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 "3.30.1" 127 #define SQLITE_VERSION_NUMBER 3030001 128 #define SQLITE_SOURCE_ID "2019-10-10 20:19:45 18db032d058f1436ce3dea84081f4ee5a0f2259ad97301d43c426bc7f3df1b0b" 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 ** ^If the database connection is associated with unfinalized prepared 303 ** statements or unfinished sqlite3_backup objects then sqlite3_close() 304 ** will leave the database connection open and return [SQLITE_BUSY]. 305 ** ^If sqlite3_close_v2() is called with unfinalized prepared statements 306 ** and/or unfinished sqlite3_backups, then the database connection becomes 307 ** an unusable "zombie" which will automatically be deallocated when the 308 ** last prepared statement is finalized or the last sqlite3_backup is 309 ** finished. The sqlite3_close_v2() interface is intended for use with 310 ** host languages that are garbage collected, and where the order in which 311 ** destructors are called is arbitrary. 312 ** 313 ** Applications should [sqlite3_finalize | finalize] all [prepared statements], 314 ** [sqlite3_blob_close | close] all [BLOB handles], and 315 ** [sqlite3_backup_finish | finish] all [sqlite3_backup] objects associated 316 ** with the [sqlite3] object prior to attempting to close the object. ^If 317 ** sqlite3_close_v2() is called on a [database connection] that still has 318 ** outstanding [prepared statements], [BLOB handles], and/or 319 ** [sqlite3_backup] objects then it returns [SQLITE_OK] and the deallocation 320 ** of resources is deferred until all [prepared statements], [BLOB handles], 321 ** and [sqlite3_backup] objects are also destroyed. 322 ** 323 ** ^If an [sqlite3] object is destroyed while a transaction is open, 324 ** the transaction is automatically rolled back. 325 ** 326 ** The C parameter to [sqlite3_close(C)] and [sqlite3_close_v2(C)] 327 ** must be either a NULL 328 ** pointer or an [sqlite3] object pointer obtained 329 ** from [sqlite3_open()], [sqlite3_open16()], or 330 ** [sqlite3_open_v2()], and not previously closed. 331 ** ^Calling sqlite3_close() or sqlite3_close_v2() with a NULL pointer 332 ** argument is a harmless no-op. 333 */ 334 SQLITE_API int sqlite3_close(sqlite3*); 335 SQLITE_API int sqlite3_close_v2(sqlite3*); 336 337 /* 338 ** The type for a callback function. 339 ** This is legacy and deprecated. It is included for historical 340 ** compatibility and is not documented. 341 */ 342 typedef int (*sqlite3_callback)(void*,int,char**, char**); 343 344 /* 345 ** CAPI3REF: One-Step Query Execution Interface 346 ** METHOD: sqlite3 347 ** 348 ** The sqlite3_exec() interface is a convenience wrapper around 349 ** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()], 350 ** that allows an application to run multiple statements of SQL 351 ** without having to use a lot of C code. 352 ** 353 ** ^The sqlite3_exec() interface runs zero or more UTF-8 encoded, 354 ** semicolon-separate SQL statements passed into its 2nd argument, 355 ** in the context of the [database connection] passed in as its 1st 356 ** argument. ^If the callback function of the 3rd argument to 357 ** sqlite3_exec() is not NULL, then it is invoked for each result row 358 ** coming out of the evaluated SQL statements. ^The 4th argument to 359 ** sqlite3_exec() is relayed through to the 1st argument of each 360 ** callback invocation. ^If the callback pointer to sqlite3_exec() 361 ** is NULL, then no callback is ever invoked and result rows are 362 ** ignored. 363 ** 364 ** ^If an error occurs while evaluating the SQL statements passed into 365 ** sqlite3_exec(), then execution of the current statement stops and 366 ** subsequent statements are skipped. ^If the 5th parameter to sqlite3_exec() 367 ** is not NULL then any error message is written into memory obtained 368 ** from [sqlite3_malloc()] and passed back through the 5th parameter. 369 ** To avoid memory leaks, the application should invoke [sqlite3_free()] 370 ** on error message strings returned through the 5th parameter of 371 ** sqlite3_exec() after the error message string is no longer needed. 372 ** ^If the 5th parameter to sqlite3_exec() is not NULL and no errors 373 ** occur, then sqlite3_exec() sets the pointer in its 5th parameter to 374 ** NULL before returning. 375 ** 376 ** ^If an sqlite3_exec() callback returns non-zero, the sqlite3_exec() 377 ** routine returns SQLITE_ABORT without invoking the callback again and 378 ** without running any subsequent SQL statements. 379 ** 380 ** ^The 2nd argument to the sqlite3_exec() callback function is the 381 ** number of columns in the result. ^The 3rd argument to the sqlite3_exec() 382 ** callback is an array of pointers to strings obtained as if from 383 ** [sqlite3_column_text()], one for each column. ^If an element of a 384 ** result row is NULL then the corresponding string pointer for the 385 ** sqlite3_exec() callback is a NULL pointer. ^The 4th argument to the 386 ** sqlite3_exec() callback is an array of pointers to strings where each 387 ** entry represents the name of corresponding result column as obtained 388 ** from [sqlite3_column_name()]. 389 ** 390 ** ^If the 2nd parameter to sqlite3_exec() is a NULL pointer, a pointer 391 ** to an empty string, or a pointer that contains only whitespace and/or 392 ** SQL comments, then no SQL statements are evaluated and the database 393 ** is not changed. 394 ** 395 ** Restrictions: 396 ** 397 ** <ul> 398 ** <li> The application must ensure that the 1st parameter to sqlite3_exec() 399 ** is a valid and open [database connection]. 400 ** <li> The application must not close the [database connection] specified by 401 ** the 1st parameter to sqlite3_exec() while sqlite3_exec() is running. 402 ** <li> The application must not modify the SQL statement text passed into 403 ** the 2nd parameter of sqlite3_exec() while sqlite3_exec() is running. 404 ** </ul> 405 */ 406 SQLITE_API int sqlite3_exec( 407 sqlite3*, /* An open database */ 408 const char *sql, /* SQL to be evaluated */ 409 int (*callback)(void*,int,char**,char**), /* Callback function */ 410 void *, /* 1st argument to callback */ 411 char **errmsg /* Error msg written here */ 412 ); 413 414 /* 415 ** CAPI3REF: Result Codes 416 ** KEYWORDS: {result code definitions} 417 ** 418 ** Many SQLite functions return an integer result code from the set shown 419 ** here in order to indicate success or failure. 420 ** 421 ** New error codes may be added in future versions of SQLite. 422 ** 423 ** See also: [extended result code definitions] 424 */ 425 #define SQLITE_OK 0 /* Successful result */ 426 /* beginning-of-error-codes */ 427 #define SQLITE_ERROR 1 /* Generic error */ 428 #define SQLITE_INTERNAL 2 /* Internal logic error in SQLite */ 429 #define SQLITE_PERM 3 /* Access permission denied */ 430 #define SQLITE_ABORT 4 /* Callback routine requested an abort */ 431 #define SQLITE_BUSY 5 /* The database file is locked */ 432 #define SQLITE_LOCKED 6 /* A table in the database is locked */ 433 #define SQLITE_NOMEM 7 /* A malloc() failed */ 434 #define SQLITE_READONLY 8 /* Attempt to write a readonly database */ 435 #define SQLITE_INTERRUPT 9 /* Operation terminated by sqlite3_interrupt()*/ 436 #define SQLITE_IOERR 10 /* Some kind of disk I/O error occurred */ 437 #define SQLITE_CORRUPT 11 /* The database disk image is malformed */ 438 #define SQLITE_NOTFOUND 12 /* Unknown opcode in sqlite3_file_control() */ 439 #define SQLITE_FULL 13 /* Insertion failed because database is full */ 440 #define SQLITE_CANTOPEN 14 /* Unable to open the database file */ 441 #define SQLITE_PROTOCOL 15 /* Database lock protocol error */ 442 #define SQLITE_EMPTY 16 /* Internal use only */ 443 #define SQLITE_SCHEMA 17 /* The database schema changed */ 444 #define SQLITE_TOOBIG 18 /* String or BLOB exceeds size limit */ 445 #define SQLITE_CONSTRAINT 19 /* Abort due to constraint violation */ 446 #define SQLITE_MISMATCH 20 /* Data type mismatch */ 447 #define SQLITE_MISUSE 21 /* Library used incorrectly */ 448 #define SQLITE_NOLFS 22 /* Uses OS features not supported on host */ 449 #define SQLITE_AUTH 23 /* Authorization denied */ 450 #define SQLITE_FORMAT 24 /* Not used */ 451 #define SQLITE_RANGE 25 /* 2nd parameter to sqlite3_bind out of range */ 452 #define SQLITE_NOTADB 26 /* File opened that is not a database file */ 453 #define SQLITE_NOTICE 27 /* Notifications from sqlite3_log() */ 454 #define SQLITE_WARNING 28 /* Warnings from sqlite3_log() */ 455 #define SQLITE_ROW 100 /* sqlite3_step() has another row ready */ 456 #define SQLITE_DONE 101 /* sqlite3_step() has finished executing */ 457 /* end-of-error-codes */ 458 459 /* 460 ** CAPI3REF: Extended Result Codes 461 ** KEYWORDS: {extended result code definitions} 462 ** 463 ** In its default configuration, SQLite API routines return one of 30 integer 464 ** [result codes]. However, experience has shown that many of 465 ** these result codes are too coarse-grained. They do not provide as 466 ** much information about problems as programmers might like. In an effort to 467 ** address this, newer versions of SQLite (version 3.3.8 [dateof:3.3.8] 468 ** and later) include 469 ** support for additional result codes that provide more detailed information 470 ** about errors. These [extended result codes] are enabled or disabled 471 ** on a per database connection basis using the 472 ** [sqlite3_extended_result_codes()] API. Or, the extended code for 473 ** the most recent error can be obtained using 474 ** [sqlite3_extended_errcode()]. 475 */ 476 #define SQLITE_ERROR_MISSING_COLLSEQ (SQLITE_ERROR | (1<<8)) 477 #define SQLITE_ERROR_RETRY (SQLITE_ERROR | (2<<8)) 478 #define SQLITE_ERROR_SNAPSHOT (SQLITE_ERROR | (3<<8)) 479 #define SQLITE_IOERR_READ (SQLITE_IOERR | (1<<8)) 480 #define SQLITE_IOERR_SHORT_READ (SQLITE_IOERR | (2<<8)) 481 #define SQLITE_IOERR_WRITE (SQLITE_IOERR | (3<<8)) 482 #define SQLITE_IOERR_FSYNC (SQLITE_IOERR | (4<<8)) 483 #define SQLITE_IOERR_DIR_FSYNC (SQLITE_IOERR | (5<<8)) 484 #define SQLITE_IOERR_TRUNCATE (SQLITE_IOERR | (6<<8)) 485 #define SQLITE_IOERR_FSTAT (SQLITE_IOERR | (7<<8)) 486 #define SQLITE_IOERR_UNLOCK (SQLITE_IOERR | (8<<8)) 487 #define SQLITE_IOERR_RDLOCK (SQLITE_IOERR | (9<<8)) 488 #define SQLITE_IOERR_DELETE (SQLITE_IOERR | (10<<8)) 489 #define SQLITE_IOERR_BLOCKED (SQLITE_IOERR | (11<<8)) 490 #define SQLITE_IOERR_NOMEM (SQLITE_IOERR | (12<<8)) 491 #define SQLITE_IOERR_ACCESS (SQLITE_IOERR | (13<<8)) 492 #define SQLITE_IOERR_CHECKRESERVEDLOCK (SQLITE_IOERR | (14<<8)) 493 #define SQLITE_IOERR_LOCK (SQLITE_IOERR | (15<<8)) 494 #define SQLITE_IOERR_CLOSE (SQLITE_IOERR | (16<<8)) 495 #define SQLITE_IOERR_DIR_CLOSE (SQLITE_IOERR | (17<<8)) 496 #define SQLITE_IOERR_SHMOPEN (SQLITE_IOERR | (18<<8)) 497 #define SQLITE_IOERR_SHMSIZE (SQLITE_IOERR | (19<<8)) 498 #define SQLITE_IOERR_SHMLOCK (SQLITE_IOERR | (20<<8)) 499 #define SQLITE_IOERR_SHMMAP (SQLITE_IOERR | (21<<8)) 500 #define SQLITE_IOERR_SEEK (SQLITE_IOERR | (22<<8)) 501 #define SQLITE_IOERR_DELETE_NOENT (SQLITE_IOERR | (23<<8)) 502 #define SQLITE_IOERR_MMAP (SQLITE_IOERR | (24<<8)) 503 #define SQLITE_IOERR_GETTEMPPATH (SQLITE_IOERR | (25<<8)) 504 #define SQLITE_IOERR_CONVPATH (SQLITE_IOERR | (26<<8)) 505 #define SQLITE_IOERR_VNODE (SQLITE_IOERR | (27<<8)) 506 #define SQLITE_IOERR_AUTH (SQLITE_IOERR | (28<<8)) 507 #define SQLITE_IOERR_BEGIN_ATOMIC (SQLITE_IOERR | (29<<8)) 508 #define SQLITE_IOERR_COMMIT_ATOMIC (SQLITE_IOERR | (30<<8)) 509 #define SQLITE_IOERR_ROLLBACK_ATOMIC (SQLITE_IOERR | (31<<8)) 510 #define SQLITE_LOCKED_SHAREDCACHE (SQLITE_LOCKED | (1<<8)) 511 #define SQLITE_LOCKED_VTAB (SQLITE_LOCKED | (2<<8)) 512 #define SQLITE_BUSY_RECOVERY (SQLITE_BUSY | (1<<8)) 513 #define SQLITE_BUSY_SNAPSHOT (SQLITE_BUSY | (2<<8)) 514 #define SQLITE_CANTOPEN_NOTEMPDIR (SQLITE_CANTOPEN | (1<<8)) 515 #define SQLITE_CANTOPEN_ISDIR (SQLITE_CANTOPEN | (2<<8)) 516 #define SQLITE_CANTOPEN_FULLPATH (SQLITE_CANTOPEN | (3<<8)) 517 #define SQLITE_CANTOPEN_CONVPATH (SQLITE_CANTOPEN | (4<<8)) 518 #define SQLITE_CANTOPEN_DIRTYWAL (SQLITE_CANTOPEN | (5<<8)) /* Not Used */ 519 #define SQLITE_CORRUPT_VTAB (SQLITE_CORRUPT | (1<<8)) 520 #define SQLITE_CORRUPT_SEQUENCE (SQLITE_CORRUPT | (2<<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_NOTICE_RECOVER_WAL (SQLITE_NOTICE | (1<<8)) 539 #define SQLITE_NOTICE_RECOVER_ROLLBACK (SQLITE_NOTICE | (2<<8)) 540 #define SQLITE_WARNING_AUTOINDEX (SQLITE_WARNING | (1<<8)) 541 #define SQLITE_AUTH_USER (SQLITE_AUTH | (1<<8)) 542 #define SQLITE_OK_LOAD_PERMANENTLY (SQLITE_OK | (1<<8)) 543 544 /* 545 ** CAPI3REF: Flags For File Open Operations 546 ** 547 ** These bit values are intended for use in the 548 ** 3rd parameter to the [sqlite3_open_v2()] interface and 549 ** in the 4th parameter to the [sqlite3_vfs.xOpen] method. 550 */ 551 #define SQLITE_OPEN_READONLY 0x00000001 /* Ok for sqlite3_open_v2() */ 552 #define SQLITE_OPEN_READWRITE 0x00000002 /* Ok for sqlite3_open_v2() */ 553 #define SQLITE_OPEN_CREATE 0x00000004 /* Ok for sqlite3_open_v2() */ 554 #define SQLITE_OPEN_DELETEONCLOSE 0x00000008 /* VFS only */ 555 #define SQLITE_OPEN_EXCLUSIVE 0x00000010 /* VFS only */ 556 #define SQLITE_OPEN_AUTOPROXY 0x00000020 /* VFS only */ 557 #define SQLITE_OPEN_URI 0x00000040 /* Ok for sqlite3_open_v2() */ 558 #define SQLITE_OPEN_MEMORY 0x00000080 /* Ok for sqlite3_open_v2() */ 559 #define SQLITE_OPEN_MAIN_DB 0x00000100 /* VFS only */ 560 #define SQLITE_OPEN_TEMP_DB 0x00000200 /* VFS only */ 561 #define SQLITE_OPEN_TRANSIENT_DB 0x00000400 /* VFS only */ 562 #define SQLITE_OPEN_MAIN_JOURNAL 0x00000800 /* VFS only */ 563 #define SQLITE_OPEN_TEMP_JOURNAL 0x00001000 /* VFS only */ 564 #define SQLITE_OPEN_SUBJOURNAL 0x00002000 /* VFS only */ 565 #define SQLITE_OPEN_MASTER_JOURNAL 0x00004000 /* VFS only */ 566 #define SQLITE_OPEN_NOMUTEX 0x00008000 /* Ok for sqlite3_open_v2() */ 567 #define SQLITE_OPEN_FULLMUTEX 0x00010000 /* Ok for sqlite3_open_v2() */ 568 #define SQLITE_OPEN_SHAREDCACHE 0x00020000 /* Ok for sqlite3_open_v2() */ 569 #define SQLITE_OPEN_PRIVATECACHE 0x00040000 /* Ok for sqlite3_open_v2() */ 570 #define SQLITE_OPEN_WAL 0x00080000 /* VFS only */ 571 572 /* Reserved: 0x00F00000 */ 573 574 /* 575 ** CAPI3REF: Device Characteristics 576 ** 577 ** The xDeviceCharacteristics method of the [sqlite3_io_methods] 578 ** object returns an integer which is a vector of these 579 ** bit values expressing I/O characteristics of the mass storage 580 ** device that holds the file that the [sqlite3_io_methods] 581 ** refers to. 582 ** 583 ** The SQLITE_IOCAP_ATOMIC property means that all writes of 584 ** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 585 ** mean that writes of blocks that are nnn bytes in size and 586 ** are aligned to an address which is an integer multiple of 587 ** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 588 ** that when data is appended to a file, the data is appended 589 ** first then the size of the file is extended, never the other 590 ** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 591 ** information is written to disk in the same order as calls 592 ** to xWrite(). The SQLITE_IOCAP_POWERSAFE_OVERWRITE property means that 593 ** after reboot following a crash or power loss, the only bytes in a 594 ** file that were written at the application level might have changed 595 ** and that adjacent bytes, even bytes within the same sector are 596 ** guaranteed to be unchanged. The SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 597 ** flag indicates that a file cannot be deleted when open. The 598 ** SQLITE_IOCAP_IMMUTABLE flag indicates that the file is on 599 ** read-only media and cannot be changed even by processes with 600 ** elevated privileges. 601 ** 602 ** The SQLITE_IOCAP_BATCH_ATOMIC property means that the underlying 603 ** filesystem supports doing multiple write operations atomically when those 604 ** write operations are bracketed by [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] and 605 ** [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]. 606 */ 607 #define SQLITE_IOCAP_ATOMIC 0x00000001 608 #define SQLITE_IOCAP_ATOMIC512 0x00000002 609 #define SQLITE_IOCAP_ATOMIC1K 0x00000004 610 #define SQLITE_IOCAP_ATOMIC2K 0x00000008 611 #define SQLITE_IOCAP_ATOMIC4K 0x00000010 612 #define SQLITE_IOCAP_ATOMIC8K 0x00000020 613 #define SQLITE_IOCAP_ATOMIC16K 0x00000040 614 #define SQLITE_IOCAP_ATOMIC32K 0x00000080 615 #define SQLITE_IOCAP_ATOMIC64K 0x00000100 616 #define SQLITE_IOCAP_SAFE_APPEND 0x00000200 617 #define SQLITE_IOCAP_SEQUENTIAL 0x00000400 618 #define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 0x00000800 619 #define SQLITE_IOCAP_POWERSAFE_OVERWRITE 0x00001000 620 #define SQLITE_IOCAP_IMMUTABLE 0x00002000 621 #define SQLITE_IOCAP_BATCH_ATOMIC 0x00004000 622 623 /* 624 ** CAPI3REF: File Locking Levels 625 ** 626 ** SQLite uses one of these integer values as the second 627 ** argument to calls it makes to the xLock() and xUnlock() methods 628 ** of an [sqlite3_io_methods] object. 629 */ 630 #define SQLITE_LOCK_NONE 0 631 #define SQLITE_LOCK_SHARED 1 632 #define SQLITE_LOCK_RESERVED 2 633 #define SQLITE_LOCK_PENDING 3 634 #define SQLITE_LOCK_EXCLUSIVE 4 635 636 /* 637 ** CAPI3REF: Synchronization Type Flags 638 ** 639 ** When SQLite invokes the xSync() method of an 640 ** [sqlite3_io_methods] object it uses a combination of 641 ** these integer values as the second argument. 642 ** 643 ** When the SQLITE_SYNC_DATAONLY flag is used, it means that the 644 ** sync operation only needs to flush data to mass storage. Inode 645 ** information need not be flushed. If the lower four bits of the flag 646 ** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics. 647 ** If the lower four bits equal SQLITE_SYNC_FULL, that means 648 ** to use Mac OS X style fullsync instead of fsync(). 649 ** 650 ** Do not confuse the SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags 651 ** with the [PRAGMA synchronous]=NORMAL and [PRAGMA synchronous]=FULL 652 ** settings. The [synchronous pragma] determines when calls to the 653 ** xSync VFS method occur and applies uniformly across all platforms. 654 ** The SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags determine how 655 ** energetic or rigorous or forceful the sync operations are and 656 ** only make a difference on Mac OSX for the default SQLite code. 657 ** (Third-party VFS implementations might also make the distinction 658 ** between SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL, but among the 659 ** operating systems natively supported by SQLite, only Mac OSX 660 ** cares about the difference.) 661 */ 662 #define SQLITE_SYNC_NORMAL 0x00002 663 #define SQLITE_SYNC_FULL 0x00003 664 #define SQLITE_SYNC_DATAONLY 0x00010 665 666 /* 667 ** CAPI3REF: OS Interface Open File Handle 668 ** 669 ** An [sqlite3_file] object represents an open file in the 670 ** [sqlite3_vfs | OS interface layer]. Individual OS interface 671 ** implementations will 672 ** want to subclass this object by appending additional fields 673 ** for their own use. The pMethods entry is a pointer to an 674 ** [sqlite3_io_methods] object that defines methods for performing 675 ** I/O operations on the open file. 676 */ 677 typedef struct sqlite3_file sqlite3_file; 678 struct sqlite3_file { 679 const struct sqlite3_io_methods *pMethods; /* Methods for an open file */ 680 }; 681 682 /* 683 ** CAPI3REF: OS Interface File Virtual Methods Object 684 ** 685 ** Every file opened by the [sqlite3_vfs.xOpen] method populates an 686 ** [sqlite3_file] object (or, more commonly, a subclass of the 687 ** [sqlite3_file] object) with a pointer to an instance of this object. 688 ** This object defines the methods used to perform various operations 689 ** against the open file represented by the [sqlite3_file] object. 690 ** 691 ** If the [sqlite3_vfs.xOpen] method sets the sqlite3_file.pMethods element 692 ** to a non-NULL pointer, then the sqlite3_io_methods.xClose method 693 ** may be invoked even if the [sqlite3_vfs.xOpen] reported that it failed. The 694 ** only way to prevent a call to xClose following a failed [sqlite3_vfs.xOpen] 695 ** is for the [sqlite3_vfs.xOpen] to set the sqlite3_file.pMethods element 696 ** to NULL. 697 ** 698 ** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or 699 ** [SQLITE_SYNC_FULL]. The first choice is the normal fsync(). 700 ** The second choice is a Mac OS X style fullsync. The [SQLITE_SYNC_DATAONLY] 701 ** flag may be ORed in to indicate that only the data of the file 702 ** and not its inode needs to be synced. 703 ** 704 ** The integer values to xLock() and xUnlock() are one of 705 ** <ul> 706 ** <li> [SQLITE_LOCK_NONE], 707 ** <li> [SQLITE_LOCK_SHARED], 708 ** <li> [SQLITE_LOCK_RESERVED], 709 ** <li> [SQLITE_LOCK_PENDING], or 710 ** <li> [SQLITE_LOCK_EXCLUSIVE]. 711 ** </ul> 712 ** xLock() increases the lock. xUnlock() decreases the lock. 713 ** The xCheckReservedLock() method checks whether any database connection, 714 ** either in this process or in some other process, is holding a RESERVED, 715 ** PENDING, or EXCLUSIVE lock on the file. It returns true 716 ** if such a lock exists and false otherwise. 717 ** 718 ** The xFileControl() method is a generic interface that allows custom 719 ** VFS implementations to directly control an open file using the 720 ** [sqlite3_file_control()] interface. The second "op" argument is an 721 ** integer opcode. The third argument is a generic pointer intended to 722 ** point to a structure that may contain arguments or space in which to 723 ** write return values. Potential uses for xFileControl() might be 724 ** functions to enable blocking locks with timeouts, to change the 725 ** locking strategy (for example to use dot-file locks), to inquire 726 ** about the status of a lock, or to break stale locks. The SQLite 727 ** core reserves all opcodes less than 100 for its own use. 728 ** A [file control opcodes | list of opcodes] less than 100 is available. 729 ** Applications that define a custom xFileControl method should use opcodes 730 ** greater than 100 to avoid conflicts. VFS implementations should 731 ** return [SQLITE_NOTFOUND] for file control opcodes that they do not 732 ** recognize. 733 ** 734 ** The xSectorSize() method returns the sector size of the 735 ** device that underlies the file. The sector size is the 736 ** minimum write that can be performed without disturbing 737 ** other bytes in the file. The xDeviceCharacteristics() 738 ** method returns a bit vector describing behaviors of the 739 ** underlying device: 740 ** 741 ** <ul> 742 ** <li> [SQLITE_IOCAP_ATOMIC] 743 ** <li> [SQLITE_IOCAP_ATOMIC512] 744 ** <li> [SQLITE_IOCAP_ATOMIC1K] 745 ** <li> [SQLITE_IOCAP_ATOMIC2K] 746 ** <li> [SQLITE_IOCAP_ATOMIC4K] 747 ** <li> [SQLITE_IOCAP_ATOMIC8K] 748 ** <li> [SQLITE_IOCAP_ATOMIC16K] 749 ** <li> [SQLITE_IOCAP_ATOMIC32K] 750 ** <li> [SQLITE_IOCAP_ATOMIC64K] 751 ** <li> [SQLITE_IOCAP_SAFE_APPEND] 752 ** <li> [SQLITE_IOCAP_SEQUENTIAL] 753 ** <li> [SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN] 754 ** <li> [SQLITE_IOCAP_POWERSAFE_OVERWRITE] 755 ** <li> [SQLITE_IOCAP_IMMUTABLE] 756 ** <li> [SQLITE_IOCAP_BATCH_ATOMIC] 757 ** </ul> 758 ** 759 ** The SQLITE_IOCAP_ATOMIC property means that all writes of 760 ** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 761 ** mean that writes of blocks that are nnn bytes in size and 762 ** are aligned to an address which is an integer multiple of 763 ** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 764 ** that when data is appended to a file, the data is appended 765 ** first then the size of the file is extended, never the other 766 ** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 767 ** information is written to disk in the same order as calls 768 ** to xWrite(). 769 ** 770 ** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill 771 ** in the unread portions of the buffer with zeros. A VFS that 772 ** fails to zero-fill short reads might seem to work. However, 773 ** failure to zero-fill short reads will eventually lead to 774 ** database corruption. 775 */ 776 typedef struct sqlite3_io_methods sqlite3_io_methods; 777 struct sqlite3_io_methods { 778 int iVersion; 779 int (*xClose)(sqlite3_file*); 780 int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst); 781 int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst); 782 int (*xTruncate)(sqlite3_file*, sqlite3_int64 size); 783 int (*xSync)(sqlite3_file*, int flags); 784 int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize); 785 int (*xLock)(sqlite3_file*, int); 786 int (*xUnlock)(sqlite3_file*, int); 787 int (*xCheckReservedLock)(sqlite3_file*, int *pResOut); 788 int (*xFileControl)(sqlite3_file*, int op, void *pArg); 789 int (*xSectorSize)(sqlite3_file*); 790 int (*xDeviceCharacteristics)(sqlite3_file*); 791 /* Methods above are valid for version 1 */ 792 int (*xShmMap)(sqlite3_file*, int iPg, int pgsz, int, void volatile**); 793 int (*xShmLock)(sqlite3_file*, int offset, int n, int flags); 794 void (*xShmBarrier)(sqlite3_file*); 795 int (*xShmUnmap)(sqlite3_file*, int deleteFlag); 796 /* Methods above are valid for version 2 */ 797 int (*xFetch)(sqlite3_file*, sqlite3_int64 iOfst, int iAmt, void **pp); 798 int (*xUnfetch)(sqlite3_file*, sqlite3_int64 iOfst, void *p); 799 /* Methods above are valid for version 3 */ 800 /* Additional methods may be added in future releases */ 801 }; 802 803 /* 804 ** CAPI3REF: Standard File Control Opcodes 805 ** KEYWORDS: {file control opcodes} {file control opcode} 806 ** 807 ** These integer constants are opcodes for the xFileControl method 808 ** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()] 809 ** interface. 810 ** 811 ** <ul> 812 ** <li>[[SQLITE_FCNTL_LOCKSTATE]] 813 ** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging. This 814 ** opcode causes the xFileControl method to write the current state of 815 ** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED], 816 ** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE]) 817 ** into an integer that the pArg argument points to. This capability 818 ** is used during testing and is only available when the SQLITE_TEST 819 ** compile-time option is used. 820 ** 821 ** <li>[[SQLITE_FCNTL_SIZE_HINT]] 822 ** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS 823 ** layer a hint of how large the database file will grow to be during the 824 ** current transaction. This hint is not guaranteed to be accurate but it 825 ** is often close. The underlying VFS might choose to preallocate database 826 ** file space based on this hint in order to help writes to the database 827 ** file run faster. 828 ** 829 ** <li>[[SQLITE_FCNTL_SIZE_LIMIT]] 830 ** The [SQLITE_FCNTL_SIZE_LIMIT] opcode is used by in-memory VFS that 831 ** implements [sqlite3_deserialize()] to set an upper bound on the size 832 ** of the in-memory database. The argument is a pointer to a [sqlite3_int64]. 833 ** If the integer pointed to is negative, then it is filled in with the 834 ** current limit. Otherwise the limit is set to the larger of the value 835 ** of the integer pointed to and the current database size. The integer 836 ** pointed to is set to the new limit. 837 ** 838 ** <li>[[SQLITE_FCNTL_CHUNK_SIZE]] 839 ** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS 840 ** extends and truncates the database file in chunks of a size specified 841 ** by the user. The fourth argument to [sqlite3_file_control()] should 842 ** point to an integer (type int) containing the new chunk-size to use 843 ** for the nominated database. Allocating database file space in large 844 ** chunks (say 1MB at a time), may reduce file-system fragmentation and 845 ** improve performance on some systems. 846 ** 847 ** <li>[[SQLITE_FCNTL_FILE_POINTER]] 848 ** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer 849 ** to the [sqlite3_file] object associated with a particular database 850 ** connection. See also [SQLITE_FCNTL_JOURNAL_POINTER]. 851 ** 852 ** <li>[[SQLITE_FCNTL_JOURNAL_POINTER]] 853 ** The [SQLITE_FCNTL_JOURNAL_POINTER] opcode is used to obtain a pointer 854 ** to the [sqlite3_file] object associated with the journal file (either 855 ** the [rollback journal] or the [write-ahead log]) for a particular database 856 ** connection. See also [SQLITE_FCNTL_FILE_POINTER]. 857 ** 858 ** <li>[[SQLITE_FCNTL_SYNC_OMITTED]] 859 ** No longer in use. 860 ** 861 ** <li>[[SQLITE_FCNTL_SYNC]] 862 ** The [SQLITE_FCNTL_SYNC] opcode is generated internally by SQLite and 863 ** sent to the VFS immediately before the xSync method is invoked on a 864 ** database file descriptor. Or, if the xSync method is not invoked 865 ** because the user has configured SQLite with 866 ** [PRAGMA synchronous | PRAGMA synchronous=OFF] it is invoked in place 867 ** of the xSync method. In most cases, the pointer argument passed with 868 ** this file-control is NULL. However, if the database file is being synced 869 ** as part of a multi-database commit, the argument points to a nul-terminated 870 ** string containing the transactions master-journal file name. VFSes that 871 ** do not need this signal should silently ignore this opcode. Applications 872 ** should not call [sqlite3_file_control()] with this opcode as doing so may 873 ** disrupt the operation of the specialized VFSes that do require it. 874 ** 875 ** <li>[[SQLITE_FCNTL_COMMIT_PHASETWO]] 876 ** The [SQLITE_FCNTL_COMMIT_PHASETWO] opcode is generated internally by SQLite 877 ** and sent to the VFS after a transaction has been committed immediately 878 ** but before the database is unlocked. VFSes that do not need this signal 879 ** should silently ignore this opcode. Applications should not call 880 ** [sqlite3_file_control()] with this opcode as doing so may disrupt the 881 ** operation of the specialized VFSes that do require it. 882 ** 883 ** <li>[[SQLITE_FCNTL_WIN32_AV_RETRY]] 884 ** ^The [SQLITE_FCNTL_WIN32_AV_RETRY] opcode is used to configure automatic 885 ** retry counts and intervals for certain disk I/O operations for the 886 ** windows [VFS] in order to provide robustness in the presence of 887 ** anti-virus programs. By default, the windows VFS will retry file read, 888 ** file write, and file delete operations up to 10 times, with a delay 889 ** of 25 milliseconds before the first retry and with the delay increasing 890 ** by an additional 25 milliseconds with each subsequent retry. This 891 ** opcode allows these two values (10 retries and 25 milliseconds of delay) 892 ** to be adjusted. The values are changed for all database connections 893 ** within the same process. The argument is a pointer to an array of two 894 ** integers where the first integer is the new retry count and the second 895 ** integer is the delay. If either integer is negative, then the setting 896 ** is not changed but instead the prior value of that setting is written 897 ** into the array entry, allowing the current retry settings to be 898 ** interrogated. The zDbName parameter is ignored. 899 ** 900 ** <li>[[SQLITE_FCNTL_PERSIST_WAL]] 901 ** ^The [SQLITE_FCNTL_PERSIST_WAL] opcode is used to set or query the 902 ** persistent [WAL | Write Ahead Log] setting. By default, the auxiliary 903 ** write ahead log ([WAL file]) and shared memory 904 ** files used for transaction control 905 ** are automatically deleted when the latest connection to the database 906 ** closes. Setting persistent WAL mode causes those files to persist after 907 ** close. Persisting the files is useful when other processes that do not 908 ** have write permission on the directory containing the database file want 909 ** to read the database file, as the WAL and shared memory files must exist 910 ** in order for the database to be readable. The fourth parameter to 911 ** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 912 ** That integer is 0 to disable persistent WAL mode or 1 to enable persistent 913 ** WAL mode. If the integer is -1, then it is overwritten with the current 914 ** WAL persistence setting. 915 ** 916 ** <li>[[SQLITE_FCNTL_POWERSAFE_OVERWRITE]] 917 ** ^The [SQLITE_FCNTL_POWERSAFE_OVERWRITE] opcode is used to set or query the 918 ** persistent "powersafe-overwrite" or "PSOW" setting. The PSOW setting 919 ** determines the [SQLITE_IOCAP_POWERSAFE_OVERWRITE] bit of the 920 ** xDeviceCharacteristics methods. The fourth parameter to 921 ** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 922 ** That integer is 0 to disable zero-damage mode or 1 to enable zero-damage 923 ** mode. If the integer is -1, then it is overwritten with the current 924 ** zero-damage mode setting. 925 ** 926 ** <li>[[SQLITE_FCNTL_OVERWRITE]] 927 ** ^The [SQLITE_FCNTL_OVERWRITE] opcode is invoked by SQLite after opening 928 ** a write transaction to indicate that, unless it is rolled back for some 929 ** reason, the entire database file will be overwritten by the current 930 ** transaction. This is used by VACUUM operations. 931 ** 932 ** <li>[[SQLITE_FCNTL_VFSNAME]] 933 ** ^The [SQLITE_FCNTL_VFSNAME] opcode can be used to obtain the names of 934 ** all [VFSes] in the VFS stack. The names are of all VFS shims and the 935 ** final bottom-level VFS are written into memory obtained from 936 ** [sqlite3_malloc()] and the result is stored in the char* variable 937 ** that the fourth parameter of [sqlite3_file_control()] points to. 938 ** The caller is responsible for freeing the memory when done. As with 939 ** all file-control actions, there is no guarantee that this will actually 940 ** do anything. Callers should initialize the char* variable to a NULL 941 ** pointer in case this file-control is not implemented. This file-control 942 ** is intended for diagnostic use only. 943 ** 944 ** <li>[[SQLITE_FCNTL_VFS_POINTER]] 945 ** ^The [SQLITE_FCNTL_VFS_POINTER] opcode finds a pointer to the top-level 946 ** [VFSes] currently in use. ^(The argument X in 947 ** sqlite3_file_control(db,SQLITE_FCNTL_VFS_POINTER,X) must be 948 ** of type "[sqlite3_vfs] **". This opcodes will set *X 949 ** to a pointer to the top-level VFS.)^ 950 ** ^When there are multiple VFS shims in the stack, this opcode finds the 951 ** upper-most shim only. 952 ** 953 ** <li>[[SQLITE_FCNTL_PRAGMA]] 954 ** ^Whenever a [PRAGMA] statement is parsed, an [SQLITE_FCNTL_PRAGMA] 955 ** file control is sent to the open [sqlite3_file] object corresponding 956 ** to the database file to which the pragma statement refers. ^The argument 957 ** to the [SQLITE_FCNTL_PRAGMA] file control is an array of 958 ** pointers to strings (char**) in which the second element of the array 959 ** is the name of the pragma and the third element is the argument to the 960 ** pragma or NULL if the pragma has no argument. ^The handler for an 961 ** [SQLITE_FCNTL_PRAGMA] file control can optionally make the first element 962 ** of the char** argument point to a string obtained from [sqlite3_mprintf()] 963 ** or the equivalent and that string will become the result of the pragma or 964 ** the error message if the pragma fails. ^If the 965 ** [SQLITE_FCNTL_PRAGMA] file control returns [SQLITE_NOTFOUND], then normal 966 ** [PRAGMA] processing continues. ^If the [SQLITE_FCNTL_PRAGMA] 967 ** file control returns [SQLITE_OK], then the parser assumes that the 968 ** VFS has handled the PRAGMA itself and the parser generates a no-op 969 ** prepared statement if result string is NULL, or that returns a copy 970 ** of the result string if the string is non-NULL. 971 ** ^If the [SQLITE_FCNTL_PRAGMA] file control returns 972 ** any result code other than [SQLITE_OK] or [SQLITE_NOTFOUND], that means 973 ** that the VFS encountered an error while handling the [PRAGMA] and the 974 ** compilation of the PRAGMA fails with an error. ^The [SQLITE_FCNTL_PRAGMA] 975 ** file control occurs at the beginning of pragma statement analysis and so 976 ** it is able to override built-in [PRAGMA] statements. 977 ** 978 ** <li>[[SQLITE_FCNTL_BUSYHANDLER]] 979 ** ^The [SQLITE_FCNTL_BUSYHANDLER] 980 ** file-control may be invoked by SQLite on the database file handle 981 ** shortly after it is opened in order to provide a custom VFS with access 982 ** to the connections busy-handler callback. The argument is of type (void **) 983 ** - an array of two (void *) values. The first (void *) actually points 984 ** to a function of type (int (*)(void *)). In order to invoke the connections 985 ** busy-handler, this function should be invoked with the second (void *) in 986 ** the array as the only argument. If it returns non-zero, then the operation 987 ** should be retried. If it returns zero, the custom VFS should abandon the 988 ** current operation. 989 ** 990 ** <li>[[SQLITE_FCNTL_TEMPFILENAME]] 991 ** ^Application can invoke the [SQLITE_FCNTL_TEMPFILENAME] file-control 992 ** to have SQLite generate a 993 ** temporary filename using the same algorithm that is followed to generate 994 ** temporary filenames for TEMP tables and other internal uses. The 995 ** argument should be a char** which will be filled with the filename 996 ** written into memory obtained from [sqlite3_malloc()]. The caller should 997 ** invoke [sqlite3_free()] on the result to avoid a memory leak. 998 ** 999 ** <li>[[SQLITE_FCNTL_MMAP_SIZE]] 1000 ** The [SQLITE_FCNTL_MMAP_SIZE] file control is used to query or set the 1001 ** maximum number of bytes that will be used for memory-mapped I/O. 1002 ** The argument is a pointer to a value of type sqlite3_int64 that 1003 ** is an advisory maximum number of bytes in the file to memory map. The 1004 ** pointer is overwritten with the old value. The limit is not changed if 1005 ** the value originally pointed to is negative, and so the current limit 1006 ** can be queried by passing in a pointer to a negative number. This 1007 ** file-control is used internally to implement [PRAGMA mmap_size]. 1008 ** 1009 ** <li>[[SQLITE_FCNTL_TRACE]] 1010 ** The [SQLITE_FCNTL_TRACE] file control provides advisory information 1011 ** to the VFS about what the higher layers of the SQLite stack are doing. 1012 ** This file control is used by some VFS activity tracing [shims]. 1013 ** The argument is a zero-terminated string. Higher layers in the 1014 ** SQLite stack may generate instances of this file control if 1015 ** the [SQLITE_USE_FCNTL_TRACE] compile-time option is enabled. 1016 ** 1017 ** <li>[[SQLITE_FCNTL_HAS_MOVED]] 1018 ** The [SQLITE_FCNTL_HAS_MOVED] file control interprets its argument as a 1019 ** pointer to an integer and it writes a boolean into that integer depending 1020 ** on whether or not the file has been renamed, moved, or deleted since it 1021 ** was first opened. 1022 ** 1023 ** <li>[[SQLITE_FCNTL_WIN32_GET_HANDLE]] 1024 ** The [SQLITE_FCNTL_WIN32_GET_HANDLE] opcode can be used to obtain the 1025 ** underlying native file handle associated with a file handle. This file 1026 ** control interprets its argument as a pointer to a native file handle and 1027 ** writes the resulting value there. 1028 ** 1029 ** <li>[[SQLITE_FCNTL_WIN32_SET_HANDLE]] 1030 ** The [SQLITE_FCNTL_WIN32_SET_HANDLE] opcode is used for debugging. This 1031 ** opcode causes the xFileControl method to swap the file handle with the one 1032 ** pointed to by the pArg argument. This capability is used during testing 1033 ** and only needs to be supported when SQLITE_TEST is defined. 1034 ** 1035 ** <li>[[SQLITE_FCNTL_WAL_BLOCK]] 1036 ** The [SQLITE_FCNTL_WAL_BLOCK] is a signal to the VFS layer that it might 1037 ** be advantageous to block on the next WAL lock if the lock is not immediately 1038 ** available. The WAL subsystem issues this signal during rare 1039 ** circumstances in order to fix a problem with priority inversion. 1040 ** Applications should <em>not</em> use this file-control. 1041 ** 1042 ** <li>[[SQLITE_FCNTL_ZIPVFS]] 1043 ** The [SQLITE_FCNTL_ZIPVFS] opcode is implemented by zipvfs only. All other 1044 ** VFS should return SQLITE_NOTFOUND for this opcode. 1045 ** 1046 ** <li>[[SQLITE_FCNTL_RBU]] 1047 ** The [SQLITE_FCNTL_RBU] opcode is implemented by the special VFS used by 1048 ** the RBU extension only. All other VFS should return SQLITE_NOTFOUND for 1049 ** this opcode. 1050 ** 1051 ** <li>[[SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]] 1052 ** If the [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] opcode returns SQLITE_OK, then 1053 ** the file descriptor is placed in "batch write mode", which 1054 ** means all subsequent write operations will be deferred and done 1055 ** atomically at the next [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]. Systems 1056 ** that do not support batch atomic writes will return SQLITE_NOTFOUND. 1057 ** ^Following a successful SQLITE_FCNTL_BEGIN_ATOMIC_WRITE and prior to 1058 ** the closing [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] or 1059 ** [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE], SQLite will make 1060 ** no VFS interface calls on the same [sqlite3_file] file descriptor 1061 ** except for calls to the xWrite method and the xFileControl method 1062 ** with [SQLITE_FCNTL_SIZE_HINT]. 1063 ** 1064 ** <li>[[SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]] 1065 ** The [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] opcode causes all write 1066 ** operations since the previous successful call to 1067 ** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be performed atomically. 1068 ** This file control returns [SQLITE_OK] if and only if the writes were 1069 ** all performed successfully and have been committed to persistent storage. 1070 ** ^Regardless of whether or not it is successful, this file control takes 1071 ** the file descriptor out of batch write mode so that all subsequent 1072 ** write operations are independent. 1073 ** ^SQLite will never invoke SQLITE_FCNTL_COMMIT_ATOMIC_WRITE without 1074 ** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]. 1075 ** 1076 ** <li>[[SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE]] 1077 ** The [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE] opcode causes all write 1078 ** operations since the previous successful call to 1079 ** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be rolled back. 1080 ** ^This file control takes the file descriptor out of batch write mode 1081 ** so that all subsequent write operations are independent. 1082 ** ^SQLite will never invoke SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE without 1083 ** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]. 1084 ** 1085 ** <li>[[SQLITE_FCNTL_LOCK_TIMEOUT]] 1086 ** The [SQLITE_FCNTL_LOCK_TIMEOUT] opcode causes attempts to obtain 1087 ** a file lock using the xLock or xShmLock methods of the VFS to wait 1088 ** for up to M milliseconds before failing, where M is the single 1089 ** unsigned integer parameter. 1090 ** 1091 ** <li>[[SQLITE_FCNTL_DATA_VERSION]] 1092 ** The [SQLITE_FCNTL_DATA_VERSION] opcode is used to detect changes to 1093 ** a database file. The argument is a pointer to a 32-bit unsigned integer. 1094 ** The "data version" for the pager is written into the pointer. The 1095 ** "data version" changes whenever any change occurs to the corresponding 1096 ** database file, either through SQL statements on the same database 1097 ** connection or through transactions committed by separate database 1098 ** connections possibly in other processes. The [sqlite3_total_changes()] 1099 ** interface can be used to find if any database on the connection has changed, 1100 ** but that interface responds to changes on TEMP as well as MAIN and does 1101 ** not provide a mechanism to detect changes to MAIN only. Also, the 1102 ** [sqlite3_total_changes()] interface responds to internal changes only and 1103 ** omits changes made by other database connections. The 1104 ** [PRAGMA data_version] command provide a mechanism to detect changes to 1105 ** a single attached database that occur due to other database connections, 1106 ** but omits changes implemented by the database connection on which it is 1107 ** called. This file control is the only mechanism to detect changes that 1108 ** happen either internally or externally and that are associated with 1109 ** a particular attached database. 1110 ** </ul> 1111 */ 1112 #define SQLITE_FCNTL_LOCKSTATE 1 1113 #define SQLITE_FCNTL_GET_LOCKPROXYFILE 2 1114 #define SQLITE_FCNTL_SET_LOCKPROXYFILE 3 1115 #define SQLITE_FCNTL_LAST_ERRNO 4 1116 #define SQLITE_FCNTL_SIZE_HINT 5 1117 #define SQLITE_FCNTL_CHUNK_SIZE 6 1118 #define SQLITE_FCNTL_FILE_POINTER 7 1119 #define SQLITE_FCNTL_SYNC_OMITTED 8 1120 #define SQLITE_FCNTL_WIN32_AV_RETRY 9 1121 #define SQLITE_FCNTL_PERSIST_WAL 10 1122 #define SQLITE_FCNTL_OVERWRITE 11 1123 #define SQLITE_FCNTL_VFSNAME 12 1124 #define SQLITE_FCNTL_POWERSAFE_OVERWRITE 13 1125 #define SQLITE_FCNTL_PRAGMA 14 1126 #define SQLITE_FCNTL_BUSYHANDLER 15 1127 #define SQLITE_FCNTL_TEMPFILENAME 16 1128 #define SQLITE_FCNTL_MMAP_SIZE 18 1129 #define SQLITE_FCNTL_TRACE 19 1130 #define SQLITE_FCNTL_HAS_MOVED 20 1131 #define SQLITE_FCNTL_SYNC 21 1132 #define SQLITE_FCNTL_COMMIT_PHASETWO 22 1133 #define SQLITE_FCNTL_WIN32_SET_HANDLE 23 1134 #define SQLITE_FCNTL_WAL_BLOCK 24 1135 #define SQLITE_FCNTL_ZIPVFS 25 1136 #define SQLITE_FCNTL_RBU 26 1137 #define SQLITE_FCNTL_VFS_POINTER 27 1138 #define SQLITE_FCNTL_JOURNAL_POINTER 28 1139 #define SQLITE_FCNTL_WIN32_GET_HANDLE 29 1140 #define SQLITE_FCNTL_PDB 30 1141 #define SQLITE_FCNTL_BEGIN_ATOMIC_WRITE 31 1142 #define SQLITE_FCNTL_COMMIT_ATOMIC_WRITE 32 1143 #define SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE 33 1144 #define SQLITE_FCNTL_LOCK_TIMEOUT 34 1145 #define SQLITE_FCNTL_DATA_VERSION 35 1146 #define SQLITE_FCNTL_SIZE_LIMIT 36 1147 1148 /* deprecated names */ 1149 #define SQLITE_GET_LOCKPROXYFILE SQLITE_FCNTL_GET_LOCKPROXYFILE 1150 #define SQLITE_SET_LOCKPROXYFILE SQLITE_FCNTL_SET_LOCKPROXYFILE 1151 #define SQLITE_LAST_ERRNO SQLITE_FCNTL_LAST_ERRNO 1152 1153 1154 /* 1155 ** CAPI3REF: Mutex Handle 1156 ** 1157 ** The mutex module within SQLite defines [sqlite3_mutex] to be an 1158 ** abstract type for a mutex object. The SQLite core never looks 1159 ** at the internal representation of an [sqlite3_mutex]. It only 1160 ** deals with pointers to the [sqlite3_mutex] object. 1161 ** 1162 ** Mutexes are created using [sqlite3_mutex_alloc()]. 1163 */ 1164 typedef struct sqlite3_mutex sqlite3_mutex; 1165 1166 /* 1167 ** CAPI3REF: Loadable Extension Thunk 1168 ** 1169 ** A pointer to the opaque sqlite3_api_routines structure is passed as 1170 ** the third parameter to entry points of [loadable extensions]. This 1171 ** structure must be typedefed in order to work around compiler warnings 1172 ** on some platforms. 1173 */ 1174 typedef struct sqlite3_api_routines sqlite3_api_routines; 1175 1176 /* 1177 ** CAPI3REF: OS Interface Object 1178 ** 1179 ** An instance of the sqlite3_vfs object defines the interface between 1180 ** the SQLite core and the underlying operating system. The "vfs" 1181 ** in the name of the object stands for "virtual file system". See 1182 ** the [VFS | VFS documentation] for further information. 1183 ** 1184 ** The VFS interface is sometimes extended by adding new methods onto 1185 ** the end. Each time such an extension occurs, the iVersion field 1186 ** is incremented. The iVersion value started out as 1 in 1187 ** SQLite [version 3.5.0] on [dateof:3.5.0], then increased to 2 1188 ** with SQLite [version 3.7.0] on [dateof:3.7.0], and then increased 1189 ** to 3 with SQLite [version 3.7.6] on [dateof:3.7.6]. Additional fields 1190 ** may be appended to the sqlite3_vfs object and the iVersion value 1191 ** may increase again in future versions of SQLite. 1192 ** Note that the structure 1193 ** of the sqlite3_vfs object changes in the transition from 1194 ** SQLite [version 3.5.9] to [version 3.6.0] on [dateof:3.6.0] 1195 ** and yet the iVersion field was not modified. 1196 ** 1197 ** The szOsFile field is the size of the subclassed [sqlite3_file] 1198 ** structure used by this VFS. mxPathname is the maximum length of 1199 ** a pathname in this VFS. 1200 ** 1201 ** Registered sqlite3_vfs objects are kept on a linked list formed by 1202 ** the pNext pointer. The [sqlite3_vfs_register()] 1203 ** and [sqlite3_vfs_unregister()] interfaces manage this list 1204 ** in a thread-safe way. The [sqlite3_vfs_find()] interface 1205 ** searches the list. Neither the application code nor the VFS 1206 ** implementation should use the pNext pointer. 1207 ** 1208 ** The pNext field is the only field in the sqlite3_vfs 1209 ** structure that SQLite will ever modify. SQLite will only access 1210 ** or modify this field while holding a particular static mutex. 1211 ** The application should never modify anything within the sqlite3_vfs 1212 ** object once the object has been registered. 1213 ** 1214 ** The zName field holds the name of the VFS module. The name must 1215 ** be unique across all VFS modules. 1216 ** 1217 ** [[sqlite3_vfs.xOpen]] 1218 ** ^SQLite guarantees that the zFilename parameter to xOpen 1219 ** is either a NULL pointer or string obtained 1220 ** from xFullPathname() with an optional suffix added. 1221 ** ^If a suffix is added to the zFilename parameter, it will 1222 ** consist of a single "-" character followed by no more than 1223 ** 11 alphanumeric and/or "-" characters. 1224 ** ^SQLite further guarantees that 1225 ** the string will be valid and unchanged until xClose() is 1226 ** called. Because of the previous sentence, 1227 ** the [sqlite3_file] can safely store a pointer to the 1228 ** filename if it needs to remember the filename for some reason. 1229 ** If the zFilename parameter to xOpen is a NULL pointer then xOpen 1230 ** must invent its own temporary name for the file. ^Whenever the 1231 ** xFilename parameter is NULL it will also be the case that the 1232 ** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE]. 1233 ** 1234 ** The flags argument to xOpen() includes all bits set in 1235 ** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()] 1236 ** or [sqlite3_open16()] is used, then flags includes at least 1237 ** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]. 1238 ** If xOpen() opens a file read-only then it sets *pOutFlags to 1239 ** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be set. 1240 ** 1241 ** ^(SQLite will also add one of the following flags to the xOpen() 1242 ** call, depending on the object being opened: 1243 ** 1244 ** <ul> 1245 ** <li> [SQLITE_OPEN_MAIN_DB] 1246 ** <li> [SQLITE_OPEN_MAIN_JOURNAL] 1247 ** <li> [SQLITE_OPEN_TEMP_DB] 1248 ** <li> [SQLITE_OPEN_TEMP_JOURNAL] 1249 ** <li> [SQLITE_OPEN_TRANSIENT_DB] 1250 ** <li> [SQLITE_OPEN_SUBJOURNAL] 1251 ** <li> [SQLITE_OPEN_MASTER_JOURNAL] 1252 ** <li> [SQLITE_OPEN_WAL] 1253 ** </ul>)^ 1254 ** 1255 ** The file I/O implementation can use the object type flags to 1256 ** change the way it deals with files. For example, an application 1257 ** that does not care about crash recovery or rollback might make 1258 ** the open of a journal file a no-op. Writes to this journal would 1259 ** also be no-ops, and any attempt to read the journal would return 1260 ** SQLITE_IOERR. Or the implementation might recognize that a database 1261 ** file will be doing page-aligned sector reads and writes in a random 1262 ** order and set up its I/O subsystem accordingly. 1263 ** 1264 ** SQLite might also add one of the following flags to the xOpen method: 1265 ** 1266 ** <ul> 1267 ** <li> [SQLITE_OPEN_DELETEONCLOSE] 1268 ** <li> [SQLITE_OPEN_EXCLUSIVE] 1269 ** </ul> 1270 ** 1271 ** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be 1272 ** deleted when it is closed. ^The [SQLITE_OPEN_DELETEONCLOSE] 1273 ** will be set for TEMP databases and their journals, transient 1274 ** databases, and subjournals. 1275 ** 1276 ** ^The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction 1277 ** with the [SQLITE_OPEN_CREATE] flag, which are both directly 1278 ** analogous to the O_EXCL and O_CREAT flags of the POSIX open() 1279 ** API. The SQLITE_OPEN_EXCLUSIVE flag, when paired with the 1280 ** SQLITE_OPEN_CREATE, is used to indicate that file should always 1281 ** be created, and that it is an error if it already exists. 1282 ** It is <i>not</i> used to indicate the file should be opened 1283 ** for exclusive access. 1284 ** 1285 ** ^At least szOsFile bytes of memory are allocated by SQLite 1286 ** to hold the [sqlite3_file] structure passed as the third 1287 ** argument to xOpen. The xOpen method does not have to 1288 ** allocate the structure; it should just fill it in. Note that 1289 ** the xOpen method must set the sqlite3_file.pMethods to either 1290 ** a valid [sqlite3_io_methods] object or to NULL. xOpen must do 1291 ** this even if the open fails. SQLite expects that the sqlite3_file.pMethods 1292 ** element will be valid after xOpen returns regardless of the success 1293 ** or failure of the xOpen call. 1294 ** 1295 ** [[sqlite3_vfs.xAccess]] 1296 ** ^The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS] 1297 ** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to 1298 ** test whether a file is readable and writable, or [SQLITE_ACCESS_READ] 1299 ** to test whether a file is at least readable. The SQLITE_ACCESS_READ 1300 ** flag is never actually used and is not implemented in the built-in 1301 ** VFSes of SQLite. The file is named by the second argument and can be a 1302 ** directory. The xAccess method returns [SQLITE_OK] on success or some 1303 ** non-zero error code if there is an I/O error or if the name of 1304 ** the file given in the second argument is illegal. If SQLITE_OK 1305 ** is returned, then non-zero or zero is written into *pResOut to indicate 1306 ** whether or not the file is accessible. 1307 ** 1308 ** ^SQLite will always allocate at least mxPathname+1 bytes for the 1309 ** output buffer xFullPathname. The exact size of the output buffer 1310 ** is also passed as a parameter to both methods. If the output buffer 1311 ** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is 1312 ** handled as a fatal error by SQLite, vfs implementations should endeavor 1313 ** to prevent this by setting mxPathname to a sufficiently large value. 1314 ** 1315 ** The xRandomness(), xSleep(), xCurrentTime(), and xCurrentTimeInt64() 1316 ** interfaces are not strictly a part of the filesystem, but they are 1317 ** included in the VFS structure for completeness. 1318 ** The xRandomness() function attempts to return nBytes bytes 1319 ** of good-quality randomness into zOut. The return value is 1320 ** the actual number of bytes of randomness obtained. 1321 ** The xSleep() method causes the calling thread to sleep for at 1322 ** least the number of microseconds given. ^The xCurrentTime() 1323 ** method returns a Julian Day Number for the current date and time as 1324 ** a floating point value. 1325 ** ^The xCurrentTimeInt64() method returns, as an integer, the Julian 1326 ** Day Number multiplied by 86400000 (the number of milliseconds in 1327 ** a 24-hour day). 1328 ** ^SQLite will use the xCurrentTimeInt64() method to get the current 1329 ** date and time if that method is available (if iVersion is 2 or 1330 ** greater and the function pointer is not NULL) and will fall back 1331 ** to xCurrentTime() if xCurrentTimeInt64() is unavailable. 1332 ** 1333 ** ^The xSetSystemCall(), xGetSystemCall(), and xNestSystemCall() interfaces 1334 ** are not used by the SQLite core. These optional interfaces are provided 1335 ** by some VFSes to facilitate testing of the VFS code. By overriding 1336 ** system calls with functions under its control, a test program can 1337 ** simulate faults and error conditions that would otherwise be difficult 1338 ** or impossible to induce. The set of system calls that can be overridden 1339 ** varies from one VFS to another, and from one version of the same VFS to the 1340 ** next. Applications that use these interfaces must be prepared for any 1341 ** or all of these interfaces to be NULL or for their behavior to change 1342 ** from one release to the next. Applications must not attempt to access 1343 ** any of these methods if the iVersion of the VFS is less than 3. 1344 */ 1345 typedef struct sqlite3_vfs sqlite3_vfs; 1346 typedef void (*sqlite3_syscall_ptr)(void); 1347 struct sqlite3_vfs { 1348 int iVersion; /* Structure version number (currently 3) */ 1349 int szOsFile; /* Size of subclassed sqlite3_file */ 1350 int mxPathname; /* Maximum file pathname length */ 1351 sqlite3_vfs *pNext; /* Next registered VFS */ 1352 const char *zName; /* Name of this virtual file system */ 1353 void *pAppData; /* Pointer to application-specific data */ 1354 int (*xOpen)(sqlite3_vfs*, const char *zName, sqlite3_file*, 1355 int flags, int *pOutFlags); 1356 int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir); 1357 int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut); 1358 int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut); 1359 void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename); 1360 void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg); 1361 void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void); 1362 void (*xDlClose)(sqlite3_vfs*, void*); 1363 int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut); 1364 int (*xSleep)(sqlite3_vfs*, int microseconds); 1365 int (*xCurrentTime)(sqlite3_vfs*, double*); 1366 int (*xGetLastError)(sqlite3_vfs*, int, char *); 1367 /* 1368 ** The methods above are in version 1 of the sqlite_vfs object 1369 ** definition. Those that follow are added in version 2 or later 1370 */ 1371 int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*); 1372 /* 1373 ** The methods above are in versions 1 and 2 of the sqlite_vfs object. 1374 ** Those below are for version 3 and greater. 1375 */ 1376 int (*xSetSystemCall)(sqlite3_vfs*, const char *zName, sqlite3_syscall_ptr); 1377 sqlite3_syscall_ptr (*xGetSystemCall)(sqlite3_vfs*, const char *zName); 1378 const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName); 1379 /* 1380 ** The methods above are in versions 1 through 3 of the sqlite_vfs object. 1381 ** New fields may be appended in future versions. The iVersion 1382 ** value will increment whenever this happens. 1383 */ 1384 }; 1385 1386 /* 1387 ** CAPI3REF: Flags for the xAccess VFS method 1388 ** 1389 ** These integer constants can be used as the third parameter to 1390 ** the xAccess method of an [sqlite3_vfs] object. They determine 1391 ** what kind of permissions the xAccess method is looking for. 1392 ** With SQLITE_ACCESS_EXISTS, the xAccess method 1393 ** simply checks whether the file exists. 1394 ** With SQLITE_ACCESS_READWRITE, the xAccess method 1395 ** checks whether the named directory is both readable and writable 1396 ** (in other words, if files can be added, removed, and renamed within 1397 ** the directory). 1398 ** The SQLITE_ACCESS_READWRITE constant is currently used only by the 1399 ** [temp_store_directory pragma], though this could change in a future 1400 ** release of SQLite. 1401 ** With SQLITE_ACCESS_READ, the xAccess method 1402 ** checks whether the file is readable. The SQLITE_ACCESS_READ constant is 1403 ** currently unused, though it might be used in a future release of 1404 ** SQLite. 1405 */ 1406 #define SQLITE_ACCESS_EXISTS 0 1407 #define SQLITE_ACCESS_READWRITE 1 /* Used by PRAGMA temp_store_directory */ 1408 #define SQLITE_ACCESS_READ 2 /* Unused */ 1409 1410 /* 1411 ** CAPI3REF: Flags for the xShmLock VFS method 1412 ** 1413 ** These integer constants define the various locking operations 1414 ** allowed by the xShmLock method of [sqlite3_io_methods]. The 1415 ** following are the only legal combinations of flags to the 1416 ** xShmLock method: 1417 ** 1418 ** <ul> 1419 ** <li> SQLITE_SHM_LOCK | SQLITE_SHM_SHARED 1420 ** <li> SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE 1421 ** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED 1422 ** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE 1423 ** </ul> 1424 ** 1425 ** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as 1426 ** was given on the corresponding lock. 1427 ** 1428 ** The xShmLock method can transition between unlocked and SHARED or 1429 ** between unlocked and EXCLUSIVE. It cannot transition between SHARED 1430 ** and EXCLUSIVE. 1431 */ 1432 #define SQLITE_SHM_UNLOCK 1 1433 #define SQLITE_SHM_LOCK 2 1434 #define SQLITE_SHM_SHARED 4 1435 #define SQLITE_SHM_EXCLUSIVE 8 1436 1437 /* 1438 ** CAPI3REF: Maximum xShmLock index 1439 ** 1440 ** The xShmLock method on [sqlite3_io_methods] may use values 1441 ** between 0 and this upper bound as its "offset" argument. 1442 ** The SQLite core will never attempt to acquire or release a 1443 ** lock outside of this range 1444 */ 1445 #define SQLITE_SHM_NLOCK 8 1446 1447 1448 /* 1449 ** CAPI3REF: Initialize The SQLite Library 1450 ** 1451 ** ^The sqlite3_initialize() routine initializes the 1452 ** SQLite library. ^The sqlite3_shutdown() routine 1453 ** deallocates any resources that were allocated by sqlite3_initialize(). 1454 ** These routines are designed to aid in process initialization and 1455 ** shutdown on embedded systems. Workstation applications using 1456 ** SQLite normally do not need to invoke either of these routines. 1457 ** 1458 ** A call to sqlite3_initialize() is an "effective" call if it is 1459 ** the first time sqlite3_initialize() is invoked during the lifetime of 1460 ** the process, or if it is the first time sqlite3_initialize() is invoked 1461 ** following a call to sqlite3_shutdown(). ^(Only an effective call 1462 ** of sqlite3_initialize() does any initialization. All other calls 1463 ** are harmless no-ops.)^ 1464 ** 1465 ** A call to sqlite3_shutdown() is an "effective" call if it is the first 1466 ** call to sqlite3_shutdown() since the last sqlite3_initialize(). ^(Only 1467 ** an effective call to sqlite3_shutdown() does any deinitialization. 1468 ** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^ 1469 ** 1470 ** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown() 1471 ** is not. The sqlite3_shutdown() interface must only be called from a 1472 ** single thread. All open [database connections] must be closed and all 1473 ** other SQLite resources must be deallocated prior to invoking 1474 ** sqlite3_shutdown(). 1475 ** 1476 ** Among other things, ^sqlite3_initialize() will invoke 1477 ** sqlite3_os_init(). Similarly, ^sqlite3_shutdown() 1478 ** will invoke sqlite3_os_end(). 1479 ** 1480 ** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success. 1481 ** ^If for some reason, sqlite3_initialize() is unable to initialize 1482 ** the library (perhaps it is unable to allocate a needed resource such 1483 ** as a mutex) it returns an [error code] other than [SQLITE_OK]. 1484 ** 1485 ** ^The sqlite3_initialize() routine is called internally by many other 1486 ** SQLite interfaces so that an application usually does not need to 1487 ** invoke sqlite3_initialize() directly. For example, [sqlite3_open()] 1488 ** calls sqlite3_initialize() so the SQLite library will be automatically 1489 ** initialized when [sqlite3_open()] is called if it has not be initialized 1490 ** already. ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT] 1491 ** compile-time option, then the automatic calls to sqlite3_initialize() 1492 ** are omitted and the application must call sqlite3_initialize() directly 1493 ** prior to using any other SQLite interface. For maximum portability, 1494 ** it is recommended that applications always invoke sqlite3_initialize() 1495 ** directly prior to using any other SQLite interface. Future releases 1496 ** of SQLite may require this. In other words, the behavior exhibited 1497 ** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the 1498 ** default behavior in some future release of SQLite. 1499 ** 1500 ** The sqlite3_os_init() routine does operating-system specific 1501 ** initialization of the SQLite library. The sqlite3_os_end() 1502 ** routine undoes the effect of sqlite3_os_init(). Typical tasks 1503 ** performed by these routines include allocation or deallocation 1504 ** of static resources, initialization of global variables, 1505 ** setting up a default [sqlite3_vfs] module, or setting up 1506 ** a default configuration using [sqlite3_config()]. 1507 ** 1508 ** The application should never invoke either sqlite3_os_init() 1509 ** or sqlite3_os_end() directly. The application should only invoke 1510 ** sqlite3_initialize() and sqlite3_shutdown(). The sqlite3_os_init() 1511 ** interface is called automatically by sqlite3_initialize() and 1512 ** sqlite3_os_end() is called by sqlite3_shutdown(). Appropriate 1513 ** implementations for sqlite3_os_init() and sqlite3_os_end() 1514 ** are built into SQLite when it is compiled for Unix, Windows, or OS/2. 1515 ** When [custom builds | built for other platforms] 1516 ** (using the [SQLITE_OS_OTHER=1] compile-time 1517 ** option) the application must supply a suitable implementation for 1518 ** sqlite3_os_init() and sqlite3_os_end(). An application-supplied 1519 ** implementation of sqlite3_os_init() or sqlite3_os_end() 1520 ** must return [SQLITE_OK] on success and some other [error code] upon 1521 ** failure. 1522 */ 1523 SQLITE_API int sqlite3_initialize(void); 1524 SQLITE_API int sqlite3_shutdown(void); 1525 SQLITE_API int sqlite3_os_init(void); 1526 SQLITE_API int sqlite3_os_end(void); 1527 1528 /* 1529 ** CAPI3REF: Configuring The SQLite Library 1530 ** 1531 ** The sqlite3_config() interface is used to make global configuration 1532 ** changes to SQLite in order to tune SQLite to the specific needs of 1533 ** the application. The default configuration is recommended for most 1534 ** applications and so this routine is usually not necessary. It is 1535 ** provided to support rare applications with unusual needs. 1536 ** 1537 ** <b>The sqlite3_config() interface is not threadsafe. The application 1538 ** must ensure that no other SQLite interfaces are invoked by other 1539 ** threads while sqlite3_config() is running.</b> 1540 ** 1541 ** The sqlite3_config() interface 1542 ** may only be invoked prior to library initialization using 1543 ** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()]. 1544 ** ^If sqlite3_config() is called after [sqlite3_initialize()] and before 1545 ** [sqlite3_shutdown()] then it will return SQLITE_MISUSE. 1546 ** Note, however, that ^sqlite3_config() can be called as part of the 1547 ** implementation of an application-defined [sqlite3_os_init()]. 1548 ** 1549 ** The first argument to sqlite3_config() is an integer 1550 ** [configuration option] that determines 1551 ** what property of SQLite is to be configured. Subsequent arguments 1552 ** vary depending on the [configuration option] 1553 ** in the first argument. 1554 ** 1555 ** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK]. 1556 ** ^If the option is unknown or SQLite is unable to set the option 1557 ** then this routine returns a non-zero [error code]. 1558 */ 1559 SQLITE_API int sqlite3_config(int, ...); 1560 1561 /* 1562 ** CAPI3REF: Configure database connections 1563 ** METHOD: sqlite3 1564 ** 1565 ** The sqlite3_db_config() interface is used to make configuration 1566 ** changes to a [database connection]. The interface is similar to 1567 ** [sqlite3_config()] except that the changes apply to a single 1568 ** [database connection] (specified in the first argument). 1569 ** 1570 ** The second argument to sqlite3_db_config(D,V,...) is the 1571 ** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code 1572 ** that indicates what aspect of the [database connection] is being configured. 1573 ** Subsequent arguments vary depending on the configuration verb. 1574 ** 1575 ** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if 1576 ** the call is considered successful. 1577 */ 1578 SQLITE_API int sqlite3_db_config(sqlite3*, int op, ...); 1579 1580 /* 1581 ** CAPI3REF: Memory Allocation Routines 1582 ** 1583 ** An instance of this object defines the interface between SQLite 1584 ** and low-level memory allocation routines. 1585 ** 1586 ** This object is used in only one place in the SQLite interface. 1587 ** A pointer to an instance of this object is the argument to 1588 ** [sqlite3_config()] when the configuration option is 1589 ** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC]. 1590 ** By creating an instance of this object 1591 ** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC]) 1592 ** during configuration, an application can specify an alternative 1593 ** memory allocation subsystem for SQLite to use for all of its 1594 ** dynamic memory needs. 1595 ** 1596 ** Note that SQLite comes with several [built-in memory allocators] 1597 ** that are perfectly adequate for the overwhelming majority of applications 1598 ** and that this object is only useful to a tiny minority of applications 1599 ** with specialized memory allocation requirements. This object is 1600 ** also used during testing of SQLite in order to specify an alternative 1601 ** memory allocator that simulates memory out-of-memory conditions in 1602 ** order to verify that SQLite recovers gracefully from such 1603 ** conditions. 1604 ** 1605 ** The xMalloc, xRealloc, and xFree methods must work like the 1606 ** malloc(), realloc() and free() functions from the standard C library. 1607 ** ^SQLite guarantees that the second argument to 1608 ** xRealloc is always a value returned by a prior call to xRoundup. 1609 ** 1610 ** xSize should return the allocated size of a memory allocation 1611 ** previously obtained from xMalloc or xRealloc. The allocated size 1612 ** is always at least as big as the requested size but may be larger. 1613 ** 1614 ** The xRoundup method returns what would be the allocated size of 1615 ** a memory allocation given a particular requested size. Most memory 1616 ** allocators round up memory allocations at least to the next multiple 1617 ** of 8. Some allocators round up to a larger multiple or to a power of 2. 1618 ** Every memory allocation request coming in through [sqlite3_malloc()] 1619 ** or [sqlite3_realloc()] first calls xRoundup. If xRoundup returns 0, 1620 ** that causes the corresponding memory allocation to fail. 1621 ** 1622 ** The xInit method initializes the memory allocator. For example, 1623 ** it might allocate any require mutexes or initialize internal data 1624 ** structures. The xShutdown method is invoked (indirectly) by 1625 ** [sqlite3_shutdown()] and should deallocate any resources acquired 1626 ** by xInit. The pAppData pointer is used as the only parameter to 1627 ** xInit and xShutdown. 1628 ** 1629 ** SQLite holds the [SQLITE_MUTEX_STATIC_MASTER] mutex when it invokes 1630 ** the xInit method, so the xInit method need not be threadsafe. The 1631 ** xShutdown method is only called from [sqlite3_shutdown()] so it does 1632 ** not need to be threadsafe either. For all other methods, SQLite 1633 ** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the 1634 ** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which 1635 ** it is by default) and so the methods are automatically serialized. 1636 ** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other 1637 ** methods must be threadsafe or else make their own arrangements for 1638 ** serialization. 1639 ** 1640 ** SQLite will never invoke xInit() more than once without an intervening 1641 ** call to xShutdown(). 1642 */ 1643 typedef struct sqlite3_mem_methods sqlite3_mem_methods; 1644 struct sqlite3_mem_methods { 1645 void *(*xMalloc)(int); /* Memory allocation function */ 1646 void (*xFree)(void*); /* Free a prior allocation */ 1647 void *(*xRealloc)(void*,int); /* Resize an allocation */ 1648 int (*xSize)(void*); /* Return the size of an allocation */ 1649 int (*xRoundup)(int); /* Round up request size to allocation size */ 1650 int (*xInit)(void*); /* Initialize the memory allocator */ 1651 void (*xShutdown)(void*); /* Deinitialize the memory allocator */ 1652 void *pAppData; /* Argument to xInit() and xShutdown() */ 1653 }; 1654 1655 /* 1656 ** CAPI3REF: Configuration Options 1657 ** KEYWORDS: {configuration option} 1658 ** 1659 ** These constants are the available integer configuration options that 1660 ** can be passed as the first argument to the [sqlite3_config()] interface. 1661 ** 1662 ** New configuration options may be added in future releases of SQLite. 1663 ** Existing configuration options might be discontinued. Applications 1664 ** should check the return code from [sqlite3_config()] to make sure that 1665 ** the call worked. The [sqlite3_config()] interface will return a 1666 ** non-zero [error code] if a discontinued or unsupported configuration option 1667 ** is invoked. 1668 ** 1669 ** <dl> 1670 ** [[SQLITE_CONFIG_SINGLETHREAD]] <dt>SQLITE_CONFIG_SINGLETHREAD</dt> 1671 ** <dd>There are no arguments to this option. ^This option sets the 1672 ** [threading mode] to Single-thread. In other words, it disables 1673 ** all mutexing and puts SQLite into a mode where it can only be used 1674 ** by a single thread. ^If SQLite is compiled with 1675 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1676 ** it is not possible to change the [threading mode] from its default 1677 ** value of Single-thread and so [sqlite3_config()] will return 1678 ** [SQLITE_ERROR] if called with the SQLITE_CONFIG_SINGLETHREAD 1679 ** configuration option.</dd> 1680 ** 1681 ** [[SQLITE_CONFIG_MULTITHREAD]] <dt>SQLITE_CONFIG_MULTITHREAD</dt> 1682 ** <dd>There are no arguments to this option. ^This option sets the 1683 ** [threading mode] to Multi-thread. In other words, it disables 1684 ** mutexing on [database connection] and [prepared statement] objects. 1685 ** The application is responsible for serializing access to 1686 ** [database connections] and [prepared statements]. But other mutexes 1687 ** are enabled so that SQLite will be safe to use in a multi-threaded 1688 ** environment as long as no two threads attempt to use the same 1689 ** [database connection] at the same time. ^If SQLite is compiled with 1690 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1691 ** it is not possible to set the Multi-thread [threading mode] and 1692 ** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1693 ** SQLITE_CONFIG_MULTITHREAD configuration option.</dd> 1694 ** 1695 ** [[SQLITE_CONFIG_SERIALIZED]] <dt>SQLITE_CONFIG_SERIALIZED</dt> 1696 ** <dd>There are no arguments to this option. ^This option sets the 1697 ** [threading mode] to Serialized. In other words, this option enables 1698 ** all mutexes including the recursive 1699 ** mutexes on [database connection] and [prepared statement] objects. 1700 ** In this mode (which is the default when SQLite is compiled with 1701 ** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access 1702 ** to [database connections] and [prepared statements] so that the 1703 ** application is free to use the same [database connection] or the 1704 ** same [prepared statement] in different threads at the same time. 1705 ** ^If SQLite is compiled with 1706 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1707 ** it is not possible to set the Serialized [threading mode] and 1708 ** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1709 ** SQLITE_CONFIG_SERIALIZED configuration option.</dd> 1710 ** 1711 ** [[SQLITE_CONFIG_MALLOC]] <dt>SQLITE_CONFIG_MALLOC</dt> 1712 ** <dd> ^(The SQLITE_CONFIG_MALLOC option takes a single argument which is 1713 ** a pointer to an instance of the [sqlite3_mem_methods] structure. 1714 ** The argument specifies 1715 ** alternative low-level memory allocation routines to be used in place of 1716 ** the memory allocation routines built into SQLite.)^ ^SQLite makes 1717 ** its own private copy of the content of the [sqlite3_mem_methods] structure 1718 ** before the [sqlite3_config()] call returns.</dd> 1719 ** 1720 ** [[SQLITE_CONFIG_GETMALLOC]] <dt>SQLITE_CONFIG_GETMALLOC</dt> 1721 ** <dd> ^(The SQLITE_CONFIG_GETMALLOC option takes a single argument which 1722 ** is a pointer to an instance of the [sqlite3_mem_methods] structure. 1723 ** The [sqlite3_mem_methods] 1724 ** structure is filled with the currently defined memory allocation routines.)^ 1725 ** This option can be used to overload the default memory allocation 1726 ** routines with a wrapper that simulations memory allocation failure or 1727 ** tracks memory usage, for example. </dd> 1728 ** 1729 ** [[SQLITE_CONFIG_SMALL_MALLOC]] <dt>SQLITE_CONFIG_SMALL_MALLOC</dt> 1730 ** <dd> ^The SQLITE_CONFIG_SMALL_MALLOC option takes single argument of 1731 ** type int, interpreted as a boolean, which if true provides a hint to 1732 ** SQLite that it should avoid large memory allocations if possible. 1733 ** SQLite will run faster if it is free to make large memory allocations, 1734 ** but some application might prefer to run slower in exchange for 1735 ** guarantees about memory fragmentation that are possible if large 1736 ** allocations are avoided. This hint is normally off. 1737 ** </dd> 1738 ** 1739 ** [[SQLITE_CONFIG_MEMSTATUS]] <dt>SQLITE_CONFIG_MEMSTATUS</dt> 1740 ** <dd> ^The SQLITE_CONFIG_MEMSTATUS option takes single argument of type int, 1741 ** interpreted as a boolean, which enables or disables the collection of 1742 ** memory allocation statistics. ^(When memory allocation statistics are 1743 ** disabled, the following SQLite interfaces become non-operational: 1744 ** <ul> 1745 ** <li> [sqlite3_memory_used()] 1746 ** <li> [sqlite3_memory_highwater()] 1747 ** <li> [sqlite3_soft_heap_limit64()] 1748 ** <li> [sqlite3_status64()] 1749 ** </ul>)^ 1750 ** ^Memory allocation statistics are enabled by default unless SQLite is 1751 ** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory 1752 ** allocation statistics are disabled by default. 1753 ** </dd> 1754 ** 1755 ** [[SQLITE_CONFIG_SCRATCH]] <dt>SQLITE_CONFIG_SCRATCH</dt> 1756 ** <dd> The SQLITE_CONFIG_SCRATCH option is no longer used. 1757 ** </dd> 1758 ** 1759 ** [[SQLITE_CONFIG_PAGECACHE]] <dt>SQLITE_CONFIG_PAGECACHE</dt> 1760 ** <dd> ^The SQLITE_CONFIG_PAGECACHE option specifies a memory pool 1761 ** that SQLite can use for the database page cache with the default page 1762 ** cache implementation. 1763 ** This configuration option is a no-op if an application-define page 1764 ** cache implementation is loaded using the [SQLITE_CONFIG_PCACHE2]. 1765 ** ^There are three arguments to SQLITE_CONFIG_PAGECACHE: A pointer to 1766 ** 8-byte aligned memory (pMem), the size of each page cache line (sz), 1767 ** and the number of cache lines (N). 1768 ** The sz argument should be the size of the largest database page 1769 ** (a power of two between 512 and 65536) plus some extra bytes for each 1770 ** page header. ^The number of extra bytes needed by the page header 1771 ** can be determined using [SQLITE_CONFIG_PCACHE_HDRSZ]. 1772 ** ^It is harmless, apart from the wasted memory, 1773 ** for the sz parameter to be larger than necessary. The pMem 1774 ** argument must be either a NULL pointer or a pointer to an 8-byte 1775 ** aligned block of memory of at least sz*N bytes, otherwise 1776 ** subsequent behavior is undefined. 1777 ** ^When pMem is not NULL, SQLite will strive to use the memory provided 1778 ** to satisfy page cache needs, falling back to [sqlite3_malloc()] if 1779 ** a page cache line is larger than sz bytes or if all of the pMem buffer 1780 ** is exhausted. 1781 ** ^If pMem is NULL and N is non-zero, then each database connection 1782 ** does an initial bulk allocation for page cache memory 1783 ** from [sqlite3_malloc()] sufficient for N cache lines if N is positive or 1784 ** of -1024*N bytes if N is negative, . ^If additional 1785 ** page cache memory is needed beyond what is provided by the initial 1786 ** allocation, then SQLite goes to [sqlite3_malloc()] separately for each 1787 ** additional cache line. </dd> 1788 ** 1789 ** [[SQLITE_CONFIG_HEAP]] <dt>SQLITE_CONFIG_HEAP</dt> 1790 ** <dd> ^The SQLITE_CONFIG_HEAP option specifies a static memory buffer 1791 ** that SQLite will use for all of its dynamic memory allocation needs 1792 ** beyond those provided for by [SQLITE_CONFIG_PAGECACHE]. 1793 ** ^The SQLITE_CONFIG_HEAP option is only available if SQLite is compiled 1794 ** with either [SQLITE_ENABLE_MEMSYS3] or [SQLITE_ENABLE_MEMSYS5] and returns 1795 ** [SQLITE_ERROR] if invoked otherwise. 1796 ** ^There are three arguments to SQLITE_CONFIG_HEAP: 1797 ** An 8-byte aligned pointer to the memory, 1798 ** the number of bytes in the memory buffer, and the minimum allocation size. 1799 ** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts 1800 ** to using its default memory allocator (the system malloc() implementation), 1801 ** undoing any prior invocation of [SQLITE_CONFIG_MALLOC]. ^If the 1802 ** memory pointer is not NULL then the alternative memory 1803 ** allocator is engaged to handle all of SQLites memory allocation needs. 1804 ** The first pointer (the memory pointer) must be aligned to an 8-byte 1805 ** boundary or subsequent behavior of SQLite will be undefined. 1806 ** The minimum allocation size is capped at 2**12. Reasonable values 1807 ** for the minimum allocation size are 2**5 through 2**8.</dd> 1808 ** 1809 ** [[SQLITE_CONFIG_MUTEX]] <dt>SQLITE_CONFIG_MUTEX</dt> 1810 ** <dd> ^(The SQLITE_CONFIG_MUTEX option takes a single argument which is a 1811 ** pointer to an instance of the [sqlite3_mutex_methods] structure. 1812 ** The argument specifies alternative low-level mutex routines to be used 1813 ** in place the mutex routines built into SQLite.)^ ^SQLite makes a copy of 1814 ** the content of the [sqlite3_mutex_methods] structure before the call to 1815 ** [sqlite3_config()] returns. ^If SQLite is compiled with 1816 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1817 ** the entire mutexing subsystem is omitted from the build and hence calls to 1818 ** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will 1819 ** return [SQLITE_ERROR].</dd> 1820 ** 1821 ** [[SQLITE_CONFIG_GETMUTEX]] <dt>SQLITE_CONFIG_GETMUTEX</dt> 1822 ** <dd> ^(The SQLITE_CONFIG_GETMUTEX option takes a single argument which 1823 ** is a pointer to an instance of the [sqlite3_mutex_methods] structure. The 1824 ** [sqlite3_mutex_methods] 1825 ** structure is filled with the currently defined mutex routines.)^ 1826 ** This option can be used to overload the default mutex allocation 1827 ** routines with a wrapper used to track mutex usage for performance 1828 ** profiling or testing, for example. ^If SQLite is compiled with 1829 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1830 ** the entire mutexing subsystem is omitted from the build and hence calls to 1831 ** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will 1832 ** return [SQLITE_ERROR].</dd> 1833 ** 1834 ** [[SQLITE_CONFIG_LOOKASIDE]] <dt>SQLITE_CONFIG_LOOKASIDE</dt> 1835 ** <dd> ^(The SQLITE_CONFIG_LOOKASIDE option takes two arguments that determine 1836 ** the default size of lookaside memory on each [database connection]. 1837 ** The first argument is the 1838 ** size of each lookaside buffer slot and the second is the number of 1839 ** slots allocated to each database connection.)^ ^(SQLITE_CONFIG_LOOKASIDE 1840 ** sets the <i>default</i> lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE] 1841 ** option to [sqlite3_db_config()] can be used to change the lookaside 1842 ** configuration on individual connections.)^ </dd> 1843 ** 1844 ** [[SQLITE_CONFIG_PCACHE2]] <dt>SQLITE_CONFIG_PCACHE2</dt> 1845 ** <dd> ^(The SQLITE_CONFIG_PCACHE2 option takes a single argument which is 1846 ** a pointer to an [sqlite3_pcache_methods2] object. This object specifies 1847 ** the interface to a custom page cache implementation.)^ 1848 ** ^SQLite makes a copy of the [sqlite3_pcache_methods2] object.</dd> 1849 ** 1850 ** [[SQLITE_CONFIG_GETPCACHE2]] <dt>SQLITE_CONFIG_GETPCACHE2</dt> 1851 ** <dd> ^(The SQLITE_CONFIG_GETPCACHE2 option takes a single argument which 1852 ** is a pointer to an [sqlite3_pcache_methods2] object. SQLite copies of 1853 ** the current page cache implementation into that object.)^ </dd> 1854 ** 1855 ** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt> 1856 ** <dd> The SQLITE_CONFIG_LOG option is used to configure the SQLite 1857 ** global [error log]. 1858 ** (^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a 1859 ** function with a call signature of void(*)(void*,int,const char*), 1860 ** and a pointer to void. ^If the function pointer is not NULL, it is 1861 ** invoked by [sqlite3_log()] to process each logging event. ^If the 1862 ** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op. 1863 ** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is 1864 ** passed through as the first parameter to the application-defined logger 1865 ** function whenever that function is invoked. ^The second parameter to 1866 ** the logger function is a copy of the first parameter to the corresponding 1867 ** [sqlite3_log()] call and is intended to be a [result code] or an 1868 ** [extended result code]. ^The third parameter passed to the logger is 1869 ** log message after formatting via [sqlite3_snprintf()]. 1870 ** The SQLite logging interface is not reentrant; the logger function 1871 ** supplied by the application must not invoke any SQLite interface. 1872 ** In a multi-threaded application, the application-defined logger 1873 ** function must be threadsafe. </dd> 1874 ** 1875 ** [[SQLITE_CONFIG_URI]] <dt>SQLITE_CONFIG_URI 1876 ** <dd>^(The SQLITE_CONFIG_URI option takes a single argument of type int. 1877 ** If non-zero, then URI handling is globally enabled. If the parameter is zero, 1878 ** then URI handling is globally disabled.)^ ^If URI handling is globally 1879 ** enabled, all filenames passed to [sqlite3_open()], [sqlite3_open_v2()], 1880 ** [sqlite3_open16()] or 1881 ** specified as part of [ATTACH] commands are interpreted as URIs, regardless 1882 ** of whether or not the [SQLITE_OPEN_URI] flag is set when the database 1883 ** connection is opened. ^If it is globally disabled, filenames are 1884 ** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the 1885 ** database connection is opened. ^(By default, URI handling is globally 1886 ** disabled. The default value may be changed by compiling with the 1887 ** [SQLITE_USE_URI] symbol defined.)^ 1888 ** 1889 ** [[SQLITE_CONFIG_COVERING_INDEX_SCAN]] <dt>SQLITE_CONFIG_COVERING_INDEX_SCAN 1890 ** <dd>^The SQLITE_CONFIG_COVERING_INDEX_SCAN option takes a single integer 1891 ** argument which is interpreted as a boolean in order to enable or disable 1892 ** the use of covering indices for full table scans in the query optimizer. 1893 ** ^The default setting is determined 1894 ** by the [SQLITE_ALLOW_COVERING_INDEX_SCAN] compile-time option, or is "on" 1895 ** if that compile-time option is omitted. 1896 ** The ability to disable the use of covering indices for full table scans 1897 ** is because some incorrectly coded legacy applications might malfunction 1898 ** when the optimization is enabled. Providing the ability to 1899 ** disable the optimization allows the older, buggy application code to work 1900 ** without change even with newer versions of SQLite. 1901 ** 1902 ** [[SQLITE_CONFIG_PCACHE]] [[SQLITE_CONFIG_GETPCACHE]] 1903 ** <dt>SQLITE_CONFIG_PCACHE and SQLITE_CONFIG_GETPCACHE 1904 ** <dd> These options are obsolete and should not be used by new code. 1905 ** They are retained for backwards compatibility but are now no-ops. 1906 ** </dd> 1907 ** 1908 ** [[SQLITE_CONFIG_SQLLOG]] 1909 ** <dt>SQLITE_CONFIG_SQLLOG 1910 ** <dd>This option is only available if sqlite is compiled with the 1911 ** [SQLITE_ENABLE_SQLLOG] pre-processor macro defined. The first argument should 1912 ** be a pointer to a function of type void(*)(void*,sqlite3*,const char*, int). 1913 ** The second should be of type (void*). The callback is invoked by the library 1914 ** in three separate circumstances, identified by the value passed as the 1915 ** fourth parameter. If the fourth parameter is 0, then the database connection 1916 ** passed as the second argument has just been opened. The third argument 1917 ** points to a buffer containing the name of the main database file. If the 1918 ** fourth parameter is 1, then the SQL statement that the third parameter 1919 ** points to has just been executed. Or, if the fourth parameter is 2, then 1920 ** the connection being passed as the second parameter is being closed. The 1921 ** third parameter is passed NULL In this case. An example of using this 1922 ** configuration option can be seen in the "test_sqllog.c" source file in 1923 ** the canonical SQLite source tree.</dd> 1924 ** 1925 ** [[SQLITE_CONFIG_MMAP_SIZE]] 1926 ** <dt>SQLITE_CONFIG_MMAP_SIZE 1927 ** <dd>^SQLITE_CONFIG_MMAP_SIZE takes two 64-bit integer (sqlite3_int64) values 1928 ** that are the default mmap size limit (the default setting for 1929 ** [PRAGMA mmap_size]) and the maximum allowed mmap size limit. 1930 ** ^The default setting can be overridden by each database connection using 1931 ** either the [PRAGMA mmap_size] command, or by using the 1932 ** [SQLITE_FCNTL_MMAP_SIZE] file control. ^(The maximum allowed mmap size 1933 ** will be silently truncated if necessary so that it does not exceed the 1934 ** compile-time maximum mmap size set by the 1935 ** [SQLITE_MAX_MMAP_SIZE] compile-time option.)^ 1936 ** ^If either argument to this option is negative, then that argument is 1937 ** changed to its compile-time default. 1938 ** 1939 ** [[SQLITE_CONFIG_WIN32_HEAPSIZE]] 1940 ** <dt>SQLITE_CONFIG_WIN32_HEAPSIZE 1941 ** <dd>^The SQLITE_CONFIG_WIN32_HEAPSIZE option is only available if SQLite is 1942 ** compiled for Windows with the [SQLITE_WIN32_MALLOC] pre-processor macro 1943 ** defined. ^SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit unsigned integer value 1944 ** that specifies the maximum size of the created heap. 1945 ** 1946 ** [[SQLITE_CONFIG_PCACHE_HDRSZ]] 1947 ** <dt>SQLITE_CONFIG_PCACHE_HDRSZ 1948 ** <dd>^The SQLITE_CONFIG_PCACHE_HDRSZ option takes a single parameter which 1949 ** is a pointer to an integer and writes into that integer the number of extra 1950 ** bytes per page required for each page in [SQLITE_CONFIG_PAGECACHE]. 1951 ** The amount of extra space required can change depending on the compiler, 1952 ** target platform, and SQLite version. 1953 ** 1954 ** [[SQLITE_CONFIG_PMASZ]] 1955 ** <dt>SQLITE_CONFIG_PMASZ 1956 ** <dd>^The SQLITE_CONFIG_PMASZ option takes a single parameter which 1957 ** is an unsigned integer and sets the "Minimum PMA Size" for the multithreaded 1958 ** sorter to that integer. The default minimum PMA Size is set by the 1959 ** [SQLITE_SORTER_PMASZ] compile-time option. New threads are launched 1960 ** to help with sort operations when multithreaded sorting 1961 ** is enabled (using the [PRAGMA threads] command) and the amount of content 1962 ** to be sorted exceeds the page size times the minimum of the 1963 ** [PRAGMA cache_size] setting and this value. 1964 ** 1965 ** [[SQLITE_CONFIG_STMTJRNL_SPILL]] 1966 ** <dt>SQLITE_CONFIG_STMTJRNL_SPILL 1967 ** <dd>^The SQLITE_CONFIG_STMTJRNL_SPILL option takes a single parameter which 1968 ** becomes the [statement journal] spill-to-disk threshold. 1969 ** [Statement journals] are held in memory until their size (in bytes) 1970 ** exceeds this threshold, at which point they are written to disk. 1971 ** Or if the threshold is -1, statement journals are always held 1972 ** exclusively in memory. 1973 ** Since many statement journals never become large, setting the spill 1974 ** threshold to a value such as 64KiB can greatly reduce the amount of 1975 ** I/O required to support statement rollback. 1976 ** The default value for this setting is controlled by the 1977 ** [SQLITE_STMTJRNL_SPILL] compile-time option. 1978 ** 1979 ** [[SQLITE_CONFIG_SORTERREF_SIZE]] 1980 ** <dt>SQLITE_CONFIG_SORTERREF_SIZE 1981 ** <dd>The SQLITE_CONFIG_SORTERREF_SIZE option accepts a single parameter 1982 ** of type (int) - the new value of the sorter-reference size threshold. 1983 ** Usually, when SQLite uses an external sort to order records according 1984 ** to an ORDER BY clause, all fields required by the caller are present in the 1985 ** sorted records. However, if SQLite determines based on the declared type 1986 ** of a table column that its values are likely to be very large - larger 1987 ** than the configured sorter-reference size threshold - then a reference 1988 ** is stored in each sorted record and the required column values loaded 1989 ** from the database as records are returned in sorted order. The default 1990 ** value for this option is to never use this optimization. Specifying a 1991 ** negative value for this option restores the default behaviour. 1992 ** This option is only available if SQLite is compiled with the 1993 ** [SQLITE_ENABLE_SORTER_REFERENCES] compile-time option. 1994 ** 1995 ** [[SQLITE_CONFIG_MEMDB_MAXSIZE]] 1996 ** <dt>SQLITE_CONFIG_MEMDB_MAXSIZE 1997 ** <dd>The SQLITE_CONFIG_MEMDB_MAXSIZE option accepts a single parameter 1998 ** [sqlite3_int64] parameter which is the default maximum size for an in-memory 1999 ** database created using [sqlite3_deserialize()]. This default maximum 2000 ** size can be adjusted up or down for individual databases using the 2001 ** [SQLITE_FCNTL_SIZE_LIMIT] [sqlite3_file_control|file-control]. If this 2002 ** configuration setting is never used, then the default maximum is determined 2003 ** by the [SQLITE_MEMDB_DEFAULT_MAXSIZE] compile-time option. If that 2004 ** compile-time option is not set, then the default maximum is 1073741824. 2005 ** </dl> 2006 */ 2007 #define SQLITE_CONFIG_SINGLETHREAD 1 /* nil */ 2008 #define SQLITE_CONFIG_MULTITHREAD 2 /* nil */ 2009 #define SQLITE_CONFIG_SERIALIZED 3 /* nil */ 2010 #define SQLITE_CONFIG_MALLOC 4 /* sqlite3_mem_methods* */ 2011 #define SQLITE_CONFIG_GETMALLOC 5 /* sqlite3_mem_methods* */ 2012 #define SQLITE_CONFIG_SCRATCH 6 /* No longer used */ 2013 #define SQLITE_CONFIG_PAGECACHE 7 /* void*, int sz, int N */ 2014 #define SQLITE_CONFIG_HEAP 8 /* void*, int nByte, int min */ 2015 #define SQLITE_CONFIG_MEMSTATUS 9 /* boolean */ 2016 #define SQLITE_CONFIG_MUTEX 10 /* sqlite3_mutex_methods* */ 2017 #define SQLITE_CONFIG_GETMUTEX 11 /* sqlite3_mutex_methods* */ 2018 /* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */ 2019 #define SQLITE_CONFIG_LOOKASIDE 13 /* int int */ 2020 #define SQLITE_CONFIG_PCACHE 14 /* no-op */ 2021 #define SQLITE_CONFIG_GETPCACHE 15 /* no-op */ 2022 #define SQLITE_CONFIG_LOG 16 /* xFunc, void* */ 2023 #define SQLITE_CONFIG_URI 17 /* int */ 2024 #define SQLITE_CONFIG_PCACHE2 18 /* sqlite3_pcache_methods2* */ 2025 #define SQLITE_CONFIG_GETPCACHE2 19 /* sqlite3_pcache_methods2* */ 2026 #define SQLITE_CONFIG_COVERING_INDEX_SCAN 20 /* int */ 2027 #define SQLITE_CONFIG_SQLLOG 21 /* xSqllog, void* */ 2028 #define SQLITE_CONFIG_MMAP_SIZE 22 /* sqlite3_int64, sqlite3_int64 */ 2029 #define SQLITE_CONFIG_WIN32_HEAPSIZE 23 /* int nByte */ 2030 #define SQLITE_CONFIG_PCACHE_HDRSZ 24 /* int *psz */ 2031 #define SQLITE_CONFIG_PMASZ 25 /* unsigned int szPma */ 2032 #define SQLITE_CONFIG_STMTJRNL_SPILL 26 /* int nByte */ 2033 #define SQLITE_CONFIG_SMALL_MALLOC 27 /* boolean */ 2034 #define SQLITE_CONFIG_SORTERREF_SIZE 28 /* int nByte */ 2035 #define SQLITE_CONFIG_MEMDB_MAXSIZE 29 /* sqlite3_int64 */ 2036 2037 /* 2038 ** CAPI3REF: Database Connection Configuration Options 2039 ** 2040 ** These constants are the available integer configuration options that 2041 ** can be passed as the second argument to the [sqlite3_db_config()] interface. 2042 ** 2043 ** New configuration options may be added in future releases of SQLite. 2044 ** Existing configuration options might be discontinued. Applications 2045 ** should check the return code from [sqlite3_db_config()] to make sure that 2046 ** the call worked. ^The [sqlite3_db_config()] interface will return a 2047 ** non-zero [error code] if a discontinued or unsupported configuration option 2048 ** is invoked. 2049 ** 2050 ** <dl> 2051 ** [[SQLITE_DBCONFIG_LOOKASIDE]] 2052 ** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt> 2053 ** <dd> ^This option takes three additional arguments that determine the 2054 ** [lookaside memory allocator] configuration for the [database connection]. 2055 ** ^The first argument (the third parameter to [sqlite3_db_config()] is a 2056 ** pointer to a memory buffer to use for lookaside memory. 2057 ** ^The first argument after the SQLITE_DBCONFIG_LOOKASIDE verb 2058 ** may be NULL in which case SQLite will allocate the 2059 ** lookaside buffer itself using [sqlite3_malloc()]. ^The second argument is the 2060 ** size of each lookaside buffer slot. ^The third argument is the number of 2061 ** slots. The size of the buffer in the first argument must be greater than 2062 ** or equal to the product of the second and third arguments. The buffer 2063 ** must be aligned to an 8-byte boundary. ^If the second argument to 2064 ** SQLITE_DBCONFIG_LOOKASIDE is not a multiple of 8, it is internally 2065 ** rounded down to the next smaller multiple of 8. ^(The lookaside memory 2066 ** configuration for a database connection can only be changed when that 2067 ** connection is not currently using lookaside memory, or in other words 2068 ** when the "current value" returned by 2069 ** [sqlite3_db_status](D,[SQLITE_CONFIG_LOOKASIDE],...) is zero. 2070 ** Any attempt to change the lookaside memory configuration when lookaside 2071 ** memory is in use leaves the configuration unchanged and returns 2072 ** [SQLITE_BUSY].)^</dd> 2073 ** 2074 ** [[SQLITE_DBCONFIG_ENABLE_FKEY]] 2075 ** <dt>SQLITE_DBCONFIG_ENABLE_FKEY</dt> 2076 ** <dd> ^This option is used to enable or disable the enforcement of 2077 ** [foreign key constraints]. There should be two additional arguments. 2078 ** The first argument is an integer which is 0 to disable FK enforcement, 2079 ** positive to enable FK enforcement or negative to leave FK enforcement 2080 ** unchanged. The second parameter is a pointer to an integer into which 2081 ** is written 0 or 1 to indicate whether FK enforcement is off or on 2082 ** following this call. The second parameter may be a NULL pointer, in 2083 ** which case the FK enforcement setting is not reported back. </dd> 2084 ** 2085 ** [[SQLITE_DBCONFIG_ENABLE_TRIGGER]] 2086 ** <dt>SQLITE_DBCONFIG_ENABLE_TRIGGER</dt> 2087 ** <dd> ^This option is used to enable or disable [CREATE TRIGGER | triggers]. 2088 ** There should be two additional arguments. 2089 ** The first argument is an integer which is 0 to disable triggers, 2090 ** positive to enable triggers or negative to leave the setting unchanged. 2091 ** The second parameter is a pointer to an integer into which 2092 ** is written 0 or 1 to indicate whether triggers are disabled or enabled 2093 ** following this call. The second parameter may be a NULL pointer, in 2094 ** which case the trigger setting is not reported back. </dd> 2095 ** 2096 ** [[SQLITE_DBCONFIG_ENABLE_VIEW]] 2097 ** <dt>SQLITE_DBCONFIG_ENABLE_VIEW</dt> 2098 ** <dd> ^This option is used to enable or disable [CREATE VIEW | views]. 2099 ** There should be two additional arguments. 2100 ** The first argument is an integer which is 0 to disable views, 2101 ** positive to enable views or negative to leave the setting unchanged. 2102 ** The second parameter is a pointer to an integer into which 2103 ** is written 0 or 1 to indicate whether views are disabled or enabled 2104 ** following this call. The second parameter may be a NULL pointer, in 2105 ** which case the view setting is not reported back. </dd> 2106 ** 2107 ** [[SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER]] 2108 ** <dt>SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER</dt> 2109 ** <dd> ^This option is used to enable or disable the 2110 ** [fts3_tokenizer()] function which is part of the 2111 ** [FTS3] full-text search engine extension. 2112 ** There should be two additional arguments. 2113 ** The first argument is an integer which is 0 to disable fts3_tokenizer() or 2114 ** positive to enable fts3_tokenizer() or negative to leave the setting 2115 ** unchanged. 2116 ** The second parameter is a pointer to an integer into which 2117 ** is written 0 or 1 to indicate whether fts3_tokenizer is disabled or enabled 2118 ** following this call. The second parameter may be a NULL pointer, in 2119 ** which case the new setting is not reported back. </dd> 2120 ** 2121 ** [[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION]] 2122 ** <dt>SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION</dt> 2123 ** <dd> ^This option is used to enable or disable the [sqlite3_load_extension()] 2124 ** interface independently of the [load_extension()] SQL function. 2125 ** The [sqlite3_enable_load_extension()] API enables or disables both the 2126 ** C-API [sqlite3_load_extension()] and the SQL function [load_extension()]. 2127 ** There should be two additional arguments. 2128 ** When the first argument to this interface is 1, then only the C-API is 2129 ** enabled and the SQL function remains disabled. If the first argument to 2130 ** this interface is 0, then both the C-API and the SQL function are disabled. 2131 ** If the first argument is -1, then no changes are made to state of either the 2132 ** C-API or the SQL function. 2133 ** The second parameter is a pointer to an integer into which 2134 ** is written 0 or 1 to indicate whether [sqlite3_load_extension()] interface 2135 ** is disabled or enabled following this call. The second parameter may 2136 ** be a NULL pointer, in which case the new setting is not reported back. 2137 ** </dd> 2138 ** 2139 ** [[SQLITE_DBCONFIG_MAINDBNAME]] <dt>SQLITE_DBCONFIG_MAINDBNAME</dt> 2140 ** <dd> ^This option is used to change the name of the "main" database 2141 ** schema. ^The sole argument is a pointer to a constant UTF8 string 2142 ** which will become the new schema name in place of "main". ^SQLite 2143 ** does not make a copy of the new main schema name string, so the application 2144 ** must ensure that the argument passed into this DBCONFIG option is unchanged 2145 ** until after the database connection closes. 2146 ** </dd> 2147 ** 2148 ** [[SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE]] 2149 ** <dt>SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE</dt> 2150 ** <dd> Usually, when a database in wal mode is closed or detached from a 2151 ** database handle, SQLite checks if this will mean that there are now no 2152 ** connections at all to the database. If so, it performs a checkpoint 2153 ** operation before closing the connection. This option may be used to 2154 ** override this behaviour. The first parameter passed to this operation 2155 ** is an integer - positive to disable checkpoints-on-close, or zero (the 2156 ** default) to enable them, and negative to leave the setting unchanged. 2157 ** The second parameter is a pointer to an integer 2158 ** into which is written 0 or 1 to indicate whether checkpoints-on-close 2159 ** have been disabled - 0 if they are not disabled, 1 if they are. 2160 ** </dd> 2161 ** 2162 ** [[SQLITE_DBCONFIG_ENABLE_QPSG]] <dt>SQLITE_DBCONFIG_ENABLE_QPSG</dt> 2163 ** <dd>^(The SQLITE_DBCONFIG_ENABLE_QPSG option activates or deactivates 2164 ** the [query planner stability guarantee] (QPSG). When the QPSG is active, 2165 ** a single SQL query statement will always use the same algorithm regardless 2166 ** of values of [bound parameters].)^ The QPSG disables some query optimizations 2167 ** that look at the values of bound parameters, which can make some queries 2168 ** slower. But the QPSG has the advantage of more predictable behavior. With 2169 ** the QPSG active, SQLite will always use the same query plan in the field as 2170 ** was used during testing in the lab. 2171 ** The first argument to this setting is an integer which is 0 to disable 2172 ** the QPSG, positive to enable QPSG, or negative to leave the setting 2173 ** unchanged. The second parameter is a pointer to an integer into which 2174 ** is written 0 or 1 to indicate whether the QPSG is disabled or enabled 2175 ** following this call. 2176 ** </dd> 2177 ** 2178 ** [[SQLITE_DBCONFIG_TRIGGER_EQP]] <dt>SQLITE_DBCONFIG_TRIGGER_EQP</dt> 2179 ** <dd> By default, the output of EXPLAIN QUERY PLAN commands does not 2180 ** include output for any operations performed by trigger programs. This 2181 ** option is used to set or clear (the default) a flag that governs this 2182 ** behavior. The first parameter passed to this operation is an integer - 2183 ** positive to enable output for trigger programs, or zero to disable it, 2184 ** or negative to leave the setting unchanged. 2185 ** The second parameter is a pointer to an integer into which is written 2186 ** 0 or 1 to indicate whether output-for-triggers has been disabled - 0 if 2187 ** it is not disabled, 1 if it is. 2188 ** </dd> 2189 ** 2190 ** [[SQLITE_DBCONFIG_RESET_DATABASE]] <dt>SQLITE_DBCONFIG_RESET_DATABASE</dt> 2191 ** <dd> Set the SQLITE_DBCONFIG_RESET_DATABASE flag and then run 2192 ** [VACUUM] in order to reset a database back to an empty database 2193 ** with no schema and no content. The following process works even for 2194 ** a badly corrupted database file: 2195 ** <ol> 2196 ** <li> If the database connection is newly opened, make sure it has read the 2197 ** database schema by preparing then discarding some query against the 2198 ** database, or calling sqlite3_table_column_metadata(), ignoring any 2199 ** errors. This step is only necessary if the application desires to keep 2200 ** the database in WAL mode after the reset if it was in WAL mode before 2201 ** the reset. 2202 ** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 1, 0); 2203 ** <li> [sqlite3_exec](db, "[VACUUM]", 0, 0, 0); 2204 ** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 0, 0); 2205 ** </ol> 2206 ** Because resetting a database is destructive and irreversible, the 2207 ** process requires the use of this obscure API and multiple steps to help 2208 ** ensure that it does not happen by accident. 2209 ** 2210 ** [[SQLITE_DBCONFIG_DEFENSIVE]] <dt>SQLITE_DBCONFIG_DEFENSIVE</dt> 2211 ** <dd>The SQLITE_DBCONFIG_DEFENSIVE option activates or deactivates the 2212 ** "defensive" flag for a database connection. When the defensive 2213 ** flag is enabled, language features that allow ordinary SQL to 2214 ** deliberately corrupt the database file are disabled. The disabled 2215 ** features include but are not limited to the following: 2216 ** <ul> 2217 ** <li> The [PRAGMA writable_schema=ON] statement. 2218 ** <li> The [PRAGMA journal_mode=OFF] statement. 2219 ** <li> Writes to the [sqlite_dbpage] virtual table. 2220 ** <li> Direct writes to [shadow tables]. 2221 ** </ul> 2222 ** </dd> 2223 ** 2224 ** [[SQLITE_DBCONFIG_WRITABLE_SCHEMA]] <dt>SQLITE_DBCONFIG_WRITABLE_SCHEMA</dt> 2225 ** <dd>The SQLITE_DBCONFIG_WRITABLE_SCHEMA option activates or deactivates the 2226 ** "writable_schema" flag. This has the same effect and is logically equivalent 2227 ** to setting [PRAGMA writable_schema=ON] or [PRAGMA writable_schema=OFF]. 2228 ** The first argument to this setting is an integer which is 0 to disable 2229 ** the writable_schema, positive to enable writable_schema, or negative to 2230 ** leave the setting unchanged. The second parameter is a pointer to an 2231 ** integer into which is written 0 or 1 to indicate whether the writable_schema 2232 ** is enabled or disabled following this call. 2233 ** </dd> 2234 ** 2235 ** [[SQLITE_DBCONFIG_LEGACY_ALTER_TABLE]] 2236 ** <dt>SQLITE_DBCONFIG_LEGACY_ALTER_TABLE</dt> 2237 ** <dd>The SQLITE_DBCONFIG_LEGACY_ALTER_TABLE option activates or deactivates 2238 ** the legacy behavior of the [ALTER TABLE RENAME] command such it 2239 ** behaves as it did prior to [version 3.24.0] (2018-06-04). See the 2240 ** "Compatibility Notice" on the [ALTER TABLE RENAME documentation] for 2241 ** additional information. This feature can also be turned on and off 2242 ** using the [PRAGMA legacy_alter_table] statement. 2243 ** </dd> 2244 ** 2245 ** [[SQLITE_DBCONFIG_DQS_DML]] 2246 ** <dt>SQLITE_DBCONFIG_DQS_DML</td> 2247 ** <dd>The SQLITE_DBCONFIG_DQS_DML option activates or deactivates 2248 ** the legacy [double-quoted string literal] misfeature for DML statement 2249 ** only, that is DELETE, INSERT, SELECT, and UPDATE statements. The 2250 ** default value of this setting is determined by the [-DSQLITE_DQS] 2251 ** compile-time option. 2252 ** </dd> 2253 ** 2254 ** [[SQLITE_DBCONFIG_DQS_DDL]] 2255 ** <dt>SQLITE_DBCONFIG_DQS_DDL</td> 2256 ** <dd>The SQLITE_DBCONFIG_DQS option activates or deactivates 2257 ** the legacy [double-quoted string literal] misfeature for DDL statements, 2258 ** such as CREATE TABLE and CREATE INDEX. The 2259 ** default value of this setting is determined by the [-DSQLITE_DQS] 2260 ** compile-time option. 2261 ** </dd> 2262 ** </dl> 2263 */ 2264 #define SQLITE_DBCONFIG_MAINDBNAME 1000 /* const char* */ 2265 #define SQLITE_DBCONFIG_LOOKASIDE 1001 /* void* int int */ 2266 #define SQLITE_DBCONFIG_ENABLE_FKEY 1002 /* int int* */ 2267 #define SQLITE_DBCONFIG_ENABLE_TRIGGER 1003 /* int int* */ 2268 #define SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER 1004 /* int int* */ 2269 #define SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION 1005 /* int int* */ 2270 #define SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE 1006 /* int int* */ 2271 #define SQLITE_DBCONFIG_ENABLE_QPSG 1007 /* int int* */ 2272 #define SQLITE_DBCONFIG_TRIGGER_EQP 1008 /* int int* */ 2273 #define SQLITE_DBCONFIG_RESET_DATABASE 1009 /* int int* */ 2274 #define SQLITE_DBCONFIG_DEFENSIVE 1010 /* int int* */ 2275 #define SQLITE_DBCONFIG_WRITABLE_SCHEMA 1011 /* int int* */ 2276 #define SQLITE_DBCONFIG_LEGACY_ALTER_TABLE 1012 /* int int* */ 2277 #define SQLITE_DBCONFIG_DQS_DML 1013 /* int int* */ 2278 #define SQLITE_DBCONFIG_DQS_DDL 1014 /* int int* */ 2279 #define SQLITE_DBCONFIG_ENABLE_VIEW 1015 /* int int* */ 2280 #define SQLITE_DBCONFIG_MAX 1015 /* Largest DBCONFIG */ 2281 2282 /* 2283 ** CAPI3REF: Enable Or Disable Extended Result Codes 2284 ** METHOD: sqlite3 2285 ** 2286 ** ^The sqlite3_extended_result_codes() routine enables or disables the 2287 ** [extended result codes] feature of SQLite. ^The extended result 2288 ** codes are disabled by default for historical compatibility. 2289 */ 2290 SQLITE_API int sqlite3_extended_result_codes(sqlite3*, int onoff); 2291 2292 /* 2293 ** CAPI3REF: Last Insert Rowid 2294 ** METHOD: sqlite3 2295 ** 2296 ** ^Each entry in most SQLite tables (except for [WITHOUT ROWID] tables) 2297 ** has a unique 64-bit signed 2298 ** integer key called the [ROWID | "rowid"]. ^The rowid is always available 2299 ** as an undeclared column named ROWID, OID, or _ROWID_ as long as those 2300 ** names are not also used by explicitly declared columns. ^If 2301 ** the table has a column of type [INTEGER PRIMARY KEY] then that column 2302 ** is another alias for the rowid. 2303 ** 2304 ** ^The sqlite3_last_insert_rowid(D) interface usually returns the [rowid] of 2305 ** the most recent successful [INSERT] into a rowid table or [virtual table] 2306 ** on database connection D. ^Inserts into [WITHOUT ROWID] tables are not 2307 ** recorded. ^If no successful [INSERT]s into rowid tables have ever occurred 2308 ** on the database connection D, then sqlite3_last_insert_rowid(D) returns 2309 ** zero. 2310 ** 2311 ** As well as being set automatically as rows are inserted into database 2312 ** tables, the value returned by this function may be set explicitly by 2313 ** [sqlite3_set_last_insert_rowid()] 2314 ** 2315 ** Some virtual table implementations may INSERT rows into rowid tables as 2316 ** part of committing a transaction (e.g. to flush data accumulated in memory 2317 ** to disk). In this case subsequent calls to this function return the rowid 2318 ** associated with these internal INSERT operations, which leads to 2319 ** unintuitive results. Virtual table implementations that do write to rowid 2320 ** tables in this way can avoid this problem by restoring the original 2321 ** rowid value using [sqlite3_set_last_insert_rowid()] before returning 2322 ** control to the user. 2323 ** 2324 ** ^(If an [INSERT] occurs within a trigger then this routine will 2325 ** return the [rowid] of the inserted row as long as the trigger is 2326 ** running. Once the trigger program ends, the value returned 2327 ** by this routine reverts to what it was before the trigger was fired.)^ 2328 ** 2329 ** ^An [INSERT] that fails due to a constraint violation is not a 2330 ** successful [INSERT] and does not change the value returned by this 2331 ** routine. ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK, 2332 ** and INSERT OR ABORT make no changes to the return value of this 2333 ** routine when their insertion fails. ^(When INSERT OR REPLACE 2334 ** encounters a constraint violation, it does not fail. The 2335 ** INSERT continues to completion after deleting rows that caused 2336 ** the constraint problem so INSERT OR REPLACE will always change 2337 ** the return value of this interface.)^ 2338 ** 2339 ** ^For the purposes of this routine, an [INSERT] is considered to 2340 ** be successful even if it is subsequently rolled back. 2341 ** 2342 ** This function is accessible to SQL statements via the 2343 ** [last_insert_rowid() SQL function]. 2344 ** 2345 ** If a separate thread performs a new [INSERT] on the same 2346 ** database connection while the [sqlite3_last_insert_rowid()] 2347 ** function is running and thus changes the last insert [rowid], 2348 ** then the value returned by [sqlite3_last_insert_rowid()] is 2349 ** unpredictable and might not equal either the old or the new 2350 ** last insert [rowid]. 2351 */ 2352 SQLITE_API sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*); 2353 2354 /* 2355 ** CAPI3REF: Set the Last Insert Rowid value. 2356 ** METHOD: sqlite3 2357 ** 2358 ** The sqlite3_set_last_insert_rowid(D, R) method allows the application to 2359 ** set the value returned by calling sqlite3_last_insert_rowid(D) to R 2360 ** without inserting a row into the database. 2361 */ 2362 SQLITE_API void sqlite3_set_last_insert_rowid(sqlite3*,sqlite3_int64); 2363 2364 /* 2365 ** CAPI3REF: Count The Number Of Rows Modified 2366 ** METHOD: sqlite3 2367 ** 2368 ** ^This function returns the number of rows modified, inserted or 2369 ** deleted by the most recently completed INSERT, UPDATE or DELETE 2370 ** statement on the database connection specified by the only parameter. 2371 ** ^Executing any other type of SQL statement does not modify the value 2372 ** returned by this function. 2373 ** 2374 ** ^Only changes made directly by the INSERT, UPDATE or DELETE statement are 2375 ** considered - auxiliary changes caused by [CREATE TRIGGER | triggers], 2376 ** [foreign key actions] or [REPLACE] constraint resolution are not counted. 2377 ** 2378 ** Changes to a view that are intercepted by 2379 ** [INSTEAD OF trigger | INSTEAD OF triggers] are not counted. ^The value 2380 ** returned by sqlite3_changes() immediately after an INSERT, UPDATE or 2381 ** DELETE statement run on a view is always zero. Only changes made to real 2382 ** tables are counted. 2383 ** 2384 ** Things are more complicated if the sqlite3_changes() function is 2385 ** executed while a trigger program is running. This may happen if the 2386 ** program uses the [changes() SQL function], or if some other callback 2387 ** function invokes sqlite3_changes() directly. Essentially: 2388 ** 2389 ** <ul> 2390 ** <li> ^(Before entering a trigger program the value returned by 2391 ** sqlite3_changes() function is saved. After the trigger program 2392 ** has finished, the original value is restored.)^ 2393 ** 2394 ** <li> ^(Within a trigger program each INSERT, UPDATE and DELETE 2395 ** statement sets the value returned by sqlite3_changes() 2396 ** upon completion as normal. Of course, this value will not include 2397 ** any changes performed by sub-triggers, as the sqlite3_changes() 2398 ** value will be saved and restored after each sub-trigger has run.)^ 2399 ** </ul> 2400 ** 2401 ** ^This means that if the changes() SQL function (or similar) is used 2402 ** by the first INSERT, UPDATE or DELETE statement within a trigger, it 2403 ** returns the value as set when the calling statement began executing. 2404 ** ^If it is used by the second or subsequent such statement within a trigger 2405 ** program, the value returned reflects the number of rows modified by the 2406 ** previous INSERT, UPDATE or DELETE statement within the same trigger. 2407 ** 2408 ** If a separate thread makes changes on the same database connection 2409 ** while [sqlite3_changes()] is running then the value returned 2410 ** is unpredictable and not meaningful. 2411 ** 2412 ** See also: 2413 ** <ul> 2414 ** <li> the [sqlite3_total_changes()] interface 2415 ** <li> the [count_changes pragma] 2416 ** <li> the [changes() SQL function] 2417 ** <li> the [data_version pragma] 2418 ** </ul> 2419 */ 2420 SQLITE_API int sqlite3_changes(sqlite3*); 2421 2422 /* 2423 ** CAPI3REF: Total Number Of Rows Modified 2424 ** METHOD: sqlite3 2425 ** 2426 ** ^This function returns the total number of rows inserted, modified or 2427 ** deleted by all [INSERT], [UPDATE] or [DELETE] statements completed 2428 ** since the database connection was opened, including those executed as 2429 ** part of trigger programs. ^Executing any other type of SQL statement 2430 ** does not affect the value returned by sqlite3_total_changes(). 2431 ** 2432 ** ^Changes made as part of [foreign key actions] are included in the 2433 ** count, but those made as part of REPLACE constraint resolution are 2434 ** not. ^Changes to a view that are intercepted by INSTEAD OF triggers 2435 ** are not counted. 2436 ** 2437 ** The [sqlite3_total_changes(D)] interface only reports the number 2438 ** of rows that changed due to SQL statement run against database 2439 ** connection D. Any changes by other database connections are ignored. 2440 ** To detect changes against a database file from other database 2441 ** connections use the [PRAGMA data_version] command or the 2442 ** [SQLITE_FCNTL_DATA_VERSION] [file control]. 2443 ** 2444 ** If a separate thread makes changes on the same database connection 2445 ** while [sqlite3_total_changes()] is running then the value 2446 ** returned is unpredictable and not meaningful. 2447 ** 2448 ** See also: 2449 ** <ul> 2450 ** <li> the [sqlite3_changes()] interface 2451 ** <li> the [count_changes pragma] 2452 ** <li> the [changes() SQL function] 2453 ** <li> the [data_version pragma] 2454 ** <li> the [SQLITE_FCNTL_DATA_VERSION] [file control] 2455 ** </ul> 2456 */ 2457 SQLITE_API int sqlite3_total_changes(sqlite3*); 2458 2459 /* 2460 ** CAPI3REF: Interrupt A Long-Running Query 2461 ** METHOD: sqlite3 2462 ** 2463 ** ^This function causes any pending database operation to abort and 2464 ** return at its earliest opportunity. This routine is typically 2465 ** called in response to a user action such as pressing "Cancel" 2466 ** or Ctrl-C where the user wants a long query operation to halt 2467 ** immediately. 2468 ** 2469 ** ^It is safe to call this routine from a thread different from the 2470 ** thread that is currently running the database operation. But it 2471 ** is not safe to call this routine with a [database connection] that 2472 ** is closed or might close before sqlite3_interrupt() returns. 2473 ** 2474 ** ^If an SQL operation is very nearly finished at the time when 2475 ** sqlite3_interrupt() is called, then it might not have an opportunity 2476 ** to be interrupted and might continue to completion. 2477 ** 2478 ** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT]. 2479 ** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE 2480 ** that is inside an explicit transaction, then the entire transaction 2481 ** will be rolled back automatically. 2482 ** 2483 ** ^The sqlite3_interrupt(D) call is in effect until all currently running 2484 ** SQL statements on [database connection] D complete. ^Any new SQL statements 2485 ** that are started after the sqlite3_interrupt() call and before the 2486 ** running statements reaches zero are interrupted as if they had been 2487 ** running prior to the sqlite3_interrupt() call. ^New SQL statements 2488 ** that are started after the running statement count reaches zero are 2489 ** not effected by the sqlite3_interrupt(). 2490 ** ^A call to sqlite3_interrupt(D) that occurs when there are no running 2491 ** SQL statements is a no-op and has no effect on SQL statements 2492 ** that are started after the sqlite3_interrupt() call returns. 2493 */ 2494 SQLITE_API void sqlite3_interrupt(sqlite3*); 2495 2496 /* 2497 ** CAPI3REF: Determine If An SQL Statement Is Complete 2498 ** 2499 ** These routines are useful during command-line input to determine if the 2500 ** currently entered text seems to form a complete SQL statement or 2501 ** if additional input is needed before sending the text into 2502 ** SQLite for parsing. ^These routines return 1 if the input string 2503 ** appears to be a complete SQL statement. ^A statement is judged to be 2504 ** complete if it ends with a semicolon token and is not a prefix of a 2505 ** well-formed CREATE TRIGGER statement. ^Semicolons that are embedded within 2506 ** string literals or quoted identifier names or comments are not 2507 ** independent tokens (they are part of the token in which they are 2508 ** embedded) and thus do not count as a statement terminator. ^Whitespace 2509 ** and comments that follow the final semicolon are ignored. 2510 ** 2511 ** ^These routines return 0 if the statement is incomplete. ^If a 2512 ** memory allocation fails, then SQLITE_NOMEM is returned. 2513 ** 2514 ** ^These routines do not parse the SQL statements thus 2515 ** will not detect syntactically incorrect SQL. 2516 ** 2517 ** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior 2518 ** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked 2519 ** automatically by sqlite3_complete16(). If that initialization fails, 2520 ** then the return value from sqlite3_complete16() will be non-zero 2521 ** regardless of whether or not the input SQL is complete.)^ 2522 ** 2523 ** The input to [sqlite3_complete()] must be a zero-terminated 2524 ** UTF-8 string. 2525 ** 2526 ** The input to [sqlite3_complete16()] must be a zero-terminated 2527 ** UTF-16 string in native byte order. 2528 */ 2529 SQLITE_API int sqlite3_complete(const char *sql); 2530 SQLITE_API int sqlite3_complete16(const void *sql); 2531 2532 /* 2533 ** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors 2534 ** KEYWORDS: {busy-handler callback} {busy handler} 2535 ** METHOD: sqlite3 2536 ** 2537 ** ^The sqlite3_busy_handler(D,X,P) routine sets a callback function X 2538 ** that might be invoked with argument P whenever 2539 ** an attempt is made to access a database table associated with 2540 ** [database connection] D when another thread 2541 ** or process has the table locked. 2542 ** The sqlite3_busy_handler() interface is used to implement 2543 ** [sqlite3_busy_timeout()] and [PRAGMA busy_timeout]. 2544 ** 2545 ** ^If the busy callback is NULL, then [SQLITE_BUSY] 2546 ** is returned immediately upon encountering the lock. ^If the busy callback 2547 ** is not NULL, then the callback might be invoked with two arguments. 2548 ** 2549 ** ^The first argument to the busy handler is a copy of the void* pointer which 2550 ** is the third argument to sqlite3_busy_handler(). ^The second argument to 2551 ** the busy handler callback is the number of times that the busy handler has 2552 ** been invoked previously for the same locking event. ^If the 2553 ** busy callback returns 0, then no additional attempts are made to 2554 ** access the database and [SQLITE_BUSY] is returned 2555 ** to the application. 2556 ** ^If the callback returns non-zero, then another attempt 2557 ** is made to access the database and the cycle repeats. 2558 ** 2559 ** The presence of a busy handler does not guarantee that it will be invoked 2560 ** when there is lock contention. ^If SQLite determines that invoking the busy 2561 ** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY] 2562 ** to the application instead of invoking the 2563 ** busy handler. 2564 ** Consider a scenario where one process is holding a read lock that 2565 ** it is trying to promote to a reserved lock and 2566 ** a second process is holding a reserved lock that it is trying 2567 ** to promote to an exclusive lock. The first process cannot proceed 2568 ** because it is blocked by the second and the second process cannot 2569 ** proceed because it is blocked by the first. If both processes 2570 ** invoke the busy handlers, neither will make any progress. Therefore, 2571 ** SQLite returns [SQLITE_BUSY] for the first process, hoping that this 2572 ** will induce the first process to release its read lock and allow 2573 ** the second process to proceed. 2574 ** 2575 ** ^The default busy callback is NULL. 2576 ** 2577 ** ^(There can only be a single busy handler defined for each 2578 ** [database connection]. Setting a new busy handler clears any 2579 ** previously set handler.)^ ^Note that calling [sqlite3_busy_timeout()] 2580 ** or evaluating [PRAGMA busy_timeout=N] will change the 2581 ** busy handler and thus clear any previously set busy handler. 2582 ** 2583 ** The busy callback should not take any actions which modify the 2584 ** database connection that invoked the busy handler. In other words, 2585 ** the busy handler is not reentrant. Any such actions 2586 ** result in undefined behavior. 2587 ** 2588 ** A busy handler must not close the database connection 2589 ** or [prepared statement] that invoked the busy handler. 2590 */ 2591 SQLITE_API int sqlite3_busy_handler(sqlite3*,int(*)(void*,int),void*); 2592 2593 /* 2594 ** CAPI3REF: Set A Busy Timeout 2595 ** METHOD: sqlite3 2596 ** 2597 ** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps 2598 ** for a specified amount of time when a table is locked. ^The handler 2599 ** will sleep multiple times until at least "ms" milliseconds of sleeping 2600 ** have accumulated. ^After at least "ms" milliseconds of sleeping, 2601 ** the handler returns 0 which causes [sqlite3_step()] to return 2602 ** [SQLITE_BUSY]. 2603 ** 2604 ** ^Calling this routine with an argument less than or equal to zero 2605 ** turns off all busy handlers. 2606 ** 2607 ** ^(There can only be a single busy handler for a particular 2608 ** [database connection] at any given moment. If another busy handler 2609 ** was defined (using [sqlite3_busy_handler()]) prior to calling 2610 ** this routine, that other busy handler is cleared.)^ 2611 ** 2612 ** See also: [PRAGMA busy_timeout] 2613 */ 2614 SQLITE_API int sqlite3_busy_timeout(sqlite3*, int ms); 2615 2616 /* 2617 ** CAPI3REF: Convenience Routines For Running Queries 2618 ** METHOD: sqlite3 2619 ** 2620 ** This is a legacy interface that is preserved for backwards compatibility. 2621 ** Use of this interface is not recommended. 2622 ** 2623 ** Definition: A <b>result table</b> is memory data structure created by the 2624 ** [sqlite3_get_table()] interface. A result table records the 2625 ** complete query results from one or more queries. 2626 ** 2627 ** The table conceptually has a number of rows and columns. But 2628 ** these numbers are not part of the result table itself. These 2629 ** numbers are obtained separately. Let N be the number of rows 2630 ** and M be the number of columns. 2631 ** 2632 ** A result table is an array of pointers to zero-terminated UTF-8 strings. 2633 ** There are (N+1)*M elements in the array. The first M pointers point 2634 ** to zero-terminated strings that contain the names of the columns. 2635 ** The remaining entries all point to query results. NULL values result 2636 ** in NULL pointers. All other values are in their UTF-8 zero-terminated 2637 ** string representation as returned by [sqlite3_column_text()]. 2638 ** 2639 ** A result table might consist of one or more memory allocations. 2640 ** It is not safe to pass a result table directly to [sqlite3_free()]. 2641 ** A result table should be deallocated using [sqlite3_free_table()]. 2642 ** 2643 ** ^(As an example of the result table format, suppose a query result 2644 ** is as follows: 2645 ** 2646 ** <blockquote><pre> 2647 ** Name | Age 2648 ** ----------------------- 2649 ** Alice | 43 2650 ** Bob | 28 2651 ** Cindy | 21 2652 ** </pre></blockquote> 2653 ** 2654 ** There are two column (M==2) and three rows (N==3). Thus the 2655 ** result table has 8 entries. Suppose the result table is stored 2656 ** in an array names azResult. Then azResult holds this content: 2657 ** 2658 ** <blockquote><pre> 2659 ** azResult[0] = "Name"; 2660 ** azResult[1] = "Age"; 2661 ** azResult[2] = "Alice"; 2662 ** azResult[3] = "43"; 2663 ** azResult[4] = "Bob"; 2664 ** azResult[5] = "28"; 2665 ** azResult[6] = "Cindy"; 2666 ** azResult[7] = "21"; 2667 ** </pre></blockquote>)^ 2668 ** 2669 ** ^The sqlite3_get_table() function evaluates one or more 2670 ** semicolon-separated SQL statements in the zero-terminated UTF-8 2671 ** string of its 2nd parameter and returns a result table to the 2672 ** pointer given in its 3rd parameter. 2673 ** 2674 ** After the application has finished with the result from sqlite3_get_table(), 2675 ** it must pass the result table pointer to sqlite3_free_table() in order to 2676 ** release the memory that was malloced. Because of the way the 2677 ** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling 2678 ** function must not try to call [sqlite3_free()] directly. Only 2679 ** [sqlite3_free_table()] is able to release the memory properly and safely. 2680 ** 2681 ** The sqlite3_get_table() interface is implemented as a wrapper around 2682 ** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access 2683 ** to any internal data structures of SQLite. It uses only the public 2684 ** interface defined here. As a consequence, errors that occur in the 2685 ** wrapper layer outside of the internal [sqlite3_exec()] call are not 2686 ** reflected in subsequent calls to [sqlite3_errcode()] or 2687 ** [sqlite3_errmsg()]. 2688 */ 2689 SQLITE_API int sqlite3_get_table( 2690 sqlite3 *db, /* An open database */ 2691 const char *zSql, /* SQL to be evaluated */ 2692 char ***pazResult, /* Results of the query */ 2693 int *pnRow, /* Number of result rows written here */ 2694 int *pnColumn, /* Number of result columns written here */ 2695 char **pzErrmsg /* Error msg written here */ 2696 ); 2697 SQLITE_API void sqlite3_free_table(char **result); 2698 2699 /* 2700 ** CAPI3REF: Formatted String Printing Functions 2701 ** 2702 ** These routines are work-alikes of the "printf()" family of functions 2703 ** from the standard C library. 2704 ** These routines understand most of the common formatting options from 2705 ** the standard library printf() 2706 ** plus some additional non-standard formats ([%q], [%Q], [%w], and [%z]). 2707 ** See the [built-in printf()] documentation for details. 2708 ** 2709 ** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their 2710 ** results into memory obtained from [sqlite3_malloc64()]. 2711 ** The strings returned by these two routines should be 2712 ** released by [sqlite3_free()]. ^Both routines return a 2713 ** NULL pointer if [sqlite3_malloc64()] is unable to allocate enough 2714 ** memory to hold the resulting string. 2715 ** 2716 ** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from 2717 ** the standard C library. The result is written into the 2718 ** buffer supplied as the second parameter whose size is given by 2719 ** the first parameter. Note that the order of the 2720 ** first two parameters is reversed from snprintf().)^ This is an 2721 ** historical accident that cannot be fixed without breaking 2722 ** backwards compatibility. ^(Note also that sqlite3_snprintf() 2723 ** returns a pointer to its buffer instead of the number of 2724 ** characters actually written into the buffer.)^ We admit that 2725 ** the number of characters written would be a more useful return 2726 ** value but we cannot change the implementation of sqlite3_snprintf() 2727 ** now without breaking compatibility. 2728 ** 2729 ** ^As long as the buffer size is greater than zero, sqlite3_snprintf() 2730 ** guarantees that the buffer is always zero-terminated. ^The first 2731 ** parameter "n" is the total size of the buffer, including space for 2732 ** the zero terminator. So the longest string that can be completely 2733 ** written will be n-1 characters. 2734 ** 2735 ** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf(). 2736 ** 2737 ** See also: [built-in printf()], [printf() SQL function] 2738 */ 2739 SQLITE_API char *sqlite3_mprintf(const char*,...); 2740 SQLITE_API char *sqlite3_vmprintf(const char*, va_list); 2741 SQLITE_API char *sqlite3_snprintf(int,char*,const char*, ...); 2742 SQLITE_API char *sqlite3_vsnprintf(int,char*,const char*, va_list); 2743 2744 /* 2745 ** CAPI3REF: Memory Allocation Subsystem 2746 ** 2747 ** The SQLite core uses these three routines for all of its own 2748 ** internal memory allocation needs. "Core" in the previous sentence 2749 ** does not include operating-system specific VFS implementation. The 2750 ** Windows VFS uses native malloc() and free() for some operations. 2751 ** 2752 ** ^The sqlite3_malloc() routine returns a pointer to a block 2753 ** of memory at least N bytes in length, where N is the parameter. 2754 ** ^If sqlite3_malloc() is unable to obtain sufficient free 2755 ** memory, it returns a NULL pointer. ^If the parameter N to 2756 ** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns 2757 ** a NULL pointer. 2758 ** 2759 ** ^The sqlite3_malloc64(N) routine works just like 2760 ** sqlite3_malloc(N) except that N is an unsigned 64-bit integer instead 2761 ** of a signed 32-bit integer. 2762 ** 2763 ** ^Calling sqlite3_free() with a pointer previously returned 2764 ** by sqlite3_malloc() or sqlite3_realloc() releases that memory so 2765 ** that it might be reused. ^The sqlite3_free() routine is 2766 ** a no-op if is called with a NULL pointer. Passing a NULL pointer 2767 ** to sqlite3_free() is harmless. After being freed, memory 2768 ** should neither be read nor written. Even reading previously freed 2769 ** memory might result in a segmentation fault or other severe error. 2770 ** Memory corruption, a segmentation fault, or other severe error 2771 ** might result if sqlite3_free() is called with a non-NULL pointer that 2772 ** was not obtained from sqlite3_malloc() or sqlite3_realloc(). 2773 ** 2774 ** ^The sqlite3_realloc(X,N) interface attempts to resize a 2775 ** prior memory allocation X to be at least N bytes. 2776 ** ^If the X parameter to sqlite3_realloc(X,N) 2777 ** is a NULL pointer then its behavior is identical to calling 2778 ** sqlite3_malloc(N). 2779 ** ^If the N parameter to sqlite3_realloc(X,N) is zero or 2780 ** negative then the behavior is exactly the same as calling 2781 ** sqlite3_free(X). 2782 ** ^sqlite3_realloc(X,N) returns a pointer to a memory allocation 2783 ** of at least N bytes in size or NULL if insufficient memory is available. 2784 ** ^If M is the size of the prior allocation, then min(N,M) bytes 2785 ** of the prior allocation are copied into the beginning of buffer returned 2786 ** by sqlite3_realloc(X,N) and the prior allocation is freed. 2787 ** ^If sqlite3_realloc(X,N) returns NULL and N is positive, then the 2788 ** prior allocation is not freed. 2789 ** 2790 ** ^The sqlite3_realloc64(X,N) interfaces works the same as 2791 ** sqlite3_realloc(X,N) except that N is a 64-bit unsigned integer instead 2792 ** of a 32-bit signed integer. 2793 ** 2794 ** ^If X is a memory allocation previously obtained from sqlite3_malloc(), 2795 ** sqlite3_malloc64(), sqlite3_realloc(), or sqlite3_realloc64(), then 2796 ** sqlite3_msize(X) returns the size of that memory allocation in bytes. 2797 ** ^The value returned by sqlite3_msize(X) might be larger than the number 2798 ** of bytes requested when X was allocated. ^If X is a NULL pointer then 2799 ** sqlite3_msize(X) returns zero. If X points to something that is not 2800 ** the beginning of memory allocation, or if it points to a formerly 2801 ** valid memory allocation that has now been freed, then the behavior 2802 ** of sqlite3_msize(X) is undefined and possibly harmful. 2803 ** 2804 ** ^The memory returned by sqlite3_malloc(), sqlite3_realloc(), 2805 ** sqlite3_malloc64(), and sqlite3_realloc64() 2806 ** is always aligned to at least an 8 byte boundary, or to a 2807 ** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time 2808 ** option is used. 2809 ** 2810 ** In SQLite version 3.5.0 and 3.5.1, it was possible to define 2811 ** the SQLITE_OMIT_MEMORY_ALLOCATION which would cause the built-in 2812 ** implementation of these routines to be omitted. That capability 2813 ** is no longer provided. Only built-in memory allocators can be used. 2814 ** 2815 ** Prior to SQLite version 3.7.10, the Windows OS interface layer called 2816 ** the system malloc() and free() directly when converting 2817 ** filenames between the UTF-8 encoding used by SQLite 2818 ** and whatever filename encoding is used by the particular Windows 2819 ** installation. Memory allocation errors were detected, but 2820 ** they were reported back as [SQLITE_CANTOPEN] or 2821 ** [SQLITE_IOERR] rather than [SQLITE_NOMEM]. 2822 ** 2823 ** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()] 2824 ** must be either NULL or else pointers obtained from a prior 2825 ** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have 2826 ** not yet been released. 2827 ** 2828 ** The application must not read or write any part of 2829 ** a block of memory after it has been released using 2830 ** [sqlite3_free()] or [sqlite3_realloc()]. 2831 */ 2832 SQLITE_API void *sqlite3_malloc(int); 2833 SQLITE_API void *sqlite3_malloc64(sqlite3_uint64); 2834 SQLITE_API void *sqlite3_realloc(void*, int); 2835 SQLITE_API void *sqlite3_realloc64(void*, sqlite3_uint64); 2836 SQLITE_API void sqlite3_free(void*); 2837 SQLITE_API sqlite3_uint64 sqlite3_msize(void*); 2838 2839 /* 2840 ** CAPI3REF: Memory Allocator Statistics 2841 ** 2842 ** SQLite provides these two interfaces for reporting on the status 2843 ** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()] 2844 ** routines, which form the built-in memory allocation subsystem. 2845 ** 2846 ** ^The [sqlite3_memory_used()] routine returns the number of bytes 2847 ** of memory currently outstanding (malloced but not freed). 2848 ** ^The [sqlite3_memory_highwater()] routine returns the maximum 2849 ** value of [sqlite3_memory_used()] since the high-water mark 2850 ** was last reset. ^The values returned by [sqlite3_memory_used()] and 2851 ** [sqlite3_memory_highwater()] include any overhead 2852 ** added by SQLite in its implementation of [sqlite3_malloc()], 2853 ** but not overhead added by the any underlying system library 2854 ** routines that [sqlite3_malloc()] may call. 2855 ** 2856 ** ^The memory high-water mark is reset to the current value of 2857 ** [sqlite3_memory_used()] if and only if the parameter to 2858 ** [sqlite3_memory_highwater()] is true. ^The value returned 2859 ** by [sqlite3_memory_highwater(1)] is the high-water mark 2860 ** prior to the reset. 2861 */ 2862 SQLITE_API sqlite3_int64 sqlite3_memory_used(void); 2863 SQLITE_API sqlite3_int64 sqlite3_memory_highwater(int resetFlag); 2864 2865 /* 2866 ** CAPI3REF: Pseudo-Random Number Generator 2867 ** 2868 ** SQLite contains a high-quality pseudo-random number generator (PRNG) used to 2869 ** select random [ROWID | ROWIDs] when inserting new records into a table that 2870 ** already uses the largest possible [ROWID]. The PRNG is also used for 2871 ** the build-in random() and randomblob() SQL functions. This interface allows 2872 ** applications to access the same PRNG for other purposes. 2873 ** 2874 ** ^A call to this routine stores N bytes of randomness into buffer P. 2875 ** ^The P parameter can be a NULL pointer. 2876 ** 2877 ** ^If this routine has not been previously called or if the previous 2878 ** call had N less than one or a NULL pointer for P, then the PRNG is 2879 ** seeded using randomness obtained from the xRandomness method of 2880 ** the default [sqlite3_vfs] object. 2881 ** ^If the previous call to this routine had an N of 1 or more and a 2882 ** non-NULL P then the pseudo-randomness is generated 2883 ** internally and without recourse to the [sqlite3_vfs] xRandomness 2884 ** method. 2885 */ 2886 SQLITE_API void sqlite3_randomness(int N, void *P); 2887 2888 /* 2889 ** CAPI3REF: Compile-Time Authorization Callbacks 2890 ** METHOD: sqlite3 2891 ** KEYWORDS: {authorizer callback} 2892 ** 2893 ** ^This routine registers an authorizer callback with a particular 2894 ** [database connection], supplied in the first argument. 2895 ** ^The authorizer callback is invoked as SQL statements are being compiled 2896 ** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()], 2897 ** [sqlite3_prepare_v3()], [sqlite3_prepare16()], [sqlite3_prepare16_v2()], 2898 ** and [sqlite3_prepare16_v3()]. ^At various 2899 ** points during the compilation process, as logic is being created 2900 ** to perform various actions, the authorizer callback is invoked to 2901 ** see if those actions are allowed. ^The authorizer callback should 2902 ** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the 2903 ** specific action but allow the SQL statement to continue to be 2904 ** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be 2905 ** rejected with an error. ^If the authorizer callback returns 2906 ** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY] 2907 ** then the [sqlite3_prepare_v2()] or equivalent call that triggered 2908 ** the authorizer will fail with an error message. 2909 ** 2910 ** When the callback returns [SQLITE_OK], that means the operation 2911 ** requested is ok. ^When the callback returns [SQLITE_DENY], the 2912 ** [sqlite3_prepare_v2()] or equivalent call that triggered the 2913 ** authorizer will fail with an error message explaining that 2914 ** access is denied. 2915 ** 2916 ** ^The first parameter to the authorizer callback is a copy of the third 2917 ** parameter to the sqlite3_set_authorizer() interface. ^The second parameter 2918 ** to the callback is an integer [SQLITE_COPY | action code] that specifies 2919 ** the particular action to be authorized. ^The third through sixth parameters 2920 ** to the callback are either NULL pointers or zero-terminated strings 2921 ** that contain additional details about the action to be authorized. 2922 ** Applications must always be prepared to encounter a NULL pointer in any 2923 ** of the third through the sixth parameters of the authorization callback. 2924 ** 2925 ** ^If the action code is [SQLITE_READ] 2926 ** and the callback returns [SQLITE_IGNORE] then the 2927 ** [prepared statement] statement is constructed to substitute 2928 ** a NULL value in place of the table column that would have 2929 ** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE] 2930 ** return can be used to deny an untrusted user access to individual 2931 ** columns of a table. 2932 ** ^When a table is referenced by a [SELECT] but no column values are 2933 ** extracted from that table (for example in a query like 2934 ** "SELECT count(*) FROM tab") then the [SQLITE_READ] authorizer callback 2935 ** is invoked once for that table with a column name that is an empty string. 2936 ** ^If the action code is [SQLITE_DELETE] and the callback returns 2937 ** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the 2938 ** [truncate optimization] is disabled and all rows are deleted individually. 2939 ** 2940 ** An authorizer is used when [sqlite3_prepare | preparing] 2941 ** SQL statements from an untrusted source, to ensure that the SQL statements 2942 ** do not try to access data they are not allowed to see, or that they do not 2943 ** try to execute malicious statements that damage the database. For 2944 ** example, an application may allow a user to enter arbitrary 2945 ** SQL queries for evaluation by a database. But the application does 2946 ** not want the user to be able to make arbitrary changes to the 2947 ** database. An authorizer could then be put in place while the 2948 ** user-entered SQL is being [sqlite3_prepare | prepared] that 2949 ** disallows everything except [SELECT] statements. 2950 ** 2951 ** Applications that need to process SQL from untrusted sources 2952 ** might also consider lowering resource limits using [sqlite3_limit()] 2953 ** and limiting database size using the [max_page_count] [PRAGMA] 2954 ** in addition to using an authorizer. 2955 ** 2956 ** ^(Only a single authorizer can be in place on a database connection 2957 ** at a time. Each call to sqlite3_set_authorizer overrides the 2958 ** previous call.)^ ^Disable the authorizer by installing a NULL callback. 2959 ** The authorizer is disabled by default. 2960 ** 2961 ** The authorizer callback must not do anything that will modify 2962 ** the database connection that invoked the authorizer callback. 2963 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 2964 ** database connections for the meaning of "modify" in this paragraph. 2965 ** 2966 ** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the 2967 ** statement might be re-prepared during [sqlite3_step()] due to a 2968 ** schema change. Hence, the application should ensure that the 2969 ** correct authorizer callback remains in place during the [sqlite3_step()]. 2970 ** 2971 ** ^Note that the authorizer callback is invoked only during 2972 ** [sqlite3_prepare()] or its variants. Authorization is not 2973 ** performed during statement evaluation in [sqlite3_step()], unless 2974 ** as stated in the previous paragraph, sqlite3_step() invokes 2975 ** sqlite3_prepare_v2() to reprepare a statement after a schema change. 2976 */ 2977 SQLITE_API int sqlite3_set_authorizer( 2978 sqlite3*, 2979 int (*xAuth)(void*,int,const char*,const char*,const char*,const char*), 2980 void *pUserData 2981 ); 2982 2983 /* 2984 ** CAPI3REF: Authorizer Return Codes 2985 ** 2986 ** The [sqlite3_set_authorizer | authorizer callback function] must 2987 ** return either [SQLITE_OK] or one of these two constants in order 2988 ** to signal SQLite whether or not the action is permitted. See the 2989 ** [sqlite3_set_authorizer | authorizer documentation] for additional 2990 ** information. 2991 ** 2992 ** Note that SQLITE_IGNORE is also used as a [conflict resolution mode] 2993 ** returned from the [sqlite3_vtab_on_conflict()] interface. 2994 */ 2995 #define SQLITE_DENY 1 /* Abort the SQL statement with an error */ 2996 #define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */ 2997 2998 /* 2999 ** CAPI3REF: Authorizer Action Codes 3000 ** 3001 ** The [sqlite3_set_authorizer()] interface registers a callback function 3002 ** that is invoked to authorize certain SQL statement actions. The 3003 ** second parameter to the callback is an integer code that specifies 3004 ** what action is being authorized. These are the integer action codes that 3005 ** the authorizer callback may be passed. 3006 ** 3007 ** These action code values signify what kind of operation is to be 3008 ** authorized. The 3rd and 4th parameters to the authorization 3009 ** callback function will be parameters or NULL depending on which of these 3010 ** codes is used as the second parameter. ^(The 5th parameter to the 3011 ** authorizer callback is the name of the database ("main", "temp", 3012 ** etc.) if applicable.)^ ^The 6th parameter to the authorizer callback 3013 ** is the name of the inner-most trigger or view that is responsible for 3014 ** the access attempt or NULL if this access attempt is directly from 3015 ** top-level SQL code. 3016 */ 3017 /******************************************* 3rd ************ 4th ***********/ 3018 #define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */ 3019 #define SQLITE_CREATE_TABLE 2 /* Table Name NULL */ 3020 #define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */ 3021 #define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */ 3022 #define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */ 3023 #define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */ 3024 #define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */ 3025 #define SQLITE_CREATE_VIEW 8 /* View Name NULL */ 3026 #define SQLITE_DELETE 9 /* Table Name NULL */ 3027 #define SQLITE_DROP_INDEX 10 /* Index Name Table Name */ 3028 #define SQLITE_DROP_TABLE 11 /* Table Name NULL */ 3029 #define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */ 3030 #define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */ 3031 #define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */ 3032 #define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */ 3033 #define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */ 3034 #define SQLITE_DROP_VIEW 17 /* View Name NULL */ 3035 #define SQLITE_INSERT 18 /* Table Name NULL */ 3036 #define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */ 3037 #define SQLITE_READ 20 /* Table Name Column Name */ 3038 #define SQLITE_SELECT 21 /* NULL NULL */ 3039 #define SQLITE_TRANSACTION 22 /* Operation NULL */ 3040 #define SQLITE_UPDATE 23 /* Table Name Column Name */ 3041 #define SQLITE_ATTACH 24 /* Filename NULL */ 3042 #define SQLITE_DETACH 25 /* Database Name NULL */ 3043 #define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */ 3044 #define SQLITE_REINDEX 27 /* Index Name NULL */ 3045 #define SQLITE_ANALYZE 28 /* Table Name NULL */ 3046 #define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */ 3047 #define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */ 3048 #define SQLITE_FUNCTION 31 /* NULL Function Name */ 3049 #define SQLITE_SAVEPOINT 32 /* Operation Savepoint Name */ 3050 #define SQLITE_COPY 0 /* No longer used */ 3051 #define SQLITE_RECURSIVE 33 /* NULL NULL */ 3052 3053 /* 3054 ** CAPI3REF: Tracing And Profiling Functions 3055 ** METHOD: sqlite3 3056 ** 3057 ** These routines are deprecated. Use the [sqlite3_trace_v2()] interface 3058 ** instead of the routines described here. 3059 ** 3060 ** These routines register callback functions that can be used for 3061 ** tracing and profiling the execution of SQL statements. 3062 ** 3063 ** ^The callback function registered by sqlite3_trace() is invoked at 3064 ** various times when an SQL statement is being run by [sqlite3_step()]. 3065 ** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the 3066 ** SQL statement text as the statement first begins executing. 3067 ** ^(Additional sqlite3_trace() callbacks might occur 3068 ** as each triggered subprogram is entered. The callbacks for triggers 3069 ** contain a UTF-8 SQL comment that identifies the trigger.)^ 3070 ** 3071 ** The [SQLITE_TRACE_SIZE_LIMIT] compile-time option can be used to limit 3072 ** the length of [bound parameter] expansion in the output of sqlite3_trace(). 3073 ** 3074 ** ^The callback function registered by sqlite3_profile() is invoked 3075 ** as each SQL statement finishes. ^The profile callback contains 3076 ** the original statement text and an estimate of wall-clock time 3077 ** of how long that statement took to run. ^The profile callback 3078 ** time is in units of nanoseconds, however the current implementation 3079 ** is only capable of millisecond resolution so the six least significant 3080 ** digits in the time are meaningless. Future versions of SQLite 3081 ** might provide greater resolution on the profiler callback. Invoking 3082 ** either [sqlite3_trace()] or [sqlite3_trace_v2()] will cancel the 3083 ** profile callback. 3084 */ 3085 SQLITE_API SQLITE_DEPRECATED void *sqlite3_trace(sqlite3*, 3086 void(*xTrace)(void*,const char*), void*); 3087 SQLITE_API SQLITE_DEPRECATED void *sqlite3_profile(sqlite3*, 3088 void(*xProfile)(void*,const char*,sqlite3_uint64), void*); 3089 3090 /* 3091 ** CAPI3REF: SQL Trace Event Codes 3092 ** KEYWORDS: SQLITE_TRACE 3093 ** 3094 ** These constants identify classes of events that can be monitored 3095 ** using the [sqlite3_trace_v2()] tracing logic. The M argument 3096 ** to [sqlite3_trace_v2(D,M,X,P)] is an OR-ed combination of one or more of 3097 ** the following constants. ^The first argument to the trace callback 3098 ** is one of the following constants. 3099 ** 3100 ** New tracing constants may be added in future releases. 3101 ** 3102 ** ^A trace callback has four arguments: xCallback(T,C,P,X). 3103 ** ^The T argument is one of the integer type codes above. 3104 ** ^The C argument is a copy of the context pointer passed in as the 3105 ** fourth argument to [sqlite3_trace_v2()]. 3106 ** The P and X arguments are pointers whose meanings depend on T. 3107 ** 3108 ** <dl> 3109 ** [[SQLITE_TRACE_STMT]] <dt>SQLITE_TRACE_STMT</dt> 3110 ** <dd>^An SQLITE_TRACE_STMT callback is invoked when a prepared statement 3111 ** first begins running and possibly at other times during the 3112 ** execution of the prepared statement, such as at the start of each 3113 ** trigger subprogram. ^The P argument is a pointer to the 3114 ** [prepared statement]. ^The X argument is a pointer to a string which 3115 ** is the unexpanded SQL text of the prepared statement or an SQL comment 3116 ** that indicates the invocation of a trigger. ^The callback can compute 3117 ** the same text that would have been returned by the legacy [sqlite3_trace()] 3118 ** interface by using the X argument when X begins with "--" and invoking 3119 ** [sqlite3_expanded_sql(P)] otherwise. 3120 ** 3121 ** [[SQLITE_TRACE_PROFILE]] <dt>SQLITE_TRACE_PROFILE</dt> 3122 ** <dd>^An SQLITE_TRACE_PROFILE callback provides approximately the same 3123 ** information as is provided by the [sqlite3_profile()] callback. 3124 ** ^The P argument is a pointer to the [prepared statement] and the 3125 ** X argument points to a 64-bit integer which is the estimated of 3126 ** the number of nanosecond that the prepared statement took to run. 3127 ** ^The SQLITE_TRACE_PROFILE callback is invoked when the statement finishes. 3128 ** 3129 ** [[SQLITE_TRACE_ROW]] <dt>SQLITE_TRACE_ROW</dt> 3130 ** <dd>^An SQLITE_TRACE_ROW callback is invoked whenever a prepared 3131 ** statement generates a single row of result. 3132 ** ^The P argument is a pointer to the [prepared statement] and the 3133 ** X argument is unused. 3134 ** 3135 ** [[SQLITE_TRACE_CLOSE]] <dt>SQLITE_TRACE_CLOSE</dt> 3136 ** <dd>^An SQLITE_TRACE_CLOSE callback is invoked when a database 3137 ** connection closes. 3138 ** ^The P argument is a pointer to the [database connection] object 3139 ** and the X argument is unused. 3140 ** </dl> 3141 */ 3142 #define SQLITE_TRACE_STMT 0x01 3143 #define SQLITE_TRACE_PROFILE 0x02 3144 #define SQLITE_TRACE_ROW 0x04 3145 #define SQLITE_TRACE_CLOSE 0x08 3146 3147 /* 3148 ** CAPI3REF: SQL Trace Hook 3149 ** METHOD: sqlite3 3150 ** 3151 ** ^The sqlite3_trace_v2(D,M,X,P) interface registers a trace callback 3152 ** function X against [database connection] D, using property mask M 3153 ** and context pointer P. ^If the X callback is 3154 ** NULL or if the M mask is zero, then tracing is disabled. The 3155 ** M argument should be the bitwise OR-ed combination of 3156 ** zero or more [SQLITE_TRACE] constants. 3157 ** 3158 ** ^Each call to either sqlite3_trace() or sqlite3_trace_v2() overrides 3159 ** (cancels) any prior calls to sqlite3_trace() or sqlite3_trace_v2(). 3160 ** 3161 ** ^The X callback is invoked whenever any of the events identified by 3162 ** mask M occur. ^The integer return value from the callback is currently 3163 ** ignored, though this may change in future releases. Callback 3164 ** implementations should return zero to ensure future compatibility. 3165 ** 3166 ** ^A trace callback is invoked with four arguments: callback(T,C,P,X). 3167 ** ^The T argument is one of the [SQLITE_TRACE] 3168 ** constants to indicate why the callback was invoked. 3169 ** ^The C argument is a copy of the context pointer. 3170 ** The P and X arguments are pointers whose meanings depend on T. 3171 ** 3172 ** The sqlite3_trace_v2() interface is intended to replace the legacy 3173 ** interfaces [sqlite3_trace()] and [sqlite3_profile()], both of which 3174 ** are deprecated. 3175 */ 3176 SQLITE_API int sqlite3_trace_v2( 3177 sqlite3*, 3178 unsigned uMask, 3179 int(*xCallback)(unsigned,void*,void*,void*), 3180 void *pCtx 3181 ); 3182 3183 /* 3184 ** CAPI3REF: Query Progress Callbacks 3185 ** METHOD: sqlite3 3186 ** 3187 ** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback 3188 ** function X to be invoked periodically during long running calls to 3189 ** [sqlite3_exec()], [sqlite3_step()] and [sqlite3_get_table()] for 3190 ** database connection D. An example use for this 3191 ** interface is to keep a GUI updated during a large query. 3192 ** 3193 ** ^The parameter P is passed through as the only parameter to the 3194 ** callback function X. ^The parameter N is the approximate number of 3195 ** [virtual machine instructions] that are evaluated between successive 3196 ** invocations of the callback X. ^If N is less than one then the progress 3197 ** handler is disabled. 3198 ** 3199 ** ^Only a single progress handler may be defined at one time per 3200 ** [database connection]; setting a new progress handler cancels the 3201 ** old one. ^Setting parameter X to NULL disables the progress handler. 3202 ** ^The progress handler is also disabled by setting N to a value less 3203 ** than 1. 3204 ** 3205 ** ^If the progress callback returns non-zero, the operation is 3206 ** interrupted. This feature can be used to implement a 3207 ** "Cancel" button on a GUI progress dialog box. 3208 ** 3209 ** The progress handler callback must not do anything that will modify 3210 ** the database connection that invoked the progress handler. 3211 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 3212 ** database connections for the meaning of "modify" in this paragraph. 3213 ** 3214 */ 3215 SQLITE_API void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*); 3216 3217 /* 3218 ** CAPI3REF: Opening A New Database Connection 3219 ** CONSTRUCTOR: sqlite3 3220 ** 3221 ** ^These routines open an SQLite database file as specified by the 3222 ** filename argument. ^The filename argument is interpreted as UTF-8 for 3223 ** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte 3224 ** order for sqlite3_open16(). ^(A [database connection] handle is usually 3225 ** returned in *ppDb, even if an error occurs. The only exception is that 3226 ** if SQLite is unable to allocate memory to hold the [sqlite3] object, 3227 ** a NULL will be written into *ppDb instead of a pointer to the [sqlite3] 3228 ** object.)^ ^(If the database is opened (and/or created) successfully, then 3229 ** [SQLITE_OK] is returned. Otherwise an [error code] is returned.)^ ^The 3230 ** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain 3231 ** an English language description of the error following a failure of any 3232 ** of the sqlite3_open() routines. 3233 ** 3234 ** ^The default encoding will be UTF-8 for databases created using 3235 ** sqlite3_open() or sqlite3_open_v2(). ^The default encoding for databases 3236 ** created using sqlite3_open16() will be UTF-16 in the native byte order. 3237 ** 3238 ** Whether or not an error occurs when it is opened, resources 3239 ** associated with the [database connection] handle should be released by 3240 ** passing it to [sqlite3_close()] when it is no longer required. 3241 ** 3242 ** The sqlite3_open_v2() interface works like sqlite3_open() 3243 ** except that it accepts two additional parameters for additional control 3244 ** over the new database connection. ^(The flags parameter to 3245 ** sqlite3_open_v2() can take one of 3246 ** the following three values, optionally combined with the 3247 ** [SQLITE_OPEN_NOMUTEX], [SQLITE_OPEN_FULLMUTEX], [SQLITE_OPEN_SHAREDCACHE], 3248 ** [SQLITE_OPEN_PRIVATECACHE], and/or [SQLITE_OPEN_URI] flags:)^ 3249 ** 3250 ** <dl> 3251 ** ^(<dt>[SQLITE_OPEN_READONLY]</dt> 3252 ** <dd>The database is opened in read-only mode. If the database does not 3253 ** already exist, an error is returned.</dd>)^ 3254 ** 3255 ** ^(<dt>[SQLITE_OPEN_READWRITE]</dt> 3256 ** <dd>The database is opened for reading and writing if possible, or reading 3257 ** only if the file is write protected by the operating system. In either 3258 ** case the database must already exist, otherwise an error is returned.</dd>)^ 3259 ** 3260 ** ^(<dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt> 3261 ** <dd>The database is opened for reading and writing, and is created if 3262 ** it does not already exist. This is the behavior that is always used for 3263 ** sqlite3_open() and sqlite3_open16().</dd>)^ 3264 ** </dl> 3265 ** 3266 ** If the 3rd parameter to sqlite3_open_v2() is not one of the 3267 ** combinations shown above optionally combined with other 3268 ** [SQLITE_OPEN_READONLY | SQLITE_OPEN_* bits] 3269 ** then the behavior is undefined. 3270 ** 3271 ** ^If the [SQLITE_OPEN_NOMUTEX] flag is set, then the database connection 3272 ** opens in the multi-thread [threading mode] as long as the single-thread 3273 ** mode has not been set at compile-time or start-time. ^If the 3274 ** [SQLITE_OPEN_FULLMUTEX] flag is set then the database connection opens 3275 ** in the serialized [threading mode] unless single-thread was 3276 ** previously selected at compile-time or start-time. 3277 ** ^The [SQLITE_OPEN_SHAREDCACHE] flag causes the database connection to be 3278 ** eligible to use [shared cache mode], regardless of whether or not shared 3279 ** cache is enabled using [sqlite3_enable_shared_cache()]. ^The 3280 ** [SQLITE_OPEN_PRIVATECACHE] flag causes the database connection to not 3281 ** participate in [shared cache mode] even if it is enabled. 3282 ** 3283 ** ^The fourth parameter to sqlite3_open_v2() is the name of the 3284 ** [sqlite3_vfs] object that defines the operating system interface that 3285 ** the new database connection should use. ^If the fourth parameter is 3286 ** a NULL pointer then the default [sqlite3_vfs] object is used. 3287 ** 3288 ** ^If the filename is ":memory:", then a private, temporary in-memory database 3289 ** is created for the connection. ^This in-memory database will vanish when 3290 ** the database connection is closed. Future versions of SQLite might 3291 ** make use of additional special filenames that begin with the ":" character. 3292 ** It is recommended that when a database filename actually does begin with 3293 ** a ":" character you should prefix the filename with a pathname such as 3294 ** "./" to avoid ambiguity. 3295 ** 3296 ** ^If the filename is an empty string, then a private, temporary 3297 ** on-disk database will be created. ^This private database will be 3298 ** automatically deleted as soon as the database connection is closed. 3299 ** 3300 ** [[URI filenames in sqlite3_open()]] <h3>URI Filenames</h3> 3301 ** 3302 ** ^If [URI filename] interpretation is enabled, and the filename argument 3303 ** begins with "file:", then the filename is interpreted as a URI. ^URI 3304 ** filename interpretation is enabled if the [SQLITE_OPEN_URI] flag is 3305 ** set in the third argument to sqlite3_open_v2(), or if it has 3306 ** been enabled globally using the [SQLITE_CONFIG_URI] option with the 3307 ** [sqlite3_config()] method or by the [SQLITE_USE_URI] compile-time option. 3308 ** URI filename interpretation is turned off 3309 ** by default, but future releases of SQLite might enable URI filename 3310 ** interpretation by default. See "[URI filenames]" for additional 3311 ** information. 3312 ** 3313 ** URI filenames are parsed according to RFC 3986. ^If the URI contains an 3314 ** authority, then it must be either an empty string or the string 3315 ** "localhost". ^If the authority is not an empty string or "localhost", an 3316 ** error is returned to the caller. ^The fragment component of a URI, if 3317 ** present, is ignored. 3318 ** 3319 ** ^SQLite uses the path component of the URI as the name of the disk file 3320 ** which contains the database. ^If the path begins with a '/' character, 3321 ** then it is interpreted as an absolute path. ^If the path does not begin 3322 ** with a '/' (meaning that the authority section is omitted from the URI) 3323 ** then the path is interpreted as a relative path. 3324 ** ^(On windows, the first component of an absolute path 3325 ** is a drive specification (e.g. "C:").)^ 3326 ** 3327 ** [[core URI query parameters]] 3328 ** The query component of a URI may contain parameters that are interpreted 3329 ** either by SQLite itself, or by a [VFS | custom VFS implementation]. 3330 ** SQLite and its built-in [VFSes] interpret the 3331 ** following query parameters: 3332 ** 3333 ** <ul> 3334 ** <li> <b>vfs</b>: ^The "vfs" parameter may be used to specify the name of 3335 ** a VFS object that provides the operating system interface that should 3336 ** be used to access the database file on disk. ^If this option is set to 3337 ** an empty string the default VFS object is used. ^Specifying an unknown 3338 ** VFS is an error. ^If sqlite3_open_v2() is used and the vfs option is 3339 ** present, then the VFS specified by the option takes precedence over 3340 ** the value passed as the fourth parameter to sqlite3_open_v2(). 3341 ** 3342 ** <li> <b>mode</b>: ^(The mode parameter may be set to either "ro", "rw", 3343 ** "rwc", or "memory". Attempting to set it to any other value is 3344 ** an error)^. 3345 ** ^If "ro" is specified, then the database is opened for read-only 3346 ** access, just as if the [SQLITE_OPEN_READONLY] flag had been set in the 3347 ** third argument to sqlite3_open_v2(). ^If the mode option is set to 3348 ** "rw", then the database is opened for read-write (but not create) 3349 ** access, as if SQLITE_OPEN_READWRITE (but not SQLITE_OPEN_CREATE) had 3350 ** been set. ^Value "rwc" is equivalent to setting both 3351 ** SQLITE_OPEN_READWRITE and SQLITE_OPEN_CREATE. ^If the mode option is 3352 ** set to "memory" then a pure [in-memory database] that never reads 3353 ** or writes from disk is used. ^It is an error to specify a value for 3354 ** the mode parameter that is less restrictive than that specified by 3355 ** the flags passed in the third parameter to sqlite3_open_v2(). 3356 ** 3357 ** <li> <b>cache</b>: ^The cache parameter may be set to either "shared" or 3358 ** "private". ^Setting it to "shared" is equivalent to setting the 3359 ** SQLITE_OPEN_SHAREDCACHE bit in the flags argument passed to 3360 ** sqlite3_open_v2(). ^Setting the cache parameter to "private" is 3361 ** equivalent to setting the SQLITE_OPEN_PRIVATECACHE bit. 3362 ** ^If sqlite3_open_v2() is used and the "cache" parameter is present in 3363 ** a URI filename, its value overrides any behavior requested by setting 3364 ** SQLITE_OPEN_PRIVATECACHE or SQLITE_OPEN_SHAREDCACHE flag. 3365 ** 3366 ** <li> <b>psow</b>: ^The psow parameter indicates whether or not the 3367 ** [powersafe overwrite] property does or does not apply to the 3368 ** storage media on which the database file resides. 3369 ** 3370 ** <li> <b>nolock</b>: ^The nolock parameter is a boolean query parameter 3371 ** which if set disables file locking in rollback journal modes. This 3372 ** is useful for accessing a database on a filesystem that does not 3373 ** support locking. Caution: Database corruption might result if two 3374 ** or more processes write to the same database and any one of those 3375 ** processes uses nolock=1. 3376 ** 3377 ** <li> <b>immutable</b>: ^The immutable parameter is a boolean query 3378 ** parameter that indicates that the database file is stored on 3379 ** read-only media. ^When immutable is set, SQLite assumes that the 3380 ** database file cannot be changed, even by a process with higher 3381 ** privilege, and so the database is opened read-only and all locking 3382 ** and change detection is disabled. Caution: Setting the immutable 3383 ** property on a database file that does in fact change can result 3384 ** in incorrect query results and/or [SQLITE_CORRUPT] errors. 3385 ** See also: [SQLITE_IOCAP_IMMUTABLE]. 3386 ** 3387 ** </ul> 3388 ** 3389 ** ^Specifying an unknown parameter in the query component of a URI is not an 3390 ** error. Future versions of SQLite might understand additional query 3391 ** parameters. See "[query parameters with special meaning to SQLite]" for 3392 ** additional information. 3393 ** 3394 ** [[URI filename examples]] <h3>URI filename examples</h3> 3395 ** 3396 ** <table border="1" align=center cellpadding=5> 3397 ** <tr><th> URI filenames <th> Results 3398 ** <tr><td> file:data.db <td> 3399 ** Open the file "data.db" in the current directory. 3400 ** <tr><td> file:/home/fred/data.db<br> 3401 ** file:///home/fred/data.db <br> 3402 ** file://localhost/home/fred/data.db <br> <td> 3403 ** Open the database file "/home/fred/data.db". 3404 ** <tr><td> file://darkstar/home/fred/data.db <td> 3405 ** An error. "darkstar" is not a recognized authority. 3406 ** <tr><td style="white-space:nowrap"> 3407 ** file:///C:/Documents%20and%20Settings/fred/Desktop/data.db 3408 ** <td> Windows only: Open the file "data.db" on fred's desktop on drive 3409 ** C:. Note that the %20 escaping in this example is not strictly 3410 ** necessary - space characters can be used literally 3411 ** in URI filenames. 3412 ** <tr><td> file:data.db?mode=ro&cache=private <td> 3413 ** Open file "data.db" in the current directory for read-only access. 3414 ** Regardless of whether or not shared-cache mode is enabled by 3415 ** default, use a private cache. 3416 ** <tr><td> file:/home/fred/data.db?vfs=unix-dotfile <td> 3417 ** Open file "/home/fred/data.db". Use the special VFS "unix-dotfile" 3418 ** that uses dot-files in place of posix advisory locking. 3419 ** <tr><td> file:data.db?mode=readonly <td> 3420 ** An error. "readonly" is not a valid option for the "mode" parameter. 3421 ** </table> 3422 ** 3423 ** ^URI hexadecimal escape sequences (%HH) are supported within the path and 3424 ** query components of a URI. A hexadecimal escape sequence consists of a 3425 ** percent sign - "%" - followed by exactly two hexadecimal digits 3426 ** specifying an octet value. ^Before the path or query components of a 3427 ** URI filename are interpreted, they are encoded using UTF-8 and all 3428 ** hexadecimal escape sequences replaced by a single byte containing the 3429 ** corresponding octet. If this process generates an invalid UTF-8 encoding, 3430 ** the results are undefined. 3431 ** 3432 ** <b>Note to Windows users:</b> The encoding used for the filename argument 3433 ** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever 3434 ** codepage is currently defined. Filenames containing international 3435 ** characters must be converted to UTF-8 prior to passing them into 3436 ** sqlite3_open() or sqlite3_open_v2(). 3437 ** 3438 ** <b>Note to Windows Runtime users:</b> The temporary directory must be set 3439 ** prior to calling sqlite3_open() or sqlite3_open_v2(). Otherwise, various 3440 ** features that require the use of temporary files may fail. 3441 ** 3442 ** See also: [sqlite3_temp_directory] 3443 */ 3444 SQLITE_API int sqlite3_open( 3445 const char *filename, /* Database filename (UTF-8) */ 3446 sqlite3 **ppDb /* OUT: SQLite db handle */ 3447 ); 3448 SQLITE_API int sqlite3_open16( 3449 const void *filename, /* Database filename (UTF-16) */ 3450 sqlite3 **ppDb /* OUT: SQLite db handle */ 3451 ); 3452 SQLITE_API int sqlite3_open_v2( 3453 const char *filename, /* Database filename (UTF-8) */ 3454 sqlite3 **ppDb, /* OUT: SQLite db handle */ 3455 int flags, /* Flags */ 3456 const char *zVfs /* Name of VFS module to use */ 3457 ); 3458 3459 /* 3460 ** CAPI3REF: Obtain Values For URI Parameters 3461 ** 3462 ** These are utility routines, useful to VFS implementations, that check 3463 ** to see if a database file was a URI that contained a specific query 3464 ** parameter, and if so obtains the value of that query parameter. 3465 ** 3466 ** If F is the database filename pointer passed into the xOpen() method of 3467 ** a VFS implementation when the flags parameter to xOpen() has one or 3468 ** more of the [SQLITE_OPEN_URI] or [SQLITE_OPEN_MAIN_DB] bits set and 3469 ** P is the name of the query parameter, then 3470 ** sqlite3_uri_parameter(F,P) returns the value of the P 3471 ** parameter if it exists or a NULL pointer if P does not appear as a 3472 ** query parameter on F. If P is a query parameter of F 3473 ** has no explicit value, then sqlite3_uri_parameter(F,P) returns 3474 ** a pointer to an empty string. 3475 ** 3476 ** The sqlite3_uri_boolean(F,P,B) routine assumes that P is a boolean 3477 ** parameter and returns true (1) or false (0) according to the value 3478 ** of P. The sqlite3_uri_boolean(F,P,B) routine returns true (1) if the 3479 ** value of query parameter P is one of "yes", "true", or "on" in any 3480 ** case or if the value begins with a non-zero number. The 3481 ** sqlite3_uri_boolean(F,P,B) routines returns false (0) if the value of 3482 ** query parameter P is one of "no", "false", or "off" in any case or 3483 ** if the value begins with a numeric zero. If P is not a query 3484 ** parameter on F or if the value of P is does not match any of the 3485 ** above, then sqlite3_uri_boolean(F,P,B) returns (B!=0). 3486 ** 3487 ** The sqlite3_uri_int64(F,P,D) routine converts the value of P into a 3488 ** 64-bit signed integer and returns that integer, or D if P does not 3489 ** exist. If the value of P is something other than an integer, then 3490 ** zero is returned. 3491 ** 3492 ** If F is a NULL pointer, then sqlite3_uri_parameter(F,P) returns NULL and 3493 ** sqlite3_uri_boolean(F,P,B) returns B. If F is not a NULL pointer and 3494 ** is not a database file pathname pointer that SQLite passed into the xOpen 3495 ** VFS method, then the behavior of this routine is undefined and probably 3496 ** undesirable. 3497 ** 3498 ** See the [URI filename] documentation for additional information. 3499 */ 3500 SQLITE_API const char *sqlite3_uri_parameter(const char *zFilename, const char *zParam); 3501 SQLITE_API int sqlite3_uri_boolean(const char *zFile, const char *zParam, int bDefault); 3502 SQLITE_API sqlite3_int64 sqlite3_uri_int64(const char*, const char*, sqlite3_int64); 3503 3504 3505 /* 3506 ** CAPI3REF: Error Codes And Messages 3507 ** METHOD: sqlite3 3508 ** 3509 ** ^If the most recent sqlite3_* API call associated with 3510 ** [database connection] D failed, then the sqlite3_errcode(D) interface 3511 ** returns the numeric [result code] or [extended result code] for that 3512 ** API call. 3513 ** ^The sqlite3_extended_errcode() 3514 ** interface is the same except that it always returns the 3515 ** [extended result code] even when extended result codes are 3516 ** disabled. 3517 ** 3518 ** The values returned by sqlite3_errcode() and/or 3519 ** sqlite3_extended_errcode() might change with each API call. 3520 ** Except, there are some interfaces that are guaranteed to never 3521 ** change the value of the error code. The error-code preserving 3522 ** interfaces are: 3523 ** 3524 ** <ul> 3525 ** <li> sqlite3_errcode() 3526 ** <li> sqlite3_extended_errcode() 3527 ** <li> sqlite3_errmsg() 3528 ** <li> sqlite3_errmsg16() 3529 ** </ul> 3530 ** 3531 ** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language 3532 ** text that describes the error, as either UTF-8 or UTF-16 respectively. 3533 ** ^(Memory to hold the error message string is managed internally. 3534 ** The application does not need to worry about freeing the result. 3535 ** However, the error string might be overwritten or deallocated by 3536 ** subsequent calls to other SQLite interface functions.)^ 3537 ** 3538 ** ^The sqlite3_errstr() interface returns the English-language text 3539 ** that describes the [result code], as UTF-8. 3540 ** ^(Memory to hold the error message string is managed internally 3541 ** and must not be freed by the application)^. 3542 ** 3543 ** When the serialized [threading mode] is in use, it might be the 3544 ** case that a second error occurs on a separate thread in between 3545 ** the time of the first error and the call to these interfaces. 3546 ** When that happens, the second error will be reported since these 3547 ** interfaces always report the most recent result. To avoid 3548 ** this, each thread can obtain exclusive use of the [database connection] D 3549 ** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning 3550 ** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after 3551 ** all calls to the interfaces listed here are completed. 3552 ** 3553 ** If an interface fails with SQLITE_MISUSE, that means the interface 3554 ** was invoked incorrectly by the application. In that case, the 3555 ** error code and message may or may not be set. 3556 */ 3557 SQLITE_API int sqlite3_errcode(sqlite3 *db); 3558 SQLITE_API int sqlite3_extended_errcode(sqlite3 *db); 3559 SQLITE_API const char *sqlite3_errmsg(sqlite3*); 3560 SQLITE_API const void *sqlite3_errmsg16(sqlite3*); 3561 SQLITE_API const char *sqlite3_errstr(int); 3562 3563 /* 3564 ** CAPI3REF: Prepared Statement Object 3565 ** KEYWORDS: {prepared statement} {prepared statements} 3566 ** 3567 ** An instance of this object represents a single SQL statement that 3568 ** has been compiled into binary form and is ready to be evaluated. 3569 ** 3570 ** Think of each SQL statement as a separate computer program. The 3571 ** original SQL text is source code. A prepared statement object 3572 ** is the compiled object code. All SQL must be converted into a 3573 ** prepared statement before it can be run. 3574 ** 3575 ** The life-cycle of a prepared statement object usually goes like this: 3576 ** 3577 ** <ol> 3578 ** <li> Create the prepared statement object using [sqlite3_prepare_v2()]. 3579 ** <li> Bind values to [parameters] using the sqlite3_bind_*() 3580 ** interfaces. 3581 ** <li> Run the SQL by calling [sqlite3_step()] one or more times. 3582 ** <li> Reset the prepared statement using [sqlite3_reset()] then go back 3583 ** to step 2. Do this zero or more times. 3584 ** <li> Destroy the object using [sqlite3_finalize()]. 3585 ** </ol> 3586 */ 3587 typedef struct sqlite3_stmt sqlite3_stmt; 3588 3589 /* 3590 ** CAPI3REF: Run-time Limits 3591 ** METHOD: sqlite3 3592 ** 3593 ** ^(This interface allows the size of various constructs to be limited 3594 ** on a connection by connection basis. The first parameter is the 3595 ** [database connection] whose limit is to be set or queried. The 3596 ** second parameter is one of the [limit categories] that define a 3597 ** class of constructs to be size limited. The third parameter is the 3598 ** new limit for that construct.)^ 3599 ** 3600 ** ^If the new limit is a negative number, the limit is unchanged. 3601 ** ^(For each limit category SQLITE_LIMIT_<i>NAME</i> there is a 3602 ** [limits | hard upper bound] 3603 ** set at compile-time by a C preprocessor macro called 3604 ** [limits | SQLITE_MAX_<i>NAME</i>]. 3605 ** (The "_LIMIT_" in the name is changed to "_MAX_".))^ 3606 ** ^Attempts to increase a limit above its hard upper bound are 3607 ** silently truncated to the hard upper bound. 3608 ** 3609 ** ^Regardless of whether or not the limit was changed, the 3610 ** [sqlite3_limit()] interface returns the prior value of the limit. 3611 ** ^Hence, to find the current value of a limit without changing it, 3612 ** simply invoke this interface with the third parameter set to -1. 3613 ** 3614 ** Run-time limits are intended for use in applications that manage 3615 ** both their own internal database and also databases that are controlled 3616 ** by untrusted external sources. An example application might be a 3617 ** web browser that has its own databases for storing history and 3618 ** separate databases controlled by JavaScript applications downloaded 3619 ** off the Internet. The internal databases can be given the 3620 ** large, default limits. Databases managed by external sources can 3621 ** be given much smaller limits designed to prevent a denial of service 3622 ** attack. Developers might also want to use the [sqlite3_set_authorizer()] 3623 ** interface to further control untrusted SQL. The size of the database 3624 ** created by an untrusted script can be contained using the 3625 ** [max_page_count] [PRAGMA]. 3626 ** 3627 ** New run-time limit categories may be added in future releases. 3628 */ 3629 SQLITE_API int sqlite3_limit(sqlite3*, int id, int newVal); 3630 3631 /* 3632 ** CAPI3REF: Run-Time Limit Categories 3633 ** KEYWORDS: {limit category} {*limit categories} 3634 ** 3635 ** These constants define various performance limits 3636 ** that can be lowered at run-time using [sqlite3_limit()]. 3637 ** The synopsis of the meanings of the various limits is shown below. 3638 ** Additional information is available at [limits | Limits in SQLite]. 3639 ** 3640 ** <dl> 3641 ** [[SQLITE_LIMIT_LENGTH]] ^(<dt>SQLITE_LIMIT_LENGTH</dt> 3642 ** <dd>The maximum size of any string or BLOB or table row, in bytes.<dd>)^ 3643 ** 3644 ** [[SQLITE_LIMIT_SQL_LENGTH]] ^(<dt>SQLITE_LIMIT_SQL_LENGTH</dt> 3645 ** <dd>The maximum length of an SQL statement, in bytes.</dd>)^ 3646 ** 3647 ** [[SQLITE_LIMIT_COLUMN]] ^(<dt>SQLITE_LIMIT_COLUMN</dt> 3648 ** <dd>The maximum number of columns in a table definition or in the 3649 ** result set of a [SELECT] or the maximum number of columns in an index 3650 ** or in an ORDER BY or GROUP BY clause.</dd>)^ 3651 ** 3652 ** [[SQLITE_LIMIT_EXPR_DEPTH]] ^(<dt>SQLITE_LIMIT_EXPR_DEPTH</dt> 3653 ** <dd>The maximum depth of the parse tree on any expression.</dd>)^ 3654 ** 3655 ** [[SQLITE_LIMIT_COMPOUND_SELECT]] ^(<dt>SQLITE_LIMIT_COMPOUND_SELECT</dt> 3656 ** <dd>The maximum number of terms in a compound SELECT statement.</dd>)^ 3657 ** 3658 ** [[SQLITE_LIMIT_VDBE_OP]] ^(<dt>SQLITE_LIMIT_VDBE_OP</dt> 3659 ** <dd>The maximum number of instructions in a virtual machine program 3660 ** used to implement an SQL statement. If [sqlite3_prepare_v2()] or 3661 ** the equivalent tries to allocate space for more than this many opcodes 3662 ** in a single prepared statement, an SQLITE_NOMEM error is returned.</dd>)^ 3663 ** 3664 ** [[SQLITE_LIMIT_FUNCTION_ARG]] ^(<dt>SQLITE_LIMIT_FUNCTION_ARG</dt> 3665 ** <dd>The maximum number of arguments on a function.</dd>)^ 3666 ** 3667 ** [[SQLITE_LIMIT_ATTACHED]] ^(<dt>SQLITE_LIMIT_ATTACHED</dt> 3668 ** <dd>The maximum number of [ATTACH | attached databases].)^</dd> 3669 ** 3670 ** [[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]] 3671 ** ^(<dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt> 3672 ** <dd>The maximum length of the pattern argument to the [LIKE] or 3673 ** [GLOB] operators.</dd>)^ 3674 ** 3675 ** [[SQLITE_LIMIT_VARIABLE_NUMBER]] 3676 ** ^(<dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt> 3677 ** <dd>The maximum index number of any [parameter] in an SQL statement.)^ 3678 ** 3679 ** [[SQLITE_LIMIT_TRIGGER_DEPTH]] ^(<dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt> 3680 ** <dd>The maximum depth of recursion for triggers.</dd>)^ 3681 ** 3682 ** [[SQLITE_LIMIT_WORKER_THREADS]] ^(<dt>SQLITE_LIMIT_WORKER_THREADS</dt> 3683 ** <dd>The maximum number of auxiliary worker threads that a single 3684 ** [prepared statement] may start.</dd>)^ 3685 ** </dl> 3686 */ 3687 #define SQLITE_LIMIT_LENGTH 0 3688 #define SQLITE_LIMIT_SQL_LENGTH 1 3689 #define SQLITE_LIMIT_COLUMN 2 3690 #define SQLITE_LIMIT_EXPR_DEPTH 3 3691 #define SQLITE_LIMIT_COMPOUND_SELECT 4 3692 #define SQLITE_LIMIT_VDBE_OP 5 3693 #define SQLITE_LIMIT_FUNCTION_ARG 6 3694 #define SQLITE_LIMIT_ATTACHED 7 3695 #define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8 3696 #define SQLITE_LIMIT_VARIABLE_NUMBER 9 3697 #define SQLITE_LIMIT_TRIGGER_DEPTH 10 3698 #define SQLITE_LIMIT_WORKER_THREADS 11 3699 3700 /* 3701 ** CAPI3REF: Prepare Flags 3702 ** 3703 ** These constants define various flags that can be passed into 3704 ** "prepFlags" parameter of the [sqlite3_prepare_v3()] and 3705 ** [sqlite3_prepare16_v3()] interfaces. 3706 ** 3707 ** New flags may be added in future releases of SQLite. 3708 ** 3709 ** <dl> 3710 ** [[SQLITE_PREPARE_PERSISTENT]] ^(<dt>SQLITE_PREPARE_PERSISTENT</dt> 3711 ** <dd>The SQLITE_PREPARE_PERSISTENT flag is a hint to the query planner 3712 ** that the prepared statement will be retained for a long time and 3713 ** probably reused many times.)^ ^Without this flag, [sqlite3_prepare_v3()] 3714 ** and [sqlite3_prepare16_v3()] assume that the prepared statement will 3715 ** be used just once or at most a few times and then destroyed using 3716 ** [sqlite3_finalize()] relatively soon. The current implementation acts 3717 ** on this hint by avoiding the use of [lookaside memory] so as not to 3718 ** deplete the limited store of lookaside memory. Future versions of 3719 ** SQLite may act on this hint differently. 3720 ** 3721 ** [[SQLITE_PREPARE_NORMALIZE]] <dt>SQLITE_PREPARE_NORMALIZE</dt> 3722 ** <dd>The SQLITE_PREPARE_NORMALIZE flag is a no-op. This flag used 3723 ** to be required for any prepared statement that wanted to use the 3724 ** [sqlite3_normalized_sql()] interface. However, the 3725 ** [sqlite3_normalized_sql()] interface is now available to all 3726 ** prepared statements, regardless of whether or not they use this 3727 ** flag. 3728 ** 3729 ** [[SQLITE_PREPARE_NO_VTAB]] <dt>SQLITE_PREPARE_NO_VTAB</dt> 3730 ** <dd>The SQLITE_PREPARE_NO_VTAB flag causes the SQL compiler 3731 ** to return an error (error code SQLITE_ERROR) if the statement uses 3732 ** any virtual tables. 3733 ** </dl> 3734 */ 3735 #define SQLITE_PREPARE_PERSISTENT 0x01 3736 #define SQLITE_PREPARE_NORMALIZE 0x02 3737 #define SQLITE_PREPARE_NO_VTAB 0x04 3738 3739 /* 3740 ** CAPI3REF: Compiling An SQL Statement 3741 ** KEYWORDS: {SQL statement compiler} 3742 ** METHOD: sqlite3 3743 ** CONSTRUCTOR: sqlite3_stmt 3744 ** 3745 ** To execute an SQL statement, it must first be compiled into a byte-code 3746 ** program using one of these routines. Or, in other words, these routines 3747 ** are constructors for the [prepared statement] object. 3748 ** 3749 ** The preferred routine to use is [sqlite3_prepare_v2()]. The 3750 ** [sqlite3_prepare()] interface is legacy and should be avoided. 3751 ** [sqlite3_prepare_v3()] has an extra "prepFlags" option that is used 3752 ** for special purposes. 3753 ** 3754 ** The use of the UTF-8 interfaces is preferred, as SQLite currently 3755 ** does all parsing using UTF-8. The UTF-16 interfaces are provided 3756 ** as a convenience. The UTF-16 interfaces work by converting the 3757 ** input text into UTF-8, then invoking the corresponding UTF-8 interface. 3758 ** 3759 ** The first argument, "db", is a [database connection] obtained from a 3760 ** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or 3761 ** [sqlite3_open16()]. The database connection must not have been closed. 3762 ** 3763 ** The second argument, "zSql", is the statement to be compiled, encoded 3764 ** as either UTF-8 or UTF-16. The sqlite3_prepare(), sqlite3_prepare_v2(), 3765 ** and sqlite3_prepare_v3() 3766 ** interfaces use UTF-8, and sqlite3_prepare16(), sqlite3_prepare16_v2(), 3767 ** and sqlite3_prepare16_v3() use UTF-16. 3768 ** 3769 ** ^If the nByte argument is negative, then zSql is read up to the 3770 ** first zero terminator. ^If nByte is positive, then it is the 3771 ** number of bytes read from zSql. ^If nByte is zero, then no prepared 3772 ** statement is generated. 3773 ** If the caller knows that the supplied string is nul-terminated, then 3774 ** there is a small performance advantage to passing an nByte parameter that 3775 ** is the number of bytes in the input string <i>including</i> 3776 ** the nul-terminator. 3777 ** 3778 ** ^If pzTail is not NULL then *pzTail is made to point to the first byte 3779 ** past the end of the first SQL statement in zSql. These routines only 3780 ** compile the first statement in zSql, so *pzTail is left pointing to 3781 ** what remains uncompiled. 3782 ** 3783 ** ^*ppStmt is left pointing to a compiled [prepared statement] that can be 3784 ** executed using [sqlite3_step()]. ^If there is an error, *ppStmt is set 3785 ** to NULL. ^If the input text contains no SQL (if the input is an empty 3786 ** string or a comment) then *ppStmt is set to NULL. 3787 ** The calling procedure is responsible for deleting the compiled 3788 ** SQL statement using [sqlite3_finalize()] after it has finished with it. 3789 ** ppStmt may not be NULL. 3790 ** 3791 ** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK]; 3792 ** otherwise an [error code] is returned. 3793 ** 3794 ** The sqlite3_prepare_v2(), sqlite3_prepare_v3(), sqlite3_prepare16_v2(), 3795 ** and sqlite3_prepare16_v3() interfaces are recommended for all new programs. 3796 ** The older interfaces (sqlite3_prepare() and sqlite3_prepare16()) 3797 ** are retained for backwards compatibility, but their use is discouraged. 3798 ** ^In the "vX" interfaces, the prepared statement 3799 ** that is returned (the [sqlite3_stmt] object) contains a copy of the 3800 ** original SQL text. This causes the [sqlite3_step()] interface to 3801 ** behave differently in three ways: 3802 ** 3803 ** <ol> 3804 ** <li> 3805 ** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it 3806 ** always used to do, [sqlite3_step()] will automatically recompile the SQL 3807 ** statement and try to run it again. As many as [SQLITE_MAX_SCHEMA_RETRY] 3808 ** retries will occur before sqlite3_step() gives up and returns an error. 3809 ** </li> 3810 ** 3811 ** <li> 3812 ** ^When an error occurs, [sqlite3_step()] will return one of the detailed 3813 ** [error codes] or [extended error codes]. ^The legacy behavior was that 3814 ** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code 3815 ** and the application would have to make a second call to [sqlite3_reset()] 3816 ** in order to find the underlying cause of the problem. With the "v2" prepare 3817 ** interfaces, the underlying reason for the error is returned immediately. 3818 ** </li> 3819 ** 3820 ** <li> 3821 ** ^If the specific value bound to [parameter | host parameter] in the 3822 ** WHERE clause might influence the choice of query plan for a statement, 3823 ** then the statement will be automatically recompiled, as if there had been 3824 ** a schema change, on the first [sqlite3_step()] call following any change 3825 ** to the [sqlite3_bind_text | bindings] of that [parameter]. 3826 ** ^The specific value of WHERE-clause [parameter] might influence the 3827 ** choice of query plan if the parameter is the left-hand side of a [LIKE] 3828 ** or [GLOB] operator or if the parameter is compared to an indexed column 3829 ** and the [SQLITE_ENABLE_STAT4] compile-time option is enabled. 3830 ** </li> 3831 ** </ol> 3832 ** 3833 ** <p>^sqlite3_prepare_v3() differs from sqlite3_prepare_v2() only in having 3834 ** the extra prepFlags parameter, which is a bit array consisting of zero or 3835 ** more of the [SQLITE_PREPARE_PERSISTENT|SQLITE_PREPARE_*] flags. ^The 3836 ** sqlite3_prepare_v2() interface works exactly the same as 3837 ** sqlite3_prepare_v3() with a zero prepFlags parameter. 3838 */ 3839 SQLITE_API int sqlite3_prepare( 3840 sqlite3 *db, /* Database handle */ 3841 const char *zSql, /* SQL statement, UTF-8 encoded */ 3842 int nByte, /* Maximum length of zSql in bytes. */ 3843 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3844 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 3845 ); 3846 SQLITE_API int sqlite3_prepare_v2( 3847 sqlite3 *db, /* Database handle */ 3848 const char *zSql, /* SQL statement, UTF-8 encoded */ 3849 int nByte, /* Maximum length of zSql in bytes. */ 3850 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3851 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 3852 ); 3853 SQLITE_API int sqlite3_prepare_v3( 3854 sqlite3 *db, /* Database handle */ 3855 const char *zSql, /* SQL statement, UTF-8 encoded */ 3856 int nByte, /* Maximum length of zSql in bytes. */ 3857 unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */ 3858 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3859 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 3860 ); 3861 SQLITE_API int sqlite3_prepare16( 3862 sqlite3 *db, /* Database handle */ 3863 const void *zSql, /* SQL statement, UTF-16 encoded */ 3864 int nByte, /* Maximum length of zSql in bytes. */ 3865 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3866 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 3867 ); 3868 SQLITE_API int sqlite3_prepare16_v2( 3869 sqlite3 *db, /* Database handle */ 3870 const void *zSql, /* SQL statement, UTF-16 encoded */ 3871 int nByte, /* Maximum length of zSql in bytes. */ 3872 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3873 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 3874 ); 3875 SQLITE_API int sqlite3_prepare16_v3( 3876 sqlite3 *db, /* Database handle */ 3877 const void *zSql, /* SQL statement, UTF-16 encoded */ 3878 int nByte, /* Maximum length of zSql in bytes. */ 3879 unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */ 3880 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3881 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 3882 ); 3883 3884 /* 3885 ** CAPI3REF: Retrieving Statement SQL 3886 ** METHOD: sqlite3_stmt 3887 ** 3888 ** ^The sqlite3_sql(P) interface returns a pointer to a copy of the UTF-8 3889 ** SQL text used to create [prepared statement] P if P was 3890 ** created by [sqlite3_prepare_v2()], [sqlite3_prepare_v3()], 3891 ** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()]. 3892 ** ^The sqlite3_expanded_sql(P) interface returns a pointer to a UTF-8 3893 ** string containing the SQL text of prepared statement P with 3894 ** [bound parameters] expanded. 3895 ** ^The sqlite3_normalized_sql(P) interface returns a pointer to a UTF-8 3896 ** string containing the normalized SQL text of prepared statement P. The 3897 ** semantics used to normalize a SQL statement are unspecified and subject 3898 ** to change. At a minimum, literal values will be replaced with suitable 3899 ** placeholders. 3900 ** 3901 ** ^(For example, if a prepared statement is created using the SQL 3902 ** text "SELECT $abc,:xyz" and if parameter $abc is bound to integer 2345 3903 ** and parameter :xyz is unbound, then sqlite3_sql() will return 3904 ** the original string, "SELECT $abc,:xyz" but sqlite3_expanded_sql() 3905 ** will return "SELECT 2345,NULL".)^ 3906 ** 3907 ** ^The sqlite3_expanded_sql() interface returns NULL if insufficient memory 3908 ** is available to hold the result, or if the result would exceed the 3909 ** the maximum string length determined by the [SQLITE_LIMIT_LENGTH]. 3910 ** 3911 ** ^The [SQLITE_TRACE_SIZE_LIMIT] compile-time option limits the size of 3912 ** bound parameter expansions. ^The [SQLITE_OMIT_TRACE] compile-time 3913 ** option causes sqlite3_expanded_sql() to always return NULL. 3914 ** 3915 ** ^The strings returned by sqlite3_sql(P) and sqlite3_normalized_sql(P) 3916 ** are managed by SQLite and are automatically freed when the prepared 3917 ** statement is finalized. 3918 ** ^The string returned by sqlite3_expanded_sql(P), on the other hand, 3919 ** is obtained from [sqlite3_malloc()] and must be free by the application 3920 ** by passing it to [sqlite3_free()]. 3921 */ 3922 SQLITE_API const char *sqlite3_sql(sqlite3_stmt *pStmt); 3923 SQLITE_API char *sqlite3_expanded_sql(sqlite3_stmt *pStmt); 3924 SQLITE_API const char *sqlite3_normalized_sql(sqlite3_stmt *pStmt); 3925 3926 /* 3927 ** CAPI3REF: Determine If An SQL Statement Writes The Database 3928 ** METHOD: sqlite3_stmt 3929 ** 3930 ** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if 3931 ** and only if the [prepared statement] X makes no direct changes to 3932 ** the content of the database file. 3933 ** 3934 ** Note that [application-defined SQL functions] or 3935 ** [virtual tables] might change the database indirectly as a side effect. 3936 ** ^(For example, if an application defines a function "eval()" that 3937 ** calls [sqlite3_exec()], then the following SQL statement would 3938 ** change the database file through side-effects: 3939 ** 3940 ** <blockquote><pre> 3941 ** SELECT eval('DELETE FROM t1') FROM t2; 3942 ** </pre></blockquote> 3943 ** 3944 ** But because the [SELECT] statement does not change the database file 3945 ** directly, sqlite3_stmt_readonly() would still return true.)^ 3946 ** 3947 ** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK], 3948 ** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true, 3949 ** since the statements themselves do not actually modify the database but 3950 ** rather they control the timing of when other statements modify the 3951 ** database. ^The [ATTACH] and [DETACH] statements also cause 3952 ** sqlite3_stmt_readonly() to return true since, while those statements 3953 ** change the configuration of a database connection, they do not make 3954 ** changes to the content of the database files on disk. 3955 ** ^The sqlite3_stmt_readonly() interface returns true for [BEGIN] since 3956 ** [BEGIN] merely sets internal flags, but the [BEGIN|BEGIN IMMEDIATE] and 3957 ** [BEGIN|BEGIN EXCLUSIVE] commands do touch the database and so 3958 ** sqlite3_stmt_readonly() returns false for those commands. 3959 */ 3960 SQLITE_API int sqlite3_stmt_readonly(sqlite3_stmt *pStmt); 3961 3962 /* 3963 ** CAPI3REF: Query The EXPLAIN Setting For A Prepared Statement 3964 ** METHOD: sqlite3_stmt 3965 ** 3966 ** ^The sqlite3_stmt_isexplain(S) interface returns 1 if the 3967 ** prepared statement S is an EXPLAIN statement, or 2 if the 3968 ** statement S is an EXPLAIN QUERY PLAN. 3969 ** ^The sqlite3_stmt_isexplain(S) interface returns 0 if S is 3970 ** an ordinary statement or a NULL pointer. 3971 */ 3972 SQLITE_API int sqlite3_stmt_isexplain(sqlite3_stmt *pStmt); 3973 3974 /* 3975 ** CAPI3REF: Determine If A Prepared Statement Has Been Reset 3976 ** METHOD: sqlite3_stmt 3977 ** 3978 ** ^The sqlite3_stmt_busy(S) interface returns true (non-zero) if the 3979 ** [prepared statement] S has been stepped at least once using 3980 ** [sqlite3_step(S)] but has neither run to completion (returned 3981 ** [SQLITE_DONE] from [sqlite3_step(S)]) nor 3982 ** been reset using [sqlite3_reset(S)]. ^The sqlite3_stmt_busy(S) 3983 ** interface returns false if S is a NULL pointer. If S is not a 3984 ** NULL pointer and is not a pointer to a valid [prepared statement] 3985 ** object, then the behavior is undefined and probably undesirable. 3986 ** 3987 ** This interface can be used in combination [sqlite3_next_stmt()] 3988 ** to locate all prepared statements associated with a database 3989 ** connection that are in need of being reset. This can be used, 3990 ** for example, in diagnostic routines to search for prepared 3991 ** statements that are holding a transaction open. 3992 */ 3993 SQLITE_API int sqlite3_stmt_busy(sqlite3_stmt*); 3994 3995 /* 3996 ** CAPI3REF: Dynamically Typed Value Object 3997 ** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value} 3998 ** 3999 ** SQLite uses the sqlite3_value object to represent all values 4000 ** that can be stored in a database table. SQLite uses dynamic typing 4001 ** for the values it stores. ^Values stored in sqlite3_value objects 4002 ** can be integers, floating point values, strings, BLOBs, or NULL. 4003 ** 4004 ** An sqlite3_value object may be either "protected" or "unprotected". 4005 ** Some interfaces require a protected sqlite3_value. Other interfaces 4006 ** will accept either a protected or an unprotected sqlite3_value. 4007 ** Every interface that accepts sqlite3_value arguments specifies 4008 ** whether or not it requires a protected sqlite3_value. The 4009 ** [sqlite3_value_dup()] interface can be used to construct a new 4010 ** protected sqlite3_value from an unprotected sqlite3_value. 4011 ** 4012 ** The terms "protected" and "unprotected" refer to whether or not 4013 ** a mutex is held. An internal mutex is held for a protected 4014 ** sqlite3_value object but no mutex is held for an unprotected 4015 ** sqlite3_value object. If SQLite is compiled to be single-threaded 4016 ** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0) 4017 ** or if SQLite is run in one of reduced mutex modes 4018 ** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD] 4019 ** then there is no distinction between protected and unprotected 4020 ** sqlite3_value objects and they can be used interchangeably. However, 4021 ** for maximum code portability it is recommended that applications 4022 ** still make the distinction between protected and unprotected 4023 ** sqlite3_value objects even when not strictly required. 4024 ** 4025 ** ^The sqlite3_value objects that are passed as parameters into the 4026 ** implementation of [application-defined SQL functions] are protected. 4027 ** ^The sqlite3_value object returned by 4028 ** [sqlite3_column_value()] is unprotected. 4029 ** Unprotected sqlite3_value objects may only be used as arguments 4030 ** to [sqlite3_result_value()], [sqlite3_bind_value()], and 4031 ** [sqlite3_value_dup()]. 4032 ** The [sqlite3_value_blob | sqlite3_value_type()] family of 4033 ** interfaces require protected sqlite3_value objects. 4034 */ 4035 typedef struct sqlite3_value sqlite3_value; 4036 4037 /* 4038 ** CAPI3REF: SQL Function Context Object 4039 ** 4040 ** The context in which an SQL function executes is stored in an 4041 ** sqlite3_context object. ^A pointer to an sqlite3_context object 4042 ** is always first parameter to [application-defined SQL functions]. 4043 ** The application-defined SQL function implementation will pass this 4044 ** pointer through into calls to [sqlite3_result_int | sqlite3_result()], 4045 ** [sqlite3_aggregate_context()], [sqlite3_user_data()], 4046 ** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()], 4047 ** and/or [sqlite3_set_auxdata()]. 4048 */ 4049 typedef struct sqlite3_context sqlite3_context; 4050 4051 /* 4052 ** CAPI3REF: Binding Values To Prepared Statements 4053 ** KEYWORDS: {host parameter} {host parameters} {host parameter name} 4054 ** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding} 4055 ** METHOD: sqlite3_stmt 4056 ** 4057 ** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants, 4058 ** literals may be replaced by a [parameter] that matches one of following 4059 ** templates: 4060 ** 4061 ** <ul> 4062 ** <li> ? 4063 ** <li> ?NNN 4064 ** <li> :VVV 4065 ** <li> @VVV 4066 ** <li> $VVV 4067 ** </ul> 4068 ** 4069 ** In the templates above, NNN represents an integer literal, 4070 ** and VVV represents an alphanumeric identifier.)^ ^The values of these 4071 ** parameters (also called "host parameter names" or "SQL parameters") 4072 ** can be set using the sqlite3_bind_*() routines defined here. 4073 ** 4074 ** ^The first argument to the sqlite3_bind_*() routines is always 4075 ** a pointer to the [sqlite3_stmt] object returned from 4076 ** [sqlite3_prepare_v2()] or its variants. 4077 ** 4078 ** ^The second argument is the index of the SQL parameter to be set. 4079 ** ^The leftmost SQL parameter has an index of 1. ^When the same named 4080 ** SQL parameter is used more than once, second and subsequent 4081 ** occurrences have the same index as the first occurrence. 4082 ** ^The index for named parameters can be looked up using the 4083 ** [sqlite3_bind_parameter_index()] API if desired. ^The index 4084 ** for "?NNN" parameters is the value of NNN. 4085 ** ^The NNN value must be between 1 and the [sqlite3_limit()] 4086 ** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 999). 4087 ** 4088 ** ^The third argument is the value to bind to the parameter. 4089 ** ^If the third parameter to sqlite3_bind_text() or sqlite3_bind_text16() 4090 ** or sqlite3_bind_blob() is a NULL pointer then the fourth parameter 4091 ** is ignored and the end result is the same as sqlite3_bind_null(). 4092 ** 4093 ** ^(In those routines that have a fourth argument, its value is the 4094 ** number of bytes in the parameter. To be clear: the value is the 4095 ** number of <u>bytes</u> in the value, not the number of characters.)^ 4096 ** ^If the fourth parameter to sqlite3_bind_text() or sqlite3_bind_text16() 4097 ** is negative, then the length of the string is 4098 ** the number of bytes up to the first zero terminator. 4099 ** If the fourth parameter to sqlite3_bind_blob() is negative, then 4100 ** the behavior is undefined. 4101 ** If a non-negative fourth parameter is provided to sqlite3_bind_text() 4102 ** or sqlite3_bind_text16() or sqlite3_bind_text64() then 4103 ** that parameter must be the byte offset 4104 ** where the NUL terminator would occur assuming the string were NUL 4105 ** terminated. If any NUL characters occur at byte offsets less than 4106 ** the value of the fourth parameter then the resulting string value will 4107 ** contain embedded NULs. The result of expressions involving strings 4108 ** with embedded NULs is undefined. 4109 ** 4110 ** ^The fifth argument to the BLOB and string binding interfaces 4111 ** is a destructor used to dispose of the BLOB or 4112 ** string after SQLite has finished with it. ^The destructor is called 4113 ** to dispose of the BLOB or string even if the call to the bind API fails, 4114 ** except the destructor is not called if the third parameter is a NULL 4115 ** pointer or the fourth parameter is negative. 4116 ** ^If the fifth argument is 4117 ** the special value [SQLITE_STATIC], then SQLite assumes that the 4118 ** information is in static, unmanaged space and does not need to be freed. 4119 ** ^If the fifth argument has the value [SQLITE_TRANSIENT], then 4120 ** SQLite makes its own private copy of the data immediately, before 4121 ** the sqlite3_bind_*() routine returns. 4122 ** 4123 ** ^The sixth argument to sqlite3_bind_text64() must be one of 4124 ** [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE] 4125 ** to specify the encoding of the text in the third parameter. If 4126 ** the sixth argument to sqlite3_bind_text64() is not one of the 4127 ** allowed values shown above, or if the text encoding is different 4128 ** from the encoding specified by the sixth parameter, then the behavior 4129 ** is undefined. 4130 ** 4131 ** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that 4132 ** is filled with zeroes. ^A zeroblob uses a fixed amount of memory 4133 ** (just an integer to hold its size) while it is being processed. 4134 ** Zeroblobs are intended to serve as placeholders for BLOBs whose 4135 ** content is later written using 4136 ** [sqlite3_blob_open | incremental BLOB I/O] routines. 4137 ** ^A negative value for the zeroblob results in a zero-length BLOB. 4138 ** 4139 ** ^The sqlite3_bind_pointer(S,I,P,T,D) routine causes the I-th parameter in 4140 ** [prepared statement] S to have an SQL value of NULL, but to also be 4141 ** associated with the pointer P of type T. ^D is either a NULL pointer or 4142 ** a pointer to a destructor function for P. ^SQLite will invoke the 4143 ** destructor D with a single argument of P when it is finished using 4144 ** P. The T parameter should be a static string, preferably a string 4145 ** literal. The sqlite3_bind_pointer() routine is part of the 4146 ** [pointer passing interface] added for SQLite 3.20.0. 4147 ** 4148 ** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer 4149 ** for the [prepared statement] or with a prepared statement for which 4150 ** [sqlite3_step()] has been called more recently than [sqlite3_reset()], 4151 ** then the call will return [SQLITE_MISUSE]. If any sqlite3_bind_() 4152 ** routine is passed a [prepared statement] that has been finalized, the 4153 ** result is undefined and probably harmful. 4154 ** 4155 ** ^Bindings are not cleared by the [sqlite3_reset()] routine. 4156 ** ^Unbound parameters are interpreted as NULL. 4157 ** 4158 ** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an 4159 ** [error code] if anything goes wrong. 4160 ** ^[SQLITE_TOOBIG] might be returned if the size of a string or BLOB 4161 ** exceeds limits imposed by [sqlite3_limit]([SQLITE_LIMIT_LENGTH]) or 4162 ** [SQLITE_MAX_LENGTH]. 4163 ** ^[SQLITE_RANGE] is returned if the parameter 4164 ** index is out of range. ^[SQLITE_NOMEM] is returned if malloc() fails. 4165 ** 4166 ** See also: [sqlite3_bind_parameter_count()], 4167 ** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()]. 4168 */ 4169 SQLITE_API int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*)); 4170 SQLITE_API int sqlite3_bind_blob64(sqlite3_stmt*, int, const void*, sqlite3_uint64, 4171 void(*)(void*)); 4172 SQLITE_API int sqlite3_bind_double(sqlite3_stmt*, int, double); 4173 SQLITE_API int sqlite3_bind_int(sqlite3_stmt*, int, int); 4174 SQLITE_API int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64); 4175 SQLITE_API int sqlite3_bind_null(sqlite3_stmt*, int); 4176 SQLITE_API int sqlite3_bind_text(sqlite3_stmt*,int,const char*,int,void(*)(void*)); 4177 SQLITE_API int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*)); 4178 SQLITE_API int sqlite3_bind_text64(sqlite3_stmt*, int, const char*, sqlite3_uint64, 4179 void(*)(void*), unsigned char encoding); 4180 SQLITE_API int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*); 4181 SQLITE_API int sqlite3_bind_pointer(sqlite3_stmt*, int, void*, const char*,void(*)(void*)); 4182 SQLITE_API int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n); 4183 SQLITE_API int sqlite3_bind_zeroblob64(sqlite3_stmt*, int, sqlite3_uint64); 4184 4185 /* 4186 ** CAPI3REF: Number Of SQL Parameters 4187 ** METHOD: sqlite3_stmt 4188 ** 4189 ** ^This routine can be used to find the number of [SQL parameters] 4190 ** in a [prepared statement]. SQL parameters are tokens of the 4191 ** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as 4192 ** placeholders for values that are [sqlite3_bind_blob | bound] 4193 ** to the parameters at a later time. 4194 ** 4195 ** ^(This routine actually returns the index of the largest (rightmost) 4196 ** parameter. For all forms except ?NNN, this will correspond to the 4197 ** number of unique parameters. If parameters of the ?NNN form are used, 4198 ** there may be gaps in the list.)^ 4199 ** 4200 ** See also: [sqlite3_bind_blob|sqlite3_bind()], 4201 ** [sqlite3_bind_parameter_name()], and 4202 ** [sqlite3_bind_parameter_index()]. 4203 */ 4204 SQLITE_API int sqlite3_bind_parameter_count(sqlite3_stmt*); 4205 4206 /* 4207 ** CAPI3REF: Name Of A Host Parameter 4208 ** METHOD: sqlite3_stmt 4209 ** 4210 ** ^The sqlite3_bind_parameter_name(P,N) interface returns 4211 ** the name of the N-th [SQL parameter] in the [prepared statement] P. 4212 ** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA" 4213 ** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA" 4214 ** respectively. 4215 ** In other words, the initial ":" or "$" or "@" or "?" 4216 ** is included as part of the name.)^ 4217 ** ^Parameters of the form "?" without a following integer have no name 4218 ** and are referred to as "nameless" or "anonymous parameters". 4219 ** 4220 ** ^The first host parameter has an index of 1, not 0. 4221 ** 4222 ** ^If the value N is out of range or if the N-th parameter is 4223 ** nameless, then NULL is returned. ^The returned string is 4224 ** always in UTF-8 encoding even if the named parameter was 4225 ** originally specified as UTF-16 in [sqlite3_prepare16()], 4226 ** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()]. 4227 ** 4228 ** See also: [sqlite3_bind_blob|sqlite3_bind()], 4229 ** [sqlite3_bind_parameter_count()], and 4230 ** [sqlite3_bind_parameter_index()]. 4231 */ 4232 SQLITE_API const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int); 4233 4234 /* 4235 ** CAPI3REF: Index Of A Parameter With A Given Name 4236 ** METHOD: sqlite3_stmt 4237 ** 4238 ** ^Return the index of an SQL parameter given its name. ^The 4239 ** index value returned is suitable for use as the second 4240 ** parameter to [sqlite3_bind_blob|sqlite3_bind()]. ^A zero 4241 ** is returned if no matching parameter is found. ^The parameter 4242 ** name must be given in UTF-8 even if the original statement 4243 ** was prepared from UTF-16 text using [sqlite3_prepare16_v2()] or 4244 ** [sqlite3_prepare16_v3()]. 4245 ** 4246 ** See also: [sqlite3_bind_blob|sqlite3_bind()], 4247 ** [sqlite3_bind_parameter_count()], and 4248 ** [sqlite3_bind_parameter_name()]. 4249 */ 4250 SQLITE_API int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName); 4251 4252 /* 4253 ** CAPI3REF: Reset All Bindings On A Prepared Statement 4254 ** METHOD: sqlite3_stmt 4255 ** 4256 ** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset 4257 ** the [sqlite3_bind_blob | bindings] on a [prepared statement]. 4258 ** ^Use this routine to reset all host parameters to NULL. 4259 */ 4260 SQLITE_API int sqlite3_clear_bindings(sqlite3_stmt*); 4261 4262 /* 4263 ** CAPI3REF: Number Of Columns In A Result Set 4264 ** METHOD: sqlite3_stmt 4265 ** 4266 ** ^Return the number of columns in the result set returned by the 4267 ** [prepared statement]. ^If this routine returns 0, that means the 4268 ** [prepared statement] returns no data (for example an [UPDATE]). 4269 ** ^However, just because this routine returns a positive number does not 4270 ** mean that one or more rows of data will be returned. ^A SELECT statement 4271 ** will always have a positive sqlite3_column_count() but depending on the 4272 ** WHERE clause constraints and the table content, it might return no rows. 4273 ** 4274 ** See also: [sqlite3_data_count()] 4275 */ 4276 SQLITE_API int sqlite3_column_count(sqlite3_stmt *pStmt); 4277 4278 /* 4279 ** CAPI3REF: Column Names In A Result Set 4280 ** METHOD: sqlite3_stmt 4281 ** 4282 ** ^These routines return the name assigned to a particular column 4283 ** in the result set of a [SELECT] statement. ^The sqlite3_column_name() 4284 ** interface returns a pointer to a zero-terminated UTF-8 string 4285 ** and sqlite3_column_name16() returns a pointer to a zero-terminated 4286 ** UTF-16 string. ^The first parameter is the [prepared statement] 4287 ** that implements the [SELECT] statement. ^The second parameter is the 4288 ** column number. ^The leftmost column is number 0. 4289 ** 4290 ** ^The returned string pointer is valid until either the [prepared statement] 4291 ** is destroyed by [sqlite3_finalize()] or until the statement is automatically 4292 ** reprepared by the first call to [sqlite3_step()] for a particular run 4293 ** or until the next call to 4294 ** sqlite3_column_name() or sqlite3_column_name16() on the same column. 4295 ** 4296 ** ^If sqlite3_malloc() fails during the processing of either routine 4297 ** (for example during a conversion from UTF-8 to UTF-16) then a 4298 ** NULL pointer is returned. 4299 ** 4300 ** ^The name of a result column is the value of the "AS" clause for 4301 ** that column, if there is an AS clause. If there is no AS clause 4302 ** then the name of the column is unspecified and may change from 4303 ** one release of SQLite to the next. 4304 */ 4305 SQLITE_API const char *sqlite3_column_name(sqlite3_stmt*, int N); 4306 SQLITE_API const void *sqlite3_column_name16(sqlite3_stmt*, int N); 4307 4308 /* 4309 ** CAPI3REF: Source Of Data In A Query Result 4310 ** METHOD: sqlite3_stmt 4311 ** 4312 ** ^These routines provide a means to determine the database, table, and 4313 ** table column that is the origin of a particular result column in 4314 ** [SELECT] statement. 4315 ** ^The name of the database or table or column can be returned as 4316 ** either a UTF-8 or UTF-16 string. ^The _database_ routines return 4317 ** the database name, the _table_ routines return the table name, and 4318 ** the origin_ routines return the column name. 4319 ** ^The returned string is valid until the [prepared statement] is destroyed 4320 ** using [sqlite3_finalize()] or until the statement is automatically 4321 ** reprepared by the first call to [sqlite3_step()] for a particular run 4322 ** or until the same information is requested 4323 ** again in a different encoding. 4324 ** 4325 ** ^The names returned are the original un-aliased names of the 4326 ** database, table, and column. 4327 ** 4328 ** ^The first argument to these interfaces is a [prepared statement]. 4329 ** ^These functions return information about the Nth result column returned by 4330 ** the statement, where N is the second function argument. 4331 ** ^The left-most column is column 0 for these routines. 4332 ** 4333 ** ^If the Nth column returned by the statement is an expression or 4334 ** subquery and is not a column value, then all of these functions return 4335 ** NULL. ^These routine might also return NULL if a memory allocation error 4336 ** occurs. ^Otherwise, they return the name of the attached database, table, 4337 ** or column that query result column was extracted from. 4338 ** 4339 ** ^As with all other SQLite APIs, those whose names end with "16" return 4340 ** UTF-16 encoded strings and the other functions return UTF-8. 4341 ** 4342 ** ^These APIs are only available if the library was compiled with the 4343 ** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol. 4344 ** 4345 ** If two or more threads call one or more of these routines against the same 4346 ** prepared statement and column at the same time then the results are 4347 ** undefined. 4348 ** 4349 ** If two or more threads call one or more 4350 ** [sqlite3_column_database_name | column metadata interfaces] 4351 ** for the same [prepared statement] and result column 4352 ** at the same time then the results are undefined. 4353 */ 4354 SQLITE_API const char *sqlite3_column_database_name(sqlite3_stmt*,int); 4355 SQLITE_API const void *sqlite3_column_database_name16(sqlite3_stmt*,int); 4356 SQLITE_API const char *sqlite3_column_table_name(sqlite3_stmt*,int); 4357 SQLITE_API const void *sqlite3_column_table_name16(sqlite3_stmt*,int); 4358 SQLITE_API const char *sqlite3_column_origin_name(sqlite3_stmt*,int); 4359 SQLITE_API const void *sqlite3_column_origin_name16(sqlite3_stmt*,int); 4360 4361 /* 4362 ** CAPI3REF: Declared Datatype Of A Query Result 4363 ** METHOD: sqlite3_stmt 4364 ** 4365 ** ^(The first parameter is a [prepared statement]. 4366 ** If this statement is a [SELECT] statement and the Nth column of the 4367 ** returned result set of that [SELECT] is a table column (not an 4368 ** expression or subquery) then the declared type of the table 4369 ** column is returned.)^ ^If the Nth column of the result set is an 4370 ** expression or subquery, then a NULL pointer is returned. 4371 ** ^The returned string is always UTF-8 encoded. 4372 ** 4373 ** ^(For example, given the database schema: 4374 ** 4375 ** CREATE TABLE t1(c1 VARIANT); 4376 ** 4377 ** and the following statement to be compiled: 4378 ** 4379 ** SELECT c1 + 1, c1 FROM t1; 4380 ** 4381 ** this routine would return the string "VARIANT" for the second result 4382 ** column (i==1), and a NULL pointer for the first result column (i==0).)^ 4383 ** 4384 ** ^SQLite uses dynamic run-time typing. ^So just because a column 4385 ** is declared to contain a particular type does not mean that the 4386 ** data stored in that column is of the declared type. SQLite is 4387 ** strongly typed, but the typing is dynamic not static. ^Type 4388 ** is associated with individual values, not with the containers 4389 ** used to hold those values. 4390 */ 4391 SQLITE_API const char *sqlite3_column_decltype(sqlite3_stmt*,int); 4392 SQLITE_API const void *sqlite3_column_decltype16(sqlite3_stmt*,int); 4393 4394 /* 4395 ** CAPI3REF: Evaluate An SQL Statement 4396 ** METHOD: sqlite3_stmt 4397 ** 4398 ** After a [prepared statement] has been prepared using any of 4399 ** [sqlite3_prepare_v2()], [sqlite3_prepare_v3()], [sqlite3_prepare16_v2()], 4400 ** or [sqlite3_prepare16_v3()] or one of the legacy 4401 ** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function 4402 ** must be called one or more times to evaluate the statement. 4403 ** 4404 ** The details of the behavior of the sqlite3_step() interface depend 4405 ** on whether the statement was prepared using the newer "vX" interfaces 4406 ** [sqlite3_prepare_v3()], [sqlite3_prepare_v2()], [sqlite3_prepare16_v3()], 4407 ** [sqlite3_prepare16_v2()] or the older legacy 4408 ** interfaces [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the 4409 ** new "vX" interface is recommended for new applications but the legacy 4410 ** interface will continue to be supported. 4411 ** 4412 ** ^In the legacy interface, the return value will be either [SQLITE_BUSY], 4413 ** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE]. 4414 ** ^With the "v2" interface, any of the other [result codes] or 4415 ** [extended result codes] might be returned as well. 4416 ** 4417 ** ^[SQLITE_BUSY] means that the database engine was unable to acquire the 4418 ** database locks it needs to do its job. ^If the statement is a [COMMIT] 4419 ** or occurs outside of an explicit transaction, then you can retry the 4420 ** statement. If the statement is not a [COMMIT] and occurs within an 4421 ** explicit transaction then you should rollback the transaction before 4422 ** continuing. 4423 ** 4424 ** ^[SQLITE_DONE] means that the statement has finished executing 4425 ** successfully. sqlite3_step() should not be called again on this virtual 4426 ** machine without first calling [sqlite3_reset()] to reset the virtual 4427 ** machine back to its initial state. 4428 ** 4429 ** ^If the SQL statement being executed returns any data, then [SQLITE_ROW] 4430 ** is returned each time a new row of data is ready for processing by the 4431 ** caller. The values may be accessed using the [column access functions]. 4432 ** sqlite3_step() is called again to retrieve the next row of data. 4433 ** 4434 ** ^[SQLITE_ERROR] means that a run-time error (such as a constraint 4435 ** violation) has occurred. sqlite3_step() should not be called again on 4436 ** the VM. More information may be found by calling [sqlite3_errmsg()]. 4437 ** ^With the legacy interface, a more specific error code (for example, 4438 ** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth) 4439 ** can be obtained by calling [sqlite3_reset()] on the 4440 ** [prepared statement]. ^In the "v2" interface, 4441 ** the more specific error code is returned directly by sqlite3_step(). 4442 ** 4443 ** [SQLITE_MISUSE] means that the this routine was called inappropriately. 4444 ** Perhaps it was called on a [prepared statement] that has 4445 ** already been [sqlite3_finalize | finalized] or on one that had 4446 ** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could 4447 ** be the case that the same database connection is being used by two or 4448 ** more threads at the same moment in time. 4449 ** 4450 ** For all versions of SQLite up to and including 3.6.23.1, a call to 4451 ** [sqlite3_reset()] was required after sqlite3_step() returned anything 4452 ** other than [SQLITE_ROW] before any subsequent invocation of 4453 ** sqlite3_step(). Failure to reset the prepared statement using 4454 ** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from 4455 ** sqlite3_step(). But after [version 3.6.23.1] ([dateof:3.6.23.1], 4456 ** sqlite3_step() began 4457 ** calling [sqlite3_reset()] automatically in this circumstance rather 4458 ** than returning [SQLITE_MISUSE]. This is not considered a compatibility 4459 ** break because any application that ever receives an SQLITE_MISUSE error 4460 ** is broken by definition. The [SQLITE_OMIT_AUTORESET] compile-time option 4461 ** can be used to restore the legacy behavior. 4462 ** 4463 ** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step() 4464 ** API always returns a generic error code, [SQLITE_ERROR], following any 4465 ** error other than [SQLITE_BUSY] and [SQLITE_MISUSE]. You must call 4466 ** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the 4467 ** specific [error codes] that better describes the error. 4468 ** We admit that this is a goofy design. The problem has been fixed 4469 ** with the "v2" interface. If you prepare all of your SQL statements 4470 ** using [sqlite3_prepare_v3()] or [sqlite3_prepare_v2()] 4471 ** or [sqlite3_prepare16_v2()] or [sqlite3_prepare16_v3()] instead 4472 ** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces, 4473 ** then the more specific [error codes] are returned directly 4474 ** by sqlite3_step(). The use of the "vX" interfaces is recommended. 4475 */ 4476 SQLITE_API int sqlite3_step(sqlite3_stmt*); 4477 4478 /* 4479 ** CAPI3REF: Number of columns in a result set 4480 ** METHOD: sqlite3_stmt 4481 ** 4482 ** ^The sqlite3_data_count(P) interface returns the number of columns in the 4483 ** current row of the result set of [prepared statement] P. 4484 ** ^If prepared statement P does not have results ready to return 4485 ** (via calls to the [sqlite3_column_int | sqlite3_column_*()] of 4486 ** interfaces) then sqlite3_data_count(P) returns 0. 4487 ** ^The sqlite3_data_count(P) routine also returns 0 if P is a NULL pointer. 4488 ** ^The sqlite3_data_count(P) routine returns 0 if the previous call to 4489 ** [sqlite3_step](P) returned [SQLITE_DONE]. ^The sqlite3_data_count(P) 4490 ** will return non-zero if previous call to [sqlite3_step](P) returned 4491 ** [SQLITE_ROW], except in the case of the [PRAGMA incremental_vacuum] 4492 ** where it always returns zero since each step of that multi-step 4493 ** pragma returns 0 columns of data. 4494 ** 4495 ** See also: [sqlite3_column_count()] 4496 */ 4497 SQLITE_API int sqlite3_data_count(sqlite3_stmt *pStmt); 4498 4499 /* 4500 ** CAPI3REF: Fundamental Datatypes 4501 ** KEYWORDS: SQLITE_TEXT 4502 ** 4503 ** ^(Every value in SQLite has one of five fundamental datatypes: 4504 ** 4505 ** <ul> 4506 ** <li> 64-bit signed integer 4507 ** <li> 64-bit IEEE floating point number 4508 ** <li> string 4509 ** <li> BLOB 4510 ** <li> NULL 4511 ** </ul>)^ 4512 ** 4513 ** These constants are codes for each of those types. 4514 ** 4515 ** Note that the SQLITE_TEXT constant was also used in SQLite version 2 4516 ** for a completely different meaning. Software that links against both 4517 ** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not 4518 ** SQLITE_TEXT. 4519 */ 4520 #define SQLITE_INTEGER 1 4521 #define SQLITE_FLOAT 2 4522 #define SQLITE_BLOB 4 4523 #define SQLITE_NULL 5 4524 #ifdef SQLITE_TEXT 4525 # undef SQLITE_TEXT 4526 #else 4527 # define SQLITE_TEXT 3 4528 #endif 4529 #define SQLITE3_TEXT 3 4530 4531 /* 4532 ** CAPI3REF: Result Values From A Query 4533 ** KEYWORDS: {column access functions} 4534 ** METHOD: sqlite3_stmt 4535 ** 4536 ** <b>Summary:</b> 4537 ** <blockquote><table border=0 cellpadding=0 cellspacing=0> 4538 ** <tr><td><b>sqlite3_column_blob</b><td>→<td>BLOB result 4539 ** <tr><td><b>sqlite3_column_double</b><td>→<td>REAL result 4540 ** <tr><td><b>sqlite3_column_int</b><td>→<td>32-bit INTEGER result 4541 ** <tr><td><b>sqlite3_column_int64</b><td>→<td>64-bit INTEGER result 4542 ** <tr><td><b>sqlite3_column_text</b><td>→<td>UTF-8 TEXT result 4543 ** <tr><td><b>sqlite3_column_text16</b><td>→<td>UTF-16 TEXT result 4544 ** <tr><td><b>sqlite3_column_value</b><td>→<td>The result as an 4545 ** [sqlite3_value|unprotected sqlite3_value] object. 4546 ** <tr><td> <td> <td> 4547 ** <tr><td><b>sqlite3_column_bytes</b><td>→<td>Size of a BLOB 4548 ** or a UTF-8 TEXT result in bytes 4549 ** <tr><td><b>sqlite3_column_bytes16 </b> 4550 ** <td>→ <td>Size of UTF-16 4551 ** TEXT in bytes 4552 ** <tr><td><b>sqlite3_column_type</b><td>→<td>Default 4553 ** datatype of the result 4554 ** </table></blockquote> 4555 ** 4556 ** <b>Details:</b> 4557 ** 4558 ** ^These routines return information about a single column of the current 4559 ** result row of a query. ^In every case the first argument is a pointer 4560 ** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*] 4561 ** that was returned from [sqlite3_prepare_v2()] or one of its variants) 4562 ** and the second argument is the index of the column for which information 4563 ** should be returned. ^The leftmost column of the result set has the index 0. 4564 ** ^The number of columns in the result can be determined using 4565 ** [sqlite3_column_count()]. 4566 ** 4567 ** If the SQL statement does not currently point to a valid row, or if the 4568 ** column index is out of range, the result is undefined. 4569 ** These routines may only be called when the most recent call to 4570 ** [sqlite3_step()] has returned [SQLITE_ROW] and neither 4571 ** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently. 4572 ** If any of these routines are called after [sqlite3_reset()] or 4573 ** [sqlite3_finalize()] or after [sqlite3_step()] has returned 4574 ** something other than [SQLITE_ROW], the results are undefined. 4575 ** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()] 4576 ** are called from a different thread while any of these routines 4577 ** are pending, then the results are undefined. 4578 ** 4579 ** The first six interfaces (_blob, _double, _int, _int64, _text, and _text16) 4580 ** each return the value of a result column in a specific data format. If 4581 ** the result column is not initially in the requested format (for example, 4582 ** if the query returns an integer but the sqlite3_column_text() interface 4583 ** is used to extract the value) then an automatic type conversion is performed. 4584 ** 4585 ** ^The sqlite3_column_type() routine returns the 4586 ** [SQLITE_INTEGER | datatype code] for the initial data type 4587 ** of the result column. ^The returned value is one of [SQLITE_INTEGER], 4588 ** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL]. 4589 ** The return value of sqlite3_column_type() can be used to decide which 4590 ** of the first six interface should be used to extract the column value. 4591 ** The value returned by sqlite3_column_type() is only meaningful if no 4592 ** automatic type conversions have occurred for the value in question. 4593 ** After a type conversion, the result of calling sqlite3_column_type() 4594 ** is undefined, though harmless. Future 4595 ** versions of SQLite may change the behavior of sqlite3_column_type() 4596 ** following a type conversion. 4597 ** 4598 ** If the result is a BLOB or a TEXT string, then the sqlite3_column_bytes() 4599 ** or sqlite3_column_bytes16() interfaces can be used to determine the size 4600 ** of that BLOB or string. 4601 ** 4602 ** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes() 4603 ** routine returns the number of bytes in that BLOB or string. 4604 ** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts 4605 ** the string to UTF-8 and then returns the number of bytes. 4606 ** ^If the result is a numeric value then sqlite3_column_bytes() uses 4607 ** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns 4608 ** the number of bytes in that string. 4609 ** ^If the result is NULL, then sqlite3_column_bytes() returns zero. 4610 ** 4611 ** ^If the result is a BLOB or UTF-16 string then the sqlite3_column_bytes16() 4612 ** routine returns the number of bytes in that BLOB or string. 4613 ** ^If the result is a UTF-8 string, then sqlite3_column_bytes16() converts 4614 ** the string to UTF-16 and then returns the number of bytes. 4615 ** ^If the result is a numeric value then sqlite3_column_bytes16() uses 4616 ** [sqlite3_snprintf()] to convert that value to a UTF-16 string and returns 4617 ** the number of bytes in that string. 4618 ** ^If the result is NULL, then sqlite3_column_bytes16() returns zero. 4619 ** 4620 ** ^The values returned by [sqlite3_column_bytes()] and 4621 ** [sqlite3_column_bytes16()] do not include the zero terminators at the end 4622 ** of the string. ^For clarity: the values returned by 4623 ** [sqlite3_column_bytes()] and [sqlite3_column_bytes16()] are the number of 4624 ** bytes in the string, not the number of characters. 4625 ** 4626 ** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(), 4627 ** even empty strings, are always zero-terminated. ^The return 4628 ** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer. 4629 ** 4630 ** <b>Warning:</b> ^The object returned by [sqlite3_column_value()] is an 4631 ** [unprotected sqlite3_value] object. In a multithreaded environment, 4632 ** an unprotected sqlite3_value object may only be used safely with 4633 ** [sqlite3_bind_value()] and [sqlite3_result_value()]. 4634 ** If the [unprotected sqlite3_value] object returned by 4635 ** [sqlite3_column_value()] is used in any other way, including calls 4636 ** to routines like [sqlite3_value_int()], [sqlite3_value_text()], 4637 ** or [sqlite3_value_bytes()], the behavior is not threadsafe. 4638 ** Hence, the sqlite3_column_value() interface 4639 ** is normally only useful within the implementation of 4640 ** [application-defined SQL functions] or [virtual tables], not within 4641 ** top-level application code. 4642 ** 4643 ** The these routines may attempt to convert the datatype of the result. 4644 ** ^For example, if the internal representation is FLOAT and a text result 4645 ** is requested, [sqlite3_snprintf()] is used internally to perform the 4646 ** conversion automatically. ^(The following table details the conversions 4647 ** that are applied: 4648 ** 4649 ** <blockquote> 4650 ** <table border="1"> 4651 ** <tr><th> Internal<br>Type <th> Requested<br>Type <th> Conversion 4652 ** 4653 ** <tr><td> NULL <td> INTEGER <td> Result is 0 4654 ** <tr><td> NULL <td> FLOAT <td> Result is 0.0 4655 ** <tr><td> NULL <td> TEXT <td> Result is a NULL pointer 4656 ** <tr><td> NULL <td> BLOB <td> Result is a NULL pointer 4657 ** <tr><td> INTEGER <td> FLOAT <td> Convert from integer to float 4658 ** <tr><td> INTEGER <td> TEXT <td> ASCII rendering of the integer 4659 ** <tr><td> INTEGER <td> BLOB <td> Same as INTEGER->TEXT 4660 ** <tr><td> FLOAT <td> INTEGER <td> [CAST] to INTEGER 4661 ** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float 4662 ** <tr><td> FLOAT <td> BLOB <td> [CAST] to BLOB 4663 ** <tr><td> TEXT <td> INTEGER <td> [CAST] to INTEGER 4664 ** <tr><td> TEXT <td> FLOAT <td> [CAST] to REAL 4665 ** <tr><td> TEXT <td> BLOB <td> No change 4666 ** <tr><td> BLOB <td> INTEGER <td> [CAST] to INTEGER 4667 ** <tr><td> BLOB <td> FLOAT <td> [CAST] to REAL 4668 ** <tr><td> BLOB <td> TEXT <td> Add a zero terminator if needed 4669 ** </table> 4670 ** </blockquote>)^ 4671 ** 4672 ** Note that when type conversions occur, pointers returned by prior 4673 ** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or 4674 ** sqlite3_column_text16() may be invalidated. 4675 ** Type conversions and pointer invalidations might occur 4676 ** in the following cases: 4677 ** 4678 ** <ul> 4679 ** <li> The initial content is a BLOB and sqlite3_column_text() or 4680 ** sqlite3_column_text16() is called. A zero-terminator might 4681 ** need to be added to the string.</li> 4682 ** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or 4683 ** sqlite3_column_text16() is called. The content must be converted 4684 ** to UTF-16.</li> 4685 ** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or 4686 ** sqlite3_column_text() is called. The content must be converted 4687 ** to UTF-8.</li> 4688 ** </ul> 4689 ** 4690 ** ^Conversions between UTF-16be and UTF-16le are always done in place and do 4691 ** not invalidate a prior pointer, though of course the content of the buffer 4692 ** that the prior pointer references will have been modified. Other kinds 4693 ** of conversion are done in place when it is possible, but sometimes they 4694 ** are not possible and in those cases prior pointers are invalidated. 4695 ** 4696 ** The safest policy is to invoke these routines 4697 ** in one of the following ways: 4698 ** 4699 ** <ul> 4700 ** <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li> 4701 ** <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li> 4702 ** <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li> 4703 ** </ul> 4704 ** 4705 ** In other words, you should call sqlite3_column_text(), 4706 ** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result 4707 ** into the desired format, then invoke sqlite3_column_bytes() or 4708 ** sqlite3_column_bytes16() to find the size of the result. Do not mix calls 4709 ** to sqlite3_column_text() or sqlite3_column_blob() with calls to 4710 ** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16() 4711 ** with calls to sqlite3_column_bytes(). 4712 ** 4713 ** ^The pointers returned are valid until a type conversion occurs as 4714 ** described above, or until [sqlite3_step()] or [sqlite3_reset()] or 4715 ** [sqlite3_finalize()] is called. ^The memory space used to hold strings 4716 ** and BLOBs is freed automatically. Do not pass the pointers returned 4717 ** from [sqlite3_column_blob()], [sqlite3_column_text()], etc. into 4718 ** [sqlite3_free()]. 4719 ** 4720 ** As long as the input parameters are correct, these routines will only 4721 ** fail if an out-of-memory error occurs during a format conversion. 4722 ** Only the following subset of interfaces are subject to out-of-memory 4723 ** errors: 4724 ** 4725 ** <ul> 4726 ** <li> sqlite3_column_blob() 4727 ** <li> sqlite3_column_text() 4728 ** <li> sqlite3_column_text16() 4729 ** <li> sqlite3_column_bytes() 4730 ** <li> sqlite3_column_bytes16() 4731 ** </ul> 4732 ** 4733 ** If an out-of-memory error occurs, then the return value from these 4734 ** routines is the same as if the column had contained an SQL NULL value. 4735 ** Valid SQL NULL returns can be distinguished from out-of-memory errors 4736 ** by invoking the [sqlite3_errcode()] immediately after the suspect 4737 ** return value is obtained and before any 4738 ** other SQLite interface is called on the same [database connection]. 4739 */ 4740 SQLITE_API const void *sqlite3_column_blob(sqlite3_stmt*, int iCol); 4741 SQLITE_API double sqlite3_column_double(sqlite3_stmt*, int iCol); 4742 SQLITE_API int sqlite3_column_int(sqlite3_stmt*, int iCol); 4743 SQLITE_API sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol); 4744 SQLITE_API const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol); 4745 SQLITE_API const void *sqlite3_column_text16(sqlite3_stmt*, int iCol); 4746 SQLITE_API sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol); 4747 SQLITE_API int sqlite3_column_bytes(sqlite3_stmt*, int iCol); 4748 SQLITE_API int sqlite3_column_bytes16(sqlite3_stmt*, int iCol); 4749 SQLITE_API int sqlite3_column_type(sqlite3_stmt*, int iCol); 4750 4751 /* 4752 ** CAPI3REF: Destroy A Prepared Statement Object 4753 ** DESTRUCTOR: sqlite3_stmt 4754 ** 4755 ** ^The sqlite3_finalize() function is called to delete a [prepared statement]. 4756 ** ^If the most recent evaluation of the statement encountered no errors 4757 ** or if the statement is never been evaluated, then sqlite3_finalize() returns 4758 ** SQLITE_OK. ^If the most recent evaluation of statement S failed, then 4759 ** sqlite3_finalize(S) returns the appropriate [error code] or 4760 ** [extended error code]. 4761 ** 4762 ** ^The sqlite3_finalize(S) routine can be called at any point during 4763 ** the life cycle of [prepared statement] S: 4764 ** before statement S is ever evaluated, after 4765 ** one or more calls to [sqlite3_reset()], or after any call 4766 ** to [sqlite3_step()] regardless of whether or not the statement has 4767 ** completed execution. 4768 ** 4769 ** ^Invoking sqlite3_finalize() on a NULL pointer is a harmless no-op. 4770 ** 4771 ** The application must finalize every [prepared statement] in order to avoid 4772 ** resource leaks. It is a grievous error for the application to try to use 4773 ** a prepared statement after it has been finalized. Any use of a prepared 4774 ** statement after it has been finalized can result in undefined and 4775 ** undesirable behavior such as segfaults and heap corruption. 4776 */ 4777 SQLITE_API int sqlite3_finalize(sqlite3_stmt *pStmt); 4778 4779 /* 4780 ** CAPI3REF: Reset A Prepared Statement Object 4781 ** METHOD: sqlite3_stmt 4782 ** 4783 ** The sqlite3_reset() function is called to reset a [prepared statement] 4784 ** object back to its initial state, ready to be re-executed. 4785 ** ^Any SQL statement variables that had values bound to them using 4786 ** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values. 4787 ** Use [sqlite3_clear_bindings()] to reset the bindings. 4788 ** 4789 ** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S 4790 ** back to the beginning of its program. 4791 ** 4792 ** ^If the most recent call to [sqlite3_step(S)] for the 4793 ** [prepared statement] S returned [SQLITE_ROW] or [SQLITE_DONE], 4794 ** or if [sqlite3_step(S)] has never before been called on S, 4795 ** then [sqlite3_reset(S)] returns [SQLITE_OK]. 4796 ** 4797 ** ^If the most recent call to [sqlite3_step(S)] for the 4798 ** [prepared statement] S indicated an error, then 4799 ** [sqlite3_reset(S)] returns an appropriate [error code]. 4800 ** 4801 ** ^The [sqlite3_reset(S)] interface does not change the values 4802 ** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S. 4803 */ 4804 SQLITE_API int sqlite3_reset(sqlite3_stmt *pStmt); 4805 4806 /* 4807 ** CAPI3REF: Create Or Redefine SQL Functions 4808 ** KEYWORDS: {function creation routines} 4809 ** KEYWORDS: {application-defined SQL function} 4810 ** KEYWORDS: {application-defined SQL functions} 4811 ** METHOD: sqlite3 4812 ** 4813 ** ^These functions (collectively known as "function creation routines") 4814 ** are used to add SQL functions or aggregates or to redefine the behavior 4815 ** of existing SQL functions or aggregates. The only differences between 4816 ** the three "sqlite3_create_function*" routines are the text encoding 4817 ** expected for the second parameter (the name of the function being 4818 ** created) and the presence or absence of a destructor callback for 4819 ** the application data pointer. Function sqlite3_create_window_function() 4820 ** is similar, but allows the user to supply the extra callback functions 4821 ** needed by [aggregate window functions]. 4822 ** 4823 ** ^The first parameter is the [database connection] to which the SQL 4824 ** function is to be added. ^If an application uses more than one database 4825 ** connection then application-defined SQL functions must be added 4826 ** to each database connection separately. 4827 ** 4828 ** ^The second parameter is the name of the SQL function to be created or 4829 ** redefined. ^The length of the name is limited to 255 bytes in a UTF-8 4830 ** representation, exclusive of the zero-terminator. ^Note that the name 4831 ** length limit is in UTF-8 bytes, not characters nor UTF-16 bytes. 4832 ** ^Any attempt to create a function with a longer name 4833 ** will result in [SQLITE_MISUSE] being returned. 4834 ** 4835 ** ^The third parameter (nArg) 4836 ** is the number of arguments that the SQL function or 4837 ** aggregate takes. ^If this parameter is -1, then the SQL function or 4838 ** aggregate may take any number of arguments between 0 and the limit 4839 ** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]). If the third 4840 ** parameter is less than -1 or greater than 127 then the behavior is 4841 ** undefined. 4842 ** 4843 ** ^The fourth parameter, eTextRep, specifies what 4844 ** [SQLITE_UTF8 | text encoding] this SQL function prefers for 4845 ** its parameters. The application should set this parameter to 4846 ** [SQLITE_UTF16LE] if the function implementation invokes 4847 ** [sqlite3_value_text16le()] on an input, or [SQLITE_UTF16BE] if the 4848 ** implementation invokes [sqlite3_value_text16be()] on an input, or 4849 ** [SQLITE_UTF16] if [sqlite3_value_text16()] is used, or [SQLITE_UTF8] 4850 ** otherwise. ^The same SQL function may be registered multiple times using 4851 ** different preferred text encodings, with different implementations for 4852 ** each encoding. 4853 ** ^When multiple implementations of the same function are available, SQLite 4854 ** will pick the one that involves the least amount of data conversion. 4855 ** 4856 ** ^The fourth parameter may optionally be ORed with [SQLITE_DETERMINISTIC] 4857 ** to signal that the function will always return the same result given 4858 ** the same inputs within a single SQL statement. Most SQL functions are 4859 ** deterministic. The built-in [random()] SQL function is an example of a 4860 ** function that is not deterministic. The SQLite query planner is able to 4861 ** perform additional optimizations on deterministic functions, so use 4862 ** of the [SQLITE_DETERMINISTIC] flag is recommended where possible. 4863 ** 4864 ** ^The fourth parameter may also optionally include the [SQLITE_DIRECTONLY] 4865 ** flag, which if present prevents the function from being invoked from 4866 ** within VIEWs or TRIGGERs. For security reasons, the [SQLITE_DIRECTONLY] 4867 ** flag is recommended for any application-defined SQL function that has 4868 ** side-effects. 4869 ** 4870 ** ^(The fifth parameter is an arbitrary pointer. The implementation of the 4871 ** function can gain access to this pointer using [sqlite3_user_data()].)^ 4872 ** 4873 ** ^The sixth, seventh and eighth parameters passed to the three 4874 ** "sqlite3_create_function*" functions, xFunc, xStep and xFinal, are 4875 ** pointers to C-language functions that implement the SQL function or 4876 ** aggregate. ^A scalar SQL function requires an implementation of the xFunc 4877 ** callback only; NULL pointers must be passed as the xStep and xFinal 4878 ** parameters. ^An aggregate SQL function requires an implementation of xStep 4879 ** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing 4880 ** SQL function or aggregate, pass NULL pointers for all three function 4881 ** callbacks. 4882 ** 4883 ** ^The sixth, seventh, eighth and ninth parameters (xStep, xFinal, xValue 4884 ** and xInverse) passed to sqlite3_create_window_function are pointers to 4885 ** C-language callbacks that implement the new function. xStep and xFinal 4886 ** must both be non-NULL. xValue and xInverse may either both be NULL, in 4887 ** which case a regular aggregate function is created, or must both be 4888 ** non-NULL, in which case the new function may be used as either an aggregate 4889 ** or aggregate window function. More details regarding the implementation 4890 ** of aggregate window functions are 4891 ** [user-defined window functions|available here]. 4892 ** 4893 ** ^(If the final parameter to sqlite3_create_function_v2() or 4894 ** sqlite3_create_window_function() is not NULL, then it is destructor for 4895 ** the application data pointer. The destructor is invoked when the function 4896 ** is deleted, either by being overloaded or when the database connection 4897 ** closes.)^ ^The destructor is also invoked if the call to 4898 ** sqlite3_create_function_v2() fails. ^When the destructor callback is 4899 ** invoked, it is passed a single argument which is a copy of the application 4900 ** data pointer which was the fifth parameter to sqlite3_create_function_v2(). 4901 ** 4902 ** ^It is permitted to register multiple implementations of the same 4903 ** functions with the same name but with either differing numbers of 4904 ** arguments or differing preferred text encodings. ^SQLite will use 4905 ** the implementation that most closely matches the way in which the 4906 ** SQL function is used. ^A function implementation with a non-negative 4907 ** nArg parameter is a better match than a function implementation with 4908 ** a negative nArg. ^A function where the preferred text encoding 4909 ** matches the database encoding is a better 4910 ** match than a function where the encoding is different. 4911 ** ^A function where the encoding difference is between UTF16le and UTF16be 4912 ** is a closer match than a function where the encoding difference is 4913 ** between UTF8 and UTF16. 4914 ** 4915 ** ^Built-in functions may be overloaded by new application-defined functions. 4916 ** 4917 ** ^An application-defined function is permitted to call other 4918 ** SQLite interfaces. However, such calls must not 4919 ** close the database connection nor finalize or reset the prepared 4920 ** statement in which the function is running. 4921 */ 4922 SQLITE_API int sqlite3_create_function( 4923 sqlite3 *db, 4924 const char *zFunctionName, 4925 int nArg, 4926 int eTextRep, 4927 void *pApp, 4928 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 4929 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 4930 void (*xFinal)(sqlite3_context*) 4931 ); 4932 SQLITE_API int sqlite3_create_function16( 4933 sqlite3 *db, 4934 const void *zFunctionName, 4935 int nArg, 4936 int eTextRep, 4937 void *pApp, 4938 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 4939 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 4940 void (*xFinal)(sqlite3_context*) 4941 ); 4942 SQLITE_API int sqlite3_create_function_v2( 4943 sqlite3 *db, 4944 const char *zFunctionName, 4945 int nArg, 4946 int eTextRep, 4947 void *pApp, 4948 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 4949 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 4950 void (*xFinal)(sqlite3_context*), 4951 void(*xDestroy)(void*) 4952 ); 4953 SQLITE_API int sqlite3_create_window_function( 4954 sqlite3 *db, 4955 const char *zFunctionName, 4956 int nArg, 4957 int eTextRep, 4958 void *pApp, 4959 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 4960 void (*xFinal)(sqlite3_context*), 4961 void (*xValue)(sqlite3_context*), 4962 void (*xInverse)(sqlite3_context*,int,sqlite3_value**), 4963 void(*xDestroy)(void*) 4964 ); 4965 4966 /* 4967 ** CAPI3REF: Text Encodings 4968 ** 4969 ** These constant define integer codes that represent the various 4970 ** text encodings supported by SQLite. 4971 */ 4972 #define SQLITE_UTF8 1 /* IMP: R-37514-35566 */ 4973 #define SQLITE_UTF16LE 2 /* IMP: R-03371-37637 */ 4974 #define SQLITE_UTF16BE 3 /* IMP: R-51971-34154 */ 4975 #define SQLITE_UTF16 4 /* Use native byte order */ 4976 #define SQLITE_ANY 5 /* Deprecated */ 4977 #define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */ 4978 4979 /* 4980 ** CAPI3REF: Function Flags 4981 ** 4982 ** These constants may be ORed together with the 4983 ** [SQLITE_UTF8 | preferred text encoding] as the fourth argument 4984 ** to [sqlite3_create_function()], [sqlite3_create_function16()], or 4985 ** [sqlite3_create_function_v2()]. 4986 ** 4987 ** The SQLITE_DETERMINISTIC flag means that the new function will always 4988 ** maps the same inputs into the same output. The abs() function is 4989 ** deterministic, for example, but randomblob() is not. 4990 ** 4991 ** The SQLITE_DIRECTONLY flag means that the function may only be invoked 4992 ** from top-level SQL, and cannot be used in VIEWs or TRIGGERs. This is 4993 ** a security feature which is recommended for all 4994 ** [application-defined SQL functions] that have side-effects. This flag 4995 ** prevents an attacker from adding triggers and views to a schema then 4996 ** tricking a high-privilege application into causing unintended side-effects 4997 ** while performing ordinary queries. 4998 ** 4999 ** The SQLITE_SUBTYPE flag indicates to SQLite that a function may call 5000 ** [sqlite3_value_subtype()] to inspect the sub-types of its arguments. 5001 ** Specifying this flag makes no difference for scalar or aggregate user 5002 ** functions. However, if it is not specified for a user-defined window 5003 ** function, then any sub-types belonging to arguments passed to the window 5004 ** function may be discarded before the window function is called (i.e. 5005 ** sqlite3_value_subtype() will always return 0). 5006 */ 5007 #define SQLITE_DETERMINISTIC 0x000000800 5008 #define SQLITE_DIRECTONLY 0x000080000 5009 #define SQLITE_SUBTYPE 0x000100000 5010 5011 /* 5012 ** CAPI3REF: Deprecated Functions 5013 ** DEPRECATED 5014 ** 5015 ** These functions are [deprecated]. In order to maintain 5016 ** backwards compatibility with older code, these functions continue 5017 ** to be supported. However, new applications should avoid 5018 ** the use of these functions. To encourage programmers to avoid 5019 ** these functions, we will not explain what they do. 5020 */ 5021 #ifndef SQLITE_OMIT_DEPRECATED 5022 SQLITE_API SQLITE_DEPRECATED int sqlite3_aggregate_count(sqlite3_context*); 5023 SQLITE_API SQLITE_DEPRECATED int sqlite3_expired(sqlite3_stmt*); 5024 SQLITE_API SQLITE_DEPRECATED int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*); 5025 SQLITE_API SQLITE_DEPRECATED int sqlite3_global_recover(void); 5026 SQLITE_API SQLITE_DEPRECATED void sqlite3_thread_cleanup(void); 5027 SQLITE_API SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int), 5028 void*,sqlite3_int64); 5029 #endif 5030 5031 /* 5032 ** CAPI3REF: Obtaining SQL Values 5033 ** METHOD: sqlite3_value 5034 ** 5035 ** <b>Summary:</b> 5036 ** <blockquote><table border=0 cellpadding=0 cellspacing=0> 5037 ** <tr><td><b>sqlite3_value_blob</b><td>→<td>BLOB value 5038 ** <tr><td><b>sqlite3_value_double</b><td>→<td>REAL value 5039 ** <tr><td><b>sqlite3_value_int</b><td>→<td>32-bit INTEGER value 5040 ** <tr><td><b>sqlite3_value_int64</b><td>→<td>64-bit INTEGER value 5041 ** <tr><td><b>sqlite3_value_pointer</b><td>→<td>Pointer value 5042 ** <tr><td><b>sqlite3_value_text</b><td>→<td>UTF-8 TEXT value 5043 ** <tr><td><b>sqlite3_value_text16</b><td>→<td>UTF-16 TEXT value in 5044 ** the native byteorder 5045 ** <tr><td><b>sqlite3_value_text16be</b><td>→<td>UTF-16be TEXT value 5046 ** <tr><td><b>sqlite3_value_text16le</b><td>→<td>UTF-16le TEXT value 5047 ** <tr><td> <td> <td> 5048 ** <tr><td><b>sqlite3_value_bytes</b><td>→<td>Size of a BLOB 5049 ** or a UTF-8 TEXT in bytes 5050 ** <tr><td><b>sqlite3_value_bytes16 </b> 5051 ** <td>→ <td>Size of UTF-16 5052 ** TEXT in bytes 5053 ** <tr><td><b>sqlite3_value_type</b><td>→<td>Default 5054 ** datatype of the value 5055 ** <tr><td><b>sqlite3_value_numeric_type </b> 5056 ** <td>→ <td>Best numeric datatype of the value 5057 ** <tr><td><b>sqlite3_value_nochange </b> 5058 ** <td>→ <td>True if the column is unchanged in an UPDATE 5059 ** against a virtual table. 5060 ** <tr><td><b>sqlite3_value_frombind </b> 5061 ** <td>→ <td>True if value originated from a [bound parameter] 5062 ** </table></blockquote> 5063 ** 5064 ** <b>Details:</b> 5065 ** 5066 ** These routines extract type, size, and content information from 5067 ** [protected sqlite3_value] objects. Protected sqlite3_value objects 5068 ** are used to pass parameter information into implementation of 5069 ** [application-defined SQL functions] and [virtual tables]. 5070 ** 5071 ** These routines work only with [protected sqlite3_value] objects. 5072 ** Any attempt to use these routines on an [unprotected sqlite3_value] 5073 ** is not threadsafe. 5074 ** 5075 ** ^These routines work just like the corresponding [column access functions] 5076 ** except that these routines take a single [protected sqlite3_value] object 5077 ** pointer instead of a [sqlite3_stmt*] pointer and an integer column number. 5078 ** 5079 ** ^The sqlite3_value_text16() interface extracts a UTF-16 string 5080 ** in the native byte-order of the host machine. ^The 5081 ** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces 5082 ** extract UTF-16 strings as big-endian and little-endian respectively. 5083 ** 5084 ** ^If [sqlite3_value] object V was initialized 5085 ** using [sqlite3_bind_pointer(S,I,P,X,D)] or [sqlite3_result_pointer(C,P,X,D)] 5086 ** and if X and Y are strings that compare equal according to strcmp(X,Y), 5087 ** then sqlite3_value_pointer(V,Y) will return the pointer P. ^Otherwise, 5088 ** sqlite3_value_pointer(V,Y) returns a NULL. The sqlite3_bind_pointer() 5089 ** routine is part of the [pointer passing interface] added for SQLite 3.20.0. 5090 ** 5091 ** ^(The sqlite3_value_type(V) interface returns the 5092 ** [SQLITE_INTEGER | datatype code] for the initial datatype of the 5093 ** [sqlite3_value] object V. The returned value is one of [SQLITE_INTEGER], 5094 ** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL].)^ 5095 ** Other interfaces might change the datatype for an sqlite3_value object. 5096 ** For example, if the datatype is initially SQLITE_INTEGER and 5097 ** sqlite3_value_text(V) is called to extract a text value for that 5098 ** integer, then subsequent calls to sqlite3_value_type(V) might return 5099 ** SQLITE_TEXT. Whether or not a persistent internal datatype conversion 5100 ** occurs is undefined and may change from one release of SQLite to the next. 5101 ** 5102 ** ^(The sqlite3_value_numeric_type() interface attempts to apply 5103 ** numeric affinity to the value. This means that an attempt is 5104 ** made to convert the value to an integer or floating point. If 5105 ** such a conversion is possible without loss of information (in other 5106 ** words, if the value is a string that looks like a number) 5107 ** then the conversion is performed. Otherwise no conversion occurs. 5108 ** The [SQLITE_INTEGER | datatype] after conversion is returned.)^ 5109 ** 5110 ** ^Within the [xUpdate] method of a [virtual table], the 5111 ** sqlite3_value_nochange(X) interface returns true if and only if 5112 ** the column corresponding to X is unchanged by the UPDATE operation 5113 ** that the xUpdate method call was invoked to implement and if 5114 ** and the prior [xColumn] method call that was invoked to extracted 5115 ** the value for that column returned without setting a result (probably 5116 ** because it queried [sqlite3_vtab_nochange()] and found that the column 5117 ** was unchanging). ^Within an [xUpdate] method, any value for which 5118 ** sqlite3_value_nochange(X) is true will in all other respects appear 5119 ** to be a NULL value. If sqlite3_value_nochange(X) is invoked anywhere other 5120 ** than within an [xUpdate] method call for an UPDATE statement, then 5121 ** the return value is arbitrary and meaningless. 5122 ** 5123 ** ^The sqlite3_value_frombind(X) interface returns non-zero if the 5124 ** value X originated from one of the [sqlite3_bind_int|sqlite3_bind()] 5125 ** interfaces. ^If X comes from an SQL literal value, or a table column, 5126 ** and expression, then sqlite3_value_frombind(X) returns zero. 5127 ** 5128 ** Please pay particular attention to the fact that the pointer returned 5129 ** from [sqlite3_value_blob()], [sqlite3_value_text()], or 5130 ** [sqlite3_value_text16()] can be invalidated by a subsequent call to 5131 ** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()], 5132 ** or [sqlite3_value_text16()]. 5133 ** 5134 ** These routines must be called from the same thread as 5135 ** the SQL function that supplied the [sqlite3_value*] parameters. 5136 ** 5137 ** As long as the input parameter is correct, these routines can only 5138 ** fail if an out-of-memory error occurs during a format conversion. 5139 ** Only the following subset of interfaces are subject to out-of-memory 5140 ** errors: 5141 ** 5142 ** <ul> 5143 ** <li> sqlite3_value_blob() 5144 ** <li> sqlite3_value_text() 5145 ** <li> sqlite3_value_text16() 5146 ** <li> sqlite3_value_text16le() 5147 ** <li> sqlite3_value_text16be() 5148 ** <li> sqlite3_value_bytes() 5149 ** <li> sqlite3_value_bytes16() 5150 ** </ul> 5151 ** 5152 ** If an out-of-memory error occurs, then the return value from these 5153 ** routines is the same as if the column had contained an SQL NULL value. 5154 ** Valid SQL NULL returns can be distinguished from out-of-memory errors 5155 ** by invoking the [sqlite3_errcode()] immediately after the suspect 5156 ** return value is obtained and before any 5157 ** other SQLite interface is called on the same [database connection]. 5158 */ 5159 SQLITE_API const void *sqlite3_value_blob(sqlite3_value*); 5160 SQLITE_API double sqlite3_value_double(sqlite3_value*); 5161 SQLITE_API int sqlite3_value_int(sqlite3_value*); 5162 SQLITE_API sqlite3_int64 sqlite3_value_int64(sqlite3_value*); 5163 SQLITE_API void *sqlite3_value_pointer(sqlite3_value*, const char*); 5164 SQLITE_API const unsigned char *sqlite3_value_text(sqlite3_value*); 5165 SQLITE_API const void *sqlite3_value_text16(sqlite3_value*); 5166 SQLITE_API const void *sqlite3_value_text16le(sqlite3_value*); 5167 SQLITE_API const void *sqlite3_value_text16be(sqlite3_value*); 5168 SQLITE_API int sqlite3_value_bytes(sqlite3_value*); 5169 SQLITE_API int sqlite3_value_bytes16(sqlite3_value*); 5170 SQLITE_API int sqlite3_value_type(sqlite3_value*); 5171 SQLITE_API int sqlite3_value_numeric_type(sqlite3_value*); 5172 SQLITE_API int sqlite3_value_nochange(sqlite3_value*); 5173 SQLITE_API int sqlite3_value_frombind(sqlite3_value*); 5174 5175 /* 5176 ** CAPI3REF: Finding The Subtype Of SQL Values 5177 ** METHOD: sqlite3_value 5178 ** 5179 ** The sqlite3_value_subtype(V) function returns the subtype for 5180 ** an [application-defined SQL function] argument V. The subtype 5181 ** information can be used to pass a limited amount of context from 5182 ** one SQL function to another. Use the [sqlite3_result_subtype()] 5183 ** routine to set the subtype for the return value of an SQL function. 5184 */ 5185 SQLITE_API unsigned int sqlite3_value_subtype(sqlite3_value*); 5186 5187 /* 5188 ** CAPI3REF: Copy And Free SQL Values 5189 ** METHOD: sqlite3_value 5190 ** 5191 ** ^The sqlite3_value_dup(V) interface makes a copy of the [sqlite3_value] 5192 ** object D and returns a pointer to that copy. ^The [sqlite3_value] returned 5193 ** is a [protected sqlite3_value] object even if the input is not. 5194 ** ^The sqlite3_value_dup(V) interface returns NULL if V is NULL or if a 5195 ** memory allocation fails. 5196 ** 5197 ** ^The sqlite3_value_free(V) interface frees an [sqlite3_value] object 5198 ** previously obtained from [sqlite3_value_dup()]. ^If V is a NULL pointer 5199 ** then sqlite3_value_free(V) is a harmless no-op. 5200 */ 5201 SQLITE_API sqlite3_value *sqlite3_value_dup(const sqlite3_value*); 5202 SQLITE_API void sqlite3_value_free(sqlite3_value*); 5203 5204 /* 5205 ** CAPI3REF: Obtain Aggregate Function Context 5206 ** METHOD: sqlite3_context 5207 ** 5208 ** Implementations of aggregate SQL functions use this 5209 ** routine to allocate memory for storing their state. 5210 ** 5211 ** ^The first time the sqlite3_aggregate_context(C,N) routine is called 5212 ** for a particular aggregate function, SQLite 5213 ** allocates N of memory, zeroes out that memory, and returns a pointer 5214 ** to the new memory. ^On second and subsequent calls to 5215 ** sqlite3_aggregate_context() for the same aggregate function instance, 5216 ** the same buffer is returned. Sqlite3_aggregate_context() is normally 5217 ** called once for each invocation of the xStep callback and then one 5218 ** last time when the xFinal callback is invoked. ^(When no rows match 5219 ** an aggregate query, the xStep() callback of the aggregate function 5220 ** implementation is never called and xFinal() is called exactly once. 5221 ** In those cases, sqlite3_aggregate_context() might be called for the 5222 ** first time from within xFinal().)^ 5223 ** 5224 ** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer 5225 ** when first called if N is less than or equal to zero or if a memory 5226 ** allocate error occurs. 5227 ** 5228 ** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is 5229 ** determined by the N parameter on first successful call. Changing the 5230 ** value of N in subsequent call to sqlite3_aggregate_context() within 5231 ** the same aggregate function instance will not resize the memory 5232 ** allocation.)^ Within the xFinal callback, it is customary to set 5233 ** N=0 in calls to sqlite3_aggregate_context(C,N) so that no 5234 ** pointless memory allocations occur. 5235 ** 5236 ** ^SQLite automatically frees the memory allocated by 5237 ** sqlite3_aggregate_context() when the aggregate query concludes. 5238 ** 5239 ** The first parameter must be a copy of the 5240 ** [sqlite3_context | SQL function context] that is the first parameter 5241 ** to the xStep or xFinal callback routine that implements the aggregate 5242 ** function. 5243 ** 5244 ** This routine must be called from the same thread in which 5245 ** the aggregate SQL function is running. 5246 */ 5247 SQLITE_API void *sqlite3_aggregate_context(sqlite3_context*, int nBytes); 5248 5249 /* 5250 ** CAPI3REF: User Data For Functions 5251 ** METHOD: sqlite3_context 5252 ** 5253 ** ^The sqlite3_user_data() interface returns a copy of 5254 ** the pointer that was the pUserData parameter (the 5th parameter) 5255 ** of the [sqlite3_create_function()] 5256 ** and [sqlite3_create_function16()] routines that originally 5257 ** registered the application defined function. 5258 ** 5259 ** This routine must be called from the same thread in which 5260 ** the application-defined function is running. 5261 */ 5262 SQLITE_API void *sqlite3_user_data(sqlite3_context*); 5263 5264 /* 5265 ** CAPI3REF: Database Connection For Functions 5266 ** METHOD: sqlite3_context 5267 ** 5268 ** ^The sqlite3_context_db_handle() interface returns a copy of 5269 ** the pointer to the [database connection] (the 1st parameter) 5270 ** of the [sqlite3_create_function()] 5271 ** and [sqlite3_create_function16()] routines that originally 5272 ** registered the application defined function. 5273 */ 5274 SQLITE_API sqlite3 *sqlite3_context_db_handle(sqlite3_context*); 5275 5276 /* 5277 ** CAPI3REF: Function Auxiliary Data 5278 ** METHOD: sqlite3_context 5279 ** 5280 ** These functions may be used by (non-aggregate) SQL functions to 5281 ** associate metadata with argument values. If the same value is passed to 5282 ** multiple invocations of the same SQL function during query execution, under 5283 ** some circumstances the associated metadata may be preserved. An example 5284 ** of where this might be useful is in a regular-expression matching 5285 ** function. The compiled version of the regular expression can be stored as 5286 ** metadata associated with the pattern string. 5287 ** Then as long as the pattern string remains the same, 5288 ** the compiled regular expression can be reused on multiple 5289 ** invocations of the same function. 5290 ** 5291 ** ^The sqlite3_get_auxdata(C,N) interface returns a pointer to the metadata 5292 ** associated by the sqlite3_set_auxdata(C,N,P,X) function with the Nth argument 5293 ** value to the application-defined function. ^N is zero for the left-most 5294 ** function argument. ^If there is no metadata 5295 ** associated with the function argument, the sqlite3_get_auxdata(C,N) interface 5296 ** returns a NULL pointer. 5297 ** 5298 ** ^The sqlite3_set_auxdata(C,N,P,X) interface saves P as metadata for the N-th 5299 ** argument of the application-defined function. ^Subsequent 5300 ** calls to sqlite3_get_auxdata(C,N) return P from the most recent 5301 ** sqlite3_set_auxdata(C,N,P,X) call if the metadata is still valid or 5302 ** NULL if the metadata has been discarded. 5303 ** ^After each call to sqlite3_set_auxdata(C,N,P,X) where X is not NULL, 5304 ** SQLite will invoke the destructor function X with parameter P exactly 5305 ** once, when the metadata is discarded. 5306 ** SQLite is free to discard the metadata at any time, including: <ul> 5307 ** <li> ^(when the corresponding function parameter changes)^, or 5308 ** <li> ^(when [sqlite3_reset()] or [sqlite3_finalize()] is called for the 5309 ** SQL statement)^, or 5310 ** <li> ^(when sqlite3_set_auxdata() is invoked again on the same 5311 ** parameter)^, or 5312 ** <li> ^(during the original sqlite3_set_auxdata() call when a memory 5313 ** allocation error occurs.)^ </ul> 5314 ** 5315 ** Note the last bullet in particular. The destructor X in 5316 ** sqlite3_set_auxdata(C,N,P,X) might be called immediately, before the 5317 ** sqlite3_set_auxdata() interface even returns. Hence sqlite3_set_auxdata() 5318 ** should be called near the end of the function implementation and the 5319 ** function implementation should not make any use of P after 5320 ** sqlite3_set_auxdata() has been called. 5321 ** 5322 ** ^(In practice, metadata is preserved between function calls for 5323 ** function parameters that are compile-time constants, including literal 5324 ** values and [parameters] and expressions composed from the same.)^ 5325 ** 5326 ** The value of the N parameter to these interfaces should be non-negative. 5327 ** Future enhancements may make use of negative N values to define new 5328 ** kinds of function caching behavior. 5329 ** 5330 ** These routines must be called from the same thread in which 5331 ** the SQL function is running. 5332 */ 5333 SQLITE_API void *sqlite3_get_auxdata(sqlite3_context*, int N); 5334 SQLITE_API void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*)); 5335 5336 5337 /* 5338 ** CAPI3REF: Constants Defining Special Destructor Behavior 5339 ** 5340 ** These are special values for the destructor that is passed in as the 5341 ** final argument to routines like [sqlite3_result_blob()]. ^If the destructor 5342 ** argument is SQLITE_STATIC, it means that the content pointer is constant 5343 ** and will never change. It does not need to be destroyed. ^The 5344 ** SQLITE_TRANSIENT value means that the content will likely change in 5345 ** the near future and that SQLite should make its own private copy of 5346 ** the content before returning. 5347 ** 5348 ** The typedef is necessary to work around problems in certain 5349 ** C++ compilers. 5350 */ 5351 typedef void (*sqlite3_destructor_type)(void*); 5352 #define SQLITE_STATIC ((sqlite3_destructor_type)0) 5353 #define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1) 5354 5355 /* 5356 ** CAPI3REF: Setting The Result Of An SQL Function 5357 ** METHOD: sqlite3_context 5358 ** 5359 ** These routines are used by the xFunc or xFinal callbacks that 5360 ** implement SQL functions and aggregates. See 5361 ** [sqlite3_create_function()] and [sqlite3_create_function16()] 5362 ** for additional information. 5363 ** 5364 ** These functions work very much like the [parameter binding] family of 5365 ** functions used to bind values to host parameters in prepared statements. 5366 ** Refer to the [SQL parameter] documentation for additional information. 5367 ** 5368 ** ^The sqlite3_result_blob() interface sets the result from 5369 ** an application-defined function to be the BLOB whose content is pointed 5370 ** to by the second parameter and which is N bytes long where N is the 5371 ** third parameter. 5372 ** 5373 ** ^The sqlite3_result_zeroblob(C,N) and sqlite3_result_zeroblob64(C,N) 5374 ** interfaces set the result of the application-defined function to be 5375 ** a BLOB containing all zero bytes and N bytes in size. 5376 ** 5377 ** ^The sqlite3_result_double() interface sets the result from 5378 ** an application-defined function to be a floating point value specified 5379 ** by its 2nd argument. 5380 ** 5381 ** ^The sqlite3_result_error() and sqlite3_result_error16() functions 5382 ** cause the implemented SQL function to throw an exception. 5383 ** ^SQLite uses the string pointed to by the 5384 ** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16() 5385 ** as the text of an error message. ^SQLite interprets the error 5386 ** message string from sqlite3_result_error() as UTF-8. ^SQLite 5387 ** interprets the string from sqlite3_result_error16() as UTF-16 in native 5388 ** byte order. ^If the third parameter to sqlite3_result_error() 5389 ** or sqlite3_result_error16() is negative then SQLite takes as the error 5390 ** message all text up through the first zero character. 5391 ** ^If the third parameter to sqlite3_result_error() or 5392 ** sqlite3_result_error16() is non-negative then SQLite takes that many 5393 ** bytes (not characters) from the 2nd parameter as the error message. 5394 ** ^The sqlite3_result_error() and sqlite3_result_error16() 5395 ** routines make a private copy of the error message text before 5396 ** they return. Hence, the calling function can deallocate or 5397 ** modify the text after they return without harm. 5398 ** ^The sqlite3_result_error_code() function changes the error code 5399 ** returned by SQLite as a result of an error in a function. ^By default, 5400 ** the error code is SQLITE_ERROR. ^A subsequent call to sqlite3_result_error() 5401 ** or sqlite3_result_error16() resets the error code to SQLITE_ERROR. 5402 ** 5403 ** ^The sqlite3_result_error_toobig() interface causes SQLite to throw an 5404 ** error indicating that a string or BLOB is too long to represent. 5405 ** 5406 ** ^The sqlite3_result_error_nomem() interface causes SQLite to throw an 5407 ** error indicating that a memory allocation failed. 5408 ** 5409 ** ^The sqlite3_result_int() interface sets the return value 5410 ** of the application-defined function to be the 32-bit signed integer 5411 ** value given in the 2nd argument. 5412 ** ^The sqlite3_result_int64() interface sets the return value 5413 ** of the application-defined function to be the 64-bit signed integer 5414 ** value given in the 2nd argument. 5415 ** 5416 ** ^The sqlite3_result_null() interface sets the return value 5417 ** of the application-defined function to be NULL. 5418 ** 5419 ** ^The sqlite3_result_text(), sqlite3_result_text16(), 5420 ** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces 5421 ** set the return value of the application-defined function to be 5422 ** a text string which is represented as UTF-8, UTF-16 native byte order, 5423 ** UTF-16 little endian, or UTF-16 big endian, respectively. 5424 ** ^The sqlite3_result_text64() interface sets the return value of an 5425 ** application-defined function to be a text string in an encoding 5426 ** specified by the fifth (and last) parameter, which must be one 5427 ** of [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE]. 5428 ** ^SQLite takes the text result from the application from 5429 ** the 2nd parameter of the sqlite3_result_text* interfaces. 5430 ** ^If the 3rd parameter to the sqlite3_result_text* interfaces 5431 ** is negative, then SQLite takes result text from the 2nd parameter 5432 ** through the first zero character. 5433 ** ^If the 3rd parameter to the sqlite3_result_text* interfaces 5434 ** is non-negative, then as many bytes (not characters) of the text 5435 ** pointed to by the 2nd parameter are taken as the application-defined 5436 ** function result. If the 3rd parameter is non-negative, then it 5437 ** must be the byte offset into the string where the NUL terminator would 5438 ** appear if the string where NUL terminated. If any NUL characters occur 5439 ** in the string at a byte offset that is less than the value of the 3rd 5440 ** parameter, then the resulting string will contain embedded NULs and the 5441 ** result of expressions operating on strings with embedded NULs is undefined. 5442 ** ^If the 4th parameter to the sqlite3_result_text* interfaces 5443 ** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that 5444 ** function as the destructor on the text or BLOB result when it has 5445 ** finished using that result. 5446 ** ^If the 4th parameter to the sqlite3_result_text* interfaces or to 5447 ** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite 5448 ** assumes that the text or BLOB result is in constant space and does not 5449 ** copy the content of the parameter nor call a destructor on the content 5450 ** when it has finished using that result. 5451 ** ^If the 4th parameter to the sqlite3_result_text* interfaces 5452 ** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT 5453 ** then SQLite makes a copy of the result into space obtained 5454 ** from [sqlite3_malloc()] before it returns. 5455 ** 5456 ** ^The sqlite3_result_value() interface sets the result of 5457 ** the application-defined function to be a copy of the 5458 ** [unprotected sqlite3_value] object specified by the 2nd parameter. ^The 5459 ** sqlite3_result_value() interface makes a copy of the [sqlite3_value] 5460 ** so that the [sqlite3_value] specified in the parameter may change or 5461 ** be deallocated after sqlite3_result_value() returns without harm. 5462 ** ^A [protected sqlite3_value] object may always be used where an 5463 ** [unprotected sqlite3_value] object is required, so either 5464 ** kind of [sqlite3_value] object can be used with this interface. 5465 ** 5466 ** ^The sqlite3_result_pointer(C,P,T,D) interface sets the result to an 5467 ** SQL NULL value, just like [sqlite3_result_null(C)], except that it 5468 ** also associates the host-language pointer P or type T with that 5469 ** NULL value such that the pointer can be retrieved within an 5470 ** [application-defined SQL function] using [sqlite3_value_pointer()]. 5471 ** ^If the D parameter is not NULL, then it is a pointer to a destructor 5472 ** for the P parameter. ^SQLite invokes D with P as its only argument 5473 ** when SQLite is finished with P. The T parameter should be a static 5474 ** string and preferably a string literal. The sqlite3_result_pointer() 5475 ** routine is part of the [pointer passing interface] added for SQLite 3.20.0. 5476 ** 5477 ** If these routines are called from within the different thread 5478 ** than the one containing the application-defined function that received 5479 ** the [sqlite3_context] pointer, the results are undefined. 5480 */ 5481 SQLITE_API void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*)); 5482 SQLITE_API void sqlite3_result_blob64(sqlite3_context*,const void*, 5483 sqlite3_uint64,void(*)(void*)); 5484 SQLITE_API void sqlite3_result_double(sqlite3_context*, double); 5485 SQLITE_API void sqlite3_result_error(sqlite3_context*, const char*, int); 5486 SQLITE_API void sqlite3_result_error16(sqlite3_context*, const void*, int); 5487 SQLITE_API void sqlite3_result_error_toobig(sqlite3_context*); 5488 SQLITE_API void sqlite3_result_error_nomem(sqlite3_context*); 5489 SQLITE_API void sqlite3_result_error_code(sqlite3_context*, int); 5490 SQLITE_API void sqlite3_result_int(sqlite3_context*, int); 5491 SQLITE_API void sqlite3_result_int64(sqlite3_context*, sqlite3_int64); 5492 SQLITE_API void sqlite3_result_null(sqlite3_context*); 5493 SQLITE_API void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*)); 5494 SQLITE_API void sqlite3_result_text64(sqlite3_context*, const char*,sqlite3_uint64, 5495 void(*)(void*), unsigned char encoding); 5496 SQLITE_API void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*)); 5497 SQLITE_API void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*)); 5498 SQLITE_API void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*)); 5499 SQLITE_API void sqlite3_result_value(sqlite3_context*, sqlite3_value*); 5500 SQLITE_API void sqlite3_result_pointer(sqlite3_context*, void*,const char*,void(*)(void*)); 5501 SQLITE_API void sqlite3_result_zeroblob(sqlite3_context*, int n); 5502 SQLITE_API int sqlite3_result_zeroblob64(sqlite3_context*, sqlite3_uint64 n); 5503 5504 5505 /* 5506 ** CAPI3REF: Setting The Subtype Of An SQL Function 5507 ** METHOD: sqlite3_context 5508 ** 5509 ** The sqlite3_result_subtype(C,T) function causes the subtype of 5510 ** the result from the [application-defined SQL function] with 5511 ** [sqlite3_context] C to be the value T. Only the lower 8 bits 5512 ** of the subtype T are preserved in current versions of SQLite; 5513 ** higher order bits are discarded. 5514 ** The number of subtype bytes preserved by SQLite might increase 5515 ** in future releases of SQLite. 5516 */ 5517 SQLITE_API void sqlite3_result_subtype(sqlite3_context*,unsigned int); 5518 5519 /* 5520 ** CAPI3REF: Define New Collating Sequences 5521 ** METHOD: sqlite3 5522 ** 5523 ** ^These functions add, remove, or modify a [collation] associated 5524 ** with the [database connection] specified as the first argument. 5525 ** 5526 ** ^The name of the collation is a UTF-8 string 5527 ** for sqlite3_create_collation() and sqlite3_create_collation_v2() 5528 ** and a UTF-16 string in native byte order for sqlite3_create_collation16(). 5529 ** ^Collation names that compare equal according to [sqlite3_strnicmp()] are 5530 ** considered to be the same name. 5531 ** 5532 ** ^(The third argument (eTextRep) must be one of the constants: 5533 ** <ul> 5534 ** <li> [SQLITE_UTF8], 5535 ** <li> [SQLITE_UTF16LE], 5536 ** <li> [SQLITE_UTF16BE], 5537 ** <li> [SQLITE_UTF16], or 5538 ** <li> [SQLITE_UTF16_ALIGNED]. 5539 ** </ul>)^ 5540 ** ^The eTextRep argument determines the encoding of strings passed 5541 ** to the collating function callback, xCallback. 5542 ** ^The [SQLITE_UTF16] and [SQLITE_UTF16_ALIGNED] values for eTextRep 5543 ** force strings to be UTF16 with native byte order. 5544 ** ^The [SQLITE_UTF16_ALIGNED] value for eTextRep forces strings to begin 5545 ** on an even byte address. 5546 ** 5547 ** ^The fourth argument, pArg, is an application data pointer that is passed 5548 ** through as the first argument to the collating function callback. 5549 ** 5550 ** ^The fifth argument, xCallback, is a pointer to the collating function. 5551 ** ^Multiple collating functions can be registered using the same name but 5552 ** with different eTextRep parameters and SQLite will use whichever 5553 ** function requires the least amount of data transformation. 5554 ** ^If the xCallback argument is NULL then the collating function is 5555 ** deleted. ^When all collating functions having the same name are deleted, 5556 ** that collation is no longer usable. 5557 ** 5558 ** ^The collating function callback is invoked with a copy of the pArg 5559 ** application data pointer and with two strings in the encoding specified 5560 ** by the eTextRep argument. The collating function must return an 5561 ** integer that is negative, zero, or positive 5562 ** if the first string is less than, equal to, or greater than the second, 5563 ** respectively. A collating function must always return the same answer 5564 ** given the same inputs. If two or more collating functions are registered 5565 ** to the same collation name (using different eTextRep values) then all 5566 ** must give an equivalent answer when invoked with equivalent strings. 5567 ** The collating function must obey the following properties for all 5568 ** strings A, B, and C: 5569 ** 5570 ** <ol> 5571 ** <li> If A==B then B==A. 5572 ** <li> If A==B and B==C then A==C. 5573 ** <li> If A<B THEN B>A. 5574 ** <li> If A<B and B<C then A<C. 5575 ** </ol> 5576 ** 5577 ** If a collating function fails any of the above constraints and that 5578 ** collating function is registered and used, then the behavior of SQLite 5579 ** is undefined. 5580 ** 5581 ** ^The sqlite3_create_collation_v2() works like sqlite3_create_collation() 5582 ** with the addition that the xDestroy callback is invoked on pArg when 5583 ** the collating function is deleted. 5584 ** ^Collating functions are deleted when they are overridden by later 5585 ** calls to the collation creation functions or when the 5586 ** [database connection] is closed using [sqlite3_close()]. 5587 ** 5588 ** ^The xDestroy callback is <u>not</u> called if the 5589 ** sqlite3_create_collation_v2() function fails. Applications that invoke 5590 ** sqlite3_create_collation_v2() with a non-NULL xDestroy argument should 5591 ** check the return code and dispose of the application data pointer 5592 ** themselves rather than expecting SQLite to deal with it for them. 5593 ** This is different from every other SQLite interface. The inconsistency 5594 ** is unfortunate but cannot be changed without breaking backwards 5595 ** compatibility. 5596 ** 5597 ** See also: [sqlite3_collation_needed()] and [sqlite3_collation_needed16()]. 5598 */ 5599 SQLITE_API int sqlite3_create_collation( 5600 sqlite3*, 5601 const char *zName, 5602 int eTextRep, 5603 void *pArg, 5604 int(*xCompare)(void*,int,const void*,int,const void*) 5605 ); 5606 SQLITE_API int sqlite3_create_collation_v2( 5607 sqlite3*, 5608 const char *zName, 5609 int eTextRep, 5610 void *pArg, 5611 int(*xCompare)(void*,int,const void*,int,const void*), 5612 void(*xDestroy)(void*) 5613 ); 5614 SQLITE_API int sqlite3_create_collation16( 5615 sqlite3*, 5616 const void *zName, 5617 int eTextRep, 5618 void *pArg, 5619 int(*xCompare)(void*,int,const void*,int,const void*) 5620 ); 5621 5622 /* 5623 ** CAPI3REF: Collation Needed Callbacks 5624 ** METHOD: sqlite3 5625 ** 5626 ** ^To avoid having to register all collation sequences before a database 5627 ** can be used, a single callback function may be registered with the 5628 ** [database connection] to be invoked whenever an undefined collation 5629 ** sequence is required. 5630 ** 5631 ** ^If the function is registered using the sqlite3_collation_needed() API, 5632 ** then it is passed the names of undefined collation sequences as strings 5633 ** encoded in UTF-8. ^If sqlite3_collation_needed16() is used, 5634 ** the names are passed as UTF-16 in machine native byte order. 5635 ** ^A call to either function replaces the existing collation-needed callback. 5636 ** 5637 ** ^(When the callback is invoked, the first argument passed is a copy 5638 ** of the second argument to sqlite3_collation_needed() or 5639 ** sqlite3_collation_needed16(). The second argument is the database 5640 ** connection. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE], 5641 ** or [SQLITE_UTF16LE], indicating the most desirable form of the collation 5642 ** sequence function required. The fourth parameter is the name of the 5643 ** required collation sequence.)^ 5644 ** 5645 ** The callback function should register the desired collation using 5646 ** [sqlite3_create_collation()], [sqlite3_create_collation16()], or 5647 ** [sqlite3_create_collation_v2()]. 5648 */ 5649 SQLITE_API int sqlite3_collation_needed( 5650 sqlite3*, 5651 void*, 5652 void(*)(void*,sqlite3*,int eTextRep,const char*) 5653 ); 5654 SQLITE_API int sqlite3_collation_needed16( 5655 sqlite3*, 5656 void*, 5657 void(*)(void*,sqlite3*,int eTextRep,const void*) 5658 ); 5659 5660 #ifdef SQLITE_HAS_CODEC 5661 /* 5662 ** Specify the key for an encrypted database. This routine should be 5663 ** called right after sqlite3_open(). 5664 ** 5665 ** The code to implement this API is not available in the public release 5666 ** of SQLite. 5667 */ 5668 SQLITE_API int sqlite3_key( 5669 sqlite3 *db, /* Database to be rekeyed */ 5670 const void *pKey, int nKey /* The key */ 5671 ); 5672 SQLITE_API int sqlite3_key_v2( 5673 sqlite3 *db, /* Database to be rekeyed */ 5674 const char *zDbName, /* Name of the database */ 5675 const void *pKey, int nKey /* The key */ 5676 ); 5677 5678 /* 5679 ** Change the key on an open database. If the current database is not 5680 ** encrypted, this routine will encrypt it. If pNew==0 or nNew==0, the 5681 ** database is decrypted. 5682 ** 5683 ** The code to implement this API is not available in the public release 5684 ** of SQLite. 5685 */ 5686 SQLITE_API int sqlite3_rekey( 5687 sqlite3 *db, /* Database to be rekeyed */ 5688 const void *pKey, int nKey /* The new key */ 5689 ); 5690 SQLITE_API int sqlite3_rekey_v2( 5691 sqlite3 *db, /* Database to be rekeyed */ 5692 const char *zDbName, /* Name of the database */ 5693 const void *pKey, int nKey /* The new key */ 5694 ); 5695 5696 /* 5697 ** Specify the activation key for a SEE database. Unless 5698 ** activated, none of the SEE routines will work. 5699 */ 5700 SQLITE_API void sqlite3_activate_see( 5701 const char *zPassPhrase /* Activation phrase */ 5702 ); 5703 #endif 5704 5705 #ifdef SQLITE_ENABLE_CEROD 5706 /* 5707 ** Specify the activation key for a CEROD database. Unless 5708 ** activated, none of the CEROD routines will work. 5709 */ 5710 SQLITE_API void sqlite3_activate_cerod( 5711 const char *zPassPhrase /* Activation phrase */ 5712 ); 5713 #endif 5714 5715 /* 5716 ** CAPI3REF: Suspend Execution For A Short Time 5717 ** 5718 ** The sqlite3_sleep() function causes the current thread to suspend execution 5719 ** for at least a number of milliseconds specified in its parameter. 5720 ** 5721 ** If the operating system does not support sleep requests with 5722 ** millisecond time resolution, then the time will be rounded up to 5723 ** the nearest second. The number of milliseconds of sleep actually 5724 ** requested from the operating system is returned. 5725 ** 5726 ** ^SQLite implements this interface by calling the xSleep() 5727 ** method of the default [sqlite3_vfs] object. If the xSleep() method 5728 ** of the default VFS is not implemented correctly, or not implemented at 5729 ** all, then the behavior of sqlite3_sleep() may deviate from the description 5730 ** in the previous paragraphs. 5731 */ 5732 SQLITE_API int sqlite3_sleep(int); 5733 5734 /* 5735 ** CAPI3REF: Name Of The Folder Holding Temporary Files 5736 ** 5737 ** ^(If this global variable is made to point to a string which is 5738 ** the name of a folder (a.k.a. directory), then all temporary files 5739 ** created by SQLite when using a built-in [sqlite3_vfs | VFS] 5740 ** will be placed in that directory.)^ ^If this variable 5741 ** is a NULL pointer, then SQLite performs a search for an appropriate 5742 ** temporary file directory. 5743 ** 5744 ** Applications are strongly discouraged from using this global variable. 5745 ** It is required to set a temporary folder on Windows Runtime (WinRT). 5746 ** But for all other platforms, it is highly recommended that applications 5747 ** neither read nor write this variable. This global variable is a relic 5748 ** that exists for backwards compatibility of legacy applications and should 5749 ** be avoided in new projects. 5750 ** 5751 ** It is not safe to read or modify this variable in more than one 5752 ** thread at a time. It is not safe to read or modify this variable 5753 ** if a [database connection] is being used at the same time in a separate 5754 ** thread. 5755 ** It is intended that this variable be set once 5756 ** as part of process initialization and before any SQLite interface 5757 ** routines have been called and that this variable remain unchanged 5758 ** thereafter. 5759 ** 5760 ** ^The [temp_store_directory pragma] may modify this variable and cause 5761 ** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 5762 ** the [temp_store_directory pragma] always assumes that any string 5763 ** that this variable points to is held in memory obtained from 5764 ** [sqlite3_malloc] and the pragma may attempt to free that memory 5765 ** using [sqlite3_free]. 5766 ** Hence, if this variable is modified directly, either it should be 5767 ** made NULL or made to point to memory obtained from [sqlite3_malloc] 5768 ** or else the use of the [temp_store_directory pragma] should be avoided. 5769 ** Except when requested by the [temp_store_directory pragma], SQLite 5770 ** does not free the memory that sqlite3_temp_directory points to. If 5771 ** the application wants that memory to be freed, it must do 5772 ** so itself, taking care to only do so after all [database connection] 5773 ** objects have been destroyed. 5774 ** 5775 ** <b>Note to Windows Runtime users:</b> The temporary directory must be set 5776 ** prior to calling [sqlite3_open] or [sqlite3_open_v2]. Otherwise, various 5777 ** features that require the use of temporary files may fail. Here is an 5778 ** example of how to do this using C++ with the Windows Runtime: 5779 ** 5780 ** <blockquote><pre> 5781 ** LPCWSTR zPath = Windows::Storage::ApplicationData::Current-> 5782 ** TemporaryFolder->Path->Data(); 5783 ** char zPathBuf[MAX_PATH + 1]; 5784 ** memset(zPathBuf, 0, sizeof(zPathBuf)); 5785 ** WideCharToMultiByte(CP_UTF8, 0, zPath, -1, zPathBuf, sizeof(zPathBuf), 5786 ** NULL, NULL); 5787 ** sqlite3_temp_directory = sqlite3_mprintf("%s", zPathBuf); 5788 ** </pre></blockquote> 5789 */ 5790 SQLITE_API SQLITE_EXTERN char *sqlite3_temp_directory; 5791 5792 /* 5793 ** CAPI3REF: Name Of The Folder Holding Database Files 5794 ** 5795 ** ^(If this global variable is made to point to a string which is 5796 ** the name of a folder (a.k.a. directory), then all database files 5797 ** specified with a relative pathname and created or accessed by 5798 ** SQLite when using a built-in windows [sqlite3_vfs | VFS] will be assumed 5799 ** to be relative to that directory.)^ ^If this variable is a NULL 5800 ** pointer, then SQLite assumes that all database files specified 5801 ** with a relative pathname are relative to the current directory 5802 ** for the process. Only the windows VFS makes use of this global 5803 ** variable; it is ignored by the unix VFS. 5804 ** 5805 ** Changing the value of this variable while a database connection is 5806 ** open can result in a corrupt database. 5807 ** 5808 ** It is not safe to read or modify this variable in more than one 5809 ** thread at a time. It is not safe to read or modify this variable 5810 ** if a [database connection] is being used at the same time in a separate 5811 ** thread. 5812 ** It is intended that this variable be set once 5813 ** as part of process initialization and before any SQLite interface 5814 ** routines have been called and that this variable remain unchanged 5815 ** thereafter. 5816 ** 5817 ** ^The [data_store_directory pragma] may modify this variable and cause 5818 ** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 5819 ** the [data_store_directory pragma] always assumes that any string 5820 ** that this variable points to is held in memory obtained from 5821 ** [sqlite3_malloc] and the pragma may attempt to free that memory 5822 ** using [sqlite3_free]. 5823 ** Hence, if this variable is modified directly, either it should be 5824 ** made NULL or made to point to memory obtained from [sqlite3_malloc] 5825 ** or else the use of the [data_store_directory pragma] should be avoided. 5826 */ 5827 SQLITE_API SQLITE_EXTERN char *sqlite3_data_directory; 5828 5829 /* 5830 ** CAPI3REF: Win32 Specific Interface 5831 ** 5832 ** These interfaces are available only on Windows. The 5833 ** [sqlite3_win32_set_directory] interface is used to set the value associated 5834 ** with the [sqlite3_temp_directory] or [sqlite3_data_directory] variable, to 5835 ** zValue, depending on the value of the type parameter. The zValue parameter 5836 ** should be NULL to cause the previous value to be freed via [sqlite3_free]; 5837 ** a non-NULL value will be copied into memory obtained from [sqlite3_malloc] 5838 ** prior to being used. The [sqlite3_win32_set_directory] interface returns 5839 ** [SQLITE_OK] to indicate success, [SQLITE_ERROR] if the type is unsupported, 5840 ** or [SQLITE_NOMEM] if memory could not be allocated. The value of the 5841 ** [sqlite3_data_directory] variable is intended to act as a replacement for 5842 ** the current directory on the sub-platforms of Win32 where that concept is 5843 ** not present, e.g. WinRT and UWP. The [sqlite3_win32_set_directory8] and 5844 ** [sqlite3_win32_set_directory16] interfaces behave exactly the same as the 5845 ** sqlite3_win32_set_directory interface except the string parameter must be 5846 ** UTF-8 or UTF-16, respectively. 5847 */ 5848 SQLITE_API int sqlite3_win32_set_directory( 5849 unsigned long type, /* Identifier for directory being set or reset */ 5850 void *zValue /* New value for directory being set or reset */ 5851 ); 5852 SQLITE_API int sqlite3_win32_set_directory8(unsigned long type, const char *zValue); 5853 SQLITE_API int sqlite3_win32_set_directory16(unsigned long type, const void *zValue); 5854 5855 /* 5856 ** CAPI3REF: Win32 Directory Types 5857 ** 5858 ** These macros are only available on Windows. They define the allowed values 5859 ** for the type argument to the [sqlite3_win32_set_directory] interface. 5860 */ 5861 #define SQLITE_WIN32_DATA_DIRECTORY_TYPE 1 5862 #define SQLITE_WIN32_TEMP_DIRECTORY_TYPE 2 5863 5864 /* 5865 ** CAPI3REF: Test For Auto-Commit Mode 5866 ** KEYWORDS: {autocommit mode} 5867 ** METHOD: sqlite3 5868 ** 5869 ** ^The sqlite3_get_autocommit() interface returns non-zero or 5870 ** zero if the given database connection is or is not in autocommit mode, 5871 ** respectively. ^Autocommit mode is on by default. 5872 ** ^Autocommit mode is disabled by a [BEGIN] statement. 5873 ** ^Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK]. 5874 ** 5875 ** If certain kinds of errors occur on a statement within a multi-statement 5876 ** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR], 5877 ** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the 5878 ** transaction might be rolled back automatically. The only way to 5879 ** find out whether SQLite automatically rolled back the transaction after 5880 ** an error is to use this function. 5881 ** 5882 ** If another thread changes the autocommit status of the database 5883 ** connection while this routine is running, then the return value 5884 ** is undefined. 5885 */ 5886 SQLITE_API int sqlite3_get_autocommit(sqlite3*); 5887 5888 /* 5889 ** CAPI3REF: Find The Database Handle Of A Prepared Statement 5890 ** METHOD: sqlite3_stmt 5891 ** 5892 ** ^The sqlite3_db_handle interface returns the [database connection] handle 5893 ** to which a [prepared statement] belongs. ^The [database connection] 5894 ** returned by sqlite3_db_handle is the same [database connection] 5895 ** that was the first argument 5896 ** to the [sqlite3_prepare_v2()] call (or its variants) that was used to 5897 ** create the statement in the first place. 5898 */ 5899 SQLITE_API sqlite3 *sqlite3_db_handle(sqlite3_stmt*); 5900 5901 /* 5902 ** CAPI3REF: Return The Filename For A Database Connection 5903 ** METHOD: sqlite3 5904 ** 5905 ** ^The sqlite3_db_filename(D,N) interface returns a pointer to a filename 5906 ** associated with database N of connection D. ^The main database file 5907 ** has the name "main". If there is no attached database N on the database 5908 ** connection D, or if database N is a temporary or in-memory database, then 5909 ** this function will return either a NULL pointer or an empty string. 5910 ** 5911 ** ^The filename returned by this function is the output of the 5912 ** xFullPathname method of the [VFS]. ^In other words, the filename 5913 ** will be an absolute pathname, even if the filename used 5914 ** to open the database originally was a URI or relative pathname. 5915 */ 5916 SQLITE_API const char *sqlite3_db_filename(sqlite3 *db, const char *zDbName); 5917 5918 /* 5919 ** CAPI3REF: Determine if a database is read-only 5920 ** METHOD: sqlite3 5921 ** 5922 ** ^The sqlite3_db_readonly(D,N) interface returns 1 if the database N 5923 ** of connection D is read-only, 0 if it is read/write, or -1 if N is not 5924 ** the name of a database on connection D. 5925 */ 5926 SQLITE_API int sqlite3_db_readonly(sqlite3 *db, const char *zDbName); 5927 5928 /* 5929 ** CAPI3REF: Find the next prepared statement 5930 ** METHOD: sqlite3 5931 ** 5932 ** ^This interface returns a pointer to the next [prepared statement] after 5933 ** pStmt associated with the [database connection] pDb. ^If pStmt is NULL 5934 ** then this interface returns a pointer to the first prepared statement 5935 ** associated with the database connection pDb. ^If no prepared statement 5936 ** satisfies the conditions of this routine, it returns NULL. 5937 ** 5938 ** The [database connection] pointer D in a call to 5939 ** [sqlite3_next_stmt(D,S)] must refer to an open database 5940 ** connection and in particular must not be a NULL pointer. 5941 */ 5942 SQLITE_API sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt); 5943 5944 /* 5945 ** CAPI3REF: Commit And Rollback Notification Callbacks 5946 ** METHOD: sqlite3 5947 ** 5948 ** ^The sqlite3_commit_hook() interface registers a callback 5949 ** function to be invoked whenever a transaction is [COMMIT | committed]. 5950 ** ^Any callback set by a previous call to sqlite3_commit_hook() 5951 ** for the same database connection is overridden. 5952 ** ^The sqlite3_rollback_hook() interface registers a callback 5953 ** function to be invoked whenever a transaction is [ROLLBACK | rolled back]. 5954 ** ^Any callback set by a previous call to sqlite3_rollback_hook() 5955 ** for the same database connection is overridden. 5956 ** ^The pArg argument is passed through to the callback. 5957 ** ^If the callback on a commit hook function returns non-zero, 5958 ** then the commit is converted into a rollback. 5959 ** 5960 ** ^The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions 5961 ** return the P argument from the previous call of the same function 5962 ** on the same [database connection] D, or NULL for 5963 ** the first call for each function on D. 5964 ** 5965 ** The commit and rollback hook callbacks are not reentrant. 5966 ** The callback implementation must not do anything that will modify 5967 ** the database connection that invoked the callback. Any actions 5968 ** to modify the database connection must be deferred until after the 5969 ** completion of the [sqlite3_step()] call that triggered the commit 5970 ** or rollback hook in the first place. 5971 ** Note that running any other SQL statements, including SELECT statements, 5972 ** or merely calling [sqlite3_prepare_v2()] and [sqlite3_step()] will modify 5973 ** the database connections for the meaning of "modify" in this paragraph. 5974 ** 5975 ** ^Registering a NULL function disables the callback. 5976 ** 5977 ** ^When the commit hook callback routine returns zero, the [COMMIT] 5978 ** operation is allowed to continue normally. ^If the commit hook 5979 ** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK]. 5980 ** ^The rollback hook is invoked on a rollback that results from a commit 5981 ** hook returning non-zero, just as it would be with any other rollback. 5982 ** 5983 ** ^For the purposes of this API, a transaction is said to have been 5984 ** rolled back if an explicit "ROLLBACK" statement is executed, or 5985 ** an error or constraint causes an implicit rollback to occur. 5986 ** ^The rollback callback is not invoked if a transaction is 5987 ** automatically rolled back because the database connection is closed. 5988 ** 5989 ** See also the [sqlite3_update_hook()] interface. 5990 */ 5991 SQLITE_API void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*); 5992 SQLITE_API void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*); 5993 5994 /* 5995 ** CAPI3REF: Data Change Notification Callbacks 5996 ** METHOD: sqlite3 5997 ** 5998 ** ^The sqlite3_update_hook() interface registers a callback function 5999 ** with the [database connection] identified by the first argument 6000 ** to be invoked whenever a row is updated, inserted or deleted in 6001 ** a [rowid table]. 6002 ** ^Any callback set by a previous call to this function 6003 ** for the same database connection is overridden. 6004 ** 6005 ** ^The second argument is a pointer to the function to invoke when a 6006 ** row is updated, inserted or deleted in a rowid table. 6007 ** ^The first argument to the callback is a copy of the third argument 6008 ** to sqlite3_update_hook(). 6009 ** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE], 6010 ** or [SQLITE_UPDATE], depending on the operation that caused the callback 6011 ** to be invoked. 6012 ** ^The third and fourth arguments to the callback contain pointers to the 6013 ** database and table name containing the affected row. 6014 ** ^The final callback parameter is the [rowid] of the row. 6015 ** ^In the case of an update, this is the [rowid] after the update takes place. 6016 ** 6017 ** ^(The update hook is not invoked when internal system tables are 6018 ** modified (i.e. sqlite_master and sqlite_sequence).)^ 6019 ** ^The update hook is not invoked when [WITHOUT ROWID] tables are modified. 6020 ** 6021 ** ^In the current implementation, the update hook 6022 ** is not invoked when conflicting rows are deleted because of an 6023 ** [ON CONFLICT | ON CONFLICT REPLACE] clause. ^Nor is the update hook 6024 ** invoked when rows are deleted using the [truncate optimization]. 6025 ** The exceptions defined in this paragraph might change in a future 6026 ** release of SQLite. 6027 ** 6028 ** The update hook implementation must not do anything that will modify 6029 ** the database connection that invoked the update hook. Any actions 6030 ** to modify the database connection must be deferred until after the 6031 ** completion of the [sqlite3_step()] call that triggered the update hook. 6032 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 6033 ** database connections for the meaning of "modify" in this paragraph. 6034 ** 6035 ** ^The sqlite3_update_hook(D,C,P) function 6036 ** returns the P argument from the previous call 6037 ** on the same [database connection] D, or NULL for 6038 ** the first call on D. 6039 ** 6040 ** See also the [sqlite3_commit_hook()], [sqlite3_rollback_hook()], 6041 ** and [sqlite3_preupdate_hook()] interfaces. 6042 */ 6043 SQLITE_API void *sqlite3_update_hook( 6044 sqlite3*, 6045 void(*)(void *,int ,char const *,char const *,sqlite3_int64), 6046 void* 6047 ); 6048 6049 /* 6050 ** CAPI3REF: Enable Or Disable Shared Pager Cache 6051 ** 6052 ** ^(This routine enables or disables the sharing of the database cache 6053 ** and schema data structures between [database connection | connections] 6054 ** to the same database. Sharing is enabled if the argument is true 6055 ** and disabled if the argument is false.)^ 6056 ** 6057 ** ^Cache sharing is enabled and disabled for an entire process. 6058 ** This is a change as of SQLite [version 3.5.0] ([dateof:3.5.0]). 6059 ** In prior versions of SQLite, 6060 ** sharing was enabled or disabled for each thread separately. 6061 ** 6062 ** ^(The cache sharing mode set by this interface effects all subsequent 6063 ** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()]. 6064 ** Existing database connections continue use the sharing mode 6065 ** that was in effect at the time they were opened.)^ 6066 ** 6067 ** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled 6068 ** successfully. An [error code] is returned otherwise.)^ 6069 ** 6070 ** ^Shared cache is disabled by default. But this might change in 6071 ** future releases of SQLite. Applications that care about shared 6072 ** cache setting should set it explicitly. 6073 ** 6074 ** Note: This method is disabled on MacOS X 10.7 and iOS version 5.0 6075 ** and will always return SQLITE_MISUSE. On those systems, 6076 ** shared cache mode should be enabled per-database connection via 6077 ** [sqlite3_open_v2()] with [SQLITE_OPEN_SHAREDCACHE]. 6078 ** 6079 ** This interface is threadsafe on processors where writing a 6080 ** 32-bit integer is atomic. 6081 ** 6082 ** See Also: [SQLite Shared-Cache Mode] 6083 */ 6084 SQLITE_API int sqlite3_enable_shared_cache(int); 6085 6086 /* 6087 ** CAPI3REF: Attempt To Free Heap Memory 6088 ** 6089 ** ^The sqlite3_release_memory() interface attempts to free N bytes 6090 ** of heap memory by deallocating non-essential memory allocations 6091 ** held by the database library. Memory used to cache database 6092 ** pages to improve performance is an example of non-essential memory. 6093 ** ^sqlite3_release_memory() returns the number of bytes actually freed, 6094 ** which might be more or less than the amount requested. 6095 ** ^The sqlite3_release_memory() routine is a no-op returning zero 6096 ** if SQLite is not compiled with [SQLITE_ENABLE_MEMORY_MANAGEMENT]. 6097 ** 6098 ** See also: [sqlite3_db_release_memory()] 6099 */ 6100 SQLITE_API int sqlite3_release_memory(int); 6101 6102 /* 6103 ** CAPI3REF: Free Memory Used By A Database Connection 6104 ** METHOD: sqlite3 6105 ** 6106 ** ^The sqlite3_db_release_memory(D) interface attempts to free as much heap 6107 ** memory as possible from database connection D. Unlike the 6108 ** [sqlite3_release_memory()] interface, this interface is in effect even 6109 ** when the [SQLITE_ENABLE_MEMORY_MANAGEMENT] compile-time option is 6110 ** omitted. 6111 ** 6112 ** See also: [sqlite3_release_memory()] 6113 */ 6114 SQLITE_API int sqlite3_db_release_memory(sqlite3*); 6115 6116 /* 6117 ** CAPI3REF: Impose A Limit On Heap Size 6118 ** 6119 ** ^The sqlite3_soft_heap_limit64() interface sets and/or queries the 6120 ** soft limit on the amount of heap memory that may be allocated by SQLite. 6121 ** ^SQLite strives to keep heap memory utilization below the soft heap 6122 ** limit by reducing the number of pages held in the page cache 6123 ** as heap memory usages approaches the limit. 6124 ** ^The soft heap limit is "soft" because even though SQLite strives to stay 6125 ** below the limit, it will exceed the limit rather than generate 6126 ** an [SQLITE_NOMEM] error. In other words, the soft heap limit 6127 ** is advisory only. 6128 ** 6129 ** ^The return value from sqlite3_soft_heap_limit64() is the size of 6130 ** the soft heap limit prior to the call, or negative in the case of an 6131 ** error. ^If the argument N is negative 6132 ** then no change is made to the soft heap limit. Hence, the current 6133 ** size of the soft heap limit can be determined by invoking 6134 ** sqlite3_soft_heap_limit64() with a negative argument. 6135 ** 6136 ** ^If the argument N is zero then the soft heap limit is disabled. 6137 ** 6138 ** ^(The soft heap limit is not enforced in the current implementation 6139 ** if one or more of following conditions are true: 6140 ** 6141 ** <ul> 6142 ** <li> The soft heap limit is set to zero. 6143 ** <li> Memory accounting is disabled using a combination of the 6144 ** [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],...) start-time option and 6145 ** the [SQLITE_DEFAULT_MEMSTATUS] compile-time option. 6146 ** <li> An alternative page cache implementation is specified using 6147 ** [sqlite3_config]([SQLITE_CONFIG_PCACHE2],...). 6148 ** <li> The page cache allocates from its own memory pool supplied 6149 ** by [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],...) rather than 6150 ** from the heap. 6151 ** </ul>)^ 6152 ** 6153 ** Beginning with SQLite [version 3.7.3] ([dateof:3.7.3]), 6154 ** the soft heap limit is enforced 6155 ** regardless of whether or not the [SQLITE_ENABLE_MEMORY_MANAGEMENT] 6156 ** compile-time option is invoked. With [SQLITE_ENABLE_MEMORY_MANAGEMENT], 6157 ** the soft heap limit is enforced on every memory allocation. Without 6158 ** [SQLITE_ENABLE_MEMORY_MANAGEMENT], the soft heap limit is only enforced 6159 ** when memory is allocated by the page cache. Testing suggests that because 6160 ** the page cache is the predominate memory user in SQLite, most 6161 ** applications will achieve adequate soft heap limit enforcement without 6162 ** the use of [SQLITE_ENABLE_MEMORY_MANAGEMENT]. 6163 ** 6164 ** The circumstances under which SQLite will enforce the soft heap limit may 6165 ** changes in future releases of SQLite. 6166 */ 6167 SQLITE_API sqlite3_int64 sqlite3_soft_heap_limit64(sqlite3_int64 N); 6168 6169 /* 6170 ** CAPI3REF: Deprecated Soft Heap Limit Interface 6171 ** DEPRECATED 6172 ** 6173 ** This is a deprecated version of the [sqlite3_soft_heap_limit64()] 6174 ** interface. This routine is provided for historical compatibility 6175 ** only. All new applications should use the 6176 ** [sqlite3_soft_heap_limit64()] interface rather than this one. 6177 */ 6178 SQLITE_API SQLITE_DEPRECATED void sqlite3_soft_heap_limit(int N); 6179 6180 6181 /* 6182 ** CAPI3REF: Extract Metadata About A Column Of A Table 6183 ** METHOD: sqlite3 6184 ** 6185 ** ^(The sqlite3_table_column_metadata(X,D,T,C,....) routine returns 6186 ** information about column C of table T in database D 6187 ** on [database connection] X.)^ ^The sqlite3_table_column_metadata() 6188 ** interface returns SQLITE_OK and fills in the non-NULL pointers in 6189 ** the final five arguments with appropriate values if the specified 6190 ** column exists. ^The sqlite3_table_column_metadata() interface returns 6191 ** SQLITE_ERROR and if the specified column does not exist. 6192 ** ^If the column-name parameter to sqlite3_table_column_metadata() is a 6193 ** NULL pointer, then this routine simply checks for the existence of the 6194 ** table and returns SQLITE_OK if the table exists and SQLITE_ERROR if it 6195 ** does not. If the table name parameter T in a call to 6196 ** sqlite3_table_column_metadata(X,D,T,C,...) is NULL then the result is 6197 ** undefined behavior. 6198 ** 6199 ** ^The column is identified by the second, third and fourth parameters to 6200 ** this function. ^(The second parameter is either the name of the database 6201 ** (i.e. "main", "temp", or an attached database) containing the specified 6202 ** table or NULL.)^ ^If it is NULL, then all attached databases are searched 6203 ** for the table using the same algorithm used by the database engine to 6204 ** resolve unqualified table references. 6205 ** 6206 ** ^The third and fourth parameters to this function are the table and column 6207 ** name of the desired column, respectively. 6208 ** 6209 ** ^Metadata is returned by writing to the memory locations passed as the 5th 6210 ** and subsequent parameters to this function. ^Any of these arguments may be 6211 ** NULL, in which case the corresponding element of metadata is omitted. 6212 ** 6213 ** ^(<blockquote> 6214 ** <table border="1"> 6215 ** <tr><th> Parameter <th> Output<br>Type <th> Description 6216 ** 6217 ** <tr><td> 5th <td> const char* <td> Data type 6218 ** <tr><td> 6th <td> const char* <td> Name of default collation sequence 6219 ** <tr><td> 7th <td> int <td> True if column has a NOT NULL constraint 6220 ** <tr><td> 8th <td> int <td> True if column is part of the PRIMARY KEY 6221 ** <tr><td> 9th <td> int <td> True if column is [AUTOINCREMENT] 6222 ** </table> 6223 ** </blockquote>)^ 6224 ** 6225 ** ^The memory pointed to by the character pointers returned for the 6226 ** declaration type and collation sequence is valid until the next 6227 ** call to any SQLite API function. 6228 ** 6229 ** ^If the specified table is actually a view, an [error code] is returned. 6230 ** 6231 ** ^If the specified column is "rowid", "oid" or "_rowid_" and the table 6232 ** is not a [WITHOUT ROWID] table and an 6233 ** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output 6234 ** parameters are set for the explicitly declared column. ^(If there is no 6235 ** [INTEGER PRIMARY KEY] column, then the outputs 6236 ** for the [rowid] are set as follows: 6237 ** 6238 ** <pre> 6239 ** data type: "INTEGER" 6240 ** collation sequence: "BINARY" 6241 ** not null: 0 6242 ** primary key: 1 6243 ** auto increment: 0 6244 ** </pre>)^ 6245 ** 6246 ** ^This function causes all database schemas to be read from disk and 6247 ** parsed, if that has not already been done, and returns an error if 6248 ** any errors are encountered while loading the schema. 6249 */ 6250 SQLITE_API int sqlite3_table_column_metadata( 6251 sqlite3 *db, /* Connection handle */ 6252 const char *zDbName, /* Database name or NULL */ 6253 const char *zTableName, /* Table name */ 6254 const char *zColumnName, /* Column name */ 6255 char const **pzDataType, /* OUTPUT: Declared data type */ 6256 char const **pzCollSeq, /* OUTPUT: Collation sequence name */ 6257 int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */ 6258 int *pPrimaryKey, /* OUTPUT: True if column part of PK */ 6259 int *pAutoinc /* OUTPUT: True if column is auto-increment */ 6260 ); 6261 6262 /* 6263 ** CAPI3REF: Load An Extension 6264 ** METHOD: sqlite3 6265 ** 6266 ** ^This interface loads an SQLite extension library from the named file. 6267 ** 6268 ** ^The sqlite3_load_extension() interface attempts to load an 6269 ** [SQLite extension] library contained in the file zFile. If 6270 ** the file cannot be loaded directly, attempts are made to load 6271 ** with various operating-system specific extensions added. 6272 ** So for example, if "samplelib" cannot be loaded, then names like 6273 ** "samplelib.so" or "samplelib.dylib" or "samplelib.dll" might 6274 ** be tried also. 6275 ** 6276 ** ^The entry point is zProc. 6277 ** ^(zProc may be 0, in which case SQLite will try to come up with an 6278 ** entry point name on its own. It first tries "sqlite3_extension_init". 6279 ** If that does not work, it constructs a name "sqlite3_X_init" where the 6280 ** X is consists of the lower-case equivalent of all ASCII alphabetic 6281 ** characters in the filename from the last "/" to the first following 6282 ** "." and omitting any initial "lib".)^ 6283 ** ^The sqlite3_load_extension() interface returns 6284 ** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong. 6285 ** ^If an error occurs and pzErrMsg is not 0, then the 6286 ** [sqlite3_load_extension()] interface shall attempt to 6287 ** fill *pzErrMsg with error message text stored in memory 6288 ** obtained from [sqlite3_malloc()]. The calling function 6289 ** should free this memory by calling [sqlite3_free()]. 6290 ** 6291 ** ^Extension loading must be enabled using 6292 ** [sqlite3_enable_load_extension()] or 6293 ** [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],1,NULL) 6294 ** prior to calling this API, 6295 ** otherwise an error will be returned. 6296 ** 6297 ** <b>Security warning:</b> It is recommended that the 6298 ** [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method be used to enable only this 6299 ** interface. The use of the [sqlite3_enable_load_extension()] interface 6300 ** should be avoided. This will keep the SQL function [load_extension()] 6301 ** disabled and prevent SQL injections from giving attackers 6302 ** access to extension loading capabilities. 6303 ** 6304 ** See also the [load_extension() SQL function]. 6305 */ 6306 SQLITE_API int sqlite3_load_extension( 6307 sqlite3 *db, /* Load the extension into this database connection */ 6308 const char *zFile, /* Name of the shared library containing extension */ 6309 const char *zProc, /* Entry point. Derived from zFile if 0 */ 6310 char **pzErrMsg /* Put error message here if not 0 */ 6311 ); 6312 6313 /* 6314 ** CAPI3REF: Enable Or Disable Extension Loading 6315 ** METHOD: sqlite3 6316 ** 6317 ** ^So as not to open security holes in older applications that are 6318 ** unprepared to deal with [extension loading], and as a means of disabling 6319 ** [extension loading] while evaluating user-entered SQL, the following API 6320 ** is provided to turn the [sqlite3_load_extension()] mechanism on and off. 6321 ** 6322 ** ^Extension loading is off by default. 6323 ** ^Call the sqlite3_enable_load_extension() routine with onoff==1 6324 ** to turn extension loading on and call it with onoff==0 to turn 6325 ** it back off again. 6326 ** 6327 ** ^This interface enables or disables both the C-API 6328 ** [sqlite3_load_extension()] and the SQL function [load_extension()]. 6329 ** ^(Use [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],..) 6330 ** to enable or disable only the C-API.)^ 6331 ** 6332 ** <b>Security warning:</b> It is recommended that extension loading 6333 ** be disabled using the [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method 6334 ** rather than this interface, so the [load_extension()] SQL function 6335 ** remains disabled. This will prevent SQL injections from giving attackers 6336 ** access to extension loading capabilities. 6337 */ 6338 SQLITE_API int sqlite3_enable_load_extension(sqlite3 *db, int onoff); 6339 6340 /* 6341 ** CAPI3REF: Automatically Load Statically Linked Extensions 6342 ** 6343 ** ^This interface causes the xEntryPoint() function to be invoked for 6344 ** each new [database connection] that is created. The idea here is that 6345 ** xEntryPoint() is the entry point for a statically linked [SQLite extension] 6346 ** that is to be automatically loaded into all new database connections. 6347 ** 6348 ** ^(Even though the function prototype shows that xEntryPoint() takes 6349 ** no arguments and returns void, SQLite invokes xEntryPoint() with three 6350 ** arguments and expects an integer result as if the signature of the 6351 ** entry point where as follows: 6352 ** 6353 ** <blockquote><pre> 6354 ** int xEntryPoint( 6355 ** sqlite3 *db, 6356 ** const char **pzErrMsg, 6357 ** const struct sqlite3_api_routines *pThunk 6358 ** ); 6359 ** </pre></blockquote>)^ 6360 ** 6361 ** If the xEntryPoint routine encounters an error, it should make *pzErrMsg 6362 ** point to an appropriate error message (obtained from [sqlite3_mprintf()]) 6363 ** and return an appropriate [error code]. ^SQLite ensures that *pzErrMsg 6364 ** is NULL before calling the xEntryPoint(). ^SQLite will invoke 6365 ** [sqlite3_free()] on *pzErrMsg after xEntryPoint() returns. ^If any 6366 ** xEntryPoint() returns an error, the [sqlite3_open()], [sqlite3_open16()], 6367 ** or [sqlite3_open_v2()] call that provoked the xEntryPoint() will fail. 6368 ** 6369 ** ^Calling sqlite3_auto_extension(X) with an entry point X that is already 6370 ** on the list of automatic extensions is a harmless no-op. ^No entry point 6371 ** will be called more than once for each database connection that is opened. 6372 ** 6373 ** See also: [sqlite3_reset_auto_extension()] 6374 ** and [sqlite3_cancel_auto_extension()] 6375 */ 6376 SQLITE_API int sqlite3_auto_extension(void(*xEntryPoint)(void)); 6377 6378 /* 6379 ** CAPI3REF: Cancel Automatic Extension Loading 6380 ** 6381 ** ^The [sqlite3_cancel_auto_extension(X)] interface unregisters the 6382 ** initialization routine X that was registered using a prior call to 6383 ** [sqlite3_auto_extension(X)]. ^The [sqlite3_cancel_auto_extension(X)] 6384 ** routine returns 1 if initialization routine X was successfully 6385 ** unregistered and it returns 0 if X was not on the list of initialization 6386 ** routines. 6387 */ 6388 SQLITE_API int sqlite3_cancel_auto_extension(void(*xEntryPoint)(void)); 6389 6390 /* 6391 ** CAPI3REF: Reset Automatic Extension Loading 6392 ** 6393 ** ^This interface disables all automatic extensions previously 6394 ** registered using [sqlite3_auto_extension()]. 6395 */ 6396 SQLITE_API void sqlite3_reset_auto_extension(void); 6397 6398 /* 6399 ** The interface to the virtual-table mechanism is currently considered 6400 ** to be experimental. The interface might change in incompatible ways. 6401 ** If this is a problem for you, do not use the interface at this time. 6402 ** 6403 ** When the virtual-table mechanism stabilizes, we will declare the 6404 ** interface fixed, support it indefinitely, and remove this comment. 6405 */ 6406 6407 /* 6408 ** Structures used by the virtual table interface 6409 */ 6410 typedef struct sqlite3_vtab sqlite3_vtab; 6411 typedef struct sqlite3_index_info sqlite3_index_info; 6412 typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor; 6413 typedef struct sqlite3_module sqlite3_module; 6414 6415 /* 6416 ** CAPI3REF: Virtual Table Object 6417 ** KEYWORDS: sqlite3_module {virtual table module} 6418 ** 6419 ** This structure, sometimes called a "virtual table module", 6420 ** defines the implementation of a [virtual tables]. 6421 ** This structure consists mostly of methods for the module. 6422 ** 6423 ** ^A virtual table module is created by filling in a persistent 6424 ** instance of this structure and passing a pointer to that instance 6425 ** to [sqlite3_create_module()] or [sqlite3_create_module_v2()]. 6426 ** ^The registration remains valid until it is replaced by a different 6427 ** module or until the [database connection] closes. The content 6428 ** of this structure must not change while it is registered with 6429 ** any database connection. 6430 */ 6431 struct sqlite3_module { 6432 int iVersion; 6433 int (*xCreate)(sqlite3*, void *pAux, 6434 int argc, const char *const*argv, 6435 sqlite3_vtab **ppVTab, char**); 6436 int (*xConnect)(sqlite3*, void *pAux, 6437 int argc, const char *const*argv, 6438 sqlite3_vtab **ppVTab, char**); 6439 int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*); 6440 int (*xDisconnect)(sqlite3_vtab *pVTab); 6441 int (*xDestroy)(sqlite3_vtab *pVTab); 6442 int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor); 6443 int (*xClose)(sqlite3_vtab_cursor*); 6444 int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr, 6445 int argc, sqlite3_value **argv); 6446 int (*xNext)(sqlite3_vtab_cursor*); 6447 int (*xEof)(sqlite3_vtab_cursor*); 6448 int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int); 6449 int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid); 6450 int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *); 6451 int (*xBegin)(sqlite3_vtab *pVTab); 6452 int (*xSync)(sqlite3_vtab *pVTab); 6453 int (*xCommit)(sqlite3_vtab *pVTab); 6454 int (*xRollback)(sqlite3_vtab *pVTab); 6455 int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName, 6456 void (**pxFunc)(sqlite3_context*,int,sqlite3_value**), 6457 void **ppArg); 6458 int (*xRename)(sqlite3_vtab *pVtab, const char *zNew); 6459 /* The methods above are in version 1 of the sqlite_module object. Those 6460 ** below are for version 2 and greater. */ 6461 int (*xSavepoint)(sqlite3_vtab *pVTab, int); 6462 int (*xRelease)(sqlite3_vtab *pVTab, int); 6463 int (*xRollbackTo)(sqlite3_vtab *pVTab, int); 6464 /* The methods above are in versions 1 and 2 of the sqlite_module object. 6465 ** Those below are for version 3 and greater. */ 6466 int (*xShadowName)(const char*); 6467 }; 6468 6469 /* 6470 ** CAPI3REF: Virtual Table Indexing Information 6471 ** KEYWORDS: sqlite3_index_info 6472 ** 6473 ** The sqlite3_index_info structure and its substructures is used as part 6474 ** of the [virtual table] interface to 6475 ** pass information into and receive the reply from the [xBestIndex] 6476 ** method of a [virtual table module]. The fields under **Inputs** are the 6477 ** inputs to xBestIndex and are read-only. xBestIndex inserts its 6478 ** results into the **Outputs** fields. 6479 ** 6480 ** ^(The aConstraint[] array records WHERE clause constraints of the form: 6481 ** 6482 ** <blockquote>column OP expr</blockquote> 6483 ** 6484 ** where OP is =, <, <=, >, or >=.)^ ^(The particular operator is 6485 ** stored in aConstraint[].op using one of the 6486 ** [SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_ values].)^ 6487 ** ^(The index of the column is stored in 6488 ** aConstraint[].iColumn.)^ ^(aConstraint[].usable is TRUE if the 6489 ** expr on the right-hand side can be evaluated (and thus the constraint 6490 ** is usable) and false if it cannot.)^ 6491 ** 6492 ** ^The optimizer automatically inverts terms of the form "expr OP column" 6493 ** and makes other simplifications to the WHERE clause in an attempt to 6494 ** get as many WHERE clause terms into the form shown above as possible. 6495 ** ^The aConstraint[] array only reports WHERE clause terms that are 6496 ** relevant to the particular virtual table being queried. 6497 ** 6498 ** ^Information about the ORDER BY clause is stored in aOrderBy[]. 6499 ** ^Each term of aOrderBy records a column of the ORDER BY clause. 6500 ** 6501 ** The colUsed field indicates which columns of the virtual table may be 6502 ** required by the current scan. Virtual table columns are numbered from 6503 ** zero in the order in which they appear within the CREATE TABLE statement 6504 ** passed to sqlite3_declare_vtab(). For the first 63 columns (columns 0-62), 6505 ** the corresponding bit is set within the colUsed mask if the column may be 6506 ** required by SQLite. If the table has at least 64 columns and any column 6507 ** to the right of the first 63 is required, then bit 63 of colUsed is also 6508 ** set. In other words, column iCol may be required if the expression 6509 ** (colUsed & ((sqlite3_uint64)1 << (iCol>=63 ? 63 : iCol))) evaluates to 6510 ** non-zero. 6511 ** 6512 ** The [xBestIndex] method must fill aConstraintUsage[] with information 6513 ** about what parameters to pass to xFilter. ^If argvIndex>0 then 6514 ** the right-hand side of the corresponding aConstraint[] is evaluated 6515 ** and becomes the argvIndex-th entry in argv. ^(If aConstraintUsage[].omit 6516 ** is true, then the constraint is assumed to be fully handled by the 6517 ** virtual table and is not checked again by SQLite.)^ 6518 ** 6519 ** ^The idxNum and idxPtr values are recorded and passed into the 6520 ** [xFilter] method. 6521 ** ^[sqlite3_free()] is used to free idxPtr if and only if 6522 ** needToFreeIdxPtr is true. 6523 ** 6524 ** ^The orderByConsumed means that output from [xFilter]/[xNext] will occur in 6525 ** the correct order to satisfy the ORDER BY clause so that no separate 6526 ** sorting step is required. 6527 ** 6528 ** ^The estimatedCost value is an estimate of the cost of a particular 6529 ** strategy. A cost of N indicates that the cost of the strategy is similar 6530 ** to a linear scan of an SQLite table with N rows. A cost of log(N) 6531 ** indicates that the expense of the operation is similar to that of a 6532 ** binary search on a unique indexed field of an SQLite table with N rows. 6533 ** 6534 ** ^The estimatedRows value is an estimate of the number of rows that 6535 ** will be returned by the strategy. 6536 ** 6537 ** The xBestIndex method may optionally populate the idxFlags field with a 6538 ** mask of SQLITE_INDEX_SCAN_* flags. Currently there is only one such flag - 6539 ** SQLITE_INDEX_SCAN_UNIQUE. If the xBestIndex method sets this flag, SQLite 6540 ** assumes that the strategy may visit at most one row. 6541 ** 6542 ** Additionally, if xBestIndex sets the SQLITE_INDEX_SCAN_UNIQUE flag, then 6543 ** SQLite also assumes that if a call to the xUpdate() method is made as 6544 ** part of the same statement to delete or update a virtual table row and the 6545 ** implementation returns SQLITE_CONSTRAINT, then there is no need to rollback 6546 ** any database changes. In other words, if the xUpdate() returns 6547 ** SQLITE_CONSTRAINT, the database contents must be exactly as they were 6548 ** before xUpdate was called. By contrast, if SQLITE_INDEX_SCAN_UNIQUE is not 6549 ** set and xUpdate returns SQLITE_CONSTRAINT, any database changes made by 6550 ** the xUpdate method are automatically rolled back by SQLite. 6551 ** 6552 ** IMPORTANT: The estimatedRows field was added to the sqlite3_index_info 6553 ** structure for SQLite [version 3.8.2] ([dateof:3.8.2]). 6554 ** If a virtual table extension is 6555 ** used with an SQLite version earlier than 3.8.2, the results of attempting 6556 ** to read or write the estimatedRows field are undefined (but are likely 6557 ** to included crashing the application). The estimatedRows field should 6558 ** therefore only be used if [sqlite3_libversion_number()] returns a 6559 ** value greater than or equal to 3008002. Similarly, the idxFlags field 6560 ** was added for [version 3.9.0] ([dateof:3.9.0]). 6561 ** It may therefore only be used if 6562 ** sqlite3_libversion_number() returns a value greater than or equal to 6563 ** 3009000. 6564 */ 6565 struct sqlite3_index_info { 6566 /* Inputs */ 6567 int nConstraint; /* Number of entries in aConstraint */ 6568 struct sqlite3_index_constraint { 6569 int iColumn; /* Column constrained. -1 for ROWID */ 6570 unsigned char op; /* Constraint operator */ 6571 unsigned char usable; /* True if this constraint is usable */ 6572 int iTermOffset; /* Used internally - xBestIndex should ignore */ 6573 } *aConstraint; /* Table of WHERE clause constraints */ 6574 int nOrderBy; /* Number of terms in the ORDER BY clause */ 6575 struct sqlite3_index_orderby { 6576 int iColumn; /* Column number */ 6577 unsigned char desc; /* True for DESC. False for ASC. */ 6578 } *aOrderBy; /* The ORDER BY clause */ 6579 /* Outputs */ 6580 struct sqlite3_index_constraint_usage { 6581 int argvIndex; /* if >0, constraint is part of argv to xFilter */ 6582 unsigned char omit; /* Do not code a test for this constraint */ 6583 } *aConstraintUsage; 6584 int idxNum; /* Number used to identify the index */ 6585 char *idxStr; /* String, possibly obtained from sqlite3_malloc */ 6586 int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */ 6587 int orderByConsumed; /* True if output is already ordered */ 6588 double estimatedCost; /* Estimated cost of using this index */ 6589 /* Fields below are only available in SQLite 3.8.2 and later */ 6590 sqlite3_int64 estimatedRows; /* Estimated number of rows returned */ 6591 /* Fields below are only available in SQLite 3.9.0 and later */ 6592 int idxFlags; /* Mask of SQLITE_INDEX_SCAN_* flags */ 6593 /* Fields below are only available in SQLite 3.10.0 and later */ 6594 sqlite3_uint64 colUsed; /* Input: Mask of columns used by statement */ 6595 }; 6596 6597 /* 6598 ** CAPI3REF: Virtual Table Scan Flags 6599 ** 6600 ** Virtual table implementations are allowed to set the 6601 ** [sqlite3_index_info].idxFlags field to some combination of 6602 ** these bits. 6603 */ 6604 #define SQLITE_INDEX_SCAN_UNIQUE 1 /* Scan visits at most 1 row */ 6605 6606 /* 6607 ** CAPI3REF: Virtual Table Constraint Operator Codes 6608 ** 6609 ** These macros defined the allowed values for the 6610 ** [sqlite3_index_info].aConstraint[].op field. Each value represents 6611 ** an operator that is part of a constraint term in the wHERE clause of 6612 ** a query that uses a [virtual table]. 6613 */ 6614 #define SQLITE_INDEX_CONSTRAINT_EQ 2 6615 #define SQLITE_INDEX_CONSTRAINT_GT 4 6616 #define SQLITE_INDEX_CONSTRAINT_LE 8 6617 #define SQLITE_INDEX_CONSTRAINT_LT 16 6618 #define SQLITE_INDEX_CONSTRAINT_GE 32 6619 #define SQLITE_INDEX_CONSTRAINT_MATCH 64 6620 #define SQLITE_INDEX_CONSTRAINT_LIKE 65 6621 #define SQLITE_INDEX_CONSTRAINT_GLOB 66 6622 #define SQLITE_INDEX_CONSTRAINT_REGEXP 67 6623 #define SQLITE_INDEX_CONSTRAINT_NE 68 6624 #define SQLITE_INDEX_CONSTRAINT_ISNOT 69 6625 #define SQLITE_INDEX_CONSTRAINT_ISNOTNULL 70 6626 #define SQLITE_INDEX_CONSTRAINT_ISNULL 71 6627 #define SQLITE_INDEX_CONSTRAINT_IS 72 6628 #define SQLITE_INDEX_CONSTRAINT_FUNCTION 150 6629 6630 /* 6631 ** CAPI3REF: Register A Virtual Table Implementation 6632 ** METHOD: sqlite3 6633 ** 6634 ** ^These routines are used to register a new [virtual table module] name. 6635 ** ^Module names must be registered before 6636 ** creating a new [virtual table] using the module and before using a 6637 ** preexisting [virtual table] for the module. 6638 ** 6639 ** ^The module name is registered on the [database connection] specified 6640 ** by the first parameter. ^The name of the module is given by the 6641 ** second parameter. ^The third parameter is a pointer to 6642 ** the implementation of the [virtual table module]. ^The fourth 6643 ** parameter is an arbitrary client data pointer that is passed through 6644 ** into the [xCreate] and [xConnect] methods of the virtual table module 6645 ** when a new virtual table is be being created or reinitialized. 6646 ** 6647 ** ^The sqlite3_create_module_v2() interface has a fifth parameter which 6648 ** is a pointer to a destructor for the pClientData. ^SQLite will 6649 ** invoke the destructor function (if it is not NULL) when SQLite 6650 ** no longer needs the pClientData pointer. ^The destructor will also 6651 ** be invoked if the call to sqlite3_create_module_v2() fails. 6652 ** ^The sqlite3_create_module() 6653 ** interface is equivalent to sqlite3_create_module_v2() with a NULL 6654 ** destructor. 6655 ** 6656 ** ^If the third parameter (the pointer to the sqlite3_module object) is 6657 ** NULL then no new module is create and any existing modules with the 6658 ** same name are dropped. 6659 ** 6660 ** See also: [sqlite3_drop_modules()] 6661 */ 6662 SQLITE_API int sqlite3_create_module( 6663 sqlite3 *db, /* SQLite connection to register module with */ 6664 const char *zName, /* Name of the module */ 6665 const sqlite3_module *p, /* Methods for the module */ 6666 void *pClientData /* Client data for xCreate/xConnect */ 6667 ); 6668 SQLITE_API int sqlite3_create_module_v2( 6669 sqlite3 *db, /* SQLite connection to register module with */ 6670 const char *zName, /* Name of the module */ 6671 const sqlite3_module *p, /* Methods for the module */ 6672 void *pClientData, /* Client data for xCreate/xConnect */ 6673 void(*xDestroy)(void*) /* Module destructor function */ 6674 ); 6675 6676 /* 6677 ** CAPI3REF: Remove Unnecessary Virtual Table Implementations 6678 ** METHOD: sqlite3 6679 ** 6680 ** ^The sqlite3_drop_modules(D,L) interface removes all virtual 6681 ** table modules from database connection D except those named on list L. 6682 ** The L parameter must be either NULL or a pointer to an array of pointers 6683 ** to strings where the array is terminated by a single NULL pointer. 6684 ** ^If the L parameter is NULL, then all virtual table modules are removed. 6685 ** 6686 ** See also: [sqlite3_create_module()] 6687 */ 6688 SQLITE_API int sqlite3_drop_modules( 6689 sqlite3 *db, /* Remove modules from this connection */ 6690 const char **azKeep /* Except, do not remove the ones named here */ 6691 ); 6692 6693 /* 6694 ** CAPI3REF: Virtual Table Instance Object 6695 ** KEYWORDS: sqlite3_vtab 6696 ** 6697 ** Every [virtual table module] implementation uses a subclass 6698 ** of this object to describe a particular instance 6699 ** of the [virtual table]. Each subclass will 6700 ** be tailored to the specific needs of the module implementation. 6701 ** The purpose of this superclass is to define certain fields that are 6702 ** common to all module implementations. 6703 ** 6704 ** ^Virtual tables methods can set an error message by assigning a 6705 ** string obtained from [sqlite3_mprintf()] to zErrMsg. The method should 6706 ** take care that any prior string is freed by a call to [sqlite3_free()] 6707 ** prior to assigning a new string to zErrMsg. ^After the error message 6708 ** is delivered up to the client application, the string will be automatically 6709 ** freed by sqlite3_free() and the zErrMsg field will be zeroed. 6710 */ 6711 struct sqlite3_vtab { 6712 const sqlite3_module *pModule; /* The module for this virtual table */ 6713 int nRef; /* Number of open cursors */ 6714 char *zErrMsg; /* Error message from sqlite3_mprintf() */ 6715 /* Virtual table implementations will typically add additional fields */ 6716 }; 6717 6718 /* 6719 ** CAPI3REF: Virtual Table Cursor Object 6720 ** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor} 6721 ** 6722 ** Every [virtual table module] implementation uses a subclass of the 6723 ** following structure to describe cursors that point into the 6724 ** [virtual table] and are used 6725 ** to loop through the virtual table. Cursors are created using the 6726 ** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed 6727 ** by the [sqlite3_module.xClose | xClose] method. Cursors are used 6728 ** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods 6729 ** of the module. Each module implementation will define 6730 ** the content of a cursor structure to suit its own needs. 6731 ** 6732 ** This superclass exists in order to define fields of the cursor that 6733 ** are common to all implementations. 6734 */ 6735 struct sqlite3_vtab_cursor { 6736 sqlite3_vtab *pVtab; /* Virtual table of this cursor */ 6737 /* Virtual table implementations will typically add additional fields */ 6738 }; 6739 6740 /* 6741 ** CAPI3REF: Declare The Schema Of A Virtual Table 6742 ** 6743 ** ^The [xCreate] and [xConnect] methods of a 6744 ** [virtual table module] call this interface 6745 ** to declare the format (the names and datatypes of the columns) of 6746 ** the virtual tables they implement. 6747 */ 6748 SQLITE_API int sqlite3_declare_vtab(sqlite3*, const char *zSQL); 6749 6750 /* 6751 ** CAPI3REF: Overload A Function For A Virtual Table 6752 ** METHOD: sqlite3 6753 ** 6754 ** ^(Virtual tables can provide alternative implementations of functions 6755 ** using the [xFindFunction] method of the [virtual table module]. 6756 ** But global versions of those functions 6757 ** must exist in order to be overloaded.)^ 6758 ** 6759 ** ^(This API makes sure a global version of a function with a particular 6760 ** name and number of parameters exists. If no such function exists 6761 ** before this API is called, a new function is created.)^ ^The implementation 6762 ** of the new function always causes an exception to be thrown. So 6763 ** the new function is not good for anything by itself. Its only 6764 ** purpose is to be a placeholder function that can be overloaded 6765 ** by a [virtual table]. 6766 */ 6767 SQLITE_API int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg); 6768 6769 /* 6770 ** The interface to the virtual-table mechanism defined above (back up 6771 ** to a comment remarkably similar to this one) is currently considered 6772 ** to be experimental. The interface might change in incompatible ways. 6773 ** If this is a problem for you, do not use the interface at this time. 6774 ** 6775 ** When the virtual-table mechanism stabilizes, we will declare the 6776 ** interface fixed, support it indefinitely, and remove this comment. 6777 */ 6778 6779 /* 6780 ** CAPI3REF: A Handle To An Open BLOB 6781 ** KEYWORDS: {BLOB handle} {BLOB handles} 6782 ** 6783 ** An instance of this object represents an open BLOB on which 6784 ** [sqlite3_blob_open | incremental BLOB I/O] can be performed. 6785 ** ^Objects of this type are created by [sqlite3_blob_open()] 6786 ** and destroyed by [sqlite3_blob_close()]. 6787 ** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces 6788 ** can be used to read or write small subsections of the BLOB. 6789 ** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes. 6790 */ 6791 typedef struct sqlite3_blob sqlite3_blob; 6792 6793 /* 6794 ** CAPI3REF: Open A BLOB For Incremental I/O 6795 ** METHOD: sqlite3 6796 ** CONSTRUCTOR: sqlite3_blob 6797 ** 6798 ** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located 6799 ** in row iRow, column zColumn, table zTable in database zDb; 6800 ** in other words, the same BLOB that would be selected by: 6801 ** 6802 ** <pre> 6803 ** SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow; 6804 ** </pre>)^ 6805 ** 6806 ** ^(Parameter zDb is not the filename that contains the database, but 6807 ** rather the symbolic name of the database. For attached databases, this is 6808 ** the name that appears after the AS keyword in the [ATTACH] statement. 6809 ** For the main database file, the database name is "main". For TEMP 6810 ** tables, the database name is "temp".)^ 6811 ** 6812 ** ^If the flags parameter is non-zero, then the BLOB is opened for read 6813 ** and write access. ^If the flags parameter is zero, the BLOB is opened for 6814 ** read-only access. 6815 ** 6816 ** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is stored 6817 ** in *ppBlob. Otherwise an [error code] is returned and, unless the error 6818 ** code is SQLITE_MISUSE, *ppBlob is set to NULL.)^ ^This means that, provided 6819 ** the API is not misused, it is always safe to call [sqlite3_blob_close()] 6820 ** on *ppBlob after this function it returns. 6821 ** 6822 ** This function fails with SQLITE_ERROR if any of the following are true: 6823 ** <ul> 6824 ** <li> ^(Database zDb does not exist)^, 6825 ** <li> ^(Table zTable does not exist within database zDb)^, 6826 ** <li> ^(Table zTable is a WITHOUT ROWID table)^, 6827 ** <li> ^(Column zColumn does not exist)^, 6828 ** <li> ^(Row iRow is not present in the table)^, 6829 ** <li> ^(The specified column of row iRow contains a value that is not 6830 ** a TEXT or BLOB value)^, 6831 ** <li> ^(Column zColumn is part of an index, PRIMARY KEY or UNIQUE 6832 ** constraint and the blob is being opened for read/write access)^, 6833 ** <li> ^([foreign key constraints | Foreign key constraints] are enabled, 6834 ** column zColumn is part of a [child key] definition and the blob is 6835 ** being opened for read/write access)^. 6836 ** </ul> 6837 ** 6838 ** ^Unless it returns SQLITE_MISUSE, this function sets the 6839 ** [database connection] error code and message accessible via 6840 ** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions. 6841 ** 6842 ** A BLOB referenced by sqlite3_blob_open() may be read using the 6843 ** [sqlite3_blob_read()] interface and modified by using 6844 ** [sqlite3_blob_write()]. The [BLOB handle] can be moved to a 6845 ** different row of the same table using the [sqlite3_blob_reopen()] 6846 ** interface. However, the column, table, or database of a [BLOB handle] 6847 ** cannot be changed after the [BLOB handle] is opened. 6848 ** 6849 ** ^(If the row that a BLOB handle points to is modified by an 6850 ** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects 6851 ** then the BLOB handle is marked as "expired". 6852 ** This is true if any column of the row is changed, even a column 6853 ** other than the one the BLOB handle is open on.)^ 6854 ** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for 6855 ** an expired BLOB handle fail with a return code of [SQLITE_ABORT]. 6856 ** ^(Changes written into a BLOB prior to the BLOB expiring are not 6857 ** rolled back by the expiration of the BLOB. Such changes will eventually 6858 ** commit if the transaction continues to completion.)^ 6859 ** 6860 ** ^Use the [sqlite3_blob_bytes()] interface to determine the size of 6861 ** the opened blob. ^The size of a blob may not be changed by this 6862 ** interface. Use the [UPDATE] SQL command to change the size of a 6863 ** blob. 6864 ** 6865 ** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces 6866 ** and the built-in [zeroblob] SQL function may be used to create a 6867 ** zero-filled blob to read or write using the incremental-blob interface. 6868 ** 6869 ** To avoid a resource leak, every open [BLOB handle] should eventually 6870 ** be released by a call to [sqlite3_blob_close()]. 6871 ** 6872 ** See also: [sqlite3_blob_close()], 6873 ** [sqlite3_blob_reopen()], [sqlite3_blob_read()], 6874 ** [sqlite3_blob_bytes()], [sqlite3_blob_write()]. 6875 */ 6876 SQLITE_API int sqlite3_blob_open( 6877 sqlite3*, 6878 const char *zDb, 6879 const char *zTable, 6880 const char *zColumn, 6881 sqlite3_int64 iRow, 6882 int flags, 6883 sqlite3_blob **ppBlob 6884 ); 6885 6886 /* 6887 ** CAPI3REF: Move a BLOB Handle to a New Row 6888 ** METHOD: sqlite3_blob 6889 ** 6890 ** ^This function is used to move an existing [BLOB handle] so that it points 6891 ** to a different row of the same database table. ^The new row is identified 6892 ** by the rowid value passed as the second argument. Only the row can be 6893 ** changed. ^The database, table and column on which the blob handle is open 6894 ** remain the same. Moving an existing [BLOB handle] to a new row is 6895 ** faster than closing the existing handle and opening a new one. 6896 ** 6897 ** ^(The new row must meet the same criteria as for [sqlite3_blob_open()] - 6898 ** it must exist and there must be either a blob or text value stored in 6899 ** the nominated column.)^ ^If the new row is not present in the table, or if 6900 ** it does not contain a blob or text value, or if another error occurs, an 6901 ** SQLite error code is returned and the blob handle is considered aborted. 6902 ** ^All subsequent calls to [sqlite3_blob_read()], [sqlite3_blob_write()] or 6903 ** [sqlite3_blob_reopen()] on an aborted blob handle immediately return 6904 ** SQLITE_ABORT. ^Calling [sqlite3_blob_bytes()] on an aborted blob handle 6905 ** always returns zero. 6906 ** 6907 ** ^This function sets the database handle error code and message. 6908 */ 6909 SQLITE_API int sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64); 6910 6911 /* 6912 ** CAPI3REF: Close A BLOB Handle 6913 ** DESTRUCTOR: sqlite3_blob 6914 ** 6915 ** ^This function closes an open [BLOB handle]. ^(The BLOB handle is closed 6916 ** unconditionally. Even if this routine returns an error code, the 6917 ** handle is still closed.)^ 6918 ** 6919 ** ^If the blob handle being closed was opened for read-write access, and if 6920 ** the database is in auto-commit mode and there are no other open read-write 6921 ** blob handles or active write statements, the current transaction is 6922 ** committed. ^If an error occurs while committing the transaction, an error 6923 ** code is returned and the transaction rolled back. 6924 ** 6925 ** Calling this function with an argument that is not a NULL pointer or an 6926 ** open blob handle results in undefined behaviour. ^Calling this routine 6927 ** with a null pointer (such as would be returned by a failed call to 6928 ** [sqlite3_blob_open()]) is a harmless no-op. ^Otherwise, if this function 6929 ** is passed a valid open blob handle, the values returned by the 6930 ** sqlite3_errcode() and sqlite3_errmsg() functions are set before returning. 6931 */ 6932 SQLITE_API int sqlite3_blob_close(sqlite3_blob *); 6933 6934 /* 6935 ** CAPI3REF: Return The Size Of An Open BLOB 6936 ** METHOD: sqlite3_blob 6937 ** 6938 ** ^Returns the size in bytes of the BLOB accessible via the 6939 ** successfully opened [BLOB handle] in its only argument. ^The 6940 ** incremental blob I/O routines can only read or overwriting existing 6941 ** blob content; they cannot change the size of a blob. 6942 ** 6943 ** This routine only works on a [BLOB handle] which has been created 6944 ** by a prior successful call to [sqlite3_blob_open()] and which has not 6945 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in 6946 ** to this routine results in undefined and probably undesirable behavior. 6947 */ 6948 SQLITE_API int sqlite3_blob_bytes(sqlite3_blob *); 6949 6950 /* 6951 ** CAPI3REF: Read Data From A BLOB Incrementally 6952 ** METHOD: sqlite3_blob 6953 ** 6954 ** ^(This function is used to read data from an open [BLOB handle] into a 6955 ** caller-supplied buffer. N bytes of data are copied into buffer Z 6956 ** from the open BLOB, starting at offset iOffset.)^ 6957 ** 6958 ** ^If offset iOffset is less than N bytes from the end of the BLOB, 6959 ** [SQLITE_ERROR] is returned and no data is read. ^If N or iOffset is 6960 ** less than zero, [SQLITE_ERROR] is returned and no data is read. 6961 ** ^The size of the blob (and hence the maximum value of N+iOffset) 6962 ** can be determined using the [sqlite3_blob_bytes()] interface. 6963 ** 6964 ** ^An attempt to read from an expired [BLOB handle] fails with an 6965 ** error code of [SQLITE_ABORT]. 6966 ** 6967 ** ^(On success, sqlite3_blob_read() returns SQLITE_OK. 6968 ** Otherwise, an [error code] or an [extended error code] is returned.)^ 6969 ** 6970 ** This routine only works on a [BLOB handle] which has been created 6971 ** by a prior successful call to [sqlite3_blob_open()] and which has not 6972 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in 6973 ** to this routine results in undefined and probably undesirable behavior. 6974 ** 6975 ** See also: [sqlite3_blob_write()]. 6976 */ 6977 SQLITE_API int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset); 6978 6979 /* 6980 ** CAPI3REF: Write Data Into A BLOB Incrementally 6981 ** METHOD: sqlite3_blob 6982 ** 6983 ** ^(This function is used to write data into an open [BLOB handle] from a 6984 ** caller-supplied buffer. N bytes of data are copied from the buffer Z 6985 ** into the open BLOB, starting at offset iOffset.)^ 6986 ** 6987 ** ^(On success, sqlite3_blob_write() returns SQLITE_OK. 6988 ** Otherwise, an [error code] or an [extended error code] is returned.)^ 6989 ** ^Unless SQLITE_MISUSE is returned, this function sets the 6990 ** [database connection] error code and message accessible via 6991 ** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions. 6992 ** 6993 ** ^If the [BLOB handle] passed as the first argument was not opened for 6994 ** writing (the flags parameter to [sqlite3_blob_open()] was zero), 6995 ** this function returns [SQLITE_READONLY]. 6996 ** 6997 ** This function may only modify the contents of the BLOB; it is 6998 ** not possible to increase the size of a BLOB using this API. 6999 ** ^If offset iOffset is less than N bytes from the end of the BLOB, 7000 ** [SQLITE_ERROR] is returned and no data is written. The size of the 7001 ** BLOB (and hence the maximum value of N+iOffset) can be determined 7002 ** using the [sqlite3_blob_bytes()] interface. ^If N or iOffset are less 7003 ** than zero [SQLITE_ERROR] is returned and no data is written. 7004 ** 7005 ** ^An attempt to write to an expired [BLOB handle] fails with an 7006 ** error code of [SQLITE_ABORT]. ^Writes to the BLOB that occurred 7007 ** before the [BLOB handle] expired are not rolled back by the 7008 ** expiration of the handle, though of course those changes might 7009 ** have been overwritten by the statement that expired the BLOB handle 7010 ** or by other independent statements. 7011 ** 7012 ** This routine only works on a [BLOB handle] which has been created 7013 ** by a prior successful call to [sqlite3_blob_open()] and which has not 7014 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in 7015 ** to this routine results in undefined and probably undesirable behavior. 7016 ** 7017 ** See also: [sqlite3_blob_read()]. 7018 */ 7019 SQLITE_API int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset); 7020 7021 /* 7022 ** CAPI3REF: Virtual File System Objects 7023 ** 7024 ** A virtual filesystem (VFS) is an [sqlite3_vfs] object 7025 ** that SQLite uses to interact 7026 ** with the underlying operating system. Most SQLite builds come with a 7027 ** single default VFS that is appropriate for the host computer. 7028 ** New VFSes can be registered and existing VFSes can be unregistered. 7029 ** The following interfaces are provided. 7030 ** 7031 ** ^The sqlite3_vfs_find() interface returns a pointer to a VFS given its name. 7032 ** ^Names are case sensitive. 7033 ** ^Names are zero-terminated UTF-8 strings. 7034 ** ^If there is no match, a NULL pointer is returned. 7035 ** ^If zVfsName is NULL then the default VFS is returned. 7036 ** 7037 ** ^New VFSes are registered with sqlite3_vfs_register(). 7038 ** ^Each new VFS becomes the default VFS if the makeDflt flag is set. 7039 ** ^The same VFS can be registered multiple times without injury. 7040 ** ^To make an existing VFS into the default VFS, register it again 7041 ** with the makeDflt flag set. If two different VFSes with the 7042 ** same name are registered, the behavior is undefined. If a 7043 ** VFS is registered with a name that is NULL or an empty string, 7044 ** then the behavior is undefined. 7045 ** 7046 ** ^Unregister a VFS with the sqlite3_vfs_unregister() interface. 7047 ** ^(If the default VFS is unregistered, another VFS is chosen as 7048 ** the default. The choice for the new VFS is arbitrary.)^ 7049 */ 7050 SQLITE_API sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName); 7051 SQLITE_API int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt); 7052 SQLITE_API int sqlite3_vfs_unregister(sqlite3_vfs*); 7053 7054 /* 7055 ** CAPI3REF: Mutexes 7056 ** 7057 ** The SQLite core uses these routines for thread 7058 ** synchronization. Though they are intended for internal 7059 ** use by SQLite, code that links against SQLite is 7060 ** permitted to use any of these routines. 7061 ** 7062 ** The SQLite source code contains multiple implementations 7063 ** of these mutex routines. An appropriate implementation 7064 ** is selected automatically at compile-time. The following 7065 ** implementations are available in the SQLite core: 7066 ** 7067 ** <ul> 7068 ** <li> SQLITE_MUTEX_PTHREADS 7069 ** <li> SQLITE_MUTEX_W32 7070 ** <li> SQLITE_MUTEX_NOOP 7071 ** </ul> 7072 ** 7073 ** The SQLITE_MUTEX_NOOP implementation is a set of routines 7074 ** that does no real locking and is appropriate for use in 7075 ** a single-threaded application. The SQLITE_MUTEX_PTHREADS and 7076 ** SQLITE_MUTEX_W32 implementations are appropriate for use on Unix 7077 ** and Windows. 7078 ** 7079 ** If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor 7080 ** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex 7081 ** implementation is included with the library. In this case the 7082 ** application must supply a custom mutex implementation using the 7083 ** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function 7084 ** before calling sqlite3_initialize() or any other public sqlite3_ 7085 ** function that calls sqlite3_initialize(). 7086 ** 7087 ** ^The sqlite3_mutex_alloc() routine allocates a new 7088 ** mutex and returns a pointer to it. ^The sqlite3_mutex_alloc() 7089 ** routine returns NULL if it is unable to allocate the requested 7090 ** mutex. The argument to sqlite3_mutex_alloc() must one of these 7091 ** integer constants: 7092 ** 7093 ** <ul> 7094 ** <li> SQLITE_MUTEX_FAST 7095 ** <li> SQLITE_MUTEX_RECURSIVE 7096 ** <li> SQLITE_MUTEX_STATIC_MASTER 7097 ** <li> SQLITE_MUTEX_STATIC_MEM 7098 ** <li> SQLITE_MUTEX_STATIC_OPEN 7099 ** <li> SQLITE_MUTEX_STATIC_PRNG 7100 ** <li> SQLITE_MUTEX_STATIC_LRU 7101 ** <li> SQLITE_MUTEX_STATIC_PMEM 7102 ** <li> SQLITE_MUTEX_STATIC_APP1 7103 ** <li> SQLITE_MUTEX_STATIC_APP2 7104 ** <li> SQLITE_MUTEX_STATIC_APP3 7105 ** <li> SQLITE_MUTEX_STATIC_VFS1 7106 ** <li> SQLITE_MUTEX_STATIC_VFS2 7107 ** <li> SQLITE_MUTEX_STATIC_VFS3 7108 ** </ul> 7109 ** 7110 ** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) 7111 ** cause sqlite3_mutex_alloc() to create 7112 ** a new mutex. ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE 7113 ** is used but not necessarily so when SQLITE_MUTEX_FAST is used. 7114 ** The mutex implementation does not need to make a distinction 7115 ** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does 7116 ** not want to. SQLite will only request a recursive mutex in 7117 ** cases where it really needs one. If a faster non-recursive mutex 7118 ** implementation is available on the host platform, the mutex subsystem 7119 ** might return such a mutex in response to SQLITE_MUTEX_FAST. 7120 ** 7121 ** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other 7122 ** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return 7123 ** a pointer to a static preexisting mutex. ^Nine static mutexes are 7124 ** used by the current version of SQLite. Future versions of SQLite 7125 ** may add additional static mutexes. Static mutexes are for internal 7126 ** use by SQLite only. Applications that use SQLite mutexes should 7127 ** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or 7128 ** SQLITE_MUTEX_RECURSIVE. 7129 ** 7130 ** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST 7131 ** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc() 7132 ** returns a different mutex on every call. ^For the static 7133 ** mutex types, the same mutex is returned on every call that has 7134 ** the same type number. 7135 ** 7136 ** ^The sqlite3_mutex_free() routine deallocates a previously 7137 ** allocated dynamic mutex. Attempting to deallocate a static 7138 ** mutex results in undefined behavior. 7139 ** 7140 ** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt 7141 ** to enter a mutex. ^If another thread is already within the mutex, 7142 ** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return 7143 ** SQLITE_BUSY. ^The sqlite3_mutex_try() interface returns [SQLITE_OK] 7144 ** upon successful entry. ^(Mutexes created using 7145 ** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread. 7146 ** In such cases, the 7147 ** mutex must be exited an equal number of times before another thread 7148 ** can enter.)^ If the same thread tries to enter any mutex other 7149 ** than an SQLITE_MUTEX_RECURSIVE more than once, the behavior is undefined. 7150 ** 7151 ** ^(Some systems (for example, Windows 95) do not support the operation 7152 ** implemented by sqlite3_mutex_try(). On those systems, sqlite3_mutex_try() 7153 ** will always return SQLITE_BUSY. The SQLite core only ever uses 7154 ** sqlite3_mutex_try() as an optimization so this is acceptable 7155 ** behavior.)^ 7156 ** 7157 ** ^The sqlite3_mutex_leave() routine exits a mutex that was 7158 ** previously entered by the same thread. The behavior 7159 ** is undefined if the mutex is not currently entered by the 7160 ** calling thread or is not currently allocated. 7161 ** 7162 ** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), or 7163 ** sqlite3_mutex_leave() is a NULL pointer, then all three routines 7164 ** behave as no-ops. 7165 ** 7166 ** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()]. 7167 */ 7168 SQLITE_API sqlite3_mutex *sqlite3_mutex_alloc(int); 7169 SQLITE_API void sqlite3_mutex_free(sqlite3_mutex*); 7170 SQLITE_API void sqlite3_mutex_enter(sqlite3_mutex*); 7171 SQLITE_API int sqlite3_mutex_try(sqlite3_mutex*); 7172 SQLITE_API void sqlite3_mutex_leave(sqlite3_mutex*); 7173 7174 /* 7175 ** CAPI3REF: Mutex Methods Object 7176 ** 7177 ** An instance of this structure defines the low-level routines 7178 ** used to allocate and use mutexes. 7179 ** 7180 ** Usually, the default mutex implementations provided by SQLite are 7181 ** sufficient, however the application has the option of substituting a custom 7182 ** implementation for specialized deployments or systems for which SQLite 7183 ** does not provide a suitable implementation. In this case, the application 7184 ** creates and populates an instance of this structure to pass 7185 ** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option. 7186 ** Additionally, an instance of this structure can be used as an 7187 ** output variable when querying the system for the current mutex 7188 ** implementation, using the [SQLITE_CONFIG_GETMUTEX] option. 7189 ** 7190 ** ^The xMutexInit method defined by this structure is invoked as 7191 ** part of system initialization by the sqlite3_initialize() function. 7192 ** ^The xMutexInit routine is called by SQLite exactly once for each 7193 ** effective call to [sqlite3_initialize()]. 7194 ** 7195 ** ^The xMutexEnd method defined by this structure is invoked as 7196 ** part of system shutdown by the sqlite3_shutdown() function. The 7197 ** implementation of this method is expected to release all outstanding 7198 ** resources obtained by the mutex methods implementation, especially 7199 ** those obtained by the xMutexInit method. ^The xMutexEnd() 7200 ** interface is invoked exactly once for each call to [sqlite3_shutdown()]. 7201 ** 7202 ** ^(The remaining seven methods defined by this structure (xMutexAlloc, 7203 ** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and 7204 ** xMutexNotheld) implement the following interfaces (respectively): 7205 ** 7206 ** <ul> 7207 ** <li> [sqlite3_mutex_alloc()] </li> 7208 ** <li> [sqlite3_mutex_free()] </li> 7209 ** <li> [sqlite3_mutex_enter()] </li> 7210 ** <li> [sqlite3_mutex_try()] </li> 7211 ** <li> [sqlite3_mutex_leave()] </li> 7212 ** <li> [sqlite3_mutex_held()] </li> 7213 ** <li> [sqlite3_mutex_notheld()] </li> 7214 ** </ul>)^ 7215 ** 7216 ** The only difference is that the public sqlite3_XXX functions enumerated 7217 ** above silently ignore any invocations that pass a NULL pointer instead 7218 ** of a valid mutex handle. The implementations of the methods defined 7219 ** by this structure are not required to handle this case, the results 7220 ** of passing a NULL pointer instead of a valid mutex handle are undefined 7221 ** (i.e. it is acceptable to provide an implementation that segfaults if 7222 ** it is passed a NULL pointer). 7223 ** 7224 ** The xMutexInit() method must be threadsafe. It must be harmless to 7225 ** invoke xMutexInit() multiple times within the same process and without 7226 ** intervening calls to xMutexEnd(). Second and subsequent calls to 7227 ** xMutexInit() must be no-ops. 7228 ** 7229 ** xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()] 7230 ** and its associates). Similarly, xMutexAlloc() must not use SQLite memory 7231 ** allocation for a static mutex. ^However xMutexAlloc() may use SQLite 7232 ** memory allocation for a fast or recursive mutex. 7233 ** 7234 ** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is 7235 ** called, but only if the prior call to xMutexInit returned SQLITE_OK. 7236 ** If xMutexInit fails in any way, it is expected to clean up after itself 7237 ** prior to returning. 7238 */ 7239 typedef struct sqlite3_mutex_methods sqlite3_mutex_methods; 7240 struct sqlite3_mutex_methods { 7241 int (*xMutexInit)(void); 7242 int (*xMutexEnd)(void); 7243 sqlite3_mutex *(*xMutexAlloc)(int); 7244 void (*xMutexFree)(sqlite3_mutex *); 7245 void (*xMutexEnter)(sqlite3_mutex *); 7246 int (*xMutexTry)(sqlite3_mutex *); 7247 void (*xMutexLeave)(sqlite3_mutex *); 7248 int (*xMutexHeld)(sqlite3_mutex *); 7249 int (*xMutexNotheld)(sqlite3_mutex *); 7250 }; 7251 7252 /* 7253 ** CAPI3REF: Mutex Verification Routines 7254 ** 7255 ** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines 7256 ** are intended for use inside assert() statements. The SQLite core 7257 ** never uses these routines except inside an assert() and applications 7258 ** are advised to follow the lead of the core. The SQLite core only 7259 ** provides implementations for these routines when it is compiled 7260 ** with the SQLITE_DEBUG flag. External mutex implementations 7261 ** are only required to provide these routines if SQLITE_DEBUG is 7262 ** defined and if NDEBUG is not defined. 7263 ** 7264 ** These routines should return true if the mutex in their argument 7265 ** is held or not held, respectively, by the calling thread. 7266 ** 7267 ** The implementation is not required to provide versions of these 7268 ** routines that actually work. If the implementation does not provide working 7269 ** versions of these routines, it should at least provide stubs that always 7270 ** return true so that one does not get spurious assertion failures. 7271 ** 7272 ** If the argument to sqlite3_mutex_held() is a NULL pointer then 7273 ** the routine should return 1. This seems counter-intuitive since 7274 ** clearly the mutex cannot be held if it does not exist. But 7275 ** the reason the mutex does not exist is because the build is not 7276 ** using mutexes. And we do not want the assert() containing the 7277 ** call to sqlite3_mutex_held() to fail, so a non-zero return is 7278 ** the appropriate thing to do. The sqlite3_mutex_notheld() 7279 ** interface should also return 1 when given a NULL pointer. 7280 */ 7281 #ifndef NDEBUG 7282 SQLITE_API int sqlite3_mutex_held(sqlite3_mutex*); 7283 SQLITE_API int sqlite3_mutex_notheld(sqlite3_mutex*); 7284 #endif 7285 7286 /* 7287 ** CAPI3REF: Mutex Types 7288 ** 7289 ** The [sqlite3_mutex_alloc()] interface takes a single argument 7290 ** which is one of these integer constants. 7291 ** 7292 ** The set of static mutexes may change from one SQLite release to the 7293 ** next. Applications that override the built-in mutex logic must be 7294 ** prepared to accommodate additional static mutexes. 7295 */ 7296 #define SQLITE_MUTEX_FAST 0 7297 #define SQLITE_MUTEX_RECURSIVE 1 7298 #define SQLITE_MUTEX_STATIC_MASTER 2 7299 #define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */ 7300 #define SQLITE_MUTEX_STATIC_MEM2 4 /* NOT USED */ 7301 #define SQLITE_MUTEX_STATIC_OPEN 4 /* sqlite3BtreeOpen() */ 7302 #define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_randomness() */ 7303 #define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */ 7304 #define SQLITE_MUTEX_STATIC_LRU2 7 /* NOT USED */ 7305 #define SQLITE_MUTEX_STATIC_PMEM 7 /* sqlite3PageMalloc() */ 7306 #define SQLITE_MUTEX_STATIC_APP1 8 /* For use by application */ 7307 #define SQLITE_MUTEX_STATIC_APP2 9 /* For use by application */ 7308 #define SQLITE_MUTEX_STATIC_APP3 10 /* For use by application */ 7309 #define SQLITE_MUTEX_STATIC_VFS1 11 /* For use by built-in VFS */ 7310 #define SQLITE_MUTEX_STATIC_VFS2 12 /* For use by extension VFS */ 7311 #define SQLITE_MUTEX_STATIC_VFS3 13 /* For use by application VFS */ 7312 7313 /* 7314 ** CAPI3REF: Retrieve the mutex for a database connection 7315 ** METHOD: sqlite3 7316 ** 7317 ** ^This interface returns a pointer the [sqlite3_mutex] object that 7318 ** serializes access to the [database connection] given in the argument 7319 ** when the [threading mode] is Serialized. 7320 ** ^If the [threading mode] is Single-thread or Multi-thread then this 7321 ** routine returns a NULL pointer. 7322 */ 7323 SQLITE_API sqlite3_mutex *sqlite3_db_mutex(sqlite3*); 7324 7325 /* 7326 ** CAPI3REF: Low-Level Control Of Database Files 7327 ** METHOD: sqlite3 7328 ** KEYWORDS: {file control} 7329 ** 7330 ** ^The [sqlite3_file_control()] interface makes a direct call to the 7331 ** xFileControl method for the [sqlite3_io_methods] object associated 7332 ** with a particular database identified by the second argument. ^The 7333 ** name of the database is "main" for the main database or "temp" for the 7334 ** TEMP database, or the name that appears after the AS keyword for 7335 ** databases that are added using the [ATTACH] SQL command. 7336 ** ^A NULL pointer can be used in place of "main" to refer to the 7337 ** main database file. 7338 ** ^The third and fourth parameters to this routine 7339 ** are passed directly through to the second and third parameters of 7340 ** the xFileControl method. ^The return value of the xFileControl 7341 ** method becomes the return value of this routine. 7342 ** 7343 ** A few opcodes for [sqlite3_file_control()] are handled directly 7344 ** by the SQLite core and never invoke the 7345 ** sqlite3_io_methods.xFileControl method. 7346 ** ^The [SQLITE_FCNTL_FILE_POINTER] value for the op parameter causes 7347 ** a pointer to the underlying [sqlite3_file] object to be written into 7348 ** the space pointed to by the 4th parameter. The 7349 ** [SQLITE_FCNTL_JOURNAL_POINTER] works similarly except that it returns 7350 ** the [sqlite3_file] object associated with the journal file instead of 7351 ** the main database. The [SQLITE_FCNTL_VFS_POINTER] opcode returns 7352 ** a pointer to the underlying [sqlite3_vfs] object for the file. 7353 ** The [SQLITE_FCNTL_DATA_VERSION] returns the data version counter 7354 ** from the pager. 7355 ** 7356 ** ^If the second parameter (zDbName) does not match the name of any 7357 ** open database file, then SQLITE_ERROR is returned. ^This error 7358 ** code is not remembered and will not be recalled by [sqlite3_errcode()] 7359 ** or [sqlite3_errmsg()]. The underlying xFileControl method might 7360 ** also return SQLITE_ERROR. There is no way to distinguish between 7361 ** an incorrect zDbName and an SQLITE_ERROR return from the underlying 7362 ** xFileControl method. 7363 ** 7364 ** See also: [file control opcodes] 7365 */ 7366 SQLITE_API int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*); 7367 7368 /* 7369 ** CAPI3REF: Testing Interface 7370 ** 7371 ** ^The sqlite3_test_control() interface is used to read out internal 7372 ** state of SQLite and to inject faults into SQLite for testing 7373 ** purposes. ^The first parameter is an operation code that determines 7374 ** the number, meaning, and operation of all subsequent parameters. 7375 ** 7376 ** This interface is not for use by applications. It exists solely 7377 ** for verifying the correct operation of the SQLite library. Depending 7378 ** on how the SQLite library is compiled, this interface might not exist. 7379 ** 7380 ** The details of the operation codes, their meanings, the parameters 7381 ** they take, and what they do are all subject to change without notice. 7382 ** Unlike most of the SQLite API, this function is not guaranteed to 7383 ** operate consistently from one release to the next. 7384 */ 7385 SQLITE_API int sqlite3_test_control(int op, ...); 7386 7387 /* 7388 ** CAPI3REF: Testing Interface Operation Codes 7389 ** 7390 ** These constants are the valid operation code parameters used 7391 ** as the first argument to [sqlite3_test_control()]. 7392 ** 7393 ** These parameters and their meanings are subject to change 7394 ** without notice. These values are for testing purposes only. 7395 ** Applications should not use any of these parameters or the 7396 ** [sqlite3_test_control()] interface. 7397 */ 7398 #define SQLITE_TESTCTRL_FIRST 5 7399 #define SQLITE_TESTCTRL_PRNG_SAVE 5 7400 #define SQLITE_TESTCTRL_PRNG_RESTORE 6 7401 #define SQLITE_TESTCTRL_PRNG_RESET 7 /* NOT USED */ 7402 #define SQLITE_TESTCTRL_BITVEC_TEST 8 7403 #define SQLITE_TESTCTRL_FAULT_INSTALL 9 7404 #define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS 10 7405 #define SQLITE_TESTCTRL_PENDING_BYTE 11 7406 #define SQLITE_TESTCTRL_ASSERT 12 7407 #define SQLITE_TESTCTRL_ALWAYS 13 7408 #define SQLITE_TESTCTRL_RESERVE 14 7409 #define SQLITE_TESTCTRL_OPTIMIZATIONS 15 7410 #define SQLITE_TESTCTRL_ISKEYWORD 16 /* NOT USED */ 7411 #define SQLITE_TESTCTRL_SCRATCHMALLOC 17 /* NOT USED */ 7412 #define SQLITE_TESTCTRL_INTERNAL_FUNCTIONS 17 7413 #define SQLITE_TESTCTRL_LOCALTIME_FAULT 18 7414 #define SQLITE_TESTCTRL_EXPLAIN_STMT 19 /* NOT USED */ 7415 #define SQLITE_TESTCTRL_ONCE_RESET_THRESHOLD 19 7416 #define SQLITE_TESTCTRL_NEVER_CORRUPT 20 7417 #define SQLITE_TESTCTRL_VDBE_COVERAGE 21 7418 #define SQLITE_TESTCTRL_BYTEORDER 22 7419 #define SQLITE_TESTCTRL_ISINIT 23 7420 #define SQLITE_TESTCTRL_SORTER_MMAP 24 7421 #define SQLITE_TESTCTRL_IMPOSTER 25 7422 #define SQLITE_TESTCTRL_PARSER_COVERAGE 26 7423 #define SQLITE_TESTCTRL_RESULT_INTREAL 27 7424 #define SQLITE_TESTCTRL_PRNG_SEED 28 7425 #define SQLITE_TESTCTRL_EXTRA_SCHEMA_CHECKS 29 7426 #define SQLITE_TESTCTRL_LAST 29 /* Largest TESTCTRL */ 7427 7428 /* 7429 ** CAPI3REF: SQL Keyword Checking 7430 ** 7431 ** These routines provide access to the set of SQL language keywords 7432 ** recognized by SQLite. Applications can uses these routines to determine 7433 ** whether or not a specific identifier needs to be escaped (for example, 7434 ** by enclosing in double-quotes) so as not to confuse the parser. 7435 ** 7436 ** The sqlite3_keyword_count() interface returns the number of distinct 7437 ** keywords understood by SQLite. 7438 ** 7439 ** The sqlite3_keyword_name(N,Z,L) interface finds the N-th keyword and 7440 ** makes *Z point to that keyword expressed as UTF8 and writes the number 7441 ** of bytes in the keyword into *L. The string that *Z points to is not 7442 ** zero-terminated. The sqlite3_keyword_name(N,Z,L) routine returns 7443 ** SQLITE_OK if N is within bounds and SQLITE_ERROR if not. If either Z 7444 ** or L are NULL or invalid pointers then calls to 7445 ** sqlite3_keyword_name(N,Z,L) result in undefined behavior. 7446 ** 7447 ** The sqlite3_keyword_check(Z,L) interface checks to see whether or not 7448 ** the L-byte UTF8 identifier that Z points to is a keyword, returning non-zero 7449 ** if it is and zero if not. 7450 ** 7451 ** The parser used by SQLite is forgiving. It is often possible to use 7452 ** a keyword as an identifier as long as such use does not result in a 7453 ** parsing ambiguity. For example, the statement 7454 ** "CREATE TABLE BEGIN(REPLACE,PRAGMA,END);" is accepted by SQLite, and 7455 ** creates a new table named "BEGIN" with three columns named 7456 ** "REPLACE", "PRAGMA", and "END". Nevertheless, best practice is to avoid 7457 ** using keywords as identifiers. Common techniques used to avoid keyword 7458 ** name collisions include: 7459 ** <ul> 7460 ** <li> Put all identifier names inside double-quotes. This is the official 7461 ** SQL way to escape identifier names. 7462 ** <li> Put identifier names inside [...]. This is not standard SQL, 7463 ** but it is what SQL Server does and so lots of programmers use this 7464 ** technique. 7465 ** <li> Begin every identifier with the letter "Z" as no SQL keywords start 7466 ** with "Z". 7467 ** <li> Include a digit somewhere in every identifier name. 7468 ** </ul> 7469 ** 7470 ** Note that the number of keywords understood by SQLite can depend on 7471 ** compile-time options. For example, "VACUUM" is not a keyword if 7472 ** SQLite is compiled with the [-DSQLITE_OMIT_VACUUM] option. Also, 7473 ** new keywords may be added to future releases of SQLite. 7474 */ 7475 SQLITE_API int sqlite3_keyword_count(void); 7476 SQLITE_API int sqlite3_keyword_name(int,const char**,int*); 7477 SQLITE_API int sqlite3_keyword_check(const char*,int); 7478 7479 /* 7480 ** CAPI3REF: Dynamic String Object 7481 ** KEYWORDS: {dynamic string} 7482 ** 7483 ** An instance of the sqlite3_str object contains a dynamically-sized 7484 ** string under construction. 7485 ** 7486 ** The lifecycle of an sqlite3_str object is as follows: 7487 ** <ol> 7488 ** <li> ^The sqlite3_str object is created using [sqlite3_str_new()]. 7489 ** <li> ^Text is appended to the sqlite3_str object using various 7490 ** methods, such as [sqlite3_str_appendf()]. 7491 ** <li> ^The sqlite3_str object is destroyed and the string it created 7492 ** is returned using the [sqlite3_str_finish()] interface. 7493 ** </ol> 7494 */ 7495 typedef struct sqlite3_str sqlite3_str; 7496 7497 /* 7498 ** CAPI3REF: Create A New Dynamic String Object 7499 ** CONSTRUCTOR: sqlite3_str 7500 ** 7501 ** ^The [sqlite3_str_new(D)] interface allocates and initializes 7502 ** a new [sqlite3_str] object. To avoid memory leaks, the object returned by 7503 ** [sqlite3_str_new()] must be freed by a subsequent call to 7504 ** [sqlite3_str_finish(X)]. 7505 ** 7506 ** ^The [sqlite3_str_new(D)] interface always returns a pointer to a 7507 ** valid [sqlite3_str] object, though in the event of an out-of-memory 7508 ** error the returned object might be a special singleton that will 7509 ** silently reject new text, always return SQLITE_NOMEM from 7510 ** [sqlite3_str_errcode()], always return 0 for 7511 ** [sqlite3_str_length()], and always return NULL from 7512 ** [sqlite3_str_finish(X)]. It is always safe to use the value 7513 ** returned by [sqlite3_str_new(D)] as the sqlite3_str parameter 7514 ** to any of the other [sqlite3_str] methods. 7515 ** 7516 ** The D parameter to [sqlite3_str_new(D)] may be NULL. If the 7517 ** D parameter in [sqlite3_str_new(D)] is not NULL, then the maximum 7518 ** length of the string contained in the [sqlite3_str] object will be 7519 ** the value set for [sqlite3_limit](D,[SQLITE_LIMIT_LENGTH]) instead 7520 ** of [SQLITE_MAX_LENGTH]. 7521 */ 7522 SQLITE_API sqlite3_str *sqlite3_str_new(sqlite3*); 7523 7524 /* 7525 ** CAPI3REF: Finalize A Dynamic String 7526 ** DESTRUCTOR: sqlite3_str 7527 ** 7528 ** ^The [sqlite3_str_finish(X)] interface destroys the sqlite3_str object X 7529 ** and returns a pointer to a memory buffer obtained from [sqlite3_malloc64()] 7530 ** that contains the constructed string. The calling application should 7531 ** pass the returned value to [sqlite3_free()] to avoid a memory leak. 7532 ** ^The [sqlite3_str_finish(X)] interface may return a NULL pointer if any 7533 ** errors were encountered during construction of the string. ^The 7534 ** [sqlite3_str_finish(X)] interface will also return a NULL pointer if the 7535 ** string in [sqlite3_str] object X is zero bytes long. 7536 */ 7537 SQLITE_API char *sqlite3_str_finish(sqlite3_str*); 7538 7539 /* 7540 ** CAPI3REF: Add Content To A Dynamic String 7541 ** METHOD: sqlite3_str 7542 ** 7543 ** These interfaces add content to an sqlite3_str object previously obtained 7544 ** from [sqlite3_str_new()]. 7545 ** 7546 ** ^The [sqlite3_str_appendf(X,F,...)] and 7547 ** [sqlite3_str_vappendf(X,F,V)] interfaces uses the [built-in printf] 7548 ** functionality of SQLite to append formatted text onto the end of 7549 ** [sqlite3_str] object X. 7550 ** 7551 ** ^The [sqlite3_str_append(X,S,N)] method appends exactly N bytes from string S 7552 ** onto the end of the [sqlite3_str] object X. N must be non-negative. 7553 ** S must contain at least N non-zero bytes of content. To append a 7554 ** zero-terminated string in its entirety, use the [sqlite3_str_appendall()] 7555 ** method instead. 7556 ** 7557 ** ^The [sqlite3_str_appendall(X,S)] method appends the complete content of 7558 ** zero-terminated string S onto the end of [sqlite3_str] object X. 7559 ** 7560 ** ^The [sqlite3_str_appendchar(X,N,C)] method appends N copies of the 7561 ** single-byte character C onto the end of [sqlite3_str] object X. 7562 ** ^This method can be used, for example, to add whitespace indentation. 7563 ** 7564 ** ^The [sqlite3_str_reset(X)] method resets the string under construction 7565 ** inside [sqlite3_str] object X back to zero bytes in length. 7566 ** 7567 ** These methods do not return a result code. ^If an error occurs, that fact 7568 ** is recorded in the [sqlite3_str] object and can be recovered by a 7569 ** subsequent call to [sqlite3_str_errcode(X)]. 7570 */ 7571 SQLITE_API void sqlite3_str_appendf(sqlite3_str*, const char *zFormat, ...); 7572 SQLITE_API void sqlite3_str_vappendf(sqlite3_str*, const char *zFormat, va_list); 7573 SQLITE_API void sqlite3_str_append(sqlite3_str*, const char *zIn, int N); 7574 SQLITE_API void sqlite3_str_appendall(sqlite3_str*, const char *zIn); 7575 SQLITE_API void sqlite3_str_appendchar(sqlite3_str*, int N, char C); 7576 SQLITE_API void sqlite3_str_reset(sqlite3_str*); 7577 7578 /* 7579 ** CAPI3REF: Status Of A Dynamic String 7580 ** METHOD: sqlite3_str 7581 ** 7582 ** These interfaces return the current status of an [sqlite3_str] object. 7583 ** 7584 ** ^If any prior errors have occurred while constructing the dynamic string 7585 ** in sqlite3_str X, then the [sqlite3_str_errcode(X)] method will return 7586 ** an appropriate error code. ^The [sqlite3_str_errcode(X)] method returns 7587 ** [SQLITE_NOMEM] following any out-of-memory error, or 7588 ** [SQLITE_TOOBIG] if the size of the dynamic string exceeds 7589 ** [SQLITE_MAX_LENGTH], or [SQLITE_OK] if there have been no errors. 7590 ** 7591 ** ^The [sqlite3_str_length(X)] method returns the current length, in bytes, 7592 ** of the dynamic string under construction in [sqlite3_str] object X. 7593 ** ^The length returned by [sqlite3_str_length(X)] does not include the 7594 ** zero-termination byte. 7595 ** 7596 ** ^The [sqlite3_str_value(X)] method returns a pointer to the current 7597 ** content of the dynamic string under construction in X. The value 7598 ** returned by [sqlite3_str_value(X)] is managed by the sqlite3_str object X 7599 ** and might be freed or altered by any subsequent method on the same 7600 ** [sqlite3_str] object. Applications must not used the pointer returned 7601 ** [sqlite3_str_value(X)] after any subsequent method call on the same 7602 ** object. ^Applications may change the content of the string returned 7603 ** by [sqlite3_str_value(X)] as long as they do not write into any bytes 7604 ** outside the range of 0 to [sqlite3_str_length(X)] and do not read or 7605 ** write any byte after any subsequent sqlite3_str method call. 7606 */ 7607 SQLITE_API int sqlite3_str_errcode(sqlite3_str*); 7608 SQLITE_API int sqlite3_str_length(sqlite3_str*); 7609 SQLITE_API char *sqlite3_str_value(sqlite3_str*); 7610 7611 /* 7612 ** CAPI3REF: SQLite Runtime Status 7613 ** 7614 ** ^These interfaces are used to retrieve runtime status information 7615 ** about the performance of SQLite, and optionally to reset various 7616 ** highwater marks. ^The first argument is an integer code for 7617 ** the specific parameter to measure. ^(Recognized integer codes 7618 ** are of the form [status parameters | SQLITE_STATUS_...].)^ 7619 ** ^The current value of the parameter is returned into *pCurrent. 7620 ** ^The highest recorded value is returned in *pHighwater. ^If the 7621 ** resetFlag is true, then the highest record value is reset after 7622 ** *pHighwater is written. ^(Some parameters do not record the highest 7623 ** value. For those parameters 7624 ** nothing is written into *pHighwater and the resetFlag is ignored.)^ 7625 ** ^(Other parameters record only the highwater mark and not the current 7626 ** value. For these latter parameters nothing is written into *pCurrent.)^ 7627 ** 7628 ** ^The sqlite3_status() and sqlite3_status64() routines return 7629 ** SQLITE_OK on success and a non-zero [error code] on failure. 7630 ** 7631 ** If either the current value or the highwater mark is too large to 7632 ** be represented by a 32-bit integer, then the values returned by 7633 ** sqlite3_status() are undefined. 7634 ** 7635 ** See also: [sqlite3_db_status()] 7636 */ 7637 SQLITE_API int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag); 7638 SQLITE_API int sqlite3_status64( 7639 int op, 7640 sqlite3_int64 *pCurrent, 7641 sqlite3_int64 *pHighwater, 7642 int resetFlag 7643 ); 7644 7645 7646 /* 7647 ** CAPI3REF: Status Parameters 7648 ** KEYWORDS: {status parameters} 7649 ** 7650 ** These integer constants designate various run-time status parameters 7651 ** that can be returned by [sqlite3_status()]. 7652 ** 7653 ** <dl> 7654 ** [[SQLITE_STATUS_MEMORY_USED]] ^(<dt>SQLITE_STATUS_MEMORY_USED</dt> 7655 ** <dd>This parameter is the current amount of memory checked out 7656 ** using [sqlite3_malloc()], either directly or indirectly. The 7657 ** figure includes calls made to [sqlite3_malloc()] by the application 7658 ** and internal memory usage by the SQLite library. Auxiliary page-cache 7659 ** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in 7660 ** this parameter. The amount returned is the sum of the allocation 7661 ** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>)^ 7662 ** 7663 ** [[SQLITE_STATUS_MALLOC_SIZE]] ^(<dt>SQLITE_STATUS_MALLOC_SIZE</dt> 7664 ** <dd>This parameter records the largest memory allocation request 7665 ** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their 7666 ** internal equivalents). Only the value returned in the 7667 ** *pHighwater parameter to [sqlite3_status()] is of interest. 7668 ** The value written into the *pCurrent parameter is undefined.</dd>)^ 7669 ** 7670 ** [[SQLITE_STATUS_MALLOC_COUNT]] ^(<dt>SQLITE_STATUS_MALLOC_COUNT</dt> 7671 ** <dd>This parameter records the number of separate memory allocations 7672 ** currently checked out.</dd>)^ 7673 ** 7674 ** [[SQLITE_STATUS_PAGECACHE_USED]] ^(<dt>SQLITE_STATUS_PAGECACHE_USED</dt> 7675 ** <dd>This parameter returns the number of pages used out of the 7676 ** [pagecache memory allocator] that was configured using 7677 ** [SQLITE_CONFIG_PAGECACHE]. The 7678 ** value returned is in pages, not in bytes.</dd>)^ 7679 ** 7680 ** [[SQLITE_STATUS_PAGECACHE_OVERFLOW]] 7681 ** ^(<dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt> 7682 ** <dd>This parameter returns the number of bytes of page cache 7683 ** allocation which could not be satisfied by the [SQLITE_CONFIG_PAGECACHE] 7684 ** buffer and where forced to overflow to [sqlite3_malloc()]. The 7685 ** returned value includes allocations that overflowed because they 7686 ** where too large (they were larger than the "sz" parameter to 7687 ** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because 7688 ** no space was left in the page cache.</dd>)^ 7689 ** 7690 ** [[SQLITE_STATUS_PAGECACHE_SIZE]] ^(<dt>SQLITE_STATUS_PAGECACHE_SIZE</dt> 7691 ** <dd>This parameter records the largest memory allocation request 7692 ** handed to [pagecache memory allocator]. Only the value returned in the 7693 ** *pHighwater parameter to [sqlite3_status()] is of interest. 7694 ** The value written into the *pCurrent parameter is undefined.</dd>)^ 7695 ** 7696 ** [[SQLITE_STATUS_SCRATCH_USED]] <dt>SQLITE_STATUS_SCRATCH_USED</dt> 7697 ** <dd>No longer used.</dd> 7698 ** 7699 ** [[SQLITE_STATUS_SCRATCH_OVERFLOW]] ^(<dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt> 7700 ** <dd>No longer used.</dd> 7701 ** 7702 ** [[SQLITE_STATUS_SCRATCH_SIZE]] <dt>SQLITE_STATUS_SCRATCH_SIZE</dt> 7703 ** <dd>No longer used.</dd> 7704 ** 7705 ** [[SQLITE_STATUS_PARSER_STACK]] ^(<dt>SQLITE_STATUS_PARSER_STACK</dt> 7706 ** <dd>The *pHighwater parameter records the deepest parser stack. 7707 ** The *pCurrent value is undefined. The *pHighwater value is only 7708 ** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>)^ 7709 ** </dl> 7710 ** 7711 ** New status parameters may be added from time to time. 7712 */ 7713 #define SQLITE_STATUS_MEMORY_USED 0 7714 #define SQLITE_STATUS_PAGECACHE_USED 1 7715 #define SQLITE_STATUS_PAGECACHE_OVERFLOW 2 7716 #define SQLITE_STATUS_SCRATCH_USED 3 /* NOT USED */ 7717 #define SQLITE_STATUS_SCRATCH_OVERFLOW 4 /* NOT USED */ 7718 #define SQLITE_STATUS_MALLOC_SIZE 5 7719 #define SQLITE_STATUS_PARSER_STACK 6 7720 #define SQLITE_STATUS_PAGECACHE_SIZE 7 7721 #define SQLITE_STATUS_SCRATCH_SIZE 8 /* NOT USED */ 7722 #define SQLITE_STATUS_MALLOC_COUNT 9 7723 7724 /* 7725 ** CAPI3REF: Database Connection Status 7726 ** METHOD: sqlite3 7727 ** 7728 ** ^This interface is used to retrieve runtime status information 7729 ** about a single [database connection]. ^The first argument is the 7730 ** database connection object to be interrogated. ^The second argument 7731 ** is an integer constant, taken from the set of 7732 ** [SQLITE_DBSTATUS options], that 7733 ** determines the parameter to interrogate. The set of 7734 ** [SQLITE_DBSTATUS options] is likely 7735 ** to grow in future releases of SQLite. 7736 ** 7737 ** ^The current value of the requested parameter is written into *pCur 7738 ** and the highest instantaneous value is written into *pHiwtr. ^If 7739 ** the resetFlg is true, then the highest instantaneous value is 7740 ** reset back down to the current value. 7741 ** 7742 ** ^The sqlite3_db_status() routine returns SQLITE_OK on success and a 7743 ** non-zero [error code] on failure. 7744 ** 7745 ** See also: [sqlite3_status()] and [sqlite3_stmt_status()]. 7746 */ 7747 SQLITE_API int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg); 7748 7749 /* 7750 ** CAPI3REF: Status Parameters for database connections 7751 ** KEYWORDS: {SQLITE_DBSTATUS options} 7752 ** 7753 ** These constants are the available integer "verbs" that can be passed as 7754 ** the second argument to the [sqlite3_db_status()] interface. 7755 ** 7756 ** New verbs may be added in future releases of SQLite. Existing verbs 7757 ** might be discontinued. Applications should check the return code from 7758 ** [sqlite3_db_status()] to make sure that the call worked. 7759 ** The [sqlite3_db_status()] interface will return a non-zero error code 7760 ** if a discontinued or unsupported verb is invoked. 7761 ** 7762 ** <dl> 7763 ** [[SQLITE_DBSTATUS_LOOKASIDE_USED]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt> 7764 ** <dd>This parameter returns the number of lookaside memory slots currently 7765 ** checked out.</dd>)^ 7766 ** 7767 ** [[SQLITE_DBSTATUS_LOOKASIDE_HIT]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_HIT</dt> 7768 ** <dd>This parameter returns the number malloc attempts that were 7769 ** satisfied using lookaside memory. Only the high-water value is meaningful; 7770 ** the current value is always zero.)^ 7771 ** 7772 ** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE]] 7773 ** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE</dt> 7774 ** <dd>This parameter returns the number malloc attempts that might have 7775 ** been satisfied using lookaside memory but failed due to the amount of 7776 ** memory requested being larger than the lookaside slot size. 7777 ** Only the high-water value is meaningful; 7778 ** the current value is always zero.)^ 7779 ** 7780 ** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL]] 7781 ** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL</dt> 7782 ** <dd>This parameter returns the number malloc attempts that might have 7783 ** been satisfied using lookaside memory but failed due to all lookaside 7784 ** memory already being in use. 7785 ** Only the high-water value is meaningful; 7786 ** the current value is always zero.)^ 7787 ** 7788 ** [[SQLITE_DBSTATUS_CACHE_USED]] ^(<dt>SQLITE_DBSTATUS_CACHE_USED</dt> 7789 ** <dd>This parameter returns the approximate number of bytes of heap 7790 ** memory used by all pager caches associated with the database connection.)^ 7791 ** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0. 7792 ** 7793 ** [[SQLITE_DBSTATUS_CACHE_USED_SHARED]] 7794 ** ^(<dt>SQLITE_DBSTATUS_CACHE_USED_SHARED</dt> 7795 ** <dd>This parameter is similar to DBSTATUS_CACHE_USED, except that if a 7796 ** pager cache is shared between two or more connections the bytes of heap 7797 ** memory used by that pager cache is divided evenly between the attached 7798 ** connections.)^ In other words, if none of the pager caches associated 7799 ** with the database connection are shared, this request returns the same 7800 ** value as DBSTATUS_CACHE_USED. Or, if one or more or the pager caches are 7801 ** shared, the value returned by this call will be smaller than that returned 7802 ** by DBSTATUS_CACHE_USED. ^The highwater mark associated with 7803 ** SQLITE_DBSTATUS_CACHE_USED_SHARED is always 0. 7804 ** 7805 ** [[SQLITE_DBSTATUS_SCHEMA_USED]] ^(<dt>SQLITE_DBSTATUS_SCHEMA_USED</dt> 7806 ** <dd>This parameter returns the approximate number of bytes of heap 7807 ** memory used to store the schema for all databases associated 7808 ** with the connection - main, temp, and any [ATTACH]-ed databases.)^ 7809 ** ^The full amount of memory used by the schemas is reported, even if the 7810 ** schema memory is shared with other database connections due to 7811 ** [shared cache mode] being enabled. 7812 ** ^The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0. 7813 ** 7814 ** [[SQLITE_DBSTATUS_STMT_USED]] ^(<dt>SQLITE_DBSTATUS_STMT_USED</dt> 7815 ** <dd>This parameter returns the approximate number of bytes of heap 7816 ** and lookaside memory used by all prepared statements associated with 7817 ** the database connection.)^ 7818 ** ^The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0. 7819 ** </dd> 7820 ** 7821 ** [[SQLITE_DBSTATUS_CACHE_HIT]] ^(<dt>SQLITE_DBSTATUS_CACHE_HIT</dt> 7822 ** <dd>This parameter returns the number of pager cache hits that have 7823 ** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_HIT 7824 ** is always 0. 7825 ** </dd> 7826 ** 7827 ** [[SQLITE_DBSTATUS_CACHE_MISS]] ^(<dt>SQLITE_DBSTATUS_CACHE_MISS</dt> 7828 ** <dd>This parameter returns the number of pager cache misses that have 7829 ** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_MISS 7830 ** is always 0. 7831 ** </dd> 7832 ** 7833 ** [[SQLITE_DBSTATUS_CACHE_WRITE]] ^(<dt>SQLITE_DBSTATUS_CACHE_WRITE</dt> 7834 ** <dd>This parameter returns the number of dirty cache entries that have 7835 ** been written to disk. Specifically, the number of pages written to the 7836 ** wal file in wal mode databases, or the number of pages written to the 7837 ** database file in rollback mode databases. Any pages written as part of 7838 ** transaction rollback or database recovery operations are not included. 7839 ** If an IO or other error occurs while writing a page to disk, the effect 7840 ** on subsequent SQLITE_DBSTATUS_CACHE_WRITE requests is undefined.)^ ^The 7841 ** highwater mark associated with SQLITE_DBSTATUS_CACHE_WRITE is always 0. 7842 ** </dd> 7843 ** 7844 ** [[SQLITE_DBSTATUS_CACHE_SPILL]] ^(<dt>SQLITE_DBSTATUS_CACHE_SPILL</dt> 7845 ** <dd>This parameter returns the number of dirty cache entries that have 7846 ** been written to disk in the middle of a transaction due to the page 7847 ** cache overflowing. Transactions are more efficient if they are written 7848 ** to disk all at once. When pages spill mid-transaction, that introduces 7849 ** additional overhead. This parameter can be used help identify 7850 ** inefficiencies that can be resolve by increasing the cache size. 7851 ** </dd> 7852 ** 7853 ** [[SQLITE_DBSTATUS_DEFERRED_FKS]] ^(<dt>SQLITE_DBSTATUS_DEFERRED_FKS</dt> 7854 ** <dd>This parameter returns zero for the current value if and only if 7855 ** all foreign key constraints (deferred or immediate) have been 7856 ** resolved.)^ ^The highwater mark is always 0. 7857 ** </dd> 7858 ** </dl> 7859 */ 7860 #define SQLITE_DBSTATUS_LOOKASIDE_USED 0 7861 #define SQLITE_DBSTATUS_CACHE_USED 1 7862 #define SQLITE_DBSTATUS_SCHEMA_USED 2 7863 #define SQLITE_DBSTATUS_STMT_USED 3 7864 #define SQLITE_DBSTATUS_LOOKASIDE_HIT 4 7865 #define SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE 5 7866 #define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL 6 7867 #define SQLITE_DBSTATUS_CACHE_HIT 7 7868 #define SQLITE_DBSTATUS_CACHE_MISS 8 7869 #define SQLITE_DBSTATUS_CACHE_WRITE 9 7870 #define SQLITE_DBSTATUS_DEFERRED_FKS 10 7871 #define SQLITE_DBSTATUS_CACHE_USED_SHARED 11 7872 #define SQLITE_DBSTATUS_CACHE_SPILL 12 7873 #define SQLITE_DBSTATUS_MAX 12 /* Largest defined DBSTATUS */ 7874 7875 7876 /* 7877 ** CAPI3REF: Prepared Statement Status 7878 ** METHOD: sqlite3_stmt 7879 ** 7880 ** ^(Each prepared statement maintains various 7881 ** [SQLITE_STMTSTATUS counters] that measure the number 7882 ** of times it has performed specific operations.)^ These counters can 7883 ** be used to monitor the performance characteristics of the prepared 7884 ** statements. For example, if the number of table steps greatly exceeds 7885 ** the number of table searches or result rows, that would tend to indicate 7886 ** that the prepared statement is using a full table scan rather than 7887 ** an index. 7888 ** 7889 ** ^(This interface is used to retrieve and reset counter values from 7890 ** a [prepared statement]. The first argument is the prepared statement 7891 ** object to be interrogated. The second argument 7892 ** is an integer code for a specific [SQLITE_STMTSTATUS counter] 7893 ** to be interrogated.)^ 7894 ** ^The current value of the requested counter is returned. 7895 ** ^If the resetFlg is true, then the counter is reset to zero after this 7896 ** interface call returns. 7897 ** 7898 ** See also: [sqlite3_status()] and [sqlite3_db_status()]. 7899 */ 7900 SQLITE_API int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg); 7901 7902 /* 7903 ** CAPI3REF: Status Parameters for prepared statements 7904 ** KEYWORDS: {SQLITE_STMTSTATUS counter} {SQLITE_STMTSTATUS counters} 7905 ** 7906 ** These preprocessor macros define integer codes that name counter 7907 ** values associated with the [sqlite3_stmt_status()] interface. 7908 ** The meanings of the various counters are as follows: 7909 ** 7910 ** <dl> 7911 ** [[SQLITE_STMTSTATUS_FULLSCAN_STEP]] <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt> 7912 ** <dd>^This is the number of times that SQLite has stepped forward in 7913 ** a table as part of a full table scan. Large numbers for this counter 7914 ** may indicate opportunities for performance improvement through 7915 ** careful use of indices.</dd> 7916 ** 7917 ** [[SQLITE_STMTSTATUS_SORT]] <dt>SQLITE_STMTSTATUS_SORT</dt> 7918 ** <dd>^This is the number of sort operations that have occurred. 7919 ** A non-zero value in this counter may indicate an opportunity to 7920 ** improvement performance through careful use of indices.</dd> 7921 ** 7922 ** [[SQLITE_STMTSTATUS_AUTOINDEX]] <dt>SQLITE_STMTSTATUS_AUTOINDEX</dt> 7923 ** <dd>^This is the number of rows inserted into transient indices that 7924 ** were created automatically in order to help joins run faster. 7925 ** A non-zero value in this counter may indicate an opportunity to 7926 ** improvement performance by adding permanent indices that do not 7927 ** need to be reinitialized each time the statement is run.</dd> 7928 ** 7929 ** [[SQLITE_STMTSTATUS_VM_STEP]] <dt>SQLITE_STMTSTATUS_VM_STEP</dt> 7930 ** <dd>^This is the number of virtual machine operations executed 7931 ** by the prepared statement if that number is less than or equal 7932 ** to 2147483647. The number of virtual machine operations can be 7933 ** used as a proxy for the total work done by the prepared statement. 7934 ** If the number of virtual machine operations exceeds 2147483647 7935 ** then the value returned by this statement status code is undefined. 7936 ** 7937 ** [[SQLITE_STMTSTATUS_REPREPARE]] <dt>SQLITE_STMTSTATUS_REPREPARE</dt> 7938 ** <dd>^This is the number of times that the prepare statement has been 7939 ** automatically regenerated due to schema changes or change to 7940 ** [bound parameters] that might affect the query plan. 7941 ** 7942 ** [[SQLITE_STMTSTATUS_RUN]] <dt>SQLITE_STMTSTATUS_RUN</dt> 7943 ** <dd>^This is the number of times that the prepared statement has 7944 ** been run. A single "run" for the purposes of this counter is one 7945 ** or more calls to [sqlite3_step()] followed by a call to [sqlite3_reset()]. 7946 ** The counter is incremented on the first [sqlite3_step()] call of each 7947 ** cycle. 7948 ** 7949 ** [[SQLITE_STMTSTATUS_MEMUSED]] <dt>SQLITE_STMTSTATUS_MEMUSED</dt> 7950 ** <dd>^This is the approximate number of bytes of heap memory 7951 ** used to store the prepared statement. ^This value is not actually 7952 ** a counter, and so the resetFlg parameter to sqlite3_stmt_status() 7953 ** is ignored when the opcode is SQLITE_STMTSTATUS_MEMUSED. 7954 ** </dd> 7955 ** </dl> 7956 */ 7957 #define SQLITE_STMTSTATUS_FULLSCAN_STEP 1 7958 #define SQLITE_STMTSTATUS_SORT 2 7959 #define SQLITE_STMTSTATUS_AUTOINDEX 3 7960 #define SQLITE_STMTSTATUS_VM_STEP 4 7961 #define SQLITE_STMTSTATUS_REPREPARE 5 7962 #define SQLITE_STMTSTATUS_RUN 6 7963 #define SQLITE_STMTSTATUS_MEMUSED 99 7964 7965 /* 7966 ** CAPI3REF: Custom Page Cache Object 7967 ** 7968 ** The sqlite3_pcache type is opaque. It is implemented by 7969 ** the pluggable module. The SQLite core has no knowledge of 7970 ** its size or internal structure and never deals with the 7971 ** sqlite3_pcache object except by holding and passing pointers 7972 ** to the object. 7973 ** 7974 ** See [sqlite3_pcache_methods2] for additional information. 7975 */ 7976 typedef struct sqlite3_pcache sqlite3_pcache; 7977 7978 /* 7979 ** CAPI3REF: Custom Page Cache Object 7980 ** 7981 ** The sqlite3_pcache_page object represents a single page in the 7982 ** page cache. The page cache will allocate instances of this 7983 ** object. Various methods of the page cache use pointers to instances 7984 ** of this object as parameters or as their return value. 7985 ** 7986 ** See [sqlite3_pcache_methods2] for additional information. 7987 */ 7988 typedef struct sqlite3_pcache_page sqlite3_pcache_page; 7989 struct sqlite3_pcache_page { 7990 void *pBuf; /* The content of the page */ 7991 void *pExtra; /* Extra information associated with the page */ 7992 }; 7993 7994 /* 7995 ** CAPI3REF: Application Defined Page Cache. 7996 ** KEYWORDS: {page cache} 7997 ** 7998 ** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE2], ...) interface can 7999 ** register an alternative page cache implementation by passing in an 8000 ** instance of the sqlite3_pcache_methods2 structure.)^ 8001 ** In many applications, most of the heap memory allocated by 8002 ** SQLite is used for the page cache. 8003 ** By implementing a 8004 ** custom page cache using this API, an application can better control 8005 ** the amount of memory consumed by SQLite, the way in which 8006 ** that memory is allocated and released, and the policies used to 8007 ** determine exactly which parts of a database file are cached and for 8008 ** how long. 8009 ** 8010 ** The alternative page cache mechanism is an 8011 ** extreme measure that is only needed by the most demanding applications. 8012 ** The built-in page cache is recommended for most uses. 8013 ** 8014 ** ^(The contents of the sqlite3_pcache_methods2 structure are copied to an 8015 ** internal buffer by SQLite within the call to [sqlite3_config]. Hence 8016 ** the application may discard the parameter after the call to 8017 ** [sqlite3_config()] returns.)^ 8018 ** 8019 ** [[the xInit() page cache method]] 8020 ** ^(The xInit() method is called once for each effective 8021 ** call to [sqlite3_initialize()])^ 8022 ** (usually only once during the lifetime of the process). ^(The xInit() 8023 ** method is passed a copy of the sqlite3_pcache_methods2.pArg value.)^ 8024 ** The intent of the xInit() method is to set up global data structures 8025 ** required by the custom page cache implementation. 8026 ** ^(If the xInit() method is NULL, then the 8027 ** built-in default page cache is used instead of the application defined 8028 ** page cache.)^ 8029 ** 8030 ** [[the xShutdown() page cache method]] 8031 ** ^The xShutdown() method is called by [sqlite3_shutdown()]. 8032 ** It can be used to clean up 8033 ** any outstanding resources before process shutdown, if required. 8034 ** ^The xShutdown() method may be NULL. 8035 ** 8036 ** ^SQLite automatically serializes calls to the xInit method, 8037 ** so the xInit method need not be threadsafe. ^The 8038 ** xShutdown method is only called from [sqlite3_shutdown()] so it does 8039 ** not need to be threadsafe either. All other methods must be threadsafe 8040 ** in multithreaded applications. 8041 ** 8042 ** ^SQLite will never invoke xInit() more than once without an intervening 8043 ** call to xShutdown(). 8044 ** 8045 ** [[the xCreate() page cache methods]] 8046 ** ^SQLite invokes the xCreate() method to construct a new cache instance. 8047 ** SQLite will typically create one cache instance for each open database file, 8048 ** though this is not guaranteed. ^The 8049 ** first parameter, szPage, is the size in bytes of the pages that must 8050 ** be allocated by the cache. ^szPage will always a power of two. ^The 8051 ** second parameter szExtra is a number of bytes of extra storage 8052 ** associated with each page cache entry. ^The szExtra parameter will 8053 ** a number less than 250. SQLite will use the 8054 ** extra szExtra bytes on each page to store metadata about the underlying 8055 ** database page on disk. The value passed into szExtra depends 8056 ** on the SQLite version, the target platform, and how SQLite was compiled. 8057 ** ^The third argument to xCreate(), bPurgeable, is true if the cache being 8058 ** created will be used to cache database pages of a file stored on disk, or 8059 ** false if it is used for an in-memory database. The cache implementation 8060 ** does not have to do anything special based with the value of bPurgeable; 8061 ** it is purely advisory. ^On a cache where bPurgeable is false, SQLite will 8062 ** never invoke xUnpin() except to deliberately delete a page. 8063 ** ^In other words, calls to xUnpin() on a cache with bPurgeable set to 8064 ** false will always have the "discard" flag set to true. 8065 ** ^Hence, a cache created with bPurgeable false will 8066 ** never contain any unpinned pages. 8067 ** 8068 ** [[the xCachesize() page cache method]] 8069 ** ^(The xCachesize() method may be called at any time by SQLite to set the 8070 ** suggested maximum cache-size (number of pages stored by) the cache 8071 ** instance passed as the first argument. This is the value configured using 8072 ** the SQLite "[PRAGMA cache_size]" command.)^ As with the bPurgeable 8073 ** parameter, the implementation is not required to do anything with this 8074 ** value; it is advisory only. 8075 ** 8076 ** [[the xPagecount() page cache methods]] 8077 ** The xPagecount() method must return the number of pages currently 8078 ** stored in the cache, both pinned and unpinned. 8079 ** 8080 ** [[the xFetch() page cache methods]] 8081 ** The xFetch() method locates a page in the cache and returns a pointer to 8082 ** an sqlite3_pcache_page object associated with that page, or a NULL pointer. 8083 ** The pBuf element of the returned sqlite3_pcache_page object will be a 8084 ** pointer to a buffer of szPage bytes used to store the content of a 8085 ** single database page. The pExtra element of sqlite3_pcache_page will be 8086 ** a pointer to the szExtra bytes of extra storage that SQLite has requested 8087 ** for each entry in the page cache. 8088 ** 8089 ** The page to be fetched is determined by the key. ^The minimum key value 8090 ** is 1. After it has been retrieved using xFetch, the page is considered 8091 ** to be "pinned". 8092 ** 8093 ** If the requested page is already in the page cache, then the page cache 8094 ** implementation must return a pointer to the page buffer with its content 8095 ** intact. If the requested page is not already in the cache, then the 8096 ** cache implementation should use the value of the createFlag 8097 ** parameter to help it determined what action to take: 8098 ** 8099 ** <table border=1 width=85% align=center> 8100 ** <tr><th> createFlag <th> Behavior when page is not already in cache 8101 ** <tr><td> 0 <td> Do not allocate a new page. Return NULL. 8102 ** <tr><td> 1 <td> Allocate a new page if it easy and convenient to do so. 8103 ** Otherwise return NULL. 8104 ** <tr><td> 2 <td> Make every effort to allocate a new page. Only return 8105 ** NULL if allocating a new page is effectively impossible. 8106 ** </table> 8107 ** 8108 ** ^(SQLite will normally invoke xFetch() with a createFlag of 0 or 1. SQLite 8109 ** will only use a createFlag of 2 after a prior call with a createFlag of 1 8110 ** failed.)^ In between the to xFetch() calls, SQLite may 8111 ** attempt to unpin one or more cache pages by spilling the content of 8112 ** pinned pages to disk and synching the operating system disk cache. 8113 ** 8114 ** [[the xUnpin() page cache method]] 8115 ** ^xUnpin() is called by SQLite with a pointer to a currently pinned page 8116 ** as its second argument. If the third parameter, discard, is non-zero, 8117 ** then the page must be evicted from the cache. 8118 ** ^If the discard parameter is 8119 ** zero, then the page may be discarded or retained at the discretion of 8120 ** page cache implementation. ^The page cache implementation 8121 ** may choose to evict unpinned pages at any time. 8122 ** 8123 ** The cache must not perform any reference counting. A single 8124 ** call to xUnpin() unpins the page regardless of the number of prior calls 8125 ** to xFetch(). 8126 ** 8127 ** [[the xRekey() page cache methods]] 8128 ** The xRekey() method is used to change the key value associated with the 8129 ** page passed as the second argument. If the cache 8130 ** previously contains an entry associated with newKey, it must be 8131 ** discarded. ^Any prior cache entry associated with newKey is guaranteed not 8132 ** to be pinned. 8133 ** 8134 ** When SQLite calls the xTruncate() method, the cache must discard all 8135 ** existing cache entries with page numbers (keys) greater than or equal 8136 ** to the value of the iLimit parameter passed to xTruncate(). If any 8137 ** of these pages are pinned, they are implicitly unpinned, meaning that 8138 ** they can be safely discarded. 8139 ** 8140 ** [[the xDestroy() page cache method]] 8141 ** ^The xDestroy() method is used to delete a cache allocated by xCreate(). 8142 ** All resources associated with the specified cache should be freed. ^After 8143 ** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*] 8144 ** handle invalid, and will not use it with any other sqlite3_pcache_methods2 8145 ** functions. 8146 ** 8147 ** [[the xShrink() page cache method]] 8148 ** ^SQLite invokes the xShrink() method when it wants the page cache to 8149 ** free up as much of heap memory as possible. The page cache implementation 8150 ** is not obligated to free any memory, but well-behaved implementations should 8151 ** do their best. 8152 */ 8153 typedef struct sqlite3_pcache_methods2 sqlite3_pcache_methods2; 8154 struct sqlite3_pcache_methods2 { 8155 int iVersion; 8156 void *pArg; 8157 int (*xInit)(void*); 8158 void (*xShutdown)(void*); 8159 sqlite3_pcache *(*xCreate)(int szPage, int szExtra, int bPurgeable); 8160 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 8161 int (*xPagecount)(sqlite3_pcache*); 8162 sqlite3_pcache_page *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 8163 void (*xUnpin)(sqlite3_pcache*, sqlite3_pcache_page*, int discard); 8164 void (*xRekey)(sqlite3_pcache*, sqlite3_pcache_page*, 8165 unsigned oldKey, unsigned newKey); 8166 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 8167 void (*xDestroy)(sqlite3_pcache*); 8168 void (*xShrink)(sqlite3_pcache*); 8169 }; 8170 8171 /* 8172 ** This is the obsolete pcache_methods object that has now been replaced 8173 ** by sqlite3_pcache_methods2. This object is not used by SQLite. It is 8174 ** retained in the header file for backwards compatibility only. 8175 */ 8176 typedef struct sqlite3_pcache_methods sqlite3_pcache_methods; 8177 struct sqlite3_pcache_methods { 8178 void *pArg; 8179 int (*xInit)(void*); 8180 void (*xShutdown)(void*); 8181 sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable); 8182 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 8183 int (*xPagecount)(sqlite3_pcache*); 8184 void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 8185 void (*xUnpin)(sqlite3_pcache*, void*, int discard); 8186 void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey); 8187 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 8188 void (*xDestroy)(sqlite3_pcache*); 8189 }; 8190 8191 8192 /* 8193 ** CAPI3REF: Online Backup Object 8194 ** 8195 ** The sqlite3_backup object records state information about an ongoing 8196 ** online backup operation. ^The sqlite3_backup object is created by 8197 ** a call to [sqlite3_backup_init()] and is destroyed by a call to 8198 ** [sqlite3_backup_finish()]. 8199 ** 8200 ** See Also: [Using the SQLite Online Backup API] 8201 */ 8202 typedef struct sqlite3_backup sqlite3_backup; 8203 8204 /* 8205 ** CAPI3REF: Online Backup API. 8206 ** 8207 ** The backup API copies the content of one database into another. 8208 ** It is useful either for creating backups of databases or 8209 ** for copying in-memory databases to or from persistent files. 8210 ** 8211 ** See Also: [Using the SQLite Online Backup API] 8212 ** 8213 ** ^SQLite holds a write transaction open on the destination database file 8214 ** for the duration of the backup operation. 8215 ** ^The source database is read-locked only while it is being read; 8216 ** it is not locked continuously for the entire backup operation. 8217 ** ^Thus, the backup may be performed on a live source database without 8218 ** preventing other database connections from 8219 ** reading or writing to the source database while the backup is underway. 8220 ** 8221 ** ^(To perform a backup operation: 8222 ** <ol> 8223 ** <li><b>sqlite3_backup_init()</b> is called once to initialize the 8224 ** backup, 8225 ** <li><b>sqlite3_backup_step()</b> is called one or more times to transfer 8226 ** the data between the two databases, and finally 8227 ** <li><b>sqlite3_backup_finish()</b> is called to release all resources 8228 ** associated with the backup operation. 8229 ** </ol>)^ 8230 ** There should be exactly one call to sqlite3_backup_finish() for each 8231 ** successful call to sqlite3_backup_init(). 8232 ** 8233 ** [[sqlite3_backup_init()]] <b>sqlite3_backup_init()</b> 8234 ** 8235 ** ^The D and N arguments to sqlite3_backup_init(D,N,S,M) are the 8236 ** [database connection] associated with the destination database 8237 ** and the database name, respectively. 8238 ** ^The database name is "main" for the main database, "temp" for the 8239 ** temporary database, or the name specified after the AS keyword in 8240 ** an [ATTACH] statement for an attached database. 8241 ** ^The S and M arguments passed to 8242 ** sqlite3_backup_init(D,N,S,M) identify the [database connection] 8243 ** and database name of the source database, respectively. 8244 ** ^The source and destination [database connections] (parameters S and D) 8245 ** must be different or else sqlite3_backup_init(D,N,S,M) will fail with 8246 ** an error. 8247 ** 8248 ** ^A call to sqlite3_backup_init() will fail, returning NULL, if 8249 ** there is already a read or read-write transaction open on the 8250 ** destination database. 8251 ** 8252 ** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is 8253 ** returned and an error code and error message are stored in the 8254 ** destination [database connection] D. 8255 ** ^The error code and message for the failed call to sqlite3_backup_init() 8256 ** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or 8257 ** [sqlite3_errmsg16()] functions. 8258 ** ^A successful call to sqlite3_backup_init() returns a pointer to an 8259 ** [sqlite3_backup] object. 8260 ** ^The [sqlite3_backup] object may be used with the sqlite3_backup_step() and 8261 ** sqlite3_backup_finish() functions to perform the specified backup 8262 ** operation. 8263 ** 8264 ** [[sqlite3_backup_step()]] <b>sqlite3_backup_step()</b> 8265 ** 8266 ** ^Function sqlite3_backup_step(B,N) will copy up to N pages between 8267 ** the source and destination databases specified by [sqlite3_backup] object B. 8268 ** ^If N is negative, all remaining source pages are copied. 8269 ** ^If sqlite3_backup_step(B,N) successfully copies N pages and there 8270 ** are still more pages to be copied, then the function returns [SQLITE_OK]. 8271 ** ^If sqlite3_backup_step(B,N) successfully finishes copying all pages 8272 ** from source to destination, then it returns [SQLITE_DONE]. 8273 ** ^If an error occurs while running sqlite3_backup_step(B,N), 8274 ** then an [error code] is returned. ^As well as [SQLITE_OK] and 8275 ** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY], 8276 ** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an 8277 ** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code. 8278 ** 8279 ** ^(The sqlite3_backup_step() might return [SQLITE_READONLY] if 8280 ** <ol> 8281 ** <li> the destination database was opened read-only, or 8282 ** <li> the destination database is using write-ahead-log journaling 8283 ** and the destination and source page sizes differ, or 8284 ** <li> the destination database is an in-memory database and the 8285 ** destination and source page sizes differ. 8286 ** </ol>)^ 8287 ** 8288 ** ^If sqlite3_backup_step() cannot obtain a required file-system lock, then 8289 ** the [sqlite3_busy_handler | busy-handler function] 8290 ** is invoked (if one is specified). ^If the 8291 ** busy-handler returns non-zero before the lock is available, then 8292 ** [SQLITE_BUSY] is returned to the caller. ^In this case the call to 8293 ** sqlite3_backup_step() can be retried later. ^If the source 8294 ** [database connection] 8295 ** is being used to write to the source database when sqlite3_backup_step() 8296 ** is called, then [SQLITE_LOCKED] is returned immediately. ^Again, in this 8297 ** case the call to sqlite3_backup_step() can be retried later on. ^(If 8298 ** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or 8299 ** [SQLITE_READONLY] is returned, then 8300 ** there is no point in retrying the call to sqlite3_backup_step(). These 8301 ** errors are considered fatal.)^ The application must accept 8302 ** that the backup operation has failed and pass the backup operation handle 8303 ** to the sqlite3_backup_finish() to release associated resources. 8304 ** 8305 ** ^The first call to sqlite3_backup_step() obtains an exclusive lock 8306 ** on the destination file. ^The exclusive lock is not released until either 8307 ** sqlite3_backup_finish() is called or the backup operation is complete 8308 ** and sqlite3_backup_step() returns [SQLITE_DONE]. ^Every call to 8309 ** sqlite3_backup_step() obtains a [shared lock] on the source database that 8310 ** lasts for the duration of the sqlite3_backup_step() call. 8311 ** ^Because the source database is not locked between calls to 8312 ** sqlite3_backup_step(), the source database may be modified mid-way 8313 ** through the backup process. ^If the source database is modified by an 8314 ** external process or via a database connection other than the one being 8315 ** used by the backup operation, then the backup will be automatically 8316 ** restarted by the next call to sqlite3_backup_step(). ^If the source 8317 ** database is modified by the using the same database connection as is used 8318 ** by the backup operation, then the backup database is automatically 8319 ** updated at the same time. 8320 ** 8321 ** [[sqlite3_backup_finish()]] <b>sqlite3_backup_finish()</b> 8322 ** 8323 ** When sqlite3_backup_step() has returned [SQLITE_DONE], or when the 8324 ** application wishes to abandon the backup operation, the application 8325 ** should destroy the [sqlite3_backup] by passing it to sqlite3_backup_finish(). 8326 ** ^The sqlite3_backup_finish() interfaces releases all 8327 ** resources associated with the [sqlite3_backup] object. 8328 ** ^If sqlite3_backup_step() has not yet returned [SQLITE_DONE], then any 8329 ** active write-transaction on the destination database is rolled back. 8330 ** The [sqlite3_backup] object is invalid 8331 ** and may not be used following a call to sqlite3_backup_finish(). 8332 ** 8333 ** ^The value returned by sqlite3_backup_finish is [SQLITE_OK] if no 8334 ** sqlite3_backup_step() errors occurred, regardless or whether or not 8335 ** sqlite3_backup_step() completed. 8336 ** ^If an out-of-memory condition or IO error occurred during any prior 8337 ** sqlite3_backup_step() call on the same [sqlite3_backup] object, then 8338 ** sqlite3_backup_finish() returns the corresponding [error code]. 8339 ** 8340 ** ^A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step() 8341 ** is not a permanent error and does not affect the return value of 8342 ** sqlite3_backup_finish(). 8343 ** 8344 ** [[sqlite3_backup_remaining()]] [[sqlite3_backup_pagecount()]] 8345 ** <b>sqlite3_backup_remaining() and sqlite3_backup_pagecount()</b> 8346 ** 8347 ** ^The sqlite3_backup_remaining() routine returns the number of pages still 8348 ** to be backed up at the conclusion of the most recent sqlite3_backup_step(). 8349 ** ^The sqlite3_backup_pagecount() routine returns the total number of pages 8350 ** in the source database at the conclusion of the most recent 8351 ** sqlite3_backup_step(). 8352 ** ^(The values returned by these functions are only updated by 8353 ** sqlite3_backup_step(). If the source database is modified in a way that 8354 ** changes the size of the source database or the number of pages remaining, 8355 ** those changes are not reflected in the output of sqlite3_backup_pagecount() 8356 ** and sqlite3_backup_remaining() until after the next 8357 ** sqlite3_backup_step().)^ 8358 ** 8359 ** <b>Concurrent Usage of Database Handles</b> 8360 ** 8361 ** ^The source [database connection] may be used by the application for other 8362 ** purposes while a backup operation is underway or being initialized. 8363 ** ^If SQLite is compiled and configured to support threadsafe database 8364 ** connections, then the source database connection may be used concurrently 8365 ** from within other threads. 8366 ** 8367 ** However, the application must guarantee that the destination 8368 ** [database connection] is not passed to any other API (by any thread) after 8369 ** sqlite3_backup_init() is called and before the corresponding call to 8370 ** sqlite3_backup_finish(). SQLite does not currently check to see 8371 ** if the application incorrectly accesses the destination [database connection] 8372 ** and so no error code is reported, but the operations may malfunction 8373 ** nevertheless. Use of the destination database connection while a 8374 ** backup is in progress might also also cause a mutex deadlock. 8375 ** 8376 ** If running in [shared cache mode], the application must 8377 ** guarantee that the shared cache used by the destination database 8378 ** is not accessed while the backup is running. In practice this means 8379 ** that the application must guarantee that the disk file being 8380 ** backed up to is not accessed by any connection within the process, 8381 ** not just the specific connection that was passed to sqlite3_backup_init(). 8382 ** 8383 ** The [sqlite3_backup] object itself is partially threadsafe. Multiple 8384 ** threads may safely make multiple concurrent calls to sqlite3_backup_step(). 8385 ** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount() 8386 ** APIs are not strictly speaking threadsafe. If they are invoked at the 8387 ** same time as another thread is invoking sqlite3_backup_step() it is 8388 ** possible that they return invalid values. 8389 */ 8390 SQLITE_API sqlite3_backup *sqlite3_backup_init( 8391 sqlite3 *pDest, /* Destination database handle */ 8392 const char *zDestName, /* Destination database name */ 8393 sqlite3 *pSource, /* Source database handle */ 8394 const char *zSourceName /* Source database name */ 8395 ); 8396 SQLITE_API int sqlite3_backup_step(sqlite3_backup *p, int nPage); 8397 SQLITE_API int sqlite3_backup_finish(sqlite3_backup *p); 8398 SQLITE_API int sqlite3_backup_remaining(sqlite3_backup *p); 8399 SQLITE_API int sqlite3_backup_pagecount(sqlite3_backup *p); 8400 8401 /* 8402 ** CAPI3REF: Unlock Notification 8403 ** METHOD: sqlite3 8404 ** 8405 ** ^When running in shared-cache mode, a database operation may fail with 8406 ** an [SQLITE_LOCKED] error if the required locks on the shared-cache or 8407 ** individual tables within the shared-cache cannot be obtained. See 8408 ** [SQLite Shared-Cache Mode] for a description of shared-cache locking. 8409 ** ^This API may be used to register a callback that SQLite will invoke 8410 ** when the connection currently holding the required lock relinquishes it. 8411 ** ^This API is only available if the library was compiled with the 8412 ** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined. 8413 ** 8414 ** See Also: [Using the SQLite Unlock Notification Feature]. 8415 ** 8416 ** ^Shared-cache locks are released when a database connection concludes 8417 ** its current transaction, either by committing it or rolling it back. 8418 ** 8419 ** ^When a connection (known as the blocked connection) fails to obtain a 8420 ** shared-cache lock and SQLITE_LOCKED is returned to the caller, the 8421 ** identity of the database connection (the blocking connection) that 8422 ** has locked the required resource is stored internally. ^After an 8423 ** application receives an SQLITE_LOCKED error, it may call the 8424 ** sqlite3_unlock_notify() method with the blocked connection handle as 8425 ** the first argument to register for a callback that will be invoked 8426 ** when the blocking connections current transaction is concluded. ^The 8427 ** callback is invoked from within the [sqlite3_step] or [sqlite3_close] 8428 ** call that concludes the blocking connections transaction. 8429 ** 8430 ** ^(If sqlite3_unlock_notify() is called in a multi-threaded application, 8431 ** there is a chance that the blocking connection will have already 8432 ** concluded its transaction by the time sqlite3_unlock_notify() is invoked. 8433 ** If this happens, then the specified callback is invoked immediately, 8434 ** from within the call to sqlite3_unlock_notify().)^ 8435 ** 8436 ** ^If the blocked connection is attempting to obtain a write-lock on a 8437 ** shared-cache table, and more than one other connection currently holds 8438 ** a read-lock on the same table, then SQLite arbitrarily selects one of 8439 ** the other connections to use as the blocking connection. 8440 ** 8441 ** ^(There may be at most one unlock-notify callback registered by a 8442 ** blocked connection. If sqlite3_unlock_notify() is called when the 8443 ** blocked connection already has a registered unlock-notify callback, 8444 ** then the new callback replaces the old.)^ ^If sqlite3_unlock_notify() is 8445 ** called with a NULL pointer as its second argument, then any existing 8446 ** unlock-notify callback is canceled. ^The blocked connections 8447 ** unlock-notify callback may also be canceled by closing the blocked 8448 ** connection using [sqlite3_close()]. 8449 ** 8450 ** The unlock-notify callback is not reentrant. If an application invokes 8451 ** any sqlite3_xxx API functions from within an unlock-notify callback, a 8452 ** crash or deadlock may be the result. 8453 ** 8454 ** ^Unless deadlock is detected (see below), sqlite3_unlock_notify() always 8455 ** returns SQLITE_OK. 8456 ** 8457 ** <b>Callback Invocation Details</b> 8458 ** 8459 ** When an unlock-notify callback is registered, the application provides a 8460 ** single void* pointer that is passed to the callback when it is invoked. 8461 ** However, the signature of the callback function allows SQLite to pass 8462 ** it an array of void* context pointers. The first argument passed to 8463 ** an unlock-notify callback is a pointer to an array of void* pointers, 8464 ** and the second is the number of entries in the array. 8465 ** 8466 ** When a blocking connections transaction is concluded, there may be 8467 ** more than one blocked connection that has registered for an unlock-notify 8468 ** callback. ^If two or more such blocked connections have specified the 8469 ** same callback function, then instead of invoking the callback function 8470 ** multiple times, it is invoked once with the set of void* context pointers 8471 ** specified by the blocked connections bundled together into an array. 8472 ** This gives the application an opportunity to prioritize any actions 8473 ** related to the set of unblocked database connections. 8474 ** 8475 ** <b>Deadlock Detection</b> 8476 ** 8477 ** Assuming that after registering for an unlock-notify callback a 8478 ** database waits for the callback to be issued before taking any further 8479 ** action (a reasonable assumption), then using this API may cause the 8480 ** application to deadlock. For example, if connection X is waiting for 8481 ** connection Y's transaction to be concluded, and similarly connection 8482 ** Y is waiting on connection X's transaction, then neither connection 8483 ** will proceed and the system may remain deadlocked indefinitely. 8484 ** 8485 ** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock 8486 ** detection. ^If a given call to sqlite3_unlock_notify() would put the 8487 ** system in a deadlocked state, then SQLITE_LOCKED is returned and no 8488 ** unlock-notify callback is registered. The system is said to be in 8489 ** a deadlocked state if connection A has registered for an unlock-notify 8490 ** callback on the conclusion of connection B's transaction, and connection 8491 ** B has itself registered for an unlock-notify callback when connection 8492 ** A's transaction is concluded. ^Indirect deadlock is also detected, so 8493 ** the system is also considered to be deadlocked if connection B has 8494 ** registered for an unlock-notify callback on the conclusion of connection 8495 ** C's transaction, where connection C is waiting on connection A. ^Any 8496 ** number of levels of indirection are allowed. 8497 ** 8498 ** <b>The "DROP TABLE" Exception</b> 8499 ** 8500 ** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost 8501 ** always appropriate to call sqlite3_unlock_notify(). There is however, 8502 ** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement, 8503 ** SQLite checks if there are any currently executing SELECT statements 8504 ** that belong to the same connection. If there are, SQLITE_LOCKED is 8505 ** returned. In this case there is no "blocking connection", so invoking 8506 ** sqlite3_unlock_notify() results in the unlock-notify callback being 8507 ** invoked immediately. If the application then re-attempts the "DROP TABLE" 8508 ** or "DROP INDEX" query, an infinite loop might be the result. 8509 ** 8510 ** One way around this problem is to check the extended error code returned 8511 ** by an sqlite3_step() call. ^(If there is a blocking connection, then the 8512 ** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in 8513 ** the special "DROP TABLE/INDEX" case, the extended error code is just 8514 ** SQLITE_LOCKED.)^ 8515 */ 8516 SQLITE_API int sqlite3_unlock_notify( 8517 sqlite3 *pBlocked, /* Waiting connection */ 8518 void (*xNotify)(void **apArg, int nArg), /* Callback function to invoke */ 8519 void *pNotifyArg /* Argument to pass to xNotify */ 8520 ); 8521 8522 8523 /* 8524 ** CAPI3REF: String Comparison 8525 ** 8526 ** ^The [sqlite3_stricmp()] and [sqlite3_strnicmp()] APIs allow applications 8527 ** and extensions to compare the contents of two buffers containing UTF-8 8528 ** strings in a case-independent fashion, using the same definition of "case 8529 ** independence" that SQLite uses internally when comparing identifiers. 8530 */ 8531 SQLITE_API int sqlite3_stricmp(const char *, const char *); 8532 SQLITE_API int sqlite3_strnicmp(const char *, const char *, int); 8533 8534 /* 8535 ** CAPI3REF: String Globbing 8536 * 8537 ** ^The [sqlite3_strglob(P,X)] interface returns zero if and only if 8538 ** string X matches the [GLOB] pattern P. 8539 ** ^The definition of [GLOB] pattern matching used in 8540 ** [sqlite3_strglob(P,X)] is the same as for the "X GLOB P" operator in the 8541 ** SQL dialect understood by SQLite. ^The [sqlite3_strglob(P,X)] function 8542 ** is case sensitive. 8543 ** 8544 ** Note that this routine returns zero on a match and non-zero if the strings 8545 ** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()]. 8546 ** 8547 ** See also: [sqlite3_strlike()]. 8548 */ 8549 SQLITE_API int sqlite3_strglob(const char *zGlob, const char *zStr); 8550 8551 /* 8552 ** CAPI3REF: String LIKE Matching 8553 * 8554 ** ^The [sqlite3_strlike(P,X,E)] interface returns zero if and only if 8555 ** string X matches the [LIKE] pattern P with escape character E. 8556 ** ^The definition of [LIKE] pattern matching used in 8557 ** [sqlite3_strlike(P,X,E)] is the same as for the "X LIKE P ESCAPE E" 8558 ** operator in the SQL dialect understood by SQLite. ^For "X LIKE P" without 8559 ** the ESCAPE clause, set the E parameter of [sqlite3_strlike(P,X,E)] to 0. 8560 ** ^As with the LIKE operator, the [sqlite3_strlike(P,X,E)] function is case 8561 ** insensitive - equivalent upper and lower case ASCII characters match 8562 ** one another. 8563 ** 8564 ** ^The [sqlite3_strlike(P,X,E)] function matches Unicode characters, though 8565 ** only ASCII characters are case folded. 8566 ** 8567 ** Note that this routine returns zero on a match and non-zero if the strings 8568 ** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()]. 8569 ** 8570 ** See also: [sqlite3_strglob()]. 8571 */ 8572 SQLITE_API int sqlite3_strlike(const char *zGlob, const char *zStr, unsigned int cEsc); 8573 8574 /* 8575 ** CAPI3REF: Error Logging Interface 8576 ** 8577 ** ^The [sqlite3_log()] interface writes a message into the [error log] 8578 ** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()]. 8579 ** ^If logging is enabled, the zFormat string and subsequent arguments are 8580 ** used with [sqlite3_snprintf()] to generate the final output string. 8581 ** 8582 ** The sqlite3_log() interface is intended for use by extensions such as 8583 ** virtual tables, collating functions, and SQL functions. While there is 8584 ** nothing to prevent an application from calling sqlite3_log(), doing so 8585 ** is considered bad form. 8586 ** 8587 ** The zFormat string must not be NULL. 8588 ** 8589 ** To avoid deadlocks and other threading problems, the sqlite3_log() routine 8590 ** will not use dynamically allocated memory. The log message is stored in 8591 ** a fixed-length buffer on the stack. If the log message is longer than 8592 ** a few hundred characters, it will be truncated to the length of the 8593 ** buffer. 8594 */ 8595 SQLITE_API void sqlite3_log(int iErrCode, const char *zFormat, ...); 8596 8597 /* 8598 ** CAPI3REF: Write-Ahead Log Commit Hook 8599 ** METHOD: sqlite3 8600 ** 8601 ** ^The [sqlite3_wal_hook()] function is used to register a callback that 8602 ** is invoked each time data is committed to a database in wal mode. 8603 ** 8604 ** ^(The callback is invoked by SQLite after the commit has taken place and 8605 ** the associated write-lock on the database released)^, so the implementation 8606 ** may read, write or [checkpoint] the database as required. 8607 ** 8608 ** ^The first parameter passed to the callback function when it is invoked 8609 ** is a copy of the third parameter passed to sqlite3_wal_hook() when 8610 ** registering the callback. ^The second is a copy of the database handle. 8611 ** ^The third parameter is the name of the database that was written to - 8612 ** either "main" or the name of an [ATTACH]-ed database. ^The fourth parameter 8613 ** is the number of pages currently in the write-ahead log file, 8614 ** including those that were just committed. 8615 ** 8616 ** The callback function should normally return [SQLITE_OK]. ^If an error 8617 ** code is returned, that error will propagate back up through the 8618 ** SQLite code base to cause the statement that provoked the callback 8619 ** to report an error, though the commit will have still occurred. If the 8620 ** callback returns [SQLITE_ROW] or [SQLITE_DONE], or if it returns a value 8621 ** that does not correspond to any valid SQLite error code, the results 8622 ** are undefined. 8623 ** 8624 ** A single database handle may have at most a single write-ahead log callback 8625 ** registered at one time. ^Calling [sqlite3_wal_hook()] replaces any 8626 ** previously registered write-ahead log callback. ^Note that the 8627 ** [sqlite3_wal_autocheckpoint()] interface and the 8628 ** [wal_autocheckpoint pragma] both invoke [sqlite3_wal_hook()] and will 8629 ** overwrite any prior [sqlite3_wal_hook()] settings. 8630 */ 8631 SQLITE_API void *sqlite3_wal_hook( 8632 sqlite3*, 8633 int(*)(void *,sqlite3*,const char*,int), 8634 void* 8635 ); 8636 8637 /* 8638 ** CAPI3REF: Configure an auto-checkpoint 8639 ** METHOD: sqlite3 8640 ** 8641 ** ^The [sqlite3_wal_autocheckpoint(D,N)] is a wrapper around 8642 ** [sqlite3_wal_hook()] that causes any database on [database connection] D 8643 ** to automatically [checkpoint] 8644 ** after committing a transaction if there are N or 8645 ** more frames in the [write-ahead log] file. ^Passing zero or 8646 ** a negative value as the nFrame parameter disables automatic 8647 ** checkpoints entirely. 8648 ** 8649 ** ^The callback registered by this function replaces any existing callback 8650 ** registered using [sqlite3_wal_hook()]. ^Likewise, registering a callback 8651 ** using [sqlite3_wal_hook()] disables the automatic checkpoint mechanism 8652 ** configured by this function. 8653 ** 8654 ** ^The [wal_autocheckpoint pragma] can be used to invoke this interface 8655 ** from SQL. 8656 ** 8657 ** ^Checkpoints initiated by this mechanism are 8658 ** [sqlite3_wal_checkpoint_v2|PASSIVE]. 8659 ** 8660 ** ^Every new [database connection] defaults to having the auto-checkpoint 8661 ** enabled with a threshold of 1000 or [SQLITE_DEFAULT_WAL_AUTOCHECKPOINT] 8662 ** pages. The use of this interface 8663 ** is only necessary if the default setting is found to be suboptimal 8664 ** for a particular application. 8665 */ 8666 SQLITE_API int sqlite3_wal_autocheckpoint(sqlite3 *db, int N); 8667 8668 /* 8669 ** CAPI3REF: Checkpoint a database 8670 ** METHOD: sqlite3 8671 ** 8672 ** ^(The sqlite3_wal_checkpoint(D,X) is equivalent to 8673 ** [sqlite3_wal_checkpoint_v2](D,X,[SQLITE_CHECKPOINT_PASSIVE],0,0).)^ 8674 ** 8675 ** In brief, sqlite3_wal_checkpoint(D,X) causes the content in the 8676 ** [write-ahead log] for database X on [database connection] D to be 8677 ** transferred into the database file and for the write-ahead log to 8678 ** be reset. See the [checkpointing] documentation for addition 8679 ** information. 8680 ** 8681 ** This interface used to be the only way to cause a checkpoint to 8682 ** occur. But then the newer and more powerful [sqlite3_wal_checkpoint_v2()] 8683 ** interface was added. This interface is retained for backwards 8684 ** compatibility and as a convenience for applications that need to manually 8685 ** start a callback but which do not need the full power (and corresponding 8686 ** complication) of [sqlite3_wal_checkpoint_v2()]. 8687 */ 8688 SQLITE_API int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb); 8689 8690 /* 8691 ** CAPI3REF: Checkpoint a database 8692 ** METHOD: sqlite3 8693 ** 8694 ** ^(The sqlite3_wal_checkpoint_v2(D,X,M,L,C) interface runs a checkpoint 8695 ** operation on database X of [database connection] D in mode M. Status 8696 ** information is written back into integers pointed to by L and C.)^ 8697 ** ^(The M parameter must be a valid [checkpoint mode]:)^ 8698 ** 8699 ** <dl> 8700 ** <dt>SQLITE_CHECKPOINT_PASSIVE<dd> 8701 ** ^Checkpoint as many frames as possible without waiting for any database 8702 ** readers or writers to finish, then sync the database file if all frames 8703 ** in the log were checkpointed. ^The [busy-handler callback] 8704 ** is never invoked in the SQLITE_CHECKPOINT_PASSIVE mode. 8705 ** ^On the other hand, passive mode might leave the checkpoint unfinished 8706 ** if there are concurrent readers or writers. 8707 ** 8708 ** <dt>SQLITE_CHECKPOINT_FULL<dd> 8709 ** ^This mode blocks (it invokes the 8710 ** [sqlite3_busy_handler|busy-handler callback]) until there is no 8711 ** database writer and all readers are reading from the most recent database 8712 ** snapshot. ^It then checkpoints all frames in the log file and syncs the 8713 ** database file. ^This mode blocks new database writers while it is pending, 8714 ** but new database readers are allowed to continue unimpeded. 8715 ** 8716 ** <dt>SQLITE_CHECKPOINT_RESTART<dd> 8717 ** ^This mode works the same way as SQLITE_CHECKPOINT_FULL with the addition 8718 ** that after checkpointing the log file it blocks (calls the 8719 ** [busy-handler callback]) 8720 ** until all readers are reading from the database file only. ^This ensures 8721 ** that the next writer will restart the log file from the beginning. 8722 ** ^Like SQLITE_CHECKPOINT_FULL, this mode blocks new 8723 ** database writer attempts while it is pending, but does not impede readers. 8724 ** 8725 ** <dt>SQLITE_CHECKPOINT_TRUNCATE<dd> 8726 ** ^This mode works the same way as SQLITE_CHECKPOINT_RESTART with the 8727 ** addition that it also truncates the log file to zero bytes just prior 8728 ** to a successful return. 8729 ** </dl> 8730 ** 8731 ** ^If pnLog is not NULL, then *pnLog is set to the total number of frames in 8732 ** the log file or to -1 if the checkpoint could not run because 8733 ** of an error or because the database is not in [WAL mode]. ^If pnCkpt is not 8734 ** NULL,then *pnCkpt is set to the total number of checkpointed frames in the 8735 ** log file (including any that were already checkpointed before the function 8736 ** was called) or to -1 if the checkpoint could not run due to an error or 8737 ** because the database is not in WAL mode. ^Note that upon successful 8738 ** completion of an SQLITE_CHECKPOINT_TRUNCATE, the log file will have been 8739 ** truncated to zero bytes and so both *pnLog and *pnCkpt will be set to zero. 8740 ** 8741 ** ^All calls obtain an exclusive "checkpoint" lock on the database file. ^If 8742 ** any other process is running a checkpoint operation at the same time, the 8743 ** lock cannot be obtained and SQLITE_BUSY is returned. ^Even if there is a 8744 ** busy-handler configured, it will not be invoked in this case. 8745 ** 8746 ** ^The SQLITE_CHECKPOINT_FULL, RESTART and TRUNCATE modes also obtain the 8747 ** exclusive "writer" lock on the database file. ^If the writer lock cannot be 8748 ** obtained immediately, and a busy-handler is configured, it is invoked and 8749 ** the writer lock retried until either the busy-handler returns 0 or the lock 8750 ** is successfully obtained. ^The busy-handler is also invoked while waiting for 8751 ** database readers as described above. ^If the busy-handler returns 0 before 8752 ** the writer lock is obtained or while waiting for database readers, the 8753 ** checkpoint operation proceeds from that point in the same way as 8754 ** SQLITE_CHECKPOINT_PASSIVE - checkpointing as many frames as possible 8755 ** without blocking any further. ^SQLITE_BUSY is returned in this case. 8756 ** 8757 ** ^If parameter zDb is NULL or points to a zero length string, then the 8758 ** specified operation is attempted on all WAL databases [attached] to 8759 ** [database connection] db. In this case the 8760 ** values written to output parameters *pnLog and *pnCkpt are undefined. ^If 8761 ** an SQLITE_BUSY error is encountered when processing one or more of the 8762 ** attached WAL databases, the operation is still attempted on any remaining 8763 ** attached databases and SQLITE_BUSY is returned at the end. ^If any other 8764 ** error occurs while processing an attached database, processing is abandoned 8765 ** and the error code is returned to the caller immediately. ^If no error 8766 ** (SQLITE_BUSY or otherwise) is encountered while processing the attached 8767 ** databases, SQLITE_OK is returned. 8768 ** 8769 ** ^If database zDb is the name of an attached database that is not in WAL 8770 ** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. ^If 8771 ** zDb is not NULL (or a zero length string) and is not the name of any 8772 ** attached database, SQLITE_ERROR is returned to the caller. 8773 ** 8774 ** ^Unless it returns SQLITE_MISUSE, 8775 ** the sqlite3_wal_checkpoint_v2() interface 8776 ** sets the error information that is queried by 8777 ** [sqlite3_errcode()] and [sqlite3_errmsg()]. 8778 ** 8779 ** ^The [PRAGMA wal_checkpoint] command can be used to invoke this interface 8780 ** from SQL. 8781 */ 8782 SQLITE_API int sqlite3_wal_checkpoint_v2( 8783 sqlite3 *db, /* Database handle */ 8784 const char *zDb, /* Name of attached database (or NULL) */ 8785 int eMode, /* SQLITE_CHECKPOINT_* value */ 8786 int *pnLog, /* OUT: Size of WAL log in frames */ 8787 int *pnCkpt /* OUT: Total number of frames checkpointed */ 8788 ); 8789 8790 /* 8791 ** CAPI3REF: Checkpoint Mode Values 8792 ** KEYWORDS: {checkpoint mode} 8793 ** 8794 ** These constants define all valid values for the "checkpoint mode" passed 8795 ** as the third parameter to the [sqlite3_wal_checkpoint_v2()] interface. 8796 ** See the [sqlite3_wal_checkpoint_v2()] documentation for details on the 8797 ** meaning of each of these checkpoint modes. 8798 */ 8799 #define SQLITE_CHECKPOINT_PASSIVE 0 /* Do as much as possible w/o blocking */ 8800 #define SQLITE_CHECKPOINT_FULL 1 /* Wait for writers, then checkpoint */ 8801 #define SQLITE_CHECKPOINT_RESTART 2 /* Like FULL but wait for for readers */ 8802 #define SQLITE_CHECKPOINT_TRUNCATE 3 /* Like RESTART but also truncate WAL */ 8803 8804 /* 8805 ** CAPI3REF: Virtual Table Interface Configuration 8806 ** 8807 ** This function may be called by either the [xConnect] or [xCreate] method 8808 ** of a [virtual table] implementation to configure 8809 ** various facets of the virtual table interface. 8810 ** 8811 ** If this interface is invoked outside the context of an xConnect or 8812 ** xCreate virtual table method then the behavior is undefined. 8813 ** 8814 ** At present, there is only one option that may be configured using 8815 ** this function. (See [SQLITE_VTAB_CONSTRAINT_SUPPORT].) Further options 8816 ** may be added in the future. 8817 */ 8818 SQLITE_API int sqlite3_vtab_config(sqlite3*, int op, ...); 8819 8820 /* 8821 ** CAPI3REF: Virtual Table Configuration Options 8822 ** 8823 ** These macros define the various options to the 8824 ** [sqlite3_vtab_config()] interface that [virtual table] implementations 8825 ** can use to customize and optimize their behavior. 8826 ** 8827 ** <dl> 8828 ** [[SQLITE_VTAB_CONSTRAINT_SUPPORT]] 8829 ** <dt>SQLITE_VTAB_CONSTRAINT_SUPPORT 8830 ** <dd>Calls of the form 8831 ** [sqlite3_vtab_config](db,SQLITE_VTAB_CONSTRAINT_SUPPORT,X) are supported, 8832 ** where X is an integer. If X is zero, then the [virtual table] whose 8833 ** [xCreate] or [xConnect] method invoked [sqlite3_vtab_config()] does not 8834 ** support constraints. In this configuration (which is the default) if 8835 ** a call to the [xUpdate] method returns [SQLITE_CONSTRAINT], then the entire 8836 ** statement is rolled back as if [ON CONFLICT | OR ABORT] had been 8837 ** specified as part of the users SQL statement, regardless of the actual 8838 ** ON CONFLICT mode specified. 8839 ** 8840 ** If X is non-zero, then the virtual table implementation guarantees 8841 ** that if [xUpdate] returns [SQLITE_CONSTRAINT], it will do so before 8842 ** any modifications to internal or persistent data structures have been made. 8843 ** If the [ON CONFLICT] mode is ABORT, FAIL, IGNORE or ROLLBACK, SQLite 8844 ** is able to roll back a statement or database transaction, and abandon 8845 ** or continue processing the current SQL statement as appropriate. 8846 ** If the ON CONFLICT mode is REPLACE and the [xUpdate] method returns 8847 ** [SQLITE_CONSTRAINT], SQLite handles this as if the ON CONFLICT mode 8848 ** had been ABORT. 8849 ** 8850 ** Virtual table implementations that are required to handle OR REPLACE 8851 ** must do so within the [xUpdate] method. If a call to the 8852 ** [sqlite3_vtab_on_conflict()] function indicates that the current ON 8853 ** CONFLICT policy is REPLACE, the virtual table implementation should 8854 ** silently replace the appropriate rows within the xUpdate callback and 8855 ** return SQLITE_OK. Or, if this is not possible, it may return 8856 ** SQLITE_CONSTRAINT, in which case SQLite falls back to OR ABORT 8857 ** constraint handling. 8858 ** </dl> 8859 */ 8860 #define SQLITE_VTAB_CONSTRAINT_SUPPORT 1 8861 8862 /* 8863 ** CAPI3REF: Determine The Virtual Table Conflict Policy 8864 ** 8865 ** This function may only be called from within a call to the [xUpdate] method 8866 ** of a [virtual table] implementation for an INSERT or UPDATE operation. ^The 8867 ** value returned is one of [SQLITE_ROLLBACK], [SQLITE_IGNORE], [SQLITE_FAIL], 8868 ** [SQLITE_ABORT], or [SQLITE_REPLACE], according to the [ON CONFLICT] mode 8869 ** of the SQL statement that triggered the call to the [xUpdate] method of the 8870 ** [virtual table]. 8871 */ 8872 SQLITE_API int sqlite3_vtab_on_conflict(sqlite3 *); 8873 8874 /* 8875 ** CAPI3REF: Determine If Virtual Table Column Access Is For UPDATE 8876 ** 8877 ** If the sqlite3_vtab_nochange(X) routine is called within the [xColumn] 8878 ** method of a [virtual table], then it returns true if and only if the 8879 ** column is being fetched as part of an UPDATE operation during which the 8880 ** column value will not change. Applications might use this to substitute 8881 ** a return value that is less expensive to compute and that the corresponding 8882 ** [xUpdate] method understands as a "no-change" value. 8883 ** 8884 ** If the [xColumn] method calls sqlite3_vtab_nochange() and finds that 8885 ** the column is not changed by the UPDATE statement, then the xColumn 8886 ** method can optionally return without setting a result, without calling 8887 ** any of the [sqlite3_result_int|sqlite3_result_xxxxx() interfaces]. 8888 ** In that case, [sqlite3_value_nochange(X)] will return true for the 8889 ** same column in the [xUpdate] method. 8890 */ 8891 SQLITE_API int sqlite3_vtab_nochange(sqlite3_context*); 8892 8893 /* 8894 ** CAPI3REF: Determine The Collation For a Virtual Table Constraint 8895 ** 8896 ** This function may only be called from within a call to the [xBestIndex] 8897 ** method of a [virtual table]. 8898 ** 8899 ** The first argument must be the sqlite3_index_info object that is the 8900 ** first parameter to the xBestIndex() method. The second argument must be 8901 ** an index into the aConstraint[] array belonging to the sqlite3_index_info 8902 ** structure passed to xBestIndex. This function returns a pointer to a buffer 8903 ** containing the name of the collation sequence for the corresponding 8904 ** constraint. 8905 */ 8906 SQLITE_API SQLITE_EXPERIMENTAL const char *sqlite3_vtab_collation(sqlite3_index_info*,int); 8907 8908 /* 8909 ** CAPI3REF: Conflict resolution modes 8910 ** KEYWORDS: {conflict resolution mode} 8911 ** 8912 ** These constants are returned by [sqlite3_vtab_on_conflict()] to 8913 ** inform a [virtual table] implementation what the [ON CONFLICT] mode 8914 ** is for the SQL statement being evaluated. 8915 ** 8916 ** Note that the [SQLITE_IGNORE] constant is also used as a potential 8917 ** return value from the [sqlite3_set_authorizer()] callback and that 8918 ** [SQLITE_ABORT] is also a [result code]. 8919 */ 8920 #define SQLITE_ROLLBACK 1 8921 /* #define SQLITE_IGNORE 2 // Also used by sqlite3_authorizer() callback */ 8922 #define SQLITE_FAIL 3 8923 /* #define SQLITE_ABORT 4 // Also an error code */ 8924 #define SQLITE_REPLACE 5 8925 8926 /* 8927 ** CAPI3REF: Prepared Statement Scan Status Opcodes 8928 ** KEYWORDS: {scanstatus options} 8929 ** 8930 ** The following constants can be used for the T parameter to the 8931 ** [sqlite3_stmt_scanstatus(S,X,T,V)] interface. Each constant designates a 8932 ** different metric for sqlite3_stmt_scanstatus() to return. 8933 ** 8934 ** When the value returned to V is a string, space to hold that string is 8935 ** managed by the prepared statement S and will be automatically freed when 8936 ** S is finalized. 8937 ** 8938 ** <dl> 8939 ** [[SQLITE_SCANSTAT_NLOOP]] <dt>SQLITE_SCANSTAT_NLOOP</dt> 8940 ** <dd>^The [sqlite3_int64] variable pointed to by the T parameter will be 8941 ** set to the total number of times that the X-th loop has run.</dd> 8942 ** 8943 ** [[SQLITE_SCANSTAT_NVISIT]] <dt>SQLITE_SCANSTAT_NVISIT</dt> 8944 ** <dd>^The [sqlite3_int64] variable pointed to by the T parameter will be set 8945 ** to the total number of rows examined by all iterations of the X-th loop.</dd> 8946 ** 8947 ** [[SQLITE_SCANSTAT_EST]] <dt>SQLITE_SCANSTAT_EST</dt> 8948 ** <dd>^The "double" variable pointed to by the T parameter will be set to the 8949 ** query planner's estimate for the average number of rows output from each 8950 ** iteration of the X-th loop. If the query planner's estimates was accurate, 8951 ** then this value will approximate the quotient NVISIT/NLOOP and the 8952 ** product of this value for all prior loops with the same SELECTID will 8953 ** be the NLOOP value for the current loop. 8954 ** 8955 ** [[SQLITE_SCANSTAT_NAME]] <dt>SQLITE_SCANSTAT_NAME</dt> 8956 ** <dd>^The "const char *" variable pointed to by the T parameter will be set 8957 ** to a zero-terminated UTF-8 string containing the name of the index or table 8958 ** used for the X-th loop. 8959 ** 8960 ** [[SQLITE_SCANSTAT_EXPLAIN]] <dt>SQLITE_SCANSTAT_EXPLAIN</dt> 8961 ** <dd>^The "const char *" variable pointed to by the T parameter will be set 8962 ** to a zero-terminated UTF-8 string containing the [EXPLAIN QUERY PLAN] 8963 ** description for the X-th loop. 8964 ** 8965 ** [[SQLITE_SCANSTAT_SELECTID]] <dt>SQLITE_SCANSTAT_SELECT</dt> 8966 ** <dd>^The "int" variable pointed to by the T parameter will be set to the 8967 ** "select-id" for the X-th loop. The select-id identifies which query or 8968 ** subquery the loop is part of. The main query has a select-id of zero. 8969 ** The select-id is the same value as is output in the first column 8970 ** of an [EXPLAIN QUERY PLAN] query. 8971 ** </dl> 8972 */ 8973 #define SQLITE_SCANSTAT_NLOOP 0 8974 #define SQLITE_SCANSTAT_NVISIT 1 8975 #define SQLITE_SCANSTAT_EST 2 8976 #define SQLITE_SCANSTAT_NAME 3 8977 #define SQLITE_SCANSTAT_EXPLAIN 4 8978 #define SQLITE_SCANSTAT_SELECTID 5 8979 8980 /* 8981 ** CAPI3REF: Prepared Statement Scan Status 8982 ** METHOD: sqlite3_stmt 8983 ** 8984 ** This interface returns information about the predicted and measured 8985 ** performance for pStmt. Advanced applications can use this 8986 ** interface to compare the predicted and the measured performance and 8987 ** issue warnings and/or rerun [ANALYZE] if discrepancies are found. 8988 ** 8989 ** Since this interface is expected to be rarely used, it is only 8990 ** available if SQLite is compiled using the [SQLITE_ENABLE_STMT_SCANSTATUS] 8991 ** compile-time option. 8992 ** 8993 ** The "iScanStatusOp" parameter determines which status information to return. 8994 ** The "iScanStatusOp" must be one of the [scanstatus options] or the behavior 8995 ** of this interface is undefined. 8996 ** ^The requested measurement is written into a variable pointed to by 8997 ** the "pOut" parameter. 8998 ** Parameter "idx" identifies the specific loop to retrieve statistics for. 8999 ** Loops are numbered starting from zero. ^If idx is out of range - less than 9000 ** zero or greater than or equal to the total number of loops used to implement 9001 ** the statement - a non-zero value is returned and the variable that pOut 9002 ** points to is unchanged. 9003 ** 9004 ** ^Statistics might not be available for all loops in all statements. ^In cases 9005 ** where there exist loops with no available statistics, this function behaves 9006 ** as if the loop did not exist - it returns non-zero and leave the variable 9007 ** that pOut points to unchanged. 9008 ** 9009 ** See also: [sqlite3_stmt_scanstatus_reset()] 9010 */ 9011 SQLITE_API int sqlite3_stmt_scanstatus( 9012 sqlite3_stmt *pStmt, /* Prepared statement for which info desired */ 9013 int idx, /* Index of loop to report on */ 9014 int iScanStatusOp, /* Information desired. SQLITE_SCANSTAT_* */ 9015 void *pOut /* Result written here */ 9016 ); 9017 9018 /* 9019 ** CAPI3REF: Zero Scan-Status Counters 9020 ** METHOD: sqlite3_stmt 9021 ** 9022 ** ^Zero all [sqlite3_stmt_scanstatus()] related event counters. 9023 ** 9024 ** This API is only available if the library is built with pre-processor 9025 ** symbol [SQLITE_ENABLE_STMT_SCANSTATUS] defined. 9026 */ 9027 SQLITE_API void sqlite3_stmt_scanstatus_reset(sqlite3_stmt*); 9028 9029 /* 9030 ** CAPI3REF: Flush caches to disk mid-transaction 9031 ** 9032 ** ^If a write-transaction is open on [database connection] D when the 9033 ** [sqlite3_db_cacheflush(D)] interface invoked, any dirty 9034 ** pages in the pager-cache that are not currently in use are written out 9035 ** to disk. A dirty page may be in use if a database cursor created by an 9036 ** active SQL statement is reading from it, or if it is page 1 of a database 9037 ** file (page 1 is always "in use"). ^The [sqlite3_db_cacheflush(D)] 9038 ** interface flushes caches for all schemas - "main", "temp", and 9039 ** any [attached] databases. 9040 ** 9041 ** ^If this function needs to obtain extra database locks before dirty pages 9042 ** can be flushed to disk, it does so. ^If those locks cannot be obtained 9043 ** immediately and there is a busy-handler callback configured, it is invoked 9044 ** in the usual manner. ^If the required lock still cannot be obtained, then 9045 ** the database is skipped and an attempt made to flush any dirty pages 9046 ** belonging to the next (if any) database. ^If any databases are skipped 9047 ** because locks cannot be obtained, but no other error occurs, this 9048 ** function returns SQLITE_BUSY. 9049 ** 9050 ** ^If any other error occurs while flushing dirty pages to disk (for 9051 ** example an IO error or out-of-memory condition), then processing is 9052 ** abandoned and an SQLite [error code] is returned to the caller immediately. 9053 ** 9054 ** ^Otherwise, if no error occurs, [sqlite3_db_cacheflush()] returns SQLITE_OK. 9055 ** 9056 ** ^This function does not set the database handle error code or message 9057 ** returned by the [sqlite3_errcode()] and [sqlite3_errmsg()] functions. 9058 */ 9059 SQLITE_API int sqlite3_db_cacheflush(sqlite3*); 9060 9061 /* 9062 ** CAPI3REF: The pre-update hook. 9063 ** 9064 ** ^These interfaces are only available if SQLite is compiled using the 9065 ** [SQLITE_ENABLE_PREUPDATE_HOOK] compile-time option. 9066 ** 9067 ** ^The [sqlite3_preupdate_hook()] interface registers a callback function 9068 ** that is invoked prior to each [INSERT], [UPDATE], and [DELETE] operation 9069 ** on a database table. 9070 ** ^At most one preupdate hook may be registered at a time on a single 9071 ** [database connection]; each call to [sqlite3_preupdate_hook()] overrides 9072 ** the previous setting. 9073 ** ^The preupdate hook is disabled by invoking [sqlite3_preupdate_hook()] 9074 ** with a NULL pointer as the second parameter. 9075 ** ^The third parameter to [sqlite3_preupdate_hook()] is passed through as 9076 ** the first parameter to callbacks. 9077 ** 9078 ** ^The preupdate hook only fires for changes to real database tables; the 9079 ** preupdate hook is not invoked for changes to [virtual tables] or to 9080 ** system tables like sqlite_master or sqlite_stat1. 9081 ** 9082 ** ^The second parameter to the preupdate callback is a pointer to 9083 ** the [database connection] that registered the preupdate hook. 9084 ** ^The third parameter to the preupdate callback is one of the constants 9085 ** [SQLITE_INSERT], [SQLITE_DELETE], or [SQLITE_UPDATE] to identify the 9086 ** kind of update operation that is about to occur. 9087 ** ^(The fourth parameter to the preupdate callback is the name of the 9088 ** database within the database connection that is being modified. This 9089 ** will be "main" for the main database or "temp" for TEMP tables or 9090 ** the name given after the AS keyword in the [ATTACH] statement for attached 9091 ** databases.)^ 9092 ** ^The fifth parameter to the preupdate callback is the name of the 9093 ** table that is being modified. 9094 ** 9095 ** For an UPDATE or DELETE operation on a [rowid table], the sixth 9096 ** parameter passed to the preupdate callback is the initial [rowid] of the 9097 ** row being modified or deleted. For an INSERT operation on a rowid table, 9098 ** or any operation on a WITHOUT ROWID table, the value of the sixth 9099 ** parameter is undefined. For an INSERT or UPDATE on a rowid table the 9100 ** seventh parameter is the final rowid value of the row being inserted 9101 ** or updated. The value of the seventh parameter passed to the callback 9102 ** function is not defined for operations on WITHOUT ROWID tables, or for 9103 ** INSERT operations on rowid tables. 9104 ** 9105 ** The [sqlite3_preupdate_old()], [sqlite3_preupdate_new()], 9106 ** [sqlite3_preupdate_count()], and [sqlite3_preupdate_depth()] interfaces 9107 ** provide additional information about a preupdate event. These routines 9108 ** may only be called from within a preupdate callback. Invoking any of 9109 ** these routines from outside of a preupdate callback or with a 9110 ** [database connection] pointer that is different from the one supplied 9111 ** to the preupdate callback results in undefined and probably undesirable 9112 ** behavior. 9113 ** 9114 ** ^The [sqlite3_preupdate_count(D)] interface returns the number of columns 9115 ** in the row that is being inserted, updated, or deleted. 9116 ** 9117 ** ^The [sqlite3_preupdate_old(D,N,P)] interface writes into P a pointer to 9118 ** a [protected sqlite3_value] that contains the value of the Nth column of 9119 ** the table row before it is updated. The N parameter must be between 0 9120 ** and one less than the number of columns or the behavior will be 9121 ** undefined. This must only be used within SQLITE_UPDATE and SQLITE_DELETE 9122 ** preupdate callbacks; if it is used by an SQLITE_INSERT callback then the 9123 ** behavior is undefined. The [sqlite3_value] that P points to 9124 ** will be destroyed when the preupdate callback returns. 9125 ** 9126 ** ^The [sqlite3_preupdate_new(D,N,P)] interface writes into P a pointer to 9127 ** a [protected sqlite3_value] that contains the value of the Nth column of 9128 ** the table row after it is updated. The N parameter must be between 0 9129 ** and one less than the number of columns or the behavior will be 9130 ** undefined. This must only be used within SQLITE_INSERT and SQLITE_UPDATE 9131 ** preupdate callbacks; if it is used by an SQLITE_DELETE callback then the 9132 ** behavior is undefined. The [sqlite3_value] that P points to 9133 ** will be destroyed when the preupdate callback returns. 9134 ** 9135 ** ^The [sqlite3_preupdate_depth(D)] interface returns 0 if the preupdate 9136 ** callback was invoked as a result of a direct insert, update, or delete 9137 ** operation; or 1 for inserts, updates, or deletes invoked by top-level 9138 ** triggers; or 2 for changes resulting from triggers called by top-level 9139 ** triggers; and so forth. 9140 ** 9141 ** See also: [sqlite3_update_hook()] 9142 */ 9143 #if defined(SQLITE_ENABLE_PREUPDATE_HOOK) 9144 SQLITE_API void *sqlite3_preupdate_hook( 9145 sqlite3 *db, 9146 void(*xPreUpdate)( 9147 void *pCtx, /* Copy of third arg to preupdate_hook() */ 9148 sqlite3 *db, /* Database handle */ 9149 int op, /* SQLITE_UPDATE, DELETE or INSERT */ 9150 char const *zDb, /* Database name */ 9151 char const *zName, /* Table name */ 9152 sqlite3_int64 iKey1, /* Rowid of row about to be deleted/updated */ 9153 sqlite3_int64 iKey2 /* New rowid value (for a rowid UPDATE) */ 9154 ), 9155 void* 9156 ); 9157 SQLITE_API int sqlite3_preupdate_old(sqlite3 *, int, sqlite3_value **); 9158 SQLITE_API int sqlite3_preupdate_count(sqlite3 *); 9159 SQLITE_API int sqlite3_preupdate_depth(sqlite3 *); 9160 SQLITE_API int sqlite3_preupdate_new(sqlite3 *, int, sqlite3_value **); 9161 #endif 9162 9163 /* 9164 ** CAPI3REF: Low-level system error code 9165 ** 9166 ** ^Attempt to return the underlying operating system error code or error 9167 ** number that caused the most recent I/O error or failure to open a file. 9168 ** The return value is OS-dependent. For example, on unix systems, after 9169 ** [sqlite3_open_v2()] returns [SQLITE_CANTOPEN], this interface could be 9170 ** called to get back the underlying "errno" that caused the problem, such 9171 ** as ENOSPC, EAUTH, EISDIR, and so forth. 9172 */ 9173 SQLITE_API int sqlite3_system_errno(sqlite3*); 9174 9175 /* 9176 ** CAPI3REF: Database Snapshot 9177 ** KEYWORDS: {snapshot} {sqlite3_snapshot} 9178 ** 9179 ** An instance of the snapshot object records the state of a [WAL mode] 9180 ** database for some specific point in history. 9181 ** 9182 ** In [WAL mode], multiple [database connections] that are open on the 9183 ** same database file can each be reading a different historical version 9184 ** of the database file. When a [database connection] begins a read 9185 ** transaction, that connection sees an unchanging copy of the database 9186 ** as it existed for the point in time when the transaction first started. 9187 ** Subsequent changes to the database from other connections are not seen 9188 ** by the reader until a new read transaction is started. 9189 ** 9190 ** The sqlite3_snapshot object records state information about an historical 9191 ** version of the database file so that it is possible to later open a new read 9192 ** transaction that sees that historical version of the database rather than 9193 ** the most recent version. 9194 */ 9195 typedef struct sqlite3_snapshot { 9196 unsigned char hidden[48]; 9197 } sqlite3_snapshot; 9198 9199 /* 9200 ** CAPI3REF: Record A Database Snapshot 9201 ** CONSTRUCTOR: sqlite3_snapshot 9202 ** 9203 ** ^The [sqlite3_snapshot_get(D,S,P)] interface attempts to make a 9204 ** new [sqlite3_snapshot] object that records the current state of 9205 ** schema S in database connection D. ^On success, the 9206 ** [sqlite3_snapshot_get(D,S,P)] interface writes a pointer to the newly 9207 ** created [sqlite3_snapshot] object into *P and returns SQLITE_OK. 9208 ** If there is not already a read-transaction open on schema S when 9209 ** this function is called, one is opened automatically. 9210 ** 9211 ** The following must be true for this function to succeed. If any of 9212 ** the following statements are false when sqlite3_snapshot_get() is 9213 ** called, SQLITE_ERROR is returned. The final value of *P is undefined 9214 ** in this case. 9215 ** 9216 ** <ul> 9217 ** <li> The database handle must not be in [autocommit mode]. 9218 ** 9219 ** <li> Schema S of [database connection] D must be a [WAL mode] database. 9220 ** 9221 ** <li> There must not be a write transaction open on schema S of database 9222 ** connection D. 9223 ** 9224 ** <li> One or more transactions must have been written to the current wal 9225 ** file since it was created on disk (by any connection). This means 9226 ** that a snapshot cannot be taken on a wal mode database with no wal 9227 ** file immediately after it is first opened. At least one transaction 9228 ** must be written to it first. 9229 ** </ul> 9230 ** 9231 ** This function may also return SQLITE_NOMEM. If it is called with the 9232 ** database handle in autocommit mode but fails for some other reason, 9233 ** whether or not a read transaction is opened on schema S is undefined. 9234 ** 9235 ** The [sqlite3_snapshot] object returned from a successful call to 9236 ** [sqlite3_snapshot_get()] must be freed using [sqlite3_snapshot_free()] 9237 ** to avoid a memory leak. 9238 ** 9239 ** The [sqlite3_snapshot_get()] interface is only available when the 9240 ** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used. 9241 */ 9242 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_get( 9243 sqlite3 *db, 9244 const char *zSchema, 9245 sqlite3_snapshot **ppSnapshot 9246 ); 9247 9248 /* 9249 ** CAPI3REF: Start a read transaction on an historical snapshot 9250 ** METHOD: sqlite3_snapshot 9251 ** 9252 ** ^The [sqlite3_snapshot_open(D,S,P)] interface either starts a new read 9253 ** transaction or upgrades an existing one for schema S of 9254 ** [database connection] D such that the read transaction refers to 9255 ** historical [snapshot] P, rather than the most recent change to the 9256 ** database. ^The [sqlite3_snapshot_open()] interface returns SQLITE_OK 9257 ** on success or an appropriate [error code] if it fails. 9258 ** 9259 ** ^In order to succeed, the database connection must not be in 9260 ** [autocommit mode] when [sqlite3_snapshot_open(D,S,P)] is called. If there 9261 ** is already a read transaction open on schema S, then the database handle 9262 ** must have no active statements (SELECT statements that have been passed 9263 ** to sqlite3_step() but not sqlite3_reset() or sqlite3_finalize()). 9264 ** SQLITE_ERROR is returned if either of these conditions is violated, or 9265 ** if schema S does not exist, or if the snapshot object is invalid. 9266 ** 9267 ** ^A call to sqlite3_snapshot_open() will fail to open if the specified 9268 ** snapshot has been overwritten by a [checkpoint]. In this case 9269 ** SQLITE_ERROR_SNAPSHOT is returned. 9270 ** 9271 ** If there is already a read transaction open when this function is 9272 ** invoked, then the same read transaction remains open (on the same 9273 ** database snapshot) if SQLITE_ERROR, SQLITE_BUSY or SQLITE_ERROR_SNAPSHOT 9274 ** is returned. If another error code - for example SQLITE_PROTOCOL or an 9275 ** SQLITE_IOERR error code - is returned, then the final state of the 9276 ** read transaction is undefined. If SQLITE_OK is returned, then the 9277 ** read transaction is now open on database snapshot P. 9278 ** 9279 ** ^(A call to [sqlite3_snapshot_open(D,S,P)] will fail if the 9280 ** database connection D does not know that the database file for 9281 ** schema S is in [WAL mode]. A database connection might not know 9282 ** that the database file is in [WAL mode] if there has been no prior 9283 ** I/O on that database connection, or if the database entered [WAL mode] 9284 ** after the most recent I/O on the database connection.)^ 9285 ** (Hint: Run "[PRAGMA application_id]" against a newly opened 9286 ** database connection in order to make it ready to use snapshots.) 9287 ** 9288 ** The [sqlite3_snapshot_open()] interface is only available when the 9289 ** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used. 9290 */ 9291 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_open( 9292 sqlite3 *db, 9293 const char *zSchema, 9294 sqlite3_snapshot *pSnapshot 9295 ); 9296 9297 /* 9298 ** CAPI3REF: Destroy a snapshot 9299 ** DESTRUCTOR: sqlite3_snapshot 9300 ** 9301 ** ^The [sqlite3_snapshot_free(P)] interface destroys [sqlite3_snapshot] P. 9302 ** The application must eventually free every [sqlite3_snapshot] object 9303 ** using this routine to avoid a memory leak. 9304 ** 9305 ** The [sqlite3_snapshot_free()] interface is only available when the 9306 ** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used. 9307 */ 9308 SQLITE_API SQLITE_EXPERIMENTAL void sqlite3_snapshot_free(sqlite3_snapshot*); 9309 9310 /* 9311 ** CAPI3REF: Compare the ages of two snapshot handles. 9312 ** METHOD: sqlite3_snapshot 9313 ** 9314 ** The sqlite3_snapshot_cmp(P1, P2) interface is used to compare the ages 9315 ** of two valid snapshot handles. 9316 ** 9317 ** If the two snapshot handles are not associated with the same database 9318 ** file, the result of the comparison is undefined. 9319 ** 9320 ** Additionally, the result of the comparison is only valid if both of the 9321 ** snapshot handles were obtained by calling sqlite3_snapshot_get() since the 9322 ** last time the wal file was deleted. The wal file is deleted when the 9323 ** database is changed back to rollback mode or when the number of database 9324 ** clients drops to zero. If either snapshot handle was obtained before the 9325 ** wal file was last deleted, the value returned by this function 9326 ** is undefined. 9327 ** 9328 ** Otherwise, this API returns a negative value if P1 refers to an older 9329 ** snapshot than P2, zero if the two handles refer to the same database 9330 ** snapshot, and a positive value if P1 is a newer snapshot than P2. 9331 ** 9332 ** This interface is only available if SQLite is compiled with the 9333 ** [SQLITE_ENABLE_SNAPSHOT] option. 9334 */ 9335 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_cmp( 9336 sqlite3_snapshot *p1, 9337 sqlite3_snapshot *p2 9338 ); 9339 9340 /* 9341 ** CAPI3REF: Recover snapshots from a wal file 9342 ** METHOD: sqlite3_snapshot 9343 ** 9344 ** If a [WAL file] remains on disk after all database connections close 9345 ** (either through the use of the [SQLITE_FCNTL_PERSIST_WAL] [file control] 9346 ** or because the last process to have the database opened exited without 9347 ** calling [sqlite3_close()]) and a new connection is subsequently opened 9348 ** on that database and [WAL file], the [sqlite3_snapshot_open()] interface 9349 ** will only be able to open the last transaction added to the WAL file 9350 ** even though the WAL file contains other valid transactions. 9351 ** 9352 ** This function attempts to scan the WAL file associated with database zDb 9353 ** of database handle db and make all valid snapshots available to 9354 ** sqlite3_snapshot_open(). It is an error if there is already a read 9355 ** transaction open on the database, or if the database is not a WAL mode 9356 ** database. 9357 ** 9358 ** SQLITE_OK is returned if successful, or an SQLite error code otherwise. 9359 ** 9360 ** This interface is only available if SQLite is compiled with the 9361 ** [SQLITE_ENABLE_SNAPSHOT] option. 9362 */ 9363 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_recover(sqlite3 *db, const char *zDb); 9364 9365 /* 9366 ** CAPI3REF: Serialize a database 9367 ** 9368 ** The sqlite3_serialize(D,S,P,F) interface returns a pointer to memory 9369 ** that is a serialization of the S database on [database connection] D. 9370 ** If P is not a NULL pointer, then the size of the database in bytes 9371 ** is written into *P. 9372 ** 9373 ** For an ordinary on-disk database file, the serialization is just a 9374 ** copy of the disk file. For an in-memory database or a "TEMP" database, 9375 ** the serialization is the same sequence of bytes which would be written 9376 ** to disk if that database where backed up to disk. 9377 ** 9378 ** The usual case is that sqlite3_serialize() copies the serialization of 9379 ** the database into memory obtained from [sqlite3_malloc64()] and returns 9380 ** a pointer to that memory. The caller is responsible for freeing the 9381 ** returned value to avoid a memory leak. However, if the F argument 9382 ** contains the SQLITE_SERIALIZE_NOCOPY bit, then no memory allocations 9383 ** are made, and the sqlite3_serialize() function will return a pointer 9384 ** to the contiguous memory representation of the database that SQLite 9385 ** is currently using for that database, or NULL if the no such contiguous 9386 ** memory representation of the database exists. A contiguous memory 9387 ** representation of the database will usually only exist if there has 9388 ** been a prior call to [sqlite3_deserialize(D,S,...)] with the same 9389 ** values of D and S. 9390 ** The size of the database is written into *P even if the 9391 ** SQLITE_SERIALIZE_NOCOPY bit is set but no contiguous copy 9392 ** of the database exists. 9393 ** 9394 ** A call to sqlite3_serialize(D,S,P,F) might return NULL even if the 9395 ** SQLITE_SERIALIZE_NOCOPY bit is omitted from argument F if a memory 9396 ** allocation error occurs. 9397 ** 9398 ** This interface is only available if SQLite is compiled with the 9399 ** [SQLITE_ENABLE_DESERIALIZE] option. 9400 */ 9401 SQLITE_API unsigned char *sqlite3_serialize( 9402 sqlite3 *db, /* The database connection */ 9403 const char *zSchema, /* Which DB to serialize. ex: "main", "temp", ... */ 9404 sqlite3_int64 *piSize, /* Write size of the DB here, if not NULL */ 9405 unsigned int mFlags /* Zero or more SQLITE_SERIALIZE_* flags */ 9406 ); 9407 9408 /* 9409 ** CAPI3REF: Flags for sqlite3_serialize 9410 ** 9411 ** Zero or more of the following constants can be OR-ed together for 9412 ** the F argument to [sqlite3_serialize(D,S,P,F)]. 9413 ** 9414 ** SQLITE_SERIALIZE_NOCOPY means that [sqlite3_serialize()] will return 9415 ** a pointer to contiguous in-memory database that it is currently using, 9416 ** without making a copy of the database. If SQLite is not currently using 9417 ** a contiguous in-memory database, then this option causes 9418 ** [sqlite3_serialize()] to return a NULL pointer. SQLite will only be 9419 ** using a contiguous in-memory database if it has been initialized by a 9420 ** prior call to [sqlite3_deserialize()]. 9421 */ 9422 #define SQLITE_SERIALIZE_NOCOPY 0x001 /* Do no memory allocations */ 9423 9424 /* 9425 ** CAPI3REF: Deserialize a database 9426 ** 9427 ** The sqlite3_deserialize(D,S,P,N,M,F) interface causes the 9428 ** [database connection] D to disconnect from database S and then 9429 ** reopen S as an in-memory database based on the serialization contained 9430 ** in P. The serialized database P is N bytes in size. M is the size of 9431 ** the buffer P, which might be larger than N. If M is larger than N, and 9432 ** the SQLITE_DESERIALIZE_READONLY bit is not set in F, then SQLite is 9433 ** permitted to add content to the in-memory database as long as the total 9434 ** size does not exceed M bytes. 9435 ** 9436 ** If the SQLITE_DESERIALIZE_FREEONCLOSE bit is set in F, then SQLite will 9437 ** invoke sqlite3_free() on the serialization buffer when the database 9438 ** connection closes. If the SQLITE_DESERIALIZE_RESIZEABLE bit is set, then 9439 ** SQLite will try to increase the buffer size using sqlite3_realloc64() 9440 ** if writes on the database cause it to grow larger than M bytes. 9441 ** 9442 ** The sqlite3_deserialize() interface will fail with SQLITE_BUSY if the 9443 ** database is currently in a read transaction or is involved in a backup 9444 ** operation. 9445 ** 9446 ** If sqlite3_deserialize(D,S,P,N,M,F) fails for any reason and if the 9447 ** SQLITE_DESERIALIZE_FREEONCLOSE bit is set in argument F, then 9448 ** [sqlite3_free()] is invoked on argument P prior to returning. 9449 ** 9450 ** This interface is only available if SQLite is compiled with the 9451 ** [SQLITE_ENABLE_DESERIALIZE] option. 9452 */ 9453 SQLITE_API int sqlite3_deserialize( 9454 sqlite3 *db, /* The database connection */ 9455 const char *zSchema, /* Which DB to reopen with the deserialization */ 9456 unsigned char *pData, /* The serialized database content */ 9457 sqlite3_int64 szDb, /* Number bytes in the deserialization */ 9458 sqlite3_int64 szBuf, /* Total size of buffer pData[] */ 9459 unsigned mFlags /* Zero or more SQLITE_DESERIALIZE_* flags */ 9460 ); 9461 9462 /* 9463 ** CAPI3REF: Flags for sqlite3_deserialize() 9464 ** 9465 ** The following are allowed values for 6th argument (the F argument) to 9466 ** the [sqlite3_deserialize(D,S,P,N,M,F)] interface. 9467 ** 9468 ** The SQLITE_DESERIALIZE_FREEONCLOSE means that the database serialization 9469 ** in the P argument is held in memory obtained from [sqlite3_malloc64()] 9470 ** and that SQLite should take ownership of this memory and automatically 9471 ** free it when it has finished using it. Without this flag, the caller 9472 ** is responsible for freeing any dynamically allocated memory. 9473 ** 9474 ** The SQLITE_DESERIALIZE_RESIZEABLE flag means that SQLite is allowed to 9475 ** grow the size of the database using calls to [sqlite3_realloc64()]. This 9476 ** flag should only be used if SQLITE_DESERIALIZE_FREEONCLOSE is also used. 9477 ** Without this flag, the deserialized database cannot increase in size beyond 9478 ** the number of bytes specified by the M parameter. 9479 ** 9480 ** The SQLITE_DESERIALIZE_READONLY flag means that the deserialized database 9481 ** should be treated as read-only. 9482 */ 9483 #define SQLITE_DESERIALIZE_FREEONCLOSE 1 /* Call sqlite3_free() on close */ 9484 #define SQLITE_DESERIALIZE_RESIZEABLE 2 /* Resize using sqlite3_realloc64() */ 9485 #define SQLITE_DESERIALIZE_READONLY 4 /* Database is read-only */ 9486 9487 /* 9488 ** Undo the hack that converts floating point types to integer for 9489 ** builds on processors without floating point support. 9490 */ 9491 #ifdef SQLITE_OMIT_FLOATING_POINT 9492 # undef double 9493 #endif 9494 9495 #ifdef __cplusplus 9496 } /* End of the 'extern "C"' block */ 9497 #endif 9498 #endif /* SQLITE3_H */ 9499 9500 /******** Begin file sqlite3rtree.h *********/ 9501 /* 9502 ** 2010 August 30 9503 ** 9504 ** The author disclaims copyright to this source code. In place of 9505 ** a legal notice, here is a blessing: 9506 ** 9507 ** May you do good and not evil. 9508 ** May you find forgiveness for yourself and forgive others. 9509 ** May you share freely, never taking more than you give. 9510 ** 9511 ************************************************************************* 9512 */ 9513 9514 #ifndef _SQLITE3RTREE_H_ 9515 #define _SQLITE3RTREE_H_ 9516 9517 9518 #ifdef __cplusplus 9519 extern "C" { 9520 #endif 9521 9522 typedef struct sqlite3_rtree_geometry sqlite3_rtree_geometry; 9523 typedef struct sqlite3_rtree_query_info sqlite3_rtree_query_info; 9524 9525 /* The double-precision datatype used by RTree depends on the 9526 ** SQLITE_RTREE_INT_ONLY compile-time option. 9527 */ 9528 #ifdef SQLITE_RTREE_INT_ONLY 9529 typedef sqlite3_int64 sqlite3_rtree_dbl; 9530 #else 9531 typedef double sqlite3_rtree_dbl; 9532 #endif 9533 9534 /* 9535 ** Register a geometry callback named zGeom that can be used as part of an 9536 ** R-Tree geometry query as follows: 9537 ** 9538 ** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zGeom(... params ...) 9539 */ 9540 SQLITE_API int sqlite3_rtree_geometry_callback( 9541 sqlite3 *db, 9542 const char *zGeom, 9543 int (*xGeom)(sqlite3_rtree_geometry*, int, sqlite3_rtree_dbl*,int*), 9544 void *pContext 9545 ); 9546 9547 9548 /* 9549 ** A pointer to a structure of the following type is passed as the first 9550 ** argument to callbacks registered using rtree_geometry_callback(). 9551 */ 9552 struct sqlite3_rtree_geometry { 9553 void *pContext; /* Copy of pContext passed to s_r_g_c() */ 9554 int nParam; /* Size of array aParam[] */ 9555 sqlite3_rtree_dbl *aParam; /* Parameters passed to SQL geom function */ 9556 void *pUser; /* Callback implementation user data */ 9557 void (*xDelUser)(void *); /* Called by SQLite to clean up pUser */ 9558 }; 9559 9560 /* 9561 ** Register a 2nd-generation geometry callback named zScore that can be 9562 ** used as part of an R-Tree geometry query as follows: 9563 ** 9564 ** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zQueryFunc(... params ...) 9565 */ 9566 SQLITE_API int sqlite3_rtree_query_callback( 9567 sqlite3 *db, 9568 const char *zQueryFunc, 9569 int (*xQueryFunc)(sqlite3_rtree_query_info*), 9570 void *pContext, 9571 void (*xDestructor)(void*) 9572 ); 9573 9574 9575 /* 9576 ** A pointer to a structure of the following type is passed as the 9577 ** argument to scored geometry callback registered using 9578 ** sqlite3_rtree_query_callback(). 9579 ** 9580 ** Note that the first 5 fields of this structure are identical to 9581 ** sqlite3_rtree_geometry. This structure is a subclass of 9582 ** sqlite3_rtree_geometry. 9583 */ 9584 struct sqlite3_rtree_query_info { 9585 void *pContext; /* pContext from when function registered */ 9586 int nParam; /* Number of function parameters */ 9587 sqlite3_rtree_dbl *aParam; /* value of function parameters */ 9588 void *pUser; /* callback can use this, if desired */ 9589 void (*xDelUser)(void*); /* function to free pUser */ 9590 sqlite3_rtree_dbl *aCoord; /* Coordinates of node or entry to check */ 9591 unsigned int *anQueue; /* Number of pending entries in the queue */ 9592 int nCoord; /* Number of coordinates */ 9593 int iLevel; /* Level of current node or entry */ 9594 int mxLevel; /* The largest iLevel value in the tree */ 9595 sqlite3_int64 iRowid; /* Rowid for current entry */ 9596 sqlite3_rtree_dbl rParentScore; /* Score of parent node */ 9597 int eParentWithin; /* Visibility of parent node */ 9598 int eWithin; /* OUT: Visibility */ 9599 sqlite3_rtree_dbl rScore; /* OUT: Write the score here */ 9600 /* The following fields are only available in 3.8.11 and later */ 9601 sqlite3_value **apSqlParam; /* Original SQL values of parameters */ 9602 }; 9603 9604 /* 9605 ** Allowed values for sqlite3_rtree_query.eWithin and .eParentWithin. 9606 */ 9607 #define NOT_WITHIN 0 /* Object completely outside of query region */ 9608 #define PARTLY_WITHIN 1 /* Object partially overlaps query region */ 9609 #define FULLY_WITHIN 2 /* Object fully contained within query region */ 9610 9611 9612 #ifdef __cplusplus 9613 } /* end of the 'extern "C"' block */ 9614 #endif 9615 9616 #endif /* ifndef _SQLITE3RTREE_H_ */ 9617 9618 /******** End of sqlite3rtree.h *********/ 9619 /******** Begin file sqlite3session.h *********/ 9620 9621 #if !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION) 9622 #define __SQLITESESSION_H_ 1 9623 9624 /* 9625 ** Make sure we can call this stuff from C++. 9626 */ 9627 #ifdef __cplusplus 9628 extern "C" { 9629 #endif 9630 9631 9632 /* 9633 ** CAPI3REF: Session Object Handle 9634 ** 9635 ** An instance of this object is a [session] that can be used to 9636 ** record changes to a database. 9637 */ 9638 typedef struct sqlite3_session sqlite3_session; 9639 9640 /* 9641 ** CAPI3REF: Changeset Iterator Handle 9642 ** 9643 ** An instance of this object acts as a cursor for iterating 9644 ** over the elements of a [changeset] or [patchset]. 9645 */ 9646 typedef struct sqlite3_changeset_iter sqlite3_changeset_iter; 9647 9648 /* 9649 ** CAPI3REF: Create A New Session Object 9650 ** CONSTRUCTOR: sqlite3_session 9651 ** 9652 ** Create a new session object attached to database handle db. If successful, 9653 ** a pointer to the new object is written to *ppSession and SQLITE_OK is 9654 ** returned. If an error occurs, *ppSession is set to NULL and an SQLite 9655 ** error code (e.g. SQLITE_NOMEM) is returned. 9656 ** 9657 ** It is possible to create multiple session objects attached to a single 9658 ** database handle. 9659 ** 9660 ** Session objects created using this function should be deleted using the 9661 ** [sqlite3session_delete()] function before the database handle that they 9662 ** are attached to is itself closed. If the database handle is closed before 9663 ** the session object is deleted, then the results of calling any session 9664 ** module function, including [sqlite3session_delete()] on the session object 9665 ** are undefined. 9666 ** 9667 ** Because the session module uses the [sqlite3_preupdate_hook()] API, it 9668 ** is not possible for an application to register a pre-update hook on a 9669 ** database handle that has one or more session objects attached. Nor is 9670 ** it possible to create a session object attached to a database handle for 9671 ** which a pre-update hook is already defined. The results of attempting 9672 ** either of these things are undefined. 9673 ** 9674 ** The session object will be used to create changesets for tables in 9675 ** database zDb, where zDb is either "main", or "temp", or the name of an 9676 ** attached database. It is not an error if database zDb is not attached 9677 ** to the database when the session object is created. 9678 */ 9679 SQLITE_API int sqlite3session_create( 9680 sqlite3 *db, /* Database handle */ 9681 const char *zDb, /* Name of db (e.g. "main") */ 9682 sqlite3_session **ppSession /* OUT: New session object */ 9683 ); 9684 9685 /* 9686 ** CAPI3REF: Delete A Session Object 9687 ** DESTRUCTOR: sqlite3_session 9688 ** 9689 ** Delete a session object previously allocated using 9690 ** [sqlite3session_create()]. Once a session object has been deleted, the 9691 ** results of attempting to use pSession with any other session module 9692 ** function are undefined. 9693 ** 9694 ** Session objects must be deleted before the database handle to which they 9695 ** are attached is closed. Refer to the documentation for 9696 ** [sqlite3session_create()] for details. 9697 */ 9698 SQLITE_API void sqlite3session_delete(sqlite3_session *pSession); 9699 9700 9701 /* 9702 ** CAPI3REF: Enable Or Disable A Session Object 9703 ** METHOD: sqlite3_session 9704 ** 9705 ** Enable or disable the recording of changes by a session object. When 9706 ** enabled, a session object records changes made to the database. When 9707 ** disabled - it does not. A newly created session object is enabled. 9708 ** Refer to the documentation for [sqlite3session_changeset()] for further 9709 ** details regarding how enabling and disabling a session object affects 9710 ** the eventual changesets. 9711 ** 9712 ** Passing zero to this function disables the session. Passing a value 9713 ** greater than zero enables it. Passing a value less than zero is a 9714 ** no-op, and may be used to query the current state of the session. 9715 ** 9716 ** The return value indicates the final state of the session object: 0 if 9717 ** the session is disabled, or 1 if it is enabled. 9718 */ 9719 SQLITE_API int sqlite3session_enable(sqlite3_session *pSession, int bEnable); 9720 9721 /* 9722 ** CAPI3REF: Set Or Clear the Indirect Change Flag 9723 ** METHOD: sqlite3_session 9724 ** 9725 ** Each change recorded by a session object is marked as either direct or 9726 ** indirect. A change is marked as indirect if either: 9727 ** 9728 ** <ul> 9729 ** <li> The session object "indirect" flag is set when the change is 9730 ** made, or 9731 ** <li> The change is made by an SQL trigger or foreign key action 9732 ** instead of directly as a result of a users SQL statement. 9733 ** </ul> 9734 ** 9735 ** If a single row is affected by more than one operation within a session, 9736 ** then the change is considered indirect if all operations meet the criteria 9737 ** for an indirect change above, or direct otherwise. 9738 ** 9739 ** This function is used to set, clear or query the session object indirect 9740 ** flag. If the second argument passed to this function is zero, then the 9741 ** indirect flag is cleared. If it is greater than zero, the indirect flag 9742 ** is set. Passing a value less than zero does not modify the current value 9743 ** of the indirect flag, and may be used to query the current state of the 9744 ** indirect flag for the specified session object. 9745 ** 9746 ** The return value indicates the final state of the indirect flag: 0 if 9747 ** it is clear, or 1 if it is set. 9748 */ 9749 SQLITE_API int sqlite3session_indirect(sqlite3_session *pSession, int bIndirect); 9750 9751 /* 9752 ** CAPI3REF: Attach A Table To A Session Object 9753 ** METHOD: sqlite3_session 9754 ** 9755 ** If argument zTab is not NULL, then it is the name of a table to attach 9756 ** to the session object passed as the first argument. All subsequent changes 9757 ** made to the table while the session object is enabled will be recorded. See 9758 ** documentation for [sqlite3session_changeset()] for further details. 9759 ** 9760 ** Or, if argument zTab is NULL, then changes are recorded for all tables 9761 ** in the database. If additional tables are added to the database (by 9762 ** executing "CREATE TABLE" statements) after this call is made, changes for 9763 ** the new tables are also recorded. 9764 ** 9765 ** Changes can only be recorded for tables that have a PRIMARY KEY explicitly 9766 ** defined as part of their CREATE TABLE statement. It does not matter if the 9767 ** PRIMARY KEY is an "INTEGER PRIMARY KEY" (rowid alias) or not. The PRIMARY 9768 ** KEY may consist of a single column, or may be a composite key. 9769 ** 9770 ** It is not an error if the named table does not exist in the database. Nor 9771 ** is it an error if the named table does not have a PRIMARY KEY. However, 9772 ** no changes will be recorded in either of these scenarios. 9773 ** 9774 ** Changes are not recorded for individual rows that have NULL values stored 9775 ** in one or more of their PRIMARY KEY columns. 9776 ** 9777 ** SQLITE_OK is returned if the call completes without error. Or, if an error 9778 ** occurs, an SQLite error code (e.g. SQLITE_NOMEM) is returned. 9779 ** 9780 ** <h3>Special sqlite_stat1 Handling</h3> 9781 ** 9782 ** As of SQLite version 3.22.0, the "sqlite_stat1" table is an exception to 9783 ** some of the rules above. In SQLite, the schema of sqlite_stat1 is: 9784 ** <pre> 9785 ** CREATE TABLE sqlite_stat1(tbl,idx,stat) 9786 ** </pre> 9787 ** 9788 ** Even though sqlite_stat1 does not have a PRIMARY KEY, changes are 9789 ** recorded for it as if the PRIMARY KEY is (tbl,idx). Additionally, changes 9790 ** are recorded for rows for which (idx IS NULL) is true. However, for such 9791 ** rows a zero-length blob (SQL value X'') is stored in the changeset or 9792 ** patchset instead of a NULL value. This allows such changesets to be 9793 ** manipulated by legacy implementations of sqlite3changeset_invert(), 9794 ** concat() and similar. 9795 ** 9796 ** The sqlite3changeset_apply() function automatically converts the 9797 ** zero-length blob back to a NULL value when updating the sqlite_stat1 9798 ** table. However, if the application calls sqlite3changeset_new(), 9799 ** sqlite3changeset_old() or sqlite3changeset_conflict on a changeset 9800 ** iterator directly (including on a changeset iterator passed to a 9801 ** conflict-handler callback) then the X'' value is returned. The application 9802 ** must translate X'' to NULL itself if required. 9803 ** 9804 ** Legacy (older than 3.22.0) versions of the sessions module cannot capture 9805 ** changes made to the sqlite_stat1 table. Legacy versions of the 9806 ** sqlite3changeset_apply() function silently ignore any modifications to the 9807 ** sqlite_stat1 table that are part of a changeset or patchset. 9808 */ 9809 SQLITE_API int sqlite3session_attach( 9810 sqlite3_session *pSession, /* Session object */ 9811 const char *zTab /* Table name */ 9812 ); 9813 9814 /* 9815 ** CAPI3REF: Set a table filter on a Session Object. 9816 ** METHOD: sqlite3_session 9817 ** 9818 ** The second argument (xFilter) is the "filter callback". For changes to rows 9819 ** in tables that are not attached to the Session object, the filter is called 9820 ** to determine whether changes to the table's rows should be tracked or not. 9821 ** If xFilter returns 0, changes is not tracked. Note that once a table is 9822 ** attached, xFilter will not be called again. 9823 */ 9824 SQLITE_API void sqlite3session_table_filter( 9825 sqlite3_session *pSession, /* Session object */ 9826 int(*xFilter)( 9827 void *pCtx, /* Copy of third arg to _filter_table() */ 9828 const char *zTab /* Table name */ 9829 ), 9830 void *pCtx /* First argument passed to xFilter */ 9831 ); 9832 9833 /* 9834 ** CAPI3REF: Generate A Changeset From A Session Object 9835 ** METHOD: sqlite3_session 9836 ** 9837 ** Obtain a changeset containing changes to the tables attached to the 9838 ** session object passed as the first argument. If successful, 9839 ** set *ppChangeset to point to a buffer containing the changeset 9840 ** and *pnChangeset to the size of the changeset in bytes before returning 9841 ** SQLITE_OK. If an error occurs, set both *ppChangeset and *pnChangeset to 9842 ** zero and return an SQLite error code. 9843 ** 9844 ** A changeset consists of zero or more INSERT, UPDATE and/or DELETE changes, 9845 ** each representing a change to a single row of an attached table. An INSERT 9846 ** change contains the values of each field of a new database row. A DELETE 9847 ** contains the original values of each field of a deleted database row. An 9848 ** UPDATE change contains the original values of each field of an updated 9849 ** database row along with the updated values for each updated non-primary-key 9850 ** column. It is not possible for an UPDATE change to represent a change that 9851 ** modifies the values of primary key columns. If such a change is made, it 9852 ** is represented in a changeset as a DELETE followed by an INSERT. 9853 ** 9854 ** Changes are not recorded for rows that have NULL values stored in one or 9855 ** more of their PRIMARY KEY columns. If such a row is inserted or deleted, 9856 ** no corresponding change is present in the changesets returned by this 9857 ** function. If an existing row with one or more NULL values stored in 9858 ** PRIMARY KEY columns is updated so that all PRIMARY KEY columns are non-NULL, 9859 ** only an INSERT is appears in the changeset. Similarly, if an existing row 9860 ** with non-NULL PRIMARY KEY values is updated so that one or more of its 9861 ** PRIMARY KEY columns are set to NULL, the resulting changeset contains a 9862 ** DELETE change only. 9863 ** 9864 ** The contents of a changeset may be traversed using an iterator created 9865 ** using the [sqlite3changeset_start()] API. A changeset may be applied to 9866 ** a database with a compatible schema using the [sqlite3changeset_apply()] 9867 ** API. 9868 ** 9869 ** Within a changeset generated by this function, all changes related to a 9870 ** single table are grouped together. In other words, when iterating through 9871 ** a changeset or when applying a changeset to a database, all changes related 9872 ** to a single table are processed before moving on to the next table. Tables 9873 ** are sorted in the same order in which they were attached (or auto-attached) 9874 ** to the sqlite3_session object. The order in which the changes related to 9875 ** a single table are stored is undefined. 9876 ** 9877 ** Following a successful call to this function, it is the responsibility of 9878 ** the caller to eventually free the buffer that *ppChangeset points to using 9879 ** [sqlite3_free()]. 9880 ** 9881 ** <h3>Changeset Generation</h3> 9882 ** 9883 ** Once a table has been attached to a session object, the session object 9884 ** records the primary key values of all new rows inserted into the table. 9885 ** It also records the original primary key and other column values of any 9886 ** deleted or updated rows. For each unique primary key value, data is only 9887 ** recorded once - the first time a row with said primary key is inserted, 9888 ** updated or deleted in the lifetime of the session. 9889 ** 9890 ** There is one exception to the previous paragraph: when a row is inserted, 9891 ** updated or deleted, if one or more of its primary key columns contain a 9892 ** NULL value, no record of the change is made. 9893 ** 9894 ** The session object therefore accumulates two types of records - those 9895 ** that consist of primary key values only (created when the user inserts 9896 ** a new record) and those that consist of the primary key values and the 9897 ** original values of other table columns (created when the users deletes 9898 ** or updates a record). 9899 ** 9900 ** When this function is called, the requested changeset is created using 9901 ** both the accumulated records and the current contents of the database 9902 ** file. Specifically: 9903 ** 9904 ** <ul> 9905 ** <li> For each record generated by an insert, the database is queried 9906 ** for a row with a matching primary key. If one is found, an INSERT 9907 ** change is added to the changeset. If no such row is found, no change 9908 ** is added to the changeset. 9909 ** 9910 ** <li> For each record generated by an update or delete, the database is 9911 ** queried for a row with a matching primary key. If such a row is 9912 ** found and one or more of the non-primary key fields have been 9913 ** modified from their original values, an UPDATE change is added to 9914 ** the changeset. Or, if no such row is found in the table, a DELETE 9915 ** change is added to the changeset. If there is a row with a matching 9916 ** primary key in the database, but all fields contain their original 9917 ** values, no change is added to the changeset. 9918 ** </ul> 9919 ** 9920 ** This means, amongst other things, that if a row is inserted and then later 9921 ** deleted while a session object is active, neither the insert nor the delete 9922 ** will be present in the changeset. Or if a row is deleted and then later a 9923 ** row with the same primary key values inserted while a session object is 9924 ** active, the resulting changeset will contain an UPDATE change instead of 9925 ** a DELETE and an INSERT. 9926 ** 9927 ** When a session object is disabled (see the [sqlite3session_enable()] API), 9928 ** it does not accumulate records when rows are inserted, updated or deleted. 9929 ** This may appear to have some counter-intuitive effects if a single row 9930 ** is written to more than once during a session. For example, if a row 9931 ** is inserted while a session object is enabled, then later deleted while 9932 ** the same session object is disabled, no INSERT record will appear in the 9933 ** changeset, even though the delete took place while the session was disabled. 9934 ** Or, if one field of a row is updated while a session is disabled, and 9935 ** another field of the same row is updated while the session is enabled, the 9936 ** resulting changeset will contain an UPDATE change that updates both fields. 9937 */ 9938 SQLITE_API int sqlite3session_changeset( 9939 sqlite3_session *pSession, /* Session object */ 9940 int *pnChangeset, /* OUT: Size of buffer at *ppChangeset */ 9941 void **ppChangeset /* OUT: Buffer containing changeset */ 9942 ); 9943 9944 /* 9945 ** CAPI3REF: Load The Difference Between Tables Into A Session 9946 ** METHOD: sqlite3_session 9947 ** 9948 ** If it is not already attached to the session object passed as the first 9949 ** argument, this function attaches table zTbl in the same manner as the 9950 ** [sqlite3session_attach()] function. If zTbl does not exist, or if it 9951 ** does not have a primary key, this function is a no-op (but does not return 9952 ** an error). 9953 ** 9954 ** Argument zFromDb must be the name of a database ("main", "temp" etc.) 9955 ** attached to the same database handle as the session object that contains 9956 ** a table compatible with the table attached to the session by this function. 9957 ** A table is considered compatible if it: 9958 ** 9959 ** <ul> 9960 ** <li> Has the same name, 9961 ** <li> Has the same set of columns declared in the same order, and 9962 ** <li> Has the same PRIMARY KEY definition. 9963 ** </ul> 9964 ** 9965 ** If the tables are not compatible, SQLITE_SCHEMA is returned. If the tables 9966 ** are compatible but do not have any PRIMARY KEY columns, it is not an error 9967 ** but no changes are added to the session object. As with other session 9968 ** APIs, tables without PRIMARY KEYs are simply ignored. 9969 ** 9970 ** This function adds a set of changes to the session object that could be 9971 ** used to update the table in database zFrom (call this the "from-table") 9972 ** so that its content is the same as the table attached to the session 9973 ** object (call this the "to-table"). Specifically: 9974 ** 9975 ** <ul> 9976 ** <li> For each row (primary key) that exists in the to-table but not in 9977 ** the from-table, an INSERT record is added to the session object. 9978 ** 9979 ** <li> For each row (primary key) that exists in the to-table but not in 9980 ** the from-table, a DELETE record is added to the session object. 9981 ** 9982 ** <li> For each row (primary key) that exists in both tables, but features 9983 ** different non-PK values in each, an UPDATE record is added to the 9984 ** session. 9985 ** </ul> 9986 ** 9987 ** To clarify, if this function is called and then a changeset constructed 9988 ** using [sqlite3session_changeset()], then after applying that changeset to 9989 ** database zFrom the contents of the two compatible tables would be 9990 ** identical. 9991 ** 9992 ** It an error if database zFrom does not exist or does not contain the 9993 ** required compatible table. 9994 ** 9995 ** If the operation successful, SQLITE_OK is returned. Otherwise, an SQLite 9996 ** error code. In this case, if argument pzErrMsg is not NULL, *pzErrMsg 9997 ** may be set to point to a buffer containing an English language error 9998 ** message. It is the responsibility of the caller to free this buffer using 9999 ** sqlite3_free(). 10000 */ 10001 SQLITE_API int sqlite3session_diff( 10002 sqlite3_session *pSession, 10003 const char *zFromDb, 10004 const char *zTbl, 10005 char **pzErrMsg 10006 ); 10007 10008 10009 /* 10010 ** CAPI3REF: Generate A Patchset From A Session Object 10011 ** METHOD: sqlite3_session 10012 ** 10013 ** The differences between a patchset and a changeset are that: 10014 ** 10015 ** <ul> 10016 ** <li> DELETE records consist of the primary key fields only. The 10017 ** original values of other fields are omitted. 10018 ** <li> The original values of any modified fields are omitted from 10019 ** UPDATE records. 10020 ** </ul> 10021 ** 10022 ** A patchset blob may be used with up to date versions of all 10023 ** sqlite3changeset_xxx API functions except for sqlite3changeset_invert(), 10024 ** which returns SQLITE_CORRUPT if it is passed a patchset. Similarly, 10025 ** attempting to use a patchset blob with old versions of the 10026 ** sqlite3changeset_xxx APIs also provokes an SQLITE_CORRUPT error. 10027 ** 10028 ** Because the non-primary key "old.*" fields are omitted, no 10029 ** SQLITE_CHANGESET_DATA conflicts can be detected or reported if a patchset 10030 ** is passed to the sqlite3changeset_apply() API. Other conflict types work 10031 ** in the same way as for changesets. 10032 ** 10033 ** Changes within a patchset are ordered in the same way as for changesets 10034 ** generated by the sqlite3session_changeset() function (i.e. all changes for 10035 ** a single table are grouped together, tables appear in the order in which 10036 ** they were attached to the session object). 10037 */ 10038 SQLITE_API int sqlite3session_patchset( 10039 sqlite3_session *pSession, /* Session object */ 10040 int *pnPatchset, /* OUT: Size of buffer at *ppPatchset */ 10041 void **ppPatchset /* OUT: Buffer containing patchset */ 10042 ); 10043 10044 /* 10045 ** CAPI3REF: Test if a changeset has recorded any changes. 10046 ** 10047 ** Return non-zero if no changes to attached tables have been recorded by 10048 ** the session object passed as the first argument. Otherwise, if one or 10049 ** more changes have been recorded, return zero. 10050 ** 10051 ** Even if this function returns zero, it is possible that calling 10052 ** [sqlite3session_changeset()] on the session handle may still return a 10053 ** changeset that contains no changes. This can happen when a row in 10054 ** an attached table is modified and then later on the original values 10055 ** are restored. However, if this function returns non-zero, then it is 10056 ** guaranteed that a call to sqlite3session_changeset() will return a 10057 ** changeset containing zero changes. 10058 */ 10059 SQLITE_API int sqlite3session_isempty(sqlite3_session *pSession); 10060 10061 /* 10062 ** CAPI3REF: Create An Iterator To Traverse A Changeset 10063 ** CONSTRUCTOR: sqlite3_changeset_iter 10064 ** 10065 ** Create an iterator used to iterate through the contents of a changeset. 10066 ** If successful, *pp is set to point to the iterator handle and SQLITE_OK 10067 ** is returned. Otherwise, if an error occurs, *pp is set to zero and an 10068 ** SQLite error code is returned. 10069 ** 10070 ** The following functions can be used to advance and query a changeset 10071 ** iterator created by this function: 10072 ** 10073 ** <ul> 10074 ** <li> [sqlite3changeset_next()] 10075 ** <li> [sqlite3changeset_op()] 10076 ** <li> [sqlite3changeset_new()] 10077 ** <li> [sqlite3changeset_old()] 10078 ** </ul> 10079 ** 10080 ** It is the responsibility of the caller to eventually destroy the iterator 10081 ** by passing it to [sqlite3changeset_finalize()]. The buffer containing the 10082 ** changeset (pChangeset) must remain valid until after the iterator is 10083 ** destroyed. 10084 ** 10085 ** Assuming the changeset blob was created by one of the 10086 ** [sqlite3session_changeset()], [sqlite3changeset_concat()] or 10087 ** [sqlite3changeset_invert()] functions, all changes within the changeset 10088 ** that apply to a single table are grouped together. This means that when 10089 ** an application iterates through a changeset using an iterator created by 10090 ** this function, all changes that relate to a single table are visited 10091 ** consecutively. There is no chance that the iterator will visit a change 10092 ** the applies to table X, then one for table Y, and then later on visit 10093 ** another change for table X. 10094 ** 10095 ** The behavior of sqlite3changeset_start_v2() and its streaming equivalent 10096 ** may be modified by passing a combination of 10097 ** [SQLITE_CHANGESETSTART_INVERT | supported flags] as the 4th parameter. 10098 ** 10099 ** Note that the sqlite3changeset_start_v2() API is still <b>experimental</b> 10100 ** and therefore subject to change. 10101 */ 10102 SQLITE_API int sqlite3changeset_start( 10103 sqlite3_changeset_iter **pp, /* OUT: New changeset iterator handle */ 10104 int nChangeset, /* Size of changeset blob in bytes */ 10105 void *pChangeset /* Pointer to blob containing changeset */ 10106 ); 10107 SQLITE_API int sqlite3changeset_start_v2( 10108 sqlite3_changeset_iter **pp, /* OUT: New changeset iterator handle */ 10109 int nChangeset, /* Size of changeset blob in bytes */ 10110 void *pChangeset, /* Pointer to blob containing changeset */ 10111 int flags /* SESSION_CHANGESETSTART_* flags */ 10112 ); 10113 10114 /* 10115 ** CAPI3REF: Flags for sqlite3changeset_start_v2 10116 ** 10117 ** The following flags may passed via the 4th parameter to 10118 ** [sqlite3changeset_start_v2] and [sqlite3changeset_start_v2_strm]: 10119 ** 10120 ** <dt>SQLITE_CHANGESETAPPLY_INVERT <dd> 10121 ** Invert the changeset while iterating through it. This is equivalent to 10122 ** inverting a changeset using sqlite3changeset_invert() before applying it. 10123 ** It is an error to specify this flag with a patchset. 10124 */ 10125 #define SQLITE_CHANGESETSTART_INVERT 0x0002 10126 10127 10128 /* 10129 ** CAPI3REF: Advance A Changeset Iterator 10130 ** METHOD: sqlite3_changeset_iter 10131 ** 10132 ** This function may only be used with iterators created by function 10133 ** [sqlite3changeset_start()]. If it is called on an iterator passed to 10134 ** a conflict-handler callback by [sqlite3changeset_apply()], SQLITE_MISUSE 10135 ** is returned and the call has no effect. 10136 ** 10137 ** Immediately after an iterator is created by sqlite3changeset_start(), it 10138 ** does not point to any change in the changeset. Assuming the changeset 10139 ** is not empty, the first call to this function advances the iterator to 10140 ** point to the first change in the changeset. Each subsequent call advances 10141 ** the iterator to point to the next change in the changeset (if any). If 10142 ** no error occurs and the iterator points to a valid change after a call 10143 ** to sqlite3changeset_next() has advanced it, SQLITE_ROW is returned. 10144 ** Otherwise, if all changes in the changeset have already been visited, 10145 ** SQLITE_DONE is returned. 10146 ** 10147 ** If an error occurs, an SQLite error code is returned. Possible error 10148 ** codes include SQLITE_CORRUPT (if the changeset buffer is corrupt) or 10149 ** SQLITE_NOMEM. 10150 */ 10151 SQLITE_API int sqlite3changeset_next(sqlite3_changeset_iter *pIter); 10152 10153 /* 10154 ** CAPI3REF: Obtain The Current Operation From A Changeset Iterator 10155 ** METHOD: sqlite3_changeset_iter 10156 ** 10157 ** The pIter argument passed to this function may either be an iterator 10158 ** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator 10159 ** created by [sqlite3changeset_start()]. In the latter case, the most recent 10160 ** call to [sqlite3changeset_next()] must have returned [SQLITE_ROW]. If this 10161 ** is not the case, this function returns [SQLITE_MISUSE]. 10162 ** 10163 ** If argument pzTab is not NULL, then *pzTab is set to point to a 10164 ** nul-terminated utf-8 encoded string containing the name of the table 10165 ** affected by the current change. The buffer remains valid until either 10166 ** sqlite3changeset_next() is called on the iterator or until the 10167 ** conflict-handler function returns. If pnCol is not NULL, then *pnCol is 10168 ** set to the number of columns in the table affected by the change. If 10169 ** pbIndirect is not NULL, then *pbIndirect is set to true (1) if the change 10170 ** is an indirect change, or false (0) otherwise. See the documentation for 10171 ** [sqlite3session_indirect()] for a description of direct and indirect 10172 ** changes. Finally, if pOp is not NULL, then *pOp is set to one of 10173 ** [SQLITE_INSERT], [SQLITE_DELETE] or [SQLITE_UPDATE], depending on the 10174 ** type of change that the iterator currently points to. 10175 ** 10176 ** If no error occurs, SQLITE_OK is returned. If an error does occur, an 10177 ** SQLite error code is returned. The values of the output variables may not 10178 ** be trusted in this case. 10179 */ 10180 SQLITE_API int sqlite3changeset_op( 10181 sqlite3_changeset_iter *pIter, /* Iterator object */ 10182 const char **pzTab, /* OUT: Pointer to table name */ 10183 int *pnCol, /* OUT: Number of columns in table */ 10184 int *pOp, /* OUT: SQLITE_INSERT, DELETE or UPDATE */ 10185 int *pbIndirect /* OUT: True for an 'indirect' change */ 10186 ); 10187 10188 /* 10189 ** CAPI3REF: Obtain The Primary Key Definition Of A Table 10190 ** METHOD: sqlite3_changeset_iter 10191 ** 10192 ** For each modified table, a changeset includes the following: 10193 ** 10194 ** <ul> 10195 ** <li> The number of columns in the table, and 10196 ** <li> Which of those columns make up the tables PRIMARY KEY. 10197 ** </ul> 10198 ** 10199 ** This function is used to find which columns comprise the PRIMARY KEY of 10200 ** the table modified by the change that iterator pIter currently points to. 10201 ** If successful, *pabPK is set to point to an array of nCol entries, where 10202 ** nCol is the number of columns in the table. Elements of *pabPK are set to 10203 ** 0x01 if the corresponding column is part of the tables primary key, or 10204 ** 0x00 if it is not. 10205 ** 10206 ** If argument pnCol is not NULL, then *pnCol is set to the number of columns 10207 ** in the table. 10208 ** 10209 ** If this function is called when the iterator does not point to a valid 10210 ** entry, SQLITE_MISUSE is returned and the output variables zeroed. Otherwise, 10211 ** SQLITE_OK is returned and the output variables populated as described 10212 ** above. 10213 */ 10214 SQLITE_API int sqlite3changeset_pk( 10215 sqlite3_changeset_iter *pIter, /* Iterator object */ 10216 unsigned char **pabPK, /* OUT: Array of boolean - true for PK cols */ 10217 int *pnCol /* OUT: Number of entries in output array */ 10218 ); 10219 10220 /* 10221 ** CAPI3REF: Obtain old.* Values From A Changeset Iterator 10222 ** METHOD: sqlite3_changeset_iter 10223 ** 10224 ** The pIter argument passed to this function may either be an iterator 10225 ** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator 10226 ** created by [sqlite3changeset_start()]. In the latter case, the most recent 10227 ** call to [sqlite3changeset_next()] must have returned SQLITE_ROW. 10228 ** Furthermore, it may only be called if the type of change that the iterator 10229 ** currently points to is either [SQLITE_DELETE] or [SQLITE_UPDATE]. Otherwise, 10230 ** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL. 10231 ** 10232 ** Argument iVal must be greater than or equal to 0, and less than the number 10233 ** of columns in the table affected by the current change. Otherwise, 10234 ** [SQLITE_RANGE] is returned and *ppValue is set to NULL. 10235 ** 10236 ** If successful, this function sets *ppValue to point to a protected 10237 ** sqlite3_value object containing the iVal'th value from the vector of 10238 ** original row values stored as part of the UPDATE or DELETE change and 10239 ** returns SQLITE_OK. The name of the function comes from the fact that this 10240 ** is similar to the "old.*" columns available to update or delete triggers. 10241 ** 10242 ** If some other error occurs (e.g. an OOM condition), an SQLite error code 10243 ** is returned and *ppValue is set to NULL. 10244 */ 10245 SQLITE_API int sqlite3changeset_old( 10246 sqlite3_changeset_iter *pIter, /* Changeset iterator */ 10247 int iVal, /* Column number */ 10248 sqlite3_value **ppValue /* OUT: Old value (or NULL pointer) */ 10249 ); 10250 10251 /* 10252 ** CAPI3REF: Obtain new.* Values From A Changeset Iterator 10253 ** METHOD: sqlite3_changeset_iter 10254 ** 10255 ** The pIter argument passed to this function may either be an iterator 10256 ** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator 10257 ** created by [sqlite3changeset_start()]. In the latter case, the most recent 10258 ** call to [sqlite3changeset_next()] must have returned SQLITE_ROW. 10259 ** Furthermore, it may only be called if the type of change that the iterator 10260 ** currently points to is either [SQLITE_UPDATE] or [SQLITE_INSERT]. Otherwise, 10261 ** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL. 10262 ** 10263 ** Argument iVal must be greater than or equal to 0, and less than the number 10264 ** of columns in the table affected by the current change. Otherwise, 10265 ** [SQLITE_RANGE] is returned and *ppValue is set to NULL. 10266 ** 10267 ** If successful, this function sets *ppValue to point to a protected 10268 ** sqlite3_value object containing the iVal'th value from the vector of 10269 ** new row values stored as part of the UPDATE or INSERT change and 10270 ** returns SQLITE_OK. If the change is an UPDATE and does not include 10271 ** a new value for the requested column, *ppValue is set to NULL and 10272 ** SQLITE_OK returned. The name of the function comes from the fact that 10273 ** this is similar to the "new.*" columns available to update or delete 10274 ** triggers. 10275 ** 10276 ** If some other error occurs (e.g. an OOM condition), an SQLite error code 10277 ** is returned and *ppValue is set to NULL. 10278 */ 10279 SQLITE_API int sqlite3changeset_new( 10280 sqlite3_changeset_iter *pIter, /* Changeset iterator */ 10281 int iVal, /* Column number */ 10282 sqlite3_value **ppValue /* OUT: New value (or NULL pointer) */ 10283 ); 10284 10285 /* 10286 ** CAPI3REF: Obtain Conflicting Row Values From A Changeset Iterator 10287 ** METHOD: sqlite3_changeset_iter 10288 ** 10289 ** This function should only be used with iterator objects passed to a 10290 ** conflict-handler callback by [sqlite3changeset_apply()] with either 10291 ** [SQLITE_CHANGESET_DATA] or [SQLITE_CHANGESET_CONFLICT]. If this function 10292 ** is called on any other iterator, [SQLITE_MISUSE] is returned and *ppValue 10293 ** is set to NULL. 10294 ** 10295 ** Argument iVal must be greater than or equal to 0, and less than the number 10296 ** of columns in the table affected by the current change. Otherwise, 10297 ** [SQLITE_RANGE] is returned and *ppValue is set to NULL. 10298 ** 10299 ** If successful, this function sets *ppValue to point to a protected 10300 ** sqlite3_value object containing the iVal'th value from the 10301 ** "conflicting row" associated with the current conflict-handler callback 10302 ** and returns SQLITE_OK. 10303 ** 10304 ** If some other error occurs (e.g. an OOM condition), an SQLite error code 10305 ** is returned and *ppValue is set to NULL. 10306 */ 10307 SQLITE_API int sqlite3changeset_conflict( 10308 sqlite3_changeset_iter *pIter, /* Changeset iterator */ 10309 int iVal, /* Column number */ 10310 sqlite3_value **ppValue /* OUT: Value from conflicting row */ 10311 ); 10312 10313 /* 10314 ** CAPI3REF: Determine The Number Of Foreign Key Constraint Violations 10315 ** METHOD: sqlite3_changeset_iter 10316 ** 10317 ** This function may only be called with an iterator passed to an 10318 ** SQLITE_CHANGESET_FOREIGN_KEY conflict handler callback. In this case 10319 ** it sets the output variable to the total number of known foreign key 10320 ** violations in the destination database and returns SQLITE_OK. 10321 ** 10322 ** In all other cases this function returns SQLITE_MISUSE. 10323 */ 10324 SQLITE_API int sqlite3changeset_fk_conflicts( 10325 sqlite3_changeset_iter *pIter, /* Changeset iterator */ 10326 int *pnOut /* OUT: Number of FK violations */ 10327 ); 10328 10329 10330 /* 10331 ** CAPI3REF: Finalize A Changeset Iterator 10332 ** METHOD: sqlite3_changeset_iter 10333 ** 10334 ** This function is used to finalize an iterator allocated with 10335 ** [sqlite3changeset_start()]. 10336 ** 10337 ** This function should only be called on iterators created using the 10338 ** [sqlite3changeset_start()] function. If an application calls this 10339 ** function with an iterator passed to a conflict-handler by 10340 ** [sqlite3changeset_apply()], [SQLITE_MISUSE] is immediately returned and the 10341 ** call has no effect. 10342 ** 10343 ** If an error was encountered within a call to an sqlite3changeset_xxx() 10344 ** function (for example an [SQLITE_CORRUPT] in [sqlite3changeset_next()] or an 10345 ** [SQLITE_NOMEM] in [sqlite3changeset_new()]) then an error code corresponding 10346 ** to that error is returned by this function. Otherwise, SQLITE_OK is 10347 ** returned. This is to allow the following pattern (pseudo-code): 10348 ** 10349 ** <pre> 10350 ** sqlite3changeset_start(); 10351 ** while( SQLITE_ROW==sqlite3changeset_next() ){ 10352 ** // Do something with change. 10353 ** } 10354 ** rc = sqlite3changeset_finalize(); 10355 ** if( rc!=SQLITE_OK ){ 10356 ** // An error has occurred 10357 ** } 10358 ** </pre> 10359 */ 10360 SQLITE_API int sqlite3changeset_finalize(sqlite3_changeset_iter *pIter); 10361 10362 /* 10363 ** CAPI3REF: Invert A Changeset 10364 ** 10365 ** This function is used to "invert" a changeset object. Applying an inverted 10366 ** changeset to a database reverses the effects of applying the uninverted 10367 ** changeset. Specifically: 10368 ** 10369 ** <ul> 10370 ** <li> Each DELETE change is changed to an INSERT, and 10371 ** <li> Each INSERT change is changed to a DELETE, and 10372 ** <li> For each UPDATE change, the old.* and new.* values are exchanged. 10373 ** </ul> 10374 ** 10375 ** This function does not change the order in which changes appear within 10376 ** the changeset. It merely reverses the sense of each individual change. 10377 ** 10378 ** If successful, a pointer to a buffer containing the inverted changeset 10379 ** is stored in *ppOut, the size of the same buffer is stored in *pnOut, and 10380 ** SQLITE_OK is returned. If an error occurs, both *pnOut and *ppOut are 10381 ** zeroed and an SQLite error code returned. 10382 ** 10383 ** It is the responsibility of the caller to eventually call sqlite3_free() 10384 ** on the *ppOut pointer to free the buffer allocation following a successful 10385 ** call to this function. 10386 ** 10387 ** WARNING/TODO: This function currently assumes that the input is a valid 10388 ** changeset. If it is not, the results are undefined. 10389 */ 10390 SQLITE_API int sqlite3changeset_invert( 10391 int nIn, const void *pIn, /* Input changeset */ 10392 int *pnOut, void **ppOut /* OUT: Inverse of input */ 10393 ); 10394 10395 /* 10396 ** CAPI3REF: Concatenate Two Changeset Objects 10397 ** 10398 ** This function is used to concatenate two changesets, A and B, into a 10399 ** single changeset. The result is a changeset equivalent to applying 10400 ** changeset A followed by changeset B. 10401 ** 10402 ** This function combines the two input changesets using an 10403 ** sqlite3_changegroup object. Calling it produces similar results as the 10404 ** following code fragment: 10405 ** 10406 ** <pre> 10407 ** sqlite3_changegroup *pGrp; 10408 ** rc = sqlite3_changegroup_new(&pGrp); 10409 ** if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nA, pA); 10410 ** if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nB, pB); 10411 ** if( rc==SQLITE_OK ){ 10412 ** rc = sqlite3changegroup_output(pGrp, pnOut, ppOut); 10413 ** }else{ 10414 ** *ppOut = 0; 10415 ** *pnOut = 0; 10416 ** } 10417 ** </pre> 10418 ** 10419 ** Refer to the sqlite3_changegroup documentation below for details. 10420 */ 10421 SQLITE_API int sqlite3changeset_concat( 10422 int nA, /* Number of bytes in buffer pA */ 10423 void *pA, /* Pointer to buffer containing changeset A */ 10424 int nB, /* Number of bytes in buffer pB */ 10425 void *pB, /* Pointer to buffer containing changeset B */ 10426 int *pnOut, /* OUT: Number of bytes in output changeset */ 10427 void **ppOut /* OUT: Buffer containing output changeset */ 10428 ); 10429 10430 10431 /* 10432 ** CAPI3REF: Changegroup Handle 10433 ** 10434 ** A changegroup is an object used to combine two or more 10435 ** [changesets] or [patchsets] 10436 */ 10437 typedef struct sqlite3_changegroup sqlite3_changegroup; 10438 10439 /* 10440 ** CAPI3REF: Create A New Changegroup Object 10441 ** CONSTRUCTOR: sqlite3_changegroup 10442 ** 10443 ** An sqlite3_changegroup object is used to combine two or more changesets 10444 ** (or patchsets) into a single changeset (or patchset). A single changegroup 10445 ** object may combine changesets or patchsets, but not both. The output is 10446 ** always in the same format as the input. 10447 ** 10448 ** If successful, this function returns SQLITE_OK and populates (*pp) with 10449 ** a pointer to a new sqlite3_changegroup object before returning. The caller 10450 ** should eventually free the returned object using a call to 10451 ** sqlite3changegroup_delete(). If an error occurs, an SQLite error code 10452 ** (i.e. SQLITE_NOMEM) is returned and *pp is set to NULL. 10453 ** 10454 ** The usual usage pattern for an sqlite3_changegroup object is as follows: 10455 ** 10456 ** <ul> 10457 ** <li> It is created using a call to sqlite3changegroup_new(). 10458 ** 10459 ** <li> Zero or more changesets (or patchsets) are added to the object 10460 ** by calling sqlite3changegroup_add(). 10461 ** 10462 ** <li> The result of combining all input changesets together is obtained 10463 ** by the application via a call to sqlite3changegroup_output(). 10464 ** 10465 ** <li> The object is deleted using a call to sqlite3changegroup_delete(). 10466 ** </ul> 10467 ** 10468 ** Any number of calls to add() and output() may be made between the calls to 10469 ** new() and delete(), and in any order. 10470 ** 10471 ** As well as the regular sqlite3changegroup_add() and 10472 ** sqlite3changegroup_output() functions, also available are the streaming 10473 ** versions sqlite3changegroup_add_strm() and sqlite3changegroup_output_strm(). 10474 */ 10475 SQLITE_API int sqlite3changegroup_new(sqlite3_changegroup **pp); 10476 10477 /* 10478 ** CAPI3REF: Add A Changeset To A Changegroup 10479 ** METHOD: sqlite3_changegroup 10480 ** 10481 ** Add all changes within the changeset (or patchset) in buffer pData (size 10482 ** nData bytes) to the changegroup. 10483 ** 10484 ** If the buffer contains a patchset, then all prior calls to this function 10485 ** on the same changegroup object must also have specified patchsets. Or, if 10486 ** the buffer contains a changeset, so must have the earlier calls to this 10487 ** function. Otherwise, SQLITE_ERROR is returned and no changes are added 10488 ** to the changegroup. 10489 ** 10490 ** Rows within the changeset and changegroup are identified by the values in 10491 ** their PRIMARY KEY columns. A change in the changeset is considered to 10492 ** apply to the same row as a change already present in the changegroup if 10493 ** the two rows have the same primary key. 10494 ** 10495 ** Changes to rows that do not already appear in the changegroup are 10496 ** simply copied into it. Or, if both the new changeset and the changegroup 10497 ** contain changes that apply to a single row, the final contents of the 10498 ** changegroup depends on the type of each change, as follows: 10499 ** 10500 ** <table border=1 style="margin-left:8ex;margin-right:8ex"> 10501 ** <tr><th style="white-space:pre">Existing Change </th> 10502 ** <th style="white-space:pre">New Change </th> 10503 ** <th>Output Change 10504 ** <tr><td>INSERT <td>INSERT <td> 10505 ** The new change is ignored. This case does not occur if the new 10506 ** changeset was recorded immediately after the changesets already 10507 ** added to the changegroup. 10508 ** <tr><td>INSERT <td>UPDATE <td> 10509 ** The INSERT change remains in the changegroup. The values in the 10510 ** INSERT change are modified as if the row was inserted by the 10511 ** existing change and then updated according to the new change. 10512 ** <tr><td>INSERT <td>DELETE <td> 10513 ** The existing INSERT is removed from the changegroup. The DELETE is 10514 ** not added. 10515 ** <tr><td>UPDATE <td>INSERT <td> 10516 ** The new change is ignored. This case does not occur if the new 10517 ** changeset was recorded immediately after the changesets already 10518 ** added to the changegroup. 10519 ** <tr><td>UPDATE <td>UPDATE <td> 10520 ** The existing UPDATE remains within the changegroup. It is amended 10521 ** so that the accompanying values are as if the row was updated once 10522 ** by the existing change and then again by the new change. 10523 ** <tr><td>UPDATE <td>DELETE <td> 10524 ** The existing UPDATE is replaced by the new DELETE within the 10525 ** changegroup. 10526 ** <tr><td>DELETE <td>INSERT <td> 10527 ** If one or more of the column values in the row inserted by the 10528 ** new change differ from those in the row deleted by the existing 10529 ** change, the existing DELETE is replaced by an UPDATE within the 10530 ** changegroup. Otherwise, if the inserted row is exactly the same 10531 ** as the deleted row, the existing DELETE is simply discarded. 10532 ** <tr><td>DELETE <td>UPDATE <td> 10533 ** The new change is ignored. This case does not occur if the new 10534 ** changeset was recorded immediately after the changesets already 10535 ** added to the changegroup. 10536 ** <tr><td>DELETE <td>DELETE <td> 10537 ** The new change is ignored. This case does not occur if the new 10538 ** changeset was recorded immediately after the changesets already 10539 ** added to the changegroup. 10540 ** </table> 10541 ** 10542 ** If the new changeset contains changes to a table that is already present 10543 ** in the changegroup, then the number of columns and the position of the 10544 ** primary key columns for the table must be consistent. If this is not the 10545 ** case, this function fails with SQLITE_SCHEMA. If the input changeset 10546 ** appears to be corrupt and the corruption is detected, SQLITE_CORRUPT is 10547 ** returned. Or, if an out-of-memory condition occurs during processing, this 10548 ** function returns SQLITE_NOMEM. In all cases, if an error occurs the 10549 ** final contents of the changegroup is undefined. 10550 ** 10551 ** If no error occurs, SQLITE_OK is returned. 10552 */ 10553 SQLITE_API int sqlite3changegroup_add(sqlite3_changegroup*, int nData, void *pData); 10554 10555 /* 10556 ** CAPI3REF: Obtain A Composite Changeset From A Changegroup 10557 ** METHOD: sqlite3_changegroup 10558 ** 10559 ** Obtain a buffer containing a changeset (or patchset) representing the 10560 ** current contents of the changegroup. If the inputs to the changegroup 10561 ** were themselves changesets, the output is a changeset. Or, if the 10562 ** inputs were patchsets, the output is also a patchset. 10563 ** 10564 ** As with the output of the sqlite3session_changeset() and 10565 ** sqlite3session_patchset() functions, all changes related to a single 10566 ** table are grouped together in the output of this function. Tables appear 10567 ** in the same order as for the very first changeset added to the changegroup. 10568 ** If the second or subsequent changesets added to the changegroup contain 10569 ** changes for tables that do not appear in the first changeset, they are 10570 ** appended onto the end of the output changeset, again in the order in 10571 ** which they are first encountered. 10572 ** 10573 ** If an error occurs, an SQLite error code is returned and the output 10574 ** variables (*pnData) and (*ppData) are set to 0. Otherwise, SQLITE_OK 10575 ** is returned and the output variables are set to the size of and a 10576 ** pointer to the output buffer, respectively. In this case it is the 10577 ** responsibility of the caller to eventually free the buffer using a 10578 ** call to sqlite3_free(). 10579 */ 10580 SQLITE_API int sqlite3changegroup_output( 10581 sqlite3_changegroup*, 10582 int *pnData, /* OUT: Size of output buffer in bytes */ 10583 void **ppData /* OUT: Pointer to output buffer */ 10584 ); 10585 10586 /* 10587 ** CAPI3REF: Delete A Changegroup Object 10588 ** DESTRUCTOR: sqlite3_changegroup 10589 */ 10590 SQLITE_API void sqlite3changegroup_delete(sqlite3_changegroup*); 10591 10592 /* 10593 ** CAPI3REF: Apply A Changeset To A Database 10594 ** 10595 ** Apply a changeset or patchset to a database. These functions attempt to 10596 ** update the "main" database attached to handle db with the changes found in 10597 ** the changeset passed via the second and third arguments. 10598 ** 10599 ** The fourth argument (xFilter) passed to these functions is the "filter 10600 ** callback". If it is not NULL, then for each table affected by at least one 10601 ** change in the changeset, the filter callback is invoked with 10602 ** the table name as the second argument, and a copy of the context pointer 10603 ** passed as the sixth argument as the first. If the "filter callback" 10604 ** returns zero, then no attempt is made to apply any changes to the table. 10605 ** Otherwise, if the return value is non-zero or the xFilter argument to 10606 ** is NULL, all changes related to the table are attempted. 10607 ** 10608 ** For each table that is not excluded by the filter callback, this function 10609 ** tests that the target database contains a compatible table. A table is 10610 ** considered compatible if all of the following are true: 10611 ** 10612 ** <ul> 10613 ** <li> The table has the same name as the name recorded in the 10614 ** changeset, and 10615 ** <li> The table has at least as many columns as recorded in the 10616 ** changeset, and 10617 ** <li> The table has primary key columns in the same position as 10618 ** recorded in the changeset. 10619 ** </ul> 10620 ** 10621 ** If there is no compatible table, it is not an error, but none of the 10622 ** changes associated with the table are applied. A warning message is issued 10623 ** via the sqlite3_log() mechanism with the error code SQLITE_SCHEMA. At most 10624 ** one such warning is issued for each table in the changeset. 10625 ** 10626 ** For each change for which there is a compatible table, an attempt is made 10627 ** to modify the table contents according to the UPDATE, INSERT or DELETE 10628 ** change. If a change cannot be applied cleanly, the conflict handler 10629 ** function passed as the fifth argument to sqlite3changeset_apply() may be 10630 ** invoked. A description of exactly when the conflict handler is invoked for 10631 ** each type of change is below. 10632 ** 10633 ** Unlike the xFilter argument, xConflict may not be passed NULL. The results 10634 ** of passing anything other than a valid function pointer as the xConflict 10635 ** argument are undefined. 10636 ** 10637 ** Each time the conflict handler function is invoked, it must return one 10638 ** of [SQLITE_CHANGESET_OMIT], [SQLITE_CHANGESET_ABORT] or 10639 ** [SQLITE_CHANGESET_REPLACE]. SQLITE_CHANGESET_REPLACE may only be returned 10640 ** if the second argument passed to the conflict handler is either 10641 ** SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If the conflict-handler 10642 ** returns an illegal value, any changes already made are rolled back and 10643 ** the call to sqlite3changeset_apply() returns SQLITE_MISUSE. Different 10644 ** actions are taken by sqlite3changeset_apply() depending on the value 10645 ** returned by each invocation of the conflict-handler function. Refer to 10646 ** the documentation for the three 10647 ** [SQLITE_CHANGESET_OMIT|available return values] for details. 10648 ** 10649 ** <dl> 10650 ** <dt>DELETE Changes<dd> 10651 ** For each DELETE change, the function checks if the target database 10652 ** contains a row with the same primary key value (or values) as the 10653 ** original row values stored in the changeset. If it does, and the values 10654 ** stored in all non-primary key columns also match the values stored in 10655 ** the changeset the row is deleted from the target database. 10656 ** 10657 ** If a row with matching primary key values is found, but one or more of 10658 ** the non-primary key fields contains a value different from the original 10659 ** row value stored in the changeset, the conflict-handler function is 10660 ** invoked with [SQLITE_CHANGESET_DATA] as the second argument. If the 10661 ** database table has more columns than are recorded in the changeset, 10662 ** only the values of those non-primary key fields are compared against 10663 ** the current database contents - any trailing database table columns 10664 ** are ignored. 10665 ** 10666 ** If no row with matching primary key values is found in the database, 10667 ** the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND] 10668 ** passed as the second argument. 10669 ** 10670 ** If the DELETE operation is attempted, but SQLite returns SQLITE_CONSTRAINT 10671 ** (which can only happen if a foreign key constraint is violated), the 10672 ** conflict-handler function is invoked with [SQLITE_CHANGESET_CONSTRAINT] 10673 ** passed as the second argument. This includes the case where the DELETE 10674 ** operation is attempted because an earlier call to the conflict handler 10675 ** function returned [SQLITE_CHANGESET_REPLACE]. 10676 ** 10677 ** <dt>INSERT Changes<dd> 10678 ** For each INSERT change, an attempt is made to insert the new row into 10679 ** the database. If the changeset row contains fewer fields than the 10680 ** database table, the trailing fields are populated with their default 10681 ** values. 10682 ** 10683 ** If the attempt to insert the row fails because the database already 10684 ** contains a row with the same primary key values, the conflict handler 10685 ** function is invoked with the second argument set to 10686 ** [SQLITE_CHANGESET_CONFLICT]. 10687 ** 10688 ** If the attempt to insert the row fails because of some other constraint 10689 ** violation (e.g. NOT NULL or UNIQUE), the conflict handler function is 10690 ** invoked with the second argument set to [SQLITE_CHANGESET_CONSTRAINT]. 10691 ** This includes the case where the INSERT operation is re-attempted because 10692 ** an earlier call to the conflict handler function returned 10693 ** [SQLITE_CHANGESET_REPLACE]. 10694 ** 10695 ** <dt>UPDATE Changes<dd> 10696 ** For each UPDATE change, the function checks if the target database 10697 ** contains a row with the same primary key value (or values) as the 10698 ** original row values stored in the changeset. If it does, and the values 10699 ** stored in all modified non-primary key columns also match the values 10700 ** stored in the changeset the row is updated within the target database. 10701 ** 10702 ** If a row with matching primary key values is found, but one or more of 10703 ** the modified non-primary key fields contains a value different from an 10704 ** original row value stored in the changeset, the conflict-handler function 10705 ** is invoked with [SQLITE_CHANGESET_DATA] as the second argument. Since 10706 ** UPDATE changes only contain values for non-primary key fields that are 10707 ** to be modified, only those fields need to match the original values to 10708 ** avoid the SQLITE_CHANGESET_DATA conflict-handler callback. 10709 ** 10710 ** If no row with matching primary key values is found in the database, 10711 ** the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND] 10712 ** passed as the second argument. 10713 ** 10714 ** If the UPDATE operation is attempted, but SQLite returns 10715 ** SQLITE_CONSTRAINT, the conflict-handler function is invoked with 10716 ** [SQLITE_CHANGESET_CONSTRAINT] passed as the second argument. 10717 ** This includes the case where the UPDATE operation is attempted after 10718 ** an earlier call to the conflict handler function returned 10719 ** [SQLITE_CHANGESET_REPLACE]. 10720 ** </dl> 10721 ** 10722 ** It is safe to execute SQL statements, including those that write to the 10723 ** table that the callback related to, from within the xConflict callback. 10724 ** This can be used to further customize the applications conflict 10725 ** resolution strategy. 10726 ** 10727 ** All changes made by these functions are enclosed in a savepoint transaction. 10728 ** If any other error (aside from a constraint failure when attempting to 10729 ** write to the target database) occurs, then the savepoint transaction is 10730 ** rolled back, restoring the target database to its original state, and an 10731 ** SQLite error code returned. 10732 ** 10733 ** If the output parameters (ppRebase) and (pnRebase) are non-NULL and 10734 ** the input is a changeset (not a patchset), then sqlite3changeset_apply_v2() 10735 ** may set (*ppRebase) to point to a "rebase" that may be used with the 10736 ** sqlite3_rebaser APIs buffer before returning. In this case (*pnRebase) 10737 ** is set to the size of the buffer in bytes. It is the responsibility of the 10738 ** caller to eventually free any such buffer using sqlite3_free(). The buffer 10739 ** is only allocated and populated if one or more conflicts were encountered 10740 ** while applying the patchset. See comments surrounding the sqlite3_rebaser 10741 ** APIs for further details. 10742 ** 10743 ** The behavior of sqlite3changeset_apply_v2() and its streaming equivalent 10744 ** may be modified by passing a combination of 10745 ** [SQLITE_CHANGESETAPPLY_NOSAVEPOINT | supported flags] as the 9th parameter. 10746 ** 10747 ** Note that the sqlite3changeset_apply_v2() API is still <b>experimental</b> 10748 ** and therefore subject to change. 10749 */ 10750 SQLITE_API int sqlite3changeset_apply( 10751 sqlite3 *db, /* Apply change to "main" db of this handle */ 10752 int nChangeset, /* Size of changeset in bytes */ 10753 void *pChangeset, /* Changeset blob */ 10754 int(*xFilter)( 10755 void *pCtx, /* Copy of sixth arg to _apply() */ 10756 const char *zTab /* Table name */ 10757 ), 10758 int(*xConflict)( 10759 void *pCtx, /* Copy of sixth arg to _apply() */ 10760 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */ 10761 sqlite3_changeset_iter *p /* Handle describing change and conflict */ 10762 ), 10763 void *pCtx /* First argument passed to xConflict */ 10764 ); 10765 SQLITE_API int sqlite3changeset_apply_v2( 10766 sqlite3 *db, /* Apply change to "main" db of this handle */ 10767 int nChangeset, /* Size of changeset in bytes */ 10768 void *pChangeset, /* Changeset blob */ 10769 int(*xFilter)( 10770 void *pCtx, /* Copy of sixth arg to _apply() */ 10771 const char *zTab /* Table name */ 10772 ), 10773 int(*xConflict)( 10774 void *pCtx, /* Copy of sixth arg to _apply() */ 10775 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */ 10776 sqlite3_changeset_iter *p /* Handle describing change and conflict */ 10777 ), 10778 void *pCtx, /* First argument passed to xConflict */ 10779 void **ppRebase, int *pnRebase, /* OUT: Rebase data */ 10780 int flags /* SESSION_CHANGESETAPPLY_* flags */ 10781 ); 10782 10783 /* 10784 ** CAPI3REF: Flags for sqlite3changeset_apply_v2 10785 ** 10786 ** The following flags may passed via the 9th parameter to 10787 ** [sqlite3changeset_apply_v2] and [sqlite3changeset_apply_v2_strm]: 10788 ** 10789 ** <dl> 10790 ** <dt>SQLITE_CHANGESETAPPLY_NOSAVEPOINT <dd> 10791 ** Usually, the sessions module encloses all operations performed by 10792 ** a single call to apply_v2() or apply_v2_strm() in a [SAVEPOINT]. The 10793 ** SAVEPOINT is committed if the changeset or patchset is successfully 10794 ** applied, or rolled back if an error occurs. Specifying this flag 10795 ** causes the sessions module to omit this savepoint. In this case, if the 10796 ** caller has an open transaction or savepoint when apply_v2() is called, 10797 ** it may revert the partially applied changeset by rolling it back. 10798 ** 10799 ** <dt>SQLITE_CHANGESETAPPLY_INVERT <dd> 10800 ** Invert the changeset before applying it. This is equivalent to inverting 10801 ** a changeset using sqlite3changeset_invert() before applying it. It is 10802 ** an error to specify this flag with a patchset. 10803 */ 10804 #define SQLITE_CHANGESETAPPLY_NOSAVEPOINT 0x0001 10805 #define SQLITE_CHANGESETAPPLY_INVERT 0x0002 10806 10807 /* 10808 ** CAPI3REF: Constants Passed To The Conflict Handler 10809 ** 10810 ** Values that may be passed as the second argument to a conflict-handler. 10811 ** 10812 ** <dl> 10813 ** <dt>SQLITE_CHANGESET_DATA<dd> 10814 ** The conflict handler is invoked with CHANGESET_DATA as the second argument 10815 ** when processing a DELETE or UPDATE change if a row with the required 10816 ** PRIMARY KEY fields is present in the database, but one or more other 10817 ** (non primary-key) fields modified by the update do not contain the 10818 ** expected "before" values. 10819 ** 10820 ** The conflicting row, in this case, is the database row with the matching 10821 ** primary key. 10822 ** 10823 ** <dt>SQLITE_CHANGESET_NOTFOUND<dd> 10824 ** The conflict handler is invoked with CHANGESET_NOTFOUND as the second 10825 ** argument when processing a DELETE or UPDATE change if a row with the 10826 ** required PRIMARY KEY fields is not present in the database. 10827 ** 10828 ** There is no conflicting row in this case. The results of invoking the 10829 ** sqlite3changeset_conflict() API are undefined. 10830 ** 10831 ** <dt>SQLITE_CHANGESET_CONFLICT<dd> 10832 ** CHANGESET_CONFLICT is passed as the second argument to the conflict 10833 ** handler while processing an INSERT change if the operation would result 10834 ** in duplicate primary key values. 10835 ** 10836 ** The conflicting row in this case is the database row with the matching 10837 ** primary key. 10838 ** 10839 ** <dt>SQLITE_CHANGESET_FOREIGN_KEY<dd> 10840 ** If foreign key handling is enabled, and applying a changeset leaves the 10841 ** database in a state containing foreign key violations, the conflict 10842 ** handler is invoked with CHANGESET_FOREIGN_KEY as the second argument 10843 ** exactly once before the changeset is committed. If the conflict handler 10844 ** returns CHANGESET_OMIT, the changes, including those that caused the 10845 ** foreign key constraint violation, are committed. Or, if it returns 10846 ** CHANGESET_ABORT, the changeset is rolled back. 10847 ** 10848 ** No current or conflicting row information is provided. The only function 10849 ** it is possible to call on the supplied sqlite3_changeset_iter handle 10850 ** is sqlite3changeset_fk_conflicts(). 10851 ** 10852 ** <dt>SQLITE_CHANGESET_CONSTRAINT<dd> 10853 ** If any other constraint violation occurs while applying a change (i.e. 10854 ** a UNIQUE, CHECK or NOT NULL constraint), the conflict handler is 10855 ** invoked with CHANGESET_CONSTRAINT as the second argument. 10856 ** 10857 ** There is no conflicting row in this case. The results of invoking the 10858 ** sqlite3changeset_conflict() API are undefined. 10859 ** 10860 ** </dl> 10861 */ 10862 #define SQLITE_CHANGESET_DATA 1 10863 #define SQLITE_CHANGESET_NOTFOUND 2 10864 #define SQLITE_CHANGESET_CONFLICT 3 10865 #define SQLITE_CHANGESET_CONSTRAINT 4 10866 #define SQLITE_CHANGESET_FOREIGN_KEY 5 10867 10868 /* 10869 ** CAPI3REF: Constants Returned By The Conflict Handler 10870 ** 10871 ** A conflict handler callback must return one of the following three values. 10872 ** 10873 ** <dl> 10874 ** <dt>SQLITE_CHANGESET_OMIT<dd> 10875 ** If a conflict handler returns this value no special action is taken. The 10876 ** change that caused the conflict is not applied. The session module 10877 ** continues to the next change in the changeset. 10878 ** 10879 ** <dt>SQLITE_CHANGESET_REPLACE<dd> 10880 ** This value may only be returned if the second argument to the conflict 10881 ** handler was SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If this 10882 ** is not the case, any changes applied so far are rolled back and the 10883 ** call to sqlite3changeset_apply() returns SQLITE_MISUSE. 10884 ** 10885 ** If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_DATA conflict 10886 ** handler, then the conflicting row is either updated or deleted, depending 10887 ** on the type of change. 10888 ** 10889 ** If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_CONFLICT conflict 10890 ** handler, then the conflicting row is removed from the database and a 10891 ** second attempt to apply the change is made. If this second attempt fails, 10892 ** the original row is restored to the database before continuing. 10893 ** 10894 ** <dt>SQLITE_CHANGESET_ABORT<dd> 10895 ** If this value is returned, any changes applied so far are rolled back 10896 ** and the call to sqlite3changeset_apply() returns SQLITE_ABORT. 10897 ** </dl> 10898 */ 10899 #define SQLITE_CHANGESET_OMIT 0 10900 #define SQLITE_CHANGESET_REPLACE 1 10901 #define SQLITE_CHANGESET_ABORT 2 10902 10903 /* 10904 ** CAPI3REF: Rebasing changesets 10905 ** EXPERIMENTAL 10906 ** 10907 ** Suppose there is a site hosting a database in state S0. And that 10908 ** modifications are made that move that database to state S1 and a 10909 ** changeset recorded (the "local" changeset). Then, a changeset based 10910 ** on S0 is received from another site (the "remote" changeset) and 10911 ** applied to the database. The database is then in state 10912 ** (S1+"remote"), where the exact state depends on any conflict 10913 ** resolution decisions (OMIT or REPLACE) made while applying "remote". 10914 ** Rebasing a changeset is to update it to take those conflict 10915 ** resolution decisions into account, so that the same conflicts 10916 ** do not have to be resolved elsewhere in the network. 10917 ** 10918 ** For example, if both the local and remote changesets contain an 10919 ** INSERT of the same key on "CREATE TABLE t1(a PRIMARY KEY, b)": 10920 ** 10921 ** local: INSERT INTO t1 VALUES(1, 'v1'); 10922 ** remote: INSERT INTO t1 VALUES(1, 'v2'); 10923 ** 10924 ** and the conflict resolution is REPLACE, then the INSERT change is 10925 ** removed from the local changeset (it was overridden). Or, if the 10926 ** conflict resolution was "OMIT", then the local changeset is modified 10927 ** to instead contain: 10928 ** 10929 ** UPDATE t1 SET b = 'v2' WHERE a=1; 10930 ** 10931 ** Changes within the local changeset are rebased as follows: 10932 ** 10933 ** <dl> 10934 ** <dt>Local INSERT<dd> 10935 ** This may only conflict with a remote INSERT. If the conflict 10936 ** resolution was OMIT, then add an UPDATE change to the rebased 10937 ** changeset. Or, if the conflict resolution was REPLACE, add 10938 ** nothing to the rebased changeset. 10939 ** 10940 ** <dt>Local DELETE<dd> 10941 ** This may conflict with a remote UPDATE or DELETE. In both cases the 10942 ** only possible resolution is OMIT. If the remote operation was a 10943 ** DELETE, then add no change to the rebased changeset. If the remote 10944 ** operation was an UPDATE, then the old.* fields of change are updated 10945 ** to reflect the new.* values in the UPDATE. 10946 ** 10947 ** <dt>Local UPDATE<dd> 10948 ** This may conflict with a remote UPDATE or DELETE. If it conflicts 10949 ** with a DELETE, and the conflict resolution was OMIT, then the update 10950 ** is changed into an INSERT. Any undefined values in the new.* record 10951 ** from the update change are filled in using the old.* values from 10952 ** the conflicting DELETE. Or, if the conflict resolution was REPLACE, 10953 ** the UPDATE change is simply omitted from the rebased changeset. 10954 ** 10955 ** If conflict is with a remote UPDATE and the resolution is OMIT, then 10956 ** the old.* values are rebased using the new.* values in the remote 10957 ** change. Or, if the resolution is REPLACE, then the change is copied 10958 ** into the rebased changeset with updates to columns also updated by 10959 ** the conflicting remote UPDATE removed. If this means no columns would 10960 ** be updated, the change is omitted. 10961 ** </dl> 10962 ** 10963 ** A local change may be rebased against multiple remote changes 10964 ** simultaneously. If a single key is modified by multiple remote 10965 ** changesets, they are combined as follows before the local changeset 10966 ** is rebased: 10967 ** 10968 ** <ul> 10969 ** <li> If there has been one or more REPLACE resolutions on a 10970 ** key, it is rebased according to a REPLACE. 10971 ** 10972 ** <li> If there have been no REPLACE resolutions on a key, then 10973 ** the local changeset is rebased according to the most recent 10974 ** of the OMIT resolutions. 10975 ** </ul> 10976 ** 10977 ** Note that conflict resolutions from multiple remote changesets are 10978 ** combined on a per-field basis, not per-row. This means that in the 10979 ** case of multiple remote UPDATE operations, some fields of a single 10980 ** local change may be rebased for REPLACE while others are rebased for 10981 ** OMIT. 10982 ** 10983 ** In order to rebase a local changeset, the remote changeset must first 10984 ** be applied to the local database using sqlite3changeset_apply_v2() and 10985 ** the buffer of rebase information captured. Then: 10986 ** 10987 ** <ol> 10988 ** <li> An sqlite3_rebaser object is created by calling 10989 ** sqlite3rebaser_create(). 10990 ** <li> The new object is configured with the rebase buffer obtained from 10991 ** sqlite3changeset_apply_v2() by calling sqlite3rebaser_configure(). 10992 ** If the local changeset is to be rebased against multiple remote 10993 ** changesets, then sqlite3rebaser_configure() should be called 10994 ** multiple times, in the same order that the multiple 10995 ** sqlite3changeset_apply_v2() calls were made. 10996 ** <li> Each local changeset is rebased by calling sqlite3rebaser_rebase(). 10997 ** <li> The sqlite3_rebaser object is deleted by calling 10998 ** sqlite3rebaser_delete(). 10999 ** </ol> 11000 */ 11001 typedef struct sqlite3_rebaser sqlite3_rebaser; 11002 11003 /* 11004 ** CAPI3REF: Create a changeset rebaser object. 11005 ** EXPERIMENTAL 11006 ** 11007 ** Allocate a new changeset rebaser object. If successful, set (*ppNew) to 11008 ** point to the new object and return SQLITE_OK. Otherwise, if an error 11009 ** occurs, return an SQLite error code (e.g. SQLITE_NOMEM) and set (*ppNew) 11010 ** to NULL. 11011 */ 11012 SQLITE_API int sqlite3rebaser_create(sqlite3_rebaser **ppNew); 11013 11014 /* 11015 ** CAPI3REF: Configure a changeset rebaser object. 11016 ** EXPERIMENTAL 11017 ** 11018 ** Configure the changeset rebaser object to rebase changesets according 11019 ** to the conflict resolutions described by buffer pRebase (size nRebase 11020 ** bytes), which must have been obtained from a previous call to 11021 ** sqlite3changeset_apply_v2(). 11022 */ 11023 SQLITE_API int sqlite3rebaser_configure( 11024 sqlite3_rebaser*, 11025 int nRebase, const void *pRebase 11026 ); 11027 11028 /* 11029 ** CAPI3REF: Rebase a changeset 11030 ** EXPERIMENTAL 11031 ** 11032 ** Argument pIn must point to a buffer containing a changeset nIn bytes 11033 ** in size. This function allocates and populates a buffer with a copy 11034 ** of the changeset rebased rebased according to the configuration of the 11035 ** rebaser object passed as the first argument. If successful, (*ppOut) 11036 ** is set to point to the new buffer containing the rebased changeset and 11037 ** (*pnOut) to its size in bytes and SQLITE_OK returned. It is the 11038 ** responsibility of the caller to eventually free the new buffer using 11039 ** sqlite3_free(). Otherwise, if an error occurs, (*ppOut) and (*pnOut) 11040 ** are set to zero and an SQLite error code returned. 11041 */ 11042 SQLITE_API int sqlite3rebaser_rebase( 11043 sqlite3_rebaser*, 11044 int nIn, const void *pIn, 11045 int *pnOut, void **ppOut 11046 ); 11047 11048 /* 11049 ** CAPI3REF: Delete a changeset rebaser object. 11050 ** EXPERIMENTAL 11051 ** 11052 ** Delete the changeset rebaser object and all associated resources. There 11053 ** should be one call to this function for each successful invocation 11054 ** of sqlite3rebaser_create(). 11055 */ 11056 SQLITE_API void sqlite3rebaser_delete(sqlite3_rebaser *p); 11057 11058 /* 11059 ** CAPI3REF: Streaming Versions of API functions. 11060 ** 11061 ** The six streaming API xxx_strm() functions serve similar purposes to the 11062 ** corresponding non-streaming API functions: 11063 ** 11064 ** <table border=1 style="margin-left:8ex;margin-right:8ex"> 11065 ** <tr><th>Streaming function<th>Non-streaming equivalent</th> 11066 ** <tr><td>sqlite3changeset_apply_strm<td>[sqlite3changeset_apply] 11067 ** <tr><td>sqlite3changeset_apply_strm_v2<td>[sqlite3changeset_apply_v2] 11068 ** <tr><td>sqlite3changeset_concat_strm<td>[sqlite3changeset_concat] 11069 ** <tr><td>sqlite3changeset_invert_strm<td>[sqlite3changeset_invert] 11070 ** <tr><td>sqlite3changeset_start_strm<td>[sqlite3changeset_start] 11071 ** <tr><td>sqlite3session_changeset_strm<td>[sqlite3session_changeset] 11072 ** <tr><td>sqlite3session_patchset_strm<td>[sqlite3session_patchset] 11073 ** </table> 11074 ** 11075 ** Non-streaming functions that accept changesets (or patchsets) as input 11076 ** require that the entire changeset be stored in a single buffer in memory. 11077 ** Similarly, those that return a changeset or patchset do so by returning 11078 ** a pointer to a single large buffer allocated using sqlite3_malloc(). 11079 ** Normally this is convenient. However, if an application running in a 11080 ** low-memory environment is required to handle very large changesets, the 11081 ** large contiguous memory allocations required can become onerous. 11082 ** 11083 ** In order to avoid this problem, instead of a single large buffer, input 11084 ** is passed to a streaming API functions by way of a callback function that 11085 ** the sessions module invokes to incrementally request input data as it is 11086 ** required. In all cases, a pair of API function parameters such as 11087 ** 11088 ** <pre> 11089 ** int nChangeset, 11090 ** void *pChangeset, 11091 ** </pre> 11092 ** 11093 ** Is replaced by: 11094 ** 11095 ** <pre> 11096 ** int (*xInput)(void *pIn, void *pData, int *pnData), 11097 ** void *pIn, 11098 ** </pre> 11099 ** 11100 ** Each time the xInput callback is invoked by the sessions module, the first 11101 ** argument passed is a copy of the supplied pIn context pointer. The second 11102 ** argument, pData, points to a buffer (*pnData) bytes in size. Assuming no 11103 ** error occurs the xInput method should copy up to (*pnData) bytes of data 11104 ** into the buffer and set (*pnData) to the actual number of bytes copied 11105 ** before returning SQLITE_OK. If the input is completely exhausted, (*pnData) 11106 ** should be set to zero to indicate this. Or, if an error occurs, an SQLite 11107 ** error code should be returned. In all cases, if an xInput callback returns 11108 ** an error, all processing is abandoned and the streaming API function 11109 ** returns a copy of the error code to the caller. 11110 ** 11111 ** In the case of sqlite3changeset_start_strm(), the xInput callback may be 11112 ** invoked by the sessions module at any point during the lifetime of the 11113 ** iterator. If such an xInput callback returns an error, the iterator enters 11114 ** an error state, whereby all subsequent calls to iterator functions 11115 ** immediately fail with the same error code as returned by xInput. 11116 ** 11117 ** Similarly, streaming API functions that return changesets (or patchsets) 11118 ** return them in chunks by way of a callback function instead of via a 11119 ** pointer to a single large buffer. In this case, a pair of parameters such 11120 ** as: 11121 ** 11122 ** <pre> 11123 ** int *pnChangeset, 11124 ** void **ppChangeset, 11125 ** </pre> 11126 ** 11127 ** Is replaced by: 11128 ** 11129 ** <pre> 11130 ** int (*xOutput)(void *pOut, const void *pData, int nData), 11131 ** void *pOut 11132 ** </pre> 11133 ** 11134 ** The xOutput callback is invoked zero or more times to return data to 11135 ** the application. The first parameter passed to each call is a copy of the 11136 ** pOut pointer supplied by the application. The second parameter, pData, 11137 ** points to a buffer nData bytes in size containing the chunk of output 11138 ** data being returned. If the xOutput callback successfully processes the 11139 ** supplied data, it should return SQLITE_OK to indicate success. Otherwise, 11140 ** it should return some other SQLite error code. In this case processing 11141 ** is immediately abandoned and the streaming API function returns a copy 11142 ** of the xOutput error code to the application. 11143 ** 11144 ** The sessions module never invokes an xOutput callback with the third 11145 ** parameter set to a value less than or equal to zero. Other than this, 11146 ** no guarantees are made as to the size of the chunks of data returned. 11147 */ 11148 SQLITE_API int sqlite3changeset_apply_strm( 11149 sqlite3 *db, /* Apply change to "main" db of this handle */ 11150 int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */ 11151 void *pIn, /* First arg for xInput */ 11152 int(*xFilter)( 11153 void *pCtx, /* Copy of sixth arg to _apply() */ 11154 const char *zTab /* Table name */ 11155 ), 11156 int(*xConflict)( 11157 void *pCtx, /* Copy of sixth arg to _apply() */ 11158 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */ 11159 sqlite3_changeset_iter *p /* Handle describing change and conflict */ 11160 ), 11161 void *pCtx /* First argument passed to xConflict */ 11162 ); 11163 SQLITE_API int sqlite3changeset_apply_v2_strm( 11164 sqlite3 *db, /* Apply change to "main" db of this handle */ 11165 int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */ 11166 void *pIn, /* First arg for xInput */ 11167 int(*xFilter)( 11168 void *pCtx, /* Copy of sixth arg to _apply() */ 11169 const char *zTab /* Table name */ 11170 ), 11171 int(*xConflict)( 11172 void *pCtx, /* Copy of sixth arg to _apply() */ 11173 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */ 11174 sqlite3_changeset_iter *p /* Handle describing change and conflict */ 11175 ), 11176 void *pCtx, /* First argument passed to xConflict */ 11177 void **ppRebase, int *pnRebase, 11178 int flags 11179 ); 11180 SQLITE_API int sqlite3changeset_concat_strm( 11181 int (*xInputA)(void *pIn, void *pData, int *pnData), 11182 void *pInA, 11183 int (*xInputB)(void *pIn, void *pData, int *pnData), 11184 void *pInB, 11185 int (*xOutput)(void *pOut, const void *pData, int nData), 11186 void *pOut 11187 ); 11188 SQLITE_API int sqlite3changeset_invert_strm( 11189 int (*xInput)(void *pIn, void *pData, int *pnData), 11190 void *pIn, 11191 int (*xOutput)(void *pOut, const void *pData, int nData), 11192 void *pOut 11193 ); 11194 SQLITE_API int sqlite3changeset_start_strm( 11195 sqlite3_changeset_iter **pp, 11196 int (*xInput)(void *pIn, void *pData, int *pnData), 11197 void *pIn 11198 ); 11199 SQLITE_API int sqlite3changeset_start_v2_strm( 11200 sqlite3_changeset_iter **pp, 11201 int (*xInput)(void *pIn, void *pData, int *pnData), 11202 void *pIn, 11203 int flags 11204 ); 11205 SQLITE_API int sqlite3session_changeset_strm( 11206 sqlite3_session *pSession, 11207 int (*xOutput)(void *pOut, const void *pData, int nData), 11208 void *pOut 11209 ); 11210 SQLITE_API int sqlite3session_patchset_strm( 11211 sqlite3_session *pSession, 11212 int (*xOutput)(void *pOut, const void *pData, int nData), 11213 void *pOut 11214 ); 11215 SQLITE_API int sqlite3changegroup_add_strm(sqlite3_changegroup*, 11216 int (*xInput)(void *pIn, void *pData, int *pnData), 11217 void *pIn 11218 ); 11219 SQLITE_API int sqlite3changegroup_output_strm(sqlite3_changegroup*, 11220 int (*xOutput)(void *pOut, const void *pData, int nData), 11221 void *pOut 11222 ); 11223 SQLITE_API int sqlite3rebaser_rebase_strm( 11224 sqlite3_rebaser *pRebaser, 11225 int (*xInput)(void *pIn, void *pData, int *pnData), 11226 void *pIn, 11227 int (*xOutput)(void *pOut, const void *pData, int nData), 11228 void *pOut 11229 ); 11230 11231 /* 11232 ** CAPI3REF: Configure global parameters 11233 ** 11234 ** The sqlite3session_config() interface is used to make global configuration 11235 ** changes to the sessions module in order to tune it to the specific needs 11236 ** of the application. 11237 ** 11238 ** The sqlite3session_config() interface is not threadsafe. If it is invoked 11239 ** while any other thread is inside any other sessions method then the 11240 ** results are undefined. Furthermore, if it is invoked after any sessions 11241 ** related objects have been created, the results are also undefined. 11242 ** 11243 ** The first argument to the sqlite3session_config() function must be one 11244 ** of the SQLITE_SESSION_CONFIG_XXX constants defined below. The 11245 ** interpretation of the (void*) value passed as the second parameter and 11246 ** the effect of calling this function depends on the value of the first 11247 ** parameter. 11248 ** 11249 ** <dl> 11250 ** <dt>SQLITE_SESSION_CONFIG_STRMSIZE<dd> 11251 ** By default, the sessions module streaming interfaces attempt to input 11252 ** and output data in approximately 1 KiB chunks. This operand may be used 11253 ** to set and query the value of this configuration setting. The pointer 11254 ** passed as the second argument must point to a value of type (int). 11255 ** If this value is greater than 0, it is used as the new streaming data 11256 ** chunk size for both input and output. Before returning, the (int) value 11257 ** pointed to by pArg is set to the final value of the streaming interface 11258 ** chunk size. 11259 ** </dl> 11260 ** 11261 ** This function returns SQLITE_OK if successful, or an SQLite error code 11262 ** otherwise. 11263 */ 11264 SQLITE_API int sqlite3session_config(int op, void *pArg); 11265 11266 /* 11267 ** CAPI3REF: Values for sqlite3session_config(). 11268 */ 11269 #define SQLITE_SESSION_CONFIG_STRMSIZE 1 11270 11271 /* 11272 ** Make sure we can call this stuff from C++. 11273 */ 11274 #ifdef __cplusplus 11275 } 11276 #endif 11277 11278 #endif /* !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION) */ 11279 11280 /******** End of sqlite3session.h *********/ 11281 /******** Begin file fts5.h *********/ 11282 /* 11283 ** 2014 May 31 11284 ** 11285 ** The author disclaims copyright to this source code. In place of 11286 ** a legal notice, here is a blessing: 11287 ** 11288 ** May you do good and not evil. 11289 ** May you find forgiveness for yourself and forgive others. 11290 ** May you share freely, never taking more than you give. 11291 ** 11292 ****************************************************************************** 11293 ** 11294 ** Interfaces to extend FTS5. Using the interfaces defined in this file, 11295 ** FTS5 may be extended with: 11296 ** 11297 ** * custom tokenizers, and 11298 ** * custom auxiliary functions. 11299 */ 11300 11301 11302 #ifndef _FTS5_H 11303 #define _FTS5_H 11304 11305 11306 #ifdef __cplusplus 11307 extern "C" { 11308 #endif 11309 11310 /************************************************************************* 11311 ** CUSTOM AUXILIARY FUNCTIONS 11312 ** 11313 ** Virtual table implementations may overload SQL functions by implementing 11314 ** the sqlite3_module.xFindFunction() method. 11315 */ 11316 11317 typedef struct Fts5ExtensionApi Fts5ExtensionApi; 11318 typedef struct Fts5Context Fts5Context; 11319 typedef struct Fts5PhraseIter Fts5PhraseIter; 11320 11321 typedef void (*fts5_extension_function)( 11322 const Fts5ExtensionApi *pApi, /* API offered by current FTS version */ 11323 Fts5Context *pFts, /* First arg to pass to pApi functions */ 11324 sqlite3_context *pCtx, /* Context for returning result/error */ 11325 int nVal, /* Number of values in apVal[] array */ 11326 sqlite3_value **apVal /* Array of trailing arguments */ 11327 ); 11328 11329 struct Fts5PhraseIter { 11330 const unsigned char *a; 11331 const unsigned char *b; 11332 }; 11333 11334 /* 11335 ** EXTENSION API FUNCTIONS 11336 ** 11337 ** xUserData(pFts): 11338 ** Return a copy of the context pointer the extension function was 11339 ** registered with. 11340 ** 11341 ** xColumnTotalSize(pFts, iCol, pnToken): 11342 ** If parameter iCol is less than zero, set output variable *pnToken 11343 ** to the total number of tokens in the FTS5 table. Or, if iCol is 11344 ** non-negative but less than the number of columns in the table, return 11345 ** the total number of tokens in column iCol, considering all rows in 11346 ** the FTS5 table. 11347 ** 11348 ** If parameter iCol is greater than or equal to the number of columns 11349 ** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g. 11350 ** an OOM condition or IO error), an appropriate SQLite error code is 11351 ** returned. 11352 ** 11353 ** xColumnCount(pFts): 11354 ** Return the number of columns in the table. 11355 ** 11356 ** xColumnSize(pFts, iCol, pnToken): 11357 ** If parameter iCol is less than zero, set output variable *pnToken 11358 ** to the total number of tokens in the current row. Or, if iCol is 11359 ** non-negative but less than the number of columns in the table, set 11360 ** *pnToken to the number of tokens in column iCol of the current row. 11361 ** 11362 ** If parameter iCol is greater than or equal to the number of columns 11363 ** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g. 11364 ** an OOM condition or IO error), an appropriate SQLite error code is 11365 ** returned. 11366 ** 11367 ** This function may be quite inefficient if used with an FTS5 table 11368 ** created with the "columnsize=0" option. 11369 ** 11370 ** xColumnText: 11371 ** This function attempts to retrieve the text of column iCol of the 11372 ** current document. If successful, (*pz) is set to point to a buffer 11373 ** containing the text in utf-8 encoding, (*pn) is set to the size in bytes 11374 ** (not characters) of the buffer and SQLITE_OK is returned. Otherwise, 11375 ** if an error occurs, an SQLite error code is returned and the final values 11376 ** of (*pz) and (*pn) are undefined. 11377 ** 11378 ** xPhraseCount: 11379 ** Returns the number of phrases in the current query expression. 11380 ** 11381 ** xPhraseSize: 11382 ** Returns the number of tokens in phrase iPhrase of the query. Phrases 11383 ** are numbered starting from zero. 11384 ** 11385 ** xInstCount: 11386 ** Set *pnInst to the total number of occurrences of all phrases within 11387 ** the query within the current row. Return SQLITE_OK if successful, or 11388 ** an error code (i.e. SQLITE_NOMEM) if an error occurs. 11389 ** 11390 ** This API can be quite slow if used with an FTS5 table created with the 11391 ** "detail=none" or "detail=column" option. If the FTS5 table is created 11392 ** with either "detail=none" or "detail=column" and "content=" option 11393 ** (i.e. if it is a contentless table), then this API always returns 0. 11394 ** 11395 ** xInst: 11396 ** Query for the details of phrase match iIdx within the current row. 11397 ** Phrase matches are numbered starting from zero, so the iIdx argument 11398 ** should be greater than or equal to zero and smaller than the value 11399 ** output by xInstCount(). 11400 ** 11401 ** Usually, output parameter *piPhrase is set to the phrase number, *piCol 11402 ** to the column in which it occurs and *piOff the token offset of the 11403 ** first token of the phrase. Returns SQLITE_OK if successful, or an error 11404 ** code (i.e. SQLITE_NOMEM) if an error occurs. 11405 ** 11406 ** This API can be quite slow if used with an FTS5 table created with the 11407 ** "detail=none" or "detail=column" option. 11408 ** 11409 ** xRowid: 11410 ** Returns the rowid of the current row. 11411 ** 11412 ** xTokenize: 11413 ** Tokenize text using the tokenizer belonging to the FTS5 table. 11414 ** 11415 ** xQueryPhrase(pFts5, iPhrase, pUserData, xCallback): 11416 ** This API function is used to query the FTS table for phrase iPhrase 11417 ** of the current query. Specifically, a query equivalent to: 11418 ** 11419 ** ... FROM ftstable WHERE ftstable MATCH $p ORDER BY rowid 11420 ** 11421 ** with $p set to a phrase equivalent to the phrase iPhrase of the 11422 ** current query is executed. Any column filter that applies to 11423 ** phrase iPhrase of the current query is included in $p. For each 11424 ** row visited, the callback function passed as the fourth argument 11425 ** is invoked. The context and API objects passed to the callback 11426 ** function may be used to access the properties of each matched row. 11427 ** Invoking Api.xUserData() returns a copy of the pointer passed as 11428 ** the third argument to pUserData. 11429 ** 11430 ** If the callback function returns any value other than SQLITE_OK, the 11431 ** query is abandoned and the xQueryPhrase function returns immediately. 11432 ** If the returned value is SQLITE_DONE, xQueryPhrase returns SQLITE_OK. 11433 ** Otherwise, the error code is propagated upwards. 11434 ** 11435 ** If the query runs to completion without incident, SQLITE_OK is returned. 11436 ** Or, if some error occurs before the query completes or is aborted by 11437 ** the callback, an SQLite error code is returned. 11438 ** 11439 ** 11440 ** xSetAuxdata(pFts5, pAux, xDelete) 11441 ** 11442 ** Save the pointer passed as the second argument as the extension functions 11443 ** "auxiliary data". The pointer may then be retrieved by the current or any 11444 ** future invocation of the same fts5 extension function made as part of 11445 ** the same MATCH query using the xGetAuxdata() API. 11446 ** 11447 ** Each extension function is allocated a single auxiliary data slot for 11448 ** each FTS query (MATCH expression). If the extension function is invoked 11449 ** more than once for a single FTS query, then all invocations share a 11450 ** single auxiliary data context. 11451 ** 11452 ** If there is already an auxiliary data pointer when this function is 11453 ** invoked, then it is replaced by the new pointer. If an xDelete callback 11454 ** was specified along with the original pointer, it is invoked at this 11455 ** point. 11456 ** 11457 ** The xDelete callback, if one is specified, is also invoked on the 11458 ** auxiliary data pointer after the FTS5 query has finished. 11459 ** 11460 ** If an error (e.g. an OOM condition) occurs within this function, 11461 ** the auxiliary data is set to NULL and an error code returned. If the 11462 ** xDelete parameter was not NULL, it is invoked on the auxiliary data 11463 ** pointer before returning. 11464 ** 11465 ** 11466 ** xGetAuxdata(pFts5, bClear) 11467 ** 11468 ** Returns the current auxiliary data pointer for the fts5 extension 11469 ** function. See the xSetAuxdata() method for details. 11470 ** 11471 ** If the bClear argument is non-zero, then the auxiliary data is cleared 11472 ** (set to NULL) before this function returns. In this case the xDelete, 11473 ** if any, is not invoked. 11474 ** 11475 ** 11476 ** xRowCount(pFts5, pnRow) 11477 ** 11478 ** This function is used to retrieve the total number of rows in the table. 11479 ** In other words, the same value that would be returned by: 11480 ** 11481 ** SELECT count(*) FROM ftstable; 11482 ** 11483 ** xPhraseFirst() 11484 ** This function is used, along with type Fts5PhraseIter and the xPhraseNext 11485 ** method, to iterate through all instances of a single query phrase within 11486 ** the current row. This is the same information as is accessible via the 11487 ** xInstCount/xInst APIs. While the xInstCount/xInst APIs are more convenient 11488 ** to use, this API may be faster under some circumstances. To iterate 11489 ** through instances of phrase iPhrase, use the following code: 11490 ** 11491 ** Fts5PhraseIter iter; 11492 ** int iCol, iOff; 11493 ** for(pApi->xPhraseFirst(pFts, iPhrase, &iter, &iCol, &iOff); 11494 ** iCol>=0; 11495 ** pApi->xPhraseNext(pFts, &iter, &iCol, &iOff) 11496 ** ){ 11497 ** // An instance of phrase iPhrase at offset iOff of column iCol 11498 ** } 11499 ** 11500 ** The Fts5PhraseIter structure is defined above. Applications should not 11501 ** modify this structure directly - it should only be used as shown above 11502 ** with the xPhraseFirst() and xPhraseNext() API methods (and by 11503 ** xPhraseFirstColumn() and xPhraseNextColumn() as illustrated below). 11504 ** 11505 ** This API can be quite slow if used with an FTS5 table created with the 11506 ** "detail=none" or "detail=column" option. If the FTS5 table is created 11507 ** with either "detail=none" or "detail=column" and "content=" option 11508 ** (i.e. if it is a contentless table), then this API always iterates 11509 ** through an empty set (all calls to xPhraseFirst() set iCol to -1). 11510 ** 11511 ** xPhraseNext() 11512 ** See xPhraseFirst above. 11513 ** 11514 ** xPhraseFirstColumn() 11515 ** This function and xPhraseNextColumn() are similar to the xPhraseFirst() 11516 ** and xPhraseNext() APIs described above. The difference is that instead 11517 ** of iterating through all instances of a phrase in the current row, these 11518 ** APIs are used to iterate through the set of columns in the current row 11519 ** that contain one or more instances of a specified phrase. For example: 11520 ** 11521 ** Fts5PhraseIter iter; 11522 ** int iCol; 11523 ** for(pApi->xPhraseFirstColumn(pFts, iPhrase, &iter, &iCol); 11524 ** iCol>=0; 11525 ** pApi->xPhraseNextColumn(pFts, &iter, &iCol) 11526 ** ){ 11527 ** // Column iCol contains at least one instance of phrase iPhrase 11528 ** } 11529 ** 11530 ** This API can be quite slow if used with an FTS5 table created with the 11531 ** "detail=none" option. If the FTS5 table is created with either 11532 ** "detail=none" "content=" option (i.e. if it is a contentless table), 11533 ** then this API always iterates through an empty set (all calls to 11534 ** xPhraseFirstColumn() set iCol to -1). 11535 ** 11536 ** The information accessed using this API and its companion 11537 ** xPhraseFirstColumn() may also be obtained using xPhraseFirst/xPhraseNext 11538 ** (or xInst/xInstCount). The chief advantage of this API is that it is 11539 ** significantly more efficient than those alternatives when used with 11540 ** "detail=column" tables. 11541 ** 11542 ** xPhraseNextColumn() 11543 ** See xPhraseFirstColumn above. 11544 */ 11545 struct Fts5ExtensionApi { 11546 int iVersion; /* Currently always set to 3 */ 11547 11548 void *(*xUserData)(Fts5Context*); 11549 11550 int (*xColumnCount)(Fts5Context*); 11551 int (*xRowCount)(Fts5Context*, sqlite3_int64 *pnRow); 11552 int (*xColumnTotalSize)(Fts5Context*, int iCol, sqlite3_int64 *pnToken); 11553 11554 int (*xTokenize)(Fts5Context*, 11555 const char *pText, int nText, /* Text to tokenize */ 11556 void *pCtx, /* Context passed to xToken() */ 11557 int (*xToken)(void*, int, const char*, int, int, int) /* Callback */ 11558 ); 11559 11560 int (*xPhraseCount)(Fts5Context*); 11561 int (*xPhraseSize)(Fts5Context*, int iPhrase); 11562 11563 int (*xInstCount)(Fts5Context*, int *pnInst); 11564 int (*xInst)(Fts5Context*, int iIdx, int *piPhrase, int *piCol, int *piOff); 11565 11566 sqlite3_int64 (*xRowid)(Fts5Context*); 11567 int (*xColumnText)(Fts5Context*, int iCol, const char **pz, int *pn); 11568 int (*xColumnSize)(Fts5Context*, int iCol, int *pnToken); 11569 11570 int (*xQueryPhrase)(Fts5Context*, int iPhrase, void *pUserData, 11571 int(*)(const Fts5ExtensionApi*,Fts5Context*,void*) 11572 ); 11573 int (*xSetAuxdata)(Fts5Context*, void *pAux, void(*xDelete)(void*)); 11574 void *(*xGetAuxdata)(Fts5Context*, int bClear); 11575 11576 int (*xPhraseFirst)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*, int*); 11577 void (*xPhraseNext)(Fts5Context*, Fts5PhraseIter*, int *piCol, int *piOff); 11578 11579 int (*xPhraseFirstColumn)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*); 11580 void (*xPhraseNextColumn)(Fts5Context*, Fts5PhraseIter*, int *piCol); 11581 }; 11582 11583 /* 11584 ** CUSTOM AUXILIARY FUNCTIONS 11585 *************************************************************************/ 11586 11587 /************************************************************************* 11588 ** CUSTOM TOKENIZERS 11589 ** 11590 ** Applications may also register custom tokenizer types. A tokenizer 11591 ** is registered by providing fts5 with a populated instance of the 11592 ** following structure. All structure methods must be defined, setting 11593 ** any member of the fts5_tokenizer struct to NULL leads to undefined 11594 ** behaviour. The structure methods are expected to function as follows: 11595 ** 11596 ** xCreate: 11597 ** This function is used to allocate and initialize a tokenizer instance. 11598 ** A tokenizer instance is required to actually tokenize text. 11599 ** 11600 ** The first argument passed to this function is a copy of the (void*) 11601 ** pointer provided by the application when the fts5_tokenizer object 11602 ** was registered with FTS5 (the third argument to xCreateTokenizer()). 11603 ** The second and third arguments are an array of nul-terminated strings 11604 ** containing the tokenizer arguments, if any, specified following the 11605 ** tokenizer name as part of the CREATE VIRTUAL TABLE statement used 11606 ** to create the FTS5 table. 11607 ** 11608 ** The final argument is an output variable. If successful, (*ppOut) 11609 ** should be set to point to the new tokenizer handle and SQLITE_OK 11610 ** returned. If an error occurs, some value other than SQLITE_OK should 11611 ** be returned. In this case, fts5 assumes that the final value of *ppOut 11612 ** is undefined. 11613 ** 11614 ** xDelete: 11615 ** This function is invoked to delete a tokenizer handle previously 11616 ** allocated using xCreate(). Fts5 guarantees that this function will 11617 ** be invoked exactly once for each successful call to xCreate(). 11618 ** 11619 ** xTokenize: 11620 ** This function is expected to tokenize the nText byte string indicated 11621 ** by argument pText. pText may or may not be nul-terminated. The first 11622 ** argument passed to this function is a pointer to an Fts5Tokenizer object 11623 ** returned by an earlier call to xCreate(). 11624 ** 11625 ** The second argument indicates the reason that FTS5 is requesting 11626 ** tokenization of the supplied text. This is always one of the following 11627 ** four values: 11628 ** 11629 ** <ul><li> <b>FTS5_TOKENIZE_DOCUMENT</b> - A document is being inserted into 11630 ** or removed from the FTS table. The tokenizer is being invoked to 11631 ** determine the set of tokens to add to (or delete from) the 11632 ** FTS index. 11633 ** 11634 ** <li> <b>FTS5_TOKENIZE_QUERY</b> - A MATCH query is being executed 11635 ** against the FTS index. The tokenizer is being called to tokenize 11636 ** a bareword or quoted string specified as part of the query. 11637 ** 11638 ** <li> <b>(FTS5_TOKENIZE_QUERY | FTS5_TOKENIZE_PREFIX)</b> - Same as 11639 ** FTS5_TOKENIZE_QUERY, except that the bareword or quoted string is 11640 ** followed by a "*" character, indicating that the last token 11641 ** returned by the tokenizer will be treated as a token prefix. 11642 ** 11643 ** <li> <b>FTS5_TOKENIZE_AUX</b> - The tokenizer is being invoked to 11644 ** satisfy an fts5_api.xTokenize() request made by an auxiliary 11645 ** function. Or an fts5_api.xColumnSize() request made by the same 11646 ** on a columnsize=0 database. 11647 ** </ul> 11648 ** 11649 ** For each token in the input string, the supplied callback xToken() must 11650 ** be invoked. The first argument to it should be a copy of the pointer 11651 ** passed as the second argument to xTokenize(). The third and fourth 11652 ** arguments are a pointer to a buffer containing the token text, and the 11653 ** size of the token in bytes. The 4th and 5th arguments are the byte offsets 11654 ** of the first byte of and first byte immediately following the text from 11655 ** which the token is derived within the input. 11656 ** 11657 ** The second argument passed to the xToken() callback ("tflags") should 11658 ** normally be set to 0. The exception is if the tokenizer supports 11659 ** synonyms. In this case see the discussion below for details. 11660 ** 11661 ** FTS5 assumes the xToken() callback is invoked for each token in the 11662 ** order that they occur within the input text. 11663 ** 11664 ** If an xToken() callback returns any value other than SQLITE_OK, then 11665 ** the tokenization should be abandoned and the xTokenize() method should 11666 ** immediately return a copy of the xToken() return value. Or, if the 11667 ** input buffer is exhausted, xTokenize() should return SQLITE_OK. Finally, 11668 ** if an error occurs with the xTokenize() implementation itself, it 11669 ** may abandon the tokenization and return any error code other than 11670 ** SQLITE_OK or SQLITE_DONE. 11671 ** 11672 ** SYNONYM SUPPORT 11673 ** 11674 ** Custom tokenizers may also support synonyms. Consider a case in which a 11675 ** user wishes to query for a phrase such as "first place". Using the 11676 ** built-in tokenizers, the FTS5 query 'first + place' will match instances 11677 ** of "first place" within the document set, but not alternative forms 11678 ** such as "1st place". In some applications, it would be better to match 11679 ** all instances of "first place" or "1st place" regardless of which form 11680 ** the user specified in the MATCH query text. 11681 ** 11682 ** There are several ways to approach this in FTS5: 11683 ** 11684 ** <ol><li> By mapping all synonyms to a single token. In this case, the 11685 ** In the above example, this means that the tokenizer returns the 11686 ** same token for inputs "first" and "1st". Say that token is in 11687 ** fact "first", so that when the user inserts the document "I won 11688 ** 1st place" entries are added to the index for tokens "i", "won", 11689 ** "first" and "place". If the user then queries for '1st + place', 11690 ** the tokenizer substitutes "first" for "1st" and the query works 11691 ** as expected. 11692 ** 11693 ** <li> By querying the index for all synonyms of each query term 11694 ** separately. In this case, when tokenizing query text, the 11695 ** tokenizer may provide multiple synonyms for a single term 11696 ** within the document. FTS5 then queries the index for each 11697 ** synonym individually. For example, faced with the query: 11698 ** 11699 ** <codeblock> 11700 ** ... MATCH 'first place'</codeblock> 11701 ** 11702 ** the tokenizer offers both "1st" and "first" as synonyms for the 11703 ** first token in the MATCH query and FTS5 effectively runs a query 11704 ** similar to: 11705 ** 11706 ** <codeblock> 11707 ** ... MATCH '(first OR 1st) place'</codeblock> 11708 ** 11709 ** except that, for the purposes of auxiliary functions, the query 11710 ** still appears to contain just two phrases - "(first OR 1st)" 11711 ** being treated as a single phrase. 11712 ** 11713 ** <li> By adding multiple synonyms for a single term to the FTS index. 11714 ** Using this method, when tokenizing document text, the tokenizer 11715 ** provides multiple synonyms for each token. So that when a 11716 ** document such as "I won first place" is tokenized, entries are 11717 ** added to the FTS index for "i", "won", "first", "1st" and 11718 ** "place". 11719 ** 11720 ** This way, even if the tokenizer does not provide synonyms 11721 ** when tokenizing query text (it should not - to do so would be 11722 ** inefficient), it doesn't matter if the user queries for 11723 ** 'first + place' or '1st + place', as there are entries in the 11724 ** FTS index corresponding to both forms of the first token. 11725 ** </ol> 11726 ** 11727 ** Whether it is parsing document or query text, any call to xToken that 11728 ** specifies a <i>tflags</i> argument with the FTS5_TOKEN_COLOCATED bit 11729 ** is considered to supply a synonym for the previous token. For example, 11730 ** when parsing the document "I won first place", a tokenizer that supports 11731 ** synonyms would call xToken() 5 times, as follows: 11732 ** 11733 ** <codeblock> 11734 ** xToken(pCtx, 0, "i", 1, 0, 1); 11735 ** xToken(pCtx, 0, "won", 3, 2, 5); 11736 ** xToken(pCtx, 0, "first", 5, 6, 11); 11737 ** xToken(pCtx, FTS5_TOKEN_COLOCATED, "1st", 3, 6, 11); 11738 ** xToken(pCtx, 0, "place", 5, 12, 17); 11739 **</codeblock> 11740 ** 11741 ** It is an error to specify the FTS5_TOKEN_COLOCATED flag the first time 11742 ** xToken() is called. Multiple synonyms may be specified for a single token 11743 ** by making multiple calls to xToken(FTS5_TOKEN_COLOCATED) in sequence. 11744 ** There is no limit to the number of synonyms that may be provided for a 11745 ** single token. 11746 ** 11747 ** In many cases, method (1) above is the best approach. It does not add 11748 ** extra data to the FTS index or require FTS5 to query for multiple terms, 11749 ** so it is efficient in terms of disk space and query speed. However, it 11750 ** does not support prefix queries very well. If, as suggested above, the 11751 ** token "first" is substituted for "1st" by the tokenizer, then the query: 11752 ** 11753 ** <codeblock> 11754 ** ... MATCH '1s*'</codeblock> 11755 ** 11756 ** will not match documents that contain the token "1st" (as the tokenizer 11757 ** will probably not map "1s" to any prefix of "first"). 11758 ** 11759 ** For full prefix support, method (3) may be preferred. In this case, 11760 ** because the index contains entries for both "first" and "1st", prefix 11761 ** queries such as 'fi*' or '1s*' will match correctly. However, because 11762 ** extra entries are added to the FTS index, this method uses more space 11763 ** within the database. 11764 ** 11765 ** Method (2) offers a midpoint between (1) and (3). Using this method, 11766 ** a query such as '1s*' will match documents that contain the literal 11767 ** token "1st", but not "first" (assuming the tokenizer is not able to 11768 ** provide synonyms for prefixes). However, a non-prefix query like '1st' 11769 ** will match against "1st" and "first". This method does not require 11770 ** extra disk space, as no extra entries are added to the FTS index. 11771 ** On the other hand, it may require more CPU cycles to run MATCH queries, 11772 ** as separate queries of the FTS index are required for each synonym. 11773 ** 11774 ** When using methods (2) or (3), it is important that the tokenizer only 11775 ** provide synonyms when tokenizing document text (method (2)) or query 11776 ** text (method (3)), not both. Doing so will not cause any errors, but is 11777 ** inefficient. 11778 */ 11779 typedef struct Fts5Tokenizer Fts5Tokenizer; 11780 typedef struct fts5_tokenizer fts5_tokenizer; 11781 struct fts5_tokenizer { 11782 int (*xCreate)(void*, const char **azArg, int nArg, Fts5Tokenizer **ppOut); 11783 void (*xDelete)(Fts5Tokenizer*); 11784 int (*xTokenize)(Fts5Tokenizer*, 11785 void *pCtx, 11786 int flags, /* Mask of FTS5_TOKENIZE_* flags */ 11787 const char *pText, int nText, 11788 int (*xToken)( 11789 void *pCtx, /* Copy of 2nd argument to xTokenize() */ 11790 int tflags, /* Mask of FTS5_TOKEN_* flags */ 11791 const char *pToken, /* Pointer to buffer containing token */ 11792 int nToken, /* Size of token in bytes */ 11793 int iStart, /* Byte offset of token within input text */ 11794 int iEnd /* Byte offset of end of token within input text */ 11795 ) 11796 ); 11797 }; 11798 11799 /* Flags that may be passed as the third argument to xTokenize() */ 11800 #define FTS5_TOKENIZE_QUERY 0x0001 11801 #define FTS5_TOKENIZE_PREFIX 0x0002 11802 #define FTS5_TOKENIZE_DOCUMENT 0x0004 11803 #define FTS5_TOKENIZE_AUX 0x0008 11804 11805 /* Flags that may be passed by the tokenizer implementation back to FTS5 11806 ** as the third argument to the supplied xToken callback. */ 11807 #define FTS5_TOKEN_COLOCATED 0x0001 /* Same position as prev. token */ 11808 11809 /* 11810 ** END OF CUSTOM TOKENIZERS 11811 *************************************************************************/ 11812 11813 /************************************************************************* 11814 ** FTS5 EXTENSION REGISTRATION API 11815 */ 11816 typedef struct fts5_api fts5_api; 11817 struct fts5_api { 11818 int iVersion; /* Currently always set to 2 */ 11819 11820 /* Create a new tokenizer */ 11821 int (*xCreateTokenizer)( 11822 fts5_api *pApi, 11823 const char *zName, 11824 void *pContext, 11825 fts5_tokenizer *pTokenizer, 11826 void (*xDestroy)(void*) 11827 ); 11828 11829 /* Find an existing tokenizer */ 11830 int (*xFindTokenizer)( 11831 fts5_api *pApi, 11832 const char *zName, 11833 void **ppContext, 11834 fts5_tokenizer *pTokenizer 11835 ); 11836 11837 /* Create a new auxiliary function */ 11838 int (*xCreateFunction)( 11839 fts5_api *pApi, 11840 const char *zName, 11841 void *pContext, 11842 fts5_extension_function xFunction, 11843 void (*xDestroy)(void*) 11844 ); 11845 }; 11846 11847 /* 11848 ** END OF REGISTRATION API 11849 *************************************************************************/ 11850 11851 #ifdef __cplusplus 11852 } /* end of the 'extern "C"' block */ 11853 #endif 11854 11855 #endif /* _FTS5_H */ 11856 11857 /******** End of fts5.h *********/ 11858