3_stmt *pStmt); 5328 5329 5330 /* 5331 ** CAPI3REF: Create Or Redefine SQL Functions 5332 ** KEYWORDS: {function creation routines} 5333 ** METHOD: sqlite3 5334 ** 5335 ** ^These functions (collectively known as "function creation routines") 5336 ** are used to add SQL functions or aggregates or to redefine the behavior 5337 ** of existing SQL functions or aggregates. The only differences between 5338 ** the three "sqlite3_create_function*" routines are the text encoding 5339 ** expected for the second parameter (the name of the function being 5340 ** created) and the presence or absence of a destructor callback for 5341 ** the application data pointer. Function sqlite3_create_window_function() 5342 ** is similar, but allows the user to supply the extra callback functions 5343 ** needed by [aggregate window functions]. 5344 ** 5345 ** ^The first parameter is the [database connection] to which the SQL 5346 ** function is to be added. ^If an application uses more than one database 5347 ** connection then application-defined SQL functions must be added 5348 ** to each database connection separately. 5349 ** 5350 ** ^The second parameter is the name of the SQL function to be created or 5351 ** redefined. ^The length of the name is limited to 255 bytes in a UTF-8 5352 ** representation, exclusive of the zero-terminator. ^Note that the name 5353 ** length limit is in UTF-8 bytes, not characters nor UTF-16 bytes. 5354 ** ^Any attempt to create a function with a longer name 5355 ** will result in [SQLITE_MISUSE] being returned. 5356 ** 5357 ** ^The third parameter (nArg) 5358 ** is the number of arguments that the SQL function or 5359 ** aggregate takes. ^If this parameter is -1, then the SQL function or 5360 ** aggregate may take any number of arguments between 0 and the limit 5361 ** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]). If the third 5362 ** parameter is less than -1 or greater than 127 then the behavior is 5363 ** undefined. 5364 ** 5365 ** ^The fourth parameter, eTextRep, specifies what 5366 ** [SQLITE_UTF8 | text encoding] this SQL function prefers for 5367 ** its parameters. The application should set this parameter to 5368 ** [SQLITE_UTF16LE] if the function implementation invokes 5369 ** [sqlite3_value_text16le()] on an input, or [SQLITE_UTF16BE] if the 5370 ** implementation invokes [sqlite3_value_text16be()] on an input, or 5371 ** [SQLITE_UTF16] if [sqlite3_value_text16()] is used, or [SQLITE_UTF8] 5372 ** otherwise. ^The same SQL function may be registered multiple times using 5373 ** different preferred text encodings, with different implementations for 5374 ** each encoding. 5375 ** ^When multiple implementations of the same function are available, SQLite 5376 ** will pick the one that involves the least amount of data conversion. 5377 ** 5378 ** ^The fourth parameter may optionally be ORed with [SQLITE_DETERMINISTIC] 5379 ** to signal that the function will always return the same result given 5380 ** the same inputs within a single SQL statement. Most SQL functions are 5381 ** deterministic. The built-in [random()] SQL function is an example of a 5382 ** function that is not deterministic. The SQLite query planner is able to 5383 ** perform additional optimizations on deterministic functions, so use 5384 ** of the [SQLITE_DETERMINISTIC] flag is recommended where possible. 5385 ** 5386 ** ^The fourth parameter may also optionally include the [SQLITE_DIRECTONLY] 5387 ** flag, which if present prevents the function from being invoked from 5388 ** within VIEWs, TRIGGERs, CHECK constraints, generated column expressions, 5389 ** index expressions, or the WHERE clause of partial indexes. 5390 ** 5391 ** For best security, the [SQLITE_DIRECTONLY] flag is recommended for 5392 ** all application-defined SQL functions that do not need to be 5393 ** used inside of triggers, view, CHECK constraints, or other elements of 5394 ** the database schema. This flags is especially recommended for SQL 5395 ** functions that have side effects or reveal internal application state. 5396 ** Without this flag, an attacker might be able to modify the schema of 5397 ** a database file to include invocations of the function with parameters 5398 ** chosen by the attacker, which the application will then execute when 5399 ** the database file is opened and read. 5400 ** 5401 ** ^(The fifth parameter is an arbitrary pointer. The implementation of the 5402 ** function can gain access to this pointer using [sqlite3_user_data()].)^ 5403 ** 5404 ** ^The sixth, seventh and eighth parameters passed to the three 5405 ** "sqlite3_create_function*" functions, xFunc, xStep and xFinal, are 5406 ** pointers to C-language functions that implement the SQL function or 5407 ** aggregate. ^A scalar SQL function requires an implementation of the xFunc 5408 ** callback only; NULL pointers must be passed as the xStep and xFinal 5409 ** parameters. ^An aggregate SQL function requires an implementation of xStep 5410 ** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing 5411 ** SQL function or aggregate, pass NULL pointers for all three function 5412 ** callbacks. 5413 ** 5414 ** ^The sixth, seventh, eighth and ninth parameters (xStep, xFinal, xValue 5415 ** and xInverse) passed to sqlite3_create_window_function are pointers to 5416 ** C-language callbacks that implement the new function. xStep and xFinal 5417 ** must both be non-NULL. xValue and xInverse may either both be NULL, in 5418 ** which case a regular aggregate function is created, or must both be 5419 ** non-NULL, in which case the new function may be used as either an aggregate 5420 ** or aggregate window function. More details regarding the implementation 5421 ** of aggregate window functions are 5422 ** [user-defined window functions|available here]. 5423 ** 5424 ** ^(If the final parameter to sqlite3_create_function_v2() or 5425 ** sqlite3_create_window_function() is not NULL, then it is destructor for 5426 ** the application data pointer. The destructor is invoked when the function 5427 ** is deleted, either by being overloaded or when the database connection 5428 ** closes.)^ ^The destructor is also invoked if the call to 5429 ** sqlite3_create_function_v2() fails. ^When the destructor callback is 5430 ** invoked, it is passed a single argument which is a copy of the application 5431 ** data pointer which was the fifth parameter to sqlite3_create_function_v2(). 5432 ** 5433 ** ^It is permitted to register multiple implementations of the same 5434 ** functions with the same name but with either differing numbers of 5435 ** arguments or differing preferred text encodings. ^SQLite will use 5436 ** the implementation that most closely matches the way in which the 5437 ** SQL function is used. ^A function implementation with a non-negative 5438 ** nArg parameter is a better match than a function implementation with 5439 ** a negative nArg. ^A function where the preferred text encoding 5440 ** matches the database encoding is a better 5441 ** match than a function where the encoding is different. 5442 ** ^A function where the encoding difference is between UTF16le and UTF16be 5443 ** is a closer match than a function where the encoding difference is 5444 ** between UTF8 and UTF16. 5445 ** 5446 ** ^Built-in functions may be overloaded by new application-defined functions. 5447 ** 5448 ** ^An application-defined function is permitted to call other 5449 ** SQLite interfaces. However, such calls must not 5450 ** close the database connection nor finalize or reset the prepared 5451 ** statement in which the function is running. 5452 */ 5453 SQLITE_API int sqlite3_create_function( 5454 sqlite3 *db, 5455 const char *zFunctionName, 5456 int nArg, 5457 int eTextRep, 5458 void *pApp, 5459 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 5460 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 5461 void (*xFinal)(sqlite3_context*) 5462 ); 5463 SQLITE_API int sqlite3_create_function16( 5464 sqlite3 *db, 5465 const void *zFunctionName, 5466 int nArg, 5467 int eTextRep, 5468 void *pApp, 5469 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 5470 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 5471 void (*xFinal)(sqlite3_context*) 5472 ); 5473 SQLITE_API int sqlite3_create_function_v2( 5474 sqlite3 *db, 5475 const char *zFunctionName, 5476 int nArg, 5477 int eTextRep, 5478 void *pApp, 5479 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 5480 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 5481 void (*xFinal)(sqlite3_context*), 5482 void(*xDestroy)(void*) 5483 ); 5484 SQLITE_API int sqlite3_create_window_function( 5485 sqlite3 *db, 5486 const char *zFunctionName, 5487 int nArg, 5488 int eTextRep, 5489 void *pApp, 5490 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 5491 void (*xFinal)(sqlite3_context*), 5492 void (*xValue)(sqlite3_context*), 5493 void (*xInverse)(sqlite3_context*,int,sqlite3_value**), 5494 void(*xDestroy)(void*) 5495 ); 5496 5497 /* 5498 ** CAPI3REF: Text Encodings 5499 ** 5500 ** These constant define integer codes that represent the various 5501 ** text encodings supported by SQLite. 5502 */ 5503 #define SQLITE_UTF8 1 /* IMP: R-37514-35566 */ 5504 #define SQLITE_UTF16LE 2 /* IMP: R-03371-37637 */ 5505 #define SQLITE_UTF16BE 3 /* IMP: R-51971-34154 */ 5506 #define SQLITE_UTF16 4 /* Use native byte order */ 5507 #define SQLITE_ANY 5 /* Deprecated */ 5508 #define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */ 5509 5510 /* 5511 ** CAPI3REF: Function Flags 5512 ** 5513 ** These constants may be ORed together with the 5514 ** [SQLITE_UTF8 | preferred text encoding] as the fourth argument 5515 ** to [sqlite3_create_function()], [sqlite3_create_function16()], or 5516 ** [sqlite3_create_function_v2()]. 5517 ** 5518 ** <dl> 5519 ** [[SQLITE_DETERMINISTIC]] <dt>SQLITE_DETERMINISTIC</dt><dd> 5520 ** The SQLITE_DETERMINISTIC flag means that the new function always gives 5521 ** the same output when the input parameters are the same. 5522 ** The [abs|abs() function] is deterministic, for example, but 5523 ** [randomblob|randomblob()] is not. Functions must 5524 ** be deterministic in order to be used in certain contexts such as 5525 ** with the WHERE clause of [partial indexes] or in [generated columns]. 5526 ** SQLite might also optimize deterministic functions by factoring them 5527 ** out of inner loops. 5528 ** </dd> 5529 ** 5530 ** [[SQLITE_DIRECTONLY]] <dt>SQLITE_DIRECTONLY</dt><dd> 5531 ** The SQLITE_DIRECTONLY flag means that the function may only be invoked 5532 ** from top-level SQL, and cannot be used in VIEWs or TRIGGERs nor in 5533 ** schema structures such as [CHECK constraints], [DEFAULT clauses], 5534 ** [expression indexes], [partial indexes], or [generated columns]. 5535 ** <p> 5536 ** The SQLITE_DIRECTONLY flag is recommended for any 5537 ** [application-defined SQL function] 5538 ** that has side-effects or that could potentially leak sensitive information. 5539 ** This will prevent attacks in which an application is tricked 5540 ** into using a database file that has had its schema surreptitiously 5541 ** modified to invoke the application-defined function in ways that are 5542 ** harmful. 5543 ** <p> 5544 ** Some people say it is good practice to set SQLITE_DIRECTONLY on all 5545 ** [application-defined SQL functions], regardless of whether or not they 5546 ** are security sensitive, as doing so prevents those functions from being used 5547 ** inside of the database schema, and thus ensures that the database 5548 ** can be inspected and modified using generic tools (such as the [CLI]) 5549 ** that do not have access to the application-defined functions. 5550 ** </dd> 5551 ** 5552 ** [[SQLITE_INNOCUOUS]] <dt>SQLITE_INNOCUOUS</dt><dd> 5553 ** The SQLITE_INNOCUOUS flag means that the function is unlikely 5554 ** to cause problems even if misused. An innocuous function should have 5555 ** no side effects and should not depend on any values other than its 5556 ** input parameters. The [abs|abs() function] is an example of an 5557 ** innocuous function. 5558 ** The [load_extension() SQL function] is not innocuous because of its 5559 ** side effects. 5560 ** <p> SQLITE_INNOCUOUS is similar to SQLITE_DETERMINISTIC, but is not 5561 ** exactly the same. The [random|random() function] is an example of a 5562 ** function that is innocuous but not deterministic. 5563 ** <p>Some heightened security settings 5564 ** ([SQLITE_DBCONFIG_TRUSTED_SCHEMA] and [PRAGMA trusted_schema=OFF]) 5565 ** disable the use of SQL functions inside views and triggers and in 5566 ** schema structures such as [CHECK constraints], [DEFAULT clauses], 5567 ** [expression indexes], [partial indexes], and [generated columns] unless 5568 ** the function is tagged with SQLITE_INNOCUOUS. Most built-in functions 5569 ** are innocuous. Developers are advised to avoid using the 5570 ** SQLITE_INNOCUOUS flag for application-defined functions unless the 5571 ** function has been carefully audited and found to be free of potentially 5572 ** security-adverse side-effects and information-leaks. 5573 ** </dd> 5574 ** 5575 ** [[SQLITE_SUBTYPE]] <dt>SQLITE_SUBTYPE</dt><dd> 5576 ** The SQLITE_SUBTYPE flag indicates to SQLite that a function may call 5577 ** [sqlite3_value_subtype()] to inspect the sub-types of its arguments. 5578 ** Specifying this flag makes no difference for scalar or aggregate user 5579 ** functions. However, if it is not specified for a user-defined window 5580 ** function, then any sub-types belonging to arguments passed to the window 5581 ** function may be discarded before the window function is called (i.e. 5582 ** sqlite3_value_subtype() will always return 0). 5583 ** </dd> 5584 ** </dl> 5585 */ 5586 #define SQLITE_DETERMINISTIC 0x000000800 5587 #define SQLITE_DIRECTONLY 0x000080000 5588 #define SQLITE_SUBTYPE 0x000100000 5589 #define SQLITE_INNOCUOUS 0x000200000 5590 5591 /* 5592 ** CAPI3REF: Deprecated Functions 5593 ** DEPRECATED 5594 ** 5595 ** These functions are [deprecated]. In order to maintain 5596 ** backwards compatibility with older code, these functions continue 5597 ** to be supported. However, new applications should avoid 5598 ** the use of these functions. To encourage programmers to avoid 5599 ** these functions, we will not explain what they do. 5600 */ 5601 #ifndef SQLITE_OMIT_DEPRECATED 5602 SQLITE_API SQLITE_DEPRECATED int sqlite3_aggregate_count(sqlite3_context*); 5603 SQLITE_API SQLITE_DEPRECATED int sqlite3_expired(sqlite3_stmt*); 5604 SQLITE_API SQLITE_DEPRECATED int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*); 5605 SQLITE_API SQLITE_DEPRECATED int sqlite3_global_recover(void); 5606 SQLITE_API SQLITE_DEPRECATED void sqlite3_thread_cleanup(void); 5607 SQLITE_API SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int), 5608 void*,sqlite3_int64); 5609 #endif 5610 5611 /* 5612 ** CAPI3REF: Obtaining SQL Values 5613 ** METHOD: sqlite3_value 5614 ** 5615 ** <b>Summary:</b> 5616 ** <blockquote><table border=0 cellpadding=0 cellspacing=0> 5617 ** <tr><td><b>sqlite3_value_blob</b><td>→<td>BLOB value 5618 ** <tr><td><b>sqlite3_value_double</b><td>→<td>REAL value 5619 ** <tr><td><b>sqlite3_value_int</b><td>→<td>32-bit INTEGER value 5620 ** <tr><td><b>sqlite3_value_int64</b><td>→<td>64-bit INTEGER value 5621 ** <tr><td><b>sqlite3_value_pointer</b><td>→<td>Pointer value 5622 ** <tr><td><b>sqlite3_value_text</b><td>→<td>UTF-8 TEXT value 5623 ** <tr><td><b>sqlite3_value_text16</b><td>→<td>UTF-16 TEXT value in 5624 ** the native byteorder 5625 ** <tr><td><b>sqlite3_value_text16be</b><td>→<td>UTF-16be TEXT value 5626 ** <tr><td><b>sqlite3_value_text16le</b><td>→<td>UTF-16le TEXT value 5627 ** <tr><td> <td> <td> 5628 ** <tr><td><b>sqlite3_value_bytes</b><td>→<td>Size of a BLOB 5629 ** or a UTF-8 TEXT in bytes 5630 ** <tr><td><b>sqlite3_value_bytes16 </b> 5631 ** <td>→ <td>Size of UTF-16 5632 ** TEXT in bytes 5633 ** <tr><td><b>sqlite3_value_type</b><td>→<td>Default 5634 ** datatype of the value 5635 ** <tr><td><b>sqlite3_value_numeric_type </b> 5636 ** <td>→ <td>Best numeric datatype of the value 5637 ** <tr><td><b>sqlite3_value_nochange </b> 5638 ** <td>→ <td>True if the column is unchanged in an UPDATE 5639 ** against a virtual table. 5640 ** <tr><td><b>sqlite3_value_frombind </b> 5641 ** <td>→ <td>True if value originated from a [bound parameter] 5642 ** </table></blockquote> 5643 ** 5644 ** <b>Details:</b> 5645 ** 5646 ** These routines extract type, size, and content information from 5647 ** [protected sqlite3_value] objects. Protected sqlite3_value objects 5648 ** are used to pass parameter information into the functions that 5649 ** implement [application-defined SQL functions] and [virtual tables]. 5650 ** 5651 ** These routines work only with [protected sqlite3_value] objects. 5652 ** Any attempt to use these routines on an [unprotected sqlite3_value] 5653 ** is not threadsafe. 5654 ** 5655 ** ^These routines work just like the corresponding [column access functions] 5656 ** except that these routines take a single [protected sqlite3_value] object 5657 ** pointer instead of a [sqlite3_stmt*] pointer and an integer column number. 5658 ** 5659 ** ^The sqlite3_value_text16() interface extracts a UTF-16 string 5660 ** in the native byte-order of the host machine. ^The 5661 ** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces 5662 ** extract UTF-16 strings as big-endian and little-endian respectively. 5663 ** 5664 ** ^If [sqlite3_value] object V was initialized 5665 ** using [sqlite3_bind_pointer(S,I,P,X,D)] or [sqlite3_result_pointer(C,P,X,D)] 5666 ** and if X and Y are strings that compare equal according to strcmp(X,Y), 5667 ** then sqlite3_value_pointer(V,Y) will return the pointer P. ^Otherwise, 5668 ** sqlite3_value_pointer(V,Y) returns a NULL. The sqlite3_bind_pointer() 5669 ** routine is part of the [pointer passing interface] added for SQLite 3.20.0. 5670 ** 5671 ** ^(The sqlite3_value_type(V) interface returns the 5672 ** [SQLITE_INTEGER | datatype code] for the initial datatype of the 5673 ** [sqlite3_value] object V. The returned value is one of [SQLITE_INTEGER], 5674 ** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL].)^ 5675 ** Other interfaces might change the datatype for an sqlite3_value object. 5676 ** For example, if the datatype is initially SQLITE_INTEGER and 5677 ** sqlite3_value_text(V) is called to extract a text value for that 5678 ** integer, then subsequent calls to sqlite3_value_type(V) might return 5679 ** SQLITE_TEXT. Whether or not a persistent internal datatype conversion 5680 ** occurs is undefined and may change from one release of SQLite to the next. 5681 ** 5682 ** ^(The sqlite3_value_numeric_type() interface attempts to apply 5683 ** numeric affinity to the value. This means that an attempt is 5684 ** made to convert the value to an integer or floating point. If 5685 ** such a conversion is possible without loss of information (in other 5686 ** words, if the value is a string that looks like a number) 5687 ** then the conversion is performed. Otherwise no conversion occurs. 5688 ** The [SQLITE_INTEGER | datatype] after conversion is returned.)^ 5689 ** 5690 ** ^Within the [xUpdate] method of a [virtual table], the 5691 ** sqlite3_value_nochange(X) interface returns true if and only if 5692 ** the column corresponding to X is unchanged by the UPDATE operation 5693 ** that the xUpdate method call was invoked to implement and if 5694 ** and the prior [xColumn] method call that was invoked to extracted 5695 ** the value for that column returned without setting a result (probably 5696 ** because it queried [sqlite3_vtab_nochange()] and found that the column 5697 ** was unchanging). ^Within an [xUpdate] method, any value for which 5698 ** sqlite3_value_nochange(X) is true will in all other respects appear 5699 ** to be a NULL value. If sqlite3_value_nochange(X) is invoked anywhere other 5700 ** than within an [xUpdate] method call for an UPDATE statement, then 5701 ** the return value is arbitrary and meaningless. 5702 ** 5703 ** ^The sqlite3_value_frombind(X) interface returns non-zero if the 5704 ** value X originated from one of the [sqlite3_bind_int|sqlite3_bind()] 5705 ** interfaces. ^If X comes from an SQL literal value, or a table column, 5706 ** or an expression, then sqlite3_value_frombind(X) returns zero. 5707 ** 5708 ** Please pay particular attention to the fact that the pointer returned 5709 ** from [sqlite3_value_blob()], [sqlite3_value_text()], or 5710 ** [sqlite3_value_text16()] can be invalidated by a subsequent call to 5711 ** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()], 5712 ** or [sqlite3_value_text16()]. 5713 ** 5714 ** These routines must be called from the same thread as 5715 ** the SQL function that supplied the [sqlite3_value*] parameters. 5716 ** 5717 ** As long as the input parameter is correct, these routines can only 5718 ** fail if an out-of-memory error occurs during a format conversion. 5719 ** Only the following subset of interfaces are subject to out-of-memory 5720 ** errors: 5721 ** 5722 ** <ul> 5723 ** <li> sqlite3_value_blob() 5724 ** <li> sqlite3_value_text() 5725 ** <li> sqlite3_value_text16() 5726 ** <li> sqlite3_value_text16le() 5727 ** <li> sqlite3_value_text16be() 5728 ** <li> sqlite3_value_bytes() 5729 ** <li> sqlite3_value_bytes16() 5730 ** </ul> 5731 ** 5732 ** If an out-of-memory error occurs, then the return value from these 5733 ** routines is the same as if the column had contained an SQL NULL value. 5734 ** Valid SQL NULL returns can be distinguished from out-of-memory errors 5735 ** by invoking the [sqlite3_errcode()] immediately after the suspect 5736 ** return value is obtained and before any 5737 ** other SQLite interface is called on the same [database connection]. 5738 */ 5739 SQLITE_API const void *sqlite3_value_blob(sqlite3_value*); 5740 SQLITE_API double sqlite3_value_double(sqlite3_value*); 5741 SQLITE_API int sqlite3_value_int(sqlite3_value*); 5742 SQLITE_API sqlite3_int64 sqlite3_value_int64(sqlite3_value*); 5743 SQLITE_API void *sqlite3_value_pointer(sqlite3_value*, const char*); 5744 SQLITE_API const unsigned char *sqlite3_value_text(sqlite3_value*); 5745 SQLITE_API const void *sqlite3_value_text16(sqlite3_value*); 5746 SQLITE_API const void *sqlite3_value_text16le(sqlite3_value*); 5747 SQLITE_API const void *sqlite3_value_text16be(sqlite3_value*); 5748 SQLITE_API int sqlite3_value_bytes(sqlite3_value*); 5749 SQLITE_API int sqlite3_value_bytes16(sqlite3_value*); 5750 SQLITE_API int sqlite3_value_type(sqlite3_value*); 5751 SQLITE_API int sqlite3_value_numeric_type(sqlite3_value*); 5752 SQLITE_API int sqlite3_value_nochange(sqlite3_value*); 5753 SQLITE_API int sqlite3_value_frombind(sqlite3_value*); 5754 5755 /* 5756 ** CAPI3REF: Report the internal text encoding state of an sqlite3_value object 5757 ** METHOD: sqlite3_value 5758 ** 5759 ** ^(The sqlite3_value_encoding(X) interface returns one of [SQLITE_UTF8], 5760 ** [SQLITE_UTF16BE], or [SQLITE_UTF16LE] according to the current text encoding 5761 ** of the value X, assuming that X has type TEXT.)^ If sqlite3_value_type(X) 5762 ** returns something other than SQLITE_TEXT, then the return value from 5763 ** sqlite3_value_encoding(X) is meaningless. ^Calls to 5764 ** [sqlite3_value_text(X)], [sqlite3_value_text16(X)], [sqlite3_value_text16be(X)], 5765 ** [sqlite3_value_text16le(X)], [sqlite3_value_bytes(X)], or 5766 ** [sqlite3_value_bytes16(X)] might change the encoding of the value X and 5767 ** thus change the return from subsequent calls to sqlite3_value_encoding(X). 5768 ** 5769 ** This routine is intended for used by applications that test and validate 5770 ** the SQLite implementation. This routine is inquiring about the opaque 5771 ** internal state of an [sqlite3_value] object. Ordinary applications should 5772 ** not need to know what the internal state of an sqlite3_value object is and 5773 ** hence should not need to use this interface. 5774 */ 5775 SQLITE_API int sqlite3_value_encoding(sqlite3_value*); 5776 5777 /* 5778 ** CAPI3REF: Finding The Subtype Of SQL Values 5779 ** METHOD: sqlite3_value 5780 ** 5781 ** The sqlite3_value_subtype(V) function returns the subtype for 5782 ** an [application-defined SQL function] argument V. The subtype 5783 ** information can be used to pass a limited amount of context from 5784 ** one SQL function to another. Use the [sqlite3_result_subtype()] 5785 ** routine to set the subtype for the return value of an SQL function. 5786 */ 5787 SQLITE_API unsigned int sqlite3_value_subtype(sqlite3_value*); 5788 5789 /* 5790 ** CAPI3REF: Copy And Free SQL Values 5791 ** METHOD: sqlite3_value 5792 ** 5793 ** ^The sqlite3_value_dup(V) interface makes a copy of the [sqlite3_value] 5794 ** object D and returns a pointer to that copy. ^The [sqlite3_value] returned 5795 ** is a [protected sqlite3_value] object even if the input is not. 5796 ** ^The sqlite3_value_dup(V) interface returns NULL if V is NULL or if a 5797 ** memory allocation fails. ^If V is a [pointer value], then the result 5798 ** of sqlite3_value_dup(V) is a NULL value. 5799 ** 5800 ** ^The sqlite3_value_free(V) interface frees an [sqlite3_value] object 5801 ** previously obtained from [sqlite3_value_dup()]. ^If V is a NULL pointer 5802 ** then sqlite3_value_free(V) is a harmless no-op. 5803 */ 5804 SQLITE_API sqlite3_value *sqlite3_value_dup(const sqlite3_value*); 5805 SQLITE_API void sqlite3_value_free(sqlite3_value*); 5806 5807 /* 5808 ** CAPI3REF: Obtain Aggregate Function Context 5809 ** METHOD: sqlite3_context 5810 ** 5811 ** Implementations of aggregate SQL functions use this 5812 ** routine to allocate memory for storing their state. 5813 ** 5814 ** ^The first time the sqlite3_aggregate_context(C,N) routine is called 5815 ** for a particular aggregate function, SQLite allocates 5816 ** N bytes of memory, zeroes out that memory, and returns a pointer 5817 ** to the new memory. ^On second and subsequent calls to 5818 ** sqlite3_aggregate_context() for the same aggregate function instance, 5819 ** the same buffer is returned. Sqlite3_aggregate_context() is normally 5820 ** called once for each invocation of the xStep callback and then one 5821 ** last time when the xFinal callback is invoked. ^(When no rows match 5822 ** an aggregate query, the xStep() callback of the aggregate function 5823 ** implementation is never called and xFinal() is called exactly once. 5824 ** In those cases, sqlite3_aggregate_context() might be called for the 5825 ** first time from within xFinal().)^ 5826 ** 5827 ** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer 5828 ** when first called if N is less than or equal to zero or if a memory 5829 ** allocation error occurs. 5830 ** 5831 ** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is 5832 ** determined by the N parameter on first successful call. Changing the 5833 ** value of N in any subsequent call to sqlite3_aggregate_context() within 5834 ** the same aggregate function instance will not resize the memory 5835 ** allocation.)^ Within the xFinal callback, it is customary to set 5836 ** N=0 in calls to sqlite3_aggregate_context(C,N) so that no 5837 ** pointless memory allocations occur. 5838 ** 5839 ** ^SQLite automatically frees the memory allocated by 5840 ** sqlite3_aggregate_context() when the aggregate query concludes. 5841 ** 5842 ** The first parameter must be a copy of the 5843 ** [sqlite3_context | SQL function context] that is the first parameter 5844 ** to the xStep or xFinal callback routine that implements the aggregate 5845 ** function. 5846 ** 5847 ** This routine must be called from the same thread in which 5848 ** the aggregate SQL function is running. 5849 */ 5850 SQLITE_API void *sqlite3_aggregate_context(sqlite3_context*, int nBytes); 5851 5852 /* 5853 ** CAPI3REF: User Data For Functions 5854 ** METHOD: sqlite3_context 5855 ** 5856 ** ^The sqlite3_user_data() interface returns a copy of 5857 ** the pointer that was the pUserData parameter (the 5th parameter) 5858 ** of the [sqlite3_create_function()] 5859 ** and [sqlite3_create_function16()] routines that originally 5860 ** registered the application defined function. 5861 ** 5862 ** This routine must be called from the same thread in which 5863 ** the application-defined function is running. 5864 */ 5865 SQLITE_API void *sqlite3_user_data(sqlite3_context*); 5866 5867 /* 5868 ** CAPI3REF: Database Connection For Functions 5869 ** METHOD: sqlite3_context 5870 ** 5871 ** ^The sqlite3_context_db_handle() interface returns a copy of 5872 ** the pointer to the [database connection] (the 1st parameter) 5873 ** of the [sqlite3_create_function()] 5874 ** and [sqlite3_create_function16()] routines that originally 5875 ** registered the application defined function. 5876 */ 5877 SQLITE_API sqlite3 *sqlite3_context_db_handle(sqlite3_context*); 5878 5879 /* 5880 ** CAPI3REF: Function Auxiliary Data 5881 ** METHOD: sqlite3_context 5882 ** 5883 ** These functions may be used by (non-aggregate) SQL functions to 5884 ** associate auxiliary data with argument values. If the same argument 5885 ** value is passed to multiple invocations of the same SQL function during 5886 ** query execution, under some circumstances the associated auxiliary data 5887 ** might be preserved. An example of where this might be useful is in a 5888 ** regular-expression matching function. The compiled version of the regular 5889 ** expression can be stored as auxiliary data associated with the pattern string. 5890 ** Then as long as the pattern string remains the same, 5891 ** the compiled regular expression can be reused on multiple 5892 ** invocations of the same function. 5893 ** 5894 ** ^The sqlite3_get_auxdata(C,N) interface returns a pointer to the auxiliary data 5895 ** associated by the sqlite3_set_auxdata(C,N,P,X) function with the Nth argument 5896 ** value to the application-defined function. ^N is zero for the left-most 5897 ** function argument. ^If there is no auxiliary data 5898 ** associated with the function argument, the sqlite3_get_auxdata(C,N) interface 5899 ** returns a NULL pointer. 5900 ** 5901 ** ^The sqlite3_set_auxdata(C,N,P,X) interface saves P as auxiliary data for the 5902 ** N-th argument of the application-defined function. ^Subsequent 5903 ** calls to sqlite3_get_auxdata(C,N) return P from the most recent 5904 ** sqlite3_set_auxdata(C,N,P,X) call if the auxiliary data is still valid or 5905 ** NULL if the auxiliary data has been discarded. 5906 ** ^After each call to sqlite3_set_auxdata(C,N,P,X) where X is not NULL, 5907 ** SQLite will invoke the destructor function X with parameter P exactly 5908 ** once, when the auxiliary data is discarded. 5909 ** SQLite is free to discard the auxiliary data at any time, including: <ul> 5910 ** <li> ^(when the corresponding function parameter changes)^, or 5911 ** <li> ^(when [sqlite3_reset()] or [sqlite3_finalize()] is called for the 5912 ** SQL statement)^, or 5913 ** <li> ^(when sqlite3_set_auxdata() is invoked again on the same 5914 ** parameter)^, or 5915 ** <li> ^(during the original sqlite3_set_auxdata() call when a memory 5916 ** allocation error occurs.)^ </ul> 5917 ** 5918 ** Note the last bullet in particular. The destructor X in 5919 ** sqlite3_set_auxdata(C,N,P,X) might be called immediately, before the 5920 ** sqlite3_set_auxdata() interface even returns. Hence sqlite3_set_auxdata() 5921 ** should be called near the end of the function implementation and the 5922 ** function implementation should not make any use of P after 5923 ** sqlite3_set_auxdata() has been called. 5924 ** 5925 ** ^(In practice, auxiliary data is preserved between function calls for 5926 ** function parameters that are compile-time constants, including literal 5927 ** values and [parameters] and expressions composed from the same.)^ 5928 ** 5929 ** The value of the N parameter to these interfaces should be non-negative. 5930 ** Future enhancements may make use of negative N values to define new 5931 ** kinds of function caching behavior. 5932 ** 5933 ** These routines must be called from the same thread in which 5934 ** the SQL function is running. 5935 ** 5936 ** See also: [sqlite3_get_clientdata()] and [sqlite3_set_clientdata()]. 5937 */ 5938 SQLITE_API void *sqlite3_get_auxdata(sqlite3_context*, int N); 5939 SQLITE_API void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*)); 5940 5941 /* 5942 ** CAPI3REF: Database Connection Client Data 5943 ** METHOD: sqlite3 5944 ** 5945 ** These functions are used to associate one or more named pointers 5946 ** with a [database connection]. 5947 ** A call to sqlite3_set_clientdata(D,N,P,X) causes the pointer P 5948 ** to be attached to [database connection] D using name N. Subsequent 5949 ** calls to sqlite3_get_clientdata(D,N) will return a copy of pointer P 5950 ** or a NULL pointer if there were no prior calls to 5951 ** sqlite3_set_clientdata() with the same values of D and N. 5952 ** Names are compared using strcmp() and are thus case sensitive. 5953 ** 5954 ** If P and X are both non-NULL, then the destructor X is invoked with 5955 ** argument P on the first of the following occurrences: 5956 ** <ul> 5957 ** <li> An out-of-memory error occurs during the call to 5958 ** sqlite3_set_clientdata() which attempts to register pointer P. 5959 ** <li> A subsequent call to sqlite3_set_clientdata(D,N,P,X) is made 5960 ** with the same D and N parameters. 5961 ** <li> The database connection closes. SQLite does not make any guarantees 5962 ** about the order in which destructors are called, only that all 5963 ** destructors will be called exactly once at some point during the 5964 ** database connection closing process. 5965 ** </ul> 5966 ** 5967 ** SQLite does not do anything with client data other than invoke 5968 ** destructors on the client data at the appropriate time. The intended 5969 ** use for client data is to provide a mechanism for wrapper libraries 5970 ** to store additional information about an SQLite database connection. 5971 ** 5972 ** There is no limit (other than available memory) on the number of different 5973 ** client data pointers (with different names) that can be attached to a 5974 ** single database connection. However, the implementation is optimized 5975 ** for the case of having only one or two different client data names. 5976 ** Applications and wrapper libraries are discouraged from using more than 5977 ** one client data name each. 5978 ** 5979 ** There is no way to enumerate the client data pointers 5980 ** associated with a database connection. The N parameter can be thought 5981 ** of as a secret key such that only code that knows the secret key is able 5982 ** to access the associated data. 5983 ** 5984 ** Security Warning: These interfaces should not be exposed in scripting 5985 ** languages or in other circumstances where it might be possible for an 5986 ** an attacker to invoke them. Any agent that can invoke these interfaces 5987 ** can probably also take control of the process. 5988 ** 5989 ** Database connection client data is only available for SQLite 5990 ** version 3.44.0 ([dateof:3.44.0]) and later. 5991 ** 5992 ** See also: [sqlite3_set_auxdata()] and [sqlite3_get_auxdata()]. 5993 */ 5994 SQLITE_API void *sqlite3_get_clientdata(sqlite3*,const char*); 5995 SQLITE_API int sqlite3_set_clientdata(sqlite3*, const char*, void*, void(*)(void*)); 5996 5997 /* 5998 ** CAPI3REF: Constants Defining Special Destructor Behavior 5999 ** 6000 ** These are special values for the destructor that is passed in as the 6001 ** final argument to routines like [sqlite3_result_blob()]. ^If the destructor 6002 ** argument is SQLITE_STATIC, it means that the content pointer is constant 6003 ** and will never change. It does not need to be destroyed. ^The 6004 ** SQLITE_TRANSIENT value means that the content will likely change in 6005 ** the near future and that SQLite should make its own private copy of 6006 ** the content before returning. 6007 ** 6008 ** The typedef is necessary to work around problems in certain 6009 ** C++ compilers. 6010 */ 6011 typedef void (*sqlite3_destructor_type)(void*); 6012 #define SQLITE_STATIC ((sqlite3_destructor_type)0) 6013 #define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1) 6014 6015 /* 6016 ** CAPI3REF: Setting The Result Of An SQL Function 6017 ** METHOD: sqlite3_context 6018 ** 6019 ** These routines are used by the xFunc or xFinal callbacks that 6020 ** implement SQL functions and aggregates. See 6021 ** [sqlite3_create_function()] and [sqlite3_create_function16()] 6022 ** for additional information. 6023 ** 6024 ** These functions work very much like the [parameter binding] family of 6025 ** functions used to bind values to host parameters in prepared statements. 6026 ** Refer to the [SQL parameter] documentation for additional information. 6027 ** 6028 ** ^The sqlite3_result_blob() interface sets the result from 6029 ** an application-defined function to be the BLOB whose content is pointed 6030 ** to by the second parameter and which is N bytes long where N is the 6031 ** third parameter. 6032 ** 6033 ** ^The sqlite3_result_zeroblob(C,N) and sqlite3_result_zeroblob64(C,N) 6034 ** interfaces set the result of the application-defined function to be 6035 ** a BLOB containing all zero bytes and N bytes in size. 6036 ** 6037 ** ^The sqlite3_result_double() interface sets the result from 6038 ** an application-defined function to be a floating point value specified 6039 ** by its 2nd argument. 6040 ** 6041 ** ^The sqlite3_result_error() and sqlite3_result_error16() functions 6042 ** cause the implemented SQL function to throw an exception. 6043 ** ^SQLite uses the string pointed to by the 6044 ** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16() 6045 ** as the text of an error message. ^SQLite interprets the error 6046 ** message string from sqlite3_result_error() as UTF-8. ^SQLite 6047 ** interprets the string from sqlite3_result_error16() as UTF-16 using 6048 ** the same [byte-order determination rules] as [sqlite3_bind_text16()]. 6049 ** ^If the third parameter to sqlite3_result_error() 6050 ** or sqlite3_result_error16() is negative then SQLite takes as the error 6051 ** message all text up through the first zero character. 6052 ** ^If the third parameter to sqlite3_result_error() or 6053 ** sqlite3_result_error16() is non-negative then SQLite takes that many 6054 ** bytes (not characters) from the 2nd parameter as the error message. 6055 ** ^The sqlite3_result_error() and sqlite3_result_error16() 6056 ** routines make a private copy of the error message text before 6057 ** they return. Hence, the calling function can deallocate or 6058 ** modify the text after they return without harm. 6059 ** ^The sqlite3_result_error_code() function changes the error code 6060 ** returned by SQLite as a result of an error in a function. ^By default, 6061 ** the error code is SQLITE_ERROR. ^A subsequent call to sqlite3_result_error() 6062 ** or sqlite3_result_error16() resets the error code to SQLITE_ERROR. 6063 ** 6064 ** ^The sqlite3_result_error_toobig() interface causes SQLite to throw an 6065 ** error indicating that a string or BLOB is too long to represent. 6066 ** 6067 ** ^The sqlite3_result_error_nomem() interface causes SQLite to throw an 6068 ** error indicating that a memory allocation failed. 6069 ** 6070 ** ^The sqlite3_result_int() interface sets the return value 6071 ** of the application-defined function to be the 32-bit signed integer 6072 ** value given in the 2nd argument. 6073 ** ^The sqlite3_result_int64() interface sets the return value 6074 ** of the application-defined function to be the 64-bit signed integer 6075 ** value given in the 2nd argument. 6076 ** 6077 ** ^The sqlite3_result_null() interface sets the return value 6078 ** of the application-defined function to be NULL. 6079 ** 6080 ** ^The sqlite3_result_text(), sqlite3_result_text16(), 6081 ** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces 6082 ** set the return value of the application-defined function to be 6083 ** a text string which is represented as UTF-8, UTF-16 native byte order, 6084 ** UTF-16 little endian, or UTF-16 big endian, respectively. 6085 ** ^The sqlite3_result_text64() interface sets the return value of an 6086 ** application-defined function to be a text string in an encoding 6087 ** specified by the fifth (and last) parameter, which must be one 6088 ** of [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE]. 6089 ** ^SQLite takes the text result from the application from 6090 ** the 2nd parameter of the sqlite3_result_text* interfaces. 6091 ** ^If the 3rd parameter to any of the sqlite3_result_text* interfaces 6092 ** other than sqlite3_result_text64() is negative, then SQLite computes 6093 ** the string length itself by searching the 2nd parameter for the first 6094 ** zero character. 6095 ** ^If the 3rd parameter to the sqlite3_result_text* interfaces 6096 ** is non-negative, then as many bytes (not characters) of the text 6097 ** pointed to by the 2nd parameter are taken as the application-defined 6098 ** function result. If the 3rd parameter is non-negative, then it 6099 ** must be the byte offset into the string where the NUL terminator would 6100 ** appear if the string where NUL terminated. If any NUL characters occur 6101 ** in the string at a byte offset that is less than the value of the 3rd 6102 ** parameter, then the resulting string will contain embedded NULs and the 6103 ** result of expressions operating on strings with embedded NULs is undefined. 6104 ** ^If the 4th parameter to the sqlite3_result_text* interfaces 6105 ** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that 6106 ** function as the destructor on the text or BLOB result when it has 6107 ** finished using that result. 6108 ** ^If the 4th parameter to the sqlite3_result_text* interfaces or to 6109 ** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite 6110 ** assumes that the text or BLOB result is in constant space and does not 6111 ** copy the content of the parameter nor call a destructor on the content 6112 ** when it has finished using that result. 6113 ** ^If the 4th parameter to the sqlite3_result_text* interfaces 6114 ** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT 6115 ** then SQLite makes a copy of the result into space obtained 6116 ** from [sqlite3_malloc()] before it returns. 6117 ** 6118 ** ^For the sqlite3_result_text16(), sqlite3_result_text16le(), and 6119 ** sqlite3_result_text16be() routines, and for sqlite3_result_text64() 6120 ** when the encoding is not UTF8, if the input UTF16 begins with a 6121 ** byte-order mark (BOM, U+FEFF) then the BOM is removed from the 6122 ** string and the rest of the string is interpreted according to the 6123 ** byte-order specified by the BOM. ^The byte-order specified by 6124 ** the BOM at the beginning of the text overrides the byte-order 6125 ** specified by the interface procedure. ^So, for example, if 6126 ** sqlite3_result_text16le() is invoked with text that begins 6127 ** with bytes 0xfe, 0xff (a big-endian byte-order mark) then the 6128 ** first two bytes of input are skipped and the remaining input 6129 ** is interpreted as UTF16BE text. 6130 ** 6131 ** ^For UTF16 input text to the sqlite3_result_text16(), 6132 ** sqlite3_result_text16be(), sqlite3_result_text16le(), and 6133 ** sqlite3_result_text64() routines, if the text contains invalid 6134 ** UTF16 characters, the invalid characters might be converted 6135 ** into the unicode replacement character, U+FFFD. 6136 ** 6137 ** ^The sqlite3_result_value() interface sets the result of 6138 ** the application-defined function to be a copy of the 6139 ** [unprotected sqlite3_value] object specified by the 2nd parameter. ^The 6140 ** sqlite3_result_value() interface makes a copy of the [sqlite3_value] 6141 ** so that the [sqlite3_value] specified in the parameter may change or 6142 ** be deallocated after sqlite3_result_value() returns without harm. 6143 ** ^A [protected sqlite3_value] object may always be used where an 6144 ** [unprotected sqlite3_value] object is required, so either 6145 ** kind of [sqlite3_value] object can be used with this interface. 6146 ** 6147 ** ^The sqlite3_result_pointer(C,P,T,D) interface sets the result to an 6148 ** SQL NULL value, just like [sqlite3_result_null(C)], except that it 6149 ** also associates the host-language pointer P or type T with that 6150 ** NULL value such that the pointer can be retrieved within an 6151 ** [application-defined SQL function] using [sqlite3_value_pointer()]. 6152 ** ^If the D parameter is not NULL, then it is a pointer to a destructor 6153 ** for the P parameter. ^SQLite invokes D with P as its only argument 6154 ** when SQLite is finished with P. The T parameter should be a static 6155 ** string and preferably a string literal. The sqlite3_result_pointer() 6156 ** routine is part of the [pointer passing interface] added for SQLite 3.20.0. 6157 ** 6158 ** If these routines are called from within the different thread 6159 ** than the one containing the application-defined function that received 6160 ** the [sqlite3_context] pointer, the results are undefined. 6161 */ 6162 SQLITE_API void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*)); 6163 SQLITE_API void sqlite3_result_blob64(sqlite3_context*,const void*, 6164 sqlite3_uint64,void(*)(void*)); 6165 SQLITE_API void sqlite3_result_double(sqlite3_context*, double); 6166 SQLITE_API void sqlite3_result_error(sqlite3_context*, const char*, int); 6167 SQLITE_API void sqlite3_result_error16(sqlite3_context*, const void*, int); 6168 SQLITE_API void sqlite3_result_error_toobig(sqlite3_context*); 6169 SQLITE_API void sqlite3_result_error_nomem(sqlite3_context*); 6170 SQLITE_API void sqlite3_result_error_code(sqlite3_context*, int); 6171 SQLITE_API void sqlite3_result_int(sqlite3_context*, int); 6172 SQLITE_API void sqlite3_result_int64(sqlite3_context*, sqlite3_int64); 6173 SQLITE_API void sqlite3_result_null(sqlite3_context*); 6174 SQLITE_API void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*)); 6175 SQLITE_API void sqlite3_result_text64(sqlite3_context*, const char*,sqlite3_uint64, 6176 void(*)(void*), unsigned char encoding); 6177 SQLITE_API void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*)); 6178 SQLITE_API void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*)); 6179 SQLITE_API void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*)); 6180 SQLITE_API void sqlite3_result_value(sqlite3_context*, sqlite3_value*); 6181 SQLITE_API void sqlite3_result_pointer(sqlite3_context*, void*,const char*,void(*)(void*)); 6182 SQLITE_API void sqlite3_result_zeroblob(sqlite3_context*, int n); 6183 SQLITE_API int sqlite3_result_zeroblob64(sqlite3_context*, sqlite3_uint64 n); 6184 6185 6186 /* 6187 ** CAPI3REF: Setting The Subtype Of An SQL Function 6188 ** METHOD: sqlite3_context 6189 ** 6190 ** The sqlite3_result_subtype(C,T) function causes the subtype of 6191 ** the result from the [application-defined SQL function] with 6192 ** [sqlite3_context] C to be the value T. Only the lower 8 bits 6193 ** of the subtype T are preserved in current versions of SQLite; 6194 ** higher order bits are discarded. 6195 ** The number of subtype bytes preserved by SQLite might increase 6196 ** in future releases of SQLite. 6197 */ 6198 SQLITE_API void sqlite3_result_subtype(sqlite3_context*,unsigned int); 6199 6200 /* 6201 ** CAPI3REF: Define New Collating Sequences 6202 ** METHOD: sqlite3 6203 ** 6204 ** ^These functions add, remove, or modify a [collation] associated 6205 ** with the [database connection] specified as the first argument. 6206 ** 6207 ** ^The name of the collation is a UTF-8 string 6208 ** for sqlite3_create_collation() and sqlite3_create_collation_v2() 6209 ** and a UTF-16 string in native byte order for sqlite3_create_collation16(). 6210 ** ^Collation names that compare equal according to [sqlite3_strnicmp()] are 6211 ** considered to be the same name. 6212 ** 6213 ** ^(The third argument (eTextRep) must be one of the constants: 6214 ** <ul> 6215 ** <li> [SQLITE_UTF8], 6216 ** <li> [SQLITE_UTF16LE], 6217 ** <li> [SQLITE_UTF16BE], 6218 ** <li> [SQLITE_UTF16], or 6219 ** <li> [SQLITE_UTF16_ALIGNED]. 6220 ** </ul>)^ 6221 ** ^The eTextRep argument determines the encoding of strings passed 6222 ** to the collating function callback, xCompare. 6223 ** ^The [SQLITE_UTF16] and [SQLITE_UTF16_ALIGNED] values for eTextRep 6224 ** force strings to be UTF16 with native byte order. 6225 ** ^The [SQLITE_UTF16_ALIGNED] value for eTextRep forces strings to begin 6226 ** on an even byte address. 6227 ** 6228 ** ^The fourth argument, pArg, is an application data pointer that is passed 6229 ** through as the first argument to the collating function callback. 6230 ** 6231 ** ^The fifth argument, xCompare, is a pointer to the collating function. 6232 ** ^Multiple collating functions can be registered using the same name but 6233 ** with different eTextRep parameters and SQLite will use whichever 6234 ** function requires the least amount of data transformation. 6235 ** ^If the xCompare argument is NULL then the collating function is 6236 ** deleted. ^When all collating functions having the same name are deleted, 6237 ** that collation is no longer usable. 6238 ** 6239 ** ^The collating function callback is invoked with a copy of the pArg 6240 ** application data pointer and with two strings in the encoding specified 6241 ** by the eTextRep argument. The two integer parameters to the collating 6242 ** function callback are the length of the two strings, in bytes. The collating 6243 ** function must return an integer that is negative, zero, or positive 6244 ** if the first string is less than, equal to, or greater than the second, 6245 ** respectively. A collating function must always return the same answer 6246 ** given the same inputs. If two or more collating functions are registered 6247 ** to the same collation name (using different eTextRep values) then all 6248 ** must give an equivalent answer when invoked with equivalent strings. 6249 ** The collating function must obey the following properties for all 6250 ** strings A, B, and C: 6251 ** 6252 ** <ol> 6253 ** <li> If A==B then B==A. 6254 ** <li> If A==B and B==C then A==C. 6255 ** <li> If A<B THEN B>A. 6256 ** <li> If A<B and B<C then A<C. 6257 ** </ol> 6258 ** 6259 ** If a collating function fails any of the above constraints and that 6260 ** collating function is registered and used, then the behavior of SQLite 6261 ** is undefined. 6262 ** 6263 ** ^The sqlite3_create_collation_v2() works like sqlite3_create_collation() 6264 ** with the addition that the xDestroy callback is invoked on pArg when 6265 ** the collating function is deleted. 6266 ** ^Collating functions are deleted when they are overridden by later 6267 ** calls to the collation creation functions or when the 6268 ** [database connection] is closed using [sqlite3_close()]. 6269 ** 6270 ** ^The xDestroy callback is <u>not</u> called if the 6271 ** sqlite3_create_collation_v2() function fails. Applications that invoke 6272 ** sqlite3_create_collation_v2() with a non-NULL xDestroy argument should 6273 ** check the return code and dispose of the application data pointer 6274 ** themselves rather than expecting SQLite to deal with it for them. 6275 ** This is different from every other SQLite interface. The inconsistency 6276 ** is unfortunate but cannot be changed without breaking backwards 6277 ** compatibility. 6278 ** 6279 ** See also: [sqlite3_collation_needed()] and [sqlite3_collation_needed16()]. 6280 */ 6281 SQLITE_API int sqlite3_create_collation( 6282 sqlite3*, 6283 const char *zName, 6284 int eTextRep, 6285 void *pArg, 6286 int(*xCompare)(void*,int,const void*,int,const void*) 6287 ); 6288 SQLITE_API int sqlite3_create_collation_v2( 6289 sqlite3*, 6290 const char *zName, 6291 int eTextRep, 6292 void *pArg, 6293 int(*xCompare)(void*,int,const void*,int,const void*), 6294 void(*xDestroy)(void*) 6295 ); 6296 SQLITE_API int sqlite3_create_collation16( 6297 sqlite3*, 6298 const void *zName, 6299 int eTextRep, 6300 void *pArg, 6301 int(*xCompare)(void*,int,const void*,int,const void*) 6302 ); 6303 6304 /* 6305 ** CAPI3REF: Collation Needed Callbacks 6306 ** METHOD: sqlite3 6307 ** 6308 ** ^To avoid having to register all collation sequences before a database 6309 ** can be used, a single callback function may be registered with the 6310 ** [database connection] to be invoked whenever an undefined collation 6311 ** sequence is required. 6312 ** 6313 ** ^If the function is registered using the sqlite3_collation_needed() API, 6314 ** then it is passed the names of undefined collation sequences as strings 6315 ** encoded in UTF-8. ^If sqlite3_collation_needed16() is used, 6316 ** the names are passed as UTF-16 in machine native byte order. 6317 ** ^A call to either function replaces the existing collation-needed callback. 6318 ** 6319 ** ^(When the callback is invoked, the first argument passed is a copy 6320 ** of the second argument to sqlite3_collation_needed() or 6321 ** sqlite3_collation_needed16(). The second argument is the database 6322 ** connection. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE], 6323 ** or [SQLITE_UTF16LE], indicating the most desirable form of the collation 6324 ** sequence function required. The fourth parameter is the name of the 6325 ** required collation sequence.)^ 6326 ** 6327 ** The callback function should register the desired collation using 6328 ** [sqlite3_create_collation()], [sqlite3_create_collation16()], or 6329 ** [sqlite3_create_collation_v2()]. 6330 */ 6331 SQLITE_API int sqlite3_collation_needed( 6332 sqlite3*, 6333 void*, 6334 void(*)(void*,sqlite3*,int eTextRep,const char*) 6335 ); 6336 SQLITE_API int sqlite3_collation_needed16( 6337 sqlite3*, 6338 void*, 6339 void(*)(void*,sqlite3*,int eTextRep,const void*) 6340 ); 6341 6342 #ifdef SQLITE_ENABLE_CEROD 6343 /* 6344 ** Specify the activation key for a CEROD database. Unless 6345 ** activated, none of the CEROD routines will work. 6346 */ 6347 SQLITE_API void sqlite3_activate_cerod( 6348 const char *zPassPhrase /* Activation phrase */ 6349 ); 6350 #endif 6351 6352 /* 6353 ** CAPI3REF: Suspend Execution For A Short Time 6354 ** 6355 ** The sqlite3_sleep() function causes the current thread to suspend execution 6356 ** for at least a number of milliseconds specified in its parameter. 6357 ** 6358 ** If the operating system does not support sleep requests with 6359 ** millisecond time resolution, then the time will be rounded up to 6360 ** the nearest second. The number of milliseconds of sleep actually 6361 ** requested from the operating system is returned. 6362 ** 6363 ** ^SQLite implements this interface by calling the xSleep() 6364 ** method of the default [sqlite3_vfs] object. If the xSleep() method 6365 ** of the default VFS is not implemented correctly, or not implemented at 6366 ** all, then the behavior of sqlite3_sleep() may deviate from the description 6367 ** in the previous paragraphs. 6368 ** 6369 ** If a negative argument is passed to sqlite3_sleep() the results vary by 6370 ** VFS and operating system. Some system treat a negative argument as an 6371 ** instruction to sleep forever. Others understand it to mean do not sleep 6372 ** at all. ^In SQLite version 3.42.0 and later, a negative 6373 ** argument passed into sqlite3_sleep() is changed to zero before it is relayed 6374 ** down into the xSleep method of the VFS. 6375 */ 6376 SQLITE_API int sqlite3_sleep(int); 6377 6378 /* 6379 ** CAPI3REF: Name Of The Folder Holding Temporary Files 6380 ** 6381 ** ^(If this global variable is made to point to a string which is 6382 ** the name of a folder (a.k.a. directory), then all temporary files 6383 ** created by SQLite when using a built-in [sqlite3_vfs | VFS] 6384 ** will be placed in that directory.)^ ^If this variable 6385 ** is a NULL pointer, then SQLite performs a search for an appropriate 6386 ** temporary file directory. 6387 ** 6388 ** Applications are strongly discouraged from using this global variable. 6389 ** It is required to set a temporary folder on Windows Runtime (WinRT). 6390 ** But for all other platforms, it is highly recommended that applications 6391 ** neither read nor write this variable. This global variable is a relic 6392 ** that exists for backwards compatibility of legacy applications and should 6393 ** be avoided in new projects. 6394 ** 6395 ** It is not safe to read or modify this variable in more than one 6396 ** thread at a time. It is not safe to read or modify this variable 6397 ** if a [database connection] is being used at the same time in a separate 6398 ** thread. 6399 ** It is intended that this variable be set once 6400 ** as part of process initialization and before any SQLite interface 6401 ** routines have been called and that this variable remain unchanged 6402 ** thereafter. 6403 ** 6404 ** ^The [temp_store_directory pragma] may modify this variable and cause 6405 ** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 6406 ** the [temp_store_directory pragma] always assumes that any string 6407 ** that this variable points to is held in memory obtained from 6408 ** [sqlite3_malloc] and the pragma may attempt to free that memory 6409 ** using [sqlite3_free]. 6410 ** Hence, if this variable is modified directly, either it should be 6411 ** made NULL or made to point to memory obtained from [sqlite3_malloc] 6412 ** or else the use of the [temp_store_directory pragma] should be avoided. 6413 ** Except when requested by the [temp_store_directory pragma], SQLite 6414 ** does not free the memory that sqlite3_temp_directory points to. If 6415 ** the application wants that memory to be freed, it must do 6416 ** so itself, taking care to only do so after all [database connection] 6417 ** objects have been destroyed. 6418 ** 6419 ** <b>Note to Windows Runtime users:</b> The temporary directory must be set 6420 ** prior to calling [sqlite3_open] or [sqlite3_open_v2]. Otherwise, various 6421 ** features that require the use of temporary files may fail. Here is an 6422 ** example of how to do this using C++ with the Windows Runtime: 6423 ** 6424 ** <blockquote><pre> 6425 ** LPCWSTR zPath = Windows::Storage::ApplicationData::Current-> 6426 ** TemporaryFolder->Path->Data(); 6427 ** char zPathBuf[MAX_PATH + 1]; 6428 ** memset(zPathBuf, 0, sizeof(zPathBuf)); 6429 ** WideCharToMultiByte(CP_UTF8, 0, zPath, -1, zPathBuf, sizeof(zPathBuf), 6430 ** NULL, NULL); 6431 ** sqlite3_temp_directory = sqlite3_mprintf("%s", zPathBuf); 6432 ** </pre></blockquote> 6433 */ 6434 SQLITE_API SQLITE_EXTERN char *sqlite3_temp_directory; 6435 6436 /* 6437 ** CAPI3REF: Name Of The Folder Holding Database Files 6438 ** 6439 ** ^(If this global variable is made to point to a string which is 6440 ** the name of a folder (a.k.a. directory), then all database files 6441 ** specified with a relative pathname and created or accessed by 6442 ** SQLite when using a built-in windows [sqlite3_vfs | VFS] will be assumed 6443 ** to be relative to that directory.)^ ^If this variable is a NULL 6444 ** pointer, then SQLite assumes that all database files specified 6445 ** with a relative pathname are relative to the current directory 6446 ** for the process. Only the windows VFS makes use of this global 6447 ** variable; it is ignored by the unix VFS. 6448 ** 6449 ** Changing the value of this variable while a database connection is 6450 ** open can result in a corrupt database. 6451 ** 6452 ** It is not safe to read or modify this variable in more than one 6453 ** thread at a time. It is not safe to read or modify this variable 6454 ** if a [database connection] is being used at the same time in a separate 6455 ** thread. 6456 ** It is intended that this variable be set once 6457 ** as part of process initialization and before any SQLite interface 6458 ** routines have been called and that this variable remain unchanged 6459 ** thereafter. 6460 ** 6461 ** ^The [data_store_directory pragma] may modify this variable and cause 6462 ** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 6463 ** the [data_store_directory pragma] always assumes that any string 6464 ** that this variable points to is held in memory obtained from 6465 ** [sqlite3_malloc] and the pragma may attempt to free that memory 6466 ** using [sqlite3_free]. 6467 ** Hence, if this variable is modified directly, either it should be 6468 ** made NULL or made to point to memory obtained from [sqlite3_malloc] 6469 ** or else the use of the [data_store_directory pragma] should be avoided. 6470 */ 6471 SQLITE_API SQLITE_EXTERN char *sqlite3_data_directory; 6472 6473 /* 6474 ** CAPI3REF: Win32 Specific Interface 6475 ** 6476 ** These interfaces are available only on Windows. The 6477 ** [sqlite3_win32_set_directory] interface is used to set the value associated 6478 ** with the [sqlite3_temp_directory] or [sqlite3_data_directory] variable, to 6479 ** zValue, depending on the value of the type parameter. The zValue parameter 6480 ** should be NULL to cause the previous value to be freed via [sqlite3_free]; 6481 ** a non-NULL value will be copied into memory obtained from [sqlite3_malloc] 6482 ** prior to being used. The [sqlite3_win32_set_directory] interface returns 6483 ** [SQLITE_OK] to indicate success, [SQLITE_ERROR] if the type is unsupported, 6484 ** or [SQLITE_NOMEM] if memory could not be allocated. The value of the 6485 ** [sqlite3_data_directory] variable is intended to act as a replacement for 6486 ** the current directory on the sub-platforms of Win32 where that concept is 6487 ** not present, e.g. WinRT and UWP. The [sqlite3_win32_set_directory8] and 6488 ** [sqlite3_win32_set_directory16] interfaces behave exactly the same as the 6489 ** sqlite3_win32_set_directory interface except the string parameter must be 6490 ** UTF-8 or UTF-16, respectively. 6491 */ 6492 SQLITE_API int sqlite3_win32_set_directory( 6493 unsigned long type, /* Identifier for directory being set or reset */ 6494 void *zValue /* New value for directory being set or reset */ 6495 ); 6496 SQLITE_API int sqlite3_win32_set_directory8(unsigned long type, const char *zValue); 6497 SQLITE_API int sqlite3_win32_set_directory16(unsigned long type, const void *zValue); 6498 6499 /* 6500 ** CAPI3REF: Win32 Directory Types 6501 ** 6502 ** These macros are only available on Windows. They define the allowed values 6503 ** for the type argument to the [sqlite3_win32_set_directory] interface. 6504 */ 6505 #define SQLITE_WIN32_DATA_DIRECTORY_TYPE 1 6506 #define SQLITE_WIN32_TEMP_DIRECTORY_TYPE 2 6507 6508 /* 6509 ** CAPI3REF: Test For Auto-Commit Mode 6510 ** KEYWORDS: {autocommit mode} 6511 ** METHOD: sqlite3 6512 ** 6513 ** ^The sqlite3_get_autocommit() interface returns non-zero or 6514 ** zero if the given database connection is or is not in autocommit mode, 6515 ** respectively. ^Autocommit mode is on by default. 6516 ** ^Autocommit mode is disabled by a [BEGIN] statement. 6517 ** ^Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK]. 6518 ** 6519 ** If certain kinds of errors occur on a statement within a multi-statement 6520 ** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR], 6521 ** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the 6522 ** transaction might be rolled back automatically. The only way to 6523 ** find out whether SQLite automatically rolled back the transaction after 6524 ** an error is to use this function. 6525 ** 6526 ** If another thread changes the autocommit status of the database 6527 ** connection while this routine is running, then the return value 6528 ** is undefined. 6529 */ 6530 SQLITE_API int sqlite3_get_autocommit(sqlite3*); 6531 6532 /* 6533 ** CAPI3REF: Find The Database Handle Of A Prepared Statement 6534 ** METHOD: sqlite3_stmt 6535 ** 6536 ** ^The sqlite3_db_handle interface returns the [database connection] handle 6537 ** to which a [prepared statement] belongs. ^The [database connection] 6538 ** returned by sqlite3_db_handle is the same [database connection] 6539 ** that was the first argument 6540 ** to the [sqlite3_prepare_v2()] call (or its variants) that was used to 6541 ** create the statement in the first place. 6542 */ 6543 SQLITE_API sqlite3 *sqlite3_db_handle(sqlite3_stmt*); 6544 6545 /* 6546 ** CAPI3REF: Return The Schema Name For A Database Connection 6547 ** METHOD: sqlite3 6548 ** 6549 ** ^The sqlite3_db_name(D,N) interface returns a pointer to the schema name 6550 ** for the N-th database on database connection D, or a NULL pointer of N is 6551 ** out of range. An N value of 0 means the main database file. An N of 1 is 6552 ** the "temp" schema. Larger values of N correspond to various ATTACH-ed 6553 ** databases. 6554 ** 6555 ** Space to hold the string that is returned by sqlite3_db_name() is managed 6556 ** by SQLite itself. The string might be deallocated by any operation that 6557 ** changes the schema, including [ATTACH] or [DETACH] or calls to 6558 ** [sqlite3_serialize()] or [sqlite3_deserialize()], even operations that 6559 ** occur on a different thread. Applications that need to 6560 ** remember the string long-term should make their own copy. Applications that 6561 ** are accessing the same database connection simultaneously on multiple 6562 ** threads should mutex-protect calls to this API and should make their own 6563 ** private copy of the result prior to releasing the mutex. 6564 */ 6565 SQLITE_API const char *sqlite3_db_name(sqlite3 *db, int N); 6566 6567 /* 6568 ** CAPI3REF: Return The Filename For A Database Connection 6569 ** METHOD: sqlite3 6570 ** 6571 ** ^The sqlite3_db_filename(D,N) interface returns a pointer to the filename 6572 ** associated with database N of connection D. 6573 ** ^If there is no attached database N on the database 6574 ** connection D, or if database N is a temporary or in-memory database, then 6575 ** this function will return either a NULL pointer or an empty string. 6576 ** 6577 ** ^The string value returned by this routine is owned and managed by 6578 ** the database connection. ^The value will be valid until the database N 6579 ** is [DETACH]-ed or until the database connection closes. 6580 ** 6581 ** ^The filename returned by this function is the output of the 6582 ** xFullPathname method of the [VFS]. ^In other words, the filename 6583 ** will be an absolute pathname, even if the filename used 6584 ** to open the database originally was a URI or relative pathname. 6585 ** 6586 ** If the filename pointer returned by this routine is not NULL, then it 6587 ** can be used as the filename input parameter to these routines: 6588 ** <ul> 6589 ** <li> [sqlite3_uri_parameter()] 6590 ** <li> [sqlite3_uri_boolean()] 6591 ** <li> [sqlite3_uri_int64()] 6592 ** <li> [sqlite3_filename_database()] 6593 ** <li> [sqlite3_filename_journal()] 6594 ** <li> [sqlite3_filename_wal()] 6595 ** </ul> 6596 */ 6597 SQLITE_API sqlite3_filename sqlite3_db_filename(sqlite3 *db, const char *zDbName); 6598 6599 /* 6600 ** CAPI3REF: Determine if a database is read-only 6601 ** METHOD: sqlite3 6602 ** 6603 ** ^The sqlite3_db_readonly(D,N) interface returns 1 if the database N 6604 ** of connection D is read-only, 0 if it is read/write, or -1 if N is not 6605 ** the name of a database on connection D. 6606 */ 6607 SQLITE_API int sqlite3_db_readonly(sqlite3 *db, const char *zDbName); 6608 6609 /* 6610 ** CAPI3REF: Determine the transaction state of a database 6611 ** METHOD: sqlite3 6612 ** 6613 ** ^The sqlite3_txn_state(D,S) interface returns the current 6614 ** [transaction state] of schema S in database connection D. ^If S is NULL, 6615 ** then the highest transaction state of any schema on database connection D 6616 ** is returned. Transaction states are (in order of lowest to highest): 6617 ** <ol> 6618 ** <li value="0"> SQLITE_TXN_NONE 6619 ** <li value="1"> SQLITE_TXN_READ 6620 ** <li value="2"> SQLITE_TXN_WRITE 6621 ** </ol> 6622 ** ^If the S argument to sqlite3_txn_state(D,S) is not the name of 6623 ** a valid schema, then -1 is returned. 6624 */ 6625 SQLITE_API int sqlite3_txn_state(sqlite3*,const char *zSchema); 6626 6627 /* 6628 ** CAPI3REF: Allowed return values from sqlite3_txn_state() 6629 ** KEYWORDS: {transaction state} 6630 ** 6631 ** These constants define the current transaction state of a database file. 6632 ** ^The [sqlite3_txn_state(D,S)] interface returns one of these 6633 ** constants in order to describe the transaction state of schema S 6634 ** in [database connection] D. 6635 ** 6636 ** <dl> 6637 ** [[SQLITE_TXN_NONE]] <dt>SQLITE_TXN_NONE</dt> 6638 ** <dd>The SQLITE_TXN_NONE state means that no transaction is currently 6639 ** pending.</dd> 6640 ** 6641 ** [[SQLITE_TXN_READ]] <dt>SQLITE_TXN_READ</dt> 6642 ** <dd>The SQLITE_TXN_READ state means that the database is currently 6643 ** in a read transaction. Content has been read from the database file 6644 ** but nothing in the database file has changed. The transaction state 6645 ** will advanced to SQLITE_TXN_WRITE if any changes occur and there are 6646 ** no other conflicting concurrent write transactions. The transaction 6647 ** state will revert to SQLITE_TXN_NONE following a [ROLLBACK] or 6648 ** [COMMIT].</dd> 6649 ** 6650 ** [[SQLITE_TXN_WRITE]] <dt>SQLITE_TXN_WRITE</dt> 6651 ** <dd>The SQLITE_TXN_WRITE state means that the database is currently 6652 ** in a write transaction. Content has been written to the database file 6653 ** but has not yet committed. The transaction state will change to 6654 ** to SQLITE_TXN_NONE at the next [ROLLBACK] or [COMMIT].</dd> 6655 */ 6656 #define SQLITE_TXN_NONE 0 6657 #define SQLITE_TXN_READ 1 6658 #define SQLITE_TXN_WRITE 2 6659 6660 /* 6661 ** CAPI3REF: Find the next prepared statement 6662 ** METHOD: sqlite3 6663 ** 6664 ** ^This interface returns a pointer to the next [prepared statement] after 6665 ** pStmt associated with the [database connection] pDb. ^If pStmt is NULL 6666 ** then this interface returns a pointer to the first prepared statement 6667 ** associated with the database connection pDb. ^If no prepared statement 6668 ** satisfies the conditions of this routine, it returns NULL. 6669 ** 6670 ** The [database connection] pointer D in a call to 6671 ** [sqlite3_next_stmt(D,S)] must refer to an open database 6672 ** connection and in particular must not be a NULL pointer. 6673 */ 6674 SQLITE_API sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt); 6675 6676 /* 6677 ** CAPI3REF: Commit And Rollback Notification Callbacks 6678 ** METHOD: sqlite3 6679 ** 6680 ** ^The sqlite3_commit_hook() interface registers a callback 6681 ** function to be invoked whenever a transaction is [COMMIT | committed]. 6682 ** ^Any callback set by a previous call to sqlite3_commit_hook() 6683 ** for the same database connection is overridden. 6684 ** ^The sqlite3_rollback_hook() interface registers a callback 6685 ** function to be invoked whenever a transaction is [ROLLBACK | rolled back]. 6686 ** ^Any callback set by a previous call to sqlite3_rollback_hook() 6687 ** for the same database connection is overridden. 6688 ** ^The pArg argument is passed through to the callback. 6689 ** ^If the callback on a commit hook function returns non-zero, 6690 ** then the commit is converted into a rollback. 6691 ** 6692 ** ^The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions 6693 ** return the P argument from the previous call of the same function 6694 ** on the same [database connection] D, or NULL for 6695 ** the first call for each function on D. 6696 ** 6697 ** The commit and rollback hook callbacks are not reentrant. 6698 ** The callback implementation must not do anything that will modify 6699 ** the database connection that invoked the callback. Any actions 6700 ** to modify the database connection must be deferred until after the 6701 ** completion of the [sqlite3_step()] call that triggered the commit 6702 ** or rollback hook in the first place. 6703 ** Note that running any other SQL statements, including SELECT statements, 6704 ** or merely calling [sqlite3_prepare_v2()] and [sqlite3_step()] will modify 6705 ** the database connections for the meaning of "modify" in this paragraph. 6706 ** 6707 ** ^Registering a NULL function disables the callback. 6708 ** 6709 ** ^When the commit hook callback routine returns zero, the [COMMIT] 6710 ** operation is allowed to continue normally. ^If the commit hook 6711 ** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK]. 6712 ** ^The rollback hook is invoked on a rollback that results from a commit 6713 ** hook returning non-zero, just as it would be with any other rollback. 6714 ** 6715 ** ^For the purposes of this API, a transaction is said to have been 6716 ** rolled back if an explicit "ROLLBACK" statement is executed, or 6717 ** an error or constraint causes an implicit rollback to occur. 6718 ** ^The rollback callback is not invoked if a transaction is 6719 ** automatically rolled back because the database connection is closed. 6720 ** 6721 ** See also the [sqlite3_update_hook()] interface. 6722 */ 6723 SQLITE_API void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*); 6724 SQLITE_API void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*); 6725 6726 /* 6727 ** CAPI3REF: Autovacuum Compaction Amount Callback 6728 ** METHOD: sqlite3 6729 ** 6730 ** ^The sqlite3_autovacuum_pages(D,C,P,X) interface registers a callback 6731 ** function C that is invoked prior to each autovacuum of the database 6732 ** file. ^The callback is passed a copy of the generic data pointer (P), 6733 ** the schema-name of the attached database that is being autovacuumed, 6734 ** the size of the database file in pages, the number of free pages, 6735 ** and the number of bytes per page, respectively. The callback should 6736 ** return the number of free pages that should be removed by the 6737 ** autovacuum. ^If the callback returns zero, then no autovacuum happens. 6738 ** ^If the value returned is greater than or equal to the number of 6739 ** free pages, then a complete autovacuum happens. 6740 ** 6741 ** <p>^If there are multiple ATTACH-ed database files that are being 6742 ** modified as part of a transaction commit, then the autovacuum pages 6743 ** callback is invoked separately for each file. 6744 ** 6745 ** <p><b>The callback is not reentrant.</b> The callback function should 6746 ** not attempt to invoke any other SQLite interface. If it does, bad 6747 ** things may happen, including segmentation faults and corrupt database 6748 ** files. The callback function should be a simple function that 6749 ** does some arithmetic on its input parameters and returns a result. 6750 ** 6751 ** ^The X parameter to sqlite3_autovacuum_pages(D,C,P,X) is an optional 6752 ** destructor for the P parameter. ^If X is not NULL, then X(P) is 6753 ** invoked whenever the database connection closes or when the callback 6754 ** is overwritten by another invocation of sqlite3_autovacuum_pages(). 6755 ** 6756 ** <p>^There is only one autovacuum pages callback per database connection. 6757 ** ^Each call to the sqlite3_autovacuum_pages() interface overrides all 6758 ** previous invocations for that database connection. ^If the callback 6759 ** argument (C) to sqlite3_autovacuum_pages(D,C,P,X) is a NULL pointer, 6760 ** then the autovacuum steps callback is canceled. The return value 6761 ** from sqlite3_autovacuum_pages() is normally SQLITE_OK, but might 6762 ** be some other error code if something goes wrong. The current 6763 ** implementation will only return SQLITE_OK or SQLITE_MISUSE, but other 6764 ** return codes might be added in future releases. 6765 ** 6766 ** <p>If no autovacuum pages callback is specified (the usual case) or 6767 ** a NULL pointer is provided for the callback, 6768 ** then the default behavior is to vacuum all free pages. So, in other 6769 ** words, the default behavior is the same as if the callback function 6770 ** were something like this: 6771 ** 6772 ** <blockquote><pre> 6773 ** unsigned int demonstration_autovac_pages_callback( 6774 ** void *pClientData, 6775 ** const char *zSchema, 6776 ** unsigned int nDbPage, 6777 ** unsigned int nFreePage, 6778 ** unsigned int nBytePerPage 6779 ** ){ 6780 ** return nFreePage; 6781 ** } 6782 ** </pre></blockquote> 6783 */ 6784 SQLITE_API int sqlite3_autovacuum_pages( 6785 sqlite3 *db, 6786 unsigned int(*)(void*,const char*,unsigned int,unsigned int,unsigned int), 6787 void*, 6788 void(*)(void*) 6789 ); 6790 6791 6792 /* 6793 ** CAPI3REF: Data Change Notification Callbacks 6794 ** METHOD: sqlite3 6795 ** 6796 ** ^The sqlite3_update_hook() interface registers a callback function 6797 ** with the [database connection] identified by the first argument 6798 ** to be invoked whenever a row is updated, inserted or deleted in 6799 ** a [rowid table]. 6800 ** ^Any callback set by a previous call to this function 6801 ** for the same database connection is overridden. 6802 ** 6803 ** ^The second argument is a pointer to the function to invoke when a 6804 ** row is updated, inserted or deleted in a rowid table. 6805 ** ^The first argument to the callback is a copy of the third argument 6806 ** to sqlite3_update_hook(). 6807 ** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE], 6808 ** or [SQLITE_UPDATE], depending on the operation that caused the callback 6809 ** to be invoked. 6810 ** ^The third and fourth arguments to the callback contain pointers to the 6811 ** database and table name containing the affected row. 6812 ** ^The final callback parameter is the [rowid] of the row. 6813 ** ^In the case of an update, this is the [rowid] after the update takes place. 6814 ** 6815 ** ^(The update hook is not invoked when internal system tables are 6816 ** modified (i.e. sqlite_sequence).)^ 6817 ** ^The update hook is not invoked when [WITHOUT ROWID] tables are modified. 6818 ** 6819 ** ^In the current implementation, the update hook 6820 ** is not invoked when conflicting rows are deleted because of an 6821 ** [ON CONFLICT | ON CONFLICT REPLACE] clause. ^Nor is the update hook 6822 ** invoked when rows are deleted using the [truncate optimization]. 6823 ** The exceptions defined in this paragraph might change in a future 6824 ** release of SQLite. 6825 ** 6826 ** The update hook implementation must not do anything that will modify 6827 ** the database connection that invoked the update hook. Any actions 6828 ** to modify the database connection must be deferred until after the 6829 ** completion of the [sqlite3_step()] call that triggered the update hook. 6830 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 6831 ** database connections for the meaning of "modify" in this paragraph. 6832 ** 6833 ** ^The sqlite3_update_hook(D,C,P) function 6834 ** returns the P argument from the previous call 6835 ** on the same [database connection] D, or NULL for 6836 ** the first call on D. 6837 ** 6838 ** See also the [sqlite3_commit_hook()], [sqlite3_rollback_hook()], 6839 ** and [sqlite3_preupdate_hook()] interfaces. 6840 */ 6841 SQLITE_API void *sqlite3_update_hook( 6842 sqlite3*, 6843 void(*)(void *,int ,char const *,char const *,sqlite3_int64), 6844 void* 6845 ); 6846 6847 /* 6848 ** CAPI3REF: Enable Or Disable Shared Pager Cache 6849 ** 6850 ** ^(This routine enables or disables the sharing of the database cache 6851 ** and schema data structures between [database connection | connections] 6852 ** to the same database. Sharing is enabled if the argument is true 6853 ** and disabled if the argument is false.)^ 6854 ** 6855 ** This interface is omitted if SQLite is compiled with 6856 ** [-DSQLITE_OMIT_SHARED_CACHE]. The [-DSQLITE_OMIT_SHARED_CACHE] 6857 ** compile-time option is recommended because the 6858 ** [use of shared cache mode is discouraged]. 6859 ** 6860 ** ^Cache sharing is enabled and disabled for an entire process. 6861 ** This is a change as of SQLite [version 3.5.0] ([dateof:3.5.0]). 6862 ** In prior versions of SQLite, 6863 ** sharing was enabled or disabled for each thread separately. 6864 ** 6865 ** ^(The cache sharing mode set by this interface effects all subsequent 6866 ** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()]. 6867 ** Existing database connections continue to use the sharing mode 6868 ** that was in effect at the time they were opened.)^ 6869 ** 6870 ** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled 6871 ** successfully. An [error code] is returned otherwise.)^ 6872 ** 6873 ** ^Shared cache is disabled by default. It is recommended that it stay 6874 ** that way. In other words, do not use this routine. This interface 6875 ** continues to be provided for historical compatibility, but its use is 6876 ** discouraged. Any use of shared cache is discouraged. If shared cache 6877 ** must be used, it is recommended that shared cache only be enabled for 6878 ** individual database connections using the [sqlite3_open_v2()] interface 6879 ** with the [SQLITE_OPEN_SHAREDCACHE] flag. 6880 ** 6881 ** Note: This method is disabled on MacOS X 10.7 and iOS version 5.0 6882 ** and will always return SQLITE_MISUSE. On those systems, 6883 ** shared cache mode should be enabled per-database connection via 6884 ** [sqlite3_open_v2()] with [SQLITE_OPEN_SHAREDCACHE]. 6885 ** 6886 ** This interface is threadsafe on processors where writing a 6887 ** 32-bit integer is atomic. 6888 ** 6889 ** See Also: [SQLite Shared-Cache Mode] 6890 */ 6891 SQLITE_API int sqlite3_enable_shared_cache(int); 6892 6893 /* 6894 ** CAPI3REF: Attempt To Free Heap Memory 6895 ** 6896 ** ^The sqlite3_release_memory() interface attempts to free N bytes 6897 ** of heap memory by deallocating non-essential memory allocations 6898 ** held by the database library. Memory used to cache database 6899 ** pages to improve performance is an example of non-essential memory. 6900 ** ^sqlite3_release_memory() returns the number of bytes actually freed, 6901 ** which might be more or less than the amount requested. 6902 ** ^The sqlite3_release_memory() routine is a no-op returning zero 6903 ** if SQLite is not compiled with [SQLITE_ENABLE_MEMORY_MANAGEMENT]. 6904 ** 6905 ** See also: [sqlite3_db_release_memory()] 6906 */ 6907 SQLITE_API int sqlite3_release_memory(int); 6908 6909 /* 6910 ** CAPI3REF: Free Memory Used By A Database Connection 6911 ** METHOD: sqlite3 6912 ** 6913 ** ^The sqlite3_db_release_memory(D) interface attempts to free as much heap 6914 ** memory as possible from database connection D. Unlike the 6915 ** [sqlite3_release_memory()] interface, this interface is in effect even 6916 ** when the [SQLITE_ENABLE_MEMORY_MANAGEMENT] compile-time option is 6917 ** omitted. 6918 ** 6919 ** See also: [sqlite3_release_memory()] 6920 */ 6921 SQLITE_API int sqlite3_db_release_memory(sqlite3*); 6922 6923 /* 6924 ** CAPI3REF: Impose A Limit On Heap Size 6925 ** 6926 ** These interfaces impose limits on the amount of heap memory that will be 6927 ** by all database connections within a single process. 6928 ** 6929 ** ^The sqlite3_soft_heap_limit64() interface sets and/or queries the 6930 ** soft limit on the amount of heap memory that may be allocated by SQLite. 6931 ** ^SQLite strives to keep heap memory utilization below the soft heap 6932 ** limit by reducing the number of pages held in the page cache 6933 ** as heap memory usages approaches the limit. 6934 ** ^The soft heap limit is "soft" because even though SQLite strives to stay 6935 ** below the limit, it will exceed the limit rather than generate 6936 ** an [SQLITE_NOMEM] error. In other words, the soft heap limit 6937 ** is advisory only. 6938 ** 6939 ** ^The sqlite3_hard_heap_limit64(N) interface sets a hard upper bound of 6940 ** N bytes on the amount of memory that will be allocated. ^The 6941 ** sqlite3_hard_heap_limit64(N) interface is similar to 6942 ** sqlite3_soft_heap_limit64(N) except that memory allocations will fail 6943 ** when the hard heap limit is reached. 6944 ** 6945 ** ^The return value from both sqlite3_soft_heap_limit64() and 6946 ** sqlite3_hard_heap_limit64() is the size of 6947 ** the heap limit prior to the call, or negative in the case of an 6948 ** error. ^If the argument N is negative 6949 ** then no change is made to the heap limit. Hence, the current 6950 ** size of heap limits can be determined by invoking 6951 ** sqlite3_soft_heap_limit64(-1) or sqlite3_hard_heap_limit(-1). 6952 ** 6953 ** ^Setting the heap limits to zero disables the heap limiter mechanism. 6954 ** 6955 ** ^The soft heap limit may not be greater than the hard heap limit. 6956 ** ^If the hard heap limit is enabled and if sqlite3_soft_heap_limit(N) 6957 ** is invoked with a value of N that is greater than the hard heap limit, 6958 ** the soft heap limit is set to the value of the hard heap limit. 6959 ** ^The soft heap limit is automatically enabled whenever the hard heap 6960 ** limit is enabled. ^When sqlite3_hard_heap_limit64(N) is invoked and 6961 ** the soft heap limit is outside the range of 1..N, then the soft heap 6962 ** limit is set to N. ^Invoking sqlite3_soft_heap_limit64(0) when the 6963 ** hard heap limit is enabled makes the soft heap limit equal to the 6964 ** hard heap limit. 6965 ** 6966 ** The memory allocation limits can also be adjusted using 6967 ** [PRAGMA soft_heap_limit] and [PRAGMA hard_heap_limit]. 6968 ** 6969 ** ^(The heap limits are not enforced in the current implementation 6970 ** if one or more of following conditions are true: 6971 ** 6972 ** <ul> 6973 ** <li> The limit value is set to zero. 6974 ** <li> Memory accounting is disabled using a combination of the 6975 ** [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],...) start-time option and 6976 ** the [SQLITE_DEFAULT_MEMSTATUS] compile-time option. 6977 ** <li> An alternative page cache implementation is specified using 6978 ** [sqlite3_config]([SQLITE_CONFIG_PCACHE2],...). 6979 ** <li> The page cache allocates from its own memory pool supplied 6980 ** by [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],...) rather than 6981 ** from the heap. 6982 ** </ul>)^ 6983 ** 6984 ** The circumstances under which SQLite will enforce the heap limits may 6985 ** changes in future releases of SQLite. 6986 */ 6987 SQLITE_API sqlite3_int64 sqlite3_soft_heap_limit64(sqlite3_int64 N); 6988 SQLITE_API sqlite3_int64 sqlite3_hard_heap_limit64(sqlite3_int64 N); 6989 6990 /* 6991 ** CAPI3REF: Deprecated Soft Heap Limit Interface 6992 ** DEPRECATED 6993 ** 6994 ** This is a deprecated version of the [sqlite3_soft_heap_limit64()] 6995 ** interface. This routine is provided for historical compatibility 6996 ** only. All new applications should use the 6997 ** [sqlite3_soft_heap_limit64()] interface rather than this one. 6998 */ 6999 SQLITE_API SQLITE_DEPRECATED void sqlite3_soft_heap_limit(int N); 7000 7001 7002 /* 7003 ** CAPI3REF: Extract Metadata About A Column Of A Table 7004 ** METHOD: sqlite3 7005 ** 7006 ** ^(The sqlite3_table_column_metadata(X,D,T,C,....) routine returns 7007 ** information about column C of table T in database D 7008 ** on [database connection] X.)^ ^The sqlite3_table_column_metadata() 7009 ** interface returns SQLITE_OK and fills in the non-NULL pointers in 7010 ** the final five arguments with appropriate values if the specified 7011 ** column exists. ^The sqlite3_table_column_metadata() interface returns 7012 ** SQLITE_ERROR if the specified column does not exist. 7013 ** ^If the column-name parameter to sqlite3_table_column_metadata() is a 7014 ** NULL pointer, then this routine simply checks for the existence of the 7015 ** table and returns SQLITE_OK if the table exists and SQLITE_ERROR if it 7016 ** does not. If the table name parameter T in a call to 7017 ** sqlite3_table_column_metadata(X,D,T,C,...) is NULL then the result is 7018 ** undefined behavior. 7019 ** 7020 ** ^The column is identified by the second, third and fourth parameters to 7021 ** this function. ^(The second parameter is either the name of the database 7022 ** (i.e. "main", "temp", or an attached database) containing the specified 7023 ** table or NULL.)^ ^If it is NULL, then all attached databases are searched 7024 ** for the table using the same algorithm used by the database engine to 7025 ** resolve unqualified table references. 7026 ** 7027 ** ^The third and fourth parameters to this function are the table and column 7028 ** name of the desired column, respectively. 7029 ** 7030 ** ^Metadata is returned by writing to the memory locations passed as the 5th 7031 ** and subsequent parameters to this function. ^Any of these arguments may be 7032 ** NULL, in which case the corresponding element of metadata is omitted. 7033 ** 7034 ** ^(<blockquote> 7035 ** <table border="1"> 7036 ** <tr><th> Parameter <th> Output<br>Type <th> Description 7037 ** 7038 ** <tr><td> 5th <td> const char* <td> Data type 7039 ** <tr><td> 6th <td> const char* <td> Name of default collation sequence 7040 ** <tr><td> 7th <td> int <td> True if column has a NOT NULL constraint 7041 ** <tr><td> 8th <td> int <td> True if column is part of the PRIMARY KEY 7042 ** <tr><td> 9th <td> int <td> True if column is [AUTOINCREMENT] 7043 ** </table> 7044 ** </blockquote>)^ 7045 ** 7046 ** ^The memory pointed to by the character pointers returned for the 7047 ** declaration type and collation sequence is valid until the next 7048 ** call to any SQLite API function. 7049 ** 7050 ** ^If the specified table is actually a view, an [error code] is returned. 7051 ** 7052 ** ^If the specified column is "rowid", "oid" or "_rowid_" and the table 7053 ** is not a [WITHOUT ROWID] table and an 7054 ** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output 7055 ** parameters are set for the explicitly declared column. ^(If there is no 7056 ** [INTEGER PRIMARY KEY] column, then the outputs 7057 ** for the [rowid] are set as follows: 7058 ** 7059 ** <pre> 7060 ** data type: "INTEGER" 7061 ** collation sequence: "BINARY" 7062 ** not null: 0 7063 ** primary key: 1 7064 ** auto increment: 0 7065 ** </pre>)^ 7066 ** 7067 ** ^This function causes all database schemas to be read from disk and 7068 ** parsed, if that has not already been done, and returns an error if 7069 ** any errors are encountered while loading the schema. 7070 */ 7071 SQLITE_API int sqlite3_table_column_metadata( 7072 sqlite3 *db, /* Connection handle */ 7073 const char *zDbName, /* Database name or NULL */ 7074 const char *zTableName, /* Table name */ 7075 const char *zColumnName, /* Column name */ 7076 char const **pzDataType, /* OUTPUT: Declared data type */ 7077 char const **pzCollSeq, /* OUTPUT: Collation sequence name */ 7078 int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */ 7079 int *pPrimaryKey, /* OUTPUT: True if column part of PK */ 7080 int *pAutoinc /* OUTPUT: True if column is auto-increment */ 7081 ); 7082 7083 /* 7084 ** CAPI3REF: Load An Extension 7085 ** METHOD: sqlite3 7086 ** 7087 ** ^This interface loads an SQLite extension library from the named file. 7088 ** 7089 ** ^The sqlite3_load_extension() interface attempts to load an 7090 ** [SQLite extension] library contained in the file zFile. If 7091 ** the file cannot be loaded directly, attempts are made to load 7092 ** with various operating-system specific extensions added. 7093 ** So for example, if "samplelib" cannot be loaded, then names like 7094 ** "samplelib.so" or "samplelib.dylib" or "samplelib.dll" might 7095 ** be tried also. 7096 ** 7097 ** ^The entry point is zProc. 7098 ** ^(zProc may be 0, in which case SQLite will try to come up with an 7099 ** entry point name on its own. It first tries "sqlite3_extension_init". 7100 ** If that does not work, it constructs a name "sqlite3_X_init" where the 7101 ** X is consists of the lower-case equivalent of all ASCII alphabetic 7102 ** characters in the filename from the last "/" to the first following 7103 ** "." and omitting any initial "lib".)^ 7104 ** ^The sqlite3_load_extension() interface returns 7105 ** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong. 7106 ** ^If an error occurs and pzErrMsg is not 0, then the 7107 ** [sqlite3_load_extension()] interface shall attempt to 7108 ** fill *pzErrMsg with error message text stored in memory 7109 ** obtained from [sqlite3_malloc()]. The calling function 7110 ** should free this memory by calling [sqlite3_free()]. 7111 ** 7112 ** ^Extension loading must be enabled using 7113 ** [sqlite3_enable_load_extension()] or 7114 ** [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],1,NULL) 7115 ** prior to calling this API, 7116 ** otherwise an error will be returned. 7117 ** 7118 ** <b>Security warning:</b> It is recommended that the 7119 ** [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method be used to enable only this 7120 ** interface. The use of the [sqlite3_enable_load_extension()] interface 7121 ** should be avoided. This will keep the SQL function [load_extension()] 7122 ** disabled and prevent SQL injections from giving attackers 7123 ** access to extension loading capabilities. 7124 ** 7125 ** See also the [load_extension() SQL function]. 7126 */ 7127 SQLITE_API int sqlite3_load_extension( 7128 sqlite3 *db, /* Load the extension into this database connection */ 7129 const char *zFile, /* Name of the shared library containing extension */ 7130 const char *zProc, /* Entry point. Derived from zFile if 0 */ 7131 char **pzErrMsg /* Put error message here if not 0 */ 7132 ); 7133 7134 /* 7135 ** CAPI3REF: Enable Or Disable Extension Loading 7136 ** METHOD: sqlite3 7137 ** 7138 ** ^So as not to open security holes in older applications that are 7139 ** unprepared to deal with [extension loading], and as a means of disabling 7140 ** [extension loading] while evaluating user-entered SQL, the following API 7141 ** is provided to turn the [sqlite3_load_extension()] mechanism on and off. 7142 ** 7143 ** ^Extension loading is off by default. 7144 ** ^Call the sqlite3_enable_load_extension() routine with onoff==1 7145 ** to turn extension loading on and call it with onoff==0 to turn 7146 ** it back off again. 7147 ** 7148 ** ^This interface enables or disables both the C-API 7149 ** [sqlite3_load_extension()] and the SQL function [load_extension()]. 7150 ** ^(Use [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],..) 7151 ** to enable or disable only the C-API.)^ 7152 ** 7153 ** <b>Security warning:</b> It is recommended that extension loading 7154 ** be enabled using the [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method 7155 ** rather than this interface, so the [load_extension()] SQL function 7156 ** remains disabled. This will prevent SQL injections from giving attackers 7157 ** access to extension loading capabilities. 7158 */ 7159 SQLITE_API int sqlite3_enable_load_extension(sqlite3 *db, int onoff); 7160 7161 /* 7162 ** CAPI3REF: Automatically Load Statically Linked Extensions 7163 ** 7164 ** ^This interface causes the xEntryPoint() function to be invoked for 7165 ** each new [database connection] that is created. The idea here is that 7166 ** xEntryPoint() is the entry point for a statically linked [SQLite extension] 7167 ** that is to be automatically loaded into all new database connections. 7168 ** 7169 ** ^(Even though the function prototype shows that xEntryPoint() takes 7170 ** no arguments and returns void, SQLite invokes xEntryPoint() with three 7171 ** arguments and expects an integer result as if the signature of the 7172 ** entry point where as follows: 7173 ** 7174 ** <blockquote><pre> 7175 ** int xEntryPoint( 7176 ** sqlite3 *db, 7177 ** const char **pzErrMsg, 7178 ** const struct sqlite3_api_routines *pThunk 7179 ** ); 7180 ** </pre></blockquote>)^ 7181 ** 7182 ** If the xEntryPoint routine encounters an error, it should make *pzErrMsg 7183 ** point to an appropriate error message (obtained from [sqlite3_mprintf()]) 7184 ** and return an appropriate [error code]. ^SQLite ensures that *pzErrMsg 7185 ** is NULL before calling the xEntryPoint(). ^SQLite will invoke 7186 ** [sqlite3_free()] on *pzErrMsg after xEntryPoint() returns. ^If any 7187 ** xEntryPoint() returns an error, the [sqlite3_open()], [sqlite3_open16()], 7188 ** or [sqlite3_open_v2()] call that provoked the xEntryPoint() will fail. 7189 ** 7190 ** ^Calling sqlite3_auto_extension(X) with an entry point X that is already 7191 ** on the list of automatic extensions is a harmless no-op. ^No entry point 7192 ** will be called more than once for each database connection that is opened. 7193 ** 7194 ** See also: [sqlite3_reset_auto_extension()] 7195 ** and [sqlite3_cancel_auto_extension()] 7196 */ 7197 SQLITE_API int sqlite3_auto_extension(void(*xEntryPoint)(void)); 7198 7199 /* 7200 ** CAPI3REF: Cancel Automatic Extension Loading 7201 ** 7202 ** ^The [sqlite3_cancel_auto_extension(X)] interface unregisters the 7203 ** initialization routine X that was registered using a prior call to 7204 ** [sqlite3_auto_extension(X)]. ^The [sqlite3_cancel_auto_extension(X)] 7205 ** routine returns 1 if initialization routine X was successfully 7206 ** unregistered and it returns 0 if X was not on the list of initialization 7207 ** routines. 7208 */ 7209 SQLITE_API int sqlite3_cancel_auto_extension(void(*xEntryPoint)(void)); 7210 7211 /* 7212 ** CAPI3REF: Reset Automatic Extension Loading 7213 ** 7214 ** ^This interface disables all automatic extensions previously 7215 ** registered using [sqlite3_auto_extension()]. 7216 */ 7217 SQLITE_API void sqlite3_reset_auto_extension(void); 7218 7219 /* 7220 ** Structures used by the virtual table interface 7221 */ 7222 typedef struct sqlite3_vtab sqlite3_vtab; 7223 typedef struct sqlite3_index_info sqlite3_index_info; 7224 typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor; 7225 typedef struct sqlite3_module sqlite3_module; 7226 7227 /* 7228 ** CAPI3REF: Virtual Table Object 7229 ** KEYWORDS: sqlite3_module {virtual table module} 7230 ** 7231 ** This structure, sometimes called a "virtual table module", 7232 ** defines the implementation of a [virtual table]. 7233 ** This structure consists mostly of methods for the module. 7234 ** 7235 ** ^A virtual table module is created by filling in a persistent 7236 ** instance of this structure and passing a pointer to that instance 7237 ** to [sqlite3_create_module()] or [sqlite3_create_module_v2()]. 7238 ** ^The registration remains valid until it is replaced by a different 7239 ** module or until the [database connection] closes. The content 7240 ** of this structure must not change while it is registered with 7241 ** any database connection. 7242 */ 7243 struct sqlite3_module { 7244 int iVersion; 7245 int (*xCreate)(sqlite3*, void *pAux, 7246 int argc, const char *const*argv, 7247 sqlite3_vtab **ppVTab, char**); 7248 int (*xConnect)(sqlite3*, void *pAux, 7249 int argc, const char *const*argv, 7250 sqlite3_vtab **ppVTab, char**); 7251 int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*); 7252 int (*xDisconnect)(sqlite3_vtab *pVTab); 7253 int (*xDestroy)(sqlite3_vtab *pVTab); 7254 int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor); 7255 int (*xClose)(sqlite3_vtab_cursor*); 7256 int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr, 7257 int argc, sqlite3_value **argv); 7258 int (*xNext)(sqlite3_vtab_cursor*); 7259 int (*xEof)(sqlite3_vtab_cursor*); 7260 int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int); 7261 int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid); 7262 int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *); 7263 int (*xBegin)(sqlite3_vtab *pVTab); 7264 int (*xSync)(sqlite3_vtab *pVTab); 7265 int (*xCommit)(sqlite3_vtab *pVTab); 7266 int (*xRollback)(sqlite3_vtab *pVTab); 7267 int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName, 7268 void (**pxFunc)(sqlite3_context*,int,sqlite3_value**), 7269 void **ppArg); 7270 int (*xRename)(sqlite3_vtab *pVtab, const char *zNew); 7271 /* The methods above are in version 1 of the sqlite_module object. Those 7272 ** below are for version 2 and greater. */ 7273 int (*xSavepoint)(sqlite3_vtab *pVTab, int); 7274 int (*xRelease)(sqlite3_vtab *pVTab, int); 7275 int (*xRollbackTo)(sqlite3_vtab *pVTab, int); 7276 /* The methods above are in versions 1 and 2 of the sqlite_module object. 7277 ** Those below are for version 3 and greater. */ 7278 int (*xShadowName)(const char*); 7279 /* The methods above are in versions 1 through 3 of the sqlite_module object. 7280 ** Those below are for version 4 and greater. */ 7281 int (*xIntegrity)(sqlite3_vtab *pVTab, const char *zSchema, 7282 const char *zTabName, int mFlags, char **pzErr); 7283 }; 7284 7285 /* 7286 ** CAPI3REF: Virtual Table Indexing Information 7287 ** KEYWORDS: sqlite3_index_info 7288 ** 7289 ** The sqlite3_index_info structure and its substructures is used as part 7290 ** of the [virtual table] interface to 7291 ** pass information into and receive the reply from the [xBestIndex] 7292 ** method of a [virtual table module]. The fields under **Inputs** are the 7293 ** inputs to xBestIndex and are read-only. xBestIndex inserts its 7294 ** results into the **Outputs** fields. 7295 ** 7296 ** ^(The aConstraint[] array records WHERE clause constraints of the form: 7297 ** 7298 ** <blockquote>column OP expr</blockquote> 7299 ** 7300 ** where OP is =, <, <=, >, or >=.)^ ^(The particular operator is 7301 ** stored in aConstraint[].op using one of the 7302 ** [SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_ values].)^ 7303 ** ^(The index of the column is stored in 7304 ** aConstraint[].iColumn.)^ ^(aConstraint[].usable is TRUE if the 7305 ** expr on the right-hand side can be evaluated (and thus the constraint 7306 ** is usable) and false if it cannot.)^ 7307 ** 7308 ** ^The optimizer automatically inverts terms of the form "expr OP column" 7309 ** and makes other simplifications to the WHERE clause in an attempt to 7310 ** get as many WHERE clause terms into the form shown above as possible. 7311 ** ^The aConstraint[] array only reports WHERE clause terms that are 7312 ** relevant to the particular virtual table being queried. 7313 ** 7314 ** ^Information about the ORDER BY clause is stored in aOrderBy[]. 7315 ** ^Each term of aOrderBy records a column of the ORDER BY clause. 7316 ** 7317 ** The colUsed field indicates which columns of the virtual table may be 7318 ** required by the current scan. Virtual table columns are numbered from 7319 ** zero in the order in which they appear within the CREATE TABLE statement 7320 ** passed to sqlite3_declare_vtab(). For the first 63 columns (columns 0-62), 7321 ** the corresponding bit is set within the colUsed mask if the column may be 7322 ** required by SQLite. If the table has at least 64 columns and any column 7323 ** to the right of the first 63 is required, then bit 63 of colUsed is also 7324 ** set. In other words, column iCol may be required if the expression 7325 ** (colUsed & ((sqlite3_uint64)1 << (iCol>=63 ? 63 : iCol))) evaluates to 7326 ** non-zero. 7327 ** 7328 ** The [xBestIndex] method must fill aConstraintUsage[] with information 7329 ** about what parameters to pass to xFilter. ^If argvIndex>0 then 7330 ** the right-hand side of the corresponding aConstraint[] is evaluated 7331 ** and becomes the argvIndex-th entry in argv. ^(If aConstraintUsage[].omit 7332 ** is true, then the constraint is assumed to be fully handled by the 7333 ** virtual table and might not be checked again by the byte code.)^ ^(The 7334 ** aConstraintUsage[].omit flag is an optimization hint. When the omit flag 7335 ** is left in its default setting of false, the constraint will always be 7336 ** checked separately in byte code. If the omit flag is change to true, then 7337 ** the constraint may or may not be checked in byte code. In other words, 7338 ** when the omit flag is true there is no guarantee that the constraint will 7339 ** not be checked again using byte code.)^ 7340 ** 7341 ** ^The idxNum and idxStr values are recorded and passed into the 7342 ** [xFilter] method. 7343 ** ^[sqlite3_free()] is used to free idxStr if and only if 7344 ** needToFreeIdxStr is true. 7345 ** 7346 ** ^The orderByConsumed means that output from [xFilter]/[xNext] will occur in 7347 ** the correct order to satisfy the ORDER BY clause so that no separate 7348 ** sorting step is required. 7349 ** 7350 ** ^The estimatedCost value is an estimate of the cost of a particular 7351 ** strategy. A cost of N indicates that the cost of the strategy is similar 7352 ** to a linear scan of an SQLite table with N rows. A cost of log(N) 7353 ** indicates that the expense of the operation is similar to that of a 7354 ** binary search on a unique indexed field of an SQLite table with N rows. 7355 ** 7356 ** ^The estimatedRows value is an estimate of the number of rows that 7357 ** will be returned by the strategy. 7358 ** 7359 ** The xBestIndex method may optionally populate the idxFlags field with a 7360 ** mask of SQLITE_INDEX_SCAN_* flags. Currently there is only one such flag - 7361 ** SQLITE_INDEX_SCAN_UNIQUE. If the xBestIndex method sets this flag, SQLite 7362 ** assumes that the strategy may visit at most one row. 7363 ** 7364 ** Additionally, if xBestIndex sets the SQLITE_INDEX_SCAN_UNIQUE flag, then 7365 ** SQLite also assumes that if a call to the xUpdate() method is made as 7366 ** part of the same statement to delete or update a virtual table row and the 7367 ** implementation returns SQLITE_CONSTRAINT, then there is no need to rollback 7368 ** any database changes. In other words, if the xUpdate() returns 7369 ** SQLITE_CONSTRAINT, the database contents must be exactly as they were 7370 ** before xUpdate was called. By contrast, if SQLITE_INDEX_SCAN_UNIQUE is not 7371 ** set and xUpdate returns SQLITE_CONSTRAINT, any database changes made by 7372 ** the xUpdate method are automatically rolled back by SQLite. 7373 ** 7374 ** IMPORTANT: The estimatedRows field was added to the sqlite3_index_info 7375 ** structure for SQLite [version 3.8.2] ([dateof:3.8.2]). 7376 ** If a virtual table extension is 7377 ** used with an SQLite version earlier than 3.8.2, the results of attempting 7378 ** to read or write the estimatedRows field are undefined (but are likely 7379 ** to include crashing the application). The estimatedRows field should 7380 ** therefore only be used if [sqlite3_libversion_number()] returns a 7381 ** value greater than or equal to 3008002. Similarly, the idxFlags field 7382 ** was added for [version 3.9.0] ([dateof:3.9.0]). 7383 ** It may therefore only be used if 7384 ** sqlite3_libversion_number() returns a value greater than or equal to 7385 ** 3009000. 7386 */ 7387 struct sqlite3_index_info { 7388 /* Inputs */ 7389 int nConstraint; /* Number of entries in aConstraint */ 7390 struct sqlite3_index_constraint { 7391 int iColumn; /* Column constrained. -1 for ROWID */ 7392 unsigned char op; /* Constraint operator */ 7393 unsigned char usable; /* True if this constraint is usable */ 7394 int iTermOffset; /* Used internally - xBestIndex should ignore */ 7395 } *aConstraint; /* Table of WHERE clause constraints */ 7396 int nOrderBy; /* Number of terms in the ORDER BY clause */ 7397 struct sqlite3_index_orderby { 7398 int iColumn; /* Column number */ 7399 unsigned char desc; /* True for DESC. False for ASC. */ 7400 } *aOrderBy; /* The ORDER BY clause */ 7401 /* Outputs */ 7402 struct sqlite3_index_constraint_usage { 7403 int argvIndex; /* if >0, constraint is part of argv to xFilter */ 7404 unsigned char omit; /* Do not code a test for this constraint */ 7405 } *aConstraintUsage; 7406 int idxNum; /* Number used to identify the index */ 7407 char *idxStr; /* String, possibly obtained from sqlite3_malloc */ 7408 int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */ 7409 int orderByConsumed; /* True if output is already ordered */ 7410 double estimatedCost; /* Estimated cost of using this index */ 7411 /* Fields below are only available in SQLite 3.8.2 and later */ 7412 sqlite3_int64 estimatedRows; /* Estimated number of rows returned */ 7413 /* Fields below are only available in SQLite 3.9.0 and later */ 7414 int idxFlags; /* Mask of SQLITE_INDEX_SCAN_* flags */ 7415 /* Fields below are only available in SQLite 3.10.0 and later */ 7416 sqlite3_uint64 colUsed; /* Input: Mask of columns used by statement */ 7417 }; 7418 7419 /* 7420 ** CAPI3REF: Virtual Table Scan Flags 7421 ** 7422 ** Virtual table implementations are allowed to set the 7423 ** [sqlite3_index_info].idxFlags field to some combination of 7424 ** these bits. 7425 */ 7426 #define SQLITE_INDEX_SCAN_UNIQUE 1 /* Scan visits at most 1 row */ 7427 7428 /* 7429 ** CAPI3REF: Virtual Table Constraint Operator Codes 7430 ** 7431 ** These macros define the allowed values for the 7432 ** [sqlite3_index_info].aConstraint[].op field. Each value represents 7433 ** an operator that is part of a constraint term in the WHERE clause of 7434 ** a query that uses a [virtual table]. 7435 ** 7436 ** ^The left-hand operand of the operator is given by the corresponding 7437 ** aConstraint[].iColumn field. ^An iColumn of -1 indicates the left-hand 7438 ** operand is the rowid. 7439 ** The SQLITE_INDEX_CONSTRAINT_LIMIT and SQLITE_INDEX_CONSTRAINT_OFFSET 7440 ** operators have no left-hand operand, and so for those operators the 7441 ** corresponding aConstraint[].iColumn is meaningless and should not be 7442 ** used. 7443 ** 7444 ** All operator values from SQLITE_INDEX_CONSTRAINT_FUNCTION through 7445 ** value 255 are reserved to represent functions that are overloaded 7446 ** by the [xFindFunction|xFindFunction method] of the virtual table 7447 ** implementation. 7448 ** 7449 ** The right-hand operands for each constraint might be accessible using 7450 ** the [sqlite3_vtab_rhs_value()] interface. Usually the right-hand 7451 ** operand is only available if it appears as a single constant literal 7452 ** in the input SQL. If the right-hand operand is another column or an 7453 ** expression (even a constant expression) or a parameter, then the 7454 ** sqlite3_vtab_rhs_value() probably will not be able to extract it. 7455 ** ^The SQLITE_INDEX_CONSTRAINT_ISNULL and 7456 ** SQLITE_INDEX_CONSTRAINT_ISNOTNULL operators have no right-hand operand 7457 ** and hence calls to sqlite3_vtab_rhs_value() for those operators will 7458 ** always return SQLITE_NOTFOUND. 7459 ** 7460 ** The collating sequence to be used for comparison can be found using 7461 ** the [sqlite3_vtab_collation()] interface. For most real-world virtual 7462 ** tables, the collating sequence of constraints does not matter (for example 7463 ** because the constraints are numeric) and so the sqlite3_vtab_collation() 7464 ** interface is not commonly needed. 7465 */ 7466 #define SQLITE_INDEX_CONSTRAINT_EQ 2 7467 #define SQLITE_INDEX_CONSTRAINT_GT 4 7468 #define SQLITE_INDEX_CONSTRAINT_LE 8 7469 #define SQLITE_INDEX_CONSTRAINT_LT 16 7470 #define SQLITE_INDEX_CONSTRAINT_GE 32 7471 #define SQLITE_INDEX_CONSTRAINT_MATCH 64 7472 #define SQLITE_INDEX_CONSTRAINT_LIKE 65 7473 #define SQLITE_INDEX_CONSTRAINT_GLOB 66 7474 #define SQLITE_INDEX_CONSTRAINT_REGEXP 67 7475 #define SQLITE_INDEX_CONSTRAINT_NE 68 7476 #define SQLITE_INDEX_CONSTRAINT_ISNOT 69 7477 #define SQLITE_INDEX_CONSTRAINT_ISNOTNULL 70 7478 #define SQLITE_INDEX_CONSTRAINT_ISNULL 71 7479 #define SQLITE_INDEX_CONSTRAINT_IS 72 7480 #define SQLITE_INDEX_CONSTRAINT_LIMIT 73 7481 #define SQLITE_INDEX_CONSTRAINT_OFFSET 74 7482 #define SQLITE_INDEX_CONSTRAINT_FUNCTION 150 7483 7484 /* 7485 ** CAPI3REF: Register A Virtual Table Implementation 7486 ** METHOD: sqlite3 7487 ** 7488 ** ^These routines are used to register a new [virtual table module] name. 7489 ** ^Module names must be registered before 7490 ** creating a new [virtual table] using the module and before using a 7491 ** preexisting [virtual table] for the module. 7492 ** 7493 ** ^The module name is registered on the [database connection] specified 7494 ** by the first parameter. ^The name of the module is given by the 7495 ** second parameter. ^The third parameter is a pointer to 7496 ** the implementation of the [virtual table module]. ^The fourth 7497 ** parameter is an arbitrary client data pointer that is passed through 7498 ** into the [xCreate] and [xConnect] methods of the virtual table module 7499 ** when a new virtual table is be being created or reinitialized. 7500 ** 7501 ** ^The sqlite3_create_module_v2() interface has a fifth parameter which 7502 ** is a pointer to a destructor for the pClientData. ^SQLite will 7503 ** invoke the destructor function (if it is not NULL) when SQLite 7504 ** no longer needs the pClientData pointer. ^The destructor will also 7505 ** be invoked if the call to sqlite3_create_module_v2() fails. 7506 ** ^The sqlite3_create_module() 7507 ** interface is equivalent to sqlite3_create_module_v2() with a NULL 7508 ** destructor. 7509 ** 7510 ** ^If the third parameter (the pointer to the sqlite3_module object) is 7511 ** NULL then no new module is created and any existing modules with the 7512 ** same name are dropped. 7513 ** 7514 ** See also: [sqlite3_drop_modules()] 7515 */ 7516 SQLITE_API int sqlite3_create_module( 7517 sqlite3 *db, /* SQLite connection to register module with */ 7518 const char *zName, /* Name of the module */ 7519 const sqlite3_module *p, /* Methods for the module */ 7520 void *pClientData /* Client data for xCreate/xConnect */ 7521 ); 7522 SQLITE_API int sqlite3_create_module_v2( 7523 sqlite3 *db, /* SQLite connection to register module with */ 7524 const char *zName, /* Name of the module */ 7525 const sqlite3_module *p, /* Methods for the module */ 7526 void *pClientData, /* Client data for xCreate/xConnect */ 7527 void(*xDestroy)(void*) /* Module destructor function */ 7528 ); 7529 7530 /* 7531 ** CAPI3REF: Remove Unnecessary Virtual Table Implementations 7532 ** METHOD: sqlite3 7533 ** 7534 ** ^The sqlite3_drop_modules(D,L) interface removes all virtual 7535 ** table modules from database connection D except those named on list L. 7536 ** The L parameter must be either NULL or a pointer to an array of pointers 7537 ** to strings where the array is terminated by a single NULL pointer. 7538 ** ^If the L parameter is NULL, then all virtual table modules are removed. 7539 ** 7540 ** See also: [sqlite3_create_module()] 7541 */ 7542 SQLITE_API int sqlite3_drop_modules( 7543 sqlite3 *db, /* Remove modules from this connection */ 7544 const char **azKeep /* Except, do not remove the ones named here */ 7545 ); 7546 7547 /* 7548 ** CAPI3REF: Virtual Table Instance Object 7549 ** KEYWORDS: sqlite3_vtab 7550 ** 7551 ** Every [virtual table module] implementation uses a subclass 7552 ** of this object to describe a particular instance 7553 ** of the [virtual table]. Each subclass will 7554 ** be tailored to the specific needs of the module implementation. 7555 ** The purpose of this superclass is to define certain fields that are 7556 ** common to all module implementations. 7557 ** 7558 ** ^Virtual tables methods can set an error message by assigning a 7559 ** string obtained from [sqlite3_mprintf()] to zErrMsg. The method should 7560 ** take care that any prior string is freed by a call to [sqlite3_free()] 7561 ** prior to assigning a new string to zErrMsg. ^After the error message 7562 ** is delivered up to the client application, the string will be automatically 7563 ** freed by sqlite3_free() and the zErrMsg field will be zeroed. 7564 */ 7565 struct sqlite3_vtab { 7566 const sqlite3_module *pModule; /* The module for this virtual table */ 7567 int nRef; /* Number of open cursors */ 7568 char *zErrMsg; /* Error message from sqlite3_mprintf() */ 7569 /* Virtual table implementations will typically add additional fields */ 7570 }; 7571 7572 /* 7573 ** CAPI3REF: Virtual Table Cursor Object 7574 ** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor} 7575 ** 7576 ** Every [virtual table module] implementation uses a subclass of the 7577 ** following structure to describe cursors that point into the 7578 ** [virtual table] and are used 7579 ** to loop through the virtual table. Cursors are created using the 7580 ** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed 7581 ** by the [sqlite3_module.xClose | xClose] method. Cursors are used 7582 ** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods 7583 ** of the module. Each module implementation will define 7584 ** the content of a cursor structure to suit its own needs. 7585 ** 7586 ** This superclass exists in order to define fields of the cursor that 7587 ** are common to all implementations. 7588 */ 7589 struct sqlite3_vtab_cursor { 7590 sqlite3_vtab *pVtab; /* Virtual table of this cursor */ 7591 /* Virtual table implementations will typically add additional fields */ 7592 }; 7593 7594 /* 7595 ** CAPI3REF: Declare The Schema Of A Virtual Table 7596 ** 7597 ** ^The [xCreate] and [xConnect] methods of a 7598 ** [virtual table module] call this interface 7599 ** to declare the format (the names and datatypes of the columns) of 7600 ** the virtual tables they implement. 7601 */ 7602 SQLITE_API int sqlite3_declare_vtab(sqlite3*, const char *zSQL); 7603 7604 /* 7605 ** CAPI3REF: Overload A Function For A Virtual Table 7606 ** METHOD: sqlite3 7607 ** 7608 ** ^(Virtual tables can provide alternative implementations of functions 7609 ** using the [xFindFunction] method of the [virtual table module]. 7610 ** But global versions of those functions 7611 ** must exist in order to be overloaded.)^ 7612 ** 7613 ** ^(This API makes sure a global version of a function with a particular 7614 ** name and number of parameters exists. If no such function exists 7615 ** before this API is called, a new function is created.)^ ^The implementation 7616 ** of the new function always causes an exception to be thrown. So 7617 ** the new function is not good for anything by itself. Its only 7618 ** purpose is to be a placeholder function that can be overloaded 7619 ** by a [virtual table]. 7620 */ 7621 SQLITE_API int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg); 7622 7623 /* 7624 ** CAPI3REF: A Handle To An Open BLOB 7625 ** KEYWORDS: {BLOB handle} {BLOB handles} 7626 ** 7627 ** An instance of this object represents an open BLOB on which 7628 ** [sqlite3_blob_open | incremental BLOB I/O] can be performed. 7629 ** ^Objects of this type are created by [sqlite3_blob_open()] 7630 ** and destroyed by [sqlite3_blob_close()]. 7631 ** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces 7632 ** can be used to read or write small subsections of the BLOB. 7633 ** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes. 7634 */ 7635 typedef struct sqlite3_blob sqlite3_blob; 7636 7637 /* 7638 ** CAPI3REF: Open A BLOB For Incremental I/O 7639 ** METHOD: sqlite3 7640 ** CONSTRUCTOR: sqlite3_blob 7641 ** 7642 ** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located 7643 ** in row iRow, column zColumn, table zTable in database zDb; 7644 ** in other words, the same BLOB that would be selected by: 7645 ** 7646 ** <pre> 7647 ** SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow; 7648 ** </pre>)^ 7649 ** 7650 ** ^(Parameter zDb is not the filename that contains the database, but 7651 ** rather the symbolic name of the database. For attached databases, this is 7652 ** the name that appears after the AS keyword in the [ATTACH] statement. 7653 ** For the main database file, the database name is "main". For TEMP 7654 ** tables, the database name is "temp".)^ 7655 ** 7656 ** ^If the flags parameter is non-zero, then the BLOB is opened for read 7657 ** and write access. ^If the flags parameter is zero, the BLOB is opened for 7658 ** read-only access. 7659 ** 7660 ** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is stored 7661 ** in *ppBlob. Otherwise an [error code] is returned and, unless the error 7662 ** code is SQLITE_MISUSE, *ppBlob is set to NULL.)^ ^This means that, provided 7663 ** the API is not misused, it is always safe to call [sqlite3_blob_close()] 7664 ** on *ppBlob after this function it returns. 7665 ** 7666 ** This function fails with SQLITE_ERROR if any of the following are true: 7667 ** <ul> 7668 ** <li> ^(Database zDb does not exist)^, 7669 ** <li> ^(Table zTable does not exist within database zDb)^, 7670 ** <li> ^(Table zTable is a WITHOUT ROWID table)^, 7671 ** <li> ^(Column zColumn does not exist)^, 7672 ** <li> ^(Row iRow is not present in the table)^, 7673 ** <li> ^(The specified column of row iRow contains a value that is not 7674 ** a TEXT or BLOB value)^, 7675 ** <li> ^(Column zColumn is part of an index, PRIMARY KEY or UNIQUE 7676 ** constraint and the blob is being opened for read/write access)^, 7677 ** <li> ^([foreign key constraints | Foreign key constraints] are enabled, 7678 ** column zColumn is part of a [child key] definition and the blob is 7679 ** being opened for read/write access)^. 7680 ** </ul> 7681 ** 7682 ** ^Unless it returns SQLITE_MISUSE, this function sets the 7683 ** [database connection] error code and message accessible via 7684 ** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions. 7685 ** 7686 ** A BLOB referenced by sqlite3_blob_open() may be read using the 7687 ** [sqlite3_blob_read()] interface and modified by using 7688 ** [sqlite3_blob_write()]. The [BLOB handle] can be moved to a 7689 ** different row of the same table using the [sqlite3_blob_reopen()] 7690 ** interface. However, the column, table, or database of a [BLOB handle] 7691 ** cannot be changed after the [BLOB handle] is opened. 7692 ** 7693 ** ^(If the row that a BLOB handle points to is modified by an 7694 ** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects 7695 ** then the BLOB handle is marked as "expired". 7696 ** This is true if any column of the row is changed, even a column 7697 ** other than the one the BLOB handle is open on.)^ 7698 ** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for 7699 ** an expired BLOB handle fail with a return code of [SQLITE_ABORT]. 7700 ** ^(Changes written into a BLOB prior to the BLOB expiring are not 7701 ** rolled back by the expiration of the BLOB. Such changes will eventually 7702 ** commit if the transaction continues to completion.)^ 7703 ** 7704 ** ^Use the [sqlite3_blob_bytes()] interface to determine the size of 7705 ** the opened blob. ^The size of a blob may not be changed by this 7706 ** interface. Use the [UPDATE] SQL command to change the size of a 7707 ** blob. 7708 ** 7709 ** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces 7710 ** and the built-in [zeroblob] SQL function may be used to create a 7711 ** zero-filled blob to read or write using the incremental-blob interface. 7712 ** 7713 ** To avoid a resource leak, every open [BLOB handle] should eventually 7714 ** be released by a call to [sqlite3_blob_close()]. 7715 ** 7716 ** See also: [sqlite3_blob_close()], 7717 ** [sqlite3_blob_reopen()], [sqlite3_blob_read()], 7718 ** [sqlite3_blob_bytes()], [sqlite3_blob_write()]. 7719 */ 7720 SQLITE_API int sqlite3_blob_open( 7721 sqlite3*, 7722 const char *zDb, 7723 const char *zTable, 7724 const char *zColumn, 7725 sqlite3_int64 iRow, 7726 int flags, 7727 sqlite3_blob **ppBlob 7728 ); 7729 7730 /* 7731 ** CAPI3REF: Move a BLOB Handle to a New Row 7732 ** METHOD: sqlite3_blob 7733 ** 7734 ** ^This function is used to move an existing [BLOB handle] so that it points 7735 ** to a different row of the same database table. ^The new row is identified 7736 ** by the rowid value passed as the second argument. Only the row can be 7737 ** changed. ^The database, table and column on which the blob handle is open 7738 ** remain the same. Moving an existing [BLOB handle] to a new row is 7739 ** faster than closing the existing handle and opening a new one. 7740 ** 7741 ** ^(The new row must meet the same criteria as for [sqlite3_blob_open()] - 7742 ** it must exist and there must be either a blob or text value stored in 7743 ** the nominated column.)^ ^If the new row is not present in the table, or if 7744 ** it does not contain a blob or text value, or if another error occurs, an 7745 ** SQLite error code is returned and the blob handle is considered aborted. 7746 ** ^All subsequent calls to [sqlite3_blob_read()], [sqlite3_blob_write()] or 7747 ** [sqlite3_blob_reopen()] on an aborted blob handle immediately return 7748 ** SQLITE_ABORT. ^Calling [sqlite3_blob_bytes()] on an aborted blob handle 7749 ** always returns zero. 7750 ** 7751 ** ^This function sets the database handle error code and message. 7752 */ 7753 SQLITE_API int sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64); 7754 7755 /* 7756 ** CAPI3REF: Close A BLOB Handle 7757 ** DESTRUCTOR: sqlite3_blob 7758 ** 7759 ** ^This function closes an open [BLOB handle]. ^(The BLOB handle is closed 7760 ** unconditionally. Even if this routine returns an error code, the 7761 ** handle is still closed.)^ 7762 ** 7763 ** ^If the blob handle being closed was opened for read-write access, and if 7764 ** the database is in auto-commit mode and there are no other open read-write 7765 ** blob handles or active write statements, the current transaction is 7766 ** committed. ^If an error occurs while committing the transaction, an error 7767 ** code is returned and the transaction rolled back. 7768 ** 7769 ** Calling this function with an argument that is not a NULL pointer or an 7770 ** open blob handle results in undefined behavior. ^Calling this routine 7771 ** with a null pointer (such as would be returned by a failed call to 7772 ** [sqlite3_blob_open()]) is a harmless no-op. ^Otherwise, if this function 7773 ** is passed a valid open blob handle, the values returned by the 7774 ** sqlite3_errcode() and sqlite3_errmsg() functions are set before returning. 7775 */ 7776 SQLITE_API int sqlite3_blob_close(sqlite3_blob *); 7777 7778 /* 7779 ** CAPI3REF: Return The Size Of An Open BLOB 7780 ** METHOD: sqlite3_blob 7781 ** 7782 ** ^Returns the size in bytes of the BLOB accessible via the 7783 ** successfully opened [BLOB handle] in its only argument. ^The 7784 ** incremental blob I/O routines can only read or overwriting existing 7785 ** blob content; they cannot change the size of a blob. 7786 ** 7787 ** This routine only works on a [BLOB handle] which has been created 7788 ** by a prior successful call to [sqlite3_blob_open()] and which has not 7789 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in 7790 ** to this routine results in undefined and probably undesirable behavior. 7791 */ 7792 SQLITE_API int sqlite3_blob_bytes(sqlite3_blob *); 7793 7794 /* 7795 ** CAPI3REF: Read Data From A BLOB Incrementally 7796 ** METHOD: sqlite3_blob 7797 ** 7798 ** ^(This function is used to read data from an open [BLOB handle] into a 7799 ** caller-supplied buffer. N bytes of data are copied into buffer Z 7800 ** from the open BLOB, starting at offset iOffset.)^ 7801 ** 7802 ** ^If offset iOffset is less than N bytes from the end of the BLOB, 7803 ** [SQLITE_ERROR] is returned and no data is read. ^If N or iOffset is 7804 ** less than zero, [SQLITE_ERROR] is returned and no data is read. 7805 ** ^The size of the blob (and hence the maximum value of N+iOffset) 7806 ** can be determined using the [sqlite3_blob_bytes()] interface. 7807 ** 7808 ** ^An attempt to read from an expired [BLOB handle] fails with an 7809 ** error code of [SQLITE_ABORT]. 7810 ** 7811 ** ^(On success, sqlite3_blob_read() returns SQLITE_OK. 7812 ** Otherwise, an [error code] or an [extended error code] is returned.)^ 7813 ** 7814 ** This routine only works on a [BLOB handle] which has been created 7815 ** by a prior successful call to [sqlite3_blob_open()] and which has not 7816 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in 7817 ** to this routine results in undefined and probably undesirable behavior. 7818 ** 7819 ** See also: [sqlite3_blob_write()]. 7820 */ 7821 SQLITE_API int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset); 7822 7823 /* 7824 ** CAPI3REF: Write Data Into A BLOB Incrementally 7825 ** METHOD: sqlite3_blob 7826 ** 7827 ** ^(This function is used to write data into an open [BLOB handle] from a 7828 ** caller-supplied buffer. N bytes of data are copied from the buffer Z 7829 ** into the open BLOB, starting at offset iOffset.)^ 7830 ** 7831 ** ^(On success, sqlite3_blob_write() returns SQLITE_OK. 7832 ** Otherwise, an [error code] or an [extended error code] is returned.)^ 7833 ** ^Unless SQLITE_MISUSE is returned, this function sets the 7834 ** [database connection] error code and message accessible via 7835 ** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions. 7836 ** 7837 ** ^If the [BLOB handle] passed as the first argument was not opened for 7838 ** writing (the flags parameter to [sqlite3_blob_open()] was zero), 7839 ** this function returns [SQLITE_READONLY]. 7840 ** 7841 ** This function may only modify the contents of the BLOB; it is 7842 ** not possible to increase the size of a BLOB using this API. 7843 ** ^If offset iOffset is less than N bytes from the end of the BLOB, 7844 ** [SQLITE_ERROR] is returned and no data is written. The size of the 7845 ** BLOB (and hence the maximum value of N+iOffset) can be determined 7846 ** using the [sqlite3_blob_bytes()] interface. ^If N or iOffset are less 7847 ** than zero [SQLITE_ERROR] is returned and no data is written. 7848 ** 7849 ** ^An attempt to write to an expired [BLOB handle] fails with an 7850 ** error code of [SQLITE_ABORT]. ^Writes to the BLOB that occurred 7851 ** before the [BLOB handle] expired are not rolled back by the 7852 ** expiration of the handle, though of course those changes might 7853 ** have been overwritten by the statement that expired the BLOB handle 7854 ** or by other independent statements. 7855 ** 7856 ** This routine only works on a [BLOB handle] which has been created 7857 ** by a prior successful call to [sqlite3_blob_open()] and which has not 7858 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in 7859 ** to this routine results in undefined and probably undesirable behavior. 7860 ** 7861 ** See also: [sqlite3_blob_read()]. 7862 */ 7863 SQLITE_API int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset); 7864 7865 /* 7866 ** CAPI3REF: Virtual File System Objects 7867 ** 7868 ** A virtual filesystem (VFS) is an [sqlite3_vfs] object 7869 ** that SQLite uses to interact 7870 ** with the underlying operating system. Most SQLite builds come with a 7871 ** single default VFS that is appropriate for the host computer. 7872 ** New VFSes can be registered and existing VFSes can be unregistered. 7873 ** The following interfaces are provided. 7874 ** 7875 ** ^The sqlite3_vfs_find() interface returns a pointer to a VFS given its name. 7876 ** ^Names are case sensitive. 7877 ** ^Names are zero-terminated UTF-8 strings. 7878 ** ^If there is no match, a NULL pointer is returned. 7879 ** ^If zVfsName is NULL then the default VFS is returned. 7880 ** 7881 ** ^New VFSes are registered with sqlite3_vfs_register(). 7882 ** ^Each new VFS becomes the default VFS if the makeDflt flag is set. 7883 ** ^The same VFS can be registered multiple times without injury. 7884 ** ^To make an existing VFS into the default VFS, register it again 7885 ** with the makeDflt flag set. If two different VFSes with the 7886 ** same name are registered, the behavior is undefined. If a 7887 ** VFS is registered with a name that is NULL or an empty string, 7888 ** then the behavior is undefined. 7889 ** 7890 ** ^Unregister a VFS with the sqlite3_vfs_unregister() interface. 7891 ** ^(If the default VFS is unregistered, another VFS is chosen as 7892 ** the default. The choice for the new VFS is arbitrary.)^ 7893 */ 7894 SQLITE_API sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName); 7895 SQLITE_API int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt); 7896 SQLITE_API int sqlite3_vfs_unregister(sqlite3_vfs*); 7897 7898 /* 7899 ** CAPI3REF: Mutexes 7900 ** 7901 ** The SQLite core uses these routines for thread 7902 ** synchronization. Though they are intended for internal 7903 ** use by SQLite, code that links against SQLite is 7904 ** permitted to use any of these routines. 7905 ** 7906 ** The SQLite source code contains multiple implementations 7907 ** of these mutex routines. An appropriate implementation 7908 ** is selected automatically at compile-time. The following 7909 ** implementations are available in the SQLite core: 7910 ** 7911 ** <ul> 7912 ** <li> SQLITE_MUTEX_PTHREADS 7913 ** <li> SQLITE_MUTEX_W32 7914 ** <li> SQLITE_MUTEX_NOOP 7915 ** </ul> 7916 ** 7917 ** The SQLITE_MUTEX_NOOP implementation is a set of routines 7918 ** that does no real locking and is appropriate for use in 7919 ** a single-threaded application. The SQLITE_MUTEX_PTHREADS and 7920 ** SQLITE_MUTEX_W32 implementations are appropriate for use on Unix 7921 ** and Windows. 7922 ** 7923 ** If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor 7924 ** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex 7925 ** implementation is included with the library. In this case the 7926 ** application must supply a custom mutex implementation using the 7927 ** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function 7928 ** before calling sqlite3_initialize() or any other public sqlite3_ 7929 ** function that calls sqlite3_initialize(). 7930 ** 7931 ** ^The sqlite3_mutex_alloc() routine allocates a new 7932 ** mutex and returns a pointer to it. ^The sqlite3_mutex_alloc() 7933 ** routine returns NULL if it is unable to allocate the requested 7934 ** mutex. The argument to sqlite3_mutex_alloc() must one of these 7935 ** integer constants: 7936 ** 7937 ** <ul> 7938 ** <li> SQLITE_MUTEX_FAST 7939 ** <li> SQLITE_MUTEX_RECURSIVE 7940 ** <li> SQLITE_MUTEX_STATIC_MAIN 7941 ** <li> SQLITE_MUTEX_STATIC_MEM 7942 ** <li> SQLITE_MUTEX_STATIC_OPEN 7943 ** <li> SQLITE_MUTEX_STATIC_PRNG 7944 ** <li> SQLITE_MUTEX_STATIC_LRU 7945 ** <li> SQLITE_MUTEX_STATIC_PMEM 7946 ** <li> SQLITE_MUTEX_STATIC_APP1 7947 ** <li> SQLITE_MUTEX_STATIC_APP2 7948 ** <li> SQLITE_MUTEX_STATIC_APP3 7949 ** <li> SQLITE_MUTEX_STATIC_VFS1 7950 ** <li> SQLITE_MUTEX_STATIC_VFS2 7951 ** <li> SQLITE_MUTEX_STATIC_VFS3 7952 ** </ul> 7953 ** 7954 ** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) 7955 ** cause sqlite3_mutex_alloc() to create 7956 ** a new mutex. ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE 7957 ** is used but not necessarily so when SQLITE_MUTEX_FAST is used. 7958 ** The mutex implementation does not need to make a distinction 7959 ** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does 7960 ** not want to. SQLite will only request a recursive mutex in 7961 ** cases where it really needs one. If a faster non-recursive mutex 7962 ** implementation is available on the host platform, the mutex subsystem 7963 ** might return such a mutex in response to SQLITE_MUTEX_FAST. 7964 ** 7965 ** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other 7966 ** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return 7967 ** a pointer to a static preexisting mutex. ^Nine static mutexes are 7968 ** used by the current version of SQLite. Future versions of SQLite 7969 ** may add additional static mutexes. Static mutexes are for internal 7970 ** use by SQLite only. Applications that use SQLite mutexes should 7971 ** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or 7972 ** SQLITE_MUTEX_RECURSIVE. 7973 ** 7974 ** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST 7975 ** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc() 7976 ** returns a different mutex on every call. ^For the static 7977 ** mutex types, the same mutex is returned on every call that has 7978 ** the same type number. 7979 ** 7980 ** ^The sqlite3_mutex_free() routine deallocates a previously 7981 ** allocated dynamic mutex. Attempting to deallocate a static 7982 ** mutex results in undefined behavior. 7983 ** 7984 ** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt 7985 ** to enter a mutex. ^If another thread is already within the mutex, 7986 ** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return 7987 ** SQLITE_BUSY. ^The sqlite3_mutex_try() interface returns [SQLITE_OK] 7988 ** upon successful entry. ^(Mutexes created using 7989 ** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread. 7990 ** In such cases, the 7991 ** mutex must be exited an equal number of times before another thread 7992 ** can enter.)^ If the same thread tries to enter any mutex other 7993 ** than an SQLITE_MUTEX_RECURSIVE more than once, the behavior is undefined. 7994 ** 7995 ** ^(Some systems (for example, Windows 95) do not support the operation 7996 ** implemented by sqlite3_mutex_try(). On those systems, sqlite3_mutex_try() 7997 ** will always return SQLITE_BUSY. The SQLite core only ever uses 7998 ** sqlite3_mutex_try() as an optimization so this is acceptable 7999 ** behavior.)^ 8000 ** 8001 ** ^The sqlite3_mutex_leave() routine exits a mutex that was 8002 ** previously entered by the same thread. The behavior 8003 ** is undefined if the mutex is not currently entered by the 8004 ** calling thread or is not currently allocated. 8005 ** 8006 ** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), 8007 ** sqlite3_mutex_leave(), or sqlite3_mutex_free() is a NULL pointer, 8008 ** then any of the four routines behaves as a no-op. 8009 ** 8010 ** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()]. 8011 */ 8012 SQLITE_API sqlite3_mutex *sqlite3_mutex_alloc(int); 8013 SQLITE_API void sqlite3_mutex_free(sqlite3_mutex*); 8014 SQLITE_API void sqlite3_mutex_enter(sqlite3_mutex*); 8015 SQLITE_API int sqlite3_mutex_try(sqlite3_mutex*); 8016 SQLITE_API void sqlite3_mutex_leave(sqlite3_mutex*); 8017 8018 /* 8019 ** CAPI3REF: Mutex Methods Object 8020 ** 8021 ** An instance of this structure defines the low-level routines 8022 ** used to allocate and use mutexes. 8023 ** 8024 ** Usually, the default mutex implementations provided by SQLite are 8025 ** sufficient, however the application has the option of substituting a custom 8026 ** implementation for specialized deployments or systems for which SQLite 8027 ** does not provide a suitable implementation. In this case, the application 8028 ** creates and populates an instance of this structure to pass 8029 ** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option. 8030 ** Additionally, an instance of this structure can be used as an 8031 ** output variable when querying the system for the current mutex 8032 ** implementation, using the [SQLITE_CONFIG_GETMUTEX] option. 8033 ** 8034 ** ^The xMutexInit method defined by this structure is invoked as 8035 ** part of system initialization by the sqlite3_initialize() function. 8036 ** ^The xMutexInit routine is called by SQLite exactly once for each 8037 ** effective call to [sqlite3_initialize()]. 8038 ** 8039 ** ^The xMutexEnd method defined by this structure is invoked as 8040 ** part of system shutdown by the sqlite3_shutdown() function. The 8041 ** implementation of this method is expected to release all outstanding 8042 ** resources obtained by the mutex methods implementation, especially 8043 ** those obtained by the xMutexInit method. ^The xMutexEnd() 8044 ** interface is invoked exactly once for each call to [sqlite3_shutdown()]. 8045 ** 8046 ** ^(The remaining seven methods defined by this structure (xMutexAlloc, 8047 ** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and 8048 ** xMutexNotheld) implement the following interfaces (respectively): 8049 ** 8050 ** <ul> 8051 ** <li> [sqlite3_mutex_alloc()] </li> 8052 ** <li> [sqlite3_mutex_free()] </li> 8053 ** <li> [sqlite3_mutex_enter()] </li> 8054 ** <li> [sqlite3_mutex_try()] </li> 8055 ** <li> [sqlite3_mutex_leave()] </li> 8056 ** <li> [sqlite3_mutex_held()] </li> 8057 ** <li> [sqlite3_mutex_notheld()] </li> 8058 ** </ul>)^ 8059 ** 8060 ** The only difference is that the public sqlite3_XXX functions enumerated 8061 ** above silently ignore any invocations that pass a NULL pointer instead 8062 ** of a valid mutex handle. The implementations of the methods defined 8063 ** by this structure are not required to handle this case. The results 8064 ** of passing a NULL pointer instead of a valid mutex handle are undefined 8065 ** (i.e. it is acceptable to provide an implementation that segfaults if 8066 ** it is passed a NULL pointer). 8067 ** 8068 ** The xMutexInit() method must be threadsafe. It must be harmless to 8069 ** invoke xMutexInit() multiple times within the same process and without 8070 ** intervening calls to xMutexEnd(). Second and subsequent calls to 8071 ** xMutexInit() must be no-ops. 8072 ** 8073 ** xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()] 8074 ** and its associates). Similarly, xMutexAlloc() must not use SQLite memory 8075 ** allocation for a static mutex. ^However xMutexAlloc() may use SQLite 8076 ** memory allocation for a fast or recursive mutex. 8077 ** 8078 ** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is 8079 ** called, but only if the prior call to xMutexInit returned SQLITE_OK. 8080 ** If xMutexInit fails in any way, it is expected to clean up after itself 8081 ** prior to returning. 8082 */ 8083 typedef struct sqlite3_mutex_methods sqlite3_mutex_methods; 8084 struct sqlite3_mutex_methods { 8085 int (*xMutexInit)(void); 8086 int (*xMutexEnd)(void); 8087 sqlite3_mutex *(*xMutexAlloc)(int); 8088 void (*xMutexFree)(sqlite3_mutex *); 8089 void (*xMutexEnter)(sqlite3_mutex *); 8090 int (*xMutexTry)(sqlite3_mutex *); 8091 void (*xMutexLeave)(sqlite3_mutex *); 8092 int (*xMutexHeld)(sqlite3_mutex *); 8093 int (*xMutexNotheld)(sqlite3_mutex *); 8094 }; 8095 8096 /* 8097 ** CAPI3REF: Mutex Verification Routines 8098 ** 8099 ** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines 8100 ** are intended for use inside assert() statements. The SQLite core 8101 ** never uses these routines except inside an assert() and applications 8102 ** are advised to follow the lead of the core. The SQLite core only 8103 ** provides implementations for these routines when it is compiled 8104 ** with the SQLITE_DEBUG flag. External mutex implementations 8105 ** are only required to provide these routines if SQLITE_DEBUG is 8106 ** defined and if NDEBUG is not defined. 8107 ** 8108 ** These routines should return true if the mutex in their argument 8109 ** is held or not held, respectively, by the calling thread. 8110 ** 8111 ** The implementation is not required to provide versions of these 8112 ** routines that actually work. If the implementation does not provide working 8113 ** versions of these routines, it should at least provide stubs that always 8114 ** return true so that one does not get spurious assertion failures. 8115 ** 8116 ** If the argument to sqlite3_mutex_held() is a NULL pointer then 8117 ** the routine should return 1. This seems counter-intuitive since 8118 ** clearly the mutex cannot be held if it does not exist. But 8119 ** the reason the mutex does not exist is because the build is not 8120 ** using mutexes. And we do not want the assert() containing the 8121 ** call to sqlite3_mutex_held() to fail, so a non-zero return is 8122 ** the appropriate thing to do. The sqlite3_mutex_notheld() 8123 ** interface should also return 1 when given a NULL pointer. 8124 */ 8125 #ifndef NDEBUG 8126 SQLITE_API int sqlite3_mutex_held(sqlite3_mutex*); 8127 SQLITE_API int sqlite3_mutex_notheld(sqlite3_mutex*); 8128 #endif 8129 8130 /* 8131 ** CAPI3REF: Mutex Types 8132 ** 8133 ** The [sqlite3_mutex_alloc()] interface takes a single argument 8134 ** which is one of these integer constants. 8135 ** 8136 ** The set of static mutexes may change from one SQLite release to the 8137 ** next. Applications that override the built-in mutex logic must be 8138 ** prepared to accommodate additional static mutexes. 8139 */ 8140 #define SQLITE_MUTEX_FAST 0 8141 #define SQLITE_MUTEX_RECURSIVE 1 8142 #define SQLITE_MUTEX_STATIC_MAIN 2 8143 #define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */ 8144 #define SQLITE_MUTEX_STATIC_MEM2 4 /* NOT USED */ 8145 #define SQLITE_MUTEX_STATIC_OPEN 4 /* sqlite3BtreeOpen() */ 8146 #define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_randomness() */ 8147 #define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */ 8148 #define SQLITE_MUTEX_STATIC_LRU2 7 /* NOT USED */ 8149 #define SQLITE_MUTEX_STATIC_PMEM 7 /* sqlite3PageMalloc() */ 8150 #define SQLITE_MUTEX_STATIC_APP1 8 /* For use by application */ 8151 #define SQLITE_MUTEX_STATIC_APP2 9 /* For use by application */ 8152 #define SQLITE_MUTEX_STATIC_APP3 10 /* For use by application */ 8153 #define SQLITE_MUTEX_STATIC_VFS1 11 /* For use by built-in VFS */ 8154 #define SQLITE_MUTEX_STATIC_VFS2 12 /* For use by extension VFS */ 8155 #define SQLITE_MUTEX_STATIC_VFS3 13 /* For use by application VFS */ 8156 8157 /* Legacy compatibility: */ 8158 #define SQLITE_MUTEX_STATIC_MASTER 2 8159 8160 8161 /* 8162 ** CAPI3REF: Retrieve the mutex for a database connection 8163 ** METHOD: sqlite3 8164 ** 8165 ** ^This interface returns a pointer the [sqlite3_mutex] object that 8166 ** serializes access to the [database connection] given in the argument 8167 ** when the [threading mode] is Serialized. 8168 ** ^If the [threading mode] is Single-thread or Multi-thread then this 8169 ** routine returns a NULL pointer. 8170 */ 8171 SQLITE_API sqlite3_mutex *sqlite3_db_mutex(sqlite3*); 8172 8173 /* 8174 ** CAPI3REF: Low-Level Control Of Database Files 8175 ** METHOD: sqlite3 8176 ** KEYWORDS: {file control} 8177 ** 8178 ** ^The [sqlite3_file_control()] interface makes a direct call to the 8179 ** xFileControl method for the [sqlite3_io_methods] object associated 8180 ** with a particular database identified by the second argument. ^The 8181 ** name of the database is "main" for the main database or "temp" for the 8182 ** TEMP database, or the name that appears after the AS keyword for 8183 ** databases that are added using the [ATTACH] SQL command. 8184 ** ^A NULL pointer can be used in place of "main" to refer to the 8185 ** main database file. 8186 ** ^The third and fourth parameters to this routine 8187 ** are passed directly through to the second and third parameters of 8188 ** the xFileControl method. ^The return value of the xFileControl 8189 ** method becomes the return value of this routine. 8190 ** 8191 ** A few opcodes for [sqlite3_file_control()] are handled directly 8192 ** by the SQLite core and never invoke the 8193 ** sqlite3_io_methods.xFileControl method. 8194 ** ^The [SQLITE_FCNTL_FILE_POINTER] value for the op parameter causes 8195 ** a pointer to the underlying [sqlite3_file] object to be written into 8196 ** the space pointed to by the 4th parameter. The 8197 ** [SQLITE_FCNTL_JOURNAL_POINTER] works similarly except that it returns 8198 ** the [sqlite3_file] object associated with the journal file instead of 8199 ** the main database. The [SQLITE_FCNTL_VFS_POINTER] opcode returns 8200 ** a pointer to the underlying [sqlite3_vfs] object for the file. 8201 ** The [SQLITE_FCNTL_DATA_VERSION] returns the data version counter 8202 ** from the pager. 8203 ** 8204 ** ^If the second parameter (zDbName) does not match the name of any 8205 ** open database file, then SQLITE_ERROR is returned. ^This error 8206 ** code is not remembered and will not be recalled by [sqlite3_errcode()] 8207 ** or [sqlite3_errmsg()]. The underlying xFileControl method might 8208 ** also return SQLITE_ERROR. There is no way to distinguish between 8209 ** an incorrect zDbName and an SQLITE_ERROR return from the underlying 8210 ** xFileControl method. 8211 ** 8212 ** See also: [file control opcodes] 8213 */ 8214 SQLITE_API int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*); 8215 8216 /* 8217 ** CAPI3REF: Testing Interface 8218 ** 8219 ** ^The sqlite3_test_control() interface is used to read out internal 8220 ** state of SQLite and to inject faults into SQLite for testing 8221 ** purposes. ^The first parameter is an operation code that determines 8222 ** the number, meaning, and operation of all subsequent parameters. 8223 ** 8224 ** This interface is not for use by applications. It exists solely 8225 ** for verifying the correct operation of the SQLite library. Depending 8226 ** on how the SQLite library is compiled, this interface might not exist. 8227 ** 8228 ** The details of the operation codes, their meanings, the parameters 8229 ** they take, and what they do are all subject to change without notice. 8230 ** Unlike most of the SQLite API, this function is not guaranteed to 8231 ** operate consistently from one release to the next. 8232 */ 8233 SQLITE_API int sqlite3_test_control(int op, ...); 8234 8235 /* 8236 ** CAPI3REF: Testing Interface Operation Codes 8237 ** 8238 ** These constants are the valid operation code parameters used 8239 ** as the first argument to [sqlite3_test_control()]. 8240 ** 8241 ** These parameters and their meanings are subject to change 8242 ** without notice. These values are for testing purposes only. 8243 ** Applications should not use any of these parameters or the 8244 ** [sqlite3_test_control()] interface. 8245 */ 8246 #define SQLITE_TESTCTRL_FIRST 5 8247 #define SQLITE_TESTCTRL_PRNG_SAVE 5 8248 #define SQLITE_TESTCTRL_PRNG_RESTORE 6 8249 #define SQLITE_TESTCTRL_PRNG_RESET 7 /* NOT USED */ 8250 #define SQLITE_TESTCTRL_FK_NO_ACTION 7 8251 #define SQLITE_TESTCTRL_BITVEC_TEST 8 8252 #define SQLITE_TESTCTRL_FAULT_INSTALL 9 8253 #define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS 10 8254 #define SQLITE_TESTCTRL_PENDING_BYTE 11 8255 #define SQLITE_TESTCTRL_ASSERT 12 8256 #define SQLITE_TESTCTRL_ALWAYS 13 8257 #define SQLITE_TESTCTRL_RESERVE 14 /* NOT USED */ 8258 #define SQLITE_TESTCTRL_OPTIMIZATIONS 15 8259 #define SQLITE_TESTCTRL_ISKEYWORD 16 /* NOT USED */ 8260 #define SQLITE_TESTCTRL_SCRATCHMALLOC 17 /* NOT USED */ 8261 #define SQLITE_TESTCTRL_INTERNAL_FUNCTIONS 17 8262 #define SQLITE_TESTCTRL_LOCALTIME_FAULT 18 8263 #define SQLITE_TESTCTRL_EXPLAIN_STMT 19 /* NOT USED */ 8264 #define SQLITE_TESTCTRL_ONCE_RESET_THRESHOLD 19 8265 #define SQLITE_TESTCTRL_NEVER_CORRUPT 20 8266 #define SQLITE_TESTCTRL_VDBE_COVERAGE 21 8267 #define SQLITE_TESTCTRL_BYTEORDER 22 8268 #define SQLITE_TESTCTRL_ISINIT 23 8269 #define SQLITE_TESTCTRL_SORTER_MMAP 24 8270 #define SQLITE_TESTCTRL_IMPOSTER 25 8271 #define SQLITE_TESTCTRL_PARSER_COVERAGE 26 8272 #define SQLITE_TESTCTRL_RESULT_INTREAL 27 8273 #define SQLITE_TESTCTRL_PRNG_SEED 28 8274 #define SQLITE_TESTCTRL_EXTRA_SCHEMA_CHECKS 29 8275 #define SQLITE_TESTCTRL_SEEK_COUNT 30 8276 #define SQLITE_TESTCTRL_TRACEFLAGS 31 8277 #define SQLITE_TESTCTRL_TUNE 32 8278 #define SQLITE_TESTCTRL_LOGEST 33 8279 #define SQLITE_TESTCTRL_USELONGDOUBLE 34 8280 #define SQLITE_TESTCTRL_LAST 34 /* Largest TESTCTRL */ 8281 8282 /* 8283 ** CAPI3REF: SQL Keyword Checking 8284 ** 8285 ** These routines provide access to the set of SQL language keywords 8286 ** recognized by SQLite. Applications can uses these routines to determine 8287 ** whether or not a specific identifier needs to be escaped (for example, 8288 ** by enclosing in double-quotes) so as not to confuse the parser. 8289 ** 8290 ** The sqlite3_keyword_count() interface returns the number of distinct 8291 ** keywords understood by SQLite. 8292 ** 8293 ** The sqlite3_keyword_name(N,Z,L) interface finds the N-th keyword and 8294 ** makes *Z point to that keyword expressed as UTF8 and writes the number 8295 ** of bytes in the keyword into *L. The string that *Z points to is not 8296 ** zero-terminated. The sqlite3_keyword_name(N,Z,L) routine returns 8297 ** SQLITE_OK if N is within bounds and SQLITE_ERROR if not. If either Z 8298 ** or L are NULL or invalid pointers then calls to 8299 ** sqlite3_keyword_name(N,Z,L) result in undefined behavior. 8300 ** 8301 ** The sqlite3_keyword_check(Z,L) interface checks to see whether or not 8302 ** the L-byte UTF8 identifier that Z points to is a keyword, returning non-zero 8303 ** if it is and zero if not. 8304 ** 8305 ** The parser used by SQLite is forgiving. It is often possible to use 8306 ** a keyword as an identifier as long as such use does not result in a 8307 ** parsing ambiguity. For example, the statement 8308 ** "CREATE TABLE BEGIN(REPLACE,PRAGMA,END);" is accepted by SQLite, and 8309 ** creates a new table named "BEGIN" with three columns named 8310 ** "REPLACE", "PRAGMA", and "END". Nevertheless, best practice is to avoid 8311 ** using keywords as identifiers. Common techniques used to avoid keyword 8312 ** name collisions include: 8313 ** <ul> 8314 ** <li> Put all identifier names inside double-quotes. This is the official 8315 ** SQL way to escape identifier names. 8316 ** <li> Put identifier names inside [...]. This is not standard SQL, 8317 ** but it is what SQL Server does and so lots of programmers use this 8318 ** technique. 8319 ** <li> Begin every identifier with the letter "Z" as no SQL keywords start 8320 ** with "Z". 8321 ** <li> Include a digit somewhere in every identifier name. 8322 ** </ul> 8323 ** 8324 ** Note that the number of keywords understood by SQLite can depend on 8325 ** compile-time options. For example, "VACUUM" is not a keyword if 8326 ** SQLite is compiled with the [-DSQLITE_OMIT_VACUUM] option. Also, 8327 ** new keywords may be added to future releases of SQLite. 8328 */ 8329 SQLITE_API int sqlite3_keyword_count(void); 8330 SQLITE_API int sqlite3_keyword_name(int,const char**,int*); 8331 SQLITE_API int sqlite3_keyword_check(const char*,int); 8332 8333 /* 8334 ** CAPI3REF: Dynamic String Object 8335 ** KEYWORDS: {dynamic string} 8336 ** 8337 ** An instance of the sqlite3_str object contains a dynamically-sized 8338 ** string under construction. 8339 ** 8340 ** The lifecycle of an sqlite3_str object is as follows: 8341 ** <ol> 8342 ** <li> ^The sqlite3_str object is created using [sqlite3_str_new()]. 8343 ** <li> ^Text is appended to the sqlite3_str object using various 8344 ** methods, such as [sqlite3_str_appendf()]. 8345 ** <li> ^The sqlite3_str object is destroyed and the string it created 8346 ** is returned using the [sqlite3_str_finish()] interface. 8347 ** </ol> 8348 */ 8349 typedef struct sqlite3_str sqlite3_str; 8350 8351 /* 8352 ** CAPI3REF: Create A New Dynamic String Object 8353 ** CONSTRUCTOR: sqlite3_str 8354 ** 8355 ** ^The [sqlite3_str_new(D)] interface allocates and initializes 8356 ** a new [sqlite3_str] object. To avoid memory leaks, the object returned by 8357 ** [sqlite3_str_new()] must be freed by a subsequent call to 8358 ** [sqlite3_str_finish(X)]. 8359 ** 8360 ** ^The [sqlite3_str_new(D)] interface always returns a pointer to a 8361 ** valid [sqlite3_str] object, though in the event of an out-of-memory 8362 ** error the returned object might be a special singleton that will 8363 ** silently reject new text, always return SQLITE_NOMEM from 8364 ** [sqlite3_str_errcode()], always return 0 for 8365 ** [sqlite3_str_length()], and always return NULL from 8366 ** [sqlite3_str_finish(X)]. It is always safe to use the value 8367 ** returned by [sqlite3_str_new(D)] as the sqlite3_str parameter 8368 ** to any of the other [sqlite3_str] methods. 8369 ** 8370 ** The D parameter to [sqlite3_str_new(D)] may be NULL. If the 8371 ** D parameter in [sqlite3_str_new(D)] is not NULL, then the maximum 8372 ** length of the string contained in the [sqlite3_str] object will be 8373 ** the value set for [sqlite3_limit](D,[SQLITE_LIMIT_LENGTH]) instead 8374 ** of [SQLITE_MAX_LENGTH]. 8375 */ 8376 SQLITE_API sqlite3_str *sqlite3_str_new(sqlite3*); 8377 8378 /* 8379 ** CAPI3REF: Finalize A Dynamic String 8380 ** DESTRUCTOR: sqlite3_str 8381 ** 8382 ** ^The [sqlite3_str_finish(X)] interface destroys the sqlite3_str object X 8383 ** and returns a pointer to a memory buffer obtained from [sqlite3_malloc64()] 8384 ** that contains the constructed string. The calling application should 8385 ** pass the returned value to [sqlite3_free()] to avoid a memory leak. 8386 ** ^The [sqlite3_str_finish(X)] interface may return a NULL pointer if any 8387 ** errors were encountered during construction of the string. ^The 8388 ** [sqlite3_str_finish(X)] interface will also return a NULL pointer if the 8389 ** string in [sqlite3_str] object X is zero bytes long. 8390 */ 8391 SQLITE_API char *sqlite3_str_finish(sqlite3_str*); 8392 8393 /* 8394 ** CAPI3REF: Add Content To A Dynamic String 8395 ** METHOD: sqlite3_str 8396 ** 8397 ** These interfaces add content to an sqlite3_str object previously obtained 8398 ** from [sqlite3_str_new()]. 8399 ** 8400 ** ^The [sqlite3_str_appendf(X,F,...)] and 8401 ** [sqlite3_str_vappendf(X,F,V)] interfaces uses the [built-in printf] 8402 ** functionality of SQLite to append formatted text onto the end of 8403 ** [sqlite3_str] object X. 8404 ** 8405 ** ^The [sqlite3_str_append(X,S,N)] method appends exactly N bytes from string S 8406 ** onto the end of the [sqlite3_str] object X. N must be non-negative. 8407 ** S must contain at least N non-zero bytes of content. To append a 8408 ** zero-terminated string in its entirety, use the [sqlite3_str_appendall()] 8409 ** method instead. 8410 ** 8411 ** ^The [sqlite3_str_appendall(X,S)] method appends the complete content of 8412 ** zero-terminated string S onto the end of [sqlite3_str] object X. 8413 ** 8414 ** ^The [sqlite3_str_appendchar(X,N,C)] method appends N copies of the 8415 ** single-byte character C onto the end of [sqlite3_str] object X. 8416 ** ^This method can be used, for example, to add whitespace indentation. 8417 ** 8418 ** ^The [sqlite3_str_reset(X)] method resets the string under construction 8419 ** inside [sqlite3_str] object X back to zero bytes in length. 8420 ** 8421 ** These methods do not return a result code. ^If an error occurs, that fact 8422 ** is recorded in the [sqlite3_str] object and can be recovered by a 8423 ** subsequent call to [sqlite3_str_errcode(X)]. 8424 */ 8425 SQLITE_API void sqlite3_str_appendf(sqlite3_str*, const char *zFormat, ...); 8426 SQLITE_API void sqlite3_str_vappendf(sqlite3_str*, const char *zFormat, va_list); 8427 SQLITE_API void sqlite3_str_append(sqlite3_str*, const char *zIn, int N); 8428 SQLITE_API void sqlite3_str_appendall(sqlite3_str*, const char *zIn); 8429 SQLITE_API void sqlite3_str_appendchar(sqlite3_str*, int N, char C); 8430 SQLITE_API void sqlite3_str_reset(sqlite3_str*); 8431 8432 /* 8433 ** CAPI3REF: Status Of A Dynamic String 8434 ** METHOD: sqlite3_str 8435 ** 8436 ** These interfaces return the current status of an [sqlite3_str] object. 8437 ** 8438 ** ^If any prior errors have occurred while constructing the dynamic string 8439 ** in sqlite3_str X, then the [sqlite3_str_errcode(X)] method will return 8440 ** an appropriate error code. ^The [sqlite3_str_errcode(X)] method returns 8441 ** [SQLITE_NOMEM] following any out-of-memory error, or 8442 ** [SQLITE_TOOBIG] if the size of the dynamic string exceeds 8443 ** [SQLITE_MAX_LENGTH], or [SQLITE_OK] if there have been no errors. 8444 ** 8445 ** ^The [sqlite3_str_length(X)] method returns the current length, in bytes, 8446 ** of the dynamic string under construction in [sqlite3_str] object X. 8447 ** ^The length returned by [sqlite3_str_length(X)] does not include the 8448 ** zero-termination byte. 8449 ** 8450 ** ^The [sqlite3_str_value(X)] method returns a pointer to the current 8451 ** content of the dynamic string under construction in X. The value 8452 ** returned by [sqlite3_str_value(X)] is managed by the sqlite3_str object X 8453 ** and might be freed or altered by any subsequent method on the same 8454 ** [sqlite3_str] object. Applications must not used the pointer returned 8455 ** [sqlite3_str_value(X)] after any subsequent method call on the same 8456 ** object. ^Applications may change the content of the string returned 8457 ** by [sqlite3_str_value(X)] as long as they do not write into any bytes 8458 ** outside the range of 0 to [sqlite3_str_length(X)] and do not read or 8459 ** write any byte after any subsequent sqlite3_str method call. 8460 */ 8461 SQLITE_API int sqlite3_str_errcode(sqlite3_str*); 8462 SQLITE_API int sqlite3_str_length(sqlite3_str*); 8463 SQLITE_API char *sqlite3_str_value(sqlite3_str*); 8464 8465 /* 8466 ** CAPI3REF: SQLite Runtime Status 8467 ** 8468 ** ^These interfaces are used to retrieve runtime status information 8469 ** about the performance of SQLite, and optionally to reset various 8470 ** highwater marks. ^The first argument is an integer code for 8471 ** the specific parameter to measure. ^(Recognized integer codes 8472 ** are of the form [status parameters | SQLITE_STATUS_...].)^ 8473 ** ^The current value of the parameter is returned into *pCurrent. 8474 ** ^The highest recorded value is returned in *pHighwater. ^If the 8475 ** resetFlag is true, then the highest record value is reset after 8476 ** *pHighwater is written. ^(Some parameters do not record the highest 8477 ** value. For those parameters 8478 ** nothing is written into *pHighwater and the resetFlag is ignored.)^ 8479 ** ^(Other parameters record only the highwater mark and not the current 8480 ** value. For these latter parameters nothing is written into *pCurrent.)^ 8481 ** 8482 ** ^The sqlite3_status() and sqlite3_status64() routines return 8483 ** SQLITE_OK on success and a non-zero [error code] on failure. 8484 ** 8485 ** If either the current value or the highwater mark is too large to 8486 ** be represented by a 32-bit integer, then the values returned by 8487 ** sqlite3_status() are undefined. 8488 ** 8489 ** See also: [sqlite3_db_status()] 8490 */ 8491 SQLITE_API int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag); 8492 SQLITE_API int sqlite3_status64( 8493 int op, 8494 sqlite3_int64 *pCurrent, 8495 sqlite3_int64 *pHighwater, 8496 int resetFlag 8497 ); 8498 8499 8500 /* 8501 ** CAPI3REF: Status Parameters 8502 ** KEYWORDS: {status parameters} 8503 ** 8504 ** These integer constants designate various run-time status parameters 8505 ** that can be returned by [sqlite3_status()]. 8506 ** 8507 ** <dl> 8508 ** [[SQLITE_STATUS_MEMORY_USED]] ^(<dt>SQLITE_STATUS_MEMORY_USED</dt> 8509 ** <dd>This parameter is the current amount of memory checked out 8510 ** using [sqlite3_malloc()], either directly or indirectly. The 8511 ** figure includes calls made to [sqlite3_malloc()] by the application 8512 ** and internal memory usage by the SQLite library. Auxiliary page-cache 8513 ** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in 8514 ** this parameter. The amount returned is the sum of the allocation 8515 ** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>)^ 8516 ** 8517 ** [[SQLITE_STATUS_MALLOC_SIZE]] ^(<dt>SQLITE_STATUS_MALLOC_SIZE</dt> 8518 ** <dd>This parameter records the largest memory allocation request 8519 ** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their 8520 ** internal equivalents). Only the value returned in the 8521 ** *pHighwater parameter to [sqlite3_status()] is of interest. 8522 ** The value written into the *pCurrent parameter is undefined.</dd>)^ 8523 ** 8524 ** [[SQLITE_STATUS_MALLOC_COUNT]] ^(<dt>SQLITE_STATUS_MALLOC_COUNT</dt> 8525 ** <dd>This parameter records the number of separate memory allocations 8526 ** currently checked out.</dd>)^ 8527 ** 8528 ** [[SQLITE_STATUS_PAGECACHE_USED]] ^(<dt>SQLITE_STATUS_PAGECACHE_USED</dt> 8529 ** <dd>This parameter returns the number of pages used out of the 8530 ** [pagecache memory allocator] that was configured using 8531 ** [SQLITE_CONFIG_PAGECACHE]. The 8532 ** value returned is in pages, not in bytes.</dd>)^ 8533 ** 8534 ** [[SQLITE_STATUS_PAGECACHE_OVERFLOW]] 8535 ** ^(<dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt> 8536 ** <dd>This parameter returns the number of bytes of page cache 8537 ** allocation which could not be satisfied by the [SQLITE_CONFIG_PAGECACHE] 8538 ** buffer and where forced to overflow to [sqlite3_malloc()]. The 8539 ** returned value includes allocations that overflowed because they 8540 ** where too large (they were larger than the "sz" parameter to 8541 ** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because 8542 ** no space was left in the page cache.</dd>)^ 8543 ** 8544 ** [[SQLITE_STATUS_PAGECACHE_SIZE]] ^(<dt>SQLITE_STATUS_PAGECACHE_SIZE</dt> 8545 ** <dd>This parameter records the largest memory allocation request 8546 ** handed to the [pagecache memory allocator]. Only the value returned in the 8547 ** *pHighwater parameter to [sqlite3_status()] is of interest. 8548 ** The value written into the *pCurrent parameter is undefined.</dd>)^ 8549 ** 8550 ** [[SQLITE_STATUS_SCRATCH_USED]] <dt>SQLITE_STATUS_SCRATCH_USED</dt> 8551 ** <dd>No longer used.</dd> 8552 ** 8553 ** [[SQLITE_STATUS_SCRATCH_OVERFLOW]] ^(<dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt> 8554 ** <dd>No longer used.</dd> 8555 ** 8556 ** [[SQLITE_STATUS_SCRATCH_SIZE]] <dt>SQLITE_STATUS_SCRATCH_SIZE</dt> 8557 ** <dd>No longer used.</dd> 8558 ** 8559 ** [[SQLITE_STATUS_PARSER_STACK]] ^(<dt>SQLITE_STATUS_PARSER_STACK</dt> 8560 ** <dd>The *pHighwater parameter records the deepest parser stack. 8561 ** The *pCurrent value is undefined. The *pHighwater value is only 8562 ** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>)^ 8563 ** </dl> 8564 ** 8565 ** New status parameters may be added from time to time. 8566 */ 8567 #define SQLITE_STATUS_MEMORY_USED 0 8568 #define SQLITE_STATUS_PAGECACHE_USED 1 8569 #define SQLITE_STATUS_PAGECACHE_OVERFLOW 2 8570 #define SQLITE_STATUS_SCRATCH_USED 3 /* NOT USED */ 8571 #define SQLITE_STATUS_SCRATCH_OVERFLOW 4 /* NOT USED */ 8572 #define SQLITE_STATUS_MALLOC_SIZE 5 8573 #define SQLITE_STATUS_PARSER_STACK 6 8574 #define SQLITE_STATUS_PAGECACHE_SIZE 7 8575 #define SQLITE_STATUS_SCRATCH_SIZE 8 /* NOT USED */ 8576 #define SQLITE_STATUS_MALLOC_COUNT 9 8577 8578 /* 8579 ** CAPI3REF: Database Connection Status 8580 ** METHOD: sqlite3 8581 ** 8582 ** ^This interface is used to retrieve runtime status information 8583 ** about a single [database connection]. ^The first argument is the 8584 ** database connection object to be interrogated. ^The second argument 8585 ** is an integer constant, taken from the set of 8586 ** [SQLITE_DBSTATUS options], that 8587 ** determines the parameter to interrogate. The set of 8588 ** [SQLITE_DBSTATUS options] is likely 8589 ** to grow in future releases of SQLite. 8590 ** 8591 ** ^The current value of the requested parameter is written into *pCur 8592 ** and the highest instantaneous value is written into *pHiwtr. ^If 8593 ** the resetFlg is true, then the highest instantaneous value is 8594 ** reset back down to the current value. 8595 ** 8596 ** ^The sqlite3_db_status() routine returns SQLITE_OK on success and a 8597 ** non-zero [error code] on failure. 8598 ** 8599 ** See also: [sqlite3_status()] and [sqlite3_stmt_status()]. 8600 */ 8601 SQLITE_API int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg); 8602 8603 /* 8604 ** CAPI3REF: Status Parameters for database connections 8605 ** KEYWORDS: {SQLITE_DBSTATUS options} 8606 ** 8607 ** These constants are the available integer "verbs" that can be passed as 8608 ** the second argument to the [sqlite3_db_status()] interface. 8609 ** 8610 ** New verbs may be added in future releases of SQLite. Existing verbs 8611 ** might be discontinued. Applications should check the return code from 8612 ** [sqlite3_db_status()] to make sure that the call worked. 8613 ** The [sqlite3_db_status()] interface will return a non-zero error code 8614 ** if a discontinued or unsupported verb is invoked. 8615 ** 8616 ** <dl> 8617 ** [[SQLITE_DBSTATUS_LOOKASIDE_USED]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt> 8618 ** <dd>This parameter returns the number of lookaside memory slots currently 8619 ** checked out.</dd>)^ 8620 ** 8621 ** [[SQLITE_DBSTATUS_LOOKASIDE_HIT]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_HIT</dt> 8622 ** <dd>This parameter returns the number of malloc attempts that were 8623 ** satisfied using lookaside memory. Only the high-water value is meaningful; 8624 ** the current value is always zero.)^ 8625 ** 8626 ** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE]] 8627 ** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE</dt> 8628 ** <dd>This parameter returns the number malloc attempts that might have 8629 ** been satisfied using lookaside memory but failed due to the amount of 8630 ** memory requested being larger than the lookaside slot size. 8631 ** Only the high-water value is meaningful; 8632 ** the current value is always zero.)^ 8633 ** 8634 ** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL]] 8635 ** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL</dt> 8636 ** <dd>This parameter returns the number malloc attempts that might have 8637 ** been satisfied using lookaside memory but failed due to all lookaside 8638 ** memory already being in use. 8639 ** Only the high-water value is meaningful; 8640 ** the current value is always zero.)^ 8641 ** 8642 ** [[SQLITE_DBSTATUS_CACHE_USED]] ^(<dt>SQLITE_DBSTATUS_CACHE_USED</dt> 8643 ** <dd>This parameter returns the approximate number of bytes of heap 8644 ** memory used by all pager caches associated with the database connection.)^ 8645 ** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0. 8646 ** 8647 ** [[SQLITE_DBSTATUS_CACHE_USED_SHARED]] 8648 ** ^(<dt>SQLITE_DBSTATUS_CACHE_USED_SHARED</dt> 8649 ** <dd>This parameter is similar to DBSTATUS_CACHE_USED, except that if a 8650 ** pager cache is shared between two or more connections the bytes of heap 8651 ** memory used by that pager cache is divided evenly between the attached 8652 ** connections.)^ In other words, if none of the pager caches associated 8653 ** with the database connection are shared, this request returns the same 8654 ** value as DBSTATUS_CACHE_USED. Or, if one or more or the pager caches are 8655 ** shared, the value returned by this call will be smaller than that returned 8656 ** by DBSTATUS_CACHE_USED. ^The highwater mark associated with 8657 ** SQLITE_DBSTATUS_CACHE_USED_SHARED is always 0. 8658 ** 8659 ** [[SQLITE_DBSTATUS_SCHEMA_USED]] ^(<dt>SQLITE_DBSTATUS_SCHEMA_USED</dt> 8660 ** <dd>This parameter returns the approximate number of bytes of heap 8661 ** memory used to store the schema for all databases associated 8662 ** with the connection - main, temp, and any [ATTACH]-ed databases.)^ 8663 ** ^The full amount of memory used by the schemas is reported, even if the 8664 ** schema memory is shared with other database connections due to 8665 ** [shared cache mode] being enabled. 8666 ** ^The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0. 8667 ** 8668 ** [[SQLITE_DBSTATUS_STMT_USED]] ^(<dt>SQLITE_DBSTATUS_STMT_USED</dt> 8669 ** <dd>This parameter returns the approximate number of bytes of heap 8670 ** and lookaside memory used by all prepared statements associated with 8671 ** the database connection.)^ 8672 ** ^The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0. 8673 ** </dd> 8674 ** 8675 ** [[SQLITE_DBSTATUS_CACHE_HIT]] ^(<dt>SQLITE_DBSTATUS_CACHE_HIT</dt> 8676 ** <dd>This parameter returns the number of pager cache hits that have 8677 ** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_HIT 8678 ** is always 0. 8679 ** </dd> 8680 ** 8681 ** [[SQLITE_DBSTATUS_CACHE_MISS]] ^(<dt>SQLITE_DBSTATUS_CACHE_MISS</dt> 8682 ** <dd>This parameter returns the number of pager cache misses that have 8683 ** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_MISS 8684 ** is always 0. 8685 ** </dd> 8686 ** 8687 ** [[SQLITE_DBSTATUS_CACHE_WRITE]] ^(<dt>SQLITE_DBSTATUS_CACHE_WRITE</dt> 8688 ** <dd>This parameter returns the number of dirty cache entries that have 8689 ** been written to disk. Specifically, the number of pages written to the 8690 ** wal file in wal mode databases, or the number of pages written to the 8691 ** database file in rollback mode databases. Any pages written as part of 8692 ** transaction rollback or database recovery operations are not included. 8693 ** If an IO or other error occurs while writing a page to disk, the effect 8694 ** on subsequent SQLITE_DBSTATUS_CACHE_WRITE requests is undefined.)^ ^The 8695 ** highwater mark associated with SQLITE_DBSTATUS_CACHE_WRITE is always 0. 8696 ** </dd> 8697 ** 8698 ** [[SQLITE_DBSTATUS_CACHE_SPILL]] ^(<dt>SQLITE_DBSTATUS_CACHE_SPILL</dt> 8699 ** <dd>This parameter returns the number of dirty cache entries that have 8700 ** been written to disk in the middle of a transaction due to the page 8701 ** cache overflowing. Transactions are more efficient if they are written 8702 ** to disk all at once. When pages spill mid-transaction, that introduces 8703 ** additional overhead. This parameter can be used help identify 8704 ** inefficiencies that can be resolved by increasing the cache size. 8705 ** </dd> 8706 ** 8707 ** [[SQLITE_DBSTATUS_DEFERRED_FKS]] ^(<dt>SQLITE_DBSTATUS_DEFERRED_FKS</dt> 8708 ** <dd>This parameter returns zero for the current value if and only if 8709 ** all foreign key constraints (deferred or immediate) have been 8710 ** resolved.)^ ^The highwater mark is always 0. 8711 ** </dd> 8712 ** </dl> 8713 */ 8714 #define SQLITE_DBSTATUS_LOOKASIDE_USED 0 8715 #define SQLITE_DBSTATUS_CACHE_USED 1 8716 #define SQLITE_DBSTATUS_SCHEMA_USED 2 8717 #define SQLITE_DBSTATUS_STMT_USED 3 8718 #define SQLITE_DBSTATUS_LOOKASIDE_HIT 4 8719 #define SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE 5 8720 #define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL 6 8721 #define SQLITE_DBSTATUS_CACHE_HIT 7 8722 #define SQLITE_DBSTATUS_CACHE_MISS 8 8723 #define SQLITE_DBSTATUS_CACHE_WRITE 9 8724 #define SQLITE_DBSTATUS_DEFERRED_FKS 10 8725 #define SQLITE_DBSTATUS_CACHE_USED_SHARED 11 8726 #define SQLITE_DBSTATUS_CACHE_SPILL 12 8727 #define SQLITE_DBSTATUS_MAX 12 /* Largest defined DBSTATUS */ 8728 8729 8730 /* 8731 ** CAPI3REF: Prepared Statement Status 8732 ** METHOD: sqlite3_stmt 8733 ** 8734 ** ^(Each prepared statement maintains various 8735 ** [SQLITE_STMTSTATUS counters] that measure the number 8736 ** of times it has performed specific operations.)^ These counters can 8737 ** be used to monitor the performance characteristics of the prepared 8738 ** statements. For example, if the number of table steps greatly exceeds 8739 ** the number of table searches or result rows, that would tend to indicate 8740 ** that the prepared statement is using a full table scan rather than 8741 ** an index. 8742 ** 8743 ** ^(This interface is used to retrieve and reset counter values from 8744 ** a [prepared statement]. The first argument is the prepared statement 8745 ** object to be interrogated. The second argument 8746 ** is an integer code for a specific [SQLITE_STMTSTATUS counter] 8747 ** to be interrogated.)^ 8748 ** ^The current value of the requested counter is returned. 8749 ** ^If the resetFlg is true, then the counter is reset to zero after this 8750 ** interface call returns. 8751 ** 8752 ** See also: [sqlite3_status()] and [sqlite3_db_status()]. 8753 */ 8754 SQLITE_API int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg); 8755 8756 /* 8757 ** CAPI3REF: Status Parameters for prepared statements 8758 ** KEYWORDS: {SQLITE_STMTSTATUS counter} {SQLITE_STMTSTATUS counters} 8759 ** 8760 ** These preprocessor macros define integer codes that name counter 8761 ** values associated with the [sqlite3_stmt_status()] interface. 8762 ** The meanings of the various counters are as follows: 8763 ** 8764 ** <dl> 8765 ** [[SQLITE_STMTSTATUS_FULLSCAN_STEP]] <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt> 8766 ** <dd>^This is the number of times that SQLite has stepped forward in 8767 ** a table as part of a full table scan. Large numbers for this counter 8768 ** may indicate opportunities for performance improvement through 8769 ** careful use of indices.</dd> 8770 ** 8771 ** [[SQLITE_STMTSTATUS_SORT]] <dt>SQLITE_STMTSTATUS_SORT</dt> 8772 ** <dd>^This is the number of sort operations that have occurred. 8773 ** A non-zero value in this counter may indicate an opportunity to 8774 ** improvement performance through careful use of indices.</dd> 8775 ** 8776 ** [[SQLITE_STMTSTATUS_AUTOINDEX]] <dt>SQLITE_STMTSTATUS_AUTOINDEX</dt> 8777 ** <dd>^This is the number of rows inserted into transient indices that 8778 ** were created automatically in order to help joins run faster. 8779 ** A non-zero value in this counter may indicate an opportunity to 8780 ** improvement performance by adding permanent indices that do not 8781 ** need to be reinitialized each time the statement is run.</dd> 8782 ** 8783 ** [[SQLITE_STMTSTATUS_VM_STEP]] <dt>SQLITE_STMTSTATUS_VM_STEP</dt> 8784 ** <dd>^This is the number of virtual machine operations executed 8785 ** by the prepared statement if that number is less than or equal 8786 ** to 2147483647. The number of virtual machine operations can be 8787 ** used as a proxy for the total work done by the prepared statement. 8788 ** If the number of virtual machine operations exceeds 2147483647 8789 ** then the value returned by this statement status code is undefined. 8790 ** 8791 ** [[SQLITE_STMTSTATUS_REPREPARE]] <dt>SQLITE_STMTSTATUS_REPREPARE</dt> 8792 ** <dd>^This is the number of times that the prepare statement has been 8793 ** automatically regenerated due to schema changes or changes to 8794 ** [bound parameters] that might affect the query plan. 8795 ** 8796 ** [[SQLITE_STMTSTATUS_RUN]] <dt>SQLITE_STMTSTATUS_RUN</dt> 8797 ** <dd>^This is the number of times that the prepared statement has 8798 ** been run. A single "run" for the purposes of this counter is one 8799 ** or more calls to [sqlite3_step()] followed by a call to [sqlite3_reset()]. 8800 ** The counter is incremented on the first [sqlite3_step()] call of each 8801 ** cycle. 8802 ** 8803 ** [[SQLITE_STMTSTATUS_FILTER_MISS]] 8804 ** [[SQLITE_STMTSTATUS_FILTER HIT]] 8805 ** <dt>SQLITE_STMTSTATUS_FILTER_HIT<br> 8806 ** SQLITE_STMTSTATUS_FILTER_MISS</dt> 8807 ** <dd>^SQLITE_STMTSTATUS_FILTER_HIT is the number of times that a join 8808 ** step was bypassed because a Bloom filter returned not-found. The 8809 ** corresponding SQLITE_STMTSTATUS_FILTER_MISS value is the number of 8810 ** times that the Bloom filter returned a find, and thus the join step 8811 ** had to be processed as normal. 8812 ** 8813 ** [[SQLITE_STMTSTATUS_MEMUSED]] <dt>SQLITE_STMTSTATUS_MEMUSED</dt> 8814 ** <dd>^This is the approximate number of bytes of heap memory 8815 ** used to store the prepared statement. ^This value is not actually 8816 ** a counter, and so the resetFlg parameter to sqlite3_stmt_status() 8817 ** is ignored when the opcode is SQLITE_STMTSTATUS_MEMUSED. 8818 ** </dd> 8819 ** </dl> 8820 */ 8821 #define SQLITE_STMTSTATUS_FULLSCAN_STEP 1 8822 #define SQLITE_STMTSTATUS_SORT 2 8823 #define SQLITE_STMTSTATUS_AUTOINDEX 3 8824 #define SQLITE_STMTSTATUS_VM_STEP 4 8825 #define SQLITE_STMTSTATUS_REPREPARE 5 8826 #define SQLITE_STMTSTATUS_RUN 6 8827 #define SQLITE_STMTSTATUS_FILTER_MISS 7 8828 #define SQLITE_STMTSTATUS_FILTER_HIT 8 8829 #define SQLITE_STMTSTATUS_MEMUSED 99 8830 8831 /* 8832 ** CAPI3REF: Custom Page Cache Object 8833 ** 8834 ** The sqlite3_pcache type is opaque. It is implemented by 8835 ** the pluggable module. The SQLite core has no knowledge of 8836 ** its size or internal structure and never deals with the 8837 ** sqlite3_pcache object except by holding and passing pointers 8838 ** to the object. 8839 ** 8840 ** See [sqlite3_pcache_methods2] for additional information. 8841 */ 8842 typedef struct sqlite3_pcache sqlite3_pcache; 8843 8844 /* 8845 ** CAPI3REF: Custom Page Cache Object 8846 ** 8847 ** The sqlite3_pcache_page object represents a single page in the 8848 ** page cache. The page cache will allocate instances of this 8849 ** object. Various methods of the page cache use pointers to instances 8850 ** of this object as parameters or as their return value. 8851 ** 8852 ** See [sqlite3_pcache_methods2] for additional information. 8853 */ 8854 typedef struct sqlite3_pcache_page sqlite3_pcache_page; 8855 struct sqlite3_pcache_page { 8856 void *pBuf; /* The content of the page */ 8857 void *pExtra; /* Extra information associated with the page */ 8858 }; 8859 8860 /* 8861 ** CAPI3REF: Application Defined Page Cache. 8862 ** KEYWORDS: {page cache} 8863 ** 8864 ** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE2], ...) interface can 8865 ** register an alternative page cache implementation by passing in an 8866 ** instance of the sqlite3_pcache_methods2 structure.)^ 8867 ** In many applications, most of the heap memory allocated by 8868 ** SQLite is used for the page cache. 8869 ** By implementing a 8870 ** custom page cache using this API, an application can better control 8871 ** the amount of memory consumed by SQLite, the way in which 8872 ** that memory is allocated and released, and the policies used to 8873 ** determine exactly which parts of a database file are cached and for 8874 ** how long. 8875 ** 8876 ** The alternative page cache mechanism is an 8877 ** extreme measure that is only needed by the most demanding applications. 8878 ** The built-in page cache is recommended for most uses. 8879 ** 8880 ** ^(The contents of the sqlite3_pcache_methods2 structure are copied to an 8881 ** internal buffer by SQLite within the call to [sqlite3_config]. Hence 8882 ** the application may discard the parameter after the call to 8883 ** [sqlite3_config()] returns.)^ 8884 ** 8885 ** [[the xInit() page cache method]] 8886 ** ^(The xInit() method is called once for each effective 8887 ** call to [sqlite3_initialize()])^ 8888 ** (usually only once during the lifetime of the process). ^(The xInit() 8889 ** method is passed a copy of the sqlite3_pcache_methods2.pArg value.)^ 8890 ** The intent of the xInit() method is to set up global data structures 8891 ** required by the custom page cache implementation. 8892 ** ^(If the xInit() method is NULL, then the 8893 ** built-in default page cache is used instead of the application defined 8894 ** page cache.)^ 8895 ** 8896 ** [[the xShutdown() page cache method]] 8897 ** ^The xShutdown() method is called by [sqlite3_shutdown()]. 8898 ** It can be used to clean up 8899 ** any outstanding resources before process shutdown, if required. 8900 ** ^The xShutdown() method may be NULL. 8901 ** 8902 ** ^SQLite automatically serializes calls to the xInit method, 8903 ** so the xInit method need not be threadsafe. ^The 8904 ** xShutdown method is only called from [sqlite3_shutdown()] so it does 8905 ** not need to be threadsafe either. All other methods must be threadsafe 8906 ** in multithreaded applications. 8907 ** 8908 ** ^SQLite will never invoke xInit() more than once without an intervening 8909 ** call to xShutdown(). 8910 ** 8911 ** [[the xCreate() page cache methods]] 8912 ** ^SQLite invokes the xCreate() method to construct a new cache instance. 8913 ** SQLite will typically create one cache instance for each open database file, 8914 ** though this is not guaranteed. ^The 8915 ** first parameter, szPage, is the size in bytes of the pages that must 8916 ** be allocated by the cache. ^szPage will always a power of two. ^The 8917 ** second parameter szExtra is a number of bytes of extra storage 8918 ** associated with each page cache entry. ^The szExtra parameter will 8919 ** a number less than 250. SQLite will use the 8920 ** extra szExtra bytes on each page to store metadata about the underlying 8921 ** database page on disk. The value passed into szExtra depends 8922 ** on the SQLite version, the target platform, and how SQLite was compiled. 8923 ** ^The third argument to xCreate(), bPurgeable, is true if the cache being 8924 ** created will be used to cache database pages of a file stored on disk, or 8925 ** false if it is used for an in-memory database. The cache implementation 8926 ** does not have to do anything special based with the value of bPurgeable; 8927 ** it is purely advisory. ^On a cache where bPurgeable is false, SQLite will 8928 ** never invoke xUnpin() except to deliberately delete a page. 8929 ** ^In other words, calls to xUnpin() on a cache with bPurgeable set to 8930 ** false will always have the "discard" flag set to true. 8931 ** ^Hence, a cache created with bPurgeable false will 8932 ** never contain any unpinned pages. 8933 ** 8934 ** [[the xCachesize() page cache method]] 8935 ** ^(The xCachesize() method may be called at any time by SQLite to set the 8936 ** suggested maximum cache-size (number of pages stored by) the cache 8937 ** instance passed as the first argument. This is the value configured using 8938 ** the SQLite "[PRAGMA cache_size]" command.)^ As with the bPurgeable 8939 ** parameter, the implementation is not required to do anything with this 8940 ** value; it is advisory only. 8941 ** 8942 ** [[the xPagecount() page cache methods]] 8943 ** The xPagecount() method must return the number of pages currently 8944 ** stored in the cache, both pinned and unpinned. 8945 ** 8946 ** [[the xFetch() page cache methods]] 8947 ** The xFetch() method locates a page in the cache and returns a pointer to 8948 ** an sqlite3_pcache_page object associated with that page, or a NULL pointer. 8949 ** The pBuf element of the returned sqlite3_pcache_page object will be a 8950 ** pointer to a buffer of szPage bytes used to store the content of a 8951 ** single database page. The pExtra element of sqlite3_pcache_page will be 8952 ** a pointer to the szExtra bytes of extra storage that SQLite has requested 8953 ** for each entry in the page cache. 8954 ** 8955 ** The page to be fetched is determined by the key. ^The minimum key value 8956 ** is 1. After it has been retrieved using xFetch, the page is considered 8957 ** to be "pinned". 8958 ** 8959 ** If the requested page is already in the page cache, then the page cache 8960 ** implementation must return a pointer to the page buffer with its content 8961 ** intact. If the requested page is not already in the cache, then the 8962 ** cache implementation should use the value of the createFlag 8963 ** parameter to help it determined what action to take: 8964 ** 8965 ** <table border=1 width=85% align=center> 8966 ** <tr><th> createFlag <th> Behavior when page is not already in cache 8967 ** <tr><td> 0 <td> Do not allocate a new page. Return NULL. 8968 ** <tr><td> 1 <td> Allocate a new page if it easy and convenient to do so. 8969 ** Otherwise return NULL. 8970 ** <tr><td> 2 <td> Make every effort to allocate a new page. Only return 8971 ** NULL if allocating a new page is effectively impossible. 8972 ** </table> 8973 ** 8974 ** ^(SQLite will normally invoke xFetch() with a createFlag of 0 or 1. SQLite 8975 ** will only use a createFlag of 2 after a prior call with a createFlag of 1 8976 ** failed.)^ In between the xFetch() calls, SQLite may 8977 ** attempt to unpin one or more cache pages by spilling the content of 8978 ** pinned pages to disk and synching the operating system disk cache. 8979 ** 8980 ** [[the xUnpin() page cache method]] 8981 ** ^xUnpin() is called by SQLite with a pointer to a currently pinned page 8982 ** as its second argument. If the third parameter, discard, is non-zero, 8983 ** then the page must be evicted from the cache. 8984 ** ^If the discard parameter is 8985 ** zero, then the page may be discarded or retained at the discretion of 8986 ** page cache implementation. ^The page cache implementation 8987 ** may choose to evict unpinned pages at any time. 8988 ** 8989 ** The cache must not perform any reference counting. A single 8990 ** call to xUnpin() unpins the page regardless of the number of prior calls 8991 ** to xFetch(). 8992 ** 8993 ** [[the xRekey() page cache methods]] 8994 ** The xRekey() method is used to change the key value associated with the 8995 ** page passed as the second argument. If the cache 8996 ** previously contains an entry associated with newKey, it must be 8997 ** discarded. ^Any prior cache entry associated with newKey is guaranteed not 8998 ** to be pinned. 8999 ** 9000 ** When SQLite calls the xTruncate() method, the cache must discard all 9001 ** existing cache entries with page numbers (keys) greater than or equal 9002 ** to the value of the iLimit parameter passed to xTruncate(). If any 9003 ** of these pages are pinned, they are implicitly unpinned, meaning that 9004 ** they can be safely discarded. 9005 ** 9006 ** [[the xDestroy() page cache method]] 9007 ** ^The xDestroy() method is used to delete a cache allocated by xCreate(). 9008 ** All resources associated with the specified cache should be freed. ^After 9009 ** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*] 9010 ** handle invalid, and will not use it with any other sqlite3_pcache_methods2 9011 ** functions. 9012 ** 9013 ** [[the xShrink() page cache method]] 9014 ** ^SQLite invokes the xShrink() method when it wants the page cache to 9015 ** free up as much of heap memory as possible. The page cache implementation 9016 ** is not obligated to free any memory, but well-behaved implementations should 9017 ** do their best. 9018 */ 9019 typedef struct sqlite3_pcache_methods2 sqlite3_pcache_methods2; 9020 struct sqlite3_pcache_methods2 { 9021 int iVersion; 9022 void *pArg; 9023 int (*xInit)(void*); 9024 void (*xShutdown)(void*); 9025 sqlite3_pcache *(*xCreate)(int szPage, int szExtra, int bPurgeable); 9026 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 9027 int (*xPagecount)(sqlite3_pcache*); 9028 sqlite3_pcache_page *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 9029 void (*xUnpin)(sqlite3_pcache*, sqlite3_pcache_page*, int discard); 9030 void (*xRekey)(sqlite3_pcache*, sqlite3_pcache_page*, 9031 unsigned oldKey, unsigned newKey); 9032 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 9033 void (*xDestroy)(sqlite3_pcache*); 9034 void (*xShrink)(sqlite3_pcache*); 9035 }; 9036 9037 /* 9038 ** This is the obsolete pcache_methods object that has now been replaced 9039 ** by sqlite3_pcache_methods2. This object is not used by SQLite. It is 9040 ** retained in the header file for backwards compatibility only. 9041 */ 9042 typedef struct sqlite3_pcache_methods sqlite3_pcache_methods; 9043 struct sqlite3_pcache_methods { 9044 void *pArg; 9045 int (*xInit)(void*); 9046 void (*xShutdown)(void*); 9047 sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable); 9048 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 9049 int (*xPagecount)(sqlite3_pcache*); 9050 void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 9051 void (*xUnpin)(sqlite3_pcache*, void*, int discard); 9052 void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey); 9053 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 9054 void (*xDestroy)(sqlite3_pcache*); 9055 }; 9056 9057 9058 /* 9059 ** CAPI3REF: Online Backup Object 9060 ** 9061 ** The sqlite3_backup object records state information about an ongoing 9062 ** online backup operation. ^The sqlite3_backup object is created by 9063 ** a call to [sqlite3_backup_init()] and is destroyed by a call to 9064 ** [sqlite3_backup_finish()]. 9065 ** 9066 ** See Also: [Using the SQLite Online Backup API] 9067 */ 9068 typedef struct sqlite3_backup sqlite3_backup; 9069 9070 /* 9071 ** CAPI3REF: Online Backup API. 9072 ** 9073 ** The backup API copies the content of one database into another. 9074 ** It is useful either for creating backups of databases or 9075 ** for copying in-memory databases to or from persistent files. 9076 ** 9077 ** See Also: [Using the SQLite Online Backup API] 9078 ** 9079 ** ^SQLite holds a write transaction open on the destination database file 9080 ** for the duration of the backup operation. 9081 ** ^The source database is read-locked only while it is being read; 9082 ** it is not locked continuously for the entire backup operation. 9083 ** ^Thus, the backup may be performed on a live source database without 9084 ** preventing other database connections from 9085 ** reading or writing to the source database while the backup is underway. 9086 ** 9087 ** ^(To perform a backup operation: 9088 ** <ol> 9089 ** <li><b>sqlite3_backup_init()</b> is called once to initialize the 9090 ** backup, 9091 ** <li><b>sqlite3_backup_step()</b> is called one or more times to transfer 9092 ** the data between the two databases, and finally 9093 ** <li><b>sqlite3_backup_finish()</b> is called to release all resources 9094 ** associated with the backup operation. 9095 ** </ol>)^ 9096 ** There should be exactly one call to sqlite3_backup_finish() for each 9097 ** successful call to sqlite3_backup_init(). 9098 ** 9099 ** [[sqlite3_backup_init()]] <b>sqlite3_backup_init()</b> 9100 ** 9101 ** ^The D and N arguments to sqlite3_backup_init(D,N,S,M) are the 9102 ** [database connection] associated with the destination database 9103 ** and the database name, respectively. 9104 ** ^The database name is "main" for the main database, "temp" for the 9105 ** temporary database, or the name specified after the AS keyword in 9106 ** an [ATTACH] statement for an attached database. 9107 ** ^The S and M arguments passed to 9108 ** sqlite3_backup_init(D,N,S,M) identify the [database connection] 9109 ** and database name of the source database, respectively. 9110 ** ^The source and destination [database connections] (parameters S and D) 9111 ** must be different or else sqlite3_backup_init(D,N,S,M) will fail with 9112 ** an error. 9113 ** 9114 ** ^A call to sqlite3_backup_init() will fail, returning NULL, if 9115 ** there is already a read or read-write transaction open on the 9116 ** destination database. 9117 ** 9118 ** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is 9119 ** returned and an error code and error message are stored in the 9120 ** destination [database connection] D. 9121 ** ^The error code and message for the failed call to sqlite3_backup_init() 9122 ** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or 9123 ** [sqlite3_errmsg16()] functions. 9124 ** ^A successful call to sqlite3_backup_init() returns a pointer to an 9125 ** [sqlite3_backup] object. 9126 ** ^The [sqlite3_backup] object may be used with the sqlite3_backup_step() and 9127 ** sqlite3_backup_finish() functions to perform the specified backup 9128 ** operation. 9129 ** 9130 ** [[sqlite3_backup_step()]] <b>sqlite3_backup_step()</b> 9131 ** 9132 ** ^Function sqlite3_backup_step(B,N) will copy up to N pages between 9133 ** the source and destination databases specified by [sqlite3_backup] object B. 9134 ** ^If N is negative, all remaining source pages are copied. 9135 ** ^If sqlite3_backup_step(B,N) successfully copies N pages and there 9136 ** are still more pages to be copied, then the function returns [SQLITE_OK]. 9137 ** ^If sqlite3_backup_step(B,N) successfully finishes copying all pages 9138 ** from source to destination, then it returns [SQLITE_DONE]. 9139 ** ^If an error occurs while running sqlite3_backup_step(B,N), 9140 ** then an [error code] is returned. ^As well as [SQLITE_OK] and 9141 ** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY], 9142 ** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an 9143 ** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code. 9144 ** 9145 ** ^(The sqlite3_backup_step() might return [SQLITE_READONLY] if 9146 ** <ol> 9147 ** <li> the destination database was opened read-only, or 9148 ** <li> the destination database is using write-ahead-log journaling 9149 ** and the destination and source page sizes differ, or 9150 ** <li> the destination database is an in-memory database and the 9151 ** destination and source page sizes differ. 9152 ** </ol>)^ 9153 ** 9154 ** ^If sqlite3_backup_step() cannot obtain a required file-system lock, then 9155 ** the [sqlite3_busy_handler | busy-handler function] 9156 ** is invoked (if one is specified). ^If the 9157 ** busy-handler returns non-zero before the lock is available, then 9158 ** [SQLITE_BUSY] is returned to the caller. ^In this case the call to 9159 ** sqlite3_backup_step() can be retried later. ^If the source 9160 ** [database connection] 9161 ** is being used to write to the source database when sqlite3_backup_step() 9162 ** is called, then [SQLITE_LOCKED] is returned immediately. ^Again, in this 9163 ** case the call to sqlite3_backup_step() can be retried later on. ^(If 9164 ** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or 9165 ** [SQLITE_READONLY] is returned, then 9166 ** there is no point in retrying the call to sqlite3_backup_step(). These 9167 ** errors are considered fatal.)^ The application must accept 9168 ** that the backup operation has failed and pass the backup operation handle 9169 ** to the sqlite3_backup_finish() to release associated resources. 9170 ** 9171 ** ^The first call to sqlite3_backup_step() obtains an exclusive lock 9172 ** on the destination file. ^The exclusive lock is not released until either 9173 ** sqlite3_backup_finish() is called or the backup operation is complete 9174 ** and sqlite3_backup_step() returns [SQLITE_DONE]. ^Every call to 9175 ** sqlite3_backup_step() obtains a [shared lock] on the source database that 9176 ** lasts for the duration of the sqlite3_backup_step() call. 9177 ** ^Because the source database is not locked between calls to 9178 ** sqlite3_backup_step(), the source database may be modified mid-way 9179 ** through the backup process. ^If the source database is modified by an 9180 ** external process or via a database connection other than the one being 9181 ** used by the backup operation, then the backup will be automatically 9182 ** restarted by the next call to sqlite3_backup_step(). ^If the source 9183 ** database is modified by the using the same database connection as is used 9184 ** by the backup operation, then the backup database is automatically 9185 ** updated at the same time. 9186 ** 9187 ** [[sqlite3_backup_finish()]] <b>sqlite3_backup_finish()</b> 9188 ** 9189 ** When sqlite3_backup_step() has returned [SQLITE_DONE], or when the 9190 ** application wishes to abandon the backup operation, the application 9191 ** should destroy the [sqlite3_backup] by passing it to sqlite3_backup_finish(). 9192 ** ^The sqlite3_backup_finish() interfaces releases all 9193 ** resources associated with the [sqlite3_backup] object. 9194 ** ^If sqlite3_backup_step() has not yet returned [SQLITE_DONE], then any 9195 ** active write-transaction on the destination database is rolled back. 9196 ** The [sqlite3_backup] object is invalid 9197 ** and may not be used following a call to sqlite3_backup_finish(). 9198 ** 9199 ** ^The value returned by sqlite3_backup_finish is [SQLITE_OK] if no 9200 ** sqlite3_backup_step() errors occurred, regardless or whether or not 9201 ** sqlite3_backup_step() completed. 9202 ** ^If an out-of-memory condition or IO error occurred during any prior 9203 ** sqlite3_backup_step() call on the same [sqlite3_backup] object, then 9204 ** sqlite3_backup_finish() returns the corresponding [error code]. 9205 ** 9206 ** ^A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step() 9207 ** is not a permanent error and does not affect the return value of 9208 ** sqlite3_backup_finish(). 9209 ** 9210 ** [[sqlite3_backup_remaining()]] [[sqlite3_backup_pagecount()]] 9211 ** <b>sqlite3_backup_remaining() and sqlite3_backup_pagecount()</b> 9212 ** 9213 ** ^The sqlite3_backup_remaining() routine returns the number of pages still 9214 ** to be backed up at the conclusion of the most recent sqlite3_backup_step(). 9215 ** ^The sqlite3_backup_pagecount() routine returns the total number of pages 9216 ** in the source database at the conclusion of the most recent 9217 ** sqlite3_backup_step(). 9218 ** ^(The values returned by these functions are only updated by 9219 ** sqlite3_backup_step(). If the source database is modified in a way that 9220 ** changes the size of the source database or the number of pages remaining, 9221 ** those changes are not reflected in the output of sqlite3_backup_pagecount() 9222 ** and sqlite3_backup_remaining() until after the next 9223 ** sqlite3_backup_step().)^ 9224 ** 9225 ** <b>Concurrent Usage of Database Handles</b> 9226 ** 9227 ** ^The source [database connection] may be used by the application for other 9228 ** purposes while a backup operation is underway or being initialized. 9229 ** ^If SQLite is compiled and configured to support threadsafe database 9230 ** connections, then the source database connection may be used concurrently 9231 ** from within other threads. 9232 ** 9233 ** However, the application must guarantee that the destination 9234 ** [database connection] is not passed to any other API (by any thread) after 9235 ** sqlite3_backup_init() is called and before the corresponding call to 9236 ** sqlite3_backup_finish(). SQLite does not currently check to see 9237 ** if the application incorrectly accesses the destination [database connection] 9238 ** and so no error code is reported, but the operations may malfunction 9239 ** nevertheless. Use of the destination database connection while a 9240 ** backup is in progress might also cause a mutex deadlock. 9241 ** 9242 ** If running in [shared cache mode], the application must 9243 ** guarantee that the shared cache used by the destination database 9244 ** is not accessed while the backup is running. In practice this means 9245 ** that the application must guarantee that the disk file being 9246 ** backed up to is not accessed by any connection within the process, 9247 ** not just the specific connection that was passed to sqlite3_backup_init(). 9248 ** 9249 ** The [sqlite3_backup] object itself is partially threadsafe. Multiple 9250 ** threads may safely make multiple concurrent calls to sqlite3_backup_step(). 9251 ** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount() 9252 ** APIs are not strictly speaking threadsafe. If they are invoked at the 9253 ** same time as another thread is invoking sqlite3_backup_step() it is 9254 ** possible that they return invalid values. 9255 */ 9256 SQLITE_API sqlite3_backup *sqlite3_backup_init( 9257 sqlite3 *pDest, /* Destination database handle */ 9258 const char *zDestName, /* Destination database name */ 9259 sqlite3 *pSource, /* Source database handle */ 9260 const char *zSourceName /* Source database name */ 9261 ); 9262 SQLITE_API int sqlite3_backup_step(sqlite3_backup *p, int nPage); 9263 SQLITE_API int sqlite3_backup_finish(sqlite3_backup *p); 9264 SQLITE_API int sqlite3_backup_remaining(sqlite3_backup *p); 9265 SQLITE_API int sqlite3_backup_pagecount(sqlite3_backup *p); 9266 9267 /* 9268 ** CAPI3REF: Unlock Notification 9269 ** METHOD: sqlite3 9270 ** 9271 ** ^When running in shared-cache mode, a database operation may fail with 9272 ** an [SQLITE_LOCKED] error if the required locks on the shared-cache or 9273 ** individual tables within the shared-cache cannot be obtained. See 9274 ** [SQLite Shared-Cache Mode] for a description of shared-cache locking. 9275 ** ^This API may be used to register a callback that SQLite will invoke 9276 ** when the connection currently holding the required lock relinquishes it. 9277 ** ^This API is only available if the library was compiled with the 9278 ** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined. 9279 ** 9280 ** See Also: [Using the SQLite Unlock Notification Feature]. 9281 ** 9282 ** ^Shared-cache locks are released when a database connection concludes 9283 ** its current transaction, either by committing it or rolling it back. 9284 ** 9285 ** ^When a connection (known as the blocked connection) fails to obtain a 9286 ** shared-cache lock and SQLITE_LOCKED is returned to the caller, the 9287 ** identity of the database connection (the blocking connection) that 9288 ** has locked the required resource is stored internally. ^After an 9289 ** application receives an SQLITE_LOCKED error, it may call the 9290 ** sqlite3_unlock_notify() method with the blocked connection handle as 9291 ** the first argument to register for a callback that will be invoked 9292 ** when the blocking connections current transaction is concluded. ^The 9293 ** callback is invoked from within the [sqlite3_step] or [sqlite3_close] 9294 ** call that concludes the blocking connection's transaction. 9295 ** 9296 ** ^(If sqlite3_unlock_notify() is called in a multi-threaded application, 9297 ** there is a chance that the blocking connection will have already 9298 ** concluded its transaction by the time sqlite3_unlock_notify() is invoked. 9299 ** If this happens, then the specified callback is invoked immediately, 9300 ** from within the call to sqlite3_unlock_notify().)^ 9301 ** 9302 ** ^If the blocked connection is attempting to obtain a write-lock on a 9303 ** shared-cache table, and more than one other connection currently holds 9304 ** a read-lock on the same table, then SQLite arbitrarily selects one of 9305 ** the other connections to use as the blocking connection. 9306 ** 9307 ** ^(There may be at most one unlock-notify callback registered by a 9308 ** blocked connection. If sqlite3_unlock_notify() is called when the 9309 ** blocked connection already has a registered unlock-notify callback, 9310 ** then the new callback replaces the old.)^ ^If sqlite3_unlock_notify() is 9311 ** called with a NULL pointer as its second argument, then any existing 9312 ** unlock-notify callback is canceled. ^The blocked connections 9313 ** unlock-notify callback may also be canceled by closing the blocked 9314 ** connection using [sqlite3_close()]. 9315 ** 9316 ** The unlock-notify callback is not reentrant. If an application invokes 9317 ** any sqlite3_xxx API functions from within an unlock-notify callback, a 9318 ** crash or deadlock may be the result. 9319 ** 9320 ** ^Unless deadlock is detected (see below), sqlite3_unlock_notify() always 9321 ** returns SQLITE_OK. 9322 ** 9323 ** <b>Callback Invocation Details</b> 9324 ** 9325 ** When an unlock-notify callback is registered, the application provides a 9326 ** single void* pointer that is passed to the callback when it is invoked. 9327 ** However, the signature of the callback function allows SQLite to pass 9328 ** it an array of void* context pointers. The first argument passed to 9329 ** an unlock-notify callback is a pointer to an array of void* pointers, 9330 ** and the second is the number of entries in the array. 9331 ** 9332 ** When a blocking connection's transaction is concluded, there may be 9333 ** more than one blocked connection that has registered for an unlock-notify 9334 ** callback. ^If two or more such blocked connections have specified the 9335 ** same callback function, then instead of invoking the callback function 9336 ** multiple times, it is invoked once with the set of void* context pointers 9337 ** specified by the blocked connections bundled together into an array. 9338 ** This gives the application an opportunity to prioritize any actions 9339 ** related to the set of unblocked database connections. 9340 ** 9341 ** <b>Deadlock Detection</b> 9342 ** 9343 ** Assuming that after registering for an unlock-notify callback a 9344 ** database waits for the callback to be issued before taking any further 9345 ** action (a reasonable assumption), then using this API may cause the 9346 ** application to deadlock. For example, if connection X is waiting for 9347 ** connection Y's transaction to be concluded, and similarly connection 9348 ** Y is waiting on connection X's transaction, then neither connection 9349 ** will proceed and the system may remain deadlocked indefinitely. 9350 ** 9351 ** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock 9352 ** detection. ^If a given call to sqlite3_unlock_notify() would put the 9353 ** system in a deadlocked state, then SQLITE_LOCKED is returned and no 9354 ** unlock-notify callback is registered. The system is said to be in 9355 ** a deadlocked state if connection A has registered for an unlock-notify 9356 ** callback on the conclusion of connection B's transaction, and connection 9357 ** B has itself registered for an unlock-notify callback when connection 9358 ** A's transaction is concluded. ^Indirect deadlock is also detected, so 9359 ** the system is also considered to be deadlocked if connection B has 9360 ** registered for an unlock-notify callback on the conclusion of connection 9361 ** C's transaction, where connection C is waiting on connection A. ^Any 9362 ** number of levels of indirection are allowed. 9363 ** 9364 ** <b>The "DROP TABLE" Exception</b> 9365 ** 9366 ** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost 9367 ** always appropriate to call sqlite3_unlock_notify(). There is however, 9368 ** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement, 9369 ** SQLite checks if there are any currently executing SELECT statements 9370 ** that belong to the same connection. If there are, SQLITE_LOCKED is 9371 ** returned. In this case there is no "blocking connection", so invoking 9372 ** sqlite3_unlock_notify() results in the unlock-notify callback being 9373 ** invoked immediately. If the application then re-attempts the "DROP TABLE" 9374 ** or "DROP INDEX" query, an infinite loop might be the result. 9375 ** 9376 ** One way around this problem is to check the extended error code returned 9377 ** by an sqlite3_step() call. ^(If there is a blocking connection, then the 9378 ** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in 9379 ** the special "DROP TABLE/INDEX" case, the extended error code is just 9380 ** SQLITE_LOCKED.)^ 9381 */ 9382 SQLITE_API int sqlite3_unlock_notify( 9383 sqlite3 *pBlocked, /* Waiting connection */ 9384 void (*xNotify)(void **apArg, int nArg), /* Callback function to invoke */ 9385 void *pNotifyArg /* Argument to pass to xNotify */ 9386 ); 9387 9388 9389 /* 9390 ** CAPI3REF: String Comparison 9391 ** 9392 ** ^The [sqlite3_stricmp()] and [sqlite3_strnicmp()] APIs allow applications 9393 ** and extensions to compare the contents of two buffers containing UTF-8 9394 ** strings in a case-independent fashion, using the same definition of "case 9395 ** independence" that SQLite uses internally when comparing identifiers. 9396 */ 9397 SQLITE_API int sqlite3_stricmp(const char *, const char *); 9398 SQLITE_API int sqlite3_strnicmp(const char *, const char *, int); 9399 9400 /* 9401 ** CAPI3REF: String Globbing 9402 * 9403 ** ^The [sqlite3_strglob(P,X)] interface returns zero if and only if 9404 ** string X matches the [GLOB] pattern P. 9405 ** ^The definition of [GLOB] pattern matching used in 9406 ** [sqlite3_strglob(P,X)] is the same as for the "X GLOB P" operator in the 9407 ** SQL dialect understood by SQLite. ^The [sqlite3_strglob(P,X)] function 9408 ** is case sensitive. 9409 ** 9410 ** Note that this routine returns zero on a match and non-zero if the strings 9411 ** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()]. 9412 ** 9413 ** See also: [sqlite3_strlike()]. 9414 */ 9415 SQLITE_API int sqlite3_strglob(const char *zGlob, const char *zStr); 9416 9417 /* 9418 ** CAPI3REF: String LIKE Matching 9419 * 9420 ** ^The [sqlite3_strlike(P,X,E)] interface returns zero if and only if 9421 ** string X matches the [LIKE] pattern P with escape character E. 9422 ** ^The definition of [LIKE] pattern matching used in 9423 ** [sqlite3_strlike(P,X,E)] is the same as for the "X LIKE P ESCAPE E" 9424 ** operator in the SQL dialect understood by SQLite. ^For "X LIKE P" without 9425 ** the ESCAPE clause, set the E parameter of [sqlite3_strlike(P,X,E)] to 0. 9426 ** ^As with the LIKE operator, the [sqlite3_strlike(P,X,E)] function is case 9427 ** insensitive - equivalent upper and lower case ASCII characters match 9428 ** one another. 9429 ** 9430 ** ^The [sqlite3_strlike(P,X,E)] function matches Unicode characters, though 9431 ** only ASCII characters are case folded. 9432 ** 9433 ** Note that this routine returns zero on a match and non-zero if the strings 9434 ** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()]. 9435 ** 9436 ** See also: [sqlite3_strglob()]. 9437 */ 9438 SQLITE_API int sqlite3_strlike(const char *zGlob, const char *zStr, unsigned int cEsc); 9439 9440 /* 9441 ** CAPI3REF: Error Logging Interface 9442 ** 9443 ** ^The [sqlite3_log()] interface writes a message into the [error log] 9444 ** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()]. 9445 ** ^If logging is enabled, the zFormat string and subsequent arguments are 9446 ** used with [sqlite3_snprintf()] to generate the final output string. 9447 ** 9448 ** The sqlite3_log() interface is intended for use by extensions such as 9449 ** virtual tables, collating functions, and SQL functions. While there is 9450 ** nothing to prevent an application from calling sqlite3_log(), doing so 9451 ** is considered bad form. 9452 ** 9453 ** The zFormat string must not be NULL. 9454 ** 9455 ** To avoid deadlocks and other threading problems, the sqlite3_log() routine 9456 ** will not use dynamically allocated memory. The log message is stored in 9457 ** a fixed-length buffer on the stack. If the log message is longer than 9458 ** a few hundred characters, it will be truncated to the length of the 9459 ** buffer. 9460 */ 9461 SQLITE_API void sqlite3_log(int iErrCode, const char *zFormat, ...); 9462 9463 /* 9464 ** CAPI3REF: Write-Ahead Log Commit Hook 9465 ** METHOD: sqlite3 9466 ** 9467 ** ^The [sqlite3_wal_hook()] function is used to register a callback that 9468 ** is invoked each time data is committed to a database in wal mode. 9469 ** 9470 ** ^(The callback is invoked by SQLite after the commit has taken place and 9471 ** the associated write-lock on the database released)^, so the implementation 9472 ** may read, write or [checkpoint] the database as required. 9473 ** 9474 ** ^The first parameter passed to the callback function when it is invoked 9475 ** is a copy of the third parameter passed to sqlite3_wal_hook() when 9476 ** registering the callback. ^The second is a copy of the database handle. 9477 ** ^The third parameter is the name of the database that was written to - 9478 ** either "main" or the name of an [ATTACH]-ed database. ^The fourth parameter 9479 ** is the number of pages currently in the write-ahead log file, 9480 ** including those that were just committed. 9481 ** 9482 ** The callback function should normally return [SQLITE_OK]. ^If an error 9483 ** code is returned, that error will propagate back up through the 9484 ** SQLite code base to cause the statement that provoked the callback 9485 ** to report an error, though the commit will have still occurred. If the 9486 ** callback returns [SQLITE_ROW] or [SQLITE_DONE], or if it returns a value 9487 ** that does not correspond to any valid SQLite error code, the results 9488 ** are undefined. 9489 ** 9490 ** A single database handle may have at most a single write-ahead log callback 9491 ** registered at one time. ^Calling [sqlite3_wal_hook()] replaces any 9492 ** previously registered write-ahead log callback. ^The return value is 9493 ** a copy of the third parameter from the previous call, if any, or 0. 9494 ** ^Note that the [sqlite3_wal_autocheckpoint()] interface and the 9495 ** [wal_autocheckpoint pragma] both invoke [sqlite3_wal_hook()] and will 9496 ** overwrite any prior [sqlite3_wal_hook()] settings. 9497 */ 9498 SQLITE_API void *sqlite3_wal_hook( 9499 sqlite3*, 9500 int(*)(void *,sqlite3*,const char*,int), 9501 void* 9502 ); 9503 9504 /* 9505 ** CAPI3REF: Configure an auto-checkpoint 9506 ** METHOD: sqlite3 9507 ** 9508 ** ^The [sqlite3_wal_autocheckpoint(D,N)] is a wrapper around 9509 ** [sqlite3_wal_hook()] that causes any database on [database connection] D 9510 ** to automatically [checkpoint] 9511 ** after committing a transaction if there are N or 9512 ** more frames in the [write-ahead log] file. ^Passing zero or 9513 ** a negative value as the nFrame parameter disables automatic 9514 ** checkpoints entirely. 9515 ** 9516 ** ^The callback registered by this function replaces any existing callback 9517 ** registered using [sqlite3_wal_hook()]. ^Likewise, registering a callback 9518 ** using [sqlite3_wal_hook()] disables the automatic checkpoint mechanism 9519 ** configured by this function. 9520 ** 9521 ** ^The [wal_autocheckpoint pragma] can be used to invoke this interface 9522 ** from SQL. 9523 ** 9524 ** ^Checkpoints initiated by this mechanism are 9525 ** [sqlite3_wal_checkpoint_v2|PASSIVE]. 9526 ** 9527 ** ^Every new [database connection] defaults to having the auto-checkpoint 9528 ** enabled with a threshold of 1000 or [SQLITE_DEFAULT_WAL_AUTOCHECKPOINT] 9529 ** pages. The use of this interface 9530 ** is only necessary if the default setting is found to be suboptimal 9531 ** for a particular application. 9532 */ 9533 SQLITE_API int sqlite3_wal_autocheckpoint(sqlite3 *db, int N); 9534 9535 /* 9536 ** CAPI3REF: Checkpoint a database 9537 ** METHOD: sqlite3 9538 ** 9539 ** ^(The sqlite3_wal_checkpoint(D,X) is equivalent to 9540 ** [sqlite3_wal_checkpoint_v2](D,X,[SQLITE_CHECKPOINT_PASSIVE],0,0).)^ 9541 ** 9542 ** In brief, sqlite3_wal_checkpoint(D,X) causes the content in the 9543 ** [write-ahead log] for database X on [database connection] D to be 9544 ** transferred into the database file and for the write-ahead log to 9545 ** be reset. See the [checkpointing] documentation for addition 9546 ** information. 9547 ** 9548 ** This interface used to be the only way to cause a checkpoint to 9549 ** occur. But then the newer and more powerful [sqlite3_wal_checkpoint_v2()] 9550 ** interface was added. This interface is retained for backwards 9551 ** compatibility and as a convenience for applications that need to manually 9552 ** start a callback but which do not need the full power (and corresponding 9553 ** complication) of [sqlite3_wal_checkpoint_v2()]. 9554 */ 9555 SQLITE_API int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb); 9556 9557 /* 9558 ** CAPI3REF: Checkpoint a database 9559 ** METHOD: sqlite3 9560 ** 9561 ** ^(The sqlite3_wal_checkpoint_v2(D,X,M,L,C) interface runs a checkpoint 9562 ** operation on database X of [database connection] D in mode M. Status 9563 ** information is written back into integers pointed to by L and C.)^ 9564 ** ^(The M parameter must be a valid [checkpoint mode]:)^ 9565 ** 9566 ** <dl> 9567 ** <dt>SQLITE_CHECKPOINT_PASSIVE<dd> 9568 ** ^Checkpoint as many frames as possible without waiting for any database 9569 ** readers or writers to finish, then sync the database file if all frames 9570 ** in the log were checkpointed. ^The [busy-handler callback] 9571 ** is never invoked in the SQLITE_CHECKPOINT_PASSIVE mode. 9572 ** ^On the other hand, passive mode might leave the checkpoint unfinished 9573 ** if there are concurrent readers or writers. 9574 ** 9575 ** <dt>SQLITE_CHECKPOINT_FULL<dd> 9576 ** ^This mode blocks (it invokes the 9577 ** [sqlite3_busy_handler|busy-handler callback]) until there is no 9578 ** database writer and all readers are reading from the most recent database 9579 ** snapshot. ^It then checkpoints all frames in the log file and syncs the 9580 ** database file. ^This mode blocks new database writers while it is pending, 9581 ** but new database readers are allowed to continue unimpeded. 9582 ** 9583 ** <dt>SQLITE_CHECKPOINT_RESTART<dd> 9584 ** ^This mode works the same way as SQLITE_CHECKPOINT_FULL with the addition 9585 ** that after checkpointing the log file it blocks (calls the 9586 ** [busy-handler callback]) 9587 ** until all readers are reading from the database file only. ^This ensures 9588 ** that the next writer will restart the log file from the beginning. 9589 ** ^Like SQLITE_CHECKPOINT_FULL, this mode blocks new 9590 ** database writer attempts while it is pending, but does not impede readers. 9591 ** 9592 ** <dt>SQLITE_CHECKPOINT_TRUNCATE<dd> 9593 ** ^This mode works the same way as SQLITE_CHECKPOINT_RESTART with the 9594 ** addition that it also truncates the log file to zero bytes just prior 9595 ** to a successful return. 9596 ** </dl> 9597 ** 9598 ** ^If pnLog is not NULL, then *pnLog is set to the total number of frames in 9599 ** the log file or to -1 if the checkpoint could not run because 9600 ** of an error or because the database is not in [WAL mode]. ^If pnCkpt is not 9601 ** NULL,then *pnCkpt is set to the total number of checkpointed frames in the 9602 ** log file (including any that were already checkpointed before the function 9603 ** was called) or to -1 if the checkpoint could not run due to an error or 9604 ** because the database is not in WAL mode. ^Note that upon successful 9605 ** completion of an SQLITE_CHECKPOINT_TRUNCATE, the log file will have been 9606 ** truncated to zero bytes and so both *pnLog and *pnCkpt will be set to zero. 9607 ** 9608 ** ^All calls obtain an exclusive "checkpoint" lock on the database file. ^If 9609 ** any other process is running a checkpoint operation at the same time, the 9610 ** lock cannot be obtained and SQLITE_BUSY is returned. ^Even if there is a 9611 ** busy-handler configured, it will not be invoked in this case. 9612 ** 9613 ** ^The SQLITE_CHECKPOINT_FULL, RESTART and TRUNCATE modes also obtain the 9614 ** exclusive "writer" lock on the database file. ^If the writer lock cannot be 9615 ** obtained immediately, and a busy-handler is configured, it is invoked and 9616 ** the writer lock retried until either the busy-handler returns 0 or the lock 9617 ** is successfully obtained. ^The busy-handler is also invoked while waiting for 9618 ** database readers as described above. ^If the busy-handler returns 0 before 9619 ** the writer lock is obtained or while waiting for database readers, the 9620 ** checkpoint operation proceeds from that point in the same way as 9621 ** SQLITE_CHECKPOINT_PASSIVE - checkpointing as many frames as possible 9622 ** without blocking any further. ^SQLITE_BUSY is returned in this case. 9623 ** 9624 ** ^If parameter zDb is NULL or points to a zero length string, then the 9625 ** specified operation is attempted on all WAL databases [attached] to 9626 ** [database connection] db. In this case the 9627 ** values written to output parameters *pnLog and *pnCkpt are undefined. ^If 9628 ** an SQLITE_BUSY error is encountered when processing one or more of the 9629 ** attached WAL databases, the operation is still attempted on any remaining 9630 ** attached databases and SQLITE_BUSY is returned at the end. ^If any other 9631 ** error occurs while processing an attached database, processing is abandoned 9632 ** and the error code is returned to the caller immediately. ^If no error 9633 ** (SQLITE_BUSY or otherwise) is encountered while processing the attached 9634 ** databases, SQLITE_OK is returned. 9635 ** 9636 ** ^If database zDb is the name of an attached database that is not in WAL 9637 ** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. ^If 9638 ** zDb is not NULL (or a zero length string) and is not the name of any 9639 ** attached database, SQLITE_ERROR is returned to the caller. 9640 ** 9641 ** ^Unless it returns SQLITE_MISUSE, 9642 ** the sqlite3_wal_checkpoint_v2() interface 9643 ** sets the error information that is queried by 9644 ** [sqlite3_errcode()] and [sqlite3_errmsg()]. 9645 ** 9646 ** ^The [PRAGMA wal_checkpoint] command can be used to invoke this interface 9647 ** from SQL. 9648 */ 9649 SQLITE_API int sqlite3_wal_checkpoint_v2( 9650 sqlite3 *db, /* Database handle */ 9651 const char *zDb, /* Name of attached database (or NULL) */ 9652 int eMode, /* SQLITE_CHECKPOINT_* value */ 9653 int *pnLog, /* OUT: Size of WAL log in frames */ 9654 int *pnCkpt /* OUT: Total number of frames checkpointed */ 9655 ); 9656 9657 /* 9658 ** CAPI3REF: Checkpoint Mode Values 9659 ** KEYWORDS: {checkpoint mode} 9660 ** 9661 ** These constants define all valid values for the "checkpoint mode" passed 9662 ** as the third parameter to the [sqlite3_wal_checkpoint_v2()] interface. 9663 ** See the [sqlite3_wal_checkpoint_v2()] documentation for details on the 9664 ** meaning of each of these checkpoint modes. 9665 */ 9666 #define SQLITE_CHECKPOINT_PASSIVE 0 /* Do as much as possible w/o blocking */ 9667 #define SQLITE_CHECKPOINT_FULL 1 /* Wait for writers, then checkpoint */ 9668 #define SQLITE_CHECKPOINT_RESTART 2 /* Like FULL but wait for readers */ 9669 #define SQLITE_CHECKPOINT_TRUNCATE 3 /* Like RESTART but also truncate WAL */ 9670 9671 /* 9672 ** CAPI3REF: Virtual Table Interface Configuration 9673 ** 9674 ** This function may be called by either the [xConnect] or [xCreate] method 9675 ** of a [virtual table] implementation to configure 9676 ** various facets of the virtual table interface. 9677 ** 9678 ** If this interface is invoked outside the context of an xConnect or 9679 ** xCreate virtual table method then the behavior is undefined. 9680 ** 9681 ** In the call sqlite3_vtab_config(D,C,...) the D parameter is the 9682 ** [database connection] in which the virtual table is being created and 9683 ** which is passed in as the first argument to the [xConnect] or [xCreate] 9684 ** method that is invoking sqlite3_vtab_config(). The C parameter is one 9685 ** of the [virtual table configuration options]. The presence and meaning 9686 ** of parameters after C depend on which [virtual table configuration option] 9687 ** is used. 9688 */ 9689 SQLITE_API int sqlite3_vtab_config(sqlite3*, int op, ...); 9690 9691 /* 9692 ** CAPI3REF: Virtual Table Configuration Options 9693 ** KEYWORDS: {virtual table configuration options} 9694 ** KEYWORDS: {virtual table configuration option} 9695 ** 9696 ** These macros define the various options to the 9697 ** [sqlite3_vtab_config()] interface that [virtual table] implementations 9698 ** can use to customize and optimize their behavior. 9699 ** 9700 ** <dl> 9701 ** [[SQLITE_VTAB_CONSTRAINT_SUPPORT]] 9702 ** <dt>SQLITE_VTAB_CONSTRAINT_SUPPORT</dt> 9703 ** <dd>Calls of the form 9704 ** [sqlite3_vtab_config](db,SQLITE_VTAB_CONSTRAINT_SUPPORT,X) are supported, 9705 ** where X is an integer. If X is zero, then the [virtual table] whose 9706 ** [xCreate] or [xConnect] method invoked [sqlite3_vtab_config()] does not 9707 ** support constraints. In this configuration (which is the default) if 9708 ** a call to the [xUpdate] method returns [SQLITE_CONSTRAINT], then the entire 9709 ** statement is rolled back as if [ON CONFLICT | OR ABORT] had been 9710 ** specified as part of the users SQL statement, regardless of the actual 9711 ** ON CONFLICT mode specified. 9712 ** 9713 ** If X is non-zero, then the virtual table implementation guarantees 9714 ** that if [xUpdate] returns [SQLITE_CONSTRAINT], it will do so before 9715 ** any modifications to internal or persistent data structures have been made. 9716 ** If the [ON CONFLICT] mode is ABORT, FAIL, IGNORE or ROLLBACK, SQLite 9717 ** is able to roll back a statement or database transaction, and abandon 9718 ** or continue processing the current SQL statement as appropriate. 9719 ** If the ON CONFLICT mode is REPLACE and the [xUpdate] method returns 9720 ** [SQLITE_CONSTRAINT], SQLite handles this as if the ON CONFLICT mode 9721 ** had been ABORT. 9722 ** 9723 ** Virtual table implementations that are required to handle OR REPLACE 9724 ** must do so within the [xUpdate] method. If a call to the 9725 ** [sqlite3_vtab_on_conflict()] function indicates that the current ON 9726 ** CONFLICT policy is REPLACE, the virtual table implementation should 9727 ** silently replace the appropriate rows within the xUpdate callback and 9728 ** return SQLITE_OK. Or, if this is not possible, it may return 9729 ** SQLITE_CONSTRAINT, in which case SQLite falls back to OR ABORT 9730 ** constraint handling. 9731 ** </dd> 9732 ** 9733 ** [[SQLITE_VTAB_DIRECTONLY]]<dt>SQLITE_VTAB_DIRECTONLY</dt> 9734 ** <dd>Calls of the form 9735 ** [sqlite3_vtab_config](db,SQLITE_VTAB_DIRECTONLY) from within the 9736 ** the [xConnect] or [xCreate] methods of a [virtual table] implementation 9737 ** prohibits that virtual table from being used from within triggers and 9738 ** views. 9739 ** </dd> 9740 ** 9741 ** [[SQLITE_VTAB_INNOCUOUS]]<dt>SQLITE_VTAB_INNOCUOUS</dt> 9742 ** <dd>Calls of the form 9743 ** [sqlite3_vtab_config](db,SQLITE_VTAB_INNOCUOUS) from within the 9744 ** the [xConnect] or [xCreate] methods of a [virtual table] implementation 9745 ** identify that virtual table as being safe to use from within triggers 9746 ** and views. Conceptually, the SQLITE_VTAB_INNOCUOUS tag means that the 9747 ** virtual table can do no serious harm even if it is controlled by a 9748 ** malicious hacker. Developers should avoid setting the SQLITE_VTAB_INNOCUOUS 9749 ** flag unless absolutely necessary. 9750 ** </dd> 9751 ** 9752 ** [[SQLITE_VTAB_USES_ALL_SCHEMAS]]<dt>SQLITE_VTAB_USES_ALL_SCHEMAS</dt> 9753 ** <dd>Calls of the form 9754 ** [sqlite3_vtab_config](db,SQLITE_VTAB_USES_ALL_SCHEMA) from within the 9755 ** the [xConnect] or [xCreate] methods of a [virtual table] implementation 9756 ** instruct the query planner to begin at least a read transaction on 9757 ** all schemas ("main", "temp", and any ATTACH-ed databases) whenever the 9758 ** virtual table is used. 9759 ** </dd> 9760 ** </dl> 9761 */ 9762 #define SQLITE_VTAB_CONSTRAINT_SUPPORT 1 9763 #define SQLITE_VTAB_INNOCUOUS 2 9764 #define SQLITE_VTAB_DIRECTONLY 3 9765 #define SQLITE_VTAB_USES_ALL_SCHEMAS 4 9766 9767 /* 9768 ** CAPI3REF: Determine The Virtual Table Conflict Policy 9769 ** 9770 ** This function may only be called from within a call to the [xUpdate] method 9771 ** of a [virtual table] implementation for an INSERT or UPDATE operation. ^The 9772 ** value returned is one of [SQLITE_ROLLBACK], [SQLITE_IGNORE], [SQLITE_FAIL], 9773 ** [SQLITE_ABORT], or [SQLITE_REPLACE], according to the [ON CONFLICT] mode 9774 ** of the SQL statement that triggered the call to the [xUpdate] method of the 9775 ** [virtual table]. 9776 */ 9777 SQLITE_API int sqlite3_vtab_on_conflict(sqlite3 *); 9778 9779 /* 9780 ** CAPI3REF: Determine If Virtual Table Column Access Is For UPDATE 9781 ** 9782 ** If the sqlite3_vtab_nochange(X) routine is called within the [xColumn] 9783 ** method of a [virtual table], then it might return true if the 9784 ** column is being fetched as part of an UPDATE operation during which the 9785 ** column value will not change. The virtual table implementation can use 9786 ** this hint as permission to substitute a return value that is less 9787 ** expensive to compute and that the corresponding 9788 ** [xUpdate] method understands as a "no-change" value. 9789 ** 9790 ** If the [xColumn] method calls sqlite3_vtab_nochange() and finds that 9791 ** the column is not changed by the UPDATE statement, then the xColumn 9792 ** method can optionally return without setting a result, without calling 9793 ** any of the [sqlite3_result_int|sqlite3_result_xxxxx() interfaces]. 9794 ** In that case, [sqlite3_value_nochange(X)] will return true for the 9795 ** same column in the [xUpdate] method. 9796 ** 9797 ** The sqlite3_vtab_nochange() routine is an optimization. Virtual table 9798 ** implementations should continue to give a correct answer even if the 9799 ** sqlite3_vtab_nochange() interface were to always return false. In the 9800 ** current implementation, the sqlite3_vtab_nochange() interface does always 9801 ** returns false for the enhanced [UPDATE FROM] statement. 9802 */ 9803 SQLITE_API int sqlite3_vtab_nochange(sqlite3_context*); 9804 9805 /* 9806 ** CAPI3REF: Determine The Collation For a Virtual Table Constraint 9807 ** METHOD: sqlite3_index_info 9808 ** 9809 ** This function may only be called from within a call to the [xBestIndex] 9810 ** method of a [virtual table]. This function returns a pointer to a string 9811 ** that is the name of the appropriate collation sequence to use for text 9812 ** comparisons on the constraint identified by its arguments. 9813 ** 9814 ** The first argument must be the pointer to the [sqlite3_index_info] object 9815 ** that is the first parameter to the xBestIndex() method. The second argument 9816 ** must be an index into the aConstraint[] array belonging to the 9817 ** sqlite3_index_info structure passed to xBestIndex. 9818 ** 9819 ** Important: 9820 ** The first parameter must be the same pointer that is passed into the 9821 ** xBestMethod() method. The first parameter may not be a pointer to a 9822 ** different [sqlite3_index_info] object, even an exact copy. 9823 ** 9824 ** The return value is computed as follows: 9825 ** 9826 ** <ol> 9827 ** <li><p> If the constraint comes from a WHERE clause expression that contains 9828 ** a [COLLATE operator], then the name of the collation specified by 9829 ** that COLLATE operator is returned. 9830 ** <li><p> If there is no COLLATE operator, but the column that is the subject 9831 ** of the constraint specifies an alternative collating sequence via 9832 ** a [COLLATE clause] on the column definition within the CREATE TABLE 9833 ** statement that was passed into [sqlite3_declare_vtab()], then the 9834 ** name of that alternative collating sequence is returned. 9835 ** <li><p> Otherwise, "BINARY" is returned. 9836 ** </ol> 9837 */ 9838 SQLITE_API const char *sqlite3_vtab_collation(sqlite3_index_info*,int); 9839 9840 /* 9841 ** CAPI3REF: Determine if a virtual table query is DISTINCT 9842 ** METHOD: sqlite3_index_info 9843 ** 9844 ** This API may only be used from within an [xBestIndex|xBestIndex method] 9845 ** of a [virtual table] implementation. The result of calling this 9846 ** interface from outside of xBestIndex() is undefined and probably harmful. 9847 ** 9848 ** ^The sqlite3_vtab_distinct() interface returns an integer between 0 and 9849 ** 3. The integer returned by sqlite3_vtab_distinct() 9850 ** gives the virtual table additional information about how the query 9851 ** planner wants the output to be ordered. As long as the virtual table 9852 ** can meet the ordering requirements of the query planner, it may set 9853 ** the "orderByConsumed" flag. 9854 ** 9855 ** <ol><li value="0"><p> 9856 ** ^If the sqlite3_vtab_distinct() interface returns 0, that means 9857 ** that the query planner needs the virtual table to return all rows in the 9858 ** sort order defined by the "nOrderBy" and "aOrderBy" fields of the 9859 ** [sqlite3_index_info] object. This is the default expectation. If the 9860 ** virtual table outputs all rows in sorted order, then it is always safe for 9861 ** the xBestIndex method to set the "orderByConsumed" flag, regardless of 9862 ** the return value from sqlite3_vtab_distinct(). 9863 ** <li value="1"><p> 9864 ** ^(If the sqlite3_vtab_distinct() interface returns 1, that means 9865 ** that the query planner does not need the rows to be returned in sorted order 9866 ** as long as all rows with the same values in all columns identified by the 9867 ** "aOrderBy" field are adjacent.)^ This mode is used when the query planner 9868 ** is doing a GROUP BY. 9869 ** <li value="2"><p> 9870 ** ^(If the sqlite3_vtab_distinct() interface returns 2, that means 9871 ** that the query planner does not need the rows returned in any particular 9872 ** order, as long as rows with the same values in all "aOrderBy" columns 9873 ** are adjacent.)^ ^(Furthermore, only a single row for each particular 9874 ** combination of values in the columns identified by the "aOrderBy" field 9875 ** needs to be returned.)^ ^It is always ok for two or more rows with the same 9876 ** values in all "aOrderBy" columns to be returned, as long as all such rows 9877 ** are adjacent. ^The virtual table may, if it chooses, omit extra rows 9878 ** that have the same value for all columns identified by "aOrderBy". 9879 ** ^However omitting the extra rows is optional. 9880 ** This mode is used for a DISTINCT query. 9881 ** <li value="3"><p> 9882 ** ^(If the sqlite3_vtab_distinct() interface returns 3, that means 9883 ** that the query planner needs only distinct rows but it does need the 9884 ** rows to be sorted.)^ ^The virtual table implementation is free to omit 9885 ** rows that are identical in all aOrderBy columns, if it wants to, but 9886 ** it is not required to omit any rows. This mode is used for queries 9887 ** that have both DISTINCT and ORDER BY clauses. 9888 ** </ol> 9889 ** 9890 ** ^For the purposes of comparing virtual table output values to see if the 9891 ** values are same value for sorting purposes, two NULL values are considered 9892 ** to be the same. In other words, the comparison operator is "IS" 9893 ** (or "IS NOT DISTINCT FROM") and not "==". 9894 ** 9895 ** If a virtual table implementation is unable to meet the requirements 9896 ** specified above, then it must not set the "orderByConsumed" flag in the 9897 ** [sqlite3_index_info] object or an incorrect answer may result. 9898 ** 9899 ** ^A virtual table implementation is always free to return rows in any order 9900 ** it wants, as long as the "orderByConsumed" flag is not set. ^When the 9901 ** the "orderByConsumed" flag is unset, the query planner will add extra 9902 ** [bytecode] to ensure that the final results returned by the SQL query are 9903 ** ordered correctly. The use of the "orderByConsumed" flag and the 9904 ** sqlite3_vtab_distinct() interface is merely an optimization. ^Careful 9905 ** use of the sqlite3_vtab_distinct() interface and the "orderByConsumed" 9906 ** flag might help queries against a virtual table to run faster. Being 9907 ** overly aggressive and setting the "orderByConsumed" flag when it is not 9908 ** valid to do so, on the other hand, might cause SQLite to return incorrect 9909 ** results. 9910 */ 9911 SQLITE_API int sqlite3_vtab_distinct(sqlite3_index_info*); 9912 9913 /* 9914 ** CAPI3REF: Identify and handle IN constraints in xBestIndex 9915 ** 9916 ** This interface may only be used from within an 9917 ** [xBestIndex|xBestIndex() method] of a [virtual table] implementation. 9918 ** The result of invoking this interface from any other context is 9919 ** undefined and probably harmful. 9920 ** 9921 ** ^(A constraint on a virtual table of the form 9922 ** "[IN operator|column IN (...)]" is 9923 ** communicated to the xBestIndex method as a 9924 ** [SQLITE_INDEX_CONSTRAINT_EQ] constraint.)^ If xBestIndex wants to use 9925 ** this constraint, it must set the corresponding 9926 ** aConstraintUsage[].argvIndex to a positive integer. ^(Then, under 9927 ** the usual mode of handling IN operators, SQLite generates [bytecode] 9928 ** that invokes the [xFilter|xFilter() method] once for each value 9929 ** on the right-hand side of the IN operator.)^ Thus the virtual table 9930 ** only sees a single value from the right-hand side of the IN operator 9931 ** at a time. 9932 ** 9933 ** In some cases, however, it would be advantageous for the virtual 9934 ** table to see all values on the right-hand of the IN operator all at 9935 ** once. The sqlite3_vtab_in() interfaces facilitates this in two ways: 9936 ** 9937 ** <ol> 9938 ** <li><p> 9939 ** ^A call to sqlite3_vtab_in(P,N,-1) will return true (non-zero) 9940 ** if and only if the [sqlite3_index_info|P->aConstraint][N] constraint 9941 ** is an [IN operator] that can be processed all at once. ^In other words, 9942 ** sqlite3_vtab_in() with -1 in the third argument is a mechanism 9943 ** by which the virtual table can ask SQLite if all-at-once processing 9944 ** of the IN operator is even possible. 9945 ** 9946 ** <li><p> 9947 ** ^A call to sqlite3_vtab_in(P,N,F) with F==1 or F==0 indicates 9948 ** to SQLite that the virtual table does or does not want to process 9949 ** the IN operator all-at-once, respectively. ^Thus when the third 9950 ** parameter (F) is non-negative, this interface is the mechanism by 9951 ** which the virtual table tells SQLite how it wants to process the 9952 ** IN operator. 9953 ** </ol> 9954 ** 9955 ** ^The sqlite3_vtab_in(P,N,F) interface can be invoked multiple times 9956 ** within the same xBestIndex method call. ^For any given P,N pair, 9957 ** the return value from sqlite3_vtab_in(P,N,F) will always be the same 9958 ** within the same xBestIndex call. ^If the interface returns true 9959 ** (non-zero), that means that the constraint is an IN operator 9960 ** that can be processed all-at-once. ^If the constraint is not an IN 9961 ** operator or cannot be processed all-at-once, then the interface returns 9962 ** false. 9963 ** 9964 ** ^(All-at-once processing of the IN operator is selected if both of the 9965 ** following conditions are met: 9966 ** 9967 ** <ol> 9968 ** <li><p> The P->aConstraintUsage[N].argvIndex value is set to a positive 9969 ** integer. This is how the virtual table tells SQLite that it wants to 9970 ** use the N-th constraint. 9971 ** 9972 ** <li><p> The last call to sqlite3_vtab_in(P,N,F) for which F was 9973 ** non-negative had F>=1. 9974 ** </ol>)^ 9975 ** 9976 ** ^If either or both of the conditions above are false, then SQLite uses 9977 ** the traditional one-at-a-time processing strategy for the IN constraint. 9978 ** ^If both conditions are true, then the argvIndex-th parameter to the 9979 ** xFilter method will be an [sqlite3_value] that appears to be NULL, 9980 ** but which can be passed to [sqlite3_vtab_in_first()] and 9981 ** [sqlite3_vtab_in_next()] to find all values on the right-hand side 9982 ** of the IN constraint. 9983 */ 9984 SQLITE_API int sqlite3_vtab_in(sqlite3_index_info*, int iCons, int bHandle); 9985 9986 /* 9987 ** CAPI3REF: Find all elements on the right-hand side of an IN constraint. 9988 ** 9989 ** These interfaces are only useful from within the 9990 ** [xFilter|xFilter() method] of a [virtual table] implementation. 9991 ** The result of invoking these interfaces from any other context 9992 ** is undefined and probably harmful. 9993 ** 9994 ** The X parameter in a call to sqlite3_vtab_in_first(X,P) or 9995 ** sqlite3_vtab_in_next(X,P) should be one of the parameters to the 9996 ** xFilter method which invokes these routines, and specifically 9997 ** a parameter that was previously selected for all-at-once IN constraint 9998 ** processing use the [sqlite3_vtab_in()] interface in the 9999 ** [xBestIndex|xBestIndex method]. ^(If the X parameter is not 10000 ** an xFilter argument that was selected for all-at-once IN constraint 10001 ** processing, then these routines return [SQLITE_ERROR].)^ 10002 ** 10003 ** ^(Use these routines to access all values on the right-hand side 10004 ** of the IN constraint using code like the following: 10005 ** 10006 ** <blockquote><pre> 10007 ** for(rc=sqlite3_vtab_in_first(pList, &pVal); 10008 ** rc==SQLITE_OK && pVal; 10009 ** rc=sqlite3_vtab_in_next(pList, &pVal) 10010 ** ){ 10011 ** // do something with pVal 10012 ** } 10013 ** if( rc!=SQLITE_OK ){ 10014 ** // an error has occurred 10015 ** } 10016 ** </pre></blockquote>)^ 10017 ** 10018 ** ^On success, the sqlite3_vtab_in_first(X,P) and sqlite3_vtab_in_next(X,P) 10019 ** routines return SQLITE_OK and set *P to point to the first or next value 10020 ** on the RHS of the IN constraint. ^If there are no more values on the 10021 ** right hand side of the IN constraint, then *P is set to NULL and these 10022 ** routines return [SQLITE_DONE]. ^The return value might be 10023 ** some other value, such as SQLITE_NOMEM, in the event of a malfunction. 10024 ** 10025 ** The *ppOut values returned by these routines are only valid until the 10026 ** next call to either of these routines or until the end of the xFilter 10027 ** method from which these routines were called. If the virtual table 10028 ** implementation needs to retain the *ppOut values for longer, it must make 10029 ** copies. The *ppOut values are [protected sqlite3_value|protected]. 10030 */ 10031 SQLITE_API int sqlite3_vtab_in_first(sqlite3_value *pVal, sqlite3_value **ppOut); 10032 SQLITE_API int sqlite3_vtab_in_next(sqlite3_value *pVal, sqlite3_value **ppOut); 10033 10034 /* 10035 ** CAPI3REF: Constraint values in xBestIndex() 10036 ** METHOD: sqlite3_index_info 10037 ** 10038 ** This API may only be used from within the [xBestIndex|xBestIndex method] 10039 ** of a [virtual table] implementation. The result of calling this interface 10040 ** from outside of an xBestIndex method are undefined and probably harmful. 10041 ** 10042 ** ^When the sqlite3_vtab_rhs_value(P,J,V) interface is invoked from within 10043 ** the [xBestIndex] method of a [virtual table] implementation, with P being 10044 ** a copy of the [sqlite3_index_info] object pointer passed into xBestIndex and 10045 ** J being a 0-based index into P->aConstraint[], then this routine 10046 ** attempts to set *V to the value of the right-hand operand of 10047 ** that constraint if the right-hand operand is known. ^If the 10048 ** right-hand operand is not known, then *V is set to a NULL pointer. 10049 ** ^The sqlite3_vtab_rhs_value(P,J,V) interface returns SQLITE_OK if 10050 ** and only if *V is set to a value. ^The sqlite3_vtab_rhs_value(P,J,V) 10051 ** inteface returns SQLITE_NOTFOUND if the right-hand side of the J-th 10052 ** constraint is not available. ^The sqlite3_vtab_rhs_value() interface 10053 ** can return an result code other than SQLITE_OK or SQLITE_NOTFOUND if 10054 ** something goes wrong. 10055 ** 10056 ** The sqlite3_vtab_rhs_value() interface is usually only successful if 10057 ** the right-hand operand of a constraint is a literal value in the original 10058 ** SQL statement. If the right-hand operand is an expression or a reference 10059 ** to some other column or a [host parameter], then sqlite3_vtab_rhs_value() 10060 ** will probably return [SQLITE_NOTFOUND]. 10061 ** 10062 ** ^(Some constraints, such as [SQLITE_INDEX_CONSTRAINT_ISNULL] and 10063 ** [SQLITE_INDEX_CONSTRAINT_ISNOTNULL], have no right-hand operand. For such 10064 ** constraints, sqlite3_vtab_rhs_value() always returns SQLITE_NOTFOUND.)^ 10065 ** 10066 ** ^The [sqlite3_value] object returned in *V is a protected sqlite3_value 10067 ** and remains valid for the duration of the xBestIndex method call. 10068 ** ^When xBestIndex returns, the sqlite3_value object returned by 10069 ** sqlite3_vtab_rhs_value() is automatically deallocated. 10070 ** 10071 ** The "_rhs_" in the name of this routine is an abbreviation for 10072 ** "Right-Hand Side". 10073 */ 10074 SQLITE_API int sqlite3_vtab_rhs_value(sqlite3_index_info*, int, sqlite3_value **ppVal); 10075 10076 /* 10077 ** CAPI3REF: Conflict resolution modes 10078 ** KEYWORDS: {conflict resolution mode} 10079 ** 10080 ** These constants are returned by [sqlite3_vtab_on_conflict()] to 10081 ** inform a [virtual table] implementation what the [ON CONFLICT] mode 10082 ** is for the SQL statement being evaluated. 10083 ** 10084 ** Note that the [SQLITE_IGNORE] constant is also used as a potential 10085 ** return value from the [sqlite3_set_authorizer()] callback and that 10086 ** [SQLITE_ABORT] is also a [result code]. 10087 */ 10088 #define SQLITE_ROLLBACK 1 10089 /* #define SQLITE_IGNORE 2 // Also used by sqlite3_authorizer() callback */ 10090 #define SQLITE_FAIL 3 10091 /* #define SQLITE_ABORT 4 // Also an error code */ 10092 #define SQLITE_REPLACE 5 10093 10094 /* 10095 ** CAPI3REF: Prepared Statement Scan Status Opcodes 10096 ** KEYWORDS: {scanstatus options} 10097 ** 10098 ** The following constants can be used for the T parameter to the 10099 ** [sqlite3_stmt_scanstatus(S,X,T,V)] interface. Each constant designates a 10100 ** different metric for sqlite3_stmt_scanstatus() to return. 10101 ** 10102 ** When the value returned to V is a string, space to hold that string is 10103 ** managed by the prepared statement S and will be automatically freed when 10104 ** S is finalized. 10105 ** 10106 ** Not all values are available for all query elements. When a value is 10107 ** not available, the output variable is set to -1 if the value is numeric, 10108 ** or to NULL if it is a string (SQLITE_SCANSTAT_NAME). 10109 ** 10110 ** <dl> 10111 ** [[SQLITE_SCANSTAT_NLOOP]] <dt>SQLITE_SCANSTAT_NLOOP</dt> 10112 ** <dd>^The [sqlite3_int64] variable pointed to by the V parameter will be 10113 ** set to the total number of times that the X-th loop has run.</dd> 10114 ** 10115 ** [[SQLITE_SCANSTAT_NVISIT]] <dt>SQLITE_SCANSTAT_NVISIT</dt> 10116 ** <dd>^The [sqlite3_int64] variable pointed to by the V parameter will be set 10117 ** to the total number of rows examined by all iterations of the X-th loop.</dd> 10118 ** 10119 ** [[SQLITE_SCANSTAT_EST]] <dt>SQLITE_SCANSTAT_EST</dt> 10120 ** <dd>^The "double" variable pointed to by the V parameter will be set to the 10121 ** query planner's estimate for the average number of rows output from each 10122 ** iteration of the X-th loop. If the query planner's estimates was accurate, 10123 ** then this value will approximate the quotient NVISIT/NLOOP and the 10124 ** product of this value for all prior loops with the same SELECTID will 10125 ** be the NLOOP value for the current loop. 10126 ** 10127 ** [[SQLITE_SCANSTAT_NAME]] <dt>SQLITE_SCANSTAT_NAME</dt> 10128 ** <dd>^The "const char *" variable pointed to by the V parameter will be set 10129 ** to a zero-terminated UTF-8 string containing the name of the index or table 10130 ** used for the X-th loop. 10131 ** 10132 ** [[SQLITE_SCANSTAT_EXPLAIN]] <dt>SQLITE_SCANSTAT_EXPLAIN</dt> 10133 ** <dd>^The "const char *" variable pointed to by the V parameter will be set 10134 ** to a zero-terminated UTF-8 string containing the [EXPLAIN QUERY PLAN] 10135 ** description for the X-th loop. 10136 ** 10137 ** [[SQLITE_SCANSTAT_SELECTID]] <dt>SQLITE_SCANSTAT_SELECTID</dt> 10138 ** <dd>^The "int" variable pointed to by the V parameter will be set to the 10139 ** id for the X-th query plan element. The id value is unique within the 10140 ** statement. The select-id is the same value as is output in the first 10141 ** column of an [EXPLAIN QUERY PLAN] query. 10142 ** 10143 ** [[SQLITE_SCANSTAT_PARENTID]] <dt>SQLITE_SCANSTAT_PARENTID</dt> 10144 ** <dd>The "int" variable pointed to by the V parameter will be set to the 10145 ** the id of the parent of the current query element, if applicable, or 10146 ** to zero if the query element has no parent. This is the same value as 10147 ** returned in the second column of an [EXPLAIN QUERY PLAN] query. 10148 ** 10149 ** [[SQLITE_SCANSTAT_NCYCLE]] <dt>SQLITE_SCANSTAT_NCYCLE</dt> 10150 ** <dd>The sqlite3_int64 output value is set to the number of cycles, 10151 ** according to the processor time-stamp counter, that elapsed while the 10152 ** query element was being processed. This value is not available for 10153 ** all query elements - if it is unavailable the output variable is 10154 ** set to -1. 10155 ** </dl> 10156 */ 10157 #define SQLITE_SCANSTAT_NLOOP 0 10158 #define SQLITE_SCANSTAT_NVISIT 1 10159 #define SQLITE_SCANSTAT_EST 2 10160 #define SQLITE_SCANSTAT_NAME 3 10161 #define SQLITE_SCANSTAT_EXPLAIN 4 10162 #define SQLITE_SCANSTAT_SELECTID 5 10163 #define SQLITE_SCANSTAT_PARENTID 6 10164 #define SQLITE_SCANSTAT_NCYCLE 7 10165 10166 /* 10167 ** CAPI3REF: Prepared Statement Scan Status 10168 ** METHOD: sqlite3_stmt 10169 ** 10170 ** These interfaces return information about the predicted and measured 10171 ** performance for pStmt. Advanced applications can use this 10172 ** interface to compare the predicted and the measured performance and 10173 ** issue warnings and/or rerun [ANALYZE] if discrepancies are found. 10174 ** 10175 ** Since this interface is expected to be rarely used, it is only 10176 ** available if SQLite is compiled using the [SQLITE_ENABLE_STMT_SCANSTATUS] 10177 ** compile-time option. 10178 ** 10179 ** The "iScanStatusOp" parameter determines which status information to return. 10180 ** The "iScanStatusOp" must be one of the [scanstatus options] or the behavior 10181 ** of this interface is undefined. ^The requested measurement is written into 10182 ** a variable pointed to by the "pOut" parameter. 10183 ** 10184 ** The "flags" parameter must be passed a mask of flags. At present only 10185 ** one flag is defined - SQLITE_SCANSTAT_COMPLEX. If SQLITE_SCANSTAT_COMPLEX 10186 ** is specified, then status information is available for all elements 10187 ** of a query plan that are reported by "EXPLAIN QUERY PLAN" output. If 10188 ** SQLITE_SCANSTAT_COMPLEX is not specified, then only query plan elements 10189 ** that correspond to query loops (the "SCAN..." and "SEARCH..." elements of 10190 ** the EXPLAIN QUERY PLAN output) are available. Invoking API 10191 ** sqlite3_stmt_scanstatus() is equivalent to calling 10192 ** sqlite3_stmt_scanstatus_v2() with a zeroed flags parameter. 10193 ** 10194 ** Parameter "idx" identifies the specific query element to retrieve statistics 10195 ** for. Query elements are numbered starting from zero. A value of -1 may be 10196 ** to query for statistics regarding the entire query. ^If idx is out of range 10197 ** - less than -1 or greater than or equal to the total number of query 10198 ** elements used to implement the statement - a non-zero value is returned and 10199 ** the variable that pOut points to is unchanged. 10200 ** 10201 ** See also: [sqlite3_stmt_scanstatus_reset()] 10202 */ 10203 SQLITE_API int sqlite3_stmt_scanstatus( 10204 sqlite3_stmt *pStmt, /* Prepared statement for which info desired */ 10205 int idx, /* Index of loop to report on */ 10206 int iScanStatusOp, /* Information desired. SQLITE_SCANSTAT_* */ 10207 void *pOut /* Result written here */ 10208 ); 10209 SQLITE_API int sqlite3_stmt_scanstatus_v2( 10210 sqlite3_stmt *pStmt, /* Prepared statement for which info desired */ 10211 int idx, /* Index of loop to report on */ 10212 int iScanStatusOp, /* Information desired. SQLITE_SCANSTAT_* */ 10213 int flags, /* Mask of flags defined below */ 10214 void *pOut /* Result written here */ 10215 ); 10216 10217 /* 10218 ** CAPI3REF: Prepared Statement Scan Status 10219 ** KEYWORDS: {scan status flags} 10220 */ 10221 #define SQLITE_SCANSTAT_COMPLEX 0x0001 10222 10223 /* 10224 ** CAPI3REF: Zero Scan-Status Counters 10225 ** METHOD: sqlite3_stmt 10226 ** 10227 ** ^Zero all [sqlite3_stmt_scanstatus()] related event counters. 10228 ** 10229 ** This API is only available if the library is built with pre-processor 10230 ** symbol [SQLITE_ENABLE_STMT_SCANSTATUS] defined. 10231 */ 10232 SQLITE_API void sqlite3_stmt_scanstatus_reset(sqlite3_stmt*); 10233 10234 /* 10235 ** CAPI3REF: Flush caches to disk mid-transaction 10236 ** METHOD: sqlite3 10237 ** 10238 ** ^If a write-transaction is open on [database connection] D when the 10239 ** [sqlite3_db_cacheflush(D)] interface invoked, any dirty 10240 ** pages in the pager-cache that are not currently in use are written out 10241 ** to disk. A dirty page may be in use if a database cursor created by an 10242 ** active SQL statement is reading from it, or if it is page 1 of a database 10243 ** file (page 1 is always "in use"). ^The [sqlite3_db_cacheflush(D)] 10244 ** interface flushes caches for all schemas - "main", "temp", and 10245 ** any [attached] databases. 10246 ** 10247 ** ^If this function needs to obtain extra database locks before dirty pages 10248 ** can be flushed to disk, it does so. ^If those locks cannot be obtained 10249 ** immediately and there is a busy-handler callback configured, it is invoked 10250 ** in the usual manner. ^If the required lock still cannot be obtained, then 10251 ** the database is skipped and an attempt made to flush any dirty pages 10252 ** belonging to the next (if any) database. ^If any databases are skipped 10253 ** because locks cannot be obtained, but no other error occurs, this 10254 ** function returns SQLITE_BUSY. 10255 ** 10256 ** ^If any other error occurs while flushing dirty pages to disk (for 10257 ** example an IO error or out-of-memory condition), then processing is 10258 ** abandoned and an SQLite [error code] is returned to the caller immediately. 10259 ** 10260 ** ^Otherwise, if no error occurs, [sqlite3_db_cacheflush()] returns SQLITE_OK. 10261 ** 10262 ** ^This function does not set the database handle error code or message 10263 ** returned by the [sqlite3_errcode()] and [sqlite3_errmsg()] functions. 10264 */ 10265 SQLITE_API int sqlite3_db_cacheflush(sqlite3*); 10266 10267 /* 10268 ** CAPI3REF: The pre-update hook. 10269 ** METHOD: sqlite3 10270 ** 10271 ** ^These interfaces are only available if SQLite is compiled using the 10272 ** [SQLITE_ENABLE_PREUPDATE_HOOK] compile-time option. 10273 ** 10274 ** ^The [sqlite3_preupdate_hook()] interface registers a callback function 10275 ** that is invoked prior to each [INSERT], [UPDATE], and [DELETE] operation 10276 ** on a database table. 10277 ** ^At most one preupdate hook may be registered at a time on a single 10278 ** [database connection]; each call to [sqlite3_preupdate_hook()] overrides 10279 ** the previous setting. 10280 ** ^The preupdate hook is disabled by invoking [sqlite3_preupdate_hook()] 10281 ** with a NULL pointer as the second parameter. 10282 ** ^The third parameter to [sqlite3_preupdate_hook()] is passed through as 10283 ** the first parameter to callbacks. 10284 ** 10285 ** ^The preupdate hook only fires for changes to real database tables; the 10286 ** preupdate hook is not invoked for changes to [virtual tables] or to 10287 ** system tables like sqlite_sequence or sqlite_stat1. 10288 ** 10289 ** ^The second parameter to the preupdate callback is a pointer to 10290 ** the [database connection] that registered the preupdate hook. 10291 ** ^The third parameter to the preupdate callback is one of the constants 10292 ** [SQLITE_INSERT], [SQLITE_DELETE], or [SQLITE_UPDATE] to identify the 10293 ** kind of update operation that is about to occur. 10294 ** ^(The fourth parameter to the preupdate callback is the name of the 10295 ** database within the database connection that is being modified. This 10296 ** will be "main" for the main database or "temp" for TEMP tables or 10297 ** the name given after the AS keyword in the [ATTACH] statement for attached 10298 ** databases.)^ 10299 ** ^The fifth parameter to the preupdate callback is the name of the 10300 ** table that is being modified. 10301 ** 10302 ** For an UPDATE or DELETE operation on a [rowid table], the sixth 10303 ** parameter passed to the preupdate callback is the initial [rowid] of the 10304 ** row being modified or deleted. For an INSERT operation on a rowid table, 10305 ** or any operation on a WITHOUT ROWID table, the value of the sixth 10306 ** parameter is undefined. For an INSERT or UPDATE on a rowid table the 10307 ** seventh parameter is the final rowid value of the row being inserted 10308 ** or updated. The value of the seventh parameter passed to the callback 10309 ** function is not defined for operations on WITHOUT ROWID tables, or for 10310 ** DELETE operations on rowid tables. 10311 ** 10312 ** ^The sqlite3_preupdate_hook(D,C,P) function returns the P argument from 10313 ** the previous call on the same [database connection] D, or NULL for 10314 ** the first call on D. 10315 ** 10316 ** The [sqlite3_preupdate_old()], [sqlite3_preupdate_new()], 10317 ** [sqlite3_preupdate_count()], and [sqlite3_preupdate_depth()] interfaces 10318 ** provide additional information about a preupdate event. These routines 10319 ** may only be called from within a preupdate callback. Invoking any of 10320 ** these routines from outside of a preupdate callback or with a 10321 ** [database connection] pointer that is different from the one supplied 10322 ** to the preupdate callback results in undefined and probably undesirable 10323 ** behavior. 10324 ** 10325 ** ^The [sqlite3_preupdate_count(D)] interface returns the number of columns 10326 ** in the row that is being inserted, updated, or deleted. 10327 ** 10328 ** ^The [sqlite3_preupdate_old(D,N,P)] interface writes into P a pointer to 10329 ** a [protected sqlite3_value] that contains the value of the Nth column of 10330 ** the table row before it is updated. The N parameter must be between 0 10331 ** and one less than the number of columns or the behavior will be 10332 ** undefined. This must only be used within SQLITE_UPDATE and SQLITE_DELETE 10333 ** preupdate callbacks; if it is used by an SQLITE_INSERT callback then the 10334 ** behavior is undefined. The [sqlite3_value] that P points to 10335 ** will be destroyed when the preupdate callback returns. 10336 ** 10337 ** ^The [sqlite3_preupdate_new(D,N,P)] interface writes into P a pointer to 10338 ** a [protected sqlite3_value] that contains the value of the Nth column of 10339 ** the table row after it is updated. The N parameter must be between 0 10340 ** and one less than the number of columns or the behavior will be 10341 ** undefined. This must only be used within SQLITE_INSERT and SQLITE_UPDATE 10342 ** preupdate callbacks; if it is used by an SQLITE_DELETE callback then the 10343 ** behavior is undefined. The [sqlite3_value] that P points to 10344 ** will be destroyed when the preupdate callback returns. 10345 ** 10346 ** ^The [sqlite3_preupdate_depth(D)] interface returns 0 if the preupdate 10347 ** callback was invoked as a result of a direct insert, update, or delete 10348 ** operation; or 1 for inserts, updates, or deletes invoked by top-level 10349 ** triggers; or 2 for changes resulting from triggers called by top-level 10350 ** triggers; and so forth. 10351 ** 10352 ** When the [sqlite3_blob_write()] API is used to update a blob column, 10353 ** the pre-update hook is invoked with SQLITE_DELETE. This is because the 10354 ** in this case the new values are not available. In this case, when a 10355 ** callback made with op==SQLITE_DELETE is actually a write using the 10356 ** sqlite3_blob_write() API, the [sqlite3_preupdate_blobwrite()] returns 10357 ** the index of the column being written. In other cases, where the 10358 ** pre-update hook is being invoked for some other reason, including a 10359 ** regular DELETE, sqlite3_preupdate_blobwrite() returns -1. 10360 ** 10361 ** See also: [sqlite3_update_hook()] 10362 */ 10363 #if defined(SQLITE_ENABLE_PREUPDATE_HOOK) 10364 SQLITE_API void *sqlite3_preupdate_hook( 10365 sqlite3 *db, 10366 void(*xPreUpdate)( 10367 void *pCtx, /* Copy of third arg to preupdate_hook() */ 10368 sqlite3 *db, /* Database handle */ 10369 int op, /* SQLITE_UPDATE, DELETE or INSERT */ 10370 char const *zDb, /* Database name */ 10371 char const *zName, /* Table name */ 10372 sqlite3_int64 iKey1, /* Rowid of row about to be deleted/updated */ 10373 sqlite3_int64 iKey2 /* New rowid value (for a rowid UPDATE) */ 10374 ), 10375 void* 10376 ); 10377 SQLITE_API int sqlite3_preupdate_old(sqlite3 *, int, sqlite3_value **); 10378 SQLITE_API int sqlite3_preupdate_count(sqlite3 *); 10379 SQLITE_API int sqlite3_preupdate_depth(sqlite3 *); 10380 SQLITE_API int sqlite3_preupdate_new(sqlite3 *, int, sqlite3_value **); 10381 SQLITE_API int sqlite3_preupdate_blobwrite(sqlite3 *); 10382 #endif 10383 10384 /* 10385 ** CAPI3REF: Low-level system error code 10386 ** METHOD: sqlite3 10387 ** 10388 ** ^Attempt to return the underlying operating system error code or error 10389 ** number that caused the most recent I/O error or failure to open a file. 10390 ** The return value is OS-dependent. For example, on unix systems, after 10391 ** [sqlite3_open_v2()] returns [SQLITE_CANTOPEN], this interface could be 10392 ** called to get back the underlying "errno" that caused the problem, such 10393 ** as ENOSPC, EAUTH, EISDIR, and so forth. 10394 */ 10395 SQLITE_API int sqlite3_system_errno(sqlite3*); 10396 10397 /* 10398 ** CAPI3REF: Database Snapshot 10399 ** KEYWORDS: {snapshot} {sqlite3_snapshot} 10400 ** 10401 ** An instance of the snapshot object records the state of a [WAL mode] 10402 ** database for some specific point in history. 10403 ** 10404 ** In [WAL mode], multiple [database connections] that are open on the 10405 ** same database file can each be reading a different historical version 10406 ** of the database file. When a [database connection] begins a read 10407 ** transaction, that connection sees an unchanging copy of the database 10408 ** as it existed for the point in time when the transaction first started. 10409 ** Subsequent changes to the database from other connections are not seen 10410 ** by the reader until a new read transaction is started. 10411 ** 10412 ** The sqlite3_snapshot object records state information about an historical 10413 ** version of the database file so that it is possible to later open a new read 10414 ** transaction that sees that historical version of the database rather than 10415 ** the most recent version. 10416 */ 10417 typedef struct sqlite3_snapshot { 10418 unsigned char hidden[48]; 10419 } sqlite3_snapshot; 10420 10421 /* 10422 ** CAPI3REF: Record A Database Snapshot 10423 ** CONSTRUCTOR: sqlite3_snapshot 10424 ** 10425 ** ^The [sqlite3_snapshot_get(D,S,P)] interface attempts to make a 10426 ** new [sqlite3_snapshot] object that records the current state of 10427 ** schema S in database connection D. ^On success, the 10428 ** [sqlite3_snapshot_get(D,S,P)] interface writes a pointer to the newly 10429 ** created [sqlite3_snapshot] object into *P and returns SQLITE_OK. 10430 ** If there is not already a read-transaction open on schema S when 10431 ** this function is called, one is opened automatically. 10432 ** 10433 ** The following must be true for this function to succeed. If any of 10434 ** the following statements are false when sqlite3_snapshot_get() is 10435 ** called, SQLITE_ERROR is returned. The final value of *P is undefined 10436 ** in this case. 10437 ** 10438 ** <ul> 10439 ** <li> The database handle must not be in [autocommit mode]. 10440 ** 10441 ** <li> Schema S of [database connection] D must be a [WAL mode] database. 10442 ** 10443 ** <li> There must not be a write transaction open on schema S of database 10444 ** connection D. 10445 ** 10446 ** <li> One or more transactions must have been written to the current wal 10447 ** file since it was created on disk (by any connection). This means 10448 ** that a snapshot cannot be taken on a wal mode database with no wal 10449 ** file immediately after it is first opened. At least one transaction 10450 ** must be written to it first. 10451 ** </ul> 10452 ** 10453 ** This function may also return SQLITE_NOMEM. If it is called with the 10454 ** database handle in autocommit mode but fails for some other reason, 10455 ** whether or not a read transaction is opened on schema S is undefined. 10456 ** 10457 ** The [sqlite3_snapshot] object returned from a successful call to 10458 ** [sqlite3_snapshot_get()] must be freed using [sqlite3_snapshot_free()] 10459 ** to avoid a memory leak. 10460 ** 10461 ** The [sqlite3_snapshot_get()] interface is only available when the 10462 ** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used. 10463 */ 10464 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_get( 10465 sqlite3 *db, 10466 const char *zSchema, 10467 sqlite3_snapshot **ppSnapshot 10468 ); 10469 10470 /* 10471 ** CAPI3REF: Start a read transaction on an historical snapshot 10472 ** METHOD: sqlite3_snapshot 10473 ** 10474 ** ^The [sqlite3_snapshot_open(D,S,P)] interface either starts a new read 10475 ** transaction or upgrades an existing one for schema S of 10476 ** [database connection] D such that the read transaction refers to 10477 ** historical [snapshot] P, rather than the most recent change to the 10478 ** database. ^The [sqlite3_snapshot_open()] interface returns SQLITE_OK 10479 ** on success or an appropriate [error code] if it fails. 10480 ** 10481 ** ^In order to succeed, the database connection must not be in 10482 ** [autocommit mode] when [sqlite3_snapshot_open(D,S,P)] is called. If there 10483 ** is already a read transaction open on schema S, then the database handle 10484 ** must have no active statements (SELECT statements that have been passed 10485 ** to sqlite3_step() but not sqlite3_reset() or sqlite3_finalize()). 10486 ** SQLITE_ERROR is returned if either of these conditions is violated, or 10487 ** if schema S does not exist, or if the snapshot object is invalid. 10488 ** 10489 ** ^A call to sqlite3_snapshot_open() will fail to open if the specified 10490 ** snapshot has been overwritten by a [checkpoint]. In this case 10491 ** SQLITE_ERROR_SNAPSHOT is returned. 10492 ** 10493 ** If there is already a read transaction open when this function is 10494 ** invoked, then the same read transaction remains open (on the same 10495 ** database snapshot) if SQLITE_ERROR, SQLITE_BUSY or SQLITE_ERROR_SNAPSHOT 10496 ** is returned. If another error code - for example SQLITE_PROTOCOL or an 10497 ** SQLITE_IOERR error code - is returned, then the final state of the 10498 ** read transaction is undefined. If SQLITE_OK is returned, then the 10499 ** read transaction is now open on database snapshot P. 10500 ** 10501 ** ^(A call to [sqlite3_snapshot_open(D,S,P)] will fail if the 10502 ** database connection D does not know that the database file for 10503 ** schema S is in [WAL mode]. A database connection might not know 10504 ** that the database file is in [WAL mode] if there has been no prior 10505 ** I/O on that database connection, or if the database entered [WAL mode] 10506 ** after the most recent I/O on the database connection.)^ 10507 ** (Hint: Run "[PRAGMA application_id]" against a newly opened 10508 ** database connection in order to make it ready to use snapshots.) 10509 ** 10510 ** The [sqlite3_snapshot_open()] interface is only available when the 10511 ** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used. 10512 */ 10513 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_open( 10514 sqlite3 *db, 10515 const char *zSchema, 10516 sqlite3_snapshot *pSnapshot 10517 ); 10518 10519 /* 10520 ** CAPI3REF: Destroy a snapshot 10521 ** DESTRUCTOR: sqlite3_snapshot 10522 ** 10523 ** ^The [sqlite3_snapshot_free(P)] interface destroys [sqlite3_snapshot] P. 10524 ** The application must eventually free every [sqlite3_snapshot] object 10525 ** using this routine to avoid a memory leak. 10526 ** 10527 ** The [sqlite3_snapshot_free()] interface is only available when the 10528 ** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used. 10529 */ 10530 SQLITE_API SQLITE_EXPERIMENTAL void sqlite3_snapshot_free(sqlite3_snapshot*); 10531 10532 /* 10533 ** CAPI3REF: Compare the ages of two snapshot handles. 10534 ** METHOD: sqlite3_snapshot 10535 ** 10536 ** The sqlite3_snapshot_cmp(P1, P2) interface is used to compare the ages 10537 ** of two valid snapshot handles. 10538 ** 10539 ** If the two snapshot handles are not associated with the same database 10540 ** file, the result of the comparison is undefined. 10541 ** 10542 ** Additionally, the result of the comparison is only valid if both of the 10543 ** snapshot handles were obtained by calling sqlite3_snapshot_get() since the 10544 ** last time the wal file was deleted. The wal file is deleted when the 10545 ** database is changed back to rollback mode or when the number of database 10546 ** clients drops to zero. If either snapshot handle was obtained before the 10547 ** wal file was last deleted, the value returned by this function 10548 ** is undefined. 10549 ** 10550 ** Otherwise, this API returns a negative value if P1 refers to an older 10551 ** snapshot than P2, zero if the two handles refer to the same database 10552 ** snapshot, and a positive value if P1 is a newer snapshot than P2. 10553 ** 10554 ** This interface is only available if SQLite is compiled with the 10555 ** [SQLITE_ENABLE_SNAPSHOT] option. 10556 */ 10557 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_cmp( 10558 sqlite3_snapshot *p1, 10559 sqlite3_snapshot *p2 10560 ); 10561 10562 /* 10563 ** CAPI3REF: Recover snapshots from a wal file 10564 ** METHOD: sqlite3_snapshot 10565 ** 10566 ** If a [WAL file] remains on disk after all database connections close 10567 ** (either through the use of the [SQLITE_FCNTL_PERSIST_WAL] [file control] 10568 ** or because the last process to have the database opened exited without 10569 ** calling [sqlite3_close()]) and a new connection is subsequently opened 10570 ** on that database and [WAL file], the [sqlite3_snapshot_open()] interface 10571 ** will only be able to open the last transaction added to the WAL file 10572 ** even though the WAL file contains other valid transactions. 10573 ** 10574 ** This function attempts to scan the WAL file associated with database zDb 10575 ** of database handle db and make all valid snapshots available to 10576 ** sqlite3_snapshot_open(). It is an error if there is already a read 10577 ** transaction open on the database, or if the database is not a WAL mode 10578 ** database. 10579 ** 10580 ** SQLITE_OK is returned if successful, or an SQLite error code otherwise. 10581 ** 10582 ** This interface is only available if SQLite is compiled with the 10583 ** [SQLITE_ENABLE_SNAPSHOT] option. 10584 */ 10585 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_recover(sqlite3 *db, const char *zDb); 10586 10587 /* 10588 ** CAPI3REF: Serialize a database 10589 ** 10590 ** The sqlite3_serialize(D,S,P,F) interface returns a pointer to memory 10591 ** that is a serialization of the S database on [database connection] D. 10592 ** If P is not a NULL pointer, then the size of the database in bytes 10593 ** is written into *P. 10594 ** 10595 ** For an ordinary on-disk database file, the serialization is just a 10596 ** copy of the disk file. For an in-memory database or a "TEMP" database, 10597 ** the serialization is the same sequence of bytes which would be written 10598 ** to disk if that database where backed up to disk. 10599 ** 10600 ** The usual case is that sqlite3_serialize() copies the serialization of 10601 ** the database into memory obtained from [sqlite3_malloc64()] and returns 10602 ** a pointer to that memory. The caller is responsible for freeing the 10603 ** returned value to avoid a memory leak. However, if the F argument 10604 ** contains the SQLITE_SERIALIZE_NOCOPY bit, then no memory allocations 10605 ** are made, and the sqlite3_serialize() function will return a pointer 10606 ** to the contiguous memory representation of the database that SQLite 10607 ** is currently using for that database, or NULL if the no such contiguous 10608 ** memory representation of the database exists. A contiguous memory 10609 ** representation of the database will usually only exist if there has 10610 ** been a prior call to [sqlite3_deserialize(D,S,...)] with the same 10611 ** values of D and S. 10612 ** The size of the database is written into *P even if the 10613 ** SQLITE_SERIALIZE_NOCOPY bit is set but no contiguous copy 10614 ** of the database exists. 10615 ** 10616 ** After the call, if the SQLITE_SERIALIZE_NOCOPY bit had been set, 10617 ** the returned buffer content will remain accessible and unchanged 10618 ** until either the next write operation on the connection or when 10619 ** the connection is closed, and applications must not modify the 10620 ** buffer. If the bit had been clear, the returned buffer will not 10621 ** be accessed by SQLite after the call. 10622 ** 10623 ** A call to sqlite3_serialize(D,S,P,F) might return NULL even if the 10624 ** SQLITE_SERIALIZE_NOCOPY bit is omitted from argument F if a memory 10625 ** allocation error occurs. 10626 ** 10627 ** This interface is omitted if SQLite is compiled with the 10628 ** [SQLITE_OMIT_DESERIALIZE] option. 10629 */ 10630 SQLITE_API unsigned char *sqlite3_serialize( 10631 sqlite3 *db, /* The database connection */ 10632 const char *zSchema, /* Which DB to serialize. ex: "main", "temp", ... */ 10633 sqlite3_int64 *piSize, /* Write size of the DB here, if not NULL */ 10634 unsigned int mFlags /* Zero or more SQLITE_SERIALIZE_* flags */ 10635 ); 10636 10637 /* 10638 ** CAPI3REF: Flags for sqlite3_serialize 10639 ** 10640 ** Zero or more of the following constants can be OR-ed together for 10641 ** the F argument to [sqlite3_serialize(D,S,P,F)]. 10642 ** 10643 ** SQLITE_SERIALIZE_NOCOPY means that [sqlite3_serialize()] will return 10644 ** a pointer to contiguous in-memory database that it is currently using, 10645 ** without making a copy of the database. If SQLite is not currently using 10646 ** a contiguous in-memory database, then this option causes 10647 ** [sqlite3_serialize()] to return a NULL pointer. SQLite will only be 10648 ** using a contiguous in-memory database if it has been initialized by a 10649 ** prior call to [sqlite3_deserialize()]. 10650 */ 10651 #define SQLITE_SERIALIZE_NOCOPY 0x001 /* Do no memory allocations */ 10652 10653 /* 10654 ** CAPI3REF: Deserialize a database 10655 ** 10656 ** The sqlite3_deserialize(D,S,P,N,M,F) interface causes the 10657 ** [database connection] D to disconnect from database S and then 10658 ** reopen S as an in-memory database based on the serialization contained 10659 ** in P. The serialized database P is N bytes in size. M is the size of 10660 ** the buffer P, which might be larger than N. If M is larger than N, and 10661 ** the SQLITE_DESERIALIZE_READONLY bit is not set in F, then SQLite is 10662 ** permitted to add content to the in-memory database as long as the total 10663 ** size does not exceed M bytes. 10664 ** 10665 ** If the SQLITE_DESERIALIZE_FREEONCLOSE bit is set in F, then SQLite will 10666 ** invoke sqlite3_free() on the serialization buffer when the database 10667 ** connection closes. If the SQLITE_DESERIALIZE_RESIZEABLE bit is set, then 10668 ** SQLite will try to increase the buffer size using sqlite3_realloc64() 10669 ** if writes on the database cause it to grow larger than M bytes. 10670 ** 10671 ** Applications must not modify the buffer P or invalidate it before 10672 ** the database connection D is closed. 10673 ** 10674 ** The sqlite3_deserialize() interface will fail with SQLITE_BUSY if the 10675 ** database is currently in a read transaction or is involved in a backup 10676 ** operation. 10677 ** 10678 ** It is not possible to deserialized into the TEMP database. If the 10679 ** S argument to sqlite3_deserialize(D,S,P,N,M,F) is "temp" then the 10680 ** function returns SQLITE_ERROR. 10681 ** 10682 ** The deserialized database should not be in [WAL mode]. If the database 10683 ** is in WAL mode, then any attempt to use the database file will result 10684 ** in an [SQLITE_CANTOPEN] error. The application can set the 10685 ** [file format version numbers] (bytes 18 and 19) of the input database P 10686 ** to 0x01 prior to invoking sqlite3_deserialize(D,S,P,N,M,F) to force the 10687 ** database file into rollback mode and work around this limitation. 10688 ** 10689 ** If sqlite3_deserialize(D,S,P,N,M,F) fails for any reason and if the 10690 ** SQLITE_DESERIALIZE_FREEONCLOSE bit is set in argument F, then 10691 ** [sqlite3_free()] is invoked on argument P prior to returning. 10692 ** 10693 ** This interface is omitted if SQLite is compiled with the 10694 ** [SQLITE_OMIT_DESERIALIZE] option. 10695 */ 10696 SQLITE_API int sqlite3_deserialize( 10697 sqlite3 *db, /* The database connection */ 10698 const char *zSchema, /* Which DB to reopen with the deserialization */ 10699 unsigned char *pData, /* The serialized database content */ 10700 sqlite3_int64 szDb, /* Number bytes in the deserialization */ 10701 sqlite3_int64 szBuf, /* Total size of buffer pData[] */ 10702 unsigned mFlags /* Zero or more SQLITE_DESERIALIZE_* flags */ 10703 ); 10704 10705 /* 10706 ** CAPI3REF: Flags for sqlite3_deserialize() 10707 ** 10708 ** The following are allowed values for 6th argument (the F argument) to 10709 ** the [sqlite3_deserialize(D,S,P,N,M,F)] interface. 10710 ** 10711 ** The SQLITE_DESERIALIZE_FREEONCLOSE means that the database serialization 10712 ** in the P argument is held in memory obtained from [sqlite3_malloc64()] 10713 ** and that SQLite should take ownership of this memory and automatically 10714 ** free it when it has finished using it. Without this flag, the caller 10715 ** is responsible for freeing any dynamically allocated memory. 10716 ** 10717 ** The SQLITE_DESERIALIZE_RESIZEABLE flag means that SQLite is allowed to 10718 ** grow the size of the database using calls to [sqlite3_realloc64()]. This 10719 ** flag should only be used if SQLITE_DESERIALIZE_FREEONCLOSE is also used. 10720 ** Without this flag, the deserialized database cannot increase in size beyond 10721 ** the number of bytes specified by the M parameter. 10722 ** 10723 ** The SQLITE_DESERIALIZE_READONLY flag means that the deserialized database 10724 ** should be treated as read-only. 10725 */ 10726 #define SQLITE_DESERIALIZE_FREEONCLOSE 1 /* Call sqlite3_free() on close */ 10727 #define SQLITE_DESERIALIZE_RESIZEABLE 2 /* Resize using sqlite3_realloc64() */ 10728 #define SQLITE_DESERIALIZE_READONLY 4 /* Database is read-only */ 10729 10730 /* 10731 ** Undo the hack that converts floating point types to integer for 10732 ** builds on processors without floating point support. 10733 */ 10734 #ifdef SQLITE_OMIT_FLOATING_POINT 10735 # undef double 10736 #endif 10737 10738 #if defined(__wasi__) 10739 # undef SQLITE_WASI 10740 # define SQLITE_WASI 1 10741 # undef SQLITE_OMIT_WAL 10742 # define SQLITE_OMIT_WAL 1/* because it requires shared memory APIs */ 10743 # ifndef SQLITE_OMIT_LOAD_EXTENSION 10744 # define SQLITE_OMIT_LOAD_EXTENSION 10745 # endif 10746 # ifndef SQLITE_THREADSAFE 10747 # define SQLITE_THREADSAFE 0 10748 # endif 10749 #endif 10750 10751 #ifdef __cplusplus 10752 } /* End of the 'extern "C"' block */ 10753 #endif 10754 #endif /* SQLITE3_H */ 10755 10756 /******** Begin file sqlite3rtree.h *********/ 10757 /* 10758 ** 2010 August 30 10759 ** 10760 ** The author disclaims copyright to this source code. In place of 10761 ** a legal notice, here is a blessing: 10762 ** 10763 ** May you do good and not evil. 10764 ** May you find forgiveness for yourself and forgive others. 10765 ** May you share freely, never taking more than you give. 10766 ** 10767 ************************************************************************* 10768 */ 10769 10770 #ifndef _SQLITE3RTREE_H_ 10771 #define _SQLITE3RTREE_H_ 10772 10773 10774 #ifdef __cplusplus 10775 extern "C" { 10776 #endif 10777 10778 typedef struct sqlite3_rtree_geometry sqlite3_rtree_geometry; 10779 typedef struct sqlite3_rtree_query_info sqlite3_rtree_query_info; 10780 10781 /* The double-precision datatype used by RTree depends on the 10782 ** SQLITE_RTREE_INT_ONLY compile-time option. 10783 */ 10784 #ifdef SQLITE_RTREE_INT_ONLY 10785 typedef sqlite3_int64 sqlite3_rtree_dbl; 10786 #else 10787 typedef double sqlite3_rtree_dbl; 10788 #endif 10789 10790 /* 10791 ** Register a geometry callback named zGeom that can be used as part of an 10792 ** R-Tree geometry query as follows: 10793 ** 10794 ** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zGeom(... params ...) 10795 */ 10796 SQLITE_API int sqlite3_rtree_geometry_callback( 10797 sqlite3 *db, 10798 const char *zGeom, 10799 int (*xGeom)(sqlite3_rtree_geometry*, int, sqlite3_rtree_dbl*,int*), 10800 void *pContext 10801 ); 10802 10803 10804 /* 10805 ** A pointer to a structure of the following type is passed as the first 10806 ** argument to callbacks registered using rtree_geometry_callback(). 10807 */ 10808 struct sqlite3_rtree_geometry { 10809 void *pContext; /* Copy of pContext passed to s_r_g_c() */ 10810 int nParam; /* Size of array aParam[] */ 10811 sqlite3_rtree_dbl *aParam; /* Parameters passed to SQL geom function */ 10812 void *pUser; /* Callback implementation user data */ 10813 void (*xDelUser)(void *); /* Called by SQLite to clean up pUser */ 10814 }; 10815 10816 /* 10817 ** Register a 2nd-generation geometry callback named zScore that can be 10818 ** used as part of an R-Tree geometry query as follows: 10819 ** 10820 ** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zQueryFunc(... params ...) 10821 */ 10822 SQLITE_API int sqlite3_rtree_query_callback( 10823 sqlite3 *db, 10824 const char *zQueryFunc, 10825 int (*xQueryFunc)(sqlite3_rtree_query_info*), 10826 void *pContext, 10827 void (*xDestructor)(void*) 10828 ); 10829 10830 10831 /* 10832 ** A pointer to a structure of the following type is passed as the 10833 ** argument to scored geometry callback registered using 10834 ** sqlite3_rtree_query_callback(). 10835 ** 10836 ** Note that the first 5 fields of this structure are identical to 10837 ** sqlite3_rtree_geometry. This structure is a subclass of 10838 ** sqlite3_rtree_geometry. 10839 */ 10840 struct sqlite3_rtree_query_info { 10841 void *pContext; /* pContext from when function registered */ 10842 int nParam; /* Number of function parameters */ 10843 sqlite3_rtree_dbl *aParam; /* value of function parameters */ 10844 void *pUser; /* callback can use this, if desired */ 10845 void (*xDelUser)(void*); /* function to free pUser */ 10846 sqlite3_rtree_dbl *aCoord; /* Coordinates of node or entry to check */ 10847 unsigned int *anQueue; /* Number of pending entries in the queue */ 10848 int nCoord; /* Number of coordinates */ 10849 int iLevel; /* Level of current node or entry */ 10850 int mxLevel; /* The largest iLevel value in the tree */ 10851 sqlite3_int64 iRowid; /* Rowid for current entry */ 10852 sqlite3_rtree_dbl rParentScore; /* Score of parent node */ 10853 int eParentWithin; /* Visibility of parent node */ 10854 int eWithin; /* OUT: Visibility */ 10855 sqlite3_rtree_dbl rScore; /* OUT: Write the score here */ 10856 /* The following fields are only available in 3.8.11 and later */ 10857 sqlite3_value **apSqlParam; /* Original SQL values of parameters */ 10858 }; 10859 10860 /* 10861 ** Allowed values for sqlite3_rtree_query.eWithin and .eParentWithin. 10862 */ 10863 #define NOT_WITHIN 0 /* Object completely outside of query region */ 10864 #define PARTLY_WITHIN 1 /* Object partially overlaps query region */ 10865 #define FULLY_WITHIN 2 /* Object fully contained within query region */ 10866 10867 10868 #ifdef __cplusplus 10869 } /* end of the 'extern "C"' block */ 10870 #endif 10871 10872 #endif /* ifndef _SQLITE3RTREE_H_ */ 10873 10874 /******** End of sqlite3rtree.h *********/ 10875 /******** Begin file sqlite3session.h *********/ 10876 10877 #if !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION) 10878 #define __SQLITESESSION_H_ 1 10879 10880 /* 10881 ** Make sure we can call this stuff from C++. 10882 */ 10883 #ifdef __cplusplus 10884 extern "C" { 10885 #endif 10886 10887 10888 /* 10889 ** CAPI3REF: Session Object Handle 10890 ** 10891 ** An instance of this object is a [session] that can be used to 10892 ** record changes to a database. 10893 */ 10894 typedef struct sqlite3_session sqlite3_session; 10895 10896 /* 10897 ** CAPI3REF: Changeset Iterator Handle 10898 ** 10899 ** An instance of this object acts as a cursor for iterating 10900 ** over the elements of a [changeset] or [patchset]. 10901 */ 10902 typedef struct sqlite3_changeset_iter sqlite3_changeset_iter; 10903 10904 /* 10905 ** CAPI3REF: Create A New Session Object 10906 ** CONSTRUCTOR: sqlite3_session 10907 ** 10908 ** Create a new session object attached to database handle db. If successful, 10909 ** a pointer to the new object is written to *ppSession and SQLITE_OK is 10910 ** returned. If an error occurs, *ppSession is set to NULL and an SQLite 10911 ** error code (e.g. SQLITE_NOMEM) is returned. 10912 ** 10913 ** It is possible to create multiple session objects attached to a single 10914 ** database handle. 10915 ** 10916 ** Session objects created using this function should be deleted using the 10917 ** [sqlite3session_delete()] function before the database handle that they 10918 ** are attached to is itself closed. If the database handle is closed before 10919 ** the session object is deleted, then the results of calling any session 10920 ** module function, including [sqlite3session_delete()] on the session object 10921 ** are undefined. 10922 ** 10923 ** Because the session module uses the [sqlite3_preupdate_hook()] API, it 10924 ** is not possible for an application to register a pre-update hook on a 10925 ** database handle that has one or more session objects attached. Nor is 10926 ** it possible to create a session object attached to a database handle for 10927 ** which a pre-update hook is already defined. The results of attempting 10928 ** either of these things are undefined. 10929 ** 10930 ** The session object will be used to create changesets for tables in 10931 ** database zDb, where zDb is either "main", or "temp", or the name of an 10932 ** attached database. It is not an error if database zDb is not attached 10933 ** to the database when the session object is created. 10934 */ 10935 SQLITE_API int sqlite3session_create( 10936 sqlite3 *db, /* Database handle */ 10937 const char *zDb, /* Name of db (e.g. "main") */ 10938 sqlite3_session **ppSession /* OUT: New session object */ 10939 ); 10940 10941 /* 10942 ** CAPI3REF: Delete A Session Object 10943 ** DESTRUCTOR: sqlite3_session 10944 ** 10945 ** Delete a session object previously allocated using 10946 ** [sqlite3session_create()]. Once a session object has been deleted, the 10947 ** results of attempting to use pSession with any other session module 10948 ** function are undefined. 10949 ** 10950 ** Session objects must be deleted before the database handle to which they 10951 ** are attached is closed. Refer to the documentation for 10952 ** [sqlite3session_create()] for details. 10953 */ 10954 SQLITE_API void sqlite3session_delete(sqlite3_session *pSession); 10955 10956 /* 10957 ** CAPI3REF: Configure a Session Object 10958 ** METHOD: sqlite3_session 10959 ** 10960 ** This method is used to configure a session object after it has been 10961 ** created. At present the only valid values for the second parameter are 10962 ** [SQLITE_SESSION_OBJCONFIG_SIZE] and [SQLITE_SESSION_OBJCONFIG_ROWID]. 10963 ** 10964 */ 10965 SQLITE_API int sqlite3session_object_config(sqlite3_session*, int op, void *pArg); 10966 10967 /* 10968 ** CAPI3REF: Options for sqlite3session_object_config 10969 ** 10970 ** The following values may passed as the the 2nd parameter to 10971 ** sqlite3session_object_config(). 10972 ** 10973 ** <dt>SQLITE_SESSION_OBJCONFIG_SIZE <dd> 10974 ** This option is used to set, clear or query the flag that enables 10975 ** the [sqlite3session_changeset_size()] API. Because it imposes some 10976 ** computational overhead, this API is disabled by default. Argument 10977 ** pArg must point to a value of type (int). If the value is initially 10978 ** 0, then the sqlite3session_changeset_size() API is disabled. If it 10979 ** is greater than 0, then the same API is enabled. Or, if the initial 10980 ** value is less than zero, no change is made. In all cases the (int) 10981 ** variable is set to 1 if the sqlite3session_changeset_size() API is 10982 ** enabled following the current call, or 0 otherwise. 10983 ** 10984 ** It is an error (SQLITE_MISUSE) to attempt to modify this setting after 10985 ** the first table has been attached to the session object. 10986 ** 10987 ** <dt>SQLITE_SESSION_OBJCONFIG_ROWID <dd> 10988 ** This option is used to set, clear or query the flag that enables 10989 ** collection of data for tables with no explicit PRIMARY KEY. 10990 ** 10991 ** Normally, tables with no explicit PRIMARY KEY are simply ignored 10992 ** by the sessions module. However, if this flag is set, it behaves 10993 ** as if such tables have a column "_rowid_ INTEGER PRIMARY KEY" inserted 10994 ** as their leftmost columns. 10995 ** 10996 ** It is an error (SQLITE_MISUSE) to attempt to modify this setting after 10997 ** the first table has been attached to the session object. 10998 */ 10999 #define SQLITE_SESSION_OBJCONFIG_SIZE 1 11000 #define SQLITE_SESSION_OBJCONFIG_ROWID 2 11001 11002 /* 11003 ** CAPI3REF: Enable Or Disable A Session Object 11004 ** METHOD: sqlite3_session 11005 ** 11006 ** Enable or disable the recording of changes by a session object. When 11007 ** enabled, a session object records changes made to the database. When 11008 ** disabled - it does not. A newly created session object is enabled. 11009 ** Refer to the documentation for [sqlite3session_changeset()] for further 11010 ** details regarding how enabling and disabling a session object affects 11011 ** the eventual changesets. 11012 ** 11013 ** Passing zero to this function disables the session. Passing a value 11014 ** greater than zero enables it. Passing a value less than zero is a 11015 ** no-op, and may be used to query the current state of the session. 11016 ** 11017 ** The return value indicates the final state of the session object: 0 if 11018 ** the session is disabled, or 1 if it is enabled. 11019 */ 11020 SQLITE_API int sqlite3session_enable(sqlite3_session *pSession, int bEnable); 11021 11022 /* 11023 ** CAPI3REF: Set Or Clear the Indirect Change Flag 11024 ** METHOD: sqlite3_session 11025 ** 11026 ** Each change recorded by a session object is marked as either direct or 11027 ** indirect. A change is marked as indirect if either: 11028 ** 11029 ** <ul> 11030 ** <li> The session object "indirect" flag is set when the change is 11031 ** made, or 11032 ** <li> The change is made by an SQL trigger or foreign key action 11033 ** instead of directly as a result of a users SQL statement. 11034 ** </ul> 11035 ** 11036 ** If a single row is affected by more than one operation within a session, 11037 ** then the change is considered indirect if all operations meet the criteria 11038 ** for an indirect change above, or direct otherwise. 11039 ** 11040 ** This function is used to set, clear or query the session object indirect 11041 ** flag. If the second argument passed to this function is zero, then the 11042 ** indirect flag is cleared. If it is greater than zero, the indirect flag 11043 ** is set. Passing a value less than zero does not modify the current value 11044 ** of the indirect flag, and may be used to query the current state of the 11045 ** indirect flag for the specified session object. 11046 ** 11047 ** The return value indicates the final state of the indirect flag: 0 if 11048 ** it is clear, or 1 if it is set. 11049 */ 11050 SQLITE_API int sqlite3session_indirect(sqlite3_session *pSession, int bIndirect); 11051 11052 /* 11053 ** CAPI3REF: Attach A Table To A Session Object 11054 ** METHOD: sqlite3_session 11055 ** 11056 ** If argument zTab is not NULL, then it is the name of a table to attach 11057 ** to the session object passed as the first argument. All subsequent changes 11058 ** made to the table while the session object is enabled will be recorded. See 11059 ** documentation for [sqlite3session_changeset()] for further details. 11060 ** 11061 ** Or, if argument zTab is NULL, then changes are recorded for all tables 11062 ** in the database. If additional tables are added to the database (by 11063 ** executing "CREATE TABLE" statements) after this call is made, changes for 11064 ** the new tables are also recorded. 11065 ** 11066 ** Changes can only be recorded for tables that have a PRIMARY KEY explicitly 11067 ** defined as part of their CREATE TABLE statement. It does not matter if the 11068 ** PRIMARY KEY is an "INTEGER PRIMARY KEY" (rowid alias) or not. The PRIMARY 11069 ** KEY may consist of a single column, or may be a composite key. 11070 ** 11071 ** It is not an error if the named table does not exist in the database. Nor 11072 ** is it an error if the named table does not have a PRIMARY KEY. However, 11073 ** no changes will be recorded in either of these scenarios. 11074 ** 11075 ** Changes are not recorded for individual rows that have NULL values stored 11076 ** in one or more of their PRIMARY KEY columns. 11077 ** 11078 ** SQLITE_OK is returned if the call completes without error. Or, if an error 11079 ** occurs, an SQLite error code (e.g. SQLITE_NOMEM) is returned. 11080 ** 11081 ** <h3>Special sqlite_stat1 Handling</h3> 11082 ** 11083 ** As of SQLite version 3.22.0, the "sqlite_stat1" table is an exception to 11084 ** some of the rules above. In SQLite, the schema of sqlite_stat1 is: 11085 ** <pre> 11086 ** CREATE TABLE sqlite_stat1(tbl,idx,stat) 11087 ** </pre> 11088 ** 11089 ** Even though sqlite_stat1 does not have a PRIMARY KEY, changes are 11090 ** recorded for it as if the PRIMARY KEY is (tbl,idx). Additionally, changes 11091 ** are recorded for rows for which (idx IS NULL) is true. However, for such 11092 ** rows a zero-length blob (SQL value X'') is stored in the changeset or 11093 ** patchset instead of a NULL value. This allows such changesets to be 11094 ** manipulated by legacy implementations of sqlite3changeset_invert(), 11095 ** concat() and similar. 11096 ** 11097 ** The sqlite3changeset_apply() function automatically converts the 11098 ** zero-length blob back to a NULL value when updating the sqlite_stat1 11099 ** table. However, if the application calls sqlite3changeset_new(), 11100 ** sqlite3changeset_old() or sqlite3changeset_conflict on a changeset 11101 ** iterator directly (including on a changeset iterator passed to a 11102 ** conflict-handler callback) then the X'' value is returned. The application 11103 ** must translate X'' to NULL itself if required. 11104 ** 11105 ** Legacy (older than 3.22.0) versions of the sessions module cannot capture 11106 ** changes made to the sqlite_stat1 table. Legacy versions of the 11107 ** sqlite3changeset_apply() function silently ignore any modifications to the 11108 ** sqlite_stat1 table that are part of a changeset or patchset. 11109 */ 11110 SQLITE_API int sqlite3session_attach( 11111 sqlite3_session *pSession, /* Session object */ 11112 const char *zTab /* Table name */ 11113 ); 11114 11115 /* 11116 ** CAPI3REF: Set a table filter on a Session Object. 11117 ** METHOD: sqlite3_session 11118 ** 11119 ** The second argument (xFilter) is the "filter callback". For changes to rows 11120 ** in tables that are not attached to the Session object, the filter is called 11121 ** to determine whether changes to the table's rows should be tracked or not. 11122 ** If xFilter returns 0, changes are not tracked. Note that once a table is 11123 ** attached, xFilter will not be called again. 11124 */ 11125 SQLITE_API void sqlite3session_table_filter( 11126 sqlite3_session *pSession, /* Session object */ 11127 int(*xFilter)( 11128 void *pCtx, /* Copy of third arg to _filter_table() */ 11129 const char *zTab /* Table name */ 11130 ), 11131 void *pCtx /* First argument passed to xFilter */ 11132 ); 11133 11134 /* 11135 ** CAPI3REF: Generate A Changeset From A Session Object 11136 ** METHOD: sqlite3_session 11137 ** 11138 ** Obtain a changeset containing changes to the tables attached to the 11139 ** session object passed as the first argument. If successful, 11140 ** set *ppChangeset to point to a buffer containing the changeset 11141 ** and *pnChangeset to the size of the changeset in bytes before returning 11142 ** SQLITE_OK. If an error occurs, set both *ppChangeset and *pnChangeset to 11143 ** zero and return an SQLite error code. 11144 ** 11145 ** A changeset consists of zero or more INSERT, UPDATE and/or DELETE changes, 11146 ** each representing a change to a single row of an attached table. An INSERT 11147 ** change contains the values of each field of a new database row. A DELETE 11148 ** contains the original values of each field of a deleted database row. An 11149 ** UPDATE change contains the original values of each field of an updated 11150 ** database row along with the updated values for each updated non-primary-key 11151 ** column. It is not possible for an UPDATE change to represent a change that 11152 ** modifies the values of primary key columns. If such a change is made, it 11153 ** is represented in a changeset as a DELETE followed by an INSERT. 11154 ** 11155 ** Changes are not recorded for rows that have NULL values stored in one or 11156 ** more of their PRIMARY KEY columns. If such a row is inserted or deleted, 11157 ** no corresponding change is present in the changesets returned by this 11158 ** function. If an existing row with one or more NULL values stored in 11159 ** PRIMARY KEY columns is updated so that all PRIMARY KEY columns are non-NULL, 11160 ** only an INSERT is appears in the changeset. Similarly, if an existing row 11161 ** with non-NULL PRIMARY KEY values is updated so that one or more of its 11162 ** PRIMARY KEY columns are set to NULL, the resulting changeset contains a 11163 ** DELETE change only. 11164 ** 11165 ** The contents of a changeset may be traversed using an iterator created 11166 ** using the [sqlite3changeset_start()] API. A changeset may be applied to 11167 ** a database with a compatible schema using the [sqlite3changeset_apply()] 11168 ** API. 11169 ** 11170 ** Within a changeset generated by this function, all changes related to a 11171 ** single table are grouped together. In other words, when iterating through 11172 ** a changeset or when applying a changeset to a database, all changes related 11173 ** to a single table are processed before moving on to the next table. Tables 11174 ** are sorted in the same order in which they were attached (or auto-attached) 11175 ** to the sqlite3_session object. The order in which the changes related to 11176 ** a single table are stored is undefined. 11177 ** 11178 ** Following a successful call to this function, it is the responsibility of 11179 ** the caller to eventually free the buffer that *ppChangeset points to using 11180 ** [sqlite3_free()]. 11181 ** 11182 ** <h3>Changeset Generation</h3> 11183 ** 11184 ** Once a table has been attached to a session object, the session object 11185 ** records the primary key values of all new rows inserted into the table. 11186 ** It also records the original primary key and other column values of any 11187 ** deleted or updated rows. For each unique primary key value, data is only 11188 ** recorded once - the first time a row with said primary key is inserted, 11189 ** updated or deleted in the lifetime of the session. 11190 ** 11191 ** There is one exception to the previous paragraph: when a row is inserted, 11192 ** updated or deleted, if one or more of its primary key columns contain a 11193 ** NULL value, no record of the change is made. 11194 ** 11195 ** The session object therefore accumulates two types of records - those 11196 ** that consist of primary key values only (created when the user inserts 11197 ** a new record) and those that consist of the primary key values and the 11198 ** original values of other table columns (created when the users deletes 11199 ** or updates a record). 11200 ** 11201 ** When this function is called, the requested changeset is created using 11202 ** both the accumulated records and the current contents of the database 11203 ** file. Specifically: 11204 ** 11205 ** <ul> 11206 ** <li> For each record generated by an insert, the database is queried 11207 ** for a row with a matching primary key. If one is found, an INSERT 11208 ** change is added to the changeset. If no such row is found, no change 11209 ** is added to the changeset. 11210 ** 11211 ** <li> For each record generated by an update or delete, the database is 11212 ** queried for a row with a matching primary key. If such a row is 11213 ** found and one or more of the non-primary key fields have been 11214 ** modified from their original values, an UPDATE change is added to 11215 ** the changeset. Or, if no such row is found in the table, a DELETE 11216 ** change is added to the changeset. If there is a row with a matching 11217 ** primary key in the database, but all fields contain their original 11218 ** values, no change is added to the changeset. 11219 ** </ul> 11220 ** 11221 ** This means, amongst other things, that if a row is inserted and then later 11222 ** deleted while a session object is active, neither the insert nor the delete 11223 ** will be present in the changeset. Or if a row is deleted and then later a 11224 ** row with the same primary key values inserted while a session object is 11225 ** active, the resulting changeset will contain an UPDATE change instead of 11226 ** a DELETE and an INSERT. 11227 ** 11228 ** When a session object is disabled (see the [sqlite3session_enable()] API), 11229 ** it does not accumulate records when rows are inserted, updated or deleted. 11230 ** This may appear to have some counter-intuitive effects if a single row 11231 ** is written to more than once during a session. For example, if a row 11232 ** is inserted while a session object is enabled, then later deleted while 11233 ** the same session object is disabled, no INSERT record will appear in the 11234 ** changeset, even though the delete took place while the session was disabled. 11235 ** Or, if one field of a row is updated while a session is disabled, and 11236 ** another field of the same row is updated while the session is enabled, the 11237 ** resulting changeset will contain an UPDATE change that updates both fields. 11238 */ 11239 SQLITE_API int sqlite3session_changeset( 11240 sqlite3_session *pSession, /* Session object */ 11241 int *pnChangeset, /* OUT: Size of buffer at *ppChangeset */ 11242 void **ppChangeset /* OUT: Buffer containing changeset */ 11243 ); 11244 11245 /* 11246 ** CAPI3REF: Return An Upper-limit For The Size Of The Changeset 11247 ** METHOD: sqlite3_session 11248 ** 11249 ** By default, this function always returns 0. For it to return 11250 ** a useful result, the sqlite3_session object must have been configured 11251 ** to enable this API using sqlite3session_object_config() with the 11252 ** SQLITE_SESSION_OBJCONFIG_SIZE verb. 11253 ** 11254 ** When enabled, this function returns an upper limit, in bytes, for the size 11255 ** of the changeset that might be produced if sqlite3session_changeset() were 11256 ** called. The final changeset size might be equal to or smaller than the 11257 ** size in bytes returned by this function. 11258 */ 11259 SQLITE_API sqlite3_int64 sqlite3session_changeset_size(sqlite3_session *pSession); 11260 11261 /* 11262 ** CAPI3REF: Load The Difference Between Tables Into A Session 11263 ** METHOD: sqlite3_session 11264 ** 11265 ** If it is not already attached to the session object passed as the first 11266 ** argument, this function attaches table zTbl in the same manner as the 11267 ** [sqlite3session_attach()] function. If zTbl does not exist, or if it 11268 ** does not have a primary key, this function is a no-op (but does not return 11269 ** an error). 11270 ** 11271 ** Argument zFromDb must be the name of a database ("main", "temp" etc.) 11272 ** attached to the same database handle as the session object that contains 11273 ** a table compatible with the table attached to the session by this function. 11274 ** A table is considered compatible if it: 11275 ** 11276 ** <ul> 11277 ** <li> Has the same name, 11278 ** <li> Has the same set of columns declared in the same order, and 11279 ** <li> Has the same PRIMARY KEY definition. 11280 ** </ul> 11281 ** 11282 ** If the tables are not compatible, SQLITE_SCHEMA is returned. If the tables 11283 ** are compatible but do not have any PRIMARY KEY columns, it is not an error 11284 ** but no changes are added to the session object. As with other session 11285 ** APIs, tables without PRIMARY KEYs are simply ignored. 11286 ** 11287 ** This function adds a set of changes to the session object that could be 11288 ** used to update the table in database zFrom (call this the "from-table") 11289 ** so that its content is the same as the table attached to the session 11290 ** object (call this the "to-table"). Specifically: 11291 ** 11292 ** <ul> 11293 ** <li> For each row (primary key) that exists in the to-table but not in 11294 ** the from-table, an INSERT record is added to the session object. 11295 ** 11296 ** <li> For each row (primary key) that exists in the to-table but not in 11297 ** the from-table, a DELETE record is added to the session object. 11298 ** 11299 ** <li> For each row (primary key) that exists in both tables, but features 11300 ** different non-PK values in each, an UPDATE record is added to the 11301 ** session. 11302 ** </ul> 11303 ** 11304 ** To clarify, if this function is called and then a changeset constructed 11305 ** using [sqlite3session_changeset()], then after applying that changeset to 11306 ** database zFrom the contents of the two compatible tables would be 11307 ** identical. 11308 ** 11309 ** It an error if database zFrom does not exist or does not contain the 11310 ** required compatible table. 11311 ** 11312 ** If the operation is successful, SQLITE_OK is returned. Otherwise, an SQLite 11313 ** error code. In this case, if argument pzErrMsg is not NULL, *pzErrMsg 11314 ** may be set to point to a buffer containing an English language error 11315 ** message. It is the responsibility of the caller to free this buffer using 11316 ** sqlite3_free(). 11317 */ 11318 SQLITE_API int sqlite3session_diff( 11319 sqlite3_session *pSession, 11320 const char *zFromDb, 11321 const char *zTbl, 11322 char **pzErrMsg 11323 ); 11324 11325 11326 /* 11327 ** CAPI3REF: Generate A Patchset From A Session Object 11328 ** METHOD: sqlite3_session 11329 ** 11330 ** The differences between a patchset and a changeset are that: 11331 ** 11332 ** <ul> 11333 ** <li> DELETE records consist of the primary key fields only. The 11334 ** original values of other fields are omitted. 11335 ** <li> The original values of any modified fields are omitted from 11336 ** UPDATE records. 11337 ** </ul> 11338 ** 11339 ** A patchset blob may be used with up to date versions of all 11340 ** sqlite3changeset_xxx API functions except for sqlite3changeset_invert(), 11341 ** which returns SQLITE_CORRUPT if it is passed a patchset. Similarly, 11342 ** attempting to use a patchset blob with old versions of the 11343 ** sqlite3changeset_xxx APIs also provokes an SQLITE_CORRUPT error. 11344 ** 11345 ** Because the non-primary key "old.*" fields are omitted, no 11346 ** SQLITE_CHANGESET_DATA conflicts can be detected or reported if a patchset 11347 ** is passed to the sqlite3changeset_apply() API. Other conflict types work 11348 ** in the same way as for changesets. 11349 ** 11350 ** Changes within a patchset are ordered in the same way as for changesets 11351 ** generated by the sqlite3session_changeset() function (i.e. all changes for 11352 ** a single table are grouped together, tables appear in the order in which 11353 ** they were attached to the session object). 11354 */ 11355 SQLITE_API int sqlite3session_patchset( 11356 sqlite3_session *pSession, /* Session object */ 11357 int *pnPatchset, /* OUT: Size of buffer at *ppPatchset */ 11358 void **ppPatchset /* OUT: Buffer containing patchset */ 11359 ); 11360 11361 /* 11362 ** CAPI3REF: Test if a changeset has recorded any changes. 11363 ** 11364 ** Return non-zero if no changes to attached tables have been recorded by 11365 ** the session object passed as the first argument. Otherwise, if one or 11366 ** more changes have been recorded, return zero. 11367 ** 11368 ** Even if this function returns zero, it is possible that calling 11369 ** [sqlite3session_changeset()] on the session handle may still return a 11370 ** changeset that contains no changes. This can happen when a row in 11371 ** an attached table is modified and then later on the original values 11372 ** are restored. However, if this function returns non-zero, then it is 11373 ** guaranteed that a call to sqlite3session_changeset() will return a 11374 ** changeset containing zero changes. 11375 */ 11376 SQLITE_API int sqlite3session_isempty(sqlite3_session *pSession); 11377 11378 /* 11379 ** CAPI3REF: Query for the amount of heap memory used by a session object. 11380 ** 11381 ** This API returns the total amount of heap memory in bytes currently 11382 ** used by the session object passed as the only argument. 11383 */ 11384 SQLITE_API sqlite3_int64 sqlite3session_memory_used(sqlite3_session *pSession); 11385 11386 /* 11387 ** CAPI3REF: Create An Iterator To Traverse A Changeset 11388 ** CONSTRUCTOR: sqlite3_changeset_iter 11389 ** 11390 ** Create an iterator used to iterate through the contents of a changeset. 11391 ** If successful, *pp is set to point to the iterator handle and SQLITE_OK 11392 ** is returned. Otherwise, if an error occurs, *pp is set to zero and an 11393 ** SQLite error code is returned. 11394 ** 11395 ** The following functions can be used to advance and query a changeset 11396 ** iterator created by this function: 11397 ** 11398 ** <ul> 11399 ** <li> [sqlite3changeset_next()] 11400 ** <li> [sqlite3changeset_op()] 11401 ** <li> [sqlite3changeset_new()] 11402 ** <li> [sqlite3changeset_old()] 11403 ** </ul> 11404 ** 11405 ** It is the responsibility of the caller to eventually destroy the iterator 11406 ** by passing it to [sqlite3changeset_finalize()]. The buffer containing the 11407 ** changeset (pChangeset) must remain valid until after the iterator is 11408 ** destroyed. 11409 ** 11410 ** Assuming the changeset blob was created by one of the 11411 ** [sqlite3session_changeset()], [sqlite3changeset_concat()] or 11412 ** [sqlite3changeset_invert()] functions, all changes within the changeset 11413 ** that apply to a single table are grouped together. This means that when 11414 ** an application iterates through a changeset using an iterator created by 11415 ** this function, all changes that relate to a single table are visited 11416 ** consecutively. There is no chance that the iterator will visit a change 11417 ** the applies to table X, then one for table Y, and then later on visit 11418 ** another change for table X. 11419 ** 11420 ** The behavior of sqlite3changeset_start_v2() and its streaming equivalent 11421 ** may be modified by passing a combination of 11422 ** [SQLITE_CHANGESETSTART_INVERT | supported flags] as the 4th parameter. 11423 ** 11424 ** Note that the sqlite3changeset_start_v2() API is still <b>experimental</b> 11425 ** and therefore subject to change. 11426 */ 11427 SQLITE_API int sqlite3changeset_start( 11428 sqlite3_changeset_iter **pp, /* OUT: New changeset iterator handle */ 11429 int nChangeset, /* Size of changeset blob in bytes */ 11430 void *pChangeset /* Pointer to blob containing changeset */ 11431 ); 11432 SQLITE_API int sqlite3changeset_start_v2( 11433 sqlite3_changeset_iter **pp, /* OUT: New changeset iterator handle */ 11434 int nChangeset, /* Size of changeset blob in bytes */ 11435 void *pChangeset, /* Pointer to blob containing changeset */ 11436 int flags /* SESSION_CHANGESETSTART_* flags */ 11437 ); 11438 11439 /* 11440 ** CAPI3REF: Flags for sqlite3changeset_start_v2 11441 ** 11442 ** The following flags may passed via the 4th parameter to 11443 ** [sqlite3changeset_start_v2] and [sqlite3changeset_start_v2_strm]: 11444 ** 11445 ** <dt>SQLITE_CHANGESETAPPLY_INVERT <dd> 11446 ** Invert the changeset while iterating through it. This is equivalent to 11447 ** inverting a changeset using sqlite3changeset_invert() before applying it. 11448 ** It is an error to specify this flag with a patchset. 11449 */ 11450 #define SQLITE_CHANGESETSTART_INVERT 0x0002 11451 11452 11453 /* 11454 ** CAPI3REF: Advance A Changeset Iterator 11455 ** METHOD: sqlite3_changeset_iter 11456 ** 11457 ** This function may only be used with iterators created by the function 11458 ** [sqlite3changeset_start()]. If it is called on an iterator passed to 11459 ** a conflict-handler callback by [sqlite3changeset_apply()], SQLITE_MISUSE 11460 ** is returned and the call has no effect. 11461 ** 11462 ** Immediately after an iterator is created by sqlite3changeset_start(), it 11463 ** does not point to any change in the changeset. Assuming the changeset 11464 ** is not empty, the first call to this function advances the iterator to 11465 ** point to the first change in the changeset. Each subsequent call advances 11466 ** the iterator to point to the next change in the changeset (if any). If 11467 ** no error occurs and the iterator points to a valid change after a call 11468 ** to sqlite3changeset_next() has advanced it, SQLITE_ROW is returned. 11469 ** Otherwise, if all changes in the changeset have already been visited, 11470 ** SQLITE_DONE is returned. 11471 ** 11472 ** If an error occurs, an SQLite error code is returned. Possible error 11473 ** codes include SQLITE_CORRUPT (if the changeset buffer is corrupt) or 11474 ** SQLITE_NOMEM. 11475 */ 11476 SQLITE_API int sqlite3changeset_next(sqlite3_changeset_iter *pIter); 11477 11478 /* 11479 ** CAPI3REF: Obtain The Current Operation From A Changeset Iterator 11480 ** METHOD: sqlite3_changeset_iter 11481 ** 11482 ** The pIter argument passed to this function may either be an iterator 11483 ** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator 11484 ** created by [sqlite3changeset_start()]. In the latter case, the most recent 11485 ** call to [sqlite3changeset_next()] must have returned [SQLITE_ROW]. If this 11486 ** is not the case, this function returns [SQLITE_MISUSE]. 11487 ** 11488 ** Arguments pOp, pnCol and pzTab may not be NULL. Upon return, three 11489 ** outputs are set through these pointers: 11490 ** 11491 ** *pOp is set to one of [SQLITE_INSERT], [SQLITE_DELETE] or [SQLITE_UPDATE], 11492 ** depending on the type of change that the iterator currently points to; 11493 ** 11494 ** *pnCol is set to the number of columns in the table affected by the change; and 11495 ** 11496 ** *pzTab is set to point to a nul-terminated utf-8 encoded string containing 11497 ** the name of the table affected by the current change. The buffer remains 11498 ** valid until either sqlite3changeset_next() is called on the iterator 11499 ** or until the conflict-handler function returns. 11500 ** 11501 ** If pbIndirect is not NULL, then *pbIndirect is set to true (1) if the change 11502 ** is an indirect change, or false (0) otherwise. See the documentation for 11503 ** [sqlite3session_indirect()] for a description of direct and indirect 11504 ** changes. 11505 ** 11506 ** If no error occurs, SQLITE_OK is returned. If an error does occur, an 11507 ** SQLite error code is returned. The values of the output variables may not 11508 ** be trusted in this case. 11509 */ 11510 SQLITE_API int sqlite3changeset_op( 11511 sqlite3_changeset_iter *pIter, /* Iterator object */ 11512 const char **pzTab, /* OUT: Pointer to table name */ 11513 int *pnCol, /* OUT: Number of columns in table */ 11514 int *pOp, /* OUT: SQLITE_INSERT, DELETE or UPDATE */ 11515 int *pbIndirect /* OUT: True for an 'indirect' change */ 11516 ); 11517 11518 /* 11519 ** CAPI3REF: Obtain The Primary Key Definition Of A Table 11520 ** METHOD: sqlite3_changeset_iter 11521 ** 11522 ** For each modified table, a changeset includes the following: 11523 ** 11524 ** <ul> 11525 ** <li> The number of columns in the table, and 11526 ** <li> Which of those columns make up the tables PRIMARY KEY. 11527 ** </ul> 11528 ** 11529 ** This function is used to find which columns comprise the PRIMARY KEY of 11530 ** the table modified by the change that iterator pIter currently points to. 11531 ** If successful, *pabPK is set to point to an array of nCol entries, where 11532 ** nCol is the number of columns in the table. Elements of *pabPK are set to 11533 ** 0x01 if the corresponding column is part of the tables primary key, or 11534 ** 0x00 if it is not. 11535 ** 11536 ** If argument pnCol is not NULL, then *pnCol is set to the number of columns 11537 ** in the table. 11538 ** 11539 ** If this function is called when the iterator does not point to a valid 11540 ** entry, SQLITE_MISUSE is returned and the output variables zeroed. Otherwise, 11541 ** SQLITE_OK is returned and the output variables populated as described 11542 ** above. 11543 */ 11544 SQLITE_API int sqlite3changeset_pk( 11545 sqlite3_changeset_iter *pIter, /* Iterator object */ 11546 unsigned char **pabPK, /* OUT: Array of boolean - true for PK cols */ 11547 int *pnCol /* OUT: Number of entries in output array */ 11548 ); 11549 11550 /* 11551 ** CAPI3REF: Obtain old.* Values From A Changeset Iterator 11552 ** METHOD: sqlite3_changeset_iter 11553 ** 11554 ** The pIter argument passed to this function may either be an iterator 11555 ** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator 11556 ** created by [sqlite3changeset_start()]. In the latter case, the most recent 11557 ** call to [sqlite3changeset_next()] must have returned SQLITE_ROW. 11558 ** Furthermore, it may only be called if the type of change that the iterator 11559 ** currently points to is either [SQLITE_DELETE] or [SQLITE_UPDATE]. Otherwise, 11560 ** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL. 11561 ** 11562 ** Argument iVal must be greater than or equal to 0, and less than the number 11563 ** of columns in the table affected by the current change. Otherwise, 11564 ** [SQLITE_RANGE] is returned and *ppValue is set to NULL. 11565 ** 11566 ** If successful, this function sets *ppValue to point to a protected 11567 ** sqlite3_value object containing the iVal'th value from the vector of 11568 ** original row values stored as part of the UPDATE or DELETE change and 11569 ** returns SQLITE_OK. The name of the function comes from the fact that this 11570 ** is similar to the "old.*" columns available to update or delete triggers. 11571 ** 11572 ** If some other error occurs (e.g. an OOM condition), an SQLite error code 11573 ** is returned and *ppValue is set to NULL. 11574 */ 11575 SQLITE_API int sqlite3changeset_old( 11576 sqlite3_changeset_iter *pIter, /* Changeset iterator */ 11577 int iVal, /* Column number */ 11578 sqlite3_value **ppValue /* OUT: Old value (or NULL pointer) */ 11579 ); 11580 11581 /* 11582 ** CAPI3REF: Obtain new.* Values From A Changeset Iterator 11583 ** METHOD: sqlite3_changeset_iter 11584 ** 11585 ** The pIter argument passed to this function may either be an iterator 11586 ** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator 11587 ** created by [sqlite3changeset_start()]. In the latter case, the most recent 11588 ** call to [sqlite3changeset_next()] must have returned SQLITE_ROW. 11589 ** Furthermore, it may only be called if the type of change that the iterator 11590 ** currently points to is either [SQLITE_UPDATE] or [SQLITE_INSERT]. Otherwise, 11591 ** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL. 11592 ** 11593 ** Argument iVal must be greater than or equal to 0, and less than the number 11594 ** of columns in the table affected by the current change. Otherwise, 11595 ** [SQLITE_RANGE] is returned and *ppValue is set to NULL. 11596 ** 11597 ** If successful, this function sets *ppValue to point to a protected 11598 ** sqlite3_value object containing the iVal'th value from the vector of 11599 ** new row values stored as part of the UPDATE or INSERT change and 11600 ** returns SQLITE_OK. If the change is an UPDATE and does not include 11601 ** a new value for the requested column, *ppValue is set to NULL and 11602 ** SQLITE_OK returned. The name of the function comes from the fact that 11603 ** this is similar to the "new.*" columns available to update or delete 11604 ** triggers. 11605 ** 11606 ** If some other error occurs (e.g. an OOM condition), an SQLite error code 11607 ** is returned and *ppValue is set to NULL. 11608 */ 11609 SQLITE_API int sqlite3changeset_new( 11610 sqlite3_changeset_iter *pIter, /* Changeset iterator */ 11611 int iVal, /* Column number */ 11612 sqlite3_value **ppValue /* OUT: New value (or NULL pointer) */ 11613 ); 11614 11615 /* 11616 ** CAPI3REF: Obtain Conflicting Row Values From A Changeset Iterator 11617 ** METHOD: sqlite3_changeset_iter 11618 ** 11619 ** This function should only be used with iterator objects passed to a 11620 ** conflict-handler callback by [sqlite3changeset_apply()] with either 11621 ** [SQLITE_CHANGESET_DATA] or [SQLITE_CHANGESET_CONFLICT]. If this function 11622 ** is called on any other iterator, [SQLITE_MISUSE] is returned and *ppValue 11623 ** is set to NULL. 11624 ** 11625 ** Argument iVal must be greater than or equal to 0, and less than the number 11626 ** of columns in the table affected by the current change. Otherwise, 11627 ** [SQLITE_RANGE] is returned and *ppValue is set to NULL. 11628 ** 11629 ** If successful, this function sets *ppValue to point to a protected 11630 ** sqlite3_value object containing the iVal'th value from the 11631 ** "conflicting row" associated with the current conflict-handler callback 11632 ** and returns SQLITE_OK. 11633 ** 11634 ** If some other error occurs (e.g. an OOM condition), an SQLite error code 11635 ** is returned and *ppValue is set to NULL. 11636 */ 11637 SQLITE_API int sqlite3changeset_conflict( 11638 sqlite3_changeset_iter *pIter, /* Changeset iterator */ 11639 int iVal, /* Column number */ 11640 sqlite3_value **ppValue /* OUT: Value from conflicting row */ 11641 ); 11642 11643 /* 11644 ** CAPI3REF: Determine The Number Of Foreign Key Constraint Violations 11645 ** METHOD: sqlite3_changeset_iter 11646 ** 11647 ** This function may only be called with an iterator passed to an 11648 ** SQLITE_CHANGESET_FOREIGN_KEY conflict handler callback. In this case 11649 ** it sets the output variable to the total number of known foreign key 11650 ** violations in the destination database and returns SQLITE_OK. 11651 ** 11652 ** In all other cases this function returns SQLITE_MISUSE. 11653 */ 11654 SQLITE_API int sqlite3changeset_fk_conflicts( 11655 sqlite3_changeset_iter *pIter, /* Changeset iterator */ 11656 int *pnOut /* OUT: Number of FK violations */ 11657 ); 11658 11659 11660 /* 11661 ** CAPI3REF: Finalize A Changeset Iterator 11662 ** METHOD: sqlite3_changeset_iter 11663 ** 11664 ** This function is used to finalize an iterator allocated with 11665 ** [sqlite3changeset_start()]. 11666 ** 11667 ** This function should only be called on iterators created using the 11668 ** [sqlite3changeset_start()] function. If an application calls this 11669 ** function with an iterator passed to a conflict-handler by 11670 ** [sqlite3changeset_apply()], [SQLITE_MISUSE] is immediately returned and the 11671 ** call has no effect. 11672 ** 11673 ** If an error was encountered within a call to an sqlite3changeset_xxx() 11674 ** function (for example an [SQLITE_CORRUPT] in [sqlite3changeset_next()] or an 11675 ** [SQLITE_NOMEM] in [sqlite3changeset_new()]) then an error code corresponding 11676 ** to that error is returned by this function. Otherwise, SQLITE_OK is 11677 ** returned. This is to allow the following pattern (pseudo-code): 11678 ** 11679 ** <pre> 11680 ** sqlite3changeset_start(); 11681 ** while( SQLITE_ROW==sqlite3changeset_next() ){ 11682 ** // Do something with change. 11683 ** } 11684 ** rc = sqlite3changeset_finalize(); 11685 ** if( rc!=SQLITE_OK ){ 11686 ** // An error has occurred 11687 ** } 11688 ** </pre> 11689 */ 11690 SQLITE_API int sqlite3changeset_finalize(sqlite3_changeset_iter *pIter); 11691 11692 /* 11693 ** CAPI3REF: Invert A Changeset 11694 ** 11695 ** This function is used to "invert" a changeset object. Applying an inverted 11696 ** changeset to a database reverses the effects of applying the uninverted 11697 ** changeset. Specifically: 11698 ** 11699 ** <ul> 11700 ** <li> Each DELETE change is changed to an INSERT, and 11701 ** <li> Each INSERT change is changed to a DELETE, and 11702 ** <li> For each UPDATE change, the old.* and new.* values are exchanged. 11703 ** </ul> 11704 ** 11705 ** This function does not change the order in which changes appear within 11706 ** the changeset. It merely reverses the sense of each individual change. 11707 ** 11708 ** If successful, a pointer to a buffer containing the inverted changeset 11709 ** is stored in *ppOut, the size of the same buffer is stored in *pnOut, and 11710 ** SQLITE_OK is returned. If an error occurs, both *pnOut and *ppOut are 11711 ** zeroed and an SQLite error code returned. 11712 ** 11713 ** It is the responsibility of the caller to eventually call sqlite3_free() 11714 ** on the *ppOut pointer to free the buffer allocation following a successful 11715 ** call to this function. 11716 ** 11717 ** WARNING/TODO: This function currently assumes that the input is a valid 11718 ** changeset. If it is not, the results are undefined. 11719 */ 11720 SQLITE_API int sqlite3changeset_invert( 11721 int nIn, const void *pIn, /* Input changeset */ 11722 int *pnOut, void **ppOut /* OUT: Inverse of input */ 11723 ); 11724 11725 /* 11726 ** CAPI3REF: Concatenate Two Changeset Objects 11727 ** 11728 ** This function is used to concatenate two changesets, A and B, into a 11729 ** single changeset. The result is a changeset equivalent to applying 11730 ** changeset A followed by changeset B. 11731 ** 11732 ** This function combines the two input changesets using an 11733 ** sqlite3_changegroup object. Calling it produces similar results as the 11734 ** following code fragment: 11735 ** 11736 ** <pre> 11737 ** sqlite3_changegroup *pGrp; 11738 ** rc = sqlite3_changegroup_new(&pGrp); 11739 ** if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nA, pA); 11740 ** if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nB, pB); 11741 ** if( rc==SQLITE_OK ){ 11742 ** rc = sqlite3changegroup_output(pGrp, pnOut, ppOut); 11743 ** }else{ 11744 ** *ppOut = 0; 11745 ** *pnOut = 0; 11746 ** } 11747 ** </pre> 11748 ** 11749 ** Refer to the sqlite3_changegroup documentation below for details. 11750 */ 11751 SQLITE_API int sqlite3changeset_concat( 11752 int nA, /* Number of bytes in buffer pA */ 11753 void *pA, /* Pointer to buffer containing changeset A */ 11754 int nB, /* Number of bytes in buffer pB */ 11755 void *pB, /* Pointer to buffer containing changeset B */ 11756 int *pnOut, /* OUT: Number of bytes in output changeset */ 11757 void **ppOut /* OUT: Buffer containing output changeset */ 11758 ); 11759 11760 11761 /* 11762 ** CAPI3REF: Upgrade the Schema of a Changeset/Patchset 11763 */ 11764 SQLITE_API int sqlite3changeset_upgrade( 11765 sqlite3 *db, 11766 const char *zDb, 11767 int nIn, const void *pIn, /* Input changeset */ 11768 int *pnOut, void **ppOut /* OUT: Inverse of input */ 11769 ); 11770 11771 11772 11773 /* 11774 ** CAPI3REF: Changegroup Handle 11775 ** 11776 ** A changegroup is an object used to combine two or more 11777 ** [changesets] or [patchsets] 11778 */ 11779 typedef struct sqlite3_changegroup sqlite3_changegroup; 11780 11781 /* 11782 ** CAPI3REF: Create A New Changegroup Object 11783 ** CONSTRUCTOR: sqlite3_changegroup 11784 ** 11785 ** An sqlite3_changegroup object is used to combine two or more changesets 11786 ** (or patchsets) into a single changeset (or patchset). A single changegroup 11787 ** object may combine changesets or patchsets, but not both. The output is 11788 ** always in the same format as the input. 11789 ** 11790 ** If successful, this function returns SQLITE_OK and populates (*pp) with 11791 ** a pointer to a new sqlite3_changegroup object before returning. The caller 11792 ** should eventually free the returned object using a call to 11793 ** sqlite3changegroup_delete(). If an error occurs, an SQLite error code 11794 ** (i.e. SQLITE_NOMEM) is returned and *pp is set to NULL. 11795 ** 11796 ** The usual usage pattern for an sqlite3_changegroup object is as follows: 11797 ** 11798 ** <ul> 11799 ** <li> It is created using a call to sqlite3changegroup_new(). 11800 ** 11801 ** <li> Zero or more changesets (or patchsets) are added to the object 11802 ** by calling sqlite3changegroup_add(). 11803 ** 11804 ** <li> The result of combining all input changesets together is obtained 11805 ** by the application via a call to sqlite3changegroup_output(). 11806 ** 11807 ** <li> The object is deleted using a call to sqlite3changegroup_delete(). 11808 ** </ul> 11809 ** 11810 ** Any number of calls to add() and output() may be made between the calls to 11811 ** new() and delete(), and in any order. 11812 ** 11813 ** As well as the regular sqlite3changegroup_add() and 11814 ** sqlite3changegroup_output() functions, also available are the streaming 11815 ** versions sqlite3changegroup_add_strm() and sqlite3changegroup_output_strm(). 11816 */ 11817 SQLITE_API int sqlite3changegroup_new(sqlite3_changegroup **pp); 11818 11819 /* 11820 ** CAPI3REF: Add a Schema to a Changegroup 11821 ** METHOD: sqlite3_changegroup_schema 11822 ** 11823 ** This method may be used to optionally enforce the rule that the changesets 11824 ** added to the changegroup handle must match the schema of database zDb 11825 ** ("main", "temp", or the name of an attached database). If 11826 ** sqlite3changegroup_add() is called to add a changeset that is not compatible 11827 ** with the configured schema, SQLITE_SCHEMA is returned and the changegroup 11828 ** object is left in an undefined state. 11829 ** 11830 ** A changeset schema is considered compatible with the database schema in 11831 ** the same way as for sqlite3changeset_apply(). Specifically, for each 11832 ** table in the changeset, there exists a database table with: 11833 ** 11834 ** <ul> 11835 ** <li> The name identified by the changeset, and 11836 ** <li> at least as many columns as recorded in the changeset, and 11837 ** <li> the primary key columns in the same position as recorded in 11838 ** the changeset. 11839 ** </ul> 11840 ** 11841 ** The output of the changegroup object always has the same schema as the 11842 ** database nominated using this function. In cases where changesets passed 11843 ** to sqlite3changegroup_add() have fewer columns than the corresponding table 11844 ** in the database schema, these are filled in using the default column 11845 ** values from the database schema. This makes it possible to combined 11846 ** changesets that have different numbers of columns for a single table 11847 ** within a changegroup, provided that they are otherwise compatible. 11848 */ 11849 SQLITE_API int sqlite3changegroup_schema(sqlite3_changegroup*, sqlite3*, const char *zDb); 11850 11851 /* 11852 ** CAPI3REF: Add A Changeset To A Changegroup 11853 ** METHOD: sqlite3_changegroup 11854 ** 11855 ** Add all changes within the changeset (or patchset) in buffer pData (size 11856 ** nData bytes) to the changegroup. 11857 ** 11858 ** If the buffer contains a patchset, then all prior calls to this function 11859 ** on the same changegroup object must also have specified patchsets. Or, if 11860 ** the buffer contains a changeset, so must have the earlier calls to this 11861 ** function. Otherwise, SQLITE_ERROR is returned and no changes are added 11862 ** to the changegroup. 11863 ** 11864 ** Rows within the changeset and changegroup are identified by the values in 11865 ** their PRIMARY KEY columns. A change in the changeset is considered to 11866 ** apply to the same row as a change already present in the changegroup if 11867 ** the two rows have the same primary key. 11868 ** 11869 ** Changes to rows that do not already appear in the changegroup are 11870 ** simply copied into it. Or, if both the new changeset and the changegroup 11871 ** contain changes that apply to a single row, the final contents of the 11872 ** changegroup depends on the type of each change, as follows: 11873 ** 11874 ** <table border=1 style="margin-left:8ex;margin-right:8ex"> 11875 ** <tr><th style="white-space:pre">Existing Change </th> 11876 ** <th style="white-space:pre">New Change </th> 11877 ** <th>Output Change 11878 ** <tr><td>INSERT <td>INSERT <td> 11879 ** The new change is ignored. This case does not occur if the new 11880 ** changeset was recorded immediately after the changesets already 11881 ** added to the changegroup. 11882 ** <tr><td>INSERT <td>UPDATE <td> 11883 ** The INSERT change remains in the changegroup. The values in the 11884 ** INSERT change are modified as if the row was inserted by the 11885 ** existing change and then updated according to the new change. 11886 ** <tr><td>INSERT <td>DELETE <td> 11887 ** The existing INSERT is removed from the changegroup. The DELETE is 11888 ** not added. 11889 ** <tr><td>UPDATE <td>INSERT <td> 11890 ** The new change is ignored. This case does not occur if the new 11891 ** changeset was recorded immediately after the changesets already 11892 ** added to the changegroup. 11893 ** <tr><td>UPDATE <td>UPDATE <td> 11894 ** The existing UPDATE remains within the changegroup. It is amended 11895 ** so that the accompanying values are as if the row was updated once 11896 ** by the existing change and then again by the new change. 11897 ** <tr><td>UPDATE <td>DELETE <td> 11898 ** The existing UPDATE is replaced by the new DELETE within the 11899 ** changegroup. 11900 ** <tr><td>DELETE <td>INSERT <td> 11901 ** If one or more of the column values in the row inserted by the 11902 ** new change differ from those in the row deleted by the existing 11903 ** change, the existing DELETE is replaced by an UPDATE within the 11904 ** changegroup. Otherwise, if the inserted row is exactly the same 11905 ** as the deleted row, the existing DELETE is simply discarded. 11906 ** <tr><td>DELETE <td>UPDATE <td> 11907 ** The new change is ignored. This case does not occur if the new 11908 ** changeset was recorded immediately after the changesets already 11909 ** added to the changegroup. 11910 ** <tr><td>DELETE <td>DELETE <td> 11911 ** The new change is ignored. This case does not occur if the new 11912 ** changeset was recorded immediately after the changesets already 11913 ** added to the changegroup. 11914 ** </table> 11915 ** 11916 ** If the new changeset contains changes to a table that is already present 11917 ** in the changegroup, then the number of columns and the position of the 11918 ** primary key columns for the table must be consistent. If this is not the 11919 ** case, this function fails with SQLITE_SCHEMA. Except, if the changegroup 11920 ** object has been configured with a database schema using the 11921 ** sqlite3changegroup_schema() API, then it is possible to combine changesets 11922 ** with different numbers of columns for a single table, provided that 11923 ** they are otherwise compatible. 11924 ** 11925 ** If the input changeset appears to be corrupt and the corruption is 11926 ** detected, SQLITE_CORRUPT is returned. Or, if an out-of-memory condition 11927 ** occurs during processing, this function returns SQLITE_NOMEM. 11928 ** 11929 ** In all cases, if an error occurs the state of the final contents of the 11930 ** changegroup is undefined. If no error occurs, SQLITE_OK is returned. 11931 */ 11932 SQLITE_API int sqlite3changegroup_add(sqlite3_changegroup*, int nData, void *pData); 11933 11934 /* 11935 ** CAPI3REF: Obtain A Composite Changeset From A Changegroup 11936 ** METHOD: sqlite3_changegroup 11937 ** 11938 ** Obtain a buffer containing a changeset (or patchset) representing the 11939 ** current contents of the changegroup. If the inputs to the changegroup 11940 ** were themselves changesets, the output is a changeset. Or, if the 11941 ** inputs were patchsets, the output is also a patchset. 11942 ** 11943 ** As with the output of the sqlite3session_changeset() and 11944 ** sqlite3session_patchset() functions, all changes related to a single 11945 ** table are grouped together in the output of this function. Tables appear 11946 ** in the same order as for the very first changeset added to the changegroup. 11947 ** If the second or subsequent changesets added to the changegroup contain 11948 ** changes for tables that do not appear in the first changeset, they are 11949 ** appended onto the end of the output changeset, again in the order in 11950 ** which they are first encountered. 11951 ** 11952 ** If an error occurs, an SQLite error code is returned and the output 11953 ** variables (*pnData) and (*ppData) are set to 0. Otherwise, SQLITE_OK 11954 ** is returned and the output variables are set to the size of and a 11955 ** pointer to the output buffer, respectively. In this case it is the 11956 ** responsibility of the caller to eventually free the buffer using a 11957 ** call to sqlite3_free(). 11958 */ 11959 SQLITE_API int sqlite3changegroup_output( 11960 sqlite3_changegroup*, 11961 int *pnData, /* OUT: Size of output buffer in bytes */ 11962 void **ppData /* OUT: Pointer to output buffer */ 11963 ); 11964 11965 /* 11966 ** CAPI3REF: Delete A Changegroup Object 11967 ** DESTRUCTOR: sqlite3_changegroup 11968 */ 11969 SQLITE_API void sqlite3changegroup_delete(sqlite3_changegroup*); 11970 11971 /* 11972 ** CAPI3REF: Apply A Changeset To A Database 11973 ** 11974 ** Apply a changeset or patchset to a database. These functions attempt to 11975 ** update the "main" database attached to handle db with the changes found in 11976 ** the changeset passed via the second and third arguments. 11977 ** 11978 ** The fourth argument (xFilter) passed to these functions is the "filter 11979 ** callback". If it is not NULL, then for each table affected by at least one 11980 ** change in the changeset, the filter callback is invoked with 11981 ** the table name as the second argument, and a copy of the context pointer 11982 ** passed as the sixth argument as the first. If the "filter callback" 11983 ** returns zero, then no attempt is made to apply any changes to the table. 11984 ** Otherwise, if the return value is non-zero or the xFilter argument to 11985 ** is NULL, all changes related to the table are attempted. 11986 ** 11987 ** For each table that is not excluded by the filter callback, this function 11988 ** tests that the target database contains a compatible table. A table is 11989 ** considered compatible if all of the following are true: 11990 ** 11991 ** <ul> 11992 ** <li> The table has the same name as the name recorded in the 11993 ** changeset, and 11994 ** <li> The table has at least as many columns as recorded in the 11995 ** changeset, and 11996 ** <li> The table has primary key columns in the same position as 11997 ** recorded in the changeset. 11998 ** </ul> 11999 ** 12000 ** If there is no compatible table, it is not an error, but none of the 12001 ** changes associated with the table are applied. A warning message is issued 12002 ** via the sqlite3_log() mechanism with the error code SQLITE_SCHEMA. At most 12003 ** one such warning is issued for each table in the changeset. 12004 ** 12005 ** For each change for which there is a compatible table, an attempt is made 12006 ** to modify the table contents according to the UPDATE, INSERT or DELETE 12007 ** change. If a change cannot be applied cleanly, the conflict handler 12008 ** function passed as the fifth argument to sqlite3changeset_apply() may be 12009 ** invoked. A description of exactly when the conflict handler is invoked for 12010 ** each type of change is below. 12011 ** 12012 ** Unlike the xFilter argument, xConflict may not be passed NULL. The results 12013 ** of passing anything other than a valid function pointer as the xConflict 12014 ** argument are undefined. 12015 ** 12016 ** Each time the conflict handler function is invoked, it must return one 12017 ** of [SQLITE_CHANGESET_OMIT], [SQLITE_CHANGESET_ABORT] or 12018 ** [SQLITE_CHANGESET_REPLACE]. SQLITE_CHANGESET_REPLACE may only be returned 12019 ** if the second argument passed to the conflict handler is either 12020 ** SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If the conflict-handler 12021 ** returns an illegal value, any changes already made are rolled back and 12022 ** the call to sqlite3changeset_apply() returns SQLITE_MISUSE. Different 12023 ** actions are taken by sqlite3changeset_apply() depending on the value 12024 ** returned by each invocation of the conflict-handler function. Refer to 12025 ** the documentation for the three 12026 ** [SQLITE_CHANGESET_OMIT|available return values] for details. 12027 ** 12028 ** <dl> 12029 ** <dt>DELETE Changes<dd> 12030 ** For each DELETE change, the function checks if the target database 12031 ** contains a row with the same primary key value (or values) as the 12032 ** original row values stored in the changeset. If it does, and the values 12033 ** stored in all non-primary key columns also match the values stored in 12034 ** the changeset the row is deleted from the target database. 12035 ** 12036 ** If a row with matching primary key values is found, but one or more of 12037 ** the non-primary key fields contains a value different from the original 12038 ** row value stored in the changeset, the conflict-handler function is 12039 ** invoked with [SQLITE_CHANGESET_DATA] as the second argument. If the 12040 ** database table has more columns than are recorded in the changeset, 12041 ** only the values of those non-primary key fields are compared against 12042 ** the current database contents - any trailing database table columns 12043 ** are ignored. 12044 ** 12045 ** If no row with matching primary key values is found in the database, 12046 ** the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND] 12047 ** passed as the second argument. 12048 ** 12049 ** If the DELETE operation is attempted, but SQLite returns SQLITE_CONSTRAINT 12050 ** (which can only happen if a foreign key constraint is violated), the 12051 ** conflict-handler function is invoked with [SQLITE_CHANGESET_CONSTRAINT] 12052 ** passed as the second argument. This includes the case where the DELETE 12053 ** operation is attempted because an earlier call to the conflict handler 12054 ** function returned [SQLITE_CHANGESET_REPLACE]. 12055 ** 12056 ** <dt>INSERT Changes<dd> 12057 ** For each INSERT change, an attempt is made to insert the new row into 12058 ** the database. If the changeset row contains fewer fields than the 12059 ** database table, the trailing fields are populated with their default 12060 ** values. 12061 ** 12062 ** If the attempt to insert the row fails because the database already 12063 ** contains a row with the same primary key values, the conflict handler 12064 ** function is invoked with the second argument set to 12065 ** [SQLITE_CHANGESET_CONFLICT]. 12066 ** 12067 ** If the attempt to insert the row fails because of some other constraint 12068 ** violation (e.g. NOT NULL or UNIQUE), the conflict handler function is 12069 ** invoked with the second argument set to [SQLITE_CHANGESET_CONSTRAINT]. 12070 ** This includes the case where the INSERT operation is re-attempted because 12071 ** an earlier call to the conflict handler function returned 12072 ** [SQLITE_CHANGESET_REPLACE]. 12073 ** 12074 ** <dt>UPDATE Changes<dd> 12075 ** For each UPDATE change, the function checks if the target database 12076 ** contains a row with the same primary key value (or values) as the 12077 ** original row values stored in the changeset. If it does, and the values 12078 ** stored in all modified non-primary key columns also match the values 12079 ** stored in the changeset the row is updated within the target database. 12080 ** 12081 ** If a row with matching primary key values is found, but one or more of 12082 ** the modified non-primary key fields contains a value different from an 12083 ** original row value stored in the changeset, the conflict-handler function 12084 ** is invoked with [SQLITE_CHANGESET_DATA] as the second argument. Since 12085 ** UPDATE changes only contain values for non-primary key fields that are 12086 ** to be modified, only those fields need to match the original values to 12087 ** avoid the SQLITE_CHANGESET_DATA conflict-handler callback. 12088 ** 12089 ** If no row with matching primary key values is found in the database, 12090 ** the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND] 12091 ** passed as the second argument. 12092 ** 12093 ** If the UPDATE operation is attempted, but SQLite returns 12094 ** SQLITE_CONSTRAINT, the conflict-handler function is invoked with 12095 ** [SQLITE_CHANGESET_CONSTRAINT] passed as the second argument. 12096 ** This includes the case where the UPDATE operation is attempted after 12097 ** an earlier call to the conflict handler function returned 12098 ** [SQLITE_CHANGESET_REPLACE]. 12099 ** </dl> 12100 ** 12101 ** It is safe to execute SQL statements, including those that write to the 12102 ** table that the callback related to, from within the xConflict callback. 12103 ** This can be used to further customize the application's conflict 12104 ** resolution strategy. 12105 ** 12106 ** All changes made by these functions are enclosed in a savepoint transaction. 12107 ** If any other error (aside from a constraint failure when attempting to 12108 ** write to the target database) occurs, then the savepoint transaction is 12109 ** rolled back, restoring the target database to its original state, and an 12110 ** SQLite error code returned. 12111 ** 12112 ** If the output parameters (ppRebase) and (pnRebase) are non-NULL and 12113 ** the input is a changeset (not a patchset), then sqlite3changeset_apply_v2() 12114 ** may set (*ppRebase) to point to a "rebase" that may be used with the 12115 ** sqlite3_rebaser APIs buffer before returning. In this case (*pnRebase) 12116 ** is set to the size of the buffer in bytes. It is the responsibility of the 12117 ** caller to eventually free any such buffer using sqlite3_free(). The buffer 12118 ** is only allocated and populated if one or more conflicts were encountered 12119 ** while applying the patchset. See comments surrounding the sqlite3_rebaser 12120 ** APIs for further details. 12121 ** 12122 ** The behavior of sqlite3changeset_apply_v2() and its streaming equivalent 12123 ** may be modified by passing a combination of 12124 ** [SQLITE_CHANGESETAPPLY_NOSAVEPOINT | supported flags] as the 9th parameter. 12125 ** 12126 ** Note that the sqlite3changeset_apply_v2() API is still <b>experimental</b> 12127 ** and therefore subject to change. 12128 */ 12129 SQLITE_API int sqlite3changeset_apply( 12130 sqlite3 *db, /* Apply change to "main" db of this handle */ 12131 int nChangeset, /* Size of changeset in bytes */ 12132 void *pChangeset, /* Changeset blob */ 12133 int(*xFilter)( 12134 void *pCtx, /* Copy of sixth arg to _apply() */ 12135 const char *zTab /* Table name */ 12136 ), 12137 int(*xConflict)( 12138 void *pCtx, /* Copy of sixth arg to _apply() */ 12139 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */ 12140 sqlite3_changeset_iter *p /* Handle describing change and conflict */ 12141 ), 12142 void *pCtx /* First argument passed to xConflict */ 12143 ); 12144 SQLITE_API int sqlite3changeset_apply_v2( 12145 sqlite3 *db, /* Apply change to "main" db of this handle */ 12146 int nChangeset, /* Size of changeset in bytes */ 12147 void *pChangeset, /* Changeset blob */ 12148 int(*xFilter)( 12149 void *pCtx, /* Copy of sixth arg to _apply() */ 12150 const char *zTab /* Table name */ 12151 ), 12152 int(*xConflict)( 12153 void *pCtx, /* Copy of sixth arg to _apply() */ 12154 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */ 12155 sqlite3_changeset_iter *p /* Handle describing change and conflict */ 12156 ), 12157 void *pCtx, /* First argument passed to xConflict */ 12158 void **ppRebase, int *pnRebase, /* OUT: Rebase data */ 12159 int flags /* SESSION_CHANGESETAPPLY_* flags */ 12160 ); 12161 12162 /* 12163 ** CAPI3REF: Flags for sqlite3changeset_apply_v2 12164 ** 12165 ** The following flags may passed via the 9th parameter to 12166 ** [sqlite3changeset_apply_v2] and [sqlite3changeset_apply_v2_strm]: 12167 ** 12168 ** <dl> 12169 ** <dt>SQLITE_CHANGESETAPPLY_NOSAVEPOINT <dd> 12170 ** Usually, the sessions module encloses all operations performed by 12171 ** a single call to apply_v2() or apply_v2_strm() in a [SAVEPOINT]. The 12172 ** SAVEPOINT is committed if the changeset or patchset is successfully 12173 ** applied, or rolled back if an error occurs. Specifying this flag 12174 ** causes the sessions module to omit this savepoint. In this case, if the 12175 ** caller has an open transaction or savepoint when apply_v2() is called, 12176 ** it may revert the partially applied changeset by rolling it back. 12177 ** 12178 ** <dt>SQLITE_CHANGESETAPPLY_INVERT <dd> 12179 ** Invert the changeset before applying it. This is equivalent to inverting 12180 ** a changeset using sqlite3changeset_invert() before applying it. It is 12181 ** an error to specify this flag with a patchset. 12182 ** 12183 ** <dt>SQLITE_CHANGESETAPPLY_IGNORENOOP <dd> 12184 ** Do not invoke the conflict handler callback for any changes that 12185 ** would not actually modify the database even if they were applied. 12186 ** Specifically, this means that the conflict handler is not invoked 12187 ** for: 12188 ** <ul> 12189 ** <li>a delete change if the row being deleted cannot be found, 12190 ** <li>an update change if the modified fields are already set to 12191 ** their new values in the conflicting row, or 12192 ** <li>an insert change if all fields of the conflicting row match 12193 ** the row being inserted. 12194 ** </ul> 12195 ** 12196 ** <dt>SQLITE_CHANGESETAPPLY_FKNOACTION <dd> 12197 ** If this flag it set, then all foreign key constraints in the target 12198 ** database behave as if they were declared with "ON UPDATE NO ACTION ON 12199 ** DELETE NO ACTION", even if they are actually CASCADE, RESTRICT, SET NULL 12200 ** or SET DEFAULT. 12201 */ 12202 #define SQLITE_CHANGESETAPPLY_NOSAVEPOINT 0x0001 12203 #define SQLITE_CHANGESETAPPLY_INVERT 0x0002 12204 #define SQLITE_CHANGESETAPPLY_IGNORENOOP 0x0004 12205 #define SQLITE_CHANGESETAPPLY_FKNOACTION 0x0008 12206 12207 /* 12208 ** CAPI3REF: Constants Passed To The Conflict Handler 12209 ** 12210 ** Values that may be passed as the second argument to a conflict-handler. 12211 ** 12212 ** <dl> 12213 ** <dt>SQLITE_CHANGESET_DATA<dd> 12214 ** The conflict handler is invoked with CHANGESET_DATA as the second argument 12215 ** when processing a DELETE or UPDATE change if a row with the required 12216 ** PRIMARY KEY fields is present in the database, but one or more other 12217 ** (non primary-key) fields modified by the update do not contain the 12218 ** expected "before" values. 12219 ** 12220 ** The conflicting row, in this case, is the database row with the matching 12221 ** primary key. 12222 ** 12223 ** <dt>SQLITE_CHANGESET_NOTFOUND<dd> 12224 ** The conflict handler is invoked with CHANGESET_NOTFOUND as the second 12225 ** argument when processing a DELETE or UPDATE change if a row with the 12226 ** required PRIMARY KEY fields is not present in the database. 12227 ** 12228 ** There is no conflicting row in this case. The results of invoking the 12229 ** sqlite3changeset_conflict() API are undefined. 12230 ** 12231 ** <dt>SQLITE_CHANGESET_CONFLICT<dd> 12232 ** CHANGESET_CONFLICT is passed as the second argument to the conflict 12233 ** handler while processing an INSERT change if the operation would result 12234 ** in duplicate primary key values. 12235 ** 12236 ** The conflicting row in this case is the database row with the matching 12237 ** primary key. 12238 ** 12239 ** <dt>SQLITE_CHANGESET_FOREIGN_KEY<dd> 12240 ** If foreign key handling is enabled, and applying a changeset leaves the 12241 ** database in a state containing foreign key violations, the conflict 12242 ** handler is invoked with CHANGESET_FOREIGN_KEY as the second argument 12243 ** exactly once before the changeset is committed. If the conflict handler 12244 ** returns CHANGESET_OMIT, the changes, including those that caused the 12245 ** foreign key constraint violation, are committed. Or, if it returns 12246 ** CHANGESET_ABORT, the changeset is rolled back. 12247 ** 12248 ** No current or conflicting row information is provided. The only function 12249 ** it is possible to call on the supplied sqlite3_changeset_iter handle 12250 ** is sqlite3changeset_fk_conflicts(). 12251 ** 12252 ** <dt>SQLITE_CHANGESET_CONSTRAINT<dd> 12253 ** If any other constraint violation occurs while applying a change (i.e. 12254 ** a UNIQUE, CHECK or NOT NULL constraint), the conflict handler is 12255 ** invoked with CHANGESET_CONSTRAINT as the second argument. 12256 ** 12257 ** There is no conflicting row in this case. The results of invoking the 12258 ** sqlite3changeset_conflict() API are undefined. 12259 ** 12260 ** </dl> 12261 */ 12262 #define SQLITE_CHANGESET_DATA 1 12263 #define SQLITE_CHANGESET_NOTFOUND 2 12264 #define SQLITE_CHANGESET_CONFLICT 3 12265 #define SQLITE_CHANGESET_CONSTRAINT 4 12266 #define SQLITE_CHANGESET_FOREIGN_KEY 5 12267 12268 /* 12269 ** CAPI3REF: Constants Returned By The Conflict Handler 12270 ** 12271 ** A conflict handler callback must return one of the following three values. 12272 ** 12273 ** <dl> 12274 ** <dt>SQLITE_CHANGESET_OMIT<dd> 12275 ** If a conflict handler returns this value no special action is taken. The 12276 ** change that caused the conflict is not applied. The session module 12277 ** continues to the next change in the changeset. 12278 ** 12279 ** <dt>SQLITE_CHANGESET_REPLACE<dd> 12280 ** This value may only be returned if the second argument to the conflict 12281 ** handler was SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If this 12282 ** is not the case, any changes applied so far are rolled back and the 12283 ** call to sqlite3changeset_apply() returns SQLITE_MISUSE. 12284 ** 12285 ** If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_DATA conflict 12286 ** handler, then the conflicting row is either updated or deleted, depending 12287 ** on the type of change. 12288 ** 12289 ** If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_CONFLICT conflict 12290 ** handler, then the conflicting row is removed from the database and a 12291 ** second attempt to apply the change is made. If this second attempt fails, 12292 ** the original row is restored to the database before continuing. 12293 ** 12294 ** <dt>SQLITE_CHANGESET_ABORT<dd> 12295 ** If this value is returned, any changes applied so far are rolled back 12296 ** and the call to sqlite3changeset_apply() returns SQLITE_ABORT. 12297 ** </dl> 12298 */ 12299 #define SQLITE_CHANGESET_OMIT 0 12300 #define SQLITE_CHANGESET_REPLACE 1 12301 #define SQLITE_CHANGESET_ABORT 2 12302 12303 /* 12304 ** CAPI3REF: Rebasing changesets 12305 ** EXPERIMENTAL 12306 ** 12307 ** Suppose there is a site hosting a database in state S0. And that 12308 ** modifications are made that move that database to state S1 and a 12309 ** changeset recorded (the "local" changeset). Then, a changeset based 12310 ** on S0 is received from another site (the "remote" changeset) and 12311 ** applied to the database. The database is then in state 12312 ** (S1+"remote"), where the exact state depends on any conflict 12313 ** resolution decisions (OMIT or REPLACE) made while applying "remote". 12314 ** Rebasing a changeset is to update it to take those conflict 12315 ** resolution decisions into account, so that the same conflicts 12316 ** do not have to be resolved elsewhere in the network. 12317 ** 12318 ** For example, if both the local and remote changesets contain an 12319 ** INSERT of the same key on "CREATE TABLE t1(a PRIMARY KEY, b)": 12320 ** 12321 ** local: INSERT INTO t1 VALUES(1, 'v1'); 12322 ** remote: INSERT INTO t1 VALUES(1, 'v2'); 12323 ** 12324 ** and the conflict resolution is REPLACE, then the INSERT change is 12325 ** removed from the local changeset (it was overridden). Or, if the 12326 ** conflict resolution was "OMIT", then the local changeset is modified 12327 ** to instead contain: 12328 ** 12329 ** UPDATE t1 SET b = 'v2' WHERE a=1; 12330 ** 12331 ** Changes within the local changeset are rebased as follows: 12332 ** 12333 ** <dl> 12334 ** <dt>Local INSERT<dd> 12335 ** This may only conflict with a remote INSERT. If the conflict 12336 ** resolution was OMIT, then add an UPDATE change to the rebased 12337 ** changeset. Or, if the conflict resolution was REPLACE, add 12338 ** nothing to the rebased changeset. 12339 ** 12340 ** <dt>Local DELETE<dd> 12341 ** This may conflict with a remote UPDATE or DELETE. In both cases the 12342 ** only possible resolution is OMIT. If the remote operation was a 12343 ** DELETE, then add no change to the rebased changeset. If the remote 12344 ** operation was an UPDATE, then the old.* fields of change are updated 12345 ** to reflect the new.* values in the UPDATE. 12346 ** 12347 ** <dt>Local UPDATE<dd> 12348 ** This may conflict with a remote UPDATE or DELETE. If it conflicts 12349 ** with a DELETE, and the conflict resolution was OMIT, then the update 12350 ** is changed into an INSERT. Any undefined values in the new.* record 12351 ** from the update change are filled in using the old.* values from 12352 ** the conflicting DELETE. Or, if the conflict resolution was REPLACE, 12353 ** the UPDATE change is simply omitted from the rebased changeset. 12354 ** 12355 ** If conflict is with a remote UPDATE and the resolution is OMIT, then 12356 ** the old.* values are rebased using the new.* values in the remote 12357 ** change. Or, if the resolution is REPLACE, then the change is copied 12358 ** into the rebased changeset with updates to columns also updated by 12359 ** the conflicting remote UPDATE removed. If this means no columns would 12360 ** be updated, the change is omitted. 12361 ** </dl> 12362 ** 12363 ** A local change may be rebased against multiple remote changes 12364 ** simultaneously. If a single key is modified by multiple remote 12365 ** changesets, they are combined as follows before the local changeset 12366 ** is rebased: 12367 ** 12368 ** <ul> 12369 ** <li> If there has been one or more REPLACE resolutions on a 12370 ** key, it is rebased according to a REPLACE. 12371 ** 12372 ** <li> If there have been no REPLACE resolutions on a key, then 12373 ** the local changeset is rebased according to the most recent 12374 ** of the OMIT resolutions. 12375 ** </ul> 12376 ** 12377 ** Note that conflict resolutions from multiple remote changesets are 12378 ** combined on a per-field basis, not per-row. This means that in the 12379 ** case of multiple remote UPDATE operations, some fields of a single 12380 ** local change may be rebased for REPLACE while others are rebased for 12381 ** OMIT. 12382 ** 12383 ** In order to rebase a local changeset, the remote changeset must first 12384 ** be applied to the local database using sqlite3changeset_apply_v2() and 12385 ** the buffer of rebase information captured. Then: 12386 ** 12387 ** <ol> 12388 ** <li> An sqlite3_rebaser object is created by calling 12389 ** sqlite3rebaser_create(). 12390 ** <li> The new object is configured with the rebase buffer obtained from 12391 ** sqlite3changeset_apply_v2() by calling sqlite3rebaser_configure(). 12392 ** If the local changeset is to be rebased against multiple remote 12393 ** changesets, then sqlite3rebaser_configure() should be called 12394 ** multiple times, in the same order that the multiple 12395 ** sqlite3changeset_apply_v2() calls were made. 12396 ** <li> Each local changeset is rebased by calling sqlite3rebaser_rebase(). 12397 ** <li> The sqlite3_rebaser object is deleted by calling 12398 ** sqlite3rebaser_delete(). 12399 ** </ol> 12400 */ 12401 typedef struct sqlite3_rebaser sqlite3_rebaser; 12402 12403 /* 12404 ** CAPI3REF: Create a changeset rebaser object. 12405 ** EXPERIMENTAL 12406 ** 12407 ** Allocate a new changeset rebaser object. If successful, set (*ppNew) to 12408 ** point to the new object and return SQLITE_OK. Otherwise, if an error 12409 ** occurs, return an SQLite error code (e.g. SQLITE_NOMEM) and set (*ppNew) 12410 ** to NULL. 12411 */ 12412 SQLITE_API int sqlite3rebaser_create(sqlite3_rebaser **ppNew); 12413 12414 /* 12415 ** CAPI3REF: Configure a changeset rebaser object. 12416 ** EXPERIMENTAL 12417 ** 12418 ** Configure the changeset rebaser object to rebase changesets according 12419 ** to the conflict resolutions described by buffer pRebase (size nRebase 12420 ** bytes), which must have been obtained from a previous call to 12421 ** sqlite3changeset_apply_v2(). 12422 */ 12423 SQLITE_API int sqlite3rebaser_configure( 12424 sqlite3_rebaser*, 12425 int nRebase, const void *pRebase 12426 ); 12427 12428 /* 12429 ** CAPI3REF: Rebase a changeset 12430 ** EXPERIMENTAL 12431 ** 12432 ** Argument pIn must point to a buffer containing a changeset nIn bytes 12433 ** in size. This function allocates and populates a buffer with a copy 12434 ** of the changeset rebased according to the configuration of the 12435 ** rebaser object passed as the first argument. If successful, (*ppOut) 12436 ** is set to point to the new buffer containing the rebased changeset and 12437 ** (*pnOut) to its size in bytes and SQLITE_OK returned. It is the 12438 ** responsibility of the caller to eventually free the new buffer using 12439 ** sqlite3_free(). Otherwise, if an error occurs, (*ppOut) and (*pnOut) 12440 ** are set to zero and an SQLite error code returned. 12441 */ 12442 SQLITE_API int sqlite3rebaser_rebase( 12443 sqlite3_rebaser*, 12444 int nIn, const void *pIn, 12445 int *pnOut, void **ppOut 12446 ); 12447 12448 /* 12449 ** CAPI3REF: Delete a changeset rebaser object. 12450 ** EXPERIMENTAL 12451 ** 12452 ** Delete the changeset rebaser object and all associated resources. There 12453 ** should be one call to this function for each successful invocation 12454 ** of sqlite3rebaser_create(). 12455 */ 12456 SQLITE_API void sqlite3rebaser_delete(sqlite3_rebaser *p); 12457 12458 /* 12459 ** CAPI3REF: Streaming Versions of API functions. 12460 ** 12461 ** The six streaming API xxx_strm() functions serve similar purposes to the 12462 ** corresponding non-streaming API functions: 12463 ** 12464 ** <table border=1 style="margin-left:8ex;margin-right:8ex"> 12465 ** <tr><th>Streaming function<th>Non-streaming equivalent</th> 12466 ** <tr><td>sqlite3changeset_apply_strm<td>[sqlite3changeset_apply] 12467 ** <tr><td>sqlite3changeset_apply_strm_v2<td>[sqlite3changeset_apply_v2] 12468 ** <tr><td>sqlite3changeset_concat_strm<td>[sqlite3changeset_concat] 12469 ** <tr><td>sqlite3changeset_invert_strm<td>[sqlite3changeset_invert] 12470 ** <tr><td>sqlite3changeset_start_strm<td>[sqlite3changeset_start] 12471 ** <tr><td>sqlite3session_changeset_strm<td>[sqlite3session_changeset] 12472 ** <tr><td>sqlite3session_patchset_strm<td>[sqlite3session_patchset] 12473 ** </table> 12474 ** 12475 ** Non-streaming functions that accept changesets (or patchsets) as input 12476 ** require that the entire changeset be stored in a single buffer in memory. 12477 ** Similarly, those that return a changeset or patchset do so by returning 12478 ** a pointer to a single large buffer allocated using sqlite3_malloc(). 12479 ** Normally this is convenient. However, if an application running in a 12480 ** low-memory environment is required to handle very large changesets, the 12481 ** large contiguous memory allocations required can become onerous. 12482 ** 12483 ** In order to avoid this problem, instead of a single large buffer, input 12484 ** is passed to a streaming API functions by way of a callback function that 12485 ** the sessions module invokes to incrementally request input data as it is 12486 ** required. In all cases, a pair of API function parameters such as 12487 ** 12488 ** <pre> 12489 ** int nChangeset, 12490 ** void *pChangeset, 12491 ** </pre> 12492 ** 12493 ** Is replaced by: 12494 ** 12495 ** <pre> 12496 ** int (*xInput)(void *pIn, void *pData, int *pnData), 12497 ** void *pIn, 12498 ** </pre> 12499 ** 12500 ** Each time the xInput callback is invoked by the sessions module, the first 12501 ** argument passed is a copy of the supplied pIn context pointer. The second 12502 ** argument, pData, points to a buffer (*pnData) bytes in size. Assuming no 12503 ** error occurs the xInput method should copy up to (*pnData) bytes of data 12504 ** into the buffer and set (*pnData) to the actual number of bytes copied 12505 ** before returning SQLITE_OK. If the input is completely exhausted, (*pnData) 12506 ** should be set to zero to indicate this. Or, if an error occurs, an SQLite 12507 ** error code should be returned. In all cases, if an xInput callback returns 12508 ** an error, all processing is abandoned and the streaming API function 12509 ** returns a copy of the error code to the caller. 12510 ** 12511 ** In the case of sqlite3changeset_start_strm(), the xInput callback may be 12512 ** invoked by the sessions module at any point during the lifetime of the 12513 ** iterator. If such an xInput callback returns an error, the iterator enters 12514 ** an error state, whereby all subsequent calls to iterator functions 12515 ** immediately fail with the same error code as returned by xInput. 12516 ** 12517 ** Similarly, streaming API functions that return changesets (or patchsets) 12518 ** return them in chunks by way of a callback function instead of via a 12519 ** pointer to a single large buffer. In this case, a pair of parameters such 12520 ** as: 12521 ** 12522 ** <pre> 12523 ** int *pnChangeset, 12524 ** void **ppChangeset, 12525 ** </pre> 12526 ** 12527 ** Is replaced by: 12528 ** 12529 ** <pre> 12530 ** int (*xOutput)(void *pOut, const void *pData, int nData), 12531 ** void *pOut 12532 ** </pre> 12533 ** 12534 ** The xOutput callback is invoked zero or more times to return data to 12535 ** the application. The first parameter passed to each call is a copy of the 12536 ** pOut pointer supplied by the application. The second parameter, pData, 12537 ** points to a buffer nData bytes in size containing the chunk of output 12538 ** data being returned. If the xOutput callback successfully processes the 12539 ** supplied data, it should return SQLITE_OK to indicate success. Otherwise, 12540 ** it should return some other SQLite error code. In this case processing 12541 ** is immediately abandoned and the streaming API function returns a copy 12542 ** of the xOutput error code to the application. 12543 ** 12544 ** The sessions module never invokes an xOutput callback with the third 12545 ** parameter set to a value less than or equal to zero. Other than this, 12546 ** no guarantees are made as to the size of the chunks of data returned. 12547 */ 12548 SQLITE_API int sqlite3changeset_apply_strm( 12549 sqlite3 *db, /* Apply change to "main" db of this handle */ 12550 int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */ 12551 void *pIn, /* First arg for xInput */ 12552 int(*xFilter)( 12553 void *pCtx, /* Copy of sixth arg to _apply() */ 12554 const char *zTab /* Table name */ 12555 ), 12556 int(*xConflict)( 12557 void *pCtx, /* Copy of sixth arg to _apply() */ 12558 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */ 12559 sqlite3_changeset_iter *p /* Handle describing change and conflict */ 12560 ), 12561 void *pCtx /* First argument passed to xConflict */ 12562 ); 12563 SQLITE_API int sqlite3changeset_apply_v2_strm( 12564 sqlite3 *db, /* Apply change to "main" db of this handle */ 12565 int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */ 12566 void *pIn, /* First arg for xInput */ 12567 int(*xFilter)( 12568 void *pCtx, /* Copy of sixth arg to _apply() */ 12569 const char *zTab /* Table name */ 12570 ), 12571 int(*xConflict)( 12572 void *pCtx, /* Copy of sixth arg to _apply() */ 12573 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */ 12574 sqlite3_changeset_iter *p /* Handle describing change and conflict */ 12575 ), 12576 void *pCtx, /* First argument passed to xConflict */ 12577 void **ppRebase, int *pnRebase, 12578 int flags 12579 ); 12580 SQLITE_API int sqlite3changeset_concat_strm( 12581 int (*xInputA)(void *pIn, void *pData, int *pnData), 12582 void *pInA, 12583 int (*xInputB)(void *pIn, void *pData, int *pnData), 12584 void *pInB, 12585 int (*xOutput)(void *pOut, const void *pData, int nData), 12586 void *pOut 12587 ); 12588 SQLITE_API int sqlite3changeset_invert_strm( 12589 int (*xInput)(void *pIn, void *pData, int *pnData), 12590 void *pIn, 12591 int (*xOutput)(void *pOut, const void *pData, int nData), 12592 void *pOut 12593 ); 12594 SQLITE_API int sqlite3changeset_start_strm( 12595 sqlite3_changeset_iter **pp, 12596 int (*xInput)(void *pIn, void *pData, int *pnData), 12597 void *pIn 12598 ); 12599 SQLITE_API int sqlite3changeset_start_v2_strm( 12600 sqlite3_changeset_iter **pp, 12601 int (*xInput)(void *pIn, void *pData, int *pnData), 12602 void *pIn, 12603 int flags 12604 ); 12605 SQLITE_API int sqlite3session_changeset_strm( 12606 sqlite3_session *pSession, 12607 int (*xOutput)(void *pOut, const void *pData, int nData), 12608 void *pOut 12609 ); 12610 SQLITE_API int sqlite3session_patchset_strm( 12611 sqlite3_session *pSession, 12612 int (*xOutput)(void *pOut, const void *pData, int nData), 12613 void *pOut 12614 ); 12615 SQLITE_API int sqlite3changegroup_add_strm(sqlite3_changegroup*, 12616 int (*xInput)(void *pIn, void *pData, int *pnData), 12617 void *pIn 12618 ); 12619 SQLITE_API int sqlite3changegroup_output_strm(sqlite3_changegroup*, 12620 int (*xOutput)(void *pOut, const void *pData, int nData), 12621 void *pOut 12622 ); 12623 SQLITE_API int sqlite3rebaser_rebase_strm( 12624 sqlite3_rebaser *pRebaser, 12625 int (*xInput)(void *pIn, void *pData, int *pnData), 12626 void *pIn, 12627 int (*xOutput)(void *pOut, const void *pData, int nData), 12628 void *pOut 12629 ); 12630 12631 /* 12632 ** CAPI3REF: Configure global parameters 12633 ** 12634 ** The sqlite3session_config() interface is used to make global configuration 12635 ** changes to the sessions module in order to tune it to the specific needs 12636 ** of the application. 12637 ** 12638 ** The sqlite3session_config() interface is not threadsafe. If it is invoked 12639 ** while any other thread is inside any other sessions method then the 12640 ** results are undefined. Furthermore, if it is invoked after any sessions 12641 ** related objects have been created, the results are also undefined. 12642 ** 12643 ** The first argument to the sqlite3session_config() function must be one 12644 ** of the SQLITE_SESSION_CONFIG_XXX constants defined below. The 12645 ** interpretation of the (void*) value passed as the second parameter and 12646 ** the effect of calling this function depends on the value of the first 12647 ** parameter. 12648 ** 12649 ** <dl> 12650 ** <dt>SQLITE_SESSION_CONFIG_STRMSIZE<dd> 12651 ** By default, the sessions module streaming interfaces attempt to input 12652 ** and output data in approximately 1 KiB chunks. This operand may be used 12653 ** to set and query the value of this configuration setting. The pointer 12654 ** passed as the second argument must point to a value of type (int). 12655 ** If this value is greater than 0, it is used as the new streaming data 12656 ** chunk size for both input and output. Before returning, the (int) value 12657 ** pointed to by pArg is set to the final value of the streaming interface 12658 ** chunk size. 12659 ** </dl> 12660 ** 12661 ** This function returns SQLITE_OK if successful, or an SQLite error code 12662 ** otherwise. 12663 */ 12664 SQLITE_API int sqlite3session_config(int op, void *pArg); 12665 12666 /* 12667 ** CAPI3REF: Values for sqlite3session_config(). 12668 */ 12669 #define SQLITE_SESSION_CONFIG_STRMSIZE 1 12670 12671 /* 12672 ** Make sure we can call this stuff from C++. 12673 */ 12674 #ifdef __cplusplus 12675 } 12676 #endif 12677 12678 #endif /* !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION) */ 12679 12680 /******** End of sqlite3session.h *********/ 12681 /******** Begin file fts5.h *********/ 12682 /* 12683 ** 2014 May 31 12684 ** 12685 ** The author disclaims copyright to this source code. In place of 12686 ** a legal notice, here is a blessing: 12687 ** 12688 ** May you do good and not evil. 12689 ** May you find forgiveness for yourself and forgive others. 12690 ** May you share freely, never taking more than you give. 12691 ** 12692 ****************************************************************************** 12693 ** 12694 ** Interfaces to extend FTS5. Using the interfaces defined in this file, 12695 ** FTS5 may be extended with: 12696 ** 12697 ** * custom tokenizers, and 12698 ** * custom auxiliary functions. 12699 */ 12700 12701 12702 #ifndef _FTS5_H 12703 #define _FTS5_H 12704 12705 12706 #ifdef __cplusplus 12707 extern "C" { 12708 #endif 12709 12710 /************************************************************************* 12711 ** CUSTOM AUXILIARY FUNCTIONS 12712 ** 12713 ** Virtual table implementations may overload SQL functions by implementing 12714 ** the sqlite3_module.xFindFunction() method. 12715 */ 12716 12717 typedef struct Fts5ExtensionApi Fts5ExtensionApi; 12718 typedef struct Fts5Context Fts5Context; 12719 typedef struct Fts5PhraseIter Fts5PhraseIter; 12720 12721 typedef void (*fts5_extension_function)( 12722 const Fts5ExtensionApi *pApi, /* API offered by current FTS version */ 12723 Fts5Context *pFts, /* First arg to pass to pApi functions */ 12724 sqlite3_context *pCtx, /* Context for returning result/error */ 12725 int nVal, /* Number of values in apVal[] array */ 12726 sqlite3_value **apVal /* Array of trailing arguments */ 12727 ); 12728 12729 struct Fts5PhraseIter { 12730 const unsigned char *a; 12731 const unsigned char *b; 12732 }; 12733 12734 /* 12735 ** EXTENSION API FUNCTIONS 12736 ** 12737 ** xUserData(pFts): 12738 ** Return a copy of the context pointer the extension function was 12739 ** registered with. 12740 ** 12741 ** xColumnTotalSize(pFts, iCol, pnToken): 12742 ** If parameter iCol is less than zero, set output variable *pnToken 12743 ** to the total number of tokens in the FTS5 table. Or, if iCol is 12744 ** non-negative but less than the number of columns in the table, return 12745 ** the total number of tokens in column iCol, considering all rows in 12746 ** the FTS5 table. 12747 ** 12748 ** If parameter iCol is greater than or equal to the number of columns 12749 ** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g. 12750 ** an OOM condition or IO error), an appropriate SQLite error code is 12751 ** returned. 12752 ** 12753 ** xColumnCount(pFts): 12754 ** Return the number of columns in the table. 12755 ** 12756 ** xColumnSize(pFts, iCol, pnToken): 12757 ** If parameter iCol is less than zero, set output variable *pnToken 12758 ** to the total number of tokens in the current row. Or, if iCol is 12759 ** non-negative but less than the number of columns in the table, set 12760 ** *pnToken to the number of tokens in column iCol of the current row. 12761 ** 12762 ** If parameter iCol is greater than or equal to the number of columns 12763 ** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g. 12764 ** an OOM condition or IO error), an appropriate SQLite error code is 12765 ** returned. 12766 ** 12767 ** This function may be quite inefficient if used with an FTS5 table 12768 ** created with the "columnsize=0" option. 12769 ** 12770 ** xColumnText: 12771 ** This function attempts to retrieve the text of column iCol of the 12772 ** current document. If successful, (*pz) is set to point to a buffer 12773 ** containing the text in utf-8 encoding, (*pn) is set to the size in bytes 12774 ** (not characters) of the buffer and SQLITE_OK is returned. Otherwise, 12775 ** if an error occurs, an SQLite error code is returned and the final values 12776 ** of (*pz) and (*pn) are undefined. 12777 ** 12778 ** xPhraseCount: 12779 ** Returns the number of phrases in the current query expression. 12780 ** 12781 ** xPhraseSize: 12782 ** Returns the number of tokens in phrase iPhrase of the query. Phrases 12783 ** are numbered starting from zero. 12784 ** 12785 ** xInstCount: 12786 ** Set *pnInst to the total number of occurrences of all phrases within 12787 ** the query within the current row. Return SQLITE_OK if successful, or 12788 ** an error code (i.e. SQLITE_NOMEM) if an error occurs. 12789 ** 12790 ** This API can be quite slow if used with an FTS5 table created with the 12791 ** "detail=none" or "detail=column" option. If the FTS5 table is created 12792 ** with either "detail=none" or "detail=column" and "content=" option 12793 ** (i.e. if it is a contentless table), then this API always returns 0. 12794 ** 12795 ** xInst: 12796 ** Query for the details of phrase match iIdx within the current row. 12797 ** Phrase matches are numbered starting from zero, so the iIdx argument 12798 ** should be greater than or equal to zero and smaller than the value 12799 ** output by xInstCount(). 12800 ** 12801 ** Usually, output parameter *piPhrase is set to the phrase number, *piCol 12802 ** to the column in which it occurs and *piOff the token offset of the 12803 ** first token of the phrase. Returns SQLITE_OK if successful, or an error 12804 ** code (i.e. SQLITE_NOMEM) if an error occurs. 12805 ** 12806 ** This API can be quite slow if used with an FTS5 table created with the 12807 ** "detail=none" or "detail=column" option. 12808 ** 12809 ** xRowid: 12810 ** Returns the rowid of the current row. 12811 ** 12812 ** xTokenize: 12813 ** Tokenize text using the tokenizer belonging to the FTS5 table. 12814 ** 12815 ** xQueryPhrase(pFts5, iPhrase, pUserData, xCallback): 12816 ** This API function is used to query the FTS table for phrase iPhrase 12817 ** of the current query. Specifically, a query equivalent to: 12818 ** 12819 ** ... FROM ftstable WHERE ftstable MATCH $p ORDER BY rowid 12820 ** 12821 ** with $p set to a phrase equivalent to the phrase iPhrase of the 12822 ** current query is executed. Any column filter that applies to 12823 ** phrase iPhrase of the current query is included in $p. For each 12824 ** row visited, the callback function passed as the fourth argument 12825 ** is invoked. The context and API objects passed to the callback 12826 ** function may be used to access the properties of each matched row. 12827 ** Invoking Api.xUserData() returns a copy of the pointer passed as 12828 ** the third argument to pUserData. 12829 ** 12830 ** If the callback function returns any value other than SQLITE_OK, the 12831 ** query is abandoned and the xQueryPhrase function returns immediately. 12832 ** If the returned value is SQLITE_DONE, xQueryPhrase returns SQLITE_OK. 12833 ** Otherwise, the error code is propagated upwards. 12834 ** 12835 ** If the query runs to completion without incident, SQLITE_OK is returned. 12836 ** Or, if some error occurs before the query completes or is aborted by 12837 ** the callback, an SQLite error code is returned. 12838 ** 12839 ** 12840 ** xSetAuxdata(pFts5, pAux, xDelete) 12841 ** 12842 ** Save the pointer passed as the second argument as the extension function's 12843 ** "auxiliary data". The pointer may then be retrieved by the current or any 12844 ** future invocation of the same fts5 extension function made as part of 12845 ** the same MATCH query using the xGetAuxdata() API. 12846 ** 12847 ** Each extension function is allocated a single auxiliary data slot for 12848 ** each FTS query (MATCH expression). If the extension function is invoked 12849 ** more than once for a single FTS query, then all invocations share a 12850 ** single auxiliary data context. 12851 ** 12852 ** If there is already an auxiliary data pointer when this function is 12853 ** invoked, then it is replaced by the new pointer. If an xDelete callback 12854 ** was specified along with the original pointer, it is invoked at this 12855 ** point. 12856 ** 12857 ** The xDelete callback, if one is specified, is also invoked on the 12858 ** auxiliary data pointer after the FTS5 query has finished. 12859 ** 12860 ** If an error (e.g. an OOM condition) occurs within this function, 12861 ** the auxiliary data is set to NULL and an error code returned. If the 12862 ** xDelete parameter was not NULL, it is invoked on the auxiliary data 12863 ** pointer before returning. 12864 ** 12865 ** 12866 ** xGetAuxdata(pFts5, bClear) 12867 ** 12868 ** Returns the current auxiliary data pointer for the fts5 extension 12869 ** function. See the xSetAuxdata() method for details. 12870 ** 12871 ** If the bClear argument is non-zero, then the auxiliary data is cleared 12872 ** (set to NULL) before this function returns. In this case the xDelete, 12873 ** if any, is not invoked. 12874 ** 12875 ** 12876 ** xRowCount(pFts5, pnRow) 12877 ** 12878 ** This function is used to retrieve the total number of rows in the table. 12879 ** In other words, the same value that would be returned by: 12880 ** 12881 ** SELECT count(*) FROM ftstable; 12882 ** 12883 ** xPhraseFirst() 12884 ** This function is used, along with type Fts5PhraseIter and the xPhraseNext 12885 ** method, to iterate through all instances of a single query phrase within 12886 ** the current row. This is the same information as is accessible via the 12887 ** xInstCount/xInst APIs. While the xInstCount/xInst APIs are more convenient 12888 ** to use, this API may be faster under some circumstances. To iterate 12889 ** through instances of phrase iPhrase, use the following code: 12890 ** 12891 ** Fts5PhraseIter iter; 12892 ** int iCol, iOff; 12893 ** for(pApi->xPhraseFirst(pFts, iPhrase, &iter, &iCol, &iOff); 12894 ** iCol>=0; 12895 ** pApi->xPhraseNext(pFts, &iter, &iCol, &iOff) 12896 ** ){ 12897 ** // An instance of phrase iPhrase at offset iOff of column iCol 12898 ** } 12899 ** 12900 ** The Fts5PhraseIter structure is defined above. Applications should not 12901 ** modify this structure directly - it should only be used as shown above 12902 ** with the xPhraseFirst() and xPhraseNext() API methods (and by 12903 ** xPhraseFirstColumn() and xPhraseNextColumn() as illustrated below). 12904 ** 12905 ** This API can be quite slow if used with an FTS5 table created with the 12906 ** "detail=none" or "detail=column" option. If the FTS5 table is created 12907 ** with either "detail=none" or "detail=column" and "content=" option 12908 ** (i.e. if it is a contentless table), then this API always iterates 12909 ** through an empty set (all calls to xPhraseFirst() set iCol to -1). 12910 ** 12911 ** xPhraseNext() 12912 ** See xPhraseFirst above. 12913 ** 12914 ** xPhraseFirstColumn() 12915 ** This function and xPhraseNextColumn() are similar to the xPhraseFirst() 12916 ** and xPhraseNext() APIs described above. The difference is that instead 12917 ** of iterating through all instances of a phrase in the current row, these 12918 ** APIs are used to iterate through the set of columns in the current row 12919 ** that contain one or more instances of a specified phrase. For example: 12920 ** 12921 ** Fts5PhraseIter iter; 12922 ** int iCol; 12923 ** for(pApi->xPhraseFirstColumn(pFts, iPhrase, &iter, &iCol); 12924 ** iCol>=0; 12925 ** pApi->xPhraseNextColumn(pFts, &iter, &iCol) 12926 ** ){ 12927 ** // Column iCol contains at least one instance of phrase iPhrase 12928 ** } 12929 ** 12930 ** This API can be quite slow if used with an FTS5 table created with the 12931 ** "detail=none" option. If the FTS5 table is created with either 12932 ** "detail=none" "content=" option (i.e. if it is a contentless table), 12933 ** then this API always iterates through an empty set (all calls to 12934 ** xPhraseFirstColumn() set iCol to -1). 12935 ** 12936 ** The information accessed using this API and its companion 12937 ** xPhraseFirstColumn() may also be obtained using xPhraseFirst/xPhraseNext 12938 ** (or xInst/xInstCount). The chief advantage of this API is that it is 12939 ** significantly more efficient than those alternatives when used with 12940 ** "detail=column" tables. 12941 ** 12942 ** xPhraseNextColumn() 12943 ** See xPhraseFirstColumn above. 12944 */ 12945 struct Fts5ExtensionApi { 12946 int iVersion; /* Currently always set to 2 */ 12947 12948 void *(*xUserData)(Fts5Context*); 12949 12950 int (*xColumnCount)(Fts5Context*); 12951 int (*xRowCount)(Fts5Context*, sqlite3_int64 *pnRow); 12952 int (*xColumnTotalSize)(Fts5Context*, int iCol, sqlite3_int64 *pnToken); 12953 12954 int (*xTokenize)(Fts5Context*, 12955 const char *pText, int nText, /* Text to tokenize */ 12956 void *pCtx, /* Context passed to xToken() */ 12957 int (*xToken)(void*, int, const char*, int, int, int) /* Callback */ 12958 ); 12959 12960 int (*xPhraseCount)(Fts5Context*); 12961 int (*xPhraseSize)(Fts5Context*, int iPhrase); 12962 12963 int (*xInstCount)(Fts5Context*, int *pnInst); 12964 int (*xInst)(Fts5Context*, int iIdx, int *piPhrase, int *piCol, int *piOff); 12965 12966 sqlite3_int64 (*xRowid)(Fts5Context*); 12967 int (*xColumnText)(Fts5Context*, int iCol, const char **pz, int *pn); 12968 int (*xColumnSize)(Fts5Context*, int iCol, int *pnToken); 12969 12970 int (*xQueryPhrase)(Fts5Context*, int iPhrase, void *pUserData, 12971 int(*)(const Fts5ExtensionApi*,Fts5Context*,void*) 12972 ); 12973 int (*xSetAuxdata)(Fts5Context*, void *pAux, void(*xDelete)(void*)); 12974 void *(*xGetAuxdata)(Fts5Context*, int bClear); 12975 12976 int (*xPhraseFirst)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*, int*); 12977 void (*xPhraseNext)(Fts5Context*, Fts5PhraseIter*, int *piCol, int *piOff); 12978 12979 int (*xPhraseFirstColumn)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*); 12980 void (*xPhraseNextColumn)(Fts5Context*, Fts5PhraseIter*, int *piCol); 12981 }; 12982 12983 /* 12984 ** CUSTOM AUXILIARY FUNCTIONS 12985 *************************************************************************/ 12986 12987 /************************************************************************* 12988 ** CUSTOM TOKENIZERS 12989 ** 12990 ** Applications may also register custom tokenizer types. A tokenizer 12991 ** is registered by providing fts5 with a populated instance of the 12992 ** following structure. All structure methods must be defined, setting 12993 ** any member of the fts5_tokenizer struct to NULL leads to undefined 12994 ** behaviour. The structure methods are expected to function as follows: 12995 ** 12996 ** xCreate: 12997 ** This function is used to allocate and initialize a tokenizer instance. 12998 ** A tokenizer instance is required to actually tokenize text. 12999 ** 13000 ** The first argument passed to this function is a copy of the (void*) 13001 ** pointer provided by the application when the fts5_tokenizer object 13002 ** was registered with FTS5 (the third argument to xCreateTokenizer()). 13003 ** The second and third arguments are an array of nul-terminated strings 13004 ** containing the tokenizer arguments, if any, specified following the 13005 ** tokenizer name as part of the CREATE VIRTUAL TABLE statement used 13006 ** to create the FTS5 table. 13007 ** 13008 ** The final argument is an output variable. If successful, (*ppOut) 13009 ** should be set to point to the new tokenizer handle and SQLITE_OK 13010 ** returned. If an error occurs, some value other than SQLITE_OK should 13011 ** be returned. In this case, fts5 assumes that the final value of *ppOut 13012 ** is undefined. 13013 ** 13014 ** xDelete: 13015 ** This function is invoked to delete a tokenizer handle previously 13016 ** allocated using xCreate(). Fts5 guarantees that this function will 13017 ** be invoked exactly once for each successful call to xCreate(). 13018 ** 13019 ** xTokenize: 13020 ** This function is expected to tokenize the nText byte string indicated 13021 ** by argument pText. pText may or may not be nul-terminated. The first 13022 ** argument passed to this function is a pointer to an Fts5Tokenizer object 13023 ** returned by an earlier call to xCreate(). 13024 ** 13025 ** The second argument indicates the reason that FTS5 is requesting 13026 ** tokenization of the supplied text. This is always one of the following 13027 ** four values: 13028 ** 13029 ** <ul><li> <b>FTS5_TOKENIZE_DOCUMENT</b> - A document is being inserted into 13030 ** or removed from the FTS table. The tokenizer is being invoked to 13031 ** determine the set of tokens to add to (or delete from) the 13032 ** FTS index. 13033 ** 13034 ** <li> <b>FTS5_TOKENIZE_QUERY</b> - A MATCH query is being executed 13035 ** against the FTS index. The tokenizer is being called to tokenize 13036 ** a bareword or quoted string specified as part of the query. 13037 ** 13038 ** <li> <b>(FTS5_TOKENIZE_QUERY | FTS5_TOKENIZE_PREFIX)</b> - Same as 13039 ** FTS5_TOKENIZE_QUERY, except that the bareword or quoted string is 13040 ** followed by a "*" character, indicating that the last token 13041 ** returned by the tokenizer will be treated as a token prefix. 13042 ** 13043 ** <li> <b>FTS5_TOKENIZE_AUX</b> - The tokenizer is being invoked to 13044 ** satisfy an fts5_api.xTokenize() request made by an auxiliary 13045 ** function. Or an fts5_api.xColumnSize() request made by the same 13046 ** on a columnsize=0 database. 13047 ** </ul> 13048 ** 13049 ** For each token in the input string, the supplied callback xToken() must 13050 ** be invoked. The first argument to it should be a copy of the pointer 13051 ** passed as the second argument to xTokenize(). The third and fourth 13052 ** arguments are a pointer to a buffer containing the token text, and the 13053 ** size of the token in bytes. The 4th and 5th arguments are the byte offsets 13054 ** of the first byte of and first byte immediately following the text from 13055 ** which the token is derived within the input. 13056 ** 13057 ** The second argument passed to the xToken() callback ("tflags") should 13058 ** normally be set to 0. The exception is if the tokenizer supports 13059 ** synonyms. In this case see the discussion below for details. 13060 ** 13061 ** FTS5 assumes the xToken() callback is invoked for each token in the 13062 ** order that they occur within the input text. 13063 ** 13064 ** If an xToken() callback returns any value other than SQLITE_OK, then 13065 ** the tokenization should be abandoned and the xTokenize() method should 13066 ** immediately return a copy of the xToken() return value. Or, if the 13067 ** input buffer is exhausted, xTokenize() should return SQLITE_OK. Finally, 13068 ** if an error occurs with the xTokenize() implementation itself, it 13069 ** may abandon the tokenization and return any error code other than 13070 ** SQLITE_OK or SQLITE_DONE. 13071 ** 13072 ** SYNONYM SUPPORT 13073 ** 13074 ** Custom tokenizers may also support synonyms. Consider a case in which a 13075 ** user wishes to query for a phrase such as "first place". Using the 13076 ** built-in tokenizers, the FTS5 query 'first + place' will match instances 13077 ** of "first place" within the document set, but not alternative forms 13078 ** such as "1st place". In some applications, it would be better to match 13079 ** all instances of "first place" or "1st place" regardless of which form 13080 ** the user specified in the MATCH query text. 13081 ** 13082 ** There are several ways to approach this in FTS5: 13083 ** 13084 ** <ol><li> By mapping all synonyms to a single token. In this case, using 13085 ** the above example, this means that the tokenizer returns the 13086 ** same token for inputs "first" and "1st". Say that token is in 13087 ** fact "first", so that when the user inserts the document "I won 13088 ** 1st place" entries are added to the index for tokens "i", "won", 13089 ** "first" and "place". If the user then queries for '1st + place', 13090 ** the tokenizer substitutes "first" for "1st" and the query works 13091 ** as expected. 13092 ** 13093 ** <li> By querying the index for all synonyms of each query term 13094 ** separately. In this case, when tokenizing query text, the 13095 ** tokenizer may provide multiple synonyms for a single term 13096 ** within the document. FTS5 then queries the index for each 13097 ** synonym individually. For example, faced with the query: 13098 ** 13099 ** <codeblock> 13100 ** ... MATCH 'first place'</codeblock> 13101 ** 13102 ** the tokenizer offers both "1st" and "first" as synonyms for the 13103 ** first token in the MATCH query and FTS5 effectively runs a query 13104 ** similar to: 13105 ** 13106 ** <codeblock> 13107 ** ... MATCH '(first OR 1st) place'</codeblock> 13108 ** 13109 ** except that, for the purposes of auxiliary functions, the query 13110 ** still appears to contain just two phrases - "(first OR 1st)" 13111 ** being treated as a single phrase. 13112 ** 13113 ** <li> By adding multiple synonyms for a single term to the FTS index. 13114 ** Using this method, when tokenizing document text, the tokenizer 13115 ** provides multiple synonyms for each token. So that when a 13116 ** document such as "I won first place" is tokenized, entries are 13117 ** added to the FTS index for "i", "won", "first", "1st" and 13118 ** "place". 13119 ** 13120 ** This way, even if the tokenizer does not provide synonyms 13121 ** when tokenizing query text (it should not - to do so would be 13122 ** inefficient), it doesn't matter if the user queries for 13123 ** 'first + place' or '1st + place', as there are entries in the 13124 ** FTS index corresponding to both forms of the first token. 13125 ** </ol> 13126 ** 13127 ** Whether it is parsing document or query text, any call to xToken that 13128 ** specifies a <i>tflags</i> argument with the FTS5_TOKEN_COLOCATED bit 13129 ** is considered to supply a synonym for the previous token. For example, 13130 ** when parsing the document "I won first place", a tokenizer that supports 13131 ** synonyms would call xToken() 5 times, as follows: 13132 ** 13133 ** <codeblock> 13134 ** xToken(pCtx, 0, "i", 1, 0, 1); 13135 ** xToken(pCtx, 0, "won", 3, 2, 5); 13136 ** xToken(pCtx, 0, "first", 5, 6, 11); 13137 ** xToken(pCtx, FTS5_TOKEN_COLOCATED, "1st", 3, 6, 11); 13138 ** xToken(pCtx, 0, "place", 5, 12, 17); 13139 **</codeblock> 13140 ** 13141 ** It is an error to specify the FTS5_TOKEN_COLOCATED flag the first time 13142 ** xToken() is called. Multiple synonyms may be specified for a single token 13143 ** by making multiple calls to xToken(FTS5_TOKEN_COLOCATED) in sequence. 13144 ** There is no limit to the number of synonyms that may be provided for a 13145 ** single token. 13146 ** 13147 ** In many cases, method (1) above is the best approach. It does not add 13148 ** extra data to the FTS index or require FTS5 to query for multiple terms, 13149 ** so it is efficient in terms of disk space and query speed. However, it 13150 ** does not support prefix queries very well. If, as suggested above, the 13151 ** token "first" is substituted for "1st" by the tokenizer, then the query: 13152 ** 13153 ** <codeblock> 13154 ** ... MATCH '1s*'</codeblock> 13155 ** 13156 ** will not match documents that contain the token "1st" (as the tokenizer 13157 ** will probably not map "1s" to any prefix of "first"). 13158 ** 13159 ** For full prefix support, method (3) may be preferred. In this case, 13160 ** because the index contains entries for both "first" and "1st", prefix 13161 ** queries such as 'fi*' or '1s*' will match correctly. However, because 13162 ** extra entries are added to the FTS index, this method uses more space 13163 ** within the database. 13164 ** 13165 ** Method (2) offers a midpoint between (1) and (3). Using this method, 13166 ** a query such as '1s*' will match documents that contain the literal 13167 ** token "1st", but not "first" (assuming the tokenizer is not able to 13168 ** provide synonyms for prefixes). However, a non-prefix query like '1st' 13169 ** will match against "1st" and "first". This method does not require 13170 ** extra disk space, as no extra entries are added to the FTS index. 13171 ** On the other hand, it may require more CPU cycles to run MATCH queries, 13172 ** as separate queries of the FTS index are required for each synonym. 13173 ** 13174 ** When using methods (2) or (3), it is important that the tokenizer only 13175 ** provide synonyms when tokenizing document text (method (3)) or query 13176 ** text (method (2)), not both. Doing so will not cause any errors, but is 13177 ** inefficient. 13178 */ 13179 typedef struct Fts5Tokenizer Fts5Tokenizer; 13180 typedef struct fts5_tokenizer fts5_tokenizer; 13181 struct fts5_tokenizer { 13182 int (*xCreate)(void*, const char **azArg, int nArg, Fts5Tokenizer **ppOut); 13183 void (*xDelete)(Fts5Tokenizer*); 13184 int (*xTokenize)(Fts5Tokenizer*, 13185 void *pCtx, 13186 int flags, /* Mask of FTS5_TOKENIZE_* flags */ 13187 const char *pText, int nText, 13188 int (*xToken)( 13189 void *pCtx, /* Copy of 2nd argument to xTokenize() */ 13190 int tflags, /* Mask of FTS5_TOKEN_* flags */ 13191 const char *pToken, /* Pointer to buffer containing token */ 13192 int nToken, /* Size of token in bytes */ 13193 int iStart, /* Byte offset of token within input text */ 13194 int iEnd /* Byte offset of end of token within input text */ 13195 ) 13196 ); 13197 }; 13198 13199 /* Flags that may be passed as the third argument to xTokenize() */ 13200 #define FTS5_TOKENIZE_QUERY 0x0001 13201 #define FTS5_TOKENIZE_PREFIX 0x0002 13202 #define FTS5_TOKENIZE_DOCUMENT 0x0004 13203 #define FTS5_TOKENIZE_AUX 0x0008 13204 13205 /* Flags that may be passed by the tokenizer implementation back to FTS5 13206 ** as the third argument to the supplied xToken callback. */ 13207 #define FTS5_TOKEN_COLOCATED 0x0001 /* Same position as prev. token */ 13208 13209 /* 13210 ** END OF CUSTOM TOKENIZERS 13211 *************************************************************************/ 13212 13213 /************************************************************************* 13214 ** FTS5 EXTENSION REGISTRATION API 13215 */ 13216 typedef struct fts5_api fts5_api; 13217 struct fts5_api { 13218 int iVersion; /* Currently always set to 2 */ 13219 13220 /* Create a new tokenizer */ 13221 int (*xCreateTokenizer)( 13222 fts5_api *pApi, 13223 const char *zName, 13224 void *pUserData, 13225 fts5_tokenizer *pTokenizer, 13226 void (*xDestroy)(void*) 13227 ); 13228 13229 /* Find an existing tokenizer */ 13230 int (*xFindTokenizer)( 13231 fts5_api *pApi, 13232 const char *zName, 13233 void **ppUserData, 13234 fts5_tokenizer *pTokenizer 13235 ); 13236 13237 /* Create a new auxiliary function */ 13238 int (*xCreateFunction)( 13239 fts5_api *pApi, 13240 const char *zName, 13241 void *pUserData, 13242 fts5_extension_function xFunction, 13243 void (*xDestroy)(void*) 13244 ); 13245 }; 13246 13247 /* 13248 ** END OF REGISTRATION API 13249 *************************************************************************/ 13250 13251 #ifdef __cplusplus 13252 } /* end of the 'extern "C"' block */ 13253 #endif 13254 13255 #endif /* _FTS5_H */ 13256 13257 /******** End of fts5.h *********/ 13258