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 41extern "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 "--VERS--" 127#define SQLITE_VERSION_NUMBER --VERSION-NUMBER-- 128#define SQLITE_SOURCE_ID "--SOURCE-ID--" 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*/ 162SQLITE_EXTERN const char sqlite3_version[]; 163const char *sqlite3_libversion(void); 164const char *sqlite3_sourceid(void); 165int 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 190int sqlite3_compileoption_used(const char *zOptName); 191const char *sqlite3_compileoption_get(int N); 192#endif 193 194/* 195** CAPI3REF: Test To See If The Library Is Threadsafe 196** 197** ^The sqlite3_threadsafe() function returns zero if and only if 198** SQLite was compiled with mutexing code omitted due to the 199** [SQLITE_THREADSAFE] compile-time option being set to 0. 200** 201** SQLite can be compiled with or without mutexes. When 202** the [SQLITE_THREADSAFE] C preprocessor macro is 1 or 2, mutexes 203** are enabled and SQLite is threadsafe. When the 204** [SQLITE_THREADSAFE] macro is 0, 205** the mutexes are omitted. Without the mutexes, it is not safe 206** to use SQLite concurrently from more than one thread. 207** 208** Enabling mutexes incurs a measurable performance penalty. 209** So if speed is of utmost importance, it makes sense to disable 210** the mutexes. But for maximum safety, mutexes should be enabled. 211** ^The default behavior is for mutexes to be enabled. 212** 213** This interface can be used by an application to make sure that the 214** version of SQLite that it is linking against was compiled with 215** the desired setting of the [SQLITE_THREADSAFE] macro. 216** 217** This interface only reports on the compile-time mutex setting 218** of the [SQLITE_THREADSAFE] flag. If SQLite is compiled with 219** SQLITE_THREADSAFE=1 or =2 then mutexes are enabled by default but 220** can be fully or partially disabled using a call to [sqlite3_config()] 221** with the verbs [SQLITE_CONFIG_SINGLETHREAD], [SQLITE_CONFIG_MULTITHREAD], 222** or [SQLITE_CONFIG_SERIALIZED]. ^(The return value of the 223** sqlite3_threadsafe() function shows only the compile-time setting of 224** thread safety, not any run-time changes to that setting made by 225** sqlite3_config(). In other words, the return value from sqlite3_threadsafe() 226** is unchanged by calls to sqlite3_config().)^ 227** 228** See the [threading mode] documentation for additional information. 229*/ 230int sqlite3_threadsafe(void); 231 232/* 233** CAPI3REF: Database Connection Handle 234** KEYWORDS: {database connection} {database connections} 235** 236** Each open SQLite database is represented by a pointer to an instance of 237** the opaque structure named "sqlite3". It is useful to think of an sqlite3 238** pointer as an object. The [sqlite3_open()], [sqlite3_open16()], and 239** [sqlite3_open_v2()] interfaces are its constructors, and [sqlite3_close()] 240** and [sqlite3_close_v2()] are its destructors. There are many other 241** interfaces (such as 242** [sqlite3_prepare_v2()], [sqlite3_create_function()], and 243** [sqlite3_busy_timeout()] to name but three) that are methods on an 244** sqlite3 object. 245*/ 246typedef struct sqlite3 sqlite3; 247 248/* 249** CAPI3REF: 64-Bit Integer Types 250** KEYWORDS: sqlite_int64 sqlite_uint64 251** 252** Because there is no cross-platform way to specify 64-bit integer types 253** SQLite includes typedefs for 64-bit signed and unsigned integers. 254** 255** The sqlite3_int64 and sqlite3_uint64 are the preferred type definitions. 256** The sqlite_int64 and sqlite_uint64 types are supported for backwards 257** compatibility only. 258** 259** ^The sqlite3_int64 and sqlite_int64 types can store integer values 260** between -9223372036854775808 and +9223372036854775807 inclusive. ^The 261** sqlite3_uint64 and sqlite_uint64 types can store integer values 262** between 0 and +18446744073709551615 inclusive. 263*/ 264#ifdef SQLITE_INT64_TYPE 265 typedef SQLITE_INT64_TYPE sqlite_int64; 266# ifdef SQLITE_UINT64_TYPE 267 typedef SQLITE_UINT64_TYPE sqlite_uint64; 268# else 269 typedef unsigned SQLITE_INT64_TYPE sqlite_uint64; 270# endif 271#elif defined(_MSC_VER) || defined(__BORLANDC__) 272 typedef __int64 sqlite_int64; 273 typedef unsigned __int64 sqlite_uint64; 274#else 275 typedef long long int sqlite_int64; 276 typedef unsigned long long int sqlite_uint64; 277#endif 278typedef sqlite_int64 sqlite3_int64; 279typedef sqlite_uint64 sqlite3_uint64; 280 281/* 282** If compiling for a processor that lacks floating point support, 283** substitute integer for floating-point. 284*/ 285#ifdef SQLITE_OMIT_FLOATING_POINT 286# define double sqlite3_int64 287#endif 288 289/* 290** CAPI3REF: Closing A Database Connection 291** DESTRUCTOR: sqlite3 292** 293** ^The sqlite3_close() and sqlite3_close_v2() routines are destructors 294** for the [sqlite3] object. 295** ^Calls to sqlite3_close() and sqlite3_close_v2() return [SQLITE_OK] if 296** the [sqlite3] object is successfully destroyed and all associated 297** resources are deallocated. 298** 299** ^If the database connection is associated with unfinalized prepared 300** statements or unfinished sqlite3_backup objects then sqlite3_close() 301** will leave the database connection open and return [SQLITE_BUSY]. 302** ^If sqlite3_close_v2() is called with unfinalized prepared statements 303** and/or unfinished sqlite3_backups, then the database connection becomes 304** an unusable "zombie" which will automatically be deallocated when the 305** last prepared statement is finalized or the last sqlite3_backup is 306** finished. The sqlite3_close_v2() interface is intended for use with 307** host languages that are garbage collected, and where the order in which 308** destructors are called is arbitrary. 309** 310** Applications should [sqlite3_finalize | finalize] all [prepared statements], 311** [sqlite3_blob_close | close] all [BLOB handles], and 312** [sqlite3_backup_finish | finish] all [sqlite3_backup] objects associated 313** with the [sqlite3] object prior to attempting to close the object. ^If 314** sqlite3_close_v2() is called on a [database connection] that still has 315** outstanding [prepared statements], [BLOB handles], and/or 316** [sqlite3_backup] objects then it returns [SQLITE_OK] and the deallocation 317** of resources is deferred until all [prepared statements], [BLOB handles], 318** and [sqlite3_backup] objects are also destroyed. 319** 320** ^If an [sqlite3] object is destroyed while a transaction is open, 321** the transaction is automatically rolled back. 322** 323** The C parameter to [sqlite3_close(C)] and [sqlite3_close_v2(C)] 324** must be either a NULL 325** pointer or an [sqlite3] object pointer obtained 326** from [sqlite3_open()], [sqlite3_open16()], or 327** [sqlite3_open_v2()], and not previously closed. 328** ^Calling sqlite3_close() or sqlite3_close_v2() with a NULL pointer 329** argument is a harmless no-op. 330*/ 331int sqlite3_close(sqlite3*); 332int sqlite3_close_v2(sqlite3*); 333 334/* 335** The type for a callback function. 336** This is legacy and deprecated. It is included for historical 337** compatibility and is not documented. 338*/ 339typedef int (*sqlite3_callback)(void*,int,char**, char**); 340 341/* 342** CAPI3REF: One-Step Query Execution Interface 343** METHOD: sqlite3 344** 345** The sqlite3_exec() interface is a convenience wrapper around 346** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()], 347** that allows an application to run multiple statements of SQL 348** without having to use a lot of C code. 349** 350** ^The sqlite3_exec() interface runs zero or more UTF-8 encoded, 351** semicolon-separate SQL statements passed into its 2nd argument, 352** in the context of the [database connection] passed in as its 1st 353** argument. ^If the callback function of the 3rd argument to 354** sqlite3_exec() is not NULL, then it is invoked for each result row 355** coming out of the evaluated SQL statements. ^The 4th argument to 356** sqlite3_exec() is relayed through to the 1st argument of each 357** callback invocation. ^If the callback pointer to sqlite3_exec() 358** is NULL, then no callback is ever invoked and result rows are 359** ignored. 360** 361** ^If an error occurs while evaluating the SQL statements passed into 362** sqlite3_exec(), then execution of the current statement stops and 363** subsequent statements are skipped. ^If the 5th parameter to sqlite3_exec() 364** is not NULL then any error message is written into memory obtained 365** from [sqlite3_malloc()] and passed back through the 5th parameter. 366** To avoid memory leaks, the application should invoke [sqlite3_free()] 367** on error message strings returned through the 5th parameter of 368** sqlite3_exec() after the error message string is no longer needed. 369** ^If the 5th parameter to sqlite3_exec() is not NULL and no errors 370** occur, then sqlite3_exec() sets the pointer in its 5th parameter to 371** NULL before returning. 372** 373** ^If an sqlite3_exec() callback returns non-zero, the sqlite3_exec() 374** routine returns SQLITE_ABORT without invoking the callback again and 375** without running any subsequent SQL statements. 376** 377** ^The 2nd argument to the sqlite3_exec() callback function is the 378** number of columns in the result. ^The 3rd argument to the sqlite3_exec() 379** callback is an array of pointers to strings obtained as if from 380** [sqlite3_column_text()], one for each column. ^If an element of a 381** result row is NULL then the corresponding string pointer for the 382** sqlite3_exec() callback is a NULL pointer. ^The 4th argument to the 383** sqlite3_exec() callback is an array of pointers to strings where each 384** entry represents the name of corresponding result column as obtained 385** from [sqlite3_column_name()]. 386** 387** ^If the 2nd parameter to sqlite3_exec() is a NULL pointer, a pointer 388** to an empty string, or a pointer that contains only whitespace and/or 389** SQL comments, then no SQL statements are evaluated and the database 390** is not changed. 391** 392** Restrictions: 393** 394** <ul> 395** <li> The application must ensure that the 1st parameter to sqlite3_exec() 396** is a valid and open [database connection]. 397** <li> The application must not close the [database connection] specified by 398** the 1st parameter to sqlite3_exec() while sqlite3_exec() is running. 399** <li> The application must not modify the SQL statement text passed into 400** the 2nd parameter of sqlite3_exec() while sqlite3_exec() is running. 401** </ul> 402*/ 403int sqlite3_exec( 404 sqlite3*, /* An open database */ 405 const char *sql, /* SQL to be evaluated */ 406 int (*callback)(void*,int,char**,char**), /* Callback function */ 407 void *, /* 1st argument to callback */ 408 char **errmsg /* Error msg written here */ 409); 410 411/* 412** CAPI3REF: Result Codes 413** KEYWORDS: {result code definitions} 414** 415** Many SQLite functions return an integer result code from the set shown 416** here in order to indicate success or failure. 417** 418** New error codes may be added in future versions of SQLite. 419** 420** See also: [extended result code definitions] 421*/ 422#define SQLITE_OK 0 /* Successful result */ 423/* beginning-of-error-codes */ 424#define SQLITE_ERROR 1 /* Generic error */ 425#define SQLITE_INTERNAL 2 /* Internal logic error in SQLite */ 426#define SQLITE_PERM 3 /* Access permission denied */ 427#define SQLITE_ABORT 4 /* Callback routine requested an abort */ 428#define SQLITE_BUSY 5 /* The database file is locked */ 429#define SQLITE_LOCKED 6 /* A table in the database is locked */ 430#define SQLITE_NOMEM 7 /* A malloc() failed */ 431#define SQLITE_READONLY 8 /* Attempt to write a readonly database */ 432#define SQLITE_INTERRUPT 9 /* Operation terminated by sqlite3_interrupt()*/ 433#define SQLITE_IOERR 10 /* Some kind of disk I/O error occurred */ 434#define SQLITE_CORRUPT 11 /* The database disk image is malformed */ 435#define SQLITE_NOTFOUND 12 /* Unknown opcode in sqlite3_file_control() */ 436#define SQLITE_FULL 13 /* Insertion failed because database is full */ 437#define SQLITE_CANTOPEN 14 /* Unable to open the database file */ 438#define SQLITE_PROTOCOL 15 /* Database lock protocol error */ 439#define SQLITE_EMPTY 16 /* Internal use only */ 440#define SQLITE_SCHEMA 17 /* The database schema changed */ 441#define SQLITE_TOOBIG 18 /* String or BLOB exceeds size limit */ 442#define SQLITE_CONSTRAINT 19 /* Abort due to constraint violation */ 443#define SQLITE_MISMATCH 20 /* Data type mismatch */ 444#define SQLITE_MISUSE 21 /* Library used incorrectly */ 445#define SQLITE_NOLFS 22 /* Uses OS features not supported on host */ 446#define SQLITE_AUTH 23 /* Authorization denied */ 447#define SQLITE_FORMAT 24 /* Not used */ 448#define SQLITE_RANGE 25 /* 2nd parameter to sqlite3_bind out of range */ 449#define SQLITE_NOTADB 26 /* File opened that is not a database file */ 450#define SQLITE_NOTICE 27 /* Notifications from sqlite3_log() */ 451#define SQLITE_WARNING 28 /* Warnings from sqlite3_log() */ 452#define SQLITE_ROW 100 /* sqlite3_step() has another row ready */ 453#define SQLITE_DONE 101 /* sqlite3_step() has finished executing */ 454/* end-of-error-codes */ 455 456/* 457** CAPI3REF: Extended Result Codes 458** KEYWORDS: {extended result code definitions} 459** 460** In its default configuration, SQLite API routines return one of 30 integer 461** [result codes]. However, experience has shown that many of 462** these result codes are too coarse-grained. They do not provide as 463** much information about problems as programmers might like. In an effort to 464** address this, newer versions of SQLite (version 3.3.8 [dateof:3.3.8] 465** and later) include 466** support for additional result codes that provide more detailed information 467** about errors. These [extended result codes] are enabled or disabled 468** on a per database connection basis using the 469** [sqlite3_extended_result_codes()] API. Or, the extended code for 470** the most recent error can be obtained using 471** [sqlite3_extended_errcode()]. 472*/ 473#define SQLITE_ERROR_MISSING_COLLSEQ (SQLITE_ERROR | (1<<8)) 474#define SQLITE_ERROR_RETRY (SQLITE_ERROR | (2<<8)) 475#define SQLITE_IOERR_READ (SQLITE_IOERR | (1<<8)) 476#define SQLITE_IOERR_SHORT_READ (SQLITE_IOERR | (2<<8)) 477#define SQLITE_IOERR_WRITE (SQLITE_IOERR | (3<<8)) 478#define SQLITE_IOERR_FSYNC (SQLITE_IOERR | (4<<8)) 479#define SQLITE_IOERR_DIR_FSYNC (SQLITE_IOERR | (5<<8)) 480#define SQLITE_IOERR_TRUNCATE (SQLITE_IOERR | (6<<8)) 481#define SQLITE_IOERR_FSTAT (SQLITE_IOERR | (7<<8)) 482#define SQLITE_IOERR_UNLOCK (SQLITE_IOERR | (8<<8)) 483#define SQLITE_IOERR_RDLOCK (SQLITE_IOERR | (9<<8)) 484#define SQLITE_IOERR_DELETE (SQLITE_IOERR | (10<<8)) 485#define SQLITE_IOERR_BLOCKED (SQLITE_IOERR | (11<<8)) 486#define SQLITE_IOERR_NOMEM (SQLITE_IOERR | (12<<8)) 487#define SQLITE_IOERR_ACCESS (SQLITE_IOERR | (13<<8)) 488#define SQLITE_IOERR_CHECKRESERVEDLOCK (SQLITE_IOERR | (14<<8)) 489#define SQLITE_IOERR_LOCK (SQLITE_IOERR | (15<<8)) 490#define SQLITE_IOERR_CLOSE (SQLITE_IOERR | (16<<8)) 491#define SQLITE_IOERR_DIR_CLOSE (SQLITE_IOERR | (17<<8)) 492#define SQLITE_IOERR_SHMOPEN (SQLITE_IOERR | (18<<8)) 493#define SQLITE_IOERR_SHMSIZE (SQLITE_IOERR | (19<<8)) 494#define SQLITE_IOERR_SHMLOCK (SQLITE_IOERR | (20<<8)) 495#define SQLITE_IOERR_SHMMAP (SQLITE_IOERR | (21<<8)) 496#define SQLITE_IOERR_SEEK (SQLITE_IOERR | (22<<8)) 497#define SQLITE_IOERR_DELETE_NOENT (SQLITE_IOERR | (23<<8)) 498#define SQLITE_IOERR_MMAP (SQLITE_IOERR | (24<<8)) 499#define SQLITE_IOERR_GETTEMPPATH (SQLITE_IOERR | (25<<8)) 500#define SQLITE_IOERR_CONVPATH (SQLITE_IOERR | (26<<8)) 501#define SQLITE_IOERR_VNODE (SQLITE_IOERR | (27<<8)) 502#define SQLITE_IOERR_AUTH (SQLITE_IOERR | (28<<8)) 503#define SQLITE_IOERR_BEGIN_ATOMIC (SQLITE_IOERR | (29<<8)) 504#define SQLITE_IOERR_COMMIT_ATOMIC (SQLITE_IOERR | (30<<8)) 505#define SQLITE_IOERR_ROLLBACK_ATOMIC (SQLITE_IOERR | (31<<8)) 506#define SQLITE_LOCKED_SHAREDCACHE (SQLITE_LOCKED | (1<<8)) 507#define SQLITE_LOCKED_VTAB (SQLITE_LOCKED | (2<<8)) 508#define SQLITE_BUSY_RECOVERY (SQLITE_BUSY | (1<<8)) 509#define SQLITE_BUSY_SNAPSHOT (SQLITE_BUSY | (2<<8)) 510#define SQLITE_CANTOPEN_NOTEMPDIR (SQLITE_CANTOPEN | (1<<8)) 511#define SQLITE_CANTOPEN_ISDIR (SQLITE_CANTOPEN | (2<<8)) 512#define SQLITE_CANTOPEN_FULLPATH (SQLITE_CANTOPEN | (3<<8)) 513#define SQLITE_CANTOPEN_CONVPATH (SQLITE_CANTOPEN | (4<<8)) 514#define SQLITE_CANTOPEN_DIRTYWAL (SQLITE_CANTOPEN | (5<<8)) /* Not Used */ 515#define SQLITE_CORRUPT_VTAB (SQLITE_CORRUPT | (1<<8)) 516#define SQLITE_CORRUPT_SEQUENCE (SQLITE_CORRUPT | (2<<8)) 517#define SQLITE_READONLY_RECOVERY (SQLITE_READONLY | (1<<8)) 518#define SQLITE_READONLY_CANTLOCK (SQLITE_READONLY | (2<<8)) 519#define SQLITE_READONLY_ROLLBACK (SQLITE_READONLY | (3<<8)) 520#define SQLITE_READONLY_DBMOVED (SQLITE_READONLY | (4<<8)) 521#define SQLITE_READONLY_CANTINIT (SQLITE_READONLY | (5<<8)) 522#define SQLITE_READONLY_DIRECTORY (SQLITE_READONLY | (6<<8)) 523#define SQLITE_ABORT_ROLLBACK (SQLITE_ABORT | (2<<8)) 524#define SQLITE_CONSTRAINT_CHECK (SQLITE_CONSTRAINT | (1<<8)) 525#define SQLITE_CONSTRAINT_COMMITHOOK (SQLITE_CONSTRAINT | (2<<8)) 526#define SQLITE_CONSTRAINT_FOREIGNKEY (SQLITE_CONSTRAINT | (3<<8)) 527#define SQLITE_CONSTRAINT_FUNCTION (SQLITE_CONSTRAINT | (4<<8)) 528#define SQLITE_CONSTRAINT_NOTNULL (SQLITE_CONSTRAINT | (5<<8)) 529#define SQLITE_CONSTRAINT_PRIMARYKEY (SQLITE_CONSTRAINT | (6<<8)) 530#define SQLITE_CONSTRAINT_TRIGGER (SQLITE_CONSTRAINT | (7<<8)) 531#define SQLITE_CONSTRAINT_UNIQUE (SQLITE_CONSTRAINT | (8<<8)) 532#define SQLITE_CONSTRAINT_VTAB (SQLITE_CONSTRAINT | (9<<8)) 533#define SQLITE_CONSTRAINT_ROWID (SQLITE_CONSTRAINT |(10<<8)) 534#define SQLITE_NOTICE_RECOVER_WAL (SQLITE_NOTICE | (1<<8)) 535#define SQLITE_NOTICE_RECOVER_ROLLBACK (SQLITE_NOTICE | (2<<8)) 536#define SQLITE_WARNING_AUTOINDEX (SQLITE_WARNING | (1<<8)) 537#define SQLITE_AUTH_USER (SQLITE_AUTH | (1<<8)) 538#define SQLITE_OK_LOAD_PERMANENTLY (SQLITE_OK | (1<<8)) 539 540/* 541** CAPI3REF: Flags For File Open Operations 542** 543** These bit values are intended for use in the 544** 3rd parameter to the [sqlite3_open_v2()] interface and 545** in the 4th parameter to the [sqlite3_vfs.xOpen] method. 546*/ 547#define SQLITE_OPEN_READONLY 0x00000001 /* Ok for sqlite3_open_v2() */ 548#define SQLITE_OPEN_READWRITE 0x00000002 /* Ok for sqlite3_open_v2() */ 549#define SQLITE_OPEN_CREATE 0x00000004 /* Ok for sqlite3_open_v2() */ 550#define SQLITE_OPEN_DELETEONCLOSE 0x00000008 /* VFS only */ 551#define SQLITE_OPEN_EXCLUSIVE 0x00000010 /* VFS only */ 552#define SQLITE_OPEN_AUTOPROXY 0x00000020 /* VFS only */ 553#define SQLITE_OPEN_URI 0x00000040 /* Ok for sqlite3_open_v2() */ 554#define SQLITE_OPEN_MEMORY 0x00000080 /* Ok for sqlite3_open_v2() */ 555#define SQLITE_OPEN_MAIN_DB 0x00000100 /* VFS only */ 556#define SQLITE_OPEN_TEMP_DB 0x00000200 /* VFS only */ 557#define SQLITE_OPEN_TRANSIENT_DB 0x00000400 /* VFS only */ 558#define SQLITE_OPEN_MAIN_JOURNAL 0x00000800 /* VFS only */ 559#define SQLITE_OPEN_TEMP_JOURNAL 0x00001000 /* VFS only */ 560#define SQLITE_OPEN_SUBJOURNAL 0x00002000 /* VFS only */ 561#define SQLITE_OPEN_MASTER_JOURNAL 0x00004000 /* VFS only */ 562#define SQLITE_OPEN_NOMUTEX 0x00008000 /* Ok for sqlite3_open_v2() */ 563#define SQLITE_OPEN_FULLMUTEX 0x00010000 /* Ok for sqlite3_open_v2() */ 564#define SQLITE_OPEN_SHAREDCACHE 0x00020000 /* Ok for sqlite3_open_v2() */ 565#define SQLITE_OPEN_PRIVATECACHE 0x00040000 /* Ok for sqlite3_open_v2() */ 566#define SQLITE_OPEN_WAL 0x00080000 /* VFS only */ 567 568/* Reserved: 0x00F00000 */ 569 570/* 571** CAPI3REF: Device Characteristics 572** 573** The xDeviceCharacteristics method of the [sqlite3_io_methods] 574** object returns an integer which is a vector of these 575** bit values expressing I/O characteristics of the mass storage 576** device that holds the file that the [sqlite3_io_methods] 577** refers to. 578** 579** The SQLITE_IOCAP_ATOMIC property means that all writes of 580** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 581** mean that writes of blocks that are nnn bytes in size and 582** are aligned to an address which is an integer multiple of 583** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 584** that when data is appended to a file, the data is appended 585** first then the size of the file is extended, never the other 586** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 587** information is written to disk in the same order as calls 588** to xWrite(). The SQLITE_IOCAP_POWERSAFE_OVERWRITE property means that 589** after reboot following a crash or power loss, the only bytes in a 590** file that were written at the application level might have changed 591** and that adjacent bytes, even bytes within the same sector are 592** guaranteed to be unchanged. The SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 593** flag indicates that a file cannot be deleted when open. The 594** SQLITE_IOCAP_IMMUTABLE flag indicates that the file is on 595** read-only media and cannot be changed even by processes with 596** elevated privileges. 597** 598** The SQLITE_IOCAP_BATCH_ATOMIC property means that the underlying 599** filesystem supports doing multiple write operations atomically when those 600** write operations are bracketed by [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] and 601** [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]. 602*/ 603#define SQLITE_IOCAP_ATOMIC 0x00000001 604#define SQLITE_IOCAP_ATOMIC512 0x00000002 605#define SQLITE_IOCAP_ATOMIC1K 0x00000004 606#define SQLITE_IOCAP_ATOMIC2K 0x00000008 607#define SQLITE_IOCAP_ATOMIC4K 0x00000010 608#define SQLITE_IOCAP_ATOMIC8K 0x00000020 609#define SQLITE_IOCAP_ATOMIC16K 0x00000040 610#define SQLITE_IOCAP_ATOMIC32K 0x00000080 611#define SQLITE_IOCAP_ATOMIC64K 0x00000100 612#define SQLITE_IOCAP_SAFE_APPEND 0x00000200 613#define SQLITE_IOCAP_SEQUENTIAL 0x00000400 614#define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 0x00000800 615#define SQLITE_IOCAP_POWERSAFE_OVERWRITE 0x00001000 616#define SQLITE_IOCAP_IMMUTABLE 0x00002000 617#define SQLITE_IOCAP_BATCH_ATOMIC 0x00004000 618 619/* 620** CAPI3REF: File Locking Levels 621** 622** SQLite uses one of these integer values as the second 623** argument to calls it makes to the xLock() and xUnlock() methods 624** of an [sqlite3_io_methods] object. 625*/ 626#define SQLITE_LOCK_NONE 0 627#define SQLITE_LOCK_SHARED 1 628#define SQLITE_LOCK_RESERVED 2 629#define SQLITE_LOCK_PENDING 3 630#define SQLITE_LOCK_EXCLUSIVE 4 631 632/* 633** CAPI3REF: Synchronization Type Flags 634** 635** When SQLite invokes the xSync() method of an 636** [sqlite3_io_methods] object it uses a combination of 637** these integer values as the second argument. 638** 639** When the SQLITE_SYNC_DATAONLY flag is used, it means that the 640** sync operation only needs to flush data to mass storage. Inode 641** information need not be flushed. If the lower four bits of the flag 642** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics. 643** If the lower four bits equal SQLITE_SYNC_FULL, that means 644** to use Mac OS X style fullsync instead of fsync(). 645** 646** Do not confuse the SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags 647** with the [PRAGMA synchronous]=NORMAL and [PRAGMA synchronous]=FULL 648** settings. The [synchronous pragma] determines when calls to the 649** xSync VFS method occur and applies uniformly across all platforms. 650** The SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags determine how 651** energetic or rigorous or forceful the sync operations are and 652** only make a difference on Mac OSX for the default SQLite code. 653** (Third-party VFS implementations might also make the distinction 654** between SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL, but among the 655** operating systems natively supported by SQLite, only Mac OSX 656** cares about the difference.) 657*/ 658#define SQLITE_SYNC_NORMAL 0x00002 659#define SQLITE_SYNC_FULL 0x00003 660#define SQLITE_SYNC_DATAONLY 0x00010 661 662/* 663** CAPI3REF: OS Interface Open File Handle 664** 665** An [sqlite3_file] object represents an open file in the 666** [sqlite3_vfs | OS interface layer]. Individual OS interface 667** implementations will 668** want to subclass this object by appending additional fields 669** for their own use. The pMethods entry is a pointer to an 670** [sqlite3_io_methods] object that defines methods for performing 671** I/O operations on the open file. 672*/ 673typedef struct sqlite3_file sqlite3_file; 674struct sqlite3_file { 675 const struct sqlite3_io_methods *pMethods; /* Methods for an open file */ 676}; 677 678/* 679** CAPI3REF: OS Interface File Virtual Methods Object 680** 681** Every file opened by the [sqlite3_vfs.xOpen] method populates an 682** [sqlite3_file] object (or, more commonly, a subclass of the 683** [sqlite3_file] object) with a pointer to an instance of this object. 684** This object defines the methods used to perform various operations 685** against the open file represented by the [sqlite3_file] object. 686** 687** If the [sqlite3_vfs.xOpen] method sets the sqlite3_file.pMethods element 688** to a non-NULL pointer, then the sqlite3_io_methods.xClose method 689** may be invoked even if the [sqlite3_vfs.xOpen] reported that it failed. The 690** only way to prevent a call to xClose following a failed [sqlite3_vfs.xOpen] 691** is for the [sqlite3_vfs.xOpen] to set the sqlite3_file.pMethods element 692** to NULL. 693** 694** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or 695** [SQLITE_SYNC_FULL]. The first choice is the normal fsync(). 696** The second choice is a Mac OS X style fullsync. The [SQLITE_SYNC_DATAONLY] 697** flag may be ORed in to indicate that only the data of the file 698** and not its inode needs to be synced. 699** 700** The integer values to xLock() and xUnlock() are one of 701** <ul> 702** <li> [SQLITE_LOCK_NONE], 703** <li> [SQLITE_LOCK_SHARED], 704** <li> [SQLITE_LOCK_RESERVED], 705** <li> [SQLITE_LOCK_PENDING], or 706** <li> [SQLITE_LOCK_EXCLUSIVE]. 707** </ul> 708** xLock() increases the lock. xUnlock() decreases the lock. 709** The xCheckReservedLock() method checks whether any database connection, 710** either in this process or in some other process, is holding a RESERVED, 711** PENDING, or EXCLUSIVE lock on the file. It returns true 712** if such a lock exists and false otherwise. 713** 714** The xFileControl() method is a generic interface that allows custom 715** VFS implementations to directly control an open file using the 716** [sqlite3_file_control()] interface. The second "op" argument is an 717** integer opcode. The third argument is a generic pointer intended to 718** point to a structure that may contain arguments or space in which to 719** write return values. Potential uses for xFileControl() might be 720** functions to enable blocking locks with timeouts, to change the 721** locking strategy (for example to use dot-file locks), to inquire 722** about the status of a lock, or to break stale locks. The SQLite 723** core reserves all opcodes less than 100 for its own use. 724** A [file control opcodes | list of opcodes] less than 100 is available. 725** Applications that define a custom xFileControl method should use opcodes 726** greater than 100 to avoid conflicts. VFS implementations should 727** return [SQLITE_NOTFOUND] for file control opcodes that they do not 728** recognize. 729** 730** The xSectorSize() method returns the sector size of the 731** device that underlies the file. The sector size is the 732** minimum write that can be performed without disturbing 733** other bytes in the file. The xDeviceCharacteristics() 734** method returns a bit vector describing behaviors of the 735** underlying device: 736** 737** <ul> 738** <li> [SQLITE_IOCAP_ATOMIC] 739** <li> [SQLITE_IOCAP_ATOMIC512] 740** <li> [SQLITE_IOCAP_ATOMIC1K] 741** <li> [SQLITE_IOCAP_ATOMIC2K] 742** <li> [SQLITE_IOCAP_ATOMIC4K] 743** <li> [SQLITE_IOCAP_ATOMIC8K] 744** <li> [SQLITE_IOCAP_ATOMIC16K] 745** <li> [SQLITE_IOCAP_ATOMIC32K] 746** <li> [SQLITE_IOCAP_ATOMIC64K] 747** <li> [SQLITE_IOCAP_SAFE_APPEND] 748** <li> [SQLITE_IOCAP_SEQUENTIAL] 749** <li> [SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN] 750** <li> [SQLITE_IOCAP_POWERSAFE_OVERWRITE] 751** <li> [SQLITE_IOCAP_IMMUTABLE] 752** <li> [SQLITE_IOCAP_BATCH_ATOMIC] 753** </ul> 754** 755** The SQLITE_IOCAP_ATOMIC property means that all writes of 756** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 757** mean that writes of blocks that are nnn bytes in size and 758** are aligned to an address which is an integer multiple of 759** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 760** that when data is appended to a file, the data is appended 761** first then the size of the file is extended, never the other 762** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 763** information is written to disk in the same order as calls 764** to xWrite(). 765** 766** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill 767** in the unread portions of the buffer with zeros. A VFS that 768** fails to zero-fill short reads might seem to work. However, 769** failure to zero-fill short reads will eventually lead to 770** database corruption. 771*/ 772typedef struct sqlite3_io_methods sqlite3_io_methods; 773struct sqlite3_io_methods { 774 int iVersion; 775 int (*xClose)(sqlite3_file*); 776 int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst); 777 int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst); 778 int (*xTruncate)(sqlite3_file*, sqlite3_int64 size); 779 int (*xSync)(sqlite3_file*, int flags); 780 int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize); 781 int (*xLock)(sqlite3_file*, int); 782 int (*xUnlock)(sqlite3_file*, int); 783 int (*xCheckReservedLock)(sqlite3_file*, int *pResOut); 784 int (*xFileControl)(sqlite3_file*, int op, void *pArg); 785 int (*xSectorSize)(sqlite3_file*); 786 int (*xDeviceCharacteristics)(sqlite3_file*); 787 /* Methods above are valid for version 1 */ 788 int (*xShmMap)(sqlite3_file*, int iPg, int pgsz, int, void volatile**); 789 int (*xShmLock)(sqlite3_file*, int offset, int n, int flags); 790 void (*xShmBarrier)(sqlite3_file*); 791 int (*xShmUnmap)(sqlite3_file*, int deleteFlag); 792 /* Methods above are valid for version 2 */ 793 int (*xFetch)(sqlite3_file*, sqlite3_int64 iOfst, int iAmt, void **pp); 794 int (*xUnfetch)(sqlite3_file*, sqlite3_int64 iOfst, void *p); 795 /* Methods above are valid for version 3 */ 796 /* Additional methods may be added in future releases */ 797}; 798 799/* 800** CAPI3REF: Standard File Control Opcodes 801** KEYWORDS: {file control opcodes} {file control opcode} 802** 803** These integer constants are opcodes for the xFileControl method 804** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()] 805** interface. 806** 807** <ul> 808** <li>[[SQLITE_FCNTL_LOCKSTATE]] 809** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging. This 810** opcode causes the xFileControl method to write the current state of 811** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED], 812** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE]) 813** into an integer that the pArg argument points to. This capability 814** is used during testing and is only available when the SQLITE_TEST 815** compile-time option is used. 816** 817** <li>[[SQLITE_FCNTL_SIZE_HINT]] 818** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS 819** layer a hint of how large the database file will grow to be during the 820** current transaction. This hint is not guaranteed to be accurate but it 821** is often close. The underlying VFS might choose to preallocate database 822** file space based on this hint in order to help writes to the database 823** file run faster. 824** 825** <li>[[SQLITE_FCNTL_CHUNK_SIZE]] 826** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS 827** extends and truncates the database file in chunks of a size specified 828** by the user. The fourth argument to [sqlite3_file_control()] should 829** point to an integer (type int) containing the new chunk-size to use 830** for the nominated database. Allocating database file space in large 831** chunks (say 1MB at a time), may reduce file-system fragmentation and 832** improve performance on some systems. 833** 834** <li>[[SQLITE_FCNTL_FILE_POINTER]] 835** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer 836** to the [sqlite3_file] object associated with a particular database 837** connection. See also [SQLITE_FCNTL_JOURNAL_POINTER]. 838** 839** <li>[[SQLITE_FCNTL_JOURNAL_POINTER]] 840** The [SQLITE_FCNTL_JOURNAL_POINTER] opcode is used to obtain a pointer 841** to the [sqlite3_file] object associated with the journal file (either 842** the [rollback journal] or the [write-ahead log]) for a particular database 843** connection. See also [SQLITE_FCNTL_FILE_POINTER]. 844** 845** <li>[[SQLITE_FCNTL_SYNC_OMITTED]] 846** No longer in use. 847** 848** <li>[[SQLITE_FCNTL_SYNC]] 849** The [SQLITE_FCNTL_SYNC] opcode is generated internally by SQLite and 850** sent to the VFS immediately before the xSync method is invoked on a 851** database file descriptor. Or, if the xSync method is not invoked 852** because the user has configured SQLite with 853** [PRAGMA synchronous | PRAGMA synchronous=OFF] it is invoked in place 854** of the xSync method. In most cases, the pointer argument passed with 855** this file-control is NULL. However, if the database file is being synced 856** as part of a multi-database commit, the argument points to a nul-terminated 857** string containing the transactions master-journal file name. VFSes that 858** do not need this signal should silently ignore this opcode. Applications 859** should not call [sqlite3_file_control()] with this opcode as doing so may 860** disrupt the operation of the specialized VFSes that do require it. 861** 862** <li>[[SQLITE_FCNTL_COMMIT_PHASETWO]] 863** The [SQLITE_FCNTL_COMMIT_PHASETWO] opcode is generated internally by SQLite 864** and sent to the VFS after a transaction has been committed immediately 865** but before the database is unlocked. VFSes that do not need this signal 866** should silently ignore this opcode. Applications should not call 867** [sqlite3_file_control()] with this opcode as doing so may disrupt the 868** operation of the specialized VFSes that do require it. 869** 870** <li>[[SQLITE_FCNTL_WIN32_AV_RETRY]] 871** ^The [SQLITE_FCNTL_WIN32_AV_RETRY] opcode is used to configure automatic 872** retry counts and intervals for certain disk I/O operations for the 873** windows [VFS] in order to provide robustness in the presence of 874** anti-virus programs. By default, the windows VFS will retry file read, 875** file write, and file delete operations up to 10 times, with a delay 876** of 25 milliseconds before the first retry and with the delay increasing 877** by an additional 25 milliseconds with each subsequent retry. This 878** opcode allows these two values (10 retries and 25 milliseconds of delay) 879** to be adjusted. The values are changed for all database connections 880** within the same process. The argument is a pointer to an array of two 881** integers where the first integer is the new retry count and the second 882** integer is the delay. If either integer is negative, then the setting 883** is not changed but instead the prior value of that setting is written 884** into the array entry, allowing the current retry settings to be 885** interrogated. The zDbName parameter is ignored. 886** 887** <li>[[SQLITE_FCNTL_PERSIST_WAL]] 888** ^The [SQLITE_FCNTL_PERSIST_WAL] opcode is used to set or query the 889** persistent [WAL | Write Ahead Log] setting. By default, the auxiliary 890** write ahead log and shared memory files used for transaction control 891** are automatically deleted when the latest connection to the database 892** closes. Setting persistent WAL mode causes those files to persist after 893** close. Persisting the files is useful when other processes that do not 894** have write permission on the directory containing the database file want 895** to read the database file, as the WAL and shared memory files must exist 896** in order for the database to be readable. The fourth parameter to 897** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 898** That integer is 0 to disable persistent WAL mode or 1 to enable persistent 899** WAL mode. If the integer is -1, then it is overwritten with the current 900** WAL persistence setting. 901** 902** <li>[[SQLITE_FCNTL_POWERSAFE_OVERWRITE]] 903** ^The [SQLITE_FCNTL_POWERSAFE_OVERWRITE] opcode is used to set or query the 904** persistent "powersafe-overwrite" or "PSOW" setting. The PSOW setting 905** determines the [SQLITE_IOCAP_POWERSAFE_OVERWRITE] bit of the 906** xDeviceCharacteristics methods. The fourth parameter to 907** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 908** That integer is 0 to disable zero-damage mode or 1 to enable zero-damage 909** mode. If the integer is -1, then it is overwritten with the current 910** zero-damage mode setting. 911** 912** <li>[[SQLITE_FCNTL_OVERWRITE]] 913** ^The [SQLITE_FCNTL_OVERWRITE] opcode is invoked by SQLite after opening 914** a write transaction to indicate that, unless it is rolled back for some 915** reason, the entire database file will be overwritten by the current 916** transaction. This is used by VACUUM operations. 917** 918** <li>[[SQLITE_FCNTL_VFSNAME]] 919** ^The [SQLITE_FCNTL_VFSNAME] opcode can be used to obtain the names of 920** all [VFSes] in the VFS stack. The names are of all VFS shims and the 921** final bottom-level VFS are written into memory obtained from 922** [sqlite3_malloc()] and the result is stored in the char* variable 923** that the fourth parameter of [sqlite3_file_control()] points to. 924** The caller is responsible for freeing the memory when done. As with 925** all file-control actions, there is no guarantee that this will actually 926** do anything. Callers should initialize the char* variable to a NULL 927** pointer in case this file-control is not implemented. This file-control 928** is intended for diagnostic use only. 929** 930** <li>[[SQLITE_FCNTL_VFS_POINTER]] 931** ^The [SQLITE_FCNTL_VFS_POINTER] opcode finds a pointer to the top-level 932** [VFSes] currently in use. ^(The argument X in 933** sqlite3_file_control(db,SQLITE_FCNTL_VFS_POINTER,X) must be 934** of type "[sqlite3_vfs] **". This opcodes will set *X 935** to a pointer to the top-level VFS.)^ 936** ^When there are multiple VFS shims in the stack, this opcode finds the 937** upper-most shim only. 938** 939** <li>[[SQLITE_FCNTL_PRAGMA]] 940** ^Whenever a [PRAGMA] statement is parsed, an [SQLITE_FCNTL_PRAGMA] 941** file control is sent to the open [sqlite3_file] object corresponding 942** to the database file to which the pragma statement refers. ^The argument 943** to the [SQLITE_FCNTL_PRAGMA] file control is an array of 944** pointers to strings (char**) in which the second element of the array 945** is the name of the pragma and the third element is the argument to the 946** pragma or NULL if the pragma has no argument. ^The handler for an 947** [SQLITE_FCNTL_PRAGMA] file control can optionally make the first element 948** of the char** argument point to a string obtained from [sqlite3_mprintf()] 949** or the equivalent and that string will become the result of the pragma or 950** the error message if the pragma fails. ^If the 951** [SQLITE_FCNTL_PRAGMA] file control returns [SQLITE_NOTFOUND], then normal 952** [PRAGMA] processing continues. ^If the [SQLITE_FCNTL_PRAGMA] 953** file control returns [SQLITE_OK], then the parser assumes that the 954** VFS has handled the PRAGMA itself and the parser generates a no-op 955** prepared statement if result string is NULL, or that returns a copy 956** of the result string if the string is non-NULL. 957** ^If the [SQLITE_FCNTL_PRAGMA] file control returns 958** any result code other than [SQLITE_OK] or [SQLITE_NOTFOUND], that means 959** that the VFS encountered an error while handling the [PRAGMA] and the 960** compilation of the PRAGMA fails with an error. ^The [SQLITE_FCNTL_PRAGMA] 961** file control occurs at the beginning of pragma statement analysis and so 962** it is able to override built-in [PRAGMA] statements. 963** 964** <li>[[SQLITE_FCNTL_BUSYHANDLER]] 965** ^The [SQLITE_FCNTL_BUSYHANDLER] 966** file-control may be invoked by SQLite on the database file handle 967** shortly after it is opened in order to provide a custom VFS with access 968** to the connections busy-handler callback. The argument is of type (void **) 969** - an array of two (void *) values. The first (void *) actually points 970** to a function of type (int (*)(void *)). In order to invoke the connections 971** busy-handler, this function should be invoked with the second (void *) in 972** the array as the only argument. If it returns non-zero, then the operation 973** should be retried. If it returns zero, the custom VFS should abandon the 974** current operation. 975** 976** <li>[[SQLITE_FCNTL_TEMPFILENAME]] 977** ^Application can invoke the [SQLITE_FCNTL_TEMPFILENAME] file-control 978** to have SQLite generate a 979** temporary filename using the same algorithm that is followed to generate 980** temporary filenames for TEMP tables and other internal uses. The 981** argument should be a char** which will be filled with the filename 982** written into memory obtained from [sqlite3_malloc()]. The caller should 983** invoke [sqlite3_free()] on the result to avoid a memory leak. 984** 985** <li>[[SQLITE_FCNTL_MMAP_SIZE]] 986** The [SQLITE_FCNTL_MMAP_SIZE] file control is used to query or set the 987** maximum number of bytes that will be used for memory-mapped I/O. 988** The argument is a pointer to a value of type sqlite3_int64 that 989** is an advisory maximum number of bytes in the file to memory map. The 990** pointer is overwritten with the old value. The limit is not changed if 991** the value originally pointed to is negative, and so the current limit 992** can be queried by passing in a pointer to a negative number. This 993** file-control is used internally to implement [PRAGMA mmap_size]. 994** 995** <li>[[SQLITE_FCNTL_TRACE]] 996** The [SQLITE_FCNTL_TRACE] file control provides advisory information 997** to the VFS about what the higher layers of the SQLite stack are doing. 998** This file control is used by some VFS activity tracing [shims]. 999** The argument is a zero-terminated string. Higher layers in the 1000** SQLite stack may generate instances of this file control if 1001** the [SQLITE_USE_FCNTL_TRACE] compile-time option is enabled. 1002** 1003** <li>[[SQLITE_FCNTL_HAS_MOVED]] 1004** The [SQLITE_FCNTL_HAS_MOVED] file control interprets its argument as a 1005** pointer to an integer and it writes a boolean into that integer depending 1006** on whether or not the file has been renamed, moved, or deleted since it 1007** was first opened. 1008** 1009** <li>[[SQLITE_FCNTL_WIN32_GET_HANDLE]] 1010** The [SQLITE_FCNTL_WIN32_GET_HANDLE] opcode can be used to obtain the 1011** underlying native file handle associated with a file handle. This file 1012** control interprets its argument as a pointer to a native file handle and 1013** writes the resulting value there. 1014** 1015** <li>[[SQLITE_FCNTL_WIN32_SET_HANDLE]] 1016** The [SQLITE_FCNTL_WIN32_SET_HANDLE] opcode is used for debugging. This 1017** opcode causes the xFileControl method to swap the file handle with the one 1018** pointed to by the pArg argument. This capability is used during testing 1019** and only needs to be supported when SQLITE_TEST is defined. 1020** 1021** <li>[[SQLITE_FCNTL_WAL_BLOCK]] 1022** The [SQLITE_FCNTL_WAL_BLOCK] is a signal to the VFS layer that it might 1023** be advantageous to block on the next WAL lock if the lock is not immediately 1024** available. The WAL subsystem issues this signal during rare 1025** circumstances in order to fix a problem with priority inversion. 1026** Applications should <em>not</em> use this file-control. 1027** 1028** <li>[[SQLITE_FCNTL_ZIPVFS]] 1029** The [SQLITE_FCNTL_ZIPVFS] opcode is implemented by zipvfs only. All other 1030** VFS should return SQLITE_NOTFOUND for this opcode. 1031** 1032** <li>[[SQLITE_FCNTL_RBU]] 1033** The [SQLITE_FCNTL_RBU] opcode is implemented by the special VFS used by 1034** the RBU extension only. All other VFS should return SQLITE_NOTFOUND for 1035** this opcode. 1036** 1037** <li>[[SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]] 1038** If the [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] opcode returns SQLITE_OK, then 1039** the file descriptor is placed in "batch write mode", which 1040** means all subsequent write operations will be deferred and done 1041** atomically at the next [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]. Systems 1042** that do not support batch atomic writes will return SQLITE_NOTFOUND. 1043** ^Following a successful SQLITE_FCNTL_BEGIN_ATOMIC_WRITE and prior to 1044** the closing [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] or 1045** [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE], SQLite will make 1046** no VFS interface calls on the same [sqlite3_file] file descriptor 1047** except for calls to the xWrite method and the xFileControl method 1048** with [SQLITE_FCNTL_SIZE_HINT]. 1049** 1050** <li>[[SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]] 1051** The [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] opcode causes all write 1052** operations since the previous successful call to 1053** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be performed atomically. 1054** This file control returns [SQLITE_OK] if and only if the writes were 1055** all performed successfully and have been committed to persistent storage. 1056** ^Regardless of whether or not it is successful, this file control takes 1057** the file descriptor out of batch write mode so that all subsequent 1058** write operations are independent. 1059** ^SQLite will never invoke SQLITE_FCNTL_COMMIT_ATOMIC_WRITE without 1060** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]. 1061** 1062** <li>[[SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE]] 1063** The [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE] opcode causes all write 1064** operations since the previous successful call to 1065** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be rolled back. 1066** ^This file control takes the file descriptor out of batch write mode 1067** so that all subsequent write operations are independent. 1068** ^SQLite will never invoke SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE without 1069** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]. 1070** 1071** <li>[[SQLITE_FCNTL_LOCK_TIMEOUT]] 1072** The [SQLITE_FCNTL_LOCK_TIMEOUT] opcode causes attempts to obtain 1073** a file lock using the xLock or xShmLock methods of the VFS to wait 1074** for up to M milliseconds before failing, where M is the single 1075** unsigned integer parameter. 1076** </ul> 1077*/ 1078#define SQLITE_FCNTL_LOCKSTATE 1 1079#define SQLITE_FCNTL_GET_LOCKPROXYFILE 2 1080#define SQLITE_FCNTL_SET_LOCKPROXYFILE 3 1081#define SQLITE_FCNTL_LAST_ERRNO 4 1082#define SQLITE_FCNTL_SIZE_HINT 5 1083#define SQLITE_FCNTL_CHUNK_SIZE 6 1084#define SQLITE_FCNTL_FILE_POINTER 7 1085#define SQLITE_FCNTL_SYNC_OMITTED 8 1086#define SQLITE_FCNTL_WIN32_AV_RETRY 9 1087#define SQLITE_FCNTL_PERSIST_WAL 10 1088#define SQLITE_FCNTL_OVERWRITE 11 1089#define SQLITE_FCNTL_VFSNAME 12 1090#define SQLITE_FCNTL_POWERSAFE_OVERWRITE 13 1091#define SQLITE_FCNTL_PRAGMA 14 1092#define SQLITE_FCNTL_BUSYHANDLER 15 1093#define SQLITE_FCNTL_TEMPFILENAME 16 1094#define SQLITE_FCNTL_MMAP_SIZE 18 1095#define SQLITE_FCNTL_TRACE 19 1096#define SQLITE_FCNTL_HAS_MOVED 20 1097#define SQLITE_FCNTL_SYNC 21 1098#define SQLITE_FCNTL_COMMIT_PHASETWO 22 1099#define SQLITE_FCNTL_WIN32_SET_HANDLE 23 1100#define SQLITE_FCNTL_WAL_BLOCK 24 1101#define SQLITE_FCNTL_ZIPVFS 25 1102#define SQLITE_FCNTL_RBU 26 1103#define SQLITE_FCNTL_VFS_POINTER 27 1104#define SQLITE_FCNTL_JOURNAL_POINTER 28 1105#define SQLITE_FCNTL_WIN32_GET_HANDLE 29 1106#define SQLITE_FCNTL_PDB 30 1107#define SQLITE_FCNTL_BEGIN_ATOMIC_WRITE 31 1108#define SQLITE_FCNTL_COMMIT_ATOMIC_WRITE 32 1109#define SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE 33 1110#define SQLITE_FCNTL_LOCK_TIMEOUT 34 1111 1112/* deprecated names */ 1113#define SQLITE_GET_LOCKPROXYFILE SQLITE_FCNTL_GET_LOCKPROXYFILE 1114#define SQLITE_SET_LOCKPROXYFILE SQLITE_FCNTL_SET_LOCKPROXYFILE 1115#define SQLITE_LAST_ERRNO SQLITE_FCNTL_LAST_ERRNO 1116 1117 1118/* 1119** CAPI3REF: Mutex Handle 1120** 1121** The mutex module within SQLite defines [sqlite3_mutex] to be an 1122** abstract type for a mutex object. The SQLite core never looks 1123** at the internal representation of an [sqlite3_mutex]. It only 1124** deals with pointers to the [sqlite3_mutex] object. 1125** 1126** Mutexes are created using [sqlite3_mutex_alloc()]. 1127*/ 1128typedef struct sqlite3_mutex sqlite3_mutex; 1129 1130/* 1131** CAPI3REF: Loadable Extension Thunk 1132** 1133** A pointer to the opaque sqlite3_api_routines structure is passed as 1134** the third parameter to entry points of [loadable extensions]. This 1135** structure must be typedefed in order to work around compiler warnings 1136** on some platforms. 1137*/ 1138typedef struct sqlite3_api_routines sqlite3_api_routines; 1139 1140/* 1141** CAPI3REF: OS Interface Object 1142** 1143** An instance of the sqlite3_vfs object defines the interface between 1144** the SQLite core and the underlying operating system. The "vfs" 1145** in the name of the object stands for "virtual file system". See 1146** the [VFS | VFS documentation] for further information. 1147** 1148** The VFS interface is sometimes extended by adding new methods onto 1149** the end. Each time such an extension occurs, the iVersion field 1150** is incremented. The iVersion value started out as 1 in 1151** SQLite [version 3.5.0] on [dateof:3.5.0], then increased to 2 1152** with SQLite [version 3.7.0] on [dateof:3.7.0], and then increased 1153** to 3 with SQLite [version 3.7.6] on [dateof:3.7.6]. Additional fields 1154** may be appended to the sqlite3_vfs object and the iVersion value 1155** may increase again in future versions of SQLite. 1156** Note that the structure 1157** of the sqlite3_vfs object changes in the transition from 1158** SQLite [version 3.5.9] to [version 3.6.0] on [dateof:3.6.0] 1159** and yet the iVersion field was not modified. 1160** 1161** The szOsFile field is the size of the subclassed [sqlite3_file] 1162** structure used by this VFS. mxPathname is the maximum length of 1163** a pathname in this VFS. 1164** 1165** Registered sqlite3_vfs objects are kept on a linked list formed by 1166** the pNext pointer. The [sqlite3_vfs_register()] 1167** and [sqlite3_vfs_unregister()] interfaces manage this list 1168** in a thread-safe way. The [sqlite3_vfs_find()] interface 1169** searches the list. Neither the application code nor the VFS 1170** implementation should use the pNext pointer. 1171** 1172** The pNext field is the only field in the sqlite3_vfs 1173** structure that SQLite will ever modify. SQLite will only access 1174** or modify this field while holding a particular static mutex. 1175** The application should never modify anything within the sqlite3_vfs 1176** object once the object has been registered. 1177** 1178** The zName field holds the name of the VFS module. The name must 1179** be unique across all VFS modules. 1180** 1181** [[sqlite3_vfs.xOpen]] 1182** ^SQLite guarantees that the zFilename parameter to xOpen 1183** is either a NULL pointer or string obtained 1184** from xFullPathname() with an optional suffix added. 1185** ^If a suffix is added to the zFilename parameter, it will 1186** consist of a single "-" character followed by no more than 1187** 11 alphanumeric and/or "-" characters. 1188** ^SQLite further guarantees that 1189** the string will be valid and unchanged until xClose() is 1190** called. Because of the previous sentence, 1191** the [sqlite3_file] can safely store a pointer to the 1192** filename if it needs to remember the filename for some reason. 1193** If the zFilename parameter to xOpen is a NULL pointer then xOpen 1194** must invent its own temporary name for the file. ^Whenever the 1195** xFilename parameter is NULL it will also be the case that the 1196** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE]. 1197** 1198** The flags argument to xOpen() includes all bits set in 1199** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()] 1200** or [sqlite3_open16()] is used, then flags includes at least 1201** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]. 1202** If xOpen() opens a file read-only then it sets *pOutFlags to 1203** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be set. 1204** 1205** ^(SQLite will also add one of the following flags to the xOpen() 1206** call, depending on the object being opened: 1207** 1208** <ul> 1209** <li> [SQLITE_OPEN_MAIN_DB] 1210** <li> [SQLITE_OPEN_MAIN_JOURNAL] 1211** <li> [SQLITE_OPEN_TEMP_DB] 1212** <li> [SQLITE_OPEN_TEMP_JOURNAL] 1213** <li> [SQLITE_OPEN_TRANSIENT_DB] 1214** <li> [SQLITE_OPEN_SUBJOURNAL] 1215** <li> [SQLITE_OPEN_MASTER_JOURNAL] 1216** <li> [SQLITE_OPEN_WAL] 1217** </ul>)^ 1218** 1219** The file I/O implementation can use the object type flags to 1220** change the way it deals with files. For example, an application 1221** that does not care about crash recovery or rollback might make 1222** the open of a journal file a no-op. Writes to this journal would 1223** also be no-ops, and any attempt to read the journal would return 1224** SQLITE_IOERR. Or the implementation might recognize that a database 1225** file will be doing page-aligned sector reads and writes in a random 1226** order and set up its I/O subsystem accordingly. 1227** 1228** SQLite might also add one of the following flags to the xOpen method: 1229** 1230** <ul> 1231** <li> [SQLITE_OPEN_DELETEONCLOSE] 1232** <li> [SQLITE_OPEN_EXCLUSIVE] 1233** </ul> 1234** 1235** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be 1236** deleted when it is closed. ^The [SQLITE_OPEN_DELETEONCLOSE] 1237** will be set for TEMP databases and their journals, transient 1238** databases, and subjournals. 1239** 1240** ^The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction 1241** with the [SQLITE_OPEN_CREATE] flag, which are both directly 1242** analogous to the O_EXCL and O_CREAT flags of the POSIX open() 1243** API. The SQLITE_OPEN_EXCLUSIVE flag, when paired with the 1244** SQLITE_OPEN_CREATE, is used to indicate that file should always 1245** be created, and that it is an error if it already exists. 1246** It is <i>not</i> used to indicate the file should be opened 1247** for exclusive access. 1248** 1249** ^At least szOsFile bytes of memory are allocated by SQLite 1250** to hold the [sqlite3_file] structure passed as the third 1251** argument to xOpen. The xOpen method does not have to 1252** allocate the structure; it should just fill it in. Note that 1253** the xOpen method must set the sqlite3_file.pMethods to either 1254** a valid [sqlite3_io_methods] object or to NULL. xOpen must do 1255** this even if the open fails. SQLite expects that the sqlite3_file.pMethods 1256** element will be valid after xOpen returns regardless of the success 1257** or failure of the xOpen call. 1258** 1259** [[sqlite3_vfs.xAccess]] 1260** ^The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS] 1261** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to 1262** test whether a file is readable and writable, or [SQLITE_ACCESS_READ] 1263** to test whether a file is at least readable. The file can be a 1264** directory. 1265** 1266** ^SQLite will always allocate at least mxPathname+1 bytes for the 1267** output buffer xFullPathname. The exact size of the output buffer 1268** is also passed as a parameter to both methods. If the output buffer 1269** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is 1270** handled as a fatal error by SQLite, vfs implementations should endeavor 1271** to prevent this by setting mxPathname to a sufficiently large value. 1272** 1273** The xRandomness(), xSleep(), xCurrentTime(), and xCurrentTimeInt64() 1274** interfaces are not strictly a part of the filesystem, but they are 1275** included in the VFS structure for completeness. 1276** The xRandomness() function attempts to return nBytes bytes 1277** of good-quality randomness into zOut. The return value is 1278** the actual number of bytes of randomness obtained. 1279** The xSleep() method causes the calling thread to sleep for at 1280** least the number of microseconds given. ^The xCurrentTime() 1281** method returns a Julian Day Number for the current date and time as 1282** a floating point value. 1283** ^The xCurrentTimeInt64() method returns, as an integer, the Julian 1284** Day Number multiplied by 86400000 (the number of milliseconds in 1285** a 24-hour day). 1286** ^SQLite will use the xCurrentTimeInt64() method to get the current 1287** date and time if that method is available (if iVersion is 2 or 1288** greater and the function pointer is not NULL) and will fall back 1289** to xCurrentTime() if xCurrentTimeInt64() is unavailable. 1290** 1291** ^The xSetSystemCall(), xGetSystemCall(), and xNestSystemCall() interfaces 1292** are not used by the SQLite core. These optional interfaces are provided 1293** by some VFSes to facilitate testing of the VFS code. By overriding 1294** system calls with functions under its control, a test program can 1295** simulate faults and error conditions that would otherwise be difficult 1296** or impossible to induce. The set of system calls that can be overridden 1297** varies from one VFS to another, and from one version of the same VFS to the 1298** next. Applications that use these interfaces must be prepared for any 1299** or all of these interfaces to be NULL or for their behavior to change 1300** from one release to the next. Applications must not attempt to access 1301** any of these methods if the iVersion of the VFS is less than 3. 1302*/ 1303typedef struct sqlite3_vfs sqlite3_vfs; 1304typedef void (*sqlite3_syscall_ptr)(void); 1305struct sqlite3_vfs { 1306 int iVersion; /* Structure version number (currently 3) */ 1307 int szOsFile; /* Size of subclassed sqlite3_file */ 1308 int mxPathname; /* Maximum file pathname length */ 1309 sqlite3_vfs *pNext; /* Next registered VFS */ 1310 const char *zName; /* Name of this virtual file system */ 1311 void *pAppData; /* Pointer to application-specific data */ 1312 int (*xOpen)(sqlite3_vfs*, const char *zName, sqlite3_file*, 1313 int flags, int *pOutFlags); 1314 int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir); 1315 int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut); 1316 int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut); 1317 void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename); 1318 void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg); 1319 void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void); 1320 void (*xDlClose)(sqlite3_vfs*, void*); 1321 int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut); 1322 int (*xSleep)(sqlite3_vfs*, int microseconds); 1323 int (*xCurrentTime)(sqlite3_vfs*, double*); 1324 int (*xGetLastError)(sqlite3_vfs*, int, char *); 1325 /* 1326 ** The methods above are in version 1 of the sqlite_vfs object 1327 ** definition. Those that follow are added in version 2 or later 1328 */ 1329 int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*); 1330 /* 1331 ** The methods above are in versions 1 and 2 of the sqlite_vfs object. 1332 ** Those below are for version 3 and greater. 1333 */ 1334 int (*xSetSystemCall)(sqlite3_vfs*, const char *zName, sqlite3_syscall_ptr); 1335 sqlite3_syscall_ptr (*xGetSystemCall)(sqlite3_vfs*, const char *zName); 1336 const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName); 1337 /* 1338 ** The methods above are in versions 1 through 3 of the sqlite_vfs object. 1339 ** New fields may be appended in future versions. The iVersion 1340 ** value will increment whenever this happens. 1341 */ 1342}; 1343 1344/* 1345** CAPI3REF: Flags for the xAccess VFS method 1346** 1347** These integer constants can be used as the third parameter to 1348** the xAccess method of an [sqlite3_vfs] object. They determine 1349** what kind of permissions the xAccess method is looking for. 1350** With SQLITE_ACCESS_EXISTS, the xAccess method 1351** simply checks whether the file exists. 1352** With SQLITE_ACCESS_READWRITE, the xAccess method 1353** checks whether the named directory is both readable and writable 1354** (in other words, if files can be added, removed, and renamed within 1355** the directory). 1356** The SQLITE_ACCESS_READWRITE constant is currently used only by the 1357** [temp_store_directory pragma], though this could change in a future 1358** release of SQLite. 1359** With SQLITE_ACCESS_READ, the xAccess method 1360** checks whether the file is readable. The SQLITE_ACCESS_READ constant is 1361** currently unused, though it might be used in a future release of 1362** SQLite. 1363*/ 1364#define SQLITE_ACCESS_EXISTS 0 1365#define SQLITE_ACCESS_READWRITE 1 /* Used by PRAGMA temp_store_directory */ 1366#define SQLITE_ACCESS_READ 2 /* Unused */ 1367 1368/* 1369** CAPI3REF: Flags for the xShmLock VFS method 1370** 1371** These integer constants define the various locking operations 1372** allowed by the xShmLock method of [sqlite3_io_methods]. The 1373** following are the only legal combinations of flags to the 1374** xShmLock method: 1375** 1376** <ul> 1377** <li> SQLITE_SHM_LOCK | SQLITE_SHM_SHARED 1378** <li> SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE 1379** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED 1380** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE 1381** </ul> 1382** 1383** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as 1384** was given on the corresponding lock. 1385** 1386** The xShmLock method can transition between unlocked and SHARED or 1387** between unlocked and EXCLUSIVE. It cannot transition between SHARED 1388** and EXCLUSIVE. 1389*/ 1390#define SQLITE_SHM_UNLOCK 1 1391#define SQLITE_SHM_LOCK 2 1392#define SQLITE_SHM_SHARED 4 1393#define SQLITE_SHM_EXCLUSIVE 8 1394 1395/* 1396** CAPI3REF: Maximum xShmLock index 1397** 1398** The xShmLock method on [sqlite3_io_methods] may use values 1399** between 0 and this upper bound as its "offset" argument. 1400** The SQLite core will never attempt to acquire or release a 1401** lock outside of this range 1402*/ 1403#define SQLITE_SHM_NLOCK 8 1404 1405 1406/* 1407** CAPI3REF: Initialize The SQLite Library 1408** 1409** ^The sqlite3_initialize() routine initializes the 1410** SQLite library. ^The sqlite3_shutdown() routine 1411** deallocates any resources that were allocated by sqlite3_initialize(). 1412** These routines are designed to aid in process initialization and 1413** shutdown on embedded systems. Workstation applications using 1414** SQLite normally do not need to invoke either of these routines. 1415** 1416** A call to sqlite3_initialize() is an "effective" call if it is 1417** the first time sqlite3_initialize() is invoked during the lifetime of 1418** the process, or if it is the first time sqlite3_initialize() is invoked 1419** following a call to sqlite3_shutdown(). ^(Only an effective call 1420** of sqlite3_initialize() does any initialization. All other calls 1421** are harmless no-ops.)^ 1422** 1423** A call to sqlite3_shutdown() is an "effective" call if it is the first 1424** call to sqlite3_shutdown() since the last sqlite3_initialize(). ^(Only 1425** an effective call to sqlite3_shutdown() does any deinitialization. 1426** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^ 1427** 1428** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown() 1429** is not. The sqlite3_shutdown() interface must only be called from a 1430** single thread. All open [database connections] must be closed and all 1431** other SQLite resources must be deallocated prior to invoking 1432** sqlite3_shutdown(). 1433** 1434** Among other things, ^sqlite3_initialize() will invoke 1435** sqlite3_os_init(). Similarly, ^sqlite3_shutdown() 1436** will invoke sqlite3_os_end(). 1437** 1438** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success. 1439** ^If for some reason, sqlite3_initialize() is unable to initialize 1440** the library (perhaps it is unable to allocate a needed resource such 1441** as a mutex) it returns an [error code] other than [SQLITE_OK]. 1442** 1443** ^The sqlite3_initialize() routine is called internally by many other 1444** SQLite interfaces so that an application usually does not need to 1445** invoke sqlite3_initialize() directly. For example, [sqlite3_open()] 1446** calls sqlite3_initialize() so the SQLite library will be automatically 1447** initialized when [sqlite3_open()] is called if it has not be initialized 1448** already. ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT] 1449** compile-time option, then the automatic calls to sqlite3_initialize() 1450** are omitted and the application must call sqlite3_initialize() directly 1451** prior to using any other SQLite interface. For maximum portability, 1452** it is recommended that applications always invoke sqlite3_initialize() 1453** directly prior to using any other SQLite interface. Future releases 1454** of SQLite may require this. In other words, the behavior exhibited 1455** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the 1456** default behavior in some future release of SQLite. 1457** 1458** The sqlite3_os_init() routine does operating-system specific 1459** initialization of the SQLite library. The sqlite3_os_end() 1460** routine undoes the effect of sqlite3_os_init(). Typical tasks 1461** performed by these routines include allocation or deallocation 1462** of static resources, initialization of global variables, 1463** setting up a default [sqlite3_vfs] module, or setting up 1464** a default configuration using [sqlite3_config()]. 1465** 1466** The application should never invoke either sqlite3_os_init() 1467** or sqlite3_os_end() directly. The application should only invoke 1468** sqlite3_initialize() and sqlite3_shutdown(). The sqlite3_os_init() 1469** interface is called automatically by sqlite3_initialize() and 1470** sqlite3_os_end() is called by sqlite3_shutdown(). Appropriate 1471** implementations for sqlite3_os_init() and sqlite3_os_end() 1472** are built into SQLite when it is compiled for Unix, Windows, or OS/2. 1473** When [custom builds | built for other platforms] 1474** (using the [SQLITE_OS_OTHER=1] compile-time 1475** option) the application must supply a suitable implementation for 1476** sqlite3_os_init() and sqlite3_os_end(). An application-supplied 1477** implementation of sqlite3_os_init() or sqlite3_os_end() 1478** must return [SQLITE_OK] on success and some other [error code] upon 1479** failure. 1480*/ 1481int sqlite3_initialize(void); 1482int sqlite3_shutdown(void); 1483int sqlite3_os_init(void); 1484int sqlite3_os_end(void); 1485 1486/* 1487** CAPI3REF: Configuring The SQLite Library 1488** 1489** The sqlite3_config() interface is used to make global configuration 1490** changes to SQLite in order to tune SQLite to the specific needs of 1491** the application. The default configuration is recommended for most 1492** applications and so this routine is usually not necessary. It is 1493** provided to support rare applications with unusual needs. 1494** 1495** <b>The sqlite3_config() interface is not threadsafe. The application 1496** must ensure that no other SQLite interfaces are invoked by other 1497** threads while sqlite3_config() is running.</b> 1498** 1499** The sqlite3_config() interface 1500** may only be invoked prior to library initialization using 1501** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()]. 1502** ^If sqlite3_config() is called after [sqlite3_initialize()] and before 1503** [sqlite3_shutdown()] then it will return SQLITE_MISUSE. 1504** Note, however, that ^sqlite3_config() can be called as part of the 1505** implementation of an application-defined [sqlite3_os_init()]. 1506** 1507** The first argument to sqlite3_config() is an integer 1508** [configuration option] that determines 1509** what property of SQLite is to be configured. Subsequent arguments 1510** vary depending on the [configuration option] 1511** in the first argument. 1512** 1513** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK]. 1514** ^If the option is unknown or SQLite is unable to set the option 1515** then this routine returns a non-zero [error code]. 1516*/ 1517int sqlite3_config(int, ...); 1518 1519/* 1520** CAPI3REF: Configure database connections 1521** METHOD: sqlite3 1522** 1523** The sqlite3_db_config() interface is used to make configuration 1524** changes to a [database connection]. The interface is similar to 1525** [sqlite3_config()] except that the changes apply to a single 1526** [database connection] (specified in the first argument). 1527** 1528** The second argument to sqlite3_db_config(D,V,...) is the 1529** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code 1530** that indicates what aspect of the [database connection] is being configured. 1531** Subsequent arguments vary depending on the configuration verb. 1532** 1533** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if 1534** the call is considered successful. 1535*/ 1536int sqlite3_db_config(sqlite3*, int op, ...); 1537 1538/* 1539** CAPI3REF: Memory Allocation Routines 1540** 1541** An instance of this object defines the interface between SQLite 1542** and low-level memory allocation routines. 1543** 1544** This object is used in only one place in the SQLite interface. 1545** A pointer to an instance of this object is the argument to 1546** [sqlite3_config()] when the configuration option is 1547** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC]. 1548** By creating an instance of this object 1549** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC]) 1550** during configuration, an application can specify an alternative 1551** memory allocation subsystem for SQLite to use for all of its 1552** dynamic memory needs. 1553** 1554** Note that SQLite comes with several [built-in memory allocators] 1555** that are perfectly adequate for the overwhelming majority of applications 1556** and that this object is only useful to a tiny minority of applications 1557** with specialized memory allocation requirements. This object is 1558** also used during testing of SQLite in order to specify an alternative 1559** memory allocator that simulates memory out-of-memory conditions in 1560** order to verify that SQLite recovers gracefully from such 1561** conditions. 1562** 1563** The xMalloc, xRealloc, and xFree methods must work like the 1564** malloc(), realloc() and free() functions from the standard C library. 1565** ^SQLite guarantees that the second argument to 1566** xRealloc is always a value returned by a prior call to xRoundup. 1567** 1568** xSize should return the allocated size of a memory allocation 1569** previously obtained from xMalloc or xRealloc. The allocated size 1570** is always at least as big as the requested size but may be larger. 1571** 1572** The xRoundup method returns what would be the allocated size of 1573** a memory allocation given a particular requested size. Most memory 1574** allocators round up memory allocations at least to the next multiple 1575** of 8. Some allocators round up to a larger multiple or to a power of 2. 1576** Every memory allocation request coming in through [sqlite3_malloc()] 1577** or [sqlite3_realloc()] first calls xRoundup. If xRoundup returns 0, 1578** that causes the corresponding memory allocation to fail. 1579** 1580** The xInit method initializes the memory allocator. For example, 1581** it might allocate any require mutexes or initialize internal data 1582** structures. The xShutdown method is invoked (indirectly) by 1583** [sqlite3_shutdown()] and should deallocate any resources acquired 1584** by xInit. The pAppData pointer is used as the only parameter to 1585** xInit and xShutdown. 1586** 1587** SQLite holds the [SQLITE_MUTEX_STATIC_MASTER] mutex when it invokes 1588** the xInit method, so the xInit method need not be threadsafe. The 1589** xShutdown method is only called from [sqlite3_shutdown()] so it does 1590** not need to be threadsafe either. For all other methods, SQLite 1591** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the 1592** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which 1593** it is by default) and so the methods are automatically serialized. 1594** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other 1595** methods must be threadsafe or else make their own arrangements for 1596** serialization. 1597** 1598** SQLite will never invoke xInit() more than once without an intervening 1599** call to xShutdown(). 1600*/ 1601typedef struct sqlite3_mem_methods sqlite3_mem_methods; 1602struct sqlite3_mem_methods { 1603 void *(*xMalloc)(int); /* Memory allocation function */ 1604 void (*xFree)(void*); /* Free a prior allocation */ 1605 void *(*xRealloc)(void*,int); /* Resize an allocation */ 1606 int (*xSize)(void*); /* Return the size of an allocation */ 1607 int (*xRoundup)(int); /* Round up request size to allocation size */ 1608 int (*xInit)(void*); /* Initialize the memory allocator */ 1609 void (*xShutdown)(void*); /* Deinitialize the memory allocator */ 1610 void *pAppData; /* Argument to xInit() and xShutdown() */ 1611}; 1612 1613/* 1614** CAPI3REF: Configuration Options 1615** KEYWORDS: {configuration option} 1616** 1617** These constants are the available integer configuration options that 1618** can be passed as the first argument to the [sqlite3_config()] interface. 1619** 1620** New configuration options may be added in future releases of SQLite. 1621** Existing configuration options might be discontinued. Applications 1622** should check the return code from [sqlite3_config()] to make sure that 1623** the call worked. The [sqlite3_config()] interface will return a 1624** non-zero [error code] if a discontinued or unsupported configuration option 1625** is invoked. 1626** 1627** <dl> 1628** [[SQLITE_CONFIG_SINGLETHREAD]] <dt>SQLITE_CONFIG_SINGLETHREAD</dt> 1629** <dd>There are no arguments to this option. ^This option sets the 1630** [threading mode] to Single-thread. In other words, it disables 1631** all mutexing and puts SQLite into a mode where it can only be used 1632** by a single thread. ^If SQLite is compiled with 1633** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1634** it is not possible to change the [threading mode] from its default 1635** value of Single-thread and so [sqlite3_config()] will return 1636** [SQLITE_ERROR] if called with the SQLITE_CONFIG_SINGLETHREAD 1637** configuration option.</dd> 1638** 1639** [[SQLITE_CONFIG_MULTITHREAD]] <dt>SQLITE_CONFIG_MULTITHREAD</dt> 1640** <dd>There are no arguments to this option. ^This option sets the 1641** [threading mode] to Multi-thread. In other words, it disables 1642** mutexing on [database connection] and [prepared statement] objects. 1643** The application is responsible for serializing access to 1644** [database connections] and [prepared statements]. But other mutexes 1645** are enabled so that SQLite will be safe to use in a multi-threaded 1646** environment as long as no two threads attempt to use the same 1647** [database connection] at the same time. ^If SQLite is compiled with 1648** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1649** it is not possible to set the Multi-thread [threading mode] and 1650** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1651** SQLITE_CONFIG_MULTITHREAD configuration option.</dd> 1652** 1653** [[SQLITE_CONFIG_SERIALIZED]] <dt>SQLITE_CONFIG_SERIALIZED</dt> 1654** <dd>There are no arguments to this option. ^This option sets the 1655** [threading mode] to Serialized. In other words, this option enables 1656** all mutexes including the recursive 1657** mutexes on [database connection] and [prepared statement] objects. 1658** In this mode (which is the default when SQLite is compiled with 1659** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access 1660** to [database connections] and [prepared statements] so that the 1661** application is free to use the same [database connection] or the 1662** same [prepared statement] in different threads at the same time. 1663** ^If SQLite is compiled with 1664** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1665** it is not possible to set the Serialized [threading mode] and 1666** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1667** SQLITE_CONFIG_SERIALIZED configuration option.</dd> 1668** 1669** [[SQLITE_CONFIG_MALLOC]] <dt>SQLITE_CONFIG_MALLOC</dt> 1670** <dd> ^(The SQLITE_CONFIG_MALLOC option takes a single argument which is 1671** a pointer to an instance of the [sqlite3_mem_methods] structure. 1672** The argument specifies 1673** alternative low-level memory allocation routines to be used in place of 1674** the memory allocation routines built into SQLite.)^ ^SQLite makes 1675** its own private copy of the content of the [sqlite3_mem_methods] structure 1676** before the [sqlite3_config()] call returns.</dd> 1677** 1678** [[SQLITE_CONFIG_GETMALLOC]] <dt>SQLITE_CONFIG_GETMALLOC</dt> 1679** <dd> ^(The SQLITE_CONFIG_GETMALLOC option takes a single argument which 1680** is a pointer to an instance of the [sqlite3_mem_methods] structure. 1681** The [sqlite3_mem_methods] 1682** structure is filled with the currently defined memory allocation routines.)^ 1683** This option can be used to overload the default memory allocation 1684** routines with a wrapper that simulations memory allocation failure or 1685** tracks memory usage, for example. </dd> 1686** 1687** [[SQLITE_CONFIG_SMALL_MALLOC]] <dt>SQLITE_CONFIG_SMALL_MALLOC</dt> 1688** <dd> ^The SQLITE_CONFIG_SMALL_MALLOC option takes single argument of 1689** type int, interpreted as a boolean, which if true provides a hint to 1690** SQLite that it should avoid large memory allocations if possible. 1691** SQLite will run faster if it is free to make large memory allocations, 1692** but some application might prefer to run slower in exchange for 1693** guarantees about memory fragmentation that are possible if large 1694** allocations are avoided. This hint is normally off. 1695** </dd> 1696** 1697** [[SQLITE_CONFIG_MEMSTATUS]] <dt>SQLITE_CONFIG_MEMSTATUS</dt> 1698** <dd> ^The SQLITE_CONFIG_MEMSTATUS option takes single argument of type int, 1699** interpreted as a boolean, which enables or disables the collection of 1700** memory allocation statistics. ^(When memory allocation statistics are 1701** disabled, the following SQLite interfaces become non-operational: 1702** <ul> 1703** <li> [sqlite3_memory_used()] 1704** <li> [sqlite3_memory_highwater()] 1705** <li> [sqlite3_soft_heap_limit64()] 1706** <li> [sqlite3_status64()] 1707** </ul>)^ 1708** ^Memory allocation statistics are enabled by default unless SQLite is 1709** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory 1710** allocation statistics are disabled by default. 1711** </dd> 1712** 1713** [[SQLITE_CONFIG_SCRATCH]] <dt>SQLITE_CONFIG_SCRATCH</dt> 1714** <dd> The SQLITE_CONFIG_SCRATCH option is no longer used. 1715** </dd> 1716** 1717** [[SQLITE_CONFIG_PAGECACHE]] <dt>SQLITE_CONFIG_PAGECACHE</dt> 1718** <dd> ^The SQLITE_CONFIG_PAGECACHE option specifies a memory pool 1719** that SQLite can use for the database page cache with the default page 1720** cache implementation. 1721** This configuration option is a no-op if an application-define page 1722** cache implementation is loaded using the [SQLITE_CONFIG_PCACHE2]. 1723** ^There are three arguments to SQLITE_CONFIG_PAGECACHE: A pointer to 1724** 8-byte aligned memory (pMem), the size of each page cache line (sz), 1725** and the number of cache lines (N). 1726** The sz argument should be the size of the largest database page 1727** (a power of two between 512 and 65536) plus some extra bytes for each 1728** page header. ^The number of extra bytes needed by the page header 1729** can be determined using [SQLITE_CONFIG_PCACHE_HDRSZ]. 1730** ^It is harmless, apart from the wasted memory, 1731** for the sz parameter to be larger than necessary. The pMem 1732** argument must be either a NULL pointer or a pointer to an 8-byte 1733** aligned block of memory of at least sz*N bytes, otherwise 1734** subsequent behavior is undefined. 1735** ^When pMem is not NULL, SQLite will strive to use the memory provided 1736** to satisfy page cache needs, falling back to [sqlite3_malloc()] if 1737** a page cache line is larger than sz bytes or if all of the pMem buffer 1738** is exhausted. 1739** ^If pMem is NULL and N is non-zero, then each database connection 1740** does an initial bulk allocation for page cache memory 1741** from [sqlite3_malloc()] sufficient for N cache lines if N is positive or 1742** of -1024*N bytes if N is negative, . ^If additional 1743** page cache memory is needed beyond what is provided by the initial 1744** allocation, then SQLite goes to [sqlite3_malloc()] separately for each 1745** additional cache line. </dd> 1746** 1747** [[SQLITE_CONFIG_HEAP]] <dt>SQLITE_CONFIG_HEAP</dt> 1748** <dd> ^The SQLITE_CONFIG_HEAP option specifies a static memory buffer 1749** that SQLite will use for all of its dynamic memory allocation needs 1750** beyond those provided for by [SQLITE_CONFIG_PAGECACHE]. 1751** ^The SQLITE_CONFIG_HEAP option is only available if SQLite is compiled 1752** with either [SQLITE_ENABLE_MEMSYS3] or [SQLITE_ENABLE_MEMSYS5] and returns 1753** [SQLITE_ERROR] if invoked otherwise. 1754** ^There are three arguments to SQLITE_CONFIG_HEAP: 1755** An 8-byte aligned pointer to the memory, 1756** the number of bytes in the memory buffer, and the minimum allocation size. 1757** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts 1758** to using its default memory allocator (the system malloc() implementation), 1759** undoing any prior invocation of [SQLITE_CONFIG_MALLOC]. ^If the 1760** memory pointer is not NULL then the alternative memory 1761** allocator is engaged to handle all of SQLites memory allocation needs. 1762** The first pointer (the memory pointer) must be aligned to an 8-byte 1763** boundary or subsequent behavior of SQLite will be undefined. 1764** The minimum allocation size is capped at 2**12. Reasonable values 1765** for the minimum allocation size are 2**5 through 2**8.</dd> 1766** 1767** [[SQLITE_CONFIG_MUTEX]] <dt>SQLITE_CONFIG_MUTEX</dt> 1768** <dd> ^(The SQLITE_CONFIG_MUTEX option takes a single argument which is a 1769** pointer to an instance of the [sqlite3_mutex_methods] structure. 1770** The argument specifies alternative low-level mutex routines to be used 1771** in place the mutex routines built into SQLite.)^ ^SQLite makes a copy of 1772** the content of the [sqlite3_mutex_methods] structure before the call to 1773** [sqlite3_config()] returns. ^If SQLite is compiled with 1774** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1775** the entire mutexing subsystem is omitted from the build and hence calls to 1776** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will 1777** return [SQLITE_ERROR].</dd> 1778** 1779** [[SQLITE_CONFIG_GETMUTEX]] <dt>SQLITE_CONFIG_GETMUTEX</dt> 1780** <dd> ^(The SQLITE_CONFIG_GETMUTEX option takes a single argument which 1781** is a pointer to an instance of the [sqlite3_mutex_methods] structure. The 1782** [sqlite3_mutex_methods] 1783** structure is filled with the currently defined mutex routines.)^ 1784** This option can be used to overload the default mutex allocation 1785** routines with a wrapper used to track mutex usage for performance 1786** profiling or testing, for example. ^If SQLite is compiled with 1787** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1788** the entire mutexing subsystem is omitted from the build and hence calls to 1789** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will 1790** return [SQLITE_ERROR].</dd> 1791** 1792** [[SQLITE_CONFIG_LOOKASIDE]] <dt>SQLITE_CONFIG_LOOKASIDE</dt> 1793** <dd> ^(The SQLITE_CONFIG_LOOKASIDE option takes two arguments that determine 1794** the default size of lookaside memory on each [database connection]. 1795** The first argument is the 1796** size of each lookaside buffer slot and the second is the number of 1797** slots allocated to each database connection.)^ ^(SQLITE_CONFIG_LOOKASIDE 1798** sets the <i>default</i> lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE] 1799** option to [sqlite3_db_config()] can be used to change the lookaside 1800** configuration on individual connections.)^ </dd> 1801** 1802** [[SQLITE_CONFIG_PCACHE2]] <dt>SQLITE_CONFIG_PCACHE2</dt> 1803** <dd> ^(The SQLITE_CONFIG_PCACHE2 option takes a single argument which is 1804** a pointer to an [sqlite3_pcache_methods2] object. This object specifies 1805** the interface to a custom page cache implementation.)^ 1806** ^SQLite makes a copy of the [sqlite3_pcache_methods2] object.</dd> 1807** 1808** [[SQLITE_CONFIG_GETPCACHE2]] <dt>SQLITE_CONFIG_GETPCACHE2</dt> 1809** <dd> ^(The SQLITE_CONFIG_GETPCACHE2 option takes a single argument which 1810** is a pointer to an [sqlite3_pcache_methods2] object. SQLite copies of 1811** the current page cache implementation into that object.)^ </dd> 1812** 1813** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt> 1814** <dd> The SQLITE_CONFIG_LOG option is used to configure the SQLite 1815** global [error log]. 1816** (^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a 1817** function with a call signature of void(*)(void*,int,const char*), 1818** and a pointer to void. ^If the function pointer is not NULL, it is 1819** invoked by [sqlite3_log()] to process each logging event. ^If the 1820** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op. 1821** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is 1822** passed through as the first parameter to the application-defined logger 1823** function whenever that function is invoked. ^The second parameter to 1824** the logger function is a copy of the first parameter to the corresponding 1825** [sqlite3_log()] call and is intended to be a [result code] or an 1826** [extended result code]. ^The third parameter passed to the logger is 1827** log message after formatting via [sqlite3_snprintf()]. 1828** The SQLite logging interface is not reentrant; the logger function 1829** supplied by the application must not invoke any SQLite interface. 1830** In a multi-threaded application, the application-defined logger 1831** function must be threadsafe. </dd> 1832** 1833** [[SQLITE_CONFIG_URI]] <dt>SQLITE_CONFIG_URI 1834** <dd>^(The SQLITE_CONFIG_URI option takes a single argument of type int. 1835** If non-zero, then URI handling is globally enabled. If the parameter is zero, 1836** then URI handling is globally disabled.)^ ^If URI handling is globally 1837** enabled, all filenames passed to [sqlite3_open()], [sqlite3_open_v2()], 1838** [sqlite3_open16()] or 1839** specified as part of [ATTACH] commands are interpreted as URIs, regardless 1840** of whether or not the [SQLITE_OPEN_URI] flag is set when the database 1841** connection is opened. ^If it is globally disabled, filenames are 1842** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the 1843** database connection is opened. ^(By default, URI handling is globally 1844** disabled. The default value may be changed by compiling with the 1845** [SQLITE_USE_URI] symbol defined.)^ 1846** 1847** [[SQLITE_CONFIG_COVERING_INDEX_SCAN]] <dt>SQLITE_CONFIG_COVERING_INDEX_SCAN 1848** <dd>^The SQLITE_CONFIG_COVERING_INDEX_SCAN option takes a single integer 1849** argument which is interpreted as a boolean in order to enable or disable 1850** the use of covering indices for full table scans in the query optimizer. 1851** ^The default setting is determined 1852** by the [SQLITE_ALLOW_COVERING_INDEX_SCAN] compile-time option, or is "on" 1853** if that compile-time option is omitted. 1854** The ability to disable the use of covering indices for full table scans 1855** is because some incorrectly coded legacy applications might malfunction 1856** when the optimization is enabled. Providing the ability to 1857** disable the optimization allows the older, buggy application code to work 1858** without change even with newer versions of SQLite. 1859** 1860** [[SQLITE_CONFIG_PCACHE]] [[SQLITE_CONFIG_GETPCACHE]] 1861** <dt>SQLITE_CONFIG_PCACHE and SQLITE_CONFIG_GETPCACHE 1862** <dd> These options are obsolete and should not be used by new code. 1863** They are retained for backwards compatibility but are now no-ops. 1864** </dd> 1865** 1866** [[SQLITE_CONFIG_SQLLOG]] 1867** <dt>SQLITE_CONFIG_SQLLOG 1868** <dd>This option is only available if sqlite is compiled with the 1869** [SQLITE_ENABLE_SQLLOG] pre-processor macro defined. The first argument should 1870** be a pointer to a function of type void(*)(void*,sqlite3*,const char*, int). 1871** The second should be of type (void*). The callback is invoked by the library 1872** in three separate circumstances, identified by the value passed as the 1873** fourth parameter. If the fourth parameter is 0, then the database connection 1874** passed as the second argument has just been opened. The third argument 1875** points to a buffer containing the name of the main database file. If the 1876** fourth parameter is 1, then the SQL statement that the third parameter 1877** points to has just been executed. Or, if the fourth parameter is 2, then 1878** the connection being passed as the second parameter is being closed. The 1879** third parameter is passed NULL In this case. An example of using this 1880** configuration option can be seen in the "test_sqllog.c" source file in 1881** the canonical SQLite source tree.</dd> 1882** 1883** [[SQLITE_CONFIG_MMAP_SIZE]] 1884** <dt>SQLITE_CONFIG_MMAP_SIZE 1885** <dd>^SQLITE_CONFIG_MMAP_SIZE takes two 64-bit integer (sqlite3_int64) values 1886** that are the default mmap size limit (the default setting for 1887** [PRAGMA mmap_size]) and the maximum allowed mmap size limit. 1888** ^The default setting can be overridden by each database connection using 1889** either the [PRAGMA mmap_size] command, or by using the 1890** [SQLITE_FCNTL_MMAP_SIZE] file control. ^(The maximum allowed mmap size 1891** will be silently truncated if necessary so that it does not exceed the 1892** compile-time maximum mmap size set by the 1893** [SQLITE_MAX_MMAP_SIZE] compile-time option.)^ 1894** ^If either argument to this option is negative, then that argument is 1895** changed to its compile-time default. 1896** 1897** [[SQLITE_CONFIG_WIN32_HEAPSIZE]] 1898** <dt>SQLITE_CONFIG_WIN32_HEAPSIZE 1899** <dd>^The SQLITE_CONFIG_WIN32_HEAPSIZE option is only available if SQLite is 1900** compiled for Windows with the [SQLITE_WIN32_MALLOC] pre-processor macro 1901** defined. ^SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit unsigned integer value 1902** that specifies the maximum size of the created heap. 1903** 1904** [[SQLITE_CONFIG_PCACHE_HDRSZ]] 1905** <dt>SQLITE_CONFIG_PCACHE_HDRSZ 1906** <dd>^The SQLITE_CONFIG_PCACHE_HDRSZ option takes a single parameter which 1907** is a pointer to an integer and writes into that integer the number of extra 1908** bytes per page required for each page in [SQLITE_CONFIG_PAGECACHE]. 1909** The amount of extra space required can change depending on the compiler, 1910** target platform, and SQLite version. 1911** 1912** [[SQLITE_CONFIG_PMASZ]] 1913** <dt>SQLITE_CONFIG_PMASZ 1914** <dd>^The SQLITE_CONFIG_PMASZ option takes a single parameter which 1915** is an unsigned integer and sets the "Minimum PMA Size" for the multithreaded 1916** sorter to that integer. The default minimum PMA Size is set by the 1917** [SQLITE_SORTER_PMASZ] compile-time option. New threads are launched 1918** to help with sort operations when multithreaded sorting 1919** is enabled (using the [PRAGMA threads] command) and the amount of content 1920** to be sorted exceeds the page size times the minimum of the 1921** [PRAGMA cache_size] setting and this value. 1922** 1923** [[SQLITE_CONFIG_STMTJRNL_SPILL]] 1924** <dt>SQLITE_CONFIG_STMTJRNL_SPILL 1925** <dd>^The SQLITE_CONFIG_STMTJRNL_SPILL option takes a single parameter which 1926** becomes the [statement journal] spill-to-disk threshold. 1927** [Statement journals] are held in memory until their size (in bytes) 1928** exceeds this threshold, at which point they are written to disk. 1929** Or if the threshold is -1, statement journals are always held 1930** exclusively in memory. 1931** Since many statement journals never become large, setting the spill 1932** threshold to a value such as 64KiB can greatly reduce the amount of 1933** I/O required to support statement rollback. 1934** The default value for this setting is controlled by the 1935** [SQLITE_STMTJRNL_SPILL] compile-time option. 1936** 1937** [[SQLITE_CONFIG_SORTERREF_SIZE]] 1938** <dt>SQLITE_CONFIG_SORTERREF_SIZE 1939** <dd>The SQLITE_CONFIG_SORTERREF_SIZE option accepts a single parameter 1940** of type (int) - the new value of the sorter-reference size threshold. 1941** Usually, when SQLite uses an external sort to order records according 1942** to an ORDER BY clause, all fields required by the caller are present in the 1943** sorted records. However, if SQLite determines based on the declared type 1944** of a table column that its values are likely to be very large - larger 1945** than the configured sorter-reference size threshold - then a reference 1946** is stored in each sorted record and the required column values loaded 1947** from the database as records are returned in sorted order. The default 1948** value for this option is to never use this optimization. Specifying a 1949** negative value for this option restores the default behaviour. 1950** This option is only available if SQLite is compiled with the 1951** [SQLITE_ENABLE_SORTER_REFERENCES] compile-time option. 1952** </dl> 1953*/ 1954#define SQLITE_CONFIG_SINGLETHREAD 1 /* nil */ 1955#define SQLITE_CONFIG_MULTITHREAD 2 /* nil */ 1956#define SQLITE_CONFIG_SERIALIZED 3 /* nil */ 1957#define SQLITE_CONFIG_MALLOC 4 /* sqlite3_mem_methods* */ 1958#define SQLITE_CONFIG_GETMALLOC 5 /* sqlite3_mem_methods* */ 1959#define SQLITE_CONFIG_SCRATCH 6 /* No longer used */ 1960#define SQLITE_CONFIG_PAGECACHE 7 /* void*, int sz, int N */ 1961#define SQLITE_CONFIG_HEAP 8 /* void*, int nByte, int min */ 1962#define SQLITE_CONFIG_MEMSTATUS 9 /* boolean */ 1963#define SQLITE_CONFIG_MUTEX 10 /* sqlite3_mutex_methods* */ 1964#define SQLITE_CONFIG_GETMUTEX 11 /* sqlite3_mutex_methods* */ 1965/* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */ 1966#define SQLITE_CONFIG_LOOKASIDE 13 /* int int */ 1967#define SQLITE_CONFIG_PCACHE 14 /* no-op */ 1968#define SQLITE_CONFIG_GETPCACHE 15 /* no-op */ 1969#define SQLITE_CONFIG_LOG 16 /* xFunc, void* */ 1970#define SQLITE_CONFIG_URI 17 /* int */ 1971#define SQLITE_CONFIG_PCACHE2 18 /* sqlite3_pcache_methods2* */ 1972#define SQLITE_CONFIG_GETPCACHE2 19 /* sqlite3_pcache_methods2* */ 1973#define SQLITE_CONFIG_COVERING_INDEX_SCAN 20 /* int */ 1974#define SQLITE_CONFIG_SQLLOG 21 /* xSqllog, void* */ 1975#define SQLITE_CONFIG_MMAP_SIZE 22 /* sqlite3_int64, sqlite3_int64 */ 1976#define SQLITE_CONFIG_WIN32_HEAPSIZE 23 /* int nByte */ 1977#define SQLITE_CONFIG_PCACHE_HDRSZ 24 /* int *psz */ 1978#define SQLITE_CONFIG_PMASZ 25 /* unsigned int szPma */ 1979#define SQLITE_CONFIG_STMTJRNL_SPILL 26 /* int nByte */ 1980#define SQLITE_CONFIG_SMALL_MALLOC 27 /* boolean */ 1981#define SQLITE_CONFIG_SORTERREF_SIZE 28 /* int nByte */ 1982 1983/* 1984** CAPI3REF: Database Connection Configuration Options 1985** 1986** These constants are the available integer configuration options that 1987** can be passed as the second argument to the [sqlite3_db_config()] interface. 1988** 1989** New configuration options may be added in future releases of SQLite. 1990** Existing configuration options might be discontinued. Applications 1991** should check the return code from [sqlite3_db_config()] to make sure that 1992** the call worked. ^The [sqlite3_db_config()] interface will return a 1993** non-zero [error code] if a discontinued or unsupported configuration option 1994** is invoked. 1995** 1996** <dl> 1997** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt> 1998** <dd> ^This option takes three additional arguments that determine the 1999** [lookaside memory allocator] configuration for the [database connection]. 2000** ^The first argument (the third parameter to [sqlite3_db_config()] is a 2001** pointer to a memory buffer to use for lookaside memory. 2002** ^The first argument after the SQLITE_DBCONFIG_LOOKASIDE verb 2003** may be NULL in which case SQLite will allocate the 2004** lookaside buffer itself using [sqlite3_malloc()]. ^The second argument is the 2005** size of each lookaside buffer slot. ^The third argument is the number of 2006** slots. The size of the buffer in the first argument must be greater than 2007** or equal to the product of the second and third arguments. The buffer 2008** must be aligned to an 8-byte boundary. ^If the second argument to 2009** SQLITE_DBCONFIG_LOOKASIDE is not a multiple of 8, it is internally 2010** rounded down to the next smaller multiple of 8. ^(The lookaside memory 2011** configuration for a database connection can only be changed when that 2012** connection is not currently using lookaside memory, or in other words 2013** when the "current value" returned by 2014** [sqlite3_db_status](D,[SQLITE_CONFIG_LOOKASIDE],...) is zero. 2015** Any attempt to change the lookaside memory configuration when lookaside 2016** memory is in use leaves the configuration unchanged and returns 2017** [SQLITE_BUSY].)^</dd> 2018** 2019** <dt>SQLITE_DBCONFIG_ENABLE_FKEY</dt> 2020** <dd> ^This option is used to enable or disable the enforcement of 2021** [foreign key constraints]. There should be two additional arguments. 2022** The first argument is an integer which is 0 to disable FK enforcement, 2023** positive to enable FK enforcement or negative to leave FK enforcement 2024** unchanged. The second parameter is a pointer to an integer into which 2025** is written 0 or 1 to indicate whether FK enforcement is off or on 2026** following this call. The second parameter may be a NULL pointer, in 2027** which case the FK enforcement setting is not reported back. </dd> 2028** 2029** <dt>SQLITE_DBCONFIG_ENABLE_TRIGGER</dt> 2030** <dd> ^This option is used to enable or disable [CREATE TRIGGER | triggers]. 2031** There should be two additional arguments. 2032** The first argument is an integer which is 0 to disable triggers, 2033** positive to enable triggers or negative to leave the setting unchanged. 2034** The second parameter is a pointer to an integer into which 2035** is written 0 or 1 to indicate whether triggers are disabled or enabled 2036** following this call. The second parameter may be a NULL pointer, in 2037** which case the trigger setting is not reported back. </dd> 2038** 2039** <dt>SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER</dt> 2040** <dd> ^This option is used to enable or disable the two-argument 2041** version of the [fts3_tokenizer()] function which is part of the 2042** [FTS3] full-text search engine extension. 2043** There should be two additional arguments. 2044** The first argument is an integer which is 0 to disable fts3_tokenizer() or 2045** positive to enable fts3_tokenizer() or negative to leave the setting 2046** unchanged. 2047** The second parameter is a pointer to an integer into which 2048** is written 0 or 1 to indicate whether fts3_tokenizer is disabled or enabled 2049** following this call. The second parameter may be a NULL pointer, in 2050** which case the new setting is not reported back. </dd> 2051** 2052** <dt>SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION</dt> 2053** <dd> ^This option is used to enable or disable the [sqlite3_load_extension()] 2054** interface independently of the [load_extension()] SQL function. 2055** The [sqlite3_enable_load_extension()] API enables or disables both the 2056** C-API [sqlite3_load_extension()] and the SQL function [load_extension()]. 2057** There should be two additional arguments. 2058** When the first argument to this interface is 1, then only the C-API is 2059** enabled and the SQL function remains disabled. If the first argument to 2060** this interface is 0, then both the C-API and the SQL function are disabled. 2061** If the first argument is -1, then no changes are made to state of either the 2062** C-API or the SQL function. 2063** The second parameter is a pointer to an integer into which 2064** is written 0 or 1 to indicate whether [sqlite3_load_extension()] interface 2065** is disabled or enabled following this call. The second parameter may 2066** be a NULL pointer, in which case the new setting is not reported back. 2067** </dd> 2068** 2069** <dt>SQLITE_DBCONFIG_MAINDBNAME</dt> 2070** <dd> ^This option is used to change the name of the "main" database 2071** schema. ^The sole argument is a pointer to a constant UTF8 string 2072** which will become the new schema name in place of "main". ^SQLite 2073** does not make a copy of the new main schema name string, so the application 2074** must ensure that the argument passed into this DBCONFIG option is unchanged 2075** until after the database connection closes. 2076** </dd> 2077** 2078** <dt>SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE</dt> 2079** <dd> Usually, when a database in wal mode is closed or detached from a 2080** database handle, SQLite checks if this will mean that there are now no 2081** connections at all to the database. If so, it performs a checkpoint 2082** operation before closing the connection. This option may be used to 2083** override this behaviour. The first parameter passed to this operation 2084** is an integer - positive to disable checkpoints-on-close, or zero (the 2085** default) to enable them, and negative to leave the setting unchanged. 2086** The second parameter is a pointer to an integer 2087** into which is written 0 or 1 to indicate whether checkpoints-on-close 2088** have been disabled - 0 if they are not disabled, 1 if they are. 2089** </dd> 2090** 2091** <dt>SQLITE_DBCONFIG_ENABLE_QPSG</dt> 2092** <dd>^(The SQLITE_DBCONFIG_ENABLE_QPSG option activates or deactivates 2093** the [query planner stability guarantee] (QPSG). When the QPSG is active, 2094** a single SQL query statement will always use the same algorithm regardless 2095** of values of [bound parameters].)^ The QPSG disables some query optimizations 2096** that look at the values of bound parameters, which can make some queries 2097** slower. But the QPSG has the advantage of more predictable behavior. With 2098** the QPSG active, SQLite will always use the same query plan in the field as 2099** was used during testing in the lab. 2100** The first argument to this setting is an integer which is 0 to disable 2101** the QPSG, positive to enable QPSG, or negative to leave the setting 2102** unchanged. The second parameter is a pointer to an integer into which 2103** is written 0 or 1 to indicate whether the QPSG is disabled or enabled 2104** following this call. 2105** </dd> 2106** 2107** <dt>SQLITE_DBCONFIG_TRIGGER_EQP</dt> 2108** <dd> By default, the output of EXPLAIN QUERY PLAN commands does not 2109** include output for any operations performed by trigger programs. This 2110** option is used to set or clear (the default) a flag that governs this 2111** behavior. The first parameter passed to this operation is an integer - 2112** positive to enable output for trigger programs, or zero to disable it, 2113** or negative to leave the setting unchanged. 2114** The second parameter is a pointer to an integer into which is written 2115** 0 or 1 to indicate whether output-for-triggers has been disabled - 0 if 2116** it is not disabled, 1 if it is. 2117** </dd> 2118** 2119** <dt>SQLITE_DBCONFIG_RESET_DATABASE</dt> 2120** <dd> Set the SQLITE_DBCONFIG_RESET_DATABASE flag and then run 2121** [VACUUM] in order to reset a database back to an empty database 2122** with no schema and no content. The following process works even for 2123** a badly corrupted database file: 2124** <ol> 2125** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 1, 0); 2126** <li> [sqlite3_exec](db, "[VACUUM]", 0, 0, 0); 2127** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 0, 0); 2128** </ol> 2129** Because resetting a database is destructive and irreversible, the 2130** process requires the use of this obscure API and multiple steps to help 2131** ensure that it does not happen by accident. 2132** </dd> 2133** </dl> 2134*/ 2135#define SQLITE_DBCONFIG_MAINDBNAME 1000 /* const char* */ 2136#define SQLITE_DBCONFIG_LOOKASIDE 1001 /* void* int int */ 2137#define SQLITE_DBCONFIG_ENABLE_FKEY 1002 /* int int* */ 2138#define SQLITE_DBCONFIG_ENABLE_TRIGGER 1003 /* int int* */ 2139#define SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER 1004 /* int int* */ 2140#define SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION 1005 /* int int* */ 2141#define SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE 1006 /* int int* */ 2142#define SQLITE_DBCONFIG_ENABLE_QPSG 1007 /* int int* */ 2143#define SQLITE_DBCONFIG_TRIGGER_EQP 1008 /* int int* */ 2144#define SQLITE_DBCONFIG_RESET_DATABASE 1009 /* int int* */ 2145#define SQLITE_DBCONFIG_MAX 1009 /* Largest DBCONFIG */ 2146 2147/* 2148** CAPI3REF: Enable Or Disable Extended Result Codes 2149** METHOD: sqlite3 2150** 2151** ^The sqlite3_extended_result_codes() routine enables or disables the 2152** [extended result codes] feature of SQLite. ^The extended result 2153** codes are disabled by default for historical compatibility. 2154*/ 2155int sqlite3_extended_result_codes(sqlite3*, int onoff); 2156 2157/* 2158** CAPI3REF: Last Insert Rowid 2159** METHOD: sqlite3 2160** 2161** ^Each entry in most SQLite tables (except for [WITHOUT ROWID] tables) 2162** has a unique 64-bit signed 2163** integer key called the [ROWID | "rowid"]. ^The rowid is always available 2164** as an undeclared column named ROWID, OID, or _ROWID_ as long as those 2165** names are not also used by explicitly declared columns. ^If 2166** the table has a column of type [INTEGER PRIMARY KEY] then that column 2167** is another alias for the rowid. 2168** 2169** ^The sqlite3_last_insert_rowid(D) interface usually returns the [rowid] of 2170** the most recent successful [INSERT] into a rowid table or [virtual table] 2171** on database connection D. ^Inserts into [WITHOUT ROWID] tables are not 2172** recorded. ^If no successful [INSERT]s into rowid tables have ever occurred 2173** on the database connection D, then sqlite3_last_insert_rowid(D) returns 2174** zero. 2175** 2176** As well as being set automatically as rows are inserted into database 2177** tables, the value returned by this function may be set explicitly by 2178** [sqlite3_set_last_insert_rowid()] 2179** 2180** Some virtual table implementations may INSERT rows into rowid tables as 2181** part of committing a transaction (e.g. to flush data accumulated in memory 2182** to disk). In this case subsequent calls to this function return the rowid 2183** associated with these internal INSERT operations, which leads to 2184** unintuitive results. Virtual table implementations that do write to rowid 2185** tables in this way can avoid this problem by restoring the original 2186** rowid value using [sqlite3_set_last_insert_rowid()] before returning 2187** control to the user. 2188** 2189** ^(If an [INSERT] occurs within a trigger then this routine will 2190** return the [rowid] of the inserted row as long as the trigger is 2191** running. Once the trigger program ends, the value returned 2192** by this routine reverts to what it was before the trigger was fired.)^ 2193** 2194** ^An [INSERT] that fails due to a constraint violation is not a 2195** successful [INSERT] and does not change the value returned by this 2196** routine. ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK, 2197** and INSERT OR ABORT make no changes to the return value of this 2198** routine when their insertion fails. ^(When INSERT OR REPLACE 2199** encounters a constraint violation, it does not fail. The 2200** INSERT continues to completion after deleting rows that caused 2201** the constraint problem so INSERT OR REPLACE will always change 2202** the return value of this interface.)^ 2203** 2204** ^For the purposes of this routine, an [INSERT] is considered to 2205** be successful even if it is subsequently rolled back. 2206** 2207** This function is accessible to SQL statements via the 2208** [last_insert_rowid() SQL function]. 2209** 2210** If a separate thread performs a new [INSERT] on the same 2211** database connection while the [sqlite3_last_insert_rowid()] 2212** function is running and thus changes the last insert [rowid], 2213** then the value returned by [sqlite3_last_insert_rowid()] is 2214** unpredictable and might not equal either the old or the new 2215** last insert [rowid]. 2216*/ 2217sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*); 2218 2219/* 2220** CAPI3REF: Set the Last Insert Rowid value. 2221** METHOD: sqlite3 2222** 2223** The sqlite3_set_last_insert_rowid(D, R) method allows the application to 2224** set the value returned by calling sqlite3_last_insert_rowid(D) to R 2225** without inserting a row into the database. 2226*/ 2227void sqlite3_set_last_insert_rowid(sqlite3*,sqlite3_int64); 2228 2229/* 2230** CAPI3REF: Count The Number Of Rows Modified 2231** METHOD: sqlite3 2232** 2233** ^This function returns the number of rows modified, inserted or 2234** deleted by the most recently completed INSERT, UPDATE or DELETE 2235** statement on the database connection specified by the only parameter. 2236** ^Executing any other type of SQL statement does not modify the value 2237** returned by this function. 2238** 2239** ^Only changes made directly by the INSERT, UPDATE or DELETE statement are 2240** considered - auxiliary changes caused by [CREATE TRIGGER | triggers], 2241** [foreign key actions] or [REPLACE] constraint resolution are not counted. 2242** 2243** Changes to a view that are intercepted by 2244** [INSTEAD OF trigger | INSTEAD OF triggers] are not counted. ^The value 2245** returned by sqlite3_changes() immediately after an INSERT, UPDATE or 2246** DELETE statement run on a view is always zero. Only changes made to real 2247** tables are counted. 2248** 2249** Things are more complicated if the sqlite3_changes() function is 2250** executed while a trigger program is running. This may happen if the 2251** program uses the [changes() SQL function], or if some other callback 2252** function invokes sqlite3_changes() directly. Essentially: 2253** 2254** <ul> 2255** <li> ^(Before entering a trigger program the value returned by 2256** sqlite3_changes() function is saved. After the trigger program 2257** has finished, the original value is restored.)^ 2258** 2259** <li> ^(Within a trigger program each INSERT, UPDATE and DELETE 2260** statement sets the value returned by sqlite3_changes() 2261** upon completion as normal. Of course, this value will not include 2262** any changes performed by sub-triggers, as the sqlite3_changes() 2263** value will be saved and restored after each sub-trigger has run.)^ 2264** </ul> 2265** 2266** ^This means that if the changes() SQL function (or similar) is used 2267** by the first INSERT, UPDATE or DELETE statement within a trigger, it 2268** returns the value as set when the calling statement began executing. 2269** ^If it is used by the second or subsequent such statement within a trigger 2270** program, the value returned reflects the number of rows modified by the 2271** previous INSERT, UPDATE or DELETE statement within the same trigger. 2272** 2273** See also the [sqlite3_total_changes()] interface, the 2274** [count_changes pragma], and the [changes() SQL function]. 2275** 2276** If a separate thread makes changes on the same database connection 2277** while [sqlite3_changes()] is running then the value returned 2278** is unpredictable and not meaningful. 2279*/ 2280int sqlite3_changes(sqlite3*); 2281 2282/* 2283** CAPI3REF: Total Number Of Rows Modified 2284** METHOD: sqlite3 2285** 2286** ^This function returns the total number of rows inserted, modified or 2287** deleted by all [INSERT], [UPDATE] or [DELETE] statements completed 2288** since the database connection was opened, including those executed as 2289** part of trigger programs. ^Executing any other type of SQL statement 2290** does not affect the value returned by sqlite3_total_changes(). 2291** 2292** ^Changes made as part of [foreign key actions] are included in the 2293** count, but those made as part of REPLACE constraint resolution are 2294** not. ^Changes to a view that are intercepted by INSTEAD OF triggers 2295** are not counted. 2296** 2297** See also the [sqlite3_changes()] interface, the 2298** [count_changes pragma], and the [total_changes() SQL function]. 2299** 2300** If a separate thread makes changes on the same database connection 2301** while [sqlite3_total_changes()] is running then the value 2302** returned is unpredictable and not meaningful. 2303*/ 2304int sqlite3_total_changes(sqlite3*); 2305 2306/* 2307** CAPI3REF: Interrupt A Long-Running Query 2308** METHOD: sqlite3 2309** 2310** ^This function causes any pending database operation to abort and 2311** return at its earliest opportunity. This routine is typically 2312** called in response to a user action such as pressing "Cancel" 2313** or Ctrl-C where the user wants a long query operation to halt 2314** immediately. 2315** 2316** ^It is safe to call this routine from a thread different from the 2317** thread that is currently running the database operation. But it 2318** is not safe to call this routine with a [database connection] that 2319** is closed or might close before sqlite3_interrupt() returns. 2320** 2321** ^If an SQL operation is very nearly finished at the time when 2322** sqlite3_interrupt() is called, then it might not have an opportunity 2323** to be interrupted and might continue to completion. 2324** 2325** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT]. 2326** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE 2327** that is inside an explicit transaction, then the entire transaction 2328** will be rolled back automatically. 2329** 2330** ^The sqlite3_interrupt(D) call is in effect until all currently running 2331** SQL statements on [database connection] D complete. ^Any new SQL statements 2332** that are started after the sqlite3_interrupt() call and before the 2333** running statements reaches zero are interrupted as if they had been 2334** running prior to the sqlite3_interrupt() call. ^New SQL statements 2335** that are started after the running statement count reaches zero are 2336** not effected by the sqlite3_interrupt(). 2337** ^A call to sqlite3_interrupt(D) that occurs when there are no running 2338** SQL statements is a no-op and has no effect on SQL statements 2339** that are started after the sqlite3_interrupt() call returns. 2340*/ 2341void sqlite3_interrupt(sqlite3*); 2342 2343/* 2344** CAPI3REF: Determine If An SQL Statement Is Complete 2345** 2346** These routines are useful during command-line input to determine if the 2347** currently entered text seems to form a complete SQL statement or 2348** if additional input is needed before sending the text into 2349** SQLite for parsing. ^These routines return 1 if the input string 2350** appears to be a complete SQL statement. ^A statement is judged to be 2351** complete if it ends with a semicolon token and is not a prefix of a 2352** well-formed CREATE TRIGGER statement. ^Semicolons that are embedded within 2353** string literals or quoted identifier names or comments are not 2354** independent tokens (they are part of the token in which they are 2355** embedded) and thus do not count as a statement terminator. ^Whitespace 2356** and comments that follow the final semicolon are ignored. 2357** 2358** ^These routines return 0 if the statement is incomplete. ^If a 2359** memory allocation fails, then SQLITE_NOMEM is returned. 2360** 2361** ^These routines do not parse the SQL statements thus 2362** will not detect syntactically incorrect SQL. 2363** 2364** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior 2365** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked 2366** automatically by sqlite3_complete16(). If that initialization fails, 2367** then the return value from sqlite3_complete16() will be non-zero 2368** regardless of whether or not the input SQL is complete.)^ 2369** 2370** The input to [sqlite3_complete()] must be a zero-terminated 2371** UTF-8 string. 2372** 2373** The input to [sqlite3_complete16()] must be a zero-terminated 2374** UTF-16 string in native byte order. 2375*/ 2376int sqlite3_complete(const char *sql); 2377int sqlite3_complete16(const void *sql); 2378 2379/* 2380** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors 2381** KEYWORDS: {busy-handler callback} {busy handler} 2382** METHOD: sqlite3 2383** 2384** ^The sqlite3_busy_handler(D,X,P) routine sets a callback function X 2385** that might be invoked with argument P whenever 2386** an attempt is made to access a database table associated with 2387** [database connection] D when another thread 2388** or process has the table locked. 2389** The sqlite3_busy_handler() interface is used to implement 2390** [sqlite3_busy_timeout()] and [PRAGMA busy_timeout]. 2391** 2392** ^If the busy callback is NULL, then [SQLITE_BUSY] 2393** is returned immediately upon encountering the lock. ^If the busy callback 2394** is not NULL, then the callback might be invoked with two arguments. 2395** 2396** ^The first argument to the busy handler is a copy of the void* pointer which 2397** is the third argument to sqlite3_busy_handler(). ^The second argument to 2398** the busy handler callback is the number of times that the busy handler has 2399** been invoked previously for the same locking event. ^If the 2400** busy callback returns 0, then no additional attempts are made to 2401** access the database and [SQLITE_BUSY] is returned 2402** to the application. 2403** ^If the callback returns non-zero, then another attempt 2404** is made to access the database and the cycle repeats. 2405** 2406** The presence of a busy handler does not guarantee that it will be invoked 2407** when there is lock contention. ^If SQLite determines that invoking the busy 2408** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY] 2409** to the application instead of invoking the 2410** busy handler. 2411** Consider a scenario where one process is holding a read lock that 2412** it is trying to promote to a reserved lock and 2413** a second process is holding a reserved lock that it is trying 2414** to promote to an exclusive lock. The first process cannot proceed 2415** because it is blocked by the second and the second process cannot 2416** proceed because it is blocked by the first. If both processes 2417** invoke the busy handlers, neither will make any progress. Therefore, 2418** SQLite returns [SQLITE_BUSY] for the first process, hoping that this 2419** will induce the first process to release its read lock and allow 2420** the second process to proceed. 2421** 2422** ^The default busy callback is NULL. 2423** 2424** ^(There can only be a single busy handler defined for each 2425** [database connection]. Setting a new busy handler clears any 2426** previously set handler.)^ ^Note that calling [sqlite3_busy_timeout()] 2427** or evaluating [PRAGMA busy_timeout=N] will change the 2428** busy handler and thus clear any previously set busy handler. 2429** 2430** The busy callback should not take any actions which modify the 2431** database connection that invoked the busy handler. In other words, 2432** the busy handler is not reentrant. Any such actions 2433** result in undefined behavior. 2434** 2435** A busy handler must not close the database connection 2436** or [prepared statement] that invoked the busy handler. 2437*/ 2438int sqlite3_busy_handler(sqlite3*,int(*)(void*,int),void*); 2439 2440/* 2441** CAPI3REF: Set A Busy Timeout 2442** METHOD: sqlite3 2443** 2444** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps 2445** for a specified amount of time when a table is locked. ^The handler 2446** will sleep multiple times until at least "ms" milliseconds of sleeping 2447** have accumulated. ^After at least "ms" milliseconds of sleeping, 2448** the handler returns 0 which causes [sqlite3_step()] to return 2449** [SQLITE_BUSY]. 2450** 2451** ^Calling this routine with an argument less than or equal to zero 2452** turns off all busy handlers. 2453** 2454** ^(There can only be a single busy handler for a particular 2455** [database connection] at any given moment. If another busy handler 2456** was defined (using [sqlite3_busy_handler()]) prior to calling 2457** this routine, that other busy handler is cleared.)^ 2458** 2459** See also: [PRAGMA busy_timeout] 2460*/ 2461int sqlite3_busy_timeout(sqlite3*, int ms); 2462 2463/* 2464** CAPI3REF: Convenience Routines For Running Queries 2465** METHOD: sqlite3 2466** 2467** This is a legacy interface that is preserved for backwards compatibility. 2468** Use of this interface is not recommended. 2469** 2470** Definition: A <b>result table</b> is memory data structure created by the 2471** [sqlite3_get_table()] interface. A result table records the 2472** complete query results from one or more queries. 2473** 2474** The table conceptually has a number of rows and columns. But 2475** these numbers are not part of the result table itself. These 2476** numbers are obtained separately. Let N be the number of rows 2477** and M be the number of columns. 2478** 2479** A result table is an array of pointers to zero-terminated UTF-8 strings. 2480** There are (N+1)*M elements in the array. The first M pointers point 2481** to zero-terminated strings that contain the names of the columns. 2482** The remaining entries all point to query results. NULL values result 2483** in NULL pointers. All other values are in their UTF-8 zero-terminated 2484** string representation as returned by [sqlite3_column_text()]. 2485** 2486** A result table might consist of one or more memory allocations. 2487** It is not safe to pass a result table directly to [sqlite3_free()]. 2488** A result table should be deallocated using [sqlite3_free_table()]. 2489** 2490** ^(As an example of the result table format, suppose a query result 2491** is as follows: 2492** 2493** <blockquote><pre> 2494** Name | Age 2495** ----------------------- 2496** Alice | 43 2497** Bob | 28 2498** Cindy | 21 2499** </pre></blockquote> 2500** 2501** There are two column (M==2) and three rows (N==3). Thus the 2502** result table has 8 entries. Suppose the result table is stored 2503** in an array names azResult. Then azResult holds this content: 2504** 2505** <blockquote><pre> 2506** azResult[0] = "Name"; 2507** azResult[1] = "Age"; 2508** azResult[2] = "Alice"; 2509** azResult[3] = "43"; 2510** azResult[4] = "Bob"; 2511** azResult[5] = "28"; 2512** azResult[6] = "Cindy"; 2513** azResult[7] = "21"; 2514** </pre></blockquote>)^ 2515** 2516** ^The sqlite3_get_table() function evaluates one or more 2517** semicolon-separated SQL statements in the zero-terminated UTF-8 2518** string of its 2nd parameter and returns a result table to the 2519** pointer given in its 3rd parameter. 2520** 2521** After the application has finished with the result from sqlite3_get_table(), 2522** it must pass the result table pointer to sqlite3_free_table() in order to 2523** release the memory that was malloced. Because of the way the 2524** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling 2525** function must not try to call [sqlite3_free()] directly. Only 2526** [sqlite3_free_table()] is able to release the memory properly and safely. 2527** 2528** The sqlite3_get_table() interface is implemented as a wrapper around 2529** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access 2530** to any internal data structures of SQLite. It uses only the public 2531** interface defined here. As a consequence, errors that occur in the 2532** wrapper layer outside of the internal [sqlite3_exec()] call are not 2533** reflected in subsequent calls to [sqlite3_errcode()] or 2534** [sqlite3_errmsg()]. 2535*/ 2536int sqlite3_get_table( 2537 sqlite3 *db, /* An open database */ 2538 const char *zSql, /* SQL to be evaluated */ 2539 char ***pazResult, /* Results of the query */ 2540 int *pnRow, /* Number of result rows written here */ 2541 int *pnColumn, /* Number of result columns written here */ 2542 char **pzErrmsg /* Error msg written here */ 2543); 2544void sqlite3_free_table(char **result); 2545 2546/* 2547** CAPI3REF: Formatted String Printing Functions 2548** 2549** These routines are work-alikes of the "printf()" family of functions 2550** from the standard C library. 2551** These routines understand most of the common formatting options from 2552** the standard library printf() 2553** plus some additional non-standard formats ([%q], [%Q], [%w], and [%z]). 2554** See the [built-in printf()] documentation for details. 2555** 2556** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their 2557** results into memory obtained from [sqlite3_malloc64()]. 2558** The strings returned by these two routines should be 2559** released by [sqlite3_free()]. ^Both routines return a 2560** NULL pointer if [sqlite3_malloc64()] is unable to allocate enough 2561** memory to hold the resulting string. 2562** 2563** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from 2564** the standard C library. The result is written into the 2565** buffer supplied as the second parameter whose size is given by 2566** the first parameter. Note that the order of the 2567** first two parameters is reversed from snprintf().)^ This is an 2568** historical accident that cannot be fixed without breaking 2569** backwards compatibility. ^(Note also that sqlite3_snprintf() 2570** returns a pointer to its buffer instead of the number of 2571** characters actually written into the buffer.)^ We admit that 2572** the number of characters written would be a more useful return 2573** value but we cannot change the implementation of sqlite3_snprintf() 2574** now without breaking compatibility. 2575** 2576** ^As long as the buffer size is greater than zero, sqlite3_snprintf() 2577** guarantees that the buffer is always zero-terminated. ^The first 2578** parameter "n" is the total size of the buffer, including space for 2579** the zero terminator. So the longest string that can be completely 2580** written will be n-1 characters. 2581** 2582** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf(). 2583** 2584** See also: [built-in printf()], [printf() SQL function] 2585*/ 2586char *sqlite3_mprintf(const char*,...); 2587char *sqlite3_vmprintf(const char*, va_list); 2588char *sqlite3_snprintf(int,char*,const char*, ...); 2589char *sqlite3_vsnprintf(int,char*,const char*, va_list); 2590 2591/* 2592** CAPI3REF: Memory Allocation Subsystem 2593** 2594** The SQLite core uses these three routines for all of its own 2595** internal memory allocation needs. "Core" in the previous sentence 2596** does not include operating-system specific VFS implementation. The 2597** Windows VFS uses native malloc() and free() for some operations. 2598** 2599** ^The sqlite3_malloc() routine returns a pointer to a block 2600** of memory at least N bytes in length, where N is the parameter. 2601** ^If sqlite3_malloc() is unable to obtain sufficient free 2602** memory, it returns a NULL pointer. ^If the parameter N to 2603** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns 2604** a NULL pointer. 2605** 2606** ^The sqlite3_malloc64(N) routine works just like 2607** sqlite3_malloc(N) except that N is an unsigned 64-bit integer instead 2608** of a signed 32-bit integer. 2609** 2610** ^Calling sqlite3_free() with a pointer previously returned 2611** by sqlite3_malloc() or sqlite3_realloc() releases that memory so 2612** that it might be reused. ^The sqlite3_free() routine is 2613** a no-op if is called with a NULL pointer. Passing a NULL pointer 2614** to sqlite3_free() is harmless. After being freed, memory 2615** should neither be read nor written. Even reading previously freed 2616** memory might result in a segmentation fault or other severe error. 2617** Memory corruption, a segmentation fault, or other severe error 2618** might result if sqlite3_free() is called with a non-NULL pointer that 2619** was not obtained from sqlite3_malloc() or sqlite3_realloc(). 2620** 2621** ^The sqlite3_realloc(X,N) interface attempts to resize a 2622** prior memory allocation X to be at least N bytes. 2623** ^If the X parameter to sqlite3_realloc(X,N) 2624** is a NULL pointer then its behavior is identical to calling 2625** sqlite3_malloc(N). 2626** ^If the N parameter to sqlite3_realloc(X,N) is zero or 2627** negative then the behavior is exactly the same as calling 2628** sqlite3_free(X). 2629** ^sqlite3_realloc(X,N) returns a pointer to a memory allocation 2630** of at least N bytes in size or NULL if insufficient memory is available. 2631** ^If M is the size of the prior allocation, then min(N,M) bytes 2632** of the prior allocation are copied into the beginning of buffer returned 2633** by sqlite3_realloc(X,N) and the prior allocation is freed. 2634** ^If sqlite3_realloc(X,N) returns NULL and N is positive, then the 2635** prior allocation is not freed. 2636** 2637** ^The sqlite3_realloc64(X,N) interfaces works the same as 2638** sqlite3_realloc(X,N) except that N is a 64-bit unsigned integer instead 2639** of a 32-bit signed integer. 2640** 2641** ^If X is a memory allocation previously obtained from sqlite3_malloc(), 2642** sqlite3_malloc64(), sqlite3_realloc(), or sqlite3_realloc64(), then 2643** sqlite3_msize(X) returns the size of that memory allocation in bytes. 2644** ^The value returned by sqlite3_msize(X) might be larger than the number 2645** of bytes requested when X was allocated. ^If X is a NULL pointer then 2646** sqlite3_msize(X) returns zero. If X points to something that is not 2647** the beginning of memory allocation, or if it points to a formerly 2648** valid memory allocation that has now been freed, then the behavior 2649** of sqlite3_msize(X) is undefined and possibly harmful. 2650** 2651** ^The memory returned by sqlite3_malloc(), sqlite3_realloc(), 2652** sqlite3_malloc64(), and sqlite3_realloc64() 2653** is always aligned to at least an 8 byte boundary, or to a 2654** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time 2655** option is used. 2656** 2657** In SQLite version 3.5.0 and 3.5.1, it was possible to define 2658** the SQLITE_OMIT_MEMORY_ALLOCATION which would cause the built-in 2659** implementation of these routines to be omitted. That capability 2660** is no longer provided. Only built-in memory allocators can be used. 2661** 2662** Prior to SQLite version 3.7.10, the Windows OS interface layer called 2663** the system malloc() and free() directly when converting 2664** filenames between the UTF-8 encoding used by SQLite 2665** and whatever filename encoding is used by the particular Windows 2666** installation. Memory allocation errors were detected, but 2667** they were reported back as [SQLITE_CANTOPEN] or 2668** [SQLITE_IOERR] rather than [SQLITE_NOMEM]. 2669** 2670** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()] 2671** must be either NULL or else pointers obtained from a prior 2672** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have 2673** not yet been released. 2674** 2675** The application must not read or write any part of 2676** a block of memory after it has been released using 2677** [sqlite3_free()] or [sqlite3_realloc()]. 2678*/ 2679void *sqlite3_malloc(int); 2680void *sqlite3_malloc64(sqlite3_uint64); 2681void *sqlite3_realloc(void*, int); 2682void *sqlite3_realloc64(void*, sqlite3_uint64); 2683void sqlite3_free(void*); 2684sqlite3_uint64 sqlite3_msize(void*); 2685 2686/* 2687** CAPI3REF: Memory Allocator Statistics 2688** 2689** SQLite provides these two interfaces for reporting on the status 2690** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()] 2691** routines, which form the built-in memory allocation subsystem. 2692** 2693** ^The [sqlite3_memory_used()] routine returns the number of bytes 2694** of memory currently outstanding (malloced but not freed). 2695** ^The [sqlite3_memory_highwater()] routine returns the maximum 2696** value of [sqlite3_memory_used()] since the high-water mark 2697** was last reset. ^The values returned by [sqlite3_memory_used()] and 2698** [sqlite3_memory_highwater()] include any overhead 2699** added by SQLite in its implementation of [sqlite3_malloc()], 2700** but not overhead added by the any underlying system library 2701** routines that [sqlite3_malloc()] may call. 2702** 2703** ^The memory high-water mark is reset to the current value of 2704** [sqlite3_memory_used()] if and only if the parameter to 2705** [sqlite3_memory_highwater()] is true. ^The value returned 2706** by [sqlite3_memory_highwater(1)] is the high-water mark 2707** prior to the reset. 2708*/ 2709sqlite3_int64 sqlite3_memory_used(void); 2710sqlite3_int64 sqlite3_memory_highwater(int resetFlag); 2711 2712/* 2713** CAPI3REF: Pseudo-Random Number Generator 2714** 2715** SQLite contains a high-quality pseudo-random number generator (PRNG) used to 2716** select random [ROWID | ROWIDs] when inserting new records into a table that 2717** already uses the largest possible [ROWID]. The PRNG is also used for 2718** the build-in random() and randomblob() SQL functions. This interface allows 2719** applications to access the same PRNG for other purposes. 2720** 2721** ^A call to this routine stores N bytes of randomness into buffer P. 2722** ^The P parameter can be a NULL pointer. 2723** 2724** ^If this routine has not been previously called or if the previous 2725** call had N less than one or a NULL pointer for P, then the PRNG is 2726** seeded using randomness obtained from the xRandomness method of 2727** the default [sqlite3_vfs] object. 2728** ^If the previous call to this routine had an N of 1 or more and a 2729** non-NULL P then the pseudo-randomness is generated 2730** internally and without recourse to the [sqlite3_vfs] xRandomness 2731** method. 2732*/ 2733void sqlite3_randomness(int N, void *P); 2734 2735/* 2736** CAPI3REF: Compile-Time Authorization Callbacks 2737** METHOD: sqlite3 2738** KEYWORDS: {authorizer callback} 2739** 2740** ^This routine registers an authorizer callback with a particular 2741** [database connection], supplied in the first argument. 2742** ^The authorizer callback is invoked as SQL statements are being compiled 2743** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()], 2744** [sqlite3_prepare_v3()], [sqlite3_prepare16()], [sqlite3_prepare16_v2()], 2745** and [sqlite3_prepare16_v3()]. ^At various 2746** points during the compilation process, as logic is being created 2747** to perform various actions, the authorizer callback is invoked to 2748** see if those actions are allowed. ^The authorizer callback should 2749** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the 2750** specific action but allow the SQL statement to continue to be 2751** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be 2752** rejected with an error. ^If the authorizer callback returns 2753** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY] 2754** then the [sqlite3_prepare_v2()] or equivalent call that triggered 2755** the authorizer will fail with an error message. 2756** 2757** When the callback returns [SQLITE_OK], that means the operation 2758** requested is ok. ^When the callback returns [SQLITE_DENY], the 2759** [sqlite3_prepare_v2()] or equivalent call that triggered the 2760** authorizer will fail with an error message explaining that 2761** access is denied. 2762** 2763** ^The first parameter to the authorizer callback is a copy of the third 2764** parameter to the sqlite3_set_authorizer() interface. ^The second parameter 2765** to the callback is an integer [SQLITE_COPY | action code] that specifies 2766** the particular action to be authorized. ^The third through sixth parameters 2767** to the callback are either NULL pointers or zero-terminated strings 2768** that contain additional details about the action to be authorized. 2769** Applications must always be prepared to encounter a NULL pointer in any 2770** of the third through the sixth parameters of the authorization callback. 2771** 2772** ^If the action code is [SQLITE_READ] 2773** and the callback returns [SQLITE_IGNORE] then the 2774** [prepared statement] statement is constructed to substitute 2775** a NULL value in place of the table column that would have 2776** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE] 2777** return can be used to deny an untrusted user access to individual 2778** columns of a table. 2779** ^When a table is referenced by a [SELECT] but no column values are 2780** extracted from that table (for example in a query like 2781** "SELECT count(*) FROM tab") then the [SQLITE_READ] authorizer callback 2782** is invoked once for that table with a column name that is an empty string. 2783** ^If the action code is [SQLITE_DELETE] and the callback returns 2784** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the 2785** [truncate optimization] is disabled and all rows are deleted individually. 2786** 2787** An authorizer is used when [sqlite3_prepare | preparing] 2788** SQL statements from an untrusted source, to ensure that the SQL statements 2789** do not try to access data they are not allowed to see, or that they do not 2790** try to execute malicious statements that damage the database. For 2791** example, an application may allow a user to enter arbitrary 2792** SQL queries for evaluation by a database. But the application does 2793** not want the user to be able to make arbitrary changes to the 2794** database. An authorizer could then be put in place while the 2795** user-entered SQL is being [sqlite3_prepare | prepared] that 2796** disallows everything except [SELECT] statements. 2797** 2798** Applications that need to process SQL from untrusted sources 2799** might also consider lowering resource limits using [sqlite3_limit()] 2800** and limiting database size using the [max_page_count] [PRAGMA] 2801** in addition to using an authorizer. 2802** 2803** ^(Only a single authorizer can be in place on a database connection 2804** at a time. Each call to sqlite3_set_authorizer overrides the 2805** previous call.)^ ^Disable the authorizer by installing a NULL callback. 2806** The authorizer is disabled by default. 2807** 2808** The authorizer callback must not do anything that will modify 2809** the database connection that invoked the authorizer callback. 2810** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 2811** database connections for the meaning of "modify" in this paragraph. 2812** 2813** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the 2814** statement might be re-prepared during [sqlite3_step()] due to a 2815** schema change. Hence, the application should ensure that the 2816** correct authorizer callback remains in place during the [sqlite3_step()]. 2817** 2818** ^Note that the authorizer callback is invoked only during 2819** [sqlite3_prepare()] or its variants. Authorization is not 2820** performed during statement evaluation in [sqlite3_step()], unless 2821** as stated in the previous paragraph, sqlite3_step() invokes 2822** sqlite3_prepare_v2() to reprepare a statement after a schema change. 2823*/ 2824int sqlite3_set_authorizer( 2825 sqlite3*, 2826 int (*xAuth)(void*,int,const char*,const char*,const char*,const char*), 2827 void *pUserData 2828); 2829 2830/* 2831** CAPI3REF: Authorizer Return Codes 2832** 2833** The [sqlite3_set_authorizer | authorizer callback function] must 2834** return either [SQLITE_OK] or one of these two constants in order 2835** to signal SQLite whether or not the action is permitted. See the 2836** [sqlite3_set_authorizer | authorizer documentation] for additional 2837** information. 2838** 2839** Note that SQLITE_IGNORE is also used as a [conflict resolution mode] 2840** returned from the [sqlite3_vtab_on_conflict()] interface. 2841*/ 2842#define SQLITE_DENY 1 /* Abort the SQL statement with an error */ 2843#define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */ 2844 2845/* 2846** CAPI3REF: Authorizer Action Codes 2847** 2848** The [sqlite3_set_authorizer()] interface registers a callback function 2849** that is invoked to authorize certain SQL statement actions. The 2850** second parameter to the callback is an integer code that specifies 2851** what action is being authorized. These are the integer action codes that 2852** the authorizer callback may be passed. 2853** 2854** These action code values signify what kind of operation is to be 2855** authorized. The 3rd and 4th parameters to the authorization 2856** callback function will be parameters or NULL depending on which of these 2857** codes is used as the second parameter. ^(The 5th parameter to the 2858** authorizer callback is the name of the database ("main", "temp", 2859** etc.) if applicable.)^ ^The 6th parameter to the authorizer callback 2860** is the name of the inner-most trigger or view that is responsible for 2861** the access attempt or NULL if this access attempt is directly from 2862** top-level SQL code. 2863*/ 2864/******************************************* 3rd ************ 4th ***********/ 2865#define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */ 2866#define SQLITE_CREATE_TABLE 2 /* Table Name NULL */ 2867#define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */ 2868#define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */ 2869#define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */ 2870#define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */ 2871#define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */ 2872#define SQLITE_CREATE_VIEW 8 /* View Name NULL */ 2873#define SQLITE_DELETE 9 /* Table Name NULL */ 2874#define SQLITE_DROP_INDEX 10 /* Index Name Table Name */ 2875#define SQLITE_DROP_TABLE 11 /* Table Name NULL */ 2876#define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */ 2877#define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */ 2878#define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */ 2879#define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */ 2880#define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */ 2881#define SQLITE_DROP_VIEW 17 /* View Name NULL */ 2882#define SQLITE_INSERT 18 /* Table Name NULL */ 2883#define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */ 2884#define SQLITE_READ 20 /* Table Name Column Name */ 2885#define SQLITE_SELECT 21 /* NULL NULL */ 2886#define SQLITE_TRANSACTION 22 /* Operation NULL */ 2887#define SQLITE_UPDATE 23 /* Table Name Column Name */ 2888#define SQLITE_ATTACH 24 /* Filename NULL */ 2889#define SQLITE_DETACH 25 /* Database Name NULL */ 2890#define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */ 2891#define SQLITE_REINDEX 27 /* Index Name NULL */ 2892#define SQLITE_ANALYZE 28 /* Table Name NULL */ 2893#define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */ 2894#define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */ 2895#define SQLITE_FUNCTION 31 /* NULL Function Name */ 2896#define SQLITE_SAVEPOINT 32 /* Operation Savepoint Name */ 2897#define SQLITE_COPY 0 /* No longer used */ 2898#define SQLITE_RECURSIVE 33 /* NULL NULL */ 2899 2900/* 2901** CAPI3REF: Tracing And Profiling Functions 2902** METHOD: sqlite3 2903** 2904** These routines are deprecated. Use the [sqlite3_trace_v2()] interface 2905** instead of the routines described here. 2906** 2907** These routines register callback functions that can be used for 2908** tracing and profiling the execution of SQL statements. 2909** 2910** ^The callback function registered by sqlite3_trace() is invoked at 2911** various times when an SQL statement is being run by [sqlite3_step()]. 2912** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the 2913** SQL statement text as the statement first begins executing. 2914** ^(Additional sqlite3_trace() callbacks might occur 2915** as each triggered subprogram is entered. The callbacks for triggers 2916** contain a UTF-8 SQL comment that identifies the trigger.)^ 2917** 2918** The [SQLITE_TRACE_SIZE_LIMIT] compile-time option can be used to limit 2919** the length of [bound parameter] expansion in the output of sqlite3_trace(). 2920** 2921** ^The callback function registered by sqlite3_profile() is invoked 2922** as each SQL statement finishes. ^The profile callback contains 2923** the original statement text and an estimate of wall-clock time 2924** of how long that statement took to run. ^The profile callback 2925** time is in units of nanoseconds, however the current implementation 2926** is only capable of millisecond resolution so the six least significant 2927** digits in the time are meaningless. Future versions of SQLite 2928** might provide greater resolution on the profiler callback. The 2929** sqlite3_profile() function is considered experimental and is 2930** subject to change in future versions of SQLite. 2931*/ 2932SQLITE_DEPRECATED void *sqlite3_trace(sqlite3*, 2933 void(*xTrace)(void*,const char*), void*); 2934SQLITE_DEPRECATED void *sqlite3_profile(sqlite3*, 2935 void(*xProfile)(void*,const char*,sqlite3_uint64), void*); 2936 2937/* 2938** CAPI3REF: SQL Trace Event Codes 2939** KEYWORDS: SQLITE_TRACE 2940** 2941** These constants identify classes of events that can be monitored 2942** using the [sqlite3_trace_v2()] tracing logic. The M argument 2943** to [sqlite3_trace_v2(D,M,X,P)] is an OR-ed combination of one or more of 2944** the following constants. ^The first argument to the trace callback 2945** is one of the following constants. 2946** 2947** New tracing constants may be added in future releases. 2948** 2949** ^A trace callback has four arguments: xCallback(T,C,P,X). 2950** ^The T argument is one of the integer type codes above. 2951** ^The C argument is a copy of the context pointer passed in as the 2952** fourth argument to [sqlite3_trace_v2()]. 2953** The P and X arguments are pointers whose meanings depend on T. 2954** 2955** <dl> 2956** [[SQLITE_TRACE_STMT]] <dt>SQLITE_TRACE_STMT</dt> 2957** <dd>^An SQLITE_TRACE_STMT callback is invoked when a prepared statement 2958** first begins running and possibly at other times during the 2959** execution of the prepared statement, such as at the start of each 2960** trigger subprogram. ^The P argument is a pointer to the 2961** [prepared statement]. ^The X argument is a pointer to a string which 2962** is the unexpanded SQL text of the prepared statement or an SQL comment 2963** that indicates the invocation of a trigger. ^The callback can compute 2964** the same text that would have been returned by the legacy [sqlite3_trace()] 2965** interface by using the X argument when X begins with "--" and invoking 2966** [sqlite3_expanded_sql(P)] otherwise. 2967** 2968** [[SQLITE_TRACE_PROFILE]] <dt>SQLITE_TRACE_PROFILE</dt> 2969** <dd>^An SQLITE_TRACE_PROFILE callback provides approximately the same 2970** information as is provided by the [sqlite3_profile()] callback. 2971** ^The P argument is a pointer to the [prepared statement] and the 2972** X argument points to a 64-bit integer which is the estimated of 2973** the number of nanosecond that the prepared statement took to run. 2974** ^The SQLITE_TRACE_PROFILE callback is invoked when the statement finishes. 2975** 2976** [[SQLITE_TRACE_ROW]] <dt>SQLITE_TRACE_ROW</dt> 2977** <dd>^An SQLITE_TRACE_ROW callback is invoked whenever a prepared 2978** statement generates a single row of result. 2979** ^The P argument is a pointer to the [prepared statement] and the 2980** X argument is unused. 2981** 2982** [[SQLITE_TRACE_CLOSE]] <dt>SQLITE_TRACE_CLOSE</dt> 2983** <dd>^An SQLITE_TRACE_CLOSE callback is invoked when a database 2984** connection closes. 2985** ^The P argument is a pointer to the [database connection] object 2986** and the X argument is unused. 2987** </dl> 2988*/ 2989#define SQLITE_TRACE_STMT 0x01 2990#define SQLITE_TRACE_PROFILE 0x02 2991#define SQLITE_TRACE_ROW 0x04 2992#define SQLITE_TRACE_CLOSE 0x08 2993 2994/* 2995** CAPI3REF: SQL Trace Hook 2996** METHOD: sqlite3 2997** 2998** ^The sqlite3_trace_v2(D,M,X,P) interface registers a trace callback 2999** function X against [database connection] D, using property mask M 3000** and context pointer P. ^If the X callback is 3001** NULL or if the M mask is zero, then tracing is disabled. The 3002** M argument should be the bitwise OR-ed combination of 3003** zero or more [SQLITE_TRACE] constants. 3004** 3005** ^Each call to either sqlite3_trace() or sqlite3_trace_v2() overrides 3006** (cancels) any prior calls to sqlite3_trace() or sqlite3_trace_v2(). 3007** 3008** ^The X callback is invoked whenever any of the events identified by 3009** mask M occur. ^The integer return value from the callback is currently 3010** ignored, though this may change in future releases. Callback 3011** implementations should return zero to ensure future compatibility. 3012** 3013** ^A trace callback is invoked with four arguments: callback(T,C,P,X). 3014** ^The T argument is one of the [SQLITE_TRACE] 3015** constants to indicate why the callback was invoked. 3016** ^The C argument is a copy of the context pointer. 3017** The P and X arguments are pointers whose meanings depend on T. 3018** 3019** The sqlite3_trace_v2() interface is intended to replace the legacy 3020** interfaces [sqlite3_trace()] and [sqlite3_profile()], both of which 3021** are deprecated. 3022*/ 3023int sqlite3_trace_v2( 3024 sqlite3*, 3025 unsigned uMask, 3026 int(*xCallback)(unsigned,void*,void*,void*), 3027 void *pCtx 3028); 3029 3030/* 3031** CAPI3REF: Query Progress Callbacks 3032** METHOD: sqlite3 3033** 3034** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback 3035** function X to be invoked periodically during long running calls to 3036** [sqlite3_exec()], [sqlite3_step()] and [sqlite3_get_table()] for 3037** database connection D. An example use for this 3038** interface is to keep a GUI updated during a large query. 3039** 3040** ^The parameter P is passed through as the only parameter to the 3041** callback function X. ^The parameter N is the approximate number of 3042** [virtual machine instructions] that are evaluated between successive 3043** invocations of the callback X. ^If N is less than one then the progress 3044** handler is disabled. 3045** 3046** ^Only a single progress handler may be defined at one time per 3047** [database connection]; setting a new progress handler cancels the 3048** old one. ^Setting parameter X to NULL disables the progress handler. 3049** ^The progress handler is also disabled by setting N to a value less 3050** than 1. 3051** 3052** ^If the progress callback returns non-zero, the operation is 3053** interrupted. This feature can be used to implement a 3054** "Cancel" button on a GUI progress dialog box. 3055** 3056** The progress handler callback must not do anything that will modify 3057** the database connection that invoked the progress handler. 3058** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 3059** database connections for the meaning of "modify" in this paragraph. 3060** 3061*/ 3062void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*); 3063 3064/* 3065** CAPI3REF: Opening A New Database Connection 3066** CONSTRUCTOR: sqlite3 3067** 3068** ^These routines open an SQLite database file as specified by the 3069** filename argument. ^The filename argument is interpreted as UTF-8 for 3070** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte 3071** order for sqlite3_open16(). ^(A [database connection] handle is usually 3072** returned in *ppDb, even if an error occurs. The only exception is that 3073** if SQLite is unable to allocate memory to hold the [sqlite3] object, 3074** a NULL will be written into *ppDb instead of a pointer to the [sqlite3] 3075** object.)^ ^(If the database is opened (and/or created) successfully, then 3076** [SQLITE_OK] is returned. Otherwise an [error code] is returned.)^ ^The 3077** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain 3078** an English language description of the error following a failure of any 3079** of the sqlite3_open() routines. 3080** 3081** ^The default encoding will be UTF-8 for databases created using 3082** sqlite3_open() or sqlite3_open_v2(). ^The default encoding for databases 3083** created using sqlite3_open16() will be UTF-16 in the native byte order. 3084** 3085** Whether or not an error occurs when it is opened, resources 3086** associated with the [database connection] handle should be released by 3087** passing it to [sqlite3_close()] when it is no longer required. 3088** 3089** The sqlite3_open_v2() interface works like sqlite3_open() 3090** except that it accepts two additional parameters for additional control 3091** over the new database connection. ^(The flags parameter to 3092** sqlite3_open_v2() can take one of 3093** the following three values, optionally combined with the 3094** [SQLITE_OPEN_NOMUTEX], [SQLITE_OPEN_FULLMUTEX], [SQLITE_OPEN_SHAREDCACHE], 3095** [SQLITE_OPEN_PRIVATECACHE], and/or [SQLITE_OPEN_URI] flags:)^ 3096** 3097** <dl> 3098** ^(<dt>[SQLITE_OPEN_READONLY]</dt> 3099** <dd>The database is opened in read-only mode. If the database does not 3100** already exist, an error is returned.</dd>)^ 3101** 3102** ^(<dt>[SQLITE_OPEN_READWRITE]</dt> 3103** <dd>The database is opened for reading and writing if possible, or reading 3104** only if the file is write protected by the operating system. In either 3105** case the database must already exist, otherwise an error is returned.</dd>)^ 3106** 3107** ^(<dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt> 3108** <dd>The database is opened for reading and writing, and is created if 3109** it does not already exist. This is the behavior that is always used for 3110** sqlite3_open() and sqlite3_open16().</dd>)^ 3111** </dl> 3112** 3113** If the 3rd parameter to sqlite3_open_v2() is not one of the 3114** combinations shown above optionally combined with other 3115** [SQLITE_OPEN_READONLY | SQLITE_OPEN_* bits] 3116** then the behavior is undefined. 3117** 3118** ^If the [SQLITE_OPEN_NOMUTEX] flag is set, then the database connection 3119** opens in the multi-thread [threading mode] as long as the single-thread 3120** mode has not been set at compile-time or start-time. ^If the 3121** [SQLITE_OPEN_FULLMUTEX] flag is set then the database connection opens 3122** in the serialized [threading mode] unless single-thread was 3123** previously selected at compile-time or start-time. 3124** ^The [SQLITE_OPEN_SHAREDCACHE] flag causes the database connection to be 3125** eligible to use [shared cache mode], regardless of whether or not shared 3126** cache is enabled using [sqlite3_enable_shared_cache()]. ^The 3127** [SQLITE_OPEN_PRIVATECACHE] flag causes the database connection to not 3128** participate in [shared cache mode] even if it is enabled. 3129** 3130** ^The fourth parameter to sqlite3_open_v2() is the name of the 3131** [sqlite3_vfs] object that defines the operating system interface that 3132** the new database connection should use. ^If the fourth parameter is 3133** a NULL pointer then the default [sqlite3_vfs] object is used. 3134** 3135** ^If the filename is ":memory:", then a private, temporary in-memory database 3136** is created for the connection. ^This in-memory database will vanish when 3137** the database connection is closed. Future versions of SQLite might 3138** make use of additional special filenames that begin with the ":" character. 3139** It is recommended that when a database filename actually does begin with 3140** a ":" character you should prefix the filename with a pathname such as 3141** "./" to avoid ambiguity. 3142** 3143** ^If the filename is an empty string, then a private, temporary 3144** on-disk database will be created. ^This private database will be 3145** automatically deleted as soon as the database connection is closed. 3146** 3147** [[URI filenames in sqlite3_open()]] <h3>URI Filenames</h3> 3148** 3149** ^If [URI filename] interpretation is enabled, and the filename argument 3150** begins with "file:", then the filename is interpreted as a URI. ^URI 3151** filename interpretation is enabled if the [SQLITE_OPEN_URI] flag is 3152** set in the third argument to sqlite3_open_v2(), or if it has 3153** been enabled globally using the [SQLITE_CONFIG_URI] option with the 3154** [sqlite3_config()] method or by the [SQLITE_USE_URI] compile-time option. 3155** URI filename interpretation is turned off 3156** by default, but future releases of SQLite might enable URI filename 3157** interpretation by default. See "[URI filenames]" for additional 3158** information. 3159** 3160** URI filenames are parsed according to RFC 3986. ^If the URI contains an 3161** authority, then it must be either an empty string or the string 3162** "localhost". ^If the authority is not an empty string or "localhost", an 3163** error is returned to the caller. ^The fragment component of a URI, if 3164** present, is ignored. 3165** 3166** ^SQLite uses the path component of the URI as the name of the disk file 3167** which contains the database. ^If the path begins with a '/' character, 3168** then it is interpreted as an absolute path. ^If the path does not begin 3169** with a '/' (meaning that the authority section is omitted from the URI) 3170** then the path is interpreted as a relative path. 3171** ^(On windows, the first component of an absolute path 3172** is a drive specification (e.g. "C:").)^ 3173** 3174** [[core URI query parameters]] 3175** The query component of a URI may contain parameters that are interpreted 3176** either by SQLite itself, or by a [VFS | custom VFS implementation]. 3177** SQLite and its built-in [VFSes] interpret the 3178** following query parameters: 3179** 3180** <ul> 3181** <li> <b>vfs</b>: ^The "vfs" parameter may be used to specify the name of 3182** a VFS object that provides the operating system interface that should 3183** be used to access the database file on disk. ^If this option is set to 3184** an empty string the default VFS object is used. ^Specifying an unknown 3185** VFS is an error. ^If sqlite3_open_v2() is used and the vfs option is 3186** present, then the VFS specified by the option takes precedence over 3187** the value passed as the fourth parameter to sqlite3_open_v2(). 3188** 3189** <li> <b>mode</b>: ^(The mode parameter may be set to either "ro", "rw", 3190** "rwc", or "memory". Attempting to set it to any other value is 3191** an error)^. 3192** ^If "ro" is specified, then the database is opened for read-only 3193** access, just as if the [SQLITE_OPEN_READONLY] flag had been set in the 3194** third argument to sqlite3_open_v2(). ^If the mode option is set to 3195** "rw", then the database is opened for read-write (but not create) 3196** access, as if SQLITE_OPEN_READWRITE (but not SQLITE_OPEN_CREATE) had 3197** been set. ^Value "rwc" is equivalent to setting both 3198** SQLITE_OPEN_READWRITE and SQLITE_OPEN_CREATE. ^If the mode option is 3199** set to "memory" then a pure [in-memory database] that never reads 3200** or writes from disk is used. ^It is an error to specify a value for 3201** the mode parameter that is less restrictive than that specified by 3202** the flags passed in the third parameter to sqlite3_open_v2(). 3203** 3204** <li> <b>cache</b>: ^The cache parameter may be set to either "shared" or 3205** "private". ^Setting it to "shared" is equivalent to setting the 3206** SQLITE_OPEN_SHAREDCACHE bit in the flags argument passed to 3207** sqlite3_open_v2(). ^Setting the cache parameter to "private" is 3208** equivalent to setting the SQLITE_OPEN_PRIVATECACHE bit. 3209** ^If sqlite3_open_v2() is used and the "cache" parameter is present in 3210** a URI filename, its value overrides any behavior requested by setting 3211** SQLITE_OPEN_PRIVATECACHE or SQLITE_OPEN_SHAREDCACHE flag. 3212** 3213** <li> <b>psow</b>: ^The psow parameter indicates whether or not the 3214** [powersafe overwrite] property does or does not apply to the 3215** storage media on which the database file resides. 3216** 3217** <li> <b>nolock</b>: ^The nolock parameter is a boolean query parameter 3218** which if set disables file locking in rollback journal modes. This 3219** is useful for accessing a database on a filesystem that does not 3220** support locking. Caution: Database corruption might result if two 3221** or more processes write to the same database and any one of those 3222** processes uses nolock=1. 3223** 3224** <li> <b>immutable</b>: ^The immutable parameter is a boolean query 3225** parameter that indicates that the database file is stored on 3226** read-only media. ^When immutable is set, SQLite assumes that the 3227** database file cannot be changed, even by a process with higher 3228** privilege, and so the database is opened read-only and all locking 3229** and change detection is disabled. Caution: Setting the immutable 3230** property on a database file that does in fact change can result 3231** in incorrect query results and/or [SQLITE_CORRUPT] errors. 3232** See also: [SQLITE_IOCAP_IMMUTABLE]. 3233** 3234** </ul> 3235** 3236** ^Specifying an unknown parameter in the query component of a URI is not an 3237** error. Future versions of SQLite might understand additional query 3238** parameters. See "[query parameters with special meaning to SQLite]" for 3239** additional information. 3240** 3241** [[URI filename examples]] <h3>URI filename examples</h3> 3242** 3243** <table border="1" align=center cellpadding=5> 3244** <tr><th> URI filenames <th> Results 3245** <tr><td> file:data.db <td> 3246** Open the file "data.db" in the current directory. 3247** <tr><td> file:/home/fred/data.db<br> 3248** file:///home/fred/data.db <br> 3249** file://localhost/home/fred/data.db <br> <td> 3250** Open the database file "/home/fred/data.db". 3251** <tr><td> file://darkstar/home/fred/data.db <td> 3252** An error. "darkstar" is not a recognized authority. 3253** <tr><td style="white-space:nowrap"> 3254** file:///C:/Documents%20and%20Settings/fred/Desktop/data.db 3255** <td> Windows only: Open the file "data.db" on fred's desktop on drive 3256** C:. Note that the %20 escaping in this example is not strictly 3257** necessary - space characters can be used literally 3258** in URI filenames. 3259** <tr><td> file:data.db?mode=ro&cache=private <td> 3260** Open file "data.db" in the current directory for read-only access. 3261** Regardless of whether or not shared-cache mode is enabled by 3262** default, use a private cache. 3263** <tr><td> file:/home/fred/data.db?vfs=unix-dotfile <td> 3264** Open file "/home/fred/data.db". Use the special VFS "unix-dotfile" 3265** that uses dot-files in place of posix advisory locking. 3266** <tr><td> file:data.db?mode=readonly <td> 3267** An error. "readonly" is not a valid option for the "mode" parameter. 3268** </table> 3269** 3270** ^URI hexadecimal escape sequences (%HH) are supported within the path and 3271** query components of a URI. A hexadecimal escape sequence consists of a 3272** percent sign - "%" - followed by exactly two hexadecimal digits 3273** specifying an octet value. ^Before the path or query components of a 3274** URI filename are interpreted, they are encoded using UTF-8 and all 3275** hexadecimal escape sequences replaced by a single byte containing the 3276** corresponding octet. If this process generates an invalid UTF-8 encoding, 3277** the results are undefined. 3278** 3279** <b>Note to Windows users:</b> The encoding used for the filename argument 3280** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever 3281** codepage is currently defined. Filenames containing international 3282** characters must be converted to UTF-8 prior to passing them into 3283** sqlite3_open() or sqlite3_open_v2(). 3284** 3285** <b>Note to Windows Runtime users:</b> The temporary directory must be set 3286** prior to calling sqlite3_open() or sqlite3_open_v2(). Otherwise, various 3287** features that require the use of temporary files may fail. 3288** 3289** See also: [sqlite3_temp_directory] 3290*/ 3291int sqlite3_open( 3292 const char *filename, /* Database filename (UTF-8) */ 3293 sqlite3 **ppDb /* OUT: SQLite db handle */ 3294); 3295int sqlite3_open16( 3296 const void *filename, /* Database filename (UTF-16) */ 3297 sqlite3 **ppDb /* OUT: SQLite db handle */ 3298); 3299int sqlite3_open_v2( 3300 const char *filename, /* Database filename (UTF-8) */ 3301 sqlite3 **ppDb, /* OUT: SQLite db handle */ 3302 int flags, /* Flags */ 3303 const char *zVfs /* Name of VFS module to use */ 3304); 3305 3306/* 3307** CAPI3REF: Obtain Values For URI Parameters 3308** 3309** These are utility routines, useful to VFS implementations, that check 3310** to see if a database file was a URI that contained a specific query 3311** parameter, and if so obtains the value of that query parameter. 3312** 3313** If F is the database filename pointer passed into the xOpen() method of 3314** a VFS implementation when the flags parameter to xOpen() has one or 3315** more of the [SQLITE_OPEN_URI] or [SQLITE_OPEN_MAIN_DB] bits set and 3316** P is the name of the query parameter, then 3317** sqlite3_uri_parameter(F,P) returns the value of the P 3318** parameter if it exists or a NULL pointer if P does not appear as a 3319** query parameter on F. If P is a query parameter of F 3320** has no explicit value, then sqlite3_uri_parameter(F,P) returns 3321** a pointer to an empty string. 3322** 3323** The sqlite3_uri_boolean(F,P,B) routine assumes that P is a boolean 3324** parameter and returns true (1) or false (0) according to the value 3325** of P. The sqlite3_uri_boolean(F,P,B) routine returns true (1) if the 3326** value of query parameter P is one of "yes", "true", or "on" in any 3327** case or if the value begins with a non-zero number. The 3328** sqlite3_uri_boolean(F,P,B) routines returns false (0) if the value of 3329** query parameter P is one of "no", "false", or "off" in any case or 3330** if the value begins with a numeric zero. If P is not a query 3331** parameter on F or if the value of P is does not match any of the 3332** above, then sqlite3_uri_boolean(F,P,B) returns (B!=0). 3333** 3334** The sqlite3_uri_int64(F,P,D) routine converts the value of P into a 3335** 64-bit signed integer and returns that integer, or D if P does not 3336** exist. If the value of P is something other than an integer, then 3337** zero is returned. 3338** 3339** If F is a NULL pointer, then sqlite3_uri_parameter(F,P) returns NULL and 3340** sqlite3_uri_boolean(F,P,B) returns B. If F is not a NULL pointer and 3341** is not a database file pathname pointer that SQLite passed into the xOpen 3342** VFS method, then the behavior of this routine is undefined and probably 3343** undesirable. 3344*/ 3345const char *sqlite3_uri_parameter(const char *zFilename, const char *zParam); 3346int sqlite3_uri_boolean(const char *zFile, const char *zParam, int bDefault); 3347sqlite3_int64 sqlite3_uri_int64(const char*, const char*, sqlite3_int64); 3348 3349 3350/* 3351** CAPI3REF: Error Codes And Messages 3352** METHOD: sqlite3 3353** 3354** ^If the most recent sqlite3_* API call associated with 3355** [database connection] D failed, then the sqlite3_errcode(D) interface 3356** returns the numeric [result code] or [extended result code] for that 3357** API call. 3358** ^The sqlite3_extended_errcode() 3359** interface is the same except that it always returns the 3360** [extended result code] even when extended result codes are 3361** disabled. 3362** 3363** The values returned by sqlite3_errcode() and/or 3364** sqlite3_extended_errcode() might change with each API call. 3365** Except, there are some interfaces that are guaranteed to never 3366** change the value of the error code. The error-code preserving 3367** interfaces are: 3368** 3369** <ul> 3370** <li> sqlite3_errcode() 3371** <li> sqlite3_extended_errcode() 3372** <li> sqlite3_errmsg() 3373** <li> sqlite3_errmsg16() 3374** </ul> 3375** 3376** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language 3377** text that describes the error, as either UTF-8 or UTF-16 respectively. 3378** ^(Memory to hold the error message string is managed internally. 3379** The application does not need to worry about freeing the result. 3380** However, the error string might be overwritten or deallocated by 3381** subsequent calls to other SQLite interface functions.)^ 3382** 3383** ^The sqlite3_errstr() interface returns the English-language text 3384** that describes the [result code], as UTF-8. 3385** ^(Memory to hold the error message string is managed internally 3386** and must not be freed by the application)^. 3387** 3388** When the serialized [threading mode] is in use, it might be the 3389** case that a second error occurs on a separate thread in between 3390** the time of the first error and the call to these interfaces. 3391** When that happens, the second error will be reported since these 3392** interfaces always report the most recent result. To avoid 3393** this, each thread can obtain exclusive use of the [database connection] D 3394** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning 3395** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after 3396** all calls to the interfaces listed here are completed. 3397** 3398** If an interface fails with SQLITE_MISUSE, that means the interface 3399** was invoked incorrectly by the application. In that case, the 3400** error code and message may or may not be set. 3401*/ 3402int sqlite3_errcode(sqlite3 *db); 3403int sqlite3_extended_errcode(sqlite3 *db); 3404const char *sqlite3_errmsg(sqlite3*); 3405const void *sqlite3_errmsg16(sqlite3*); 3406const char *sqlite3_errstr(int); 3407 3408/* 3409** CAPI3REF: Prepared Statement Object 3410** KEYWORDS: {prepared statement} {prepared statements} 3411** 3412** An instance of this object represents a single SQL statement that 3413** has been compiled into binary form and is ready to be evaluated. 3414** 3415** Think of each SQL statement as a separate computer program. The 3416** original SQL text is source code. A prepared statement object 3417** is the compiled object code. All SQL must be converted into a 3418** prepared statement before it can be run. 3419** 3420** The life-cycle of a prepared statement object usually goes like this: 3421** 3422** <ol> 3423** <li> Create the prepared statement object using [sqlite3_prepare_v2()]. 3424** <li> Bind values to [parameters] using the sqlite3_bind_*() 3425** interfaces. 3426** <li> Run the SQL by calling [sqlite3_step()] one or more times. 3427** <li> Reset the prepared statement using [sqlite3_reset()] then go back 3428** to step 2. Do this zero or more times. 3429** <li> Destroy the object using [sqlite3_finalize()]. 3430** </ol> 3431*/ 3432typedef struct sqlite3_stmt sqlite3_stmt; 3433 3434/* 3435** CAPI3REF: Run-time Limits 3436** METHOD: sqlite3 3437** 3438** ^(This interface allows the size of various constructs to be limited 3439** on a connection by connection basis. The first parameter is the 3440** [database connection] whose limit is to be set or queried. The 3441** second parameter is one of the [limit categories] that define a 3442** class of constructs to be size limited. The third parameter is the 3443** new limit for that construct.)^ 3444** 3445** ^If the new limit is a negative number, the limit is unchanged. 3446** ^(For each limit category SQLITE_LIMIT_<i>NAME</i> there is a 3447** [limits | hard upper bound] 3448** set at compile-time by a C preprocessor macro called 3449** [limits | SQLITE_MAX_<i>NAME</i>]. 3450** (The "_LIMIT_" in the name is changed to "_MAX_".))^ 3451** ^Attempts to increase a limit above its hard upper bound are 3452** silently truncated to the hard upper bound. 3453** 3454** ^Regardless of whether or not the limit was changed, the 3455** [sqlite3_limit()] interface returns the prior value of the limit. 3456** ^Hence, to find the current value of a limit without changing it, 3457** simply invoke this interface with the third parameter set to -1. 3458** 3459** Run-time limits are intended for use in applications that manage 3460** both their own internal database and also databases that are controlled 3461** by untrusted external sources. An example application might be a 3462** web browser that has its own databases for storing history and 3463** separate databases controlled by JavaScript applications downloaded 3464** off the Internet. The internal databases can be given the 3465** large, default limits. Databases managed by external sources can 3466** be given much smaller limits designed to prevent a denial of service 3467** attack. Developers might also want to use the [sqlite3_set_authorizer()] 3468** interface to further control untrusted SQL. The size of the database 3469** created by an untrusted script can be contained using the 3470** [max_page_count] [PRAGMA]. 3471** 3472** New run-time limit categories may be added in future releases. 3473*/ 3474int sqlite3_limit(sqlite3*, int id, int newVal); 3475 3476/* 3477** CAPI3REF: Run-Time Limit Categories 3478** KEYWORDS: {limit category} {*limit categories} 3479** 3480** These constants define various performance limits 3481** that can be lowered at run-time using [sqlite3_limit()]. 3482** The synopsis of the meanings of the various limits is shown below. 3483** Additional information is available at [limits | Limits in SQLite]. 3484** 3485** <dl> 3486** [[SQLITE_LIMIT_LENGTH]] ^(<dt>SQLITE_LIMIT_LENGTH</dt> 3487** <dd>The maximum size of any string or BLOB or table row, in bytes.<dd>)^ 3488** 3489** [[SQLITE_LIMIT_SQL_LENGTH]] ^(<dt>SQLITE_LIMIT_SQL_LENGTH</dt> 3490** <dd>The maximum length of an SQL statement, in bytes.</dd>)^ 3491** 3492** [[SQLITE_LIMIT_COLUMN]] ^(<dt>SQLITE_LIMIT_COLUMN</dt> 3493** <dd>The maximum number of columns in a table definition or in the 3494** result set of a [SELECT] or the maximum number of columns in an index 3495** or in an ORDER BY or GROUP BY clause.</dd>)^ 3496** 3497** [[SQLITE_LIMIT_EXPR_DEPTH]] ^(<dt>SQLITE_LIMIT_EXPR_DEPTH</dt> 3498** <dd>The maximum depth of the parse tree on any expression.</dd>)^ 3499** 3500** [[SQLITE_LIMIT_COMPOUND_SELECT]] ^(<dt>SQLITE_LIMIT_COMPOUND_SELECT</dt> 3501** <dd>The maximum number of terms in a compound SELECT statement.</dd>)^ 3502** 3503** [[SQLITE_LIMIT_VDBE_OP]] ^(<dt>SQLITE_LIMIT_VDBE_OP</dt> 3504** <dd>The maximum number of instructions in a virtual machine program 3505** used to implement an SQL statement. If [sqlite3_prepare_v2()] or 3506** the equivalent tries to allocate space for more than this many opcodes 3507** in a single prepared statement, an SQLITE_NOMEM error is returned.</dd>)^ 3508** 3509** [[SQLITE_LIMIT_FUNCTION_ARG]] ^(<dt>SQLITE_LIMIT_FUNCTION_ARG</dt> 3510** <dd>The maximum number of arguments on a function.</dd>)^ 3511** 3512** [[SQLITE_LIMIT_ATTACHED]] ^(<dt>SQLITE_LIMIT_ATTACHED</dt> 3513** <dd>The maximum number of [ATTACH | attached databases].)^</dd> 3514** 3515** [[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]] 3516** ^(<dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt> 3517** <dd>The maximum length of the pattern argument to the [LIKE] or 3518** [GLOB] operators.</dd>)^ 3519** 3520** [[SQLITE_LIMIT_VARIABLE_NUMBER]] 3521** ^(<dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt> 3522** <dd>The maximum index number of any [parameter] in an SQL statement.)^ 3523** 3524** [[SQLITE_LIMIT_TRIGGER_DEPTH]] ^(<dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt> 3525** <dd>The maximum depth of recursion for triggers.</dd>)^ 3526** 3527** [[SQLITE_LIMIT_WORKER_THREADS]] ^(<dt>SQLITE_LIMIT_WORKER_THREADS</dt> 3528** <dd>The maximum number of auxiliary worker threads that a single 3529** [prepared statement] may start.</dd>)^ 3530** </dl> 3531*/ 3532#define SQLITE_LIMIT_LENGTH 0 3533#define SQLITE_LIMIT_SQL_LENGTH 1 3534#define SQLITE_LIMIT_COLUMN 2 3535#define SQLITE_LIMIT_EXPR_DEPTH 3 3536#define SQLITE_LIMIT_COMPOUND_SELECT 4 3537#define SQLITE_LIMIT_VDBE_OP 5 3538#define SQLITE_LIMIT_FUNCTION_ARG 6 3539#define SQLITE_LIMIT_ATTACHED 7 3540#define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8 3541#define SQLITE_LIMIT_VARIABLE_NUMBER 9 3542#define SQLITE_LIMIT_TRIGGER_DEPTH 10 3543#define SQLITE_LIMIT_WORKER_THREADS 11 3544 3545/* 3546** CAPI3REF: Prepare Flags 3547** 3548** These constants define various flags that can be passed into 3549** "prepFlags" parameter of the [sqlite3_prepare_v3()] and 3550** [sqlite3_prepare16_v3()] interfaces. 3551** 3552** New flags may be added in future releases of SQLite. 3553** 3554** <dl> 3555** [[SQLITE_PREPARE_PERSISTENT]] ^(<dt>SQLITE_PREPARE_PERSISTENT</dt> 3556** <dd>The SQLITE_PREPARE_PERSISTENT flag is a hint to the query planner 3557** that the prepared statement will be retained for a long time and 3558** probably reused many times.)^ ^Without this flag, [sqlite3_prepare_v3()] 3559** and [sqlite3_prepare16_v3()] assume that the prepared statement will 3560** be used just once or at most a few times and then destroyed using 3561** [sqlite3_finalize()] relatively soon. The current implementation acts 3562** on this hint by avoiding the use of [lookaside memory] so as not to 3563** deplete the limited store of lookaside memory. Future versions of 3564** SQLite may act on this hint differently. 3565** </dl> 3566*/ 3567#define SQLITE_PREPARE_PERSISTENT 0x01 3568 3569/* 3570** CAPI3REF: Compiling An SQL Statement 3571** KEYWORDS: {SQL statement compiler} 3572** METHOD: sqlite3 3573** CONSTRUCTOR: sqlite3_stmt 3574** 3575** To execute an SQL statement, it must first be compiled into a byte-code 3576** program using one of these routines. Or, in other words, these routines 3577** are constructors for the [prepared statement] object. 3578** 3579** The preferred routine to use is [sqlite3_prepare_v2()]. The 3580** [sqlite3_prepare()] interface is legacy and should be avoided. 3581** [sqlite3_prepare_v3()] has an extra "prepFlags" option that is used 3582** for special purposes. 3583** 3584** The use of the UTF-8 interfaces is preferred, as SQLite currently 3585** does all parsing using UTF-8. The UTF-16 interfaces are provided 3586** as a convenience. The UTF-16 interfaces work by converting the 3587** input text into UTF-8, then invoking the corresponding UTF-8 interface. 3588** 3589** The first argument, "db", is a [database connection] obtained from a 3590** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or 3591** [sqlite3_open16()]. The database connection must not have been closed. 3592** 3593** The second argument, "zSql", is the statement to be compiled, encoded 3594** as either UTF-8 or UTF-16. The sqlite3_prepare(), sqlite3_prepare_v2(), 3595** and sqlite3_prepare_v3() 3596** interfaces use UTF-8, and sqlite3_prepare16(), sqlite3_prepare16_v2(), 3597** and sqlite3_prepare16_v3() use UTF-16. 3598** 3599** ^If the nByte argument is negative, then zSql is read up to the 3600** first zero terminator. ^If nByte is positive, then it is the 3601** number of bytes read from zSql. ^If nByte is zero, then no prepared 3602** statement is generated. 3603** If the caller knows that the supplied string is nul-terminated, then 3604** there is a small performance advantage to passing an nByte parameter that 3605** is the number of bytes in the input string <i>including</i> 3606** the nul-terminator. 3607** 3608** ^If pzTail is not NULL then *pzTail is made to point to the first byte 3609** past the end of the first SQL statement in zSql. These routines only 3610** compile the first statement in zSql, so *pzTail is left pointing to 3611** what remains uncompiled. 3612** 3613** ^*ppStmt is left pointing to a compiled [prepared statement] that can be 3614** executed using [sqlite3_step()]. ^If there is an error, *ppStmt is set 3615** to NULL. ^If the input text contains no SQL (if the input is an empty 3616** string or a comment) then *ppStmt is set to NULL. 3617** The calling procedure is responsible for deleting the compiled 3618** SQL statement using [sqlite3_finalize()] after it has finished with it. 3619** ppStmt may not be NULL. 3620** 3621** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK]; 3622** otherwise an [error code] is returned. 3623** 3624** The sqlite3_prepare_v2(), sqlite3_prepare_v3(), sqlite3_prepare16_v2(), 3625** and sqlite3_prepare16_v3() interfaces are recommended for all new programs. 3626** The older interfaces (sqlite3_prepare() and sqlite3_prepare16()) 3627** are retained for backwards compatibility, but their use is discouraged. 3628** ^In the "vX" interfaces, the prepared statement 3629** that is returned (the [sqlite3_stmt] object) contains a copy of the 3630** original SQL text. This causes the [sqlite3_step()] interface to 3631** behave differently in three ways: 3632** 3633** <ol> 3634** <li> 3635** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it 3636** always used to do, [sqlite3_step()] will automatically recompile the SQL 3637** statement and try to run it again. As many as [SQLITE_MAX_SCHEMA_RETRY] 3638** retries will occur before sqlite3_step() gives up and returns an error. 3639** </li> 3640** 3641** <li> 3642** ^When an error occurs, [sqlite3_step()] will return one of the detailed 3643** [error codes] or [extended error codes]. ^The legacy behavior was that 3644** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code 3645** and the application would have to make a second call to [sqlite3_reset()] 3646** in order to find the underlying cause of the problem. With the "v2" prepare 3647** interfaces, the underlying reason for the error is returned immediately. 3648** </li> 3649** 3650** <li> 3651** ^If the specific value bound to [parameter | host parameter] in the 3652** WHERE clause might influence the choice of query plan for a statement, 3653** then the statement will be automatically recompiled, as if there had been 3654** a schema change, on the first [sqlite3_step()] call following any change 3655** to the [sqlite3_bind_text | bindings] of that [parameter]. 3656** ^The specific value of WHERE-clause [parameter] might influence the 3657** choice of query plan if the parameter is the left-hand side of a [LIKE] 3658** or [GLOB] operator or if the parameter is compared to an indexed column 3659** and the [SQLITE_ENABLE_STAT3] compile-time option is enabled. 3660** </li> 3661** </ol> 3662** 3663** <p>^sqlite3_prepare_v3() differs from sqlite3_prepare_v2() only in having 3664** the extra prepFlags parameter, which is a bit array consisting of zero or 3665** more of the [SQLITE_PREPARE_PERSISTENT|SQLITE_PREPARE_*] flags. ^The 3666** sqlite3_prepare_v2() interface works exactly the same as 3667** sqlite3_prepare_v3() with a zero prepFlags parameter. 3668*/ 3669int sqlite3_prepare( 3670 sqlite3 *db, /* Database handle */ 3671 const char *zSql, /* SQL statement, UTF-8 encoded */ 3672 int nByte, /* Maximum length of zSql in bytes. */ 3673 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3674 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 3675); 3676int sqlite3_prepare_v2( 3677 sqlite3 *db, /* Database handle */ 3678 const char *zSql, /* SQL statement, UTF-8 encoded */ 3679 int nByte, /* Maximum length of zSql in bytes. */ 3680 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3681 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 3682); 3683int sqlite3_prepare_v3( 3684 sqlite3 *db, /* Database handle */ 3685 const char *zSql, /* SQL statement, UTF-8 encoded */ 3686 int nByte, /* Maximum length of zSql in bytes. */ 3687 unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */ 3688 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3689 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 3690); 3691int sqlite3_prepare16( 3692 sqlite3 *db, /* Database handle */ 3693 const void *zSql, /* SQL statement, UTF-16 encoded */ 3694 int nByte, /* Maximum length of zSql in bytes. */ 3695 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3696 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 3697); 3698int sqlite3_prepare16_v2( 3699 sqlite3 *db, /* Database handle */ 3700 const void *zSql, /* SQL statement, UTF-16 encoded */ 3701 int nByte, /* Maximum length of zSql in bytes. */ 3702 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3703 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 3704); 3705int sqlite3_prepare16_v3( 3706 sqlite3 *db, /* Database handle */ 3707 const void *zSql, /* SQL statement, UTF-16 encoded */ 3708 int nByte, /* Maximum length of zSql in bytes. */ 3709 unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */ 3710 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3711 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 3712); 3713 3714/* 3715** CAPI3REF: Retrieving Statement SQL 3716** METHOD: sqlite3_stmt 3717** 3718** ^The sqlite3_sql(P) interface returns a pointer to a copy of the UTF-8 3719** SQL text used to create [prepared statement] P if P was 3720** created by [sqlite3_prepare_v2()], [sqlite3_prepare_v3()], 3721** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()]. 3722** ^The sqlite3_expanded_sql(P) interface returns a pointer to a UTF-8 3723** string containing the SQL text of prepared statement P with 3724** [bound parameters] expanded. 3725** 3726** ^(For example, if a prepared statement is created using the SQL 3727** text "SELECT $abc,:xyz" and if parameter $abc is bound to integer 2345 3728** and parameter :xyz is unbound, then sqlite3_sql() will return 3729** the original string, "SELECT $abc,:xyz" but sqlite3_expanded_sql() 3730** will return "SELECT 2345,NULL".)^ 3731** 3732** ^The sqlite3_expanded_sql() interface returns NULL if insufficient memory 3733** is available to hold the result, or if the result would exceed the 3734** the maximum string length determined by the [SQLITE_LIMIT_LENGTH]. 3735** 3736** ^The [SQLITE_TRACE_SIZE_LIMIT] compile-time option limits the size of 3737** bound parameter expansions. ^The [SQLITE_OMIT_TRACE] compile-time 3738** option causes sqlite3_expanded_sql() to always return NULL. 3739** 3740** ^The string returned by sqlite3_sql(P) is managed by SQLite and is 3741** automatically freed when the prepared statement is finalized. 3742** ^The string returned by sqlite3_expanded_sql(P), on the other hand, 3743** is obtained from [sqlite3_malloc()] and must be free by the application 3744** by passing it to [sqlite3_free()]. 3745*/ 3746const char *sqlite3_sql(sqlite3_stmt *pStmt); 3747char *sqlite3_expanded_sql(sqlite3_stmt *pStmt); 3748 3749/* 3750** CAPI3REF: Determine If An SQL Statement Writes The Database 3751** METHOD: sqlite3_stmt 3752** 3753** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if 3754** and only if the [prepared statement] X makes no direct changes to 3755** the content of the database file. 3756** 3757** Note that [application-defined SQL functions] or 3758** [virtual tables] might change the database indirectly as a side effect. 3759** ^(For example, if an application defines a function "eval()" that 3760** calls [sqlite3_exec()], then the following SQL statement would 3761** change the database file through side-effects: 3762** 3763** <blockquote><pre> 3764** SELECT eval('DELETE FROM t1') FROM t2; 3765** </pre></blockquote> 3766** 3767** But because the [SELECT] statement does not change the database file 3768** directly, sqlite3_stmt_readonly() would still return true.)^ 3769** 3770** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK], 3771** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true, 3772** since the statements themselves do not actually modify the database but 3773** rather they control the timing of when other statements modify the 3774** database. ^The [ATTACH] and [DETACH] statements also cause 3775** sqlite3_stmt_readonly() to return true since, while those statements 3776** change the configuration of a database connection, they do not make 3777** changes to the content of the database files on disk. 3778** ^The sqlite3_stmt_readonly() interface returns true for [BEGIN] since 3779** [BEGIN] merely sets internal flags, but the [BEGIN|BEGIN IMMEDIATE] and 3780** [BEGIN|BEGIN EXCLUSIVE] commands do touch the database and so 3781** sqlite3_stmt_readonly() returns false for those commands. 3782*/ 3783int sqlite3_stmt_readonly(sqlite3_stmt *pStmt); 3784 3785/* 3786** CAPI3REF: Determine If A Prepared Statement Has Been Reset 3787** METHOD: sqlite3_stmt 3788** 3789** ^The sqlite3_stmt_busy(S) interface returns true (non-zero) if the 3790** [prepared statement] S has been stepped at least once using 3791** [sqlite3_step(S)] but has neither run to completion (returned 3792** [SQLITE_DONE] from [sqlite3_step(S)]) nor 3793** been reset using [sqlite3_reset(S)]. ^The sqlite3_stmt_busy(S) 3794** interface returns false if S is a NULL pointer. If S is not a 3795** NULL pointer and is not a pointer to a valid [prepared statement] 3796** object, then the behavior is undefined and probably undesirable. 3797** 3798** This interface can be used in combination [sqlite3_next_stmt()] 3799** to locate all prepared statements associated with a database 3800** connection that are in need of being reset. This can be used, 3801** for example, in diagnostic routines to search for prepared 3802** statements that are holding a transaction open. 3803*/ 3804int sqlite3_stmt_busy(sqlite3_stmt*); 3805 3806/* 3807** CAPI3REF: Dynamically Typed Value Object 3808** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value} 3809** 3810** SQLite uses the sqlite3_value object to represent all values 3811** that can be stored in a database table. SQLite uses dynamic typing 3812** for the values it stores. ^Values stored in sqlite3_value objects 3813** can be integers, floating point values, strings, BLOBs, or NULL. 3814** 3815** An sqlite3_value object may be either "protected" or "unprotected". 3816** Some interfaces require a protected sqlite3_value. Other interfaces 3817** will accept either a protected or an unprotected sqlite3_value. 3818** Every interface that accepts sqlite3_value arguments specifies 3819** whether or not it requires a protected sqlite3_value. The 3820** [sqlite3_value_dup()] interface can be used to construct a new 3821** protected sqlite3_value from an unprotected sqlite3_value. 3822** 3823** The terms "protected" and "unprotected" refer to whether or not 3824** a mutex is held. An internal mutex is held for a protected 3825** sqlite3_value object but no mutex is held for an unprotected 3826** sqlite3_value object. If SQLite is compiled to be single-threaded 3827** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0) 3828** or if SQLite is run in one of reduced mutex modes 3829** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD] 3830** then there is no distinction between protected and unprotected 3831** sqlite3_value objects and they can be used interchangeably. However, 3832** for maximum code portability it is recommended that applications 3833** still make the distinction between protected and unprotected 3834** sqlite3_value objects even when not strictly required. 3835** 3836** ^The sqlite3_value objects that are passed as parameters into the 3837** implementation of [application-defined SQL functions] are protected. 3838** ^The sqlite3_value object returned by 3839** [sqlite3_column_value()] is unprotected. 3840** Unprotected sqlite3_value objects may only be used as arguments 3841** to [sqlite3_result_value()], [sqlite3_bind_value()], and 3842** [sqlite3_value_dup()]. 3843** The [sqlite3_value_blob | sqlite3_value_type()] family of 3844** interfaces require protected sqlite3_value objects. 3845*/ 3846typedef struct sqlite3_value sqlite3_value; 3847 3848/* 3849** CAPI3REF: SQL Function Context Object 3850** 3851** The context in which an SQL function executes is stored in an 3852** sqlite3_context object. ^A pointer to an sqlite3_context object 3853** is always first parameter to [application-defined SQL functions]. 3854** The application-defined SQL function implementation will pass this 3855** pointer through into calls to [sqlite3_result_int | sqlite3_result()], 3856** [sqlite3_aggregate_context()], [sqlite3_user_data()], 3857** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()], 3858** and/or [sqlite3_set_auxdata()]. 3859*/ 3860typedef struct sqlite3_context sqlite3_context; 3861 3862/* 3863** CAPI3REF: Binding Values To Prepared Statements 3864** KEYWORDS: {host parameter} {host parameters} {host parameter name} 3865** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding} 3866** METHOD: sqlite3_stmt 3867** 3868** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants, 3869** literals may be replaced by a [parameter] that matches one of following 3870** templates: 3871** 3872** <ul> 3873** <li> ? 3874** <li> ?NNN 3875** <li> :VVV 3876** <li> @VVV 3877** <li> $VVV 3878** </ul> 3879** 3880** In the templates above, NNN represents an integer literal, 3881** and VVV represents an alphanumeric identifier.)^ ^The values of these 3882** parameters (also called "host parameter names" or "SQL parameters") 3883** can be set using the sqlite3_bind_*() routines defined here. 3884** 3885** ^The first argument to the sqlite3_bind_*() routines is always 3886** a pointer to the [sqlite3_stmt] object returned from 3887** [sqlite3_prepare_v2()] or its variants. 3888** 3889** ^The second argument is the index of the SQL parameter to be set. 3890** ^The leftmost SQL parameter has an index of 1. ^When the same named 3891** SQL parameter is used more than once, second and subsequent 3892** occurrences have the same index as the first occurrence. 3893** ^The index for named parameters can be looked up using the 3894** [sqlite3_bind_parameter_index()] API if desired. ^The index 3895** for "?NNN" parameters is the value of NNN. 3896** ^The NNN value must be between 1 and the [sqlite3_limit()] 3897** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 999). 3898** 3899** ^The third argument is the value to bind to the parameter. 3900** ^If the third parameter to sqlite3_bind_text() or sqlite3_bind_text16() 3901** or sqlite3_bind_blob() is a NULL pointer then the fourth parameter 3902** is ignored and the end result is the same as sqlite3_bind_null(). 3903** 3904** ^(In those routines that have a fourth argument, its value is the 3905** number of bytes in the parameter. To be clear: the value is the 3906** number of <u>bytes</u> in the value, not the number of characters.)^ 3907** ^If the fourth parameter to sqlite3_bind_text() or sqlite3_bind_text16() 3908** is negative, then the length of the string is 3909** the number of bytes up to the first zero terminator. 3910** If the fourth parameter to sqlite3_bind_blob() is negative, then 3911** the behavior is undefined. 3912** If a non-negative fourth parameter is provided to sqlite3_bind_text() 3913** or sqlite3_bind_text16() or sqlite3_bind_text64() then 3914** that parameter must be the byte offset 3915** where the NUL terminator would occur assuming the string were NUL 3916** terminated. If any NUL characters occur at byte offsets less than 3917** the value of the fourth parameter then the resulting string value will 3918** contain embedded NULs. The result of expressions involving strings 3919** with embedded NULs is undefined. 3920** 3921** ^The fifth argument to the BLOB and string binding interfaces 3922** is a destructor used to dispose of the BLOB or 3923** string after SQLite has finished with it. ^The destructor is called 3924** to dispose of the BLOB or string even if the call to bind API fails. 3925** ^If the fifth argument is 3926** the special value [SQLITE_STATIC], then SQLite assumes that the 3927** information is in static, unmanaged space and does not need to be freed. 3928** ^If the fifth argument has the value [SQLITE_TRANSIENT], then 3929** SQLite makes its own private copy of the data immediately, before 3930** the sqlite3_bind_*() routine returns. 3931** 3932** ^The sixth argument to sqlite3_bind_text64() must be one of 3933** [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE] 3934** to specify the encoding of the text in the third parameter. If 3935** the sixth argument to sqlite3_bind_text64() is not one of the 3936** allowed values shown above, or if the text encoding is different 3937** from the encoding specified by the sixth parameter, then the behavior 3938** is undefined. 3939** 3940** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that 3941** is filled with zeroes. ^A zeroblob uses a fixed amount of memory 3942** (just an integer to hold its size) while it is being processed. 3943** Zeroblobs are intended to serve as placeholders for BLOBs whose 3944** content is later written using 3945** [sqlite3_blob_open | incremental BLOB I/O] routines. 3946** ^A negative value for the zeroblob results in a zero-length BLOB. 3947** 3948** ^The sqlite3_bind_pointer(S,I,P,T,D) routine causes the I-th parameter in 3949** [prepared statement] S to have an SQL value of NULL, but to also be 3950** associated with the pointer P of type T. ^D is either a NULL pointer or 3951** a pointer to a destructor function for P. ^SQLite will invoke the 3952** destructor D with a single argument of P when it is finished using 3953** P. The T parameter should be a static string, preferably a string 3954** literal. The sqlite3_bind_pointer() routine is part of the 3955** [pointer passing interface] added for SQLite 3.20.0. 3956** 3957** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer 3958** for the [prepared statement] or with a prepared statement for which 3959** [sqlite3_step()] has been called more recently than [sqlite3_reset()], 3960** then the call will return [SQLITE_MISUSE]. If any sqlite3_bind_() 3961** routine is passed a [prepared statement] that has been finalized, the 3962** result is undefined and probably harmful. 3963** 3964** ^Bindings are not cleared by the [sqlite3_reset()] routine. 3965** ^Unbound parameters are interpreted as NULL. 3966** 3967** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an 3968** [error code] if anything goes wrong. 3969** ^[SQLITE_TOOBIG] might be returned if the size of a string or BLOB 3970** exceeds limits imposed by [sqlite3_limit]([SQLITE_LIMIT_LENGTH]) or 3971** [SQLITE_MAX_LENGTH]. 3972** ^[SQLITE_RANGE] is returned if the parameter 3973** index is out of range. ^[SQLITE_NOMEM] is returned if malloc() fails. 3974** 3975** See also: [sqlite3_bind_parameter_count()], 3976** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()]. 3977*/ 3978int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*)); 3979int sqlite3_bind_blob64(sqlite3_stmt*, int, const void*, sqlite3_uint64, 3980 void(*)(void*)); 3981int sqlite3_bind_double(sqlite3_stmt*, int, double); 3982int sqlite3_bind_int(sqlite3_stmt*, int, int); 3983int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64); 3984int sqlite3_bind_null(sqlite3_stmt*, int); 3985int sqlite3_bind_text(sqlite3_stmt*,int,const char*,int,void(*)(void*)); 3986int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*)); 3987int sqlite3_bind_text64(sqlite3_stmt*, int, const char*, sqlite3_uint64, 3988 void(*)(void*), unsigned char encoding); 3989int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*); 3990int sqlite3_bind_pointer(sqlite3_stmt*, int, void*, const char*,void(*)(void*)); 3991int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n); 3992int sqlite3_bind_zeroblob64(sqlite3_stmt*, int, sqlite3_uint64); 3993 3994/* 3995** CAPI3REF: Number Of SQL Parameters 3996** METHOD: sqlite3_stmt 3997** 3998** ^This routine can be used to find the number of [SQL parameters] 3999** in a [prepared statement]. SQL parameters are tokens of the 4000** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as 4001** placeholders for values that are [sqlite3_bind_blob | bound] 4002** to the parameters at a later time. 4003** 4004** ^(This routine actually returns the index of the largest (rightmost) 4005** parameter. For all forms except ?NNN, this will correspond to the 4006** number of unique parameters. If parameters of the ?NNN form are used, 4007** there may be gaps in the list.)^ 4008** 4009** See also: [sqlite3_bind_blob|sqlite3_bind()], 4010** [sqlite3_bind_parameter_name()], and 4011** [sqlite3_bind_parameter_index()]. 4012*/ 4013int sqlite3_bind_parameter_count(sqlite3_stmt*); 4014 4015/* 4016** CAPI3REF: Name Of A Host Parameter 4017** METHOD: sqlite3_stmt 4018** 4019** ^The sqlite3_bind_parameter_name(P,N) interface returns 4020** the name of the N-th [SQL parameter] in the [prepared statement] P. 4021** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA" 4022** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA" 4023** respectively. 4024** In other words, the initial ":" or "$" or "@" or "?" 4025** is included as part of the name.)^ 4026** ^Parameters of the form "?" without a following integer have no name 4027** and are referred to as "nameless" or "anonymous parameters". 4028** 4029** ^The first host parameter has an index of 1, not 0. 4030** 4031** ^If the value N is out of range or if the N-th parameter is 4032** nameless, then NULL is returned. ^The returned string is 4033** always in UTF-8 encoding even if the named parameter was 4034** originally specified as UTF-16 in [sqlite3_prepare16()], 4035** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()]. 4036** 4037** See also: [sqlite3_bind_blob|sqlite3_bind()], 4038** [sqlite3_bind_parameter_count()], and 4039** [sqlite3_bind_parameter_index()]. 4040*/ 4041const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int); 4042 4043/* 4044** CAPI3REF: Index Of A Parameter With A Given Name 4045** METHOD: sqlite3_stmt 4046** 4047** ^Return the index of an SQL parameter given its name. ^The 4048** index value returned is suitable for use as the second 4049** parameter to [sqlite3_bind_blob|sqlite3_bind()]. ^A zero 4050** is returned if no matching parameter is found. ^The parameter 4051** name must be given in UTF-8 even if the original statement 4052** was prepared from UTF-16 text using [sqlite3_prepare16_v2()] or 4053** [sqlite3_prepare16_v3()]. 4054** 4055** See also: [sqlite3_bind_blob|sqlite3_bind()], 4056** [sqlite3_bind_parameter_count()], and 4057** [sqlite3_bind_parameter_name()]. 4058*/ 4059int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName); 4060 4061/* 4062** CAPI3REF: Reset All Bindings On A Prepared Statement 4063** METHOD: sqlite3_stmt 4064** 4065** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset 4066** the [sqlite3_bind_blob | bindings] on a [prepared statement]. 4067** ^Use this routine to reset all host parameters to NULL. 4068*/ 4069int sqlite3_clear_bindings(sqlite3_stmt*); 4070 4071/* 4072** CAPI3REF: Number Of Columns In A Result Set 4073** METHOD: sqlite3_stmt 4074** 4075** ^Return the number of columns in the result set returned by the 4076** [prepared statement]. ^If this routine returns 0, that means the 4077** [prepared statement] returns no data (for example an [UPDATE]). 4078** ^However, just because this routine returns a positive number does not 4079** mean that one or more rows of data will be returned. ^A SELECT statement 4080** will always have a positive sqlite3_column_count() but depending on the 4081** WHERE clause constraints and the table content, it might return no rows. 4082** 4083** See also: [sqlite3_data_count()] 4084*/ 4085int sqlite3_column_count(sqlite3_stmt *pStmt); 4086 4087/* 4088** CAPI3REF: Column Names In A Result Set 4089** METHOD: sqlite3_stmt 4090** 4091** ^These routines return the name assigned to a particular column 4092** in the result set of a [SELECT] statement. ^The sqlite3_column_name() 4093** interface returns a pointer to a zero-terminated UTF-8 string 4094** and sqlite3_column_name16() returns a pointer to a zero-terminated 4095** UTF-16 string. ^The first parameter is the [prepared statement] 4096** that implements the [SELECT] statement. ^The second parameter is the 4097** column number. ^The leftmost column is number 0. 4098** 4099** ^The returned string pointer is valid until either the [prepared statement] 4100** is destroyed by [sqlite3_finalize()] or until the statement is automatically 4101** reprepared by the first call to [sqlite3_step()] for a particular run 4102** or until the next call to 4103** sqlite3_column_name() or sqlite3_column_name16() on the same column. 4104** 4105** ^If sqlite3_malloc() fails during the processing of either routine 4106** (for example during a conversion from UTF-8 to UTF-16) then a 4107** NULL pointer is returned. 4108** 4109** ^The name of a result column is the value of the "AS" clause for 4110** that column, if there is an AS clause. If there is no AS clause 4111** then the name of the column is unspecified and may change from 4112** one release of SQLite to the next. 4113*/ 4114const char *sqlite3_column_name(sqlite3_stmt*, int N); 4115const void *sqlite3_column_name16(sqlite3_stmt*, int N); 4116 4117/* 4118** CAPI3REF: Source Of Data In A Query Result 4119** METHOD: sqlite3_stmt 4120** 4121** ^These routines provide a means to determine the database, table, and 4122** table column that is the origin of a particular result column in 4123** [SELECT] statement. 4124** ^The name of the database or table or column can be returned as 4125** either a UTF-8 or UTF-16 string. ^The _database_ routines return 4126** the database name, the _table_ routines return the table name, and 4127** the origin_ routines return the column name. 4128** ^The returned string is valid until the [prepared statement] is destroyed 4129** using [sqlite3_finalize()] or until the statement is automatically 4130** reprepared by the first call to [sqlite3_step()] for a particular run 4131** or until the same information is requested 4132** again in a different encoding. 4133** 4134** ^The names returned are the original un-aliased names of the 4135** database, table, and column. 4136** 4137** ^The first argument to these interfaces is a [prepared statement]. 4138** ^These functions return information about the Nth result column returned by 4139** the statement, where N is the second function argument. 4140** ^The left-most column is column 0 for these routines. 4141** 4142** ^If the Nth column returned by the statement is an expression or 4143** subquery and is not a column value, then all of these functions return 4144** NULL. ^These routine might also return NULL if a memory allocation error 4145** occurs. ^Otherwise, they return the name of the attached database, table, 4146** or column that query result column was extracted from. 4147** 4148** ^As with all other SQLite APIs, those whose names end with "16" return 4149** UTF-16 encoded strings and the other functions return UTF-8. 4150** 4151** ^These APIs are only available if the library was compiled with the 4152** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol. 4153** 4154** If two or more threads call one or more of these routines against the same 4155** prepared statement and column at the same time then the results are 4156** undefined. 4157** 4158** If two or more threads call one or more 4159** [sqlite3_column_database_name | column metadata interfaces] 4160** for the same [prepared statement] and result column 4161** at the same time then the results are undefined. 4162*/ 4163const char *sqlite3_column_database_name(sqlite3_stmt*,int); 4164const void *sqlite3_column_database_name16(sqlite3_stmt*,int); 4165const char *sqlite3_column_table_name(sqlite3_stmt*,int); 4166const void *sqlite3_column_table_name16(sqlite3_stmt*,int); 4167const char *sqlite3_column_origin_name(sqlite3_stmt*,int); 4168const void *sqlite3_column_origin_name16(sqlite3_stmt*,int); 4169 4170/* 4171** CAPI3REF: Declared Datatype Of A Query Result 4172** METHOD: sqlite3_stmt 4173** 4174** ^(The first parameter is a [prepared statement]. 4175** If this statement is a [SELECT] statement and the Nth column of the 4176** returned result set of that [SELECT] is a table column (not an 4177** expression or subquery) then the declared type of the table 4178** column is returned.)^ ^If the Nth column of the result set is an 4179** expression or subquery, then a NULL pointer is returned. 4180** ^The returned string is always UTF-8 encoded. 4181** 4182** ^(For example, given the database schema: 4183** 4184** CREATE TABLE t1(c1 VARIANT); 4185** 4186** and the following statement to be compiled: 4187** 4188** SELECT c1 + 1, c1 FROM t1; 4189** 4190** this routine would return the string "VARIANT" for the second result 4191** column (i==1), and a NULL pointer for the first result column (i==0).)^ 4192** 4193** ^SQLite uses dynamic run-time typing. ^So just because a column 4194** is declared to contain a particular type does not mean that the 4195** data stored in that column is of the declared type. SQLite is 4196** strongly typed, but the typing is dynamic not static. ^Type 4197** is associated with individual values, not with the containers 4198** used to hold those values. 4199*/ 4200const char *sqlite3_column_decltype(sqlite3_stmt*,int); 4201const void *sqlite3_column_decltype16(sqlite3_stmt*,int); 4202 4203/* 4204** CAPI3REF: Evaluate An SQL Statement 4205** METHOD: sqlite3_stmt 4206** 4207** After a [prepared statement] has been prepared using any of 4208** [sqlite3_prepare_v2()], [sqlite3_prepare_v3()], [sqlite3_prepare16_v2()], 4209** or [sqlite3_prepare16_v3()] or one of the legacy 4210** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function 4211** must be called one or more times to evaluate the statement. 4212** 4213** The details of the behavior of the sqlite3_step() interface depend 4214** on whether the statement was prepared using the newer "vX" interfaces 4215** [sqlite3_prepare_v3()], [sqlite3_prepare_v2()], [sqlite3_prepare16_v3()], 4216** [sqlite3_prepare16_v2()] or the older legacy 4217** interfaces [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the 4218** new "vX" interface is recommended for new applications but the legacy 4219** interface will continue to be supported. 4220** 4221** ^In the legacy interface, the return value will be either [SQLITE_BUSY], 4222** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE]. 4223** ^With the "v2" interface, any of the other [result codes] or 4224** [extended result codes] might be returned as well. 4225** 4226** ^[SQLITE_BUSY] means that the database engine was unable to acquire the 4227** database locks it needs to do its job. ^If the statement is a [COMMIT] 4228** or occurs outside of an explicit transaction, then you can retry the 4229** statement. If the statement is not a [COMMIT] and occurs within an 4230** explicit transaction then you should rollback the transaction before 4231** continuing. 4232** 4233** ^[SQLITE_DONE] means that the statement has finished executing 4234** successfully. sqlite3_step() should not be called again on this virtual 4235** machine without first calling [sqlite3_reset()] to reset the virtual 4236** machine back to its initial state. 4237** 4238** ^If the SQL statement being executed returns any data, then [SQLITE_ROW] 4239** is returned each time a new row of data is ready for processing by the 4240** caller. The values may be accessed using the [column access functions]. 4241** sqlite3_step() is called again to retrieve the next row of data. 4242** 4243** ^[SQLITE_ERROR] means that a run-time error (such as a constraint 4244** violation) has occurred. sqlite3_step() should not be called again on 4245** the VM. More information may be found by calling [sqlite3_errmsg()]. 4246** ^With the legacy interface, a more specific error code (for example, 4247** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth) 4248** can be obtained by calling [sqlite3_reset()] on the 4249** [prepared statement]. ^In the "v2" interface, 4250** the more specific error code is returned directly by sqlite3_step(). 4251** 4252** [SQLITE_MISUSE] means that the this routine was called inappropriately. 4253** Perhaps it was called on a [prepared statement] that has 4254** already been [sqlite3_finalize | finalized] or on one that had 4255** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could 4256** be the case that the same database connection is being used by two or 4257** more threads at the same moment in time. 4258** 4259** For all versions of SQLite up to and including 3.6.23.1, a call to 4260** [sqlite3_reset()] was required after sqlite3_step() returned anything 4261** other than [SQLITE_ROW] before any subsequent invocation of 4262** sqlite3_step(). Failure to reset the prepared statement using 4263** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from 4264** sqlite3_step(). But after [version 3.6.23.1] ([dateof:3.6.23.1], 4265** sqlite3_step() began 4266** calling [sqlite3_reset()] automatically in this circumstance rather 4267** than returning [SQLITE_MISUSE]. This is not considered a compatibility 4268** break because any application that ever receives an SQLITE_MISUSE error 4269** is broken by definition. The [SQLITE_OMIT_AUTORESET] compile-time option 4270** can be used to restore the legacy behavior. 4271** 4272** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step() 4273** API always returns a generic error code, [SQLITE_ERROR], following any 4274** error other than [SQLITE_BUSY] and [SQLITE_MISUSE]. You must call 4275** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the 4276** specific [error codes] that better describes the error. 4277** We admit that this is a goofy design. The problem has been fixed 4278** with the "v2" interface. If you prepare all of your SQL statements 4279** using [sqlite3_prepare_v3()] or [sqlite3_prepare_v2()] 4280** or [sqlite3_prepare16_v2()] or [sqlite3_prepare16_v3()] instead 4281** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces, 4282** then the more specific [error codes] are returned directly 4283** by sqlite3_step(). The use of the "vX" interfaces is recommended. 4284*/ 4285int sqlite3_step(sqlite3_stmt*); 4286 4287/* 4288** CAPI3REF: Number of columns in a result set 4289** METHOD: sqlite3_stmt 4290** 4291** ^The sqlite3_data_count(P) interface returns the number of columns in the 4292** current row of the result set of [prepared statement] P. 4293** ^If prepared statement P does not have results ready to return 4294** (via calls to the [sqlite3_column_int | sqlite3_column_*()] of 4295** interfaces) then sqlite3_data_count(P) returns 0. 4296** ^The sqlite3_data_count(P) routine also returns 0 if P is a NULL pointer. 4297** ^The sqlite3_data_count(P) routine returns 0 if the previous call to 4298** [sqlite3_step](P) returned [SQLITE_DONE]. ^The sqlite3_data_count(P) 4299** will return non-zero if previous call to [sqlite3_step](P) returned 4300** [SQLITE_ROW], except in the case of the [PRAGMA incremental_vacuum] 4301** where it always returns zero since each step of that multi-step 4302** pragma returns 0 columns of data. 4303** 4304** See also: [sqlite3_column_count()] 4305*/ 4306int sqlite3_data_count(sqlite3_stmt *pStmt); 4307 4308/* 4309** CAPI3REF: Fundamental Datatypes 4310** KEYWORDS: SQLITE_TEXT 4311** 4312** ^(Every value in SQLite has one of five fundamental datatypes: 4313** 4314** <ul> 4315** <li> 64-bit signed integer 4316** <li> 64-bit IEEE floating point number 4317** <li> string 4318** <li> BLOB 4319** <li> NULL 4320** </ul>)^ 4321** 4322** These constants are codes for each of those types. 4323** 4324** Note that the SQLITE_TEXT constant was also used in SQLite version 2 4325** for a completely different meaning. Software that links against both 4326** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not 4327** SQLITE_TEXT. 4328*/ 4329#define SQLITE_INTEGER 1 4330#define SQLITE_FLOAT 2 4331#define SQLITE_BLOB 4 4332#define SQLITE_NULL 5 4333#ifdef SQLITE_TEXT 4334# undef SQLITE_TEXT 4335#else 4336# define SQLITE_TEXT 3 4337#endif 4338#define SQLITE3_TEXT 3 4339 4340/* 4341** CAPI3REF: Result Values From A Query 4342** KEYWORDS: {column access functions} 4343** METHOD: sqlite3_stmt 4344** 4345** <b>Summary:</b> 4346** <blockquote><table border=0 cellpadding=0 cellspacing=0> 4347** <tr><td><b>sqlite3_column_blob</b><td>→<td>BLOB result 4348** <tr><td><b>sqlite3_column_double</b><td>→<td>REAL result 4349** <tr><td><b>sqlite3_column_int</b><td>→<td>32-bit INTEGER result 4350** <tr><td><b>sqlite3_column_int64</b><td>→<td>64-bit INTEGER result 4351** <tr><td><b>sqlite3_column_text</b><td>→<td>UTF-8 TEXT result 4352** <tr><td><b>sqlite3_column_text16</b><td>→<td>UTF-16 TEXT result 4353** <tr><td><b>sqlite3_column_value</b><td>→<td>The result as an 4354** [sqlite3_value|unprotected sqlite3_value] object. 4355** <tr><td> <td> <td> 4356** <tr><td><b>sqlite3_column_bytes</b><td>→<td>Size of a BLOB 4357** or a UTF-8 TEXT result in bytes 4358** <tr><td><b>sqlite3_column_bytes16 </b> 4359** <td>→ <td>Size of UTF-16 4360** TEXT in bytes 4361** <tr><td><b>sqlite3_column_type</b><td>→<td>Default 4362** datatype of the result 4363** </table></blockquote> 4364** 4365** <b>Details:</b> 4366** 4367** ^These routines return information about a single column of the current 4368** result row of a query. ^In every case the first argument is a pointer 4369** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*] 4370** that was returned from [sqlite3_prepare_v2()] or one of its variants) 4371** and the second argument is the index of the column for which information 4372** should be returned. ^The leftmost column of the result set has the index 0. 4373** ^The number of columns in the result can be determined using 4374** [sqlite3_column_count()]. 4375** 4376** If the SQL statement does not currently point to a valid row, or if the 4377** column index is out of range, the result is undefined. 4378** These routines may only be called when the most recent call to 4379** [sqlite3_step()] has returned [SQLITE_ROW] and neither 4380** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently. 4381** If any of these routines are called after [sqlite3_reset()] or 4382** [sqlite3_finalize()] or after [sqlite3_step()] has returned 4383** something other than [SQLITE_ROW], the results are undefined. 4384** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()] 4385** are called from a different thread while any of these routines 4386** are pending, then the results are undefined. 4387** 4388** The first six interfaces (_blob, _double, _int, _int64, _text, and _text16) 4389** each return the value of a result column in a specific data format. If 4390** the result column is not initially in the requested format (for example, 4391** if the query returns an integer but the sqlite3_column_text() interface 4392** is used to extract the value) then an automatic type conversion is performed. 4393** 4394** ^The sqlite3_column_type() routine returns the 4395** [SQLITE_INTEGER | datatype code] for the initial data type 4396** of the result column. ^The returned value is one of [SQLITE_INTEGER], 4397** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL]. 4398** The return value of sqlite3_column_type() can be used to decide which 4399** of the first six interface should be used to extract the column value. 4400** The value returned by sqlite3_column_type() is only meaningful if no 4401** automatic type conversions have occurred for the value in question. 4402** After a type conversion, the result of calling sqlite3_column_type() 4403** is undefined, though harmless. Future 4404** versions of SQLite may change the behavior of sqlite3_column_type() 4405** following a type conversion. 4406** 4407** If the result is a BLOB or a TEXT string, then the sqlite3_column_bytes() 4408** or sqlite3_column_bytes16() interfaces can be used to determine the size 4409** of that BLOB or string. 4410** 4411** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes() 4412** routine returns the number of bytes in that BLOB or string. 4413** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts 4414** the string to UTF-8 and then returns the number of bytes. 4415** ^If the result is a numeric value then sqlite3_column_bytes() uses 4416** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns 4417** the number of bytes in that string. 4418** ^If the result is NULL, then sqlite3_column_bytes() returns zero. 4419** 4420** ^If the result is a BLOB or UTF-16 string then the sqlite3_column_bytes16() 4421** routine returns the number of bytes in that BLOB or string. 4422** ^If the result is a UTF-8 string, then sqlite3_column_bytes16() converts 4423** the string to UTF-16 and then returns the number of bytes. 4424** ^If the result is a numeric value then sqlite3_column_bytes16() uses 4425** [sqlite3_snprintf()] to convert that value to a UTF-16 string and returns 4426** the number of bytes in that string. 4427** ^If the result is NULL, then sqlite3_column_bytes16() returns zero. 4428** 4429** ^The values returned by [sqlite3_column_bytes()] and 4430** [sqlite3_column_bytes16()] do not include the zero terminators at the end 4431** of the string. ^For clarity: the values returned by 4432** [sqlite3_column_bytes()] and [sqlite3_column_bytes16()] are the number of 4433** bytes in the string, not the number of characters. 4434** 4435** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(), 4436** even empty strings, are always zero-terminated. ^The return 4437** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer. 4438** 4439** <b>Warning:</b> ^The object returned by [sqlite3_column_value()] is an 4440** [unprotected sqlite3_value] object. In a multithreaded environment, 4441** an unprotected sqlite3_value object may only be used safely with 4442** [sqlite3_bind_value()] and [sqlite3_result_value()]. 4443** If the [unprotected sqlite3_value] object returned by 4444** [sqlite3_column_value()] is used in any other way, including calls 4445** to routines like [sqlite3_value_int()], [sqlite3_value_text()], 4446** or [sqlite3_value_bytes()], the behavior is not threadsafe. 4447** Hence, the sqlite3_column_value() interface 4448** is normally only useful within the implementation of 4449** [application-defined SQL functions] or [virtual tables], not within 4450** top-level application code. 4451** 4452** The these routines may attempt to convert the datatype of the result. 4453** ^For example, if the internal representation is FLOAT and a text result 4454** is requested, [sqlite3_snprintf()] is used internally to perform the 4455** conversion automatically. ^(The following table details the conversions 4456** that are applied: 4457** 4458** <blockquote> 4459** <table border="1"> 4460** <tr><th> Internal<br>Type <th> Requested<br>Type <th> Conversion 4461** 4462** <tr><td> NULL <td> INTEGER <td> Result is 0 4463** <tr><td> NULL <td> FLOAT <td> Result is 0.0 4464** <tr><td> NULL <td> TEXT <td> Result is a NULL pointer 4465** <tr><td> NULL <td> BLOB <td> Result is a NULL pointer 4466** <tr><td> INTEGER <td> FLOAT <td> Convert from integer to float 4467** <tr><td> INTEGER <td> TEXT <td> ASCII rendering of the integer 4468** <tr><td> INTEGER <td> BLOB <td> Same as INTEGER->TEXT 4469** <tr><td> FLOAT <td> INTEGER <td> [CAST] to INTEGER 4470** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float 4471** <tr><td> FLOAT <td> BLOB <td> [CAST] to BLOB 4472** <tr><td> TEXT <td> INTEGER <td> [CAST] to INTEGER 4473** <tr><td> TEXT <td> FLOAT <td> [CAST] to REAL 4474** <tr><td> TEXT <td> BLOB <td> No change 4475** <tr><td> BLOB <td> INTEGER <td> [CAST] to INTEGER 4476** <tr><td> BLOB <td> FLOAT <td> [CAST] to REAL 4477** <tr><td> BLOB <td> TEXT <td> Add a zero terminator if needed 4478** </table> 4479** </blockquote>)^ 4480** 4481** Note that when type conversions occur, pointers returned by prior 4482** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or 4483** sqlite3_column_text16() may be invalidated. 4484** Type conversions and pointer invalidations might occur 4485** in the following cases: 4486** 4487** <ul> 4488** <li> The initial content is a BLOB and sqlite3_column_text() or 4489** sqlite3_column_text16() is called. A zero-terminator might 4490** need to be added to the string.</li> 4491** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or 4492** sqlite3_column_text16() is called. The content must be converted 4493** to UTF-16.</li> 4494** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or 4495** sqlite3_column_text() is called. The content must be converted 4496** to UTF-8.</li> 4497** </ul> 4498** 4499** ^Conversions between UTF-16be and UTF-16le are always done in place and do 4500** not invalidate a prior pointer, though of course the content of the buffer 4501** that the prior pointer references will have been modified. Other kinds 4502** of conversion are done in place when it is possible, but sometimes they 4503** are not possible and in those cases prior pointers are invalidated. 4504** 4505** The safest policy is to invoke these routines 4506** in one of the following ways: 4507** 4508** <ul> 4509** <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li> 4510** <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li> 4511** <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li> 4512** </ul> 4513** 4514** In other words, you should call sqlite3_column_text(), 4515** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result 4516** into the desired format, then invoke sqlite3_column_bytes() or 4517** sqlite3_column_bytes16() to find the size of the result. Do not mix calls 4518** to sqlite3_column_text() or sqlite3_column_blob() with calls to 4519** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16() 4520** with calls to sqlite3_column_bytes(). 4521** 4522** ^The pointers returned are valid until a type conversion occurs as 4523** described above, or until [sqlite3_step()] or [sqlite3_reset()] or 4524** [sqlite3_finalize()] is called. ^The memory space used to hold strings 4525** and BLOBs is freed automatically. Do not pass the pointers returned 4526** from [sqlite3_column_blob()], [sqlite3_column_text()], etc. into 4527** [sqlite3_free()]. 4528** 4529** As long as the input parameters are correct, these routines will only 4530** fail if an out-of-memory error occurs during a format conversion. 4531** Only the following subset of interfaces are subject to out-of-memory 4532** errors: 4533** 4534** <ul> 4535** <li> sqlite3_column_blob() 4536** <li> sqlite3_column_text() 4537** <li> sqlite3_column_text16() 4538** <li> sqlite3_column_bytes() 4539** <li> sqlite3_column_bytes16() 4540** </ul> 4541** 4542** If an out-of-memory error occurs, then the return value from these 4543** routines is the same as if the column had contained an SQL NULL value. 4544** Valid SQL NULL returns can be distinguished from out-of-memory errors 4545** by invoking the [sqlite3_errcode()] immediately after the suspect 4546** return value is obtained and before any 4547** other SQLite interface is called on the same [database connection]. 4548*/ 4549const void *sqlite3_column_blob(sqlite3_stmt*, int iCol); 4550double sqlite3_column_double(sqlite3_stmt*, int iCol); 4551int sqlite3_column_int(sqlite3_stmt*, int iCol); 4552sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol); 4553const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol); 4554const void *sqlite3_column_text16(sqlite3_stmt*, int iCol); 4555sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol); 4556int sqlite3_column_bytes(sqlite3_stmt*, int iCol); 4557int sqlite3_column_bytes16(sqlite3_stmt*, int iCol); 4558int sqlite3_column_type(sqlite3_stmt*, int iCol); 4559 4560/* 4561** CAPI3REF: Destroy A Prepared Statement Object 4562** DESTRUCTOR: sqlite3_stmt 4563** 4564** ^The sqlite3_finalize() function is called to delete a [prepared statement]. 4565** ^If the most recent evaluation of the statement encountered no errors 4566** or if the statement is never been evaluated, then sqlite3_finalize() returns 4567** SQLITE_OK. ^If the most recent evaluation of statement S failed, then 4568** sqlite3_finalize(S) returns the appropriate [error code] or 4569** [extended error code]. 4570** 4571** ^The sqlite3_finalize(S) routine can be called at any point during 4572** the life cycle of [prepared statement] S: 4573** before statement S is ever evaluated, after 4574** one or more calls to [sqlite3_reset()], or after any call 4575** to [sqlite3_step()] regardless of whether or not the statement has 4576** completed execution. 4577** 4578** ^Invoking sqlite3_finalize() on a NULL pointer is a harmless no-op. 4579** 4580** The application must finalize every [prepared statement] in order to avoid 4581** resource leaks. It is a grievous error for the application to try to use 4582** a prepared statement after it has been finalized. Any use of a prepared 4583** statement after it has been finalized can result in undefined and 4584** undesirable behavior such as segfaults and heap corruption. 4585*/ 4586int sqlite3_finalize(sqlite3_stmt *pStmt); 4587 4588/* 4589** CAPI3REF: Reset A Prepared Statement Object 4590** METHOD: sqlite3_stmt 4591** 4592** The sqlite3_reset() function is called to reset a [prepared statement] 4593** object back to its initial state, ready to be re-executed. 4594** ^Any SQL statement variables that had values bound to them using 4595** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values. 4596** Use [sqlite3_clear_bindings()] to reset the bindings. 4597** 4598** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S 4599** back to the beginning of its program. 4600** 4601** ^If the most recent call to [sqlite3_step(S)] for the 4602** [prepared statement] S returned [SQLITE_ROW] or [SQLITE_DONE], 4603** or if [sqlite3_step(S)] has never before been called on S, 4604** then [sqlite3_reset(S)] returns [SQLITE_OK]. 4605** 4606** ^If the most recent call to [sqlite3_step(S)] for the 4607** [prepared statement] S indicated an error, then 4608** [sqlite3_reset(S)] returns an appropriate [error code]. 4609** 4610** ^The [sqlite3_reset(S)] interface does not change the values 4611** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S. 4612*/ 4613int sqlite3_reset(sqlite3_stmt *pStmt); 4614 4615/* 4616** CAPI3REF: Create Or Redefine SQL Functions 4617** KEYWORDS: {function creation routines} 4618** KEYWORDS: {application-defined SQL function} 4619** KEYWORDS: {application-defined SQL functions} 4620** METHOD: sqlite3 4621** 4622** ^These functions (collectively known as "function creation routines") 4623** are used to add SQL functions or aggregates or to redefine the behavior 4624** of existing SQL functions or aggregates. The only differences between 4625** these routines are the text encoding expected for 4626** the second parameter (the name of the function being created) 4627** and the presence or absence of a destructor callback for 4628** the application data pointer. 4629** 4630** ^The first parameter is the [database connection] to which the SQL 4631** function is to be added. ^If an application uses more than one database 4632** connection then application-defined SQL functions must be added 4633** to each database connection separately. 4634** 4635** ^The second parameter is the name of the SQL function to be created or 4636** redefined. ^The length of the name is limited to 255 bytes in a UTF-8 4637** representation, exclusive of the zero-terminator. ^Note that the name 4638** length limit is in UTF-8 bytes, not characters nor UTF-16 bytes. 4639** ^Any attempt to create a function with a longer name 4640** will result in [SQLITE_MISUSE] being returned. 4641** 4642** ^The third parameter (nArg) 4643** is the number of arguments that the SQL function or 4644** aggregate takes. ^If this parameter is -1, then the SQL function or 4645** aggregate may take any number of arguments between 0 and the limit 4646** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]). If the third 4647** parameter is less than -1 or greater than 127 then the behavior is 4648** undefined. 4649** 4650** ^The fourth parameter, eTextRep, specifies what 4651** [SQLITE_UTF8 | text encoding] this SQL function prefers for 4652** its parameters. The application should set this parameter to 4653** [SQLITE_UTF16LE] if the function implementation invokes 4654** [sqlite3_value_text16le()] on an input, or [SQLITE_UTF16BE] if the 4655** implementation invokes [sqlite3_value_text16be()] on an input, or 4656** [SQLITE_UTF16] if [sqlite3_value_text16()] is used, or [SQLITE_UTF8] 4657** otherwise. ^The same SQL function may be registered multiple times using 4658** different preferred text encodings, with different implementations for 4659** each encoding. 4660** ^When multiple implementations of the same function are available, SQLite 4661** will pick the one that involves the least amount of data conversion. 4662** 4663** ^The fourth parameter may optionally be ORed with [SQLITE_DETERMINISTIC] 4664** to signal that the function will always return the same result given 4665** the same inputs within a single SQL statement. Most SQL functions are 4666** deterministic. The built-in [random()] SQL function is an example of a 4667** function that is not deterministic. The SQLite query planner is able to 4668** perform additional optimizations on deterministic functions, so use 4669** of the [SQLITE_DETERMINISTIC] flag is recommended where possible. 4670** 4671** ^(The fifth parameter is an arbitrary pointer. The implementation of the 4672** function can gain access to this pointer using [sqlite3_user_data()].)^ 4673** 4674** ^The sixth, seventh and eighth parameters, xFunc, xStep and xFinal, are 4675** pointers to C-language functions that implement the SQL function or 4676** aggregate. ^A scalar SQL function requires an implementation of the xFunc 4677** callback only; NULL pointers must be passed as the xStep and xFinal 4678** parameters. ^An aggregate SQL function requires an implementation of xStep 4679** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing 4680** SQL function or aggregate, pass NULL pointers for all three function 4681** callbacks. 4682** 4683** ^(If the ninth parameter to sqlite3_create_function_v2() is not NULL, 4684** then it is destructor for the application data pointer. 4685** The destructor is invoked when the function is deleted, either by being 4686** overloaded or when the database connection closes.)^ 4687** ^The destructor is also invoked if the call to 4688** sqlite3_create_function_v2() fails. 4689** ^When the destructor callback of the tenth parameter is invoked, it 4690** is passed a single argument which is a copy of the application data 4691** pointer which was the fifth parameter to sqlite3_create_function_v2(). 4692** 4693** ^It is permitted to register multiple implementations of the same 4694** functions with the same name but with either differing numbers of 4695** arguments or differing preferred text encodings. ^SQLite will use 4696** the implementation that most closely matches the way in which the 4697** SQL function is used. ^A function implementation with a non-negative 4698** nArg parameter is a better match than a function implementation with 4699** a negative nArg. ^A function where the preferred text encoding 4700** matches the database encoding is a better 4701** match than a function where the encoding is different. 4702** ^A function where the encoding difference is between UTF16le and UTF16be 4703** is a closer match than a function where the encoding difference is 4704** between UTF8 and UTF16. 4705** 4706** ^Built-in functions may be overloaded by new application-defined functions. 4707** 4708** ^An application-defined function is permitted to call other 4709** SQLite interfaces. However, such calls must not 4710** close the database connection nor finalize or reset the prepared 4711** statement in which the function is running. 4712*/ 4713int sqlite3_create_function( 4714 sqlite3 *db, 4715 const char *zFunctionName, 4716 int nArg, 4717 int eTextRep, 4718 void *pApp, 4719 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 4720 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 4721 void (*xFinal)(sqlite3_context*) 4722); 4723int sqlite3_create_function16( 4724 sqlite3 *db, 4725 const void *zFunctionName, 4726 int nArg, 4727 int eTextRep, 4728 void *pApp, 4729 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 4730 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 4731 void (*xFinal)(sqlite3_context*) 4732); 4733int sqlite3_create_function_v2( 4734 sqlite3 *db, 4735 const char *zFunctionName, 4736 int nArg, 4737 int eTextRep, 4738 void *pApp, 4739 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 4740 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 4741 void (*xFinal)(sqlite3_context*), 4742 void(*xDestroy)(void*) 4743); 4744 4745/* 4746** CAPI3REF: Text Encodings 4747** 4748** These constant define integer codes that represent the various 4749** text encodings supported by SQLite. 4750*/ 4751#define SQLITE_UTF8 1 /* IMP: R-37514-35566 */ 4752#define SQLITE_UTF16LE 2 /* IMP: R-03371-37637 */ 4753#define SQLITE_UTF16BE 3 /* IMP: R-51971-34154 */ 4754#define SQLITE_UTF16 4 /* Use native byte order */ 4755#define SQLITE_ANY 5 /* Deprecated */ 4756#define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */ 4757 4758/* 4759** CAPI3REF: Function Flags 4760** 4761** These constants may be ORed together with the 4762** [SQLITE_UTF8 | preferred text encoding] as the fourth argument 4763** to [sqlite3_create_function()], [sqlite3_create_function16()], or 4764** [sqlite3_create_function_v2()]. 4765*/ 4766#define SQLITE_DETERMINISTIC 0x800 4767 4768/* 4769** CAPI3REF: Deprecated Functions 4770** DEPRECATED 4771** 4772** These functions are [deprecated]. In order to maintain 4773** backwards compatibility with older code, these functions continue 4774** to be supported. However, new applications should avoid 4775** the use of these functions. To encourage programmers to avoid 4776** these functions, we will not explain what they do. 4777*/ 4778#ifndef SQLITE_OMIT_DEPRECATED 4779SQLITE_DEPRECATED int sqlite3_aggregate_count(sqlite3_context*); 4780SQLITE_DEPRECATED int sqlite3_expired(sqlite3_stmt*); 4781SQLITE_DEPRECATED int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*); 4782SQLITE_DEPRECATED int sqlite3_global_recover(void); 4783SQLITE_DEPRECATED void sqlite3_thread_cleanup(void); 4784SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int), 4785 void*,sqlite3_int64); 4786#endif 4787 4788/* 4789** CAPI3REF: Obtaining SQL Values 4790** METHOD: sqlite3_value 4791** 4792** <b>Summary:</b> 4793** <blockquote><table border=0 cellpadding=0 cellspacing=0> 4794** <tr><td><b>sqlite3_value_blob</b><td>→<td>BLOB value 4795** <tr><td><b>sqlite3_value_double</b><td>→<td>REAL value 4796** <tr><td><b>sqlite3_value_int</b><td>→<td>32-bit INTEGER value 4797** <tr><td><b>sqlite3_value_int64</b><td>→<td>64-bit INTEGER value 4798** <tr><td><b>sqlite3_value_pointer</b><td>→<td>Pointer value 4799** <tr><td><b>sqlite3_value_text</b><td>→<td>UTF-8 TEXT value 4800** <tr><td><b>sqlite3_value_text16</b><td>→<td>UTF-16 TEXT value in 4801** the native byteorder 4802** <tr><td><b>sqlite3_value_text16be</b><td>→<td>UTF-16be TEXT value 4803** <tr><td><b>sqlite3_value_text16le</b><td>→<td>UTF-16le TEXT value 4804** <tr><td> <td> <td> 4805** <tr><td><b>sqlite3_value_bytes</b><td>→<td>Size of a BLOB 4806** or a UTF-8 TEXT in bytes 4807** <tr><td><b>sqlite3_value_bytes16 </b> 4808** <td>→ <td>Size of UTF-16 4809** TEXT in bytes 4810** <tr><td><b>sqlite3_value_type</b><td>→<td>Default 4811** datatype of the value 4812** <tr><td><b>sqlite3_value_numeric_type </b> 4813** <td>→ <td>Best numeric datatype of the value 4814** <tr><td><b>sqlite3_value_nochange </b> 4815** <td>→ <td>True if the column is unchanged in an UPDATE 4816** against a virtual table. 4817** </table></blockquote> 4818** 4819** <b>Details:</b> 4820** 4821** These routines extract type, size, and content information from 4822** [protected sqlite3_value] objects. Protected sqlite3_value objects 4823** are used to pass parameter information into implementation of 4824** [application-defined SQL functions] and [virtual tables]. 4825** 4826** These routines work only with [protected sqlite3_value] objects. 4827** Any attempt to use these routines on an [unprotected sqlite3_value] 4828** is not threadsafe. 4829** 4830** ^These routines work just like the corresponding [column access functions] 4831** except that these routines take a single [protected sqlite3_value] object 4832** pointer instead of a [sqlite3_stmt*] pointer and an integer column number. 4833** 4834** ^The sqlite3_value_text16() interface extracts a UTF-16 string 4835** in the native byte-order of the host machine. ^The 4836** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces 4837** extract UTF-16 strings as big-endian and little-endian respectively. 4838** 4839** ^If [sqlite3_value] object V was initialized 4840** using [sqlite3_bind_pointer(S,I,P,X,D)] or [sqlite3_result_pointer(C,P,X,D)] 4841** and if X and Y are strings that compare equal according to strcmp(X,Y), 4842** then sqlite3_value_pointer(V,Y) will return the pointer P. ^Otherwise, 4843** sqlite3_value_pointer(V,Y) returns a NULL. The sqlite3_bind_pointer() 4844** routine is part of the [pointer passing interface] added for SQLite 3.20.0. 4845** 4846** ^(The sqlite3_value_type(V) interface returns the 4847** [SQLITE_INTEGER | datatype code] for the initial datatype of the 4848** [sqlite3_value] object V. The returned value is one of [SQLITE_INTEGER], 4849** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL].)^ 4850** Other interfaces might change the datatype for an sqlite3_value object. 4851** For example, if the datatype is initially SQLITE_INTEGER and 4852** sqlite3_value_text(V) is called to extract a text value for that 4853** integer, then subsequent calls to sqlite3_value_type(V) might return 4854** SQLITE_TEXT. Whether or not a persistent internal datatype conversion 4855** occurs is undefined and may change from one release of SQLite to the next. 4856** 4857** ^(The sqlite3_value_numeric_type() interface attempts to apply 4858** numeric affinity to the value. This means that an attempt is 4859** made to convert the value to an integer or floating point. If 4860** such a conversion is possible without loss of information (in other 4861** words, if the value is a string that looks like a number) 4862** then the conversion is performed. Otherwise no conversion occurs. 4863** The [SQLITE_INTEGER | datatype] after conversion is returned.)^ 4864** 4865** ^Within the [xUpdate] method of a [virtual table], the 4866** sqlite3_value_nochange(X) interface returns true if and only if 4867** the column corresponding to X is unchanged by the UPDATE operation 4868** that the xUpdate method call was invoked to implement and if 4869** and the prior [xColumn] method call that was invoked to extracted 4870** the value for that column returned without setting a result (probably 4871** because it queried [sqlite3_vtab_nochange()] and found that the column 4872** was unchanging). ^Within an [xUpdate] method, any value for which 4873** sqlite3_value_nochange(X) is true will in all other respects appear 4874** to be a NULL value. If sqlite3_value_nochange(X) is invoked anywhere other 4875** than within an [xUpdate] method call for an UPDATE statement, then 4876** the return value is arbitrary and meaningless. 4877** 4878** Please pay particular attention to the fact that the pointer returned 4879** from [sqlite3_value_blob()], [sqlite3_value_text()], or 4880** [sqlite3_value_text16()] can be invalidated by a subsequent call to 4881** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()], 4882** or [sqlite3_value_text16()]. 4883** 4884** These routines must be called from the same thread as 4885** the SQL function that supplied the [sqlite3_value*] parameters. 4886** 4887** As long as the input parameter is correct, these routines can only 4888** fail if an out-of-memory error occurs during a format conversion. 4889** Only the following subset of interfaces are subject to out-of-memory 4890** errors: 4891** 4892** <ul> 4893** <li> sqlite3_value_blob() 4894** <li> sqlite3_value_text() 4895** <li> sqlite3_value_text16() 4896** <li> sqlite3_value_text16le() 4897** <li> sqlite3_value_text16be() 4898** <li> sqlite3_value_bytes() 4899** <li> sqlite3_value_bytes16() 4900** </ul> 4901** 4902** If an out-of-memory error occurs, then the return value from these 4903** routines is the same as if the column had contained an SQL NULL value. 4904** Valid SQL NULL returns can be distinguished from out-of-memory errors 4905** by invoking the [sqlite3_errcode()] immediately after the suspect 4906** return value is obtained and before any 4907** other SQLite interface is called on the same [database connection]. 4908*/ 4909const void *sqlite3_value_blob(sqlite3_value*); 4910double sqlite3_value_double(sqlite3_value*); 4911int sqlite3_value_int(sqlite3_value*); 4912sqlite3_int64 sqlite3_value_int64(sqlite3_value*); 4913void *sqlite3_value_pointer(sqlite3_value*, const char*); 4914const unsigned char *sqlite3_value_text(sqlite3_value*); 4915const void *sqlite3_value_text16(sqlite3_value*); 4916const void *sqlite3_value_text16le(sqlite3_value*); 4917const void *sqlite3_value_text16be(sqlite3_value*); 4918int sqlite3_value_bytes(sqlite3_value*); 4919int sqlite3_value_bytes16(sqlite3_value*); 4920int sqlite3_value_type(sqlite3_value*); 4921int sqlite3_value_numeric_type(sqlite3_value*); 4922int sqlite3_value_nochange(sqlite3_value*); 4923 4924/* 4925** CAPI3REF: Finding The Subtype Of SQL Values 4926** METHOD: sqlite3_value 4927** 4928** The sqlite3_value_subtype(V) function returns the subtype for 4929** an [application-defined SQL function] argument V. The subtype 4930** information can be used to pass a limited amount of context from 4931** one SQL function to another. Use the [sqlite3_result_subtype()] 4932** routine to set the subtype for the return value of an SQL function. 4933*/ 4934unsigned int sqlite3_value_subtype(sqlite3_value*); 4935 4936/* 4937** CAPI3REF: Copy And Free SQL Values 4938** METHOD: sqlite3_value 4939** 4940** ^The sqlite3_value_dup(V) interface makes a copy of the [sqlite3_value] 4941** object D and returns a pointer to that copy. ^The [sqlite3_value] returned 4942** is a [protected sqlite3_value] object even if the input is not. 4943** ^The sqlite3_value_dup(V) interface returns NULL if V is NULL or if a 4944** memory allocation fails. 4945** 4946** ^The sqlite3_value_free(V) interface frees an [sqlite3_value] object 4947** previously obtained from [sqlite3_value_dup()]. ^If V is a NULL pointer 4948** then sqlite3_value_free(V) is a harmless no-op. 4949*/ 4950sqlite3_value *sqlite3_value_dup(const sqlite3_value*); 4951void sqlite3_value_free(sqlite3_value*); 4952 4953/* 4954** CAPI3REF: Obtain Aggregate Function Context 4955** METHOD: sqlite3_context 4956** 4957** Implementations of aggregate SQL functions use this 4958** routine to allocate memory for storing their state. 4959** 4960** ^The first time the sqlite3_aggregate_context(C,N) routine is called 4961** for a particular aggregate function, SQLite 4962** allocates N of memory, zeroes out that memory, and returns a pointer 4963** to the new memory. ^On second and subsequent calls to 4964** sqlite3_aggregate_context() for the same aggregate function instance, 4965** the same buffer is returned. Sqlite3_aggregate_context() is normally 4966** called once for each invocation of the xStep callback and then one 4967** last time when the xFinal callback is invoked. ^(When no rows match 4968** an aggregate query, the xStep() callback of the aggregate function 4969** implementation is never called and xFinal() is called exactly once. 4970** In those cases, sqlite3_aggregate_context() might be called for the 4971** first time from within xFinal().)^ 4972** 4973** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer 4974** when first called if N is less than or equal to zero or if a memory 4975** allocate error occurs. 4976** 4977** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is 4978** determined by the N parameter on first successful call. Changing the 4979** value of N in subsequent call to sqlite3_aggregate_context() within 4980** the same aggregate function instance will not resize the memory 4981** allocation.)^ Within the xFinal callback, it is customary to set 4982** N=0 in calls to sqlite3_aggregate_context(C,N) so that no 4983** pointless memory allocations occur. 4984** 4985** ^SQLite automatically frees the memory allocated by 4986** sqlite3_aggregate_context() when the aggregate query concludes. 4987** 4988** The first parameter must be a copy of the 4989** [sqlite3_context | SQL function context] that is the first parameter 4990** to the xStep or xFinal callback routine that implements the aggregate 4991** function. 4992** 4993** This routine must be called from the same thread in which 4994** the aggregate SQL function is running. 4995*/ 4996void *sqlite3_aggregate_context(sqlite3_context*, int nBytes); 4997 4998/* 4999** CAPI3REF: User Data For Functions 5000** METHOD: sqlite3_context 5001** 5002** ^The sqlite3_user_data() interface returns a copy of 5003** the pointer that was the pUserData parameter (the 5th parameter) 5004** of the [sqlite3_create_function()] 5005** and [sqlite3_create_function16()] routines that originally 5006** registered the application defined function. 5007** 5008** This routine must be called from the same thread in which 5009** the application-defined function is running. 5010*/ 5011void *sqlite3_user_data(sqlite3_context*); 5012 5013/* 5014** CAPI3REF: Database Connection For Functions 5015** METHOD: sqlite3_context 5016** 5017** ^The sqlite3_context_db_handle() interface returns a copy of 5018** the pointer to the [database connection] (the 1st parameter) 5019** of the [sqlite3_create_function()] 5020** and [sqlite3_create_function16()] routines that originally 5021** registered the application defined function. 5022*/ 5023sqlite3 *sqlite3_context_db_handle(sqlite3_context*); 5024 5025/* 5026** CAPI3REF: Function Auxiliary Data 5027** METHOD: sqlite3_context 5028** 5029** These functions may be used by (non-aggregate) SQL functions to 5030** associate metadata with argument values. If the same value is passed to 5031** multiple invocations of the same SQL function during query execution, under 5032** some circumstances the associated metadata may be preserved. An example 5033** of where this might be useful is in a regular-expression matching 5034** function. The compiled version of the regular expression can be stored as 5035** metadata associated with the pattern string. 5036** Then as long as the pattern string remains the same, 5037** the compiled regular expression can be reused on multiple 5038** invocations of the same function. 5039** 5040** ^The sqlite3_get_auxdata(C,N) interface returns a pointer to the metadata 5041** associated by the sqlite3_set_auxdata(C,N,P,X) function with the Nth argument 5042** value to the application-defined function. ^N is zero for the left-most 5043** function argument. ^If there is no metadata 5044** associated with the function argument, the sqlite3_get_auxdata(C,N) interface 5045** returns a NULL pointer. 5046** 5047** ^The sqlite3_set_auxdata(C,N,P,X) interface saves P as metadata for the N-th 5048** argument of the application-defined function. ^Subsequent 5049** calls to sqlite3_get_auxdata(C,N) return P from the most recent 5050** sqlite3_set_auxdata(C,N,P,X) call if the metadata is still valid or 5051** NULL if the metadata has been discarded. 5052** ^After each call to sqlite3_set_auxdata(C,N,P,X) where X is not NULL, 5053** SQLite will invoke the destructor function X with parameter P exactly 5054** once, when the metadata is discarded. 5055** SQLite is free to discard the metadata at any time, including: <ul> 5056** <li> ^(when the corresponding function parameter changes)^, or 5057** <li> ^(when [sqlite3_reset()] or [sqlite3_finalize()] is called for the 5058** SQL statement)^, or 5059** <li> ^(when sqlite3_set_auxdata() is invoked again on the same 5060** parameter)^, or 5061** <li> ^(during the original sqlite3_set_auxdata() call when a memory 5062** allocation error occurs.)^ </ul> 5063** 5064** Note the last bullet in particular. The destructor X in 5065** sqlite3_set_auxdata(C,N,P,X) might be called immediately, before the 5066** sqlite3_set_auxdata() interface even returns. Hence sqlite3_set_auxdata() 5067** should be called near the end of the function implementation and the 5068** function implementation should not make any use of P after 5069** sqlite3_set_auxdata() has been called. 5070** 5071** ^(In practice, metadata is preserved between function calls for 5072** function parameters that are compile-time constants, including literal 5073** values and [parameters] and expressions composed from the same.)^ 5074** 5075** The value of the N parameter to these interfaces should be non-negative. 5076** Future enhancements may make use of negative N values to define new 5077** kinds of function caching behavior. 5078** 5079** These routines must be called from the same thread in which 5080** the SQL function is running. 5081*/ 5082void *sqlite3_get_auxdata(sqlite3_context*, int N); 5083void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*)); 5084 5085 5086/* 5087** CAPI3REF: Constants Defining Special Destructor Behavior 5088** 5089** These are special values for the destructor that is passed in as the 5090** final argument to routines like [sqlite3_result_blob()]. ^If the destructor 5091** argument is SQLITE_STATIC, it means that the content pointer is constant 5092** and will never change. It does not need to be destroyed. ^The 5093** SQLITE_TRANSIENT value means that the content will likely change in 5094** the near future and that SQLite should make its own private copy of 5095** the content before returning. 5096** 5097** The typedef is necessary to work around problems in certain 5098** C++ compilers. 5099*/ 5100typedef void (*sqlite3_destructor_type)(void*); 5101#define SQLITE_STATIC ((sqlite3_destructor_type)0) 5102#define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1) 5103 5104/* 5105** CAPI3REF: Setting The Result Of An SQL Function 5106** METHOD: sqlite3_context 5107** 5108** These routines are used by the xFunc or xFinal callbacks that 5109** implement SQL functions and aggregates. See 5110** [sqlite3_create_function()] and [sqlite3_create_function16()] 5111** for additional information. 5112** 5113** These functions work very much like the [parameter binding] family of 5114** functions used to bind values to host parameters in prepared statements. 5115** Refer to the [SQL parameter] documentation for additional information. 5116** 5117** ^The sqlite3_result_blob() interface sets the result from 5118** an application-defined function to be the BLOB whose content is pointed 5119** to by the second parameter and which is N bytes long where N is the 5120** third parameter. 5121** 5122** ^The sqlite3_result_zeroblob(C,N) and sqlite3_result_zeroblob64(C,N) 5123** interfaces set the result of the application-defined function to be 5124** a BLOB containing all zero bytes and N bytes in size. 5125** 5126** ^The sqlite3_result_double() interface sets the result from 5127** an application-defined function to be a floating point value specified 5128** by its 2nd argument. 5129** 5130** ^The sqlite3_result_error() and sqlite3_result_error16() functions 5131** cause the implemented SQL function to throw an exception. 5132** ^SQLite uses the string pointed to by the 5133** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16() 5134** as the text of an error message. ^SQLite interprets the error 5135** message string from sqlite3_result_error() as UTF-8. ^SQLite 5136** interprets the string from sqlite3_result_error16() as UTF-16 in native 5137** byte order. ^If the third parameter to sqlite3_result_error() 5138** or sqlite3_result_error16() is negative then SQLite takes as the error 5139** message all text up through the first zero character. 5140** ^If the third parameter to sqlite3_result_error() or 5141** sqlite3_result_error16() is non-negative then SQLite takes that many 5142** bytes (not characters) from the 2nd parameter as the error message. 5143** ^The sqlite3_result_error() and sqlite3_result_error16() 5144** routines make a private copy of the error message text before 5145** they return. Hence, the calling function can deallocate or 5146** modify the text after they return without harm. 5147** ^The sqlite3_result_error_code() function changes the error code 5148** returned by SQLite as a result of an error in a function. ^By default, 5149** the error code is SQLITE_ERROR. ^A subsequent call to sqlite3_result_error() 5150** or sqlite3_result_error16() resets the error code to SQLITE_ERROR. 5151** 5152** ^The sqlite3_result_error_toobig() interface causes SQLite to throw an 5153** error indicating that a string or BLOB is too long to represent. 5154** 5155** ^The sqlite3_result_error_nomem() interface causes SQLite to throw an 5156** error indicating that a memory allocation failed. 5157** 5158** ^The sqlite3_result_int() interface sets the return value 5159** of the application-defined function to be the 32-bit signed integer 5160** value given in the 2nd argument. 5161** ^The sqlite3_result_int64() interface sets the return value 5162** of the application-defined function to be the 64-bit signed integer 5163** value given in the 2nd argument. 5164** 5165** ^The sqlite3_result_null() interface sets the return value 5166** of the application-defined function to be NULL. 5167** 5168** ^The sqlite3_result_text(), sqlite3_result_text16(), 5169** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces 5170** set the return value of the application-defined function to be 5171** a text string which is represented as UTF-8, UTF-16 native byte order, 5172** UTF-16 little endian, or UTF-16 big endian, respectively. 5173** ^The sqlite3_result_text64() interface sets the return value of an 5174** application-defined function to be a text string in an encoding 5175** specified by the fifth (and last) parameter, which must be one 5176** of [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE]. 5177** ^SQLite takes the text result from the application from 5178** the 2nd parameter of the sqlite3_result_text* interfaces. 5179** ^If the 3rd parameter to the sqlite3_result_text* interfaces 5180** is negative, then SQLite takes result text from the 2nd parameter 5181** through the first zero character. 5182** ^If the 3rd parameter to the sqlite3_result_text* interfaces 5183** is non-negative, then as many bytes (not characters) of the text 5184** pointed to by the 2nd parameter are taken as the application-defined 5185** function result. If the 3rd parameter is non-negative, then it 5186** must be the byte offset into the string where the NUL terminator would 5187** appear if the string where NUL terminated. If any NUL characters occur 5188** in the string at a byte offset that is less than the value of the 3rd 5189** parameter, then the resulting string will contain embedded NULs and the 5190** result of expressions operating on strings with embedded NULs is undefined. 5191** ^If the 4th parameter to the sqlite3_result_text* interfaces 5192** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that 5193** function as the destructor on the text or BLOB result when it has 5194** finished using that result. 5195** ^If the 4th parameter to the sqlite3_result_text* interfaces or to 5196** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite 5197** assumes that the text or BLOB result is in constant space and does not 5198** copy the content of the parameter nor call a destructor on the content 5199** when it has finished using that result. 5200** ^If the 4th parameter to the sqlite3_result_text* interfaces 5201** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT 5202** then SQLite makes a copy of the result into space obtained 5203** from [sqlite3_malloc()] before it returns. 5204** 5205** ^The sqlite3_result_value() interface sets the result of 5206** the application-defined function to be a copy of the 5207** [unprotected sqlite3_value] object specified by the 2nd parameter. ^The 5208** sqlite3_result_value() interface makes a copy of the [sqlite3_value] 5209** so that the [sqlite3_value] specified in the parameter may change or 5210** be deallocated after sqlite3_result_value() returns without harm. 5211** ^A [protected sqlite3_value] object may always be used where an 5212** [unprotected sqlite3_value] object is required, so either 5213** kind of [sqlite3_value] object can be used with this interface. 5214** 5215** ^The sqlite3_result_pointer(C,P,T,D) interface sets the result to an 5216** SQL NULL value, just like [sqlite3_result_null(C)], except that it 5217** also associates the host-language pointer P or type T with that 5218** NULL value such that the pointer can be retrieved within an 5219** [application-defined SQL function] using [sqlite3_value_pointer()]. 5220** ^If the D parameter is not NULL, then it is a pointer to a destructor 5221** for the P parameter. ^SQLite invokes D with P as its only argument 5222** when SQLite is finished with P. The T parameter should be a static 5223** string and preferably a string literal. The sqlite3_result_pointer() 5224** routine is part of the [pointer passing interface] added for SQLite 3.20.0. 5225** 5226** If these routines are called from within the different thread 5227** than the one containing the application-defined function that received 5228** the [sqlite3_context] pointer, the results are undefined. 5229*/ 5230void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*)); 5231void sqlite3_result_blob64(sqlite3_context*,const void*, 5232 sqlite3_uint64,void(*)(void*)); 5233void sqlite3_result_double(sqlite3_context*, double); 5234void sqlite3_result_error(sqlite3_context*, const char*, int); 5235void sqlite3_result_error16(sqlite3_context*, const void*, int); 5236void sqlite3_result_error_toobig(sqlite3_context*); 5237void sqlite3_result_error_nomem(sqlite3_context*); 5238void sqlite3_result_error_code(sqlite3_context*, int); 5239void sqlite3_result_int(sqlite3_context*, int); 5240void sqlite3_result_int64(sqlite3_context*, sqlite3_int64); 5241void sqlite3_result_null(sqlite3_context*); 5242void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*)); 5243void sqlite3_result_text64(sqlite3_context*, const char*,sqlite3_uint64, 5244 void(*)(void*), unsigned char encoding); 5245void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*)); 5246void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*)); 5247void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*)); 5248void sqlite3_result_value(sqlite3_context*, sqlite3_value*); 5249void sqlite3_result_pointer(sqlite3_context*, void*,const char*,void(*)(void*)); 5250void sqlite3_result_zeroblob(sqlite3_context*, int n); 5251int sqlite3_result_zeroblob64(sqlite3_context*, sqlite3_uint64 n); 5252 5253 5254/* 5255** CAPI3REF: Setting The Subtype Of An SQL Function 5256** METHOD: sqlite3_context 5257** 5258** The sqlite3_result_subtype(C,T) function causes the subtype of 5259** the result from the [application-defined SQL function] with 5260** [sqlite3_context] C to be the value T. Only the lower 8 bits 5261** of the subtype T are preserved in current versions of SQLite; 5262** higher order bits are discarded. 5263** The number of subtype bytes preserved by SQLite might increase 5264** in future releases of SQLite. 5265*/ 5266void sqlite3_result_subtype(sqlite3_context*,unsigned int); 5267 5268/* 5269** CAPI3REF: Define New Collating Sequences 5270** METHOD: sqlite3 5271** 5272** ^These functions add, remove, or modify a [collation] associated 5273** with the [database connection] specified as the first argument. 5274** 5275** ^The name of the collation is a UTF-8 string 5276** for sqlite3_create_collation() and sqlite3_create_collation_v2() 5277** and a UTF-16 string in native byte order for sqlite3_create_collation16(). 5278** ^Collation names that compare equal according to [sqlite3_strnicmp()] are 5279** considered to be the same name. 5280** 5281** ^(The third argument (eTextRep) must be one of the constants: 5282** <ul> 5283** <li> [SQLITE_UTF8], 5284** <li> [SQLITE_UTF16LE], 5285** <li> [SQLITE_UTF16BE], 5286** <li> [SQLITE_UTF16], or 5287** <li> [SQLITE_UTF16_ALIGNED]. 5288** </ul>)^ 5289** ^The eTextRep argument determines the encoding of strings passed 5290** to the collating function callback, xCallback. 5291** ^The [SQLITE_UTF16] and [SQLITE_UTF16_ALIGNED] values for eTextRep 5292** force strings to be UTF16 with native byte order. 5293** ^The [SQLITE_UTF16_ALIGNED] value for eTextRep forces strings to begin 5294** on an even byte address. 5295** 5296** ^The fourth argument, pArg, is an application data pointer that is passed 5297** through as the first argument to the collating function callback. 5298** 5299** ^The fifth argument, xCallback, is a pointer to the collating function. 5300** ^Multiple collating functions can be registered using the same name but 5301** with different eTextRep parameters and SQLite will use whichever 5302** function requires the least amount of data transformation. 5303** ^If the xCallback argument is NULL then the collating function is 5304** deleted. ^When all collating functions having the same name are deleted, 5305** that collation is no longer usable. 5306** 5307** ^The collating function callback is invoked with a copy of the pArg 5308** application data pointer and with two strings in the encoding specified 5309** by the eTextRep argument. The collating function must return an 5310** integer that is negative, zero, or positive 5311** if the first string is less than, equal to, or greater than the second, 5312** respectively. A collating function must always return the same answer 5313** given the same inputs. If two or more collating functions are registered 5314** to the same collation name (using different eTextRep values) then all 5315** must give an equivalent answer when invoked with equivalent strings. 5316** The collating function must obey the following properties for all 5317** strings A, B, and C: 5318** 5319** <ol> 5320** <li> If A==B then B==A. 5321** <li> If A==B and B==C then A==C. 5322** <li> If A<B THEN B>A. 5323** <li> If A<B and B<C then A<C. 5324** </ol> 5325** 5326** If a collating function fails any of the above constraints and that 5327** collating function is registered and used, then the behavior of SQLite 5328** is undefined. 5329** 5330** ^The sqlite3_create_collation_v2() works like sqlite3_create_collation() 5331** with the addition that the xDestroy callback is invoked on pArg when 5332** the collating function is deleted. 5333** ^Collating functions are deleted when they are overridden by later 5334** calls to the collation creation functions or when the 5335** [database connection] is closed using [sqlite3_close()]. 5336** 5337** ^The xDestroy callback is <u>not</u> called if the 5338** sqlite3_create_collation_v2() function fails. Applications that invoke 5339** sqlite3_create_collation_v2() with a non-NULL xDestroy argument should 5340** check the return code and dispose of the application data pointer 5341** themselves rather than expecting SQLite to deal with it for them. 5342** This is different from every other SQLite interface. The inconsistency 5343** is unfortunate but cannot be changed without breaking backwards 5344** compatibility. 5345** 5346** See also: [sqlite3_collation_needed()] and [sqlite3_collation_needed16()]. 5347*/ 5348int sqlite3_create_collation( 5349 sqlite3*, 5350 const char *zName, 5351 int eTextRep, 5352 void *pArg, 5353 int(*xCompare)(void*,int,const void*,int,const void*) 5354); 5355int sqlite3_create_collation_v2( 5356 sqlite3*, 5357 const char *zName, 5358 int eTextRep, 5359 void *pArg, 5360 int(*xCompare)(void*,int,const void*,int,const void*), 5361 void(*xDestroy)(void*) 5362); 5363int sqlite3_create_collation16( 5364 sqlite3*, 5365 const void *zName, 5366 int eTextRep, 5367 void *pArg, 5368 int(*xCompare)(void*,int,const void*,int,const void*) 5369); 5370 5371/* 5372** CAPI3REF: Collation Needed Callbacks 5373** METHOD: sqlite3 5374** 5375** ^To avoid having to register all collation sequences before a database 5376** can be used, a single callback function may be registered with the 5377** [database connection] to be invoked whenever an undefined collation 5378** sequence is required. 5379** 5380** ^If the function is registered using the sqlite3_collation_needed() API, 5381** then it is passed the names of undefined collation sequences as strings 5382** encoded in UTF-8. ^If sqlite3_collation_needed16() is used, 5383** the names are passed as UTF-16 in machine native byte order. 5384** ^A call to either function replaces the existing collation-needed callback. 5385** 5386** ^(When the callback is invoked, the first argument passed is a copy 5387** of the second argument to sqlite3_collation_needed() or 5388** sqlite3_collation_needed16(). The second argument is the database 5389** connection. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE], 5390** or [SQLITE_UTF16LE], indicating the most desirable form of the collation 5391** sequence function required. The fourth parameter is the name of the 5392** required collation sequence.)^ 5393** 5394** The callback function should register the desired collation using 5395** [sqlite3_create_collation()], [sqlite3_create_collation16()], or 5396** [sqlite3_create_collation_v2()]. 5397*/ 5398int sqlite3_collation_needed( 5399 sqlite3*, 5400 void*, 5401 void(*)(void*,sqlite3*,int eTextRep,const char*) 5402); 5403int sqlite3_collation_needed16( 5404 sqlite3*, 5405 void*, 5406 void(*)(void*,sqlite3*,int eTextRep,const void*) 5407); 5408 5409#ifdef SQLITE_HAS_CODEC 5410/* 5411** Specify the key for an encrypted database. This routine should be 5412** called right after sqlite3_open(). 5413** 5414** The code to implement this API is not available in the public release 5415** of SQLite. 5416*/ 5417int sqlite3_key( 5418 sqlite3 *db, /* Database to be rekeyed */ 5419 const void *pKey, int nKey /* The key */ 5420); 5421int sqlite3_key_v2( 5422 sqlite3 *db, /* Database to be rekeyed */ 5423 const char *zDbName, /* Name of the database */ 5424 const void *pKey, int nKey /* The key */ 5425); 5426 5427/* 5428** Change the key on an open database. If the current database is not 5429** encrypted, this routine will encrypt it. If pNew==0 or nNew==0, the 5430** database is decrypted. 5431** 5432** The code to implement this API is not available in the public release 5433** of SQLite. 5434*/ 5435int sqlite3_rekey( 5436 sqlite3 *db, /* Database to be rekeyed */ 5437 const void *pKey, int nKey /* The new key */ 5438); 5439int sqlite3_rekey_v2( 5440 sqlite3 *db, /* Database to be rekeyed */ 5441 const char *zDbName, /* Name of the database */ 5442 const void *pKey, int nKey /* The new key */ 5443); 5444 5445/* 5446** Specify the activation key for a SEE database. Unless 5447** activated, none of the SEE routines will work. 5448*/ 5449void sqlite3_activate_see( 5450 const char *zPassPhrase /* Activation phrase */ 5451); 5452#endif 5453 5454#ifdef SQLITE_ENABLE_CEROD 5455/* 5456** Specify the activation key for a CEROD database. Unless 5457** activated, none of the CEROD routines will work. 5458*/ 5459void sqlite3_activate_cerod( 5460 const char *zPassPhrase /* Activation phrase */ 5461); 5462#endif 5463 5464/* 5465** CAPI3REF: Suspend Execution For A Short Time 5466** 5467** The sqlite3_sleep() function causes the current thread to suspend execution 5468** for at least a number of milliseconds specified in its parameter. 5469** 5470** If the operating system does not support sleep requests with 5471** millisecond time resolution, then the time will be rounded up to 5472** the nearest second. The number of milliseconds of sleep actually 5473** requested from the operating system is returned. 5474** 5475** ^SQLite implements this interface by calling the xSleep() 5476** method of the default [sqlite3_vfs] object. If the xSleep() method 5477** of the default VFS is not implemented correctly, or not implemented at 5478** all, then the behavior of sqlite3_sleep() may deviate from the description 5479** in the previous paragraphs. 5480*/ 5481int sqlite3_sleep(int); 5482 5483/* 5484** CAPI3REF: Name Of The Folder Holding Temporary Files 5485** 5486** ^(If this global variable is made to point to a string which is 5487** the name of a folder (a.k.a. directory), then all temporary files 5488** created by SQLite when using a built-in [sqlite3_vfs | VFS] 5489** will be placed in that directory.)^ ^If this variable 5490** is a NULL pointer, then SQLite performs a search for an appropriate 5491** temporary file directory. 5492** 5493** Applications are strongly discouraged from using this global variable. 5494** It is required to set a temporary folder on Windows Runtime (WinRT). 5495** But for all other platforms, it is highly recommended that applications 5496** neither read nor write this variable. This global variable is a relic 5497** that exists for backwards compatibility of legacy applications and should 5498** be avoided in new projects. 5499** 5500** It is not safe to read or modify this variable in more than one 5501** thread at a time. It is not safe to read or modify this variable 5502** if a [database connection] is being used at the same time in a separate 5503** thread. 5504** It is intended that this variable be set once 5505** as part of process initialization and before any SQLite interface 5506** routines have been called and that this variable remain unchanged 5507** thereafter. 5508** 5509** ^The [temp_store_directory pragma] may modify this variable and cause 5510** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 5511** the [temp_store_directory pragma] always assumes that any string 5512** that this variable points to is held in memory obtained from 5513** [sqlite3_malloc] and the pragma may attempt to free that memory 5514** using [sqlite3_free]. 5515** Hence, if this variable is modified directly, either it should be 5516** made NULL or made to point to memory obtained from [sqlite3_malloc] 5517** or else the use of the [temp_store_directory pragma] should be avoided. 5518** Except when requested by the [temp_store_directory pragma], SQLite 5519** does not free the memory that sqlite3_temp_directory points to. If 5520** the application wants that memory to be freed, it must do 5521** so itself, taking care to only do so after all [database connection] 5522** objects have been destroyed. 5523** 5524** <b>Note to Windows Runtime users:</b> The temporary directory must be set 5525** prior to calling [sqlite3_open] or [sqlite3_open_v2]. Otherwise, various 5526** features that require the use of temporary files may fail. Here is an 5527** example of how to do this using C++ with the Windows Runtime: 5528** 5529** <blockquote><pre> 5530** LPCWSTR zPath = Windows::Storage::ApplicationData::Current-> 5531** TemporaryFolder->Path->Data(); 5532** char zPathBuf[MAX_PATH + 1]; 5533** memset(zPathBuf, 0, sizeof(zPathBuf)); 5534** WideCharToMultiByte(CP_UTF8, 0, zPath, -1, zPathBuf, sizeof(zPathBuf), 5535** NULL, NULL); 5536** sqlite3_temp_directory = sqlite3_mprintf("%s", zPathBuf); 5537** </pre></blockquote> 5538*/ 5539SQLITE_EXTERN char *sqlite3_temp_directory; 5540 5541/* 5542** CAPI3REF: Name Of The Folder Holding Database Files 5543** 5544** ^(If this global variable is made to point to a string which is 5545** the name of a folder (a.k.a. directory), then all database files 5546** specified with a relative pathname and created or accessed by 5547** SQLite when using a built-in windows [sqlite3_vfs | VFS] will be assumed 5548** to be relative to that directory.)^ ^If this variable is a NULL 5549** pointer, then SQLite assumes that all database files specified 5550** with a relative pathname are relative to the current directory 5551** for the process. Only the windows VFS makes use of this global 5552** variable; it is ignored by the unix VFS. 5553** 5554** Changing the value of this variable while a database connection is 5555** open can result in a corrupt database. 5556** 5557** It is not safe to read or modify this variable in more than one 5558** thread at a time. It is not safe to read or modify this variable 5559** if a [database connection] is being used at the same time in a separate 5560** thread. 5561** It is intended that this variable be set once 5562** as part of process initialization and before any SQLite interface 5563** routines have been called and that this variable remain unchanged 5564** thereafter. 5565** 5566** ^The [data_store_directory pragma] may modify this variable and cause 5567** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 5568** the [data_store_directory pragma] always assumes that any string 5569** that this variable points to is held in memory obtained from 5570** [sqlite3_malloc] and the pragma may attempt to free that memory 5571** using [sqlite3_free]. 5572** Hence, if this variable is modified directly, either it should be 5573** made NULL or made to point to memory obtained from [sqlite3_malloc] 5574** or else the use of the [data_store_directory pragma] should be avoided. 5575*/ 5576SQLITE_EXTERN char *sqlite3_data_directory; 5577 5578/* 5579** CAPI3REF: Win32 Specific Interface 5580** 5581** These interfaces are available only on Windows. The 5582** [sqlite3_win32_set_directory] interface is used to set the value associated 5583** with the [sqlite3_temp_directory] or [sqlite3_data_directory] variable, to 5584** zValue, depending on the value of the type parameter. The zValue parameter 5585** should be NULL to cause the previous value to be freed via [sqlite3_free]; 5586** a non-NULL value will be copied into memory obtained from [sqlite3_malloc] 5587** prior to being used. The [sqlite3_win32_set_directory] interface returns 5588** [SQLITE_OK] to indicate success, [SQLITE_ERROR] if the type is unsupported, 5589** or [SQLITE_NOMEM] if memory could not be allocated. The value of the 5590** [sqlite3_data_directory] variable is intended to act as a replacement for 5591** the current directory on the sub-platforms of Win32 where that concept is 5592** not present, e.g. WinRT and UWP. The [sqlite3_win32_set_directory8] and 5593** [sqlite3_win32_set_directory16] interfaces behave exactly the same as the 5594** sqlite3_win32_set_directory interface except the string parameter must be 5595** UTF-8 or UTF-16, respectively. 5596*/ 5597int sqlite3_win32_set_directory( 5598 unsigned long type, /* Identifier for directory being set or reset */ 5599 void *zValue /* New value for directory being set or reset */ 5600); 5601int sqlite3_win32_set_directory8(unsigned long type, const char *zValue); 5602int sqlite3_win32_set_directory16(unsigned long type, const void *zValue); 5603 5604/* 5605** CAPI3REF: Win32 Directory Types 5606** 5607** These macros are only available on Windows. They define the allowed values 5608** for the type argument to the [sqlite3_win32_set_directory] interface. 5609*/ 5610#define SQLITE_WIN32_DATA_DIRECTORY_TYPE 1 5611#define SQLITE_WIN32_TEMP_DIRECTORY_TYPE 2 5612 5613/* 5614** CAPI3REF: Test For Auto-Commit Mode 5615** KEYWORDS: {autocommit mode} 5616** METHOD: sqlite3 5617** 5618** ^The sqlite3_get_autocommit() interface returns non-zero or 5619** zero if the given database connection is or is not in autocommit mode, 5620** respectively. ^Autocommit mode is on by default. 5621** ^Autocommit mode is disabled by a [BEGIN] statement. 5622** ^Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK]. 5623** 5624** If certain kinds of errors occur on a statement within a multi-statement 5625** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR], 5626** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the 5627** transaction might be rolled back automatically. The only way to 5628** find out whether SQLite automatically rolled back the transaction after 5629** an error is to use this function. 5630** 5631** If another thread changes the autocommit status of the database 5632** connection while this routine is running, then the return value 5633** is undefined. 5634*/ 5635int sqlite3_get_autocommit(sqlite3*); 5636 5637/* 5638** CAPI3REF: Find The Database Handle Of A Prepared Statement 5639** METHOD: sqlite3_stmt 5640** 5641** ^The sqlite3_db_handle interface returns the [database connection] handle 5642** to which a [prepared statement] belongs. ^The [database connection] 5643** returned by sqlite3_db_handle is the same [database connection] 5644** that was the first argument 5645** to the [sqlite3_prepare_v2()] call (or its variants) that was used to 5646** create the statement in the first place. 5647*/ 5648sqlite3 *sqlite3_db_handle(sqlite3_stmt*); 5649 5650/* 5651** CAPI3REF: Return The Filename For A Database Connection 5652** METHOD: sqlite3 5653** 5654** ^The sqlite3_db_filename(D,N) interface returns a pointer to a filename 5655** associated with database N of connection D. ^The main database file 5656** has the name "main". If there is no attached database N on the database 5657** connection D, or if database N is a temporary or in-memory database, then 5658** a NULL pointer is returned. 5659** 5660** ^The filename returned by this function is the output of the 5661** xFullPathname method of the [VFS]. ^In other words, the filename 5662** will be an absolute pathname, even if the filename used 5663** to open the database originally was a URI or relative pathname. 5664*/ 5665const char *sqlite3_db_filename(sqlite3 *db, const char *zDbName); 5666 5667/* 5668** CAPI3REF: Determine if a database is read-only 5669** METHOD: sqlite3 5670** 5671** ^The sqlite3_db_readonly(D,N) interface returns 1 if the database N 5672** of connection D is read-only, 0 if it is read/write, or -1 if N is not 5673** the name of a database on connection D. 5674*/ 5675int sqlite3_db_readonly(sqlite3 *db, const char *zDbName); 5676 5677/* 5678** CAPI3REF: Find the next prepared statement 5679** METHOD: sqlite3 5680** 5681** ^This interface returns a pointer to the next [prepared statement] after 5682** pStmt associated with the [database connection] pDb. ^If pStmt is NULL 5683** then this interface returns a pointer to the first prepared statement 5684** associated with the database connection pDb. ^If no prepared statement 5685** satisfies the conditions of this routine, it returns NULL. 5686** 5687** The [database connection] pointer D in a call to 5688** [sqlite3_next_stmt(D,S)] must refer to an open database 5689** connection and in particular must not be a NULL pointer. 5690*/ 5691sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt); 5692 5693/* 5694** CAPI3REF: Commit And Rollback Notification Callbacks 5695** METHOD: sqlite3 5696** 5697** ^The sqlite3_commit_hook() interface registers a callback 5698** function to be invoked whenever a transaction is [COMMIT | committed]. 5699** ^Any callback set by a previous call to sqlite3_commit_hook() 5700** for the same database connection is overridden. 5701** ^The sqlite3_rollback_hook() interface registers a callback 5702** function to be invoked whenever a transaction is [ROLLBACK | rolled back]. 5703** ^Any callback set by a previous call to sqlite3_rollback_hook() 5704** for the same database connection is overridden. 5705** ^The pArg argument is passed through to the callback. 5706** ^If the callback on a commit hook function returns non-zero, 5707** then the commit is converted into a rollback. 5708** 5709** ^The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions 5710** return the P argument from the previous call of the same function 5711** on the same [database connection] D, or NULL for 5712** the first call for each function on D. 5713** 5714** The commit and rollback hook callbacks are not reentrant. 5715** The callback implementation must not do anything that will modify 5716** the database connection that invoked the callback. Any actions 5717** to modify the database connection must be deferred until after the 5718** completion of the [sqlite3_step()] call that triggered the commit 5719** or rollback hook in the first place. 5720** Note that running any other SQL statements, including SELECT statements, 5721** or merely calling [sqlite3_prepare_v2()] and [sqlite3_step()] will modify 5722** the database connections for the meaning of "modify" in this paragraph. 5723** 5724** ^Registering a NULL function disables the callback. 5725** 5726** ^When the commit hook callback routine returns zero, the [COMMIT] 5727** operation is allowed to continue normally. ^If the commit hook 5728** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK]. 5729** ^The rollback hook is invoked on a rollback that results from a commit 5730** hook returning non-zero, just as it would be with any other rollback. 5731** 5732** ^For the purposes of this API, a transaction is said to have been 5733** rolled back if an explicit "ROLLBACK" statement is executed, or 5734** an error or constraint causes an implicit rollback to occur. 5735** ^The rollback callback is not invoked if a transaction is 5736** automatically rolled back because the database connection is closed. 5737** 5738** See also the [sqlite3_update_hook()] interface. 5739*/ 5740void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*); 5741void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*); 5742 5743/* 5744** CAPI3REF: Data Change Notification Callbacks 5745** METHOD: sqlite3 5746** 5747** ^The sqlite3_update_hook() interface registers a callback function 5748** with the [database connection] identified by the first argument 5749** to be invoked whenever a row is updated, inserted or deleted in 5750** a [rowid table]. 5751** ^Any callback set by a previous call to this function 5752** for the same database connection is overridden. 5753** 5754** ^The second argument is a pointer to the function to invoke when a 5755** row is updated, inserted or deleted in a rowid table. 5756** ^The first argument to the callback is a copy of the third argument 5757** to sqlite3_update_hook(). 5758** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE], 5759** or [SQLITE_UPDATE], depending on the operation that caused the callback 5760** to be invoked. 5761** ^The third and fourth arguments to the callback contain pointers to the 5762** database and table name containing the affected row. 5763** ^The final callback parameter is the [rowid] of the row. 5764** ^In the case of an update, this is the [rowid] after the update takes place. 5765** 5766** ^(The update hook is not invoked when internal system tables are 5767** modified (i.e. sqlite_master and sqlite_sequence).)^ 5768** ^The update hook is not invoked when [WITHOUT ROWID] tables are modified. 5769** 5770** ^In the current implementation, the update hook 5771** is not invoked when conflicting rows are deleted because of an 5772** [ON CONFLICT | ON CONFLICT REPLACE] clause. ^Nor is the update hook 5773** invoked when rows are deleted using the [truncate optimization]. 5774** The exceptions defined in this paragraph might change in a future 5775** release of SQLite. 5776** 5777** The update hook implementation must not do anything that will modify 5778** the database connection that invoked the update hook. Any actions 5779** to modify the database connection must be deferred until after the 5780** completion of the [sqlite3_step()] call that triggered the update hook. 5781** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 5782** database connections for the meaning of "modify" in this paragraph. 5783** 5784** ^The sqlite3_update_hook(D,C,P) function 5785** returns the P argument from the previous call 5786** on the same [database connection] D, or NULL for 5787** the first call on D. 5788** 5789** See also the [sqlite3_commit_hook()], [sqlite3_rollback_hook()], 5790** and [sqlite3_preupdate_hook()] interfaces. 5791*/ 5792void *sqlite3_update_hook( 5793 sqlite3*, 5794 void(*)(void *,int ,char const *,char const *,sqlite3_int64), 5795 void* 5796); 5797 5798/* 5799** CAPI3REF: Enable Or Disable Shared Pager Cache 5800** 5801** ^(This routine enables or disables the sharing of the database cache 5802** and schema data structures between [database connection | connections] 5803** to the same database. Sharing is enabled if the argument is true 5804** and disabled if the argument is false.)^ 5805** 5806** ^Cache sharing is enabled and disabled for an entire process. 5807** This is a change as of SQLite [version 3.5.0] ([dateof:3.5.0]). 5808** In prior versions of SQLite, 5809** sharing was enabled or disabled for each thread separately. 5810** 5811** ^(The cache sharing mode set by this interface effects all subsequent 5812** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()]. 5813** Existing database connections continue use the sharing mode 5814** that was in effect at the time they were opened.)^ 5815** 5816** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled 5817** successfully. An [error code] is returned otherwise.)^ 5818** 5819** ^Shared cache is disabled by default. But this might change in 5820** future releases of SQLite. Applications that care about shared 5821** cache setting should set it explicitly. 5822** 5823** Note: This method is disabled on MacOS X 10.7 and iOS version 5.0 5824** and will always return SQLITE_MISUSE. On those systems, 5825** shared cache mode should be enabled per-database connection via 5826** [sqlite3_open_v2()] with [SQLITE_OPEN_SHAREDCACHE]. 5827** 5828** This interface is threadsafe on processors where writing a 5829** 32-bit integer is atomic. 5830** 5831** See Also: [SQLite Shared-Cache Mode] 5832*/ 5833int sqlite3_enable_shared_cache(int); 5834 5835/* 5836** CAPI3REF: Attempt To Free Heap Memory 5837** 5838** ^The sqlite3_release_memory() interface attempts to free N bytes 5839** of heap memory by deallocating non-essential memory allocations 5840** held by the database library. Memory used to cache database 5841** pages to improve performance is an example of non-essential memory. 5842** ^sqlite3_release_memory() returns the number of bytes actually freed, 5843** which might be more or less than the amount requested. 5844** ^The sqlite3_release_memory() routine is a no-op returning zero 5845** if SQLite is not compiled with [SQLITE_ENABLE_MEMORY_MANAGEMENT]. 5846** 5847** See also: [sqlite3_db_release_memory()] 5848*/ 5849int sqlite3_release_memory(int); 5850 5851/* 5852** CAPI3REF: Free Memory Used By A Database Connection 5853** METHOD: sqlite3 5854** 5855** ^The sqlite3_db_release_memory(D) interface attempts to free as much heap 5856** memory as possible from database connection D. Unlike the 5857** [sqlite3_release_memory()] interface, this interface is in effect even 5858** when the [SQLITE_ENABLE_MEMORY_MANAGEMENT] compile-time option is 5859** omitted. 5860** 5861** See also: [sqlite3_release_memory()] 5862*/ 5863int sqlite3_db_release_memory(sqlite3*); 5864 5865/* 5866** CAPI3REF: Impose A Limit On Heap Size 5867** 5868** ^The sqlite3_soft_heap_limit64() interface sets and/or queries the 5869** soft limit on the amount of heap memory that may be allocated by SQLite. 5870** ^SQLite strives to keep heap memory utilization below the soft heap 5871** limit by reducing the number of pages held in the page cache 5872** as heap memory usages approaches the limit. 5873** ^The soft heap limit is "soft" because even though SQLite strives to stay 5874** below the limit, it will exceed the limit rather than generate 5875** an [SQLITE_NOMEM] error. In other words, the soft heap limit 5876** is advisory only. 5877** 5878** ^The return value from sqlite3_soft_heap_limit64() is the size of 5879** the soft heap limit prior to the call, or negative in the case of an 5880** error. ^If the argument N is negative 5881** then no change is made to the soft heap limit. Hence, the current 5882** size of the soft heap limit can be determined by invoking 5883** sqlite3_soft_heap_limit64() with a negative argument. 5884** 5885** ^If the argument N is zero then the soft heap limit is disabled. 5886** 5887** ^(The soft heap limit is not enforced in the current implementation 5888** if one or more of following conditions are true: 5889** 5890** <ul> 5891** <li> The soft heap limit is set to zero. 5892** <li> Memory accounting is disabled using a combination of the 5893** [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],...) start-time option and 5894** the [SQLITE_DEFAULT_MEMSTATUS] compile-time option. 5895** <li> An alternative page cache implementation is specified using 5896** [sqlite3_config]([SQLITE_CONFIG_PCACHE2],...). 5897** <li> The page cache allocates from its own memory pool supplied 5898** by [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],...) rather than 5899** from the heap. 5900** </ul>)^ 5901** 5902** Beginning with SQLite [version 3.7.3] ([dateof:3.7.3]), 5903** the soft heap limit is enforced 5904** regardless of whether or not the [SQLITE_ENABLE_MEMORY_MANAGEMENT] 5905** compile-time option is invoked. With [SQLITE_ENABLE_MEMORY_MANAGEMENT], 5906** the soft heap limit is enforced on every memory allocation. Without 5907** [SQLITE_ENABLE_MEMORY_MANAGEMENT], the soft heap limit is only enforced 5908** when memory is allocated by the page cache. Testing suggests that because 5909** the page cache is the predominate memory user in SQLite, most 5910** applications will achieve adequate soft heap limit enforcement without 5911** the use of [SQLITE_ENABLE_MEMORY_MANAGEMENT]. 5912** 5913** The circumstances under which SQLite will enforce the soft heap limit may 5914** changes in future releases of SQLite. 5915*/ 5916sqlite3_int64 sqlite3_soft_heap_limit64(sqlite3_int64 N); 5917 5918/* 5919** CAPI3REF: Deprecated Soft Heap Limit Interface 5920** DEPRECATED 5921** 5922** This is a deprecated version of the [sqlite3_soft_heap_limit64()] 5923** interface. This routine is provided for historical compatibility 5924** only. All new applications should use the 5925** [sqlite3_soft_heap_limit64()] interface rather than this one. 5926*/ 5927SQLITE_DEPRECATED void sqlite3_soft_heap_limit(int N); 5928 5929 5930/* 5931** CAPI3REF: Extract Metadata About A Column Of A Table 5932** METHOD: sqlite3 5933** 5934** ^(The sqlite3_table_column_metadata(X,D,T,C,....) routine returns 5935** information about column C of table T in database D 5936** on [database connection] X.)^ ^The sqlite3_table_column_metadata() 5937** interface returns SQLITE_OK and fills in the non-NULL pointers in 5938** the final five arguments with appropriate values if the specified 5939** column exists. ^The sqlite3_table_column_metadata() interface returns 5940** SQLITE_ERROR and if the specified column does not exist. 5941** ^If the column-name parameter to sqlite3_table_column_metadata() is a 5942** NULL pointer, then this routine simply checks for the existence of the 5943** table and returns SQLITE_OK if the table exists and SQLITE_ERROR if it 5944** does not. If the table name parameter T in a call to 5945** sqlite3_table_column_metadata(X,D,T,C,...) is NULL then the result is 5946** undefined behavior. 5947** 5948** ^The column is identified by the second, third and fourth parameters to 5949** this function. ^(The second parameter is either the name of the database 5950** (i.e. "main", "temp", or an attached database) containing the specified 5951** table or NULL.)^ ^If it is NULL, then all attached databases are searched 5952** for the table using the same algorithm used by the database engine to 5953** resolve unqualified table references. 5954** 5955** ^The third and fourth parameters to this function are the table and column 5956** name of the desired column, respectively. 5957** 5958** ^Metadata is returned by writing to the memory locations passed as the 5th 5959** and subsequent parameters to this function. ^Any of these arguments may be 5960** NULL, in which case the corresponding element of metadata is omitted. 5961** 5962** ^(<blockquote> 5963** <table border="1"> 5964** <tr><th> Parameter <th> Output<br>Type <th> Description 5965** 5966** <tr><td> 5th <td> const char* <td> Data type 5967** <tr><td> 6th <td> const char* <td> Name of default collation sequence 5968** <tr><td> 7th <td> int <td> True if column has a NOT NULL constraint 5969** <tr><td> 8th <td> int <td> True if column is part of the PRIMARY KEY 5970** <tr><td> 9th <td> int <td> True if column is [AUTOINCREMENT] 5971** </table> 5972** </blockquote>)^ 5973** 5974** ^The memory pointed to by the character pointers returned for the 5975** declaration type and collation sequence is valid until the next 5976** call to any SQLite API function. 5977** 5978** ^If the specified table is actually a view, an [error code] is returned. 5979** 5980** ^If the specified column is "rowid", "oid" or "_rowid_" and the table 5981** is not a [WITHOUT ROWID] table and an 5982** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output 5983** parameters are set for the explicitly declared column. ^(If there is no 5984** [INTEGER PRIMARY KEY] column, then the outputs 5985** for the [rowid] are set as follows: 5986** 5987** <pre> 5988** data type: "INTEGER" 5989** collation sequence: "BINARY" 5990** not null: 0 5991** primary key: 1 5992** auto increment: 0 5993** </pre>)^ 5994** 5995** ^This function causes all database schemas to be read from disk and 5996** parsed, if that has not already been done, and returns an error if 5997** any errors are encountered while loading the schema. 5998*/ 5999int sqlite3_table_column_metadata( 6000 sqlite3 *db, /* Connection handle */ 6001 const char *zDbName, /* Database name or NULL */ 6002 const char *zTableName, /* Table name */ 6003 const char *zColumnName, /* Column name */ 6004 char const **pzDataType, /* OUTPUT: Declared data type */ 6005 char const **pzCollSeq, /* OUTPUT: Collation sequence name */ 6006 int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */ 6007 int *pPrimaryKey, /* OUTPUT: True if column part of PK */ 6008 int *pAutoinc /* OUTPUT: True if column is auto-increment */ 6009); 6010 6011/* 6012** CAPI3REF: Load An Extension 6013** METHOD: sqlite3 6014** 6015** ^This interface loads an SQLite extension library from the named file. 6016** 6017** ^The sqlite3_load_extension() interface attempts to load an 6018** [SQLite extension] library contained in the file zFile. If 6019** the file cannot be loaded directly, attempts are made to load 6020** with various operating-system specific extensions added. 6021** So for example, if "samplelib" cannot be loaded, then names like 6022** "samplelib.so" or "samplelib.dylib" or "samplelib.dll" might 6023** be tried also. 6024** 6025** ^The entry point is zProc. 6026** ^(zProc may be 0, in which case SQLite will try to come up with an 6027** entry point name on its own. It first tries "sqlite3_extension_init". 6028** If that does not work, it constructs a name "sqlite3_X_init" where the 6029** X is consists of the lower-case equivalent of all ASCII alphabetic 6030** characters in the filename from the last "/" to the first following 6031** "." and omitting any initial "lib".)^ 6032** ^The sqlite3_load_extension() interface returns 6033** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong. 6034** ^If an error occurs and pzErrMsg is not 0, then the 6035** [sqlite3_load_extension()] interface shall attempt to 6036** fill *pzErrMsg with error message text stored in memory 6037** obtained from [sqlite3_malloc()]. The calling function 6038** should free this memory by calling [sqlite3_free()]. 6039** 6040** ^Extension loading must be enabled using 6041** [sqlite3_enable_load_extension()] or 6042** [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],1,NULL) 6043** prior to calling this API, 6044** otherwise an error will be returned. 6045** 6046** <b>Security warning:</b> It is recommended that the 6047** [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method be used to enable only this 6048** interface. The use of the [sqlite3_enable_load_extension()] interface 6049** should be avoided. This will keep the SQL function [load_extension()] 6050** disabled and prevent SQL injections from giving attackers 6051** access to extension loading capabilities. 6052** 6053** See also the [load_extension() SQL function]. 6054*/ 6055int sqlite3_load_extension( 6056 sqlite3 *db, /* Load the extension into this database connection */ 6057 const char *zFile, /* Name of the shared library containing extension */ 6058 const char *zProc, /* Entry point. Derived from zFile if 0 */ 6059 char **pzErrMsg /* Put error message here if not 0 */ 6060); 6061 6062/* 6063** CAPI3REF: Enable Or Disable Extension Loading 6064** METHOD: sqlite3 6065** 6066** ^So as not to open security holes in older applications that are 6067** unprepared to deal with [extension loading], and as a means of disabling 6068** [extension loading] while evaluating user-entered SQL, the following API 6069** is provided to turn the [sqlite3_load_extension()] mechanism on and off. 6070** 6071** ^Extension loading is off by default. 6072** ^Call the sqlite3_enable_load_extension() routine with onoff==1 6073** to turn extension loading on and call it with onoff==0 to turn 6074** it back off again. 6075** 6076** ^This interface enables or disables both the C-API 6077** [sqlite3_load_extension()] and the SQL function [load_extension()]. 6078** ^(Use [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],..) 6079** to enable or disable only the C-API.)^ 6080** 6081** <b>Security warning:</b> It is recommended that extension loading 6082** be disabled using the [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method 6083** rather than this interface, so the [load_extension()] SQL function 6084** remains disabled. This will prevent SQL injections from giving attackers 6085** access to extension loading capabilities. 6086*/ 6087int sqlite3_enable_load_extension(sqlite3 *db, int onoff); 6088 6089/* 6090** CAPI3REF: Automatically Load Statically Linked Extensions 6091** 6092** ^This interface causes the xEntryPoint() function to be invoked for 6093** each new [database connection] that is created. The idea here is that 6094** xEntryPoint() is the entry point for a statically linked [SQLite extension] 6095** that is to be automatically loaded into all new database connections. 6096** 6097** ^(Even though the function prototype shows that xEntryPoint() takes 6098** no arguments and returns void, SQLite invokes xEntryPoint() with three 6099** arguments and expects an integer result as if the signature of the 6100** entry point where as follows: 6101** 6102** <blockquote><pre> 6103** int xEntryPoint( 6104** sqlite3 *db, 6105** const char **pzErrMsg, 6106** const struct sqlite3_api_routines *pThunk 6107** ); 6108** </pre></blockquote>)^ 6109** 6110** If the xEntryPoint routine encounters an error, it should make *pzErrMsg 6111** point to an appropriate error message (obtained from [sqlite3_mprintf()]) 6112** and return an appropriate [error code]. ^SQLite ensures that *pzErrMsg 6113** is NULL before calling the xEntryPoint(). ^SQLite will invoke 6114** [sqlite3_free()] on *pzErrMsg after xEntryPoint() returns. ^If any 6115** xEntryPoint() returns an error, the [sqlite3_open()], [sqlite3_open16()], 6116** or [sqlite3_open_v2()] call that provoked the xEntryPoint() will fail. 6117** 6118** ^Calling sqlite3_auto_extension(X) with an entry point X that is already 6119** on the list of automatic extensions is a harmless no-op. ^No entry point 6120** will be called more than once for each database connection that is opened. 6121** 6122** See also: [sqlite3_reset_auto_extension()] 6123** and [sqlite3_cancel_auto_extension()] 6124*/ 6125int sqlite3_auto_extension(void(*xEntryPoint)(void)); 6126 6127/* 6128** CAPI3REF: Cancel Automatic Extension Loading 6129** 6130** ^The [sqlite3_cancel_auto_extension(X)] interface unregisters the 6131** initialization routine X that was registered using a prior call to 6132** [sqlite3_auto_extension(X)]. ^The [sqlite3_cancel_auto_extension(X)] 6133** routine returns 1 if initialization routine X was successfully 6134** unregistered and it returns 0 if X was not on the list of initialization 6135** routines. 6136*/ 6137int sqlite3_cancel_auto_extension(void(*xEntryPoint)(void)); 6138 6139/* 6140** CAPI3REF: Reset Automatic Extension Loading 6141** 6142** ^This interface disables all automatic extensions previously 6143** registered using [sqlite3_auto_extension()]. 6144*/ 6145void sqlite3_reset_auto_extension(void); 6146 6147/* 6148** The interface to the virtual-table mechanism is currently considered 6149** to be experimental. The interface might change in incompatible ways. 6150** If this is a problem for you, do not use the interface at this time. 6151** 6152** When the virtual-table mechanism stabilizes, we will declare the 6153** interface fixed, support it indefinitely, and remove this comment. 6154*/ 6155 6156/* 6157** Structures used by the virtual table interface 6158*/ 6159typedef struct sqlite3_vtab sqlite3_vtab; 6160typedef struct sqlite3_index_info sqlite3_index_info; 6161typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor; 6162typedef struct sqlite3_module sqlite3_module; 6163 6164/* 6165** CAPI3REF: Virtual Table Object 6166** KEYWORDS: sqlite3_module {virtual table module} 6167** 6168** This structure, sometimes called a "virtual table module", 6169** defines the implementation of a [virtual tables]. 6170** This structure consists mostly of methods for the module. 6171** 6172** ^A virtual table module is created by filling in a persistent 6173** instance of this structure and passing a pointer to that instance 6174** to [sqlite3_create_module()] or [sqlite3_create_module_v2()]. 6175** ^The registration remains valid until it is replaced by a different 6176** module or until the [database connection] closes. The content 6177** of this structure must not change while it is registered with 6178** any database connection. 6179*/ 6180struct sqlite3_module { 6181 int iVersion; 6182 int (*xCreate)(sqlite3*, void *pAux, 6183 int argc, const char *const*argv, 6184 sqlite3_vtab **ppVTab, char**); 6185 int (*xConnect)(sqlite3*, void *pAux, 6186 int argc, const char *const*argv, 6187 sqlite3_vtab **ppVTab, char**); 6188 int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*); 6189 int (*xDisconnect)(sqlite3_vtab *pVTab); 6190 int (*xDestroy)(sqlite3_vtab *pVTab); 6191 int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor); 6192 int (*xClose)(sqlite3_vtab_cursor*); 6193 int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr, 6194 int argc, sqlite3_value **argv); 6195 int (*xNext)(sqlite3_vtab_cursor*); 6196 int (*xEof)(sqlite3_vtab_cursor*); 6197 int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int); 6198 int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid); 6199 int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *); 6200 int (*xBegin)(sqlite3_vtab *pVTab); 6201 int (*xSync)(sqlite3_vtab *pVTab); 6202 int (*xCommit)(sqlite3_vtab *pVTab); 6203 int (*xRollback)(sqlite3_vtab *pVTab); 6204 int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName, 6205 void (**pxFunc)(sqlite3_context*,int,sqlite3_value**), 6206 void **ppArg); 6207 int (*xRename)(sqlite3_vtab *pVtab, const char *zNew); 6208 /* The methods above are in version 1 of the sqlite_module object. Those 6209 ** below are for version 2 and greater. */ 6210 int (*xSavepoint)(sqlite3_vtab *pVTab, int); 6211 int (*xRelease)(sqlite3_vtab *pVTab, int); 6212 int (*xRollbackTo)(sqlite3_vtab *pVTab, int); 6213}; 6214 6215/* 6216** CAPI3REF: Virtual Table Indexing Information 6217** KEYWORDS: sqlite3_index_info 6218** 6219** The sqlite3_index_info structure and its substructures is used as part 6220** of the [virtual table] interface to 6221** pass information into and receive the reply from the [xBestIndex] 6222** method of a [virtual table module]. The fields under **Inputs** are the 6223** inputs to xBestIndex and are read-only. xBestIndex inserts its 6224** results into the **Outputs** fields. 6225** 6226** ^(The aConstraint[] array records WHERE clause constraints of the form: 6227** 6228** <blockquote>column OP expr</blockquote> 6229** 6230** where OP is =, <, <=, >, or >=.)^ ^(The particular operator is 6231** stored in aConstraint[].op using one of the 6232** [SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_ values].)^ 6233** ^(The index of the column is stored in 6234** aConstraint[].iColumn.)^ ^(aConstraint[].usable is TRUE if the 6235** expr on the right-hand side can be evaluated (and thus the constraint 6236** is usable) and false if it cannot.)^ 6237** 6238** ^The optimizer automatically inverts terms of the form "expr OP column" 6239** and makes other simplifications to the WHERE clause in an attempt to 6240** get as many WHERE clause terms into the form shown above as possible. 6241** ^The aConstraint[] array only reports WHERE clause terms that are 6242** relevant to the particular virtual table being queried. 6243** 6244** ^Information about the ORDER BY clause is stored in aOrderBy[]. 6245** ^Each term of aOrderBy records a column of the ORDER BY clause. 6246** 6247** The colUsed field indicates which columns of the virtual table may be 6248** required by the current scan. Virtual table columns are numbered from 6249** zero in the order in which they appear within the CREATE TABLE statement 6250** passed to sqlite3_declare_vtab(). For the first 63 columns (columns 0-62), 6251** the corresponding bit is set within the colUsed mask if the column may be 6252** required by SQLite. If the table has at least 64 columns and any column 6253** to the right of the first 63 is required, then bit 63 of colUsed is also 6254** set. In other words, column iCol may be required if the expression 6255** (colUsed & ((sqlite3_uint64)1 << (iCol>=63 ? 63 : iCol))) evaluates to 6256** non-zero. 6257** 6258** The [xBestIndex] method must fill aConstraintUsage[] with information 6259** about what parameters to pass to xFilter. ^If argvIndex>0 then 6260** the right-hand side of the corresponding aConstraint[] is evaluated 6261** and becomes the argvIndex-th entry in argv. ^(If aConstraintUsage[].omit 6262** is true, then the constraint is assumed to be fully handled by the 6263** virtual table and is not checked again by SQLite.)^ 6264** 6265** ^The idxNum and idxPtr values are recorded and passed into the 6266** [xFilter] method. 6267** ^[sqlite3_free()] is used to free idxPtr if and only if 6268** needToFreeIdxPtr is true. 6269** 6270** ^The orderByConsumed means that output from [xFilter]/[xNext] will occur in 6271** the correct order to satisfy the ORDER BY clause so that no separate 6272** sorting step is required. 6273** 6274** ^The estimatedCost value is an estimate of the cost of a particular 6275** strategy. A cost of N indicates that the cost of the strategy is similar 6276** to a linear scan of an SQLite table with N rows. A cost of log(N) 6277** indicates that the expense of the operation is similar to that of a 6278** binary search on a unique indexed field of an SQLite table with N rows. 6279** 6280** ^The estimatedRows value is an estimate of the number of rows that 6281** will be returned by the strategy. 6282** 6283** The xBestIndex method may optionally populate the idxFlags field with a 6284** mask of SQLITE_INDEX_SCAN_* flags. Currently there is only one such flag - 6285** SQLITE_INDEX_SCAN_UNIQUE. If the xBestIndex method sets this flag, SQLite 6286** assumes that the strategy may visit at most one row. 6287** 6288** Additionally, if xBestIndex sets the SQLITE_INDEX_SCAN_UNIQUE flag, then 6289** SQLite also assumes that if a call to the xUpdate() method is made as 6290** part of the same statement to delete or update a virtual table row and the 6291** implementation returns SQLITE_CONSTRAINT, then there is no need to rollback 6292** any database changes. In other words, if the xUpdate() returns 6293** SQLITE_CONSTRAINT, the database contents must be exactly as they were 6294** before xUpdate was called. By contrast, if SQLITE_INDEX_SCAN_UNIQUE is not 6295** set and xUpdate returns SQLITE_CONSTRAINT, any database changes made by 6296** the xUpdate method are automatically rolled back by SQLite. 6297** 6298** IMPORTANT: The estimatedRows field was added to the sqlite3_index_info 6299** structure for SQLite [version 3.8.2] ([dateof:3.8.2]). 6300** If a virtual table extension is 6301** used with an SQLite version earlier than 3.8.2, the results of attempting 6302** to read or write the estimatedRows field are undefined (but are likely 6303** to included crashing the application). The estimatedRows field should 6304** therefore only be used if [sqlite3_libversion_number()] returns a 6305** value greater than or equal to 3008002. Similarly, the idxFlags field 6306** was added for [version 3.9.0] ([dateof:3.9.0]). 6307** It may therefore only be used if 6308** sqlite3_libversion_number() returns a value greater than or equal to 6309** 3009000. 6310*/ 6311struct sqlite3_index_info { 6312 /* Inputs */ 6313 int nConstraint; /* Number of entries in aConstraint */ 6314 struct sqlite3_index_constraint { 6315 int iColumn; /* Column constrained. -1 for ROWID */ 6316 unsigned char op; /* Constraint operator */ 6317 unsigned char usable; /* True if this constraint is usable */ 6318 int iTermOffset; /* Used internally - xBestIndex should ignore */ 6319 } *aConstraint; /* Table of WHERE clause constraints */ 6320 int nOrderBy; /* Number of terms in the ORDER BY clause */ 6321 struct sqlite3_index_orderby { 6322 int iColumn; /* Column number */ 6323 unsigned char desc; /* True for DESC. False for ASC. */ 6324 } *aOrderBy; /* The ORDER BY clause */ 6325 /* Outputs */ 6326 struct sqlite3_index_constraint_usage { 6327 int argvIndex; /* if >0, constraint is part of argv to xFilter */ 6328 unsigned char omit; /* Do not code a test for this constraint */ 6329 } *aConstraintUsage; 6330 int idxNum; /* Number used to identify the index */ 6331 char *idxStr; /* String, possibly obtained from sqlite3_malloc */ 6332 int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */ 6333 int orderByConsumed; /* True if output is already ordered */ 6334 double estimatedCost; /* Estimated cost of using this index */ 6335 /* Fields below are only available in SQLite 3.8.2 and later */ 6336 sqlite3_int64 estimatedRows; /* Estimated number of rows returned */ 6337 /* Fields below are only available in SQLite 3.9.0 and later */ 6338 int idxFlags; /* Mask of SQLITE_INDEX_SCAN_* flags */ 6339 /* Fields below are only available in SQLite 3.10.0 and later */ 6340 sqlite3_uint64 colUsed; /* Input: Mask of columns used by statement */ 6341}; 6342 6343/* 6344** CAPI3REF: Virtual Table Scan Flags 6345** 6346** Virtual table implementations are allowed to set the 6347** [sqlite3_index_info].idxFlags field to some combination of 6348** these bits. 6349*/ 6350#define SQLITE_INDEX_SCAN_UNIQUE 1 /* Scan visits at most 1 row */ 6351 6352/* 6353** CAPI3REF: Virtual Table Constraint Operator Codes 6354** 6355** These macros defined the allowed values for the 6356** [sqlite3_index_info].aConstraint[].op field. Each value represents 6357** an operator that is part of a constraint term in the wHERE clause of 6358** a query that uses a [virtual table]. 6359*/ 6360#define SQLITE_INDEX_CONSTRAINT_EQ 2 6361#define SQLITE_INDEX_CONSTRAINT_GT 4 6362#define SQLITE_INDEX_CONSTRAINT_LE 8 6363#define SQLITE_INDEX_CONSTRAINT_LT 16 6364#define SQLITE_INDEX_CONSTRAINT_GE 32 6365#define SQLITE_INDEX_CONSTRAINT_MATCH 64 6366#define SQLITE_INDEX_CONSTRAINT_LIKE 65 6367#define SQLITE_INDEX_CONSTRAINT_GLOB 66 6368#define SQLITE_INDEX_CONSTRAINT_REGEXP 67 6369#define SQLITE_INDEX_CONSTRAINT_NE 68 6370#define SQLITE_INDEX_CONSTRAINT_ISNOT 69 6371#define SQLITE_INDEX_CONSTRAINT_ISNOTNULL 70 6372#define SQLITE_INDEX_CONSTRAINT_ISNULL 71 6373#define SQLITE_INDEX_CONSTRAINT_IS 72 6374 6375/* 6376** CAPI3REF: Register A Virtual Table Implementation 6377** METHOD: sqlite3 6378** 6379** ^These routines are used to register a new [virtual table module] name. 6380** ^Module names must be registered before 6381** creating a new [virtual table] using the module and before using a 6382** preexisting [virtual table] for the module. 6383** 6384** ^The module name is registered on the [database connection] specified 6385** by the first parameter. ^The name of the module is given by the 6386** second parameter. ^The third parameter is a pointer to 6387** the implementation of the [virtual table module]. ^The fourth 6388** parameter is an arbitrary client data pointer that is passed through 6389** into the [xCreate] and [xConnect] methods of the virtual table module 6390** when a new virtual table is be being created or reinitialized. 6391** 6392** ^The sqlite3_create_module_v2() interface has a fifth parameter which 6393** is a pointer to a destructor for the pClientData. ^SQLite will 6394** invoke the destructor function (if it is not NULL) when SQLite 6395** no longer needs the pClientData pointer. ^The destructor will also 6396** be invoked if the call to sqlite3_create_module_v2() fails. 6397** ^The sqlite3_create_module() 6398** interface is equivalent to sqlite3_create_module_v2() with a NULL 6399** destructor. 6400*/ 6401int sqlite3_create_module( 6402 sqlite3 *db, /* SQLite connection to register module with */ 6403 const char *zName, /* Name of the module */ 6404 const sqlite3_module *p, /* Methods for the module */ 6405 void *pClientData /* Client data for xCreate/xConnect */ 6406); 6407int sqlite3_create_module_v2( 6408 sqlite3 *db, /* SQLite connection to register module with */ 6409 const char *zName, /* Name of the module */ 6410 const sqlite3_module *p, /* Methods for the module */ 6411 void *pClientData, /* Client data for xCreate/xConnect */ 6412 void(*xDestroy)(void*) /* Module destructor function */ 6413); 6414 6415/* 6416** CAPI3REF: Virtual Table Instance Object 6417** KEYWORDS: sqlite3_vtab 6418** 6419** Every [virtual table module] implementation uses a subclass 6420** of this object to describe a particular instance 6421** of the [virtual table]. Each subclass will 6422** be tailored to the specific needs of the module implementation. 6423** The purpose of this superclass is to define certain fields that are 6424** common to all module implementations. 6425** 6426** ^Virtual tables methods can set an error message by assigning a 6427** string obtained from [sqlite3_mprintf()] to zErrMsg. The method should 6428** take care that any prior string is freed by a call to [sqlite3_free()] 6429** prior to assigning a new string to zErrMsg. ^After the error message 6430** is delivered up to the client application, the string will be automatically 6431** freed by sqlite3_free() and the zErrMsg field will be zeroed. 6432*/ 6433struct sqlite3_vtab { 6434 const sqlite3_module *pModule; /* The module for this virtual table */ 6435 int nRef; /* Number of open cursors */ 6436 char *zErrMsg; /* Error message from sqlite3_mprintf() */ 6437 /* Virtual table implementations will typically add additional fields */ 6438}; 6439 6440/* 6441** CAPI3REF: Virtual Table Cursor Object 6442** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor} 6443** 6444** Every [virtual table module] implementation uses a subclass of the 6445** following structure to describe cursors that point into the 6446** [virtual table] and are used 6447** to loop through the virtual table. Cursors are created using the 6448** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed 6449** by the [sqlite3_module.xClose | xClose] method. Cursors are used 6450** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods 6451** of the module. Each module implementation will define 6452** the content of a cursor structure to suit its own needs. 6453** 6454** This superclass exists in order to define fields of the cursor that 6455** are common to all implementations. 6456*/ 6457struct sqlite3_vtab_cursor { 6458 sqlite3_vtab *pVtab; /* Virtual table of this cursor */ 6459 /* Virtual table implementations will typically add additional fields */ 6460}; 6461 6462/* 6463** CAPI3REF: Declare The Schema Of A Virtual Table 6464** 6465** ^The [xCreate] and [xConnect] methods of a 6466** [virtual table module] call this interface 6467** to declare the format (the names and datatypes of the columns) of 6468** the virtual tables they implement. 6469*/ 6470int sqlite3_declare_vtab(sqlite3*, const char *zSQL); 6471 6472/* 6473** CAPI3REF: Overload A Function For A Virtual Table 6474** METHOD: sqlite3 6475** 6476** ^(Virtual tables can provide alternative implementations of functions 6477** using the [xFindFunction] method of the [virtual table module]. 6478** But global versions of those functions 6479** must exist in order to be overloaded.)^ 6480** 6481** ^(This API makes sure a global version of a function with a particular 6482** name and number of parameters exists. If no such function exists 6483** before this API is called, a new function is created.)^ ^The implementation 6484** of the new function always causes an exception to be thrown. So 6485** the new function is not good for anything by itself. Its only 6486** purpose is to be a placeholder function that can be overloaded 6487** by a [virtual table]. 6488*/ 6489int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg); 6490 6491/* 6492** The interface to the virtual-table mechanism defined above (back up 6493** to a comment remarkably similar to this one) is currently considered 6494** to be experimental. The interface might change in incompatible ways. 6495** If this is a problem for you, do not use the interface at this time. 6496** 6497** When the virtual-table mechanism stabilizes, we will declare the 6498** interface fixed, support it indefinitely, and remove this comment. 6499*/ 6500 6501/* 6502** CAPI3REF: A Handle To An Open BLOB 6503** KEYWORDS: {BLOB handle} {BLOB handles} 6504** 6505** An instance of this object represents an open BLOB on which 6506** [sqlite3_blob_open | incremental BLOB I/O] can be performed. 6507** ^Objects of this type are created by [sqlite3_blob_open()] 6508** and destroyed by [sqlite3_blob_close()]. 6509** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces 6510** can be used to read or write small subsections of the BLOB. 6511** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes. 6512*/ 6513typedef struct sqlite3_blob sqlite3_blob; 6514 6515/* 6516** CAPI3REF: Open A BLOB For Incremental I/O 6517** METHOD: sqlite3 6518** CONSTRUCTOR: sqlite3_blob 6519** 6520** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located 6521** in row iRow, column zColumn, table zTable in database zDb; 6522** in other words, the same BLOB that would be selected by: 6523** 6524** <pre> 6525** SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow; 6526** </pre>)^ 6527** 6528** ^(Parameter zDb is not the filename that contains the database, but 6529** rather the symbolic name of the database. For attached databases, this is 6530** the name that appears after the AS keyword in the [ATTACH] statement. 6531** For the main database file, the database name is "main". For TEMP 6532** tables, the database name is "temp".)^ 6533** 6534** ^If the flags parameter is non-zero, then the BLOB is opened for read 6535** and write access. ^If the flags parameter is zero, the BLOB is opened for 6536** read-only access. 6537** 6538** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is stored 6539** in *ppBlob. Otherwise an [error code] is returned and, unless the error 6540** code is SQLITE_MISUSE, *ppBlob is set to NULL.)^ ^This means that, provided 6541** the API is not misused, it is always safe to call [sqlite3_blob_close()] 6542** on *ppBlob after this function it returns. 6543** 6544** This function fails with SQLITE_ERROR if any of the following are true: 6545** <ul> 6546** <li> ^(Database zDb does not exist)^, 6547** <li> ^(Table zTable does not exist within database zDb)^, 6548** <li> ^(Table zTable is a WITHOUT ROWID table)^, 6549** <li> ^(Column zColumn does not exist)^, 6550** <li> ^(Row iRow is not present in the table)^, 6551** <li> ^(The specified column of row iRow contains a value that is not 6552** a TEXT or BLOB value)^, 6553** <li> ^(Column zColumn is part of an index, PRIMARY KEY or UNIQUE 6554** constraint and the blob is being opened for read/write access)^, 6555** <li> ^([foreign key constraints | Foreign key constraints] are enabled, 6556** column zColumn is part of a [child key] definition and the blob is 6557** being opened for read/write access)^. 6558** </ul> 6559** 6560** ^Unless it returns SQLITE_MISUSE, this function sets the 6561** [database connection] error code and message accessible via 6562** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions. 6563** 6564** A BLOB referenced by sqlite3_blob_open() may be read using the 6565** [sqlite3_blob_read()] interface and modified by using 6566** [sqlite3_blob_write()]. The [BLOB handle] can be moved to a 6567** different row of the same table using the [sqlite3_blob_reopen()] 6568** interface. However, the column, table, or database of a [BLOB handle] 6569** cannot be changed after the [BLOB handle] is opened. 6570** 6571** ^(If the row that a BLOB handle points to is modified by an 6572** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects 6573** then the BLOB handle is marked as "expired". 6574** This is true if any column of the row is changed, even a column 6575** other than the one the BLOB handle is open on.)^ 6576** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for 6577** an expired BLOB handle fail with a return code of [SQLITE_ABORT]. 6578** ^(Changes written into a BLOB prior to the BLOB expiring are not 6579** rolled back by the expiration of the BLOB. Such changes will eventually 6580** commit if the transaction continues to completion.)^ 6581** 6582** ^Use the [sqlite3_blob_bytes()] interface to determine the size of 6583** the opened blob. ^The size of a blob may not be changed by this 6584** interface. Use the [UPDATE] SQL command to change the size of a 6585** blob. 6586** 6587** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces 6588** and the built-in [zeroblob] SQL function may be used to create a 6589** zero-filled blob to read or write using the incremental-blob interface. 6590** 6591** To avoid a resource leak, every open [BLOB handle] should eventually 6592** be released by a call to [sqlite3_blob_close()]. 6593** 6594** See also: [sqlite3_blob_close()], 6595** [sqlite3_blob_reopen()], [sqlite3_blob_read()], 6596** [sqlite3_blob_bytes()], [sqlite3_blob_write()]. 6597*/ 6598int sqlite3_blob_open( 6599 sqlite3*, 6600 const char *zDb, 6601 const char *zTable, 6602 const char *zColumn, 6603 sqlite3_int64 iRow, 6604 int flags, 6605 sqlite3_blob **ppBlob 6606); 6607 6608/* 6609** CAPI3REF: Move a BLOB Handle to a New Row 6610** METHOD: sqlite3_blob 6611** 6612** ^This function is used to move an existing [BLOB handle] so that it points 6613** to a different row of the same database table. ^The new row is identified 6614** by the rowid value passed as the second argument. Only the row can be 6615** changed. ^The database, table and column on which the blob handle is open 6616** remain the same. Moving an existing [BLOB handle] to a new row is 6617** faster than closing the existing handle and opening a new one. 6618** 6619** ^(The new row must meet the same criteria as for [sqlite3_blob_open()] - 6620** it must exist and there must be either a blob or text value stored in 6621** the nominated column.)^ ^If the new row is not present in the table, or if 6622** it does not contain a blob or text value, or if another error occurs, an 6623** SQLite error code is returned and the blob handle is considered aborted. 6624** ^All subsequent calls to [sqlite3_blob_read()], [sqlite3_blob_write()] or 6625** [sqlite3_blob_reopen()] on an aborted blob handle immediately return 6626** SQLITE_ABORT. ^Calling [sqlite3_blob_bytes()] on an aborted blob handle 6627** always returns zero. 6628** 6629** ^This function sets the database handle error code and message. 6630*/ 6631int sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64); 6632 6633/* 6634** CAPI3REF: Close A BLOB Handle 6635** DESTRUCTOR: sqlite3_blob 6636** 6637** ^This function closes an open [BLOB handle]. ^(The BLOB handle is closed 6638** unconditionally. Even if this routine returns an error code, the 6639** handle is still closed.)^ 6640** 6641** ^If the blob handle being closed was opened for read-write access, and if 6642** the database is in auto-commit mode and there are no other open read-write 6643** blob handles or active write statements, the current transaction is 6644** committed. ^If an error occurs while committing the transaction, an error 6645** code is returned and the transaction rolled back. 6646** 6647** Calling this function with an argument that is not a NULL pointer or an 6648** open blob handle results in undefined behaviour. ^Calling this routine 6649** with a null pointer (such as would be returned by a failed call to 6650** [sqlite3_blob_open()]) is a harmless no-op. ^Otherwise, if this function 6651** is passed a valid open blob handle, the values returned by the 6652** sqlite3_errcode() and sqlite3_errmsg() functions are set before returning. 6653*/ 6654int sqlite3_blob_close(sqlite3_blob *); 6655 6656/* 6657** CAPI3REF: Return The Size Of An Open BLOB 6658** METHOD: sqlite3_blob 6659** 6660** ^Returns the size in bytes of the BLOB accessible via the 6661** successfully opened [BLOB handle] in its only argument. ^The 6662** incremental blob I/O routines can only read or overwriting existing 6663** blob content; they cannot change the size of a blob. 6664** 6665** This routine only works on a [BLOB handle] which has been created 6666** by a prior successful call to [sqlite3_blob_open()] and which has not 6667** been closed by [sqlite3_blob_close()]. Passing any other pointer in 6668** to this routine results in undefined and probably undesirable behavior. 6669*/ 6670int sqlite3_blob_bytes(sqlite3_blob *); 6671 6672/* 6673** CAPI3REF: Read Data From A BLOB Incrementally 6674** METHOD: sqlite3_blob 6675** 6676** ^(This function is used to read data from an open [BLOB handle] into a 6677** caller-supplied buffer. N bytes of data are copied into buffer Z 6678** from the open BLOB, starting at offset iOffset.)^ 6679** 6680** ^If offset iOffset is less than N bytes from the end of the BLOB, 6681** [SQLITE_ERROR] is returned and no data is read. ^If N or iOffset is 6682** less than zero, [SQLITE_ERROR] is returned and no data is read. 6683** ^The size of the blob (and hence the maximum value of N+iOffset) 6684** can be determined using the [sqlite3_blob_bytes()] interface. 6685** 6686** ^An attempt to read from an expired [BLOB handle] fails with an 6687** error code of [SQLITE_ABORT]. 6688** 6689** ^(On success, sqlite3_blob_read() returns SQLITE_OK. 6690** Otherwise, an [error code] or an [extended error code] is returned.)^ 6691** 6692** This routine only works on a [BLOB handle] which has been created 6693** by a prior successful call to [sqlite3_blob_open()] and which has not 6694** been closed by [sqlite3_blob_close()]. Passing any other pointer in 6695** to this routine results in undefined and probably undesirable behavior. 6696** 6697** See also: [sqlite3_blob_write()]. 6698*/ 6699int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset); 6700 6701/* 6702** CAPI3REF: Write Data Into A BLOB Incrementally 6703** METHOD: sqlite3_blob 6704** 6705** ^(This function is used to write data into an open [BLOB handle] from a 6706** caller-supplied buffer. N bytes of data are copied from the buffer Z 6707** into the open BLOB, starting at offset iOffset.)^ 6708** 6709** ^(On success, sqlite3_blob_write() returns SQLITE_OK. 6710** Otherwise, an [error code] or an [extended error code] is returned.)^ 6711** ^Unless SQLITE_MISUSE is returned, this function sets the 6712** [database connection] error code and message accessible via 6713** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions. 6714** 6715** ^If the [BLOB handle] passed as the first argument was not opened for 6716** writing (the flags parameter to [sqlite3_blob_open()] was zero), 6717** this function returns [SQLITE_READONLY]. 6718** 6719** This function may only modify the contents of the BLOB; it is 6720** not possible to increase the size of a BLOB using this API. 6721** ^If offset iOffset is less than N bytes from the end of the BLOB, 6722** [SQLITE_ERROR] is returned and no data is written. The size of the 6723** BLOB (and hence the maximum value of N+iOffset) can be determined 6724** using the [sqlite3_blob_bytes()] interface. ^If N or iOffset are less 6725** than zero [SQLITE_ERROR] is returned and no data is written. 6726** 6727** ^An attempt to write to an expired [BLOB handle] fails with an 6728** error code of [SQLITE_ABORT]. ^Writes to the BLOB that occurred 6729** before the [BLOB handle] expired are not rolled back by the 6730** expiration of the handle, though of course those changes might 6731** have been overwritten by the statement that expired the BLOB handle 6732** or by other independent statements. 6733** 6734** This routine only works on a [BLOB handle] which has been created 6735** by a prior successful call to [sqlite3_blob_open()] and which has not 6736** been closed by [sqlite3_blob_close()]. Passing any other pointer in 6737** to this routine results in undefined and probably undesirable behavior. 6738** 6739** See also: [sqlite3_blob_read()]. 6740*/ 6741int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset); 6742 6743/* 6744** CAPI3REF: Virtual File System Objects 6745** 6746** A virtual filesystem (VFS) is an [sqlite3_vfs] object 6747** that SQLite uses to interact 6748** with the underlying operating system. Most SQLite builds come with a 6749** single default VFS that is appropriate for the host computer. 6750** New VFSes can be registered and existing VFSes can be unregistered. 6751** The following interfaces are provided. 6752** 6753** ^The sqlite3_vfs_find() interface returns a pointer to a VFS given its name. 6754** ^Names are case sensitive. 6755** ^Names are zero-terminated UTF-8 strings. 6756** ^If there is no match, a NULL pointer is returned. 6757** ^If zVfsName is NULL then the default VFS is returned. 6758** 6759** ^New VFSes are registered with sqlite3_vfs_register(). 6760** ^Each new VFS becomes the default VFS if the makeDflt flag is set. 6761** ^The same VFS can be registered multiple times without injury. 6762** ^To make an existing VFS into the default VFS, register it again 6763** with the makeDflt flag set. If two different VFSes with the 6764** same name are registered, the behavior is undefined. If a 6765** VFS is registered with a name that is NULL or an empty string, 6766** then the behavior is undefined. 6767** 6768** ^Unregister a VFS with the sqlite3_vfs_unregister() interface. 6769** ^(If the default VFS is unregistered, another VFS is chosen as 6770** the default. The choice for the new VFS is arbitrary.)^ 6771*/ 6772sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName); 6773int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt); 6774int sqlite3_vfs_unregister(sqlite3_vfs*); 6775 6776/* 6777** CAPI3REF: Mutexes 6778** 6779** The SQLite core uses these routines for thread 6780** synchronization. Though they are intended for internal 6781** use by SQLite, code that links against SQLite is 6782** permitted to use any of these routines. 6783** 6784** The SQLite source code contains multiple implementations 6785** of these mutex routines. An appropriate implementation 6786** is selected automatically at compile-time. The following 6787** implementations are available in the SQLite core: 6788** 6789** <ul> 6790** <li> SQLITE_MUTEX_PTHREADS 6791** <li> SQLITE_MUTEX_W32 6792** <li> SQLITE_MUTEX_NOOP 6793** </ul> 6794** 6795** The SQLITE_MUTEX_NOOP implementation is a set of routines 6796** that does no real locking and is appropriate for use in 6797** a single-threaded application. The SQLITE_MUTEX_PTHREADS and 6798** SQLITE_MUTEX_W32 implementations are appropriate for use on Unix 6799** and Windows. 6800** 6801** If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor 6802** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex 6803** implementation is included with the library. In this case the 6804** application must supply a custom mutex implementation using the 6805** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function 6806** before calling sqlite3_initialize() or any other public sqlite3_ 6807** function that calls sqlite3_initialize(). 6808** 6809** ^The sqlite3_mutex_alloc() routine allocates a new 6810** mutex and returns a pointer to it. ^The sqlite3_mutex_alloc() 6811** routine returns NULL if it is unable to allocate the requested 6812** mutex. The argument to sqlite3_mutex_alloc() must one of these 6813** integer constants: 6814** 6815** <ul> 6816** <li> SQLITE_MUTEX_FAST 6817** <li> SQLITE_MUTEX_RECURSIVE 6818** <li> SQLITE_MUTEX_STATIC_MASTER 6819** <li> SQLITE_MUTEX_STATIC_MEM 6820** <li> SQLITE_MUTEX_STATIC_OPEN 6821** <li> SQLITE_MUTEX_STATIC_PRNG 6822** <li> SQLITE_MUTEX_STATIC_LRU 6823** <li> SQLITE_MUTEX_STATIC_PMEM 6824** <li> SQLITE_MUTEX_STATIC_APP1 6825** <li> SQLITE_MUTEX_STATIC_APP2 6826** <li> SQLITE_MUTEX_STATIC_APP3 6827** <li> SQLITE_MUTEX_STATIC_VFS1 6828** <li> SQLITE_MUTEX_STATIC_VFS2 6829** <li> SQLITE_MUTEX_STATIC_VFS3 6830** </ul> 6831** 6832** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) 6833** cause sqlite3_mutex_alloc() to create 6834** a new mutex. ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE 6835** is used but not necessarily so when SQLITE_MUTEX_FAST is used. 6836** The mutex implementation does not need to make a distinction 6837** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does 6838** not want to. SQLite will only request a recursive mutex in 6839** cases where it really needs one. If a faster non-recursive mutex 6840** implementation is available on the host platform, the mutex subsystem 6841** might return such a mutex in response to SQLITE_MUTEX_FAST. 6842** 6843** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other 6844** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return 6845** a pointer to a static preexisting mutex. ^Nine static mutexes are 6846** used by the current version of SQLite. Future versions of SQLite 6847** may add additional static mutexes. Static mutexes are for internal 6848** use by SQLite only. Applications that use SQLite mutexes should 6849** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or 6850** SQLITE_MUTEX_RECURSIVE. 6851** 6852** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST 6853** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc() 6854** returns a different mutex on every call. ^For the static 6855** mutex types, the same mutex is returned on every call that has 6856** the same type number. 6857** 6858** ^The sqlite3_mutex_free() routine deallocates a previously 6859** allocated dynamic mutex. Attempting to deallocate a static 6860** mutex results in undefined behavior. 6861** 6862** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt 6863** to enter a mutex. ^If another thread is already within the mutex, 6864** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return 6865** SQLITE_BUSY. ^The sqlite3_mutex_try() interface returns [SQLITE_OK] 6866** upon successful entry. ^(Mutexes created using 6867** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread. 6868** In such cases, the 6869** mutex must be exited an equal number of times before another thread 6870** can enter.)^ If the same thread tries to enter any mutex other 6871** than an SQLITE_MUTEX_RECURSIVE more than once, the behavior is undefined. 6872** 6873** ^(Some systems (for example, Windows 95) do not support the operation 6874** implemented by sqlite3_mutex_try(). On those systems, sqlite3_mutex_try() 6875** will always return SQLITE_BUSY. The SQLite core only ever uses 6876** sqlite3_mutex_try() as an optimization so this is acceptable 6877** behavior.)^ 6878** 6879** ^The sqlite3_mutex_leave() routine exits a mutex that was 6880** previously entered by the same thread. The behavior 6881** is undefined if the mutex is not currently entered by the 6882** calling thread or is not currently allocated. 6883** 6884** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), or 6885** sqlite3_mutex_leave() is a NULL pointer, then all three routines 6886** behave as no-ops. 6887** 6888** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()]. 6889*/ 6890sqlite3_mutex *sqlite3_mutex_alloc(int); 6891void sqlite3_mutex_free(sqlite3_mutex*); 6892void sqlite3_mutex_enter(sqlite3_mutex*); 6893int sqlite3_mutex_try(sqlite3_mutex*); 6894void sqlite3_mutex_leave(sqlite3_mutex*); 6895 6896/* 6897** CAPI3REF: Mutex Methods Object 6898** 6899** An instance of this structure defines the low-level routines 6900** used to allocate and use mutexes. 6901** 6902** Usually, the default mutex implementations provided by SQLite are 6903** sufficient, however the application has the option of substituting a custom 6904** implementation for specialized deployments or systems for which SQLite 6905** does not provide a suitable implementation. In this case, the application 6906** creates and populates an instance of this structure to pass 6907** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option. 6908** Additionally, an instance of this structure can be used as an 6909** output variable when querying the system for the current mutex 6910** implementation, using the [SQLITE_CONFIG_GETMUTEX] option. 6911** 6912** ^The xMutexInit method defined by this structure is invoked as 6913** part of system initialization by the sqlite3_initialize() function. 6914** ^The xMutexInit routine is called by SQLite exactly once for each 6915** effective call to [sqlite3_initialize()]. 6916** 6917** ^The xMutexEnd method defined by this structure is invoked as 6918** part of system shutdown by the sqlite3_shutdown() function. The 6919** implementation of this method is expected to release all outstanding 6920** resources obtained by the mutex methods implementation, especially 6921** those obtained by the xMutexInit method. ^The xMutexEnd() 6922** interface is invoked exactly once for each call to [sqlite3_shutdown()]. 6923** 6924** ^(The remaining seven methods defined by this structure (xMutexAlloc, 6925** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and 6926** xMutexNotheld) implement the following interfaces (respectively): 6927** 6928** <ul> 6929** <li> [sqlite3_mutex_alloc()] </li> 6930** <li> [sqlite3_mutex_free()] </li> 6931** <li> [sqlite3_mutex_enter()] </li> 6932** <li> [sqlite3_mutex_try()] </li> 6933** <li> [sqlite3_mutex_leave()] </li> 6934** <li> [sqlite3_mutex_held()] </li> 6935** <li> [sqlite3_mutex_notheld()] </li> 6936** </ul>)^ 6937** 6938** The only difference is that the public sqlite3_XXX functions enumerated 6939** above silently ignore any invocations that pass a NULL pointer instead 6940** of a valid mutex handle. The implementations of the methods defined 6941** by this structure are not required to handle this case, the results 6942** of passing a NULL pointer instead of a valid mutex handle are undefined 6943** (i.e. it is acceptable to provide an implementation that segfaults if 6944** it is passed a NULL pointer). 6945** 6946** The xMutexInit() method must be threadsafe. It must be harmless to 6947** invoke xMutexInit() multiple times within the same process and without 6948** intervening calls to xMutexEnd(). Second and subsequent calls to 6949** xMutexInit() must be no-ops. 6950** 6951** xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()] 6952** and its associates). Similarly, xMutexAlloc() must not use SQLite memory 6953** allocation for a static mutex. ^However xMutexAlloc() may use SQLite 6954** memory allocation for a fast or recursive mutex. 6955** 6956** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is 6957** called, but only if the prior call to xMutexInit returned SQLITE_OK. 6958** If xMutexInit fails in any way, it is expected to clean up after itself 6959** prior to returning. 6960*/ 6961typedef struct sqlite3_mutex_methods sqlite3_mutex_methods; 6962struct sqlite3_mutex_methods { 6963 int (*xMutexInit)(void); 6964 int (*xMutexEnd)(void); 6965 sqlite3_mutex *(*xMutexAlloc)(int); 6966 void (*xMutexFree)(sqlite3_mutex *); 6967 void (*xMutexEnter)(sqlite3_mutex *); 6968 int (*xMutexTry)(sqlite3_mutex *); 6969 void (*xMutexLeave)(sqlite3_mutex *); 6970 int (*xMutexHeld)(sqlite3_mutex *); 6971 int (*xMutexNotheld)(sqlite3_mutex *); 6972}; 6973 6974/* 6975** CAPI3REF: Mutex Verification Routines 6976** 6977** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines 6978** are intended for use inside assert() statements. The SQLite core 6979** never uses these routines except inside an assert() and applications 6980** are advised to follow the lead of the core. The SQLite core only 6981** provides implementations for these routines when it is compiled 6982** with the SQLITE_DEBUG flag. External mutex implementations 6983** are only required to provide these routines if SQLITE_DEBUG is 6984** defined and if NDEBUG is not defined. 6985** 6986** These routines should return true if the mutex in their argument 6987** is held or not held, respectively, by the calling thread. 6988** 6989** The implementation is not required to provide versions of these 6990** routines that actually work. If the implementation does not provide working 6991** versions of these routines, it should at least provide stubs that always 6992** return true so that one does not get spurious assertion failures. 6993** 6994** If the argument to sqlite3_mutex_held() is a NULL pointer then 6995** the routine should return 1. This seems counter-intuitive since 6996** clearly the mutex cannot be held if it does not exist. But 6997** the reason the mutex does not exist is because the build is not 6998** using mutexes. And we do not want the assert() containing the 6999** call to sqlite3_mutex_held() to fail, so a non-zero return is 7000** the appropriate thing to do. The sqlite3_mutex_notheld() 7001** interface should also return 1 when given a NULL pointer. 7002*/ 7003#ifndef NDEBUG 7004int sqlite3_mutex_held(sqlite3_mutex*); 7005int sqlite3_mutex_notheld(sqlite3_mutex*); 7006#endif 7007 7008/* 7009** CAPI3REF: Mutex Types 7010** 7011** The [sqlite3_mutex_alloc()] interface takes a single argument 7012** which is one of these integer constants. 7013** 7014** The set of static mutexes may change from one SQLite release to the 7015** next. Applications that override the built-in mutex logic must be 7016** prepared to accommodate additional static mutexes. 7017*/ 7018#define SQLITE_MUTEX_FAST 0 7019#define SQLITE_MUTEX_RECURSIVE 1 7020#define SQLITE_MUTEX_STATIC_MASTER 2 7021#define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */ 7022#define SQLITE_MUTEX_STATIC_MEM2 4 /* NOT USED */ 7023#define SQLITE_MUTEX_STATIC_OPEN 4 /* sqlite3BtreeOpen() */ 7024#define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_randomness() */ 7025#define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */ 7026#define SQLITE_MUTEX_STATIC_LRU2 7 /* NOT USED */ 7027#define SQLITE_MUTEX_STATIC_PMEM 7 /* sqlite3PageMalloc() */ 7028#define SQLITE_MUTEX_STATIC_APP1 8 /* For use by application */ 7029#define SQLITE_MUTEX_STATIC_APP2 9 /* For use by application */ 7030#define SQLITE_MUTEX_STATIC_APP3 10 /* For use by application */ 7031#define SQLITE_MUTEX_STATIC_VFS1 11 /* For use by built-in VFS */ 7032#define SQLITE_MUTEX_STATIC_VFS2 12 /* For use by extension VFS */ 7033#define SQLITE_MUTEX_STATIC_VFS3 13 /* For use by application VFS */ 7034 7035/* 7036** CAPI3REF: Retrieve the mutex for a database connection 7037** METHOD: sqlite3 7038** 7039** ^This interface returns a pointer the [sqlite3_mutex] object that 7040** serializes access to the [database connection] given in the argument 7041** when the [threading mode] is Serialized. 7042** ^If the [threading mode] is Single-thread or Multi-thread then this 7043** routine returns a NULL pointer. 7044*/ 7045sqlite3_mutex *sqlite3_db_mutex(sqlite3*); 7046 7047/* 7048** CAPI3REF: Low-Level Control Of Database Files 7049** METHOD: sqlite3 7050** 7051** ^The [sqlite3_file_control()] interface makes a direct call to the 7052** xFileControl method for the [sqlite3_io_methods] object associated 7053** with a particular database identified by the second argument. ^The 7054** name of the database is "main" for the main database or "temp" for the 7055** TEMP database, or the name that appears after the AS keyword for 7056** databases that are added using the [ATTACH] SQL command. 7057** ^A NULL pointer can be used in place of "main" to refer to the 7058** main database file. 7059** ^The third and fourth parameters to this routine 7060** are passed directly through to the second and third parameters of 7061** the xFileControl method. ^The return value of the xFileControl 7062** method becomes the return value of this routine. 7063** 7064** ^The [SQLITE_FCNTL_FILE_POINTER] value for the op parameter causes 7065** a pointer to the underlying [sqlite3_file] object to be written into 7066** the space pointed to by the 4th parameter. ^The [SQLITE_FCNTL_FILE_POINTER] 7067** case is a short-circuit path which does not actually invoke the 7068** underlying sqlite3_io_methods.xFileControl method. 7069** 7070** ^If the second parameter (zDbName) does not match the name of any 7071** open database file, then SQLITE_ERROR is returned. ^This error 7072** code is not remembered and will not be recalled by [sqlite3_errcode()] 7073** or [sqlite3_errmsg()]. The underlying xFileControl method might 7074** also return SQLITE_ERROR. There is no way to distinguish between 7075** an incorrect zDbName and an SQLITE_ERROR return from the underlying 7076** xFileControl method. 7077** 7078** See also: [file control opcodes] 7079*/ 7080int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*); 7081 7082/* 7083** CAPI3REF: Testing Interface 7084** 7085** ^The sqlite3_test_control() interface is used to read out internal 7086** state of SQLite and to inject faults into SQLite for testing 7087** purposes. ^The first parameter is an operation code that determines 7088** the number, meaning, and operation of all subsequent parameters. 7089** 7090** This interface is not for use by applications. It exists solely 7091** for verifying the correct operation of the SQLite library. Depending 7092** on how the SQLite library is compiled, this interface might not exist. 7093** 7094** The details of the operation codes, their meanings, the parameters 7095** they take, and what they do are all subject to change without notice. 7096** Unlike most of the SQLite API, this function is not guaranteed to 7097** operate consistently from one release to the next. 7098*/ 7099int sqlite3_test_control(int op, ...); 7100 7101/* 7102** CAPI3REF: Testing Interface Operation Codes 7103** 7104** These constants are the valid operation code parameters used 7105** as the first argument to [sqlite3_test_control()]. 7106** 7107** These parameters and their meanings are subject to change 7108** without notice. These values are for testing purposes only. 7109** Applications should not use any of these parameters or the 7110** [sqlite3_test_control()] interface. 7111*/ 7112#define SQLITE_TESTCTRL_FIRST 5 7113#define SQLITE_TESTCTRL_PRNG_SAVE 5 7114#define SQLITE_TESTCTRL_PRNG_RESTORE 6 7115#define SQLITE_TESTCTRL_PRNG_RESET 7 7116#define SQLITE_TESTCTRL_BITVEC_TEST 8 7117#define SQLITE_TESTCTRL_FAULT_INSTALL 9 7118#define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS 10 7119#define SQLITE_TESTCTRL_PENDING_BYTE 11 7120#define SQLITE_TESTCTRL_ASSERT 12 7121#define SQLITE_TESTCTRL_ALWAYS 13 7122#define SQLITE_TESTCTRL_RESERVE 14 7123#define SQLITE_TESTCTRL_OPTIMIZATIONS 15 7124#define SQLITE_TESTCTRL_ISKEYWORD 16 /* NOT USED */ 7125#define SQLITE_TESTCTRL_SCRATCHMALLOC 17 /* NOT USED */ 7126#define SQLITE_TESTCTRL_LOCALTIME_FAULT 18 7127#define SQLITE_TESTCTRL_EXPLAIN_STMT 19 /* NOT USED */ 7128#define SQLITE_TESTCTRL_ONCE_RESET_THRESHOLD 19 7129#define SQLITE_TESTCTRL_NEVER_CORRUPT 20 7130#define SQLITE_TESTCTRL_VDBE_COVERAGE 21 7131#define SQLITE_TESTCTRL_BYTEORDER 22 7132#define SQLITE_TESTCTRL_ISINIT 23 7133#define SQLITE_TESTCTRL_SORTER_MMAP 24 7134#define SQLITE_TESTCTRL_IMPOSTER 25 7135#define SQLITE_TESTCTRL_PARSER_COVERAGE 26 7136#define SQLITE_TESTCTRL_LAST 26 /* Largest TESTCTRL */ 7137 7138/* 7139** CAPI3REF: SQL Keyword Checking 7140** 7141** These routines provide access to the set of SQL language keywords 7142** recognized by SQLite. Applications can uses these routines to determine 7143** whether or not a specific identifier needs to be escaped (for example, 7144** by enclosing in double-quotes) so as not to confuse the parser. 7145** 7146** The sqlite3_keyword_count() interface returns the number of distinct 7147** keywords understood by SQLite. 7148** 7149** The sqlite3_keyword_name(N,Z,L) interface finds the N-th keyword and 7150** makes *Z point to that keyword expressed as UTF8 and writes the number 7151** of bytes in the keyword into *L. The string that *Z points to is not 7152** zero-terminated. The sqlite3_keyword_name(N,Z,L) routine returns 7153** SQLITE_OK if N is within bounds and SQLITE_ERROR if not. If either Z 7154** or L are NULL or invalid pointers then calls to 7155** sqlite3_keyword_name(N,Z,L) result in undefined behavior. 7156** 7157** The sqlite3_keyword_check(Z,L) interface checks to see whether or not 7158** the L-byte UTF8 identifier that Z points to is a keyword, returning non-zero 7159** if it is and zero if not. 7160** 7161** The parser used by SQLite is forgiving. It is often possible to use 7162** a keyword as an identifier as long as such use does not result in a 7163** parsing ambiguity. For example, the statement 7164** "CREATE TABLE BEGIN(REPLACE,PRAGMA,END);" is accepted by SQLite, and 7165** creates a new table named "BEGIN" with three columns named 7166** "REPLACE", "PRAGMA", and "END". Nevertheless, best practice is to avoid 7167** using keywords as identifiers. Common techniques used to avoid keyword 7168** name collisions include: 7169** <ul> 7170** <li> Put all identifier names inside double-quotes. This is the official 7171** SQL way to escape identifier names. 7172** <li> Put identifier names inside [...]. This is not standard SQL, 7173** but it is what SQL Server does and so lots of programmers use this 7174** technique. 7175** <li> Begin every identifier with the letter "Z" as no SQL keywords start 7176** with "Z". 7177** <li> Include a digit somewhere in every identifier name. 7178** </ul> 7179** 7180** Note that the number of keywords understood by SQLite can depend on 7181** compile-time options. For example, "VACUUM" is not a keyword if 7182** SQLite is compiled with the [-DSQLITE_OMIT_VACUUM] option. Also, 7183** new keywords may be added to future releases of SQLite. 7184*/ 7185int sqlite3_keyword_count(void); 7186int sqlite3_keyword_name(int,const char**,int*); 7187int sqlite3_keyword_check(const char*,int); 7188 7189/* 7190** CAPI3REF: Dynamic String Object 7191** KEYWORDS: {dynamic string} 7192** 7193** An instance of the sqlite3_str object contains a dynamically-sized 7194** string under construction. 7195** 7196** The lifecycle of an sqlite3_str object is as follows: 7197** <ol> 7198** <li> ^The sqlite3_str object is created using [sqlite3_str_new()]. 7199** <li> ^Text is appended to the sqlite3_str object using various 7200** methods, such as [sqlite3_str_appendf()]. 7201** <li> ^The sqlite3_str object is destroyed and the string it created 7202** is returned using the [sqlite3_str_finish()] interface. 7203** </ol> 7204*/ 7205typedef struct sqlite3_str sqlite3_str; 7206 7207/* 7208** CAPI3REF: Create A New Dynamic String Object 7209** CONSTRUCTOR: sqlite3_str 7210** 7211** ^The [sqlite3_str_new(D)] interface allocates and initializes 7212** a new [sqlite3_str] object. To avoid memory leaks, the object returned by 7213** [sqlite3_str_new()] must be freed by a subsequent call to 7214** [sqlite3_str_finish(X)]. 7215** 7216** ^The [sqlite3_str_new(D)] interface always returns a pointer to a 7217** valid [sqlite3_str] object, though in the event of an out-of-memory 7218** error the returned object might be a special singleton that will 7219** silently reject new text, always return SQLITE_NOMEM from 7220** [sqlite3_str_errcode()], always return 0 for 7221** [sqlite3_str_length()], and always return NULL from 7222** [sqlite3_str_finish(X)]. It is always safe to use the value 7223** returned by [sqlite3_str_new(D)] as the sqlite3_str parameter 7224** to any of the other [sqlite3_str] methods. 7225** 7226** The D parameter to [sqlite3_str_new(D)] may be NULL. If the 7227** D parameter in [sqlite3_str_new(D)] is not NULL, then the maximum 7228** length of the string contained in the [sqlite3_str] object will be 7229** the value set for [sqlite3_limit](D,[SQLITE_LIMIT_LENGTH]) instead 7230** of [SQLITE_MAX_LENGTH]. 7231*/ 7232sqlite3_str *sqlite3_str_new(sqlite3*); 7233 7234/* 7235** CAPI3REF: Finalize A Dynamic String 7236** DESTRUCTOR: sqlite3_str 7237** 7238** ^The [sqlite3_str_finish(X)] interface destroys the sqlite3_str object X 7239** and returns a pointer to a memory buffer obtained from [sqlite3_malloc64()] 7240** that contains the constructed string. The calling application should 7241** pass the returned value to [sqlite3_free()] to avoid a memory leak. 7242** ^The [sqlite3_str_finish(X)] interface may return a NULL pointer if any 7243** errors were encountered during construction of the string. ^The 7244** [sqlite3_str_finish(X)] interface will also return a NULL pointer if the 7245** string in [sqlite3_str] object X is zero bytes long. 7246*/ 7247char *sqlite3_str_finish(sqlite3_str*); 7248 7249/* 7250** CAPI3REF: Add Content To A Dynamic String 7251** METHOD: sqlite3_str 7252** 7253** These interfaces add content to an sqlite3_str object previously obtained 7254** from [sqlite3_str_new()]. 7255** 7256** ^The [sqlite3_str_appendf(X,F,...)] and 7257** [sqlite3_str_vappendf(X,F,V)] interfaces uses the [built-in printf] 7258** functionality of SQLite to append formatted text onto the end of 7259** [sqlite3_str] object X. 7260** 7261** ^The [sqlite3_str_append(X,S,N)] method appends exactly N bytes from string S 7262** onto the end of the [sqlite3_str] object X. N must be non-negative. 7263** S must contain at least N non-zero bytes of content. To append a 7264** zero-terminated string in its entirety, use the [sqlite3_str_appendall()] 7265** method instead. 7266** 7267** ^The [sqlite3_str_appendall(X,S)] method appends the complete content of 7268** zero-terminated string S onto the end of [sqlite3_str] object X. 7269** 7270** ^The [sqlite3_str_appendchar(X,N,C)] method appends N copies of the 7271** single-byte character C onto the end of [sqlite3_str] object X. 7272** ^This method can be used, for example, to add whitespace indentation. 7273** 7274** ^The [sqlite3_str_reset(X)] method resets the string under construction 7275** inside [sqlite3_str] object X back to zero bytes in length. 7276** 7277** These methods do not return a result code. ^If an error occurs, that fact 7278** is recorded in the [sqlite3_str] object and can be recovered by a 7279** subsequent call to [sqlite3_str_errcode(X)]. 7280*/ 7281void sqlite3_str_appendf(sqlite3_str*, const char *zFormat, ...); 7282void sqlite3_str_vappendf(sqlite3_str*, const char *zFormat, va_list); 7283void sqlite3_str_append(sqlite3_str*, const char *zIn, int N); 7284void sqlite3_str_appendall(sqlite3_str*, const char *zIn); 7285void sqlite3_str_appendchar(sqlite3_str*, int N, char C); 7286void sqlite3_str_reset(sqlite3_str*); 7287 7288/* 7289** CAPI3REF: Status Of A Dynamic String 7290** METHOD: sqlite3_str 7291** 7292** These interfaces return the current status of an [sqlite3_str] object. 7293** 7294** ^If any prior errors have occurred while constructing the dynamic string 7295** in sqlite3_str X, then the [sqlite3_str_errcode(X)] method will return 7296** an appropriate error code. ^The [sqlite3_str_errcode(X)] method returns 7297** [SQLITE_NOMEM] following any out-of-memory error, or 7298** [SQLITE_TOOBIG] if the size of the dynamic string exceeds 7299** [SQLITE_MAX_LENGTH], or [SQLITE_OK] if there have been no errors. 7300** 7301** ^The [sqlite3_str_length(X)] method returns the current length, in bytes, 7302** of the dynamic string under construction in [sqlite3_str] object X. 7303** ^The length returned by [sqlite3_str_length(X)] does not include the 7304** zero-termination byte. 7305** 7306** ^The [sqlite3_str_value(X)] method returns a pointer to the current 7307** content of the dynamic string under construction in X. The value 7308** returned by [sqlite3_str_value(X)] is managed by the sqlite3_str object X 7309** and might be freed or altered by any subsequent method on the same 7310** [sqlite3_str] object. Applications must not used the pointer returned 7311** [sqlite3_str_value(X)] after any subsequent method call on the same 7312** object. ^Applications may change the content of the string returned 7313** by [sqlite3_str_value(X)] as long as they do not write into any bytes 7314** outside the range of 0 to [sqlite3_str_length(X)] and do not read or 7315** write any byte after any subsequent sqlite3_str method call. 7316*/ 7317int sqlite3_str_errcode(sqlite3_str*); 7318int sqlite3_str_length(sqlite3_str*); 7319char *sqlite3_str_value(sqlite3_str*); 7320 7321/* 7322** CAPI3REF: SQLite Runtime Status 7323** 7324** ^These interfaces are used to retrieve runtime status information 7325** about the performance of SQLite, and optionally to reset various 7326** highwater marks. ^The first argument is an integer code for 7327** the specific parameter to measure. ^(Recognized integer codes 7328** are of the form [status parameters | SQLITE_STATUS_...].)^ 7329** ^The current value of the parameter is returned into *pCurrent. 7330** ^The highest recorded value is returned in *pHighwater. ^If the 7331** resetFlag is true, then the highest record value is reset after 7332** *pHighwater is written. ^(Some parameters do not record the highest 7333** value. For those parameters 7334** nothing is written into *pHighwater and the resetFlag is ignored.)^ 7335** ^(Other parameters record only the highwater mark and not the current 7336** value. For these latter parameters nothing is written into *pCurrent.)^ 7337** 7338** ^The sqlite3_status() and sqlite3_status64() routines return 7339** SQLITE_OK on success and a non-zero [error code] on failure. 7340** 7341** If either the current value or the highwater mark is too large to 7342** be represented by a 32-bit integer, then the values returned by 7343** sqlite3_status() are undefined. 7344** 7345** See also: [sqlite3_db_status()] 7346*/ 7347int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag); 7348int sqlite3_status64( 7349 int op, 7350 sqlite3_int64 *pCurrent, 7351 sqlite3_int64 *pHighwater, 7352 int resetFlag 7353); 7354 7355 7356/* 7357** CAPI3REF: Status Parameters 7358** KEYWORDS: {status parameters} 7359** 7360** These integer constants designate various run-time status parameters 7361** that can be returned by [sqlite3_status()]. 7362** 7363** <dl> 7364** [[SQLITE_STATUS_MEMORY_USED]] ^(<dt>SQLITE_STATUS_MEMORY_USED</dt> 7365** <dd>This parameter is the current amount of memory checked out 7366** using [sqlite3_malloc()], either directly or indirectly. The 7367** figure includes calls made to [sqlite3_malloc()] by the application 7368** and internal memory usage by the SQLite library. Auxiliary page-cache 7369** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in 7370** this parameter. The amount returned is the sum of the allocation 7371** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>)^ 7372** 7373** [[SQLITE_STATUS_MALLOC_SIZE]] ^(<dt>SQLITE_STATUS_MALLOC_SIZE</dt> 7374** <dd>This parameter records the largest memory allocation request 7375** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their 7376** internal equivalents). Only the value returned in the 7377** *pHighwater parameter to [sqlite3_status()] is of interest. 7378** The value written into the *pCurrent parameter is undefined.</dd>)^ 7379** 7380** [[SQLITE_STATUS_MALLOC_COUNT]] ^(<dt>SQLITE_STATUS_MALLOC_COUNT</dt> 7381** <dd>This parameter records the number of separate memory allocations 7382** currently checked out.</dd>)^ 7383** 7384** [[SQLITE_STATUS_PAGECACHE_USED]] ^(<dt>SQLITE_STATUS_PAGECACHE_USED</dt> 7385** <dd>This parameter returns the number of pages used out of the 7386** [pagecache memory allocator] that was configured using 7387** [SQLITE_CONFIG_PAGECACHE]. The 7388** value returned is in pages, not in bytes.</dd>)^ 7389** 7390** [[SQLITE_STATUS_PAGECACHE_OVERFLOW]] 7391** ^(<dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt> 7392** <dd>This parameter returns the number of bytes of page cache 7393** allocation which could not be satisfied by the [SQLITE_CONFIG_PAGECACHE] 7394** buffer and where forced to overflow to [sqlite3_malloc()]. The 7395** returned value includes allocations that overflowed because they 7396** where too large (they were larger than the "sz" parameter to 7397** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because 7398** no space was left in the page cache.</dd>)^ 7399** 7400** [[SQLITE_STATUS_PAGECACHE_SIZE]] ^(<dt>SQLITE_STATUS_PAGECACHE_SIZE</dt> 7401** <dd>This parameter records the largest memory allocation request 7402** handed to [pagecache memory allocator]. Only the value returned in the 7403** *pHighwater parameter to [sqlite3_status()] is of interest. 7404** The value written into the *pCurrent parameter is undefined.</dd>)^ 7405** 7406** [[SQLITE_STATUS_SCRATCH_USED]] <dt>SQLITE_STATUS_SCRATCH_USED</dt> 7407** <dd>No longer used.</dd> 7408** 7409** [[SQLITE_STATUS_SCRATCH_OVERFLOW]] ^(<dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt> 7410** <dd>No longer used.</dd> 7411** 7412** [[SQLITE_STATUS_SCRATCH_SIZE]] <dt>SQLITE_STATUS_SCRATCH_SIZE</dt> 7413** <dd>No longer used.</dd> 7414** 7415** [[SQLITE_STATUS_PARSER_STACK]] ^(<dt>SQLITE_STATUS_PARSER_STACK</dt> 7416** <dd>The *pHighwater parameter records the deepest parser stack. 7417** The *pCurrent value is undefined. The *pHighwater value is only 7418** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>)^ 7419** </dl> 7420** 7421** New status parameters may be added from time to time. 7422*/ 7423#define SQLITE_STATUS_MEMORY_USED 0 7424#define SQLITE_STATUS_PAGECACHE_USED 1 7425#define SQLITE_STATUS_PAGECACHE_OVERFLOW 2 7426#define SQLITE_STATUS_SCRATCH_USED 3 /* NOT USED */ 7427#define SQLITE_STATUS_SCRATCH_OVERFLOW 4 /* NOT USED */ 7428#define SQLITE_STATUS_MALLOC_SIZE 5 7429#define SQLITE_STATUS_PARSER_STACK 6 7430#define SQLITE_STATUS_PAGECACHE_SIZE 7 7431#define SQLITE_STATUS_SCRATCH_SIZE 8 /* NOT USED */ 7432#define SQLITE_STATUS_MALLOC_COUNT 9 7433 7434/* 7435** CAPI3REF: Database Connection Status 7436** METHOD: sqlite3 7437** 7438** ^This interface is used to retrieve runtime status information 7439** about a single [database connection]. ^The first argument is the 7440** database connection object to be interrogated. ^The second argument 7441** is an integer constant, taken from the set of 7442** [SQLITE_DBSTATUS options], that 7443** determines the parameter to interrogate. The set of 7444** [SQLITE_DBSTATUS options] is likely 7445** to grow in future releases of SQLite. 7446** 7447** ^The current value of the requested parameter is written into *pCur 7448** and the highest instantaneous value is written into *pHiwtr. ^If 7449** the resetFlg is true, then the highest instantaneous value is 7450** reset back down to the current value. 7451** 7452** ^The sqlite3_db_status() routine returns SQLITE_OK on success and a 7453** non-zero [error code] on failure. 7454** 7455** See also: [sqlite3_status()] and [sqlite3_stmt_status()]. 7456*/ 7457int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg); 7458 7459/* 7460** CAPI3REF: Status Parameters for database connections 7461** KEYWORDS: {SQLITE_DBSTATUS options} 7462** 7463** These constants are the available integer "verbs" that can be passed as 7464** the second argument to the [sqlite3_db_status()] interface. 7465** 7466** New verbs may be added in future releases of SQLite. Existing verbs 7467** might be discontinued. Applications should check the return code from 7468** [sqlite3_db_status()] to make sure that the call worked. 7469** The [sqlite3_db_status()] interface will return a non-zero error code 7470** if a discontinued or unsupported verb is invoked. 7471** 7472** <dl> 7473** [[SQLITE_DBSTATUS_LOOKASIDE_USED]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt> 7474** <dd>This parameter returns the number of lookaside memory slots currently 7475** checked out.</dd>)^ 7476** 7477** [[SQLITE_DBSTATUS_LOOKASIDE_HIT]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_HIT</dt> 7478** <dd>This parameter returns the number malloc attempts that were 7479** satisfied using lookaside memory. Only the high-water value is meaningful; 7480** the current value is always zero.)^ 7481** 7482** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE]] 7483** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE</dt> 7484** <dd>This parameter returns the number malloc attempts that might have 7485** been satisfied using lookaside memory but failed due to the amount of 7486** memory requested being larger than the lookaside slot size. 7487** Only the high-water value is meaningful; 7488** the current value is always zero.)^ 7489** 7490** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL]] 7491** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL</dt> 7492** <dd>This parameter returns the number malloc attempts that might have 7493** been satisfied using lookaside memory but failed due to all lookaside 7494** memory already being in use. 7495** Only the high-water value is meaningful; 7496** the current value is always zero.)^ 7497** 7498** [[SQLITE_DBSTATUS_CACHE_USED]] ^(<dt>SQLITE_DBSTATUS_CACHE_USED</dt> 7499** <dd>This parameter returns the approximate number of bytes of heap 7500** memory used by all pager caches associated with the database connection.)^ 7501** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0. 7502** 7503** [[SQLITE_DBSTATUS_CACHE_USED_SHARED]] 7504** ^(<dt>SQLITE_DBSTATUS_CACHE_USED_SHARED</dt> 7505** <dd>This parameter is similar to DBSTATUS_CACHE_USED, except that if a 7506** pager cache is shared between two or more connections the bytes of heap 7507** memory used by that pager cache is divided evenly between the attached 7508** connections.)^ In other words, if none of the pager caches associated 7509** with the database connection are shared, this request returns the same 7510** value as DBSTATUS_CACHE_USED. Or, if one or more or the pager caches are 7511** shared, the value returned by this call will be smaller than that returned 7512** by DBSTATUS_CACHE_USED. ^The highwater mark associated with 7513** SQLITE_DBSTATUS_CACHE_USED_SHARED is always 0. 7514** 7515** [[SQLITE_DBSTATUS_SCHEMA_USED]] ^(<dt>SQLITE_DBSTATUS_SCHEMA_USED</dt> 7516** <dd>This parameter returns the approximate number of bytes of heap 7517** memory used to store the schema for all databases associated 7518** with the connection - main, temp, and any [ATTACH]-ed databases.)^ 7519** ^The full amount of memory used by the schemas is reported, even if the 7520** schema memory is shared with other database connections due to 7521** [shared cache mode] being enabled. 7522** ^The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0. 7523** 7524** [[SQLITE_DBSTATUS_STMT_USED]] ^(<dt>SQLITE_DBSTATUS_STMT_USED</dt> 7525** <dd>This parameter returns the approximate number of bytes of heap 7526** and lookaside memory used by all prepared statements associated with 7527** the database connection.)^ 7528** ^The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0. 7529** </dd> 7530** 7531** [[SQLITE_DBSTATUS_CACHE_HIT]] ^(<dt>SQLITE_DBSTATUS_CACHE_HIT</dt> 7532** <dd>This parameter returns the number of pager cache hits that have 7533** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_HIT 7534** is always 0. 7535** </dd> 7536** 7537** [[SQLITE_DBSTATUS_CACHE_MISS]] ^(<dt>SQLITE_DBSTATUS_CACHE_MISS</dt> 7538** <dd>This parameter returns the number of pager cache misses that have 7539** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_MISS 7540** is always 0. 7541** </dd> 7542** 7543** [[SQLITE_DBSTATUS_CACHE_WRITE]] ^(<dt>SQLITE_DBSTATUS_CACHE_WRITE</dt> 7544** <dd>This parameter returns the number of dirty cache entries that have 7545** been written to disk. Specifically, the number of pages written to the 7546** wal file in wal mode databases, or the number of pages written to the 7547** database file in rollback mode databases. Any pages written as part of 7548** transaction rollback or database recovery operations are not included. 7549** If an IO or other error occurs while writing a page to disk, the effect 7550** on subsequent SQLITE_DBSTATUS_CACHE_WRITE requests is undefined.)^ ^The 7551** highwater mark associated with SQLITE_DBSTATUS_CACHE_WRITE is always 0. 7552** </dd> 7553** 7554** [[SQLITE_DBSTATUS_CACHE_SPILL]] ^(<dt>SQLITE_DBSTATUS_CACHE_SPILL</dt> 7555** <dd>This parameter returns the number of dirty cache entries that have 7556** been written to disk in the middle of a transaction due to the page 7557** cache overflowing. Transactions are more efficient if they are written 7558** to disk all at once. When pages spill mid-transaction, that introduces 7559** additional overhead. This parameter can be used help identify 7560** inefficiencies that can be resolve by increasing the cache size. 7561** </dd> 7562** 7563** [[SQLITE_DBSTATUS_DEFERRED_FKS]] ^(<dt>SQLITE_DBSTATUS_DEFERRED_FKS</dt> 7564** <dd>This parameter returns zero for the current value if and only if 7565** all foreign key constraints (deferred or immediate) have been 7566** resolved.)^ ^The highwater mark is always 0. 7567** </dd> 7568** </dl> 7569*/ 7570#define SQLITE_DBSTATUS_LOOKASIDE_USED 0 7571#define SQLITE_DBSTATUS_CACHE_USED 1 7572#define SQLITE_DBSTATUS_SCHEMA_USED 2 7573#define SQLITE_DBSTATUS_STMT_USED 3 7574#define SQLITE_DBSTATUS_LOOKASIDE_HIT 4 7575#define SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE 5 7576#define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL 6 7577#define SQLITE_DBSTATUS_CACHE_HIT 7 7578#define SQLITE_DBSTATUS_CACHE_MISS 8 7579#define SQLITE_DBSTATUS_CACHE_WRITE 9 7580#define SQLITE_DBSTATUS_DEFERRED_FKS 10 7581#define SQLITE_DBSTATUS_CACHE_USED_SHARED 11 7582#define SQLITE_DBSTATUS_CACHE_SPILL 12 7583#define SQLITE_DBSTATUS_MAX 12 /* Largest defined DBSTATUS */ 7584 7585 7586/* 7587** CAPI3REF: Prepared Statement Status 7588** METHOD: sqlite3_stmt 7589** 7590** ^(Each prepared statement maintains various 7591** [SQLITE_STMTSTATUS counters] that measure the number 7592** of times it has performed specific operations.)^ These counters can 7593** be used to monitor the performance characteristics of the prepared 7594** statements. For example, if the number of table steps greatly exceeds 7595** the number of table searches or result rows, that would tend to indicate 7596** that the prepared statement is using a full table scan rather than 7597** an index. 7598** 7599** ^(This interface is used to retrieve and reset counter values from 7600** a [prepared statement]. The first argument is the prepared statement 7601** object to be interrogated. The second argument 7602** is an integer code for a specific [SQLITE_STMTSTATUS counter] 7603** to be interrogated.)^ 7604** ^The current value of the requested counter is returned. 7605** ^If the resetFlg is true, then the counter is reset to zero after this 7606** interface call returns. 7607** 7608** See also: [sqlite3_status()] and [sqlite3_db_status()]. 7609*/ 7610int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg); 7611 7612/* 7613** CAPI3REF: Status Parameters for prepared statements 7614** KEYWORDS: {SQLITE_STMTSTATUS counter} {SQLITE_STMTSTATUS counters} 7615** 7616** These preprocessor macros define integer codes that name counter 7617** values associated with the [sqlite3_stmt_status()] interface. 7618** The meanings of the various counters are as follows: 7619** 7620** <dl> 7621** [[SQLITE_STMTSTATUS_FULLSCAN_STEP]] <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt> 7622** <dd>^This is the number of times that SQLite has stepped forward in 7623** a table as part of a full table scan. Large numbers for this counter 7624** may indicate opportunities for performance improvement through 7625** careful use of indices.</dd> 7626** 7627** [[SQLITE_STMTSTATUS_SORT]] <dt>SQLITE_STMTSTATUS_SORT</dt> 7628** <dd>^This is the number of sort operations that have occurred. 7629** A non-zero value in this counter may indicate an opportunity to 7630** improvement performance through careful use of indices.</dd> 7631** 7632** [[SQLITE_STMTSTATUS_AUTOINDEX]] <dt>SQLITE_STMTSTATUS_AUTOINDEX</dt> 7633** <dd>^This is the number of rows inserted into transient indices that 7634** were created automatically in order to help joins run faster. 7635** A non-zero value in this counter may indicate an opportunity to 7636** improvement performance by adding permanent indices that do not 7637** need to be reinitialized each time the statement is run.</dd> 7638** 7639** [[SQLITE_STMTSTATUS_VM_STEP]] <dt>SQLITE_STMTSTATUS_VM_STEP</dt> 7640** <dd>^This is the number of virtual machine operations executed 7641** by the prepared statement if that number is less than or equal 7642** to 2147483647. The number of virtual machine operations can be 7643** used as a proxy for the total work done by the prepared statement. 7644** If the number of virtual machine operations exceeds 2147483647 7645** then the value returned by this statement status code is undefined. 7646** 7647** [[SQLITE_STMTSTATUS_REPREPARE]] <dt>SQLITE_STMTSTATUS_REPREPARE</dt> 7648** <dd>^This is the number of times that the prepare statement has been 7649** automatically regenerated due to schema changes or change to 7650** [bound parameters] that might affect the query plan. 7651** 7652** [[SQLITE_STMTSTATUS_RUN]] <dt>SQLITE_STMTSTATUS_RUN</dt> 7653** <dd>^This is the number of times that the prepared statement has 7654** been run. A single "run" for the purposes of this counter is one 7655** or more calls to [sqlite3_step()] followed by a call to [sqlite3_reset()]. 7656** The counter is incremented on the first [sqlite3_step()] call of each 7657** cycle. 7658** 7659** [[SQLITE_STMTSTATUS_MEMUSED]] <dt>SQLITE_STMTSTATUS_MEMUSED</dt> 7660** <dd>^This is the approximate number of bytes of heap memory 7661** used to store the prepared statement. ^This value is not actually 7662** a counter, and so the resetFlg parameter to sqlite3_stmt_status() 7663** is ignored when the opcode is SQLITE_STMTSTATUS_MEMUSED. 7664** </dd> 7665** </dl> 7666*/ 7667#define SQLITE_STMTSTATUS_FULLSCAN_STEP 1 7668#define SQLITE_STMTSTATUS_SORT 2 7669#define SQLITE_STMTSTATUS_AUTOINDEX 3 7670#define SQLITE_STMTSTATUS_VM_STEP 4 7671#define SQLITE_STMTSTATUS_REPREPARE 5 7672#define SQLITE_STMTSTATUS_RUN 6 7673#define SQLITE_STMTSTATUS_MEMUSED 99 7674 7675/* 7676** CAPI3REF: Custom Page Cache Object 7677** 7678** The sqlite3_pcache type is opaque. It is implemented by 7679** the pluggable module. The SQLite core has no knowledge of 7680** its size or internal structure and never deals with the 7681** sqlite3_pcache object except by holding and passing pointers 7682** to the object. 7683** 7684** See [sqlite3_pcache_methods2] for additional information. 7685*/ 7686typedef struct sqlite3_pcache sqlite3_pcache; 7687 7688/* 7689** CAPI3REF: Custom Page Cache Object 7690** 7691** The sqlite3_pcache_page object represents a single page in the 7692** page cache. The page cache will allocate instances of this 7693** object. Various methods of the page cache use pointers to instances 7694** of this object as parameters or as their return value. 7695** 7696** See [sqlite3_pcache_methods2] for additional information. 7697*/ 7698typedef struct sqlite3_pcache_page sqlite3_pcache_page; 7699struct sqlite3_pcache_page { 7700 void *pBuf; /* The content of the page */ 7701 void *pExtra; /* Extra information associated with the page */ 7702}; 7703 7704/* 7705** CAPI3REF: Application Defined Page Cache. 7706** KEYWORDS: {page cache} 7707** 7708** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE2], ...) interface can 7709** register an alternative page cache implementation by passing in an 7710** instance of the sqlite3_pcache_methods2 structure.)^ 7711** In many applications, most of the heap memory allocated by 7712** SQLite is used for the page cache. 7713** By implementing a 7714** custom page cache using this API, an application can better control 7715** the amount of memory consumed by SQLite, the way in which 7716** that memory is allocated and released, and the policies used to 7717** determine exactly which parts of a database file are cached and for 7718** how long. 7719** 7720** The alternative page cache mechanism is an 7721** extreme measure that is only needed by the most demanding applications. 7722** The built-in page cache is recommended for most uses. 7723** 7724** ^(The contents of the sqlite3_pcache_methods2 structure are copied to an 7725** internal buffer by SQLite within the call to [sqlite3_config]. Hence 7726** the application may discard the parameter after the call to 7727** [sqlite3_config()] returns.)^ 7728** 7729** [[the xInit() page cache method]] 7730** ^(The xInit() method is called once for each effective 7731** call to [sqlite3_initialize()])^ 7732** (usually only once during the lifetime of the process). ^(The xInit() 7733** method is passed a copy of the sqlite3_pcache_methods2.pArg value.)^ 7734** The intent of the xInit() method is to set up global data structures 7735** required by the custom page cache implementation. 7736** ^(If the xInit() method is NULL, then the 7737** built-in default page cache is used instead of the application defined 7738** page cache.)^ 7739** 7740** [[the xShutdown() page cache method]] 7741** ^The xShutdown() method is called by [sqlite3_shutdown()]. 7742** It can be used to clean up 7743** any outstanding resources before process shutdown, if required. 7744** ^The xShutdown() method may be NULL. 7745** 7746** ^SQLite automatically serializes calls to the xInit method, 7747** so the xInit method need not be threadsafe. ^The 7748** xShutdown method is only called from [sqlite3_shutdown()] so it does 7749** not need to be threadsafe either. All other methods must be threadsafe 7750** in multithreaded applications. 7751** 7752** ^SQLite will never invoke xInit() more than once without an intervening 7753** call to xShutdown(). 7754** 7755** [[the xCreate() page cache methods]] 7756** ^SQLite invokes the xCreate() method to construct a new cache instance. 7757** SQLite will typically create one cache instance for each open database file, 7758** though this is not guaranteed. ^The 7759** first parameter, szPage, is the size in bytes of the pages that must 7760** be allocated by the cache. ^szPage will always a power of two. ^The 7761** second parameter szExtra is a number of bytes of extra storage 7762** associated with each page cache entry. ^The szExtra parameter will 7763** a number less than 250. SQLite will use the 7764** extra szExtra bytes on each page to store metadata about the underlying 7765** database page on disk. The value passed into szExtra depends 7766** on the SQLite version, the target platform, and how SQLite was compiled. 7767** ^The third argument to xCreate(), bPurgeable, is true if the cache being 7768** created will be used to cache database pages of a file stored on disk, or 7769** false if it is used for an in-memory database. The cache implementation 7770** does not have to do anything special based with the value of bPurgeable; 7771** it is purely advisory. ^On a cache where bPurgeable is false, SQLite will 7772** never invoke xUnpin() except to deliberately delete a page. 7773** ^In other words, calls to xUnpin() on a cache with bPurgeable set to 7774** false will always have the "discard" flag set to true. 7775** ^Hence, a cache created with bPurgeable false will 7776** never contain any unpinned pages. 7777** 7778** [[the xCachesize() page cache method]] 7779** ^(The xCachesize() method may be called at any time by SQLite to set the 7780** suggested maximum cache-size (number of pages stored by) the cache 7781** instance passed as the first argument. This is the value configured using 7782** the SQLite "[PRAGMA cache_size]" command.)^ As with the bPurgeable 7783** parameter, the implementation is not required to do anything with this 7784** value; it is advisory only. 7785** 7786** [[the xPagecount() page cache methods]] 7787** The xPagecount() method must return the number of pages currently 7788** stored in the cache, both pinned and unpinned. 7789** 7790** [[the xFetch() page cache methods]] 7791** The xFetch() method locates a page in the cache and returns a pointer to 7792** an sqlite3_pcache_page object associated with that page, or a NULL pointer. 7793** The pBuf element of the returned sqlite3_pcache_page object will be a 7794** pointer to a buffer of szPage bytes used to store the content of a 7795** single database page. The pExtra element of sqlite3_pcache_page will be 7796** a pointer to the szExtra bytes of extra storage that SQLite has requested 7797** for each entry in the page cache. 7798** 7799** The page to be fetched is determined by the key. ^The minimum key value 7800** is 1. After it has been retrieved using xFetch, the page is considered 7801** to be "pinned". 7802** 7803** If the requested page is already in the page cache, then the page cache 7804** implementation must return a pointer to the page buffer with its content 7805** intact. If the requested page is not already in the cache, then the 7806** cache implementation should use the value of the createFlag 7807** parameter to help it determined what action to take: 7808** 7809** <table border=1 width=85% align=center> 7810** <tr><th> createFlag <th> Behavior when page is not already in cache 7811** <tr><td> 0 <td> Do not allocate a new page. Return NULL. 7812** <tr><td> 1 <td> Allocate a new page if it easy and convenient to do so. 7813** Otherwise return NULL. 7814** <tr><td> 2 <td> Make every effort to allocate a new page. Only return 7815** NULL if allocating a new page is effectively impossible. 7816** </table> 7817** 7818** ^(SQLite will normally invoke xFetch() with a createFlag of 0 or 1. SQLite 7819** will only use a createFlag of 2 after a prior call with a createFlag of 1 7820** failed.)^ In between the to xFetch() calls, SQLite may 7821** attempt to unpin one or more cache pages by spilling the content of 7822** pinned pages to disk and synching the operating system disk cache. 7823** 7824** [[the xUnpin() page cache method]] 7825** ^xUnpin() is called by SQLite with a pointer to a currently pinned page 7826** as its second argument. If the third parameter, discard, is non-zero, 7827** then the page must be evicted from the cache. 7828** ^If the discard parameter is 7829** zero, then the page may be discarded or retained at the discretion of 7830** page cache implementation. ^The page cache implementation 7831** may choose to evict unpinned pages at any time. 7832** 7833** The cache must not perform any reference counting. A single 7834** call to xUnpin() unpins the page regardless of the number of prior calls 7835** to xFetch(). 7836** 7837** [[the xRekey() page cache methods]] 7838** The xRekey() method is used to change the key value associated with the 7839** page passed as the second argument. If the cache 7840** previously contains an entry associated with newKey, it must be 7841** discarded. ^Any prior cache entry associated with newKey is guaranteed not 7842** to be pinned. 7843** 7844** When SQLite calls the xTruncate() method, the cache must discard all 7845** existing cache entries with page numbers (keys) greater than or equal 7846** to the value of the iLimit parameter passed to xTruncate(). If any 7847** of these pages are pinned, they are implicitly unpinned, meaning that 7848** they can be safely discarded. 7849** 7850** [[the xDestroy() page cache method]] 7851** ^The xDestroy() method is used to delete a cache allocated by xCreate(). 7852** All resources associated with the specified cache should be freed. ^After 7853** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*] 7854** handle invalid, and will not use it with any other sqlite3_pcache_methods2 7855** functions. 7856** 7857** [[the xShrink() page cache method]] 7858** ^SQLite invokes the xShrink() method when it wants the page cache to 7859** free up as much of heap memory as possible. The page cache implementation 7860** is not obligated to free any memory, but well-behaved implementations should 7861** do their best. 7862*/ 7863typedef struct sqlite3_pcache_methods2 sqlite3_pcache_methods2; 7864struct sqlite3_pcache_methods2 { 7865 int iVersion; 7866 void *pArg; 7867 int (*xInit)(void*); 7868 void (*xShutdown)(void*); 7869 sqlite3_pcache *(*xCreate)(int szPage, int szExtra, int bPurgeable); 7870 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 7871 int (*xPagecount)(sqlite3_pcache*); 7872 sqlite3_pcache_page *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 7873 void (*xUnpin)(sqlite3_pcache*, sqlite3_pcache_page*, int discard); 7874 void (*xRekey)(sqlite3_pcache*, sqlite3_pcache_page*, 7875 unsigned oldKey, unsigned newKey); 7876 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 7877 void (*xDestroy)(sqlite3_pcache*); 7878 void (*xShrink)(sqlite3_pcache*); 7879}; 7880 7881/* 7882** This is the obsolete pcache_methods object that has now been replaced 7883** by sqlite3_pcache_methods2. This object is not used by SQLite. It is 7884** retained in the header file for backwards compatibility only. 7885*/ 7886typedef struct sqlite3_pcache_methods sqlite3_pcache_methods; 7887struct sqlite3_pcache_methods { 7888 void *pArg; 7889 int (*xInit)(void*); 7890 void (*xShutdown)(void*); 7891 sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable); 7892 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 7893 int (*xPagecount)(sqlite3_pcache*); 7894 void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 7895 void (*xUnpin)(sqlite3_pcache*, void*, int discard); 7896 void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey); 7897 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 7898 void (*xDestroy)(sqlite3_pcache*); 7899}; 7900 7901 7902/* 7903** CAPI3REF: Online Backup Object 7904** 7905** The sqlite3_backup object records state information about an ongoing 7906** online backup operation. ^The sqlite3_backup object is created by 7907** a call to [sqlite3_backup_init()] and is destroyed by a call to 7908** [sqlite3_backup_finish()]. 7909** 7910** See Also: [Using the SQLite Online Backup API] 7911*/ 7912typedef struct sqlite3_backup sqlite3_backup; 7913 7914/* 7915** CAPI3REF: Online Backup API. 7916** 7917** The backup API copies the content of one database into another. 7918** It is useful either for creating backups of databases or 7919** for copying in-memory databases to or from persistent files. 7920** 7921** See Also: [Using the SQLite Online Backup API] 7922** 7923** ^SQLite holds a write transaction open on the destination database file 7924** for the duration of the backup operation. 7925** ^The source database is read-locked only while it is being read; 7926** it is not locked continuously for the entire backup operation. 7927** ^Thus, the backup may be performed on a live source database without 7928** preventing other database connections from 7929** reading or writing to the source database while the backup is underway. 7930** 7931** ^(To perform a backup operation: 7932** <ol> 7933** <li><b>sqlite3_backup_init()</b> is called once to initialize the 7934** backup, 7935** <li><b>sqlite3_backup_step()</b> is called one or more times to transfer 7936** the data between the two databases, and finally 7937** <li><b>sqlite3_backup_finish()</b> is called to release all resources 7938** associated with the backup operation. 7939** </ol>)^ 7940** There should be exactly one call to sqlite3_backup_finish() for each 7941** successful call to sqlite3_backup_init(). 7942** 7943** [[sqlite3_backup_init()]] <b>sqlite3_backup_init()</b> 7944** 7945** ^The D and N arguments to sqlite3_backup_init(D,N,S,M) are the 7946** [database connection] associated with the destination database 7947** and the database name, respectively. 7948** ^The database name is "main" for the main database, "temp" for the 7949** temporary database, or the name specified after the AS keyword in 7950** an [ATTACH] statement for an attached database. 7951** ^The S and M arguments passed to 7952** sqlite3_backup_init(D,N,S,M) identify the [database connection] 7953** and database name of the source database, respectively. 7954** ^The source and destination [database connections] (parameters S and D) 7955** must be different or else sqlite3_backup_init(D,N,S,M) will fail with 7956** an error. 7957** 7958** ^A call to sqlite3_backup_init() will fail, returning NULL, if 7959** there is already a read or read-write transaction open on the 7960** destination database. 7961** 7962** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is 7963** returned and an error code and error message are stored in the 7964** destination [database connection] D. 7965** ^The error code and message for the failed call to sqlite3_backup_init() 7966** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or 7967** [sqlite3_errmsg16()] functions. 7968** ^A successful call to sqlite3_backup_init() returns a pointer to an 7969** [sqlite3_backup] object. 7970** ^The [sqlite3_backup] object may be used with the sqlite3_backup_step() and 7971** sqlite3_backup_finish() functions to perform the specified backup 7972** operation. 7973** 7974** [[sqlite3_backup_step()]] <b>sqlite3_backup_step()</b> 7975** 7976** ^Function sqlite3_backup_step(B,N) will copy up to N pages between 7977** the source and destination databases specified by [sqlite3_backup] object B. 7978** ^If N is negative, all remaining source pages are copied. 7979** ^If sqlite3_backup_step(B,N) successfully copies N pages and there 7980** are still more pages to be copied, then the function returns [SQLITE_OK]. 7981** ^If sqlite3_backup_step(B,N) successfully finishes copying all pages 7982** from source to destination, then it returns [SQLITE_DONE]. 7983** ^If an error occurs while running sqlite3_backup_step(B,N), 7984** then an [error code] is returned. ^As well as [SQLITE_OK] and 7985** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY], 7986** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an 7987** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code. 7988** 7989** ^(The sqlite3_backup_step() might return [SQLITE_READONLY] if 7990** <ol> 7991** <li> the destination database was opened read-only, or 7992** <li> the destination database is using write-ahead-log journaling 7993** and the destination and source page sizes differ, or 7994** <li> the destination database is an in-memory database and the 7995** destination and source page sizes differ. 7996** </ol>)^ 7997** 7998** ^If sqlite3_backup_step() cannot obtain a required file-system lock, then 7999** the [sqlite3_busy_handler | busy-handler function] 8000** is invoked (if one is specified). ^If the 8001** busy-handler returns non-zero before the lock is available, then 8002** [SQLITE_BUSY] is returned to the caller. ^In this case the call to 8003** sqlite3_backup_step() can be retried later. ^If the source 8004** [database connection] 8005** is being used to write to the source database when sqlite3_backup_step() 8006** is called, then [SQLITE_LOCKED] is returned immediately. ^Again, in this 8007** case the call to sqlite3_backup_step() can be retried later on. ^(If 8008** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or 8009** [SQLITE_READONLY] is returned, then 8010** there is no point in retrying the call to sqlite3_backup_step(). These 8011** errors are considered fatal.)^ The application must accept 8012** that the backup operation has failed and pass the backup operation handle 8013** to the sqlite3_backup_finish() to release associated resources. 8014** 8015** ^The first call to sqlite3_backup_step() obtains an exclusive lock 8016** on the destination file. ^The exclusive lock is not released until either 8017** sqlite3_backup_finish() is called or the backup operation is complete 8018** and sqlite3_backup_step() returns [SQLITE_DONE]. ^Every call to 8019** sqlite3_backup_step() obtains a [shared lock] on the source database that 8020** lasts for the duration of the sqlite3_backup_step() call. 8021** ^Because the source database is not locked between calls to 8022** sqlite3_backup_step(), the source database may be modified mid-way 8023** through the backup process. ^If the source database is modified by an 8024** external process or via a database connection other than the one being 8025** used by the backup operation, then the backup will be automatically 8026** restarted by the next call to sqlite3_backup_step(). ^If the source 8027** database is modified by the using the same database connection as is used 8028** by the backup operation, then the backup database is automatically 8029** updated at the same time. 8030** 8031** [[sqlite3_backup_finish()]] <b>sqlite3_backup_finish()</b> 8032** 8033** When sqlite3_backup_step() has returned [SQLITE_DONE], or when the 8034** application wishes to abandon the backup operation, the application 8035** should destroy the [sqlite3_backup] by passing it to sqlite3_backup_finish(). 8036** ^The sqlite3_backup_finish() interfaces releases all 8037** resources associated with the [sqlite3_backup] object. 8038** ^If sqlite3_backup_step() has not yet returned [SQLITE_DONE], then any 8039** active write-transaction on the destination database is rolled back. 8040** The [sqlite3_backup] object is invalid 8041** and may not be used following a call to sqlite3_backup_finish(). 8042** 8043** ^The value returned by sqlite3_backup_finish is [SQLITE_OK] if no 8044** sqlite3_backup_step() errors occurred, regardless or whether or not 8045** sqlite3_backup_step() completed. 8046** ^If an out-of-memory condition or IO error occurred during any prior 8047** sqlite3_backup_step() call on the same [sqlite3_backup] object, then 8048** sqlite3_backup_finish() returns the corresponding [error code]. 8049** 8050** ^A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step() 8051** is not a permanent error and does not affect the return value of 8052** sqlite3_backup_finish(). 8053** 8054** [[sqlite3_backup_remaining()]] [[sqlite3_backup_pagecount()]] 8055** <b>sqlite3_backup_remaining() and sqlite3_backup_pagecount()</b> 8056** 8057** ^The sqlite3_backup_remaining() routine returns the number of pages still 8058** to be backed up at the conclusion of the most recent sqlite3_backup_step(). 8059** ^The sqlite3_backup_pagecount() routine returns the total number of pages 8060** in the source database at the conclusion of the most recent 8061** sqlite3_backup_step(). 8062** ^(The values returned by these functions are only updated by 8063** sqlite3_backup_step(). If the source database is modified in a way that 8064** changes the size of the source database or the number of pages remaining, 8065** those changes are not reflected in the output of sqlite3_backup_pagecount() 8066** and sqlite3_backup_remaining() until after the next 8067** sqlite3_backup_step().)^ 8068** 8069** <b>Concurrent Usage of Database Handles</b> 8070** 8071** ^The source [database connection] may be used by the application for other 8072** purposes while a backup operation is underway or being initialized. 8073** ^If SQLite is compiled and configured to support threadsafe database 8074** connections, then the source database connection may be used concurrently 8075** from within other threads. 8076** 8077** However, the application must guarantee that the destination 8078** [database connection] is not passed to any other API (by any thread) after 8079** sqlite3_backup_init() is called and before the corresponding call to 8080** sqlite3_backup_finish(). SQLite does not currently check to see 8081** if the application incorrectly accesses the destination [database connection] 8082** and so no error code is reported, but the operations may malfunction 8083** nevertheless. Use of the destination database connection while a 8084** backup is in progress might also also cause a mutex deadlock. 8085** 8086** If running in [shared cache mode], the application must 8087** guarantee that the shared cache used by the destination database 8088** is not accessed while the backup is running. In practice this means 8089** that the application must guarantee that the disk file being 8090** backed up to is not accessed by any connection within the process, 8091** not just the specific connection that was passed to sqlite3_backup_init(). 8092** 8093** The [sqlite3_backup] object itself is partially threadsafe. Multiple 8094** threads may safely make multiple concurrent calls to sqlite3_backup_step(). 8095** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount() 8096** APIs are not strictly speaking threadsafe. If they are invoked at the 8097** same time as another thread is invoking sqlite3_backup_step() it is 8098** possible that they return invalid values. 8099*/ 8100sqlite3_backup *sqlite3_backup_init( 8101 sqlite3 *pDest, /* Destination database handle */ 8102 const char *zDestName, /* Destination database name */ 8103 sqlite3 *pSource, /* Source database handle */ 8104 const char *zSourceName /* Source database name */ 8105); 8106int sqlite3_backup_step(sqlite3_backup *p, int nPage); 8107int sqlite3_backup_finish(sqlite3_backup *p); 8108int sqlite3_backup_remaining(sqlite3_backup *p); 8109int sqlite3_backup_pagecount(sqlite3_backup *p); 8110 8111/* 8112** CAPI3REF: Unlock Notification 8113** METHOD: sqlite3 8114** 8115** ^When running in shared-cache mode, a database operation may fail with 8116** an [SQLITE_LOCKED] error if the required locks on the shared-cache or 8117** individual tables within the shared-cache cannot be obtained. See 8118** [SQLite Shared-Cache Mode] for a description of shared-cache locking. 8119** ^This API may be used to register a callback that SQLite will invoke 8120** when the connection currently holding the required lock relinquishes it. 8121** ^This API is only available if the library was compiled with the 8122** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined. 8123** 8124** See Also: [Using the SQLite Unlock Notification Feature]. 8125** 8126** ^Shared-cache locks are released when a database connection concludes 8127** its current transaction, either by committing it or rolling it back. 8128** 8129** ^When a connection (known as the blocked connection) fails to obtain a 8130** shared-cache lock and SQLITE_LOCKED is returned to the caller, the 8131** identity of the database connection (the blocking connection) that 8132** has locked the required resource is stored internally. ^After an 8133** application receives an SQLITE_LOCKED error, it may call the 8134** sqlite3_unlock_notify() method with the blocked connection handle as 8135** the first argument to register for a callback that will be invoked 8136** when the blocking connections current transaction is concluded. ^The 8137** callback is invoked from within the [sqlite3_step] or [sqlite3_close] 8138** call that concludes the blocking connections transaction. 8139** 8140** ^(If sqlite3_unlock_notify() is called in a multi-threaded application, 8141** there is a chance that the blocking connection will have already 8142** concluded its transaction by the time sqlite3_unlock_notify() is invoked. 8143** If this happens, then the specified callback is invoked immediately, 8144** from within the call to sqlite3_unlock_notify().)^ 8145** 8146** ^If the blocked connection is attempting to obtain a write-lock on a 8147** shared-cache table, and more than one other connection currently holds 8148** a read-lock on the same table, then SQLite arbitrarily selects one of 8149** the other connections to use as the blocking connection. 8150** 8151** ^(There may be at most one unlock-notify callback registered by a 8152** blocked connection. If sqlite3_unlock_notify() is called when the 8153** blocked connection already has a registered unlock-notify callback, 8154** then the new callback replaces the old.)^ ^If sqlite3_unlock_notify() is 8155** called with a NULL pointer as its second argument, then any existing 8156** unlock-notify callback is canceled. ^The blocked connections 8157** unlock-notify callback may also be canceled by closing the blocked 8158** connection using [sqlite3_close()]. 8159** 8160** The unlock-notify callback is not reentrant. If an application invokes 8161** any sqlite3_xxx API functions from within an unlock-notify callback, a 8162** crash or deadlock may be the result. 8163** 8164** ^Unless deadlock is detected (see below), sqlite3_unlock_notify() always 8165** returns SQLITE_OK. 8166** 8167** <b>Callback Invocation Details</b> 8168** 8169** When an unlock-notify callback is registered, the application provides a 8170** single void* pointer that is passed to the callback when it is invoked. 8171** However, the signature of the callback function allows SQLite to pass 8172** it an array of void* context pointers. The first argument passed to 8173** an unlock-notify callback is a pointer to an array of void* pointers, 8174** and the second is the number of entries in the array. 8175** 8176** When a blocking connections transaction is concluded, there may be 8177** more than one blocked connection that has registered for an unlock-notify 8178** callback. ^If two or more such blocked connections have specified the 8179** same callback function, then instead of invoking the callback function 8180** multiple times, it is invoked once with the set of void* context pointers 8181** specified by the blocked connections bundled together into an array. 8182** This gives the application an opportunity to prioritize any actions 8183** related to the set of unblocked database connections. 8184** 8185** <b>Deadlock Detection</b> 8186** 8187** Assuming that after registering for an unlock-notify callback a 8188** database waits for the callback to be issued before taking any further 8189** action (a reasonable assumption), then using this API may cause the 8190** application to deadlock. For example, if connection X is waiting for 8191** connection Y's transaction to be concluded, and similarly connection 8192** Y is waiting on connection X's transaction, then neither connection 8193** will proceed and the system may remain deadlocked indefinitely. 8194** 8195** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock 8196** detection. ^If a given call to sqlite3_unlock_notify() would put the 8197** system in a deadlocked state, then SQLITE_LOCKED is returned and no 8198** unlock-notify callback is registered. The system is said to be in 8199** a deadlocked state if connection A has registered for an unlock-notify 8200** callback on the conclusion of connection B's transaction, and connection 8201** B has itself registered for an unlock-notify callback when connection 8202** A's transaction is concluded. ^Indirect deadlock is also detected, so 8203** the system is also considered to be deadlocked if connection B has 8204** registered for an unlock-notify callback on the conclusion of connection 8205** C's transaction, where connection C is waiting on connection A. ^Any 8206** number of levels of indirection are allowed. 8207** 8208** <b>The "DROP TABLE" Exception</b> 8209** 8210** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost 8211** always appropriate to call sqlite3_unlock_notify(). There is however, 8212** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement, 8213** SQLite checks if there are any currently executing SELECT statements 8214** that belong to the same connection. If there are, SQLITE_LOCKED is 8215** returned. In this case there is no "blocking connection", so invoking 8216** sqlite3_unlock_notify() results in the unlock-notify callback being 8217** invoked immediately. If the application then re-attempts the "DROP TABLE" 8218** or "DROP INDEX" query, an infinite loop might be the result. 8219** 8220** One way around this problem is to check the extended error code returned 8221** by an sqlite3_step() call. ^(If there is a blocking connection, then the 8222** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in 8223** the special "DROP TABLE/INDEX" case, the extended error code is just 8224** SQLITE_LOCKED.)^ 8225*/ 8226int sqlite3_unlock_notify( 8227 sqlite3 *pBlocked, /* Waiting connection */ 8228 void (*xNotify)(void **apArg, int nArg), /* Callback function to invoke */ 8229 void *pNotifyArg /* Argument to pass to xNotify */ 8230); 8231 8232 8233/* 8234** CAPI3REF: String Comparison 8235** 8236** ^The [sqlite3_stricmp()] and [sqlite3_strnicmp()] APIs allow applications 8237** and extensions to compare the contents of two buffers containing UTF-8 8238** strings in a case-independent fashion, using the same definition of "case 8239** independence" that SQLite uses internally when comparing identifiers. 8240*/ 8241int sqlite3_stricmp(const char *, const char *); 8242int sqlite3_strnicmp(const char *, const char *, int); 8243 8244/* 8245** CAPI3REF: String Globbing 8246* 8247** ^The [sqlite3_strglob(P,X)] interface returns zero if and only if 8248** string X matches the [GLOB] pattern P. 8249** ^The definition of [GLOB] pattern matching used in 8250** [sqlite3_strglob(P,X)] is the same as for the "X GLOB P" operator in the 8251** SQL dialect understood by SQLite. ^The [sqlite3_strglob(P,X)] function 8252** is case sensitive. 8253** 8254** Note that this routine returns zero on a match and non-zero if the strings 8255** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()]. 8256** 8257** See also: [sqlite3_strlike()]. 8258*/ 8259int sqlite3_strglob(const char *zGlob, const char *zStr); 8260 8261/* 8262** CAPI3REF: String LIKE Matching 8263* 8264** ^The [sqlite3_strlike(P,X,E)] interface returns zero if and only if 8265** string X matches the [LIKE] pattern P with escape character E. 8266** ^The definition of [LIKE] pattern matching used in 8267** [sqlite3_strlike(P,X,E)] is the same as for the "X LIKE P ESCAPE E" 8268** operator in the SQL dialect understood by SQLite. ^For "X LIKE P" without 8269** the ESCAPE clause, set the E parameter of [sqlite3_strlike(P,X,E)] to 0. 8270** ^As with the LIKE operator, the [sqlite3_strlike(P,X,E)] function is case 8271** insensitive - equivalent upper and lower case ASCII characters match 8272** one another. 8273** 8274** ^The [sqlite3_strlike(P,X,E)] function matches Unicode characters, though 8275** only ASCII characters are case folded. 8276** 8277** Note that this routine returns zero on a match and non-zero if the strings 8278** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()]. 8279** 8280** See also: [sqlite3_strglob()]. 8281*/ 8282int sqlite3_strlike(const char *zGlob, const char *zStr, unsigned int cEsc); 8283 8284/* 8285** CAPI3REF: Error Logging Interface 8286** 8287** ^The [sqlite3_log()] interface writes a message into the [error log] 8288** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()]. 8289** ^If logging is enabled, the zFormat string and subsequent arguments are 8290** used with [sqlite3_snprintf()] to generate the final output string. 8291** 8292** The sqlite3_log() interface is intended for use by extensions such as 8293** virtual tables, collating functions, and SQL functions. While there is 8294** nothing to prevent an application from calling sqlite3_log(), doing so 8295** is considered bad form. 8296** 8297** The zFormat string must not be NULL. 8298** 8299** To avoid deadlocks and other threading problems, the sqlite3_log() routine 8300** will not use dynamically allocated memory. The log message is stored in 8301** a fixed-length buffer on the stack. If the log message is longer than 8302** a few hundred characters, it will be truncated to the length of the 8303** buffer. 8304*/ 8305void sqlite3_log(int iErrCode, const char *zFormat, ...); 8306 8307/* 8308** CAPI3REF: Write-Ahead Log Commit Hook 8309** METHOD: sqlite3 8310** 8311** ^The [sqlite3_wal_hook()] function is used to register a callback that 8312** is invoked each time data is committed to a database in wal mode. 8313** 8314** ^(The callback is invoked by SQLite after the commit has taken place and 8315** the associated write-lock on the database released)^, so the implementation 8316** may read, write or [checkpoint] the database as required. 8317** 8318** ^The first parameter passed to the callback function when it is invoked 8319** is a copy of the third parameter passed to sqlite3_wal_hook() when 8320** registering the callback. ^The second is a copy of the database handle. 8321** ^The third parameter is the name of the database that was written to - 8322** either "main" or the name of an [ATTACH]-ed database. ^The fourth parameter 8323** is the number of pages currently in the write-ahead log file, 8324** including those that were just committed. 8325** 8326** The callback function should normally return [SQLITE_OK]. ^If an error 8327** code is returned, that error will propagate back up through the 8328** SQLite code base to cause the statement that provoked the callback 8329** to report an error, though the commit will have still occurred. If the 8330** callback returns [SQLITE_ROW] or [SQLITE_DONE], or if it returns a value 8331** that does not correspond to any valid SQLite error code, the results 8332** are undefined. 8333** 8334** A single database handle may have at most a single write-ahead log callback 8335** registered at one time. ^Calling [sqlite3_wal_hook()] replaces any 8336** previously registered write-ahead log callback. ^Note that the 8337** [sqlite3_wal_autocheckpoint()] interface and the 8338** [wal_autocheckpoint pragma] both invoke [sqlite3_wal_hook()] and will 8339** overwrite any prior [sqlite3_wal_hook()] settings. 8340*/ 8341void *sqlite3_wal_hook( 8342 sqlite3*, 8343 int(*)(void *,sqlite3*,const char*,int), 8344 void* 8345); 8346 8347/* 8348** CAPI3REF: Configure an auto-checkpoint 8349** METHOD: sqlite3 8350** 8351** ^The [sqlite3_wal_autocheckpoint(D,N)] is a wrapper around 8352** [sqlite3_wal_hook()] that causes any database on [database connection] D 8353** to automatically [checkpoint] 8354** after committing a transaction if there are N or 8355** more frames in the [write-ahead log] file. ^Passing zero or 8356** a negative value as the nFrame parameter disables automatic 8357** checkpoints entirely. 8358** 8359** ^The callback registered by this function replaces any existing callback 8360** registered using [sqlite3_wal_hook()]. ^Likewise, registering a callback 8361** using [sqlite3_wal_hook()] disables the automatic checkpoint mechanism 8362** configured by this function. 8363** 8364** ^The [wal_autocheckpoint pragma] can be used to invoke this interface 8365** from SQL. 8366** 8367** ^Checkpoints initiated by this mechanism are 8368** [sqlite3_wal_checkpoint_v2|PASSIVE]. 8369** 8370** ^Every new [database connection] defaults to having the auto-checkpoint 8371** enabled with a threshold of 1000 or [SQLITE_DEFAULT_WAL_AUTOCHECKPOINT] 8372** pages. The use of this interface 8373** is only necessary if the default setting is found to be suboptimal 8374** for a particular application. 8375*/ 8376int sqlite3_wal_autocheckpoint(sqlite3 *db, int N); 8377 8378/* 8379** CAPI3REF: Checkpoint a database 8380** METHOD: sqlite3 8381** 8382** ^(The sqlite3_wal_checkpoint(D,X) is equivalent to 8383** [sqlite3_wal_checkpoint_v2](D,X,[SQLITE_CHECKPOINT_PASSIVE],0,0).)^ 8384** 8385** In brief, sqlite3_wal_checkpoint(D,X) causes the content in the 8386** [write-ahead log] for database X on [database connection] D to be 8387** transferred into the database file and for the write-ahead log to 8388** be reset. See the [checkpointing] documentation for addition 8389** information. 8390** 8391** This interface used to be the only way to cause a checkpoint to 8392** occur. But then the newer and more powerful [sqlite3_wal_checkpoint_v2()] 8393** interface was added. This interface is retained for backwards 8394** compatibility and as a convenience for applications that need to manually 8395** start a callback but which do not need the full power (and corresponding 8396** complication) of [sqlite3_wal_checkpoint_v2()]. 8397*/ 8398int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb); 8399 8400/* 8401** CAPI3REF: Checkpoint a database 8402** METHOD: sqlite3 8403** 8404** ^(The sqlite3_wal_checkpoint_v2(D,X,M,L,C) interface runs a checkpoint 8405** operation on database X of [database connection] D in mode M. Status 8406** information is written back into integers pointed to by L and C.)^ 8407** ^(The M parameter must be a valid [checkpoint mode]:)^ 8408** 8409** <dl> 8410** <dt>SQLITE_CHECKPOINT_PASSIVE<dd> 8411** ^Checkpoint as many frames as possible without waiting for any database 8412** readers or writers to finish, then sync the database file if all frames 8413** in the log were checkpointed. ^The [busy-handler callback] 8414** is never invoked in the SQLITE_CHECKPOINT_PASSIVE mode. 8415** ^On the other hand, passive mode might leave the checkpoint unfinished 8416** if there are concurrent readers or writers. 8417** 8418** <dt>SQLITE_CHECKPOINT_FULL<dd> 8419** ^This mode blocks (it invokes the 8420** [sqlite3_busy_handler|busy-handler callback]) until there is no 8421** database writer and all readers are reading from the most recent database 8422** snapshot. ^It then checkpoints all frames in the log file and syncs the 8423** database file. ^This mode blocks new database writers while it is pending, 8424** but new database readers are allowed to continue unimpeded. 8425** 8426** <dt>SQLITE_CHECKPOINT_RESTART<dd> 8427** ^This mode works the same way as SQLITE_CHECKPOINT_FULL with the addition 8428** that after checkpointing the log file it blocks (calls the 8429** [busy-handler callback]) 8430** until all readers are reading from the database file only. ^This ensures 8431** that the next writer will restart the log file from the beginning. 8432** ^Like SQLITE_CHECKPOINT_FULL, this mode blocks new 8433** database writer attempts while it is pending, but does not impede readers. 8434** 8435** <dt>SQLITE_CHECKPOINT_TRUNCATE<dd> 8436** ^This mode works the same way as SQLITE_CHECKPOINT_RESTART with the 8437** addition that it also truncates the log file to zero bytes just prior 8438** to a successful return. 8439** </dl> 8440** 8441** ^If pnLog is not NULL, then *pnLog is set to the total number of frames in 8442** the log file or to -1 if the checkpoint could not run because 8443** of an error or because the database is not in [WAL mode]. ^If pnCkpt is not 8444** NULL,then *pnCkpt is set to the total number of checkpointed frames in the 8445** log file (including any that were already checkpointed before the function 8446** was called) or to -1 if the checkpoint could not run due to an error or 8447** because the database is not in WAL mode. ^Note that upon successful 8448** completion of an SQLITE_CHECKPOINT_TRUNCATE, the log file will have been 8449** truncated to zero bytes and so both *pnLog and *pnCkpt will be set to zero. 8450** 8451** ^All calls obtain an exclusive "checkpoint" lock on the database file. ^If 8452** any other process is running a checkpoint operation at the same time, the 8453** lock cannot be obtained and SQLITE_BUSY is returned. ^Even if there is a 8454** busy-handler configured, it will not be invoked in this case. 8455** 8456** ^The SQLITE_CHECKPOINT_FULL, RESTART and TRUNCATE modes also obtain the 8457** exclusive "writer" lock on the database file. ^If the writer lock cannot be 8458** obtained immediately, and a busy-handler is configured, it is invoked and 8459** the writer lock retried until either the busy-handler returns 0 or the lock 8460** is successfully obtained. ^The busy-handler is also invoked while waiting for 8461** database readers as described above. ^If the busy-handler returns 0 before 8462** the writer lock is obtained or while waiting for database readers, the 8463** checkpoint operation proceeds from that point in the same way as 8464** SQLITE_CHECKPOINT_PASSIVE - checkpointing as many frames as possible 8465** without blocking any further. ^SQLITE_BUSY is returned in this case. 8466** 8467** ^If parameter zDb is NULL or points to a zero length string, then the 8468** specified operation is attempted on all WAL databases [attached] to 8469** [database connection] db. In this case the 8470** values written to output parameters *pnLog and *pnCkpt are undefined. ^If 8471** an SQLITE_BUSY error is encountered when processing one or more of the 8472** attached WAL databases, the operation is still attempted on any remaining 8473** attached databases and SQLITE_BUSY is returned at the end. ^If any other 8474** error occurs while processing an attached database, processing is abandoned 8475** and the error code is returned to the caller immediately. ^If no error 8476** (SQLITE_BUSY or otherwise) is encountered while processing the attached 8477** databases, SQLITE_OK is returned. 8478** 8479** ^If database zDb is the name of an attached database that is not in WAL 8480** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. ^If 8481** zDb is not NULL (or a zero length string) and is not the name of any 8482** attached database, SQLITE_ERROR is returned to the caller. 8483** 8484** ^Unless it returns SQLITE_MISUSE, 8485** the sqlite3_wal_checkpoint_v2() interface 8486** sets the error information that is queried by 8487** [sqlite3_errcode()] and [sqlite3_errmsg()]. 8488** 8489** ^The [PRAGMA wal_checkpoint] command can be used to invoke this interface 8490** from SQL. 8491*/ 8492int sqlite3_wal_checkpoint_v2( 8493 sqlite3 *db, /* Database handle */ 8494 const char *zDb, /* Name of attached database (or NULL) */ 8495 int eMode, /* SQLITE_CHECKPOINT_* value */ 8496 int *pnLog, /* OUT: Size of WAL log in frames */ 8497 int *pnCkpt /* OUT: Total number of frames checkpointed */ 8498); 8499 8500/* 8501** CAPI3REF: Checkpoint Mode Values 8502** KEYWORDS: {checkpoint mode} 8503** 8504** These constants define all valid values for the "checkpoint mode" passed 8505** as the third parameter to the [sqlite3_wal_checkpoint_v2()] interface. 8506** See the [sqlite3_wal_checkpoint_v2()] documentation for details on the 8507** meaning of each of these checkpoint modes. 8508*/ 8509#define SQLITE_CHECKPOINT_PASSIVE 0 /* Do as much as possible w/o blocking */ 8510#define SQLITE_CHECKPOINT_FULL 1 /* Wait for writers, then checkpoint */ 8511#define SQLITE_CHECKPOINT_RESTART 2 /* Like FULL but wait for for readers */ 8512#define SQLITE_CHECKPOINT_TRUNCATE 3 /* Like RESTART but also truncate WAL */ 8513 8514/* 8515** CAPI3REF: Virtual Table Interface Configuration 8516** 8517** This function may be called by either the [xConnect] or [xCreate] method 8518** of a [virtual table] implementation to configure 8519** various facets of the virtual table interface. 8520** 8521** If this interface is invoked outside the context of an xConnect or 8522** xCreate virtual table method then the behavior is undefined. 8523** 8524** At present, there is only one option that may be configured using 8525** this function. (See [SQLITE_VTAB_CONSTRAINT_SUPPORT].) Further options 8526** may be added in the future. 8527*/ 8528int sqlite3_vtab_config(sqlite3*, int op, ...); 8529 8530/* 8531** CAPI3REF: Virtual Table Configuration Options 8532** 8533** These macros define the various options to the 8534** [sqlite3_vtab_config()] interface that [virtual table] implementations 8535** can use to customize and optimize their behavior. 8536** 8537** <dl> 8538** <dt>SQLITE_VTAB_CONSTRAINT_SUPPORT 8539** <dd>Calls of the form 8540** [sqlite3_vtab_config](db,SQLITE_VTAB_CONSTRAINT_SUPPORT,X) are supported, 8541** where X is an integer. If X is zero, then the [virtual table] whose 8542** [xCreate] or [xConnect] method invoked [sqlite3_vtab_config()] does not 8543** support constraints. In this configuration (which is the default) if 8544** a call to the [xUpdate] method returns [SQLITE_CONSTRAINT], then the entire 8545** statement is rolled back as if [ON CONFLICT | OR ABORT] had been 8546** specified as part of the users SQL statement, regardless of the actual 8547** ON CONFLICT mode specified. 8548** 8549** If X is non-zero, then the virtual table implementation guarantees 8550** that if [xUpdate] returns [SQLITE_CONSTRAINT], it will do so before 8551** any modifications to internal or persistent data structures have been made. 8552** If the [ON CONFLICT] mode is ABORT, FAIL, IGNORE or ROLLBACK, SQLite 8553** is able to roll back a statement or database transaction, and abandon 8554** or continue processing the current SQL statement as appropriate. 8555** If the ON CONFLICT mode is REPLACE and the [xUpdate] method returns 8556** [SQLITE_CONSTRAINT], SQLite handles this as if the ON CONFLICT mode 8557** had been ABORT. 8558** 8559** Virtual table implementations that are required to handle OR REPLACE 8560** must do so within the [xUpdate] method. If a call to the 8561** [sqlite3_vtab_on_conflict()] function indicates that the current ON 8562** CONFLICT policy is REPLACE, the virtual table implementation should 8563** silently replace the appropriate rows within the xUpdate callback and 8564** return SQLITE_OK. Or, if this is not possible, it may return 8565** SQLITE_CONSTRAINT, in which case SQLite falls back to OR ABORT 8566** constraint handling. 8567** </dl> 8568*/ 8569#define SQLITE_VTAB_CONSTRAINT_SUPPORT 1 8570 8571/* 8572** CAPI3REF: Determine The Virtual Table Conflict Policy 8573** 8574** This function may only be called from within a call to the [xUpdate] method 8575** of a [virtual table] implementation for an INSERT or UPDATE operation. ^The 8576** value returned is one of [SQLITE_ROLLBACK], [SQLITE_IGNORE], [SQLITE_FAIL], 8577** [SQLITE_ABORT], or [SQLITE_REPLACE], according to the [ON CONFLICT] mode 8578** of the SQL statement that triggered the call to the [xUpdate] method of the 8579** [virtual table]. 8580*/ 8581int sqlite3_vtab_on_conflict(sqlite3 *); 8582 8583/* 8584** CAPI3REF: Determine If Virtual Table Column Access Is For UPDATE 8585** 8586** If the sqlite3_vtab_nochange(X) routine is called within the [xColumn] 8587** method of a [virtual table], then it returns true if and only if the 8588** column is being fetched as part of an UPDATE operation during which the 8589** column value will not change. Applications might use this to substitute 8590** a return value that is less expensive to compute and that the corresponding 8591** [xUpdate] method understands as a "no-change" value. 8592** 8593** If the [xColumn] method calls sqlite3_vtab_nochange() and finds that 8594** the column is not changed by the UPDATE statement, then the xColumn 8595** method can optionally return without setting a result, without calling 8596** any of the [sqlite3_result_int|sqlite3_result_xxxxx() interfaces]. 8597** In that case, [sqlite3_value_nochange(X)] will return true for the 8598** same column in the [xUpdate] method. 8599*/ 8600int sqlite3_vtab_nochange(sqlite3_context*); 8601 8602/* 8603** CAPI3REF: Determine The Collation For a Virtual Table Constraint 8604** 8605** This function may only be called from within a call to the [xBestIndex] 8606** method of a [virtual table]. 8607** 8608** The first argument must be the sqlite3_index_info object that is the 8609** first parameter to the xBestIndex() method. The second argument must be 8610** an index into the aConstraint[] array belonging to the sqlite3_index_info 8611** structure passed to xBestIndex. This function returns a pointer to a buffer 8612** containing the name of the collation sequence for the corresponding 8613** constraint. 8614*/ 8615SQLITE_EXPERIMENTAL const char *sqlite3_vtab_collation(sqlite3_index_info*,int); 8616 8617/* 8618** CAPI3REF: Conflict resolution modes 8619** KEYWORDS: {conflict resolution mode} 8620** 8621** These constants are returned by [sqlite3_vtab_on_conflict()] to 8622** inform a [virtual table] implementation what the [ON CONFLICT] mode 8623** is for the SQL statement being evaluated. 8624** 8625** Note that the [SQLITE_IGNORE] constant is also used as a potential 8626** return value from the [sqlite3_set_authorizer()] callback and that 8627** [SQLITE_ABORT] is also a [result code]. 8628*/ 8629#define SQLITE_ROLLBACK 1 8630/* #define SQLITE_IGNORE 2 // Also used by sqlite3_authorizer() callback */ 8631#define SQLITE_FAIL 3 8632/* #define SQLITE_ABORT 4 // Also an error code */ 8633#define SQLITE_REPLACE 5 8634 8635/* 8636** CAPI3REF: Prepared Statement Scan Status Opcodes 8637** KEYWORDS: {scanstatus options} 8638** 8639** The following constants can be used for the T parameter to the 8640** [sqlite3_stmt_scanstatus(S,X,T,V)] interface. Each constant designates a 8641** different metric for sqlite3_stmt_scanstatus() to return. 8642** 8643** When the value returned to V is a string, space to hold that string is 8644** managed by the prepared statement S and will be automatically freed when 8645** S is finalized. 8646** 8647** <dl> 8648** [[SQLITE_SCANSTAT_NLOOP]] <dt>SQLITE_SCANSTAT_NLOOP</dt> 8649** <dd>^The [sqlite3_int64] variable pointed to by the T parameter will be 8650** set to the total number of times that the X-th loop has run.</dd> 8651** 8652** [[SQLITE_SCANSTAT_NVISIT]] <dt>SQLITE_SCANSTAT_NVISIT</dt> 8653** <dd>^The [sqlite3_int64] variable pointed to by the T parameter will be set 8654** to the total number of rows examined by all iterations of the X-th loop.</dd> 8655** 8656** [[SQLITE_SCANSTAT_EST]] <dt>SQLITE_SCANSTAT_EST</dt> 8657** <dd>^The "double" variable pointed to by the T parameter will be set to the 8658** query planner's estimate for the average number of rows output from each 8659** iteration of the X-th loop. If the query planner's estimates was accurate, 8660** then this value will approximate the quotient NVISIT/NLOOP and the 8661** product of this value for all prior loops with the same SELECTID will 8662** be the NLOOP value for the current loop. 8663** 8664** [[SQLITE_SCANSTAT_NAME]] <dt>SQLITE_SCANSTAT_NAME</dt> 8665** <dd>^The "const char *" variable pointed to by the T parameter will be set 8666** to a zero-terminated UTF-8 string containing the name of the index or table 8667** used for the X-th loop. 8668** 8669** [[SQLITE_SCANSTAT_EXPLAIN]] <dt>SQLITE_SCANSTAT_EXPLAIN</dt> 8670** <dd>^The "const char *" variable pointed to by the T parameter will be set 8671** to a zero-terminated UTF-8 string containing the [EXPLAIN QUERY PLAN] 8672** description for the X-th loop. 8673** 8674** [[SQLITE_SCANSTAT_SELECTID]] <dt>SQLITE_SCANSTAT_SELECT</dt> 8675** <dd>^The "int" variable pointed to by the T parameter will be set to the 8676** "select-id" for the X-th loop. The select-id identifies which query or 8677** subquery the loop is part of. The main query has a select-id of zero. 8678** The select-id is the same value as is output in the first column 8679** of an [EXPLAIN QUERY PLAN] query. 8680** </dl> 8681*/ 8682#define SQLITE_SCANSTAT_NLOOP 0 8683#define SQLITE_SCANSTAT_NVISIT 1 8684#define SQLITE_SCANSTAT_EST 2 8685#define SQLITE_SCANSTAT_NAME 3 8686#define SQLITE_SCANSTAT_EXPLAIN 4 8687#define SQLITE_SCANSTAT_SELECTID 5 8688 8689/* 8690** CAPI3REF: Prepared Statement Scan Status 8691** METHOD: sqlite3_stmt 8692** 8693** This interface returns information about the predicted and measured 8694** performance for pStmt. Advanced applications can use this 8695** interface to compare the predicted and the measured performance and 8696** issue warnings and/or rerun [ANALYZE] if discrepancies are found. 8697** 8698** Since this interface is expected to be rarely used, it is only 8699** available if SQLite is compiled using the [SQLITE_ENABLE_STMT_SCANSTATUS] 8700** compile-time option. 8701** 8702** The "iScanStatusOp" parameter determines which status information to return. 8703** The "iScanStatusOp" must be one of the [scanstatus options] or the behavior 8704** of this interface is undefined. 8705** ^The requested measurement is written into a variable pointed to by 8706** the "pOut" parameter. 8707** Parameter "idx" identifies the specific loop to retrieve statistics for. 8708** Loops are numbered starting from zero. ^If idx is out of range - less than 8709** zero or greater than or equal to the total number of loops used to implement 8710** the statement - a non-zero value is returned and the variable that pOut 8711** points to is unchanged. 8712** 8713** ^Statistics might not be available for all loops in all statements. ^In cases 8714** where there exist loops with no available statistics, this function behaves 8715** as if the loop did not exist - it returns non-zero and leave the variable 8716** that pOut points to unchanged. 8717** 8718** See also: [sqlite3_stmt_scanstatus_reset()] 8719*/ 8720int sqlite3_stmt_scanstatus( 8721 sqlite3_stmt *pStmt, /* Prepared statement for which info desired */ 8722 int idx, /* Index of loop to report on */ 8723 int iScanStatusOp, /* Information desired. SQLITE_SCANSTAT_* */ 8724 void *pOut /* Result written here */ 8725); 8726 8727/* 8728** CAPI3REF: Zero Scan-Status Counters 8729** METHOD: sqlite3_stmt 8730** 8731** ^Zero all [sqlite3_stmt_scanstatus()] related event counters. 8732** 8733** This API is only available if the library is built with pre-processor 8734** symbol [SQLITE_ENABLE_STMT_SCANSTATUS] defined. 8735*/ 8736void sqlite3_stmt_scanstatus_reset(sqlite3_stmt*); 8737 8738/* 8739** CAPI3REF: Flush caches to disk mid-transaction 8740** 8741** ^If a write-transaction is open on [database connection] D when the 8742** [sqlite3_db_cacheflush(D)] interface invoked, any dirty 8743** pages in the pager-cache that are not currently in use are written out 8744** to disk. A dirty page may be in use if a database cursor created by an 8745** active SQL statement is reading from it, or if it is page 1 of a database 8746** file (page 1 is always "in use"). ^The [sqlite3_db_cacheflush(D)] 8747** interface flushes caches for all schemas - "main", "temp", and 8748** any [attached] databases. 8749** 8750** ^If this function needs to obtain extra database locks before dirty pages 8751** can be flushed to disk, it does so. ^If those locks cannot be obtained 8752** immediately and there is a busy-handler callback configured, it is invoked 8753** in the usual manner. ^If the required lock still cannot be obtained, then 8754** the database is skipped and an attempt made to flush any dirty pages 8755** belonging to the next (if any) database. ^If any databases are skipped 8756** because locks cannot be obtained, but no other error occurs, this 8757** function returns SQLITE_BUSY. 8758** 8759** ^If any other error occurs while flushing dirty pages to disk (for 8760** example an IO error or out-of-memory condition), then processing is 8761** abandoned and an SQLite [error code] is returned to the caller immediately. 8762** 8763** ^Otherwise, if no error occurs, [sqlite3_db_cacheflush()] returns SQLITE_OK. 8764** 8765** ^This function does not set the database handle error code or message 8766** returned by the [sqlite3_errcode()] and [sqlite3_errmsg()] functions. 8767*/ 8768int sqlite3_db_cacheflush(sqlite3*); 8769 8770/* 8771** CAPI3REF: The pre-update hook. 8772** 8773** ^These interfaces are only available if SQLite is compiled using the 8774** [SQLITE_ENABLE_PREUPDATE_HOOK] compile-time option. 8775** 8776** ^The [sqlite3_preupdate_hook()] interface registers a callback function 8777** that is invoked prior to each [INSERT], [UPDATE], and [DELETE] operation 8778** on a database table. 8779** ^At most one preupdate hook may be registered at a time on a single 8780** [database connection]; each call to [sqlite3_preupdate_hook()] overrides 8781** the previous setting. 8782** ^The preupdate hook is disabled by invoking [sqlite3_preupdate_hook()] 8783** with a NULL pointer as the second parameter. 8784** ^The third parameter to [sqlite3_preupdate_hook()] is passed through as 8785** the first parameter to callbacks. 8786** 8787** ^The preupdate hook only fires for changes to real database tables; the 8788** preupdate hook is not invoked for changes to [virtual tables] or to 8789** system tables like sqlite_master or sqlite_stat1. 8790** 8791** ^The second parameter to the preupdate callback is a pointer to 8792** the [database connection] that registered the preupdate hook. 8793** ^The third parameter to the preupdate callback is one of the constants 8794** [SQLITE_INSERT], [SQLITE_DELETE], or [SQLITE_UPDATE] to identify the 8795** kind of update operation that is about to occur. 8796** ^(The fourth parameter to the preupdate callback is the name of the 8797** database within the database connection that is being modified. This 8798** will be "main" for the main database or "temp" for TEMP tables or 8799** the name given after the AS keyword in the [ATTACH] statement for attached 8800** databases.)^ 8801** ^The fifth parameter to the preupdate callback is the name of the 8802** table that is being modified. 8803** 8804** For an UPDATE or DELETE operation on a [rowid table], the sixth 8805** parameter passed to the preupdate callback is the initial [rowid] of the 8806** row being modified or deleted. For an INSERT operation on a rowid table, 8807** or any operation on a WITHOUT ROWID table, the value of the sixth 8808** parameter is undefined. For an INSERT or UPDATE on a rowid table the 8809** seventh parameter is the final rowid value of the row being inserted 8810** or updated. The value of the seventh parameter passed to the callback 8811** function is not defined for operations on WITHOUT ROWID tables, or for 8812** INSERT operations on rowid tables. 8813** 8814** The [sqlite3_preupdate_old()], [sqlite3_preupdate_new()], 8815** [sqlite3_preupdate_count()], and [sqlite3_preupdate_depth()] interfaces 8816** provide additional information about a preupdate event. These routines 8817** may only be called from within a preupdate callback. Invoking any of 8818** these routines from outside of a preupdate callback or with a 8819** [database connection] pointer that is different from the one supplied 8820** to the preupdate callback results in undefined and probably undesirable 8821** behavior. 8822** 8823** ^The [sqlite3_preupdate_count(D)] interface returns the number of columns 8824** in the row that is being inserted, updated, or deleted. 8825** 8826** ^The [sqlite3_preupdate_old(D,N,P)] interface writes into P a pointer to 8827** a [protected sqlite3_value] that contains the value of the Nth column of 8828** the table row before it is updated. The N parameter must be between 0 8829** and one less than the number of columns or the behavior will be 8830** undefined. This must only be used within SQLITE_UPDATE and SQLITE_DELETE 8831** preupdate callbacks; if it is used by an SQLITE_INSERT callback then the 8832** behavior is undefined. The [sqlite3_value] that P points to 8833** will be destroyed when the preupdate callback returns. 8834** 8835** ^The [sqlite3_preupdate_new(D,N,P)] interface writes into P a pointer to 8836** a [protected sqlite3_value] that contains the value of the Nth column of 8837** the table row after it is updated. The N parameter must be between 0 8838** and one less than the number of columns or the behavior will be 8839** undefined. This must only be used within SQLITE_INSERT and SQLITE_UPDATE 8840** preupdate callbacks; if it is used by an SQLITE_DELETE callback then the 8841** behavior is undefined. The [sqlite3_value] that P points to 8842** will be destroyed when the preupdate callback returns. 8843** 8844** ^The [sqlite3_preupdate_depth(D)] interface returns 0 if the preupdate 8845** callback was invoked as a result of a direct insert, update, or delete 8846** operation; or 1 for inserts, updates, or deletes invoked by top-level 8847** triggers; or 2 for changes resulting from triggers called by top-level 8848** triggers; and so forth. 8849** 8850** See also: [sqlite3_update_hook()] 8851*/ 8852#if defined(SQLITE_ENABLE_PREUPDATE_HOOK) 8853void *sqlite3_preupdate_hook( 8854 sqlite3 *db, 8855 void(*xPreUpdate)( 8856 void *pCtx, /* Copy of third arg to preupdate_hook() */ 8857 sqlite3 *db, /* Database handle */ 8858 int op, /* SQLITE_UPDATE, DELETE or INSERT */ 8859 char const *zDb, /* Database name */ 8860 char const *zName, /* Table name */ 8861 sqlite3_int64 iKey1, /* Rowid of row about to be deleted/updated */ 8862 sqlite3_int64 iKey2 /* New rowid value (for a rowid UPDATE) */ 8863 ), 8864 void* 8865); 8866int sqlite3_preupdate_old(sqlite3 *, int, sqlite3_value **); 8867int sqlite3_preupdate_count(sqlite3 *); 8868int sqlite3_preupdate_depth(sqlite3 *); 8869int sqlite3_preupdate_new(sqlite3 *, int, sqlite3_value **); 8870#endif 8871 8872/* 8873** CAPI3REF: Low-level system error code 8874** 8875** ^Attempt to return the underlying operating system error code or error 8876** number that caused the most recent I/O error or failure to open a file. 8877** The return value is OS-dependent. For example, on unix systems, after 8878** [sqlite3_open_v2()] returns [SQLITE_CANTOPEN], this interface could be 8879** called to get back the underlying "errno" that caused the problem, such 8880** as ENOSPC, EAUTH, EISDIR, and so forth. 8881*/ 8882int sqlite3_system_errno(sqlite3*); 8883 8884/* 8885** CAPI3REF: Database Snapshot 8886** KEYWORDS: {snapshot} {sqlite3_snapshot} 8887** EXPERIMENTAL 8888** 8889** An instance of the snapshot object records the state of a [WAL mode] 8890** database for some specific point in history. 8891** 8892** In [WAL mode], multiple [database connections] that are open on the 8893** same database file can each be reading a different historical version 8894** of the database file. When a [database connection] begins a read 8895** transaction, that connection sees an unchanging copy of the database 8896** as it existed for the point in time when the transaction first started. 8897** Subsequent changes to the database from other connections are not seen 8898** by the reader until a new read transaction is started. 8899** 8900** The sqlite3_snapshot object records state information about an historical 8901** version of the database file so that it is possible to later open a new read 8902** transaction that sees that historical version of the database rather than 8903** the most recent version. 8904** 8905** The constructor for this object is [sqlite3_snapshot_get()]. The 8906** [sqlite3_snapshot_open()] method causes a fresh read transaction to refer 8907** to an historical snapshot (if possible). The destructor for 8908** sqlite3_snapshot objects is [sqlite3_snapshot_free()]. 8909*/ 8910typedef struct sqlite3_snapshot { 8911 unsigned char hidden[48]; 8912} sqlite3_snapshot; 8913 8914/* 8915** CAPI3REF: Record A Database Snapshot 8916** EXPERIMENTAL 8917** 8918** ^The [sqlite3_snapshot_get(D,S,P)] interface attempts to make a 8919** new [sqlite3_snapshot] object that records the current state of 8920** schema S in database connection D. ^On success, the 8921** [sqlite3_snapshot_get(D,S,P)] interface writes a pointer to the newly 8922** created [sqlite3_snapshot] object into *P and returns SQLITE_OK. 8923** If there is not already a read-transaction open on schema S when 8924** this function is called, one is opened automatically. 8925** 8926** The following must be true for this function to succeed. If any of 8927** the following statements are false when sqlite3_snapshot_get() is 8928** called, SQLITE_ERROR is returned. The final value of *P is undefined 8929** in this case. 8930** 8931** <ul> 8932** <li> The database handle must be in [autocommit mode]. 8933** 8934** <li> Schema S of [database connection] D must be a [WAL mode] database. 8935** 8936** <li> There must not be a write transaction open on schema S of database 8937** connection D. 8938** 8939** <li> One or more transactions must have been written to the current wal 8940** file since it was created on disk (by any connection). This means 8941** that a snapshot cannot be taken on a wal mode database with no wal 8942** file immediately after it is first opened. At least one transaction 8943** must be written to it first. 8944** </ul> 8945** 8946** This function may also return SQLITE_NOMEM. If it is called with the 8947** database handle in autocommit mode but fails for some other reason, 8948** whether or not a read transaction is opened on schema S is undefined. 8949** 8950** The [sqlite3_snapshot] object returned from a successful call to 8951** [sqlite3_snapshot_get()] must be freed using [sqlite3_snapshot_free()] 8952** to avoid a memory leak. 8953** 8954** The [sqlite3_snapshot_get()] interface is only available when the 8955** SQLITE_ENABLE_SNAPSHOT compile-time option is used. 8956*/ 8957SQLITE_EXPERIMENTAL int sqlite3_snapshot_get( 8958 sqlite3 *db, 8959 const char *zSchema, 8960 sqlite3_snapshot **ppSnapshot 8961); 8962 8963/* 8964** CAPI3REF: Start a read transaction on an historical snapshot 8965** EXPERIMENTAL 8966** 8967** ^The [sqlite3_snapshot_open(D,S,P)] interface starts a 8968** read transaction for schema S of 8969** [database connection] D such that the read transaction 8970** refers to historical [snapshot] P, rather than the most 8971** recent change to the database. 8972** ^The [sqlite3_snapshot_open()] interface returns SQLITE_OK on success 8973** or an appropriate [error code] if it fails. 8974** 8975** ^In order to succeed, a call to [sqlite3_snapshot_open(D,S,P)] must be 8976** the first operation following the [BEGIN] that takes the schema S 8977** out of [autocommit mode]. 8978** ^In other words, schema S must not currently be in 8979** a transaction for [sqlite3_snapshot_open(D,S,P)] to work, but the 8980** database connection D must be out of [autocommit mode]. 8981** ^A [snapshot] will fail to open if it has been overwritten by a 8982** [checkpoint]. 8983** ^(A call to [sqlite3_snapshot_open(D,S,P)] will fail if the 8984** database connection D does not know that the database file for 8985** schema S is in [WAL mode]. A database connection might not know 8986** that the database file is in [WAL mode] if there has been no prior 8987** I/O on that database connection, or if the database entered [WAL mode] 8988** after the most recent I/O on the database connection.)^ 8989** (Hint: Run "[PRAGMA application_id]" against a newly opened 8990** database connection in order to make it ready to use snapshots.) 8991** 8992** The [sqlite3_snapshot_open()] interface is only available when the 8993** SQLITE_ENABLE_SNAPSHOT compile-time option is used. 8994*/ 8995SQLITE_EXPERIMENTAL int sqlite3_snapshot_open( 8996 sqlite3 *db, 8997 const char *zSchema, 8998 sqlite3_snapshot *pSnapshot 8999); 9000 9001/* 9002** CAPI3REF: Destroy a snapshot 9003** EXPERIMENTAL 9004** 9005** ^The [sqlite3_snapshot_free(P)] interface destroys [sqlite3_snapshot] P. 9006** The application must eventually free every [sqlite3_snapshot] object 9007** using this routine to avoid a memory leak. 9008** 9009** The [sqlite3_snapshot_free()] interface is only available when the 9010** SQLITE_ENABLE_SNAPSHOT compile-time option is used. 9011*/ 9012SQLITE_EXPERIMENTAL void sqlite3_snapshot_free(sqlite3_snapshot*); 9013 9014/* 9015** CAPI3REF: Compare the ages of two snapshot handles. 9016** EXPERIMENTAL 9017** 9018** The sqlite3_snapshot_cmp(P1, P2) interface is used to compare the ages 9019** of two valid snapshot handles. 9020** 9021** If the two snapshot handles are not associated with the same database 9022** file, the result of the comparison is undefined. 9023** 9024** Additionally, the result of the comparison is only valid if both of the 9025** snapshot handles were obtained by calling sqlite3_snapshot_get() since the 9026** last time the wal file was deleted. The wal file is deleted when the 9027** database is changed back to rollback mode or when the number of database 9028** clients drops to zero. If either snapshot handle was obtained before the 9029** wal file was last deleted, the value returned by this function 9030** is undefined. 9031** 9032** Otherwise, this API returns a negative value if P1 refers to an older 9033** snapshot than P2, zero if the two handles refer to the same database 9034** snapshot, and a positive value if P1 is a newer snapshot than P2. 9035*/ 9036SQLITE_EXPERIMENTAL int sqlite3_snapshot_cmp( 9037 sqlite3_snapshot *p1, 9038 sqlite3_snapshot *p2 9039); 9040 9041/* 9042** CAPI3REF: Recover snapshots from a wal file 9043** EXPERIMENTAL 9044** 9045** If all connections disconnect from a database file but do not perform 9046** a checkpoint, the existing wal file is opened along with the database 9047** file the next time the database is opened. At this point it is only 9048** possible to successfully call sqlite3_snapshot_open() to open the most 9049** recent snapshot of the database (the one at the head of the wal file), 9050** even though the wal file may contain other valid snapshots for which 9051** clients have sqlite3_snapshot handles. 9052** 9053** This function attempts to scan the wal file associated with database zDb 9054** of database handle db and make all valid snapshots available to 9055** sqlite3_snapshot_open(). It is an error if there is already a read 9056** transaction open on the database, or if the database is not a wal mode 9057** database. 9058** 9059** SQLITE_OK is returned if successful, or an SQLite error code otherwise. 9060*/ 9061SQLITE_EXPERIMENTAL int sqlite3_snapshot_recover(sqlite3 *db, const char *zDb); 9062 9063/* 9064** CAPI3REF: Serialize a database 9065** 9066** The sqlite3_serialize(D,S,P,F) interface returns a pointer to memory 9067** that is a serialization of the S database on [database connection] D. 9068** If P is not a NULL pointer, then the size of the database in bytes 9069** is written into *P. 9070** 9071** For an ordinary on-disk database file, the serialization is just a 9072** copy of the disk file. For an in-memory database or a "TEMP" database, 9073** the serialization is the same sequence of bytes which would be written 9074** to disk if that database where backed up to disk. 9075** 9076** The usual case is that sqlite3_serialize() copies the serialization of 9077** the database into memory obtained from [sqlite3_malloc64()] and returns 9078** a pointer to that memory. The caller is responsible for freeing the 9079** returned value to avoid a memory leak. However, if the F argument 9080** contains the SQLITE_SERIALIZE_NOCOPY bit, then no memory allocations 9081** are made, and the sqlite3_serialize() function will return a pointer 9082** to the contiguous memory representation of the database that SQLite 9083** is currently using for that database, or NULL if the no such contiguous 9084** memory representation of the database exists. A contiguous memory 9085** representation of the database will usually only exist if there has 9086** been a prior call to [sqlite3_deserialize(D,S,...)] with the same 9087** values of D and S. 9088** The size of the database is written into *P even if the 9089** SQLITE_SERIALIZE_NOCOPY bit is set but no contiguous copy 9090** of the database exists. 9091** 9092** A call to sqlite3_serialize(D,S,P,F) might return NULL even if the 9093** SQLITE_SERIALIZE_NOCOPY bit is omitted from argument F if a memory 9094** allocation error occurs. 9095** 9096** This interface is only available if SQLite is compiled with the 9097** [SQLITE_ENABLE_DESERIALIZE] option. 9098*/ 9099unsigned char *sqlite3_serialize( 9100 sqlite3 *db, /* The database connection */ 9101 const char *zSchema, /* Which DB to serialize. ex: "main", "temp", ... */ 9102 sqlite3_int64 *piSize, /* Write size of the DB here, if not NULL */ 9103 unsigned int mFlags /* Zero or more SQLITE_SERIALIZE_* flags */ 9104); 9105 9106/* 9107** CAPI3REF: Flags for sqlite3_serialize 9108** 9109** Zero or more of the following constants can be OR-ed together for 9110** the F argument to [sqlite3_serialize(D,S,P,F)]. 9111** 9112** SQLITE_SERIALIZE_NOCOPY means that [sqlite3_serialize()] will return 9113** a pointer to contiguous in-memory database that it is currently using, 9114** without making a copy of the database. If SQLite is not currently using 9115** a contiguous in-memory database, then this option causes 9116** [sqlite3_serialize()] to return a NULL pointer. SQLite will only be 9117** using a contiguous in-memory database if it has been initialized by a 9118** prior call to [sqlite3_deserialize()]. 9119*/ 9120#define SQLITE_SERIALIZE_NOCOPY 0x001 /* Do no memory allocations */ 9121 9122/* 9123** CAPI3REF: Deserialize a database 9124** 9125** The sqlite3_deserialize(D,S,P,N,M,F) interface causes the 9126** [database connection] D to disconnect from database S and then 9127** reopen S as an in-memory database based on the serialization contained 9128** in P. The serialized database P is N bytes in size. M is the size of 9129** the buffer P, which might be larger than N. If M is larger than N, and 9130** the SQLITE_DESERIALIZE_READONLY bit is not set in F, then SQLite is 9131** permitted to add content to the in-memory database as long as the total 9132** size does not exceed M bytes. 9133** 9134** If the SQLITE_DESERIALIZE_FREEONCLOSE bit is set in F, then SQLite will 9135** invoke sqlite3_free() on the serialization buffer when the database 9136** connection closes. If the SQLITE_DESERIALIZE_RESIZEABLE bit is set, then 9137** SQLite will try to increase the buffer size using sqlite3_realloc64() 9138** if writes on the database cause it to grow larger than M bytes. 9139** 9140** The sqlite3_deserialize() interface will fail with SQLITE_BUSY if the 9141** database is currently in a read transaction or is involved in a backup 9142** operation. 9143** 9144** If sqlite3_deserialize(D,S,P,N,M,F) fails for any reason and if the 9145** SQLITE_DESERIALIZE_FREEONCLOSE bit is set in argument F, then 9146** [sqlite3_free()] is invoked on argument P prior to returning. 9147** 9148** This interface is only available if SQLite is compiled with the 9149** [SQLITE_ENABLE_DESERIALIZE] option. 9150*/ 9151int sqlite3_deserialize( 9152 sqlite3 *db, /* The database connection */ 9153 const char *zSchema, /* Which DB to reopen with the deserialization */ 9154 unsigned char *pData, /* The serialized database content */ 9155 sqlite3_int64 szDb, /* Number bytes in the deserialization */ 9156 sqlite3_int64 szBuf, /* Total size of buffer pData[] */ 9157 unsigned mFlags /* Zero or more SQLITE_DESERIALIZE_* flags */ 9158); 9159 9160/* 9161** CAPI3REF: Flags for sqlite3_deserialize() 9162** 9163** The following are allowed values for 6th argument (the F argument) to 9164** the [sqlite3_deserialize(D,S,P,N,M,F)] interface. 9165** 9166** The SQLITE_DESERIALIZE_FREEONCLOSE means that the database serialization 9167** in the P argument is held in memory obtained from [sqlite3_malloc64()] 9168** and that SQLite should take ownership of this memory and automatically 9169** free it when it has finished using it. Without this flag, the caller 9170** is resposible for freeing any dynamically allocated memory. 9171** 9172** The SQLITE_DESERIALIZE_RESIZEABLE flag means that SQLite is allowed to 9173** grow the size of the database using calls to [sqlite3_realloc64()]. This 9174** flag should only be used if SQLITE_DESERIALIZE_FREEONCLOSE is also used. 9175** Without this flag, the deserialized database cannot increase in size beyond 9176** the number of bytes specified by the M parameter. 9177** 9178** The SQLITE_DESERIALIZE_READONLY flag means that the deserialized database 9179** should be treated as read-only. 9180*/ 9181#define SQLITE_DESERIALIZE_FREEONCLOSE 1 /* Call sqlite3_free() on close */ 9182#define SQLITE_DESERIALIZE_RESIZEABLE 2 /* Resize using sqlite3_realloc64() */ 9183#define SQLITE_DESERIALIZE_READONLY 4 /* Database is read-only */ 9184 9185/* 9186** Undo the hack that converts floating point types to integer for 9187** builds on processors without floating point support. 9188*/ 9189#ifdef SQLITE_OMIT_FLOATING_POINT 9190# undef double 9191#endif 9192 9193#ifdef __cplusplus 9194} /* End of the 'extern "C"' block */ 9195#endif 9196#endif /* SQLITE3_H */ 9197