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 ** Provide the ability to override linkage features of the interface. 47 */ 48 #ifndef SQLITE_EXTERN 49 # define SQLITE_EXTERN extern 50 #endif 51 #ifndef SQLITE_API 52 # define SQLITE_API 53 #endif 54 #ifndef SQLITE_CDECL 55 # define SQLITE_CDECL 56 #endif 57 #ifndef SQLITE_APICALL 58 # define SQLITE_APICALL 59 #endif 60 #ifndef SQLITE_STDCALL 61 # define SQLITE_STDCALL SQLITE_APICALL 62 #endif 63 #ifndef SQLITE_CALLBACK 64 # define SQLITE_CALLBACK 65 #endif 66 #ifndef SQLITE_SYSAPI 67 # define SQLITE_SYSAPI 68 #endif 69 70 /* 71 ** These no-op macros are used in front of interfaces to mark those 72 ** interfaces as either deprecated or experimental. New applications 73 ** should not use deprecated interfaces - they are supported for backwards 74 ** compatibility only. Application writers should be aware that 75 ** experimental interfaces are subject to change in point releases. 76 ** 77 ** These macros used to resolve to various kinds of compiler magic that 78 ** would generate warning messages when they were used. But that 79 ** compiler magic ended up generating such a flurry of bug reports 80 ** that we have taken it all out and gone back to using simple 81 ** noop macros. 82 */ 83 #define SQLITE_DEPRECATED 84 #define SQLITE_EXPERIMENTAL 85 86 /* 87 ** Ensure these symbols were not defined by some previous header file. 88 */ 89 #ifdef SQLITE_VERSION 90 # undef SQLITE_VERSION 91 #endif 92 #ifdef SQLITE_VERSION_NUMBER 93 # undef SQLITE_VERSION_NUMBER 94 #endif 95 96 /* 97 ** CAPI3REF: Compile-Time Library Version Numbers 98 ** 99 ** ^(The [SQLITE_VERSION] C preprocessor macro in the sqlite3.h header 100 ** evaluates to a string literal that is the SQLite version in the 101 ** format "X.Y.Z" where X is the major version number (always 3 for 102 ** SQLite3) and Y is the minor version number and Z is the release number.)^ 103 ** ^(The [SQLITE_VERSION_NUMBER] C preprocessor macro resolves to an integer 104 ** with the value (X*1000000 + Y*1000 + Z) where X, Y, and Z are the same 105 ** numbers used in [SQLITE_VERSION].)^ 106 ** The SQLITE_VERSION_NUMBER for any given release of SQLite will also 107 ** be larger than the release from which it is derived. Either Y will 108 ** be held constant and Z will be incremented or else Y will be incremented 109 ** and Z will be reset to zero. 110 ** 111 ** Since [version 3.6.18] ([dateof:3.6.18]), 112 ** SQLite source code has been stored in the 113 ** <a href="http://www.fossil-scm.org/">Fossil configuration management 114 ** system</a>. ^The SQLITE_SOURCE_ID macro evaluates to 115 ** a string which identifies a particular check-in of SQLite 116 ** within its configuration management system. ^The SQLITE_SOURCE_ID 117 ** string contains the date and time of the check-in (UTC) and a SHA1 118 ** or SHA3-256 hash of the entire source tree. If the source code has 119 ** been edited in any way since it was last checked in, then the last 120 ** four hexadecimal digits of the hash may be modified. 121 ** 122 ** See also: [sqlite3_libversion()], 123 ** [sqlite3_libversion_number()], [sqlite3_sourceid()], 124 ** [sqlite_version()] and [sqlite_source_id()]. 125 */ 126 #define SQLITE_VERSION "3.33.0" 127 #define SQLITE_VERSION_NUMBER 3033000 128 #define SQLITE_SOURCE_ID "2020-08-14 13:23:32 fca8dc8b578f215a969cd899336378966156154710873e68b3d9ac5881b0ff3f" 129 130 /* 131 ** CAPI3REF: Run-Time Library Version Numbers 132 ** KEYWORDS: sqlite3_version sqlite3_sourceid 133 ** 134 ** These interfaces provide the same information as the [SQLITE_VERSION], 135 ** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros 136 ** but are associated with the library instead of the header file. ^(Cautious 137 ** programmers might include assert() statements in their application to 138 ** verify that values returned by these interfaces match the macros in 139 ** the header, and thus ensure that the application is 140 ** compiled with matching library and header files. 141 ** 142 ** <blockquote><pre> 143 ** assert( sqlite3_libversion_number()==SQLITE_VERSION_NUMBER ); 144 ** assert( strncmp(sqlite3_sourceid(),SQLITE_SOURCE_ID,80)==0 ); 145 ** assert( strcmp(sqlite3_libversion(),SQLITE_VERSION)==0 ); 146 ** </pre></blockquote>)^ 147 ** 148 ** ^The sqlite3_version[] string constant contains the text of [SQLITE_VERSION] 149 ** macro. ^The sqlite3_libversion() function returns a pointer to the 150 ** to the sqlite3_version[] string constant. The sqlite3_libversion() 151 ** function is provided for use in DLLs since DLL users usually do not have 152 ** direct access to string constants within the DLL. ^The 153 ** sqlite3_libversion_number() function returns an integer equal to 154 ** [SQLITE_VERSION_NUMBER]. ^(The sqlite3_sourceid() function returns 155 ** a pointer to a string constant whose value is the same as the 156 ** [SQLITE_SOURCE_ID] C preprocessor macro. Except if SQLite is built 157 ** using an edited copy of [the amalgamation], then the last four characters 158 ** of the hash might be different from [SQLITE_SOURCE_ID].)^ 159 ** 160 ** See also: [sqlite_version()] and [sqlite_source_id()]. 161 */ 162 SQLITE_API SQLITE_EXTERN const char sqlite3_version[]; 163 SQLITE_API const char *sqlite3_libversion(void); 164 SQLITE_API const char *sqlite3_sourceid(void); 165 SQLITE_API int sqlite3_libversion_number(void); 166 167 /* 168 ** CAPI3REF: Run-Time Library Compilation Options Diagnostics 169 ** 170 ** ^The sqlite3_compileoption_used() function returns 0 or 1 171 ** indicating whether the specified option was defined at 172 ** compile time. ^The SQLITE_ prefix may be omitted from the 173 ** option name passed to sqlite3_compileoption_used(). 174 ** 175 ** ^The sqlite3_compileoption_get() function allows iterating 176 ** over the list of options that were defined at compile time by 177 ** returning the N-th compile time option string. ^If N is out of range, 178 ** sqlite3_compileoption_get() returns a NULL pointer. ^The SQLITE_ 179 ** prefix is omitted from any strings returned by 180 ** sqlite3_compileoption_get(). 181 ** 182 ** ^Support for the diagnostic functions sqlite3_compileoption_used() 183 ** and sqlite3_compileoption_get() may be omitted by specifying the 184 ** [SQLITE_OMIT_COMPILEOPTION_DIAGS] option at compile time. 185 ** 186 ** See also: SQL functions [sqlite_compileoption_used()] and 187 ** [sqlite_compileoption_get()] and the [compile_options pragma]. 188 */ 189 #ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS 190 SQLITE_API int sqlite3_compileoption_used(const char *zOptName); 191 SQLITE_API const char *sqlite3_compileoption_get(int N); 192 #else 193 # define sqlite3_compileoption_used(X) 0 194 # define sqlite3_compileoption_get(X) ((void*)0) 195 #endif 196 197 /* 198 ** CAPI3REF: Test To See If The Library Is Threadsafe 199 ** 200 ** ^The sqlite3_threadsafe() function returns zero if and only if 201 ** SQLite was compiled with mutexing code omitted due to the 202 ** [SQLITE_THREADSAFE] compile-time option being set to 0. 203 ** 204 ** SQLite can be compiled with or without mutexes. When 205 ** the [SQLITE_THREADSAFE] C preprocessor macro is 1 or 2, mutexes 206 ** are enabled and SQLite is threadsafe. When the 207 ** [SQLITE_THREADSAFE] macro is 0, 208 ** the mutexes are omitted. Without the mutexes, it is not safe 209 ** to use SQLite concurrently from more than one thread. 210 ** 211 ** Enabling mutexes incurs a measurable performance penalty. 212 ** So if speed is of utmost importance, it makes sense to disable 213 ** the mutexes. But for maximum safety, mutexes should be enabled. 214 ** ^The default behavior is for mutexes to be enabled. 215 ** 216 ** This interface can be used by an application to make sure that the 217 ** version of SQLite that it is linking against was compiled with 218 ** the desired setting of the [SQLITE_THREADSAFE] macro. 219 ** 220 ** This interface only reports on the compile-time mutex setting 221 ** of the [SQLITE_THREADSAFE] flag. If SQLite is compiled with 222 ** SQLITE_THREADSAFE=1 or =2 then mutexes are enabled by default but 223 ** can be fully or partially disabled using a call to [sqlite3_config()] 224 ** with the verbs [SQLITE_CONFIG_SINGLETHREAD], [SQLITE_CONFIG_MULTITHREAD], 225 ** or [SQLITE_CONFIG_SERIALIZED]. ^(The return value of the 226 ** sqlite3_threadsafe() function shows only the compile-time setting of 227 ** thread safety, not any run-time changes to that setting made by 228 ** sqlite3_config(). In other words, the return value from sqlite3_threadsafe() 229 ** is unchanged by calls to sqlite3_config().)^ 230 ** 231 ** See the [threading mode] documentation for additional information. 232 */ 233 SQLITE_API int sqlite3_threadsafe(void); 234 235 /* 236 ** CAPI3REF: Database Connection Handle 237 ** KEYWORDS: {database connection} {database connections} 238 ** 239 ** Each open SQLite database is represented by a pointer to an instance of 240 ** the opaque structure named "sqlite3". It is useful to think of an sqlite3 241 ** pointer as an object. The [sqlite3_open()], [sqlite3_open16()], and 242 ** [sqlite3_open_v2()] interfaces are its constructors, and [sqlite3_close()] 243 ** and [sqlite3_close_v2()] are its destructors. There are many other 244 ** interfaces (such as 245 ** [sqlite3_prepare_v2()], [sqlite3_create_function()], and 246 ** [sqlite3_busy_timeout()] to name but three) that are methods on an 247 ** sqlite3 object. 248 */ 249 typedef struct sqlite3 sqlite3; 250 251 /* 252 ** CAPI3REF: 64-Bit Integer Types 253 ** KEYWORDS: sqlite_int64 sqlite_uint64 254 ** 255 ** Because there is no cross-platform way to specify 64-bit integer types 256 ** SQLite includes typedefs for 64-bit signed and unsigned integers. 257 ** 258 ** The sqlite3_int64 and sqlite3_uint64 are the preferred type definitions. 259 ** The sqlite_int64 and sqlite_uint64 types are supported for backwards 260 ** compatibility only. 261 ** 262 ** ^The sqlite3_int64 and sqlite_int64 types can store integer values 263 ** between -9223372036854775808 and +9223372036854775807 inclusive. ^The 264 ** sqlite3_uint64 and sqlite_uint64 types can store integer values 265 ** between 0 and +18446744073709551615 inclusive. 266 */ 267 #ifdef SQLITE_INT64_TYPE 268 typedef SQLITE_INT64_TYPE sqlite_int64; 269 # ifdef SQLITE_UINT64_TYPE 270 typedef SQLITE_UINT64_TYPE sqlite_uint64; 271 # else 272 typedef unsigned SQLITE_INT64_TYPE sqlite_uint64; 273 # endif 274 #elif defined(_MSC_VER) || defined(__BORLANDC__) 275 typedef __int64 sqlite_int64; 276 typedef unsigned __int64 sqlite_uint64; 277 #else 278 typedef long long int sqlite_int64; 279 typedef unsigned long long int sqlite_uint64; 280 #endif 281 typedef sqlite_int64 sqlite3_int64; 282 typedef sqlite_uint64 sqlite3_uint64; 283 284 /* 285 ** If compiling for a processor that lacks floating point support, 286 ** substitute integer for floating-point. 287 */ 288 #ifdef SQLITE_OMIT_FLOATING_POINT 289 # define double sqlite3_int64 290 #endif 291 292 /* 293 ** CAPI3REF: Closing A Database Connection 294 ** DESTRUCTOR: sqlite3 295 ** 296 ** ^The sqlite3_close() and sqlite3_close_v2() routines are destructors 297 ** for the [sqlite3] object. 298 ** ^Calls to sqlite3_close() and sqlite3_close_v2() return [SQLITE_OK] if 299 ** the [sqlite3] object is successfully destroyed and all associated 300 ** resources are deallocated. 301 ** 302 ** Ideally, applications should [sqlite3_finalize | finalize] all 303 ** [prepared statements], [sqlite3_blob_close | close] all [BLOB handles], and 304 ** [sqlite3_backup_finish | finish] all [sqlite3_backup] objects associated 305 ** with the [sqlite3] object prior to attempting to close the object. 306 ** ^If the database connection is associated with unfinalized prepared 307 ** statements, BLOB handlers, and/or unfinished sqlite3_backup objects then 308 ** sqlite3_close() will leave the database connection open and return 309 ** [SQLITE_BUSY]. ^If sqlite3_close_v2() is called with unfinalized prepared 310 ** statements, unclosed BLOB handlers, and/or unfinished sqlite3_backups, 311 ** it returns [SQLITE_OK] regardless, but instead of deallocating the database 312 ** connection immediately, it marks the database connection as an unusable 313 ** "zombie" and makes arrangements to automatically deallocate the database 314 ** connection after all prepared statements are finalized, all BLOB handles 315 ** are closed, and all backups have finished. The sqlite3_close_v2() interface 316 ** is intended for use with host languages that are garbage collected, and 317 ** where the order in which destructors are called is arbitrary. 318 ** 319 ** ^If an [sqlite3] object is destroyed while a transaction is open, 320 ** the transaction is automatically rolled back. 321 ** 322 ** The C parameter to [sqlite3_close(C)] and [sqlite3_close_v2(C)] 323 ** must be either a NULL 324 ** pointer or an [sqlite3] object pointer obtained 325 ** from [sqlite3_open()], [sqlite3_open16()], or 326 ** [sqlite3_open_v2()], and not previously closed. 327 ** ^Calling sqlite3_close() or sqlite3_close_v2() with a NULL pointer 328 ** argument is a harmless no-op. 329 */ 330 SQLITE_API int sqlite3_close(sqlite3*); 331 SQLITE_API int sqlite3_close_v2(sqlite3*); 332 333 /* 334 ** The type for a callback function. 335 ** This is legacy and deprecated. It is included for historical 336 ** compatibility and is not documented. 337 */ 338 typedef int (*sqlite3_callback)(void*,int,char**, char**); 339 340 /* 341 ** CAPI3REF: One-Step Query Execution Interface 342 ** METHOD: sqlite3 343 ** 344 ** The sqlite3_exec() interface is a convenience wrapper around 345 ** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()], 346 ** that allows an application to run multiple statements of SQL 347 ** without having to use a lot of C code. 348 ** 349 ** ^The sqlite3_exec() interface runs zero or more UTF-8 encoded, 350 ** semicolon-separate SQL statements passed into its 2nd argument, 351 ** in the context of the [database connection] passed in as its 1st 352 ** argument. ^If the callback function of the 3rd argument to 353 ** sqlite3_exec() is not NULL, then it is invoked for each result row 354 ** coming out of the evaluated SQL statements. ^The 4th argument to 355 ** sqlite3_exec() is relayed through to the 1st argument of each 356 ** callback invocation. ^If the callback pointer to sqlite3_exec() 357 ** is NULL, then no callback is ever invoked and result rows are 358 ** ignored. 359 ** 360 ** ^If an error occurs while evaluating the SQL statements passed into 361 ** sqlite3_exec(), then execution of the current statement stops and 362 ** subsequent statements are skipped. ^If the 5th parameter to sqlite3_exec() 363 ** is not NULL then any error message is written into memory obtained 364 ** from [sqlite3_malloc()] and passed back through the 5th parameter. 365 ** To avoid memory leaks, the application should invoke [sqlite3_free()] 366 ** on error message strings returned through the 5th parameter of 367 ** sqlite3_exec() after the error message string is no longer needed. 368 ** ^If the 5th parameter to sqlite3_exec() is not NULL and no errors 369 ** occur, then sqlite3_exec() sets the pointer in its 5th parameter to 370 ** NULL before returning. 371 ** 372 ** ^If an sqlite3_exec() callback returns non-zero, the sqlite3_exec() 373 ** routine returns SQLITE_ABORT without invoking the callback again and 374 ** without running any subsequent SQL statements. 375 ** 376 ** ^The 2nd argument to the sqlite3_exec() callback function is the 377 ** number of columns in the result. ^The 3rd argument to the sqlite3_exec() 378 ** callback is an array of pointers to strings obtained as if from 379 ** [sqlite3_column_text()], one for each column. ^If an element of a 380 ** result row is NULL then the corresponding string pointer for the 381 ** sqlite3_exec() callback is a NULL pointer. ^The 4th argument to the 382 ** sqlite3_exec() callback is an array of pointers to strings where each 383 ** entry represents the name of corresponding result column as obtained 384 ** from [sqlite3_column_name()]. 385 ** 386 ** ^If the 2nd parameter to sqlite3_exec() is a NULL pointer, a pointer 387 ** to an empty string, or a pointer that contains only whitespace and/or 388 ** SQL comments, then no SQL statements are evaluated and the database 389 ** is not changed. 390 ** 391 ** Restrictions: 392 ** 393 ** <ul> 394 ** <li> The application must ensure that the 1st parameter to sqlite3_exec() 395 ** is a valid and open [database connection]. 396 ** <li> The application must not close the [database connection] specified by 397 ** the 1st parameter to sqlite3_exec() while sqlite3_exec() is running. 398 ** <li> The application must not modify the SQL statement text passed into 399 ** the 2nd parameter of sqlite3_exec() while sqlite3_exec() is running. 400 ** </ul> 401 */ 402 SQLITE_API int sqlite3_exec( 403 sqlite3*, /* An open database */ 404 const char *sql, /* SQL to be evaluated */ 405 int (*callback)(void*,int,char**,char**), /* Callback function */ 406 void *, /* 1st argument to callback */ 407 char **errmsg /* Error msg written here */ 408 ); 409 410 /* 411 ** CAPI3REF: Result Codes 412 ** KEYWORDS: {result code definitions} 413 ** 414 ** Many SQLite functions return an integer result code from the set shown 415 ** here in order to indicate success or failure. 416 ** 417 ** New error codes may be added in future versions of SQLite. 418 ** 419 ** See also: [extended result code definitions] 420 */ 421 #define SQLITE_OK 0 /* Successful result */ 422 /* beginning-of-error-codes */ 423 #define SQLITE_ERROR 1 /* Generic error */ 424 #define SQLITE_INTERNAL 2 /* Internal logic error in SQLite */ 425 #define SQLITE_PERM 3 /* Access permission denied */ 426 #define SQLITE_ABORT 4 /* Callback routine requested an abort */ 427 #define SQLITE_BUSY 5 /* The database file is locked */ 428 #define SQLITE_LOCKED 6 /* A table in the database is locked */ 429 #define SQLITE_NOMEM 7 /* A malloc() failed */ 430 #define SQLITE_READONLY 8 /* Attempt to write a readonly database */ 431 #define SQLITE_INTERRUPT 9 /* Operation terminated by sqlite3_interrupt()*/ 432 #define SQLITE_IOERR 10 /* Some kind of disk I/O error occurred */ 433 #define SQLITE_CORRUPT 11 /* The database disk image is malformed */ 434 #define SQLITE_NOTFOUND 12 /* Unknown opcode in sqlite3_file_control() */ 435 #define SQLITE_FULL 13 /* Insertion failed because database is full */ 436 #define SQLITE_CANTOPEN 14 /* Unable to open the database file */ 437 #define SQLITE_PROTOCOL 15 /* Database lock protocol error */ 438 #define SQLITE_EMPTY 16 /* Internal use only */ 439 #define SQLITE_SCHEMA 17 /* The database schema changed */ 440 #define SQLITE_TOOBIG 18 /* String or BLOB exceeds size limit */ 441 #define SQLITE_CONSTRAINT 19 /* Abort due to constraint violation */ 442 #define SQLITE_MISMATCH 20 /* Data type mismatch */ 443 #define SQLITE_MISUSE 21 /* Library used incorrectly */ 444 #define SQLITE_NOLFS 22 /* Uses OS features not supported on host */ 445 #define SQLITE_AUTH 23 /* Authorization denied */ 446 #define SQLITE_FORMAT 24 /* Not used */ 447 #define SQLITE_RANGE 25 /* 2nd parameter to sqlite3_bind out of range */ 448 #define SQLITE_NOTADB 26 /* File opened that is not a database file */ 449 #define SQLITE_NOTICE 27 /* Notifications from sqlite3_log() */ 450 #define SQLITE_WARNING 28 /* Warnings from sqlite3_log() */ 451 #define SQLITE_ROW 100 /* sqlite3_step() has another row ready */ 452 #define SQLITE_DONE 101 /* sqlite3_step() has finished executing */ 453 /* end-of-error-codes */ 454 455 /* 456 ** CAPI3REF: Extended Result Codes 457 ** KEYWORDS: {extended result code definitions} 458 ** 459 ** In its default configuration, SQLite API routines return one of 30 integer 460 ** [result codes]. However, experience has shown that many of 461 ** these result codes are too coarse-grained. They do not provide as 462 ** much information about problems as programmers might like. In an effort to 463 ** address this, newer versions of SQLite (version 3.3.8 [dateof:3.3.8] 464 ** and later) include 465 ** support for additional result codes that provide more detailed information 466 ** about errors. These [extended result codes] are enabled or disabled 467 ** on a per database connection basis using the 468 ** [sqlite3_extended_result_codes()] API. Or, the extended code for 469 ** the most recent error can be obtained using 470 ** [sqlite3_extended_errcode()]. 471 */ 472 #define SQLITE_ERROR_MISSING_COLLSEQ (SQLITE_ERROR | (1<<8)) 473 #define SQLITE_ERROR_RETRY (SQLITE_ERROR | (2<<8)) 474 #define SQLITE_ERROR_SNAPSHOT (SQLITE_ERROR | (3<<8)) 475 #define SQLITE_IOERR_READ (SQLITE_IOERR | (1<<8)) 476 #define SQLITE_IOERR_SHORT_READ (SQLITE_IOERR | (2<<8)) 477 #define SQLITE_IOERR_WRITE (SQLITE_IOERR | (3<<8)) 478 #define SQLITE_IOERR_FSYNC (SQLITE_IOERR | (4<<8)) 479 #define SQLITE_IOERR_DIR_FSYNC (SQLITE_IOERR | (5<<8)) 480 #define SQLITE_IOERR_TRUNCATE (SQLITE_IOERR | (6<<8)) 481 #define SQLITE_IOERR_FSTAT (SQLITE_IOERR | (7<<8)) 482 #define SQLITE_IOERR_UNLOCK (SQLITE_IOERR | (8<<8)) 483 #define SQLITE_IOERR_RDLOCK (SQLITE_IOERR | (9<<8)) 484 #define SQLITE_IOERR_DELETE (SQLITE_IOERR | (10<<8)) 485 #define SQLITE_IOERR_BLOCKED (SQLITE_IOERR | (11<<8)) 486 #define SQLITE_IOERR_NOMEM (SQLITE_IOERR | (12<<8)) 487 #define SQLITE_IOERR_ACCESS (SQLITE_IOERR | (13<<8)) 488 #define SQLITE_IOERR_CHECKRESERVEDLOCK (SQLITE_IOERR | (14<<8)) 489 #define SQLITE_IOERR_LOCK (SQLITE_IOERR | (15<<8)) 490 #define SQLITE_IOERR_CLOSE (SQLITE_IOERR | (16<<8)) 491 #define SQLITE_IOERR_DIR_CLOSE (SQLITE_IOERR | (17<<8)) 492 #define SQLITE_IOERR_SHMOPEN (SQLITE_IOERR | (18<<8)) 493 #define SQLITE_IOERR_SHMSIZE (SQLITE_IOERR | (19<<8)) 494 #define SQLITE_IOERR_SHMLOCK (SQLITE_IOERR | (20<<8)) 495 #define SQLITE_IOERR_SHMMAP (SQLITE_IOERR | (21<<8)) 496 #define SQLITE_IOERR_SEEK (SQLITE_IOERR | (22<<8)) 497 #define SQLITE_IOERR_DELETE_NOENT (SQLITE_IOERR | (23<<8)) 498 #define SQLITE_IOERR_MMAP (SQLITE_IOERR | (24<<8)) 499 #define SQLITE_IOERR_GETTEMPPATH (SQLITE_IOERR | (25<<8)) 500 #define SQLITE_IOERR_CONVPATH (SQLITE_IOERR | (26<<8)) 501 #define SQLITE_IOERR_VNODE (SQLITE_IOERR | (27<<8)) 502 #define SQLITE_IOERR_AUTH (SQLITE_IOERR | (28<<8)) 503 #define SQLITE_IOERR_BEGIN_ATOMIC (SQLITE_IOERR | (29<<8)) 504 #define SQLITE_IOERR_COMMIT_ATOMIC (SQLITE_IOERR | (30<<8)) 505 #define SQLITE_IOERR_ROLLBACK_ATOMIC (SQLITE_IOERR | (31<<8)) 506 #define SQLITE_IOERR_DATA (SQLITE_IOERR | (32<<8)) 507 #define SQLITE_LOCKED_SHAREDCACHE (SQLITE_LOCKED | (1<<8)) 508 #define SQLITE_LOCKED_VTAB (SQLITE_LOCKED | (2<<8)) 509 #define SQLITE_BUSY_RECOVERY (SQLITE_BUSY | (1<<8)) 510 #define SQLITE_BUSY_SNAPSHOT (SQLITE_BUSY | (2<<8)) 511 #define SQLITE_BUSY_TIMEOUT (SQLITE_BUSY | (3<<8)) 512 #define SQLITE_CANTOPEN_NOTEMPDIR (SQLITE_CANTOPEN | (1<<8)) 513 #define SQLITE_CANTOPEN_ISDIR (SQLITE_CANTOPEN | (2<<8)) 514 #define SQLITE_CANTOPEN_FULLPATH (SQLITE_CANTOPEN | (3<<8)) 515 #define SQLITE_CANTOPEN_CONVPATH (SQLITE_CANTOPEN | (4<<8)) 516 #define SQLITE_CANTOPEN_DIRTYWAL (SQLITE_CANTOPEN | (5<<8)) /* Not Used */ 517 #define SQLITE_CANTOPEN_SYMLINK (SQLITE_CANTOPEN | (6<<8)) 518 #define SQLITE_CORRUPT_VTAB (SQLITE_CORRUPT | (1<<8)) 519 #define SQLITE_CORRUPT_SEQUENCE (SQLITE_CORRUPT | (2<<8)) 520 #define SQLITE_CORRUPT_INDEX (SQLITE_CORRUPT | (3<<8)) 521 #define SQLITE_READONLY_RECOVERY (SQLITE_READONLY | (1<<8)) 522 #define SQLITE_READONLY_CANTLOCK (SQLITE_READONLY | (2<<8)) 523 #define SQLITE_READONLY_ROLLBACK (SQLITE_READONLY | (3<<8)) 524 #define SQLITE_READONLY_DBMOVED (SQLITE_READONLY | (4<<8)) 525 #define SQLITE_READONLY_CANTINIT (SQLITE_READONLY | (5<<8)) 526 #define SQLITE_READONLY_DIRECTORY (SQLITE_READONLY | (6<<8)) 527 #define SQLITE_ABORT_ROLLBACK (SQLITE_ABORT | (2<<8)) 528 #define SQLITE_CONSTRAINT_CHECK (SQLITE_CONSTRAINT | (1<<8)) 529 #define SQLITE_CONSTRAINT_COMMITHOOK (SQLITE_CONSTRAINT | (2<<8)) 530 #define SQLITE_CONSTRAINT_FOREIGNKEY (SQLITE_CONSTRAINT | (3<<8)) 531 #define SQLITE_CONSTRAINT_FUNCTION (SQLITE_CONSTRAINT | (4<<8)) 532 #define SQLITE_CONSTRAINT_NOTNULL (SQLITE_CONSTRAINT | (5<<8)) 533 #define SQLITE_CONSTRAINT_PRIMARYKEY (SQLITE_CONSTRAINT | (6<<8)) 534 #define SQLITE_CONSTRAINT_TRIGGER (SQLITE_CONSTRAINT | (7<<8)) 535 #define SQLITE_CONSTRAINT_UNIQUE (SQLITE_CONSTRAINT | (8<<8)) 536 #define SQLITE_CONSTRAINT_VTAB (SQLITE_CONSTRAINT | (9<<8)) 537 #define SQLITE_CONSTRAINT_ROWID (SQLITE_CONSTRAINT |(10<<8)) 538 #define SQLITE_CONSTRAINT_PINNED (SQLITE_CONSTRAINT |(11<<8)) 539 #define SQLITE_NOTICE_RECOVER_WAL (SQLITE_NOTICE | (1<<8)) 540 #define SQLITE_NOTICE_RECOVER_ROLLBACK (SQLITE_NOTICE | (2<<8)) 541 #define SQLITE_WARNING_AUTOINDEX (SQLITE_WARNING | (1<<8)) 542 #define SQLITE_AUTH_USER (SQLITE_AUTH | (1<<8)) 543 #define SQLITE_OK_LOAD_PERMANENTLY (SQLITE_OK | (1<<8)) 544 #define SQLITE_OK_SYMLINK (SQLITE_OK | (2<<8)) 545 546 /* 547 ** CAPI3REF: Flags For File Open Operations 548 ** 549 ** These bit values are intended for use in the 550 ** 3rd parameter to the [sqlite3_open_v2()] interface and 551 ** in the 4th parameter to the [sqlite3_vfs.xOpen] method. 552 */ 553 #define SQLITE_OPEN_READONLY 0x00000001 /* Ok for sqlite3_open_v2() */ 554 #define SQLITE_OPEN_READWRITE 0x00000002 /* Ok for sqlite3_open_v2() */ 555 #define SQLITE_OPEN_CREATE 0x00000004 /* Ok for sqlite3_open_v2() */ 556 #define SQLITE_OPEN_DELETEONCLOSE 0x00000008 /* VFS only */ 557 #define SQLITE_OPEN_EXCLUSIVE 0x00000010 /* VFS only */ 558 #define SQLITE_OPEN_AUTOPROXY 0x00000020 /* VFS only */ 559 #define SQLITE_OPEN_URI 0x00000040 /* Ok for sqlite3_open_v2() */ 560 #define SQLITE_OPEN_MEMORY 0x00000080 /* Ok for sqlite3_open_v2() */ 561 #define SQLITE_OPEN_MAIN_DB 0x00000100 /* VFS only */ 562 #define SQLITE_OPEN_TEMP_DB 0x00000200 /* VFS only */ 563 #define SQLITE_OPEN_TRANSIENT_DB 0x00000400 /* VFS only */ 564 #define SQLITE_OPEN_MAIN_JOURNAL 0x00000800 /* VFS only */ 565 #define SQLITE_OPEN_TEMP_JOURNAL 0x00001000 /* VFS only */ 566 #define SQLITE_OPEN_SUBJOURNAL 0x00002000 /* VFS only */ 567 #define SQLITE_OPEN_SUPER_JOURNAL 0x00004000 /* VFS only */ 568 #define SQLITE_OPEN_NOMUTEX 0x00008000 /* Ok for sqlite3_open_v2() */ 569 #define SQLITE_OPEN_FULLMUTEX 0x00010000 /* Ok for sqlite3_open_v2() */ 570 #define SQLITE_OPEN_SHAREDCACHE 0x00020000 /* Ok for sqlite3_open_v2() */ 571 #define SQLITE_OPEN_PRIVATECACHE 0x00040000 /* Ok for sqlite3_open_v2() */ 572 #define SQLITE_OPEN_WAL 0x00080000 /* VFS only */ 573 #define SQLITE_OPEN_NOFOLLOW 0x01000000 /* Ok for sqlite3_open_v2() */ 574 575 /* Reserved: 0x00F00000 */ 576 /* Legacy compatibility: */ 577 #define SQLITE_OPEN_MASTER_JOURNAL 0x00004000 /* VFS only */ 578 579 580 /* 581 ** CAPI3REF: Device Characteristics 582 ** 583 ** The xDeviceCharacteristics method of the [sqlite3_io_methods] 584 ** object returns an integer which is a vector of these 585 ** bit values expressing I/O characteristics of the mass storage 586 ** device that holds the file that the [sqlite3_io_methods] 587 ** refers to. 588 ** 589 ** The SQLITE_IOCAP_ATOMIC property means that all writes of 590 ** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 591 ** mean that writes of blocks that are nnn bytes in size and 592 ** are aligned to an address which is an integer multiple of 593 ** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 594 ** that when data is appended to a file, the data is appended 595 ** first then the size of the file is extended, never the other 596 ** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 597 ** information is written to disk in the same order as calls 598 ** to xWrite(). The SQLITE_IOCAP_POWERSAFE_OVERWRITE property means that 599 ** after reboot following a crash or power loss, the only bytes in a 600 ** file that were written at the application level might have changed 601 ** and that adjacent bytes, even bytes within the same sector are 602 ** guaranteed to be unchanged. The SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 603 ** flag indicates that a file cannot be deleted when open. The 604 ** SQLITE_IOCAP_IMMUTABLE flag indicates that the file is on 605 ** read-only media and cannot be changed even by processes with 606 ** elevated privileges. 607 ** 608 ** The SQLITE_IOCAP_BATCH_ATOMIC property means that the underlying 609 ** filesystem supports doing multiple write operations atomically when those 610 ** write operations are bracketed by [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] and 611 ** [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]. 612 */ 613 #define SQLITE_IOCAP_ATOMIC 0x00000001 614 #define SQLITE_IOCAP_ATOMIC512 0x00000002 615 #define SQLITE_IOCAP_ATOMIC1K 0x00000004 616 #define SQLITE_IOCAP_ATOMIC2K 0x00000008 617 #define SQLITE_IOCAP_ATOMIC4K 0x00000010 618 #define SQLITE_IOCAP_ATOMIC8K 0x00000020 619 #define SQLITE_IOCAP_ATOMIC16K 0x00000040 620 #define SQLITE_IOCAP_ATOMIC32K 0x00000080 621 #define SQLITE_IOCAP_ATOMIC64K 0x00000100 622 #define SQLITE_IOCAP_SAFE_APPEND 0x00000200 623 #define SQLITE_IOCAP_SEQUENTIAL 0x00000400 624 #define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 0x00000800 625 #define SQLITE_IOCAP_POWERSAFE_OVERWRITE 0x00001000 626 #define SQLITE_IOCAP_IMMUTABLE 0x00002000 627 #define SQLITE_IOCAP_BATCH_ATOMIC 0x00004000 628 629 /* 630 ** CAPI3REF: File Locking Levels 631 ** 632 ** SQLite uses one of these integer values as the second 633 ** argument to calls it makes to the xLock() and xUnlock() methods 634 ** of an [sqlite3_io_methods] object. 635 */ 636 #define SQLITE_LOCK_NONE 0 637 #define SQLITE_LOCK_SHARED 1 638 #define SQLITE_LOCK_RESERVED 2 639 #define SQLITE_LOCK_PENDING 3 640 #define SQLITE_LOCK_EXCLUSIVE 4 641 642 /* 643 ** CAPI3REF: Synchronization Type Flags 644 ** 645 ** When SQLite invokes the xSync() method of an 646 ** [sqlite3_io_methods] object it uses a combination of 647 ** these integer values as the second argument. 648 ** 649 ** When the SQLITE_SYNC_DATAONLY flag is used, it means that the 650 ** sync operation only needs to flush data to mass storage. Inode 651 ** information need not be flushed. If the lower four bits of the flag 652 ** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics. 653 ** If the lower four bits equal SQLITE_SYNC_FULL, that means 654 ** to use Mac OS X style fullsync instead of fsync(). 655 ** 656 ** Do not confuse the SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags 657 ** with the [PRAGMA synchronous]=NORMAL and [PRAGMA synchronous]=FULL 658 ** settings. The [synchronous pragma] determines when calls to the 659 ** xSync VFS method occur and applies uniformly across all platforms. 660 ** The SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags determine how 661 ** energetic or rigorous or forceful the sync operations are and 662 ** only make a difference on Mac OSX for the default SQLite code. 663 ** (Third-party VFS implementations might also make the distinction 664 ** between SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL, but among the 665 ** operating systems natively supported by SQLite, only Mac OSX 666 ** cares about the difference.) 667 */ 668 #define SQLITE_SYNC_NORMAL 0x00002 669 #define SQLITE_SYNC_FULL 0x00003 670 #define SQLITE_SYNC_DATAONLY 0x00010 671 672 /* 673 ** CAPI3REF: OS Interface Open File Handle 674 ** 675 ** An [sqlite3_file] object represents an open file in the 676 ** [sqlite3_vfs | OS interface layer]. Individual OS interface 677 ** implementations will 678 ** want to subclass this object by appending additional fields 679 ** for their own use. The pMethods entry is a pointer to an 680 ** [sqlite3_io_methods] object that defines methods for performing 681 ** I/O operations on the open file. 682 */ 683 typedef struct sqlite3_file sqlite3_file; 684 struct sqlite3_file { 685 const struct sqlite3_io_methods *pMethods; /* Methods for an open file */ 686 }; 687 688 /* 689 ** CAPI3REF: OS Interface File Virtual Methods Object 690 ** 691 ** Every file opened by the [sqlite3_vfs.xOpen] method populates an 692 ** [sqlite3_file] object (or, more commonly, a subclass of the 693 ** [sqlite3_file] object) with a pointer to an instance of this object. 694 ** This object defines the methods used to perform various operations 695 ** against the open file represented by the [sqlite3_file] object. 696 ** 697 ** If the [sqlite3_vfs.xOpen] method sets the sqlite3_file.pMethods element 698 ** to a non-NULL pointer, then the sqlite3_io_methods.xClose method 699 ** may be invoked even if the [sqlite3_vfs.xOpen] reported that it failed. The 700 ** only way to prevent a call to xClose following a failed [sqlite3_vfs.xOpen] 701 ** is for the [sqlite3_vfs.xOpen] to set the sqlite3_file.pMethods element 702 ** to NULL. 703 ** 704 ** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or 705 ** [SQLITE_SYNC_FULL]. The first choice is the normal fsync(). 706 ** The second choice is a Mac OS X style fullsync. The [SQLITE_SYNC_DATAONLY] 707 ** flag may be ORed in to indicate that only the data of the file 708 ** and not its inode needs to be synced. 709 ** 710 ** The integer values to xLock() and xUnlock() are one of 711 ** <ul> 712 ** <li> [SQLITE_LOCK_NONE], 713 ** <li> [SQLITE_LOCK_SHARED], 714 ** <li> [SQLITE_LOCK_RESERVED], 715 ** <li> [SQLITE_LOCK_PENDING], or 716 ** <li> [SQLITE_LOCK_EXCLUSIVE]. 717 ** </ul> 718 ** xLock() increases the lock. xUnlock() decreases the lock. 719 ** The xCheckReservedLock() method checks whether any database connection, 720 ** either in this process or in some other process, is holding a RESERVED, 721 ** PENDING, or EXCLUSIVE lock on the file. It returns true 722 ** if such a lock exists and false otherwise. 723 ** 724 ** The xFileControl() method is a generic interface that allows custom 725 ** VFS implementations to directly control an open file using the 726 ** [sqlite3_file_control()] interface. The second "op" argument is an 727 ** integer opcode. The third argument is a generic pointer intended to 728 ** point to a structure that may contain arguments or space in which to 729 ** write return values. Potential uses for xFileControl() might be 730 ** functions to enable blocking locks with timeouts, to change the 731 ** locking strategy (for example to use dot-file locks), to inquire 732 ** about the status of a lock, or to break stale locks. The SQLite 733 ** core reserves all opcodes less than 100 for its own use. 734 ** A [file control opcodes | list of opcodes] less than 100 is available. 735 ** Applications that define a custom xFileControl method should use opcodes 736 ** greater than 100 to avoid conflicts. VFS implementations should 737 ** return [SQLITE_NOTFOUND] for file control opcodes that they do not 738 ** recognize. 739 ** 740 ** The xSectorSize() method returns the sector size of the 741 ** device that underlies the file. The sector size is the 742 ** minimum write that can be performed without disturbing 743 ** other bytes in the file. The xDeviceCharacteristics() 744 ** method returns a bit vector describing behaviors of the 745 ** underlying device: 746 ** 747 ** <ul> 748 ** <li> [SQLITE_IOCAP_ATOMIC] 749 ** <li> [SQLITE_IOCAP_ATOMIC512] 750 ** <li> [SQLITE_IOCAP_ATOMIC1K] 751 ** <li> [SQLITE_IOCAP_ATOMIC2K] 752 ** <li> [SQLITE_IOCAP_ATOMIC4K] 753 ** <li> [SQLITE_IOCAP_ATOMIC8K] 754 ** <li> [SQLITE_IOCAP_ATOMIC16K] 755 ** <li> [SQLITE_IOCAP_ATOMIC32K] 756 ** <li> [SQLITE_IOCAP_ATOMIC64K] 757 ** <li> [SQLITE_IOCAP_SAFE_APPEND] 758 ** <li> [SQLITE_IOCAP_SEQUENTIAL] 759 ** <li> [SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN] 760 ** <li> [SQLITE_IOCAP_POWERSAFE_OVERWRITE] 761 ** <li> [SQLITE_IOCAP_IMMUTABLE] 762 ** <li> [SQLITE_IOCAP_BATCH_ATOMIC] 763 ** </ul> 764 ** 765 ** The SQLITE_IOCAP_ATOMIC property means that all writes of 766 ** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 767 ** mean that writes of blocks that are nnn bytes in size and 768 ** are aligned to an address which is an integer multiple of 769 ** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 770 ** that when data is appended to a file, the data is appended 771 ** first then the size of the file is extended, never the other 772 ** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 773 ** information is written to disk in the same order as calls 774 ** to xWrite(). 775 ** 776 ** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill 777 ** in the unread portions of the buffer with zeros. A VFS that 778 ** fails to zero-fill short reads might seem to work. However, 779 ** failure to zero-fill short reads will eventually lead to 780 ** database corruption. 781 */ 782 typedef struct sqlite3_io_methods sqlite3_io_methods; 783 struct sqlite3_io_methods { 784 int iVersion; 785 int (*xClose)(sqlite3_file*); 786 int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst); 787 int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst); 788 int (*xTruncate)(sqlite3_file*, sqlite3_int64 size); 789 int (*xSync)(sqlite3_file*, int flags); 790 int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize); 791 int (*xLock)(sqlite3_file*, int); 792 int (*xUnlock)(sqlite3_file*, int); 793 int (*xCheckReservedLock)(sqlite3_file*, int *pResOut); 794 int (*xFileControl)(sqlite3_file*, int op, void *pArg); 795 int (*xSectorSize)(sqlite3_file*); 796 int (*xDeviceCharacteristics)(sqlite3_file*); 797 /* Methods above are valid for version 1 */ 798 int (*xShmMap)(sqlite3_file*, int iPg, int pgsz, int, void volatile**); 799 int (*xShmLock)(sqlite3_file*, int offset, int n, int flags); 800 void (*xShmBarrier)(sqlite3_file*); 801 int (*xShmUnmap)(sqlite3_file*, int deleteFlag); 802 /* Methods above are valid for version 2 */ 803 int (*xFetch)(sqlite3_file*, sqlite3_int64 iOfst, int iAmt, void **pp); 804 int (*xUnfetch)(sqlite3_file*, sqlite3_int64 iOfst, void *p); 805 /* Methods above are valid for version 3 */ 806 /* Additional methods may be added in future releases */ 807 }; 808 809 /* 810 ** CAPI3REF: Standard File Control Opcodes 811 ** KEYWORDS: {file control opcodes} {file control opcode} 812 ** 813 ** These integer constants are opcodes for the xFileControl method 814 ** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()] 815 ** interface. 816 ** 817 ** <ul> 818 ** <li>[[SQLITE_FCNTL_LOCKSTATE]] 819 ** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging. This 820 ** opcode causes the xFileControl method to write the current state of 821 ** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED], 822 ** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE]) 823 ** into an integer that the pArg argument points to. This capability 824 ** is used during testing and is only available when the SQLITE_TEST 825 ** compile-time option is used. 826 ** 827 ** <li>[[SQLITE_FCNTL_SIZE_HINT]] 828 ** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS 829 ** layer a hint of how large the database file will grow to be during the 830 ** current transaction. This hint is not guaranteed to be accurate but it 831 ** is often close. The underlying VFS might choose to preallocate database 832 ** file space based on this hint in order to help writes to the database 833 ** file run faster. 834 ** 835 ** <li>[[SQLITE_FCNTL_SIZE_LIMIT]] 836 ** The [SQLITE_FCNTL_SIZE_LIMIT] opcode is used by in-memory VFS that 837 ** implements [sqlite3_deserialize()] to set an upper bound on the size 838 ** of the in-memory database. The argument is a pointer to a [sqlite3_int64]. 839 ** If the integer pointed to is negative, then it is filled in with the 840 ** current limit. Otherwise the limit is set to the larger of the value 841 ** of the integer pointed to and the current database size. The integer 842 ** pointed to is set to the new limit. 843 ** 844 ** <li>[[SQLITE_FCNTL_CHUNK_SIZE]] 845 ** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS 846 ** extends and truncates the database file in chunks of a size specified 847 ** by the user. The fourth argument to [sqlite3_file_control()] should 848 ** point to an integer (type int) containing the new chunk-size to use 849 ** for the nominated database. Allocating database file space in large 850 ** chunks (say 1MB at a time), may reduce file-system fragmentation and 851 ** improve performance on some systems. 852 ** 853 ** <li>[[SQLITE_FCNTL_FILE_POINTER]] 854 ** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer 855 ** to the [sqlite3_file] object associated with a particular database 856 ** connection. See also [SQLITE_FCNTL_JOURNAL_POINTER]. 857 ** 858 ** <li>[[SQLITE_FCNTL_JOURNAL_POINTER]] 859 ** The [SQLITE_FCNTL_JOURNAL_POINTER] opcode is used to obtain a pointer 860 ** to the [sqlite3_file] object associated with the journal file (either 861 ** the [rollback journal] or the [write-ahead log]) for a particular database 862 ** connection. See also [SQLITE_FCNTL_FILE_POINTER]. 863 ** 864 ** <li>[[SQLITE_FCNTL_SYNC_OMITTED]] 865 ** No longer in use. 866 ** 867 ** <li>[[SQLITE_FCNTL_SYNC]] 868 ** The [SQLITE_FCNTL_SYNC] opcode is generated internally by SQLite and 869 ** sent to the VFS immediately before the xSync method is invoked on a 870 ** database file descriptor. Or, if the xSync method is not invoked 871 ** because the user has configured SQLite with 872 ** [PRAGMA synchronous | PRAGMA synchronous=OFF] it is invoked in place 873 ** of the xSync method. In most cases, the pointer argument passed with 874 ** this file-control is NULL. However, if the database file is being synced 875 ** as part of a multi-database commit, the argument points to a nul-terminated 876 ** string containing the transactions super-journal file name. VFSes that 877 ** do not need this signal should silently ignore this opcode. Applications 878 ** should not call [sqlite3_file_control()] with this opcode as doing so may 879 ** disrupt the operation of the specialized VFSes that do require it. 880 ** 881 ** <li>[[SQLITE_FCNTL_COMMIT_PHASETWO]] 882 ** The [SQLITE_FCNTL_COMMIT_PHASETWO] opcode is generated internally by SQLite 883 ** and sent to the VFS after a transaction has been committed immediately 884 ** but before the database is unlocked. VFSes that do not need this signal 885 ** should silently ignore this opcode. Applications should not call 886 ** [sqlite3_file_control()] with this opcode as doing so may disrupt the 887 ** operation of the specialized VFSes that do require it. 888 ** 889 ** <li>[[SQLITE_FCNTL_WIN32_AV_RETRY]] 890 ** ^The [SQLITE_FCNTL_WIN32_AV_RETRY] opcode is used to configure automatic 891 ** retry counts and intervals for certain disk I/O operations for the 892 ** windows [VFS] in order to provide robustness in the presence of 893 ** anti-virus programs. By default, the windows VFS will retry file read, 894 ** file write, and file delete operations up to 10 times, with a delay 895 ** of 25 milliseconds before the first retry and with the delay increasing 896 ** by an additional 25 milliseconds with each subsequent retry. This 897 ** opcode allows these two values (10 retries and 25 milliseconds of delay) 898 ** to be adjusted. The values are changed for all database connections 899 ** within the same process. The argument is a pointer to an array of two 900 ** integers where the first integer is the new retry count and the second 901 ** integer is the delay. If either integer is negative, then the setting 902 ** is not changed but instead the prior value of that setting is written 903 ** into the array entry, allowing the current retry settings to be 904 ** interrogated. The zDbName parameter is ignored. 905 ** 906 ** <li>[[SQLITE_FCNTL_PERSIST_WAL]] 907 ** ^The [SQLITE_FCNTL_PERSIST_WAL] opcode is used to set or query the 908 ** persistent [WAL | Write Ahead Log] setting. By default, the auxiliary 909 ** write ahead log ([WAL file]) and shared memory 910 ** files used for transaction control 911 ** are automatically deleted when the latest connection to the database 912 ** closes. Setting persistent WAL mode causes those files to persist after 913 ** close. Persisting the files is useful when other processes that do not 914 ** have write permission on the directory containing the database file want 915 ** to read the database file, as the WAL and shared memory files must exist 916 ** in order for the database to be readable. The fourth parameter to 917 ** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 918 ** That integer is 0 to disable persistent WAL mode or 1 to enable persistent 919 ** WAL mode. If the integer is -1, then it is overwritten with the current 920 ** WAL persistence setting. 921 ** 922 ** <li>[[SQLITE_FCNTL_POWERSAFE_OVERWRITE]] 923 ** ^The [SQLITE_FCNTL_POWERSAFE_OVERWRITE] opcode is used to set or query the 924 ** persistent "powersafe-overwrite" or "PSOW" setting. The PSOW setting 925 ** determines the [SQLITE_IOCAP_POWERSAFE_OVERWRITE] bit of the 926 ** xDeviceCharacteristics methods. The fourth parameter to 927 ** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 928 ** That integer is 0 to disable zero-damage mode or 1 to enable zero-damage 929 ** mode. If the integer is -1, then it is overwritten with the current 930 ** zero-damage mode setting. 931 ** 932 ** <li>[[SQLITE_FCNTL_OVERWRITE]] 933 ** ^The [SQLITE_FCNTL_OVERWRITE] opcode is invoked by SQLite after opening 934 ** a write transaction to indicate that, unless it is rolled back for some 935 ** reason, the entire database file will be overwritten by the current 936 ** transaction. This is used by VACUUM operations. 937 ** 938 ** <li>[[SQLITE_FCNTL_VFSNAME]] 939 ** ^The [SQLITE_FCNTL_VFSNAME] opcode can be used to obtain the names of 940 ** all [VFSes] in the VFS stack. The names are of all VFS shims and the 941 ** final bottom-level VFS are written into memory obtained from 942 ** [sqlite3_malloc()] and the result is stored in the char* variable 943 ** that the fourth parameter of [sqlite3_file_control()] points to. 944 ** The caller is responsible for freeing the memory when done. As with 945 ** all file-control actions, there is no guarantee that this will actually 946 ** do anything. Callers should initialize the char* variable to a NULL 947 ** pointer in case this file-control is not implemented. This file-control 948 ** is intended for diagnostic use only. 949 ** 950 ** <li>[[SQLITE_FCNTL_VFS_POINTER]] 951 ** ^The [SQLITE_FCNTL_VFS_POINTER] opcode finds a pointer to the top-level 952 ** [VFSes] currently in use. ^(The argument X in 953 ** sqlite3_file_control(db,SQLITE_FCNTL_VFS_POINTER,X) must be 954 ** of type "[sqlite3_vfs] **". This opcodes will set *X 955 ** to a pointer to the top-level VFS.)^ 956 ** ^When there are multiple VFS shims in the stack, this opcode finds the 957 ** upper-most shim only. 958 ** 959 ** <li>[[SQLITE_FCNTL_PRAGMA]] 960 ** ^Whenever a [PRAGMA] statement is parsed, an [SQLITE_FCNTL_PRAGMA] 961 ** file control is sent to the open [sqlite3_file] object corresponding 962 ** to the database file to which the pragma statement refers. ^The argument 963 ** to the [SQLITE_FCNTL_PRAGMA] file control is an array of 964 ** pointers to strings (char**) in which the second element of the array 965 ** is the name of the pragma and the third element is the argument to the 966 ** pragma or NULL if the pragma has no argument. ^The handler for an 967 ** [SQLITE_FCNTL_PRAGMA] file control can optionally make the first element 968 ** of the char** argument point to a string obtained from [sqlite3_mprintf()] 969 ** or the equivalent and that string will become the result of the pragma or 970 ** the error message if the pragma fails. ^If the 971 ** [SQLITE_FCNTL_PRAGMA] file control returns [SQLITE_NOTFOUND], then normal 972 ** [PRAGMA] processing continues. ^If the [SQLITE_FCNTL_PRAGMA] 973 ** file control returns [SQLITE_OK], then the parser assumes that the 974 ** VFS has handled the PRAGMA itself and the parser generates a no-op 975 ** prepared statement if result string is NULL, or that returns a copy 976 ** of the result string if the string is non-NULL. 977 ** ^If the [SQLITE_FCNTL_PRAGMA] file control returns 978 ** any result code other than [SQLITE_OK] or [SQLITE_NOTFOUND], that means 979 ** that the VFS encountered an error while handling the [PRAGMA] and the 980 ** compilation of the PRAGMA fails with an error. ^The [SQLITE_FCNTL_PRAGMA] 981 ** file control occurs at the beginning of pragma statement analysis and so 982 ** it is able to override built-in [PRAGMA] statements. 983 ** 984 ** <li>[[SQLITE_FCNTL_BUSYHANDLER]] 985 ** ^The [SQLITE_FCNTL_BUSYHANDLER] 986 ** file-control may be invoked by SQLite on the database file handle 987 ** shortly after it is opened in order to provide a custom VFS with access 988 ** to the connection's busy-handler callback. The argument is of type (void**) 989 ** - an array of two (void *) values. The first (void *) actually points 990 ** to a function of type (int (*)(void *)). In order to invoke the connection's 991 ** busy-handler, this function should be invoked with the second (void *) in 992 ** the array as the only argument. If it returns non-zero, then the operation 993 ** should be retried. If it returns zero, the custom VFS should abandon the 994 ** current operation. 995 ** 996 ** <li>[[SQLITE_FCNTL_TEMPFILENAME]] 997 ** ^Applications can invoke the [SQLITE_FCNTL_TEMPFILENAME] file-control 998 ** to have SQLite generate a 999 ** temporary filename using the same algorithm that is followed to generate 1000 ** temporary filenames for TEMP tables and other internal uses. The 1001 ** argument should be a char** which will be filled with the filename 1002 ** written into memory obtained from [sqlite3_malloc()]. The caller should 1003 ** invoke [sqlite3_free()] on the result to avoid a memory leak. 1004 ** 1005 ** <li>[[SQLITE_FCNTL_MMAP_SIZE]] 1006 ** The [SQLITE_FCNTL_MMAP_SIZE] file control is used to query or set the 1007 ** maximum number of bytes that will be used for memory-mapped I/O. 1008 ** The argument is a pointer to a value of type sqlite3_int64 that 1009 ** is an advisory maximum number of bytes in the file to memory map. The 1010 ** pointer is overwritten with the old value. The limit is not changed if 1011 ** the value originally pointed to is negative, and so the current limit 1012 ** can be queried by passing in a pointer to a negative number. This 1013 ** file-control is used internally to implement [PRAGMA mmap_size]. 1014 ** 1015 ** <li>[[SQLITE_FCNTL_TRACE]] 1016 ** The [SQLITE_FCNTL_TRACE] file control provides advisory information 1017 ** to the VFS about what the higher layers of the SQLite stack are doing. 1018 ** This file control is used by some VFS activity tracing [shims]. 1019 ** The argument is a zero-terminated string. Higher layers in the 1020 ** SQLite stack may generate instances of this file control if 1021 ** the [SQLITE_USE_FCNTL_TRACE] compile-time option is enabled. 1022 ** 1023 ** <li>[[SQLITE_FCNTL_HAS_MOVED]] 1024 ** The [SQLITE_FCNTL_HAS_MOVED] file control interprets its argument as a 1025 ** pointer to an integer and it writes a boolean into that integer depending 1026 ** on whether or not the file has been renamed, moved, or deleted since it 1027 ** was first opened. 1028 ** 1029 ** <li>[[SQLITE_FCNTL_WIN32_GET_HANDLE]] 1030 ** The [SQLITE_FCNTL_WIN32_GET_HANDLE] opcode can be used to obtain the 1031 ** underlying native file handle associated with a file handle. This file 1032 ** control interprets its argument as a pointer to a native file handle and 1033 ** writes the resulting value there. 1034 ** 1035 ** <li>[[SQLITE_FCNTL_WIN32_SET_HANDLE]] 1036 ** The [SQLITE_FCNTL_WIN32_SET_HANDLE] opcode is used for debugging. This 1037 ** opcode causes the xFileControl method to swap the file handle with the one 1038 ** pointed to by the pArg argument. This capability is used during testing 1039 ** and only needs to be supported when SQLITE_TEST is defined. 1040 ** 1041 ** <li>[[SQLITE_FCNTL_WAL_BLOCK]] 1042 ** The [SQLITE_FCNTL_WAL_BLOCK] is a signal to the VFS layer that it might 1043 ** be advantageous to block on the next WAL lock if the lock is not immediately 1044 ** available. The WAL subsystem issues this signal during rare 1045 ** circumstances in order to fix a problem with priority inversion. 1046 ** Applications should <em>not</em> use this file-control. 1047 ** 1048 ** <li>[[SQLITE_FCNTL_ZIPVFS]] 1049 ** The [SQLITE_FCNTL_ZIPVFS] opcode is implemented by zipvfs only. All other 1050 ** VFS should return SQLITE_NOTFOUND for this opcode. 1051 ** 1052 ** <li>[[SQLITE_FCNTL_RBU]] 1053 ** The [SQLITE_FCNTL_RBU] opcode is implemented by the special VFS used by 1054 ** the RBU extension only. All other VFS should return SQLITE_NOTFOUND for 1055 ** this opcode. 1056 ** 1057 ** <li>[[SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]] 1058 ** If the [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] opcode returns SQLITE_OK, then 1059 ** the file descriptor is placed in "batch write mode", which 1060 ** means all subsequent write operations will be deferred and done 1061 ** atomically at the next [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]. Systems 1062 ** that do not support batch atomic writes will return SQLITE_NOTFOUND. 1063 ** ^Following a successful SQLITE_FCNTL_BEGIN_ATOMIC_WRITE and prior to 1064 ** the closing [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] or 1065 ** [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE], SQLite will make 1066 ** no VFS interface calls on the same [sqlite3_file] file descriptor 1067 ** except for calls to the xWrite method and the xFileControl method 1068 ** with [SQLITE_FCNTL_SIZE_HINT]. 1069 ** 1070 ** <li>[[SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]] 1071 ** The [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] opcode causes all write 1072 ** operations since the previous successful call to 1073 ** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be performed atomically. 1074 ** This file control returns [SQLITE_OK] if and only if the writes were 1075 ** all performed successfully and have been committed to persistent storage. 1076 ** ^Regardless of whether or not it is successful, this file control takes 1077 ** the file descriptor out of batch write mode so that all subsequent 1078 ** write operations are independent. 1079 ** ^SQLite will never invoke SQLITE_FCNTL_COMMIT_ATOMIC_WRITE without 1080 ** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]. 1081 ** 1082 ** <li>[[SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE]] 1083 ** The [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE] opcode causes all write 1084 ** operations since the previous successful call to 1085 ** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be rolled back. 1086 ** ^This file control takes the file descriptor out of batch write mode 1087 ** so that all subsequent write operations are independent. 1088 ** ^SQLite will never invoke SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE without 1089 ** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]. 1090 ** 1091 ** <li>[[SQLITE_FCNTL_LOCK_TIMEOUT]] 1092 ** The [SQLITE_FCNTL_LOCK_TIMEOUT] opcode is used to configure a VFS 1093 ** to block for up to M milliseconds before failing when attempting to 1094 ** obtain a file lock using the xLock or xShmLock methods of the VFS. 1095 ** The parameter is a pointer to a 32-bit signed integer that contains 1096 ** the value that M is to be set to. Before returning, the 32-bit signed 1097 ** integer is overwritten with the previous value of M. 1098 ** 1099 ** <li>[[SQLITE_FCNTL_DATA_VERSION]] 1100 ** The [SQLITE_FCNTL_DATA_VERSION] opcode is used to detect changes to 1101 ** a database file. The argument is a pointer to a 32-bit unsigned integer. 1102 ** The "data version" for the pager is written into the pointer. The 1103 ** "data version" changes whenever any change occurs to the corresponding 1104 ** database file, either through SQL statements on the same database 1105 ** connection or through transactions committed by separate database 1106 ** connections possibly in other processes. The [sqlite3_total_changes()] 1107 ** interface can be used to find if any database on the connection has changed, 1108 ** but that interface responds to changes on TEMP as well as MAIN and does 1109 ** not provide a mechanism to detect changes to MAIN only. Also, the 1110 ** [sqlite3_total_changes()] interface responds to internal changes only and 1111 ** omits changes made by other database connections. The 1112 ** [PRAGMA data_version] command provides a mechanism to detect changes to 1113 ** a single attached database that occur due to other database connections, 1114 ** but omits changes implemented by the database connection on which it is 1115 ** called. This file control is the only mechanism to detect changes that 1116 ** happen either internally or externally and that are associated with 1117 ** a particular attached database. 1118 ** 1119 ** <li>[[SQLITE_FCNTL_CKPT_START]] 1120 ** The [SQLITE_FCNTL_CKPT_START] opcode is invoked from within a checkpoint 1121 ** in wal mode before the client starts to copy pages from the wal 1122 ** file to the database file. 1123 ** 1124 ** <li>[[SQLITE_FCNTL_CKPT_DONE]] 1125 ** The [SQLITE_FCNTL_CKPT_DONE] opcode is invoked from within a checkpoint 1126 ** in wal mode after the client has finished copying pages from the wal 1127 ** file to the database file, but before the *-shm file is updated to 1128 ** record the fact that the pages have been checkpointed. 1129 ** </ul> 1130 */ 1131 #define SQLITE_FCNTL_LOCKSTATE 1 1132 #define SQLITE_FCNTL_GET_LOCKPROXYFILE 2 1133 #define SQLITE_FCNTL_SET_LOCKPROXYFILE 3 1134 #define SQLITE_FCNTL_LAST_ERRNO 4 1135 #define SQLITE_FCNTL_SIZE_HINT 5 1136 #define SQLITE_FCNTL_CHUNK_SIZE 6 1137 #define SQLITE_FCNTL_FILE_POINTER 7 1138 #define SQLITE_FCNTL_SYNC_OMITTED 8 1139 #define SQLITE_FCNTL_WIN32_AV_RETRY 9 1140 #define SQLITE_FCNTL_PERSIST_WAL 10 1141 #define SQLITE_FCNTL_OVERWRITE 11 1142 #define SQLITE_FCNTL_VFSNAME 12 1143 #define SQLITE_FCNTL_POWERSAFE_OVERWRITE 13 1144 #define SQLITE_FCNTL_PRAGMA 14 1145 #define SQLITE_FCNTL_BUSYHANDLER 15 1146 #define SQLITE_FCNTL_TEMPFILENAME 16 1147 #define SQLITE_FCNTL_MMAP_SIZE 18 1148 #define SQLITE_FCNTL_TRACE 19 1149 #define SQLITE_FCNTL_HAS_MOVED 20 1150 #define SQLITE_FCNTL_SYNC 21 1151 #define SQLITE_FCNTL_COMMIT_PHASETWO 22 1152 #define SQLITE_FCNTL_WIN32_SET_HANDLE 23 1153 #define SQLITE_FCNTL_WAL_BLOCK 24 1154 #define SQLITE_FCNTL_ZIPVFS 25 1155 #define SQLITE_FCNTL_RBU 26 1156 #define SQLITE_FCNTL_VFS_POINTER 27 1157 #define SQLITE_FCNTL_JOURNAL_POINTER 28 1158 #define SQLITE_FCNTL_WIN32_GET_HANDLE 29 1159 #define SQLITE_FCNTL_PDB 30 1160 #define SQLITE_FCNTL_BEGIN_ATOMIC_WRITE 31 1161 #define SQLITE_FCNTL_COMMIT_ATOMIC_WRITE 32 1162 #define SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE 33 1163 #define SQLITE_FCNTL_LOCK_TIMEOUT 34 1164 #define SQLITE_FCNTL_DATA_VERSION 35 1165 #define SQLITE_FCNTL_SIZE_LIMIT 36 1166 #define SQLITE_FCNTL_CKPT_DONE 37 1167 #define SQLITE_FCNTL_RESERVE_BYTES 38 1168 #define SQLITE_FCNTL_CKPT_START 39 1169 1170 /* deprecated names */ 1171 #define SQLITE_GET_LOCKPROXYFILE SQLITE_FCNTL_GET_LOCKPROXYFILE 1172 #define SQLITE_SET_LOCKPROXYFILE SQLITE_FCNTL_SET_LOCKPROXYFILE 1173 #define SQLITE_LAST_ERRNO SQLITE_FCNTL_LAST_ERRNO 1174 1175 1176 /* 1177 ** CAPI3REF: Mutex Handle 1178 ** 1179 ** The mutex module within SQLite defines [sqlite3_mutex] to be an 1180 ** abstract type for a mutex object. The SQLite core never looks 1181 ** at the internal representation of an [sqlite3_mutex]. It only 1182 ** deals with pointers to the [sqlite3_mutex] object. 1183 ** 1184 ** Mutexes are created using [sqlite3_mutex_alloc()]. 1185 */ 1186 typedef struct sqlite3_mutex sqlite3_mutex; 1187 1188 /* 1189 ** CAPI3REF: Loadable Extension Thunk 1190 ** 1191 ** A pointer to the opaque sqlite3_api_routines structure is passed as 1192 ** the third parameter to entry points of [loadable extensions]. This 1193 ** structure must be typedefed in order to work around compiler warnings 1194 ** on some platforms. 1195 */ 1196 typedef struct sqlite3_api_routines sqlite3_api_routines; 1197 1198 /* 1199 ** CAPI3REF: OS Interface Object 1200 ** 1201 ** An instance of the sqlite3_vfs object defines the interface between 1202 ** the SQLite core and the underlying operating system. The "vfs" 1203 ** in the name of the object stands for "virtual file system". See 1204 ** the [VFS | VFS documentation] for further information. 1205 ** 1206 ** The VFS interface is sometimes extended by adding new methods onto 1207 ** the end. Each time such an extension occurs, the iVersion field 1208 ** is incremented. The iVersion value started out as 1 in 1209 ** SQLite [version 3.5.0] on [dateof:3.5.0], then increased to 2 1210 ** with SQLite [version 3.7.0] on [dateof:3.7.0], and then increased 1211 ** to 3 with SQLite [version 3.7.6] on [dateof:3.7.6]. Additional fields 1212 ** may be appended to the sqlite3_vfs object and the iVersion value 1213 ** may increase again in future versions of SQLite. 1214 ** Note that due to an oversight, the structure 1215 ** of the sqlite3_vfs object changed in the transition from 1216 ** SQLite [version 3.5.9] to [version 3.6.0] on [dateof:3.6.0] 1217 ** and yet the iVersion field was not increased. 1218 ** 1219 ** The szOsFile field is the size of the subclassed [sqlite3_file] 1220 ** structure used by this VFS. mxPathname is the maximum length of 1221 ** a pathname in this VFS. 1222 ** 1223 ** Registered sqlite3_vfs objects are kept on a linked list formed by 1224 ** the pNext pointer. The [sqlite3_vfs_register()] 1225 ** and [sqlite3_vfs_unregister()] interfaces manage this list 1226 ** in a thread-safe way. The [sqlite3_vfs_find()] interface 1227 ** searches the list. Neither the application code nor the VFS 1228 ** implementation should use the pNext pointer. 1229 ** 1230 ** The pNext field is the only field in the sqlite3_vfs 1231 ** structure that SQLite will ever modify. SQLite will only access 1232 ** or modify this field while holding a particular static mutex. 1233 ** The application should never modify anything within the sqlite3_vfs 1234 ** object once the object has been registered. 1235 ** 1236 ** The zName field holds the name of the VFS module. The name must 1237 ** be unique across all VFS modules. 1238 ** 1239 ** [[sqlite3_vfs.xOpen]] 1240 ** ^SQLite guarantees that the zFilename parameter to xOpen 1241 ** is either a NULL pointer or string obtained 1242 ** from xFullPathname() with an optional suffix added. 1243 ** ^If a suffix is added to the zFilename parameter, it will 1244 ** consist of a single "-" character followed by no more than 1245 ** 11 alphanumeric and/or "-" characters. 1246 ** ^SQLite further guarantees that 1247 ** the string will be valid and unchanged until xClose() is 1248 ** called. Because of the previous sentence, 1249 ** the [sqlite3_file] can safely store a pointer to the 1250 ** filename if it needs to remember the filename for some reason. 1251 ** If the zFilename parameter to xOpen is a NULL pointer then xOpen 1252 ** must invent its own temporary name for the file. ^Whenever the 1253 ** xFilename parameter is NULL it will also be the case that the 1254 ** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE]. 1255 ** 1256 ** The flags argument to xOpen() includes all bits set in 1257 ** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()] 1258 ** or [sqlite3_open16()] is used, then flags includes at least 1259 ** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]. 1260 ** If xOpen() opens a file read-only then it sets *pOutFlags to 1261 ** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be set. 1262 ** 1263 ** ^(SQLite will also add one of the following flags to the xOpen() 1264 ** call, depending on the object being opened: 1265 ** 1266 ** <ul> 1267 ** <li> [SQLITE_OPEN_MAIN_DB] 1268 ** <li> [SQLITE_OPEN_MAIN_JOURNAL] 1269 ** <li> [SQLITE_OPEN_TEMP_DB] 1270 ** <li> [SQLITE_OPEN_TEMP_JOURNAL] 1271 ** <li> [SQLITE_OPEN_TRANSIENT_DB] 1272 ** <li> [SQLITE_OPEN_SUBJOURNAL] 1273 ** <li> [SQLITE_OPEN_SUPER_JOURNAL] 1274 ** <li> [SQLITE_OPEN_WAL] 1275 ** </ul>)^ 1276 ** 1277 ** The file I/O implementation can use the object type flags to 1278 ** change the way it deals with files. For example, an application 1279 ** that does not care about crash recovery or rollback might make 1280 ** the open of a journal file a no-op. Writes to this journal would 1281 ** also be no-ops, and any attempt to read the journal would return 1282 ** SQLITE_IOERR. Or the implementation might recognize that a database 1283 ** file will be doing page-aligned sector reads and writes in a random 1284 ** order and set up its I/O subsystem accordingly. 1285 ** 1286 ** SQLite might also add one of the following flags to the xOpen method: 1287 ** 1288 ** <ul> 1289 ** <li> [SQLITE_OPEN_DELETEONCLOSE] 1290 ** <li> [SQLITE_OPEN_EXCLUSIVE] 1291 ** </ul> 1292 ** 1293 ** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be 1294 ** deleted when it is closed. ^The [SQLITE_OPEN_DELETEONCLOSE] 1295 ** will be set for TEMP databases and their journals, transient 1296 ** databases, and subjournals. 1297 ** 1298 ** ^The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction 1299 ** with the [SQLITE_OPEN_CREATE] flag, which are both directly 1300 ** analogous to the O_EXCL and O_CREAT flags of the POSIX open() 1301 ** API. The SQLITE_OPEN_EXCLUSIVE flag, when paired with the 1302 ** SQLITE_OPEN_CREATE, is used to indicate that file should always 1303 ** be created, and that it is an error if it already exists. 1304 ** It is <i>not</i> used to indicate the file should be opened 1305 ** for exclusive access. 1306 ** 1307 ** ^At least szOsFile bytes of memory are allocated by SQLite 1308 ** to hold the [sqlite3_file] structure passed as the third 1309 ** argument to xOpen. The xOpen method does not have to 1310 ** allocate the structure; it should just fill it in. Note that 1311 ** the xOpen method must set the sqlite3_file.pMethods to either 1312 ** a valid [sqlite3_io_methods] object or to NULL. xOpen must do 1313 ** this even if the open fails. SQLite expects that the sqlite3_file.pMethods 1314 ** element will be valid after xOpen returns regardless of the success 1315 ** or failure of the xOpen call. 1316 ** 1317 ** [[sqlite3_vfs.xAccess]] 1318 ** ^The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS] 1319 ** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to 1320 ** test whether a file is readable and writable, or [SQLITE_ACCESS_READ] 1321 ** to test whether a file is at least readable. The SQLITE_ACCESS_READ 1322 ** flag is never actually used and is not implemented in the built-in 1323 ** VFSes of SQLite. The file is named by the second argument and can be a 1324 ** directory. The xAccess method returns [SQLITE_OK] on success or some 1325 ** non-zero error code if there is an I/O error or if the name of 1326 ** the file given in the second argument is illegal. If SQLITE_OK 1327 ** is returned, then non-zero or zero is written into *pResOut to indicate 1328 ** whether or not the file is accessible. 1329 ** 1330 ** ^SQLite will always allocate at least mxPathname+1 bytes for the 1331 ** output buffer xFullPathname. The exact size of the output buffer 1332 ** is also passed as a parameter to both methods. If the output buffer 1333 ** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is 1334 ** handled as a fatal error by SQLite, vfs implementations should endeavor 1335 ** to prevent this by setting mxPathname to a sufficiently large value. 1336 ** 1337 ** The xRandomness(), xSleep(), xCurrentTime(), and xCurrentTimeInt64() 1338 ** interfaces are not strictly a part of the filesystem, but they are 1339 ** included in the VFS structure for completeness. 1340 ** The xRandomness() function attempts to return nBytes bytes 1341 ** of good-quality randomness into zOut. The return value is 1342 ** the actual number of bytes of randomness obtained. 1343 ** The xSleep() method causes the calling thread to sleep for at 1344 ** least the number of microseconds given. ^The xCurrentTime() 1345 ** method returns a Julian Day Number for the current date and time as 1346 ** a floating point value. 1347 ** ^The xCurrentTimeInt64() method returns, as an integer, the Julian 1348 ** Day Number multiplied by 86400000 (the number of milliseconds in 1349 ** a 24-hour day). 1350 ** ^SQLite will use the xCurrentTimeInt64() method to get the current 1351 ** date and time if that method is available (if iVersion is 2 or 1352 ** greater and the function pointer is not NULL) and will fall back 1353 ** to xCurrentTime() if xCurrentTimeInt64() is unavailable. 1354 ** 1355 ** ^The xSetSystemCall(), xGetSystemCall(), and xNestSystemCall() interfaces 1356 ** are not used by the SQLite core. These optional interfaces are provided 1357 ** by some VFSes to facilitate testing of the VFS code. By overriding 1358 ** system calls with functions under its control, a test program can 1359 ** simulate faults and error conditions that would otherwise be difficult 1360 ** or impossible to induce. The set of system calls that can be overridden 1361 ** varies from one VFS to another, and from one version of the same VFS to the 1362 ** next. Applications that use these interfaces must be prepared for any 1363 ** or all of these interfaces to be NULL or for their behavior to change 1364 ** from one release to the next. Applications must not attempt to access 1365 ** any of these methods if the iVersion of the VFS is less than 3. 1366 */ 1367 typedef struct sqlite3_vfs sqlite3_vfs; 1368 typedef void (*sqlite3_syscall_ptr)(void); 1369 struct sqlite3_vfs { 1370 int iVersion; /* Structure version number (currently 3) */ 1371 int szOsFile; /* Size of subclassed sqlite3_file */ 1372 int mxPathname; /* Maximum file pathname length */ 1373 sqlite3_vfs *pNext; /* Next registered VFS */ 1374 const char *zName; /* Name of this virtual file system */ 1375 void *pAppData; /* Pointer to application-specific data */ 1376 int (*xOpen)(sqlite3_vfs*, const char *zName, sqlite3_file*, 1377 int flags, int *pOutFlags); 1378 int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir); 1379 int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut); 1380 int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut); 1381 void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename); 1382 void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg); 1383 void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void); 1384 void (*xDlClose)(sqlite3_vfs*, void*); 1385 int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut); 1386 int (*xSleep)(sqlite3_vfs*, int microseconds); 1387 int (*xCurrentTime)(sqlite3_vfs*, double*); 1388 int (*xGetLastError)(sqlite3_vfs*, int, char *); 1389 /* 1390 ** The methods above are in version 1 of the sqlite_vfs object 1391 ** definition. Those that follow are added in version 2 or later 1392 */ 1393 int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*); 1394 /* 1395 ** The methods above are in versions 1 and 2 of the sqlite_vfs object. 1396 ** Those below are for version 3 and greater. 1397 */ 1398 int (*xSetSystemCall)(sqlite3_vfs*, const char *zName, sqlite3_syscall_ptr); 1399 sqlite3_syscall_ptr (*xGetSystemCall)(sqlite3_vfs*, const char *zName); 1400 const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName); 1401 /* 1402 ** The methods above are in versions 1 through 3 of the sqlite_vfs object. 1403 ** New fields may be appended in future versions. The iVersion 1404 ** value will increment whenever this happens. 1405 */ 1406 }; 1407 1408 /* 1409 ** CAPI3REF: Flags for the xAccess VFS method 1410 ** 1411 ** These integer constants can be used as the third parameter to 1412 ** the xAccess method of an [sqlite3_vfs] object. They determine 1413 ** what kind of permissions the xAccess method is looking for. 1414 ** With SQLITE_ACCESS_EXISTS, the xAccess method 1415 ** simply checks whether the file exists. 1416 ** With SQLITE_ACCESS_READWRITE, the xAccess method 1417 ** checks whether the named directory is both readable and writable 1418 ** (in other words, if files can be added, removed, and renamed within 1419 ** the directory). 1420 ** The SQLITE_ACCESS_READWRITE constant is currently used only by the 1421 ** [temp_store_directory pragma], though this could change in a future 1422 ** release of SQLite. 1423 ** With SQLITE_ACCESS_READ, the xAccess method 1424 ** checks whether the file is readable. The SQLITE_ACCESS_READ constant is 1425 ** currently unused, though it might be used in a future release of 1426 ** SQLite. 1427 */ 1428 #define SQLITE_ACCESS_EXISTS 0 1429 #define SQLITE_ACCESS_READWRITE 1 /* Used by PRAGMA temp_store_directory */ 1430 #define SQLITE_ACCESS_READ 2 /* Unused */ 1431 1432 /* 1433 ** CAPI3REF: Flags for the xShmLock VFS method 1434 ** 1435 ** These integer constants define the various locking operations 1436 ** allowed by the xShmLock method of [sqlite3_io_methods]. The 1437 ** following are the only legal combinations of flags to the 1438 ** xShmLock method: 1439 ** 1440 ** <ul> 1441 ** <li> SQLITE_SHM_LOCK | SQLITE_SHM_SHARED 1442 ** <li> SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE 1443 ** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED 1444 ** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE 1445 ** </ul> 1446 ** 1447 ** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as 1448 ** was given on the corresponding lock. 1449 ** 1450 ** The xShmLock method can transition between unlocked and SHARED or 1451 ** between unlocked and EXCLUSIVE. It cannot transition between SHARED 1452 ** and EXCLUSIVE. 1453 */ 1454 #define SQLITE_SHM_UNLOCK 1 1455 #define SQLITE_SHM_LOCK 2 1456 #define SQLITE_SHM_SHARED 4 1457 #define SQLITE_SHM_EXCLUSIVE 8 1458 1459 /* 1460 ** CAPI3REF: Maximum xShmLock index 1461 ** 1462 ** The xShmLock method on [sqlite3_io_methods] may use values 1463 ** between 0 and this upper bound as its "offset" argument. 1464 ** The SQLite core will never attempt to acquire or release a 1465 ** lock outside of this range 1466 */ 1467 #define SQLITE_SHM_NLOCK 8 1468 1469 1470 /* 1471 ** CAPI3REF: Initialize The SQLite Library 1472 ** 1473 ** ^The sqlite3_initialize() routine initializes the 1474 ** SQLite library. ^The sqlite3_shutdown() routine 1475 ** deallocates any resources that were allocated by sqlite3_initialize(). 1476 ** These routines are designed to aid in process initialization and 1477 ** shutdown on embedded systems. Workstation applications using 1478 ** SQLite normally do not need to invoke either of these routines. 1479 ** 1480 ** A call to sqlite3_initialize() is an "effective" call if it is 1481 ** the first time sqlite3_initialize() is invoked during the lifetime of 1482 ** the process, or if it is the first time sqlite3_initialize() is invoked 1483 ** following a call to sqlite3_shutdown(). ^(Only an effective call 1484 ** of sqlite3_initialize() does any initialization. All other calls 1485 ** are harmless no-ops.)^ 1486 ** 1487 ** A call to sqlite3_shutdown() is an "effective" call if it is the first 1488 ** call to sqlite3_shutdown() since the last sqlite3_initialize(). ^(Only 1489 ** an effective call to sqlite3_shutdown() does any deinitialization. 1490 ** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^ 1491 ** 1492 ** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown() 1493 ** is not. The sqlite3_shutdown() interface must only be called from a 1494 ** single thread. All open [database connections] must be closed and all 1495 ** other SQLite resources must be deallocated prior to invoking 1496 ** sqlite3_shutdown(). 1497 ** 1498 ** Among other things, ^sqlite3_initialize() will invoke 1499 ** sqlite3_os_init(). Similarly, ^sqlite3_shutdown() 1500 ** will invoke sqlite3_os_end(). 1501 ** 1502 ** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success. 1503 ** ^If for some reason, sqlite3_initialize() is unable to initialize 1504 ** the library (perhaps it is unable to allocate a needed resource such 1505 ** as a mutex) it returns an [error code] other than [SQLITE_OK]. 1506 ** 1507 ** ^The sqlite3_initialize() routine is called internally by many other 1508 ** SQLite interfaces so that an application usually does not need to 1509 ** invoke sqlite3_initialize() directly. For example, [sqlite3_open()] 1510 ** calls sqlite3_initialize() so the SQLite library will be automatically 1511 ** initialized when [sqlite3_open()] is called if it has not be initialized 1512 ** already. ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT] 1513 ** compile-time option, then the automatic calls to sqlite3_initialize() 1514 ** are omitted and the application must call sqlite3_initialize() directly 1515 ** prior to using any other SQLite interface. For maximum portability, 1516 ** it is recommended that applications always invoke sqlite3_initialize() 1517 ** directly prior to using any other SQLite interface. Future releases 1518 ** of SQLite may require this. In other words, the behavior exhibited 1519 ** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the 1520 ** default behavior in some future release of SQLite. 1521 ** 1522 ** The sqlite3_os_init() routine does operating-system specific 1523 ** initialization of the SQLite library. The sqlite3_os_end() 1524 ** routine undoes the effect of sqlite3_os_init(). Typical tasks 1525 ** performed by these routines include allocation or deallocation 1526 ** of static resources, initialization of global variables, 1527 ** setting up a default [sqlite3_vfs] module, or setting up 1528 ** a default configuration using [sqlite3_config()]. 1529 ** 1530 ** The application should never invoke either sqlite3_os_init() 1531 ** or sqlite3_os_end() directly. The application should only invoke 1532 ** sqlite3_initialize() and sqlite3_shutdown(). The sqlite3_os_init() 1533 ** interface is called automatically by sqlite3_initialize() and 1534 ** sqlite3_os_end() is called by sqlite3_shutdown(). Appropriate 1535 ** implementations for sqlite3_os_init() and sqlite3_os_end() 1536 ** are built into SQLite when it is compiled for Unix, Windows, or OS/2. 1537 ** When [custom builds | built for other platforms] 1538 ** (using the [SQLITE_OS_OTHER=1] compile-time 1539 ** option) the application must supply a suitable implementation for 1540 ** sqlite3_os_init() and sqlite3_os_end(). An application-supplied 1541 ** implementation of sqlite3_os_init() or sqlite3_os_end() 1542 ** must return [SQLITE_OK] on success and some other [error code] upon 1543 ** failure. 1544 */ 1545 SQLITE_API int sqlite3_initialize(void); 1546 SQLITE_API int sqlite3_shutdown(void); 1547 SQLITE_API int sqlite3_os_init(void); 1548 SQLITE_API int sqlite3_os_end(void); 1549 1550 /* 1551 ** CAPI3REF: Configuring The SQLite Library 1552 ** 1553 ** The sqlite3_config() interface is used to make global configuration 1554 ** changes to SQLite in order to tune SQLite to the specific needs of 1555 ** the application. The default configuration is recommended for most 1556 ** applications and so this routine is usually not necessary. It is 1557 ** provided to support rare applications with unusual needs. 1558 ** 1559 ** <b>The sqlite3_config() interface is not threadsafe. The application 1560 ** must ensure that no other SQLite interfaces are invoked by other 1561 ** threads while sqlite3_config() is running.</b> 1562 ** 1563 ** The sqlite3_config() interface 1564 ** may only be invoked prior to library initialization using 1565 ** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()]. 1566 ** ^If sqlite3_config() is called after [sqlite3_initialize()] and before 1567 ** [sqlite3_shutdown()] then it will return SQLITE_MISUSE. 1568 ** Note, however, that ^sqlite3_config() can be called as part of the 1569 ** implementation of an application-defined [sqlite3_os_init()]. 1570 ** 1571 ** The first argument to sqlite3_config() is an integer 1572 ** [configuration option] that determines 1573 ** what property of SQLite is to be configured. Subsequent arguments 1574 ** vary depending on the [configuration option] 1575 ** in the first argument. 1576 ** 1577 ** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK]. 1578 ** ^If the option is unknown or SQLite is unable to set the option 1579 ** then this routine returns a non-zero [error code]. 1580 */ 1581 SQLITE_API int sqlite3_config(int, ...); 1582 1583 /* 1584 ** CAPI3REF: Configure database connections 1585 ** METHOD: sqlite3 1586 ** 1587 ** The sqlite3_db_config() interface is used to make configuration 1588 ** changes to a [database connection]. The interface is similar to 1589 ** [sqlite3_config()] except that the changes apply to a single 1590 ** [database connection] (specified in the first argument). 1591 ** 1592 ** The second argument to sqlite3_db_config(D,V,...) is the 1593 ** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code 1594 ** that indicates what aspect of the [database connection] is being configured. 1595 ** Subsequent arguments vary depending on the configuration verb. 1596 ** 1597 ** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if 1598 ** the call is considered successful. 1599 */ 1600 SQLITE_API int sqlite3_db_config(sqlite3*, int op, ...); 1601 1602 /* 1603 ** CAPI3REF: Memory Allocation Routines 1604 ** 1605 ** An instance of this object defines the interface between SQLite 1606 ** and low-level memory allocation routines. 1607 ** 1608 ** This object is used in only one place in the SQLite interface. 1609 ** A pointer to an instance of this object is the argument to 1610 ** [sqlite3_config()] when the configuration option is 1611 ** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC]. 1612 ** By creating an instance of this object 1613 ** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC]) 1614 ** during configuration, an application can specify an alternative 1615 ** memory allocation subsystem for SQLite to use for all of its 1616 ** dynamic memory needs. 1617 ** 1618 ** Note that SQLite comes with several [built-in memory allocators] 1619 ** that are perfectly adequate for the overwhelming majority of applications 1620 ** and that this object is only useful to a tiny minority of applications 1621 ** with specialized memory allocation requirements. This object is 1622 ** also used during testing of SQLite in order to specify an alternative 1623 ** memory allocator that simulates memory out-of-memory conditions in 1624 ** order to verify that SQLite recovers gracefully from such 1625 ** conditions. 1626 ** 1627 ** The xMalloc, xRealloc, and xFree methods must work like the 1628 ** malloc(), realloc() and free() functions from the standard C library. 1629 ** ^SQLite guarantees that the second argument to 1630 ** xRealloc is always a value returned by a prior call to xRoundup. 1631 ** 1632 ** xSize should return the allocated size of a memory allocation 1633 ** previously obtained from xMalloc or xRealloc. The allocated size 1634 ** is always at least as big as the requested size but may be larger. 1635 ** 1636 ** The xRoundup method returns what would be the allocated size of 1637 ** a memory allocation given a particular requested size. Most memory 1638 ** allocators round up memory allocations at least to the next multiple 1639 ** of 8. Some allocators round up to a larger multiple or to a power of 2. 1640 ** Every memory allocation request coming in through [sqlite3_malloc()] 1641 ** or [sqlite3_realloc()] first calls xRoundup. If xRoundup returns 0, 1642 ** that causes the corresponding memory allocation to fail. 1643 ** 1644 ** The xInit method initializes the memory allocator. For example, 1645 ** it might allocate any required mutexes or initialize internal data 1646 ** structures. The xShutdown method is invoked (indirectly) by 1647 ** [sqlite3_shutdown()] and should deallocate any resources acquired 1648 ** by xInit. The pAppData pointer is used as the only parameter to 1649 ** xInit and xShutdown. 1650 ** 1651 ** SQLite holds the [SQLITE_MUTEX_STATIC_MAIN] mutex when it invokes 1652 ** the xInit method, so the xInit method need not be threadsafe. The 1653 ** xShutdown method is only called from [sqlite3_shutdown()] so it does 1654 ** not need to be threadsafe either. For all other methods, SQLite 1655 ** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the 1656 ** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which 1657 ** it is by default) and so the methods are automatically serialized. 1658 ** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other 1659 ** methods must be threadsafe or else make their own arrangements for 1660 ** serialization. 1661 ** 1662 ** SQLite will never invoke xInit() more than once without an intervening 1663 ** call to xShutdown(). 1664 */ 1665 typedef struct sqlite3_mem_methods sqlite3_mem_methods; 1666 struct sqlite3_mem_methods { 1667 void *(*xMalloc)(int); /* Memory allocation function */ 1668 void (*xFree)(void*); /* Free a prior allocation */ 1669 void *(*xRealloc)(void*,int); /* Resize an allocation */ 1670 int (*xSize)(void*); /* Return the size of an allocation */ 1671 int (*xRoundup)(int); /* Round up request size to allocation size */ 1672 int (*xInit)(void*); /* Initialize the memory allocator */ 1673 void (*xShutdown)(void*); /* Deinitialize the memory allocator */ 1674 void *pAppData; /* Argument to xInit() and xShutdown() */ 1675 }; 1676 1677 /* 1678 ** CAPI3REF: Configuration Options 1679 ** KEYWORDS: {configuration option} 1680 ** 1681 ** These constants are the available integer configuration options that 1682 ** can be passed as the first argument to the [sqlite3_config()] interface. 1683 ** 1684 ** New configuration options may be added in future releases of SQLite. 1685 ** Existing configuration options might be discontinued. Applications 1686 ** should check the return code from [sqlite3_config()] to make sure that 1687 ** the call worked. The [sqlite3_config()] interface will return a 1688 ** non-zero [error code] if a discontinued or unsupported configuration option 1689 ** is invoked. 1690 ** 1691 ** <dl> 1692 ** [[SQLITE_CONFIG_SINGLETHREAD]] <dt>SQLITE_CONFIG_SINGLETHREAD</dt> 1693 ** <dd>There are no arguments to this option. ^This option sets the 1694 ** [threading mode] to Single-thread. In other words, it disables 1695 ** all mutexing and puts SQLite into a mode where it can only be used 1696 ** by a single thread. ^If SQLite is compiled with 1697 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1698 ** it is not possible to change the [threading mode] from its default 1699 ** value of Single-thread and so [sqlite3_config()] will return 1700 ** [SQLITE_ERROR] if called with the SQLITE_CONFIG_SINGLETHREAD 1701 ** configuration option.</dd> 1702 ** 1703 ** [[SQLITE_CONFIG_MULTITHREAD]] <dt>SQLITE_CONFIG_MULTITHREAD</dt> 1704 ** <dd>There are no arguments to this option. ^This option sets the 1705 ** [threading mode] to Multi-thread. In other words, it disables 1706 ** mutexing on [database connection] and [prepared statement] objects. 1707 ** The application is responsible for serializing access to 1708 ** [database connections] and [prepared statements]. But other mutexes 1709 ** are enabled so that SQLite will be safe to use in a multi-threaded 1710 ** environment as long as no two threads attempt to use the same 1711 ** [database connection] at the same time. ^If SQLite is compiled with 1712 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1713 ** it is not possible to set the Multi-thread [threading mode] and 1714 ** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1715 ** SQLITE_CONFIG_MULTITHREAD configuration option.</dd> 1716 ** 1717 ** [[SQLITE_CONFIG_SERIALIZED]] <dt>SQLITE_CONFIG_SERIALIZED</dt> 1718 ** <dd>There are no arguments to this option. ^This option sets the 1719 ** [threading mode] to Serialized. In other words, this option enables 1720 ** all mutexes including the recursive 1721 ** mutexes on [database connection] and [prepared statement] objects. 1722 ** In this mode (which is the default when SQLite is compiled with 1723 ** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access 1724 ** to [database connections] and [prepared statements] so that the 1725 ** application is free to use the same [database connection] or the 1726 ** same [prepared statement] in different threads at the same time. 1727 ** ^If SQLite is compiled with 1728 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1729 ** it is not possible to set the Serialized [threading mode] and 1730 ** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1731 ** SQLITE_CONFIG_SERIALIZED configuration option.</dd> 1732 ** 1733 ** [[SQLITE_CONFIG_MALLOC]] <dt>SQLITE_CONFIG_MALLOC</dt> 1734 ** <dd> ^(The SQLITE_CONFIG_MALLOC option takes a single argument which is 1735 ** a pointer to an instance of the [sqlite3_mem_methods] structure. 1736 ** The argument specifies 1737 ** alternative low-level memory allocation routines to be used in place of 1738 ** the memory allocation routines built into SQLite.)^ ^SQLite makes 1739 ** its own private copy of the content of the [sqlite3_mem_methods] structure 1740 ** before the [sqlite3_config()] call returns.</dd> 1741 ** 1742 ** [[SQLITE_CONFIG_GETMALLOC]] <dt>SQLITE_CONFIG_GETMALLOC</dt> 1743 ** <dd> ^(The SQLITE_CONFIG_GETMALLOC option takes a single argument which 1744 ** is a pointer to an instance of the [sqlite3_mem_methods] structure. 1745 ** The [sqlite3_mem_methods] 1746 ** structure is filled with the currently defined memory allocation routines.)^ 1747 ** This option can be used to overload the default memory allocation 1748 ** routines with a wrapper that simulations memory allocation failure or 1749 ** tracks memory usage, for example. </dd> 1750 ** 1751 ** [[SQLITE_CONFIG_SMALL_MALLOC]] <dt>SQLITE_CONFIG_SMALL_MALLOC</dt> 1752 ** <dd> ^The SQLITE_CONFIG_SMALL_MALLOC option takes single argument of 1753 ** type int, interpreted as a boolean, which if true provides a hint to 1754 ** SQLite that it should avoid large memory allocations if possible. 1755 ** SQLite will run faster if it is free to make large memory allocations, 1756 ** but some application might prefer to run slower in exchange for 1757 ** guarantees about memory fragmentation that are possible if large 1758 ** allocations are avoided. This hint is normally off. 1759 ** </dd> 1760 ** 1761 ** [[SQLITE_CONFIG_MEMSTATUS]] <dt>SQLITE_CONFIG_MEMSTATUS</dt> 1762 ** <dd> ^The SQLITE_CONFIG_MEMSTATUS option takes single argument of type int, 1763 ** interpreted as a boolean, which enables or disables the collection of 1764 ** memory allocation statistics. ^(When memory allocation statistics are 1765 ** disabled, the following SQLite interfaces become non-operational: 1766 ** <ul> 1767 ** <li> [sqlite3_hard_heap_limit64()] 1768 ** <li> [sqlite3_memory_used()] 1769 ** <li> [sqlite3_memory_highwater()] 1770 ** <li> [sqlite3_soft_heap_limit64()] 1771 ** <li> [sqlite3_status64()] 1772 ** </ul>)^ 1773 ** ^Memory allocation statistics are enabled by default unless SQLite is 1774 ** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory 1775 ** allocation statistics are disabled by default. 1776 ** </dd> 1777 ** 1778 ** [[SQLITE_CONFIG_SCRATCH]] <dt>SQLITE_CONFIG_SCRATCH</dt> 1779 ** <dd> The SQLITE_CONFIG_SCRATCH option is no longer used. 1780 ** </dd> 1781 ** 1782 ** [[SQLITE_CONFIG_PAGECACHE]] <dt>SQLITE_CONFIG_PAGECACHE</dt> 1783 ** <dd> ^The SQLITE_CONFIG_PAGECACHE option specifies a memory pool 1784 ** that SQLite can use for the database page cache with the default page 1785 ** cache implementation. 1786 ** This configuration option is a no-op if an application-defined page 1787 ** cache implementation is loaded using the [SQLITE_CONFIG_PCACHE2]. 1788 ** ^There are three arguments to SQLITE_CONFIG_PAGECACHE: A pointer to 1789 ** 8-byte aligned memory (pMem), the size of each page cache line (sz), 1790 ** and the number of cache lines (N). 1791 ** The sz argument should be the size of the largest database page 1792 ** (a power of two between 512 and 65536) plus some extra bytes for each 1793 ** page header. ^The number of extra bytes needed by the page header 1794 ** can be determined using [SQLITE_CONFIG_PCACHE_HDRSZ]. 1795 ** ^It is harmless, apart from the wasted memory, 1796 ** for the sz parameter to be larger than necessary. The pMem 1797 ** argument must be either a NULL pointer or a pointer to an 8-byte 1798 ** aligned block of memory of at least sz*N bytes, otherwise 1799 ** subsequent behavior is undefined. 1800 ** ^When pMem is not NULL, SQLite will strive to use the memory provided 1801 ** to satisfy page cache needs, falling back to [sqlite3_malloc()] if 1802 ** a page cache line is larger than sz bytes or if all of the pMem buffer 1803 ** is exhausted. 1804 ** ^If pMem is NULL and N is non-zero, then each database connection 1805 ** does an initial bulk allocation for page cache memory 1806 ** from [sqlite3_malloc()] sufficient for N cache lines if N is positive or 1807 ** of -1024*N bytes if N is negative, . ^If additional 1808 ** page cache memory is needed beyond what is provided by the initial 1809 ** allocation, then SQLite goes to [sqlite3_malloc()] separately for each 1810 ** additional cache line. </dd> 1811 ** 1812 ** [[SQLITE_CONFIG_HEAP]] <dt>SQLITE_CONFIG_HEAP</dt> 1813 ** <dd> ^The SQLITE_CONFIG_HEAP option specifies a static memory buffer 1814 ** that SQLite will use for all of its dynamic memory allocation needs 1815 ** beyond those provided for by [SQLITE_CONFIG_PAGECACHE]. 1816 ** ^The SQLITE_CONFIG_HEAP option is only available if SQLite is compiled 1817 ** with either [SQLITE_ENABLE_MEMSYS3] or [SQLITE_ENABLE_MEMSYS5] and returns 1818 ** [SQLITE_ERROR] if invoked otherwise. 1819 ** ^There are three arguments to SQLITE_CONFIG_HEAP: 1820 ** An 8-byte aligned pointer to the memory, 1821 ** the number of bytes in the memory buffer, and the minimum allocation size. 1822 ** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts 1823 ** to using its default memory allocator (the system malloc() implementation), 1824 ** undoing any prior invocation of [SQLITE_CONFIG_MALLOC]. ^If the 1825 ** memory pointer is not NULL then the alternative memory 1826 ** allocator is engaged to handle all of SQLites memory allocation needs. 1827 ** The first pointer (the memory pointer) must be aligned to an 8-byte 1828 ** boundary or subsequent behavior of SQLite will be undefined. 1829 ** The minimum allocation size is capped at 2**12. Reasonable values 1830 ** for the minimum allocation size are 2**5 through 2**8.</dd> 1831 ** 1832 ** [[SQLITE_CONFIG_MUTEX]] <dt>SQLITE_CONFIG_MUTEX</dt> 1833 ** <dd> ^(The SQLITE_CONFIG_MUTEX option takes a single argument which is a 1834 ** pointer to an instance of the [sqlite3_mutex_methods] structure. 1835 ** The argument specifies alternative low-level mutex routines to be used 1836 ** in place the mutex routines built into SQLite.)^ ^SQLite makes a copy of 1837 ** the content of the [sqlite3_mutex_methods] structure before the call to 1838 ** [sqlite3_config()] returns. ^If SQLite is compiled with 1839 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1840 ** the entire mutexing subsystem is omitted from the build and hence calls to 1841 ** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will 1842 ** return [SQLITE_ERROR].</dd> 1843 ** 1844 ** [[SQLITE_CONFIG_GETMUTEX]] <dt>SQLITE_CONFIG_GETMUTEX</dt> 1845 ** <dd> ^(The SQLITE_CONFIG_GETMUTEX option takes a single argument which 1846 ** is a pointer to an instance of the [sqlite3_mutex_methods] structure. The 1847 ** [sqlite3_mutex_methods] 1848 ** structure is filled with the currently defined mutex routines.)^ 1849 ** This option can be used to overload the default mutex allocation 1850 ** routines with a wrapper used to track mutex usage for performance 1851 ** profiling or testing, for example. ^If SQLite is compiled with 1852 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1853 ** the entire mutexing subsystem is omitted from the build and hence calls to 1854 ** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will 1855 ** return [SQLITE_ERROR].</dd> 1856 ** 1857 ** [[SQLITE_CONFIG_LOOKASIDE]] <dt>SQLITE_CONFIG_LOOKASIDE</dt> 1858 ** <dd> ^(The SQLITE_CONFIG_LOOKASIDE option takes two arguments that determine 1859 ** the default size of lookaside memory on each [database connection]. 1860 ** The first argument is the 1861 ** size of each lookaside buffer slot and the second is the number of 1862 ** slots allocated to each database connection.)^ ^(SQLITE_CONFIG_LOOKASIDE 1863 ** sets the <i>default</i> lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE] 1864 ** option to [sqlite3_db_config()] can be used to change the lookaside 1865 ** configuration on individual connections.)^ </dd> 1866 ** 1867 ** [[SQLITE_CONFIG_PCACHE2]] <dt>SQLITE_CONFIG_PCACHE2</dt> 1868 ** <dd> ^(The SQLITE_CONFIG_PCACHE2 option takes a single argument which is 1869 ** a pointer to an [sqlite3_pcache_methods2] object. This object specifies 1870 ** the interface to a custom page cache implementation.)^ 1871 ** ^SQLite makes a copy of the [sqlite3_pcache_methods2] object.</dd> 1872 ** 1873 ** [[SQLITE_CONFIG_GETPCACHE2]] <dt>SQLITE_CONFIG_GETPCACHE2</dt> 1874 ** <dd> ^(The SQLITE_CONFIG_GETPCACHE2 option takes a single argument which 1875 ** is a pointer to an [sqlite3_pcache_methods2] object. SQLite copies of 1876 ** the current page cache implementation into that object.)^ </dd> 1877 ** 1878 ** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt> 1879 ** <dd> The SQLITE_CONFIG_LOG option is used to configure the SQLite 1880 ** global [error log]. 1881 ** (^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a 1882 ** function with a call signature of void(*)(void*,int,const char*), 1883 ** and a pointer to void. ^If the function pointer is not NULL, it is 1884 ** invoked by [sqlite3_log()] to process each logging event. ^If the 1885 ** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op. 1886 ** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is 1887 ** passed through as the first parameter to the application-defined logger 1888 ** function whenever that function is invoked. ^The second parameter to 1889 ** the logger function is a copy of the first parameter to the corresponding 1890 ** [sqlite3_log()] call and is intended to be a [result code] or an 1891 ** [extended result code]. ^The third parameter passed to the logger is 1892 ** log message after formatting via [sqlite3_snprintf()]. 1893 ** The SQLite logging interface is not reentrant; the logger function 1894 ** supplied by the application must not invoke any SQLite interface. 1895 ** In a multi-threaded application, the application-defined logger 1896 ** function must be threadsafe. </dd> 1897 ** 1898 ** [[SQLITE_CONFIG_URI]] <dt>SQLITE_CONFIG_URI 1899 ** <dd>^(The SQLITE_CONFIG_URI option takes a single argument of type int. 1900 ** If non-zero, then URI handling is globally enabled. If the parameter is zero, 1901 ** then URI handling is globally disabled.)^ ^If URI handling is globally 1902 ** enabled, all filenames passed to [sqlite3_open()], [sqlite3_open_v2()], 1903 ** [sqlite3_open16()] or 1904 ** specified as part of [ATTACH] commands are interpreted as URIs, regardless 1905 ** of whether or not the [SQLITE_OPEN_URI] flag is set when the database 1906 ** connection is opened. ^If it is globally disabled, filenames are 1907 ** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the 1908 ** database connection is opened. ^(By default, URI handling is globally 1909 ** disabled. The default value may be changed by compiling with the 1910 ** [SQLITE_USE_URI] symbol defined.)^ 1911 ** 1912 ** [[SQLITE_CONFIG_COVERING_INDEX_SCAN]] <dt>SQLITE_CONFIG_COVERING_INDEX_SCAN 1913 ** <dd>^The SQLITE_CONFIG_COVERING_INDEX_SCAN option takes a single integer 1914 ** argument which is interpreted as a boolean in order to enable or disable 1915 ** the use of covering indices for full table scans in the query optimizer. 1916 ** ^The default setting is determined 1917 ** by the [SQLITE_ALLOW_COVERING_INDEX_SCAN] compile-time option, or is "on" 1918 ** if that compile-time option is omitted. 1919 ** The ability to disable the use of covering indices for full table scans 1920 ** is because some incorrectly coded legacy applications might malfunction 1921 ** when the optimization is enabled. Providing the ability to 1922 ** disable the optimization allows the older, buggy application code to work 1923 ** without change even with newer versions of SQLite. 1924 ** 1925 ** [[SQLITE_CONFIG_PCACHE]] [[SQLITE_CONFIG_GETPCACHE]] 1926 ** <dt>SQLITE_CONFIG_PCACHE and SQLITE_CONFIG_GETPCACHE 1927 ** <dd> These options are obsolete and should not be used by new code. 1928 ** They are retained for backwards compatibility but are now no-ops. 1929 ** </dd> 1930 ** 1931 ** [[SQLITE_CONFIG_SQLLOG]] 1932 ** <dt>SQLITE_CONFIG_SQLLOG 1933 ** <dd>This option is only available if sqlite is compiled with the 1934 ** [SQLITE_ENABLE_SQLLOG] pre-processor macro defined. The first argument should 1935 ** be a pointer to a function of type void(*)(void*,sqlite3*,const char*, int). 1936 ** The second should be of type (void*). The callback is invoked by the library 1937 ** in three separate circumstances, identified by the value passed as the 1938 ** fourth parameter. If the fourth parameter is 0, then the database connection 1939 ** passed as the second argument has just been opened. The third argument 1940 ** points to a buffer containing the name of the main database file. If the 1941 ** fourth parameter is 1, then the SQL statement that the third parameter 1942 ** points to has just been executed. Or, if the fourth parameter is 2, then 1943 ** the connection being passed as the second parameter is being closed. The 1944 ** third parameter is passed NULL In this case. An example of using this 1945 ** configuration option can be seen in the "test_sqllog.c" source file in 1946 ** the canonical SQLite source tree.</dd> 1947 ** 1948 ** [[SQLITE_CONFIG_MMAP_SIZE]] 1949 ** <dt>SQLITE_CONFIG_MMAP_SIZE 1950 ** <dd>^SQLITE_CONFIG_MMAP_SIZE takes two 64-bit integer (sqlite3_int64) values 1951 ** that are the default mmap size limit (the default setting for 1952 ** [PRAGMA mmap_size]) and the maximum allowed mmap size limit. 1953 ** ^The default setting can be overridden by each database connection using 1954 ** either the [PRAGMA mmap_size] command, or by using the 1955 ** [SQLITE_FCNTL_MMAP_SIZE] file control. ^(The maximum allowed mmap size 1956 ** will be silently truncated if necessary so that it does not exceed the 1957 ** compile-time maximum mmap size set by the 1958 ** [SQLITE_MAX_MMAP_SIZE] compile-time option.)^ 1959 ** ^If either argument to this option is negative, then that argument is 1960 ** changed to its compile-time default. 1961 ** 1962 ** [[SQLITE_CONFIG_WIN32_HEAPSIZE]] 1963 ** <dt>SQLITE_CONFIG_WIN32_HEAPSIZE 1964 ** <dd>^The SQLITE_CONFIG_WIN32_HEAPSIZE option is only available if SQLite is 1965 ** compiled for Windows with the [SQLITE_WIN32_MALLOC] pre-processor macro 1966 ** defined. ^SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit unsigned integer value 1967 ** that specifies the maximum size of the created heap. 1968 ** 1969 ** [[SQLITE_CONFIG_PCACHE_HDRSZ]] 1970 ** <dt>SQLITE_CONFIG_PCACHE_HDRSZ 1971 ** <dd>^The SQLITE_CONFIG_PCACHE_HDRSZ option takes a single parameter which 1972 ** is a pointer to an integer and writes into that integer the number of extra 1973 ** bytes per page required for each page in [SQLITE_CONFIG_PAGECACHE]. 1974 ** The amount of extra space required can change depending on the compiler, 1975 ** target platform, and SQLite version. 1976 ** 1977 ** [[SQLITE_CONFIG_PMASZ]] 1978 ** <dt>SQLITE_CONFIG_PMASZ 1979 ** <dd>^The SQLITE_CONFIG_PMASZ option takes a single parameter which 1980 ** is an unsigned integer and sets the "Minimum PMA Size" for the multithreaded 1981 ** sorter to that integer. The default minimum PMA Size is set by the 1982 ** [SQLITE_SORTER_PMASZ] compile-time option. New threads are launched 1983 ** to help with sort operations when multithreaded sorting 1984 ** is enabled (using the [PRAGMA threads] command) and the amount of content 1985 ** to be sorted exceeds the page size times the minimum of the 1986 ** [PRAGMA cache_size] setting and this value. 1987 ** 1988 ** [[SQLITE_CONFIG_STMTJRNL_SPILL]] 1989 ** <dt>SQLITE_CONFIG_STMTJRNL_SPILL 1990 ** <dd>^The SQLITE_CONFIG_STMTJRNL_SPILL option takes a single parameter which 1991 ** becomes the [statement journal] spill-to-disk threshold. 1992 ** [Statement journals] are held in memory until their size (in bytes) 1993 ** exceeds this threshold, at which point they are written to disk. 1994 ** Or if the threshold is -1, statement journals are always held 1995 ** exclusively in memory. 1996 ** Since many statement journals never become large, setting the spill 1997 ** threshold to a value such as 64KiB can greatly reduce the amount of 1998 ** I/O required to support statement rollback. 1999 ** The default value for this setting is controlled by the 2000 ** [SQLITE_STMTJRNL_SPILL] compile-time option. 2001 ** 2002 ** [[SQLITE_CONFIG_SORTERREF_SIZE]] 2003 ** <dt>SQLITE_CONFIG_SORTERREF_SIZE 2004 ** <dd>The SQLITE_CONFIG_SORTERREF_SIZE option accepts a single parameter 2005 ** of type (int) - the new value of the sorter-reference size threshold. 2006 ** Usually, when SQLite uses an external sort to order records according 2007 ** to an ORDER BY clause, all fields required by the caller are present in the 2008 ** sorted records. However, if SQLite determines based on the declared type 2009 ** of a table column that its values are likely to be very large - larger 2010 ** than the configured sorter-reference size threshold - then a reference 2011 ** is stored in each sorted record and the required column values loaded 2012 ** from the database as records are returned in sorted order. The default 2013 ** value for this option is to never use this optimization. Specifying a 2014 ** negative value for this option restores the default behaviour. 2015 ** This option is only available if SQLite is compiled with the 2016 ** [SQLITE_ENABLE_SORTER_REFERENCES] compile-time option. 2017 ** 2018 ** [[SQLITE_CONFIG_MEMDB_MAXSIZE]] 2019 ** <dt>SQLITE_CONFIG_MEMDB_MAXSIZE 2020 ** <dd>The SQLITE_CONFIG_MEMDB_MAXSIZE option accepts a single parameter 2021 ** [sqlite3_int64] parameter which is the default maximum size for an in-memory 2022 ** database created using [sqlite3_deserialize()]. This default maximum 2023 ** size can be adjusted up or down for individual databases using the 2024 ** [SQLITE_FCNTL_SIZE_LIMIT] [sqlite3_file_control|file-control]. If this 2025 ** configuration setting is never used, then the default maximum is determined 2026 ** by the [SQLITE_MEMDB_DEFAULT_MAXSIZE] compile-time option. If that 2027 ** compile-time option is not set, then the default maximum is 1073741824. 2028 ** </dl> 2029 */ 2030 #define SQLITE_CONFIG_SINGLETHREAD 1 /* nil */ 2031 #define SQLITE_CONFIG_MULTITHREAD 2 /* nil */ 2032 #define SQLITE_CONFIG_SERIALIZED 3 /* nil */ 2033 #define SQLITE_CONFIG_MALLOC 4 /* sqlite3_mem_methods* */ 2034 #define SQLITE_CONFIG_GETMALLOC 5 /* sqlite3_mem_methods* */ 2035 #define SQLITE_CONFIG_SCRATCH 6 /* No longer used */ 2036 #define SQLITE_CONFIG_PAGECACHE 7 /* void*, int sz, int N */ 2037 #define SQLITE_CONFIG_HEAP 8 /* void*, int nByte, int min */ 2038 #define SQLITE_CONFIG_MEMSTATUS 9 /* boolean */ 2039 #define SQLITE_CONFIG_MUTEX 10 /* sqlite3_mutex_methods* */ 2040 #define SQLITE_CONFIG_GETMUTEX 11 /* sqlite3_mutex_methods* */ 2041 /* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */ 2042 #define SQLITE_CONFIG_LOOKASIDE 13 /* int int */ 2043 #define SQLITE_CONFIG_PCACHE 14 /* no-op */ 2044 #define SQLITE_CONFIG_GETPCACHE 15 /* no-op */ 2045 #define SQLITE_CONFIG_LOG 16 /* xFunc, void* */ 2046 #define SQLITE_CONFIG_URI 17 /* int */ 2047 #define SQLITE_CONFIG_PCACHE2 18 /* sqlite3_pcache_methods2* */ 2048 #define SQLITE_CONFIG_GETPCACHE2 19 /* sqlite3_pcache_methods2* */ 2049 #define SQLITE_CONFIG_COVERING_INDEX_SCAN 20 /* int */ 2050 #define SQLITE_CONFIG_SQLLOG 21 /* xSqllog, void* */ 2051 #define SQLITE_CONFIG_MMAP_SIZE 22 /* sqlite3_int64, sqlite3_int64 */ 2052 #define SQLITE_CONFIG_WIN32_HEAPSIZE 23 /* int nByte */ 2053 #define SQLITE_CONFIG_PCACHE_HDRSZ 24 /* int *psz */ 2054 #define SQLITE_CONFIG_PMASZ 25 /* unsigned int szPma */ 2055 #define SQLITE_CONFIG_STMTJRNL_SPILL 26 /* int nByte */ 2056 #define SQLITE_CONFIG_SMALL_MALLOC 27 /* boolean */ 2057 #define SQLITE_CONFIG_SORTERREF_SIZE 28 /* int nByte */ 2058 #define SQLITE_CONFIG_MEMDB_MAXSIZE 29 /* sqlite3_int64 */ 2059 2060 /* 2061 ** CAPI3REF: Database Connection Configuration Options 2062 ** 2063 ** These constants are the available integer configuration options that 2064 ** can be passed as the second argument to the [sqlite3_db_config()] interface. 2065 ** 2066 ** New configuration options may be added in future releases of SQLite. 2067 ** Existing configuration options might be discontinued. Applications 2068 ** should check the return code from [sqlite3_db_config()] to make sure that 2069 ** the call worked. ^The [sqlite3_db_config()] interface will return a 2070 ** non-zero [error code] if a discontinued or unsupported configuration option 2071 ** is invoked. 2072 ** 2073 ** <dl> 2074 ** [[SQLITE_DBCONFIG_LOOKASIDE]] 2075 ** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt> 2076 ** <dd> ^This option takes three additional arguments that determine the 2077 ** [lookaside memory allocator] configuration for the [database connection]. 2078 ** ^The first argument (the third parameter to [sqlite3_db_config()] is a 2079 ** pointer to a memory buffer to use for lookaside memory. 2080 ** ^The first argument after the SQLITE_DBCONFIG_LOOKASIDE verb 2081 ** may be NULL in which case SQLite will allocate the 2082 ** lookaside buffer itself using [sqlite3_malloc()]. ^The second argument is the 2083 ** size of each lookaside buffer slot. ^The third argument is the number of 2084 ** slots. The size of the buffer in the first argument must be greater than 2085 ** or equal to the product of the second and third arguments. The buffer 2086 ** must be aligned to an 8-byte boundary. ^If the second argument to 2087 ** SQLITE_DBCONFIG_LOOKASIDE is not a multiple of 8, it is internally 2088 ** rounded down to the next smaller multiple of 8. ^(The lookaside memory 2089 ** configuration for a database connection can only be changed when that 2090 ** connection is not currently using lookaside memory, or in other words 2091 ** when the "current value" returned by 2092 ** [sqlite3_db_status](D,[SQLITE_CONFIG_LOOKASIDE],...) is zero. 2093 ** Any attempt to change the lookaside memory configuration when lookaside 2094 ** memory is in use leaves the configuration unchanged and returns 2095 ** [SQLITE_BUSY].)^</dd> 2096 ** 2097 ** [[SQLITE_DBCONFIG_ENABLE_FKEY]] 2098 ** <dt>SQLITE_DBCONFIG_ENABLE_FKEY</dt> 2099 ** <dd> ^This option is used to enable or disable the enforcement of 2100 ** [foreign key constraints]. There should be two additional arguments. 2101 ** The first argument is an integer which is 0 to disable FK enforcement, 2102 ** positive to enable FK enforcement or negative to leave FK enforcement 2103 ** unchanged. The second parameter is a pointer to an integer into which 2104 ** is written 0 or 1 to indicate whether FK enforcement is off or on 2105 ** following this call. The second parameter may be a NULL pointer, in 2106 ** which case the FK enforcement setting is not reported back. </dd> 2107 ** 2108 ** [[SQLITE_DBCONFIG_ENABLE_TRIGGER]] 2109 ** <dt>SQLITE_DBCONFIG_ENABLE_TRIGGER</dt> 2110 ** <dd> ^This option is used to enable or disable [CREATE TRIGGER | triggers]. 2111 ** There should be two additional arguments. 2112 ** The first argument is an integer which is 0 to disable triggers, 2113 ** positive to enable triggers or negative to leave the setting unchanged. 2114 ** The second parameter is a pointer to an integer into which 2115 ** is written 0 or 1 to indicate whether triggers are disabled or enabled 2116 ** following this call. The second parameter may be a NULL pointer, in 2117 ** which case the trigger setting is not reported back. </dd> 2118 ** 2119 ** [[SQLITE_DBCONFIG_ENABLE_VIEW]] 2120 ** <dt>SQLITE_DBCONFIG_ENABLE_VIEW</dt> 2121 ** <dd> ^This option is used to enable or disable [CREATE VIEW | views]. 2122 ** There should be two additional arguments. 2123 ** The first argument is an integer which is 0 to disable views, 2124 ** positive to enable views or negative to leave the setting unchanged. 2125 ** The second parameter is a pointer to an integer into which 2126 ** is written 0 or 1 to indicate whether views are disabled or enabled 2127 ** following this call. The second parameter may be a NULL pointer, in 2128 ** which case the view setting is not reported back. </dd> 2129 ** 2130 ** [[SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER]] 2131 ** <dt>SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER</dt> 2132 ** <dd> ^This option is used to enable or disable the 2133 ** [fts3_tokenizer()] function which is part of the 2134 ** [FTS3] full-text search engine extension. 2135 ** There should be two additional arguments. 2136 ** The first argument is an integer which is 0 to disable fts3_tokenizer() or 2137 ** positive to enable fts3_tokenizer() or negative to leave the setting 2138 ** unchanged. 2139 ** The second parameter is a pointer to an integer into which 2140 ** is written 0 or 1 to indicate whether fts3_tokenizer is disabled or enabled 2141 ** following this call. The second parameter may be a NULL pointer, in 2142 ** which case the new setting is not reported back. </dd> 2143 ** 2144 ** [[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION]] 2145 ** <dt>SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION</dt> 2146 ** <dd> ^This option is used to enable or disable the [sqlite3_load_extension()] 2147 ** interface independently of the [load_extension()] SQL function. 2148 ** The [sqlite3_enable_load_extension()] API enables or disables both the 2149 ** C-API [sqlite3_load_extension()] and the SQL function [load_extension()]. 2150 ** There should be two additional arguments. 2151 ** When the first argument to this interface is 1, then only the C-API is 2152 ** enabled and the SQL function remains disabled. If the first argument to 2153 ** this interface is 0, then both the C-API and the SQL function are disabled. 2154 ** If the first argument is -1, then no changes are made to state of either the 2155 ** C-API or the SQL function. 2156 ** The second parameter is a pointer to an integer into which 2157 ** is written 0 or 1 to indicate whether [sqlite3_load_extension()] interface 2158 ** is disabled or enabled following this call. The second parameter may 2159 ** be a NULL pointer, in which case the new setting is not reported back. 2160 ** </dd> 2161 ** 2162 ** [[SQLITE_DBCONFIG_MAINDBNAME]] <dt>SQLITE_DBCONFIG_MAINDBNAME</dt> 2163 ** <dd> ^This option is used to change the name of the "main" database 2164 ** schema. ^The sole argument is a pointer to a constant UTF8 string 2165 ** which will become the new schema name in place of "main". ^SQLite 2166 ** does not make a copy of the new main schema name string, so the application 2167 ** must ensure that the argument passed into this DBCONFIG option is unchanged 2168 ** until after the database connection closes. 2169 ** </dd> 2170 ** 2171 ** [[SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE]] 2172 ** <dt>SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE</dt> 2173 ** <dd> Usually, when a database in wal mode is closed or detached from a 2174 ** database handle, SQLite checks if this will mean that there are now no 2175 ** connections at all to the database. If so, it performs a checkpoint 2176 ** operation before closing the connection. This option may be used to 2177 ** override this behaviour. The first parameter passed to this operation 2178 ** is an integer - positive to disable checkpoints-on-close, or zero (the 2179 ** default) to enable them, and negative to leave the setting unchanged. 2180 ** The second parameter is a pointer to an integer 2181 ** into which is written 0 or 1 to indicate whether checkpoints-on-close 2182 ** have been disabled - 0 if they are not disabled, 1 if they are. 2183 ** </dd> 2184 ** 2185 ** [[SQLITE_DBCONFIG_ENABLE_QPSG]] <dt>SQLITE_DBCONFIG_ENABLE_QPSG</dt> 2186 ** <dd>^(The SQLITE_DBCONFIG_ENABLE_QPSG option activates or deactivates 2187 ** the [query planner stability guarantee] (QPSG). When the QPSG is active, 2188 ** a single SQL query statement will always use the same algorithm regardless 2189 ** of values of [bound parameters].)^ The QPSG disables some query optimizations 2190 ** that look at the values of bound parameters, which can make some queries 2191 ** slower. But the QPSG has the advantage of more predictable behavior. With 2192 ** the QPSG active, SQLite will always use the same query plan in the field as 2193 ** was used during testing in the lab. 2194 ** The first argument to this setting is an integer which is 0 to disable 2195 ** the QPSG, positive to enable QPSG, or negative to leave the setting 2196 ** unchanged. The second parameter is a pointer to an integer into which 2197 ** is written 0 or 1 to indicate whether the QPSG is disabled or enabled 2198 ** following this call. 2199 ** </dd> 2200 ** 2201 ** [[SQLITE_DBCONFIG_TRIGGER_EQP]] <dt>SQLITE_DBCONFIG_TRIGGER_EQP</dt> 2202 ** <dd> By default, the output of EXPLAIN QUERY PLAN commands does not 2203 ** include output for any operations performed by trigger programs. This 2204 ** option is used to set or clear (the default) a flag that governs this 2205 ** behavior. The first parameter passed to this operation is an integer - 2206 ** positive to enable output for trigger programs, or zero to disable it, 2207 ** or negative to leave the setting unchanged. 2208 ** The second parameter is a pointer to an integer into which is written 2209 ** 0 or 1 to indicate whether output-for-triggers has been disabled - 0 if 2210 ** it is not disabled, 1 if it is. 2211 ** </dd> 2212 ** 2213 ** [[SQLITE_DBCONFIG_RESET_DATABASE]] <dt>SQLITE_DBCONFIG_RESET_DATABASE</dt> 2214 ** <dd> Set the SQLITE_DBCONFIG_RESET_DATABASE flag and then run 2215 ** [VACUUM] in order to reset a database back to an empty database 2216 ** with no schema and no content. The following process works even for 2217 ** a badly corrupted database file: 2218 ** <ol> 2219 ** <li> If the database connection is newly opened, make sure it has read the 2220 ** database schema by preparing then discarding some query against the 2221 ** database, or calling sqlite3_table_column_metadata(), ignoring any 2222 ** errors. This step is only necessary if the application desires to keep 2223 ** the database in WAL mode after the reset if it was in WAL mode before 2224 ** the reset. 2225 ** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 1, 0); 2226 ** <li> [sqlite3_exec](db, "[VACUUM]", 0, 0, 0); 2227 ** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 0, 0); 2228 ** </ol> 2229 ** Because resetting a database is destructive and irreversible, the 2230 ** process requires the use of this obscure API and multiple steps to help 2231 ** ensure that it does not happen by accident. 2232 ** 2233 ** [[SQLITE_DBCONFIG_DEFENSIVE]] <dt>SQLITE_DBCONFIG_DEFENSIVE</dt> 2234 ** <dd>The SQLITE_DBCONFIG_DEFENSIVE option activates or deactivates the 2235 ** "defensive" flag for a database connection. When the defensive 2236 ** flag is enabled, language features that allow ordinary SQL to 2237 ** deliberately corrupt the database file are disabled. The disabled 2238 ** features include but are not limited to the following: 2239 ** <ul> 2240 ** <li> The [PRAGMA writable_schema=ON] statement. 2241 ** <li> The [PRAGMA journal_mode=OFF] statement. 2242 ** <li> Writes to the [sqlite_dbpage] virtual table. 2243 ** <li> Direct writes to [shadow tables]. 2244 ** </ul> 2245 ** </dd> 2246 ** 2247 ** [[SQLITE_DBCONFIG_WRITABLE_SCHEMA]] <dt>SQLITE_DBCONFIG_WRITABLE_SCHEMA</dt> 2248 ** <dd>The SQLITE_DBCONFIG_WRITABLE_SCHEMA option activates or deactivates the 2249 ** "writable_schema" flag. This has the same effect and is logically equivalent 2250 ** to setting [PRAGMA writable_schema=ON] or [PRAGMA writable_schema=OFF]. 2251 ** The first argument to this setting is an integer which is 0 to disable 2252 ** the writable_schema, positive to enable writable_schema, or negative to 2253 ** leave the setting unchanged. The second parameter is a pointer to an 2254 ** integer into which is written 0 or 1 to indicate whether the writable_schema 2255 ** is enabled or disabled following this call. 2256 ** </dd> 2257 ** 2258 ** [[SQLITE_DBCONFIG_LEGACY_ALTER_TABLE]] 2259 ** <dt>SQLITE_DBCONFIG_LEGACY_ALTER_TABLE</dt> 2260 ** <dd>The SQLITE_DBCONFIG_LEGACY_ALTER_TABLE option activates or deactivates 2261 ** the legacy behavior of the [ALTER TABLE RENAME] command such it 2262 ** behaves as it did prior to [version 3.24.0] (2018-06-04). See the 2263 ** "Compatibility Notice" on the [ALTER TABLE RENAME documentation] for 2264 ** additional information. This feature can also be turned on and off 2265 ** using the [PRAGMA legacy_alter_table] statement. 2266 ** </dd> 2267 ** 2268 ** [[SQLITE_DBCONFIG_DQS_DML]] 2269 ** <dt>SQLITE_DBCONFIG_DQS_DML</td> 2270 ** <dd>The SQLITE_DBCONFIG_DQS_DML option activates or deactivates 2271 ** the legacy [double-quoted string literal] misfeature for DML statements 2272 ** only, that is DELETE, INSERT, SELECT, and UPDATE statements. The 2273 ** default value of this setting is determined by the [-DSQLITE_DQS] 2274 ** compile-time option. 2275 ** </dd> 2276 ** 2277 ** [[SQLITE_DBCONFIG_DQS_DDL]] 2278 ** <dt>SQLITE_DBCONFIG_DQS_DDL</td> 2279 ** <dd>The SQLITE_DBCONFIG_DQS option activates or deactivates 2280 ** the legacy [double-quoted string literal] misfeature for DDL statements, 2281 ** such as CREATE TABLE and CREATE INDEX. The 2282 ** default value of this setting is determined by the [-DSQLITE_DQS] 2283 ** compile-time option. 2284 ** </dd> 2285 ** 2286 ** [[SQLITE_DBCONFIG_TRUSTED_SCHEMA]] 2287 ** <dt>SQLITE_DBCONFIG_TRUSTED_SCHEMA</td> 2288 ** <dd>The SQLITE_DBCONFIG_TRUSTED_SCHEMA option tells SQLite to 2289 ** assume that database schemas are untainted by malicious content. 2290 ** When the SQLITE_DBCONFIG_TRUSTED_SCHEMA option is disabled, SQLite 2291 ** takes additional defensive steps to protect the application from harm 2292 ** including: 2293 ** <ul> 2294 ** <li> Prohibit the use of SQL functions inside triggers, views, 2295 ** CHECK constraints, DEFAULT clauses, expression indexes, 2296 ** partial indexes, or generated columns 2297 ** unless those functions are tagged with [SQLITE_INNOCUOUS]. 2298 ** <li> Prohibit the use of virtual tables inside of triggers or views 2299 ** unless those virtual tables are tagged with [SQLITE_VTAB_INNOCUOUS]. 2300 ** </ul> 2301 ** This setting defaults to "on" for legacy compatibility, however 2302 ** all applications are advised to turn it off if possible. This setting 2303 ** can also be controlled using the [PRAGMA trusted_schema] statement. 2304 ** </dd> 2305 ** 2306 ** [[SQLITE_DBCONFIG_LEGACY_FILE_FORMAT]] 2307 ** <dt>SQLITE_DBCONFIG_LEGACY_FILE_FORMAT</td> 2308 ** <dd>The SQLITE_DBCONFIG_LEGACY_FILE_FORMAT option activates or deactivates 2309 ** the legacy file format flag. When activated, this flag causes all newly 2310 ** created database file to have a schema format version number (the 4-byte 2311 ** integer found at offset 44 into the database header) of 1. This in turn 2312 ** means that the resulting database file will be readable and writable by 2313 ** any SQLite version back to 3.0.0 ([dateof:3.0.0]). Without this setting, 2314 ** newly created databases are generally not understandable by SQLite versions 2315 ** prior to 3.3.0 ([dateof:3.3.0]). As these words are written, there 2316 ** is now scarcely any need to generated database files that are compatible 2317 ** all the way back to version 3.0.0, and so this setting is of little 2318 ** practical use, but is provided so that SQLite can continue to claim the 2319 ** ability to generate new database files that are compatible with version 2320 ** 3.0.0. 2321 ** <p>Note that when the SQLITE_DBCONFIG_LEGACY_FILE_FORMAT setting is on, 2322 ** the [VACUUM] command will fail with an obscure error when attempting to 2323 ** process a table with generated columns and a descending index. This is 2324 ** not considered a bug since SQLite versions 3.3.0 and earlier do not support 2325 ** either generated columns or decending indexes. 2326 ** </dd> 2327 ** </dl> 2328 */ 2329 #define SQLITE_DBCONFIG_MAINDBNAME 1000 /* const char* */ 2330 #define SQLITE_DBCONFIG_LOOKASIDE 1001 /* void* int int */ 2331 #define SQLITE_DBCONFIG_ENABLE_FKEY 1002 /* int int* */ 2332 #define SQLITE_DBCONFIG_ENABLE_TRIGGER 1003 /* int int* */ 2333 #define SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER 1004 /* int int* */ 2334 #define SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION 1005 /* int int* */ 2335 #define SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE 1006 /* int int* */ 2336 #define SQLITE_DBCONFIG_ENABLE_QPSG 1007 /* int int* */ 2337 #define SQLITE_DBCONFIG_TRIGGER_EQP 1008 /* int int* */ 2338 #define SQLITE_DBCONFIG_RESET_DATABASE 1009 /* int int* */ 2339 #define SQLITE_DBCONFIG_DEFENSIVE 1010 /* int int* */ 2340 #define SQLITE_DBCONFIG_WRITABLE_SCHEMA 1011 /* int int* */ 2341 #define SQLITE_DBCONFIG_LEGACY_ALTER_TABLE 1012 /* int int* */ 2342 #define SQLITE_DBCONFIG_DQS_DML 1013 /* int int* */ 2343 #define SQLITE_DBCONFIG_DQS_DDL 1014 /* int int* */ 2344 #define SQLITE_DBCONFIG_ENABLE_VIEW 1015 /* int int* */ 2345 #define SQLITE_DBCONFIG_LEGACY_FILE_FORMAT 1016 /* int int* */ 2346 #define SQLITE_DBCONFIG_TRUSTED_SCHEMA 1017 /* int int* */ 2347 #define SQLITE_DBCONFIG_MAX 1017 /* Largest DBCONFIG */ 2348 2349 /* 2350 ** CAPI3REF: Enable Or Disable Extended Result Codes 2351 ** METHOD: sqlite3 2352 ** 2353 ** ^The sqlite3_extended_result_codes() routine enables or disables the 2354 ** [extended result codes] feature of SQLite. ^The extended result 2355 ** codes are disabled by default for historical compatibility. 2356 */ 2357 SQLITE_API int sqlite3_extended_result_codes(sqlite3*, int onoff); 2358 2359 /* 2360 ** CAPI3REF: Last Insert Rowid 2361 ** METHOD: sqlite3 2362 ** 2363 ** ^Each entry in most SQLite tables (except for [WITHOUT ROWID] tables) 2364 ** has a unique 64-bit signed 2365 ** integer key called the [ROWID | "rowid"]. ^The rowid is always available 2366 ** as an undeclared column named ROWID, OID, or _ROWID_ as long as those 2367 ** names are not also used by explicitly declared columns. ^If 2368 ** the table has a column of type [INTEGER PRIMARY KEY] then that column 2369 ** is another alias for the rowid. 2370 ** 2371 ** ^The sqlite3_last_insert_rowid(D) interface usually returns the [rowid] of 2372 ** the most recent successful [INSERT] into a rowid table or [virtual table] 2373 ** on database connection D. ^Inserts into [WITHOUT ROWID] tables are not 2374 ** recorded. ^If no successful [INSERT]s into rowid tables have ever occurred 2375 ** on the database connection D, then sqlite3_last_insert_rowid(D) returns 2376 ** zero. 2377 ** 2378 ** As well as being set automatically as rows are inserted into database 2379 ** tables, the value returned by this function may be set explicitly by 2380 ** [sqlite3_set_last_insert_rowid()] 2381 ** 2382 ** Some virtual table implementations may INSERT rows into rowid tables as 2383 ** part of committing a transaction (e.g. to flush data accumulated in memory 2384 ** to disk). In this case subsequent calls to this function return the rowid 2385 ** associated with these internal INSERT operations, which leads to 2386 ** unintuitive results. Virtual table implementations that do write to rowid 2387 ** tables in this way can avoid this problem by restoring the original 2388 ** rowid value using [sqlite3_set_last_insert_rowid()] before returning 2389 ** control to the user. 2390 ** 2391 ** ^(If an [INSERT] occurs within a trigger then this routine will 2392 ** return the [rowid] of the inserted row as long as the trigger is 2393 ** running. Once the trigger program ends, the value returned 2394 ** by this routine reverts to what it was before the trigger was fired.)^ 2395 ** 2396 ** ^An [INSERT] that fails due to a constraint violation is not a 2397 ** successful [INSERT] and does not change the value returned by this 2398 ** routine. ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK, 2399 ** and INSERT OR ABORT make no changes to the return value of this 2400 ** routine when their insertion fails. ^(When INSERT OR REPLACE 2401 ** encounters a constraint violation, it does not fail. The 2402 ** INSERT continues to completion after deleting rows that caused 2403 ** the constraint problem so INSERT OR REPLACE will always change 2404 ** the return value of this interface.)^ 2405 ** 2406 ** ^For the purposes of this routine, an [INSERT] is considered to 2407 ** be successful even if it is subsequently rolled back. 2408 ** 2409 ** This function is accessible to SQL statements via the 2410 ** [last_insert_rowid() SQL function]. 2411 ** 2412 ** If a separate thread performs a new [INSERT] on the same 2413 ** database connection while the [sqlite3_last_insert_rowid()] 2414 ** function is running and thus changes the last insert [rowid], 2415 ** then the value returned by [sqlite3_last_insert_rowid()] is 2416 ** unpredictable and might not equal either the old or the new 2417 ** last insert [rowid]. 2418 */ 2419 SQLITE_API sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*); 2420 2421 /* 2422 ** CAPI3REF: Set the Last Insert Rowid value. 2423 ** METHOD: sqlite3 2424 ** 2425 ** The sqlite3_set_last_insert_rowid(D, R) method allows the application to 2426 ** set the value returned by calling sqlite3_last_insert_rowid(D) to R 2427 ** without inserting a row into the database. 2428 */ 2429 SQLITE_API void sqlite3_set_last_insert_rowid(sqlite3*,sqlite3_int64); 2430 2431 /* 2432 ** CAPI3REF: Count The Number Of Rows Modified 2433 ** METHOD: sqlite3 2434 ** 2435 ** ^This function returns the number of rows modified, inserted or 2436 ** deleted by the most recently completed INSERT, UPDATE or DELETE 2437 ** statement on the database connection specified by the only parameter. 2438 ** ^Executing any other type of SQL statement does not modify the value 2439 ** returned by this function. 2440 ** 2441 ** ^Only changes made directly by the INSERT, UPDATE or DELETE statement are 2442 ** considered - auxiliary changes caused by [CREATE TRIGGER | triggers], 2443 ** [foreign key actions] or [REPLACE] constraint resolution are not counted. 2444 ** 2445 ** Changes to a view that are intercepted by 2446 ** [INSTEAD OF trigger | INSTEAD OF triggers] are not counted. ^The value 2447 ** returned by sqlite3_changes() immediately after an INSERT, UPDATE or 2448 ** DELETE statement run on a view is always zero. Only changes made to real 2449 ** tables are counted. 2450 ** 2451 ** Things are more complicated if the sqlite3_changes() function is 2452 ** executed while a trigger program is running. This may happen if the 2453 ** program uses the [changes() SQL function], or if some other callback 2454 ** function invokes sqlite3_changes() directly. Essentially: 2455 ** 2456 ** <ul> 2457 ** <li> ^(Before entering a trigger program the value returned by 2458 ** sqlite3_changes() function is saved. After the trigger program 2459 ** has finished, the original value is restored.)^ 2460 ** 2461 ** <li> ^(Within a trigger program each INSERT, UPDATE and DELETE 2462 ** statement sets the value returned by sqlite3_changes() 2463 ** upon completion as normal. Of course, this value will not include 2464 ** any changes performed by sub-triggers, as the sqlite3_changes() 2465 ** value will be saved and restored after each sub-trigger has run.)^ 2466 ** </ul> 2467 ** 2468 ** ^This means that if the changes() SQL function (or similar) is used 2469 ** by the first INSERT, UPDATE or DELETE statement within a trigger, it 2470 ** returns the value as set when the calling statement began executing. 2471 ** ^If it is used by the second or subsequent such statement within a trigger 2472 ** program, the value returned reflects the number of rows modified by the 2473 ** previous INSERT, UPDATE or DELETE statement within the same trigger. 2474 ** 2475 ** If a separate thread makes changes on the same database connection 2476 ** while [sqlite3_changes()] is running then the value returned 2477 ** is unpredictable and not meaningful. 2478 ** 2479 ** See also: 2480 ** <ul> 2481 ** <li> the [sqlite3_total_changes()] interface 2482 ** <li> the [count_changes pragma] 2483 ** <li> the [changes() SQL function] 2484 ** <li> the [data_version pragma] 2485 ** </ul> 2486 */ 2487 SQLITE_API int sqlite3_changes(sqlite3*); 2488 2489 /* 2490 ** CAPI3REF: Total Number Of Rows Modified 2491 ** METHOD: sqlite3 2492 ** 2493 ** ^This function returns the total number of rows inserted, modified or 2494 ** deleted by all [INSERT], [UPDATE] or [DELETE] statements completed 2495 ** since the database connection was opened, including those executed as 2496 ** part of trigger programs. ^Executing any other type of SQL statement 2497 ** does not affect the value returned by sqlite3_total_changes(). 2498 ** 2499 ** ^Changes made as part of [foreign key actions] are included in the 2500 ** count, but those made as part of REPLACE constraint resolution are 2501 ** not. ^Changes to a view that are intercepted by INSTEAD OF triggers 2502 ** are not counted. 2503 ** 2504 ** The [sqlite3_total_changes(D)] interface only reports the number 2505 ** of rows that changed due to SQL statement run against database 2506 ** connection D. Any changes by other database connections are ignored. 2507 ** To detect changes against a database file from other database 2508 ** connections use the [PRAGMA data_version] command or the 2509 ** [SQLITE_FCNTL_DATA_VERSION] [file control]. 2510 ** 2511 ** If a separate thread makes changes on the same database connection 2512 ** while [sqlite3_total_changes()] is running then the value 2513 ** returned is unpredictable and not meaningful. 2514 ** 2515 ** See also: 2516 ** <ul> 2517 ** <li> the [sqlite3_changes()] interface 2518 ** <li> the [count_changes pragma] 2519 ** <li> the [changes() SQL function] 2520 ** <li> the [data_version pragma] 2521 ** <li> the [SQLITE_FCNTL_DATA_VERSION] [file control] 2522 ** </ul> 2523 */ 2524 SQLITE_API int sqlite3_total_changes(sqlite3*); 2525 2526 /* 2527 ** CAPI3REF: Interrupt A Long-Running Query 2528 ** METHOD: sqlite3 2529 ** 2530 ** ^This function causes any pending database operation to abort and 2531 ** return at its earliest opportunity. This routine is typically 2532 ** called in response to a user action such as pressing "Cancel" 2533 ** or Ctrl-C where the user wants a long query operation to halt 2534 ** immediately. 2535 ** 2536 ** ^It is safe to call this routine from a thread different from the 2537 ** thread that is currently running the database operation. But it 2538 ** is not safe to call this routine with a [database connection] that 2539 ** is closed or might close before sqlite3_interrupt() returns. 2540 ** 2541 ** ^If an SQL operation is very nearly finished at the time when 2542 ** sqlite3_interrupt() is called, then it might not have an opportunity 2543 ** to be interrupted and might continue to completion. 2544 ** 2545 ** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT]. 2546 ** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE 2547 ** that is inside an explicit transaction, then the entire transaction 2548 ** will be rolled back automatically. 2549 ** 2550 ** ^The sqlite3_interrupt(D) call is in effect until all currently running 2551 ** SQL statements on [database connection] D complete. ^Any new SQL statements 2552 ** that are started after the sqlite3_interrupt() call and before the 2553 ** running statement count reaches zero are interrupted as if they had been 2554 ** running prior to the sqlite3_interrupt() call. ^New SQL statements 2555 ** that are started after the running statement count reaches zero are 2556 ** not effected by the sqlite3_interrupt(). 2557 ** ^A call to sqlite3_interrupt(D) that occurs when there are no running 2558 ** SQL statements is a no-op and has no effect on SQL statements 2559 ** that are started after the sqlite3_interrupt() call returns. 2560 */ 2561 SQLITE_API void sqlite3_interrupt(sqlite3*); 2562 2563 /* 2564 ** CAPI3REF: Determine If An SQL Statement Is Complete 2565 ** 2566 ** These routines are useful during command-line input to determine if the 2567 ** currently entered text seems to form a complete SQL statement or 2568 ** if additional input is needed before sending the text into 2569 ** SQLite for parsing. ^These routines return 1 if the input string 2570 ** appears to be a complete SQL statement. ^A statement is judged to be 2571 ** complete if it ends with a semicolon token and is not a prefix of a 2572 ** well-formed CREATE TRIGGER statement. ^Semicolons that are embedded within 2573 ** string literals or quoted identifier names or comments are not 2574 ** independent tokens (they are part of the token in which they are 2575 ** embedded) and thus do not count as a statement terminator. ^Whitespace 2576 ** and comments that follow the final semicolon are ignored. 2577 ** 2578 ** ^These routines return 0 if the statement is incomplete. ^If a 2579 ** memory allocation fails, then SQLITE_NOMEM is returned. 2580 ** 2581 ** ^These routines do not parse the SQL statements thus 2582 ** will not detect syntactically incorrect SQL. 2583 ** 2584 ** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior 2585 ** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked 2586 ** automatically by sqlite3_complete16(). If that initialization fails, 2587 ** then the return value from sqlite3_complete16() will be non-zero 2588 ** regardless of whether or not the input SQL is complete.)^ 2589 ** 2590 ** The input to [sqlite3_complete()] must be a zero-terminated 2591 ** UTF-8 string. 2592 ** 2593 ** The input to [sqlite3_complete16()] must be a zero-terminated 2594 ** UTF-16 string in native byte order. 2595 */ 2596 SQLITE_API int sqlite3_complete(const char *sql); 2597 SQLITE_API int sqlite3_complete16(const void *sql); 2598 2599 /* 2600 ** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors 2601 ** KEYWORDS: {busy-handler callback} {busy handler} 2602 ** METHOD: sqlite3 2603 ** 2604 ** ^The sqlite3_busy_handler(D,X,P) routine sets a callback function X 2605 ** that might be invoked with argument P whenever 2606 ** an attempt is made to access a database table associated with 2607 ** [database connection] D when another thread 2608 ** or process has the table locked. 2609 ** The sqlite3_busy_handler() interface is used to implement 2610 ** [sqlite3_busy_timeout()] and [PRAGMA busy_timeout]. 2611 ** 2612 ** ^If the busy callback is NULL, then [SQLITE_BUSY] 2613 ** is returned immediately upon encountering the lock. ^If the busy callback 2614 ** is not NULL, then the callback might be invoked with two arguments. 2615 ** 2616 ** ^The first argument to the busy handler is a copy of the void* pointer which 2617 ** is the third argument to sqlite3_busy_handler(). ^The second argument to 2618 ** the busy handler callback is the number of times that the busy handler has 2619 ** been invoked previously for the same locking event. ^If the 2620 ** busy callback returns 0, then no additional attempts are made to 2621 ** access the database and [SQLITE_BUSY] is returned 2622 ** to the application. 2623 ** ^If the callback returns non-zero, then another attempt 2624 ** is made to access the database and the cycle repeats. 2625 ** 2626 ** The presence of a busy handler does not guarantee that it will be invoked 2627 ** when there is lock contention. ^If SQLite determines that invoking the busy 2628 ** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY] 2629 ** to the application instead of invoking the 2630 ** busy handler. 2631 ** Consider a scenario where one process is holding a read lock that 2632 ** it is trying to promote to a reserved lock and 2633 ** a second process is holding a reserved lock that it is trying 2634 ** to promote to an exclusive lock. The first process cannot proceed 2635 ** because it is blocked by the second and the second process cannot 2636 ** proceed because it is blocked by the first. If both processes 2637 ** invoke the busy handlers, neither will make any progress. Therefore, 2638 ** SQLite returns [SQLITE_BUSY] for the first process, hoping that this 2639 ** will induce the first process to release its read lock and allow 2640 ** the second process to proceed. 2641 ** 2642 ** ^The default busy callback is NULL. 2643 ** 2644 ** ^(There can only be a single busy handler defined for each 2645 ** [database connection]. Setting a new busy handler clears any 2646 ** previously set handler.)^ ^Note that calling [sqlite3_busy_timeout()] 2647 ** or evaluating [PRAGMA busy_timeout=N] will change the 2648 ** busy handler and thus clear any previously set busy handler. 2649 ** 2650 ** The busy callback should not take any actions which modify the 2651 ** database connection that invoked the busy handler. In other words, 2652 ** the busy handler is not reentrant. Any such actions 2653 ** result in undefined behavior. 2654 ** 2655 ** A busy handler must not close the database connection 2656 ** or [prepared statement] that invoked the busy handler. 2657 */ 2658 SQLITE_API int sqlite3_busy_handler(sqlite3*,int(*)(void*,int),void*); 2659 2660 /* 2661 ** CAPI3REF: Set A Busy Timeout 2662 ** METHOD: sqlite3 2663 ** 2664 ** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps 2665 ** for a specified amount of time when a table is locked. ^The handler 2666 ** will sleep multiple times until at least "ms" milliseconds of sleeping 2667 ** have accumulated. ^After at least "ms" milliseconds of sleeping, 2668 ** the handler returns 0 which causes [sqlite3_step()] to return 2669 ** [SQLITE_BUSY]. 2670 ** 2671 ** ^Calling this routine with an argument less than or equal to zero 2672 ** turns off all busy handlers. 2673 ** 2674 ** ^(There can only be a single busy handler for a particular 2675 ** [database connection] at any given moment. If another busy handler 2676 ** was defined (using [sqlite3_busy_handler()]) prior to calling 2677 ** this routine, that other busy handler is cleared.)^ 2678 ** 2679 ** See also: [PRAGMA busy_timeout] 2680 */ 2681 SQLITE_API int sqlite3_busy_timeout(sqlite3*, int ms); 2682 2683 /* 2684 ** CAPI3REF: Convenience Routines For Running Queries 2685 ** METHOD: sqlite3 2686 ** 2687 ** This is a legacy interface that is preserved for backwards compatibility. 2688 ** Use of this interface is not recommended. 2689 ** 2690 ** Definition: A <b>result table</b> is memory data structure created by the 2691 ** [sqlite3_get_table()] interface. A result table records the 2692 ** complete query results from one or more queries. 2693 ** 2694 ** The table conceptually has a number of rows and columns. But 2695 ** these numbers are not part of the result table itself. These 2696 ** numbers are obtained separately. Let N be the number of rows 2697 ** and M be the number of columns. 2698 ** 2699 ** A result table is an array of pointers to zero-terminated UTF-8 strings. 2700 ** There are (N+1)*M elements in the array. The first M pointers point 2701 ** to zero-terminated strings that contain the names of the columns. 2702 ** The remaining entries all point to query results. NULL values result 2703 ** in NULL pointers. All other values are in their UTF-8 zero-terminated 2704 ** string representation as returned by [sqlite3_column_text()]. 2705 ** 2706 ** A result table might consist of one or more memory allocations. 2707 ** It is not safe to pass a result table directly to [sqlite3_free()]. 2708 ** A result table should be deallocated using [sqlite3_free_table()]. 2709 ** 2710 ** ^(As an example of the result table format, suppose a query result 2711 ** is as follows: 2712 ** 2713 ** <blockquote><pre> 2714 ** Name | Age 2715 ** ----------------------- 2716 ** Alice | 43 2717 ** Bob | 28 2718 ** Cindy | 21 2719 ** </pre></blockquote> 2720 ** 2721 ** There are two columns (M==2) and three rows (N==3). Thus the 2722 ** result table has 8 entries. Suppose the result table is stored 2723 ** in an array named azResult. Then azResult holds this content: 2724 ** 2725 ** <blockquote><pre> 2726 ** azResult[0] = "Name"; 2727 ** azResult[1] = "Age"; 2728 ** azResult[2] = "Alice"; 2729 ** azResult[3] = "43"; 2730 ** azResult[4] = "Bob"; 2731 ** azResult[5] = "28"; 2732 ** azResult[6] = "Cindy"; 2733 ** azResult[7] = "21"; 2734 ** </pre></blockquote>)^ 2735 ** 2736 ** ^The sqlite3_get_table() function evaluates one or more 2737 ** semicolon-separated SQL statements in the zero-terminated UTF-8 2738 ** string of its 2nd parameter and returns a result table to the 2739 ** pointer given in its 3rd parameter. 2740 ** 2741 ** After the application has finished with the result from sqlite3_get_table(), 2742 ** it must pass the result table pointer to sqlite3_free_table() in order to 2743 ** release the memory that was malloced. Because of the way the 2744 ** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling 2745 ** function must not try to call [sqlite3_free()] directly. Only 2746 ** [sqlite3_free_table()] is able to release the memory properly and safely. 2747 ** 2748 ** The sqlite3_get_table() interface is implemented as a wrapper around 2749 ** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access 2750 ** to any internal data structures of SQLite. It uses only the public 2751 ** interface defined here. As a consequence, errors that occur in the 2752 ** wrapper layer outside of the internal [sqlite3_exec()] call are not 2753 ** reflected in subsequent calls to [sqlite3_errcode()] or 2754 ** [sqlite3_errmsg()]. 2755 */ 2756 SQLITE_API int sqlite3_get_table( 2757 sqlite3 *db, /* An open database */ 2758 const char *zSql, /* SQL to be evaluated */ 2759 char ***pazResult, /* Results of the query */ 2760 int *pnRow, /* Number of result rows written here */ 2761 int *pnColumn, /* Number of result columns written here */ 2762 char **pzErrmsg /* Error msg written here */ 2763 ); 2764 SQLITE_API void sqlite3_free_table(char **result); 2765 2766 /* 2767 ** CAPI3REF: Formatted String Printing Functions 2768 ** 2769 ** These routines are work-alikes of the "printf()" family of functions 2770 ** from the standard C library. 2771 ** These routines understand most of the common formatting options from 2772 ** the standard library printf() 2773 ** plus some additional non-standard formats ([%q], [%Q], [%w], and [%z]). 2774 ** See the [built-in printf()] documentation for details. 2775 ** 2776 ** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their 2777 ** results into memory obtained from [sqlite3_malloc64()]. 2778 ** The strings returned by these two routines should be 2779 ** released by [sqlite3_free()]. ^Both routines return a 2780 ** NULL pointer if [sqlite3_malloc64()] is unable to allocate enough 2781 ** memory to hold the resulting string. 2782 ** 2783 ** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from 2784 ** the standard C library. The result is written into the 2785 ** buffer supplied as the second parameter whose size is given by 2786 ** the first parameter. Note that the order of the 2787 ** first two parameters is reversed from snprintf().)^ This is an 2788 ** historical accident that cannot be fixed without breaking 2789 ** backwards compatibility. ^(Note also that sqlite3_snprintf() 2790 ** returns a pointer to its buffer instead of the number of 2791 ** characters actually written into the buffer.)^ We admit that 2792 ** the number of characters written would be a more useful return 2793 ** value but we cannot change the implementation of sqlite3_snprintf() 2794 ** now without breaking compatibility. 2795 ** 2796 ** ^As long as the buffer size is greater than zero, sqlite3_snprintf() 2797 ** guarantees that the buffer is always zero-terminated. ^The first 2798 ** parameter "n" is the total size of the buffer, including space for 2799 ** the zero terminator. So the longest string that can be completely 2800 ** written will be n-1 characters. 2801 ** 2802 ** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf(). 2803 ** 2804 ** See also: [built-in printf()], [printf() SQL function] 2805 */ 2806 SQLITE_API char *sqlite3_mprintf(const char*,...); 2807 SQLITE_API char *sqlite3_vmprintf(const char*, va_list); 2808 SQLITE_API char *sqlite3_snprintf(int,char*,const char*, ...); 2809 SQLITE_API char *sqlite3_vsnprintf(int,char*,const char*, va_list); 2810 2811 /* 2812 ** CAPI3REF: Memory Allocation Subsystem 2813 ** 2814 ** The SQLite core uses these three routines for all of its own 2815 ** internal memory allocation needs. "Core" in the previous sentence 2816 ** does not include operating-system specific [VFS] implementation. The 2817 ** Windows VFS uses native malloc() and free() for some operations. 2818 ** 2819 ** ^The sqlite3_malloc() routine returns a pointer to a block 2820 ** of memory at least N bytes in length, where N is the parameter. 2821 ** ^If sqlite3_malloc() is unable to obtain sufficient free 2822 ** memory, it returns a NULL pointer. ^If the parameter N to 2823 ** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns 2824 ** a NULL pointer. 2825 ** 2826 ** ^The sqlite3_malloc64(N) routine works just like 2827 ** sqlite3_malloc(N) except that N is an unsigned 64-bit integer instead 2828 ** of a signed 32-bit integer. 2829 ** 2830 ** ^Calling sqlite3_free() with a pointer previously returned 2831 ** by sqlite3_malloc() or sqlite3_realloc() releases that memory so 2832 ** that it might be reused. ^The sqlite3_free() routine is 2833 ** a no-op if is called with a NULL pointer. Passing a NULL pointer 2834 ** to sqlite3_free() is harmless. After being freed, memory 2835 ** should neither be read nor written. Even reading previously freed 2836 ** memory might result in a segmentation fault or other severe error. 2837 ** Memory corruption, a segmentation fault, or other severe error 2838 ** might result if sqlite3_free() is called with a non-NULL pointer that 2839 ** was not obtained from sqlite3_malloc() or sqlite3_realloc(). 2840 ** 2841 ** ^The sqlite3_realloc(X,N) interface attempts to resize a 2842 ** prior memory allocation X to be at least N bytes. 2843 ** ^If the X parameter to sqlite3_realloc(X,N) 2844 ** is a NULL pointer then its behavior is identical to calling 2845 ** sqlite3_malloc(N). 2846 ** ^If the N parameter to sqlite3_realloc(X,N) is zero or 2847 ** negative then the behavior is exactly the same as calling 2848 ** sqlite3_free(X). 2849 ** ^sqlite3_realloc(X,N) returns a pointer to a memory allocation 2850 ** of at least N bytes in size or NULL if insufficient memory is available. 2851 ** ^If M is the size of the prior allocation, then min(N,M) bytes 2852 ** of the prior allocation are copied into the beginning of buffer returned 2853 ** by sqlite3_realloc(X,N) and the prior allocation is freed. 2854 ** ^If sqlite3_realloc(X,N) returns NULL and N is positive, then the 2855 ** prior allocation is not freed. 2856 ** 2857 ** ^The sqlite3_realloc64(X,N) interfaces works the same as 2858 ** sqlite3_realloc(X,N) except that N is a 64-bit unsigned integer instead 2859 ** of a 32-bit signed integer. 2860 ** 2861 ** ^If X is a memory allocation previously obtained from sqlite3_malloc(), 2862 ** sqlite3_malloc64(), sqlite3_realloc(), or sqlite3_realloc64(), then 2863 ** sqlite3_msize(X) returns the size of that memory allocation in bytes. 2864 ** ^The value returned by sqlite3_msize(X) might be larger than the number 2865 ** of bytes requested when X was allocated. ^If X is a NULL pointer then 2866 ** sqlite3_msize(X) returns zero. If X points to something that is not 2867 ** the beginning of memory allocation, or if it points to a formerly 2868 ** valid memory allocation that has now been freed, then the behavior 2869 ** of sqlite3_msize(X) is undefined and possibly harmful. 2870 ** 2871 ** ^The memory returned by sqlite3_malloc(), sqlite3_realloc(), 2872 ** sqlite3_malloc64(), and sqlite3_realloc64() 2873 ** is always aligned to at least an 8 byte boundary, or to a 2874 ** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time 2875 ** option is used. 2876 ** 2877 ** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()] 2878 ** must be either NULL or else pointers obtained from a prior 2879 ** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have 2880 ** not yet been released. 2881 ** 2882 ** The application must not read or write any part of 2883 ** a block of memory after it has been released using 2884 ** [sqlite3_free()] or [sqlite3_realloc()]. 2885 */ 2886 SQLITE_API void *sqlite3_malloc(int); 2887 SQLITE_API void *sqlite3_malloc64(sqlite3_uint64); 2888 SQLITE_API void *sqlite3_realloc(void*, int); 2889 SQLITE_API void *sqlite3_realloc64(void*, sqlite3_uint64); 2890 SQLITE_API void sqlite3_free(void*); 2891 SQLITE_API sqlite3_uint64 sqlite3_msize(void*); 2892 2893 /* 2894 ** CAPI3REF: Memory Allocator Statistics 2895 ** 2896 ** SQLite provides these two interfaces for reporting on the status 2897 ** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()] 2898 ** routines, which form the built-in memory allocation subsystem. 2899 ** 2900 ** ^The [sqlite3_memory_used()] routine returns the number of bytes 2901 ** of memory currently outstanding (malloced but not freed). 2902 ** ^The [sqlite3_memory_highwater()] routine returns the maximum 2903 ** value of [sqlite3_memory_used()] since the high-water mark 2904 ** was last reset. ^The values returned by [sqlite3_memory_used()] and 2905 ** [sqlite3_memory_highwater()] include any overhead 2906 ** added by SQLite in its implementation of [sqlite3_malloc()], 2907 ** but not overhead added by the any underlying system library 2908 ** routines that [sqlite3_malloc()] may call. 2909 ** 2910 ** ^The memory high-water mark is reset to the current value of 2911 ** [sqlite3_memory_used()] if and only if the parameter to 2912 ** [sqlite3_memory_highwater()] is true. ^The value returned 2913 ** by [sqlite3_memory_highwater(1)] is the high-water mark 2914 ** prior to the reset. 2915 */ 2916 SQLITE_API sqlite3_int64 sqlite3_memory_used(void); 2917 SQLITE_API sqlite3_int64 sqlite3_memory_highwater(int resetFlag); 2918 2919 /* 2920 ** CAPI3REF: Pseudo-Random Number Generator 2921 ** 2922 ** SQLite contains a high-quality pseudo-random number generator (PRNG) used to 2923 ** select random [ROWID | ROWIDs] when inserting new records into a table that 2924 ** already uses the largest possible [ROWID]. The PRNG is also used for 2925 ** the built-in random() and randomblob() SQL functions. This interface allows 2926 ** applications to access the same PRNG for other purposes. 2927 ** 2928 ** ^A call to this routine stores N bytes of randomness into buffer P. 2929 ** ^The P parameter can be a NULL pointer. 2930 ** 2931 ** ^If this routine has not been previously called or if the previous 2932 ** call had N less than one or a NULL pointer for P, then the PRNG is 2933 ** seeded using randomness obtained from the xRandomness method of 2934 ** the default [sqlite3_vfs] object. 2935 ** ^If the previous call to this routine had an N of 1 or more and a 2936 ** non-NULL P then the pseudo-randomness is generated 2937 ** internally and without recourse to the [sqlite3_vfs] xRandomness 2938 ** method. 2939 */ 2940 SQLITE_API void sqlite3_randomness(int N, void *P); 2941 2942 /* 2943 ** CAPI3REF: Compile-Time Authorization Callbacks 2944 ** METHOD: sqlite3 2945 ** KEYWORDS: {authorizer callback} 2946 ** 2947 ** ^This routine registers an authorizer callback with a particular 2948 ** [database connection], supplied in the first argument. 2949 ** ^The authorizer callback is invoked as SQL statements are being compiled 2950 ** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()], 2951 ** [sqlite3_prepare_v3()], [sqlite3_prepare16()], [sqlite3_prepare16_v2()], 2952 ** and [sqlite3_prepare16_v3()]. ^At various 2953 ** points during the compilation process, as logic is being created 2954 ** to perform various actions, the authorizer callback is invoked to 2955 ** see if those actions are allowed. ^The authorizer callback should 2956 ** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the 2957 ** specific action but allow the SQL statement to continue to be 2958 ** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be 2959 ** rejected with an error. ^If the authorizer callback returns 2960 ** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY] 2961 ** then the [sqlite3_prepare_v2()] or equivalent call that triggered 2962 ** the authorizer will fail with an error message. 2963 ** 2964 ** When the callback returns [SQLITE_OK], that means the operation 2965 ** requested is ok. ^When the callback returns [SQLITE_DENY], the 2966 ** [sqlite3_prepare_v2()] or equivalent call that triggered the 2967 ** authorizer will fail with an error message explaining that 2968 ** access is denied. 2969 ** 2970 ** ^The first parameter to the authorizer callback is a copy of the third 2971 ** parameter to the sqlite3_set_authorizer() interface. ^The second parameter 2972 ** to the callback is an integer [SQLITE_COPY | action code] that specifies 2973 ** the particular action to be authorized. ^The third through sixth parameters 2974 ** to the callback are either NULL pointers or zero-terminated strings 2975 ** that contain additional details about the action to be authorized. 2976 ** Applications must always be prepared to encounter a NULL pointer in any 2977 ** of the third through the sixth parameters of the authorization callback. 2978 ** 2979 ** ^If the action code is [SQLITE_READ] 2980 ** and the callback returns [SQLITE_IGNORE] then the 2981 ** [prepared statement] statement is constructed to substitute 2982 ** a NULL value in place of the table column that would have 2983 ** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE] 2984 ** return can be used to deny an untrusted user access to individual 2985 ** columns of a table. 2986 ** ^When a table is referenced by a [SELECT] but no column values are 2987 ** extracted from that table (for example in a query like 2988 ** "SELECT count(*) FROM tab") then the [SQLITE_READ] authorizer callback 2989 ** is invoked once for that table with a column name that is an empty string. 2990 ** ^If the action code is [SQLITE_DELETE] and the callback returns 2991 ** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the 2992 ** [truncate optimization] is disabled and all rows are deleted individually. 2993 ** 2994 ** An authorizer is used when [sqlite3_prepare | preparing] 2995 ** SQL statements from an untrusted source, to ensure that the SQL statements 2996 ** do not try to access data they are not allowed to see, or that they do not 2997 ** try to execute malicious statements that damage the database. For 2998 ** example, an application may allow a user to enter arbitrary 2999 ** SQL queries for evaluation by a database. But the application does 3000 ** not want the user to be able to make arbitrary changes to the 3001 ** database. An authorizer could then be put in place while the 3002 ** user-entered SQL is being [sqlite3_prepare | prepared] that 3003 ** disallows everything except [SELECT] statements. 3004 ** 3005 ** Applications that need to process SQL from untrusted sources 3006 ** might also consider lowering resource limits using [sqlite3_limit()] 3007 ** and limiting database size using the [max_page_count] [PRAGMA] 3008 ** in addition to using an authorizer. 3009 ** 3010 ** ^(Only a single authorizer can be in place on a database connection 3011 ** at a time. Each call to sqlite3_set_authorizer overrides the 3012 ** previous call.)^ ^Disable the authorizer by installing a NULL callback. 3013 ** The authorizer is disabled by default. 3014 ** 3015 ** The authorizer callback must not do anything that will modify 3016 ** the database connection that invoked the authorizer callback. 3017 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 3018 ** database connections for the meaning of "modify" in this paragraph. 3019 ** 3020 ** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the 3021 ** statement might be re-prepared during [sqlite3_step()] due to a 3022 ** schema change. Hence, the application should ensure that the 3023 ** correct authorizer callback remains in place during the [sqlite3_step()]. 3024 ** 3025 ** ^Note that the authorizer callback is invoked only during 3026 ** [sqlite3_prepare()] or its variants. Authorization is not 3027 ** performed during statement evaluation in [sqlite3_step()], unless 3028 ** as stated in the previous paragraph, sqlite3_step() invokes 3029 ** sqlite3_prepare_v2() to reprepare a statement after a schema change. 3030 */ 3031 SQLITE_API int sqlite3_set_authorizer( 3032 sqlite3*, 3033 int (*xAuth)(void*,int,const char*,const char*,const char*,const char*), 3034 void *pUserData 3035 ); 3036 3037 /* 3038 ** CAPI3REF: Authorizer Return Codes 3039 ** 3040 ** The [sqlite3_set_authorizer | authorizer callback function] must 3041 ** return either [SQLITE_OK] or one of these two constants in order 3042 ** to signal SQLite whether or not the action is permitted. See the 3043 ** [sqlite3_set_authorizer | authorizer documentation] for additional 3044 ** information. 3045 ** 3046 ** Note that SQLITE_IGNORE is also used as a [conflict resolution mode] 3047 ** returned from the [sqlite3_vtab_on_conflict()] interface. 3048 */ 3049 #define SQLITE_DENY 1 /* Abort the SQL statement with an error */ 3050 #define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */ 3051 3052 /* 3053 ** CAPI3REF: Authorizer Action Codes 3054 ** 3055 ** The [sqlite3_set_authorizer()] interface registers a callback function 3056 ** that is invoked to authorize certain SQL statement actions. The 3057 ** second parameter to the callback is an integer code that specifies 3058 ** what action is being authorized. These are the integer action codes that 3059 ** the authorizer callback may be passed. 3060 ** 3061 ** These action code values signify what kind of operation is to be 3062 ** authorized. The 3rd and 4th parameters to the authorization 3063 ** callback function will be parameters or NULL depending on which of these 3064 ** codes is used as the second parameter. ^(The 5th parameter to the 3065 ** authorizer callback is the name of the database ("main", "temp", 3066 ** etc.) if applicable.)^ ^The 6th parameter to the authorizer callback 3067 ** is the name of the inner-most trigger or view that is responsible for 3068 ** the access attempt or NULL if this access attempt is directly from 3069 ** top-level SQL code. 3070 */ 3071 /******************************************* 3rd ************ 4th ***********/ 3072 #define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */ 3073 #define SQLITE_CREATE_TABLE 2 /* Table Name NULL */ 3074 #define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */ 3075 #define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */ 3076 #define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */ 3077 #define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */ 3078 #define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */ 3079 #define SQLITE_CREATE_VIEW 8 /* View Name NULL */ 3080 #define SQLITE_DELETE 9 /* Table Name NULL */ 3081 #define SQLITE_DROP_INDEX 10 /* Index Name Table Name */ 3082 #define SQLITE_DROP_TABLE 11 /* Table Name NULL */ 3083 #define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */ 3084 #define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */ 3085 #define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */ 3086 #define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */ 3087 #define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */ 3088 #define SQLITE_DROP_VIEW 17 /* View Name NULL */ 3089 #define SQLITE_INSERT 18 /* Table Name NULL */ 3090 #define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */ 3091 #define SQLITE_READ 20 /* Table Name Column Name */ 3092 #define SQLITE_SELECT 21 /* NULL NULL */ 3093 #define SQLITE_TRANSACTION 22 /* Operation NULL */ 3094 #define SQLITE_UPDATE 23 /* Table Name Column Name */ 3095 #define SQLITE_ATTACH 24 /* Filename NULL */ 3096 #define SQLITE_DETACH 25 /* Database Name NULL */ 3097 #define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */ 3098 #define SQLITE_REINDEX 27 /* Index Name NULL */ 3099 #define SQLITE_ANALYZE 28 /* Table Name NULL */ 3100 #define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */ 3101 #define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */ 3102 #define SQLITE_FUNCTION 31 /* NULL Function Name */ 3103 #define SQLITE_SAVEPOINT 32 /* Operation Savepoint Name */ 3104 #define SQLITE_COPY 0 /* No longer used */ 3105 #define SQLITE_RECURSIVE 33 /* NULL NULL */ 3106 3107 /* 3108 ** CAPI3REF: Tracing And Profiling Functions 3109 ** METHOD: sqlite3 3110 ** 3111 ** These routines are deprecated. Use the [sqlite3_trace_v2()] interface 3112 ** instead of the routines described here. 3113 ** 3114 ** These routines register callback functions that can be used for 3115 ** tracing and profiling the execution of SQL statements. 3116 ** 3117 ** ^The callback function registered by sqlite3_trace() is invoked at 3118 ** various times when an SQL statement is being run by [sqlite3_step()]. 3119 ** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the 3120 ** SQL statement text as the statement first begins executing. 3121 ** ^(Additional sqlite3_trace() callbacks might occur 3122 ** as each triggered subprogram is entered. The callbacks for triggers 3123 ** contain a UTF-8 SQL comment that identifies the trigger.)^ 3124 ** 3125 ** The [SQLITE_TRACE_SIZE_LIMIT] compile-time option can be used to limit 3126 ** the length of [bound parameter] expansion in the output of sqlite3_trace(). 3127 ** 3128 ** ^The callback function registered by sqlite3_profile() is invoked 3129 ** as each SQL statement finishes. ^The profile callback contains 3130 ** the original statement text and an estimate of wall-clock time 3131 ** of how long that statement took to run. ^The profile callback 3132 ** time is in units of nanoseconds, however the current implementation 3133 ** is only capable of millisecond resolution so the six least significant 3134 ** digits in the time are meaningless. Future versions of SQLite 3135 ** might provide greater resolution on the profiler callback. Invoking 3136 ** either [sqlite3_trace()] or [sqlite3_trace_v2()] will cancel the 3137 ** profile callback. 3138 */ 3139 SQLITE_API SQLITE_DEPRECATED void *sqlite3_trace(sqlite3*, 3140 void(*xTrace)(void*,const char*), void*); 3141 SQLITE_API SQLITE_DEPRECATED void *sqlite3_profile(sqlite3*, 3142 void(*xProfile)(void*,const char*,sqlite3_uint64), void*); 3143 3144 /* 3145 ** CAPI3REF: SQL Trace Event Codes 3146 ** KEYWORDS: SQLITE_TRACE 3147 ** 3148 ** These constants identify classes of events that can be monitored 3149 ** using the [sqlite3_trace_v2()] tracing logic. The M argument 3150 ** to [sqlite3_trace_v2(D,M,X,P)] is an OR-ed combination of one or more of 3151 ** the following constants. ^The first argument to the trace callback 3152 ** is one of the following constants. 3153 ** 3154 ** New tracing constants may be added in future releases. 3155 ** 3156 ** ^A trace callback has four arguments: xCallback(T,C,P,X). 3157 ** ^The T argument is one of the integer type codes above. 3158 ** ^The C argument is a copy of the context pointer passed in as the 3159 ** fourth argument to [sqlite3_trace_v2()]. 3160 ** The P and X arguments are pointers whose meanings depend on T. 3161 ** 3162 ** <dl> 3163 ** [[SQLITE_TRACE_STMT]] <dt>SQLITE_TRACE_STMT</dt> 3164 ** <dd>^An SQLITE_TRACE_STMT callback is invoked when a prepared statement 3165 ** first begins running and possibly at other times during the 3166 ** execution of the prepared statement, such as at the start of each 3167 ** trigger subprogram. ^The P argument is a pointer to the 3168 ** [prepared statement]. ^The X argument is a pointer to a string which 3169 ** is the unexpanded SQL text of the prepared statement or an SQL comment 3170 ** that indicates the invocation of a trigger. ^The callback can compute 3171 ** the same text that would have been returned by the legacy [sqlite3_trace()] 3172 ** interface by using the X argument when X begins with "--" and invoking 3173 ** [sqlite3_expanded_sql(P)] otherwise. 3174 ** 3175 ** [[SQLITE_TRACE_PROFILE]] <dt>SQLITE_TRACE_PROFILE</dt> 3176 ** <dd>^An SQLITE_TRACE_PROFILE callback provides approximately the same 3177 ** information as is provided by the [sqlite3_profile()] callback. 3178 ** ^The P argument is a pointer to the [prepared statement] and the 3179 ** X argument points to a 64-bit integer which is the estimated of 3180 ** the number of nanosecond that the prepared statement took to run. 3181 ** ^The SQLITE_TRACE_PROFILE callback is invoked when the statement finishes. 3182 ** 3183 ** [[SQLITE_TRACE_ROW]] <dt>SQLITE_TRACE_ROW</dt> 3184 ** <dd>^An SQLITE_TRACE_ROW callback is invoked whenever a prepared 3185 ** statement generates a single row of result. 3186 ** ^The P argument is a pointer to the [prepared statement] and the 3187 ** X argument is unused. 3188 ** 3189 ** [[SQLITE_TRACE_CLOSE]] <dt>SQLITE_TRACE_CLOSE</dt> 3190 ** <dd>^An SQLITE_TRACE_CLOSE callback is invoked when a database 3191 ** connection closes. 3192 ** ^The P argument is a pointer to the [database connection] object 3193 ** and the X argument is unused. 3194 ** </dl> 3195 */ 3196 #define SQLITE_TRACE_STMT 0x01 3197 #define SQLITE_TRACE_PROFILE 0x02 3198 #define SQLITE_TRACE_ROW 0x04 3199 #define SQLITE_TRACE_CLOSE 0x08 3200 3201 /* 3202 ** CAPI3REF: SQL Trace Hook 3203 ** METHOD: sqlite3 3204 ** 3205 ** ^The sqlite3_trace_v2(D,M,X,P) interface registers a trace callback 3206 ** function X against [database connection] D, using property mask M 3207 ** and context pointer P. ^If the X callback is 3208 ** NULL or if the M mask is zero, then tracing is disabled. The 3209 ** M argument should be the bitwise OR-ed combination of 3210 ** zero or more [SQLITE_TRACE] constants. 3211 ** 3212 ** ^Each call to either sqlite3_trace() or sqlite3_trace_v2() overrides 3213 ** (cancels) any prior calls to sqlite3_trace() or sqlite3_trace_v2(). 3214 ** 3215 ** ^The X callback is invoked whenever any of the events identified by 3216 ** mask M occur. ^The integer return value from the callback is currently 3217 ** ignored, though this may change in future releases. Callback 3218 ** implementations should return zero to ensure future compatibility. 3219 ** 3220 ** ^A trace callback is invoked with four arguments: callback(T,C,P,X). 3221 ** ^The T argument is one of the [SQLITE_TRACE] 3222 ** constants to indicate why the callback was invoked. 3223 ** ^The C argument is a copy of the context pointer. 3224 ** The P and X arguments are pointers whose meanings depend on T. 3225 ** 3226 ** The sqlite3_trace_v2() interface is intended to replace the legacy 3227 ** interfaces [sqlite3_trace()] and [sqlite3_profile()], both of which 3228 ** are deprecated. 3229 */ 3230 SQLITE_API int sqlite3_trace_v2( 3231 sqlite3*, 3232 unsigned uMask, 3233 int(*xCallback)(unsigned,void*,void*,void*), 3234 void *pCtx 3235 ); 3236 3237 /* 3238 ** CAPI3REF: Query Progress Callbacks 3239 ** METHOD: sqlite3 3240 ** 3241 ** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback 3242 ** function X to be invoked periodically during long running calls to 3243 ** [sqlite3_exec()], [sqlite3_step()] and [sqlite3_get_table()] for 3244 ** database connection D. An example use for this 3245 ** interface is to keep a GUI updated during a large query. 3246 ** 3247 ** ^The parameter P is passed through as the only parameter to the 3248 ** callback function X. ^The parameter N is the approximate number of 3249 ** [virtual machine instructions] that are evaluated between successive 3250 ** invocations of the callback X. ^If N is less than one then the progress 3251 ** handler is disabled. 3252 ** 3253 ** ^Only a single progress handler may be defined at one time per 3254 ** [database connection]; setting a new progress handler cancels the 3255 ** old one. ^Setting parameter X to NULL disables the progress handler. 3256 ** ^The progress handler is also disabled by setting N to a value less 3257 ** than 1. 3258 ** 3259 ** ^If the progress callback returns non-zero, the operation is 3260 ** interrupted. This feature can be used to implement a 3261 ** "Cancel" button on a GUI progress dialog box. 3262 ** 3263 ** The progress handler callback must not do anything that will modify 3264 ** the database connection that invoked the progress handler. 3265 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 3266 ** database connections for the meaning of "modify" in this paragraph. 3267 ** 3268 */ 3269 SQLITE_API void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*); 3270 3271 /* 3272 ** CAPI3REF: Opening A New Database Connection 3273 ** CONSTRUCTOR: sqlite3 3274 ** 3275 ** ^These routines open an SQLite database file as specified by the 3276 ** filename argument. ^The filename argument is interpreted as UTF-8 for 3277 ** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte 3278 ** order for sqlite3_open16(). ^(A [database connection] handle is usually 3279 ** returned in *ppDb, even if an error occurs. The only exception is that 3280 ** if SQLite is unable to allocate memory to hold the [sqlite3] object, 3281 ** a NULL will be written into *ppDb instead of a pointer to the [sqlite3] 3282 ** object.)^ ^(If the database is opened (and/or created) successfully, then 3283 ** [SQLITE_OK] is returned. Otherwise an [error code] is returned.)^ ^The 3284 ** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain 3285 ** an English language description of the error following a failure of any 3286 ** of the sqlite3_open() routines. 3287 ** 3288 ** ^The default encoding will be UTF-8 for databases created using 3289 ** sqlite3_open() or sqlite3_open_v2(). ^The default encoding for databases 3290 ** created using sqlite3_open16() will be UTF-16 in the native byte order. 3291 ** 3292 ** Whether or not an error occurs when it is opened, resources 3293 ** associated with the [database connection] handle should be released by 3294 ** passing it to [sqlite3_close()] when it is no longer required. 3295 ** 3296 ** The sqlite3_open_v2() interface works like sqlite3_open() 3297 ** except that it accepts two additional parameters for additional control 3298 ** over the new database connection. ^(The flags parameter to 3299 ** sqlite3_open_v2() must include, at a minimum, one of the following 3300 ** three flag combinations:)^ 3301 ** 3302 ** <dl> 3303 ** ^(<dt>[SQLITE_OPEN_READONLY]</dt> 3304 ** <dd>The database is opened in read-only mode. If the database does not 3305 ** already exist, an error is returned.</dd>)^ 3306 ** 3307 ** ^(<dt>[SQLITE_OPEN_READWRITE]</dt> 3308 ** <dd>The database is opened for reading and writing if possible, or reading 3309 ** only if the file is write protected by the operating system. In either 3310 ** case the database must already exist, otherwise an error is returned.</dd>)^ 3311 ** 3312 ** ^(<dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt> 3313 ** <dd>The database is opened for reading and writing, and is created if 3314 ** it does not already exist. This is the behavior that is always used for 3315 ** sqlite3_open() and sqlite3_open16().</dd>)^ 3316 ** </dl> 3317 ** 3318 ** In addition to the required flags, the following optional flags are 3319 ** also supported: 3320 ** 3321 ** <dl> 3322 ** ^(<dt>[SQLITE_OPEN_URI]</dt> 3323 ** <dd>The filename can be interpreted as a URI if this flag is set.</dd>)^ 3324 ** 3325 ** ^(<dt>[SQLITE_OPEN_MEMORY]</dt> 3326 ** <dd>The database will be opened as an in-memory database. The database 3327 ** is named by the "filename" argument for the purposes of cache-sharing, 3328 ** if shared cache mode is enabled, but the "filename" is otherwise ignored. 3329 ** </dd>)^ 3330 ** 3331 ** ^(<dt>[SQLITE_OPEN_NOMUTEX]</dt> 3332 ** <dd>The new database connection will use the "multi-thread" 3333 ** [threading mode].)^ This means that separate threads are allowed 3334 ** to use SQLite at the same time, as long as each thread is using 3335 ** a different [database connection]. 3336 ** 3337 ** ^(<dt>[SQLITE_OPEN_FULLMUTEX]</dt> 3338 ** <dd>The new database connection will use the "serialized" 3339 ** [threading mode].)^ This means the multiple threads can safely 3340 ** attempt to use the same database connection at the same time. 3341 ** (Mutexes will block any actual concurrency, but in this mode 3342 ** there is no harm in trying.) 3343 ** 3344 ** ^(<dt>[SQLITE_OPEN_SHAREDCACHE]</dt> 3345 ** <dd>The database is opened [shared cache] enabled, overriding 3346 ** the default shared cache setting provided by 3347 ** [sqlite3_enable_shared_cache()].)^ 3348 ** 3349 ** ^(<dt>[SQLITE_OPEN_PRIVATECACHE]</dt> 3350 ** <dd>The database is opened [shared cache] disabled, overriding 3351 ** the default shared cache setting provided by 3352 ** [sqlite3_enable_shared_cache()].)^ 3353 ** 3354 ** [[OPEN_NOFOLLOW]] ^(<dt>[SQLITE_OPEN_NOFOLLOW]</dt> 3355 ** <dd>The database filename is not allowed to be a symbolic link</dd> 3356 ** </dl>)^ 3357 ** 3358 ** If the 3rd parameter to sqlite3_open_v2() is not one of the 3359 ** required combinations shown above optionally combined with other 3360 ** [SQLITE_OPEN_READONLY | SQLITE_OPEN_* bits] 3361 ** then the behavior is undefined. 3362 ** 3363 ** ^The fourth parameter to sqlite3_open_v2() is the name of the 3364 ** [sqlite3_vfs] object that defines the operating system interface that 3365 ** the new database connection should use. ^If the fourth parameter is 3366 ** a NULL pointer then the default [sqlite3_vfs] object is used. 3367 ** 3368 ** ^If the filename is ":memory:", then a private, temporary in-memory database 3369 ** is created for the connection. ^This in-memory database will vanish when 3370 ** the database connection is closed. Future versions of SQLite might 3371 ** make use of additional special filenames that begin with the ":" character. 3372 ** It is recommended that when a database filename actually does begin with 3373 ** a ":" character you should prefix the filename with a pathname such as 3374 ** "./" to avoid ambiguity. 3375 ** 3376 ** ^If the filename is an empty string, then a private, temporary 3377 ** on-disk database will be created. ^This private database will be 3378 ** automatically deleted as soon as the database connection is closed. 3379 ** 3380 ** [[URI filenames in sqlite3_open()]] <h3>URI Filenames</h3> 3381 ** 3382 ** ^If [URI filename] interpretation is enabled, and the filename argument 3383 ** begins with "file:", then the filename is interpreted as a URI. ^URI 3384 ** filename interpretation is enabled if the [SQLITE_OPEN_URI] flag is 3385 ** set in the third argument to sqlite3_open_v2(), or if it has 3386 ** been enabled globally using the [SQLITE_CONFIG_URI] option with the 3387 ** [sqlite3_config()] method or by the [SQLITE_USE_URI] compile-time option. 3388 ** URI filename interpretation is turned off 3389 ** by default, but future releases of SQLite might enable URI filename 3390 ** interpretation by default. See "[URI filenames]" for additional 3391 ** information. 3392 ** 3393 ** URI filenames are parsed according to RFC 3986. ^If the URI contains an 3394 ** authority, then it must be either an empty string or the string 3395 ** "localhost". ^If the authority is not an empty string or "localhost", an 3396 ** error is returned to the caller. ^The fragment component of a URI, if 3397 ** present, is ignored. 3398 ** 3399 ** ^SQLite uses the path component of the URI as the name of the disk file 3400 ** which contains the database. ^If the path begins with a '/' character, 3401 ** then it is interpreted as an absolute path. ^If the path does not begin 3402 ** with a '/' (meaning that the authority section is omitted from the URI) 3403 ** then the path is interpreted as a relative path. 3404 ** ^(On windows, the first component of an absolute path 3405 ** is a drive specification (e.g. "C:").)^ 3406 ** 3407 ** [[core URI query parameters]] 3408 ** The query component of a URI may contain parameters that are interpreted 3409 ** either by SQLite itself, or by a [VFS | custom VFS implementation]. 3410 ** SQLite and its built-in [VFSes] interpret the 3411 ** following query parameters: 3412 ** 3413 ** <ul> 3414 ** <li> <b>vfs</b>: ^The "vfs" parameter may be used to specify the name of 3415 ** a VFS object that provides the operating system interface that should 3416 ** be used to access the database file on disk. ^If this option is set to 3417 ** an empty string the default VFS object is used. ^Specifying an unknown 3418 ** VFS is an error. ^If sqlite3_open_v2() is used and the vfs option is 3419 ** present, then the VFS specified by the option takes precedence over 3420 ** the value passed as the fourth parameter to sqlite3_open_v2(). 3421 ** 3422 ** <li> <b>mode</b>: ^(The mode parameter may be set to either "ro", "rw", 3423 ** "rwc", or "memory". Attempting to set it to any other value is 3424 ** an error)^. 3425 ** ^If "ro" is specified, then the database is opened for read-only 3426 ** access, just as if the [SQLITE_OPEN_READONLY] flag had been set in the 3427 ** third argument to sqlite3_open_v2(). ^If the mode option is set to 3428 ** "rw", then the database is opened for read-write (but not create) 3429 ** access, as if SQLITE_OPEN_READWRITE (but not SQLITE_OPEN_CREATE) had 3430 ** been set. ^Value "rwc" is equivalent to setting both 3431 ** SQLITE_OPEN_READWRITE and SQLITE_OPEN_CREATE. ^If the mode option is 3432 ** set to "memory" then a pure [in-memory database] that never reads 3433 ** or writes from disk is used. ^It is an error to specify a value for 3434 ** the mode parameter that is less restrictive than that specified by 3435 ** the flags passed in the third parameter to sqlite3_open_v2(). 3436 ** 3437 ** <li> <b>cache</b>: ^The cache parameter may be set to either "shared" or 3438 ** "private". ^Setting it to "shared" is equivalent to setting the 3439 ** SQLITE_OPEN_SHAREDCACHE bit in the flags argument passed to 3440 ** sqlite3_open_v2(). ^Setting the cache parameter to "private" is 3441 ** equivalent to setting the SQLITE_OPEN_PRIVATECACHE bit. 3442 ** ^If sqlite3_open_v2() is used and the "cache" parameter is present in 3443 ** a URI filename, its value overrides any behavior requested by setting 3444 ** SQLITE_OPEN_PRIVATECACHE or SQLITE_OPEN_SHAREDCACHE flag. 3445 ** 3446 ** <li> <b>psow</b>: ^The psow parameter indicates whether or not the 3447 ** [powersafe overwrite] property does or does not apply to the 3448 ** storage media on which the database file resides. 3449 ** 3450 ** <li> <b>nolock</b>: ^The nolock parameter is a boolean query parameter 3451 ** which if set disables file locking in rollback journal modes. This 3452 ** is useful for accessing a database on a filesystem that does not 3453 ** support locking. Caution: Database corruption might result if two 3454 ** or more processes write to the same database and any one of those 3455 ** processes uses nolock=1. 3456 ** 3457 ** <li> <b>immutable</b>: ^The immutable parameter is a boolean query 3458 ** parameter that indicates that the database file is stored on 3459 ** read-only media. ^When immutable is set, SQLite assumes that the 3460 ** database file cannot be changed, even by a process with higher 3461 ** privilege, and so the database is opened read-only and all locking 3462 ** and change detection is disabled. Caution: Setting the immutable 3463 ** property on a database file that does in fact change can result 3464 ** in incorrect query results and/or [SQLITE_CORRUPT] errors. 3465 ** See also: [SQLITE_IOCAP_IMMUTABLE]. 3466 ** 3467 ** </ul> 3468 ** 3469 ** ^Specifying an unknown parameter in the query component of a URI is not an 3470 ** error. Future versions of SQLite might understand additional query 3471 ** parameters. See "[query parameters with special meaning to SQLite]" for 3472 ** additional information. 3473 ** 3474 ** [[URI filename examples]] <h3>URI filename examples</h3> 3475 ** 3476 ** <table border="1" align=center cellpadding=5> 3477 ** <tr><th> URI filenames <th> Results 3478 ** <tr><td> file:data.db <td> 3479 ** Open the file "data.db" in the current directory. 3480 ** <tr><td> file:/home/fred/data.db<br> 3481 ** file:///home/fred/data.db <br> 3482 ** file://localhost/home/fred/data.db <br> <td> 3483 ** Open the database file "/home/fred/data.db". 3484 ** <tr><td> file://darkstar/home/fred/data.db <td> 3485 ** An error. "darkstar" is not a recognized authority. 3486 ** <tr><td style="white-space:nowrap"> 3487 ** file:///C:/Documents%20and%20Settings/fred/Desktop/data.db 3488 ** <td> Windows only: Open the file "data.db" on fred's desktop on drive 3489 ** C:. Note that the %20 escaping in this example is not strictly 3490 ** necessary - space characters can be used literally 3491 ** in URI filenames. 3492 ** <tr><td> file:data.db?mode=ro&cache=private <td> 3493 ** Open file "data.db" in the current directory for read-only access. 3494 ** Regardless of whether or not shared-cache mode is enabled by 3495 ** default, use a private cache. 3496 ** <tr><td> file:/home/fred/data.db?vfs=unix-dotfile <td> 3497 ** Open file "/home/fred/data.db". Use the special VFS "unix-dotfile" 3498 ** that uses dot-files in place of posix advisory locking. 3499 ** <tr><td> file:data.db?mode=readonly <td> 3500 ** An error. "readonly" is not a valid option for the "mode" parameter. 3501 ** </table> 3502 ** 3503 ** ^URI hexadecimal escape sequences (%HH) are supported within the path and 3504 ** query components of a URI. A hexadecimal escape sequence consists of a 3505 ** percent sign - "%" - followed by exactly two hexadecimal digits 3506 ** specifying an octet value. ^Before the path or query components of a 3507 ** URI filename are interpreted, they are encoded using UTF-8 and all 3508 ** hexadecimal escape sequences replaced by a single byte containing the 3509 ** corresponding octet. If this process generates an invalid UTF-8 encoding, 3510 ** the results are undefined. 3511 ** 3512 ** <b>Note to Windows users:</b> The encoding used for the filename argument 3513 ** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever 3514 ** codepage is currently defined. Filenames containing international 3515 ** characters must be converted to UTF-8 prior to passing them into 3516 ** sqlite3_open() or sqlite3_open_v2(). 3517 ** 3518 ** <b>Note to Windows Runtime users:</b> The temporary directory must be set 3519 ** prior to calling sqlite3_open() or sqlite3_open_v2(). Otherwise, various 3520 ** features that require the use of temporary files may fail. 3521 ** 3522 ** See also: [sqlite3_temp_directory] 3523 */ 3524 SQLITE_API int sqlite3_open( 3525 const char *filename, /* Database filename (UTF-8) */ 3526 sqlite3 **ppDb /* OUT: SQLite db handle */ 3527 ); 3528 SQLITE_API int sqlite3_open16( 3529 const void *filename, /* Database filename (UTF-16) */ 3530 sqlite3 **ppDb /* OUT: SQLite db handle */ 3531 ); 3532 SQLITE_API int sqlite3_open_v2( 3533 const char *filename, /* Database filename (UTF-8) */ 3534 sqlite3 **ppDb, /* OUT: SQLite db handle */ 3535 int flags, /* Flags */ 3536 const char *zVfs /* Name of VFS module to use */ 3537 ); 3538 3539 /* 3540 ** CAPI3REF: Obtain Values For URI Parameters 3541 ** 3542 ** These are utility routines, useful to [VFS|custom VFS implementations], 3543 ** that check if a database file was a URI that contained a specific query 3544 ** parameter, and if so obtains the value of that query parameter. 3545 ** 3546 ** The first parameter to these interfaces (hereafter referred to 3547 ** as F) must be one of: 3548 ** <ul> 3549 ** <li> A database filename pointer created by the SQLite core and 3550 ** passed into the xOpen() method of a VFS implemention, or 3551 ** <li> A filename obtained from [sqlite3_db_filename()], or 3552 ** <li> A new filename constructed using [sqlite3_create_filename()]. 3553 ** </ul> 3554 ** If the F parameter is not one of the above, then the behavior is 3555 ** undefined and probably undesirable. Older versions of SQLite were 3556 ** more tolerant of invalid F parameters than newer versions. 3557 ** 3558 ** If F is a suitable filename (as described in the previous paragraph) 3559 ** and if P is the name of the query parameter, then 3560 ** sqlite3_uri_parameter(F,P) returns the value of the P 3561 ** parameter if it exists or a NULL pointer if P does not appear as a 3562 ** query parameter on F. If P is a query parameter of F and it 3563 ** has no explicit value, then sqlite3_uri_parameter(F,P) returns 3564 ** a pointer to an empty string. 3565 ** 3566 ** The sqlite3_uri_boolean(F,P,B) routine assumes that P is a boolean 3567 ** parameter and returns true (1) or false (0) according to the value 3568 ** of P. The sqlite3_uri_boolean(F,P,B) routine returns true (1) if the 3569 ** value of query parameter P is one of "yes", "true", or "on" in any 3570 ** case or if the value begins with a non-zero number. The 3571 ** sqlite3_uri_boolean(F,P,B) routines returns false (0) if the value of 3572 ** query parameter P is one of "no", "false", or "off" in any case or 3573 ** if the value begins with a numeric zero. If P is not a query 3574 ** parameter on F or if the value of P does not match any of the 3575 ** above, then sqlite3_uri_boolean(F,P,B) returns (B!=0). 3576 ** 3577 ** The sqlite3_uri_int64(F,P,D) routine converts the value of P into a 3578 ** 64-bit signed integer and returns that integer, or D if P does not 3579 ** exist. If the value of P is something other than an integer, then 3580 ** zero is returned. 3581 ** 3582 ** The sqlite3_uri_key(F,N) returns a pointer to the name (not 3583 ** the value) of the N-th query parameter for filename F, or a NULL 3584 ** pointer if N is less than zero or greater than the number of query 3585 ** parameters minus 1. The N value is zero-based so N should be 0 to obtain 3586 ** the name of the first query parameter, 1 for the second parameter, and 3587 ** so forth. 3588 ** 3589 ** If F is a NULL pointer, then sqlite3_uri_parameter(F,P) returns NULL and 3590 ** sqlite3_uri_boolean(F,P,B) returns B. If F is not a NULL pointer and 3591 ** is not a database file pathname pointer that the SQLite core passed 3592 ** into the xOpen VFS method, then the behavior of this routine is undefined 3593 ** and probably undesirable. 3594 ** 3595 ** Beginning with SQLite [version 3.31.0] ([dateof:3.31.0]) the input F 3596 ** parameter can also be the name of a rollback journal file or WAL file 3597 ** in addition to the main database file. Prior to version 3.31.0, these 3598 ** routines would only work if F was the name of the main database file. 3599 ** When the F parameter is the name of the rollback journal or WAL file, 3600 ** it has access to all the same query parameters as were found on the 3601 ** main database file. 3602 ** 3603 ** See the [URI filename] documentation for additional information. 3604 */ 3605 SQLITE_API const char *sqlite3_uri_parameter(const char *zFilename, const char *zParam); 3606 SQLITE_API int sqlite3_uri_boolean(const char *zFile, const char *zParam, int bDefault); 3607 SQLITE_API sqlite3_int64 sqlite3_uri_int64(const char*, const char*, sqlite3_int64); 3608 SQLITE_API const char *sqlite3_uri_key(const char *zFilename, int N); 3609 3610 /* 3611 ** CAPI3REF: Translate filenames 3612 ** 3613 ** These routines are available to [VFS|custom VFS implementations] for 3614 ** translating filenames between the main database file, the journal file, 3615 ** and the WAL file. 3616 ** 3617 ** If F is the name of an sqlite database file, journal file, or WAL file 3618 ** passed by the SQLite core into the VFS, then sqlite3_filename_database(F) 3619 ** returns the name of the corresponding database file. 3620 ** 3621 ** If F is the name of an sqlite database file, journal file, or WAL file 3622 ** passed by the SQLite core into the VFS, or if F is a database filename 3623 ** obtained from [sqlite3_db_filename()], then sqlite3_filename_journal(F) 3624 ** returns the name of the corresponding rollback journal file. 3625 ** 3626 ** If F is the name of an sqlite database file, journal file, or WAL file 3627 ** that was passed by the SQLite core into the VFS, or if F is a database 3628 ** filename obtained from [sqlite3_db_filename()], then 3629 ** sqlite3_filename_wal(F) returns the name of the corresponding 3630 ** WAL file. 3631 ** 3632 ** In all of the above, if F is not the name of a database, journal or WAL 3633 ** filename passed into the VFS from the SQLite core and F is not the 3634 ** return value from [sqlite3_db_filename()], then the result is 3635 ** undefined and is likely a memory access violation. 3636 */ 3637 SQLITE_API const char *sqlite3_filename_database(const char*); 3638 SQLITE_API const char *sqlite3_filename_journal(const char*); 3639 SQLITE_API const char *sqlite3_filename_wal(const char*); 3640 3641 /* 3642 ** CAPI3REF: Database File Corresponding To A Journal 3643 ** 3644 ** ^If X is the name of a rollback or WAL-mode journal file that is 3645 ** passed into the xOpen method of [sqlite3_vfs], then 3646 ** sqlite3_database_file_object(X) returns a pointer to the [sqlite3_file] 3647 ** object that represents the main database file. 3648 ** 3649 ** This routine is intended for use in custom [VFS] implementations 3650 ** only. It is not a general-purpose interface. 3651 ** The argument sqlite3_file_object(X) must be a filename pointer that 3652 ** has been passed into [sqlite3_vfs].xOpen method where the 3653 ** flags parameter to xOpen contains one of the bits 3654 ** [SQLITE_OPEN_MAIN_JOURNAL] or [SQLITE_OPEN_WAL]. Any other use 3655 ** of this routine results in undefined and probably undesirable 3656 ** behavior. 3657 */ 3658 SQLITE_API sqlite3_file *sqlite3_database_file_object(const char*); 3659 3660 /* 3661 ** CAPI3REF: Create and Destroy VFS Filenames 3662 ** 3663 ** These interfces are provided for use by [VFS shim] implementations and 3664 ** are not useful outside of that context. 3665 ** 3666 ** The sqlite3_create_filename(D,J,W,N,P) allocates memory to hold a version of 3667 ** database filename D with corresponding journal file J and WAL file W and 3668 ** with N URI parameters key/values pairs in the array P. The result from 3669 ** sqlite3_create_filename(D,J,W,N,P) is a pointer to a database filename that 3670 ** is safe to pass to routines like: 3671 ** <ul> 3672 ** <li> [sqlite3_uri_parameter()], 3673 ** <li> [sqlite3_uri_boolean()], 3674 ** <li> [sqlite3_uri_int64()], 3675 ** <li> [sqlite3_uri_key()], 3676 ** <li> [sqlite3_filename_database()], 3677 ** <li> [sqlite3_filename_journal()], or 3678 ** <li> [sqlite3_filename_wal()]. 3679 ** </ul> 3680 ** If a memory allocation error occurs, sqlite3_create_filename() might 3681 ** return a NULL pointer. The memory obtained from sqlite3_create_filename(X) 3682 ** must be released by a corresponding call to sqlite3_free_filename(Y). 3683 ** 3684 ** The P parameter in sqlite3_create_filename(D,J,W,N,P) should be an array 3685 ** of 2*N pointers to strings. Each pair of pointers in this array corresponds 3686 ** to a key and value for a query parameter. The P parameter may be a NULL 3687 ** pointer if N is zero. None of the 2*N pointers in the P array may be 3688 ** NULL pointers and key pointers should not be empty strings. 3689 ** None of the D, J, or W parameters to sqlite3_create_filename(D,J,W,N,P) may 3690 ** be NULL pointers, though they can be empty strings. 3691 ** 3692 ** The sqlite3_free_filename(Y) routine releases a memory allocation 3693 ** previously obtained from sqlite3_create_filename(). Invoking 3694 ** sqlite3_free_filename(Y) where Y is a NULL pointer is a harmless no-op. 3695 ** 3696 ** If the Y parameter to sqlite3_free_filename(Y) is anything other 3697 ** than a NULL pointer or a pointer previously acquired from 3698 ** sqlite3_create_filename(), then bad things such as heap 3699 ** corruption or segfaults may occur. The value Y should be 3700 ** used again after sqlite3_free_filename(Y) has been called. This means 3701 ** that if the [sqlite3_vfs.xOpen()] method of a VFS has been called using Y, 3702 ** then the corresponding [sqlite3_module.xClose() method should also be 3703 ** invoked prior to calling sqlite3_free_filename(Y). 3704 */ 3705 SQLITE_API char *sqlite3_create_filename( 3706 const char *zDatabase, 3707 const char *zJournal, 3708 const char *zWal, 3709 int nParam, 3710 const char **azParam 3711 ); 3712 SQLITE_API void sqlite3_free_filename(char*); 3713 3714 /* 3715 ** CAPI3REF: Error Codes And Messages 3716 ** METHOD: sqlite3 3717 ** 3718 ** ^If the most recent sqlite3_* API call associated with 3719 ** [database connection] D failed, then the sqlite3_errcode(D) interface 3720 ** returns the numeric [result code] or [extended result code] for that 3721 ** API call. 3722 ** ^The sqlite3_extended_errcode() 3723 ** interface is the same except that it always returns the 3724 ** [extended result code] even when extended result codes are 3725 ** disabled. 3726 ** 3727 ** The values returned by sqlite3_errcode() and/or 3728 ** sqlite3_extended_errcode() might change with each API call. 3729 ** Except, there are some interfaces that are guaranteed to never 3730 ** change the value of the error code. The error-code preserving 3731 ** interfaces are: 3732 ** 3733 ** <ul> 3734 ** <li> sqlite3_errcode() 3735 ** <li> sqlite3_extended_errcode() 3736 ** <li> sqlite3_errmsg() 3737 ** <li> sqlite3_errmsg16() 3738 ** </ul> 3739 ** 3740 ** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language 3741 ** text that describes the error, as either UTF-8 or UTF-16 respectively. 3742 ** ^(Memory to hold the error message string is managed internally. 3743 ** The application does not need to worry about freeing the result. 3744 ** However, the error string might be overwritten or deallocated by 3745 ** subsequent calls to other SQLite interface functions.)^ 3746 ** 3747 ** ^The sqlite3_errstr() interface returns the English-language text 3748 ** that describes the [result code], as UTF-8. 3749 ** ^(Memory to hold the error message string is managed internally 3750 ** and must not be freed by the application)^. 3751 ** 3752 ** When the serialized [threading mode] is in use, it might be the 3753 ** case that a second error occurs on a separate thread in between 3754 ** the time of the first error and the call to these interfaces. 3755 ** When that happens, the second error will be reported since these 3756 ** interfaces always report the most recent result. To avoid 3757 ** this, each thread can obtain exclusive use of the [database connection] D 3758 ** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning 3759 ** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after 3760 ** all calls to the interfaces listed here are completed. 3761 ** 3762 ** If an interface fails with SQLITE_MISUSE, that means the interface 3763 ** was invoked incorrectly by the application. In that case, the 3764 ** error code and message may or may not be set. 3765 */ 3766 SQLITE_API int sqlite3_errcode(sqlite3 *db); 3767 SQLITE_API int sqlite3_extended_errcode(sqlite3 *db); 3768 SQLITE_API const char *sqlite3_errmsg(sqlite3*); 3769 SQLITE_API const void *sqlite3_errmsg16(sqlite3*); 3770 SQLITE_API const char *sqlite3_errstr(int); 3771 3772 /* 3773 ** CAPI3REF: Prepared Statement Object 3774 ** KEYWORDS: {prepared statement} {prepared statements} 3775 ** 3776 ** An instance of this object represents a single SQL statement that 3777 ** has been compiled into binary form and is ready to be evaluated. 3778 ** 3779 ** Think of each SQL statement as a separate computer program. The 3780 ** original SQL text is source code. A prepared statement object 3781 ** is the compiled object code. All SQL must be converted into a 3782 ** prepared statement before it can be run. 3783 ** 3784 ** The life-cycle of a prepared statement object usually goes like this: 3785 ** 3786 ** <ol> 3787 ** <li> Create the prepared statement object using [sqlite3_prepare_v2()]. 3788 ** <li> Bind values to [parameters] using the sqlite3_bind_*() 3789 ** interfaces. 3790 ** <li> Run the SQL by calling [sqlite3_step()] one or more times. 3791 ** <li> Reset the prepared statement using [sqlite3_reset()] then go back 3792 ** to step 2. Do this zero or more times. 3793 ** <li> Destroy the object using [sqlite3_finalize()]. 3794 ** </ol> 3795 */ 3796 typedef struct sqlite3_stmt sqlite3_stmt; 3797 3798 /* 3799 ** CAPI3REF: Run-time Limits 3800 ** METHOD: sqlite3 3801 ** 3802 ** ^(This interface allows the size of various constructs to be limited 3803 ** on a connection by connection basis. The first parameter is the 3804 ** [database connection] whose limit is to be set or queried. The 3805 ** second parameter is one of the [limit categories] that define a 3806 ** class of constructs to be size limited. The third parameter is the 3807 ** new limit for that construct.)^ 3808 ** 3809 ** ^If the new limit is a negative number, the limit is unchanged. 3810 ** ^(For each limit category SQLITE_LIMIT_<i>NAME</i> there is a 3811 ** [limits | hard upper bound] 3812 ** set at compile-time by a C preprocessor macro called 3813 ** [limits | SQLITE_MAX_<i>NAME</i>]. 3814 ** (The "_LIMIT_" in the name is changed to "_MAX_".))^ 3815 ** ^Attempts to increase a limit above its hard upper bound are 3816 ** silently truncated to the hard upper bound. 3817 ** 3818 ** ^Regardless of whether or not the limit was changed, the 3819 ** [sqlite3_limit()] interface returns the prior value of the limit. 3820 ** ^Hence, to find the current value of a limit without changing it, 3821 ** simply invoke this interface with the third parameter set to -1. 3822 ** 3823 ** Run-time limits are intended for use in applications that manage 3824 ** both their own internal database and also databases that are controlled 3825 ** by untrusted external sources. An example application might be a 3826 ** web browser that has its own databases for storing history and 3827 ** separate databases controlled by JavaScript applications downloaded 3828 ** off the Internet. The internal databases can be given the 3829 ** large, default limits. Databases managed by external sources can 3830 ** be given much smaller limits designed to prevent a denial of service 3831 ** attack. Developers might also want to use the [sqlite3_set_authorizer()] 3832 ** interface to further control untrusted SQL. The size of the database 3833 ** created by an untrusted script can be contained using the 3834 ** [max_page_count] [PRAGMA]. 3835 ** 3836 ** New run-time limit categories may be added in future releases. 3837 */ 3838 SQLITE_API int sqlite3_limit(sqlite3*, int id, int newVal); 3839 3840 /* 3841 ** CAPI3REF: Run-Time Limit Categories 3842 ** KEYWORDS: {limit category} {*limit categories} 3843 ** 3844 ** These constants define various performance limits 3845 ** that can be lowered at run-time using [sqlite3_limit()]. 3846 ** The synopsis of the meanings of the various limits is shown below. 3847 ** Additional information is available at [limits | Limits in SQLite]. 3848 ** 3849 ** <dl> 3850 ** [[SQLITE_LIMIT_LENGTH]] ^(<dt>SQLITE_LIMIT_LENGTH</dt> 3851 ** <dd>The maximum size of any string or BLOB or table row, in bytes.<dd>)^ 3852 ** 3853 ** [[SQLITE_LIMIT_SQL_LENGTH]] ^(<dt>SQLITE_LIMIT_SQL_LENGTH</dt> 3854 ** <dd>The maximum length of an SQL statement, in bytes.</dd>)^ 3855 ** 3856 ** [[SQLITE_LIMIT_COLUMN]] ^(<dt>SQLITE_LIMIT_COLUMN</dt> 3857 ** <dd>The maximum number of columns in a table definition or in the 3858 ** result set of a [SELECT] or the maximum number of columns in an index 3859 ** or in an ORDER BY or GROUP BY clause.</dd>)^ 3860 ** 3861 ** [[SQLITE_LIMIT_EXPR_DEPTH]] ^(<dt>SQLITE_LIMIT_EXPR_DEPTH</dt> 3862 ** <dd>The maximum depth of the parse tree on any expression.</dd>)^ 3863 ** 3864 ** [[SQLITE_LIMIT_COMPOUND_SELECT]] ^(<dt>SQLITE_LIMIT_COMPOUND_SELECT</dt> 3865 ** <dd>The maximum number of terms in a compound SELECT statement.</dd>)^ 3866 ** 3867 ** [[SQLITE_LIMIT_VDBE_OP]] ^(<dt>SQLITE_LIMIT_VDBE_OP</dt> 3868 ** <dd>The maximum number of instructions in a virtual machine program 3869 ** used to implement an SQL statement. If [sqlite3_prepare_v2()] or 3870 ** the equivalent tries to allocate space for more than this many opcodes 3871 ** in a single prepared statement, an SQLITE_NOMEM error is returned.</dd>)^ 3872 ** 3873 ** [[SQLITE_LIMIT_FUNCTION_ARG]] ^(<dt>SQLITE_LIMIT_FUNCTION_ARG</dt> 3874 ** <dd>The maximum number of arguments on a function.</dd>)^ 3875 ** 3876 ** [[SQLITE_LIMIT_ATTACHED]] ^(<dt>SQLITE_LIMIT_ATTACHED</dt> 3877 ** <dd>The maximum number of [ATTACH | attached databases].)^</dd> 3878 ** 3879 ** [[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]] 3880 ** ^(<dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt> 3881 ** <dd>The maximum length of the pattern argument to the [LIKE] or 3882 ** [GLOB] operators.</dd>)^ 3883 ** 3884 ** [[SQLITE_LIMIT_VARIABLE_NUMBER]] 3885 ** ^(<dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt> 3886 ** <dd>The maximum index number of any [parameter] in an SQL statement.)^ 3887 ** 3888 ** [[SQLITE_LIMIT_TRIGGER_DEPTH]] ^(<dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt> 3889 ** <dd>The maximum depth of recursion for triggers.</dd>)^ 3890 ** 3891 ** [[SQLITE_LIMIT_WORKER_THREADS]] ^(<dt>SQLITE_LIMIT_WORKER_THREADS</dt> 3892 ** <dd>The maximum number of auxiliary worker threads that a single 3893 ** [prepared statement] may start.</dd>)^ 3894 ** </dl> 3895 */ 3896 #define SQLITE_LIMIT_LENGTH 0 3897 #define SQLITE_LIMIT_SQL_LENGTH 1 3898 #define SQLITE_LIMIT_COLUMN 2 3899 #define SQLITE_LIMIT_EXPR_DEPTH 3 3900 #define SQLITE_LIMIT_COMPOUND_SELECT 4 3901 #define SQLITE_LIMIT_VDBE_OP 5 3902 #define SQLITE_LIMIT_FUNCTION_ARG 6 3903 #define SQLITE_LIMIT_ATTACHED 7 3904 #define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8 3905 #define SQLITE_LIMIT_VARIABLE_NUMBER 9 3906 #define SQLITE_LIMIT_TRIGGER_DEPTH 10 3907 #define SQLITE_LIMIT_WORKER_THREADS 11 3908 3909 /* 3910 ** CAPI3REF: Prepare Flags 3911 ** 3912 ** These constants define various flags that can be passed into 3913 ** "prepFlags" parameter of the [sqlite3_prepare_v3()] and 3914 ** [sqlite3_prepare16_v3()] interfaces. 3915 ** 3916 ** New flags may be added in future releases of SQLite. 3917 ** 3918 ** <dl> 3919 ** [[SQLITE_PREPARE_PERSISTENT]] ^(<dt>SQLITE_PREPARE_PERSISTENT</dt> 3920 ** <dd>The SQLITE_PREPARE_PERSISTENT flag is a hint to the query planner 3921 ** that the prepared statement will be retained for a long time and 3922 ** probably reused many times.)^ ^Without this flag, [sqlite3_prepare_v3()] 3923 ** and [sqlite3_prepare16_v3()] assume that the prepared statement will 3924 ** be used just once or at most a few times and then destroyed using 3925 ** [sqlite3_finalize()] relatively soon. The current implementation acts 3926 ** on this hint by avoiding the use of [lookaside memory] so as not to 3927 ** deplete the limited store of lookaside memory. Future versions of 3928 ** SQLite may act on this hint differently. 3929 ** 3930 ** [[SQLITE_PREPARE_NORMALIZE]] <dt>SQLITE_PREPARE_NORMALIZE</dt> 3931 ** <dd>The SQLITE_PREPARE_NORMALIZE flag is a no-op. This flag used 3932 ** to be required for any prepared statement that wanted to use the 3933 ** [sqlite3_normalized_sql()] interface. However, the 3934 ** [sqlite3_normalized_sql()] interface is now available to all 3935 ** prepared statements, regardless of whether or not they use this 3936 ** flag. 3937 ** 3938 ** [[SQLITE_PREPARE_NO_VTAB]] <dt>SQLITE_PREPARE_NO_VTAB</dt> 3939 ** <dd>The SQLITE_PREPARE_NO_VTAB flag causes the SQL compiler 3940 ** to return an error (error code SQLITE_ERROR) if the statement uses 3941 ** any virtual tables. 3942 ** </dl> 3943 */ 3944 #define SQLITE_PREPARE_PERSISTENT 0x01 3945 #define SQLITE_PREPARE_NORMALIZE 0x02 3946 #define SQLITE_PREPARE_NO_VTAB 0x04 3947 3948 /* 3949 ** CAPI3REF: Compiling An SQL Statement 3950 ** KEYWORDS: {SQL statement compiler} 3951 ** METHOD: sqlite3 3952 ** CONSTRUCTOR: sqlite3_stmt 3953 ** 3954 ** To execute an SQL statement, it must first be compiled into a byte-code 3955 ** program using one of these routines. Or, in other words, these routines 3956 ** are constructors for the [prepared statement] object. 3957 ** 3958 ** The preferred routine to use is [sqlite3_prepare_v2()]. The 3959 ** [sqlite3_prepare()] interface is legacy and should be avoided. 3960 ** [sqlite3_prepare_v3()] has an extra "prepFlags" option that is used 3961 ** for special purposes. 3962 ** 3963 ** The use of the UTF-8 interfaces is preferred, as SQLite currently 3964 ** does all parsing using UTF-8. The UTF-16 interfaces are provided 3965 ** as a convenience. The UTF-16 interfaces work by converting the 3966 ** input text into UTF-8, then invoking the corresponding UTF-8 interface. 3967 ** 3968 ** The first argument, "db", is a [database connection] obtained from a 3969 ** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or 3970 ** [sqlite3_open16()]. The database connection must not have been closed. 3971 ** 3972 ** The second argument, "zSql", is the statement to be compiled, encoded 3973 ** as either UTF-8 or UTF-16. The sqlite3_prepare(), sqlite3_prepare_v2(), 3974 ** and sqlite3_prepare_v3() 3975 ** interfaces use UTF-8, and sqlite3_prepare16(), sqlite3_prepare16_v2(), 3976 ** and sqlite3_prepare16_v3() use UTF-16. 3977 ** 3978 ** ^If the nByte argument is negative, then zSql is read up to the 3979 ** first zero terminator. ^If nByte is positive, then it is the 3980 ** number of bytes read from zSql. ^If nByte is zero, then no prepared 3981 ** statement is generated. 3982 ** If the caller knows that the supplied string is nul-terminated, then 3983 ** there is a small performance advantage to passing an nByte parameter that 3984 ** is the number of bytes in the input string <i>including</i> 3985 ** the nul-terminator. 3986 ** 3987 ** ^If pzTail is not NULL then *pzTail is made to point to the first byte 3988 ** past the end of the first SQL statement in zSql. These routines only 3989 ** compile the first statement in zSql, so *pzTail is left pointing to 3990 ** what remains uncompiled. 3991 ** 3992 ** ^*ppStmt is left pointing to a compiled [prepared statement] that can be 3993 ** executed using [sqlite3_step()]. ^If there is an error, *ppStmt is set 3994 ** to NULL. ^If the input text contains no SQL (if the input is an empty 3995 ** string or a comment) then *ppStmt is set to NULL. 3996 ** The calling procedure is responsible for deleting the compiled 3997 ** SQL statement using [sqlite3_finalize()] after it has finished with it. 3998 ** ppStmt may not be NULL. 3999 ** 4000 ** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK]; 4001 ** otherwise an [error code] is returned. 4002 ** 4003 ** The sqlite3_prepare_v2(), sqlite3_prepare_v3(), sqlite3_prepare16_v2(), 4004 ** and sqlite3_prepare16_v3() interfaces are recommended for all new programs. 4005 ** The older interfaces (sqlite3_prepare() and sqlite3_prepare16()) 4006 ** are retained for backwards compatibility, but their use is discouraged. 4007 ** ^In the "vX" interfaces, the prepared statement 4008 ** that is returned (the [sqlite3_stmt] object) contains a copy of the 4009 ** original SQL text. This causes the [sqlite3_step()] interface to 4010 ** behave differently in three ways: 4011 ** 4012 ** <ol> 4013 ** <li> 4014 ** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it 4015 ** always used to do, [sqlite3_step()] will automatically recompile the SQL 4016 ** statement and try to run it again. As many as [SQLITE_MAX_SCHEMA_RETRY] 4017 ** retries will occur before sqlite3_step() gives up and returns an error. 4018 ** </li> 4019 ** 4020 ** <li> 4021 ** ^When an error occurs, [sqlite3_step()] will return one of the detailed 4022 ** [error codes] or [extended error codes]. ^The legacy behavior was that 4023 ** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code 4024 ** and the application would have to make a second call to [sqlite3_reset()] 4025 ** in order to find the underlying cause of the problem. With the "v2" prepare 4026 ** interfaces, the underlying reason for the error is returned immediately. 4027 ** </li> 4028 ** 4029 ** <li> 4030 ** ^If the specific value bound to a [parameter | host parameter] in the 4031 ** WHERE clause might influence the choice of query plan for a statement, 4032 ** then the statement will be automatically recompiled, as if there had been 4033 ** a schema change, on the first [sqlite3_step()] call following any change 4034 ** to the [sqlite3_bind_text | bindings] of that [parameter]. 4035 ** ^The specific value of a WHERE-clause [parameter] might influence the 4036 ** choice of query plan if the parameter is the left-hand side of a [LIKE] 4037 ** or [GLOB] operator or if the parameter is compared to an indexed column 4038 ** and the [SQLITE_ENABLE_STAT4] compile-time option is enabled. 4039 ** </li> 4040 ** </ol> 4041 ** 4042 ** <p>^sqlite3_prepare_v3() differs from sqlite3_prepare_v2() only in having 4043 ** the extra prepFlags parameter, which is a bit array consisting of zero or 4044 ** more of the [SQLITE_PREPARE_PERSISTENT|SQLITE_PREPARE_*] flags. ^The 4045 ** sqlite3_prepare_v2() interface works exactly the same as 4046 ** sqlite3_prepare_v3() with a zero prepFlags parameter. 4047 */ 4048 SQLITE_API int sqlite3_prepare( 4049 sqlite3 *db, /* Database handle */ 4050 const char *zSql, /* SQL statement, UTF-8 encoded */ 4051 int nByte, /* Maximum length of zSql in bytes. */ 4052 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 4053 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 4054 ); 4055 SQLITE_API int sqlite3_prepare_v2( 4056 sqlite3 *db, /* Database handle */ 4057 const char *zSql, /* SQL statement, UTF-8 encoded */ 4058 int nByte, /* Maximum length of zSql in bytes. */ 4059 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 4060 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 4061 ); 4062 SQLITE_API int sqlite3_prepare_v3( 4063 sqlite3 *db, /* Database handle */ 4064 const char *zSql, /* SQL statement, UTF-8 encoded */ 4065 int nByte, /* Maximum length of zSql in bytes. */ 4066 unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */ 4067 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 4068 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 4069 ); 4070 SQLITE_API int sqlite3_prepare16( 4071 sqlite3 *db, /* Database handle */ 4072 const void *zSql, /* SQL statement, UTF-16 encoded */ 4073 int nByte, /* Maximum length of zSql in bytes. */ 4074 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 4075 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 4076 ); 4077 SQLITE_API int sqlite3_prepare16_v2( 4078 sqlite3 *db, /* Database handle */ 4079 const void *zSql, /* SQL statement, UTF-16 encoded */ 4080 int nByte, /* Maximum length of zSql in bytes. */ 4081 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 4082 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 4083 ); 4084 SQLITE_API int sqlite3_prepare16_v3( 4085 sqlite3 *db, /* Database handle */ 4086 const void *zSql, /* SQL statement, UTF-16 encoded */ 4087 int nByte, /* Maximum length of zSql in bytes. */ 4088 unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */ 4089 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 4090 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 4091 ); 4092 4093 /* 4094 ** CAPI3REF: Retrieving Statement SQL 4095 ** METHOD: sqlite3_stmt 4096 ** 4097 ** ^The sqlite3_sql(P) interface returns a pointer to a copy of the UTF-8 4098 ** SQL text used to create [prepared statement] P if P was 4099 ** created by [sqlite3_prepare_v2()], [sqlite3_prepare_v3()], 4100 ** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()]. 4101 ** ^The sqlite3_expanded_sql(P) interface returns a pointer to a UTF-8 4102 ** string containing the SQL text of prepared statement P with 4103 ** [bound parameters] expanded. 4104 ** ^The sqlite3_normalized_sql(P) interface returns a pointer to a UTF-8 4105 ** string containing the normalized SQL text of prepared statement P. The 4106 ** semantics used to normalize a SQL statement are unspecified and subject 4107 ** to change. At a minimum, literal values will be replaced with suitable 4108 ** placeholders. 4109 ** 4110 ** ^(For example, if a prepared statement is created using the SQL 4111 ** text "SELECT $abc,:xyz" and if parameter $abc is bound to integer 2345 4112 ** and parameter :xyz is unbound, then sqlite3_sql() will return 4113 ** the original string, "SELECT $abc,:xyz" but sqlite3_expanded_sql() 4114 ** will return "SELECT 2345,NULL".)^ 4115 ** 4116 ** ^The sqlite3_expanded_sql() interface returns NULL if insufficient memory 4117 ** is available to hold the result, or if the result would exceed the 4118 ** the maximum string length determined by the [SQLITE_LIMIT_LENGTH]. 4119 ** 4120 ** ^The [SQLITE_TRACE_SIZE_LIMIT] compile-time option limits the size of 4121 ** bound parameter expansions. ^The [SQLITE_OMIT_TRACE] compile-time 4122 ** option causes sqlite3_expanded_sql() to always return NULL. 4123 ** 4124 ** ^The strings returned by sqlite3_sql(P) and sqlite3_normalized_sql(P) 4125 ** are managed by SQLite and are automatically freed when the prepared 4126 ** statement is finalized. 4127 ** ^The string returned by sqlite3_expanded_sql(P), on the other hand, 4128 ** is obtained from [sqlite3_malloc()] and must be free by the application 4129 ** by passing it to [sqlite3_free()]. 4130 */ 4131 SQLITE_API const char *sqlite3_sql(sqlite3_stmt *pStmt); 4132 SQLITE_API char *sqlite3_expanded_sql(sqlite3_stmt *pStmt); 4133 SQLITE_API const char *sqlite3_normalized_sql(sqlite3_stmt *pStmt); 4134 4135 /* 4136 ** CAPI3REF: Determine If An SQL Statement Writes The Database 4137 ** METHOD: sqlite3_stmt 4138 ** 4139 ** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if 4140 ** and only if the [prepared statement] X makes no direct changes to 4141 ** the content of the database file. 4142 ** 4143 ** Note that [application-defined SQL functions] or 4144 ** [virtual tables] might change the database indirectly as a side effect. 4145 ** ^(For example, if an application defines a function "eval()" that 4146 ** calls [sqlite3_exec()], then the following SQL statement would 4147 ** change the database file through side-effects: 4148 ** 4149 ** <blockquote><pre> 4150 ** SELECT eval('DELETE FROM t1') FROM t2; 4151 ** </pre></blockquote> 4152 ** 4153 ** But because the [SELECT] statement does not change the database file 4154 ** directly, sqlite3_stmt_readonly() would still return true.)^ 4155 ** 4156 ** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK], 4157 ** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true, 4158 ** since the statements themselves do not actually modify the database but 4159 ** rather they control the timing of when other statements modify the 4160 ** database. ^The [ATTACH] and [DETACH] statements also cause 4161 ** sqlite3_stmt_readonly() to return true since, while those statements 4162 ** change the configuration of a database connection, they do not make 4163 ** changes to the content of the database files on disk. 4164 ** ^The sqlite3_stmt_readonly() interface returns true for [BEGIN] since 4165 ** [BEGIN] merely sets internal flags, but the [BEGIN|BEGIN IMMEDIATE] and 4166 ** [BEGIN|BEGIN EXCLUSIVE] commands do touch the database and so 4167 ** sqlite3_stmt_readonly() returns false for those commands. 4168 */ 4169 SQLITE_API int sqlite3_stmt_readonly(sqlite3_stmt *pStmt); 4170 4171 /* 4172 ** CAPI3REF: Query The EXPLAIN Setting For A Prepared Statement 4173 ** METHOD: sqlite3_stmt 4174 ** 4175 ** ^The sqlite3_stmt_isexplain(S) interface returns 1 if the 4176 ** prepared statement S is an EXPLAIN statement, or 2 if the 4177 ** statement S is an EXPLAIN QUERY PLAN. 4178 ** ^The sqlite3_stmt_isexplain(S) interface returns 0 if S is 4179 ** an ordinary statement or a NULL pointer. 4180 */ 4181 SQLITE_API int sqlite3_stmt_isexplain(sqlite3_stmt *pStmt); 4182 4183 /* 4184 ** CAPI3REF: Determine If A Prepared Statement Has Been Reset 4185 ** METHOD: sqlite3_stmt 4186 ** 4187 ** ^The sqlite3_stmt_busy(S) interface returns true (non-zero) if the 4188 ** [prepared statement] S has been stepped at least once using 4189 ** [sqlite3_step(S)] but has neither run to completion (returned 4190 ** [SQLITE_DONE] from [sqlite3_step(S)]) nor 4191 ** been reset using [sqlite3_reset(S)]. ^The sqlite3_stmt_busy(S) 4192 ** interface returns false if S is a NULL pointer. If S is not a 4193 ** NULL pointer and is not a pointer to a valid [prepared statement] 4194 ** object, then the behavior is undefined and probably undesirable. 4195 ** 4196 ** This interface can be used in combination [sqlite3_next_stmt()] 4197 ** to locate all prepared statements associated with a database 4198 ** connection that are in need of being reset. This can be used, 4199 ** for example, in diagnostic routines to search for prepared 4200 ** statements that are holding a transaction open. 4201 */ 4202 SQLITE_API int sqlite3_stmt_busy(sqlite3_stmt*); 4203 4204 /* 4205 ** CAPI3REF: Dynamically Typed Value Object 4206 ** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value} 4207 ** 4208 ** SQLite uses the sqlite3_value object to represent all values 4209 ** that can be stored in a database table. SQLite uses dynamic typing 4210 ** for the values it stores. ^Values stored in sqlite3_value objects 4211 ** can be integers, floating point values, strings, BLOBs, or NULL. 4212 ** 4213 ** An sqlite3_value object may be either "protected" or "unprotected". 4214 ** Some interfaces require a protected sqlite3_value. Other interfaces 4215 ** will accept either a protected or an unprotected sqlite3_value. 4216 ** Every interface that accepts sqlite3_value arguments specifies 4217 ** whether or not it requires a protected sqlite3_value. The 4218 ** [sqlite3_value_dup()] interface can be used to construct a new 4219 ** protected sqlite3_value from an unprotected sqlite3_value. 4220 ** 4221 ** The terms "protected" and "unprotected" refer to whether or not 4222 ** a mutex is held. An internal mutex is held for a protected 4223 ** sqlite3_value object but no mutex is held for an unprotected 4224 ** sqlite3_value object. If SQLite is compiled to be single-threaded 4225 ** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0) 4226 ** or if SQLite is run in one of reduced mutex modes 4227 ** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD] 4228 ** then there is no distinction between protected and unprotected 4229 ** sqlite3_value objects and they can be used interchangeably. However, 4230 ** for maximum code portability it is recommended that applications 4231 ** still make the distinction between protected and unprotected 4232 ** sqlite3_value objects even when not strictly required. 4233 ** 4234 ** ^The sqlite3_value objects that are passed as parameters into the 4235 ** implementation of [application-defined SQL functions] are protected. 4236 ** ^The sqlite3_value object returned by 4237 ** [sqlite3_column_value()] is unprotected. 4238 ** Unprotected sqlite3_value objects may only be used as arguments 4239 ** to [sqlite3_result_value()], [sqlite3_bind_value()], and 4240 ** [sqlite3_value_dup()]. 4241 ** The [sqlite3_value_blob | sqlite3_value_type()] family of 4242 ** interfaces require protected sqlite3_value objects. 4243 */ 4244 typedef struct sqlite3_value sqlite3_value; 4245 4246 /* 4247 ** CAPI3REF: SQL Function Context Object 4248 ** 4249 ** The context in which an SQL function executes is stored in an 4250 ** sqlite3_context object. ^A pointer to an sqlite3_context object 4251 ** is always first parameter to [application-defined SQL functions]. 4252 ** The application-defined SQL function implementation will pass this 4253 ** pointer through into calls to [sqlite3_result_int | sqlite3_result()], 4254 ** [sqlite3_aggregate_context()], [sqlite3_user_data()], 4255 ** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()], 4256 ** and/or [sqlite3_set_auxdata()]. 4257 */ 4258 typedef struct sqlite3_context sqlite3_context; 4259 4260 /* 4261 ** CAPI3REF: Binding Values To Prepared Statements 4262 ** KEYWORDS: {host parameter} {host parameters} {host parameter name} 4263 ** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding} 4264 ** METHOD: sqlite3_stmt 4265 ** 4266 ** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants, 4267 ** literals may be replaced by a [parameter] that matches one of following 4268 ** templates: 4269 ** 4270 ** <ul> 4271 ** <li> ? 4272 ** <li> ?NNN 4273 ** <li> :VVV 4274 ** <li> @VVV 4275 ** <li> $VVV 4276 ** </ul> 4277 ** 4278 ** In the templates above, NNN represents an integer literal, 4279 ** and VVV represents an alphanumeric identifier.)^ ^The values of these 4280 ** parameters (also called "host parameter names" or "SQL parameters") 4281 ** can be set using the sqlite3_bind_*() routines defined here. 4282 ** 4283 ** ^The first argument to the sqlite3_bind_*() routines is always 4284 ** a pointer to the [sqlite3_stmt] object returned from 4285 ** [sqlite3_prepare_v2()] or its variants. 4286 ** 4287 ** ^The second argument is the index of the SQL parameter to be set. 4288 ** ^The leftmost SQL parameter has an index of 1. ^When the same named 4289 ** SQL parameter is used more than once, second and subsequent 4290 ** occurrences have the same index as the first occurrence. 4291 ** ^The index for named parameters can be looked up using the 4292 ** [sqlite3_bind_parameter_index()] API if desired. ^The index 4293 ** for "?NNN" parameters is the value of NNN. 4294 ** ^The NNN value must be between 1 and the [sqlite3_limit()] 4295 ** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 32766). 4296 ** 4297 ** ^The third argument is the value to bind to the parameter. 4298 ** ^If the third parameter to sqlite3_bind_text() or sqlite3_bind_text16() 4299 ** or sqlite3_bind_blob() is a NULL pointer then the fourth parameter 4300 ** is ignored and the end result is the same as sqlite3_bind_null(). 4301 ** ^If the third parameter to sqlite3_bind_text() is not NULL, then 4302 ** it should be a pointer to well-formed UTF8 text. 4303 ** ^If the third parameter to sqlite3_bind_text16() is not NULL, then 4304 ** it should be a pointer to well-formed UTF16 text. 4305 ** ^If the third parameter to sqlite3_bind_text64() is not NULL, then 4306 ** it should be a pointer to a well-formed unicode string that is 4307 ** either UTF8 if the sixth parameter is SQLITE_UTF8, or UTF16 4308 ** otherwise. 4309 ** 4310 ** [[byte-order determination rules]] ^The byte-order of 4311 ** UTF16 input text is determined by the byte-order mark (BOM, U+FEFF) 4312 ** found in first character, which is removed, or in the absence of a BOM 4313 ** the byte order is the native byte order of the host 4314 ** machine for sqlite3_bind_text16() or the byte order specified in 4315 ** the 6th parameter for sqlite3_bind_text64().)^ 4316 ** ^If UTF16 input text contains invalid unicode 4317 ** characters, then SQLite might change those invalid characters 4318 ** into the unicode replacement character: U+FFFD. 4319 ** 4320 ** ^(In those routines that have a fourth argument, its value is the 4321 ** number of bytes in the parameter. To be clear: the value is the 4322 ** number of <u>bytes</u> in the value, not the number of characters.)^ 4323 ** ^If the fourth parameter to sqlite3_bind_text() or sqlite3_bind_text16() 4324 ** is negative, then the length of the string is 4325 ** the number of bytes up to the first zero terminator. 4326 ** If the fourth parameter to sqlite3_bind_blob() is negative, then 4327 ** the behavior is undefined. 4328 ** If a non-negative fourth parameter is provided to sqlite3_bind_text() 4329 ** or sqlite3_bind_text16() or sqlite3_bind_text64() then 4330 ** that parameter must be the byte offset 4331 ** where the NUL terminator would occur assuming the string were NUL 4332 ** terminated. If any NUL characters occurs at byte offsets less than 4333 ** the value of the fourth parameter then the resulting string value will 4334 ** contain embedded NULs. The result of expressions involving strings 4335 ** with embedded NULs is undefined. 4336 ** 4337 ** ^The fifth argument to the BLOB and string binding interfaces 4338 ** is a destructor used to dispose of the BLOB or 4339 ** string after SQLite has finished with it. ^The destructor is called 4340 ** to dispose of the BLOB or string even if the call to the bind API fails, 4341 ** except the destructor is not called if the third parameter is a NULL 4342 ** pointer or the fourth parameter is negative. 4343 ** ^If the fifth argument is 4344 ** the special value [SQLITE_STATIC], then SQLite assumes that the 4345 ** information is in static, unmanaged space and does not need to be freed. 4346 ** ^If the fifth argument has the value [SQLITE_TRANSIENT], then 4347 ** SQLite makes its own private copy of the data immediately, before 4348 ** the sqlite3_bind_*() routine returns. 4349 ** 4350 ** ^The sixth argument to sqlite3_bind_text64() must be one of 4351 ** [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE] 4352 ** to specify the encoding of the text in the third parameter. If 4353 ** the sixth argument to sqlite3_bind_text64() is not one of the 4354 ** allowed values shown above, or if the text encoding is different 4355 ** from the encoding specified by the sixth parameter, then the behavior 4356 ** is undefined. 4357 ** 4358 ** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that 4359 ** is filled with zeroes. ^A zeroblob uses a fixed amount of memory 4360 ** (just an integer to hold its size) while it is being processed. 4361 ** Zeroblobs are intended to serve as placeholders for BLOBs whose 4362 ** content is later written using 4363 ** [sqlite3_blob_open | incremental BLOB I/O] routines. 4364 ** ^A negative value for the zeroblob results in a zero-length BLOB. 4365 ** 4366 ** ^The sqlite3_bind_pointer(S,I,P,T,D) routine causes the I-th parameter in 4367 ** [prepared statement] S to have an SQL value of NULL, but to also be 4368 ** associated with the pointer P of type T. ^D is either a NULL pointer or 4369 ** a pointer to a destructor function for P. ^SQLite will invoke the 4370 ** destructor D with a single argument of P when it is finished using 4371 ** P. The T parameter should be a static string, preferably a string 4372 ** literal. The sqlite3_bind_pointer() routine is part of the 4373 ** [pointer passing interface] added for SQLite 3.20.0. 4374 ** 4375 ** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer 4376 ** for the [prepared statement] or with a prepared statement for which 4377 ** [sqlite3_step()] has been called more recently than [sqlite3_reset()], 4378 ** then the call will return [SQLITE_MISUSE]. If any sqlite3_bind_() 4379 ** routine is passed a [prepared statement] that has been finalized, the 4380 ** result is undefined and probably harmful. 4381 ** 4382 ** ^Bindings are not cleared by the [sqlite3_reset()] routine. 4383 ** ^Unbound parameters are interpreted as NULL. 4384 ** 4385 ** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an 4386 ** [error code] if anything goes wrong. 4387 ** ^[SQLITE_TOOBIG] might be returned if the size of a string or BLOB 4388 ** exceeds limits imposed by [sqlite3_limit]([SQLITE_LIMIT_LENGTH]) or 4389 ** [SQLITE_MAX_LENGTH]. 4390 ** ^[SQLITE_RANGE] is returned if the parameter 4391 ** index is out of range. ^[SQLITE_NOMEM] is returned if malloc() fails. 4392 ** 4393 ** See also: [sqlite3_bind_parameter_count()], 4394 ** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()]. 4395 */ 4396 SQLITE_API int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*)); 4397 SQLITE_API int sqlite3_bind_blob64(sqlite3_stmt*, int, const void*, sqlite3_uint64, 4398 void(*)(void*)); 4399 SQLITE_API int sqlite3_bind_double(sqlite3_stmt*, int, double); 4400 SQLITE_API int sqlite3_bind_int(sqlite3_stmt*, int, int); 4401 SQLITE_API int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64); 4402 SQLITE_API int sqlite3_bind_null(sqlite3_stmt*, int); 4403 SQLITE_API int sqlite3_bind_text(sqlite3_stmt*,int,const char*,int,void(*)(void*)); 4404 SQLITE_API int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*)); 4405 SQLITE_API int sqlite3_bind_text64(sqlite3_stmt*, int, const char*, sqlite3_uint64, 4406 void(*)(void*), unsigned char encoding); 4407 SQLITE_API int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*); 4408 SQLITE_API int sqlite3_bind_pointer(sqlite3_stmt*, int, void*, const char*,void(*)(void*)); 4409 SQLITE_API int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n); 4410 SQLITE_API int sqlite3_bind_zeroblob64(sqlite3_stmt*, int, sqlite3_uint64); 4411 4412 /* 4413 ** CAPI3REF: Number Of SQL Parameters 4414 ** METHOD: sqlite3_stmt 4415 ** 4416 ** ^This routine can be used to find the number of [SQL parameters] 4417 ** in a [prepared statement]. SQL parameters are tokens of the 4418 ** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as 4419 ** placeholders for values that are [sqlite3_bind_blob | bound] 4420 ** to the parameters at a later time. 4421 ** 4422 ** ^(This routine actually returns the index of the largest (rightmost) 4423 ** parameter. For all forms except ?NNN, this will correspond to the 4424 ** number of unique parameters. If parameters of the ?NNN form are used, 4425 ** there may be gaps in the list.)^ 4426 ** 4427 ** See also: [sqlite3_bind_blob|sqlite3_bind()], 4428 ** [sqlite3_bind_parameter_name()], and 4429 ** [sqlite3_bind_parameter_index()]. 4430 */ 4431 SQLITE_API int sqlite3_bind_parameter_count(sqlite3_stmt*); 4432 4433 /* 4434 ** CAPI3REF: Name Of A Host Parameter 4435 ** METHOD: sqlite3_stmt 4436 ** 4437 ** ^The sqlite3_bind_parameter_name(P,N) interface returns 4438 ** the name of the N-th [SQL parameter] in the [prepared statement] P. 4439 ** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA" 4440 ** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA" 4441 ** respectively. 4442 ** In other words, the initial ":" or "$" or "@" or "?" 4443 ** is included as part of the name.)^ 4444 ** ^Parameters of the form "?" without a following integer have no name 4445 ** and are referred to as "nameless" or "anonymous parameters". 4446 ** 4447 ** ^The first host parameter has an index of 1, not 0. 4448 ** 4449 ** ^If the value N is out of range or if the N-th parameter is 4450 ** nameless, then NULL is returned. ^The returned string is 4451 ** always in UTF-8 encoding even if the named parameter was 4452 ** originally specified as UTF-16 in [sqlite3_prepare16()], 4453 ** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()]. 4454 ** 4455 ** See also: [sqlite3_bind_blob|sqlite3_bind()], 4456 ** [sqlite3_bind_parameter_count()], and 4457 ** [sqlite3_bind_parameter_index()]. 4458 */ 4459 SQLITE_API const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int); 4460 4461 /* 4462 ** CAPI3REF: Index Of A Parameter With A Given Name 4463 ** METHOD: sqlite3_stmt 4464 ** 4465 ** ^Return the index of an SQL parameter given its name. ^The 4466 ** index value returned is suitable for use as the second 4467 ** parameter to [sqlite3_bind_blob|sqlite3_bind()]. ^A zero 4468 ** is returned if no matching parameter is found. ^The parameter 4469 ** name must be given in UTF-8 even if the original statement 4470 ** was prepared from UTF-16 text using [sqlite3_prepare16_v2()] or 4471 ** [sqlite3_prepare16_v3()]. 4472 ** 4473 ** See also: [sqlite3_bind_blob|sqlite3_bind()], 4474 ** [sqlite3_bind_parameter_count()], and 4475 ** [sqlite3_bind_parameter_name()]. 4476 */ 4477 SQLITE_API int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName); 4478 4479 /* 4480 ** CAPI3REF: Reset All Bindings On A Prepared Statement 4481 ** METHOD: sqlite3_stmt 4482 ** 4483 ** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset 4484 ** the [sqlite3_bind_blob | bindings] on a [prepared statement]. 4485 ** ^Use this routine to reset all host parameters to NULL. 4486 */ 4487 SQLITE_API int sqlite3_clear_bindings(sqlite3_stmt*); 4488 4489 /* 4490 ** CAPI3REF: Number Of Columns In A Result Set 4491 ** METHOD: sqlite3_stmt 4492 ** 4493 ** ^Return the number of columns in the result set returned by the 4494 ** [prepared statement]. ^If this routine returns 0, that means the 4495 ** [prepared statement] returns no data (for example an [UPDATE]). 4496 ** ^However, just because this routine returns a positive number does not 4497 ** mean that one or more rows of data will be returned. ^A SELECT statement 4498 ** will always have a positive sqlite3_column_count() but depending on the 4499 ** WHERE clause constraints and the table content, it might return no rows. 4500 ** 4501 ** See also: [sqlite3_data_count()] 4502 */ 4503 SQLITE_API int sqlite3_column_count(sqlite3_stmt *pStmt); 4504 4505 /* 4506 ** CAPI3REF: Column Names In A Result Set 4507 ** METHOD: sqlite3_stmt 4508 ** 4509 ** ^These routines return the name assigned to a particular column 4510 ** in the result set of a [SELECT] statement. ^The sqlite3_column_name() 4511 ** interface returns a pointer to a zero-terminated UTF-8 string 4512 ** and sqlite3_column_name16() returns a pointer to a zero-terminated 4513 ** UTF-16 string. ^The first parameter is the [prepared statement] 4514 ** that implements the [SELECT] statement. ^The second parameter is the 4515 ** column number. ^The leftmost column is number 0. 4516 ** 4517 ** ^The returned string pointer is valid until either the [prepared statement] 4518 ** is destroyed by [sqlite3_finalize()] or until the statement is automatically 4519 ** reprepared by the first call to [sqlite3_step()] for a particular run 4520 ** or until the next call to 4521 ** sqlite3_column_name() or sqlite3_column_name16() on the same column. 4522 ** 4523 ** ^If sqlite3_malloc() fails during the processing of either routine 4524 ** (for example during a conversion from UTF-8 to UTF-16) then a 4525 ** NULL pointer is returned. 4526 ** 4527 ** ^The name of a result column is the value of the "AS" clause for 4528 ** that column, if there is an AS clause. If there is no AS clause 4529 ** then the name of the column is unspecified and may change from 4530 ** one release of SQLite to the next. 4531 */ 4532 SQLITE_API const char *sqlite3_column_name(sqlite3_stmt*, int N); 4533 SQLITE_API const void *sqlite3_column_name16(sqlite3_stmt*, int N); 4534 4535 /* 4536 ** CAPI3REF: Source Of Data In A Query Result 4537 ** METHOD: sqlite3_stmt 4538 ** 4539 ** ^These routines provide a means to determine the database, table, and 4540 ** table column that is the origin of a particular result column in 4541 ** [SELECT] statement. 4542 ** ^The name of the database or table or column can be returned as 4543 ** either a UTF-8 or UTF-16 string. ^The _database_ routines return 4544 ** the database name, the _table_ routines return the table name, and 4545 ** the origin_ routines return the column name. 4546 ** ^The returned string is valid until the [prepared statement] is destroyed 4547 ** using [sqlite3_finalize()] or until the statement is automatically 4548 ** reprepared by the first call to [sqlite3_step()] for a particular run 4549 ** or until the same information is requested 4550 ** again in a different encoding. 4551 ** 4552 ** ^The names returned are the original un-aliased names of the 4553 ** database, table, and column. 4554 ** 4555 ** ^The first argument to these interfaces is a [prepared statement]. 4556 ** ^These functions return information about the Nth result column returned by 4557 ** the statement, where N is the second function argument. 4558 ** ^The left-most column is column 0 for these routines. 4559 ** 4560 ** ^If the Nth column returned by the statement is an expression or 4561 ** subquery and is not a column value, then all of these functions return 4562 ** NULL. ^These routines might also return NULL if a memory allocation error 4563 ** occurs. ^Otherwise, they return the name of the attached database, table, 4564 ** or column that query result column was extracted from. 4565 ** 4566 ** ^As with all other SQLite APIs, those whose names end with "16" return 4567 ** UTF-16 encoded strings and the other functions return UTF-8. 4568 ** 4569 ** ^These APIs are only available if the library was compiled with the 4570 ** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol. 4571 ** 4572 ** If two or more threads call one or more 4573 ** [sqlite3_column_database_name | column metadata interfaces] 4574 ** for the same [prepared statement] and result column 4575 ** at the same time then the results are undefined. 4576 */ 4577 SQLITE_API const char *sqlite3_column_database_name(sqlite3_stmt*,int); 4578 SQLITE_API const void *sqlite3_column_database_name16(sqlite3_stmt*,int); 4579 SQLITE_API const char *sqlite3_column_table_name(sqlite3_stmt*,int); 4580 SQLITE_API const void *sqlite3_column_table_name16(sqlite3_stmt*,int); 4581 SQLITE_API const char *sqlite3_column_origin_name(sqlite3_stmt*,int); 4582 SQLITE_API const void *sqlite3_column_origin_name16(sqlite3_stmt*,int); 4583 4584 /* 4585 ** CAPI3REF: Declared Datatype Of A Query Result 4586 ** METHOD: sqlite3_stmt 4587 ** 4588 ** ^(The first parameter is a [prepared statement]. 4589 ** If this statement is a [SELECT] statement and the Nth column of the 4590 ** returned result set of that [SELECT] is a table column (not an 4591 ** expression or subquery) then the declared type of the table 4592 ** column is returned.)^ ^If the Nth column of the result set is an 4593 ** expression or subquery, then a NULL pointer is returned. 4594 ** ^The returned string is always UTF-8 encoded. 4595 ** 4596 ** ^(For example, given the database schema: 4597 ** 4598 ** CREATE TABLE t1(c1 VARIANT); 4599 ** 4600 ** and the following statement to be compiled: 4601 ** 4602 ** SELECT c1 + 1, c1 FROM t1; 4603 ** 4604 ** this routine would return the string "VARIANT" for the second result 4605 ** column (i==1), and a NULL pointer for the first result column (i==0).)^ 4606 ** 4607 ** ^SQLite uses dynamic run-time typing. ^So just because a column 4608 ** is declared to contain a particular type does not mean that the 4609 ** data stored in that column is of the declared type. SQLite is 4610 ** strongly typed, but the typing is dynamic not static. ^Type 4611 ** is associated with individual values, not with the containers 4612 ** used to hold those values. 4613 */ 4614 SQLITE_API const char *sqlite3_column_decltype(sqlite3_stmt*,int); 4615 SQLITE_API const void *sqlite3_column_decltype16(sqlite3_stmt*,int); 4616 4617 /* 4618 ** CAPI3REF: Evaluate An SQL Statement 4619 ** METHOD: sqlite3_stmt 4620 ** 4621 ** After a [prepared statement] has been prepared using any of 4622 ** [sqlite3_prepare_v2()], [sqlite3_prepare_v3()], [sqlite3_prepare16_v2()], 4623 ** or [sqlite3_prepare16_v3()] or one of the legacy 4624 ** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function 4625 ** must be called one or more times to evaluate the statement. 4626 ** 4627 ** The details of the behavior of the sqlite3_step() interface depend 4628 ** on whether the statement was prepared using the newer "vX" interfaces 4629 ** [sqlite3_prepare_v3()], [sqlite3_prepare_v2()], [sqlite3_prepare16_v3()], 4630 ** [sqlite3_prepare16_v2()] or the older legacy 4631 ** interfaces [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the 4632 ** new "vX" interface is recommended for new applications but the legacy 4633 ** interface will continue to be supported. 4634 ** 4635 ** ^In the legacy interface, the return value will be either [SQLITE_BUSY], 4636 ** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE]. 4637 ** ^With the "v2" interface, any of the other [result codes] or 4638 ** [extended result codes] might be returned as well. 4639 ** 4640 ** ^[SQLITE_BUSY] means that the database engine was unable to acquire the 4641 ** database locks it needs to do its job. ^If the statement is a [COMMIT] 4642 ** or occurs outside of an explicit transaction, then you can retry the 4643 ** statement. If the statement is not a [COMMIT] and occurs within an 4644 ** explicit transaction then you should rollback the transaction before 4645 ** continuing. 4646 ** 4647 ** ^[SQLITE_DONE] means that the statement has finished executing 4648 ** successfully. sqlite3_step() should not be called again on this virtual 4649 ** machine without first calling [sqlite3_reset()] to reset the virtual 4650 ** machine back to its initial state. 4651 ** 4652 ** ^If the SQL statement being executed returns any data, then [SQLITE_ROW] 4653 ** is returned each time a new row of data is ready for processing by the 4654 ** caller. The values may be accessed using the [column access functions]. 4655 ** sqlite3_step() is called again to retrieve the next row of data. 4656 ** 4657 ** ^[SQLITE_ERROR] means that a run-time error (such as a constraint 4658 ** violation) has occurred. sqlite3_step() should not be called again on 4659 ** the VM. More information may be found by calling [sqlite3_errmsg()]. 4660 ** ^With the legacy interface, a more specific error code (for example, 4661 ** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth) 4662 ** can be obtained by calling [sqlite3_reset()] on the 4663 ** [prepared statement]. ^In the "v2" interface, 4664 ** the more specific error code is returned directly by sqlite3_step(). 4665 ** 4666 ** [SQLITE_MISUSE] means that the this routine was called inappropriately. 4667 ** Perhaps it was called on a [prepared statement] that has 4668 ** already been [sqlite3_finalize | finalized] or on one that had 4669 ** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could 4670 ** be the case that the same database connection is being used by two or 4671 ** more threads at the same moment in time. 4672 ** 4673 ** For all versions of SQLite up to and including 3.6.23.1, a call to 4674 ** [sqlite3_reset()] was required after sqlite3_step() returned anything 4675 ** other than [SQLITE_ROW] before any subsequent invocation of 4676 ** sqlite3_step(). Failure to reset the prepared statement using 4677 ** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from 4678 ** sqlite3_step(). But after [version 3.6.23.1] ([dateof:3.6.23.1], 4679 ** sqlite3_step() began 4680 ** calling [sqlite3_reset()] automatically in this circumstance rather 4681 ** than returning [SQLITE_MISUSE]. This is not considered a compatibility 4682 ** break because any application that ever receives an SQLITE_MISUSE error 4683 ** is broken by definition. The [SQLITE_OMIT_AUTORESET] compile-time option 4684 ** can be used to restore the legacy behavior. 4685 ** 4686 ** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step() 4687 ** API always returns a generic error code, [SQLITE_ERROR], following any 4688 ** error other than [SQLITE_BUSY] and [SQLITE_MISUSE]. You must call 4689 ** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the 4690 ** specific [error codes] that better describes the error. 4691 ** We admit that this is a goofy design. The problem has been fixed 4692 ** with the "v2" interface. If you prepare all of your SQL statements 4693 ** using [sqlite3_prepare_v3()] or [sqlite3_prepare_v2()] 4694 ** or [sqlite3_prepare16_v2()] or [sqlite3_prepare16_v3()] instead 4695 ** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces, 4696 ** then the more specific [error codes] are returned directly 4697 ** by sqlite3_step(). The use of the "vX" interfaces is recommended. 4698 */ 4699 SQLITE_API int sqlite3_step(sqlite3_stmt*); 4700 4701 /* 4702 ** CAPI3REF: Number of columns in a result set 4703 ** METHOD: sqlite3_stmt 4704 ** 4705 ** ^The sqlite3_data_count(P) interface returns the number of columns in the 4706 ** current row of the result set of [prepared statement] P. 4707 ** ^If prepared statement P does not have results ready to return 4708 ** (via calls to the [sqlite3_column_int | sqlite3_column()] family of 4709 ** interfaces) then sqlite3_data_count(P) returns 0. 4710 ** ^The sqlite3_data_count(P) routine also returns 0 if P is a NULL pointer. 4711 ** ^The sqlite3_data_count(P) routine returns 0 if the previous call to 4712 ** [sqlite3_step](P) returned [SQLITE_DONE]. ^The sqlite3_data_count(P) 4713 ** will return non-zero if previous call to [sqlite3_step](P) returned 4714 ** [SQLITE_ROW], except in the case of the [PRAGMA incremental_vacuum] 4715 ** where it always returns zero since each step of that multi-step 4716 ** pragma returns 0 columns of data. 4717 ** 4718 ** See also: [sqlite3_column_count()] 4719 */ 4720 SQLITE_API int sqlite3_data_count(sqlite3_stmt *pStmt); 4721 4722 /* 4723 ** CAPI3REF: Fundamental Datatypes 4724 ** KEYWORDS: SQLITE_TEXT 4725 ** 4726 ** ^(Every value in SQLite has one of five fundamental datatypes: 4727 ** 4728 ** <ul> 4729 ** <li> 64-bit signed integer 4730 ** <li> 64-bit IEEE floating point number 4731 ** <li> string 4732 ** <li> BLOB 4733 ** <li> NULL 4734 ** </ul>)^ 4735 ** 4736 ** These constants are codes for each of those types. 4737 ** 4738 ** Note that the SQLITE_TEXT constant was also used in SQLite version 2 4739 ** for a completely different meaning. Software that links against both 4740 ** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not 4741 ** SQLITE_TEXT. 4742 */ 4743 #define SQLITE_INTEGER 1 4744 #define SQLITE_FLOAT 2 4745 #define SQLITE_BLOB 4 4746 #define SQLITE_NULL 5 4747 #ifdef SQLITE_TEXT 4748 # undef SQLITE_TEXT 4749 #else 4750 # define SQLITE_TEXT 3 4751 #endif 4752 #define SQLITE3_TEXT 3 4753 4754 /* 4755 ** CAPI3REF: Result Values From A Query 4756 ** KEYWORDS: {column access functions} 4757 ** METHOD: sqlite3_stmt 4758 ** 4759 ** <b>Summary:</b> 4760 ** <blockquote><table border=0 cellpadding=0 cellspacing=0> 4761 ** <tr><td><b>sqlite3_column_blob</b><td>→<td>BLOB result 4762 ** <tr><td><b>sqlite3_column_double</b><td>→<td>REAL result 4763 ** <tr><td><b>sqlite3_column_int</b><td>→<td>32-bit INTEGER result 4764 ** <tr><td><b>sqlite3_column_int64</b><td>→<td>64-bit INTEGER result 4765 ** <tr><td><b>sqlite3_column_text</b><td>→<td>UTF-8 TEXT result 4766 ** <tr><td><b>sqlite3_column_text16</b><td>→<td>UTF-16 TEXT result 4767 ** <tr><td><b>sqlite3_column_value</b><td>→<td>The result as an 4768 ** [sqlite3_value|unprotected sqlite3_value] object. 4769 ** <tr><td> <td> <td> 4770 ** <tr><td><b>sqlite3_column_bytes</b><td>→<td>Size of a BLOB 4771 ** or a UTF-8 TEXT result in bytes 4772 ** <tr><td><b>sqlite3_column_bytes16 </b> 4773 ** <td>→ <td>Size of UTF-16 4774 ** TEXT in bytes 4775 ** <tr><td><b>sqlite3_column_type</b><td>→<td>Default 4776 ** datatype of the result 4777 ** </table></blockquote> 4778 ** 4779 ** <b>Details:</b> 4780 ** 4781 ** ^These routines return information about a single column of the current 4782 ** result row of a query. ^In every case the first argument is a pointer 4783 ** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*] 4784 ** that was returned from [sqlite3_prepare_v2()] or one of its variants) 4785 ** and the second argument is the index of the column for which information 4786 ** should be returned. ^The leftmost column of the result set has the index 0. 4787 ** ^The number of columns in the result can be determined using 4788 ** [sqlite3_column_count()]. 4789 ** 4790 ** If the SQL statement does not currently point to a valid row, or if the 4791 ** column index is out of range, the result is undefined. 4792 ** These routines may only be called when the most recent call to 4793 ** [sqlite3_step()] has returned [SQLITE_ROW] and neither 4794 ** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently. 4795 ** If any of these routines are called after [sqlite3_reset()] or 4796 ** [sqlite3_finalize()] or after [sqlite3_step()] has returned 4797 ** something other than [SQLITE_ROW], the results are undefined. 4798 ** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()] 4799 ** are called from a different thread while any of these routines 4800 ** are pending, then the results are undefined. 4801 ** 4802 ** The first six interfaces (_blob, _double, _int, _int64, _text, and _text16) 4803 ** each return the value of a result column in a specific data format. If 4804 ** the result column is not initially in the requested format (for example, 4805 ** if the query returns an integer but the sqlite3_column_text() interface 4806 ** is used to extract the value) then an automatic type conversion is performed. 4807 ** 4808 ** ^The sqlite3_column_type() routine returns the 4809 ** [SQLITE_INTEGER | datatype code] for the initial data type 4810 ** of the result column. ^The returned value is one of [SQLITE_INTEGER], 4811 ** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL]. 4812 ** The return value of sqlite3_column_type() can be used to decide which 4813 ** of the first six interface should be used to extract the column value. 4814 ** The value returned by sqlite3_column_type() is only meaningful if no 4815 ** automatic type conversions have occurred for the value in question. 4816 ** After a type conversion, the result of calling sqlite3_column_type() 4817 ** is undefined, though harmless. Future 4818 ** versions of SQLite may change the behavior of sqlite3_column_type() 4819 ** following a type conversion. 4820 ** 4821 ** If the result is a BLOB or a TEXT string, then the sqlite3_column_bytes() 4822 ** or sqlite3_column_bytes16() interfaces can be used to determine the size 4823 ** of that BLOB or string. 4824 ** 4825 ** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes() 4826 ** routine returns the number of bytes in that BLOB or string. 4827 ** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts 4828 ** the string to UTF-8 and then returns the number of bytes. 4829 ** ^If the result is a numeric value then sqlite3_column_bytes() uses 4830 ** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns 4831 ** the number of bytes in that string. 4832 ** ^If the result is NULL, then sqlite3_column_bytes() returns zero. 4833 ** 4834 ** ^If the result is a BLOB or UTF-16 string then the sqlite3_column_bytes16() 4835 ** routine returns the number of bytes in that BLOB or string. 4836 ** ^If the result is a UTF-8 string, then sqlite3_column_bytes16() converts 4837 ** the string to UTF-16 and then returns the number of bytes. 4838 ** ^If the result is a numeric value then sqlite3_column_bytes16() uses 4839 ** [sqlite3_snprintf()] to convert that value to a UTF-16 string and returns 4840 ** the number of bytes in that string. 4841 ** ^If the result is NULL, then sqlite3_column_bytes16() returns zero. 4842 ** 4843 ** ^The values returned by [sqlite3_column_bytes()] and 4844 ** [sqlite3_column_bytes16()] do not include the zero terminators at the end 4845 ** of the string. ^For clarity: the values returned by 4846 ** [sqlite3_column_bytes()] and [sqlite3_column_bytes16()] are the number of 4847 ** bytes in the string, not the number of characters. 4848 ** 4849 ** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(), 4850 ** even empty strings, are always zero-terminated. ^The return 4851 ** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer. 4852 ** 4853 ** <b>Warning:</b> ^The object returned by [sqlite3_column_value()] is an 4854 ** [unprotected sqlite3_value] object. In a multithreaded environment, 4855 ** an unprotected sqlite3_value object may only be used safely with 4856 ** [sqlite3_bind_value()] and [sqlite3_result_value()]. 4857 ** If the [unprotected sqlite3_value] object returned by 4858 ** [sqlite3_column_value()] is used in any other way, including calls 4859 ** to routines like [sqlite3_value_int()], [sqlite3_value_text()], 4860 ** or [sqlite3_value_bytes()], the behavior is not threadsafe. 4861 ** Hence, the sqlite3_column_value() interface 4862 ** is normally only useful within the implementation of 4863 ** [application-defined SQL functions] or [virtual tables], not within 4864 ** top-level application code. 4865 ** 4866 ** The these routines may attempt to convert the datatype of the result. 4867 ** ^For example, if the internal representation is FLOAT and a text result 4868 ** is requested, [sqlite3_snprintf()] is used internally to perform the 4869 ** conversion automatically. ^(The following table details the conversions 4870 ** that are applied: 4871 ** 4872 ** <blockquote> 4873 ** <table border="1"> 4874 ** <tr><th> Internal<br>Type <th> Requested<br>Type <th> Conversion 4875 ** 4876 ** <tr><td> NULL <td> INTEGER <td> Result is 0 4877 ** <tr><td> NULL <td> FLOAT <td> Result is 0.0 4878 ** <tr><td> NULL <td> TEXT <td> Result is a NULL pointer 4879 ** <tr><td> NULL <td> BLOB <td> Result is a NULL pointer 4880 ** <tr><td> INTEGER <td> FLOAT <td> Convert from integer to float 4881 ** <tr><td> INTEGER <td> TEXT <td> ASCII rendering of the integer 4882 ** <tr><td> INTEGER <td> BLOB <td> Same as INTEGER->TEXT 4883 ** <tr><td> FLOAT <td> INTEGER <td> [CAST] to INTEGER 4884 ** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float 4885 ** <tr><td> FLOAT <td> BLOB <td> [CAST] to BLOB 4886 ** <tr><td> TEXT <td> INTEGER <td> [CAST] to INTEGER 4887 ** <tr><td> TEXT <td> FLOAT <td> [CAST] to REAL 4888 ** <tr><td> TEXT <td> BLOB <td> No change 4889 ** <tr><td> BLOB <td> INTEGER <td> [CAST] to INTEGER 4890 ** <tr><td> BLOB <td> FLOAT <td> [CAST] to REAL 4891 ** <tr><td> BLOB <td> TEXT <td> Add a zero terminator if needed 4892 ** </table> 4893 ** </blockquote>)^ 4894 ** 4895 ** Note that when type conversions occur, pointers returned by prior 4896 ** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or 4897 ** sqlite3_column_text16() may be invalidated. 4898 ** Type conversions and pointer invalidations might occur 4899 ** in the following cases: 4900 ** 4901 ** <ul> 4902 ** <li> The initial content is a BLOB and sqlite3_column_text() or 4903 ** sqlite3_column_text16() is called. A zero-terminator might 4904 ** need to be added to the string.</li> 4905 ** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or 4906 ** sqlite3_column_text16() is called. The content must be converted 4907 ** to UTF-16.</li> 4908 ** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or 4909 ** sqlite3_column_text() is called. The content must be converted 4910 ** to UTF-8.</li> 4911 ** </ul> 4912 ** 4913 ** ^Conversions between UTF-16be and UTF-16le are always done in place and do 4914 ** not invalidate a prior pointer, though of course the content of the buffer 4915 ** that the prior pointer references will have been modified. Other kinds 4916 ** of conversion are done in place when it is possible, but sometimes they 4917 ** are not possible and in those cases prior pointers are invalidated. 4918 ** 4919 ** The safest policy is to invoke these routines 4920 ** in one of the following ways: 4921 ** 4922 ** <ul> 4923 ** <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li> 4924 ** <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li> 4925 ** <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li> 4926 ** </ul> 4927 ** 4928 ** In other words, you should call sqlite3_column_text(), 4929 ** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result 4930 ** into the desired format, then invoke sqlite3_column_bytes() or 4931 ** sqlite3_column_bytes16() to find the size of the result. Do not mix calls 4932 ** to sqlite3_column_text() or sqlite3_column_blob() with calls to 4933 ** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16() 4934 ** with calls to sqlite3_column_bytes(). 4935 ** 4936 ** ^The pointers returned are valid until a type conversion occurs as 4937 ** described above, or until [sqlite3_step()] or [sqlite3_reset()] or 4938 ** [sqlite3_finalize()] is called. ^The memory space used to hold strings 4939 ** and BLOBs is freed automatically. Do not pass the pointers returned 4940 ** from [sqlite3_column_blob()], [sqlite3_column_text()], etc. into 4941 ** [sqlite3_free()]. 4942 ** 4943 ** As long as the input parameters are correct, these routines will only 4944 ** fail if an out-of-memory error occurs during a format conversion. 4945 ** Only the following subset of interfaces are subject to out-of-memory 4946 ** errors: 4947 ** 4948 ** <ul> 4949 ** <li> sqlite3_column_blob() 4950 ** <li> sqlite3_column_text() 4951 ** <li> sqlite3_column_text16() 4952 ** <li> sqlite3_column_bytes() 4953 ** <li> sqlite3_column_bytes16() 4954 ** </ul> 4955 ** 4956 ** If an out-of-memory error occurs, then the return value from these 4957 ** routines is the same as if the column had contained an SQL NULL value. 4958 ** Valid SQL NULL returns can be distinguished from out-of-memory errors 4959 ** by invoking the [sqlite3_errcode()] immediately after the suspect 4960 ** return value is obtained and before any 4961 ** other SQLite interface is called on the same [database connection]. 4962 */ 4963 SQLITE_API const void *sqlite3_column_blob(sqlite3_stmt*, int iCol); 4964 SQLITE_API double sqlite3_column_double(sqlite3_stmt*, int iCol); 4965 SQLITE_API int sqlite3_column_int(sqlite3_stmt*, int iCol); 4966 SQLITE_API sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol); 4967 SQLITE_API const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol); 4968 SQLITE_API const void *sqlite3_column_text16(sqlite3_stmt*, int iCol); 4969 SQLITE_API sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol); 4970 SQLITE_API int sqlite3_column_bytes(sqlite3_stmt*, int iCol); 4971 SQLITE_API int sqlite3_column_bytes16(sqlite3_stmt*, int iCol); 4972 SQLITE_API int sqlite3_column_type(sqlite3_stmt*, int iCol); 4973 4974 /* 4975 ** CAPI3REF: Destroy A Prepared Statement Object 4976 ** DESTRUCTOR: sqlite3_stmt 4977 ** 4978 ** ^The sqlite3_finalize() function is called to delete a [prepared statement]. 4979 ** ^If the most recent evaluation of the statement encountered no errors 4980 ** or if the statement is never been evaluated, then sqlite3_finalize() returns 4981 ** SQLITE_OK. ^If the most recent evaluation of statement S failed, then 4982 ** sqlite3_finalize(S) returns the appropriate [error code] or 4983 ** [extended error code]. 4984 ** 4985 ** ^The sqlite3_finalize(S) routine can be called at any point during 4986 ** the life cycle of [prepared statement] S: 4987 ** before statement S is ever evaluated, after 4988 ** one or more calls to [sqlite3_reset()], or after any call 4989 ** to [sqlite3_step()] regardless of whether or not the statement has 4990 ** completed execution. 4991 ** 4992 ** ^Invoking sqlite3_finalize() on a NULL pointer is a harmless no-op. 4993 ** 4994 ** The application must finalize every [prepared statement] in order to avoid 4995 ** resource leaks. It is a grievous error for the application to try to use 4996 ** a prepared statement after it has been finalized. Any use of a prepared 4997 ** statement after it has been finalized can result in undefined and 4998 ** undesirable behavior such as segfaults and heap corruption. 4999 */ 5000 SQLITE_API int sqlite3_finalize(sqlite3_stmt *pStmt); 5001 5002 /* 5003 ** CAPI3REF: Reset A Prepared Statement Object 5004 ** METHOD: sqlite3_stmt 5005 ** 5006 ** The sqlite3_reset() function is called to reset a [prepared statement] 5007 ** object back to its initial state, ready to be re-executed. 5008 ** ^Any SQL statement variables that had values bound to them using 5009 ** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values. 5010 ** Use [sqlite3_clear_bindings()] to reset the bindings. 5011 ** 5012 ** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S 5013 ** back to the beginning of its program. 5014 ** 5015 ** ^If the most recent call to [sqlite3_step(S)] for the 5016 ** [prepared statement] S returned [SQLITE_ROW] or [SQLITE_DONE], 5017 ** or if [sqlite3_step(S)] has never before been called on S, 5018 ** then [sqlite3_reset(S)] returns [SQLITE_OK]. 5019 ** 5020 ** ^If the most recent call to [sqlite3_step(S)] for the 5021 ** [prepared statement] S indicated an error, then 5022 ** [sqlite3_reset(S)] returns an appropriate [error code]. 5023 ** 5024 ** ^The [sqlite3_reset(S)] interface does not change the values 5025 ** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S. 5026 */ 5027 SQLITE_API int sqlite3_reset(sqlite3_stmt *pStmt); 5028 5029 /* 5030 ** CAPI3REF: Create Or Redefine SQL Functions 5031 ** KEYWORDS: {function creation routines} 5032 ** METHOD: sqlite3 5033 ** 5034 ** ^These functions (collectively known as "function creation routines") 5035 ** are used to add SQL functions or aggregates or to redefine the behavior 5036 ** of existing SQL functions or aggregates. The only differences between 5037 ** the three "sqlite3_create_function*" routines are the text encoding 5038 ** expected for the second parameter (the name of the function being 5039 ** created) and the presence or absence of a destructor callback for 5040 ** the application data pointer. Function sqlite3_create_window_function() 5041 ** is similar, but allows the user to supply the extra callback functions 5042 ** needed by [aggregate window functions]. 5043 ** 5044 ** ^The first parameter is the [database connection] to which the SQL 5045 ** function is to be added. ^If an application uses more than one database 5046 ** connection then application-defined SQL functions must be added 5047 ** to each database connection separately. 5048 ** 5049 ** ^The second parameter is the name of the SQL function to be created or 5050 ** redefined. ^The length of the name is limited to 255 bytes in a UTF-8 5051 ** representation, exclusive of the zero-terminator. ^Note that the name 5052 ** length limit is in UTF-8 bytes, not characters nor UTF-16 bytes. 5053 ** ^Any attempt to create a function with a longer name 5054 ** will result in [SQLITE_MISUSE] being returned. 5055 ** 5056 ** ^The third parameter (nArg) 5057 ** is the number of arguments that the SQL function or 5058 ** aggregate takes. ^If this parameter is -1, then the SQL function or 5059 ** aggregate may take any number of arguments between 0 and the limit 5060 ** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]). If the third 5061 ** parameter is less than -1 or greater than 127 then the behavior is 5062 ** undefined. 5063 ** 5064 ** ^The fourth parameter, eTextRep, specifies what 5065 ** [SQLITE_UTF8 | text encoding] this SQL function prefers for 5066 ** its parameters. The application should set this parameter to 5067 ** [SQLITE_UTF16LE] if the function implementation invokes 5068 ** [sqlite3_value_text16le()] on an input, or [SQLITE_UTF16BE] if the 5069 ** implementation invokes [sqlite3_value_text16be()] on an input, or 5070 ** [SQLITE_UTF16] if [sqlite3_value_text16()] is used, or [SQLITE_UTF8] 5071 ** otherwise. ^The same SQL function may be registered multiple times using 5072 ** different preferred text encodings, with different implementations for 5073 ** each encoding. 5074 ** ^When multiple implementations of the same function are available, SQLite 5075 ** will pick the one that involves the least amount of data conversion. 5076 ** 5077 ** ^The fourth parameter may optionally be ORed with [SQLITE_DETERMINISTIC] 5078 ** to signal that the function will always return the same result given 5079 ** the same inputs within a single SQL statement. Most SQL functions are 5080 ** deterministic. The built-in [random()] SQL function is an example of a 5081 ** function that is not deterministic. The SQLite query planner is able to 5082 ** perform additional optimizations on deterministic functions, so use 5083 ** of the [SQLITE_DETERMINISTIC] flag is recommended where possible. 5084 ** 5085 ** ^The fourth parameter may also optionally include the [SQLITE_DIRECTONLY] 5086 ** flag, which if present prevents the function from being invoked from 5087 ** within VIEWs, TRIGGERs, CHECK constraints, generated column expressions, 5088 ** index expressions, or the WHERE clause of partial indexes. 5089 ** 5090 ** <span style="background-color:#ffff90;"> 5091 ** For best security, the [SQLITE_DIRECTONLY] flag is recommended for 5092 ** all application-defined SQL functions that do not need to be 5093 ** used inside of triggers, view, CHECK constraints, or other elements of 5094 ** the database schema. This flags is especially recommended for SQL 5095 ** functions that have side effects or reveal internal application state. 5096 ** Without this flag, an attacker might be able to modify the schema of 5097 ** a database file to include invocations of the function with parameters 5098 ** chosen by the attacker, which the application will then execute when 5099 ** the database file is opened and read. 5100 ** </span> 5101 ** 5102 ** ^(The fifth parameter is an arbitrary pointer. The implementation of the 5103 ** function can gain access to this pointer using [sqlite3_user_data()].)^ 5104 ** 5105 ** ^The sixth, seventh and eighth parameters passed to the three 5106 ** "sqlite3_create_function*" functions, xFunc, xStep and xFinal, are 5107 ** pointers to C-language functions that implement the SQL function or 5108 ** aggregate. ^A scalar SQL function requires an implementation of the xFunc 5109 ** callback only; NULL pointers must be passed as the xStep and xFinal 5110 ** parameters. ^An aggregate SQL function requires an implementation of xStep 5111 ** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing 5112 ** SQL function or aggregate, pass NULL pointers for all three function 5113 ** callbacks. 5114 ** 5115 ** ^The sixth, seventh, eighth and ninth parameters (xStep, xFinal, xValue 5116 ** and xInverse) passed to sqlite3_create_window_function are pointers to 5117 ** C-language callbacks that implement the new function. xStep and xFinal 5118 ** must both be non-NULL. xValue and xInverse may either both be NULL, in 5119 ** which case a regular aggregate function is created, or must both be 5120 ** non-NULL, in which case the new function may be used as either an aggregate 5121 ** or aggregate window function. More details regarding the implementation 5122 ** of aggregate window functions are 5123 ** [user-defined window functions|available here]. 5124 ** 5125 ** ^(If the final parameter to sqlite3_create_function_v2() or 5126 ** sqlite3_create_window_function() is not NULL, then it is destructor for 5127 ** the application data pointer. The destructor is invoked when the function 5128 ** is deleted, either by being overloaded or when the database connection 5129 ** closes.)^ ^The destructor is also invoked if the call to 5130 ** sqlite3_create_function_v2() fails. ^When the destructor callback is 5131 ** invoked, it is passed a single argument which is a copy of the application 5132 ** data pointer which was the fifth parameter to sqlite3_create_function_v2(). 5133 ** 5134 ** ^It is permitted to register multiple implementations of the same 5135 ** functions with the same name but with either differing numbers of 5136 ** arguments or differing preferred text encodings. ^SQLite will use 5137 ** the implementation that most closely matches the way in which the 5138 ** SQL function is used. ^A function implementation with a non-negative 5139 ** nArg parameter is a better match than a function implementation with 5140 ** a negative nArg. ^A function where the preferred text encoding 5141 ** matches the database encoding is a better 5142 ** match than a function where the encoding is different. 5143 ** ^A function where the encoding difference is between UTF16le and UTF16be 5144 ** is a closer match than a function where the encoding difference is 5145 ** between UTF8 and UTF16. 5146 ** 5147 ** ^Built-in functions may be overloaded by new application-defined functions. 5148 ** 5149 ** ^An application-defined function is permitted to call other 5150 ** SQLite interfaces. However, such calls must not 5151 ** close the database connection nor finalize or reset the prepared 5152 ** statement in which the function is running. 5153 */ 5154 SQLITE_API int sqlite3_create_function( 5155 sqlite3 *db, 5156 const char *zFunctionName, 5157 int nArg, 5158 int eTextRep, 5159 void *pApp, 5160 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 5161 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 5162 void (*xFinal)(sqlite3_context*) 5163 ); 5164 SQLITE_API int sqlite3_create_function16( 5165 sqlite3 *db, 5166 const void *zFunctionName, 5167 int nArg, 5168 int eTextRep, 5169 void *pApp, 5170 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 5171 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 5172 void (*xFinal)(sqlite3_context*) 5173 ); 5174 SQLITE_API int sqlite3_create_function_v2( 5175 sqlite3 *db, 5176 const char *zFunctionName, 5177 int nArg, 5178 int eTextRep, 5179 void *pApp, 5180 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 5181 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 5182 void (*xFinal)(sqlite3_context*), 5183 void(*xDestroy)(void*) 5184 ); 5185 SQLITE_API int sqlite3_create_window_function( 5186 sqlite3 *db, 5187 const char *zFunctionName, 5188 int nArg, 5189 int eTextRep, 5190 void *pApp, 5191 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 5192 void (*xFinal)(sqlite3_context*), 5193 void (*xValue)(sqlite3_context*), 5194 void (*xInverse)(sqlite3_context*,int,sqlite3_value**), 5195 void(*xDestroy)(void*) 5196 ); 5197 5198 /* 5199 ** CAPI3REF: Text Encodings 5200 ** 5201 ** These constant define integer codes that represent the various 5202 ** text encodings supported by SQLite. 5203 */ 5204 #define SQLITE_UTF8 1 /* IMP: R-37514-35566 */ 5205 #define SQLITE_UTF16LE 2 /* IMP: R-03371-37637 */ 5206 #define SQLITE_UTF16BE 3 /* IMP: R-51971-34154 */ 5207 #define SQLITE_UTF16 4 /* Use native byte order */ 5208 #define SQLITE_ANY 5 /* Deprecated */ 5209 #define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */ 5210 5211 /* 5212 ** CAPI3REF: Function Flags 5213 ** 5214 ** These constants may be ORed together with the 5215 ** [SQLITE_UTF8 | preferred text encoding] as the fourth argument 5216 ** to [sqlite3_create_function()], [sqlite3_create_function16()], or 5217 ** [sqlite3_create_function_v2()]. 5218 ** 5219 ** <dl> 5220 ** [[SQLITE_DETERMINISTIC]] <dt>SQLITE_DETERMINISTIC</dt><dd> 5221 ** The SQLITE_DETERMINISTIC flag means that the new function always gives 5222 ** the same output when the input parameters are the same. 5223 ** The [abs|abs() function] is deterministic, for example, but 5224 ** [randomblob|randomblob()] is not. Functions must 5225 ** be deterministic in order to be used in certain contexts such as 5226 ** with the WHERE clause of [partial indexes] or in [generated columns]. 5227 ** SQLite might also optimize deterministic functions by factoring them 5228 ** out of inner loops. 5229 ** </dd> 5230 ** 5231 ** [[SQLITE_DIRECTONLY]] <dt>SQLITE_DIRECTONLY</dt><dd> 5232 ** The SQLITE_DIRECTONLY flag means that the function may only be invoked 5233 ** from top-level SQL, and cannot be used in VIEWs or TRIGGERs nor in 5234 ** schema structures such as [CHECK constraints], [DEFAULT clauses], 5235 ** [expression indexes], [partial indexes], or [generated columns]. 5236 ** The SQLITE_DIRECTONLY flags is a security feature which is recommended 5237 ** for all [application-defined SQL functions], and especially for functions 5238 ** that have side-effects or that could potentially leak sensitive 5239 ** information. 5240 ** </dd> 5241 ** 5242 ** [[SQLITE_INNOCUOUS]] <dt>SQLITE_INNOCUOUS</dt><dd> 5243 ** The SQLITE_INNOCUOUS flag means that the function is unlikely 5244 ** to cause problems even if misused. An innocuous function should have 5245 ** no side effects and should not depend on any values other than its 5246 ** input parameters. The [abs|abs() function] is an example of an 5247 ** innocuous function. 5248 ** The [load_extension() SQL function] is not innocuous because of its 5249 ** side effects. 5250 ** <p> SQLITE_INNOCUOUS is similar to SQLITE_DETERMINISTIC, but is not 5251 ** exactly the same. The [random|random() function] is an example of a 5252 ** function that is innocuous but not deterministic. 5253 ** <p>Some heightened security settings 5254 ** ([SQLITE_DBCONFIG_TRUSTED_SCHEMA] and [PRAGMA trusted_schema=OFF]) 5255 ** disable the use of SQL functions inside views and triggers and in 5256 ** schema structures such as [CHECK constraints], [DEFAULT clauses], 5257 ** [expression indexes], [partial indexes], and [generated columns] unless 5258 ** the function is tagged with SQLITE_INNOCUOUS. Most built-in functions 5259 ** are innocuous. Developers are advised to avoid using the 5260 ** SQLITE_INNOCUOUS flag for application-defined functions unless the 5261 ** function has been carefully audited and found to be free of potentially 5262 ** security-adverse side-effects and information-leaks. 5263 ** </dd> 5264 ** 5265 ** [[SQLITE_SUBTYPE]] <dt>SQLITE_SUBTYPE</dt><dd> 5266 ** The SQLITE_SUBTYPE flag indicates to SQLite that a function may call 5267 ** [sqlite3_value_subtype()] to inspect the sub-types of its arguments. 5268 ** Specifying this flag makes no difference for scalar or aggregate user 5269 ** functions. However, if it is not specified for a user-defined window 5270 ** function, then any sub-types belonging to arguments passed to the window 5271 ** function may be discarded before the window function is called (i.e. 5272 ** sqlite3_value_subtype() will always return 0). 5273 ** </dd> 5274 ** </dl> 5275 */ 5276 #define SQLITE_DETERMINISTIC 0x000000800 5277 #define SQLITE_DIRECTONLY 0x000080000 5278 #define SQLITE_SUBTYPE 0x000100000 5279 #define SQLITE_INNOCUOUS 0x000200000 5280 5281 /* 5282 ** CAPI3REF: Deprecated Functions 5283 ** DEPRECATED 5284 ** 5285 ** These functions are [deprecated]. In order to maintain 5286 ** backwards compatibility with older code, these functions continue 5287 ** to be supported. However, new applications should avoid 5288 ** the use of these functions. To encourage programmers to avoid 5289 ** these functions, we will not explain what they do. 5290 */ 5291 #ifndef SQLITE_OMIT_DEPRECATED 5292 SQLITE_API SQLITE_DEPRECATED int sqlite3_aggregate_count(sqlite3_context*); 5293 SQLITE_API SQLITE_DEPRECATED int sqlite3_expired(sqlite3_stmt*); 5294 SQLITE_API SQLITE_DEPRECATED int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*); 5295 SQLITE_API SQLITE_DEPRECATED int sqlite3_global_recover(void); 5296 SQLITE_API SQLITE_DEPRECATED void sqlite3_thread_cleanup(void); 5297 SQLITE_API SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int), 5298 void*,sqlite3_int64); 5299 #endif 5300 5301 /* 5302 ** CAPI3REF: Obtaining SQL Values 5303 ** METHOD: sqlite3_value 5304 ** 5305 ** <b>Summary:</b> 5306 ** <blockquote><table border=0 cellpadding=0 cellspacing=0> 5307 ** <tr><td><b>sqlite3_value_blob</b><td>→<td>BLOB value 5308 ** <tr><td><b>sqlite3_value_double</b><td>→<td>REAL value 5309 ** <tr><td><b>sqlite3_value_int</b><td>→<td>32-bit INTEGER value 5310 ** <tr><td><b>sqlite3_value_int64</b><td>→<td>64-bit INTEGER value 5311 ** <tr><td><b>sqlite3_value_pointer</b><td>→<td>Pointer value 5312 ** <tr><td><b>sqlite3_value_text</b><td>→<td>UTF-8 TEXT value 5313 ** <tr><td><b>sqlite3_value_text16</b><td>→<td>UTF-16 TEXT value in 5314 ** the native byteorder 5315 ** <tr><td><b>sqlite3_value_text16be</b><td>→<td>UTF-16be TEXT value 5316 ** <tr><td><b>sqlite3_value_text16le</b><td>→<td>UTF-16le TEXT value 5317 ** <tr><td> <td> <td> 5318 ** <tr><td><b>sqlite3_value_bytes</b><td>→<td>Size of a BLOB 5319 ** or a UTF-8 TEXT in bytes 5320 ** <tr><td><b>sqlite3_value_bytes16 </b> 5321 ** <td>→ <td>Size of UTF-16 5322 ** TEXT in bytes 5323 ** <tr><td><b>sqlite3_value_type</b><td>→<td>Default 5324 ** datatype of the value 5325 ** <tr><td><b>sqlite3_value_numeric_type </b> 5326 ** <td>→ <td>Best numeric datatype of the value 5327 ** <tr><td><b>sqlite3_value_nochange </b> 5328 ** <td>→ <td>True if the column is unchanged in an UPDATE 5329 ** against a virtual table. 5330 ** <tr><td><b>sqlite3_value_frombind </b> 5331 ** <td>→ <td>True if value originated from a [bound parameter] 5332 ** </table></blockquote> 5333 ** 5334 ** <b>Details:</b> 5335 ** 5336 ** These routines extract type, size, and content information from 5337 ** [protected sqlite3_value] objects. Protected sqlite3_value objects 5338 ** are used to pass parameter information into the functions that 5339 ** implement [application-defined SQL functions] and [virtual tables]. 5340 ** 5341 ** These routines work only with [protected sqlite3_value] objects. 5342 ** Any attempt to use these routines on an [unprotected sqlite3_value] 5343 ** is not threadsafe. 5344 ** 5345 ** ^These routines work just like the corresponding [column access functions] 5346 ** except that these routines take a single [protected sqlite3_value] object 5347 ** pointer instead of a [sqlite3_stmt*] pointer and an integer column number. 5348 ** 5349 ** ^The sqlite3_value_text16() interface extracts a UTF-16 string 5350 ** in the native byte-order of the host machine. ^The 5351 ** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces 5352 ** extract UTF-16 strings as big-endian and little-endian respectively. 5353 ** 5354 ** ^If [sqlite3_value] object V was initialized 5355 ** using [sqlite3_bind_pointer(S,I,P,X,D)] or [sqlite3_result_pointer(C,P,X,D)] 5356 ** and if X and Y are strings that compare equal according to strcmp(X,Y), 5357 ** then sqlite3_value_pointer(V,Y) will return the pointer P. ^Otherwise, 5358 ** sqlite3_value_pointer(V,Y) returns a NULL. The sqlite3_bind_pointer() 5359 ** routine is part of the [pointer passing interface] added for SQLite 3.20.0. 5360 ** 5361 ** ^(The sqlite3_value_type(V) interface returns the 5362 ** [SQLITE_INTEGER | datatype code] for the initial datatype of the 5363 ** [sqlite3_value] object V. The returned value is one of [SQLITE_INTEGER], 5364 ** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL].)^ 5365 ** Other interfaces might change the datatype for an sqlite3_value object. 5366 ** For example, if the datatype is initially SQLITE_INTEGER and 5367 ** sqlite3_value_text(V) is called to extract a text value for that 5368 ** integer, then subsequent calls to sqlite3_value_type(V) might return 5369 ** SQLITE_TEXT. Whether or not a persistent internal datatype conversion 5370 ** occurs is undefined and may change from one release of SQLite to the next. 5371 ** 5372 ** ^(The sqlite3_value_numeric_type() interface attempts to apply 5373 ** numeric affinity to the value. This means that an attempt is 5374 ** made to convert the value to an integer or floating point. If 5375 ** such a conversion is possible without loss of information (in other 5376 ** words, if the value is a string that looks like a number) 5377 ** then the conversion is performed. Otherwise no conversion occurs. 5378 ** The [SQLITE_INTEGER | datatype] after conversion is returned.)^ 5379 ** 5380 ** ^Within the [xUpdate] method of a [virtual table], the 5381 ** sqlite3_value_nochange(X) interface returns true if and only if 5382 ** the column corresponding to X is unchanged by the UPDATE operation 5383 ** that the xUpdate method call was invoked to implement and if 5384 ** and the prior [xColumn] method call that was invoked to extracted 5385 ** the value for that column returned without setting a result (probably 5386 ** because it queried [sqlite3_vtab_nochange()] and found that the column 5387 ** was unchanging). ^Within an [xUpdate] method, any value for which 5388 ** sqlite3_value_nochange(X) is true will in all other respects appear 5389 ** to be a NULL value. If sqlite3_value_nochange(X) is invoked anywhere other 5390 ** than within an [xUpdate] method call for an UPDATE statement, then 5391 ** the return value is arbitrary and meaningless. 5392 ** 5393 ** ^The sqlite3_value_frombind(X) interface returns non-zero if the 5394 ** value X originated from one of the [sqlite3_bind_int|sqlite3_bind()] 5395 ** interfaces. ^If X comes from an SQL literal value, or a table column, 5396 ** or an expression, then sqlite3_value_frombind(X) returns zero. 5397 ** 5398 ** Please pay particular attention to the fact that the pointer returned 5399 ** from [sqlite3_value_blob()], [sqlite3_value_text()], or 5400 ** [sqlite3_value_text16()] can be invalidated by a subsequent call to 5401 ** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()], 5402 ** or [sqlite3_value_text16()]. 5403 ** 5404 ** These routines must be called from the same thread as 5405 ** the SQL function that supplied the [sqlite3_value*] parameters. 5406 ** 5407 ** As long as the input parameter is correct, these routines can only 5408 ** fail if an out-of-memory error occurs during a format conversion. 5409 ** Only the following subset of interfaces are subject to out-of-memory 5410 ** errors: 5411 ** 5412 ** <ul> 5413 ** <li> sqlite3_value_blob() 5414 ** <li> sqlite3_value_text() 5415 ** <li> sqlite3_value_text16() 5416 ** <li> sqlite3_value_text16le() 5417 ** <li> sqlite3_value_text16be() 5418 ** <li> sqlite3_value_bytes() 5419 ** <li> sqlite3_value_bytes16() 5420 ** </ul> 5421 ** 5422 ** If an out-of-memory error occurs, then the return value from these 5423 ** routines is the same as if the column had contained an SQL NULL value. 5424 ** Valid SQL NULL returns can be distinguished from out-of-memory errors 5425 ** by invoking the [sqlite3_errcode()] immediately after the suspect 5426 ** return value is obtained and before any 5427 ** other SQLite interface is called on the same [database connection]. 5428 */ 5429 SQLITE_API const void *sqlite3_value_blob(sqlite3_value*); 5430 SQLITE_API double sqlite3_value_double(sqlite3_value*); 5431 SQLITE_API int sqlite3_value_int(sqlite3_value*); 5432 SQLITE_API sqlite3_int64 sqlite3_value_int64(sqlite3_value*); 5433 SQLITE_API void *sqlite3_value_pointer(sqlite3_value*, const char*); 5434 SQLITE_API const unsigned char *sqlite3_value_text(sqlite3_value*); 5435 SQLITE_API const void *sqlite3_value_text16(sqlite3_value*); 5436 SQLITE_API const void *sqlite3_value_text16le(sqlite3_value*); 5437 SQLITE_API const void *sqlite3_value_text16be(sqlite3_value*); 5438 SQLITE_API int sqlite3_value_bytes(sqlite3_value*); 5439 SQLITE_API int sqlite3_value_bytes16(sqlite3_value*); 5440 SQLITE_API int sqlite3_value_type(sqlite3_value*); 5441 SQLITE_API int sqlite3_value_numeric_type(sqlite3_value*); 5442 SQLITE_API int sqlite3_value_nochange(sqlite3_value*); 5443 SQLITE_API int sqlite3_value_frombind(sqlite3_value*); 5444 5445 /* 5446 ** CAPI3REF: Finding The Subtype Of SQL Values 5447 ** METHOD: sqlite3_value 5448 ** 5449 ** The sqlite3_value_subtype(V) function returns the subtype for 5450 ** an [application-defined SQL function] argument V. The subtype 5451 ** information can be used to pass a limited amount of context from 5452 ** one SQL function to another. Use the [sqlite3_result_subtype()] 5453 ** routine to set the subtype for the return value of an SQL function. 5454 */ 5455 SQLITE_API unsigned int sqlite3_value_subtype(sqlite3_value*); 5456 5457 /* 5458 ** CAPI3REF: Copy And Free SQL Values 5459 ** METHOD: sqlite3_value 5460 ** 5461 ** ^The sqlite3_value_dup(V) interface makes a copy of the [sqlite3_value] 5462 ** object D and returns a pointer to that copy. ^The [sqlite3_value] returned 5463 ** is a [protected sqlite3_value] object even if the input is not. 5464 ** ^The sqlite3_value_dup(V) interface returns NULL if V is NULL or if a 5465 ** memory allocation fails. 5466 ** 5467 ** ^The sqlite3_value_free(V) interface frees an [sqlite3_value] object 5468 ** previously obtained from [sqlite3_value_dup()]. ^If V is a NULL pointer 5469 ** then sqlite3_value_free(V) is a harmless no-op. 5470 */ 5471 SQLITE_API sqlite3_value *sqlite3_value_dup(const sqlite3_value*); 5472 SQLITE_API void sqlite3_value_free(sqlite3_value*); 5473 5474 /* 5475 ** CAPI3REF: Obtain Aggregate Function Context 5476 ** METHOD: sqlite3_context 5477 ** 5478 ** Implementations of aggregate SQL functions use this 5479 ** routine to allocate memory for storing their state. 5480 ** 5481 ** ^The first time the sqlite3_aggregate_context(C,N) routine is called 5482 ** for a particular aggregate function, SQLite allocates 5483 ** N bytes of memory, zeroes out that memory, and returns a pointer 5484 ** to the new memory. ^On second and subsequent calls to 5485 ** sqlite3_aggregate_context() for the same aggregate function instance, 5486 ** the same buffer is returned. Sqlite3_aggregate_context() is normally 5487 ** called once for each invocation of the xStep callback and then one 5488 ** last time when the xFinal callback is invoked. ^(When no rows match 5489 ** an aggregate query, the xStep() callback of the aggregate function 5490 ** implementation is never called and xFinal() is called exactly once. 5491 ** In those cases, sqlite3_aggregate_context() might be called for the 5492 ** first time from within xFinal().)^ 5493 ** 5494 ** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer 5495 ** when first called if N is less than or equal to zero or if a memory 5496 ** allocate error occurs. 5497 ** 5498 ** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is 5499 ** determined by the N parameter on first successful call. Changing the 5500 ** value of N in any subsequent call to sqlite3_aggregate_context() within 5501 ** the same aggregate function instance will not resize the memory 5502 ** allocation.)^ Within the xFinal callback, it is customary to set 5503 ** N=0 in calls to sqlite3_aggregate_context(C,N) so that no 5504 ** pointless memory allocations occur. 5505 ** 5506 ** ^SQLite automatically frees the memory allocated by 5507 ** sqlite3_aggregate_context() when the aggregate query concludes. 5508 ** 5509 ** The first parameter must be a copy of the 5510 ** [sqlite3_context | SQL function context] that is the first parameter 5511 ** to the xStep or xFinal callback routine that implements the aggregate 5512 ** function. 5513 ** 5514 ** This routine must be called from the same thread in which 5515 ** the aggregate SQL function is running. 5516 */ 5517 SQLITE_API void *sqlite3_aggregate_context(sqlite3_context*, int nBytes); 5518 5519 /* 5520 ** CAPI3REF: User Data For Functions 5521 ** METHOD: sqlite3_context 5522 ** 5523 ** ^The sqlite3_user_data() interface returns a copy of 5524 ** the pointer that was the pUserData parameter (the 5th parameter) 5525 ** of the [sqlite3_create_function()] 5526 ** and [sqlite3_create_function16()] routines that originally 5527 ** registered the application defined function. 5528 ** 5529 ** This routine must be called from the same thread in which 5530 ** the application-defined function is running. 5531 */ 5532 SQLITE_API void *sqlite3_user_data(sqlite3_context*); 5533 5534 /* 5535 ** CAPI3REF: Database Connection For Functions 5536 ** METHOD: sqlite3_context 5537 ** 5538 ** ^The sqlite3_context_db_handle() interface returns a copy of 5539 ** the pointer to the [database connection] (the 1st parameter) 5540 ** of the [sqlite3_create_function()] 5541 ** and [sqlite3_create_function16()] routines that originally 5542 ** registered the application defined function. 5543 */ 5544 SQLITE_API sqlite3 *sqlite3_context_db_handle(sqlite3_context*); 5545 5546 /* 5547 ** CAPI3REF: Function Auxiliary Data 5548 ** METHOD: sqlite3_context 5549 ** 5550 ** These functions may be used by (non-aggregate) SQL functions to 5551 ** associate metadata with argument values. If the same value is passed to 5552 ** multiple invocations of the same SQL function during query execution, under 5553 ** some circumstances the associated metadata may be preserved. An example 5554 ** of where this might be useful is in a regular-expression matching 5555 ** function. The compiled version of the regular expression can be stored as 5556 ** metadata associated with the pattern string. 5557 ** Then as long as the pattern string remains the same, 5558 ** the compiled regular expression can be reused on multiple 5559 ** invocations of the same function. 5560 ** 5561 ** ^The sqlite3_get_auxdata(C,N) interface returns a pointer to the metadata 5562 ** associated by the sqlite3_set_auxdata(C,N,P,X) function with the Nth argument 5563 ** value to the application-defined function. ^N is zero for the left-most 5564 ** function argument. ^If there is no metadata 5565 ** associated with the function argument, the sqlite3_get_auxdata(C,N) interface 5566 ** returns a NULL pointer. 5567 ** 5568 ** ^The sqlite3_set_auxdata(C,N,P,X) interface saves P as metadata for the N-th 5569 ** argument of the application-defined function. ^Subsequent 5570 ** calls to sqlite3_get_auxdata(C,N) return P from the most recent 5571 ** sqlite3_set_auxdata(C,N,P,X) call if the metadata is still valid or 5572 ** NULL if the metadata has been discarded. 5573 ** ^After each call to sqlite3_set_auxdata(C,N,P,X) where X is not NULL, 5574 ** SQLite will invoke the destructor function X with parameter P exactly 5575 ** once, when the metadata is discarded. 5576 ** SQLite is free to discard the metadata at any time, including: <ul> 5577 ** <li> ^(when the corresponding function parameter changes)^, or 5578 ** <li> ^(when [sqlite3_reset()] or [sqlite3_finalize()] is called for the 5579 ** SQL statement)^, or 5580 ** <li> ^(when sqlite3_set_auxdata() is invoked again on the same 5581 ** parameter)^, or 5582 ** <li> ^(during the original sqlite3_set_auxdata() call when a memory 5583 ** allocation error occurs.)^ </ul> 5584 ** 5585 ** Note the last bullet in particular. The destructor X in 5586 ** sqlite3_set_auxdata(C,N,P,X) might be called immediately, before the 5587 ** sqlite3_set_auxdata() interface even returns. Hence sqlite3_set_auxdata() 5588 ** should be called near the end of the function implementation and the 5589 ** function implementation should not make any use of P after 5590 ** sqlite3_set_auxdata() has been called. 5591 ** 5592 ** ^(In practice, metadata is preserved between function calls for 5593 ** function parameters that are compile-time constants, including literal 5594 ** values and [parameters] and expressions composed from the same.)^ 5595 ** 5596 ** The value of the N parameter to these interfaces should be non-negative. 5597 ** Future enhancements may make use of negative N values to define new 5598 ** kinds of function caching behavior. 5599 ** 5600 ** These routines must be called from the same thread in which 5601 ** the SQL function is running. 5602 */ 5603 SQLITE_API void *sqlite3_get_auxdata(sqlite3_context*, int N); 5604 SQLITE_API void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*)); 5605 5606 5607 /* 5608 ** CAPI3REF: Constants Defining Special Destructor Behavior 5609 ** 5610 ** These are special values for the destructor that is passed in as the 5611 ** final argument to routines like [sqlite3_result_blob()]. ^If the destructor 5612 ** argument is SQLITE_STATIC, it means that the content pointer is constant 5613 ** and will never change. It does not need to be destroyed. ^The 5614 ** SQLITE_TRANSIENT value means that the content will likely change in 5615 ** the near future and that SQLite should make its own private copy of 5616 ** the content before returning. 5617 ** 5618 ** The typedef is necessary to work around problems in certain 5619 ** C++ compilers. 5620 */ 5621 typedef void (*sqlite3_destructor_type)(void*); 5622 #define SQLITE_STATIC ((sqlite3_destructor_type)0) 5623 #define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1) 5624 5625 /* 5626 ** CAPI3REF: Setting The Result Of An SQL Function 5627 ** METHOD: sqlite3_context 5628 ** 5629 ** These routines are used by the xFunc or xFinal callbacks that 5630 ** implement SQL functions and aggregates. See 5631 ** [sqlite3_create_function()] and [sqlite3_create_function16()] 5632 ** for additional information. 5633 ** 5634 ** These functions work very much like the [parameter binding] family of 5635 ** functions used to bind values to host parameters in prepared statements. 5636 ** Refer to the [SQL parameter] documentation for additional information. 5637 ** 5638 ** ^The sqlite3_result_blob() interface sets the result from 5639 ** an application-defined function to be the BLOB whose content is pointed 5640 ** to by the second parameter and which is N bytes long where N is the 5641 ** third parameter. 5642 ** 5643 ** ^The sqlite3_result_zeroblob(C,N) and sqlite3_result_zeroblob64(C,N) 5644 ** interfaces set the result of the application-defined function to be 5645 ** a BLOB containing all zero bytes and N bytes in size. 5646 ** 5647 ** ^The sqlite3_result_double() interface sets the result from 5648 ** an application-defined function to be a floating point value specified 5649 ** by its 2nd argument. 5650 ** 5651 ** ^The sqlite3_result_error() and sqlite3_result_error16() functions 5652 ** cause the implemented SQL function to throw an exception. 5653 ** ^SQLite uses the string pointed to by the 5654 ** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16() 5655 ** as the text of an error message. ^SQLite interprets the error 5656 ** message string from sqlite3_result_error() as UTF-8. ^SQLite 5657 ** interprets the string from sqlite3_result_error16() as UTF-16 using 5658 ** the same [byte-order determination rules] as [sqlite3_bind_text16()]. 5659 ** ^If the third parameter to sqlite3_result_error() 5660 ** or sqlite3_result_error16() is negative then SQLite takes as the error 5661 ** message all text up through the first zero character. 5662 ** ^If the third parameter to sqlite3_result_error() or 5663 ** sqlite3_result_error16() is non-negative then SQLite takes that many 5664 ** bytes (not characters) from the 2nd parameter as the error message. 5665 ** ^The sqlite3_result_error() and sqlite3_result_error16() 5666 ** routines make a private copy of the error message text before 5667 ** they return. Hence, the calling function can deallocate or 5668 ** modify the text after they return without harm. 5669 ** ^The sqlite3_result_error_code() function changes the error code 5670 ** returned by SQLite as a result of an error in a function. ^By default, 5671 ** the error code is SQLITE_ERROR. ^A subsequent call to sqlite3_result_error() 5672 ** or sqlite3_result_error16() resets the error code to SQLITE_ERROR. 5673 ** 5674 ** ^The sqlite3_result_error_toobig() interface causes SQLite to throw an 5675 ** error indicating that a string or BLOB is too long to represent. 5676 ** 5677 ** ^The sqlite3_result_error_nomem() interface causes SQLite to throw an 5678 ** error indicating that a memory allocation failed. 5679 ** 5680 ** ^The sqlite3_result_int() interface sets the return value 5681 ** of the application-defined function to be the 32-bit signed integer 5682 ** value given in the 2nd argument. 5683 ** ^The sqlite3_result_int64() interface sets the return value 5684 ** of the application-defined function to be the 64-bit signed integer 5685 ** value given in the 2nd argument. 5686 ** 5687 ** ^The sqlite3_result_null() interface sets the return value 5688 ** of the application-defined function to be NULL. 5689 ** 5690 ** ^The sqlite3_result_text(), sqlite3_result_text16(), 5691 ** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces 5692 ** set the return value of the application-defined function to be 5693 ** a text string which is represented as UTF-8, UTF-16 native byte order, 5694 ** UTF-16 little endian, or UTF-16 big endian, respectively. 5695 ** ^The sqlite3_result_text64() interface sets the return value of an 5696 ** application-defined function to be a text string in an encoding 5697 ** specified by the fifth (and last) parameter, which must be one 5698 ** of [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE]. 5699 ** ^SQLite takes the text result from the application from 5700 ** the 2nd parameter of the sqlite3_result_text* interfaces. 5701 ** ^If the 3rd parameter to the sqlite3_result_text* interfaces 5702 ** is negative, then SQLite takes result text from the 2nd parameter 5703 ** through the first zero character. 5704 ** ^If the 3rd parameter to the sqlite3_result_text* interfaces 5705 ** is non-negative, then as many bytes (not characters) of the text 5706 ** pointed to by the 2nd parameter are taken as the application-defined 5707 ** function result. If the 3rd parameter is non-negative, then it 5708 ** must be the byte offset into the string where the NUL terminator would 5709 ** appear if the string where NUL terminated. If any NUL characters occur 5710 ** in the string at a byte offset that is less than the value of the 3rd 5711 ** parameter, then the resulting string will contain embedded NULs and the 5712 ** result of expressions operating on strings with embedded NULs is undefined. 5713 ** ^If the 4th parameter to the sqlite3_result_text* interfaces 5714 ** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that 5715 ** function as the destructor on the text or BLOB result when it has 5716 ** finished using that result. 5717 ** ^If the 4th parameter to the sqlite3_result_text* interfaces or to 5718 ** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite 5719 ** assumes that the text or BLOB result is in constant space and does not 5720 ** copy the content of the parameter nor call a destructor on the content 5721 ** when it has finished using that result. 5722 ** ^If the 4th parameter to the sqlite3_result_text* interfaces 5723 ** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT 5724 ** then SQLite makes a copy of the result into space obtained 5725 ** from [sqlite3_malloc()] before it returns. 5726 ** 5727 ** ^For the sqlite3_result_text16(), sqlite3_result_text16le(), and 5728 ** sqlite3_result_text16be() routines, and for sqlite3_result_text64() 5729 ** when the encoding is not UTF8, if the input UTF16 begins with a 5730 ** byte-order mark (BOM, U+FEFF) then the BOM is removed from the 5731 ** string and the rest of the string is interpreted according to the 5732 ** byte-order specified by the BOM. ^The byte-order specified by 5733 ** the BOM at the beginning of the text overrides the byte-order 5734 ** specified by the interface procedure. ^So, for example, if 5735 ** sqlite3_result_text16le() is invoked with text that begins 5736 ** with bytes 0xfe, 0xff (a big-endian byte-order mark) then the 5737 ** first two bytes of input are skipped and the remaining input 5738 ** is interpreted as UTF16BE text. 5739 ** 5740 ** ^For UTF16 input text to the sqlite3_result_text16(), 5741 ** sqlite3_result_text16be(), sqlite3_result_text16le(), and 5742 ** sqlite3_result_text64() routines, if the text contains invalid 5743 ** UTF16 characters, the invalid characters might be converted 5744 ** into the unicode replacement character, U+FFFD. 5745 ** 5746 ** ^The sqlite3_result_value() interface sets the result of 5747 ** the application-defined function to be a copy of the 5748 ** [unprotected sqlite3_value] object specified by the 2nd parameter. ^The 5749 ** sqlite3_result_value() interface makes a copy of the [sqlite3_value] 5750 ** so that the [sqlite3_value] specified in the parameter may change or 5751 ** be deallocated after sqlite3_result_value() returns without harm. 5752 ** ^A [protected sqlite3_value] object may always be used where an 5753 ** [unprotected sqlite3_value] object is required, so either 5754 ** kind of [sqlite3_value] object can be used with this interface. 5755 ** 5756 ** ^The sqlite3_result_pointer(C,P,T,D) interface sets the result to an 5757 ** SQL NULL value, just like [sqlite3_result_null(C)], except that it 5758 ** also associates the host-language pointer P or type T with that 5759 ** NULL value such that the pointer can be retrieved within an 5760 ** [application-defined SQL function] using [sqlite3_value_pointer()]. 5761 ** ^If the D parameter is not NULL, then it is a pointer to a destructor 5762 ** for the P parameter. ^SQLite invokes D with P as its only argument 5763 ** when SQLite is finished with P. The T parameter should be a static 5764 ** string and preferably a string literal. The sqlite3_result_pointer() 5765 ** routine is part of the [pointer passing interface] added for SQLite 3.20.0. 5766 ** 5767 ** If these routines are called from within the different thread 5768 ** than the one containing the application-defined function that received 5769 ** the [sqlite3_context] pointer, the results are undefined. 5770 */ 5771 SQLITE_API void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*)); 5772 SQLITE_API void sqlite3_result_blob64(sqlite3_context*,const void*, 5773 sqlite3_uint64,void(*)(void*)); 5774 SQLITE_API void sqlite3_result_double(sqlite3_context*, double); 5775 SQLITE_API void sqlite3_result_error(sqlite3_context*, const char*, int); 5776 SQLITE_API void sqlite3_result_error16(sqlite3_context*, const void*, int); 5777 SQLITE_API void sqlite3_result_error_toobig(sqlite3_context*); 5778 SQLITE_API void sqlite3_result_error_nomem(sqlite3_context*); 5779 SQLITE_API void sqlite3_result_error_code(sqlite3_context*, int); 5780 SQLITE_API void sqlite3_result_int(sqlite3_context*, int); 5781 SQLITE_API void sqlite3_result_int64(sqlite3_context*, sqlite3_int64); 5782 SQLITE_API void sqlite3_result_null(sqlite3_context*); 5783 SQLITE_API void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*)); 5784 SQLITE_API void sqlite3_result_text64(sqlite3_context*, const char*,sqlite3_uint64, 5785 void(*)(void*), unsigned char encoding); 5786 SQLITE_API void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*)); 5787 SQLITE_API void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*)); 5788 SQLITE_API void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*)); 5789 SQLITE_API void sqlite3_result_value(sqlite3_context*, sqlite3_value*); 5790 SQLITE_API void sqlite3_result_pointer(sqlite3_context*, void*,const char*,void(*)(void*)); 5791 SQLITE_API void sqlite3_result_zeroblob(sqlite3_context*, int n); 5792 SQLITE_API int sqlite3_result_zeroblob64(sqlite3_context*, sqlite3_uint64 n); 5793 5794 5795 /* 5796 ** CAPI3REF: Setting The Subtype Of An SQL Function 5797 ** METHOD: sqlite3_context 5798 ** 5799 ** The sqlite3_result_subtype(C,T) function causes the subtype of 5800 ** the result from the [application-defined SQL function] with 5801 ** [sqlite3_context] C to be the value T. Only the lower 8 bits 5802 ** of the subtype T are preserved in current versions of SQLite; 5803 ** higher order bits are discarded. 5804 ** The number of subtype bytes preserved by SQLite might increase 5805 ** in future releases of SQLite. 5806 */ 5807 SQLITE_API void sqlite3_result_subtype(sqlite3_context*,unsigned int); 5808 5809 /* 5810 ** CAPI3REF: Define New Collating Sequences 5811 ** METHOD: sqlite3 5812 ** 5813 ** ^These functions add, remove, or modify a [collation] associated 5814 ** with the [database connection] specified as the first argument. 5815 ** 5816 ** ^The name of the collation is a UTF-8 string 5817 ** for sqlite3_create_collation() and sqlite3_create_collation_v2() 5818 ** and a UTF-16 string in native byte order for sqlite3_create_collation16(). 5819 ** ^Collation names that compare equal according to [sqlite3_strnicmp()] are 5820 ** considered to be the same name. 5821 ** 5822 ** ^(The third argument (eTextRep) must be one of the constants: 5823 ** <ul> 5824 ** <li> [SQLITE_UTF8], 5825 ** <li> [SQLITE_UTF16LE], 5826 ** <li> [SQLITE_UTF16BE], 5827 ** <li> [SQLITE_UTF16], or 5828 ** <li> [SQLITE_UTF16_ALIGNED]. 5829 ** </ul>)^ 5830 ** ^The eTextRep argument determines the encoding of strings passed 5831 ** to the collating function callback, xCompare. 5832 ** ^The [SQLITE_UTF16] and [SQLITE_UTF16_ALIGNED] values for eTextRep 5833 ** force strings to be UTF16 with native byte order. 5834 ** ^The [SQLITE_UTF16_ALIGNED] value for eTextRep forces strings to begin 5835 ** on an even byte address. 5836 ** 5837 ** ^The fourth argument, pArg, is an application data pointer that is passed 5838 ** through as the first argument to the collating function callback. 5839 ** 5840 ** ^The fifth argument, xCompare, is a pointer to the collating function. 5841 ** ^Multiple collating functions can be registered using the same name but 5842 ** with different eTextRep parameters and SQLite will use whichever 5843 ** function requires the least amount of data transformation. 5844 ** ^If the xCompare argument is NULL then the collating function is 5845 ** deleted. ^When all collating functions having the same name are deleted, 5846 ** that collation is no longer usable. 5847 ** 5848 ** ^The collating function callback is invoked with a copy of the pArg 5849 ** application data pointer and with two strings in the encoding specified 5850 ** by the eTextRep argument. The two integer parameters to the collating 5851 ** function callback are the length of the two strings, in bytes. The collating 5852 ** function must return an integer that is negative, zero, or positive 5853 ** if the first string is less than, equal to, or greater than the second, 5854 ** respectively. A collating function must always return the same answer 5855 ** given the same inputs. If two or more collating functions are registered 5856 ** to the same collation name (using different eTextRep values) then all 5857 ** must give an equivalent answer when invoked with equivalent strings. 5858 ** The collating function must obey the following properties for all 5859 ** strings A, B, and C: 5860 ** 5861 ** <ol> 5862 ** <li> If A==B then B==A. 5863 ** <li> If A==B and B==C then A==C. 5864 ** <li> If A<B THEN B>A. 5865 ** <li> If A<B and B<C then A<C. 5866 ** </ol> 5867 ** 5868 ** If a collating function fails any of the above constraints and that 5869 ** collating function is registered and used, then the behavior of SQLite 5870 ** is undefined. 5871 ** 5872 ** ^The sqlite3_create_collation_v2() works like sqlite3_create_collation() 5873 ** with the addition that the xDestroy callback is invoked on pArg when 5874 ** the collating function is deleted. 5875 ** ^Collating functions are deleted when they are overridden by later 5876 ** calls to the collation creation functions or when the 5877 ** [database connection] is closed using [sqlite3_close()]. 5878 ** 5879 ** ^The xDestroy callback is <u>not</u> called if the 5880 ** sqlite3_create_collation_v2() function fails. Applications that invoke 5881 ** sqlite3_create_collation_v2() with a non-NULL xDestroy argument should 5882 ** check the return code and dispose of the application data pointer 5883 ** themselves rather than expecting SQLite to deal with it for them. 5884 ** This is different from every other SQLite interface. The inconsistency 5885 ** is unfortunate but cannot be changed without breaking backwards 5886 ** compatibility. 5887 ** 5888 ** See also: [sqlite3_collation_needed()] and [sqlite3_collation_needed16()]. 5889 */ 5890 SQLITE_API int sqlite3_create_collation( 5891 sqlite3*, 5892 const char *zName, 5893 int eTextRep, 5894 void *pArg, 5895 int(*xCompare)(void*,int,const void*,int,const void*) 5896 ); 5897 SQLITE_API int sqlite3_create_collation_v2( 5898 sqlite3*, 5899 const char *zName, 5900 int eTextRep, 5901 void *pArg, 5902 int(*xCompare)(void*,int,const void*,int,const void*), 5903 void(*xDestroy)(void*) 5904 ); 5905 SQLITE_API int sqlite3_create_collation16( 5906 sqlite3*, 5907 const void *zName, 5908 int eTextRep, 5909 void *pArg, 5910 int(*xCompare)(void*,int,const void*,int,const void*) 5911 ); 5912 5913 /* 5914 ** CAPI3REF: Collation Needed Callbacks 5915 ** METHOD: sqlite3 5916 ** 5917 ** ^To avoid having to register all collation sequences before a database 5918 ** can be used, a single callback function may be registered with the 5919 ** [database connection] to be invoked whenever an undefined collation 5920 ** sequence is required. 5921 ** 5922 ** ^If the function is registered using the sqlite3_collation_needed() API, 5923 ** then it is passed the names of undefined collation sequences as strings 5924 ** encoded in UTF-8. ^If sqlite3_collation_needed16() is used, 5925 ** the names are passed as UTF-16 in machine native byte order. 5926 ** ^A call to either function replaces the existing collation-needed callback. 5927 ** 5928 ** ^(When the callback is invoked, the first argument passed is a copy 5929 ** of the second argument to sqlite3_collation_needed() or 5930 ** sqlite3_collation_needed16(). The second argument is the database 5931 ** connection. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE], 5932 ** or [SQLITE_UTF16LE], indicating the most desirable form of the collation 5933 ** sequence function required. The fourth parameter is the name of the 5934 ** required collation sequence.)^ 5935 ** 5936 ** The callback function should register the desired collation using 5937 ** [sqlite3_create_collation()], [sqlite3_create_collation16()], or 5938 ** [sqlite3_create_collation_v2()]. 5939 */ 5940 SQLITE_API int sqlite3_collation_needed( 5941 sqlite3*, 5942 void*, 5943 void(*)(void*,sqlite3*,int eTextRep,const char*) 5944 ); 5945 SQLITE_API int sqlite3_collation_needed16( 5946 sqlite3*, 5947 void*, 5948 void(*)(void*,sqlite3*,int eTextRep,const void*) 5949 ); 5950 5951 #ifdef SQLITE_ENABLE_CEROD 5952 /* 5953 ** Specify the activation key for a CEROD database. Unless 5954 ** activated, none of the CEROD routines will work. 5955 */ 5956 SQLITE_API void sqlite3_activate_cerod( 5957 const char *zPassPhrase /* Activation phrase */ 5958 ); 5959 #endif 5960 5961 /* 5962 ** CAPI3REF: Suspend Execution For A Short Time 5963 ** 5964 ** The sqlite3_sleep() function causes the current thread to suspend execution 5965 ** for at least a number of milliseconds specified in its parameter. 5966 ** 5967 ** If the operating system does not support sleep requests with 5968 ** millisecond time resolution, then the time will be rounded up to 5969 ** the nearest second. The number of milliseconds of sleep actually 5970 ** requested from the operating system is returned. 5971 ** 5972 ** ^SQLite implements this interface by calling the xSleep() 5973 ** method of the default [sqlite3_vfs] object. If the xSleep() method 5974 ** of the default VFS is not implemented correctly, or not implemented at 5975 ** all, then the behavior of sqlite3_sleep() may deviate from the description 5976 ** in the previous paragraphs. 5977 */ 5978 SQLITE_API int sqlite3_sleep(int); 5979 5980 /* 5981 ** CAPI3REF: Name Of The Folder Holding Temporary Files 5982 ** 5983 ** ^(If this global variable is made to point to a string which is 5984 ** the name of a folder (a.k.a. directory), then all temporary files 5985 ** created by SQLite when using a built-in [sqlite3_vfs | VFS] 5986 ** will be placed in that directory.)^ ^If this variable 5987 ** is a NULL pointer, then SQLite performs a search for an appropriate 5988 ** temporary file directory. 5989 ** 5990 ** Applications are strongly discouraged from using this global variable. 5991 ** It is required to set a temporary folder on Windows Runtime (WinRT). 5992 ** But for all other platforms, it is highly recommended that applications 5993 ** neither read nor write this variable. This global variable is a relic 5994 ** that exists for backwards compatibility of legacy applications and should 5995 ** be avoided in new projects. 5996 ** 5997 ** It is not safe to read or modify this variable in more than one 5998 ** thread at a time. It is not safe to read or modify this variable 5999 ** if a [database connection] is being used at the same time in a separate 6000 ** thread. 6001 ** It is intended that this variable be set once 6002 ** as part of process initialization and before any SQLite interface 6003 ** routines have been called and that this variable remain unchanged 6004 ** thereafter. 6005 ** 6006 ** ^The [temp_store_directory pragma] may modify this variable and cause 6007 ** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 6008 ** the [temp_store_directory pragma] always assumes that any string 6009 ** that this variable points to is held in memory obtained from 6010 ** [sqlite3_malloc] and the pragma may attempt to free that memory 6011 ** using [sqlite3_free]. 6012 ** Hence, if this variable is modified directly, either it should be 6013 ** made NULL or made to point to memory obtained from [sqlite3_malloc] 6014 ** or else the use of the [temp_store_directory pragma] should be avoided. 6015 ** Except when requested by the [temp_store_directory pragma], SQLite 6016 ** does not free the memory that sqlite3_temp_directory points to. If 6017 ** the application wants that memory to be freed, it must do 6018 ** so itself, taking care to only do so after all [database connection] 6019 ** objects have been destroyed. 6020 ** 6021 ** <b>Note to Windows Runtime users:</b> The temporary directory must be set 6022 ** prior to calling [sqlite3_open] or [sqlite3_open_v2]. Otherwise, various 6023 ** features that require the use of temporary files may fail. Here is an 6024 ** example of how to do this using C++ with the Windows Runtime: 6025 ** 6026 ** <blockquote><pre> 6027 ** LPCWSTR zPath = Windows::Storage::ApplicationData::Current-> 6028 ** TemporaryFolder->Path->Data(); 6029 ** char zPathBuf[MAX_PATH + 1]; 6030 ** memset(zPathBuf, 0, sizeof(zPathBuf)); 6031 ** WideCharToMultiByte(CP_UTF8, 0, zPath, -1, zPathBuf, sizeof(zPathBuf), 6032 ** NULL, NULL); 6033 ** sqlite3_temp_directory = sqlite3_mprintf("%s", zPathBuf); 6034 ** </pre></blockquote> 6035 */ 6036 SQLITE_API SQLITE_EXTERN char *sqlite3_temp_directory; 6037 6038 /* 6039 ** CAPI3REF: Name Of The Folder Holding Database Files 6040 ** 6041 ** ^(If this global variable is made to point to a string which is 6042 ** the name of a folder (a.k.a. directory), then all database files 6043 ** specified with a relative pathname and created or accessed by 6044 ** SQLite when using a built-in windows [sqlite3_vfs | VFS] will be assumed 6045 ** to be relative to that directory.)^ ^If this variable is a NULL 6046 ** pointer, then SQLite assumes that all database files specified 6047 ** with a relative pathname are relative to the current directory 6048 ** for the process. Only the windows VFS makes use of this global 6049 ** variable; it is ignored by the unix VFS. 6050 ** 6051 ** Changing the value of this variable while a database connection is 6052 ** open can result in a corrupt database. 6053 ** 6054 ** It is not safe to read or modify this variable in more than one 6055 ** thread at a time. It is not safe to read or modify this variable 6056 ** if a [database connection] is being used at the same time in a separate 6057 ** thread. 6058 ** It is intended that this variable be set once 6059 ** as part of process initialization and before any SQLite interface 6060 ** routines have been called and that this variable remain unchanged 6061 ** thereafter. 6062 ** 6063 ** ^The [data_store_directory pragma] may modify this variable and cause 6064 ** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 6065 ** the [data_store_directory pragma] always assumes that any string 6066 ** that this variable points to is held in memory obtained from 6067 ** [sqlite3_malloc] and the pragma may attempt to free that memory 6068 ** using [sqlite3_free]. 6069 ** Hence, if this variable is modified directly, either it should be 6070 ** made NULL or made to point to memory obtained from [sqlite3_malloc] 6071 ** or else the use of the [data_store_directory pragma] should be avoided. 6072 */ 6073 SQLITE_API SQLITE_EXTERN char *sqlite3_data_directory; 6074 6075 /* 6076 ** CAPI3REF: Win32 Specific Interface 6077 ** 6078 ** These interfaces are available only on Windows. The 6079 ** [sqlite3_win32_set_directory] interface is used to set the value associated 6080 ** with the [sqlite3_temp_directory] or [sqlite3_data_directory] variable, to 6081 ** zValue, depending on the value of the type parameter. The zValue parameter 6082 ** should be NULL to cause the previous value to be freed via [sqlite3_free]; 6083 ** a non-NULL value will be copied into memory obtained from [sqlite3_malloc] 6084 ** prior to being used. The [sqlite3_win32_set_directory] interface returns 6085 ** [SQLITE_OK] to indicate success, [SQLITE_ERROR] if the type is unsupported, 6086 ** or [SQLITE_NOMEM] if memory could not be allocated. The value of the 6087 ** [sqlite3_data_directory] variable is intended to act as a replacement for 6088 ** the current directory on the sub-platforms of Win32 where that concept is 6089 ** not present, e.g. WinRT and UWP. The [sqlite3_win32_set_directory8] and 6090 ** [sqlite3_win32_set_directory16] interfaces behave exactly the same as the 6091 ** sqlite3_win32_set_directory interface except the string parameter must be 6092 ** UTF-8 or UTF-16, respectively. 6093 */ 6094 SQLITE_API int sqlite3_win32_set_directory( 6095 unsigned long type, /* Identifier for directory being set or reset */ 6096 void *zValue /* New value for directory being set or reset */ 6097 ); 6098 SQLITE_API int sqlite3_win32_set_directory8(unsigned long type, const char *zValue); 6099 SQLITE_API int sqlite3_win32_set_directory16(unsigned long type, const void *zValue); 6100 6101 /* 6102 ** CAPI3REF: Win32 Directory Types 6103 ** 6104 ** These macros are only available on Windows. They define the allowed values 6105 ** for the type argument to the [sqlite3_win32_set_directory] interface. 6106 */ 6107 #define SQLITE_WIN32_DATA_DIRECTORY_TYPE 1 6108 #define SQLITE_WIN32_TEMP_DIRECTORY_TYPE 2 6109 6110 /* 6111 ** CAPI3REF: Test For Auto-Commit Mode 6112 ** KEYWORDS: {autocommit mode} 6113 ** METHOD: sqlite3 6114 ** 6115 ** ^The sqlite3_get_autocommit() interface returns non-zero or 6116 ** zero if the given database connection is or is not in autocommit mode, 6117 ** respectively. ^Autocommit mode is on by default. 6118 ** ^Autocommit mode is disabled by a [BEGIN] statement. 6119 ** ^Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK]. 6120 ** 6121 ** If certain kinds of errors occur on a statement within a multi-statement 6122 ** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR], 6123 ** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the 6124 ** transaction might be rolled back automatically. The only way to 6125 ** find out whether SQLite automatically rolled back the transaction after 6126 ** an error is to use this function. 6127 ** 6128 ** If another thread changes the autocommit status of the database 6129 ** connection while this routine is running, then the return value 6130 ** is undefined. 6131 */ 6132 SQLITE_API int sqlite3_get_autocommit(sqlite3*); 6133 6134 /* 6135 ** CAPI3REF: Find The Database Handle Of A Prepared Statement 6136 ** METHOD: sqlite3_stmt 6137 ** 6138 ** ^The sqlite3_db_handle interface returns the [database connection] handle 6139 ** to which a [prepared statement] belongs. ^The [database connection] 6140 ** returned by sqlite3_db_handle is the same [database connection] 6141 ** that was the first argument 6142 ** to the [sqlite3_prepare_v2()] call (or its variants) that was used to 6143 ** create the statement in the first place. 6144 */ 6145 SQLITE_API sqlite3 *sqlite3_db_handle(sqlite3_stmt*); 6146 6147 /* 6148 ** CAPI3REF: Return The Filename For A Database Connection 6149 ** METHOD: sqlite3 6150 ** 6151 ** ^The sqlite3_db_filename(D,N) interface returns a pointer to the filename 6152 ** associated with database N of connection D. 6153 ** ^If there is no attached database N on the database 6154 ** connection D, or if database N is a temporary or in-memory database, then 6155 ** this function will return either a NULL pointer or an empty string. 6156 ** 6157 ** ^The string value returned by this routine is owned and managed by 6158 ** the database connection. ^The value will be valid until the database N 6159 ** is [DETACH]-ed or until the database connection closes. 6160 ** 6161 ** ^The filename returned by this function is the output of the 6162 ** xFullPathname method of the [VFS]. ^In other words, the filename 6163 ** will be an absolute pathname, even if the filename used 6164 ** to open the database originally was a URI or relative pathname. 6165 ** 6166 ** If the filename pointer returned by this routine is not NULL, then it 6167 ** can be used as the filename input parameter to these routines: 6168 ** <ul> 6169 ** <li> [sqlite3_uri_parameter()] 6170 ** <li> [sqlite3_uri_boolean()] 6171 ** <li> [sqlite3_uri_int64()] 6172 ** <li> [sqlite3_filename_database()] 6173 ** <li> [sqlite3_filename_journal()] 6174 ** <li> [sqlite3_filename_wal()] 6175 ** </ul> 6176 */ 6177 SQLITE_API const char *sqlite3_db_filename(sqlite3 *db, const char *zDbName); 6178 6179 /* 6180 ** CAPI3REF: Determine if a database is read-only 6181 ** METHOD: sqlite3 6182 ** 6183 ** ^The sqlite3_db_readonly(D,N) interface returns 1 if the database N 6184 ** of connection D is read-only, 0 if it is read/write, or -1 if N is not 6185 ** the name of a database on connection D. 6186 */ 6187 SQLITE_API int sqlite3_db_readonly(sqlite3 *db, const char *zDbName); 6188 6189 /* 6190 ** CAPI3REF: Find the next prepared statement 6191 ** METHOD: sqlite3 6192 ** 6193 ** ^This interface returns a pointer to the next [prepared statement] after 6194 ** pStmt associated with the [database connection] pDb. ^If pStmt is NULL 6195 ** then this interface returns a pointer to the first prepared statement 6196 ** associated with the database connection pDb. ^If no prepared statement 6197 ** satisfies the conditions of this routine, it returns NULL. 6198 ** 6199 ** The [database connection] pointer D in a call to 6200 ** [sqlite3_next_stmt(D,S)] must refer to an open database 6201 ** connection and in particular must not be a NULL pointer. 6202 */ 6203 SQLITE_API sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt); 6204 6205 /* 6206 ** CAPI3REF: Commit And Rollback Notification Callbacks 6207 ** METHOD: sqlite3 6208 ** 6209 ** ^The sqlite3_commit_hook() interface registers a callback 6210 ** function to be invoked whenever a transaction is [COMMIT | committed]. 6211 ** ^Any callback set by a previous call to sqlite3_commit_hook() 6212 ** for the same database connection is overridden. 6213 ** ^The sqlite3_rollback_hook() interface registers a callback 6214 ** function to be invoked whenever a transaction is [ROLLBACK | rolled back]. 6215 ** ^Any callback set by a previous call to sqlite3_rollback_hook() 6216 ** for the same database connection is overridden. 6217 ** ^The pArg argument is passed through to the callback. 6218 ** ^If the callback on a commit hook function returns non-zero, 6219 ** then the commit is converted into a rollback. 6220 ** 6221 ** ^The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions 6222 ** return the P argument from the previous call of the same function 6223 ** on the same [database connection] D, or NULL for 6224 ** the first call for each function on D. 6225 ** 6226 ** The commit and rollback hook callbacks are not reentrant. 6227 ** The callback implementation must not do anything that will modify 6228 ** the database connection that invoked the callback. Any actions 6229 ** to modify the database connection must be deferred until after the 6230 ** completion of the [sqlite3_step()] call that triggered the commit 6231 ** or rollback hook in the first place. 6232 ** Note that running any other SQL statements, including SELECT statements, 6233 ** or merely calling [sqlite3_prepare_v2()] and [sqlite3_step()] will modify 6234 ** the database connections for the meaning of "modify" in this paragraph. 6235 ** 6236 ** ^Registering a NULL function disables the callback. 6237 ** 6238 ** ^When the commit hook callback routine returns zero, the [COMMIT] 6239 ** operation is allowed to continue normally. ^If the commit hook 6240 ** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK]. 6241 ** ^The rollback hook is invoked on a rollback that results from a commit 6242 ** hook returning non-zero, just as it would be with any other rollback. 6243 ** 6244 ** ^For the purposes of this API, a transaction is said to have been 6245 ** rolled back if an explicit "ROLLBACK" statement is executed, or 6246 ** an error or constraint causes an implicit rollback to occur. 6247 ** ^The rollback callback is not invoked if a transaction is 6248 ** automatically rolled back because the database connection is closed. 6249 ** 6250 ** See also the [sqlite3_update_hook()] interface. 6251 */ 6252 SQLITE_API void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*); 6253 SQLITE_API void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*); 6254 6255 /* 6256 ** CAPI3REF: Data Change Notification Callbacks 6257 ** METHOD: sqlite3 6258 ** 6259 ** ^The sqlite3_update_hook() interface registers a callback function 6260 ** with the [database connection] identified by the first argument 6261 ** to be invoked whenever a row is updated, inserted or deleted in 6262 ** a [rowid table]. 6263 ** ^Any callback set by a previous call to this function 6264 ** for the same database connection is overridden. 6265 ** 6266 ** ^The second argument is a pointer to the function to invoke when a 6267 ** row is updated, inserted or deleted in a rowid table. 6268 ** ^The first argument to the callback is a copy of the third argument 6269 ** to sqlite3_update_hook(). 6270 ** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE], 6271 ** or [SQLITE_UPDATE], depending on the operation that caused the callback 6272 ** to be invoked. 6273 ** ^The third and fourth arguments to the callback contain pointers to the 6274 ** database and table name containing the affected row. 6275 ** ^The final callback parameter is the [rowid] of the row. 6276 ** ^In the case of an update, this is the [rowid] after the update takes place. 6277 ** 6278 ** ^(The update hook is not invoked when internal system tables are 6279 ** modified (i.e. sqlite_sequence).)^ 6280 ** ^The update hook is not invoked when [WITHOUT ROWID] tables are modified. 6281 ** 6282 ** ^In the current implementation, the update hook 6283 ** is not invoked when conflicting rows are deleted because of an 6284 ** [ON CONFLICT | ON CONFLICT REPLACE] clause. ^Nor is the update hook 6285 ** invoked when rows are deleted using the [truncate optimization]. 6286 ** The exceptions defined in this paragraph might change in a future 6287 ** release of SQLite. 6288 ** 6289 ** The update hook implementation must not do anything that will modify 6290 ** the database connection that invoked the update hook. Any actions 6291 ** to modify the database connection must be deferred until after the 6292 ** completion of the [sqlite3_step()] call that triggered the update hook. 6293 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 6294 ** database connections for the meaning of "modify" in this paragraph. 6295 ** 6296 ** ^The sqlite3_update_hook(D,C,P) function 6297 ** returns the P argument from the previous call 6298 ** on the same [database connection] D, or NULL for 6299 ** the first call on D. 6300 ** 6301 ** See also the [sqlite3_commit_hook()], [sqlite3_rollback_hook()], 6302 ** and [sqlite3_preupdate_hook()] interfaces. 6303 */ 6304 SQLITE_API void *sqlite3_update_hook( 6305 sqlite3*, 6306 void(*)(void *,int ,char const *,char const *,sqlite3_int64), 6307 void* 6308 ); 6309 6310 /* 6311 ** CAPI3REF: Enable Or Disable Shared Pager Cache 6312 ** 6313 ** ^(This routine enables or disables the sharing of the database cache 6314 ** and schema data structures between [database connection | connections] 6315 ** to the same database. Sharing is enabled if the argument is true 6316 ** and disabled if the argument is false.)^ 6317 ** 6318 ** ^Cache sharing is enabled and disabled for an entire process. 6319 ** This is a change as of SQLite [version 3.5.0] ([dateof:3.5.0]). 6320 ** In prior versions of SQLite, 6321 ** sharing was enabled or disabled for each thread separately. 6322 ** 6323 ** ^(The cache sharing mode set by this interface effects all subsequent 6324 ** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()]. 6325 ** Existing database connections continue to use the sharing mode 6326 ** that was in effect at the time they were opened.)^ 6327 ** 6328 ** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled 6329 ** successfully. An [error code] is returned otherwise.)^ 6330 ** 6331 ** ^Shared cache is disabled by default. It is recommended that it stay 6332 ** that way. In other words, do not use this routine. This interface 6333 ** continues to be provided for historical compatibility, but its use is 6334 ** discouraged. Any use of shared cache is discouraged. If shared cache 6335 ** must be used, it is recommended that shared cache only be enabled for 6336 ** individual database connections using the [sqlite3_open_v2()] interface 6337 ** with the [SQLITE_OPEN_SHAREDCACHE] flag. 6338 ** 6339 ** Note: This method is disabled on MacOS X 10.7 and iOS version 5.0 6340 ** and will always return SQLITE_MISUSE. On those systems, 6341 ** shared cache mode should be enabled per-database connection via 6342 ** [sqlite3_open_v2()] with [SQLITE_OPEN_SHAREDCACHE]. 6343 ** 6344 ** This interface is threadsafe on processors where writing a 6345 ** 32-bit integer is atomic. 6346 ** 6347 ** See Also: [SQLite Shared-Cache Mode] 6348 */ 6349 SQLITE_API int sqlite3_enable_shared_cache(int); 6350 6351 /* 6352 ** CAPI3REF: Attempt To Free Heap Memory 6353 ** 6354 ** ^The sqlite3_release_memory() interface attempts to free N bytes 6355 ** of heap memory by deallocating non-essential memory allocations 6356 ** held by the database library. Memory used to cache database 6357 ** pages to improve performance is an example of non-essential memory. 6358 ** ^sqlite3_release_memory() returns the number of bytes actually freed, 6359 ** which might be more or less than the amount requested. 6360 ** ^The sqlite3_release_memory() routine is a no-op returning zero 6361 ** if SQLite is not compiled with [SQLITE_ENABLE_MEMORY_MANAGEMENT]. 6362 ** 6363 ** See also: [sqlite3_db_release_memory()] 6364 */ 6365 SQLITE_API int sqlite3_release_memory(int); 6366 6367 /* 6368 ** CAPI3REF: Free Memory Used By A Database Connection 6369 ** METHOD: sqlite3 6370 ** 6371 ** ^The sqlite3_db_release_memory(D) interface attempts to free as much heap 6372 ** memory as possible from database connection D. Unlike the 6373 ** [sqlite3_release_memory()] interface, this interface is in effect even 6374 ** when the [SQLITE_ENABLE_MEMORY_MANAGEMENT] compile-time option is 6375 ** omitted. 6376 ** 6377 ** See also: [sqlite3_release_memory()] 6378 */ 6379 SQLITE_API int sqlite3_db_release_memory(sqlite3*); 6380 6381 /* 6382 ** CAPI3REF: Impose A Limit On Heap Size 6383 ** 6384 ** These interfaces impose limits on the amount of heap memory that will be 6385 ** by all database connections within a single process. 6386 ** 6387 ** ^The sqlite3_soft_heap_limit64() interface sets and/or queries the 6388 ** soft limit on the amount of heap memory that may be allocated by SQLite. 6389 ** ^SQLite strives to keep heap memory utilization below the soft heap 6390 ** limit by reducing the number of pages held in the page cache 6391 ** as heap memory usages approaches the limit. 6392 ** ^The soft heap limit is "soft" because even though SQLite strives to stay 6393 ** below the limit, it will exceed the limit rather than generate 6394 ** an [SQLITE_NOMEM] error. In other words, the soft heap limit 6395 ** is advisory only. 6396 ** 6397 ** ^The sqlite3_hard_heap_limit64(N) interface sets a hard upper bound of 6398 ** N bytes on the amount of memory that will be allocated. ^The 6399 ** sqlite3_hard_heap_limit64(N) interface is similar to 6400 ** sqlite3_soft_heap_limit64(N) except that memory allocations will fail 6401 ** when the hard heap limit is reached. 6402 ** 6403 ** ^The return value from both sqlite3_soft_heap_limit64() and 6404 ** sqlite3_hard_heap_limit64() is the size of 6405 ** the heap limit prior to the call, or negative in the case of an 6406 ** error. ^If the argument N is negative 6407 ** then no change is made to the heap limit. Hence, the current 6408 ** size of heap limits can be determined by invoking 6409 ** sqlite3_soft_heap_limit64(-1) or sqlite3_hard_heap_limit(-1). 6410 ** 6411 ** ^Setting the heap limits to zero disables the heap limiter mechanism. 6412 ** 6413 ** ^The soft heap limit may not be greater than the hard heap limit. 6414 ** ^If the hard heap limit is enabled and if sqlite3_soft_heap_limit(N) 6415 ** is invoked with a value of N that is greater than the hard heap limit, 6416 ** the the soft heap limit is set to the value of the hard heap limit. 6417 ** ^The soft heap limit is automatically enabled whenever the hard heap 6418 ** limit is enabled. ^When sqlite3_hard_heap_limit64(N) is invoked and 6419 ** the soft heap limit is outside the range of 1..N, then the soft heap 6420 ** limit is set to N. ^Invoking sqlite3_soft_heap_limit64(0) when the 6421 ** hard heap limit is enabled makes the soft heap limit equal to the 6422 ** hard heap limit. 6423 ** 6424 ** The memory allocation limits can also be adjusted using 6425 ** [PRAGMA soft_heap_limit] and [PRAGMA hard_heap_limit]. 6426 ** 6427 ** ^(The heap limits are not enforced in the current implementation 6428 ** if one or more of following conditions are true: 6429 ** 6430 ** <ul> 6431 ** <li> The limit value is set to zero. 6432 ** <li> Memory accounting is disabled using a combination of the 6433 ** [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],...) start-time option and 6434 ** the [SQLITE_DEFAULT_MEMSTATUS] compile-time option. 6435 ** <li> An alternative page cache implementation is specified using 6436 ** [sqlite3_config]([SQLITE_CONFIG_PCACHE2],...). 6437 ** <li> The page cache allocates from its own memory pool supplied 6438 ** by [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],...) rather than 6439 ** from the heap. 6440 ** </ul>)^ 6441 ** 6442 ** The circumstances under which SQLite will enforce the heap limits may 6443 ** changes in future releases of SQLite. 6444 */ 6445 SQLITE_API sqlite3_int64 sqlite3_soft_heap_limit64(sqlite3_int64 N); 6446 SQLITE_API sqlite3_int64 sqlite3_hard_heap_limit64(sqlite3_int64 N); 6447 6448 /* 6449 ** CAPI3REF: Deprecated Soft Heap Limit Interface 6450 ** DEPRECATED 6451 ** 6452 ** This is a deprecated version of the [sqlite3_soft_heap_limit64()] 6453 ** interface. This routine is provided for historical compatibility 6454 ** only. All new applications should use the 6455 ** [sqlite3_soft_heap_limit64()] interface rather than this one. 6456 */ 6457 SQLITE_API SQLITE_DEPRECATED void sqlite3_soft_heap_limit(int N); 6458 6459 6460 /* 6461 ** CAPI3REF: Extract Metadata About A Column Of A Table 6462 ** METHOD: sqlite3 6463 ** 6464 ** ^(The sqlite3_table_column_metadata(X,D,T,C,....) routine returns 6465 ** information about column C of table T in database D 6466 ** on [database connection] X.)^ ^The sqlite3_table_column_metadata() 6467 ** interface returns SQLITE_OK and fills in the non-NULL pointers in 6468 ** the final five arguments with appropriate values if the specified 6469 ** column exists. ^The sqlite3_table_column_metadata() interface returns 6470 ** SQLITE_ERROR if the specified column does not exist. 6471 ** ^If the column-name parameter to sqlite3_table_column_metadata() is a 6472 ** NULL pointer, then this routine simply checks for the existence of the 6473 ** table and returns SQLITE_OK if the table exists and SQLITE_ERROR if it 6474 ** does not. If the table name parameter T in a call to 6475 ** sqlite3_table_column_metadata(X,D,T,C,...) is NULL then the result is 6476 ** undefined behavior. 6477 ** 6478 ** ^The column is identified by the second, third and fourth parameters to 6479 ** this function. ^(The second parameter is either the name of the database 6480 ** (i.e. "main", "temp", or an attached database) containing the specified 6481 ** table or NULL.)^ ^If it is NULL, then all attached databases are searched 6482 ** for the table using the same algorithm used by the database engine to 6483 ** resolve unqualified table references. 6484 ** 6485 ** ^The third and fourth parameters to this function are the table and column 6486 ** name of the desired column, respectively. 6487 ** 6488 ** ^Metadata is returned by writing to the memory locations passed as the 5th 6489 ** and subsequent parameters to this function. ^Any of these arguments may be 6490 ** NULL, in which case the corresponding element of metadata is omitted. 6491 ** 6492 ** ^(<blockquote> 6493 ** <table border="1"> 6494 ** <tr><th> Parameter <th> Output<br>Type <th> Description 6495 ** 6496 ** <tr><td> 5th <td> const char* <td> Data type 6497 ** <tr><td> 6th <td> const char* <td> Name of default collation sequence 6498 ** <tr><td> 7th <td> int <td> True if column has a NOT NULL constraint 6499 ** <tr><td> 8th <td> int <td> True if column is part of the PRIMARY KEY 6500 ** <tr><td> 9th <td> int <td> True if column is [AUTOINCREMENT] 6501 ** </table> 6502 ** </blockquote>)^ 6503 ** 6504 ** ^The memory pointed to by the character pointers returned for the 6505 ** declaration type and collation sequence is valid until the next 6506 ** call to any SQLite API function. 6507 ** 6508 ** ^If the specified table is actually a view, an [error code] is returned. 6509 ** 6510 ** ^If the specified column is "rowid", "oid" or "_rowid_" and the table 6511 ** is not a [WITHOUT ROWID] table and an 6512 ** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output 6513 ** parameters are set for the explicitly declared column. ^(If there is no 6514 ** [INTEGER PRIMARY KEY] column, then the outputs 6515 ** for the [rowid] are set as follows: 6516 ** 6517 ** <pre> 6518 ** data type: "INTEGER" 6519 ** collation sequence: "BINARY" 6520 ** not null: 0 6521 ** primary key: 1 6522 ** auto increment: 0 6523 ** </pre>)^ 6524 ** 6525 ** ^This function causes all database schemas to be read from disk and 6526 ** parsed, if that has not already been done, and returns an error if 6527 ** any errors are encountered while loading the schema. 6528 */ 6529 SQLITE_API int sqlite3_table_column_metadata( 6530 sqlite3 *db, /* Connection handle */ 6531 const char *zDbName, /* Database name or NULL */ 6532 const char *zTableName, /* Table name */ 6533 const char *zColumnName, /* Column name */ 6534 char const **pzDataType, /* OUTPUT: Declared data type */ 6535 char const **pzCollSeq, /* OUTPUT: Collation sequence name */ 6536 int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */ 6537 int *pPrimaryKey, /* OUTPUT: True if column part of PK */ 6538 int *pAutoinc /* OUTPUT: True if column is auto-increment */ 6539 ); 6540 6541 /* 6542 ** CAPI3REF: Load An Extension 6543 ** METHOD: sqlite3 6544 ** 6545 ** ^This interface loads an SQLite extension library from the named file. 6546 ** 6547 ** ^The sqlite3_load_extension() interface attempts to load an 6548 ** [SQLite extension] library contained in the file zFile. If 6549 ** the file cannot be loaded directly, attempts are made to load 6550 ** with various operating-system specific extensions added. 6551 ** So for example, if "samplelib" cannot be loaded, then names like 6552 ** "samplelib.so" or "samplelib.dylib" or "samplelib.dll" might 6553 ** be tried also. 6554 ** 6555 ** ^The entry point is zProc. 6556 ** ^(zProc may be 0, in which case SQLite will try to come up with an 6557 ** entry point name on its own. It first tries "sqlite3_extension_init". 6558 ** If that does not work, it constructs a name "sqlite3_X_init" where the 6559 ** X is consists of the lower-case equivalent of all ASCII alphabetic 6560 ** characters in the filename from the last "/" to the first following 6561 ** "." and omitting any initial "lib".)^ 6562 ** ^The sqlite3_load_extension() interface returns 6563 ** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong. 6564 ** ^If an error occurs and pzErrMsg is not 0, then the 6565 ** [sqlite3_load_extension()] interface shall attempt to 6566 ** fill *pzErrMsg with error message text stored in memory 6567 ** obtained from [sqlite3_malloc()]. The calling function 6568 ** should free this memory by calling [sqlite3_free()]. 6569 ** 6570 ** ^Extension loading must be enabled using 6571 ** [sqlite3_enable_load_extension()] or 6572 ** [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],1,NULL) 6573 ** prior to calling this API, 6574 ** otherwise an error will be returned. 6575 ** 6576 ** <b>Security warning:</b> It is recommended that the 6577 ** [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method be used to enable only this 6578 ** interface. The use of the [sqlite3_enable_load_extension()] interface 6579 ** should be avoided. This will keep the SQL function [load_extension()] 6580 ** disabled and prevent SQL injections from giving attackers 6581 ** access to extension loading capabilities. 6582 ** 6583 ** See also the [load_extension() SQL function]. 6584 */ 6585 SQLITE_API int sqlite3_load_extension( 6586 sqlite3 *db, /* Load the extension into this database connection */ 6587 const char *zFile, /* Name of the shared library containing extension */ 6588 const char *zProc, /* Entry point. Derived from zFile if 0 */ 6589 char **pzErrMsg /* Put error message here if not 0 */ 6590 ); 6591 6592 /* 6593 ** CAPI3REF: Enable Or Disable Extension Loading 6594 ** METHOD: sqlite3 6595 ** 6596 ** ^So as not to open security holes in older applications that are 6597 ** unprepared to deal with [extension loading], and as a means of disabling 6598 ** [extension loading] while evaluating user-entered SQL, the following API 6599 ** is provided to turn the [sqlite3_load_extension()] mechanism on and off. 6600 ** 6601 ** ^Extension loading is off by default. 6602 ** ^Call the sqlite3_enable_load_extension() routine with onoff==1 6603 ** to turn extension loading on and call it with onoff==0 to turn 6604 ** it back off again. 6605 ** 6606 ** ^This interface enables or disables both the C-API 6607 ** [sqlite3_load_extension()] and the SQL function [load_extension()]. 6608 ** ^(Use [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],..) 6609 ** to enable or disable only the C-API.)^ 6610 ** 6611 ** <b>Security warning:</b> It is recommended that extension loading 6612 ** be enabled using the [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method 6613 ** rather than this interface, so the [load_extension()] SQL function 6614 ** remains disabled. This will prevent SQL injections from giving attackers 6615 ** access to extension loading capabilities. 6616 */ 6617 SQLITE_API int sqlite3_enable_load_extension(sqlite3 *db, int onoff); 6618 6619 /* 6620 ** CAPI3REF: Automatically Load Statically Linked Extensions 6621 ** 6622 ** ^This interface causes the xEntryPoint() function to be invoked for 6623 ** each new [database connection] that is created. The idea here is that 6624 ** xEntryPoint() is the entry point for a statically linked [SQLite extension] 6625 ** that is to be automatically loaded into all new database connections. 6626 ** 6627 ** ^(Even though the function prototype shows that xEntryPoint() takes 6628 ** no arguments and returns void, SQLite invokes xEntryPoint() with three 6629 ** arguments and expects an integer result as if the signature of the 6630 ** entry point where as follows: 6631 ** 6632 ** <blockquote><pre> 6633 ** int xEntryPoint( 6634 ** sqlite3 *db, 6635 ** const char **pzErrMsg, 6636 ** const struct sqlite3_api_routines *pThunk 6637 ** ); 6638 ** </pre></blockquote>)^ 6639 ** 6640 ** If the xEntryPoint routine encounters an error, it should make *pzErrMsg 6641 ** point to an appropriate error message (obtained from [sqlite3_mprintf()]) 6642 ** and return an appropriate [error code]. ^SQLite ensures that *pzErrMsg 6643 ** is NULL before calling the xEntryPoint(). ^SQLite will invoke 6644 ** [sqlite3_free()] on *pzErrMsg after xEntryPoint() returns. ^If any 6645 ** xEntryPoint() returns an error, the [sqlite3_open()], [sqlite3_open16()], 6646 ** or [sqlite3_open_v2()] call that provoked the xEntryPoint() will fail. 6647 ** 6648 ** ^Calling sqlite3_auto_extension(X) with an entry point X that is already 6649 ** on the list of automatic extensions is a harmless no-op. ^No entry point 6650 ** will be called more than once for each database connection that is opened. 6651 ** 6652 ** See also: [sqlite3_reset_auto_extension()] 6653 ** and [sqlite3_cancel_auto_extension()] 6654 */ 6655 SQLITE_API int sqlite3_auto_extension(void(*xEntryPoint)(void)); 6656 6657 /* 6658 ** CAPI3REF: Cancel Automatic Extension Loading 6659 ** 6660 ** ^The [sqlite3_cancel_auto_extension(X)] interface unregisters the 6661 ** initialization routine X that was registered using a prior call to 6662 ** [sqlite3_auto_extension(X)]. ^The [sqlite3_cancel_auto_extension(X)] 6663 ** routine returns 1 if initialization routine X was successfully 6664 ** unregistered and it returns 0 if X was not on the list of initialization 6665 ** routines. 6666 */ 6667 SQLITE_API int sqlite3_cancel_auto_extension(void(*xEntryPoint)(void)); 6668 6669 /* 6670 ** CAPI3REF: Reset Automatic Extension Loading 6671 ** 6672 ** ^This interface disables all automatic extensions previously 6673 ** registered using [sqlite3_auto_extension()]. 6674 */ 6675 SQLITE_API void sqlite3_reset_auto_extension(void); 6676 6677 /* 6678 ** The interface to the virtual-table mechanism is currently considered 6679 ** to be experimental. The interface might change in incompatible ways. 6680 ** If this is a problem for you, do not use the interface at this time. 6681 ** 6682 ** When the virtual-table mechanism stabilizes, we will declare the 6683 ** interface fixed, support it indefinitely, and remove this comment. 6684 */ 6685 6686 /* 6687 ** Structures used by the virtual table interface 6688 */ 6689 typedef struct sqlite3_vtab sqlite3_vtab; 6690 typedef struct sqlite3_index_info sqlite3_index_info; 6691 typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor; 6692 typedef struct sqlite3_module sqlite3_module; 6693 6694 /* 6695 ** CAPI3REF: Virtual Table Object 6696 ** KEYWORDS: sqlite3_module {virtual table module} 6697 ** 6698 ** This structure, sometimes called a "virtual table module", 6699 ** defines the implementation of a [virtual table]. 6700 ** This structure consists mostly of methods for the module. 6701 ** 6702 ** ^A virtual table module is created by filling in a persistent 6703 ** instance of this structure and passing a pointer to that instance 6704 ** to [sqlite3_create_module()] or [sqlite3_create_module_v2()]. 6705 ** ^The registration remains valid until it is replaced by a different 6706 ** module or until the [database connection] closes. The content 6707 ** of this structure must not change while it is registered with 6708 ** any database connection. 6709 */ 6710 struct sqlite3_module { 6711 int iVersion; 6712 int (*xCreate)(sqlite3*, void *pAux, 6713 int argc, const char *const*argv, 6714 sqlite3_vtab **ppVTab, char**); 6715 int (*xConnect)(sqlite3*, void *pAux, 6716 int argc, const char *const*argv, 6717 sqlite3_vtab **ppVTab, char**); 6718 int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*); 6719 int (*xDisconnect)(sqlite3_vtab *pVTab); 6720 int (*xDestroy)(sqlite3_vtab *pVTab); 6721 int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor); 6722 int (*xClose)(sqlite3_vtab_cursor*); 6723 int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr, 6724 int argc, sqlite3_value **argv); 6725 int (*xNext)(sqlite3_vtab_cursor*); 6726 int (*xEof)(sqlite3_vtab_cursor*); 6727 int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int); 6728 int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid); 6729 int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *); 6730 int (*xBegin)(sqlite3_vtab *pVTab); 6731 int (*xSync)(sqlite3_vtab *pVTab); 6732 int (*xCommit)(sqlite3_vtab *pVTab); 6733 int (*xRollback)(sqlite3_vtab *pVTab); 6734 int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName, 6735 void (**pxFunc)(sqlite3_context*,int,sqlite3_value**), 6736 void **ppArg); 6737 int (*xRename)(sqlite3_vtab *pVtab, const char *zNew); 6738 /* The methods above are in version 1 of the sqlite_module object. Those 6739 ** below are for version 2 and greater. */ 6740 int (*xSavepoint)(sqlite3_vtab *pVTab, int); 6741 int (*xRelease)(sqlite3_vtab *pVTab, int); 6742 int (*xRollbackTo)(sqlite3_vtab *pVTab, int); 6743 /* The methods above are in versions 1 and 2 of the sqlite_module object. 6744 ** Those below are for version 3 and greater. */ 6745 int (*xShadowName)(const char*); 6746 }; 6747 6748 /* 6749 ** CAPI3REF: Virtual Table Indexing Information 6750 ** KEYWORDS: sqlite3_index_info 6751 ** 6752 ** The sqlite3_index_info structure and its substructures is used as part 6753 ** of the [virtual table] interface to 6754 ** pass information into and receive the reply from the [xBestIndex] 6755 ** method of a [virtual table module]. The fields under **Inputs** are the 6756 ** inputs to xBestIndex and are read-only. xBestIndex inserts its 6757 ** results into the **Outputs** fields. 6758 ** 6759 ** ^(The aConstraint[] array records WHERE clause constraints of the form: 6760 ** 6761 ** <blockquote>column OP expr</blockquote> 6762 ** 6763 ** where OP is =, <, <=, >, or >=.)^ ^(The particular operator is 6764 ** stored in aConstraint[].op using one of the 6765 ** [SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_ values].)^ 6766 ** ^(The index of the column is stored in 6767 ** aConstraint[].iColumn.)^ ^(aConstraint[].usable is TRUE if the 6768 ** expr on the right-hand side can be evaluated (and thus the constraint 6769 ** is usable) and false if it cannot.)^ 6770 ** 6771 ** ^The optimizer automatically inverts terms of the form "expr OP column" 6772 ** and makes other simplifications to the WHERE clause in an attempt to 6773 ** get as many WHERE clause terms into the form shown above as possible. 6774 ** ^The aConstraint[] array only reports WHERE clause terms that are 6775 ** relevant to the particular virtual table being queried. 6776 ** 6777 ** ^Information about the ORDER BY clause is stored in aOrderBy[]. 6778 ** ^Each term of aOrderBy records a column of the ORDER BY clause. 6779 ** 6780 ** The colUsed field indicates which columns of the virtual table may be 6781 ** required by the current scan. Virtual table columns are numbered from 6782 ** zero in the order in which they appear within the CREATE TABLE statement 6783 ** passed to sqlite3_declare_vtab(). For the first 63 columns (columns 0-62), 6784 ** the corresponding bit is set within the colUsed mask if the column may be 6785 ** required by SQLite. If the table has at least 64 columns and any column 6786 ** to the right of the first 63 is required, then bit 63 of colUsed is also 6787 ** set. In other words, column iCol may be required if the expression 6788 ** (colUsed & ((sqlite3_uint64)1 << (iCol>=63 ? 63 : iCol))) evaluates to 6789 ** non-zero. 6790 ** 6791 ** The [xBestIndex] method must fill aConstraintUsage[] with information 6792 ** about what parameters to pass to xFilter. ^If argvIndex>0 then 6793 ** the right-hand side of the corresponding aConstraint[] is evaluated 6794 ** and becomes the argvIndex-th entry in argv. ^(If aConstraintUsage[].omit 6795 ** is true, then the constraint is assumed to be fully handled by the 6796 ** virtual table and might not be checked again by the byte code.)^ ^(The 6797 ** aConstraintUsage[].omit flag is an optimization hint. When the omit flag 6798 ** is left in its default setting of false, the constraint will always be 6799 ** checked separately in byte code. If the omit flag is change to true, then 6800 ** the constraint may or may not be checked in byte code. In other words, 6801 ** when the omit flag is true there is no guarantee that the constraint will 6802 ** not be checked again using byte code.)^ 6803 ** 6804 ** ^The idxNum and idxPtr values are recorded and passed into the 6805 ** [xFilter] method. 6806 ** ^[sqlite3_free()] is used to free idxPtr if and only if 6807 ** needToFreeIdxPtr is true. 6808 ** 6809 ** ^The orderByConsumed means that output from [xFilter]/[xNext] will occur in 6810 ** the correct order to satisfy the ORDER BY clause so that no separate 6811 ** sorting step is required. 6812 ** 6813 ** ^The estimatedCost value is an estimate of the cost of a particular 6814 ** strategy. A cost of N indicates that the cost of the strategy is similar 6815 ** to a linear scan of an SQLite table with N rows. A cost of log(N) 6816 ** indicates that the expense of the operation is similar to that of a 6817 ** binary search on a unique indexed field of an SQLite table with N rows. 6818 ** 6819 ** ^The estimatedRows value is an estimate of the number of rows that 6820 ** will be returned by the strategy. 6821 ** 6822 ** The xBestIndex method may optionally populate the idxFlags field with a 6823 ** mask of SQLITE_INDEX_SCAN_* flags. Currently there is only one such flag - 6824 ** SQLITE_INDEX_SCAN_UNIQUE. If the xBestIndex method sets this flag, SQLite 6825 ** assumes that the strategy may visit at most one row. 6826 ** 6827 ** Additionally, if xBestIndex sets the SQLITE_INDEX_SCAN_UNIQUE flag, then 6828 ** SQLite also assumes that if a call to the xUpdate() method is made as 6829 ** part of the same statement to delete or update a virtual table row and the 6830 ** implementation returns SQLITE_CONSTRAINT, then there is no need to rollback 6831 ** any database changes. In other words, if the xUpdate() returns 6832 ** SQLITE_CONSTRAINT, the database contents must be exactly as they were 6833 ** before xUpdate was called. By contrast, if SQLITE_INDEX_SCAN_UNIQUE is not 6834 ** set and xUpdate returns SQLITE_CONSTRAINT, any database changes made by 6835 ** the xUpdate method are automatically rolled back by SQLite. 6836 ** 6837 ** IMPORTANT: The estimatedRows field was added to the sqlite3_index_info 6838 ** structure for SQLite [version 3.8.2] ([dateof:3.8.2]). 6839 ** If a virtual table extension is 6840 ** used with an SQLite version earlier than 3.8.2, the results of attempting 6841 ** to read or write the estimatedRows field are undefined (but are likely 6842 ** to include crashing the application). The estimatedRows field should 6843 ** therefore only be used if [sqlite3_libversion_number()] returns a 6844 ** value greater than or equal to 3008002. Similarly, the idxFlags field 6845 ** was added for [version 3.9.0] ([dateof:3.9.0]). 6846 ** It may therefore only be used if 6847 ** sqlite3_libversion_number() returns a value greater than or equal to 6848 ** 3009000. 6849 */ 6850 struct sqlite3_index_info { 6851 /* Inputs */ 6852 int nConstraint; /* Number of entries in aConstraint */ 6853 struct sqlite3_index_constraint { 6854 int iColumn; /* Column constrained. -1 for ROWID */ 6855 unsigned char op; /* Constraint operator */ 6856 unsigned char usable; /* True if this constraint is usable */ 6857 int iTermOffset; /* Used internally - xBestIndex should ignore */ 6858 } *aConstraint; /* Table of WHERE clause constraints */ 6859 int nOrderBy; /* Number of terms in the ORDER BY clause */ 6860 struct sqlite3_index_orderby { 6861 int iColumn; /* Column number */ 6862 unsigned char desc; /* True for DESC. False for ASC. */ 6863 } *aOrderBy; /* The ORDER BY clause */ 6864 /* Outputs */ 6865 struct sqlite3_index_constraint_usage { 6866 int argvIndex; /* if >0, constraint is part of argv to xFilter */ 6867 unsigned char omit; /* Do not code a test for this constraint */ 6868 } *aConstraintUsage; 6869 int idxNum; /* Number used to identify the index */ 6870 char *idxStr; /* String, possibly obtained from sqlite3_malloc */ 6871 int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */ 6872 int orderByConsumed; /* True if output is already ordered */ 6873 double estimatedCost; /* Estimated cost of using this index */ 6874 /* Fields below are only available in SQLite 3.8.2 and later */ 6875 sqlite3_int64 estimatedRows; /* Estimated number of rows returned */ 6876 /* Fields below are only available in SQLite 3.9.0 and later */ 6877 int idxFlags; /* Mask of SQLITE_INDEX_SCAN_* flags */ 6878 /* Fields below are only available in SQLite 3.10.0 and later */ 6879 sqlite3_uint64 colUsed; /* Input: Mask of columns used by statement */ 6880 }; 6881 6882 /* 6883 ** CAPI3REF: Virtual Table Scan Flags 6884 ** 6885 ** Virtual table implementations are allowed to set the 6886 ** [sqlite3_index_info].idxFlags field to some combination of 6887 ** these bits. 6888 */ 6889 #define SQLITE_INDEX_SCAN_UNIQUE 1 /* Scan visits at most 1 row */ 6890 6891 /* 6892 ** CAPI3REF: Virtual Table Constraint Operator Codes 6893 ** 6894 ** These macros define the allowed values for the 6895 ** [sqlite3_index_info].aConstraint[].op field. Each value represents 6896 ** an operator that is part of a constraint term in the wHERE clause of 6897 ** a query that uses a [virtual table]. 6898 */ 6899 #define SQLITE_INDEX_CONSTRAINT_EQ 2 6900 #define SQLITE_INDEX_CONSTRAINT_GT 4 6901 #define SQLITE_INDEX_CONSTRAINT_LE 8 6902 #define SQLITE_INDEX_CONSTRAINT_LT 16 6903 #define SQLITE_INDEX_CONSTRAINT_GE 32 6904 #define SQLITE_INDEX_CONSTRAINT_MATCH 64 6905 #define SQLITE_INDEX_CONSTRAINT_LIKE 65 6906 #define SQLITE_INDEX_CONSTRAINT_GLOB 66 6907 #define SQLITE_INDEX_CONSTRAINT_REGEXP 67 6908 #define SQLITE_INDEX_CONSTRAINT_NE 68 6909 #define SQLITE_INDEX_CONSTRAINT_ISNOT 69 6910 #define SQLITE_INDEX_CONSTRAINT_ISNOTNULL 70 6911 #define SQLITE_INDEX_CONSTRAINT_ISNULL 71 6912 #define SQLITE_INDEX_CONSTRAINT_IS 72 6913 #define SQLITE_INDEX_CONSTRAINT_FUNCTION 150 6914 6915 /* 6916 ** CAPI3REF: Register A Virtual Table Implementation 6917 ** METHOD: sqlite3 6918 ** 6919 ** ^These routines are used to register a new [virtual table module] name. 6920 ** ^Module names must be registered before 6921 ** creating a new [virtual table] using the module and before using a 6922 ** preexisting [virtual table] for the module. 6923 ** 6924 ** ^The module name is registered on the [database connection] specified 6925 ** by the first parameter. ^The name of the module is given by the 6926 ** second parameter. ^The third parameter is a pointer to 6927 ** the implementation of the [virtual table module]. ^The fourth 6928 ** parameter is an arbitrary client data pointer that is passed through 6929 ** into the [xCreate] and [xConnect] methods of the virtual table module 6930 ** when a new virtual table is be being created or reinitialized. 6931 ** 6932 ** ^The sqlite3_create_module_v2() interface has a fifth parameter which 6933 ** is a pointer to a destructor for the pClientData. ^SQLite will 6934 ** invoke the destructor function (if it is not NULL) when SQLite 6935 ** no longer needs the pClientData pointer. ^The destructor will also 6936 ** be invoked if the call to sqlite3_create_module_v2() fails. 6937 ** ^The sqlite3_create_module() 6938 ** interface is equivalent to sqlite3_create_module_v2() with a NULL 6939 ** destructor. 6940 ** 6941 ** ^If the third parameter (the pointer to the sqlite3_module object) is 6942 ** NULL then no new module is create and any existing modules with the 6943 ** same name are dropped. 6944 ** 6945 ** See also: [sqlite3_drop_modules()] 6946 */ 6947 SQLITE_API int sqlite3_create_module( 6948 sqlite3 *db, /* SQLite connection to register module with */ 6949 const char *zName, /* Name of the module */ 6950 const sqlite3_module *p, /* Methods for the module */ 6951 void *pClientData /* Client data for xCreate/xConnect */ 6952 ); 6953 SQLITE_API int sqlite3_create_module_v2( 6954 sqlite3 *db, /* SQLite connection to register module with */ 6955 const char *zName, /* Name of the module */ 6956 const sqlite3_module *p, /* Methods for the module */ 6957 void *pClientData, /* Client data for xCreate/xConnect */ 6958 void(*xDestroy)(void*) /* Module destructor function */ 6959 ); 6960 6961 /* 6962 ** CAPI3REF: Remove Unnecessary Virtual Table Implementations 6963 ** METHOD: sqlite3 6964 ** 6965 ** ^The sqlite3_drop_modules(D,L) interface removes all virtual 6966 ** table modules from database connection D except those named on list L. 6967 ** The L parameter must be either NULL or a pointer to an array of pointers 6968 ** to strings where the array is terminated by a single NULL pointer. 6969 ** ^If the L parameter is NULL, then all virtual table modules are removed. 6970 ** 6971 ** See also: [sqlite3_create_module()] 6972 */ 6973 SQLITE_API int sqlite3_drop_modules( 6974 sqlite3 *db, /* Remove modules from this connection */ 6975 const char **azKeep /* Except, do not remove the ones named here */ 6976 ); 6977 6978 /* 6979 ** CAPI3REF: Virtual Table Instance Object 6980 ** KEYWORDS: sqlite3_vtab 6981 ** 6982 ** Every [virtual table module] implementation uses a subclass 6983 ** of this object to describe a particular instance 6984 ** of the [virtual table]. Each subclass will 6985 ** be tailored to the specific needs of the module implementation. 6986 ** The purpose of this superclass is to define certain fields that are 6987 ** common to all module implementations. 6988 ** 6989 ** ^Virtual tables methods can set an error message by assigning a 6990 ** string obtained from [sqlite3_mprintf()] to zErrMsg. The method should 6991 ** take care that any prior string is freed by a call to [sqlite3_free()] 6992 ** prior to assigning a new string to zErrMsg. ^After the error message 6993 ** is delivered up to the client application, the string will be automatically 6994 ** freed by sqlite3_free() and the zErrMsg field will be zeroed. 6995 */ 6996 struct sqlite3_vtab { 6997 const sqlite3_module *pModule; /* The module for this virtual table */ 6998 int nRef; /* Number of open cursors */ 6999 char *zErrMsg; /* Error message from sqlite3_mprintf() */ 7000 /* Virtual table implementations will typically add additional fields */ 7001 }; 7002 7003 /* 7004 ** CAPI3REF: Virtual Table Cursor Object 7005 ** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor} 7006 ** 7007 ** Every [virtual table module] implementation uses a subclass of the 7008 ** following structure to describe cursors that point into the 7009 ** [virtual table] and are used 7010 ** to loop through the virtual table. Cursors are created using the 7011 ** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed 7012 ** by the [sqlite3_module.xClose | xClose] method. Cursors are used 7013 ** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods 7014 ** of the module. Each module implementation will define 7015 ** the content of a cursor structure to suit its own needs. 7016 ** 7017 ** This superclass exists in order to define fields of the cursor that 7018 ** are common to all implementations. 7019 */ 7020 struct sqlite3_vtab_cursor { 7021 sqlite3_vtab *pVtab; /* Virtual table of this cursor */ 7022 /* Virtual table implementations will typically add additional fields */ 7023 }; 7024 7025 /* 7026 ** CAPI3REF: Declare The Schema Of A Virtual Table 7027 ** 7028 ** ^The [xCreate] and [xConnect] methods of a 7029 ** [virtual table module] call this interface 7030 ** to declare the format (the names and datatypes of the columns) of 7031 ** the virtual tables they implement. 7032 */ 7033 SQLITE_API int sqlite3_declare_vtab(sqlite3*, const char *zSQL); 7034 7035 /* 7036 ** CAPI3REF: Overload A Function For A Virtual Table 7037 ** METHOD: sqlite3 7038 ** 7039 ** ^(Virtual tables can provide alternative implementations of functions 7040 ** using the [xFindFunction] method of the [virtual table module]. 7041 ** But global versions of those functions 7042 ** must exist in order to be overloaded.)^ 7043 ** 7044 ** ^(This API makes sure a global version of a function with a particular 7045 ** name and number of parameters exists. If no such function exists 7046 ** before this API is called, a new function is created.)^ ^The implementation 7047 ** of the new function always causes an exception to be thrown. So 7048 ** the new function is not good for anything by itself. Its only 7049 ** purpose is to be a placeholder function that can be overloaded 7050 ** by a [virtual table]. 7051 */ 7052 SQLITE_API int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg); 7053 7054 /* 7055 ** The interface to the virtual-table mechanism defined above (back up 7056 ** to a comment remarkably similar to this one) is currently considered 7057 ** to be experimental. The interface might change in incompatible ways. 7058 ** If this is a problem for you, do not use the interface at this time. 7059 ** 7060 ** When the virtual-table mechanism stabilizes, we will declare the 7061 ** interface fixed, support it indefinitely, and remove this comment. 7062 */ 7063 7064 /* 7065 ** CAPI3REF: A Handle To An Open BLOB 7066 ** KEYWORDS: {BLOB handle} {BLOB handles} 7067 ** 7068 ** An instance of this object represents an open BLOB on which 7069 ** [sqlite3_blob_open | incremental BLOB I/O] can be performed. 7070 ** ^Objects of this type are created by [sqlite3_blob_open()] 7071 ** and destroyed by [sqlite3_blob_close()]. 7072 ** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces 7073 ** can be used to read or write small subsections of the BLOB. 7074 ** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes. 7075 */ 7076 typedef struct sqlite3_blob sqlite3_blob; 7077 7078 /* 7079 ** CAPI3REF: Open A BLOB For Incremental I/O 7080 ** METHOD: sqlite3 7081 ** CONSTRUCTOR: sqlite3_blob 7082 ** 7083 ** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located 7084 ** in row iRow, column zColumn, table zTable in database zDb; 7085 ** in other words, the same BLOB that would be selected by: 7086 ** 7087 ** <pre> 7088 ** SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow; 7089 ** </pre>)^ 7090 ** 7091 ** ^(Parameter zDb is not the filename that contains the database, but 7092 ** rather the symbolic name of the database. For attached databases, this is 7093 ** the name that appears after the AS keyword in the [ATTACH] statement. 7094 ** For the main database file, the database name is "main". For TEMP 7095 ** tables, the database name is "temp".)^ 7096 ** 7097 ** ^If the flags parameter is non-zero, then the BLOB is opened for read 7098 ** and write access. ^If the flags parameter is zero, the BLOB is opened for 7099 ** read-only access. 7100 ** 7101 ** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is stored 7102 ** in *ppBlob. Otherwise an [error code] is returned and, unless the error 7103 ** code is SQLITE_MISUSE, *ppBlob is set to NULL.)^ ^This means that, provided 7104 ** the API is not misused, it is always safe to call [sqlite3_blob_close()] 7105 ** on *ppBlob after this function it returns. 7106 ** 7107 ** This function fails with SQLITE_ERROR if any of the following are true: 7108 ** <ul> 7109 ** <li> ^(Database zDb does not exist)^, 7110 ** <li> ^(Table zTable does not exist within database zDb)^, 7111 ** <li> ^(Table zTable is a WITHOUT ROWID table)^, 7112 ** <li> ^(Column zColumn does not exist)^, 7113 ** <li> ^(Row iRow is not present in the table)^, 7114 ** <li> ^(The specified column of row iRow contains a value that is not 7115 ** a TEXT or BLOB value)^, 7116 ** <li> ^(Column zColumn is part of an index, PRIMARY KEY or UNIQUE 7117 ** constraint and the blob is being opened for read/write access)^, 7118 ** <li> ^([foreign key constraints | Foreign key constraints] are enabled, 7119 ** column zColumn is part of a [child key] definition and the blob is 7120 ** being opened for read/write access)^. 7121 ** </ul> 7122 ** 7123 ** ^Unless it returns SQLITE_MISUSE, this function sets the 7124 ** [database connection] error code and message accessible via 7125 ** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions. 7126 ** 7127 ** A BLOB referenced by sqlite3_blob_open() may be read using the 7128 ** [sqlite3_blob_read()] interface and modified by using 7129 ** [sqlite3_blob_write()]. The [BLOB handle] can be moved to a 7130 ** different row of the same table using the [sqlite3_blob_reopen()] 7131 ** interface. However, the column, table, or database of a [BLOB handle] 7132 ** cannot be changed after the [BLOB handle] is opened. 7133 ** 7134 ** ^(If the row that a BLOB handle points to is modified by an 7135 ** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects 7136 ** then the BLOB handle is marked as "expired". 7137 ** This is true if any column of the row is changed, even a column 7138 ** other than the one the BLOB handle is open on.)^ 7139 ** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for 7140 ** an expired BLOB handle fail with a return code of [SQLITE_ABORT]. 7141 ** ^(Changes written into a BLOB prior to the BLOB expiring are not 7142 ** rolled back by the expiration of the BLOB. Such changes will eventually 7143 ** commit if the transaction continues to completion.)^ 7144 ** 7145 ** ^Use the [sqlite3_blob_bytes()] interface to determine the size of 7146 ** the opened blob. ^The size of a blob may not be changed by this 7147 ** interface. Use the [UPDATE] SQL command to change the size of a 7148 ** blob. 7149 ** 7150 ** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces 7151 ** and the built-in [zeroblob] SQL function may be used to create a 7152 ** zero-filled blob to read or write using the incremental-blob interface. 7153 ** 7154 ** To avoid a resource leak, every open [BLOB handle] should eventually 7155 ** be released by a call to [sqlite3_blob_close()]. 7156 ** 7157 ** See also: [sqlite3_blob_close()], 7158 ** [sqlite3_blob_reopen()], [sqlite3_blob_read()], 7159 ** [sqlite3_blob_bytes()], [sqlite3_blob_write()]. 7160 */ 7161 SQLITE_API int sqlite3_blob_open( 7162 sqlite3*, 7163 const char *zDb, 7164 const char *zTable, 7165 const char *zColumn, 7166 sqlite3_int64 iRow, 7167 int flags, 7168 sqlite3_blob **ppBlob 7169 ); 7170 7171 /* 7172 ** CAPI3REF: Move a BLOB Handle to a New Row 7173 ** METHOD: sqlite3_blob 7174 ** 7175 ** ^This function is used to move an existing [BLOB handle] so that it points 7176 ** to a different row of the same database table. ^The new row is identified 7177 ** by the rowid value passed as the second argument. Only the row can be 7178 ** changed. ^The database, table and column on which the blob handle is open 7179 ** remain the same. Moving an existing [BLOB handle] to a new row is 7180 ** faster than closing the existing handle and opening a new one. 7181 ** 7182 ** ^(The new row must meet the same criteria as for [sqlite3_blob_open()] - 7183 ** it must exist and there must be either a blob or text value stored in 7184 ** the nominated column.)^ ^If the new row is not present in the table, or if 7185 ** it does not contain a blob or text value, or if another error occurs, an 7186 ** SQLite error code is returned and the blob handle is considered aborted. 7187 ** ^All subsequent calls to [sqlite3_blob_read()], [sqlite3_blob_write()] or 7188 ** [sqlite3_blob_reopen()] on an aborted blob handle immediately return 7189 ** SQLITE_ABORT. ^Calling [sqlite3_blob_bytes()] on an aborted blob handle 7190 ** always returns zero. 7191 ** 7192 ** ^This function sets the database handle error code and message. 7193 */ 7194 SQLITE_API int sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64); 7195 7196 /* 7197 ** CAPI3REF: Close A BLOB Handle 7198 ** DESTRUCTOR: sqlite3_blob 7199 ** 7200 ** ^This function closes an open [BLOB handle]. ^(The BLOB handle is closed 7201 ** unconditionally. Even if this routine returns an error code, the 7202 ** handle is still closed.)^ 7203 ** 7204 ** ^If the blob handle being closed was opened for read-write access, and if 7205 ** the database is in auto-commit mode and there are no other open read-write 7206 ** blob handles or active write statements, the current transaction is 7207 ** committed. ^If an error occurs while committing the transaction, an error 7208 ** code is returned and the transaction rolled back. 7209 ** 7210 ** Calling this function with an argument that is not a NULL pointer or an 7211 ** open blob handle results in undefined behaviour. ^Calling this routine 7212 ** with a null pointer (such as would be returned by a failed call to 7213 ** [sqlite3_blob_open()]) is a harmless no-op. ^Otherwise, if this function 7214 ** is passed a valid open blob handle, the values returned by the 7215 ** sqlite3_errcode() and sqlite3_errmsg() functions are set before returning. 7216 */ 7217 SQLITE_API int sqlite3_blob_close(sqlite3_blob *); 7218 7219 /* 7220 ** CAPI3REF: Return The Size Of An Open BLOB 7221 ** METHOD: sqlite3_blob 7222 ** 7223 ** ^Returns the size in bytes of the BLOB accessible via the 7224 ** successfully opened [BLOB handle] in its only argument. ^The 7225 ** incremental blob I/O routines can only read or overwriting existing 7226 ** blob content; they cannot change the size of a blob. 7227 ** 7228 ** This routine only works on a [BLOB handle] which has been created 7229 ** by a prior successful call to [sqlite3_blob_open()] and which has not 7230 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in 7231 ** to this routine results in undefined and probably undesirable behavior. 7232 */ 7233 SQLITE_API int sqlite3_blob_bytes(sqlite3_blob *); 7234 7235 /* 7236 ** CAPI3REF: Read Data From A BLOB Incrementally 7237 ** METHOD: sqlite3_blob 7238 ** 7239 ** ^(This function is used to read data from an open [BLOB handle] into a 7240 ** caller-supplied buffer. N bytes of data are copied into buffer Z 7241 ** from the open BLOB, starting at offset iOffset.)^ 7242 ** 7243 ** ^If offset iOffset is less than N bytes from the end of the BLOB, 7244 ** [SQLITE_ERROR] is returned and no data is read. ^If N or iOffset is 7245 ** less than zero, [SQLITE_ERROR] is returned and no data is read. 7246 ** ^The size of the blob (and hence the maximum value of N+iOffset) 7247 ** can be determined using the [sqlite3_blob_bytes()] interface. 7248 ** 7249 ** ^An attempt to read from an expired [BLOB handle] fails with an 7250 ** error code of [SQLITE_ABORT]. 7251 ** 7252 ** ^(On success, sqlite3_blob_read() returns SQLITE_OK. 7253 ** Otherwise, an [error code] or an [extended error code] is returned.)^ 7254 ** 7255 ** This routine only works on a [BLOB handle] which has been created 7256 ** by a prior successful call to [sqlite3_blob_open()] and which has not 7257 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in 7258 ** to this routine results in undefined and probably undesirable behavior. 7259 ** 7260 ** See also: [sqlite3_blob_write()]. 7261 */ 7262 SQLITE_API int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset); 7263 7264 /* 7265 ** CAPI3REF: Write Data Into A BLOB Incrementally 7266 ** METHOD: sqlite3_blob 7267 ** 7268 ** ^(This function is used to write data into an open [BLOB handle] from a 7269 ** caller-supplied buffer. N bytes of data are copied from the buffer Z 7270 ** into the open BLOB, starting at offset iOffset.)^ 7271 ** 7272 ** ^(On success, sqlite3_blob_write() returns SQLITE_OK. 7273 ** Otherwise, an [error code] or an [extended error code] is returned.)^ 7274 ** ^Unless SQLITE_MISUSE is returned, this function sets the 7275 ** [database connection] error code and message accessible via 7276 ** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions. 7277 ** 7278 ** ^If the [BLOB handle] passed as the first argument was not opened for 7279 ** writing (the flags parameter to [sqlite3_blob_open()] was zero), 7280 ** this function returns [SQLITE_READONLY]. 7281 ** 7282 ** This function may only modify the contents of the BLOB; it is 7283 ** not possible to increase the size of a BLOB using this API. 7284 ** ^If offset iOffset is less than N bytes from the end of the BLOB, 7285 ** [SQLITE_ERROR] is returned and no data is written. The size of the 7286 ** BLOB (and hence the maximum value of N+iOffset) can be determined 7287 ** using the [sqlite3_blob_bytes()] interface. ^If N or iOffset are less 7288 ** than zero [SQLITE_ERROR] is returned and no data is written. 7289 ** 7290 ** ^An attempt to write to an expired [BLOB handle] fails with an 7291 ** error code of [SQLITE_ABORT]. ^Writes to the BLOB that occurred 7292 ** before the [BLOB handle] expired are not rolled back by the 7293 ** expiration of the handle, though of course those changes might 7294 ** have been overwritten by the statement that expired the BLOB handle 7295 ** or by other independent statements. 7296 ** 7297 ** This routine only works on a [BLOB handle] which has been created 7298 ** by a prior successful call to [sqlite3_blob_open()] and which has not 7299 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in 7300 ** to this routine results in undefined and probably undesirable behavior. 7301 ** 7302 ** See also: [sqlite3_blob_read()]. 7303 */ 7304 SQLITE_API int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset); 7305 7306 /* 7307 ** CAPI3REF: Virtual File System Objects 7308 ** 7309 ** A virtual filesystem (VFS) is an [sqlite3_vfs] object 7310 ** that SQLite uses to interact 7311 ** with the underlying operating system. Most SQLite builds come with a 7312 ** single default VFS that is appropriate for the host computer. 7313 ** New VFSes can be registered and existing VFSes can be unregistered. 7314 ** The following interfaces are provided. 7315 ** 7316 ** ^The sqlite3_vfs_find() interface returns a pointer to a VFS given its name. 7317 ** ^Names are case sensitive. 7318 ** ^Names are zero-terminated UTF-8 strings. 7319 ** ^If there is no match, a NULL pointer is returned. 7320 ** ^If zVfsName is NULL then the default VFS is returned. 7321 ** 7322 ** ^New VFSes are registered with sqlite3_vfs_register(). 7323 ** ^Each new VFS becomes the default VFS if the makeDflt flag is set. 7324 ** ^The same VFS can be registered multiple times without injury. 7325 ** ^To make an existing VFS into the default VFS, register it again 7326 ** with the makeDflt flag set. If two different VFSes with the 7327 ** same name are registered, the behavior is undefined. If a 7328 ** VFS is registered with a name that is NULL or an empty string, 7329 ** then the behavior is undefined. 7330 ** 7331 ** ^Unregister a VFS with the sqlite3_vfs_unregister() interface. 7332 ** ^(If the default VFS is unregistered, another VFS is chosen as 7333 ** the default. The choice for the new VFS is arbitrary.)^ 7334 */ 7335 SQLITE_API sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName); 7336 SQLITE_API int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt); 7337 SQLITE_API int sqlite3_vfs_unregister(sqlite3_vfs*); 7338 7339 /* 7340 ** CAPI3REF: Mutexes 7341 ** 7342 ** The SQLite core uses these routines for thread 7343 ** synchronization. Though they are intended for internal 7344 ** use by SQLite, code that links against SQLite is 7345 ** permitted to use any of these routines. 7346 ** 7347 ** The SQLite source code contains multiple implementations 7348 ** of these mutex routines. An appropriate implementation 7349 ** is selected automatically at compile-time. The following 7350 ** implementations are available in the SQLite core: 7351 ** 7352 ** <ul> 7353 ** <li> SQLITE_MUTEX_PTHREADS 7354 ** <li> SQLITE_MUTEX_W32 7355 ** <li> SQLITE_MUTEX_NOOP 7356 ** </ul> 7357 ** 7358 ** The SQLITE_MUTEX_NOOP implementation is a set of routines 7359 ** that does no real locking and is appropriate for use in 7360 ** a single-threaded application. The SQLITE_MUTEX_PTHREADS and 7361 ** SQLITE_MUTEX_W32 implementations are appropriate for use on Unix 7362 ** and Windows. 7363 ** 7364 ** If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor 7365 ** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex 7366 ** implementation is included with the library. In this case the 7367 ** application must supply a custom mutex implementation using the 7368 ** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function 7369 ** before calling sqlite3_initialize() or any other public sqlite3_ 7370 ** function that calls sqlite3_initialize(). 7371 ** 7372 ** ^The sqlite3_mutex_alloc() routine allocates a new 7373 ** mutex and returns a pointer to it. ^The sqlite3_mutex_alloc() 7374 ** routine returns NULL if it is unable to allocate the requested 7375 ** mutex. The argument to sqlite3_mutex_alloc() must one of these 7376 ** integer constants: 7377 ** 7378 ** <ul> 7379 ** <li> SQLITE_MUTEX_FAST 7380 ** <li> SQLITE_MUTEX_RECURSIVE 7381 ** <li> SQLITE_MUTEX_STATIC_MAIN 7382 ** <li> SQLITE_MUTEX_STATIC_MEM 7383 ** <li> SQLITE_MUTEX_STATIC_OPEN 7384 ** <li> SQLITE_MUTEX_STATIC_PRNG 7385 ** <li> SQLITE_MUTEX_STATIC_LRU 7386 ** <li> SQLITE_MUTEX_STATIC_PMEM 7387 ** <li> SQLITE_MUTEX_STATIC_APP1 7388 ** <li> SQLITE_MUTEX_STATIC_APP2 7389 ** <li> SQLITE_MUTEX_STATIC_APP3 7390 ** <li> SQLITE_MUTEX_STATIC_VFS1 7391 ** <li> SQLITE_MUTEX_STATIC_VFS2 7392 ** <li> SQLITE_MUTEX_STATIC_VFS3 7393 ** </ul> 7394 ** 7395 ** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) 7396 ** cause sqlite3_mutex_alloc() to create 7397 ** a new mutex. ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE 7398 ** is used but not necessarily so when SQLITE_MUTEX_FAST is used. 7399 ** The mutex implementation does not need to make a distinction 7400 ** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does 7401 ** not want to. SQLite will only request a recursive mutex in 7402 ** cases where it really needs one. If a faster non-recursive mutex 7403 ** implementation is available on the host platform, the mutex subsystem 7404 ** might return such a mutex in response to SQLITE_MUTEX_FAST. 7405 ** 7406 ** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other 7407 ** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return 7408 ** a pointer to a static preexisting mutex. ^Nine static mutexes are 7409 ** used by the current version of SQLite. Future versions of SQLite 7410 ** may add additional static mutexes. Static mutexes are for internal 7411 ** use by SQLite only. Applications that use SQLite mutexes should 7412 ** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or 7413 ** SQLITE_MUTEX_RECURSIVE. 7414 ** 7415 ** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST 7416 ** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc() 7417 ** returns a different mutex on every call. ^For the static 7418 ** mutex types, the same mutex is returned on every call that has 7419 ** the same type number. 7420 ** 7421 ** ^The sqlite3_mutex_free() routine deallocates a previously 7422 ** allocated dynamic mutex. Attempting to deallocate a static 7423 ** mutex results in undefined behavior. 7424 ** 7425 ** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt 7426 ** to enter a mutex. ^If another thread is already within the mutex, 7427 ** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return 7428 ** SQLITE_BUSY. ^The sqlite3_mutex_try() interface returns [SQLITE_OK] 7429 ** upon successful entry. ^(Mutexes created using 7430 ** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread. 7431 ** In such cases, the 7432 ** mutex must be exited an equal number of times before another thread 7433 ** can enter.)^ If the same thread tries to enter any mutex other 7434 ** than an SQLITE_MUTEX_RECURSIVE more than once, the behavior is undefined. 7435 ** 7436 ** ^(Some systems (for example, Windows 95) do not support the operation 7437 ** implemented by sqlite3_mutex_try(). On those systems, sqlite3_mutex_try() 7438 ** will always return SQLITE_BUSY. The SQLite core only ever uses 7439 ** sqlite3_mutex_try() as an optimization so this is acceptable 7440 ** behavior.)^ 7441 ** 7442 ** ^The sqlite3_mutex_leave() routine exits a mutex that was 7443 ** previously entered by the same thread. The behavior 7444 ** is undefined if the mutex is not currently entered by the 7445 ** calling thread or is not currently allocated. 7446 ** 7447 ** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), or 7448 ** sqlite3_mutex_leave() is a NULL pointer, then all three routines 7449 ** behave as no-ops. 7450 ** 7451 ** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()]. 7452 */ 7453 SQLITE_API sqlite3_mutex *sqlite3_mutex_alloc(int); 7454 SQLITE_API void sqlite3_mutex_free(sqlite3_mutex*); 7455 SQLITE_API void sqlite3_mutex_enter(sqlite3_mutex*); 7456 SQLITE_API int sqlite3_mutex_try(sqlite3_mutex*); 7457 SQLITE_API void sqlite3_mutex_leave(sqlite3_mutex*); 7458 7459 /* 7460 ** CAPI3REF: Mutex Methods Object 7461 ** 7462 ** An instance of this structure defines the low-level routines 7463 ** used to allocate and use mutexes. 7464 ** 7465 ** Usually, the default mutex implementations provided by SQLite are 7466 ** sufficient, however the application has the option of substituting a custom 7467 ** implementation for specialized deployments or systems for which SQLite 7468 ** does not provide a suitable implementation. In this case, the application 7469 ** creates and populates an instance of this structure to pass 7470 ** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option. 7471 ** Additionally, an instance of this structure can be used as an 7472 ** output variable when querying the system for the current mutex 7473 ** implementation, using the [SQLITE_CONFIG_GETMUTEX] option. 7474 ** 7475 ** ^The xMutexInit method defined by this structure is invoked as 7476 ** part of system initialization by the sqlite3_initialize() function. 7477 ** ^The xMutexInit routine is called by SQLite exactly once for each 7478 ** effective call to [sqlite3_initialize()]. 7479 ** 7480 ** ^The xMutexEnd method defined by this structure is invoked as 7481 ** part of system shutdown by the sqlite3_shutdown() function. The 7482 ** implementation of this method is expected to release all outstanding 7483 ** resources obtained by the mutex methods implementation, especially 7484 ** those obtained by the xMutexInit method. ^The xMutexEnd() 7485 ** interface is invoked exactly once for each call to [sqlite3_shutdown()]. 7486 ** 7487 ** ^(The remaining seven methods defined by this structure (xMutexAlloc, 7488 ** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and 7489 ** xMutexNotheld) implement the following interfaces (respectively): 7490 ** 7491 ** <ul> 7492 ** <li> [sqlite3_mutex_alloc()] </li> 7493 ** <li> [sqlite3_mutex_free()] </li> 7494 ** <li> [sqlite3_mutex_enter()] </li> 7495 ** <li> [sqlite3_mutex_try()] </li> 7496 ** <li> [sqlite3_mutex_leave()] </li> 7497 ** <li> [sqlite3_mutex_held()] </li> 7498 ** <li> [sqlite3_mutex_notheld()] </li> 7499 ** </ul>)^ 7500 ** 7501 ** The only difference is that the public sqlite3_XXX functions enumerated 7502 ** above silently ignore any invocations that pass a NULL pointer instead 7503 ** of a valid mutex handle. The implementations of the methods defined 7504 ** by this structure are not required to handle this case. The results 7505 ** of passing a NULL pointer instead of a valid mutex handle are undefined 7506 ** (i.e. it is acceptable to provide an implementation that segfaults if 7507 ** it is passed a NULL pointer). 7508 ** 7509 ** The xMutexInit() method must be threadsafe. It must be harmless to 7510 ** invoke xMutexInit() multiple times within the same process and without 7511 ** intervening calls to xMutexEnd(). Second and subsequent calls to 7512 ** xMutexInit() must be no-ops. 7513 ** 7514 ** xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()] 7515 ** and its associates). Similarly, xMutexAlloc() must not use SQLite memory 7516 ** allocation for a static mutex. ^However xMutexAlloc() may use SQLite 7517 ** memory allocation for a fast or recursive mutex. 7518 ** 7519 ** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is 7520 ** called, but only if the prior call to xMutexInit returned SQLITE_OK. 7521 ** If xMutexInit fails in any way, it is expected to clean up after itself 7522 ** prior to returning. 7523 */ 7524 typedef struct sqlite3_mutex_methods sqlite3_mutex_methods; 7525 struct sqlite3_mutex_methods { 7526 int (*xMutexInit)(void); 7527 int (*xMutexEnd)(void); 7528 sqlite3_mutex *(*xMutexAlloc)(int); 7529 void (*xMutexFree)(sqlite3_mutex *); 7530 void (*xMutexEnter)(sqlite3_mutex *); 7531 int (*xMutexTry)(sqlite3_mutex *); 7532 void (*xMutexLeave)(sqlite3_mutex *); 7533 int (*xMutexHeld)(sqlite3_mutex *); 7534 int (*xMutexNotheld)(sqlite3_mutex *); 7535 }; 7536 7537 /* 7538 ** CAPI3REF: Mutex Verification Routines 7539 ** 7540 ** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines 7541 ** are intended for use inside assert() statements. The SQLite core 7542 ** never uses these routines except inside an assert() and applications 7543 ** are advised to follow the lead of the core. The SQLite core only 7544 ** provides implementations for these routines when it is compiled 7545 ** with the SQLITE_DEBUG flag. External mutex implementations 7546 ** are only required to provide these routines if SQLITE_DEBUG is 7547 ** defined and if NDEBUG is not defined. 7548 ** 7549 ** These routines should return true if the mutex in their argument 7550 ** is held or not held, respectively, by the calling thread. 7551 ** 7552 ** The implementation is not required to provide versions of these 7553 ** routines that actually work. If the implementation does not provide working 7554 ** versions of these routines, it should at least provide stubs that always 7555 ** return true so that one does not get spurious assertion failures. 7556 ** 7557 ** If the argument to sqlite3_mutex_held() is a NULL pointer then 7558 ** the routine should return 1. This seems counter-intuitive since 7559 ** clearly the mutex cannot be held if it does not exist. But 7560 ** the reason the mutex does not exist is because the build is not 7561 ** using mutexes. And we do not want the assert() containing the 7562 ** call to sqlite3_mutex_held() to fail, so a non-zero return is 7563 ** the appropriate thing to do. The sqlite3_mutex_notheld() 7564 ** interface should also return 1 when given a NULL pointer. 7565 */ 7566 #ifndef NDEBUG 7567 SQLITE_API int sqlite3_mutex_held(sqlite3_mutex*); 7568 SQLITE_API int sqlite3_mutex_notheld(sqlite3_mutex*); 7569 #endif 7570 7571 /* 7572 ** CAPI3REF: Mutex Types 7573 ** 7574 ** The [sqlite3_mutex_alloc()] interface takes a single argument 7575 ** which is one of these integer constants. 7576 ** 7577 ** The set of static mutexes may change from one SQLite release to the 7578 ** next. Applications that override the built-in mutex logic must be 7579 ** prepared to accommodate additional static mutexes. 7580 */ 7581 #define SQLITE_MUTEX_FAST 0 7582 #define SQLITE_MUTEX_RECURSIVE 1 7583 #define SQLITE_MUTEX_STATIC_MAIN 2 7584 #define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */ 7585 #define SQLITE_MUTEX_STATIC_MEM2 4 /* NOT USED */ 7586 #define SQLITE_MUTEX_STATIC_OPEN 4 /* sqlite3BtreeOpen() */ 7587 #define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_randomness() */ 7588 #define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */ 7589 #define SQLITE_MUTEX_STATIC_LRU2 7 /* NOT USED */ 7590 #define SQLITE_MUTEX_STATIC_PMEM 7 /* sqlite3PageMalloc() */ 7591 #define SQLITE_MUTEX_STATIC_APP1 8 /* For use by application */ 7592 #define SQLITE_MUTEX_STATIC_APP2 9 /* For use by application */ 7593 #define SQLITE_MUTEX_STATIC_APP3 10 /* For use by application */ 7594 #define SQLITE_MUTEX_STATIC_VFS1 11 /* For use by built-in VFS */ 7595 #define SQLITE_MUTEX_STATIC_VFS2 12 /* For use by extension VFS */ 7596 #define SQLITE_MUTEX_STATIC_VFS3 13 /* For use by application VFS */ 7597 7598 /* Legacy compatibility: */ 7599 #define SQLITE_MUTEX_STATIC_MASTER 2 7600 7601 7602 /* 7603 ** CAPI3REF: Retrieve the mutex for a database connection 7604 ** METHOD: sqlite3 7605 ** 7606 ** ^This interface returns a pointer the [sqlite3_mutex] object that 7607 ** serializes access to the [database connection] given in the argument 7608 ** when the [threading mode] is Serialized. 7609 ** ^If the [threading mode] is Single-thread or Multi-thread then this 7610 ** routine returns a NULL pointer. 7611 */ 7612 SQLITE_API sqlite3_mutex *sqlite3_db_mutex(sqlite3*); 7613 7614 /* 7615 ** CAPI3REF: Low-Level Control Of Database Files 7616 ** METHOD: sqlite3 7617 ** KEYWORDS: {file control} 7618 ** 7619 ** ^The [sqlite3_file_control()] interface makes a direct call to the 7620 ** xFileControl method for the [sqlite3_io_methods] object associated 7621 ** with a particular database identified by the second argument. ^The 7622 ** name of the database is "main" for the main database or "temp" for the 7623 ** TEMP database, or the name that appears after the AS keyword for 7624 ** databases that are added using the [ATTACH] SQL command. 7625 ** ^A NULL pointer can be used in place of "main" to refer to the 7626 ** main database file. 7627 ** ^The third and fourth parameters to this routine 7628 ** are passed directly through to the second and third parameters of 7629 ** the xFileControl method. ^The return value of the xFileControl 7630 ** method becomes the return value of this routine. 7631 ** 7632 ** A few opcodes for [sqlite3_file_control()] are handled directly 7633 ** by the SQLite core and never invoke the 7634 ** sqlite3_io_methods.xFileControl method. 7635 ** ^The [SQLITE_FCNTL_FILE_POINTER] value for the op parameter causes 7636 ** a pointer to the underlying [sqlite3_file] object to be written into 7637 ** the space pointed to by the 4th parameter. The 7638 ** [SQLITE_FCNTL_JOURNAL_POINTER] works similarly except that it returns 7639 ** the [sqlite3_file] object associated with the journal file instead of 7640 ** the main database. The [SQLITE_FCNTL_VFS_POINTER] opcode returns 7641 ** a pointer to the underlying [sqlite3_vfs] object for the file. 7642 ** The [SQLITE_FCNTL_DATA_VERSION] returns the data version counter 7643 ** from the pager. 7644 ** 7645 ** ^If the second parameter (zDbName) does not match the name of any 7646 ** open database file, then SQLITE_ERROR is returned. ^This error 7647 ** code is not remembered and will not be recalled by [sqlite3_errcode()] 7648 ** or [sqlite3_errmsg()]. The underlying xFileControl method might 7649 ** also return SQLITE_ERROR. There is no way to distinguish between 7650 ** an incorrect zDbName and an SQLITE_ERROR return from the underlying 7651 ** xFileControl method. 7652 ** 7653 ** See also: [file control opcodes] 7654 */ 7655 SQLITE_API int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*); 7656 7657 /* 7658 ** CAPI3REF: Testing Interface 7659 ** 7660 ** ^The sqlite3_test_control() interface is used to read out internal 7661 ** state of SQLite and to inject faults into SQLite for testing 7662 ** purposes. ^The first parameter is an operation code that determines 7663 ** the number, meaning, and operation of all subsequent parameters. 7664 ** 7665 ** This interface is not for use by applications. It exists solely 7666 ** for verifying the correct operation of the SQLite library. Depending 7667 ** on how the SQLite library is compiled, this interface might not exist. 7668 ** 7669 ** The details of the operation codes, their meanings, the parameters 7670 ** they take, and what they do are all subject to change without notice. 7671 ** Unlike most of the SQLite API, this function is not guaranteed to 7672 ** operate consistently from one release to the next. 7673 */ 7674 SQLITE_API int sqlite3_test_control(int op, ...); 7675 7676 /* 7677 ** CAPI3REF: Testing Interface Operation Codes 7678 ** 7679 ** These constants are the valid operation code parameters used 7680 ** as the first argument to [sqlite3_test_control()]. 7681 ** 7682 ** These parameters and their meanings are subject to change 7683 ** without notice. These values are for testing purposes only. 7684 ** Applications should not use any of these parameters or the 7685 ** [sqlite3_test_control()] interface. 7686 */ 7687 #define SQLITE_TESTCTRL_FIRST 5 7688 #define SQLITE_TESTCTRL_PRNG_SAVE 5 7689 #define SQLITE_TESTCTRL_PRNG_RESTORE 6 7690 #define SQLITE_TESTCTRL_PRNG_RESET 7 /* NOT USED */ 7691 #define SQLITE_TESTCTRL_BITVEC_TEST 8 7692 #define SQLITE_TESTCTRL_FAULT_INSTALL 9 7693 #define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS 10 7694 #define SQLITE_TESTCTRL_PENDING_BYTE 11 7695 #define SQLITE_TESTCTRL_ASSERT 12 7696 #define SQLITE_TESTCTRL_ALWAYS 13 7697 #define SQLITE_TESTCTRL_RESERVE 14 /* NOT USED */ 7698 #define SQLITE_TESTCTRL_OPTIMIZATIONS 15 7699 #define SQLITE_TESTCTRL_ISKEYWORD 16 /* NOT USED */ 7700 #define SQLITE_TESTCTRL_SCRATCHMALLOC 17 /* NOT USED */ 7701 #define SQLITE_TESTCTRL_INTERNAL_FUNCTIONS 17 7702 #define SQLITE_TESTCTRL_LOCALTIME_FAULT 18 7703 #define SQLITE_TESTCTRL_EXPLAIN_STMT 19 /* NOT USED */ 7704 #define SQLITE_TESTCTRL_ONCE_RESET_THRESHOLD 19 7705 #define SQLITE_TESTCTRL_NEVER_CORRUPT 20 7706 #define SQLITE_TESTCTRL_VDBE_COVERAGE 21 7707 #define SQLITE_TESTCTRL_BYTEORDER 22 7708 #define SQLITE_TESTCTRL_ISINIT 23 7709 #define SQLITE_TESTCTRL_SORTER_MMAP 24 7710 #define SQLITE_TESTCTRL_IMPOSTER 25 7711 #define SQLITE_TESTCTRL_PARSER_COVERAGE 26 7712 #define SQLITE_TESTCTRL_RESULT_INTREAL 27 7713 #define SQLITE_TESTCTRL_PRNG_SEED 28 7714 #define SQLITE_TESTCTRL_EXTRA_SCHEMA_CHECKS 29 7715 #define SQLITE_TESTCTRL_LAST 29 /* Largest TESTCTRL */ 7716 7717 /* 7718 ** CAPI3REF: SQL Keyword Checking 7719 ** 7720 ** These routines provide access to the set of SQL language keywords 7721 ** recognized by SQLite. Applications can uses these routines to determine 7722 ** whether or not a specific identifier needs to be escaped (for example, 7723 ** by enclosing in double-quotes) so as not to confuse the parser. 7724 ** 7725 ** The sqlite3_keyword_count() interface returns the number of distinct 7726 ** keywords understood by SQLite. 7727 ** 7728 ** The sqlite3_keyword_name(N,Z,L) interface finds the N-th keyword and 7729 ** makes *Z point to that keyword expressed as UTF8 and writes the number 7730 ** of bytes in the keyword into *L. The string that *Z points to is not 7731 ** zero-terminated. The sqlite3_keyword_name(N,Z,L) routine returns 7732 ** SQLITE_OK if N is within bounds and SQLITE_ERROR if not. If either Z 7733 ** or L are NULL or invalid pointers then calls to 7734 ** sqlite3_keyword_name(N,Z,L) result in undefined behavior. 7735 ** 7736 ** The sqlite3_keyword_check(Z,L) interface checks to see whether or not 7737 ** the L-byte UTF8 identifier that Z points to is a keyword, returning non-zero 7738 ** if it is and zero if not. 7739 ** 7740 ** The parser used by SQLite is forgiving. It is often possible to use 7741 ** a keyword as an identifier as long as such use does not result in a 7742 ** parsing ambiguity. For example, the statement 7743 ** "CREATE TABLE BEGIN(REPLACE,PRAGMA,END);" is accepted by SQLite, and 7744 ** creates a new table named "BEGIN" with three columns named 7745 ** "REPLACE", "PRAGMA", and "END". Nevertheless, best practice is to avoid 7746 ** using keywords as identifiers. Common techniques used to avoid keyword 7747 ** name collisions include: 7748 ** <ul> 7749 ** <li> Put all identifier names inside double-quotes. This is the official 7750 ** SQL way to escape identifier names. 7751 ** <li> Put identifier names inside [...]. This is not standard SQL, 7752 ** but it is what SQL Server does and so lots of programmers use this 7753 ** technique. 7754 ** <li> Begin every identifier with the letter "Z" as no SQL keywords start 7755 ** with "Z". 7756 ** <li> Include a digit somewhere in every identifier name. 7757 ** </ul> 7758 ** 7759 ** Note that the number of keywords understood by SQLite can depend on 7760 ** compile-time options. For example, "VACUUM" is not a keyword if 7761 ** SQLite is compiled with the [-DSQLITE_OMIT_VACUUM] option. Also, 7762 ** new keywords may be added to future releases of SQLite. 7763 */ 7764 SQLITE_API int sqlite3_keyword_count(void); 7765 SQLITE_API int sqlite3_keyword_name(int,const char**,int*); 7766 SQLITE_API int sqlite3_keyword_check(const char*,int); 7767 7768 /* 7769 ** CAPI3REF: Dynamic String Object 7770 ** KEYWORDS: {dynamic string} 7771 ** 7772 ** An instance of the sqlite3_str object contains a dynamically-sized 7773 ** string under construction. 7774 ** 7775 ** The lifecycle of an sqlite3_str object is as follows: 7776 ** <ol> 7777 ** <li> ^The sqlite3_str object is created using [sqlite3_str_new()]. 7778 ** <li> ^Text is appended to the sqlite3_str object using various 7779 ** methods, such as [sqlite3_str_appendf()]. 7780 ** <li> ^The sqlite3_str object is destroyed and the string it created 7781 ** is returned using the [sqlite3_str_finish()] interface. 7782 ** </ol> 7783 */ 7784 typedef struct sqlite3_str sqlite3_str; 7785 7786 /* 7787 ** CAPI3REF: Create A New Dynamic String Object 7788 ** CONSTRUCTOR: sqlite3_str 7789 ** 7790 ** ^The [sqlite3_str_new(D)] interface allocates and initializes 7791 ** a new [sqlite3_str] object. To avoid memory leaks, the object returned by 7792 ** [sqlite3_str_new()] must be freed by a subsequent call to 7793 ** [sqlite3_str_finish(X)]. 7794 ** 7795 ** ^The [sqlite3_str_new(D)] interface always returns a pointer to a 7796 ** valid [sqlite3_str] object, though in the event of an out-of-memory 7797 ** error the returned object might be a special singleton that will 7798 ** silently reject new text, always return SQLITE_NOMEM from 7799 ** [sqlite3_str_errcode()], always return 0 for 7800 ** [sqlite3_str_length()], and always return NULL from 7801 ** [sqlite3_str_finish(X)]. It is always safe to use the value 7802 ** returned by [sqlite3_str_new(D)] as the sqlite3_str parameter 7803 ** to any of the other [sqlite3_str] methods. 7804 ** 7805 ** The D parameter to [sqlite3_str_new(D)] may be NULL. If the 7806 ** D parameter in [sqlite3_str_new(D)] is not NULL, then the maximum 7807 ** length of the string contained in the [sqlite3_str] object will be 7808 ** the value set for [sqlite3_limit](D,[SQLITE_LIMIT_LENGTH]) instead 7809 ** of [SQLITE_MAX_LENGTH]. 7810 */ 7811 SQLITE_API sqlite3_str *sqlite3_str_new(sqlite3*); 7812 7813 /* 7814 ** CAPI3REF: Finalize A Dynamic String 7815 ** DESTRUCTOR: sqlite3_str 7816 ** 7817 ** ^The [sqlite3_str_finish(X)] interface destroys the sqlite3_str object X 7818 ** and returns a pointer to a memory buffer obtained from [sqlite3_malloc64()] 7819 ** that contains the constructed string. The calling application should 7820 ** pass the returned value to [sqlite3_free()] to avoid a memory leak. 7821 ** ^The [sqlite3_str_finish(X)] interface may return a NULL pointer if any 7822 ** errors were encountered during construction of the string. ^The 7823 ** [sqlite3_str_finish(X)] interface will also return a NULL pointer if the 7824 ** string in [sqlite3_str] object X is zero bytes long. 7825 */ 7826 SQLITE_API char *sqlite3_str_finish(sqlite3_str*); 7827 7828 /* 7829 ** CAPI3REF: Add Content To A Dynamic String 7830 ** METHOD: sqlite3_str 7831 ** 7832 ** These interfaces add content to an sqlite3_str object previously obtained 7833 ** from [sqlite3_str_new()]. 7834 ** 7835 ** ^The [sqlite3_str_appendf(X,F,...)] and 7836 ** [sqlite3_str_vappendf(X,F,V)] interfaces uses the [built-in printf] 7837 ** functionality of SQLite to append formatted text onto the end of 7838 ** [sqlite3_str] object X. 7839 ** 7840 ** ^The [sqlite3_str_append(X,S,N)] method appends exactly N bytes from string S 7841 ** onto the end of the [sqlite3_str] object X. N must be non-negative. 7842 ** S must contain at least N non-zero bytes of content. To append a 7843 ** zero-terminated string in its entirety, use the [sqlite3_str_appendall()] 7844 ** method instead. 7845 ** 7846 ** ^The [sqlite3_str_appendall(X,S)] method appends the complete content of 7847 ** zero-terminated string S onto the end of [sqlite3_str] object X. 7848 ** 7849 ** ^The [sqlite3_str_appendchar(X,N,C)] method appends N copies of the 7850 ** single-byte character C onto the end of [sqlite3_str] object X. 7851 ** ^This method can be used, for example, to add whitespace indentation. 7852 ** 7853 ** ^The [sqlite3_str_reset(X)] method resets the string under construction 7854 ** inside [sqlite3_str] object X back to zero bytes in length. 7855 ** 7856 ** These methods do not return a result code. ^If an error occurs, that fact 7857 ** is recorded in the [sqlite3_str] object and can be recovered by a 7858 ** subsequent call to [sqlite3_str_errcode(X)]. 7859 */ 7860 SQLITE_API void sqlite3_str_appendf(sqlite3_str*, const char *zFormat, ...); 7861 SQLITE_API void sqlite3_str_vappendf(sqlite3_str*, const char *zFormat, va_list); 7862 SQLITE_API void sqlite3_str_append(sqlite3_str*, const char *zIn, int N); 7863 SQLITE_API void sqlite3_str_appendall(sqlite3_str*, const char *zIn); 7864 SQLITE_API void sqlite3_str_appendchar(sqlite3_str*, int N, char C); 7865 SQLITE_API void sqlite3_str_reset(sqlite3_str*); 7866 7867 /* 7868 ** CAPI3REF: Status Of A Dynamic String 7869 ** METHOD: sqlite3_str 7870 ** 7871 ** These interfaces return the current status of an [sqlite3_str] object. 7872 ** 7873 ** ^If any prior errors have occurred while constructing the dynamic string 7874 ** in sqlite3_str X, then the [sqlite3_str_errcode(X)] method will return 7875 ** an appropriate error code. ^The [sqlite3_str_errcode(X)] method returns 7876 ** [SQLITE_NOMEM] following any out-of-memory error, or 7877 ** [SQLITE_TOOBIG] if the size of the dynamic string exceeds 7878 ** [SQLITE_MAX_LENGTH], or [SQLITE_OK] if there have been no errors. 7879 ** 7880 ** ^The [sqlite3_str_length(X)] method returns the current length, in bytes, 7881 ** of the dynamic string under construction in [sqlite3_str] object X. 7882 ** ^The length returned by [sqlite3_str_length(X)] does not include the 7883 ** zero-termination byte. 7884 ** 7885 ** ^The [sqlite3_str_value(X)] method returns a pointer to the current 7886 ** content of the dynamic string under construction in X. The value 7887 ** returned by [sqlite3_str_value(X)] is managed by the sqlite3_str object X 7888 ** and might be freed or altered by any subsequent method on the same 7889 ** [sqlite3_str] object. Applications must not used the pointer returned 7890 ** [sqlite3_str_value(X)] after any subsequent method call on the same 7891 ** object. ^Applications may change the content of the string returned 7892 ** by [sqlite3_str_value(X)] as long as they do not write into any bytes 7893 ** outside the range of 0 to [sqlite3_str_length(X)] and do not read or 7894 ** write any byte after any subsequent sqlite3_str method call. 7895 */ 7896 SQLITE_API int sqlite3_str_errcode(sqlite3_str*); 7897 SQLITE_API int sqlite3_str_length(sqlite3_str*); 7898 SQLITE_API char *sqlite3_str_value(sqlite3_str*); 7899 7900 /* 7901 ** CAPI3REF: SQLite Runtime Status 7902 ** 7903 ** ^These interfaces are used to retrieve runtime status information 7904 ** about the performance of SQLite, and optionally to reset various 7905 ** highwater marks. ^The first argument is an integer code for 7906 ** the specific parameter to measure. ^(Recognized integer codes 7907 ** are of the form [status parameters | SQLITE_STATUS_...].)^ 7908 ** ^The current value of the parameter is returned into *pCurrent. 7909 ** ^The highest recorded value is returned in *pHighwater. ^If the 7910 ** resetFlag is true, then the highest record value is reset after 7911 ** *pHighwater is written. ^(Some parameters do not record the highest 7912 ** value. For those parameters 7913 ** nothing is written into *pHighwater and the resetFlag is ignored.)^ 7914 ** ^(Other parameters record only the highwater mark and not the current 7915 ** value. For these latter parameters nothing is written into *pCurrent.)^ 7916 ** 7917 ** ^The sqlite3_status() and sqlite3_status64() routines return 7918 ** SQLITE_OK on success and a non-zero [error code] on failure. 7919 ** 7920 ** If either the current value or the highwater mark is too large to 7921 ** be represented by a 32-bit integer, then the values returned by 7922 ** sqlite3_status() are undefined. 7923 ** 7924 ** See also: [sqlite3_db_status()] 7925 */ 7926 SQLITE_API int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag); 7927 SQLITE_API int sqlite3_status64( 7928 int op, 7929 sqlite3_int64 *pCurrent, 7930 sqlite3_int64 *pHighwater, 7931 int resetFlag 7932 ); 7933 7934 7935 /* 7936 ** CAPI3REF: Status Parameters 7937 ** KEYWORDS: {status parameters} 7938 ** 7939 ** These integer constants designate various run-time status parameters 7940 ** that can be returned by [sqlite3_status()]. 7941 ** 7942 ** <dl> 7943 ** [[SQLITE_STATUS_MEMORY_USED]] ^(<dt>SQLITE_STATUS_MEMORY_USED</dt> 7944 ** <dd>This parameter is the current amount of memory checked out 7945 ** using [sqlite3_malloc()], either directly or indirectly. The 7946 ** figure includes calls made to [sqlite3_malloc()] by the application 7947 ** and internal memory usage by the SQLite library. Auxiliary page-cache 7948 ** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in 7949 ** this parameter. The amount returned is the sum of the allocation 7950 ** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>)^ 7951 ** 7952 ** [[SQLITE_STATUS_MALLOC_SIZE]] ^(<dt>SQLITE_STATUS_MALLOC_SIZE</dt> 7953 ** <dd>This parameter records the largest memory allocation request 7954 ** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their 7955 ** internal equivalents). Only the value returned in the 7956 ** *pHighwater parameter to [sqlite3_status()] is of interest. 7957 ** The value written into the *pCurrent parameter is undefined.</dd>)^ 7958 ** 7959 ** [[SQLITE_STATUS_MALLOC_COUNT]] ^(<dt>SQLITE_STATUS_MALLOC_COUNT</dt> 7960 ** <dd>This parameter records the number of separate memory allocations 7961 ** currently checked out.</dd>)^ 7962 ** 7963 ** [[SQLITE_STATUS_PAGECACHE_USED]] ^(<dt>SQLITE_STATUS_PAGECACHE_USED</dt> 7964 ** <dd>This parameter returns the number of pages used out of the 7965 ** [pagecache memory allocator] that was configured using 7966 ** [SQLITE_CONFIG_PAGECACHE]. The 7967 ** value returned is in pages, not in bytes.</dd>)^ 7968 ** 7969 ** [[SQLITE_STATUS_PAGECACHE_OVERFLOW]] 7970 ** ^(<dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt> 7971 ** <dd>This parameter returns the number of bytes of page cache 7972 ** allocation which could not be satisfied by the [SQLITE_CONFIG_PAGECACHE] 7973 ** buffer and where forced to overflow to [sqlite3_malloc()]. The 7974 ** returned value includes allocations that overflowed because they 7975 ** where too large (they were larger than the "sz" parameter to 7976 ** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because 7977 ** no space was left in the page cache.</dd>)^ 7978 ** 7979 ** [[SQLITE_STATUS_PAGECACHE_SIZE]] ^(<dt>SQLITE_STATUS_PAGECACHE_SIZE</dt> 7980 ** <dd>This parameter records the largest memory allocation request 7981 ** handed to the [pagecache memory allocator]. Only the value returned in the 7982 ** *pHighwater parameter to [sqlite3_status()] is of interest. 7983 ** The value written into the *pCurrent parameter is undefined.</dd>)^ 7984 ** 7985 ** [[SQLITE_STATUS_SCRATCH_USED]] <dt>SQLITE_STATUS_SCRATCH_USED</dt> 7986 ** <dd>No longer used.</dd> 7987 ** 7988 ** [[SQLITE_STATUS_SCRATCH_OVERFLOW]] ^(<dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt> 7989 ** <dd>No longer used.</dd> 7990 ** 7991 ** [[SQLITE_STATUS_SCRATCH_SIZE]] <dt>SQLITE_STATUS_SCRATCH_SIZE</dt> 7992 ** <dd>No longer used.</dd> 7993 ** 7994 ** [[SQLITE_STATUS_PARSER_STACK]] ^(<dt>SQLITE_STATUS_PARSER_STACK</dt> 7995 ** <dd>The *pHighwater parameter records the deepest parser stack. 7996 ** The *pCurrent value is undefined. The *pHighwater value is only 7997 ** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>)^ 7998 ** </dl> 7999 ** 8000 ** New status parameters may be added from time to time. 8001 */ 8002 #define SQLITE_STATUS_MEMORY_USED 0 8003 #define SQLITE_STATUS_PAGECACHE_USED 1 8004 #define SQLITE_STATUS_PAGECACHE_OVERFLOW 2 8005 #define SQLITE_STATUS_SCRATCH_USED 3 /* NOT USED */ 8006 #define SQLITE_STATUS_SCRATCH_OVERFLOW 4 /* NOT USED */ 8007 #define SQLITE_STATUS_MALLOC_SIZE 5 8008 #define SQLITE_STATUS_PARSER_STACK 6 8009 #define SQLITE_STATUS_PAGECACHE_SIZE 7 8010 #define SQLITE_STATUS_SCRATCH_SIZE 8 /* NOT USED */ 8011 #define SQLITE_STATUS_MALLOC_COUNT 9 8012 8013 /* 8014 ** CAPI3REF: Database Connection Status 8015 ** METHOD: sqlite3 8016 ** 8017 ** ^This interface is used to retrieve runtime status information 8018 ** about a single [database connection]. ^The first argument is the 8019 ** database connection object to be interrogated. ^The second argument 8020 ** is an integer constant, taken from the set of 8021 ** [SQLITE_DBSTATUS options], that 8022 ** determines the parameter to interrogate. The set of 8023 ** [SQLITE_DBSTATUS options] is likely 8024 ** to grow in future releases of SQLite. 8025 ** 8026 ** ^The current value of the requested parameter is written into *pCur 8027 ** and the highest instantaneous value is written into *pHiwtr. ^If 8028 ** the resetFlg is true, then the highest instantaneous value is 8029 ** reset back down to the current value. 8030 ** 8031 ** ^The sqlite3_db_status() routine returns SQLITE_OK on success and a 8032 ** non-zero [error code] on failure. 8033 ** 8034 ** See also: [sqlite3_status()] and [sqlite3_stmt_status()]. 8035 */ 8036 SQLITE_API int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg); 8037 8038 /* 8039 ** CAPI3REF: Status Parameters for database connections 8040 ** KEYWORDS: {SQLITE_DBSTATUS options} 8041 ** 8042 ** These constants are the available integer "verbs" that can be passed as 8043 ** the second argument to the [sqlite3_db_status()] interface. 8044 ** 8045 ** New verbs may be added in future releases of SQLite. Existing verbs 8046 ** might be discontinued. Applications should check the return code from 8047 ** [sqlite3_db_status()] to make sure that the call worked. 8048 ** The [sqlite3_db_status()] interface will return a non-zero error code 8049 ** if a discontinued or unsupported verb is invoked. 8050 ** 8051 ** <dl> 8052 ** [[SQLITE_DBSTATUS_LOOKASIDE_USED]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt> 8053 ** <dd>This parameter returns the number of lookaside memory slots currently 8054 ** checked out.</dd>)^ 8055 ** 8056 ** [[SQLITE_DBSTATUS_LOOKASIDE_HIT]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_HIT</dt> 8057 ** <dd>This parameter returns the number of malloc attempts that were 8058 ** satisfied using lookaside memory. Only the high-water value is meaningful; 8059 ** the current value is always zero.)^ 8060 ** 8061 ** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE]] 8062 ** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE</dt> 8063 ** <dd>This parameter returns the number malloc attempts that might have 8064 ** been satisfied using lookaside memory but failed due to the amount of 8065 ** memory requested being larger than the lookaside slot size. 8066 ** Only the high-water value is meaningful; 8067 ** the current value is always zero.)^ 8068 ** 8069 ** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL]] 8070 ** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL</dt> 8071 ** <dd>This parameter returns the number malloc attempts that might have 8072 ** been satisfied using lookaside memory but failed due to all lookaside 8073 ** memory already being in use. 8074 ** Only the high-water value is meaningful; 8075 ** the current value is always zero.)^ 8076 ** 8077 ** [[SQLITE_DBSTATUS_CACHE_USED]] ^(<dt>SQLITE_DBSTATUS_CACHE_USED</dt> 8078 ** <dd>This parameter returns the approximate number of bytes of heap 8079 ** memory used by all pager caches associated with the database connection.)^ 8080 ** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0. 8081 ** 8082 ** [[SQLITE_DBSTATUS_CACHE_USED_SHARED]] 8083 ** ^(<dt>SQLITE_DBSTATUS_CACHE_USED_SHARED</dt> 8084 ** <dd>This parameter is similar to DBSTATUS_CACHE_USED, except that if a 8085 ** pager cache is shared between two or more connections the bytes of heap 8086 ** memory used by that pager cache is divided evenly between the attached 8087 ** connections.)^ In other words, if none of the pager caches associated 8088 ** with the database connection are shared, this request returns the same 8089 ** value as DBSTATUS_CACHE_USED. Or, if one or more or the pager caches are 8090 ** shared, the value returned by this call will be smaller than that returned 8091 ** by DBSTATUS_CACHE_USED. ^The highwater mark associated with 8092 ** SQLITE_DBSTATUS_CACHE_USED_SHARED is always 0. 8093 ** 8094 ** [[SQLITE_DBSTATUS_SCHEMA_USED]] ^(<dt>SQLITE_DBSTATUS_SCHEMA_USED</dt> 8095 ** <dd>This parameter returns the approximate number of bytes of heap 8096 ** memory used to store the schema for all databases associated 8097 ** with the connection - main, temp, and any [ATTACH]-ed databases.)^ 8098 ** ^The full amount of memory used by the schemas is reported, even if the 8099 ** schema memory is shared with other database connections due to 8100 ** [shared cache mode] being enabled. 8101 ** ^The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0. 8102 ** 8103 ** [[SQLITE_DBSTATUS_STMT_USED]] ^(<dt>SQLITE_DBSTATUS_STMT_USED</dt> 8104 ** <dd>This parameter returns the approximate number of bytes of heap 8105 ** and lookaside memory used by all prepared statements associated with 8106 ** the database connection.)^ 8107 ** ^The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0. 8108 ** </dd> 8109 ** 8110 ** [[SQLITE_DBSTATUS_CACHE_HIT]] ^(<dt>SQLITE_DBSTATUS_CACHE_HIT</dt> 8111 ** <dd>This parameter returns the number of pager cache hits that have 8112 ** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_HIT 8113 ** is always 0. 8114 ** </dd> 8115 ** 8116 ** [[SQLITE_DBSTATUS_CACHE_MISS]] ^(<dt>SQLITE_DBSTATUS_CACHE_MISS</dt> 8117 ** <dd>This parameter returns the number of pager cache misses that have 8118 ** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_MISS 8119 ** is always 0. 8120 ** </dd> 8121 ** 8122 ** [[SQLITE_DBSTATUS_CACHE_WRITE]] ^(<dt>SQLITE_DBSTATUS_CACHE_WRITE</dt> 8123 ** <dd>This parameter returns the number of dirty cache entries that have 8124 ** been written to disk. Specifically, the number of pages written to the 8125 ** wal file in wal mode databases, or the number of pages written to the 8126 ** database file in rollback mode databases. Any pages written as part of 8127 ** transaction rollback or database recovery operations are not included. 8128 ** If an IO or other error occurs while writing a page to disk, the effect 8129 ** on subsequent SQLITE_DBSTATUS_CACHE_WRITE requests is undefined.)^ ^The 8130 ** highwater mark associated with SQLITE_DBSTATUS_CACHE_WRITE is always 0. 8131 ** </dd> 8132 ** 8133 ** [[SQLITE_DBSTATUS_CACHE_SPILL]] ^(<dt>SQLITE_DBSTATUS_CACHE_SPILL</dt> 8134 ** <dd>This parameter returns the number of dirty cache entries that have 8135 ** been written to disk in the middle of a transaction due to the page 8136 ** cache overflowing. Transactions are more efficient if they are written 8137 ** to disk all at once. When pages spill mid-transaction, that introduces 8138 ** additional overhead. This parameter can be used help identify 8139 ** inefficiencies that can be resolved by increasing the cache size. 8140 ** </dd> 8141 ** 8142 ** [[SQLITE_DBSTATUS_DEFERRED_FKS]] ^(<dt>SQLITE_DBSTATUS_DEFERRED_FKS</dt> 8143 ** <dd>This parameter returns zero for the current value if and only if 8144 ** all foreign key constraints (deferred or immediate) have been 8145 ** resolved.)^ ^The highwater mark is always 0. 8146 ** </dd> 8147 ** </dl> 8148 */ 8149 #define SQLITE_DBSTATUS_LOOKASIDE_USED 0 8150 #define SQLITE_DBSTATUS_CACHE_USED 1 8151 #define SQLITE_DBSTATUS_SCHEMA_USED 2 8152 #define SQLITE_DBSTATUS_STMT_USED 3 8153 #define SQLITE_DBSTATUS_LOOKASIDE_HIT 4 8154 #define SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE 5 8155 #define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL 6 8156 #define SQLITE_DBSTATUS_CACHE_HIT 7 8157 #define SQLITE_DBSTATUS_CACHE_MISS 8 8158 #define SQLITE_DBSTATUS_CACHE_WRITE 9 8159 #define SQLITE_DBSTATUS_DEFERRED_FKS 10 8160 #define SQLITE_DBSTATUS_CACHE_USED_SHARED 11 8161 #define SQLITE_DBSTATUS_CACHE_SPILL 12 8162 #define SQLITE_DBSTATUS_MAX 12 /* Largest defined DBSTATUS */ 8163 8164 8165 /* 8166 ** CAPI3REF: Prepared Statement Status 8167 ** METHOD: sqlite3_stmt 8168 ** 8169 ** ^(Each prepared statement maintains various 8170 ** [SQLITE_STMTSTATUS counters] that measure the number 8171 ** of times it has performed specific operations.)^ These counters can 8172 ** be used to monitor the performance characteristics of the prepared 8173 ** statements. For example, if the number of table steps greatly exceeds 8174 ** the number of table searches or result rows, that would tend to indicate 8175 ** that the prepared statement is using a full table scan rather than 8176 ** an index. 8177 ** 8178 ** ^(This interface is used to retrieve and reset counter values from 8179 ** a [prepared statement]. The first argument is the prepared statement 8180 ** object to be interrogated. The second argument 8181 ** is an integer code for a specific [SQLITE_STMTSTATUS counter] 8182 ** to be interrogated.)^ 8183 ** ^The current value of the requested counter is returned. 8184 ** ^If the resetFlg is true, then the counter is reset to zero after this 8185 ** interface call returns. 8186 ** 8187 ** See also: [sqlite3_status()] and [sqlite3_db_status()]. 8188 */ 8189 SQLITE_API int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg); 8190 8191 /* 8192 ** CAPI3REF: Status Parameters for prepared statements 8193 ** KEYWORDS: {SQLITE_STMTSTATUS counter} {SQLITE_STMTSTATUS counters} 8194 ** 8195 ** These preprocessor macros define integer codes that name counter 8196 ** values associated with the [sqlite3_stmt_status()] interface. 8197 ** The meanings of the various counters are as follows: 8198 ** 8199 ** <dl> 8200 ** [[SQLITE_STMTSTATUS_FULLSCAN_STEP]] <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt> 8201 ** <dd>^This is the number of times that SQLite has stepped forward in 8202 ** a table as part of a full table scan. Large numbers for this counter 8203 ** may indicate opportunities for performance improvement through 8204 ** careful use of indices.</dd> 8205 ** 8206 ** [[SQLITE_STMTSTATUS_SORT]] <dt>SQLITE_STMTSTATUS_SORT</dt> 8207 ** <dd>^This is the number of sort operations that have occurred. 8208 ** A non-zero value in this counter may indicate an opportunity to 8209 ** improvement performance through careful use of indices.</dd> 8210 ** 8211 ** [[SQLITE_STMTSTATUS_AUTOINDEX]] <dt>SQLITE_STMTSTATUS_AUTOINDEX</dt> 8212 ** <dd>^This is the number of rows inserted into transient indices that 8213 ** were created automatically in order to help joins run faster. 8214 ** A non-zero value in this counter may indicate an opportunity to 8215 ** improvement performance by adding permanent indices that do not 8216 ** need to be reinitialized each time the statement is run.</dd> 8217 ** 8218 ** [[SQLITE_STMTSTATUS_VM_STEP]] <dt>SQLITE_STMTSTATUS_VM_STEP</dt> 8219 ** <dd>^This is the number of virtual machine operations executed 8220 ** by the prepared statement if that number is less than or equal 8221 ** to 2147483647. The number of virtual machine operations can be 8222 ** used as a proxy for the total work done by the prepared statement. 8223 ** If the number of virtual machine operations exceeds 2147483647 8224 ** then the value returned by this statement status code is undefined. 8225 ** 8226 ** [[SQLITE_STMTSTATUS_REPREPARE]] <dt>SQLITE_STMTSTATUS_REPREPARE</dt> 8227 ** <dd>^This is the number of times that the prepare statement has been 8228 ** automatically regenerated due to schema changes or changes to 8229 ** [bound parameters] that might affect the query plan. 8230 ** 8231 ** [[SQLITE_STMTSTATUS_RUN]] <dt>SQLITE_STMTSTATUS_RUN</dt> 8232 ** <dd>^This is the number of times that the prepared statement has 8233 ** been run. A single "run" for the purposes of this counter is one 8234 ** or more calls to [sqlite3_step()] followed by a call to [sqlite3_reset()]. 8235 ** The counter is incremented on the first [sqlite3_step()] call of each 8236 ** cycle. 8237 ** 8238 ** [[SQLITE_STMTSTATUS_MEMUSED]] <dt>SQLITE_STMTSTATUS_MEMUSED</dt> 8239 ** <dd>^This is the approximate number of bytes of heap memory 8240 ** used to store the prepared statement. ^This value is not actually 8241 ** a counter, and so the resetFlg parameter to sqlite3_stmt_status() 8242 ** is ignored when the opcode is SQLITE_STMTSTATUS_MEMUSED. 8243 ** </dd> 8244 ** </dl> 8245 */ 8246 #define SQLITE_STMTSTATUS_FULLSCAN_STEP 1 8247 #define SQLITE_STMTSTATUS_SORT 2 8248 #define SQLITE_STMTSTATUS_AUTOINDEX 3 8249 #define SQLITE_STMTSTATUS_VM_STEP 4 8250 #define SQLITE_STMTSTATUS_REPREPARE 5 8251 #define SQLITE_STMTSTATUS_RUN 6 8252 #define SQLITE_STMTSTATUS_MEMUSED 99 8253 8254 /* 8255 ** CAPI3REF: Custom Page Cache Object 8256 ** 8257 ** The sqlite3_pcache type is opaque. It is implemented by 8258 ** the pluggable module. The SQLite core has no knowledge of 8259 ** its size or internal structure and never deals with the 8260 ** sqlite3_pcache object except by holding and passing pointers 8261 ** to the object. 8262 ** 8263 ** See [sqlite3_pcache_methods2] for additional information. 8264 */ 8265 typedef struct sqlite3_pcache sqlite3_pcache; 8266 8267 /* 8268 ** CAPI3REF: Custom Page Cache Object 8269 ** 8270 ** The sqlite3_pcache_page object represents a single page in the 8271 ** page cache. The page cache will allocate instances of this 8272 ** object. Various methods of the page cache use pointers to instances 8273 ** of this object as parameters or as their return value. 8274 ** 8275 ** See [sqlite3_pcache_methods2] for additional information. 8276 */ 8277 typedef struct sqlite3_pcache_page sqlite3_pcache_page; 8278 struct sqlite3_pcache_page { 8279 void *pBuf; /* The content of the page */ 8280 void *pExtra; /* Extra information associated with the page */ 8281 }; 8282 8283 /* 8284 ** CAPI3REF: Application Defined Page Cache. 8285 ** KEYWORDS: {page cache} 8286 ** 8287 ** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE2], ...) interface can 8288 ** register an alternative page cache implementation by passing in an 8289 ** instance of the sqlite3_pcache_methods2 structure.)^ 8290 ** In many applications, most of the heap memory allocated by 8291 ** SQLite is used for the page cache. 8292 ** By implementing a 8293 ** custom page cache using this API, an application can better control 8294 ** the amount of memory consumed by SQLite, the way in which 8295 ** that memory is allocated and released, and the policies used to 8296 ** determine exactly which parts of a database file are cached and for 8297 ** how long. 8298 ** 8299 ** The alternative page cache mechanism is an 8300 ** extreme measure that is only needed by the most demanding applications. 8301 ** The built-in page cache is recommended for most uses. 8302 ** 8303 ** ^(The contents of the sqlite3_pcache_methods2 structure are copied to an 8304 ** internal buffer by SQLite within the call to [sqlite3_config]. Hence 8305 ** the application may discard the parameter after the call to 8306 ** [sqlite3_config()] returns.)^ 8307 ** 8308 ** [[the xInit() page cache method]] 8309 ** ^(The xInit() method is called once for each effective 8310 ** call to [sqlite3_initialize()])^ 8311 ** (usually only once during the lifetime of the process). ^(The xInit() 8312 ** method is passed a copy of the sqlite3_pcache_methods2.pArg value.)^ 8313 ** The intent of the xInit() method is to set up global data structures 8314 ** required by the custom page cache implementation. 8315 ** ^(If the xInit() method is NULL, then the 8316 ** built-in default page cache is used instead of the application defined 8317 ** page cache.)^ 8318 ** 8319 ** [[the xShutdown() page cache method]] 8320 ** ^The xShutdown() method is called by [sqlite3_shutdown()]. 8321 ** It can be used to clean up 8322 ** any outstanding resources before process shutdown, if required. 8323 ** ^The xShutdown() method may be NULL. 8324 ** 8325 ** ^SQLite automatically serializes calls to the xInit method, 8326 ** so the xInit method need not be threadsafe. ^The 8327 ** xShutdown method is only called from [sqlite3_shutdown()] so it does 8328 ** not need to be threadsafe either. All other methods must be threadsafe 8329 ** in multithreaded applications. 8330 ** 8331 ** ^SQLite will never invoke xInit() more than once without an intervening 8332 ** call to xShutdown(). 8333 ** 8334 ** [[the xCreate() page cache methods]] 8335 ** ^SQLite invokes the xCreate() method to construct a new cache instance. 8336 ** SQLite will typically create one cache instance for each open database file, 8337 ** though this is not guaranteed. ^The 8338 ** first parameter, szPage, is the size in bytes of the pages that must 8339 ** be allocated by the cache. ^szPage will always a power of two. ^The 8340 ** second parameter szExtra is a number of bytes of extra storage 8341 ** associated with each page cache entry. ^The szExtra parameter will 8342 ** a number less than 250. SQLite will use the 8343 ** extra szExtra bytes on each page to store metadata about the underlying 8344 ** database page on disk. The value passed into szExtra depends 8345 ** on the SQLite version, the target platform, and how SQLite was compiled. 8346 ** ^The third argument to xCreate(), bPurgeable, is true if the cache being 8347 ** created will be used to cache database pages of a file stored on disk, or 8348 ** false if it is used for an in-memory database. The cache implementation 8349 ** does not have to do anything special based with the value of bPurgeable; 8350 ** it is purely advisory. ^On a cache where bPurgeable is false, SQLite will 8351 ** never invoke xUnpin() except to deliberately delete a page. 8352 ** ^In other words, calls to xUnpin() on a cache with bPurgeable set to 8353 ** false will always have the "discard" flag set to true. 8354 ** ^Hence, a cache created with bPurgeable false will 8355 ** never contain any unpinned pages. 8356 ** 8357 ** [[the xCachesize() page cache method]] 8358 ** ^(The xCachesize() method may be called at any time by SQLite to set the 8359 ** suggested maximum cache-size (number of pages stored by) the cache 8360 ** instance passed as the first argument. This is the value configured using 8361 ** the SQLite "[PRAGMA cache_size]" command.)^ As with the bPurgeable 8362 ** parameter, the implementation is not required to do anything with this 8363 ** value; it is advisory only. 8364 ** 8365 ** [[the xPagecount() page cache methods]] 8366 ** The xPagecount() method must return the number of pages currently 8367 ** stored in the cache, both pinned and unpinned. 8368 ** 8369 ** [[the xFetch() page cache methods]] 8370 ** The xFetch() method locates a page in the cache and returns a pointer to 8371 ** an sqlite3_pcache_page object associated with that page, or a NULL pointer. 8372 ** The pBuf element of the returned sqlite3_pcache_page object will be a 8373 ** pointer to a buffer of szPage bytes used to store the content of a 8374 ** single database page. The pExtra element of sqlite3_pcache_page will be 8375 ** a pointer to the szExtra bytes of extra storage that SQLite has requested 8376 ** for each entry in the page cache. 8377 ** 8378 ** The page to be fetched is determined by the key. ^The minimum key value 8379 ** is 1. After it has been retrieved using xFetch, the page is considered 8380 ** to be "pinned". 8381 ** 8382 ** If the requested page is already in the page cache, then the page cache 8383 ** implementation must return a pointer to the page buffer with its content 8384 ** intact. If the requested page is not already in the cache, then the 8385 ** cache implementation should use the value of the createFlag 8386 ** parameter to help it determined what action to take: 8387 ** 8388 ** <table border=1 width=85% align=center> 8389 ** <tr><th> createFlag <th> Behavior when page is not already in cache 8390 ** <tr><td> 0 <td> Do not allocate a new page. Return NULL. 8391 ** <tr><td> 1 <td> Allocate a new page if it easy and convenient to do so. 8392 ** Otherwise return NULL. 8393 ** <tr><td> 2 <td> Make every effort to allocate a new page. Only return 8394 ** NULL if allocating a new page is effectively impossible. 8395 ** </table> 8396 ** 8397 ** ^(SQLite will normally invoke xFetch() with a createFlag of 0 or 1. SQLite 8398 ** will only use a createFlag of 2 after a prior call with a createFlag of 1 8399 ** failed.)^ In between the xFetch() calls, SQLite may 8400 ** attempt to unpin one or more cache pages by spilling the content of 8401 ** pinned pages to disk and synching the operating system disk cache. 8402 ** 8403 ** [[the xUnpin() page cache method]] 8404 ** ^xUnpin() is called by SQLite with a pointer to a currently pinned page 8405 ** as its second argument. If the third parameter, discard, is non-zero, 8406 ** then the page must be evicted from the cache. 8407 ** ^If the discard parameter is 8408 ** zero, then the page may be discarded or retained at the discretion of 8409 ** page cache implementation. ^The page cache implementation 8410 ** may choose to evict unpinned pages at any time. 8411 ** 8412 ** The cache must not perform any reference counting. A single 8413 ** call to xUnpin() unpins the page regardless of the number of prior calls 8414 ** to xFetch(). 8415 ** 8416 ** [[the xRekey() page cache methods]] 8417 ** The xRekey() method is used to change the key value associated with the 8418 ** page passed as the second argument. If the cache 8419 ** previously contains an entry associated with newKey, it must be 8420 ** discarded. ^Any prior cache entry associated with newKey is guaranteed not 8421 ** to be pinned. 8422 ** 8423 ** When SQLite calls the xTruncate() method, the cache must discard all 8424 ** existing cache entries with page numbers (keys) greater than or equal 8425 ** to the value of the iLimit parameter passed to xTruncate(). If any 8426 ** of these pages are pinned, they are implicitly unpinned, meaning that 8427 ** they can be safely discarded. 8428 ** 8429 ** [[the xDestroy() page cache method]] 8430 ** ^The xDestroy() method is used to delete a cache allocated by xCreate(). 8431 ** All resources associated with the specified cache should be freed. ^After 8432 ** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*] 8433 ** handle invalid, and will not use it with any other sqlite3_pcache_methods2 8434 ** functions. 8435 ** 8436 ** [[the xShrink() page cache method]] 8437 ** ^SQLite invokes the xShrink() method when it wants the page cache to 8438 ** free up as much of heap memory as possible. The page cache implementation 8439 ** is not obligated to free any memory, but well-behaved implementations should 8440 ** do their best. 8441 */ 8442 typedef struct sqlite3_pcache_methods2 sqlite3_pcache_methods2; 8443 struct sqlite3_pcache_methods2 { 8444 int iVersion; 8445 void *pArg; 8446 int (*xInit)(void*); 8447 void (*xShutdown)(void*); 8448 sqlite3_pcache *(*xCreate)(int szPage, int szExtra, int bPurgeable); 8449 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 8450 int (*xPagecount)(sqlite3_pcache*); 8451 sqlite3_pcache_page *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 8452 void (*xUnpin)(sqlite3_pcache*, sqlite3_pcache_page*, int discard); 8453 void (*xRekey)(sqlite3_pcache*, sqlite3_pcache_page*, 8454 unsigned oldKey, unsigned newKey); 8455 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 8456 void (*xDestroy)(sqlite3_pcache*); 8457 void (*xShrink)(sqlite3_pcache*); 8458 }; 8459 8460 /* 8461 ** This is the obsolete pcache_methods object that has now been replaced 8462 ** by sqlite3_pcache_methods2. This object is not used by SQLite. It is 8463 ** retained in the header file for backwards compatibility only. 8464 */ 8465 typedef struct sqlite3_pcache_methods sqlite3_pcache_methods; 8466 struct sqlite3_pcache_methods { 8467 void *pArg; 8468 int (*xInit)(void*); 8469 void (*xShutdown)(void*); 8470 sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable); 8471 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 8472 int (*xPagecount)(sqlite3_pcache*); 8473 void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 8474 void (*xUnpin)(sqlite3_pcache*, void*, int discard); 8475 void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey); 8476 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 8477 void (*xDestroy)(sqlite3_pcache*); 8478 }; 8479 8480 8481 /* 8482 ** CAPI3REF: Online Backup Object 8483 ** 8484 ** The sqlite3_backup object records state information about an ongoing 8485 ** online backup operation. ^The sqlite3_backup object is created by 8486 ** a call to [sqlite3_backup_init()] and is destroyed by a call to 8487 ** [sqlite3_backup_finish()]. 8488 ** 8489 ** See Also: [Using the SQLite Online Backup API] 8490 */ 8491 typedef struct sqlite3_backup sqlite3_backup; 8492 8493 /* 8494 ** CAPI3REF: Online Backup API. 8495 ** 8496 ** The backup API copies the content of one database into another. 8497 ** It is useful either for creating backups of databases or 8498 ** for copying in-memory databases to or from persistent files. 8499 ** 8500 ** See Also: [Using the SQLite Online Backup API] 8501 ** 8502 ** ^SQLite holds a write transaction open on the destination database file 8503 ** for the duration of the backup operation. 8504 ** ^The source database is read-locked only while it is being read; 8505 ** it is not locked continuously for the entire backup operation. 8506 ** ^Thus, the backup may be performed on a live source database without 8507 ** preventing other database connections from 8508 ** reading or writing to the source database while the backup is underway. 8509 ** 8510 ** ^(To perform a backup operation: 8511 ** <ol> 8512 ** <li><b>sqlite3_backup_init()</b> is called once to initialize the 8513 ** backup, 8514 ** <li><b>sqlite3_backup_step()</b> is called one or more times to transfer 8515 ** the data between the two databases, and finally 8516 ** <li><b>sqlite3_backup_finish()</b> is called to release all resources 8517 ** associated with the backup operation. 8518 ** </ol>)^ 8519 ** There should be exactly one call to sqlite3_backup_finish() for each 8520 ** successful call to sqlite3_backup_init(). 8521 ** 8522 ** [[sqlite3_backup_init()]] <b>sqlite3_backup_init()</b> 8523 ** 8524 ** ^The D and N arguments to sqlite3_backup_init(D,N,S,M) are the 8525 ** [database connection] associated with the destination database 8526 ** and the database name, respectively. 8527 ** ^The database name is "main" for the main database, "temp" for the 8528 ** temporary database, or the name specified after the AS keyword in 8529 ** an [ATTACH] statement for an attached database. 8530 ** ^The S and M arguments passed to 8531 ** sqlite3_backup_init(D,N,S,M) identify the [database connection] 8532 ** and database name of the source database, respectively. 8533 ** ^The source and destination [database connections] (parameters S and D) 8534 ** must be different or else sqlite3_backup_init(D,N,S,M) will fail with 8535 ** an error. 8536 ** 8537 ** ^A call to sqlite3_backup_init() will fail, returning NULL, if 8538 ** there is already a read or read-write transaction open on the 8539 ** destination database. 8540 ** 8541 ** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is 8542 ** returned and an error code and error message are stored in the 8543 ** destination [database connection] D. 8544 ** ^The error code and message for the failed call to sqlite3_backup_init() 8545 ** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or 8546 ** [sqlite3_errmsg16()] functions. 8547 ** ^A successful call to sqlite3_backup_init() returns a pointer to an 8548 ** [sqlite3_backup] object. 8549 ** ^The [sqlite3_backup] object may be used with the sqlite3_backup_step() and 8550 ** sqlite3_backup_finish() functions to perform the specified backup 8551 ** operation. 8552 ** 8553 ** [[sqlite3_backup_step()]] <b>sqlite3_backup_step()</b> 8554 ** 8555 ** ^Function sqlite3_backup_step(B,N) will copy up to N pages between 8556 ** the source and destination databases specified by [sqlite3_backup] object B. 8557 ** ^If N is negative, all remaining source pages are copied. 8558 ** ^If sqlite3_backup_step(B,N) successfully copies N pages and there 8559 ** are still more pages to be copied, then the function returns [SQLITE_OK]. 8560 ** ^If sqlite3_backup_step(B,N) successfully finishes copying all pages 8561 ** from source to destination, then it returns [SQLITE_DONE]. 8562 ** ^If an error occurs while running sqlite3_backup_step(B,N), 8563 ** then an [error code] is returned. ^As well as [SQLITE_OK] and 8564 ** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY], 8565 ** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an 8566 ** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code. 8567 ** 8568 ** ^(The sqlite3_backup_step() might return [SQLITE_READONLY] if 8569 ** <ol> 8570 ** <li> the destination database was opened read-only, or 8571 ** <li> the destination database is using write-ahead-log journaling 8572 ** and the destination and source page sizes differ, or 8573 ** <li> the destination database is an in-memory database and the 8574 ** destination and source page sizes differ. 8575 ** </ol>)^ 8576 ** 8577 ** ^If sqlite3_backup_step() cannot obtain a required file-system lock, then 8578 ** the [sqlite3_busy_handler | busy-handler function] 8579 ** is invoked (if one is specified). ^If the 8580 ** busy-handler returns non-zero before the lock is available, then 8581 ** [SQLITE_BUSY] is returned to the caller. ^In this case the call to 8582 ** sqlite3_backup_step() can be retried later. ^If the source 8583 ** [database connection] 8584 ** is being used to write to the source database when sqlite3_backup_step() 8585 ** is called, then [SQLITE_LOCKED] is returned immediately. ^Again, in this 8586 ** case the call to sqlite3_backup_step() can be retried later on. ^(If 8587 ** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or 8588 ** [SQLITE_READONLY] is returned, then 8589 ** there is no point in retrying the call to sqlite3_backup_step(). These 8590 ** errors are considered fatal.)^ The application must accept 8591 ** that the backup operation has failed and pass the backup operation handle 8592 ** to the sqlite3_backup_finish() to release associated resources. 8593 ** 8594 ** ^The first call to sqlite3_backup_step() obtains an exclusive lock 8595 ** on the destination file. ^The exclusive lock is not released until either 8596 ** sqlite3_backup_finish() is called or the backup operation is complete 8597 ** and sqlite3_backup_step() returns [SQLITE_DONE]. ^Every call to 8598 ** sqlite3_backup_step() obtains a [shared lock] on the source database that 8599 ** lasts for the duration of the sqlite3_backup_step() call. 8600 ** ^Because the source database is not locked between calls to 8601 ** sqlite3_backup_step(), the source database may be modified mid-way 8602 ** through the backup process. ^If the source database is modified by an 8603 ** external process or via a database connection other than the one being 8604 ** used by the backup operation, then the backup will be automatically 8605 ** restarted by the next call to sqlite3_backup_step(). ^If the source 8606 ** database is modified by the using the same database connection as is used 8607 ** by the backup operation, then the backup database is automatically 8608 ** updated at the same time. 8609 ** 8610 ** [[sqlite3_backup_finish()]] <b>sqlite3_backup_finish()</b> 8611 ** 8612 ** When sqlite3_backup_step() has returned [SQLITE_DONE], or when the 8613 ** application wishes to abandon the backup operation, the application 8614 ** should destroy the [sqlite3_backup] by passing it to sqlite3_backup_finish(). 8615 ** ^The sqlite3_backup_finish() interfaces releases all 8616 ** resources associated with the [sqlite3_backup] object. 8617 ** ^If sqlite3_backup_step() has not yet returned [SQLITE_DONE], then any 8618 ** active write-transaction on the destination database is rolled back. 8619 ** The [sqlite3_backup] object is invalid 8620 ** and may not be used following a call to sqlite3_backup_finish(). 8621 ** 8622 ** ^The value returned by sqlite3_backup_finish is [SQLITE_OK] if no 8623 ** sqlite3_backup_step() errors occurred, regardless or whether or not 8624 ** sqlite3_backup_step() completed. 8625 ** ^If an out-of-memory condition or IO error occurred during any prior 8626 ** sqlite3_backup_step() call on the same [sqlite3_backup] object, then 8627 ** sqlite3_backup_finish() returns the corresponding [error code]. 8628 ** 8629 ** ^A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step() 8630 ** is not a permanent error and does not affect the return value of 8631 ** sqlite3_backup_finish(). 8632 ** 8633 ** [[sqlite3_backup_remaining()]] [[sqlite3_backup_pagecount()]] 8634 ** <b>sqlite3_backup_remaining() and sqlite3_backup_pagecount()</b> 8635 ** 8636 ** ^The sqlite3_backup_remaining() routine returns the number of pages still 8637 ** to be backed up at the conclusion of the most recent sqlite3_backup_step(). 8638 ** ^The sqlite3_backup_pagecount() routine returns the total number of pages 8639 ** in the source database at the conclusion of the most recent 8640 ** sqlite3_backup_step(). 8641 ** ^(The values returned by these functions are only updated by 8642 ** sqlite3_backup_step(). If the source database is modified in a way that 8643 ** changes the size of the source database or the number of pages remaining, 8644 ** those changes are not reflected in the output of sqlite3_backup_pagecount() 8645 ** and sqlite3_backup_remaining() until after the next 8646 ** sqlite3_backup_step().)^ 8647 ** 8648 ** <b>Concurrent Usage of Database Handles</b> 8649 ** 8650 ** ^The source [database connection] may be used by the application for other 8651 ** purposes while a backup operation is underway or being initialized. 8652 ** ^If SQLite is compiled and configured to support threadsafe database 8653 ** connections, then the source database connection may be used concurrently 8654 ** from within other threads. 8655 ** 8656 ** However, the application must guarantee that the destination 8657 ** [database connection] is not passed to any other API (by any thread) after 8658 ** sqlite3_backup_init() is called and before the corresponding call to 8659 ** sqlite3_backup_finish(). SQLite does not currently check to see 8660 ** if the application incorrectly accesses the destination [database connection] 8661 ** and so no error code is reported, but the operations may malfunction 8662 ** nevertheless. Use of the destination database connection while a 8663 ** backup is in progress might also also cause a mutex deadlock. 8664 ** 8665 ** If running in [shared cache mode], the application must 8666 ** guarantee that the shared cache used by the destination database 8667 ** is not accessed while the backup is running. In practice this means 8668 ** that the application must guarantee that the disk file being 8669 ** backed up to is not accessed by any connection within the process, 8670 ** not just the specific connection that was passed to sqlite3_backup_init(). 8671 ** 8672 ** The [sqlite3_backup] object itself is partially threadsafe. Multiple 8673 ** threads may safely make multiple concurrent calls to sqlite3_backup_step(). 8674 ** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount() 8675 ** APIs are not strictly speaking threadsafe. If they are invoked at the 8676 ** same time as another thread is invoking sqlite3_backup_step() it is 8677 ** possible that they return invalid values. 8678 */ 8679 SQLITE_API sqlite3_backup *sqlite3_backup_init( 8680 sqlite3 *pDest, /* Destination database handle */ 8681 const char *zDestName, /* Destination database name */ 8682 sqlite3 *pSource, /* Source database handle */ 8683 const char *zSourceName /* Source database name */ 8684 ); 8685 SQLITE_API int sqlite3_backup_step(sqlite3_backup *p, int nPage); 8686 SQLITE_API int sqlite3_backup_finish(sqlite3_backup *p); 8687 SQLITE_API int sqlite3_backup_remaining(sqlite3_backup *p); 8688 SQLITE_API int sqlite3_backup_pagecount(sqlite3_backup *p); 8689 8690 /* 8691 ** CAPI3REF: Unlock Notification 8692 ** METHOD: sqlite3 8693 ** 8694 ** ^When running in shared-cache mode, a database operation may fail with 8695 ** an [SQLITE_LOCKED] error if the required locks on the shared-cache or 8696 ** individual tables within the shared-cache cannot be obtained. See 8697 ** [SQLite Shared-Cache Mode] for a description of shared-cache locking. 8698 ** ^This API may be used to register a callback that SQLite will invoke 8699 ** when the connection currently holding the required lock relinquishes it. 8700 ** ^This API is only available if the library was compiled with the 8701 ** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined. 8702 ** 8703 ** See Also: [Using the SQLite Unlock Notification Feature]. 8704 ** 8705 ** ^Shared-cache locks are released when a database connection concludes 8706 ** its current transaction, either by committing it or rolling it back. 8707 ** 8708 ** ^When a connection (known as the blocked connection) fails to obtain a 8709 ** shared-cache lock and SQLITE_LOCKED is returned to the caller, the 8710 ** identity of the database connection (the blocking connection) that 8711 ** has locked the required resource is stored internally. ^After an 8712 ** application receives an SQLITE_LOCKED error, it may call the 8713 ** sqlite3_unlock_notify() method with the blocked connection handle as 8714 ** the first argument to register for a callback that will be invoked 8715 ** when the blocking connections current transaction is concluded. ^The 8716 ** callback is invoked from within the [sqlite3_step] or [sqlite3_close] 8717 ** call that concludes the blocking connection's transaction. 8718 ** 8719 ** ^(If sqlite3_unlock_notify() is called in a multi-threaded application, 8720 ** there is a chance that the blocking connection will have already 8721 ** concluded its transaction by the time sqlite3_unlock_notify() is invoked. 8722 ** If this happens, then the specified callback is invoked immediately, 8723 ** from within the call to sqlite3_unlock_notify().)^ 8724 ** 8725 ** ^If the blocked connection is attempting to obtain a write-lock on a 8726 ** shared-cache table, and more than one other connection currently holds 8727 ** a read-lock on the same table, then SQLite arbitrarily selects one of 8728 ** the other connections to use as the blocking connection. 8729 ** 8730 ** ^(There may be at most one unlock-notify callback registered by a 8731 ** blocked connection. If sqlite3_unlock_notify() is called when the 8732 ** blocked connection already has a registered unlock-notify callback, 8733 ** then the new callback replaces the old.)^ ^If sqlite3_unlock_notify() is 8734 ** called with a NULL pointer as its second argument, then any existing 8735 ** unlock-notify callback is canceled. ^The blocked connections 8736 ** unlock-notify callback may also be canceled by closing the blocked 8737 ** connection using [sqlite3_close()]. 8738 ** 8739 ** The unlock-notify callback is not reentrant. If an application invokes 8740 ** any sqlite3_xxx API functions from within an unlock-notify callback, a 8741 ** crash or deadlock may be the result. 8742 ** 8743 ** ^Unless deadlock is detected (see below), sqlite3_unlock_notify() always 8744 ** returns SQLITE_OK. 8745 ** 8746 ** <b>Callback Invocation Details</b> 8747 ** 8748 ** When an unlock-notify callback is registered, the application provides a 8749 ** single void* pointer that is passed to the callback when it is invoked. 8750 ** However, the signature of the callback function allows SQLite to pass 8751 ** it an array of void* context pointers. The first argument passed to 8752 ** an unlock-notify callback is a pointer to an array of void* pointers, 8753 ** and the second is the number of entries in the array. 8754 ** 8755 ** When a blocking connection's transaction is concluded, there may be 8756 ** more than one blocked connection that has registered for an unlock-notify 8757 ** callback. ^If two or more such blocked connections have specified the 8758 ** same callback function, then instead of invoking the callback function 8759 ** multiple times, it is invoked once with the set of void* context pointers 8760 ** specified by the blocked connections bundled together into an array. 8761 ** This gives the application an opportunity to prioritize any actions 8762 ** related to the set of unblocked database connections. 8763 ** 8764 ** <b>Deadlock Detection</b> 8765 ** 8766 ** Assuming that after registering for an unlock-notify callback a 8767 ** database waits for the callback to be issued before taking any further 8768 ** action (a reasonable assumption), then using this API may cause the 8769 ** application to deadlock. For example, if connection X is waiting for 8770 ** connection Y's transaction to be concluded, and similarly connection 8771 ** Y is waiting on connection X's transaction, then neither connection 8772 ** will proceed and the system may remain deadlocked indefinitely. 8773 ** 8774 ** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock 8775 ** detection. ^If a given call to sqlite3_unlock_notify() would put the 8776 ** system in a deadlocked state, then SQLITE_LOCKED is returned and no 8777 ** unlock-notify callback is registered. The system is said to be in 8778 ** a deadlocked state if connection A has registered for an unlock-notify 8779 ** callback on the conclusion of connection B's transaction, and connection 8780 ** B has itself registered for an unlock-notify callback when connection 8781 ** A's transaction is concluded. ^Indirect deadlock is also detected, so 8782 ** the system is also considered to be deadlocked if connection B has 8783 ** registered for an unlock-notify callback on the conclusion of connection 8784 ** C's transaction, where connection C is waiting on connection A. ^Any 8785 ** number of levels of indirection are allowed. 8786 ** 8787 ** <b>The "DROP TABLE" Exception</b> 8788 ** 8789 ** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost 8790 ** always appropriate to call sqlite3_unlock_notify(). There is however, 8791 ** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement, 8792 ** SQLite checks if there are any currently executing SELECT statements 8793 ** that belong to the same connection. If there are, SQLITE_LOCKED is 8794 ** returned. In this case there is no "blocking connection", so invoking 8795 ** sqlite3_unlock_notify() results in the unlock-notify callback being 8796 ** invoked immediately. If the application then re-attempts the "DROP TABLE" 8797 ** or "DROP INDEX" query, an infinite loop might be the result. 8798 ** 8799 ** One way around this problem is to check the extended error code returned 8800 ** by an sqlite3_step() call. ^(If there is a blocking connection, then the 8801 ** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in 8802 ** the special "DROP TABLE/INDEX" case, the extended error code is just 8803 ** SQLITE_LOCKED.)^ 8804 */ 8805 SQLITE_API int sqlite3_unlock_notify( 8806 sqlite3 *pBlocked, /* Waiting connection */ 8807 void (*xNotify)(void **apArg, int nArg), /* Callback function to invoke */ 8808 void *pNotifyArg /* Argument to pass to xNotify */ 8809 ); 8810 8811 8812 /* 8813 ** CAPI3REF: String Comparison 8814 ** 8815 ** ^The [sqlite3_stricmp()] and [sqlite3_strnicmp()] APIs allow applications 8816 ** and extensions to compare the contents of two buffers containing UTF-8 8817 ** strings in a case-independent fashion, using the same definition of "case 8818 ** independence" that SQLite uses internally when comparing identifiers. 8819 */ 8820 SQLITE_API int sqlite3_stricmp(const char *, const char *); 8821 SQLITE_API int sqlite3_strnicmp(const char *, const char *, int); 8822 8823 /* 8824 ** CAPI3REF: String Globbing 8825 * 8826 ** ^The [sqlite3_strglob(P,X)] interface returns zero if and only if 8827 ** string X matches the [GLOB] pattern P. 8828 ** ^The definition of [GLOB] pattern matching used in 8829 ** [sqlite3_strglob(P,X)] is the same as for the "X GLOB P" operator in the 8830 ** SQL dialect understood by SQLite. ^The [sqlite3_strglob(P,X)] function 8831 ** is case sensitive. 8832 ** 8833 ** Note that this routine returns zero on a match and non-zero if the strings 8834 ** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()]. 8835 ** 8836 ** See also: [sqlite3_strlike()]. 8837 */ 8838 SQLITE_API int sqlite3_strglob(const char *zGlob, const char *zStr); 8839 8840 /* 8841 ** CAPI3REF: String LIKE Matching 8842 * 8843 ** ^The [sqlite3_strlike(P,X,E)] interface returns zero if and only if 8844 ** string X matches the [LIKE] pattern P with escape character E. 8845 ** ^The definition of [LIKE] pattern matching used in 8846 ** [sqlite3_strlike(P,X,E)] is the same as for the "X LIKE P ESCAPE E" 8847 ** operator in the SQL dialect understood by SQLite. ^For "X LIKE P" without 8848 ** the ESCAPE clause, set the E parameter of [sqlite3_strlike(P,X,E)] to 0. 8849 ** ^As with the LIKE operator, the [sqlite3_strlike(P,X,E)] function is case 8850 ** insensitive - equivalent upper and lower case ASCII characters match 8851 ** one another. 8852 ** 8853 ** ^The [sqlite3_strlike(P,X,E)] function matches Unicode characters, though 8854 ** only ASCII characters are case folded. 8855 ** 8856 ** Note that this routine returns zero on a match and non-zero if the strings 8857 ** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()]. 8858 ** 8859 ** See also: [sqlite3_strglob()]. 8860 */ 8861 SQLITE_API int sqlite3_strlike(const char *zGlob, const char *zStr, unsigned int cEsc); 8862 8863 /* 8864 ** CAPI3REF: Error Logging Interface 8865 ** 8866 ** ^The [sqlite3_log()] interface writes a message into the [error log] 8867 ** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()]. 8868 ** ^If logging is enabled, the zFormat string and subsequent arguments are 8869 ** used with [sqlite3_snprintf()] to generate the final output string. 8870 ** 8871 ** The sqlite3_log() interface is intended for use by extensions such as 8872 ** virtual tables, collating functions, and SQL functions. While there is 8873 ** nothing to prevent an application from calling sqlite3_log(), doing so 8874 ** is considered bad form. 8875 ** 8876 ** The zFormat string must not be NULL. 8877 ** 8878 ** To avoid deadlocks and other threading problems, the sqlite3_log() routine 8879 ** will not use dynamically allocated memory. The log message is stored in 8880 ** a fixed-length buffer on the stack. If the log message is longer than 8881 ** a few hundred characters, it will be truncated to the length of the 8882 ** buffer. 8883 */ 8884 SQLITE_API void sqlite3_log(int iErrCode, const char *zFormat, ...); 8885 8886 /* 8887 ** CAPI3REF: Write-Ahead Log Commit Hook 8888 ** METHOD: sqlite3 8889 ** 8890 ** ^The [sqlite3_wal_hook()] function is used to register a callback that 8891 ** is invoked each time data is committed to a database in wal mode. 8892 ** 8893 ** ^(The callback is invoked by SQLite after the commit has taken place and 8894 ** the associated write-lock on the database released)^, so the implementation 8895 ** may read, write or [checkpoint] the database as required. 8896 ** 8897 ** ^The first parameter passed to the callback function when it is invoked 8898 ** is a copy of the third parameter passed to sqlite3_wal_hook() when 8899 ** registering the callback. ^The second is a copy of the database handle. 8900 ** ^The third parameter is the name of the database that was written to - 8901 ** either "main" or the name of an [ATTACH]-ed database. ^The fourth parameter 8902 ** is the number of pages currently in the write-ahead log file, 8903 ** including those that were just committed. 8904 ** 8905 ** The callback function should normally return [SQLITE_OK]. ^If an error 8906 ** code is returned, that error will propagate back up through the 8907 ** SQLite code base to cause the statement that provoked the callback 8908 ** to report an error, though the commit will have still occurred. If the 8909 ** callback returns [SQLITE_ROW] or [SQLITE_DONE], or if it returns a value 8910 ** that does not correspond to any valid SQLite error code, the results 8911 ** are undefined. 8912 ** 8913 ** A single database handle may have at most a single write-ahead log callback 8914 ** registered at one time. ^Calling [sqlite3_wal_hook()] replaces any 8915 ** previously registered write-ahead log callback. ^Note that the 8916 ** [sqlite3_wal_autocheckpoint()] interface and the 8917 ** [wal_autocheckpoint pragma] both invoke [sqlite3_wal_hook()] and will 8918 ** overwrite any prior [sqlite3_wal_hook()] settings. 8919 */ 8920 SQLITE_API void *sqlite3_wal_hook( 8921 sqlite3*, 8922 int(*)(void *,sqlite3*,const char*,int), 8923 void* 8924 ); 8925 8926 /* 8927 ** CAPI3REF: Configure an auto-checkpoint 8928 ** METHOD: sqlite3 8929 ** 8930 ** ^The [sqlite3_wal_autocheckpoint(D,N)] is a wrapper around 8931 ** [sqlite3_wal_hook()] that causes any database on [database connection] D 8932 ** to automatically [checkpoint] 8933 ** after committing a transaction if there are N or 8934 ** more frames in the [write-ahead log] file. ^Passing zero or 8935 ** a negative value as the nFrame parameter disables automatic 8936 ** checkpoints entirely. 8937 ** 8938 ** ^The callback registered by this function replaces any existing callback 8939 ** registered using [sqlite3_wal_hook()]. ^Likewise, registering a callback 8940 ** using [sqlite3_wal_hook()] disables the automatic checkpoint mechanism 8941 ** configured by this function. 8942 ** 8943 ** ^The [wal_autocheckpoint pragma] can be used to invoke this interface 8944 ** from SQL. 8945 ** 8946 ** ^Checkpoints initiated by this mechanism are 8947 ** [sqlite3_wal_checkpoint_v2|PASSIVE]. 8948 ** 8949 ** ^Every new [database connection] defaults to having the auto-checkpoint 8950 ** enabled with a threshold of 1000 or [SQLITE_DEFAULT_WAL_AUTOCHECKPOINT] 8951 ** pages. The use of this interface 8952 ** is only necessary if the default setting is found to be suboptimal 8953 ** for a particular application. 8954 */ 8955 SQLITE_API int sqlite3_wal_autocheckpoint(sqlite3 *db, int N); 8956 8957 /* 8958 ** CAPI3REF: Checkpoint a database 8959 ** METHOD: sqlite3 8960 ** 8961 ** ^(The sqlite3_wal_checkpoint(D,X) is equivalent to 8962 ** [sqlite3_wal_checkpoint_v2](D,X,[SQLITE_CHECKPOINT_PASSIVE],0,0).)^ 8963 ** 8964 ** In brief, sqlite3_wal_checkpoint(D,X) causes the content in the 8965 ** [write-ahead log] for database X on [database connection] D to be 8966 ** transferred into the database file and for the write-ahead log to 8967 ** be reset. See the [checkpointing] documentation for addition 8968 ** information. 8969 ** 8970 ** This interface used to be the only way to cause a checkpoint to 8971 ** occur. But then the newer and more powerful [sqlite3_wal_checkpoint_v2()] 8972 ** interface was added. This interface is retained for backwards 8973 ** compatibility and as a convenience for applications that need to manually 8974 ** start a callback but which do not need the full power (and corresponding 8975 ** complication) of [sqlite3_wal_checkpoint_v2()]. 8976 */ 8977 SQLITE_API int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb); 8978 8979 /* 8980 ** CAPI3REF: Checkpoint a database 8981 ** METHOD: sqlite3 8982 ** 8983 ** ^(The sqlite3_wal_checkpoint_v2(D,X,M,L,C) interface runs a checkpoint 8984 ** operation on database X of [database connection] D in mode M. Status 8985 ** information is written back into integers pointed to by L and C.)^ 8986 ** ^(The M parameter must be a valid [checkpoint mode]:)^ 8987 ** 8988 ** <dl> 8989 ** <dt>SQLITE_CHECKPOINT_PASSIVE<dd> 8990 ** ^Checkpoint as many frames as possible without waiting for any database 8991 ** readers or writers to finish, then sync the database file if all frames 8992 ** in the log were checkpointed. ^The [busy-handler callback] 8993 ** is never invoked in the SQLITE_CHECKPOINT_PASSIVE mode. 8994 ** ^On the other hand, passive mode might leave the checkpoint unfinished 8995 ** if there are concurrent readers or writers. 8996 ** 8997 ** <dt>SQLITE_CHECKPOINT_FULL<dd> 8998 ** ^This mode blocks (it invokes the 8999 ** [sqlite3_busy_handler|busy-handler callback]) until there is no 9000 ** database writer and all readers are reading from the most recent database 9001 ** snapshot. ^It then checkpoints all frames in the log file and syncs the 9002 ** database file. ^This mode blocks new database writers while it is pending, 9003 ** but new database readers are allowed to continue unimpeded. 9004 ** 9005 ** <dt>SQLITE_CHECKPOINT_RESTART<dd> 9006 ** ^This mode works the same way as SQLITE_CHECKPOINT_FULL with the addition 9007 ** that after checkpointing the log file it blocks (calls the 9008 ** [busy-handler callback]) 9009 ** until all readers are reading from the database file only. ^This ensures 9010 ** that the next writer will restart the log file from the beginning. 9011 ** ^Like SQLITE_CHECKPOINT_FULL, this mode blocks new 9012 ** database writer attempts while it is pending, but does not impede readers. 9013 ** 9014 ** <dt>SQLITE_CHECKPOINT_TRUNCATE<dd> 9015 ** ^This mode works the same way as SQLITE_CHECKPOINT_RESTART with the 9016 ** addition that it also truncates the log file to zero bytes just prior 9017 ** to a successful return. 9018 ** </dl> 9019 ** 9020 ** ^If pnLog is not NULL, then *pnLog is set to the total number of frames in 9021 ** the log file or to -1 if the checkpoint could not run because 9022 ** of an error or because the database is not in [WAL mode]. ^If pnCkpt is not 9023 ** NULL,then *pnCkpt is set to the total number of checkpointed frames in the 9024 ** log file (including any that were already checkpointed before the function 9025 ** was called) or to -1 if the checkpoint could not run due to an error or 9026 ** because the database is not in WAL mode. ^Note that upon successful 9027 ** completion of an SQLITE_CHECKPOINT_TRUNCATE, the log file will have been 9028 ** truncated to zero bytes and so both *pnLog and *pnCkpt will be set to zero. 9029 ** 9030 ** ^All calls obtain an exclusive "checkpoint" lock on the database file. ^If 9031 ** any other process is running a checkpoint operation at the same time, the 9032 ** lock cannot be obtained and SQLITE_BUSY is returned. ^Even if there is a 9033 ** busy-handler configured, it will not be invoked in this case. 9034 ** 9035 ** ^The SQLITE_CHECKPOINT_FULL, RESTART and TRUNCATE modes also obtain the 9036 ** exclusive "writer" lock on the database file. ^If the writer lock cannot be 9037 ** obtained immediately, and a busy-handler is configured, it is invoked and 9038 ** the writer lock retried until either the busy-handler returns 0 or the lock 9039 ** is successfully obtained. ^The busy-handler is also invoked while waiting for 9040 ** database readers as described above. ^If the busy-handler returns 0 before 9041 ** the writer lock is obtained or while waiting for database readers, the 9042 ** checkpoint operation proceeds from that point in the same way as 9043 ** SQLITE_CHECKPOINT_PASSIVE - checkpointing as many frames as possible 9044 ** without blocking any further. ^SQLITE_BUSY is returned in this case. 9045 ** 9046 ** ^If parameter zDb is NULL or points to a zero length string, then the 9047 ** specified operation is attempted on all WAL databases [attached] to 9048 ** [database connection] db. In this case the 9049 ** values written to output parameters *pnLog and *pnCkpt are undefined. ^If 9050 ** an SQLITE_BUSY error is encountered when processing one or more of the 9051 ** attached WAL databases, the operation is still attempted on any remaining 9052 ** attached databases and SQLITE_BUSY is returned at the end. ^If any other 9053 ** error occurs while processing an attached database, processing is abandoned 9054 ** and the error code is returned to the caller immediately. ^If no error 9055 ** (SQLITE_BUSY or otherwise) is encountered while processing the attached 9056 ** databases, SQLITE_OK is returned. 9057 ** 9058 ** ^If database zDb is the name of an attached database that is not in WAL 9059 ** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. ^If 9060 ** zDb is not NULL (or a zero length string) and is not the name of any 9061 ** attached database, SQLITE_ERROR is returned to the caller. 9062 ** 9063 ** ^Unless it returns SQLITE_MISUSE, 9064 ** the sqlite3_wal_checkpoint_v2() interface 9065 ** sets the error information that is queried by 9066 ** [sqlite3_errcode()] and [sqlite3_errmsg()]. 9067 ** 9068 ** ^The [PRAGMA wal_checkpoint] command can be used to invoke this interface 9069 ** from SQL. 9070 */ 9071 SQLITE_API int sqlite3_wal_checkpoint_v2( 9072 sqlite3 *db, /* Database handle */ 9073 const char *zDb, /* Name of attached database (or NULL) */ 9074 int eMode, /* SQLITE_CHECKPOINT_* value */ 9075 int *pnLog, /* OUT: Size of WAL log in frames */ 9076 int *pnCkpt /* OUT: Total number of frames checkpointed */ 9077 ); 9078 9079 /* 9080 ** CAPI3REF: Checkpoint Mode Values 9081 ** KEYWORDS: {checkpoint mode} 9082 ** 9083 ** These constants define all valid values for the "checkpoint mode" passed 9084 ** as the third parameter to the [sqlite3_wal_checkpoint_v2()] interface. 9085 ** See the [sqlite3_wal_checkpoint_v2()] documentation for details on the 9086 ** meaning of each of these checkpoint modes. 9087 */ 9088 #define SQLITE_CHECKPOINT_PASSIVE 0 /* Do as much as possible w/o blocking */ 9089 #define SQLITE_CHECKPOINT_FULL 1 /* Wait for writers, then checkpoint */ 9090 #define SQLITE_CHECKPOINT_RESTART 2 /* Like FULL but wait for for readers */ 9091 #define SQLITE_CHECKPOINT_TRUNCATE 3 /* Like RESTART but also truncate WAL */ 9092 9093 /* 9094 ** CAPI3REF: Virtual Table Interface Configuration 9095 ** 9096 ** This function may be called by either the [xConnect] or [xCreate] method 9097 ** of a [virtual table] implementation to configure 9098 ** various facets of the virtual table interface. 9099 ** 9100 ** If this interface is invoked outside the context of an xConnect or 9101 ** xCreate virtual table method then the behavior is undefined. 9102 ** 9103 ** In the call sqlite3_vtab_config(D,C,...) the D parameter is the 9104 ** [database connection] in which the virtual table is being created and 9105 ** which is passed in as the first argument to the [xConnect] or [xCreate] 9106 ** method that is invoking sqlite3_vtab_config(). The C parameter is one 9107 ** of the [virtual table configuration options]. The presence and meaning 9108 ** of parameters after C depend on which [virtual table configuration option] 9109 ** is used. 9110 */ 9111 SQLITE_API int sqlite3_vtab_config(sqlite3*, int op, ...); 9112 9113 /* 9114 ** CAPI3REF: Virtual Table Configuration Options 9115 ** KEYWORDS: {virtual table configuration options} 9116 ** KEYWORDS: {virtual table configuration option} 9117 ** 9118 ** These macros define the various options to the 9119 ** [sqlite3_vtab_config()] interface that [virtual table] implementations 9120 ** can use to customize and optimize their behavior. 9121 ** 9122 ** <dl> 9123 ** [[SQLITE_VTAB_CONSTRAINT_SUPPORT]] 9124 ** <dt>SQLITE_VTAB_CONSTRAINT_SUPPORT</dt> 9125 ** <dd>Calls of the form 9126 ** [sqlite3_vtab_config](db,SQLITE_VTAB_CONSTRAINT_SUPPORT,X) are supported, 9127 ** where X is an integer. If X is zero, then the [virtual table] whose 9128 ** [xCreate] or [xConnect] method invoked [sqlite3_vtab_config()] does not 9129 ** support constraints. In this configuration (which is the default) if 9130 ** a call to the [xUpdate] method returns [SQLITE_CONSTRAINT], then the entire 9131 ** statement is rolled back as if [ON CONFLICT | OR ABORT] had been 9132 ** specified as part of the users SQL statement, regardless of the actual 9133 ** ON CONFLICT mode specified. 9134 ** 9135 ** If X is non-zero, then the virtual table implementation guarantees 9136 ** that if [xUpdate] returns [SQLITE_CONSTRAINT], it will do so before 9137 ** any modifications to internal or persistent data structures have been made. 9138 ** If the [ON CONFLICT] mode is ABORT, FAIL, IGNORE or ROLLBACK, SQLite 9139 ** is able to roll back a statement or database transaction, and abandon 9140 ** or continue processing the current SQL statement as appropriate. 9141 ** If the ON CONFLICT mode is REPLACE and the [xUpdate] method returns 9142 ** [SQLITE_CONSTRAINT], SQLite handles this as if the ON CONFLICT mode 9143 ** had been ABORT. 9144 ** 9145 ** Virtual table implementations that are required to handle OR REPLACE 9146 ** must do so within the [xUpdate] method. If a call to the 9147 ** [sqlite3_vtab_on_conflict()] function indicates that the current ON 9148 ** CONFLICT policy is REPLACE, the virtual table implementation should 9149 ** silently replace the appropriate rows within the xUpdate callback and 9150 ** return SQLITE_OK. Or, if this is not possible, it may return 9151 ** SQLITE_CONSTRAINT, in which case SQLite falls back to OR ABORT 9152 ** constraint handling. 9153 ** </dd> 9154 ** 9155 ** [[SQLITE_VTAB_DIRECTONLY]]<dt>SQLITE_VTAB_DIRECTONLY</dt> 9156 ** <dd>Calls of the form 9157 ** [sqlite3_vtab_config](db,SQLITE_VTAB_DIRECTONLY) from within the 9158 ** the [xConnect] or [xCreate] methods of a [virtual table] implmentation 9159 ** prohibits that virtual table from being used from within triggers and 9160 ** views. 9161 ** </dd> 9162 ** 9163 ** [[SQLITE_VTAB_INNOCUOUS]]<dt>SQLITE_VTAB_INNOCUOUS</dt> 9164 ** <dd>Calls of the form 9165 ** [sqlite3_vtab_config](db,SQLITE_VTAB_INNOCUOUS) from within the 9166 ** the [xConnect] or [xCreate] methods of a [virtual table] implmentation 9167 ** identify that virtual table as being safe to use from within triggers 9168 ** and views. Conceptually, the SQLITE_VTAB_INNOCUOUS tag means that the 9169 ** virtual table can do no serious harm even if it is controlled by a 9170 ** malicious hacker. Developers should avoid setting the SQLITE_VTAB_INNOCUOUS 9171 ** flag unless absolutely necessary. 9172 ** </dd> 9173 ** </dl> 9174 */ 9175 #define SQLITE_VTAB_CONSTRAINT_SUPPORT 1 9176 #define SQLITE_VTAB_INNOCUOUS 2 9177 #define SQLITE_VTAB_DIRECTONLY 3 9178 9179 /* 9180 ** CAPI3REF: Determine The Virtual Table Conflict Policy 9181 ** 9182 ** This function may only be called from within a call to the [xUpdate] method 9183 ** of a [virtual table] implementation for an INSERT or UPDATE operation. ^The 9184 ** value returned is one of [SQLITE_ROLLBACK], [SQLITE_IGNORE], [SQLITE_FAIL], 9185 ** [SQLITE_ABORT], or [SQLITE_REPLACE], according to the [ON CONFLICT] mode 9186 ** of the SQL statement that triggered the call to the [xUpdate] method of the 9187 ** [virtual table]. 9188 */ 9189 SQLITE_API int sqlite3_vtab_on_conflict(sqlite3 *); 9190 9191 /* 9192 ** CAPI3REF: Determine If Virtual Table Column Access Is For UPDATE 9193 ** 9194 ** If the sqlite3_vtab_nochange(X) routine is called within the [xColumn] 9195 ** method of a [virtual table], then it returns true if and only if the 9196 ** column is being fetched as part of an UPDATE operation during which the 9197 ** column value will not change. Applications might use this to substitute 9198 ** a return value that is less expensive to compute and that the corresponding 9199 ** [xUpdate] method understands as a "no-change" value. 9200 ** 9201 ** If the [xColumn] method calls sqlite3_vtab_nochange() and finds that 9202 ** the column is not changed by the UPDATE statement, then the xColumn 9203 ** method can optionally return without setting a result, without calling 9204 ** any of the [sqlite3_result_int|sqlite3_result_xxxxx() interfaces]. 9205 ** In that case, [sqlite3_value_nochange(X)] will return true for the 9206 ** same column in the [xUpdate] method. 9207 */ 9208 SQLITE_API int sqlite3_vtab_nochange(sqlite3_context*); 9209 9210 /* 9211 ** CAPI3REF: Determine The Collation For a Virtual Table Constraint 9212 ** 9213 ** This function may only be called from within a call to the [xBestIndex] 9214 ** method of a [virtual table]. 9215 ** 9216 ** The first argument must be the sqlite3_index_info object that is the 9217 ** first parameter to the xBestIndex() method. The second argument must be 9218 ** an index into the aConstraint[] array belonging to the sqlite3_index_info 9219 ** structure passed to xBestIndex. This function returns a pointer to a buffer 9220 ** containing the name of the collation sequence for the corresponding 9221 ** constraint. 9222 */ 9223 SQLITE_API SQLITE_EXPERIMENTAL const char *sqlite3_vtab_collation(sqlite3_index_info*,int); 9224 9225 /* 9226 ** CAPI3REF: Conflict resolution modes 9227 ** KEYWORDS: {conflict resolution mode} 9228 ** 9229 ** These constants are returned by [sqlite3_vtab_on_conflict()] to 9230 ** inform a [virtual table] implementation what the [ON CONFLICT] mode 9231 ** is for the SQL statement being evaluated. 9232 ** 9233 ** Note that the [SQLITE_IGNORE] constant is also used as a potential 9234 ** return value from the [sqlite3_set_authorizer()] callback and that 9235 ** [SQLITE_ABORT] is also a [result code]. 9236 */ 9237 #define SQLITE_ROLLBACK 1 9238 /* #define SQLITE_IGNORE 2 // Also used by sqlite3_authorizer() callback */ 9239 #define SQLITE_FAIL 3 9240 /* #define SQLITE_ABORT 4 // Also an error code */ 9241 #define SQLITE_REPLACE 5 9242 9243 /* 9244 ** CAPI3REF: Prepared Statement Scan Status Opcodes 9245 ** KEYWORDS: {scanstatus options} 9246 ** 9247 ** The following constants can be used for the T parameter to the 9248 ** [sqlite3_stmt_scanstatus(S,X,T,V)] interface. Each constant designates a 9249 ** different metric for sqlite3_stmt_scanstatus() to return. 9250 ** 9251 ** When the value returned to V is a string, space to hold that string is 9252 ** managed by the prepared statement S and will be automatically freed when 9253 ** S is finalized. 9254 ** 9255 ** <dl> 9256 ** [[SQLITE_SCANSTAT_NLOOP]] <dt>SQLITE_SCANSTAT_NLOOP</dt> 9257 ** <dd>^The [sqlite3_int64] variable pointed to by the V parameter will be 9258 ** set to the total number of times that the X-th loop has run.</dd> 9259 ** 9260 ** [[SQLITE_SCANSTAT_NVISIT]] <dt>SQLITE_SCANSTAT_NVISIT</dt> 9261 ** <dd>^The [sqlite3_int64] variable pointed to by the V parameter will be set 9262 ** to the total number of rows examined by all iterations of the X-th loop.</dd> 9263 ** 9264 ** [[SQLITE_SCANSTAT_EST]] <dt>SQLITE_SCANSTAT_EST</dt> 9265 ** <dd>^The "double" variable pointed to by the V parameter will be set to the 9266 ** query planner's estimate for the average number of rows output from each 9267 ** iteration of the X-th loop. If the query planner's estimates was accurate, 9268 ** then this value will approximate the quotient NVISIT/NLOOP and the 9269 ** product of this value for all prior loops with the same SELECTID will 9270 ** be the NLOOP value for the current loop. 9271 ** 9272 ** [[SQLITE_SCANSTAT_NAME]] <dt>SQLITE_SCANSTAT_NAME</dt> 9273 ** <dd>^The "const char *" variable pointed to by the V parameter will be set 9274 ** to a zero-terminated UTF-8 string containing the name of the index or table 9275 ** used for the X-th loop. 9276 ** 9277 ** [[SQLITE_SCANSTAT_EXPLAIN]] <dt>SQLITE_SCANSTAT_EXPLAIN</dt> 9278 ** <dd>^The "const char *" variable pointed to by the V parameter will be set 9279 ** to a zero-terminated UTF-8 string containing the [EXPLAIN QUERY PLAN] 9280 ** description for the X-th loop. 9281 ** 9282 ** [[SQLITE_SCANSTAT_SELECTID]] <dt>SQLITE_SCANSTAT_SELECT</dt> 9283 ** <dd>^The "int" variable pointed to by the V parameter will be set to the 9284 ** "select-id" for the X-th loop. The select-id identifies which query or 9285 ** subquery the loop is part of. The main query has a select-id of zero. 9286 ** The select-id is the same value as is output in the first column 9287 ** of an [EXPLAIN QUERY PLAN] query. 9288 ** </dl> 9289 */ 9290 #define SQLITE_SCANSTAT_NLOOP 0 9291 #define SQLITE_SCANSTAT_NVISIT 1 9292 #define SQLITE_SCANSTAT_EST 2 9293 #define SQLITE_SCANSTAT_NAME 3 9294 #define SQLITE_SCANSTAT_EXPLAIN 4 9295 #define SQLITE_SCANSTAT_SELECTID 5 9296 9297 /* 9298 ** CAPI3REF: Prepared Statement Scan Status 9299 ** METHOD: sqlite3_stmt 9300 ** 9301 ** This interface returns information about the predicted and measured 9302 ** performance for pStmt. Advanced applications can use this 9303 ** interface to compare the predicted and the measured performance and 9304 ** issue warnings and/or rerun [ANALYZE] if discrepancies are found. 9305 ** 9306 ** Since this interface is expected to be rarely used, it is only 9307 ** available if SQLite is compiled using the [SQLITE_ENABLE_STMT_SCANSTATUS] 9308 ** compile-time option. 9309 ** 9310 ** The "iScanStatusOp" parameter determines which status information to return. 9311 ** The "iScanStatusOp" must be one of the [scanstatus options] or the behavior 9312 ** of this interface is undefined. 9313 ** ^The requested measurement is written into a variable pointed to by 9314 ** the "pOut" parameter. 9315 ** Parameter "idx" identifies the specific loop to retrieve statistics for. 9316 ** Loops are numbered starting from zero. ^If idx is out of range - less than 9317 ** zero or greater than or equal to the total number of loops used to implement 9318 ** the statement - a non-zero value is returned and the variable that pOut 9319 ** points to is unchanged. 9320 ** 9321 ** ^Statistics might not be available for all loops in all statements. ^In cases 9322 ** where there exist loops with no available statistics, this function behaves 9323 ** as if the loop did not exist - it returns non-zero and leave the variable 9324 ** that pOut points to unchanged. 9325 ** 9326 ** See also: [sqlite3_stmt_scanstatus_reset()] 9327 */ 9328 SQLITE_API int sqlite3_stmt_scanstatus( 9329 sqlite3_stmt *pStmt, /* Prepared statement for which info desired */ 9330 int idx, /* Index of loop to report on */ 9331 int iScanStatusOp, /* Information desired. SQLITE_SCANSTAT_* */ 9332 void *pOut /* Result written here */ 9333 ); 9334 9335 /* 9336 ** CAPI3REF: Zero Scan-Status Counters 9337 ** METHOD: sqlite3_stmt 9338 ** 9339 ** ^Zero all [sqlite3_stmt_scanstatus()] related event counters. 9340 ** 9341 ** This API is only available if the library is built with pre-processor 9342 ** symbol [SQLITE_ENABLE_STMT_SCANSTATUS] defined. 9343 */ 9344 SQLITE_API void sqlite3_stmt_scanstatus_reset(sqlite3_stmt*); 9345 9346 /* 9347 ** CAPI3REF: Flush caches to disk mid-transaction 9348 ** 9349 ** ^If a write-transaction is open on [database connection] D when the 9350 ** [sqlite3_db_cacheflush(D)] interface invoked, any dirty 9351 ** pages in the pager-cache that are not currently in use are written out 9352 ** to disk. A dirty page may be in use if a database cursor created by an 9353 ** active SQL statement is reading from it, or if it is page 1 of a database 9354 ** file (page 1 is always "in use"). ^The [sqlite3_db_cacheflush(D)] 9355 ** interface flushes caches for all schemas - "main", "temp", and 9356 ** any [attached] databases. 9357 ** 9358 ** ^If this function needs to obtain extra database locks before dirty pages 9359 ** can be flushed to disk, it does so. ^If those locks cannot be obtained 9360 ** immediately and there is a busy-handler callback configured, it is invoked 9361 ** in the usual manner. ^If the required lock still cannot be obtained, then 9362 ** the database is skipped and an attempt made to flush any dirty pages 9363 ** belonging to the next (if any) database. ^If any databases are skipped 9364 ** because locks cannot be obtained, but no other error occurs, this 9365 ** function returns SQLITE_BUSY. 9366 ** 9367 ** ^If any other error occurs while flushing dirty pages to disk (for 9368 ** example an IO error or out-of-memory condition), then processing is 9369 ** abandoned and an SQLite [error code] is returned to the caller immediately. 9370 ** 9371 ** ^Otherwise, if no error occurs, [sqlite3_db_cacheflush()] returns SQLITE_OK. 9372 ** 9373 ** ^This function does not set the database handle error code or message 9374 ** returned by the [sqlite3_errcode()] and [sqlite3_errmsg()] functions. 9375 */ 9376 SQLITE_API int sqlite3_db_cacheflush(sqlite3*); 9377 9378 /* 9379 ** CAPI3REF: The pre-update hook. 9380 ** 9381 ** ^These interfaces are only available if SQLite is compiled using the 9382 ** [SQLITE_ENABLE_PREUPDATE_HOOK] compile-time option. 9383 ** 9384 ** ^The [sqlite3_preupdate_hook()] interface registers a callback function 9385 ** that is invoked prior to each [INSERT], [UPDATE], and [DELETE] operation 9386 ** on a database table. 9387 ** ^At most one preupdate hook may be registered at a time on a single 9388 ** [database connection]; each call to [sqlite3_preupdate_hook()] overrides 9389 ** the previous setting. 9390 ** ^The preupdate hook is disabled by invoking [sqlite3_preupdate_hook()] 9391 ** with a NULL pointer as the second parameter. 9392 ** ^The third parameter to [sqlite3_preupdate_hook()] is passed through as 9393 ** the first parameter to callbacks. 9394 ** 9395 ** ^The preupdate hook only fires for changes to real database tables; the 9396 ** preupdate hook is not invoked for changes to [virtual tables] or to 9397 ** system tables like sqlite_sequence or sqlite_stat1. 9398 ** 9399 ** ^The second parameter to the preupdate callback is a pointer to 9400 ** the [database connection] that registered the preupdate hook. 9401 ** ^The third parameter to the preupdate callback is one of the constants 9402 ** [SQLITE_INSERT], [SQLITE_DELETE], or [SQLITE_UPDATE] to identify the 9403 ** kind of update operation that is about to occur. 9404 ** ^(The fourth parameter to the preupdate callback is the name of the 9405 ** database within the database connection that is being modified. This 9406 ** will be "main" for the main database or "temp" for TEMP tables or 9407 ** the name given after the AS keyword in the [ATTACH] statement for attached 9408 ** databases.)^ 9409 ** ^The fifth parameter to the preupdate callback is the name of the 9410 ** table that is being modified. 9411 ** 9412 ** For an UPDATE or DELETE operation on a [rowid table], the sixth 9413 ** parameter passed to the preupdate callback is the initial [rowid] of the 9414 ** row being modified or deleted. For an INSERT operation on a rowid table, 9415 ** or any operation on a WITHOUT ROWID table, the value of the sixth 9416 ** parameter is undefined. For an INSERT or UPDATE on a rowid table the 9417 ** seventh parameter is the final rowid value of the row being inserted 9418 ** or updated. The value of the seventh parameter passed to the callback 9419 ** function is not defined for operations on WITHOUT ROWID tables, or for 9420 ** INSERT operations on rowid tables. 9421 ** 9422 ** The [sqlite3_preupdate_old()], [sqlite3_preupdate_new()], 9423 ** [sqlite3_preupdate_count()], and [sqlite3_preupdate_depth()] interfaces 9424 ** provide additional information about a preupdate event. These routines 9425 ** may only be called from within a preupdate callback. Invoking any of 9426 ** these routines from outside of a preupdate callback or with a 9427 ** [database connection] pointer that is different from the one supplied 9428 ** to the preupdate callback results in undefined and probably undesirable 9429 ** behavior. 9430 ** 9431 ** ^The [sqlite3_preupdate_count(D)] interface returns the number of columns 9432 ** in the row that is being inserted, updated, or deleted. 9433 ** 9434 ** ^The [sqlite3_preupdate_old(D,N,P)] interface writes into P a pointer to 9435 ** a [protected sqlite3_value] that contains the value of the Nth column of 9436 ** the table row before it is updated. The N parameter must be between 0 9437 ** and one less than the number of columns or the behavior will be 9438 ** undefined. This must only be used within SQLITE_UPDATE and SQLITE_DELETE 9439 ** preupdate callbacks; if it is used by an SQLITE_INSERT callback then the 9440 ** behavior is undefined. The [sqlite3_value] that P points to 9441 ** will be destroyed when the preupdate callback returns. 9442 ** 9443 ** ^The [sqlite3_preupdate_new(D,N,P)] interface writes into P a pointer to 9444 ** a [protected sqlite3_value] that contains the value of the Nth column of 9445 ** the table row after it is updated. The N parameter must be between 0 9446 ** and one less than the number of columns or the behavior will be 9447 ** undefined. This must only be used within SQLITE_INSERT and SQLITE_UPDATE 9448 ** preupdate callbacks; if it is used by an SQLITE_DELETE callback then the 9449 ** behavior is undefined. The [sqlite3_value] that P points to 9450 ** will be destroyed when the preupdate callback returns. 9451 ** 9452 ** ^The [sqlite3_preupdate_depth(D)] interface returns 0 if the preupdate 9453 ** callback was invoked as a result of a direct insert, update, or delete 9454 ** operation; or 1 for inserts, updates, or deletes invoked by top-level 9455 ** triggers; or 2 for changes resulting from triggers called by top-level 9456 ** triggers; and so forth. 9457 ** 9458 ** See also: [sqlite3_update_hook()] 9459 */ 9460 #if defined(SQLITE_ENABLE_PREUPDATE_HOOK) 9461 SQLITE_API void *sqlite3_preupdate_hook( 9462 sqlite3 *db, 9463 void(*xPreUpdate)( 9464 void *pCtx, /* Copy of third arg to preupdate_hook() */ 9465 sqlite3 *db, /* Database handle */ 9466 int op, /* SQLITE_UPDATE, DELETE or INSERT */ 9467 char const *zDb, /* Database name */ 9468 char const *zName, /* Table name */ 9469 sqlite3_int64 iKey1, /* Rowid of row about to be deleted/updated */ 9470 sqlite3_int64 iKey2 /* New rowid value (for a rowid UPDATE) */ 9471 ), 9472 void* 9473 ); 9474 SQLITE_API int sqlite3_preupdate_old(sqlite3 *, int, sqlite3_value **); 9475 SQLITE_API int sqlite3_preupdate_count(sqlite3 *); 9476 SQLITE_API int sqlite3_preupdate_depth(sqlite3 *); 9477 SQLITE_API int sqlite3_preupdate_new(sqlite3 *, int, sqlite3_value **); 9478 #endif 9479 9480 /* 9481 ** CAPI3REF: Low-level system error code 9482 ** 9483 ** ^Attempt to return the underlying operating system error code or error 9484 ** number that caused the most recent I/O error or failure to open a file. 9485 ** The return value is OS-dependent. For example, on unix systems, after 9486 ** [sqlite3_open_v2()] returns [SQLITE_CANTOPEN], this interface could be 9487 ** called to get back the underlying "errno" that caused the problem, such 9488 ** as ENOSPC, EAUTH, EISDIR, and so forth. 9489 */ 9490 SQLITE_API int sqlite3_system_errno(sqlite3*); 9491 9492 /* 9493 ** CAPI3REF: Database Snapshot 9494 ** KEYWORDS: {snapshot} {sqlite3_snapshot} 9495 ** 9496 ** An instance of the snapshot object records the state of a [WAL mode] 9497 ** database for some specific point in history. 9498 ** 9499 ** In [WAL mode], multiple [database connections] that are open on the 9500 ** same database file can each be reading a different historical version 9501 ** of the database file. When a [database connection] begins a read 9502 ** transaction, that connection sees an unchanging copy of the database 9503 ** as it existed for the point in time when the transaction first started. 9504 ** Subsequent changes to the database from other connections are not seen 9505 ** by the reader until a new read transaction is started. 9506 ** 9507 ** The sqlite3_snapshot object records state information about an historical 9508 ** version of the database file so that it is possible to later open a new read 9509 ** transaction that sees that historical version of the database rather than 9510 ** the most recent version. 9511 */ 9512 typedef struct sqlite3_snapshot { 9513 unsigned char hidden[48]; 9514 } sqlite3_snapshot; 9515 9516 /* 9517 ** CAPI3REF: Record A Database Snapshot 9518 ** CONSTRUCTOR: sqlite3_snapshot 9519 ** 9520 ** ^The [sqlite3_snapshot_get(D,S,P)] interface attempts to make a 9521 ** new [sqlite3_snapshot] object that records the current state of 9522 ** schema S in database connection D. ^On success, the 9523 ** [sqlite3_snapshot_get(D,S,P)] interface writes a pointer to the newly 9524 ** created [sqlite3_snapshot] object into *P and returns SQLITE_OK. 9525 ** If there is not already a read-transaction open on schema S when 9526 ** this function is called, one is opened automatically. 9527 ** 9528 ** The following must be true for this function to succeed. If any of 9529 ** the following statements are false when sqlite3_snapshot_get() is 9530 ** called, SQLITE_ERROR is returned. The final value of *P is undefined 9531 ** in this case. 9532 ** 9533 ** <ul> 9534 ** <li> The database handle must not be in [autocommit mode]. 9535 ** 9536 ** <li> Schema S of [database connection] D must be a [WAL mode] database. 9537 ** 9538 ** <li> There must not be a write transaction open on schema S of database 9539 ** connection D. 9540 ** 9541 ** <li> One or more transactions must have been written to the current wal 9542 ** file since it was created on disk (by any connection). This means 9543 ** that a snapshot cannot be taken on a wal mode database with no wal 9544 ** file immediately after it is first opened. At least one transaction 9545 ** must be written to it first. 9546 ** </ul> 9547 ** 9548 ** This function may also return SQLITE_NOMEM. If it is called with the 9549 ** database handle in autocommit mode but fails for some other reason, 9550 ** whether or not a read transaction is opened on schema S is undefined. 9551 ** 9552 ** The [sqlite3_snapshot] object returned from a successful call to 9553 ** [sqlite3_snapshot_get()] must be freed using [sqlite3_snapshot_free()] 9554 ** to avoid a memory leak. 9555 ** 9556 ** The [sqlite3_snapshot_get()] interface is only available when the 9557 ** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used. 9558 */ 9559 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_get( 9560 sqlite3 *db, 9561 const char *zSchema, 9562 sqlite3_snapshot **ppSnapshot 9563 ); 9564 9565 /* 9566 ** CAPI3REF: Start a read transaction on an historical snapshot 9567 ** METHOD: sqlite3_snapshot 9568 ** 9569 ** ^The [sqlite3_snapshot_open(D,S,P)] interface either starts a new read 9570 ** transaction or upgrades an existing one for schema S of 9571 ** [database connection] D such that the read transaction refers to 9572 ** historical [snapshot] P, rather than the most recent change to the 9573 ** database. ^The [sqlite3_snapshot_open()] interface returns SQLITE_OK 9574 ** on success or an appropriate [error code] if it fails. 9575 ** 9576 ** ^In order to succeed, the database connection must not be in 9577 ** [autocommit mode] when [sqlite3_snapshot_open(D,S,P)] is called. If there 9578 ** is already a read transaction open on schema S, then the database handle 9579 ** must have no active statements (SELECT statements that have been passed 9580 ** to sqlite3_step() but not sqlite3_reset() or sqlite3_finalize()). 9581 ** SQLITE_ERROR is returned if either of these conditions is violated, or 9582 ** if schema S does not exist, or if the snapshot object is invalid. 9583 ** 9584 ** ^A call to sqlite3_snapshot_open() will fail to open if the specified 9585 ** snapshot has been overwritten by a [checkpoint]. In this case 9586 ** SQLITE_ERROR_SNAPSHOT is returned. 9587 ** 9588 ** If there is already a read transaction open when this function is 9589 ** invoked, then the same read transaction remains open (on the same 9590 ** database snapshot) if SQLITE_ERROR, SQLITE_BUSY or SQLITE_ERROR_SNAPSHOT 9591 ** is returned. If another error code - for example SQLITE_PROTOCOL or an 9592 ** SQLITE_IOERR error code - is returned, then the final state of the 9593 ** read transaction is undefined. If SQLITE_OK is returned, then the 9594 ** read transaction is now open on database snapshot P. 9595 ** 9596 ** ^(A call to [sqlite3_snapshot_open(D,S,P)] will fail if the 9597 ** database connection D does not know that the database file for 9598 ** schema S is in [WAL mode]. A database connection might not know 9599 ** that the database file is in [WAL mode] if there has been no prior 9600 ** I/O on that database connection, or if the database entered [WAL mode] 9601 ** after the most recent I/O on the database connection.)^ 9602 ** (Hint: Run "[PRAGMA application_id]" against a newly opened 9603 ** database connection in order to make it ready to use snapshots.) 9604 ** 9605 ** The [sqlite3_snapshot_open()] interface is only available when the 9606 ** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used. 9607 */ 9608 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_open( 9609 sqlite3 *db, 9610 const char *zSchema, 9611 sqlite3_snapshot *pSnapshot 9612 ); 9613 9614 /* 9615 ** CAPI3REF: Destroy a snapshot 9616 ** DESTRUCTOR: sqlite3_snapshot 9617 ** 9618 ** ^The [sqlite3_snapshot_free(P)] interface destroys [sqlite3_snapshot] P. 9619 ** The application must eventually free every [sqlite3_snapshot] object 9620 ** using this routine to avoid a memory leak. 9621 ** 9622 ** The [sqlite3_snapshot_free()] interface is only available when the 9623 ** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used. 9624 */ 9625 SQLITE_API SQLITE_EXPERIMENTAL void sqlite3_snapshot_free(sqlite3_snapshot*); 9626 9627 /* 9628 ** CAPI3REF: Compare the ages of two snapshot handles. 9629 ** METHOD: sqlite3_snapshot 9630 ** 9631 ** The sqlite3_snapshot_cmp(P1, P2) interface is used to compare the ages 9632 ** of two valid snapshot handles. 9633 ** 9634 ** If the two snapshot handles are not associated with the same database 9635 ** file, the result of the comparison is undefined. 9636 ** 9637 ** Additionally, the result of the comparison is only valid if both of the 9638 ** snapshot handles were obtained by calling sqlite3_snapshot_get() since the 9639 ** last time the wal file was deleted. The wal file is deleted when the 9640 ** database is changed back to rollback mode or when the number of database 9641 ** clients drops to zero. If either snapshot handle was obtained before the 9642 ** wal file was last deleted, the value returned by this function 9643 ** is undefined. 9644 ** 9645 ** Otherwise, this API returns a negative value if P1 refers to an older 9646 ** snapshot than P2, zero if the two handles refer to the same database 9647 ** snapshot, and a positive value if P1 is a newer snapshot than P2. 9648 ** 9649 ** This interface is only available if SQLite is compiled with the 9650 ** [SQLITE_ENABLE_SNAPSHOT] option. 9651 */ 9652 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_cmp( 9653 sqlite3_snapshot *p1, 9654 sqlite3_snapshot *p2 9655 ); 9656 9657 /* 9658 ** CAPI3REF: Recover snapshots from a wal file 9659 ** METHOD: sqlite3_snapshot 9660 ** 9661 ** If a [WAL file] remains on disk after all database connections close 9662 ** (either through the use of the [SQLITE_FCNTL_PERSIST_WAL] [file control] 9663 ** or because the last process to have the database opened exited without 9664 ** calling [sqlite3_close()]) and a new connection is subsequently opened 9665 ** on that database and [WAL file], the [sqlite3_snapshot_open()] interface 9666 ** will only be able to open the last transaction added to the WAL file 9667 ** even though the WAL file contains other valid transactions. 9668 ** 9669 ** This function attempts to scan the WAL file associated with database zDb 9670 ** of database handle db and make all valid snapshots available to 9671 ** sqlite3_snapshot_open(). It is an error if there is already a read 9672 ** transaction open on the database, or if the database is not a WAL mode 9673 ** database. 9674 ** 9675 ** SQLITE_OK is returned if successful, or an SQLite error code otherwise. 9676 ** 9677 ** This interface is only available if SQLite is compiled with the 9678 ** [SQLITE_ENABLE_SNAPSHOT] option. 9679 */ 9680 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_recover(sqlite3 *db, const char *zDb); 9681 9682 /* 9683 ** CAPI3REF: Serialize a database 9684 ** 9685 ** The sqlite3_serialize(D,S,P,F) interface returns a pointer to memory 9686 ** that is a serialization of the S database on [database connection] D. 9687 ** If P is not a NULL pointer, then the size of the database in bytes 9688 ** is written into *P. 9689 ** 9690 ** For an ordinary on-disk database file, the serialization is just a 9691 ** copy of the disk file. For an in-memory database or a "TEMP" database, 9692 ** the serialization is the same sequence of bytes which would be written 9693 ** to disk if that database where backed up to disk. 9694 ** 9695 ** The usual case is that sqlite3_serialize() copies the serialization of 9696 ** the database into memory obtained from [sqlite3_malloc64()] and returns 9697 ** a pointer to that memory. The caller is responsible for freeing the 9698 ** returned value to avoid a memory leak. However, if the F argument 9699 ** contains the SQLITE_SERIALIZE_NOCOPY bit, then no memory allocations 9700 ** are made, and the sqlite3_serialize() function will return a pointer 9701 ** to the contiguous memory representation of the database that SQLite 9702 ** is currently using for that database, or NULL if the no such contiguous 9703 ** memory representation of the database exists. A contiguous memory 9704 ** representation of the database will usually only exist if there has 9705 ** been a prior call to [sqlite3_deserialize(D,S,...)] with the same 9706 ** values of D and S. 9707 ** The size of the database is written into *P even if the 9708 ** SQLITE_SERIALIZE_NOCOPY bit is set but no contiguous copy 9709 ** of the database exists. 9710 ** 9711 ** A call to sqlite3_serialize(D,S,P,F) might return NULL even if the 9712 ** SQLITE_SERIALIZE_NOCOPY bit is omitted from argument F if a memory 9713 ** allocation error occurs. 9714 ** 9715 ** This interface is only available if SQLite is compiled with the 9716 ** [SQLITE_ENABLE_DESERIALIZE] option. 9717 */ 9718 SQLITE_API unsigned char *sqlite3_serialize( 9719 sqlite3 *db, /* The database connection */ 9720 const char *zSchema, /* Which DB to serialize. ex: "main", "temp", ... */ 9721 sqlite3_int64 *piSize, /* Write size of the DB here, if not NULL */ 9722 unsigned int mFlags /* Zero or more SQLITE_SERIALIZE_* flags */ 9723 ); 9724 9725 /* 9726 ** CAPI3REF: Flags for sqlite3_serialize 9727 ** 9728 ** Zero or more of the following constants can be OR-ed together for 9729 ** the F argument to [sqlite3_serialize(D,S,P,F)]. 9730 ** 9731 ** SQLITE_SERIALIZE_NOCOPY means that [sqlite3_serialize()] will return 9732 ** a pointer to contiguous in-memory database that it is currently using, 9733 ** without making a copy of the database. If SQLite is not currently using 9734 ** a contiguous in-memory database, then this option causes 9735 ** [sqlite3_serialize()] to return a NULL pointer. SQLite will only be 9736 ** using a contiguous in-memory database if it has been initialized by a 9737 ** prior call to [sqlite3_deserialize()]. 9738 */ 9739 #define SQLITE_SERIALIZE_NOCOPY 0x001 /* Do no memory allocations */ 9740 9741 /* 9742 ** CAPI3REF: Deserialize a database 9743 ** 9744 ** The sqlite3_deserialize(D,S,P,N,M,F) interface causes the 9745 ** [database connection] D to disconnect from database S and then 9746 ** reopen S as an in-memory database based on the serialization contained 9747 ** in P. The serialized database P is N bytes in size. M is the size of 9748 ** the buffer P, which might be larger than N. If M is larger than N, and 9749 ** the SQLITE_DESERIALIZE_READONLY bit is not set in F, then SQLite is 9750 ** permitted to add content to the in-memory database as long as the total 9751 ** size does not exceed M bytes. 9752 ** 9753 ** If the SQLITE_DESERIALIZE_FREEONCLOSE bit is set in F, then SQLite will 9754 ** invoke sqlite3_free() on the serialization buffer when the database 9755 ** connection closes. If the SQLITE_DESERIALIZE_RESIZEABLE bit is set, then 9756 ** SQLite will try to increase the buffer size using sqlite3_realloc64() 9757 ** if writes on the database cause it to grow larger than M bytes. 9758 ** 9759 ** The sqlite3_deserialize() interface will fail with SQLITE_BUSY if the 9760 ** database is currently in a read transaction or is involved in a backup 9761 ** operation. 9762 ** 9763 ** If sqlite3_deserialize(D,S,P,N,M,F) fails for any reason and if the 9764 ** SQLITE_DESERIALIZE_FREEONCLOSE bit is set in argument F, then 9765 ** [sqlite3_free()] is invoked on argument P prior to returning. 9766 ** 9767 ** This interface is only available if SQLite is compiled with the 9768 ** [SQLITE_ENABLE_DESERIALIZE] option. 9769 */ 9770 SQLITE_API int sqlite3_deserialize( 9771 sqlite3 *db, /* The database connection */ 9772 const char *zSchema, /* Which DB to reopen with the deserialization */ 9773 unsigned char *pData, /* The serialized database content */ 9774 sqlite3_int64 szDb, /* Number bytes in the deserialization */ 9775 sqlite3_int64 szBuf, /* Total size of buffer pData[] */ 9776 unsigned mFlags /* Zero or more SQLITE_DESERIALIZE_* flags */ 9777 ); 9778 9779 /* 9780 ** CAPI3REF: Flags for sqlite3_deserialize() 9781 ** 9782 ** The following are allowed values for 6th argument (the F argument) to 9783 ** the [sqlite3_deserialize(D,S,P,N,M,F)] interface. 9784 ** 9785 ** The SQLITE_DESERIALIZE_FREEONCLOSE means that the database serialization 9786 ** in the P argument is held in memory obtained from [sqlite3_malloc64()] 9787 ** and that SQLite should take ownership of this memory and automatically 9788 ** free it when it has finished using it. Without this flag, the caller 9789 ** is responsible for freeing any dynamically allocated memory. 9790 ** 9791 ** The SQLITE_DESERIALIZE_RESIZEABLE flag means that SQLite is allowed to 9792 ** grow the size of the database using calls to [sqlite3_realloc64()]. This 9793 ** flag should only be used if SQLITE_DESERIALIZE_FREEONCLOSE is also used. 9794 ** Without this flag, the deserialized database cannot increase in size beyond 9795 ** the number of bytes specified by the M parameter. 9796 ** 9797 ** The SQLITE_DESERIALIZE_READONLY flag means that the deserialized database 9798 ** should be treated as read-only. 9799 */ 9800 #define SQLITE_DESERIALIZE_FREEONCLOSE 1 /* Call sqlite3_free() on close */ 9801 #define SQLITE_DESERIALIZE_RESIZEABLE 2 /* Resize using sqlite3_realloc64() */ 9802 #define SQLITE_DESERIALIZE_READONLY 4 /* Database is read-only */ 9803 9804 /* 9805 ** Undo the hack that converts floating point types to integer for 9806 ** builds on processors without floating point support. 9807 */ 9808 #ifdef SQLITE_OMIT_FLOATING_POINT 9809 # undef double 9810 #endif 9811 9812 #ifdef __cplusplus 9813 } /* End of the 'extern "C"' block */ 9814 #endif 9815 #endif /* SQLITE3_H */ 9816 9817 /******** Begin file sqlite3rtree.h *********/ 9818 /* 9819 ** 2010 August 30 9820 ** 9821 ** The author disclaims copyright to this source code. In place of 9822 ** a legal notice, here is a blessing: 9823 ** 9824 ** May you do good and not evil. 9825 ** May you find forgiveness for yourself and forgive others. 9826 ** May you share freely, never taking more than you give. 9827 ** 9828 ************************************************************************* 9829 */ 9830 9831 #ifndef _SQLITE3RTREE_H_ 9832 #define _SQLITE3RTREE_H_ 9833 9834 9835 #ifdef __cplusplus 9836 extern "C" { 9837 #endif 9838 9839 typedef struct sqlite3_rtree_geometry sqlite3_rtree_geometry; 9840 typedef struct sqlite3_rtree_query_info sqlite3_rtree_query_info; 9841 9842 /* The double-precision datatype used by RTree depends on the 9843 ** SQLITE_RTREE_INT_ONLY compile-time option. 9844 */ 9845 #ifdef SQLITE_RTREE_INT_ONLY 9846 typedef sqlite3_int64 sqlite3_rtree_dbl; 9847 #else 9848 typedef double sqlite3_rtree_dbl; 9849 #endif 9850 9851 /* 9852 ** Register a geometry callback named zGeom that can be used as part of an 9853 ** R-Tree geometry query as follows: 9854 ** 9855 ** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zGeom(... params ...) 9856 */ 9857 SQLITE_API int sqlite3_rtree_geometry_callback( 9858 sqlite3 *db, 9859 const char *zGeom, 9860 int (*xGeom)(sqlite3_rtree_geometry*, int, sqlite3_rtree_dbl*,int*), 9861 void *pContext 9862 ); 9863 9864 9865 /* 9866 ** A pointer to a structure of the following type is passed as the first 9867 ** argument to callbacks registered using rtree_geometry_callback(). 9868 */ 9869 struct sqlite3_rtree_geometry { 9870 void *pContext; /* Copy of pContext passed to s_r_g_c() */ 9871 int nParam; /* Size of array aParam[] */ 9872 sqlite3_rtree_dbl *aParam; /* Parameters passed to SQL geom function */ 9873 void *pUser; /* Callback implementation user data */ 9874 void (*xDelUser)(void *); /* Called by SQLite to clean up pUser */ 9875 }; 9876 9877 /* 9878 ** Register a 2nd-generation geometry callback named zScore that can be 9879 ** used as part of an R-Tree geometry query as follows: 9880 ** 9881 ** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zQueryFunc(... params ...) 9882 */ 9883 SQLITE_API int sqlite3_rtree_query_callback( 9884 sqlite3 *db, 9885 const char *zQueryFunc, 9886 int (*xQueryFunc)(sqlite3_rtree_query_info*), 9887 void *pContext, 9888 void (*xDestructor)(void*) 9889 ); 9890 9891 9892 /* 9893 ** A pointer to a structure of the following type is passed as the 9894 ** argument to scored geometry callback registered using 9895 ** sqlite3_rtree_query_callback(). 9896 ** 9897 ** Note that the first 5 fields of this structure are identical to 9898 ** sqlite3_rtree_geometry. This structure is a subclass of 9899 ** sqlite3_rtree_geometry. 9900 */ 9901 struct sqlite3_rtree_query_info { 9902 void *pContext; /* pContext from when function registered */ 9903 int nParam; /* Number of function parameters */ 9904 sqlite3_rtree_dbl *aParam; /* value of function parameters */ 9905 void *pUser; /* callback can use this, if desired */ 9906 void (*xDelUser)(void*); /* function to free pUser */ 9907 sqlite3_rtree_dbl *aCoord; /* Coordinates of node or entry to check */ 9908 unsigned int *anQueue; /* Number of pending entries in the queue */ 9909 int nCoord; /* Number of coordinates */ 9910 int iLevel; /* Level of current node or entry */ 9911 int mxLevel; /* The largest iLevel value in the tree */ 9912 sqlite3_int64 iRowid; /* Rowid for current entry */ 9913 sqlite3_rtree_dbl rParentScore; /* Score of parent node */ 9914 int eParentWithin; /* Visibility of parent node */ 9915 int eWithin; /* OUT: Visibility */ 9916 sqlite3_rtree_dbl rScore; /* OUT: Write the score here */ 9917 /* The following fields are only available in 3.8.11 and later */ 9918 sqlite3_value **apSqlParam; /* Original SQL values of parameters */ 9919 }; 9920 9921 /* 9922 ** Allowed values for sqlite3_rtree_query.eWithin and .eParentWithin. 9923 */ 9924 #define NOT_WITHIN 0 /* Object completely outside of query region */ 9925 #define PARTLY_WITHIN 1 /* Object partially overlaps query region */ 9926 #define FULLY_WITHIN 2 /* Object fully contained within query region */ 9927 9928 9929 #ifdef __cplusplus 9930 } /* end of the 'extern "C"' block */ 9931 #endif 9932 9933 #endif /* ifndef _SQLITE3RTREE_H_ */ 9934 9935 /******** End of sqlite3rtree.h *********/ 9936 /******** Begin file sqlite3session.h *********/ 9937 9938 #if !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION) 9939 #define __SQLITESESSION_H_ 1 9940 9941 /* 9942 ** Make sure we can call this stuff from C++. 9943 */ 9944 #ifdef __cplusplus 9945 extern "C" { 9946 #endif 9947 9948 9949 /* 9950 ** CAPI3REF: Session Object Handle 9951 ** 9952 ** An instance of this object is a [session] that can be used to 9953 ** record changes to a database. 9954 */ 9955 typedef struct sqlite3_session sqlite3_session; 9956 9957 /* 9958 ** CAPI3REF: Changeset Iterator Handle 9959 ** 9960 ** An instance of this object acts as a cursor for iterating 9961 ** over the elements of a [changeset] or [patchset]. 9962 */ 9963 typedef struct sqlite3_changeset_iter sqlite3_changeset_iter; 9964 9965 /* 9966 ** CAPI3REF: Create A New Session Object 9967 ** CONSTRUCTOR: sqlite3_session 9968 ** 9969 ** Create a new session object attached to database handle db. If successful, 9970 ** a pointer to the new object is written to *ppSession and SQLITE_OK is 9971 ** returned. If an error occurs, *ppSession is set to NULL and an SQLite 9972 ** error code (e.g. SQLITE_NOMEM) is returned. 9973 ** 9974 ** It is possible to create multiple session objects attached to a single 9975 ** database handle. 9976 ** 9977 ** Session objects created using this function should be deleted using the 9978 ** [sqlite3session_delete()] function before the database handle that they 9979 ** are attached to is itself closed. If the database handle is closed before 9980 ** the session object is deleted, then the results of calling any session 9981 ** module function, including [sqlite3session_delete()] on the session object 9982 ** are undefined. 9983 ** 9984 ** Because the session module uses the [sqlite3_preupdate_hook()] API, it 9985 ** is not possible for an application to register a pre-update hook on a 9986 ** database handle that has one or more session objects attached. Nor is 9987 ** it possible to create a session object attached to a database handle for 9988 ** which a pre-update hook is already defined. The results of attempting 9989 ** either of these things are undefined. 9990 ** 9991 ** The session object will be used to create changesets for tables in 9992 ** database zDb, where zDb is either "main", or "temp", or the name of an 9993 ** attached database. It is not an error if database zDb is not attached 9994 ** to the database when the session object is created. 9995 */ 9996 SQLITE_API int sqlite3session_create( 9997 sqlite3 *db, /* Database handle */ 9998 const char *zDb, /* Name of db (e.g. "main") */ 9999 sqlite3_session **ppSession /* OUT: New session object */ 10000 ); 10001 10002 /* 10003 ** CAPI3REF: Delete A Session Object 10004 ** DESTRUCTOR: sqlite3_session 10005 ** 10006 ** Delete a session object previously allocated using 10007 ** [sqlite3session_create()]. Once a session object has been deleted, the 10008 ** results of attempting to use pSession with any other session module 10009 ** function are undefined. 10010 ** 10011 ** Session objects must be deleted before the database handle to which they 10012 ** are attached is closed. Refer to the documentation for 10013 ** [sqlite3session_create()] for details. 10014 */ 10015 SQLITE_API void sqlite3session_delete(sqlite3_session *pSession); 10016 10017 10018 /* 10019 ** CAPI3REF: Enable Or Disable A Session Object 10020 ** METHOD: sqlite3_session 10021 ** 10022 ** Enable or disable the recording of changes by a session object. When 10023 ** enabled, a session object records changes made to the database. When 10024 ** disabled - it does not. A newly created session object is enabled. 10025 ** Refer to the documentation for [sqlite3session_changeset()] for further 10026 ** details regarding how enabling and disabling a session object affects 10027 ** the eventual changesets. 10028 ** 10029 ** Passing zero to this function disables the session. Passing a value 10030 ** greater than zero enables it. Passing a value less than zero is a 10031 ** no-op, and may be used to query the current state of the session. 10032 ** 10033 ** The return value indicates the final state of the session object: 0 if 10034 ** the session is disabled, or 1 if it is enabled. 10035 */ 10036 SQLITE_API int sqlite3session_enable(sqlite3_session *pSession, int bEnable); 10037 10038 /* 10039 ** CAPI3REF: Set Or Clear the Indirect Change Flag 10040 ** METHOD: sqlite3_session 10041 ** 10042 ** Each change recorded by a session object is marked as either direct or 10043 ** indirect. A change is marked as indirect if either: 10044 ** 10045 ** <ul> 10046 ** <li> The session object "indirect" flag is set when the change is 10047 ** made, or 10048 ** <li> The change is made by an SQL trigger or foreign key action 10049 ** instead of directly as a result of a users SQL statement. 10050 ** </ul> 10051 ** 10052 ** If a single row is affected by more than one operation within a session, 10053 ** then the change is considered indirect if all operations meet the criteria 10054 ** for an indirect change above, or direct otherwise. 10055 ** 10056 ** This function is used to set, clear or query the session object indirect 10057 ** flag. If the second argument passed to this function is zero, then the 10058 ** indirect flag is cleared. If it is greater than zero, the indirect flag 10059 ** is set. Passing a value less than zero does not modify the current value 10060 ** of the indirect flag, and may be used to query the current state of the 10061 ** indirect flag for the specified session object. 10062 ** 10063 ** The return value indicates the final state of the indirect flag: 0 if 10064 ** it is clear, or 1 if it is set. 10065 */ 10066 SQLITE_API int sqlite3session_indirect(sqlite3_session *pSession, int bIndirect); 10067 10068 /* 10069 ** CAPI3REF: Attach A Table To A Session Object 10070 ** METHOD: sqlite3_session 10071 ** 10072 ** If argument zTab is not NULL, then it is the name of a table to attach 10073 ** to the session object passed as the first argument. All subsequent changes 10074 ** made to the table while the session object is enabled will be recorded. See 10075 ** documentation for [sqlite3session_changeset()] for further details. 10076 ** 10077 ** Or, if argument zTab is NULL, then changes are recorded for all tables 10078 ** in the database. If additional tables are added to the database (by 10079 ** executing "CREATE TABLE" statements) after this call is made, changes for 10080 ** the new tables are also recorded. 10081 ** 10082 ** Changes can only be recorded for tables that have a PRIMARY KEY explicitly 10083 ** defined as part of their CREATE TABLE statement. It does not matter if the 10084 ** PRIMARY KEY is an "INTEGER PRIMARY KEY" (rowid alias) or not. The PRIMARY 10085 ** KEY may consist of a single column, or may be a composite key. 10086 ** 10087 ** It is not an error if the named table does not exist in the database. Nor 10088 ** is it an error if the named table does not have a PRIMARY KEY. However, 10089 ** no changes will be recorded in either of these scenarios. 10090 ** 10091 ** Changes are not recorded for individual rows that have NULL values stored 10092 ** in one or more of their PRIMARY KEY columns. 10093 ** 10094 ** SQLITE_OK is returned if the call completes without error. Or, if an error 10095 ** occurs, an SQLite error code (e.g. SQLITE_NOMEM) is returned. 10096 ** 10097 ** <h3>Special sqlite_stat1 Handling</h3> 10098 ** 10099 ** As of SQLite version 3.22.0, the "sqlite_stat1" table is an exception to 10100 ** some of the rules above. In SQLite, the schema of sqlite_stat1 is: 10101 ** <pre> 10102 ** CREATE TABLE sqlite_stat1(tbl,idx,stat) 10103 ** </pre> 10104 ** 10105 ** Even though sqlite_stat1 does not have a PRIMARY KEY, changes are 10106 ** recorded for it as if the PRIMARY KEY is (tbl,idx). Additionally, changes 10107 ** are recorded for rows for which (idx IS NULL) is true. However, for such 10108 ** rows a zero-length blob (SQL value X'') is stored in the changeset or 10109 ** patchset instead of a NULL value. This allows such changesets to be 10110 ** manipulated by legacy implementations of sqlite3changeset_invert(), 10111 ** concat() and similar. 10112 ** 10113 ** The sqlite3changeset_apply() function automatically converts the 10114 ** zero-length blob back to a NULL value when updating the sqlite_stat1 10115 ** table. However, if the application calls sqlite3changeset_new(), 10116 ** sqlite3changeset_old() or sqlite3changeset_conflict on a changeset 10117 ** iterator directly (including on a changeset iterator passed to a 10118 ** conflict-handler callback) then the X'' value is returned. The application 10119 ** must translate X'' to NULL itself if required. 10120 ** 10121 ** Legacy (older than 3.22.0) versions of the sessions module cannot capture 10122 ** changes made to the sqlite_stat1 table. Legacy versions of the 10123 ** sqlite3changeset_apply() function silently ignore any modifications to the 10124 ** sqlite_stat1 table that are part of a changeset or patchset. 10125 */ 10126 SQLITE_API int sqlite3session_attach( 10127 sqlite3_session *pSession, /* Session object */ 10128 const char *zTab /* Table name */ 10129 ); 10130 10131 /* 10132 ** CAPI3REF: Set a table filter on a Session Object. 10133 ** METHOD: sqlite3_session 10134 ** 10135 ** The second argument (xFilter) is the "filter callback". For changes to rows 10136 ** in tables that are not attached to the Session object, the filter is called 10137 ** to determine whether changes to the table's rows should be tracked or not. 10138 ** If xFilter returns 0, changes are not tracked. Note that once a table is 10139 ** attached, xFilter will not be called again. 10140 */ 10141 SQLITE_API void sqlite3session_table_filter( 10142 sqlite3_session *pSession, /* Session object */ 10143 int(*xFilter)( 10144 void *pCtx, /* Copy of third arg to _filter_table() */ 10145 const char *zTab /* Table name */ 10146 ), 10147 void *pCtx /* First argument passed to xFilter */ 10148 ); 10149 10150 /* 10151 ** CAPI3REF: Generate A Changeset From A Session Object 10152 ** METHOD: sqlite3_session 10153 ** 10154 ** Obtain a changeset containing changes to the tables attached to the 10155 ** session object passed as the first argument. If successful, 10156 ** set *ppChangeset to point to a buffer containing the changeset 10157 ** and *pnChangeset to the size of the changeset in bytes before returning 10158 ** SQLITE_OK. If an error occurs, set both *ppChangeset and *pnChangeset to 10159 ** zero and return an SQLite error code. 10160 ** 10161 ** A changeset consists of zero or more INSERT, UPDATE and/or DELETE changes, 10162 ** each representing a change to a single row of an attached table. An INSERT 10163 ** change contains the values of each field of a new database row. A DELETE 10164 ** contains the original values of each field of a deleted database row. An 10165 ** UPDATE change contains the original values of each field of an updated 10166 ** database row along with the updated values for each updated non-primary-key 10167 ** column. It is not possible for an UPDATE change to represent a change that 10168 ** modifies the values of primary key columns. If such a change is made, it 10169 ** is represented in a changeset as a DELETE followed by an INSERT. 10170 ** 10171 ** Changes are not recorded for rows that have NULL values stored in one or 10172 ** more of their PRIMARY KEY columns. If such a row is inserted or deleted, 10173 ** no corresponding change is present in the changesets returned by this 10174 ** function. If an existing row with one or more NULL values stored in 10175 ** PRIMARY KEY columns is updated so that all PRIMARY KEY columns are non-NULL, 10176 ** only an INSERT is appears in the changeset. Similarly, if an existing row 10177 ** with non-NULL PRIMARY KEY values is updated so that one or more of its 10178 ** PRIMARY KEY columns are set to NULL, the resulting changeset contains a 10179 ** DELETE change only. 10180 ** 10181 ** The contents of a changeset may be traversed using an iterator created 10182 ** using the [sqlite3changeset_start()] API. A changeset may be applied to 10183 ** a database with a compatible schema using the [sqlite3changeset_apply()] 10184 ** API. 10185 ** 10186 ** Within a changeset generated by this function, all changes related to a 10187 ** single table are grouped together. In other words, when iterating through 10188 ** a changeset or when applying a changeset to a database, all changes related 10189 ** to a single table are processed before moving on to the next table. Tables 10190 ** are sorted in the same order in which they were attached (or auto-attached) 10191 ** to the sqlite3_session object. The order in which the changes related to 10192 ** a single table are stored is undefined. 10193 ** 10194 ** Following a successful call to this function, it is the responsibility of 10195 ** the caller to eventually free the buffer that *ppChangeset points to using 10196 ** [sqlite3_free()]. 10197 ** 10198 ** <h3>Changeset Generation</h3> 10199 ** 10200 ** Once a table has been attached to a session object, the session object 10201 ** records the primary key values of all new rows inserted into the table. 10202 ** It also records the original primary key and other column values of any 10203 ** deleted or updated rows. For each unique primary key value, data is only 10204 ** recorded once - the first time a row with said primary key is inserted, 10205 ** updated or deleted in the lifetime of the session. 10206 ** 10207 ** There is one exception to the previous paragraph: when a row is inserted, 10208 ** updated or deleted, if one or more of its primary key columns contain a 10209 ** NULL value, no record of the change is made. 10210 ** 10211 ** The session object therefore accumulates two types of records - those 10212 ** that consist of primary key values only (created when the user inserts 10213 ** a new record) and those that consist of the primary key values and the 10214 ** original values of other table columns (created when the users deletes 10215 ** or updates a record). 10216 ** 10217 ** When this function is called, the requested changeset is created using 10218 ** both the accumulated records and the current contents of the database 10219 ** file. Specifically: 10220 ** 10221 ** <ul> 10222 ** <li> For each record generated by an insert, the database is queried 10223 ** for a row with a matching primary key. If one is found, an INSERT 10224 ** change is added to the changeset. If no such row is found, no change 10225 ** is added to the changeset. 10226 ** 10227 ** <li> For each record generated by an update or delete, the database is 10228 ** queried for a row with a matching primary key. If such a row is 10229 ** found and one or more of the non-primary key fields have been 10230 ** modified from their original values, an UPDATE change is added to 10231 ** the changeset. Or, if no such row is found in the table, a DELETE 10232 ** change is added to the changeset. If there is a row with a matching 10233 ** primary key in the database, but all fields contain their original 10234 ** values, no change is added to the changeset. 10235 ** </ul> 10236 ** 10237 ** This means, amongst other things, that if a row is inserted and then later 10238 ** deleted while a session object is active, neither the insert nor the delete 10239 ** will be present in the changeset. Or if a row is deleted and then later a 10240 ** row with the same primary key values inserted while a session object is 10241 ** active, the resulting changeset will contain an UPDATE change instead of 10242 ** a DELETE and an INSERT. 10243 ** 10244 ** When a session object is disabled (see the [sqlite3session_enable()] API), 10245 ** it does not accumulate records when rows are inserted, updated or deleted. 10246 ** This may appear to have some counter-intuitive effects if a single row 10247 ** is written to more than once during a session. For example, if a row 10248 ** is inserted while a session object is enabled, then later deleted while 10249 ** the same session object is disabled, no INSERT record will appear in the 10250 ** changeset, even though the delete took place while the session was disabled. 10251 ** Or, if one field of a row is updated while a session is disabled, and 10252 ** another field of the same row is updated while the session is enabled, the 10253 ** resulting changeset will contain an UPDATE change that updates both fields. 10254 */ 10255 SQLITE_API int sqlite3session_changeset( 10256 sqlite3_session *pSession, /* Session object */ 10257 int *pnChangeset, /* OUT: Size of buffer at *ppChangeset */ 10258 void **ppChangeset /* OUT: Buffer containing changeset */ 10259 ); 10260 10261 /* 10262 ** CAPI3REF: Load The Difference Between Tables Into A Session 10263 ** METHOD: sqlite3_session 10264 ** 10265 ** If it is not already attached to the session object passed as the first 10266 ** argument, this function attaches table zTbl in the same manner as the 10267 ** [sqlite3session_attach()] function. If zTbl does not exist, or if it 10268 ** does not have a primary key, this function is a no-op (but does not return 10269 ** an error). 10270 ** 10271 ** Argument zFromDb must be the name of a database ("main", "temp" etc.) 10272 ** attached to the same database handle as the session object that contains 10273 ** a table compatible with the table attached to the session by this function. 10274 ** A table is considered compatible if it: 10275 ** 10276 ** <ul> 10277 ** <li> Has the same name, 10278 ** <li> Has the same set of columns declared in the same order, and 10279 ** <li> Has the same PRIMARY KEY definition. 10280 ** </ul> 10281 ** 10282 ** If the tables are not compatible, SQLITE_SCHEMA is returned. If the tables 10283 ** are compatible but do not have any PRIMARY KEY columns, it is not an error 10284 ** but no changes are added to the session object. As with other session 10285 ** APIs, tables without PRIMARY KEYs are simply ignored. 10286 ** 10287 ** This function adds a set of changes to the session object that could be 10288 ** used to update the table in database zFrom (call this the "from-table") 10289 ** so that its content is the same as the table attached to the session 10290 ** object (call this the "to-table"). Specifically: 10291 ** 10292 ** <ul> 10293 ** <li> For each row (primary key) that exists in the to-table but not in 10294 ** the from-table, an INSERT record is added to the session object. 10295 ** 10296 ** <li> For each row (primary key) that exists in the to-table but not in 10297 ** the from-table, a DELETE record is added to the session object. 10298 ** 10299 ** <li> For each row (primary key) that exists in both tables, but features 10300 ** different non-PK values in each, an UPDATE record is added to the 10301 ** session. 10302 ** </ul> 10303 ** 10304 ** To clarify, if this function is called and then a changeset constructed 10305 ** using [sqlite3session_changeset()], then after applying that changeset to 10306 ** database zFrom the contents of the two compatible tables would be 10307 ** identical. 10308 ** 10309 ** It an error if database zFrom does not exist or does not contain the 10310 ** required compatible table. 10311 ** 10312 ** If the operation is successful, SQLITE_OK is returned. Otherwise, an SQLite 10313 ** error code. In this case, if argument pzErrMsg is not NULL, *pzErrMsg 10314 ** may be set to point to a buffer containing an English language error 10315 ** message. It is the responsibility of the caller to free this buffer using 10316 ** sqlite3_free(). 10317 */ 10318 SQLITE_API int sqlite3session_diff( 10319 sqlite3_session *pSession, 10320 const char *zFromDb, 10321 const char *zTbl, 10322 char **pzErrMsg 10323 ); 10324 10325 10326 /* 10327 ** CAPI3REF: Generate A Patchset From A Session Object 10328 ** METHOD: sqlite3_session 10329 ** 10330 ** The differences between a patchset and a changeset are that: 10331 ** 10332 ** <ul> 10333 ** <li> DELETE records consist of the primary key fields only. The 10334 ** original values of other fields are omitted. 10335 ** <li> The original values of any modified fields are omitted from 10336 ** UPDATE records. 10337 ** </ul> 10338 ** 10339 ** A patchset blob may be used with up to date versions of all 10340 ** sqlite3changeset_xxx API functions except for sqlite3changeset_invert(), 10341 ** which returns SQLITE_CORRUPT if it is passed a patchset. Similarly, 10342 ** attempting to use a patchset blob with old versions of the 10343 ** sqlite3changeset_xxx APIs also provokes an SQLITE_CORRUPT error. 10344 ** 10345 ** Because the non-primary key "old.*" fields are omitted, no 10346 ** SQLITE_CHANGESET_DATA conflicts can be detected or reported if a patchset 10347 ** is passed to the sqlite3changeset_apply() API. Other conflict types work 10348 ** in the same way as for changesets. 10349 ** 10350 ** Changes within a patchset are ordered in the same way as for changesets 10351 ** generated by the sqlite3session_changeset() function (i.e. all changes for 10352 ** a single table are grouped together, tables appear in the order in which 10353 ** they were attached to the session object). 10354 */ 10355 SQLITE_API int sqlite3session_patchset( 10356 sqlite3_session *pSession, /* Session object */ 10357 int *pnPatchset, /* OUT: Size of buffer at *ppPatchset */ 10358 void **ppPatchset /* OUT: Buffer containing patchset */ 10359 ); 10360 10361 /* 10362 ** CAPI3REF: Test if a changeset has recorded any changes. 10363 ** 10364 ** Return non-zero if no changes to attached tables have been recorded by 10365 ** the session object passed as the first argument. Otherwise, if one or 10366 ** more changes have been recorded, return zero. 10367 ** 10368 ** Even if this function returns zero, it is possible that calling 10369 ** [sqlite3session_changeset()] on the session handle may still return a 10370 ** changeset that contains no changes. This can happen when a row in 10371 ** an attached table is modified and then later on the original values 10372 ** are restored. However, if this function returns non-zero, then it is 10373 ** guaranteed that a call to sqlite3session_changeset() will return a 10374 ** changeset containing zero changes. 10375 */ 10376 SQLITE_API int sqlite3session_isempty(sqlite3_session *pSession); 10377 10378 /* 10379 ** CAPI3REF: Create An Iterator To Traverse A Changeset 10380 ** CONSTRUCTOR: sqlite3_changeset_iter 10381 ** 10382 ** Create an iterator used to iterate through the contents of a changeset. 10383 ** If successful, *pp is set to point to the iterator handle and SQLITE_OK 10384 ** is returned. Otherwise, if an error occurs, *pp is set to zero and an 10385 ** SQLite error code is returned. 10386 ** 10387 ** The following functions can be used to advance and query a changeset 10388 ** iterator created by this function: 10389 ** 10390 ** <ul> 10391 ** <li> [sqlite3changeset_next()] 10392 ** <li> [sqlite3changeset_op()] 10393 ** <li> [sqlite3changeset_new()] 10394 ** <li> [sqlite3changeset_old()] 10395 ** </ul> 10396 ** 10397 ** It is the responsibility of the caller to eventually destroy the iterator 10398 ** by passing it to [sqlite3changeset_finalize()]. The buffer containing the 10399 ** changeset (pChangeset) must remain valid until after the iterator is 10400 ** destroyed. 10401 ** 10402 ** Assuming the changeset blob was created by one of the 10403 ** [sqlite3session_changeset()], [sqlite3changeset_concat()] or 10404 ** [sqlite3changeset_invert()] functions, all changes within the changeset 10405 ** that apply to a single table are grouped together. This means that when 10406 ** an application iterates through a changeset using an iterator created by 10407 ** this function, all changes that relate to a single table are visited 10408 ** consecutively. There is no chance that the iterator will visit a change 10409 ** the applies to table X, then one for table Y, and then later on visit 10410 ** another change for table X. 10411 ** 10412 ** The behavior of sqlite3changeset_start_v2() and its streaming equivalent 10413 ** may be modified by passing a combination of 10414 ** [SQLITE_CHANGESETSTART_INVERT | supported flags] as the 4th parameter. 10415 ** 10416 ** Note that the sqlite3changeset_start_v2() API is still <b>experimental</b> 10417 ** and therefore subject to change. 10418 */ 10419 SQLITE_API int sqlite3changeset_start( 10420 sqlite3_changeset_iter **pp, /* OUT: New changeset iterator handle */ 10421 int nChangeset, /* Size of changeset blob in bytes */ 10422 void *pChangeset /* Pointer to blob containing changeset */ 10423 ); 10424 SQLITE_API int sqlite3changeset_start_v2( 10425 sqlite3_changeset_iter **pp, /* OUT: New changeset iterator handle */ 10426 int nChangeset, /* Size of changeset blob in bytes */ 10427 void *pChangeset, /* Pointer to blob containing changeset */ 10428 int flags /* SESSION_CHANGESETSTART_* flags */ 10429 ); 10430 10431 /* 10432 ** CAPI3REF: Flags for sqlite3changeset_start_v2 10433 ** 10434 ** The following flags may passed via the 4th parameter to 10435 ** [sqlite3changeset_start_v2] and [sqlite3changeset_start_v2_strm]: 10436 ** 10437 ** <dt>SQLITE_CHANGESETAPPLY_INVERT <dd> 10438 ** Invert the changeset while iterating through it. This is equivalent to 10439 ** inverting a changeset using sqlite3changeset_invert() before applying it. 10440 ** It is an error to specify this flag with a patchset. 10441 */ 10442 #define SQLITE_CHANGESETSTART_INVERT 0x0002 10443 10444 10445 /* 10446 ** CAPI3REF: Advance A Changeset Iterator 10447 ** METHOD: sqlite3_changeset_iter 10448 ** 10449 ** This function may only be used with iterators created by the function 10450 ** [sqlite3changeset_start()]. If it is called on an iterator passed to 10451 ** a conflict-handler callback by [sqlite3changeset_apply()], SQLITE_MISUSE 10452 ** is returned and the call has no effect. 10453 ** 10454 ** Immediately after an iterator is created by sqlite3changeset_start(), it 10455 ** does not point to any change in the changeset. Assuming the changeset 10456 ** is not empty, the first call to this function advances the iterator to 10457 ** point to the first change in the changeset. Each subsequent call advances 10458 ** the iterator to point to the next change in the changeset (if any). If 10459 ** no error occurs and the iterator points to a valid change after a call 10460 ** to sqlite3changeset_next() has advanced it, SQLITE_ROW is returned. 10461 ** Otherwise, if all changes in the changeset have already been visited, 10462 ** SQLITE_DONE is returned. 10463 ** 10464 ** If an error occurs, an SQLite error code is returned. Possible error 10465 ** codes include SQLITE_CORRUPT (if the changeset buffer is corrupt) or 10466 ** SQLITE_NOMEM. 10467 */ 10468 SQLITE_API int sqlite3changeset_next(sqlite3_changeset_iter *pIter); 10469 10470 /* 10471 ** CAPI3REF: Obtain The Current Operation From A Changeset Iterator 10472 ** METHOD: sqlite3_changeset_iter 10473 ** 10474 ** The pIter argument passed to this function may either be an iterator 10475 ** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator 10476 ** created by [sqlite3changeset_start()]. In the latter case, the most recent 10477 ** call to [sqlite3changeset_next()] must have returned [SQLITE_ROW]. If this 10478 ** is not the case, this function returns [SQLITE_MISUSE]. 10479 ** 10480 ** If argument pzTab is not NULL, then *pzTab is set to point to a 10481 ** nul-terminated utf-8 encoded string containing the name of the table 10482 ** affected by the current change. The buffer remains valid until either 10483 ** sqlite3changeset_next() is called on the iterator or until the 10484 ** conflict-handler function returns. If pnCol is not NULL, then *pnCol is 10485 ** set to the number of columns in the table affected by the change. If 10486 ** pbIndirect is not NULL, then *pbIndirect is set to true (1) if the change 10487 ** is an indirect change, or false (0) otherwise. See the documentation for 10488 ** [sqlite3session_indirect()] for a description of direct and indirect 10489 ** changes. Finally, if pOp is not NULL, then *pOp is set to one of 10490 ** [SQLITE_INSERT], [SQLITE_DELETE] or [SQLITE_UPDATE], depending on the 10491 ** type of change that the iterator currently points to. 10492 ** 10493 ** If no error occurs, SQLITE_OK is returned. If an error does occur, an 10494 ** SQLite error code is returned. The values of the output variables may not 10495 ** be trusted in this case. 10496 */ 10497 SQLITE_API int sqlite3changeset_op( 10498 sqlite3_changeset_iter *pIter, /* Iterator object */ 10499 const char **pzTab, /* OUT: Pointer to table name */ 10500 int *pnCol, /* OUT: Number of columns in table */ 10501 int *pOp, /* OUT: SQLITE_INSERT, DELETE or UPDATE */ 10502 int *pbIndirect /* OUT: True for an 'indirect' change */ 10503 ); 10504 10505 /* 10506 ** CAPI3REF: Obtain The Primary Key Definition Of A Table 10507 ** METHOD: sqlite3_changeset_iter 10508 ** 10509 ** For each modified table, a changeset includes the following: 10510 ** 10511 ** <ul> 10512 ** <li> The number of columns in the table, and 10513 ** <li> Which of those columns make up the tables PRIMARY KEY. 10514 ** </ul> 10515 ** 10516 ** This function is used to find which columns comprise the PRIMARY KEY of 10517 ** the table modified by the change that iterator pIter currently points to. 10518 ** If successful, *pabPK is set to point to an array of nCol entries, where 10519 ** nCol is the number of columns in the table. Elements of *pabPK are set to 10520 ** 0x01 if the corresponding column is part of the tables primary key, or 10521 ** 0x00 if it is not. 10522 ** 10523 ** If argument pnCol is not NULL, then *pnCol is set to the number of columns 10524 ** in the table. 10525 ** 10526 ** If this function is called when the iterator does not point to a valid 10527 ** entry, SQLITE_MISUSE is returned and the output variables zeroed. Otherwise, 10528 ** SQLITE_OK is returned and the output variables populated as described 10529 ** above. 10530 */ 10531 SQLITE_API int sqlite3changeset_pk( 10532 sqlite3_changeset_iter *pIter, /* Iterator object */ 10533 unsigned char **pabPK, /* OUT: Array of boolean - true for PK cols */ 10534 int *pnCol /* OUT: Number of entries in output array */ 10535 ); 10536 10537 /* 10538 ** CAPI3REF: Obtain old.* Values From A Changeset Iterator 10539 ** METHOD: sqlite3_changeset_iter 10540 ** 10541 ** The pIter argument passed to this function may either be an iterator 10542 ** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator 10543 ** created by [sqlite3changeset_start()]. In the latter case, the most recent 10544 ** call to [sqlite3changeset_next()] must have returned SQLITE_ROW. 10545 ** Furthermore, it may only be called if the type of change that the iterator 10546 ** currently points to is either [SQLITE_DELETE] or [SQLITE_UPDATE]. Otherwise, 10547 ** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL. 10548 ** 10549 ** Argument iVal must be greater than or equal to 0, and less than the number 10550 ** of columns in the table affected by the current change. Otherwise, 10551 ** [SQLITE_RANGE] is returned and *ppValue is set to NULL. 10552 ** 10553 ** If successful, this function sets *ppValue to point to a protected 10554 ** sqlite3_value object containing the iVal'th value from the vector of 10555 ** original row values stored as part of the UPDATE or DELETE change and 10556 ** returns SQLITE_OK. The name of the function comes from the fact that this 10557 ** is similar to the "old.*" columns available to update or delete triggers. 10558 ** 10559 ** If some other error occurs (e.g. an OOM condition), an SQLite error code 10560 ** is returned and *ppValue is set to NULL. 10561 */ 10562 SQLITE_API int sqlite3changeset_old( 10563 sqlite3_changeset_iter *pIter, /* Changeset iterator */ 10564 int iVal, /* Column number */ 10565 sqlite3_value **ppValue /* OUT: Old value (or NULL pointer) */ 10566 ); 10567 10568 /* 10569 ** CAPI3REF: Obtain new.* Values From A Changeset Iterator 10570 ** METHOD: sqlite3_changeset_iter 10571 ** 10572 ** The pIter argument passed to this function may either be an iterator 10573 ** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator 10574 ** created by [sqlite3changeset_start()]. In the latter case, the most recent 10575 ** call to [sqlite3changeset_next()] must have returned SQLITE_ROW. 10576 ** Furthermore, it may only be called if the type of change that the iterator 10577 ** currently points to is either [SQLITE_UPDATE] or [SQLITE_INSERT]. Otherwise, 10578 ** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL. 10579 ** 10580 ** Argument iVal must be greater than or equal to 0, and less than the number 10581 ** of columns in the table affected by the current change. Otherwise, 10582 ** [SQLITE_RANGE] is returned and *ppValue is set to NULL. 10583 ** 10584 ** If successful, this function sets *ppValue to point to a protected 10585 ** sqlite3_value object containing the iVal'th value from the vector of 10586 ** new row values stored as part of the UPDATE or INSERT change and 10587 ** returns SQLITE_OK. If the change is an UPDATE and does not include 10588 ** a new value for the requested column, *ppValue is set to NULL and 10589 ** SQLITE_OK returned. The name of the function comes from the fact that 10590 ** this is similar to the "new.*" columns available to update or delete 10591 ** triggers. 10592 ** 10593 ** If some other error occurs (e.g. an OOM condition), an SQLite error code 10594 ** is returned and *ppValue is set to NULL. 10595 */ 10596 SQLITE_API int sqlite3changeset_new( 10597 sqlite3_changeset_iter *pIter, /* Changeset iterator */ 10598 int iVal, /* Column number */ 10599 sqlite3_value **ppValue /* OUT: New value (or NULL pointer) */ 10600 ); 10601 10602 /* 10603 ** CAPI3REF: Obtain Conflicting Row Values From A Changeset Iterator 10604 ** METHOD: sqlite3_changeset_iter 10605 ** 10606 ** This function should only be used with iterator objects passed to a 10607 ** conflict-handler callback by [sqlite3changeset_apply()] with either 10608 ** [SQLITE_CHANGESET_DATA] or [SQLITE_CHANGESET_CONFLICT]. If this function 10609 ** is called on any other iterator, [SQLITE_MISUSE] is returned and *ppValue 10610 ** is set to NULL. 10611 ** 10612 ** Argument iVal must be greater than or equal to 0, and less than the number 10613 ** of columns in the table affected by the current change. Otherwise, 10614 ** [SQLITE_RANGE] is returned and *ppValue is set to NULL. 10615 ** 10616 ** If successful, this function sets *ppValue to point to a protected 10617 ** sqlite3_value object containing the iVal'th value from the 10618 ** "conflicting row" associated with the current conflict-handler callback 10619 ** and returns SQLITE_OK. 10620 ** 10621 ** If some other error occurs (e.g. an OOM condition), an SQLite error code 10622 ** is returned and *ppValue is set to NULL. 10623 */ 10624 SQLITE_API int sqlite3changeset_conflict( 10625 sqlite3_changeset_iter *pIter, /* Changeset iterator */ 10626 int iVal, /* Column number */ 10627 sqlite3_value **ppValue /* OUT: Value from conflicting row */ 10628 ); 10629 10630 /* 10631 ** CAPI3REF: Determine The Number Of Foreign Key Constraint Violations 10632 ** METHOD: sqlite3_changeset_iter 10633 ** 10634 ** This function may only be called with an iterator passed to an 10635 ** SQLITE_CHANGESET_FOREIGN_KEY conflict handler callback. In this case 10636 ** it sets the output variable to the total number of known foreign key 10637 ** violations in the destination database and returns SQLITE_OK. 10638 ** 10639 ** In all other cases this function returns SQLITE_MISUSE. 10640 */ 10641 SQLITE_API int sqlite3changeset_fk_conflicts( 10642 sqlite3_changeset_iter *pIter, /* Changeset iterator */ 10643 int *pnOut /* OUT: Number of FK violations */ 10644 ); 10645 10646 10647 /* 10648 ** CAPI3REF: Finalize A Changeset Iterator 10649 ** METHOD: sqlite3_changeset_iter 10650 ** 10651 ** This function is used to finalize an iterator allocated with 10652 ** [sqlite3changeset_start()]. 10653 ** 10654 ** This function should only be called on iterators created using the 10655 ** [sqlite3changeset_start()] function. If an application calls this 10656 ** function with an iterator passed to a conflict-handler by 10657 ** [sqlite3changeset_apply()], [SQLITE_MISUSE] is immediately returned and the 10658 ** call has no effect. 10659 ** 10660 ** If an error was encountered within a call to an sqlite3changeset_xxx() 10661 ** function (for example an [SQLITE_CORRUPT] in [sqlite3changeset_next()] or an 10662 ** [SQLITE_NOMEM] in [sqlite3changeset_new()]) then an error code corresponding 10663 ** to that error is returned by this function. Otherwise, SQLITE_OK is 10664 ** returned. This is to allow the following pattern (pseudo-code): 10665 ** 10666 ** <pre> 10667 ** sqlite3changeset_start(); 10668 ** while( SQLITE_ROW==sqlite3changeset_next() ){ 10669 ** // Do something with change. 10670 ** } 10671 ** rc = sqlite3changeset_finalize(); 10672 ** if( rc!=SQLITE_OK ){ 10673 ** // An error has occurred 10674 ** } 10675 ** </pre> 10676 */ 10677 SQLITE_API int sqlite3changeset_finalize(sqlite3_changeset_iter *pIter); 10678 10679 /* 10680 ** CAPI3REF: Invert A Changeset 10681 ** 10682 ** This function is used to "invert" a changeset object. Applying an inverted 10683 ** changeset to a database reverses the effects of applying the uninverted 10684 ** changeset. Specifically: 10685 ** 10686 ** <ul> 10687 ** <li> Each DELETE change is changed to an INSERT, and 10688 ** <li> Each INSERT change is changed to a DELETE, and 10689 ** <li> For each UPDATE change, the old.* and new.* values are exchanged. 10690 ** </ul> 10691 ** 10692 ** This function does not change the order in which changes appear within 10693 ** the changeset. It merely reverses the sense of each individual change. 10694 ** 10695 ** If successful, a pointer to a buffer containing the inverted changeset 10696 ** is stored in *ppOut, the size of the same buffer is stored in *pnOut, and 10697 ** SQLITE_OK is returned. If an error occurs, both *pnOut and *ppOut are 10698 ** zeroed and an SQLite error code returned. 10699 ** 10700 ** It is the responsibility of the caller to eventually call sqlite3_free() 10701 ** on the *ppOut pointer to free the buffer allocation following a successful 10702 ** call to this function. 10703 ** 10704 ** WARNING/TODO: This function currently assumes that the input is a valid 10705 ** changeset. If it is not, the results are undefined. 10706 */ 10707 SQLITE_API int sqlite3changeset_invert( 10708 int nIn, const void *pIn, /* Input changeset */ 10709 int *pnOut, void **ppOut /* OUT: Inverse of input */ 10710 ); 10711 10712 /* 10713 ** CAPI3REF: Concatenate Two Changeset Objects 10714 ** 10715 ** This function is used to concatenate two changesets, A and B, into a 10716 ** single changeset. The result is a changeset equivalent to applying 10717 ** changeset A followed by changeset B. 10718 ** 10719 ** This function combines the two input changesets using an 10720 ** sqlite3_changegroup object. Calling it produces similar results as the 10721 ** following code fragment: 10722 ** 10723 ** <pre> 10724 ** sqlite3_changegroup *pGrp; 10725 ** rc = sqlite3_changegroup_new(&pGrp); 10726 ** if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nA, pA); 10727 ** if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nB, pB); 10728 ** if( rc==SQLITE_OK ){ 10729 ** rc = sqlite3changegroup_output(pGrp, pnOut, ppOut); 10730 ** }else{ 10731 ** *ppOut = 0; 10732 ** *pnOut = 0; 10733 ** } 10734 ** </pre> 10735 ** 10736 ** Refer to the sqlite3_changegroup documentation below for details. 10737 */ 10738 SQLITE_API int sqlite3changeset_concat( 10739 int nA, /* Number of bytes in buffer pA */ 10740 void *pA, /* Pointer to buffer containing changeset A */ 10741 int nB, /* Number of bytes in buffer pB */ 10742 void *pB, /* Pointer to buffer containing changeset B */ 10743 int *pnOut, /* OUT: Number of bytes in output changeset */ 10744 void **ppOut /* OUT: Buffer containing output changeset */ 10745 ); 10746 10747 10748 /* 10749 ** CAPI3REF: Changegroup Handle 10750 ** 10751 ** A changegroup is an object used to combine two or more 10752 ** [changesets] or [patchsets] 10753 */ 10754 typedef struct sqlite3_changegroup sqlite3_changegroup; 10755 10756 /* 10757 ** CAPI3REF: Create A New Changegroup Object 10758 ** CONSTRUCTOR: sqlite3_changegroup 10759 ** 10760 ** An sqlite3_changegroup object is used to combine two or more changesets 10761 ** (or patchsets) into a single changeset (or patchset). A single changegroup 10762 ** object may combine changesets or patchsets, but not both. The output is 10763 ** always in the same format as the input. 10764 ** 10765 ** If successful, this function returns SQLITE_OK and populates (*pp) with 10766 ** a pointer to a new sqlite3_changegroup object before returning. The caller 10767 ** should eventually free the returned object using a call to 10768 ** sqlite3changegroup_delete(). If an error occurs, an SQLite error code 10769 ** (i.e. SQLITE_NOMEM) is returned and *pp is set to NULL. 10770 ** 10771 ** The usual usage pattern for an sqlite3_changegroup object is as follows: 10772 ** 10773 ** <ul> 10774 ** <li> It is created using a call to sqlite3changegroup_new(). 10775 ** 10776 ** <li> Zero or more changesets (or patchsets) are added to the object 10777 ** by calling sqlite3changegroup_add(). 10778 ** 10779 ** <li> The result of combining all input changesets together is obtained 10780 ** by the application via a call to sqlite3changegroup_output(). 10781 ** 10782 ** <li> The object is deleted using a call to sqlite3changegroup_delete(). 10783 ** </ul> 10784 ** 10785 ** Any number of calls to add() and output() may be made between the calls to 10786 ** new() and delete(), and in any order. 10787 ** 10788 ** As well as the regular sqlite3changegroup_add() and 10789 ** sqlite3changegroup_output() functions, also available are the streaming 10790 ** versions sqlite3changegroup_add_strm() and sqlite3changegroup_output_strm(). 10791 */ 10792 SQLITE_API int sqlite3changegroup_new(sqlite3_changegroup **pp); 10793 10794 /* 10795 ** CAPI3REF: Add A Changeset To A Changegroup 10796 ** METHOD: sqlite3_changegroup 10797 ** 10798 ** Add all changes within the changeset (or patchset) in buffer pData (size 10799 ** nData bytes) to the changegroup. 10800 ** 10801 ** If the buffer contains a patchset, then all prior calls to this function 10802 ** on the same changegroup object must also have specified patchsets. Or, if 10803 ** the buffer contains a changeset, so must have the earlier calls to this 10804 ** function. Otherwise, SQLITE_ERROR is returned and no changes are added 10805 ** to the changegroup. 10806 ** 10807 ** Rows within the changeset and changegroup are identified by the values in 10808 ** their PRIMARY KEY columns. A change in the changeset is considered to 10809 ** apply to the same row as a change already present in the changegroup if 10810 ** the two rows have the same primary key. 10811 ** 10812 ** Changes to rows that do not already appear in the changegroup are 10813 ** simply copied into it. Or, if both the new changeset and the changegroup 10814 ** contain changes that apply to a single row, the final contents of the 10815 ** changegroup depends on the type of each change, as follows: 10816 ** 10817 ** <table border=1 style="margin-left:8ex;margin-right:8ex"> 10818 ** <tr><th style="white-space:pre">Existing Change </th> 10819 ** <th style="white-space:pre">New Change </th> 10820 ** <th>Output Change 10821 ** <tr><td>INSERT <td>INSERT <td> 10822 ** The new change is ignored. This case does not occur if the new 10823 ** changeset was recorded immediately after the changesets already 10824 ** added to the changegroup. 10825 ** <tr><td>INSERT <td>UPDATE <td> 10826 ** The INSERT change remains in the changegroup. The values in the 10827 ** INSERT change are modified as if the row was inserted by the 10828 ** existing change and then updated according to the new change. 10829 ** <tr><td>INSERT <td>DELETE <td> 10830 ** The existing INSERT is removed from the changegroup. The DELETE is 10831 ** not added. 10832 ** <tr><td>UPDATE <td>INSERT <td> 10833 ** The new change is ignored. This case does not occur if the new 10834 ** changeset was recorded immediately after the changesets already 10835 ** added to the changegroup. 10836 ** <tr><td>UPDATE <td>UPDATE <td> 10837 ** The existing UPDATE remains within the changegroup. It is amended 10838 ** so that the accompanying values are as if the row was updated once 10839 ** by the existing change and then again by the new change. 10840 ** <tr><td>UPDATE <td>DELETE <td> 10841 ** The existing UPDATE is replaced by the new DELETE within the 10842 ** changegroup. 10843 ** <tr><td>DELETE <td>INSERT <td> 10844 ** If one or more of the column values in the row inserted by the 10845 ** new change differ from those in the row deleted by the existing 10846 ** change, the existing DELETE is replaced by an UPDATE within the 10847 ** changegroup. Otherwise, if the inserted row is exactly the same 10848 ** as the deleted row, the existing DELETE is simply discarded. 10849 ** <tr><td>DELETE <td>UPDATE <td> 10850 ** The new change is ignored. This case does not occur if the new 10851 ** changeset was recorded immediately after the changesets already 10852 ** added to the changegroup. 10853 ** <tr><td>DELETE <td>DELETE <td> 10854 ** The new change is ignored. This case does not occur if the new 10855 ** changeset was recorded immediately after the changesets already 10856 ** added to the changegroup. 10857 ** </table> 10858 ** 10859 ** If the new changeset contains changes to a table that is already present 10860 ** in the changegroup, then the number of columns and the position of the 10861 ** primary key columns for the table must be consistent. If this is not the 10862 ** case, this function fails with SQLITE_SCHEMA. If the input changeset 10863 ** appears to be corrupt and the corruption is detected, SQLITE_CORRUPT is 10864 ** returned. Or, if an out-of-memory condition occurs during processing, this 10865 ** function returns SQLITE_NOMEM. In all cases, if an error occurs the state 10866 ** of the final contents of the changegroup is undefined. 10867 ** 10868 ** If no error occurs, SQLITE_OK is returned. 10869 */ 10870 SQLITE_API int sqlite3changegroup_add(sqlite3_changegroup*, int nData, void *pData); 10871 10872 /* 10873 ** CAPI3REF: Obtain A Composite Changeset From A Changegroup 10874 ** METHOD: sqlite3_changegroup 10875 ** 10876 ** Obtain a buffer containing a changeset (or patchset) representing the 10877 ** current contents of the changegroup. If the inputs to the changegroup 10878 ** were themselves changesets, the output is a changeset. Or, if the 10879 ** inputs were patchsets, the output is also a patchset. 10880 ** 10881 ** As with the output of the sqlite3session_changeset() and 10882 ** sqlite3session_patchset() functions, all changes related to a single 10883 ** table are grouped together in the output of this function. Tables appear 10884 ** in the same order as for the very first changeset added to the changegroup. 10885 ** If the second or subsequent changesets added to the changegroup contain 10886 ** changes for tables that do not appear in the first changeset, they are 10887 ** appended onto the end of the output changeset, again in the order in 10888 ** which they are first encountered. 10889 ** 10890 ** If an error occurs, an SQLite error code is returned and the output 10891 ** variables (*pnData) and (*ppData) are set to 0. Otherwise, SQLITE_OK 10892 ** is returned and the output variables are set to the size of and a 10893 ** pointer to the output buffer, respectively. In this case it is the 10894 ** responsibility of the caller to eventually free the buffer using a 10895 ** call to sqlite3_free(). 10896 */ 10897 SQLITE_API int sqlite3changegroup_output( 10898 sqlite3_changegroup*, 10899 int *pnData, /* OUT: Size of output buffer in bytes */ 10900 void **ppData /* OUT: Pointer to output buffer */ 10901 ); 10902 10903 /* 10904 ** CAPI3REF: Delete A Changegroup Object 10905 ** DESTRUCTOR: sqlite3_changegroup 10906 */ 10907 SQLITE_API void sqlite3changegroup_delete(sqlite3_changegroup*); 10908 10909 /* 10910 ** CAPI3REF: Apply A Changeset To A Database 10911 ** 10912 ** Apply a changeset or patchset to a database. These functions attempt to 10913 ** update the "main" database attached to handle db with the changes found in 10914 ** the changeset passed via the second and third arguments. 10915 ** 10916 ** The fourth argument (xFilter) passed to these functions is the "filter 10917 ** callback". If it is not NULL, then for each table affected by at least one 10918 ** change in the changeset, the filter callback is invoked with 10919 ** the table name as the second argument, and a copy of the context pointer 10920 ** passed as the sixth argument as the first. If the "filter callback" 10921 ** returns zero, then no attempt is made to apply any changes to the table. 10922 ** Otherwise, if the return value is non-zero or the xFilter argument to 10923 ** is NULL, all changes related to the table are attempted. 10924 ** 10925 ** For each table that is not excluded by the filter callback, this function 10926 ** tests that the target database contains a compatible table. A table is 10927 ** considered compatible if all of the following are true: 10928 ** 10929 ** <ul> 10930 ** <li> The table has the same name as the name recorded in the 10931 ** changeset, and 10932 ** <li> The table has at least as many columns as recorded in the 10933 ** changeset, and 10934 ** <li> The table has primary key columns in the same position as 10935 ** recorded in the changeset. 10936 ** </ul> 10937 ** 10938 ** If there is no compatible table, it is not an error, but none of the 10939 ** changes associated with the table are applied. A warning message is issued 10940 ** via the sqlite3_log() mechanism with the error code SQLITE_SCHEMA. At most 10941 ** one such warning is issued for each table in the changeset. 10942 ** 10943 ** For each change for which there is a compatible table, an attempt is made 10944 ** to modify the table contents according to the UPDATE, INSERT or DELETE 10945 ** change. If a change cannot be applied cleanly, the conflict handler 10946 ** function passed as the fifth argument to sqlite3changeset_apply() may be 10947 ** invoked. A description of exactly when the conflict handler is invoked for 10948 ** each type of change is below. 10949 ** 10950 ** Unlike the xFilter argument, xConflict may not be passed NULL. The results 10951 ** of passing anything other than a valid function pointer as the xConflict 10952 ** argument are undefined. 10953 ** 10954 ** Each time the conflict handler function is invoked, it must return one 10955 ** of [SQLITE_CHANGESET_OMIT], [SQLITE_CHANGESET_ABORT] or 10956 ** [SQLITE_CHANGESET_REPLACE]. SQLITE_CHANGESET_REPLACE may only be returned 10957 ** if the second argument passed to the conflict handler is either 10958 ** SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If the conflict-handler 10959 ** returns an illegal value, any changes already made are rolled back and 10960 ** the call to sqlite3changeset_apply() returns SQLITE_MISUSE. Different 10961 ** actions are taken by sqlite3changeset_apply() depending on the value 10962 ** returned by each invocation of the conflict-handler function. Refer to 10963 ** the documentation for the three 10964 ** [SQLITE_CHANGESET_OMIT|available return values] for details. 10965 ** 10966 ** <dl> 10967 ** <dt>DELETE Changes<dd> 10968 ** For each DELETE change, the function checks if the target database 10969 ** contains a row with the same primary key value (or values) as the 10970 ** original row values stored in the changeset. If it does, and the values 10971 ** stored in all non-primary key columns also match the values stored in 10972 ** the changeset the row is deleted from the target database. 10973 ** 10974 ** If a row with matching primary key values is found, but one or more of 10975 ** the non-primary key fields contains a value different from the original 10976 ** row value stored in the changeset, the conflict-handler function is 10977 ** invoked with [SQLITE_CHANGESET_DATA] as the second argument. If the 10978 ** database table has more columns than are recorded in the changeset, 10979 ** only the values of those non-primary key fields are compared against 10980 ** the current database contents - any trailing database table columns 10981 ** are ignored. 10982 ** 10983 ** If no row with matching primary key values is found in the database, 10984 ** the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND] 10985 ** passed as the second argument. 10986 ** 10987 ** If the DELETE operation is attempted, but SQLite returns SQLITE_CONSTRAINT 10988 ** (which can only happen if a foreign key constraint is violated), the 10989 ** conflict-handler function is invoked with [SQLITE_CHANGESET_CONSTRAINT] 10990 ** passed as the second argument. This includes the case where the DELETE 10991 ** operation is attempted because an earlier call to the conflict handler 10992 ** function returned [SQLITE_CHANGESET_REPLACE]. 10993 ** 10994 ** <dt>INSERT Changes<dd> 10995 ** For each INSERT change, an attempt is made to insert the new row into 10996 ** the database. If the changeset row contains fewer fields than the 10997 ** database table, the trailing fields are populated with their default 10998 ** values. 10999 ** 11000 ** If the attempt to insert the row fails because the database already 11001 ** contains a row with the same primary key values, the conflict handler 11002 ** function is invoked with the second argument set to 11003 ** [SQLITE_CHANGESET_CONFLICT]. 11004 ** 11005 ** If the attempt to insert the row fails because of some other constraint 11006 ** violation (e.g. NOT NULL or UNIQUE), the conflict handler function is 11007 ** invoked with the second argument set to [SQLITE_CHANGESET_CONSTRAINT]. 11008 ** This includes the case where the INSERT operation is re-attempted because 11009 ** an earlier call to the conflict handler function returned 11010 ** [SQLITE_CHANGESET_REPLACE]. 11011 ** 11012 ** <dt>UPDATE Changes<dd> 11013 ** For each UPDATE change, the function checks if the target database 11014 ** contains a row with the same primary key value (or values) as the 11015 ** original row values stored in the changeset. If it does, and the values 11016 ** stored in all modified non-primary key columns also match the values 11017 ** stored in the changeset the row is updated within the target database. 11018 ** 11019 ** If a row with matching primary key values is found, but one or more of 11020 ** the modified non-primary key fields contains a value different from an 11021 ** original row value stored in the changeset, the conflict-handler function 11022 ** is invoked with [SQLITE_CHANGESET_DATA] as the second argument. Since 11023 ** UPDATE changes only contain values for non-primary key fields that are 11024 ** to be modified, only those fields need to match the original values to 11025 ** avoid the SQLITE_CHANGESET_DATA conflict-handler callback. 11026 ** 11027 ** If no row with matching primary key values is found in the database, 11028 ** the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND] 11029 ** passed as the second argument. 11030 ** 11031 ** If the UPDATE operation is attempted, but SQLite returns 11032 ** SQLITE_CONSTRAINT, the conflict-handler function is invoked with 11033 ** [SQLITE_CHANGESET_CONSTRAINT] passed as the second argument. 11034 ** This includes the case where the UPDATE operation is attempted after 11035 ** an earlier call to the conflict handler function returned 11036 ** [SQLITE_CHANGESET_REPLACE]. 11037 ** </dl> 11038 ** 11039 ** It is safe to execute SQL statements, including those that write to the 11040 ** table that the callback related to, from within the xConflict callback. 11041 ** This can be used to further customize the application's conflict 11042 ** resolution strategy. 11043 ** 11044 ** All changes made by these functions are enclosed in a savepoint transaction. 11045 ** If any other error (aside from a constraint failure when attempting to 11046 ** write to the target database) occurs, then the savepoint transaction is 11047 ** rolled back, restoring the target database to its original state, and an 11048 ** SQLite error code returned. 11049 ** 11050 ** If the output parameters (ppRebase) and (pnRebase) are non-NULL and 11051 ** the input is a changeset (not a patchset), then sqlite3changeset_apply_v2() 11052 ** may set (*ppRebase) to point to a "rebase" that may be used with the 11053 ** sqlite3_rebaser APIs buffer before returning. In this case (*pnRebase) 11054 ** is set to the size of the buffer in bytes. It is the responsibility of the 11055 ** caller to eventually free any such buffer using sqlite3_free(). The buffer 11056 ** is only allocated and populated if one or more conflicts were encountered 11057 ** while applying the patchset. See comments surrounding the sqlite3_rebaser 11058 ** APIs for further details. 11059 ** 11060 ** The behavior of sqlite3changeset_apply_v2() and its streaming equivalent 11061 ** may be modified by passing a combination of 11062 ** [SQLITE_CHANGESETAPPLY_NOSAVEPOINT | supported flags] as the 9th parameter. 11063 ** 11064 ** Note that the sqlite3changeset_apply_v2() API is still <b>experimental</b> 11065 ** and therefore subject to change. 11066 */ 11067 SQLITE_API int sqlite3changeset_apply( 11068 sqlite3 *db, /* Apply change to "main" db of this handle */ 11069 int nChangeset, /* Size of changeset in bytes */ 11070 void *pChangeset, /* Changeset blob */ 11071 int(*xFilter)( 11072 void *pCtx, /* Copy of sixth arg to _apply() */ 11073 const char *zTab /* Table name */ 11074 ), 11075 int(*xConflict)( 11076 void *pCtx, /* Copy of sixth arg to _apply() */ 11077 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */ 11078 sqlite3_changeset_iter *p /* Handle describing change and conflict */ 11079 ), 11080 void *pCtx /* First argument passed to xConflict */ 11081 ); 11082 SQLITE_API int sqlite3changeset_apply_v2( 11083 sqlite3 *db, /* Apply change to "main" db of this handle */ 11084 int nChangeset, /* Size of changeset in bytes */ 11085 void *pChangeset, /* Changeset blob */ 11086 int(*xFilter)( 11087 void *pCtx, /* Copy of sixth arg to _apply() */ 11088 const char *zTab /* Table name */ 11089 ), 11090 int(*xConflict)( 11091 void *pCtx, /* Copy of sixth arg to _apply() */ 11092 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */ 11093 sqlite3_changeset_iter *p /* Handle describing change and conflict */ 11094 ), 11095 void *pCtx, /* First argument passed to xConflict */ 11096 void **ppRebase, int *pnRebase, /* OUT: Rebase data */ 11097 int flags /* SESSION_CHANGESETAPPLY_* flags */ 11098 ); 11099 11100 /* 11101 ** CAPI3REF: Flags for sqlite3changeset_apply_v2 11102 ** 11103 ** The following flags may passed via the 9th parameter to 11104 ** [sqlite3changeset_apply_v2] and [sqlite3changeset_apply_v2_strm]: 11105 ** 11106 ** <dl> 11107 ** <dt>SQLITE_CHANGESETAPPLY_NOSAVEPOINT <dd> 11108 ** Usually, the sessions module encloses all operations performed by 11109 ** a single call to apply_v2() or apply_v2_strm() in a [SAVEPOINT]. The 11110 ** SAVEPOINT is committed if the changeset or patchset is successfully 11111 ** applied, or rolled back if an error occurs. Specifying this flag 11112 ** causes the sessions module to omit this savepoint. In this case, if the 11113 ** caller has an open transaction or savepoint when apply_v2() is called, 11114 ** it may revert the partially applied changeset by rolling it back. 11115 ** 11116 ** <dt>SQLITE_CHANGESETAPPLY_INVERT <dd> 11117 ** Invert the changeset before applying it. This is equivalent to inverting 11118 ** a changeset using sqlite3changeset_invert() before applying it. It is 11119 ** an error to specify this flag with a patchset. 11120 */ 11121 #define SQLITE_CHANGESETAPPLY_NOSAVEPOINT 0x0001 11122 #define SQLITE_CHANGESETAPPLY_INVERT 0x0002 11123 11124 /* 11125 ** CAPI3REF: Constants Passed To The Conflict Handler 11126 ** 11127 ** Values that may be passed as the second argument to a conflict-handler. 11128 ** 11129 ** <dl> 11130 ** <dt>SQLITE_CHANGESET_DATA<dd> 11131 ** The conflict handler is invoked with CHANGESET_DATA as the second argument 11132 ** when processing a DELETE or UPDATE change if a row with the required 11133 ** PRIMARY KEY fields is present in the database, but one or more other 11134 ** (non primary-key) fields modified by the update do not contain the 11135 ** expected "before" values. 11136 ** 11137 ** The conflicting row, in this case, is the database row with the matching 11138 ** primary key. 11139 ** 11140 ** <dt>SQLITE_CHANGESET_NOTFOUND<dd> 11141 ** The conflict handler is invoked with CHANGESET_NOTFOUND as the second 11142 ** argument when processing a DELETE or UPDATE change if a row with the 11143 ** required PRIMARY KEY fields is not present in the database. 11144 ** 11145 ** There is no conflicting row in this case. The results of invoking the 11146 ** sqlite3changeset_conflict() API are undefined. 11147 ** 11148 ** <dt>SQLITE_CHANGESET_CONFLICT<dd> 11149 ** CHANGESET_CONFLICT is passed as the second argument to the conflict 11150 ** handler while processing an INSERT change if the operation would result 11151 ** in duplicate primary key values. 11152 ** 11153 ** The conflicting row in this case is the database row with the matching 11154 ** primary key. 11155 ** 11156 ** <dt>SQLITE_CHANGESET_FOREIGN_KEY<dd> 11157 ** If foreign key handling is enabled, and applying a changeset leaves the 11158 ** database in a state containing foreign key violations, the conflict 11159 ** handler is invoked with CHANGESET_FOREIGN_KEY as the second argument 11160 ** exactly once before the changeset is committed. If the conflict handler 11161 ** returns CHANGESET_OMIT, the changes, including those that caused the 11162 ** foreign key constraint violation, are committed. Or, if it returns 11163 ** CHANGESET_ABORT, the changeset is rolled back. 11164 ** 11165 ** No current or conflicting row information is provided. The only function 11166 ** it is possible to call on the supplied sqlite3_changeset_iter handle 11167 ** is sqlite3changeset_fk_conflicts(). 11168 ** 11169 ** <dt>SQLITE_CHANGESET_CONSTRAINT<dd> 11170 ** If any other constraint violation occurs while applying a change (i.e. 11171 ** a UNIQUE, CHECK or NOT NULL constraint), the conflict handler is 11172 ** invoked with CHANGESET_CONSTRAINT as the second argument. 11173 ** 11174 ** There is no conflicting row in this case. The results of invoking the 11175 ** sqlite3changeset_conflict() API are undefined. 11176 ** 11177 ** </dl> 11178 */ 11179 #define SQLITE_CHANGESET_DATA 1 11180 #define SQLITE_CHANGESET_NOTFOUND 2 11181 #define SQLITE_CHANGESET_CONFLICT 3 11182 #define SQLITE_CHANGESET_CONSTRAINT 4 11183 #define SQLITE_CHANGESET_FOREIGN_KEY 5 11184 11185 /* 11186 ** CAPI3REF: Constants Returned By The Conflict Handler 11187 ** 11188 ** A conflict handler callback must return one of the following three values. 11189 ** 11190 ** <dl> 11191 ** <dt>SQLITE_CHANGESET_OMIT<dd> 11192 ** If a conflict handler returns this value no special action is taken. The 11193 ** change that caused the conflict is not applied. The session module 11194 ** continues to the next change in the changeset. 11195 ** 11196 ** <dt>SQLITE_CHANGESET_REPLACE<dd> 11197 ** This value may only be returned if the second argument to the conflict 11198 ** handler was SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If this 11199 ** is not the case, any changes applied so far are rolled back and the 11200 ** call to sqlite3changeset_apply() returns SQLITE_MISUSE. 11201 ** 11202 ** If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_DATA conflict 11203 ** handler, then the conflicting row is either updated or deleted, depending 11204 ** on the type of change. 11205 ** 11206 ** If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_CONFLICT conflict 11207 ** handler, then the conflicting row is removed from the database and a 11208 ** second attempt to apply the change is made. If this second attempt fails, 11209 ** the original row is restored to the database before continuing. 11210 ** 11211 ** <dt>SQLITE_CHANGESET_ABORT<dd> 11212 ** If this value is returned, any changes applied so far are rolled back 11213 ** and the call to sqlite3changeset_apply() returns SQLITE_ABORT. 11214 ** </dl> 11215 */ 11216 #define SQLITE_CHANGESET_OMIT 0 11217 #define SQLITE_CHANGESET_REPLACE 1 11218 #define SQLITE_CHANGESET_ABORT 2 11219 11220 /* 11221 ** CAPI3REF: Rebasing changesets 11222 ** EXPERIMENTAL 11223 ** 11224 ** Suppose there is a site hosting a database in state S0. And that 11225 ** modifications are made that move that database to state S1 and a 11226 ** changeset recorded (the "local" changeset). Then, a changeset based 11227 ** on S0 is received from another site (the "remote" changeset) and 11228 ** applied to the database. The database is then in state 11229 ** (S1+"remote"), where the exact state depends on any conflict 11230 ** resolution decisions (OMIT or REPLACE) made while applying "remote". 11231 ** Rebasing a changeset is to update it to take those conflict 11232 ** resolution decisions into account, so that the same conflicts 11233 ** do not have to be resolved elsewhere in the network. 11234 ** 11235 ** For example, if both the local and remote changesets contain an 11236 ** INSERT of the same key on "CREATE TABLE t1(a PRIMARY KEY, b)": 11237 ** 11238 ** local: INSERT INTO t1 VALUES(1, 'v1'); 11239 ** remote: INSERT INTO t1 VALUES(1, 'v2'); 11240 ** 11241 ** and the conflict resolution is REPLACE, then the INSERT change is 11242 ** removed from the local changeset (it was overridden). Or, if the 11243 ** conflict resolution was "OMIT", then the local changeset is modified 11244 ** to instead contain: 11245 ** 11246 ** UPDATE t1 SET b = 'v2' WHERE a=1; 11247 ** 11248 ** Changes within the local changeset are rebased as follows: 11249 ** 11250 ** <dl> 11251 ** <dt>Local INSERT<dd> 11252 ** This may only conflict with a remote INSERT. If the conflict 11253 ** resolution was OMIT, then add an UPDATE change to the rebased 11254 ** changeset. Or, if the conflict resolution was REPLACE, add 11255 ** nothing to the rebased changeset. 11256 ** 11257 ** <dt>Local DELETE<dd> 11258 ** This may conflict with a remote UPDATE or DELETE. In both cases the 11259 ** only possible resolution is OMIT. If the remote operation was a 11260 ** DELETE, then add no change to the rebased changeset. If the remote 11261 ** operation was an UPDATE, then the old.* fields of change are updated 11262 ** to reflect the new.* values in the UPDATE. 11263 ** 11264 ** <dt>Local UPDATE<dd> 11265 ** This may conflict with a remote UPDATE or DELETE. If it conflicts 11266 ** with a DELETE, and the conflict resolution was OMIT, then the update 11267 ** is changed into an INSERT. Any undefined values in the new.* record 11268 ** from the update change are filled in using the old.* values from 11269 ** the conflicting DELETE. Or, if the conflict resolution was REPLACE, 11270 ** the UPDATE change is simply omitted from the rebased changeset. 11271 ** 11272 ** If conflict is with a remote UPDATE and the resolution is OMIT, then 11273 ** the old.* values are rebased using the new.* values in the remote 11274 ** change. Or, if the resolution is REPLACE, then the change is copied 11275 ** into the rebased changeset with updates to columns also updated by 11276 ** the conflicting remote UPDATE removed. If this means no columns would 11277 ** be updated, the change is omitted. 11278 ** </dl> 11279 ** 11280 ** A local change may be rebased against multiple remote changes 11281 ** simultaneously. If a single key is modified by multiple remote 11282 ** changesets, they are combined as follows before the local changeset 11283 ** is rebased: 11284 ** 11285 ** <ul> 11286 ** <li> If there has been one or more REPLACE resolutions on a 11287 ** key, it is rebased according to a REPLACE. 11288 ** 11289 ** <li> If there have been no REPLACE resolutions on a key, then 11290 ** the local changeset is rebased according to the most recent 11291 ** of the OMIT resolutions. 11292 ** </ul> 11293 ** 11294 ** Note that conflict resolutions from multiple remote changesets are 11295 ** combined on a per-field basis, not per-row. This means that in the 11296 ** case of multiple remote UPDATE operations, some fields of a single 11297 ** local change may be rebased for REPLACE while others are rebased for 11298 ** OMIT. 11299 ** 11300 ** In order to rebase a local changeset, the remote changeset must first 11301 ** be applied to the local database using sqlite3changeset_apply_v2() and 11302 ** the buffer of rebase information captured. Then: 11303 ** 11304 ** <ol> 11305 ** <li> An sqlite3_rebaser object is created by calling 11306 ** sqlite3rebaser_create(). 11307 ** <li> The new object is configured with the rebase buffer obtained from 11308 ** sqlite3changeset_apply_v2() by calling sqlite3rebaser_configure(). 11309 ** If the local changeset is to be rebased against multiple remote 11310 ** changesets, then sqlite3rebaser_configure() should be called 11311 ** multiple times, in the same order that the multiple 11312 ** sqlite3changeset_apply_v2() calls were made. 11313 ** <li> Each local changeset is rebased by calling sqlite3rebaser_rebase(). 11314 ** <li> The sqlite3_rebaser object is deleted by calling 11315 ** sqlite3rebaser_delete(). 11316 ** </ol> 11317 */ 11318 typedef struct sqlite3_rebaser sqlite3_rebaser; 11319 11320 /* 11321 ** CAPI3REF: Create a changeset rebaser object. 11322 ** EXPERIMENTAL 11323 ** 11324 ** Allocate a new changeset rebaser object. If successful, set (*ppNew) to 11325 ** point to the new object and return SQLITE_OK. Otherwise, if an error 11326 ** occurs, return an SQLite error code (e.g. SQLITE_NOMEM) and set (*ppNew) 11327 ** to NULL. 11328 */ 11329 SQLITE_API int sqlite3rebaser_create(sqlite3_rebaser **ppNew); 11330 11331 /* 11332 ** CAPI3REF: Configure a changeset rebaser object. 11333 ** EXPERIMENTAL 11334 ** 11335 ** Configure the changeset rebaser object to rebase changesets according 11336 ** to the conflict resolutions described by buffer pRebase (size nRebase 11337 ** bytes), which must have been obtained from a previous call to 11338 ** sqlite3changeset_apply_v2(). 11339 */ 11340 SQLITE_API int sqlite3rebaser_configure( 11341 sqlite3_rebaser*, 11342 int nRebase, const void *pRebase 11343 ); 11344 11345 /* 11346 ** CAPI3REF: Rebase a changeset 11347 ** EXPERIMENTAL 11348 ** 11349 ** Argument pIn must point to a buffer containing a changeset nIn bytes 11350 ** in size. This function allocates and populates a buffer with a copy 11351 ** of the changeset rebased according to the configuration of the 11352 ** rebaser object passed as the first argument. If successful, (*ppOut) 11353 ** is set to point to the new buffer containing the rebased changeset and 11354 ** (*pnOut) to its size in bytes and SQLITE_OK returned. It is the 11355 ** responsibility of the caller to eventually free the new buffer using 11356 ** sqlite3_free(). Otherwise, if an error occurs, (*ppOut) and (*pnOut) 11357 ** are set to zero and an SQLite error code returned. 11358 */ 11359 SQLITE_API int sqlite3rebaser_rebase( 11360 sqlite3_rebaser*, 11361 int nIn, const void *pIn, 11362 int *pnOut, void **ppOut 11363 ); 11364 11365 /* 11366 ** CAPI3REF: Delete a changeset rebaser object. 11367 ** EXPERIMENTAL 11368 ** 11369 ** Delete the changeset rebaser object and all associated resources. There 11370 ** should be one call to this function for each successful invocation 11371 ** of sqlite3rebaser_create(). 11372 */ 11373 SQLITE_API void sqlite3rebaser_delete(sqlite3_rebaser *p); 11374 11375 /* 11376 ** CAPI3REF: Streaming Versions of API functions. 11377 ** 11378 ** The six streaming API xxx_strm() functions serve similar purposes to the 11379 ** corresponding non-streaming API functions: 11380 ** 11381 ** <table border=1 style="margin-left:8ex;margin-right:8ex"> 11382 ** <tr><th>Streaming function<th>Non-streaming equivalent</th> 11383 ** <tr><td>sqlite3changeset_apply_strm<td>[sqlite3changeset_apply] 11384 ** <tr><td>sqlite3changeset_apply_strm_v2<td>[sqlite3changeset_apply_v2] 11385 ** <tr><td>sqlite3changeset_concat_strm<td>[sqlite3changeset_concat] 11386 ** <tr><td>sqlite3changeset_invert_strm<td>[sqlite3changeset_invert] 11387 ** <tr><td>sqlite3changeset_start_strm<td>[sqlite3changeset_start] 11388 ** <tr><td>sqlite3session_changeset_strm<td>[sqlite3session_changeset] 11389 ** <tr><td>sqlite3session_patchset_strm<td>[sqlite3session_patchset] 11390 ** </table> 11391 ** 11392 ** Non-streaming functions that accept changesets (or patchsets) as input 11393 ** require that the entire changeset be stored in a single buffer in memory. 11394 ** Similarly, those that return a changeset or patchset do so by returning 11395 ** a pointer to a single large buffer allocated using sqlite3_malloc(). 11396 ** Normally this is convenient. However, if an application running in a 11397 ** low-memory environment is required to handle very large changesets, the 11398 ** large contiguous memory allocations required can become onerous. 11399 ** 11400 ** In order to avoid this problem, instead of a single large buffer, input 11401 ** is passed to a streaming API functions by way of a callback function that 11402 ** the sessions module invokes to incrementally request input data as it is 11403 ** required. In all cases, a pair of API function parameters such as 11404 ** 11405 ** <pre> 11406 ** int nChangeset, 11407 ** void *pChangeset, 11408 ** </pre> 11409 ** 11410 ** Is replaced by: 11411 ** 11412 ** <pre> 11413 ** int (*xInput)(void *pIn, void *pData, int *pnData), 11414 ** void *pIn, 11415 ** </pre> 11416 ** 11417 ** Each time the xInput callback is invoked by the sessions module, the first 11418 ** argument passed is a copy of the supplied pIn context pointer. The second 11419 ** argument, pData, points to a buffer (*pnData) bytes in size. Assuming no 11420 ** error occurs the xInput method should copy up to (*pnData) bytes of data 11421 ** into the buffer and set (*pnData) to the actual number of bytes copied 11422 ** before returning SQLITE_OK. If the input is completely exhausted, (*pnData) 11423 ** should be set to zero to indicate this. Or, if an error occurs, an SQLite 11424 ** error code should be returned. In all cases, if an xInput callback returns 11425 ** an error, all processing is abandoned and the streaming API function 11426 ** returns a copy of the error code to the caller. 11427 ** 11428 ** In the case of sqlite3changeset_start_strm(), the xInput callback may be 11429 ** invoked by the sessions module at any point during the lifetime of the 11430 ** iterator. If such an xInput callback returns an error, the iterator enters 11431 ** an error state, whereby all subsequent calls to iterator functions 11432 ** immediately fail with the same error code as returned by xInput. 11433 ** 11434 ** Similarly, streaming API functions that return changesets (or patchsets) 11435 ** return them in chunks by way of a callback function instead of via a 11436 ** pointer to a single large buffer. In this case, a pair of parameters such 11437 ** as: 11438 ** 11439 ** <pre> 11440 ** int *pnChangeset, 11441 ** void **ppChangeset, 11442 ** </pre> 11443 ** 11444 ** Is replaced by: 11445 ** 11446 ** <pre> 11447 ** int (*xOutput)(void *pOut, const void *pData, int nData), 11448 ** void *pOut 11449 ** </pre> 11450 ** 11451 ** The xOutput callback is invoked zero or more times to return data to 11452 ** the application. The first parameter passed to each call is a copy of the 11453 ** pOut pointer supplied by the application. The second parameter, pData, 11454 ** points to a buffer nData bytes in size containing the chunk of output 11455 ** data being returned. If the xOutput callback successfully processes the 11456 ** supplied data, it should return SQLITE_OK to indicate success. Otherwise, 11457 ** it should return some other SQLite error code. In this case processing 11458 ** is immediately abandoned and the streaming API function returns a copy 11459 ** of the xOutput error code to the application. 11460 ** 11461 ** The sessions module never invokes an xOutput callback with the third 11462 ** parameter set to a value less than or equal to zero. Other than this, 11463 ** no guarantees are made as to the size of the chunks of data returned. 11464 */ 11465 SQLITE_API int sqlite3changeset_apply_strm( 11466 sqlite3 *db, /* Apply change to "main" db of this handle */ 11467 int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */ 11468 void *pIn, /* First arg for xInput */ 11469 int(*xFilter)( 11470 void *pCtx, /* Copy of sixth arg to _apply() */ 11471 const char *zTab /* Table name */ 11472 ), 11473 int(*xConflict)( 11474 void *pCtx, /* Copy of sixth arg to _apply() */ 11475 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */ 11476 sqlite3_changeset_iter *p /* Handle describing change and conflict */ 11477 ), 11478 void *pCtx /* First argument passed to xConflict */ 11479 ); 11480 SQLITE_API int sqlite3changeset_apply_v2_strm( 11481 sqlite3 *db, /* Apply change to "main" db of this handle */ 11482 int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */ 11483 void *pIn, /* First arg for xInput */ 11484 int(*xFilter)( 11485 void *pCtx, /* Copy of sixth arg to _apply() */ 11486 const char *zTab /* Table name */ 11487 ), 11488 int(*xConflict)( 11489 void *pCtx, /* Copy of sixth arg to _apply() */ 11490 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */ 11491 sqlite3_changeset_iter *p /* Handle describing change and conflict */ 11492 ), 11493 void *pCtx, /* First argument passed to xConflict */ 11494 void **ppRebase, int *pnRebase, 11495 int flags 11496 ); 11497 SQLITE_API int sqlite3changeset_concat_strm( 11498 int (*xInputA)(void *pIn, void *pData, int *pnData), 11499 void *pInA, 11500 int (*xInputB)(void *pIn, void *pData, int *pnData), 11501 void *pInB, 11502 int (*xOutput)(void *pOut, const void *pData, int nData), 11503 void *pOut 11504 ); 11505 SQLITE_API int sqlite3changeset_invert_strm( 11506 int (*xInput)(void *pIn, void *pData, int *pnData), 11507 void *pIn, 11508 int (*xOutput)(void *pOut, const void *pData, int nData), 11509 void *pOut 11510 ); 11511 SQLITE_API int sqlite3changeset_start_strm( 11512 sqlite3_changeset_iter **pp, 11513 int (*xInput)(void *pIn, void *pData, int *pnData), 11514 void *pIn 11515 ); 11516 SQLITE_API int sqlite3changeset_start_v2_strm( 11517 sqlite3_changeset_iter **pp, 11518 int (*xInput)(void *pIn, void *pData, int *pnData), 11519 void *pIn, 11520 int flags 11521 ); 11522 SQLITE_API int sqlite3session_changeset_strm( 11523 sqlite3_session *pSession, 11524 int (*xOutput)(void *pOut, const void *pData, int nData), 11525 void *pOut 11526 ); 11527 SQLITE_API int sqlite3session_patchset_strm( 11528 sqlite3_session *pSession, 11529 int (*xOutput)(void *pOut, const void *pData, int nData), 11530 void *pOut 11531 ); 11532 SQLITE_API int sqlite3changegroup_add_strm(sqlite3_changegroup*, 11533 int (*xInput)(void *pIn, void *pData, int *pnData), 11534 void *pIn 11535 ); 11536 SQLITE_API int sqlite3changegroup_output_strm(sqlite3_changegroup*, 11537 int (*xOutput)(void *pOut, const void *pData, int nData), 11538 void *pOut 11539 ); 11540 SQLITE_API int sqlite3rebaser_rebase_strm( 11541 sqlite3_rebaser *pRebaser, 11542 int (*xInput)(void *pIn, void *pData, int *pnData), 11543 void *pIn, 11544 int (*xOutput)(void *pOut, const void *pData, int nData), 11545 void *pOut 11546 ); 11547 11548 /* 11549 ** CAPI3REF: Configure global parameters 11550 ** 11551 ** The sqlite3session_config() interface is used to make global configuration 11552 ** changes to the sessions module in order to tune it to the specific needs 11553 ** of the application. 11554 ** 11555 ** The sqlite3session_config() interface is not threadsafe. If it is invoked 11556 ** while any other thread is inside any other sessions method then the 11557 ** results are undefined. Furthermore, if it is invoked after any sessions 11558 ** related objects have been created, the results are also undefined. 11559 ** 11560 ** The first argument to the sqlite3session_config() function must be one 11561 ** of the SQLITE_SESSION_CONFIG_XXX constants defined below. The 11562 ** interpretation of the (void*) value passed as the second parameter and 11563 ** the effect of calling this function depends on the value of the first 11564 ** parameter. 11565 ** 11566 ** <dl> 11567 ** <dt>SQLITE_SESSION_CONFIG_STRMSIZE<dd> 11568 ** By default, the sessions module streaming interfaces attempt to input 11569 ** and output data in approximately 1 KiB chunks. This operand may be used 11570 ** to set and query the value of this configuration setting. The pointer 11571 ** passed as the second argument must point to a value of type (int). 11572 ** If this value is greater than 0, it is used as the new streaming data 11573 ** chunk size for both input and output. Before returning, the (int) value 11574 ** pointed to by pArg is set to the final value of the streaming interface 11575 ** chunk size. 11576 ** </dl> 11577 ** 11578 ** This function returns SQLITE_OK if successful, or an SQLite error code 11579 ** otherwise. 11580 */ 11581 SQLITE_API int sqlite3session_config(int op, void *pArg); 11582 11583 /* 11584 ** CAPI3REF: Values for sqlite3session_config(). 11585 */ 11586 #define SQLITE_SESSION_CONFIG_STRMSIZE 1 11587 11588 /* 11589 ** Make sure we can call this stuff from C++. 11590 */ 11591 #ifdef __cplusplus 11592 } 11593 #endif 11594 11595 #endif /* !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION) */ 11596 11597 /******** End of sqlite3session.h *********/ 11598 /******** Begin file fts5.h *********/ 11599 /* 11600 ** 2014 May 31 11601 ** 11602 ** The author disclaims copyright to this source code. In place of 11603 ** a legal notice, here is a blessing: 11604 ** 11605 ** May you do good and not evil. 11606 ** May you find forgiveness for yourself and forgive others. 11607 ** May you share freely, never taking more than you give. 11608 ** 11609 ****************************************************************************** 11610 ** 11611 ** Interfaces to extend FTS5. Using the interfaces defined in this file, 11612 ** FTS5 may be extended with: 11613 ** 11614 ** * custom tokenizers, and 11615 ** * custom auxiliary functions. 11616 */ 11617 11618 11619 #ifndef _FTS5_H 11620 #define _FTS5_H 11621 11622 11623 #ifdef __cplusplus 11624 extern "C" { 11625 #endif 11626 11627 /************************************************************************* 11628 ** CUSTOM AUXILIARY FUNCTIONS 11629 ** 11630 ** Virtual table implementations may overload SQL functions by implementing 11631 ** the sqlite3_module.xFindFunction() method. 11632 */ 11633 11634 typedef struct Fts5ExtensionApi Fts5ExtensionApi; 11635 typedef struct Fts5Context Fts5Context; 11636 typedef struct Fts5PhraseIter Fts5PhraseIter; 11637 11638 typedef void (*fts5_extension_function)( 11639 const Fts5ExtensionApi *pApi, /* API offered by current FTS version */ 11640 Fts5Context *pFts, /* First arg to pass to pApi functions */ 11641 sqlite3_context *pCtx, /* Context for returning result/error */ 11642 int nVal, /* Number of values in apVal[] array */ 11643 sqlite3_value **apVal /* Array of trailing arguments */ 11644 ); 11645 11646 struct Fts5PhraseIter { 11647 const unsigned char *a; 11648 const unsigned char *b; 11649 }; 11650 11651 /* 11652 ** EXTENSION API FUNCTIONS 11653 ** 11654 ** xUserData(pFts): 11655 ** Return a copy of the context pointer the extension function was 11656 ** registered with. 11657 ** 11658 ** xColumnTotalSize(pFts, iCol, pnToken): 11659 ** If parameter iCol is less than zero, set output variable *pnToken 11660 ** to the total number of tokens in the FTS5 table. Or, if iCol is 11661 ** non-negative but less than the number of columns in the table, return 11662 ** the total number of tokens in column iCol, considering all rows in 11663 ** the FTS5 table. 11664 ** 11665 ** If parameter iCol is greater than or equal to the number of columns 11666 ** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g. 11667 ** an OOM condition or IO error), an appropriate SQLite error code is 11668 ** returned. 11669 ** 11670 ** xColumnCount(pFts): 11671 ** Return the number of columns in the table. 11672 ** 11673 ** xColumnSize(pFts, iCol, pnToken): 11674 ** If parameter iCol is less than zero, set output variable *pnToken 11675 ** to the total number of tokens in the current row. Or, if iCol is 11676 ** non-negative but less than the number of columns in the table, set 11677 ** *pnToken to the number of tokens in column iCol of the current row. 11678 ** 11679 ** If parameter iCol is greater than or equal to the number of columns 11680 ** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g. 11681 ** an OOM condition or IO error), an appropriate SQLite error code is 11682 ** returned. 11683 ** 11684 ** This function may be quite inefficient if used with an FTS5 table 11685 ** created with the "columnsize=0" option. 11686 ** 11687 ** xColumnText: 11688 ** This function attempts to retrieve the text of column iCol of the 11689 ** current document. If successful, (*pz) is set to point to a buffer 11690 ** containing the text in utf-8 encoding, (*pn) is set to the size in bytes 11691 ** (not characters) of the buffer and SQLITE_OK is returned. Otherwise, 11692 ** if an error occurs, an SQLite error code is returned and the final values 11693 ** of (*pz) and (*pn) are undefined. 11694 ** 11695 ** xPhraseCount: 11696 ** Returns the number of phrases in the current query expression. 11697 ** 11698 ** xPhraseSize: 11699 ** Returns the number of tokens in phrase iPhrase of the query. Phrases 11700 ** are numbered starting from zero. 11701 ** 11702 ** xInstCount: 11703 ** Set *pnInst to the total number of occurrences of all phrases within 11704 ** the query within the current row. Return SQLITE_OK if successful, or 11705 ** an error code (i.e. SQLITE_NOMEM) if an error occurs. 11706 ** 11707 ** This API can be quite slow if used with an FTS5 table created with the 11708 ** "detail=none" or "detail=column" option. If the FTS5 table is created 11709 ** with either "detail=none" or "detail=column" and "content=" option 11710 ** (i.e. if it is a contentless table), then this API always returns 0. 11711 ** 11712 ** xInst: 11713 ** Query for the details of phrase match iIdx within the current row. 11714 ** Phrase matches are numbered starting from zero, so the iIdx argument 11715 ** should be greater than or equal to zero and smaller than the value 11716 ** output by xInstCount(). 11717 ** 11718 ** Usually, output parameter *piPhrase is set to the phrase number, *piCol 11719 ** to the column in which it occurs and *piOff the token offset of the 11720 ** first token of the phrase. Returns SQLITE_OK if successful, or an error 11721 ** code (i.e. SQLITE_NOMEM) if an error occurs. 11722 ** 11723 ** This API can be quite slow if used with an FTS5 table created with the 11724 ** "detail=none" or "detail=column" option. 11725 ** 11726 ** xRowid: 11727 ** Returns the rowid of the current row. 11728 ** 11729 ** xTokenize: 11730 ** Tokenize text using the tokenizer belonging to the FTS5 table. 11731 ** 11732 ** xQueryPhrase(pFts5, iPhrase, pUserData, xCallback): 11733 ** This API function is used to query the FTS table for phrase iPhrase 11734 ** of the current query. Specifically, a query equivalent to: 11735 ** 11736 ** ... FROM ftstable WHERE ftstable MATCH $p ORDER BY rowid 11737 ** 11738 ** with $p set to a phrase equivalent to the phrase iPhrase of the 11739 ** current query is executed. Any column filter that applies to 11740 ** phrase iPhrase of the current query is included in $p. For each 11741 ** row visited, the callback function passed as the fourth argument 11742 ** is invoked. The context and API objects passed to the callback 11743 ** function may be used to access the properties of each matched row. 11744 ** Invoking Api.xUserData() returns a copy of the pointer passed as 11745 ** the third argument to pUserData. 11746 ** 11747 ** If the callback function returns any value other than SQLITE_OK, the 11748 ** query is abandoned and the xQueryPhrase function returns immediately. 11749 ** If the returned value is SQLITE_DONE, xQueryPhrase returns SQLITE_OK. 11750 ** Otherwise, the error code is propagated upwards. 11751 ** 11752 ** If the query runs to completion without incident, SQLITE_OK is returned. 11753 ** Or, if some error occurs before the query completes or is aborted by 11754 ** the callback, an SQLite error code is returned. 11755 ** 11756 ** 11757 ** xSetAuxdata(pFts5, pAux, xDelete) 11758 ** 11759 ** Save the pointer passed as the second argument as the extension function's 11760 ** "auxiliary data". The pointer may then be retrieved by the current or any 11761 ** future invocation of the same fts5 extension function made as part of 11762 ** the same MATCH query using the xGetAuxdata() API. 11763 ** 11764 ** Each extension function is allocated a single auxiliary data slot for 11765 ** each FTS query (MATCH expression). If the extension function is invoked 11766 ** more than once for a single FTS query, then all invocations share a 11767 ** single auxiliary data context. 11768 ** 11769 ** If there is already an auxiliary data pointer when this function is 11770 ** invoked, then it is replaced by the new pointer. If an xDelete callback 11771 ** was specified along with the original pointer, it is invoked at this 11772 ** point. 11773 ** 11774 ** The xDelete callback, if one is specified, is also invoked on the 11775 ** auxiliary data pointer after the FTS5 query has finished. 11776 ** 11777 ** If an error (e.g. an OOM condition) occurs within this function, 11778 ** the auxiliary data is set to NULL and an error code returned. If the 11779 ** xDelete parameter was not NULL, it is invoked on the auxiliary data 11780 ** pointer before returning. 11781 ** 11782 ** 11783 ** xGetAuxdata(pFts5, bClear) 11784 ** 11785 ** Returns the current auxiliary data pointer for the fts5 extension 11786 ** function. See the xSetAuxdata() method for details. 11787 ** 11788 ** If the bClear argument is non-zero, then the auxiliary data is cleared 11789 ** (set to NULL) before this function returns. In this case the xDelete, 11790 ** if any, is not invoked. 11791 ** 11792 ** 11793 ** xRowCount(pFts5, pnRow) 11794 ** 11795 ** This function is used to retrieve the total number of rows in the table. 11796 ** In other words, the same value that would be returned by: 11797 ** 11798 ** SELECT count(*) FROM ftstable; 11799 ** 11800 ** xPhraseFirst() 11801 ** This function is used, along with type Fts5PhraseIter and the xPhraseNext 11802 ** method, to iterate through all instances of a single query phrase within 11803 ** the current row. This is the same information as is accessible via the 11804 ** xInstCount/xInst APIs. While the xInstCount/xInst APIs are more convenient 11805 ** to use, this API may be faster under some circumstances. To iterate 11806 ** through instances of phrase iPhrase, use the following code: 11807 ** 11808 ** Fts5PhraseIter iter; 11809 ** int iCol, iOff; 11810 ** for(pApi->xPhraseFirst(pFts, iPhrase, &iter, &iCol, &iOff); 11811 ** iCol>=0; 11812 ** pApi->xPhraseNext(pFts, &iter, &iCol, &iOff) 11813 ** ){ 11814 ** // An instance of phrase iPhrase at offset iOff of column iCol 11815 ** } 11816 ** 11817 ** The Fts5PhraseIter structure is defined above. Applications should not 11818 ** modify this structure directly - it should only be used as shown above 11819 ** with the xPhraseFirst() and xPhraseNext() API methods (and by 11820 ** xPhraseFirstColumn() and xPhraseNextColumn() as illustrated below). 11821 ** 11822 ** This API can be quite slow if used with an FTS5 table created with the 11823 ** "detail=none" or "detail=column" option. If the FTS5 table is created 11824 ** with either "detail=none" or "detail=column" and "content=" option 11825 ** (i.e. if it is a contentless table), then this API always iterates 11826 ** through an empty set (all calls to xPhraseFirst() set iCol to -1). 11827 ** 11828 ** xPhraseNext() 11829 ** See xPhraseFirst above. 11830 ** 11831 ** xPhraseFirstColumn() 11832 ** This function and xPhraseNextColumn() are similar to the xPhraseFirst() 11833 ** and xPhraseNext() APIs described above. The difference is that instead 11834 ** of iterating through all instances of a phrase in the current row, these 11835 ** APIs are used to iterate through the set of columns in the current row 11836 ** that contain one or more instances of a specified phrase. For example: 11837 ** 11838 ** Fts5PhraseIter iter; 11839 ** int iCol; 11840 ** for(pApi->xPhraseFirstColumn(pFts, iPhrase, &iter, &iCol); 11841 ** iCol>=0; 11842 ** pApi->xPhraseNextColumn(pFts, &iter, &iCol) 11843 ** ){ 11844 ** // Column iCol contains at least one instance of phrase iPhrase 11845 ** } 11846 ** 11847 ** This API can be quite slow if used with an FTS5 table created with the 11848 ** "detail=none" option. If the FTS5 table is created with either 11849 ** "detail=none" "content=" option (i.e. if it is a contentless table), 11850 ** then this API always iterates through an empty set (all calls to 11851 ** xPhraseFirstColumn() set iCol to -1). 11852 ** 11853 ** The information accessed using this API and its companion 11854 ** xPhraseFirstColumn() may also be obtained using xPhraseFirst/xPhraseNext 11855 ** (or xInst/xInstCount). The chief advantage of this API is that it is 11856 ** significantly more efficient than those alternatives when used with 11857 ** "detail=column" tables. 11858 ** 11859 ** xPhraseNextColumn() 11860 ** See xPhraseFirstColumn above. 11861 */ 11862 struct Fts5ExtensionApi { 11863 int iVersion; /* Currently always set to 3 */ 11864 11865 void *(*xUserData)(Fts5Context*); 11866 11867 int (*xColumnCount)(Fts5Context*); 11868 int (*xRowCount)(Fts5Context*, sqlite3_int64 *pnRow); 11869 int (*xColumnTotalSize)(Fts5Context*, int iCol, sqlite3_int64 *pnToken); 11870 11871 int (*xTokenize)(Fts5Context*, 11872 const char *pText, int nText, /* Text to tokenize */ 11873 void *pCtx, /* Context passed to xToken() */ 11874 int (*xToken)(void*, int, const char*, int, int, int) /* Callback */ 11875 ); 11876 11877 int (*xPhraseCount)(Fts5Context*); 11878 int (*xPhraseSize)(Fts5Context*, int iPhrase); 11879 11880 int (*xInstCount)(Fts5Context*, int *pnInst); 11881 int (*xInst)(Fts5Context*, int iIdx, int *piPhrase, int *piCol, int *piOff); 11882 11883 sqlite3_int64 (*xRowid)(Fts5Context*); 11884 int (*xColumnText)(Fts5Context*, int iCol, const char **pz, int *pn); 11885 int (*xColumnSize)(Fts5Context*, int iCol, int *pnToken); 11886 11887 int (*xQueryPhrase)(Fts5Context*, int iPhrase, void *pUserData, 11888 int(*)(const Fts5ExtensionApi*,Fts5Context*,void*) 11889 ); 11890 int (*xSetAuxdata)(Fts5Context*, void *pAux, void(*xDelete)(void*)); 11891 void *(*xGetAuxdata)(Fts5Context*, int bClear); 11892 11893 int (*xPhraseFirst)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*, int*); 11894 void (*xPhraseNext)(Fts5Context*, Fts5PhraseIter*, int *piCol, int *piOff); 11895 11896 int (*xPhraseFirstColumn)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*); 11897 void (*xPhraseNextColumn)(Fts5Context*, Fts5PhraseIter*, int *piCol); 11898 }; 11899 11900 /* 11901 ** CUSTOM AUXILIARY FUNCTIONS 11902 *************************************************************************/ 11903 11904 /************************************************************************* 11905 ** CUSTOM TOKENIZERS 11906 ** 11907 ** Applications may also register custom tokenizer types. A tokenizer 11908 ** is registered by providing fts5 with a populated instance of the 11909 ** following structure. All structure methods must be defined, setting 11910 ** any member of the fts5_tokenizer struct to NULL leads to undefined 11911 ** behaviour. The structure methods are expected to function as follows: 11912 ** 11913 ** xCreate: 11914 ** This function is used to allocate and initialize a tokenizer instance. 11915 ** A tokenizer instance is required to actually tokenize text. 11916 ** 11917 ** The first argument passed to this function is a copy of the (void*) 11918 ** pointer provided by the application when the fts5_tokenizer object 11919 ** was registered with FTS5 (the third argument to xCreateTokenizer()). 11920 ** The second and third arguments are an array of nul-terminated strings 11921 ** containing the tokenizer arguments, if any, specified following the 11922 ** tokenizer name as part of the CREATE VIRTUAL TABLE statement used 11923 ** to create the FTS5 table. 11924 ** 11925 ** The final argument is an output variable. If successful, (*ppOut) 11926 ** should be set to point to the new tokenizer handle and SQLITE_OK 11927 ** returned. If an error occurs, some value other than SQLITE_OK should 11928 ** be returned. In this case, fts5 assumes that the final value of *ppOut 11929 ** is undefined. 11930 ** 11931 ** xDelete: 11932 ** This function is invoked to delete a tokenizer handle previously 11933 ** allocated using xCreate(). Fts5 guarantees that this function will 11934 ** be invoked exactly once for each successful call to xCreate(). 11935 ** 11936 ** xTokenize: 11937 ** This function is expected to tokenize the nText byte string indicated 11938 ** by argument pText. pText may or may not be nul-terminated. The first 11939 ** argument passed to this function is a pointer to an Fts5Tokenizer object 11940 ** returned by an earlier call to xCreate(). 11941 ** 11942 ** The second argument indicates the reason that FTS5 is requesting 11943 ** tokenization of the supplied text. This is always one of the following 11944 ** four values: 11945 ** 11946 ** <ul><li> <b>FTS5_TOKENIZE_DOCUMENT</b> - A document is being inserted into 11947 ** or removed from the FTS table. The tokenizer is being invoked to 11948 ** determine the set of tokens to add to (or delete from) the 11949 ** FTS index. 11950 ** 11951 ** <li> <b>FTS5_TOKENIZE_QUERY</b> - A MATCH query is being executed 11952 ** against the FTS index. The tokenizer is being called to tokenize 11953 ** a bareword or quoted string specified as part of the query. 11954 ** 11955 ** <li> <b>(FTS5_TOKENIZE_QUERY | FTS5_TOKENIZE_PREFIX)</b> - Same as 11956 ** FTS5_TOKENIZE_QUERY, except that the bareword or quoted string is 11957 ** followed by a "*" character, indicating that the last token 11958 ** returned by the tokenizer will be treated as a token prefix. 11959 ** 11960 ** <li> <b>FTS5_TOKENIZE_AUX</b> - The tokenizer is being invoked to 11961 ** satisfy an fts5_api.xTokenize() request made by an auxiliary 11962 ** function. Or an fts5_api.xColumnSize() request made by the same 11963 ** on a columnsize=0 database. 11964 ** </ul> 11965 ** 11966 ** For each token in the input string, the supplied callback xToken() must 11967 ** be invoked. The first argument to it should be a copy of the pointer 11968 ** passed as the second argument to xTokenize(). The third and fourth 11969 ** arguments are a pointer to a buffer containing the token text, and the 11970 ** size of the token in bytes. The 4th and 5th arguments are the byte offsets 11971 ** of the first byte of and first byte immediately following the text from 11972 ** which the token is derived within the input. 11973 ** 11974 ** The second argument passed to the xToken() callback ("tflags") should 11975 ** normally be set to 0. The exception is if the tokenizer supports 11976 ** synonyms. In this case see the discussion below for details. 11977 ** 11978 ** FTS5 assumes the xToken() callback is invoked for each token in the 11979 ** order that they occur within the input text. 11980 ** 11981 ** If an xToken() callback returns any value other than SQLITE_OK, then 11982 ** the tokenization should be abandoned and the xTokenize() method should 11983 ** immediately return a copy of the xToken() return value. Or, if the 11984 ** input buffer is exhausted, xTokenize() should return SQLITE_OK. Finally, 11985 ** if an error occurs with the xTokenize() implementation itself, it 11986 ** may abandon the tokenization and return any error code other than 11987 ** SQLITE_OK or SQLITE_DONE. 11988 ** 11989 ** SYNONYM SUPPORT 11990 ** 11991 ** Custom tokenizers may also support synonyms. Consider a case in which a 11992 ** user wishes to query for a phrase such as "first place". Using the 11993 ** built-in tokenizers, the FTS5 query 'first + place' will match instances 11994 ** of "first place" within the document set, but not alternative forms 11995 ** such as "1st place". In some applications, it would be better to match 11996 ** all instances of "first place" or "1st place" regardless of which form 11997 ** the user specified in the MATCH query text. 11998 ** 11999 ** There are several ways to approach this in FTS5: 12000 ** 12001 ** <ol><li> By mapping all synonyms to a single token. In this case, using 12002 ** the above example, this means that the tokenizer returns the 12003 ** same token for inputs "first" and "1st". Say that token is in 12004 ** fact "first", so that when the user inserts the document "I won 12005 ** 1st place" entries are added to the index for tokens "i", "won", 12006 ** "first" and "place". If the user then queries for '1st + place', 12007 ** the tokenizer substitutes "first" for "1st" and the query works 12008 ** as expected. 12009 ** 12010 ** <li> By querying the index for all synonyms of each query term 12011 ** separately. In this case, when tokenizing query text, the 12012 ** tokenizer may provide multiple synonyms for a single term 12013 ** within the document. FTS5 then queries the index for each 12014 ** synonym individually. For example, faced with the query: 12015 ** 12016 ** <codeblock> 12017 ** ... MATCH 'first place'</codeblock> 12018 ** 12019 ** the tokenizer offers both "1st" and "first" as synonyms for the 12020 ** first token in the MATCH query and FTS5 effectively runs a query 12021 ** similar to: 12022 ** 12023 ** <codeblock> 12024 ** ... MATCH '(first OR 1st) place'</codeblock> 12025 ** 12026 ** except that, for the purposes of auxiliary functions, the query 12027 ** still appears to contain just two phrases - "(first OR 1st)" 12028 ** being treated as a single phrase. 12029 ** 12030 ** <li> By adding multiple synonyms for a single term to the FTS index. 12031 ** Using this method, when tokenizing document text, the tokenizer 12032 ** provides multiple synonyms for each token. So that when a 12033 ** document such as "I won first place" is tokenized, entries are 12034 ** added to the FTS index for "i", "won", "first", "1st" and 12035 ** "place". 12036 ** 12037 ** This way, even if the tokenizer does not provide synonyms 12038 ** when tokenizing query text (it should not - to do so would be 12039 ** inefficient), it doesn't matter if the user queries for 12040 ** 'first + place' or '1st + place', as there are entries in the 12041 ** FTS index corresponding to both forms of the first token. 12042 ** </ol> 12043 ** 12044 ** Whether it is parsing document or query text, any call to xToken that 12045 ** specifies a <i>tflags</i> argument with the FTS5_TOKEN_COLOCATED bit 12046 ** is considered to supply a synonym for the previous token. For example, 12047 ** when parsing the document "I won first place", a tokenizer that supports 12048 ** synonyms would call xToken() 5 times, as follows: 12049 ** 12050 ** <codeblock> 12051 ** xToken(pCtx, 0, "i", 1, 0, 1); 12052 ** xToken(pCtx, 0, "won", 3, 2, 5); 12053 ** xToken(pCtx, 0, "first", 5, 6, 11); 12054 ** xToken(pCtx, FTS5_TOKEN_COLOCATED, "1st", 3, 6, 11); 12055 ** xToken(pCtx, 0, "place", 5, 12, 17); 12056 **</codeblock> 12057 ** 12058 ** It is an error to specify the FTS5_TOKEN_COLOCATED flag the first time 12059 ** xToken() is called. Multiple synonyms may be specified for a single token 12060 ** by making multiple calls to xToken(FTS5_TOKEN_COLOCATED) in sequence. 12061 ** There is no limit to the number of synonyms that may be provided for a 12062 ** single token. 12063 ** 12064 ** In many cases, method (1) above is the best approach. It does not add 12065 ** extra data to the FTS index or require FTS5 to query for multiple terms, 12066 ** so it is efficient in terms of disk space and query speed. However, it 12067 ** does not support prefix queries very well. If, as suggested above, the 12068 ** token "first" is substituted for "1st" by the tokenizer, then the query: 12069 ** 12070 ** <codeblock> 12071 ** ... MATCH '1s*'</codeblock> 12072 ** 12073 ** will not match documents that contain the token "1st" (as the tokenizer 12074 ** will probably not map "1s" to any prefix of "first"). 12075 ** 12076 ** For full prefix support, method (3) may be preferred. In this case, 12077 ** because the index contains entries for both "first" and "1st", prefix 12078 ** queries such as 'fi*' or '1s*' will match correctly. However, because 12079 ** extra entries are added to the FTS index, this method uses more space 12080 ** within the database. 12081 ** 12082 ** Method (2) offers a midpoint between (1) and (3). Using this method, 12083 ** a query such as '1s*' will match documents that contain the literal 12084 ** token "1st", but not "first" (assuming the tokenizer is not able to 12085 ** provide synonyms for prefixes). However, a non-prefix query like '1st' 12086 ** will match against "1st" and "first". This method does not require 12087 ** extra disk space, as no extra entries are added to the FTS index. 12088 ** On the other hand, it may require more CPU cycles to run MATCH queries, 12089 ** as separate queries of the FTS index are required for each synonym. 12090 ** 12091 ** When using methods (2) or (3), it is important that the tokenizer only 12092 ** provide synonyms when tokenizing document text (method (2)) or query 12093 ** text (method (3)), not both. Doing so will not cause any errors, but is 12094 ** inefficient. 12095 */ 12096 typedef struct Fts5Tokenizer Fts5Tokenizer; 12097 typedef struct fts5_tokenizer fts5_tokenizer; 12098 struct fts5_tokenizer { 12099 int (*xCreate)(void*, const char **azArg, int nArg, Fts5Tokenizer **ppOut); 12100 void (*xDelete)(Fts5Tokenizer*); 12101 int (*xTokenize)(Fts5Tokenizer*, 12102 void *pCtx, 12103 int flags, /* Mask of FTS5_TOKENIZE_* flags */ 12104 const char *pText, int nText, 12105 int (*xToken)( 12106 void *pCtx, /* Copy of 2nd argument to xTokenize() */ 12107 int tflags, /* Mask of FTS5_TOKEN_* flags */ 12108 const char *pToken, /* Pointer to buffer containing token */ 12109 int nToken, /* Size of token in bytes */ 12110 int iStart, /* Byte offset of token within input text */ 12111 int iEnd /* Byte offset of end of token within input text */ 12112 ) 12113 ); 12114 }; 12115 12116 /* Flags that may be passed as the third argument to xTokenize() */ 12117 #define FTS5_TOKENIZE_QUERY 0x0001 12118 #define FTS5_TOKENIZE_PREFIX 0x0002 12119 #define FTS5_TOKENIZE_DOCUMENT 0x0004 12120 #define FTS5_TOKENIZE_AUX 0x0008 12121 12122 /* Flags that may be passed by the tokenizer implementation back to FTS5 12123 ** as the third argument to the supplied xToken callback. */ 12124 #define FTS5_TOKEN_COLOCATED 0x0001 /* Same position as prev. token */ 12125 12126 /* 12127 ** END OF CUSTOM TOKENIZERS 12128 *************************************************************************/ 12129 12130 /************************************************************************* 12131 ** FTS5 EXTENSION REGISTRATION API 12132 */ 12133 typedef struct fts5_api fts5_api; 12134 struct fts5_api { 12135 int iVersion; /* Currently always set to 2 */ 12136 12137 /* Create a new tokenizer */ 12138 int (*xCreateTokenizer)( 12139 fts5_api *pApi, 12140 const char *zName, 12141 void *pContext, 12142 fts5_tokenizer *pTokenizer, 12143 void (*xDestroy)(void*) 12144 ); 12145 12146 /* Find an existing tokenizer */ 12147 int (*xFindTokenizer)( 12148 fts5_api *pApi, 12149 const char *zName, 12150 void **ppContext, 12151 fts5_tokenizer *pTokenizer 12152 ); 12153 12154 /* Create a new auxiliary function */ 12155 int (*xCreateFunction)( 12156 fts5_api *pApi, 12157 const char *zName, 12158 void *pContext, 12159 fts5_extension_function xFunction, 12160 void (*xDestroy)(void*) 12161 ); 12162 }; 12163 12164 /* 12165 ** END OF REGISTRATION API 12166 *************************************************************************/ 12167 12168 #ifdef __cplusplus 12169 } /* end of the 'extern "C"' block */ 12170 #endif 12171 12172 #endif /* _FTS5_H */ 12173 12174 /******** End of fts5.h *********/ 12175