SQLite

** on how SQLite interfaces are suppose to operate.
**
** The name of this file under configuration management is "sqlite.h.in".
** The makefile makes some minor changes to this file (such as inserting
** the version number) and changes its name to "sqlite3.h" as
** part of the build process.
**
** @(#) $Id: sqlite.h.in,v 1.349 2008/06/22 08:58:50 mihailim Exp $
*/
#ifndef _SQLITE3_H_
#define _SQLITE3_H_
#include <stdarg.h>     /* Needed for the definition of va_list */

/*
** Make sure we can call this stuff from C++.

);

/*
** CAPI3REF: Collation Needed Callbacks {F16700}
**
** To avoid having to register all collation sequences before a database
** can be used, a single callback function may be registered with the
** [database connection] to be called whenever an undefined collation
** sequence is required.
**
** If the function is registered using the sqlite3_collation_needed() API,
** then it is passed the names of undefined collation sequences as strings
** encoded in UTF-8. {F16703} If sqlite3_collation_needed16() is used,
** the names are passed as UTF-16 in machine native byte order.
** A call to either function replaces any existing callback.
**
** When the callback is invoked, the first argument passed is a copy
** of the second argument to sqlite3_collation_needed() or
** sqlite3_collation_needed16().  The second argument is the database
** connection.  The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE],
** or [SQLITE_UTF16LE], indicating the most desirable form of the collation

** sequence function required.  The fourth parameter is the name of the
** required collation sequence.
**
** The callback function should register the desired collation using
** [sqlite3_create_collation()], [sqlite3_create_collation16()], or
** [sqlite3_create_collation_v2()].
**
** INVARIANTS:

**          interface.
**
** {F16706} The name of the requested collating function passed in the
**          4th parameter to the callback is in UTF-8 if the callback
**          was registered using [sqlite3_collation_needed()] and
**          is in UTF-16 native byte order if the callback was
**          registered using [sqlite3_collation_needed16()].


*/
int sqlite3_collation_needed(
  sqlite3*, 
  void*, 
  void(*)(void*,sqlite3*,int eTextRep,const char*)
);
int sqlite3_collation_needed16(

  sqlite3 *db,                   /* Database to be rekeyed */
  const void *pKey, int nKey     /* The new key */
);

/*
** CAPI3REF:  Suspend Execution For A Short Time {F10530}
**
** The sqlite3_sleep() function causes the current thread to suspend execution

** for at least a number of milliseconds specified in its parameter.
**
** If the operating system does not support sleep requests with
** millisecond time resolution, then the time will be rounded up to
** the nearest second. The number of milliseconds of sleep actually
** requested from the operating system is returned.
**
** SQLite implements this interface by calling the xSleep()
** method of the default [sqlite3_vfs] object.
**
** INVARIANTS:
**

/*
** CAPI3REF:  Name Of The Folder Holding Temporary Files {F10310}
**
** If this global variable is made to point to a string which is
** the name of a folder (a.k.a. directory), then all temporary files
** created by SQLite will be placed in that directory.  If this variable
** is a NULL pointer, then SQLite performs a search for an appropriate
** temporary file directory.
**
** It is not safe to modify this variable once a [database connection]
** has been opened.  It is intended that this variable be set once
** as part of process initialization and before any SQLite interface
** routines have been call and remain unchanged thereafter.
*/
SQLITE_EXTERN char *sqlite3_temp_directory;

/*
** CAPI3REF:  Test To See If The Database Is In Auto-Commit Mode {F12930}
**
** The sqlite3_get_autocommit() interface returns non-zero or
** zero if the given database connection is or is not in autocommit mode,
** respectively.   Autocommit mode is on by default.
** Autocommit mode is disabled by a [BEGIN] statement.
** Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK].
**
** If certain kinds of errors occur on a statement within a multi-statement
** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR],
** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the
** transaction might be rolled back automatically.  The only way to
** find out whether SQLite automatically rolled back the transaction after
** an error is to use this function.
**
** INVARIANTS:
**
** {F12931} The [sqlite3_get_autocommit(D)] interface returns non-zero or
**          zero if the [database connection] D is or is not in autocommit
**          mode, respectively.
**
** {F12932} Autocommit mode is on by default.
**
** {F12933} Autocommit mode is disabled by a successful [BEGIN] statement.
**
** {F12934} Autocommit mode is enabled by a successful [COMMIT] or [ROLLBACK]
**          statement.

**
** LIMITATIONS:
***
** {U12936} If another thread changes the autocommit status of the database
**          connection while this routine is running, then the return value
**          is undefined.
*/
int sqlite3_get_autocommit(sqlite3*);

/*
** CAPI3REF:  Find The Database Handle Of A Prepared Statement {F13120}
**
** The sqlite3_db_handle interface returns the [database connection] handle

** to which a [prepared statement] belongs.  The database handle returned by

** sqlite3_db_handle is the same database handle that was the first argument
** to the [sqlite3_prepare_v2()] call (or its variants) that was used to
** create the statement in the first place.
**
** INVARIANTS:
**
** {F13123} The [sqlite3_db_handle(S)] interface returns a pointer
**          to the [database connection] associated with the
**          [prepared statement] S.
*/
sqlite3 *sqlite3_db_handle(sqlite3_stmt*);

/*
** CAPI3REF:  Find the next prepared statement {F13140}
**
** This interface returns a pointer to the next [prepared statement] after
** pStmt associated with the [database connection] pDb.  If pStmt is NULL
** then this interface returns a pointer to the first prepared statement
** associated with the database connection pDb.  If no prepared statement
** satisfies the conditions of this routine, it returns NULL.
**
** INVARIANTS:
**
** {F13143} If D is a [database connection] that holds one or more
**          unfinalized [prepared statements] and S is a NULL pointer,
**          then [sqlite3_next_stmt(D, S)] routine shall return a pointer
**          to one of the prepared statements associated with D.
**
** {F13146} If D is a [database connection] that holds no unfinalized
**          [prepared statements] and S is a NULL pointer, then
**          [sqlite3_next_stmt(D, S)] routine shall return a NULL pointer.

**
** {F13149} If S is a [prepared statement] in the [database connection] D
**          and S is not the last prepared statement in D, then
**          [sqlite3_next_stmt(D, S)] routine shall return a pointer
**          to the next prepared statement in D after S.
**
** {F13152} If S is the last [prepared statement] in the
**          [database connection] D then the [sqlite3_next_stmt(D, S)]
**          routine shall return a NULL pointer.

*/
sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt);


/*
** CAPI3REF: Commit And Rollback Notification Callbacks {F12950}
**
** The sqlite3_commit_hook() interface registers a callback
** function to be invoked whenever a transaction is committed.
** Any callback set by a previous call to sqlite3_commit_hook()
** for the same database connection is overridden.
** The sqlite3_rollback_hook() interface registers a callback
** function to be invoked whenever a transaction is committed.
** Any callback set by a previous call to sqlite3_commit_hook()
** for the same database connection is overridden.
** The pArg argument is passed through to the callback.
** If the callback on a commit hook function returns non-zero,
** then the commit is converted into a rollback.
**
** If another function was previously registered, its
** pArg value is returned.  Otherwise NULL is returned.
**
** Registering a NULL function disables the callback.
**
** For the purposes of this API, a transaction is said to have been
** rolled back if an explicit "ROLLBACK" statement is executed, or
** an error or constraint causes an implicit rollback to occur.
** The rollback callback is not invoked if a transaction is
** automatically rolled back because the database connection is closed.
** The rollback callback is not invoked if a transaction is
** rolled back because a commit callback returned non-zero.
** <todo> Check on this </todo>
**
** These are experimental interfaces and are subject to change.
**
** INVARIANTS:
**
** {F12951} The [sqlite3_commit_hook(D,F,P)] interface registers the
**          callback function F to be invoked with argument P whenever
**          a transaction commits on the [database connection] D.
**
** {F12952} The [sqlite3_commit_hook(D,F,P)] interface returns the P argument
**          from the previous call with the same [database connection] D,
**          or NULL on the first call for a particular database connection D.

**
** {F12953} Each call to [sqlite3_commit_hook()] overwrites the callback
**          registered by prior calls.
**
** {F12954} If the F argument to [sqlite3_commit_hook(D,F,P)] is NULL
**          then the commit hook callback is canceled and no callback
**          is invoked when a transaction commits.
**
** {F12955} If the commit callback returns non-zero then the commit is
**          converted into a rollback.
**
** {F12961} The [sqlite3_rollback_hook(D,F,P)] interface registers the
**          callback function F to be invoked with argument P whenever
**          a transaction rolls back on the [database connection] D.
**
** {F12962} The [sqlite3_rollback_hook(D,F,P)] interface returns the P
**          argument from the previous call with the same
**          [database connection] D, or NULL on the first call
**          for a particular database connection D.
**
** {F12963} Each call to [sqlite3_rollback_hook()] overwrites the callback
**          registered by prior calls.
**
** {F12964} If the F argument to [sqlite3_rollback_hook(D,F,P)] is NULL
**          then the rollback hook callback is canceled and no callback
**          is invoked when a transaction rolls back.
*/
void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*);
void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*);

/*
** CAPI3REF: Data Change Notification Callbacks {F12970}
**
** The sqlite3_update_hook() interface registers a callback function
** with the [database connection] identified by the first argument
** to be invoked whenever a row is updated, inserted or deleted.
** Any callback set by a previous call to this function
** for the same database connection is overridden.
**
** The second argument is a pointer to the function to invoke when a
** row is updated, inserted or deleted.
** The first argument to the callback is a copy of the third argument
** to sqlite3_update_hook().
** The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE],

** or [SQLITE_UPDATE], depending on the operation that caused the callback
** to be invoked.
** The third and fourth arguments to the callback contain pointers to the
** database and table name containing the affected row.
** The final callback parameter is the rowid of the row. In the case of

** an update, this is the rowid after the update takes place.

**
** The update hook is not invoked when internal system tables are
** modified (i.e. sqlite_master and sqlite_sequence).
**
** If another function was previously registered, its pArg value
** is returned.  Otherwise NULL is returned.
**
** INVARIANTS:
**
** {F12971} The [sqlite3_update_hook(D,F,P)] interface causes the callback
**          function F to be invoked with first parameter P whenever
**          a table row is modified, inserted, or deleted on
**          the [database connection] D.
**
** {F12973} The [sqlite3_update_hook(D,F,P)] interface returns the value
**          of P for the previous call on the same [database connection] D,
**          or NULL for the first call.
**
** {F12975} If the update hook callback F in [sqlite3_update_hook(D,F,P)]
**          is NULL then the no update callbacks are made.
**
** {F12977} Each call to [sqlite3_update_hook(D,F,P)] overrides prior calls
**          to the same interface on the same [database connection] D.
**
** {F12979} The update hook callback is not invoked when internal system
**          tables such as sqlite_master and sqlite_sequence are modified.
**
** {F12981} The second parameter to the update callback
**          is one of [SQLITE_INSERT], [SQLITE_DELETE] or [SQLITE_UPDATE],
**          depending on the operation that caused the callback to be invoked.
**
** {F12983} The third and fourth arguments to the callback contain pointers
**          to zero-terminated UTF-8 strings which are the names of the
**          database and table that is being updated.

);

/*
** CAPI3REF:  Enable Or Disable Shared Pager Cache {F10330}
** KEYWORDS: {shared cache} {shared cache mode}
**
** This routine enables or disables the sharing of the database cache
** and schema data structures between [database connection | connections]
** to the same database. Sharing is enabled if the argument is true
** and disabled if the argument is false.
**
** Cache sharing is enabled and disabled for an entire process. {END}
** This is a change as of SQLite version 3.5.0. In prior versions of SQLite,

** sharing was enabled or disabled for each thread separately.
**
** The cache sharing mode set by this interface effects all subsequent
** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()].
** Existing database connections continue use the sharing mode
** that was in effect at the time they were opened.
**
** Virtual tables cannot be used with a shared cache.  When shared
** cache is enabled, the [sqlite3_create_module()] API used to register
** virtual tables will always return an error.
**
** This routine returns [SQLITE_OK] if shared cache was enabled or disabled
** successfully.  An [error code] is returned otherwise.

**
** Shared cache is disabled by default. But this might change in
** future releases of SQLite.  Applications that care about shared
** cache setting should set it explicitly.
**
** INVARIANTS:
** 

**          than the amount requested.
*/
int sqlite3_release_memory(int);

/*
** CAPI3REF:  Impose A Limit On Heap Size {F17350}
**
** The sqlite3_soft_heap_limit() interface places a "soft" limit
** on the amount of heap memory that may be allocated by SQLite.
** If an internal allocation is requested that would exceed the
** soft heap limit, [sqlite3_release_memory()] is invoked one or
** more times to free up some space before the allocation is performed.

**
** The limit is called "soft", because if [sqlite3_release_memory()]

** cannot free sufficient memory to prevent the limit from being exceeded,
** the memory is allocated anyway and the current operation proceeds.
**
** A negative or zero value for N means that there is no soft heap limit and
** [sqlite3_release_memory()] will only be called when memory is exhausted.
** The default value for the soft heap limit is zero.
**
** SQLite makes a best effort to honor the soft heap limit.  
** But if the soft heap limit cannot be honored, execution will
** continue without error or notification.  This is why the limit is
** called a "soft" limit.  It is advisory only.
**
** Prior to SQLite version 3.5.0, this routine only constrained the memory
** allocated by a single thread - the same thread in which this routine
** runs.  Beginning with SQLite version 3.5.0, the soft heap limit is
** applied to all threads. The value specified for the soft heap limit
** is an upper bound on the total memory allocation for all threads. In

**
** {F16358} Each call to [sqlite3_soft_heap_limit(N)] overrides the
**          values set by all prior calls.
*/
void sqlite3_soft_heap_limit(int);

/*
** CAPI3REF: Extract Metadata About A Column Of A Table {F12850}
**

** This routine returns metadata about a specific column of a specific
** database table accessible using the [database connection] handle
** passed as the first function argument.
**
** The column is identified by the second, third and fourth parameters to
** this function. The second parameter is either the name of the database
** (i.e. "main", "temp" or an attached database) containing the specified
** table or NULL. If it is NULL, then all attached databases are searched
** for the table using the same algorithm used by the database engine to
** resolve unqualified table references.
**
** The third and fourth parameters to this function are the table and column
** name of the desired column, respectively. Neither of these parameters
** may be NULL.
**
** Metadata is returned by writing to the memory locations passed as the 5th
** and subsequent parameters to this function. Any of these arguments may be
** NULL, in which case the corresponding element of metadata is omitted.

** <blockquote>
** <table border="1">
** <tr><th> Parameter <th> Output<br>Type <th>  Description

**
** <tr><td> 5th <td> const char* <td> Data type
** <tr><td> 6th <td> const char* <td> Name of default collation sequence
** <tr><td> 7th <td> int         <td> True if column has a NOT NULL constraint
** <tr><td> 8th <td> int         <td> True if column is part of the PRIMARY KEY
** <tr><td> 9th <td> int         <td> True if column is AUTOINCREMENT
** </table>
** </blockquote>
**
** The memory pointed to by the character pointers returned for the
** declaration type and collation sequence is valid only until the next
** call to any SQLite API function.
**
** If the specified table is actually a view, an [error code] is returned.
**
** If the specified column is "rowid", "oid" or "_rowid_" and an
** INTEGER PRIMARY KEY column has been explicitly declared, then the output
** parameters are set for the explicitly declared column. If there is no
** explicitly declared INTEGER PRIMARY KEY column, then the output
** parameters are set as follows:
**
** <pre>
**     data type: "INTEGER"
**     collation sequence: "BINARY"
**     not null: 0
**     primary key: 1
**     auto increment: 0
** </pre>
**
** This function may load one or more schemas from database files. If an
** error occurs during this process, or if the requested table or column
** cannot be found, an [error code] is returned and an error message left
** in the [database connection] (to be retrieved using sqlite3_errmsg()).
**
** This API is only available if the library was compiled with the
** SQLITE_ENABLE_COLUMN_METADATA C preprocessor symbol defined.
*/
int sqlite3_table_column_metadata(
  sqlite3 *db,                /* Connection handle */
  const char *zDbName,        /* Database name or NULL */
  const char *zTableName,     /* Table name */
  const char *zColumnName,    /* Column name */
  char const **pzDataType,    /* OUTPUT: Declared data type */
  char const **pzCollSeq,     /* OUTPUT: Collation sequence name */
  int *pNotNull,              /* OUTPUT: True if NOT NULL constraint exists */
  int *pPrimaryKey,           /* OUTPUT: True if column part of PK */
  int *pAutoinc               /* OUTPUT: True if column is auto-increment */
);

/*
** CAPI3REF: Load An Extension {F12600}
**
** This interface loads an SQLite extension library from the named file.
**
** INVARIANTS:
**
** {F12601} The sqlite3_load_extension() interface attempts to load an
**          SQLite extension library contained in the file zFile.
**
** {F12602} The entry point is zProc.
**
** {F12603} zProc may be 0, in which case the name of the entry point
**          defaults to "sqlite3_extension_init".
**
** {F12604} The sqlite3_load_extension() interface shall return
**          [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong.
**

** {F12605} If an error occurs and pzErrMsg is not 0, then the
**          sqlite3_load_extension() interface shall attempt to fill
**          *pzErrMsg with error message text stored in memory obtained
**          from [sqlite3_malloc()]. {END} The calling function should free
**          this memory by calling [sqlite3_free()].

** {F12606} Extension loading must be enabled using
**          [sqlite3_enable_load_extension()] prior to calling this API,
**          otherwise an error will be returned.
*/
int sqlite3_load_extension(
  sqlite3 *db,          /* Load the extension into this database connection */
  const char *zFile,    /* Name of the shared library containing extension */
  const char *zProc,    /* Entry point.  Derived from zFile if 0 */
  char **pzErrMsg       /* Put error message here if not 0 */
);

/*
** CAPI3REF: Enable Or Disable Extension Loading {F12620}
**
** So as not to open security holes in older applications that are
** unprepared to deal with extension loading, and as a means of disabling
** extension loading while evaluating user-entered SQL, the following API
** is provided to turn the [sqlite3_load_extension()] mechanism on and off.
**
** Extension loading is off by default. See ticket #1863.
**
** INVARIANTS:
**
** {F12621} Call the sqlite3_enable_load_extension() routine with onoff==1
**          to turn extension loading on and call it with onoff==0 to turn
**          it back off again.
**
** {F12622} Extension loading is off by default.
*/
int sqlite3_enable_load_extension(sqlite3 *db, int onoff);

/*
** CAPI3REF: Make Arrangements To Automatically Load An Extension {F12640}
**





** This API can be invoked at program startup in order to register
** one or more statically linked extensions that will be available
** to all new [database connections].
**


** This interface is experimental and is subject to change or
** removal in future releases of SQLite.
**
** This routine stores a pointer to the extension in an array that is
** obtained from [sqlite3_malloc()].  If you run a memory leak checker
** on your program and it reports a leak because of this array, invoke
** [sqlite3_reset_auto_extension()] prior to shutdown to free the memory.
**
** INVARIANTS:
**
** {F12641} This function registers an extension entry point that is
**          automatically invoked whenever a new [database connection]
**          is opened using [sqlite3_open()], [sqlite3_open16()],
**          or [sqlite3_open_v2()].
**
** {F12642} Duplicate extensions are detected so calling this routine
**          multiple times with the same extension is harmless.
**
** {F12643} This routine stores a pointer to the extension in an array
**          that is obtained from [sqlite3_malloc()].
**
** {F12644} Automatic extensions apply across all threads.
*/
int sqlite3_auto_extension(void *xEntryPoint);


/*
** CAPI3REF: Reset Automatic Extension Loading {F12660}
**
** This function disables all previously registered automatic extensions.

** It undoes the effect of all prior [sqlite3_auto_extension()] calls.



**
** This interface is experimental and is subject to change or
** removal in future releases of SQLite.
**
** INVARIANTS:
**
** {F12661} This function disables all previously registered
**          automatic extensions.
**
** {F12662} This function disabled automatic extensions in all threads.
*/
void sqlite3_reset_auto_extension(void);


/*
****** EXPERIMENTAL - subject to change without notice **************
**
** The interface to the virtual-table mechanism is currently considered
** to be experimental.  The interface might change in incompatible ways.
** If this is a problem for you, do not use the interface at this time.