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sqlite/www/capi3ref.tcl
drh 572d11dc8f Add documentation for the sqlite3_extended_result_codes() API. (CVS 3425) 
FossilOrigin-Name: a6b3f6bed209dc27d36cd4e159159f73266e9911
2006-09-15 16:58:48 +00:00

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set rcsid {$Id: capi3ref.tcl,v 1.45 2006/09/15 16:58:49 drh Exp $}
source common.tcl
header {C/C++ Interface For SQLite Version 3}
puts {
<h2>C/C++ Interface For SQLite Version 3</h2>
}
proc api {name prototype desc {notused x}} {
global apilist specialname
if {$name==""} {
regsub -all {sqlite3_[a-z0-9_]+\(} $prototype \
{[lappend name [string trimright & (]]} x1
subst $x1
} else {
lappend specialname $name
}
lappend apilist [list $name $prototype $desc]
}
api {extended-result-codes} {
#define SQLITE_IOERR_READ
#define SQLITE_IOERR_SHORT_READ
#define SQLITE_IOERR_WRITE
#define SQLITE_IOERR_FSYNC
#define SQLITE_IOERR_DIR_FSYNC
#define SQLITE_IOERR_TRUNCATE
#define SQLITE_IOERR_FSTAT
#define SQLITE_IOERR_UNLOCK
#define SQLITE_IOERR_RDLOCK
...
} {
In its default configuration, SQLite API routines return one of 26 integer
result codes described at result-codes. However, experience has shown that
many of these result codes are too course-grained. They do not provide as
much information about problems as users might like. In an effort to
address this, newer versions of SQLite (version 3.3.8 and later) include
support for additional result codes that provide more detailed information
about errors. The extended result codes are enabled (or disabled) for
each database
connection using the sqlite3_extended_result_codes() API.
Some of the available extended result codes are listed above.
We expect the number of extended result codes will be expand
over time. Software that uses extended result codes should expect
to see new result codes in future releases of SQLite.
The symbolic name for an extended result code always contains a related
primary result code as a prefix. Primary result codes contain a single
"_" character. Extended result codes contain two or more "_" characters.
The numeric value of an extended result code can be converted to its
corresponding primary result code by masking off the lower 8 bytes.
A complete list of available extended result codes and
details about the meaning of the various extended result codes can be
found by consulting the C code, especially the sqlite3.h header
file and its antecedent sqlite.h.in. Additional information
is also available at the SQLite wiki:
http://www.sqlite.org/cvstrac/wiki?p=ExtendedResultCodes
}
api {result-codes} {
#define SQLITE_OK 0 /* Successful result */
#define SQLITE_ERROR 1 /* SQL error or missing database */
#define SQLITE_INTERNAL 2 /* An internal logic error in SQLite */
#define SQLITE_PERM 3 /* Access permission denied */
#define SQLITE_ABORT 4 /* Callback routine requested an abort */
#define SQLITE_BUSY 5 /* The database file is locked */
#define SQLITE_LOCKED 6 /* A table in the database is locked */
#define SQLITE_NOMEM 7 /* A malloc() failed */
#define SQLITE_READONLY 8 /* Attempt to write a readonly database */
#define SQLITE_INTERRUPT 9 /* Operation terminated by sqlite_interrupt() */
#define SQLITE_IOERR 10 /* Some kind of disk I/O error occurred */
#define SQLITE_CORRUPT 11 /* The database disk image is malformed */
#define SQLITE_NOTFOUND 12 /* (Internal Only) Table or record not found */
#define SQLITE_FULL 13 /* Insertion failed because database is full */
#define SQLITE_CANTOPEN 14 /* Unable to open the database file */
#define SQLITE_PROTOCOL 15 /* Database lock protocol error */
#define SQLITE_EMPTY 16 /* (Internal Only) Database table is empty */
#define SQLITE_SCHEMA 17 /* The database schema changed */
#define SQLITE_TOOBIG 18 /* Too much data for one row of a table */
#define SQLITE_CONSTRAINT 19 /* Abort due to constraint violation */
#define SQLITE_MISMATCH 20 /* Data type mismatch */
#define SQLITE_MISUSE 21 /* Library used incorrectly */
#define SQLITE_NOLFS 22 /* Uses OS features not supported on host */
#define SQLITE_AUTH 23 /* Authorization denied */
#define SQLITE_ROW 100 /* sqlite_step() has another row ready */
#define SQLITE_DONE 101 /* sqlite_step() has finished executing */
} {
Many SQLite functions return an integer result code from the set shown
above in order to indicates success or failure.
The result codes above are the only ones returned by SQLite in its
default configuration. However, the sqlite3_extended_result_codes()
API can be used to set a database connectoin to return more detailed
result codes. See the documentation on sqlite3_extended_result_codes()
or extended-result-codes for additional information.
}
api {} {
int sqlite3_extended_result_codes(sqlite3*, int onoff);
} {
This routine enables or disabled extended-result-codes feature.
By default, SQLite API routines return one of only 26 integer
result codes described at result-codes. When extended result codes
are enabled by this routine, the repetoire of result codes can be
much larger and can (hopefully) provide more detailed information
about the cause of an error.
The second argument is a boolean value that turns extended result
codes on and off. Extended result codes are off by default for
backwards compatibility with older versions of SQLite.
}
api {} {
const char *sqlite3_libversion(void);
} {
Return a pointer to a string which contains the version number of
the library. The same string is available in the global
variable named "sqlite3_version". This interface is provided since
windows is unable to access global variables in DLLs.
}
api {} {
void *sqlite3_aggregate_context(sqlite3_context*, int nBytes);
} {
Aggregate functions use this routine to allocate
a structure for storing their state. The first time this routine
is called for a particular aggregate, a new structure of size nBytes
is allocated, zeroed, and returned. On subsequent calls (for the
same aggregate instance) the same buffer is returned. The implementation
of the aggregate can use the returned buffer to accumulate data.
The buffer is freed automatically by SQLite when the query that
invoked the aggregate function terminates.
}
api {} {
int sqlite3_aggregate_count(sqlite3_context*);
} {
This function is deprecated. It continues to exist so as not to
break any legacy code that might happen to use it. But it should not
be used in any new code.
In order to encourage people to not use this function, we are not going
to tell you what it does.
}
api {} {
int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*));
int sqlite3_bind_double(sqlite3_stmt*, int, double);
int sqlite3_bind_int(sqlite3_stmt*, int, int);
int sqlite3_bind_int64(sqlite3_stmt*, int, long long int);
int sqlite3_bind_null(sqlite3_stmt*, int);
int sqlite3_bind_text(sqlite3_stmt*, int, const char*, int n, void(*)(void*));
int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int n, void(*)(void*));
#define SQLITE_STATIC ((void(*)(void *))0)
#define SQLITE_TRANSIENT ((void(*)(void *))-1)
} {
In the SQL strings input to sqlite3_prepare() and sqlite3_prepare16(),
one or more literals can be replace by a parameter "?" or ":AAA" or
"@AAA" or "\$VVV"
where AAA is an alphanumeric identifier and VVV is a variable name according
to the syntax rules of the TCL programming language.
The values of these parameters (also called "host parameter names")
can be set using the sqlite3_bind_*() routines.
The first argument to the sqlite3_bind_*() routines always is a pointer
to the sqlite3_stmt structure returned from sqlite3_prepare(). The second
argument is the index of the parameter to be set. The first parameter has
an index of 1. When the same named parameter is used more than once, second
and subsequent
occurrences have the same index as the first occurrence. The index for
named parameters can be looked up using the
sqlite3_bind_parameter_name() API if desired.
The third argument is the value to bind to the parameter.
In those
routines that have a fourth argument, its value is the number of bytes
in the parameter. To be clear: the value is the number of bytes in the
string, not the number of characters. The number
of bytes does not include the zero-terminator at the end of strings.
If the fourth parameter is negative, the length of the string is
number of bytes up to the first zero terminator.
The fifth argument to sqlite3_bind_blob(), sqlite3_bind_text(), and
sqlite3_bind_text16() is a destructor used to dispose of the BLOB or
text after SQLite has finished with it. If the fifth argument is the
special value SQLITE_STATIC, then the library assumes that the information
is in static, unmanaged space and does not need to be freed. If the
fifth argument has the value SQLITE_TRANSIENT, then SQLite makes its
own private copy of the data immediately, before the sqlite3_bind_*()
routine returns.
The sqlite3_bind_*() routines must be called after
sqlite3_prepare() or sqlite3_reset() and before sqlite3_step().
Bindings are not cleared by the sqlite3_reset() routine.
Unbound parameters are interpreted as NULL.
These routines return SQLITE_OK on success or an error code if
anything goes wrong. SQLITE_RANGE is returned if the parameter
index is out of range. SQLITE_NOMEM is returned if malloc fails.
SQLITE_MISUSE is returned if these routines are called on a virtual
machine that is the wrong state or which has already been finalized.
}
api {} {
int sqlite3_bind_parameter_count(sqlite3_stmt*);
} {
Return the number of parameters in the precompiled statement given as
the argument.
}
api {} {
const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int n);
} {
Return the name of the n-th parameter in the precompiled statement.
Parameters of the form ":AAA" or "@AAA" or "\$VVV" have a name which is the
string ":AAA" or "\$VVV". In other words, the initial ":" or "$" or "@"
is included as part of the name.
Parameters of the form "?" have no name.
The first bound parameter has an index of 1, not 0.
If the value n is out of range or if the n-th parameter is nameless,
then NULL is returned. The returned string is always in the
UTF-8 encoding.
}
api {} {
int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName);
} {
Return the index of the parameter with the given name.
The name must match exactly.
If there is no parameter with the given name, return 0.
The string zName is always in the UTF-8 encoding.
}
api {} {
int sqlite3_busy_handler(sqlite3*, int(*)(void*,int), void*);
} {
This routine identifies a callback function that might be invoked
whenever an attempt is made to open a database table
that another thread or process has locked.
If the busy callback is NULL, then SQLITE_BUSY is returned immediately
upon encountering the lock.
If the busy callback is not NULL, then the
callback will be invoked with two arguments. The
second argument is the number of prior calls to the busy callback
for the same lock. If the
busy callback returns 0, then no additional attempts are made to
access the database and SQLITE_BUSY is returned.
If the callback returns non-zero, then another attempt is made to open the
database for reading and the cycle repeats.
The presence of a busy handler does not guarantee that
it will be invoked when there is lock contention.
If SQLite determines that invoking the busy handler could result in
a deadlock, it will return SQLITE_BUSY instead.
Consider a scenario where one process is holding a read lock that
it is trying to promote to a reserved lock and
a second process is holding a reserved lock that it is trying
to promote to an exclusive lock. The first process cannot proceed
because it is blocked by the second and the second process cannot
proceed because it is blocked by the first. If both processes
invoke the busy handlers, neither will make any progress. Therefore,
SQLite returns SQLITE_BUSY for the first process, hoping that this
will induce the first process to release its read lock and allow
the second process to proceed.
The default busy callback is NULL.
Sqlite is re-entrant, so the busy handler may start a new query.
(It is not clear why anyone would every want to do this, but it
is allowed, in theory.) But the busy handler may not close the
database. Closing the database from a busy handler will delete
data structures out from under the executing query and will
probably result in a coredump.
There can only be a single busy handler defined for each database
connection. Setting a new busy handler clears any previous one.
Note that calling sqlite3_busy_timeout() will also set or clear
the busy handler.
}
api {} {
int sqlite3_busy_timeout(sqlite3*, int ms);
} {
This routine sets a busy handler that sleeps for a while when a
table is locked. The handler will sleep multiple times until
at least "ms" milliseconds of sleeping have been done. After
"ms" milliseconds of sleeping, the handler returns 0 which
causes sqlite3_exec() to return SQLITE_BUSY.
Calling this routine with an argument less than or equal to zero
turns off all busy handlers.
There can only be a single busy handler for a particular database
connection. If another busy handler was defined
(using sqlite3_busy_handler()) prior to calling
this routine, that other busy handler is cleared.
}
api {} {
int sqlite3_changes(sqlite3*);
} {
This function returns the number of database rows that were changed
(or inserted or deleted) by the most recently completed
INSERT, UPDATE, or DELETE
statement. Only changes that are directly specified by the INSERT,
UPDATE, or DELETE statement are counted. Auxiliary changes caused by
triggers are not counted. Use the sqlite3_total_changes() function
to find the total number of changes including changes caused by triggers.
Within the body of a trigger, the sqlite3_changes() function does work
to report the number of rows that were changed for the most recently
completed INSERT, UPDATE, or DELETE statement within the trigger body.
SQLite implements the command "DELETE FROM table" without a WHERE clause
by dropping and recreating the table. (This is much faster than going
through and deleting individual elements from the table.) Because of
this optimization, the change count for "DELETE FROM table" will be
zero regardless of the number of elements that were originally in the
table. To get an accurate count of the number of rows deleted, use
"DELETE FROM table WHERE 1" instead.
}
api {} {
int sqlite3_total_changes(sqlite3*);
} {
This function returns the total number of database rows that have
be modified, inserted, or deleted since the database connection was
created using sqlite3_open(). All changes are counted, including
changes by triggers and changes to TEMP and auxiliary databases.
Except, changes to the SQLITE_MASTER table (caused by statements
such as CREATE TABLE) are not counted. Nor are changes counted when
an entire table is deleted using DROP TABLE.
See also the sqlite3_changes() API.
SQLite implements the command "DELETE FROM table" without a WHERE clause
by dropping and recreating the table. (This is much faster than going
through and deleting individual elements form the table.) Because of
this optimization, the change count for "DELETE FROM table" will be
zero regardless of the number of elements that were originally in the
table. To get an accurate count of the number of rows deleted, use
"DELETE FROM table WHERE 1" instead.
}
api {} {
int sqlite3_close(sqlite3*);
} {
Call this function with a pointer to a structure that was previously
returned from sqlite3_open() or sqlite3_open16()
and the corresponding database will by closed.
SQLITE_OK is returned if the close is successful. If there are
prepared statements that have not been finalized, then SQLITE_BUSY
is returned. SQLITE_ERROR might be returned if the argument is not
a valid connection pointer returned by sqlite3_open() or if the connection
pointer has been closed previously.
}
api {} {
const void *sqlite3_column_blob(sqlite3_stmt*, int iCol);
int sqlite3_column_bytes(sqlite3_stmt*, int iCol);
int sqlite3_column_bytes16(sqlite3_stmt*, int iCol);
double sqlite3_column_double(sqlite3_stmt*, int iCol);
int sqlite3_column_int(sqlite3_stmt*, int iCol);
long long int sqlite3_column_int64(sqlite3_stmt*, int iCol);
const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol);
const void *sqlite3_column_text16(sqlite3_stmt*, int iCol);
int sqlite3_column_type(sqlite3_stmt*, int iCol);
#define SQLITE_INTEGER 1
#define SQLITE_FLOAT 2
#define SQLITE_TEXT 3
#define SQLITE_BLOB 4
#define SQLITE_NULL 5
} {
These routines return information about the information
in a single column of the current result row of a query. In every
case the first argument is a pointer to the SQL statement that is being
executed (the sqlite_stmt* that was returned from sqlite3_prepare()) and
the second argument is the index of the column for which information
should be returned. iCol is zero-indexed. The left-most column has an
index of 0.
If the SQL statement is not currently point to a valid row, or if the
the column index is out of range, the result is undefined.
If the result is a BLOB then the sqlite3_column_bytes() routine returns
the number of bytes in that BLOB. No type conversions occur.
If the result is a string (or a number since a number can be converted
into a string) then sqlite3_column_bytes() converts
the value into a UTF-8 string and returns
the number of bytes in the resulting string. The value returned does
not include the \\000 terminator at the end of the string. The
sqlite3_column_bytes16() routine converts the value into a UTF-16
encoding and returns the number of bytes (not characters) in the
resulting string. The \\u0000 terminator is not included in this count.
These routines attempt to convert the value where appropriate. For
example, if the internal representation is FLOAT and a text result
is requested, sprintf() is used internally to do the conversion
automatically. The following table details the conversions that
are applied:
<blockquote>
<table border="1">
<tr><th>Internal Type</th><th>Requested Type</th><th>Conversion</th></tr>
<tr><td> NULL </td><td> INTEGER</td><td>Result is 0</td></tr>
<tr><td> NULL </td><td> FLOAT </td><td> Result is 0.0</td></tr>
<tr><td> NULL </td><td> TEXT </td><td> Result is NULL pointer</td></tr>
<tr><td> NULL </td><td> BLOB </td><td> Result is NULL pointer</td></tr>
<tr><td> INTEGER </td><td> FLOAT </td><td> Convert from integer to float</td></tr>
<tr><td> INTEGER </td><td> TEXT </td><td> ASCII rendering of the integer</td></tr>
<tr><td> INTEGER </td><td> BLOB </td><td> Same as for INTEGER->TEXT</td></tr>
<tr><td> FLOAT </td><td> INTEGER</td><td>Convert from float to integer</td></tr>
<tr><td> FLOAT </td><td> TEXT </td><td> ASCII rendering of the float</td></tr>
<tr><td> FLOAT </td><td> BLOB </td><td> Same as FLOAT->TEXT</td></tr>
<tr><td> TEXT </td><td> INTEGER</td><td>Use atoi()</td></tr>
<tr><td> TEXT </td><td> FLOAT </td><td> Use atof()</td></tr>
<tr><td> TEXT </td><td> BLOB </td><td> No change</td></tr>
<tr><td> BLOB </td><td> INTEGER</td><td>Convert to TEXT then use atoi()</td></tr>
<tr><td> BLOB </td><td> FLOAT </td><td> Convert to TEXT then use atof()</td></tr>
<tr><td> BLOB </td><td> TEXT </td><td> Add a \\000 terminator if needed</td></tr>
</table>
</blockquote>
}
api {} {
int sqlite3_column_count(sqlite3_stmt *pStmt);
} {
Return the number of columns in the result set returned by the prepared
SQL statement. This routine returns 0 if pStmt is an SQL statement
that does not return data (for example an UPDATE).
See also sqlite3_data_count().
}
api {} {
const char *sqlite3_column_decltype(sqlite3_stmt *, int i);
const void *sqlite3_column_decltype16(sqlite3_stmt*,int);
} {
The first argument is a prepared SQL statement. If this statement
is a SELECT statement, the Nth column of the returned result set
of the SELECT is a table column then the declared type of the table
column is returned. If the Nth column of the result set is not a table
column, then a NULL pointer is returned. The returned string is
UTF-8 encoded for sqlite3_column_decltype() and UTF-16 encoded
for sqlite3_column_decltype16(). For example, in the database schema:
<blockquote><pre>
CREATE TABLE t1(c1 INTEGER);
</pre></blockquote>
And the following statement compiled:
<blockquote><pre>
SELECT c1 + 1, c1 FROM t1;
</pre></blockquote>
Then this routine would return the string "INTEGER" for the second
result column (i==1), and a NULL pointer for the first result column
(i==0).
If the following statements were compiled then this routine would
return "INTEGER" for the first (only) result column.
<blockquote><pre>
SELECT (SELECT c1) FROM t1;
SELECT (SELECT c1 FROM t1);
SELECT c1 FROM (SELECT c1 FROM t1);
SELECT * FROM (SELECT c1 FROM t1);
SELECT * FROM (SELECT * FROM t1);
</pre></blockquote>
}
api {} {
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 colums is auto-increment */
);
} {
This routine is used to obtain meta information about a specific column of a
specific database table accessible using the 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 as the database engine uses 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.
Meta information 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 meta
information is ommitted.
<pre>
Parameter Output Type Description
-----------------------------------
5th const char* Declared data type
6th const char* Name of the columns default collation sequence
7th int True if the column has a NOT NULL constraint
8th int True if the column is part of the PRIMARY KEY
9th int True if the column is AUTOINCREMENT
</pre>
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.
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 SQLITE error code is returned and an error message
left in the database handle (to be retrieved using sqlite3_errmsg()).
Specifying an SQL view instead of a table as the third argument is also
considered an error.
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 IPK column, then the data-type is "INTEGER", the
collation sequence "BINARY" and the primary-key flag is set. Both
the not-null and auto-increment flags are clear.
This API is only available if the library was compiled with the
SQLITE_ENABLE_COLUMN_METADATA preprocessor symbol defined.
}
api {} {
const char *sqlite3_column_database_name(sqlite3_stmt *pStmt, int N);
const void *sqlite3_column_database_name16(sqlite3_stmt *pStmt, int N);
} {
If the Nth column returned by statement pStmt is a column reference,
these functions may be used to access the name of the database (either
"main", "temp" or the name of an attached database) that contains
the column. If the Nth column is not a column reference, NULL is
returned.
See the description of function sqlite3_column_decltype() for a
description of exactly which expressions are considered column references.
Function sqlite3_column_database_name() returns a pointer to a UTF-8
encoded string. sqlite3_column_database_name16() returns a pointer
to a UTF-16 encoded string.
}
api {} {
const char *sqlite3_column_origin_name(sqlite3_stmt *pStmt, int N);
const void *sqlite3_column_origin_name16(sqlite3_stmt *pStmt, int N);
} {
If the Nth column returned by statement pStmt is a column reference,
these functions may be used to access the schema name of the referenced
column in the database schema. If the Nth column is not a column
reference, NULL is returned.
See the description of function sqlite3_column_decltype() for a
description of exactly which expressions are considered column references.
Function sqlite3_column_origin_name() returns a pointer to a UTF-8
encoded string. sqlite3_column_origin_name16() returns a pointer
to a UTF-16 encoded string.
}
api {} {
const char *sqlite3_column_table_name(sqlite3_stmt *pStmt, int N);
const void *sqlite3_column_table_name16(sqlite3_stmt *pStmt, int N);
} {
If the Nth column returned by statement pStmt is a column reference,
these functions may be used to access the name of the table that
contains the column. If the Nth column is not a column reference,
NULL is returned.
See the description of function sqlite3_column_decltype() for a
description of exactly which expressions are considered column references.
Function sqlite3_column_table_name() returns a pointer to a UTF-8
encoded string. sqlite3_column_table_name16() returns a pointer
to a UTF-16 encoded string.
}
api {} {
const char *sqlite3_column_name(sqlite3_stmt*,int);
const void *sqlite3_column_name16(sqlite3_stmt*,int);
} {
The first argument is a prepared SQL statement. This function returns
the column heading for the Nth column of that statement, where N is the
second function argument. The string returned is UTF-8 for
sqlite3_column_name() and UTF-16 for sqlite3_column_name16().
}
api {} {
void *sqlite3_commit_hook(sqlite3*, int(*xCallback)(void*), void *pArg);
} {
<i>Experimental</i>
Register a callback function to be invoked whenever a new transaction
is committed. The pArg argument is passed through to the callback.
callback. If the callback 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. Only a single commit
hook callback can be registered at a time.
}
api {} {
int sqlite3_complete(const char *sql);
int sqlite3_complete16(const void *sql);
} {
These functions return true if the given input string comprises
one or more complete SQL statements.
The argument must be a nul-terminated UTF-8 string for sqlite3_complete()
and a nul-terminated UTF-16 string for sqlite3_complete16().
These routines do not check to see if the SQL statement is well-formed.
They only check to see that the statement is terminated by a semicolon
that is not part of a string literal and is not inside
the body of a trigger.
} {}
api {} {
int sqlite3_create_collation(
sqlite3*,
const char *zName,
int pref16,
void*,
int(*xCompare)(void*,int,const void*,int,const void*)
);
int sqlite3_create_collation16(
sqlite3*,
const char *zName,
int pref16,
void*,
int(*xCompare)(void*,int,const void*,int,const void*)
);
#define SQLITE_UTF8 1
#define SQLITE_UTF16BE 2
#define SQLITE_UTF16LE 3
#define SQLITE_UTF16 4
} {
These two functions are used to add new collation sequences to the
sqlite3 handle specified as the first argument.
The name of the new collation sequence is specified as a UTF-8 string
for sqlite3_create_collation() and a UTF-16 string for
sqlite3_create_collation16(). In both cases the name is passed as the
second function argument.
The third argument must be one of the constants SQLITE_UTF8,
SQLITE_UTF16LE or SQLITE_UTF16BE, indicating that the user-supplied
routine expects to be passed pointers to strings encoded using UTF-8,
UTF-16 little-endian or UTF-16 big-endian respectively. The
SQLITE_UTF16 constant indicates that text strings are expected in
UTF-16 in the native byte order of the host machine.
A pointer to the user supplied routine must be passed as the fifth
argument. If it is NULL, this is the same as deleting the collation
sequence (so that SQLite cannot call it anymore). Each time the user
supplied function is invoked, it is passed a copy of the void* passed as
the fourth argument to sqlite3_create_collation() or
sqlite3_create_collation16() as its first argument.
The remaining arguments to the user-supplied routine are two strings,
each represented by a [length, data] pair and encoded in the encoding
that was passed as the third argument when the collation sequence was
registered. The user routine should return negative, zero or positive if
the first string is less than, equal to, or greater than the second
string. i.e. (STRING1 - STRING2).
}
api {} {
int sqlite3_collation_needed(
sqlite3*,
void*,
void(*)(void*,sqlite3*,int eTextRep,const char*)
);
int sqlite3_collation_needed16(
sqlite3*,
void*,
void(*)(void*,sqlite3*,int eTextRep,const void*)
);
} {
To avoid having to register all collation sequences before a database
can be used, a single callback function may be registered with the
database handle 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. 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 user-function 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
handle. 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 argument is the name of the
required collation sequence.
The collation sequence is returned to SQLite by a collation-needed
callback using the sqlite3_create_collation() or
sqlite3_create_collation16() APIs, described above.
}
api {} {
int sqlite3_create_function(
sqlite3 *,
const char *zFunctionName,
int nArg,
int eTextRep,
void *pUserData,
void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
void (*xStep)(sqlite3_context*,int,sqlite3_value**),
void (*xFinal)(sqlite3_context*)
);
int sqlite3_create_function16(
sqlite3*,
const void *zFunctionName,
int nArg,
int eTextRep,
void *pUserData,
void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
void (*xStep)(sqlite3_context*,int,sqlite3_value**),
void (*xFinal)(sqlite3_context*)
);
#define SQLITE_UTF8 1
#define SQLITE_UTF16 2
#define SQLITE_UTF16BE 3
#define SQLITE_UTF16LE 4
#define SQLITE_ANY 5
} {
These two functions are used to add SQL functions or aggregates
implemented in C. The
only difference between these two routines is that the second argument, the
name of the (scalar) function or aggregate, is encoded in UTF-8 for
sqlite3_create_function() and UTF-16 for sqlite3_create_function16().
The length of the name is limited to 255 bytes, exclusive of the
zero-terminator. Note that the name length limit is in bytes, not
characters. Any attempt to create a function with a longer name
will result in an SQLITE_ERROR error.
The first argument is the database handle that the new function or
aggregate is to be added to. If a single program uses more than one
database handle internally, then user functions or aggregates must
be added individually to each database handle with which they will be
used.
The third argument is the number of arguments that the function or
aggregate takes. If this argument is -1 then the function or
aggregate may take any number of arguments. The maximum number
of arguments to a new SQL function is 127. A number larger than
127 for the third argument results in an SQLITE_ERROR error.
The fourth argument, eTextRep, specifies what type of text arguments
this function prefers to receive. Any function should be able to work
work with UTF-8, UTF-16le, or UTF-16be. But some implementations may be
more efficient with one representation than another. Users are allowed
to specify separate implementations for the same function which are called
depending on the text representation of the arguments. The the implementation
which provides the best match is used. If there is only a single
implementation which does not care what text representation is used,
then the fourth argument should be SQLITE_ANY.
The fifth argument is an arbitrary pointer. The function implementations
can gain access to this pointer using the sqlite_user_data() API.
The sixth, seventh and eighth argumens, xFunc, xStep and xFinal, are
pointers to user implemented C functions that implement the user
function or aggregate. A scalar function requires an implementation of
the xFunc callback only, NULL pointers should be passed as the xStep
and xFinal arguments. An aggregate function requires an implementation
of xStep and xFinal, and NULL should be passed for xFunc. To delete an
existing user function or aggregate, pass NULL for all three function
callbacks. Specifying an inconstant set of callback values, such as an
xFunc and an xFinal, or an xStep but no xFinal, results in an SQLITE_ERROR
return.
}
api {} {
int sqlite3_data_count(sqlite3_stmt *pStmt);
} {
Return the number of values in the current row of the result set.
After a call to sqlite3_step() that returns SQLITE_ROW, this routine
will return the same value as the sqlite3_column_count() function.
After sqlite3_step() has returned an SQLITE_DONE, SQLITE_BUSY or
error code, or before sqlite3_step() has been called on a
prepared SQL statement, this routine returns zero.
}
api {} {
int sqlite3_errcode(sqlite3 *db);
} {
Return the error code for the most recent failed sqlite3_* API call associated
with sqlite3 handle 'db'. If a prior API call failed but the most recent
API call succeeded, the return value from this routine is undefined.
Calls to many sqlite3_* functions set the error code and string returned
by sqlite3_errcode(), sqlite3_errmsg() and sqlite3_errmsg16()
(overwriting the previous values). Note that calls to sqlite3_errcode(),
sqlite3_errmsg() and sqlite3_errmsg16() themselves do not affect the
results of future invocations. Calls to API routines that do not return
an error code (examples: sqlite3_data_count() or sqlite3_mprintf()) do
not change the error code returned by this routine.
Assuming no other intervening sqlite3_* API calls are made, the error
code returned by this function is associated with the same error as
the strings returned by sqlite3_errmsg() and sqlite3_errmsg16().
} {}
api {} {
const char *sqlite3_errmsg(sqlite3*);
const void *sqlite3_errmsg16(sqlite3*);
} {
Return a pointer to a UTF-8 encoded string (sqlite3_errmsg)
or a UTF-16 encoded string (sqlite3_errmsg16) describing in English the
error condition for the most recent sqlite3_* API call. The returned
string is always terminated by an 0x00 byte.
The string "not an error" is returned when the most recent API call was
successful.
}
api {} {
int sqlite3_exec(
sqlite3*, /* An open database */
const char *sql, /* SQL to be executed */
sqlite_callback, /* Callback function */
void *, /* 1st argument to callback function */
char **errmsg /* Error msg written here */
);
} {
A function to executes one or more statements of SQL.
If one or more of the SQL statements are queries, then
the callback function specified by the 3rd argument is
invoked once for each row of the query result. This callback
should normally return 0. If the callback returns a non-zero
value then the query is aborted, all subsequent SQL statements
are skipped and the sqlite3_exec() function returns the SQLITE_ABORT.
The 4th argument is an arbitrary pointer that is passed
to the callback function as its first argument.
The 2nd argument to the callback function is the number of
columns in the query result. The 3rd argument to the callback
is an array of strings holding the values for each column.
The 4th argument to the callback is an array of strings holding
the names of each column.
The callback function may be NULL, even for queries. A NULL
callback is not an error. It just means that no callback
will be invoked.
If an error occurs while parsing or evaluating the SQL (but
not while executing the callback) then an appropriate error
message is written into memory obtained from malloc() and
*errmsg is made to point to that message. The calling function
is responsible for freeing the memory that holds the error
message. Use sqlite3_free() for this. If errmsg==NULL,
then no error message is ever written.
The return value is is SQLITE_OK if there are no errors and
some other return code if there is an error. The particular
return value depends on the type of error.
If the query could not be executed because a database file is
locked or busy, then this function returns SQLITE_BUSY. (This
behavior can be modified somewhat using the sqlite3_busy_handler()
and sqlite3_busy_timeout() functions.)
} {}
api {} {
int sqlite3_finalize(sqlite3_stmt *pStmt);
} {
The sqlite3_finalize() function is called to delete a prepared
SQL statement obtained by a previous call to sqlite3_prepare()
or sqlite3_prepare16(). If the statement was executed successfully, or
not executed at all, then SQLITE_OK is returned. If execution of the
statement failed then an error code is returned.
All prepared statements must finalized before sqlite3_close() is
called or else the close will fail with a return code of SQLITE_BUSY.
This routine can be called at any point during the execution of the
virtual machine. If the virtual machine has not completed execution
when this routine is called, that is like encountering an error or
an interrupt. (See sqlite3_interrupt().) Incomplete updates may be
rolled back and transactions canceled, depending on the circumstances,
and the result code returned will be SQLITE_ABORT.
}
api {} {
void *sqlite3_malloc(int);
void *sqlite3_realloc(void*, int);
void sqlite3_free(void*);
} {
These routines provide access to the memory allocator used by SQLite.
Depending on how SQLite has been compiled and the OS-layer backend,
the memory allocator used by SQLite might be the standard system
malloc()/realloc()/free(), or it might be something different. With
certain compile-time flags, SQLite will add wrapper logic around the
memory allocator to add memory leak and buffer overrun detection. The
OS layer might substitute a completely different memory allocator.
Use these APIs to be sure you are always using the correct memory
allocator.
The sqlite3_free() API, not the standard free() from the system library,
should always be used to free the memory buffer returned by
sqlite3_mprintf() or sqlite3_vmprintf() and to free the error message
string returned by sqlite3_exec(). Using free() instead of sqlite3_free()
might accidentally work on some systems and build configurations but
will fail on others.
Compatibility Note: Prior to version 3.4.0, the sqlite3_free API
was prototyped to take a <tt>char*</tt> parameter rather than
<tt>void*</tt>. Like this:
<blockquote><pre>
void sqlite3_free(char*);
</pre></blockquote>
The change to using <tt>void*</tt> might cause warnings when
compiling older code against
newer libraries, but everything should still work correctly.
}
api {} {
int sqlite3_get_table(
sqlite3*, /* An open database */
const char *sql, /* SQL to be executed */
char ***resultp, /* Result written to a char *[] that this points to */
int *nrow, /* Number of result rows written here */
int *ncolumn, /* Number of result columns written here */
char **errmsg /* Error msg written here */
);
void sqlite3_free_table(char **result);
} {
This next routine is really just a wrapper around sqlite3_exec().
Instead of invoking a user-supplied callback for each row of the
result, this routine remembers each row of the result in memory
obtained from malloc(), then returns all of the result after the
query has finished.
As an example, suppose the query result where this table:
<pre>
Name | Age
-----------------------
Alice | 43
Bob | 28
Cindy | 21
</pre>
If the 3rd argument were &azResult then after the function returns
azResult will contain the following data:
<pre>
azResult[0] = "Name";
azResult[1] = "Age";
azResult[2] = "Alice";
azResult[3] = "43";
azResult[4] = "Bob";
azResult[5] = "28";
azResult[6] = "Cindy";
azResult[7] = "21";
</pre>
Notice that there is an extra row of data containing the column
headers. But the *nrow return value is still 3. *ncolumn is
set to 2. In general, the number of values inserted into azResult
will be ((*nrow) + 1)*(*ncolumn).
After the calling function has finished using the result, it should
pass the result data pointer to sqlite3_free_table() in order to
release the memory that was malloc-ed. Because of the way the
malloc() happens, the calling function must not try to call
malloc() directly. Only sqlite3_free_table() is able to release
the memory properly and safely.
The return value of this routine is the same as from sqlite3_exec().
}
api {sqlite3_interrupt} {
void sqlite3_interrupt(sqlite3*);
} {
This function causes any pending database operation to abort and
return at its earliest opportunity. This routine is typically
called in response to a user action such as pressing "Cancel"
or Ctrl-C where the user wants a long query operation to halt
immediately.
} {}
api {} {
long long int sqlite3_last_insert_rowid(sqlite3*);
} {
Each entry in an SQLite table has a unique integer key called the "rowid".
The rowid is always available as an undeclared column
named ROWID, OID, or _ROWID_.
If the table has a column of type INTEGER PRIMARY KEY then that column
is another an alias for the rowid.
This routine
returns the rowid of the most recent INSERT into the database
from the database connection given in the first argument. If
no inserts have ever occurred on this database connection, zero
is returned.
If an INSERT occurs within a trigger, then the rowid of the
inserted row is returned by this routine as long as the trigger
is running. But once the trigger terminates, the value returned
by this routine reverts to the last value inserted before the
trigger fired.
} {}
api {} {
char *sqlite3_mprintf(const char*,...);
char *sqlite3_vmprintf(const char*, va_list);
} {
These routines are variants of the "sprintf()" from the
standard C library. The resulting string is written into memory
obtained from malloc() so that there is never a possibility of buffer
overflow. These routines also implement some additional formatting
options that are useful for constructing SQL statements.
The strings returned by these routines should be freed by calling
sqlite3_free().
All of the usual printf formatting options apply. In addition, there
is a "%q" option. %q works like %s in that it substitutes a null-terminated
string from the argument list. But %q also doubles every '\\'' character.
%q is designed for use inside a string literal. By doubling each '\\''
character it escapes that character and allows it to be inserted into
the string.
For example, so some string variable contains text as follows:
<blockquote><pre>
char *zText = "It's a happy day!";
</pre></blockquote>
One can use this text in an SQL statement as follows:
<blockquote><pre>
sqlite3_exec_printf(db, "INSERT INTO table VALUES('%q')",
callback1, 0, 0, zText);
</pre></blockquote>
Because the %q format string is used, the '\\'' character in zText
is escaped and the SQL generated is as follows:
<blockquote><pre>
INSERT INTO table1 VALUES('It''s a happy day!')
</pre></blockquote>
This is correct. Had we used %s instead of %q, the generated SQL
would have looked like this:
<blockquote><pre>
INSERT INTO table1 VALUES('It's a happy day!');
</pre></blockquote>
This second example is an SQL syntax error. As a general rule you
should always use %q instead of %s when inserting text into a string
literal.
} {}
api {} {
int sqlite3_open(
const char *filename, /* Database filename (UTF-8) */
sqlite3 **ppDb /* OUT: SQLite db handle */
);
int sqlite3_open16(
const void *filename, /* Database filename (UTF-16) */
sqlite3 **ppDb /* OUT: SQLite db handle */
);
} {
Open the sqlite database file "filename". The "filename" is UTF-8
encoded for sqlite3_open() and UTF-16 encoded in the native byte order
for sqlite3_open16(). An sqlite3* handle is returned in *ppDb, even
if an error occurs. If the database is opened (or created) successfully,
then SQLITE_OK is returned. Otherwise an error code is returned. The
sqlite3_errmsg() or sqlite3_errmsg16() routines can be used to obtain
an English language description of the error.
If the database file does not exist, then a new database will be created
as needed.
The encoding for the database will be UTF-8 if sqlite3_open() is called and
UTF-16 if sqlite3_open16 is used.
Whether or not an error occurs when it is opened, resources associated
with the sqlite3* handle should be released by passing it to
sqlite3_close() when it is no longer required.
The returned sqlite3* can only be used in the same thread in which it
was created. It is an error to call sqlite3_open() in one thread then
pass the resulting database handle off to another thread to use. This
restriction is due to goofy design decisions (bugs?) in the way some
threading implementations interact with file locks.
Note to windows users: The encoding used for the filename argument
of sqlite3_open() must be UTF-8, not whatever codepage is currently
defined. Filenames containing international characters must be converted
to UTF-8 prior to passing them into sqlite3_open().
}
api {} {
int sqlite3_prepare(
sqlite3 *db, /* Database handle */
const char *zSql, /* SQL statement, UTF-8 encoded */
int nBytes, /* Length of zSql in bytes. */
sqlite3_stmt **ppStmt, /* OUT: Statement handle */
const char **pzTail /* OUT: Pointer to unused portion of zSql */
);
int sqlite3_prepare16(
sqlite3 *db, /* Database handle */
const void *zSql, /* SQL statement, UTF-16 encoded */
int nBytes, /* Length of zSql in bytes. */
sqlite3_stmt **ppStmt, /* OUT: Statement handle */
const void **pzTail /* OUT: Pointer to unused portion of zSql */
);
} {
To execute an SQL query, it must first be compiled into a byte-code
program using one of the following routines. The only difference between
them is that the second argument, specifying the SQL statement to
compile, is assumed to be encoded in UTF-8 for the sqlite3_prepare()
function and UTF-16 for sqlite3_prepare16().
The first argument "db" is an SQLite database handle. The second
argument "zSql" is the statement to be compiled, encoded as either
UTF-8 or UTF-16 (see above). If the next argument, "nBytes", is less
than zero, then zSql is read up to the first nul terminator. If
"nBytes" is not less than zero, then it is the length of the string zSql
in bytes (not characters).
*pzTail is made to point to the first byte past the end of the first
SQL statement in zSql. This routine only compiles the first statement
in zSql, so *pzTail is left pointing to what remains uncompiled.
*ppStmt is left pointing to a compiled SQL statement that can be
executed using sqlite3_step(). Or if there is an error, *ppStmt may be
set to NULL. If the input text contained no SQL (if the input is and
empty string or a comment) then *ppStmt is set to NULL. The calling
procedure is responsible for deleting this compiled SQL statement
using sqlite3_finalize() after it has finished with it.
On success, SQLITE_OK is returned. Otherwise an error code is returned.
}
api {} {
void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*);
} {
<i>Experimental</i>
This routine configures a callback function - the progress callback - that
is invoked periodically during long running calls to sqlite3_exec(),
sqlite3_step() and sqlite3_get_table().
An example use for this API is to keep
a GUI updated during a large query.
The progress callback is invoked once for every N virtual machine opcodes,
where N is the second argument to this function. The progress callback
itself is identified by the third argument to this function. The fourth
argument to this function is a void pointer passed to the progress callback
function each time it is invoked.
If a call to sqlite3_exec(), sqlite3_step() or sqlite3_get_table() results
in less than N opcodes being executed, then the progress callback is not
invoked.
To remove the progress callback altogether, pass NULL as the third
argument to this function.
If the progress callback returns a result other than 0, then the current
query is immediately terminated and any database changes rolled back. If the
query was part of a larger transaction, then the transaction is not rolled
back and remains active. The sqlite3_exec() call returns SQLITE_ABORT.
}
api {} {
int sqlite3_reset(sqlite3_stmt *pStmt);
} {
The sqlite3_reset() function is called to reset a prepared SQL
statement obtained by a previous call to sqlite3_prepare() or
sqlite3_prepare16() back to it's initial state, ready to be re-executed.
Any SQL statement variables that had values bound to them using
the sqlite3_bind_*() API retain their values.
}
api {} {
void sqlite3_result_blob(sqlite3_context*, const void*, int n, void(*)(void*));
void sqlite3_result_double(sqlite3_context*, double);
void sqlite3_result_error(sqlite3_context*, const char*, int);
void sqlite3_result_error16(sqlite3_context*, const void*, int);
void sqlite3_result_int(sqlite3_context*, int);
void sqlite3_result_int64(sqlite3_context*, long long int);
void sqlite3_result_null(sqlite3_context*);
void sqlite3_result_text(sqlite3_context*, const char*, int n, void(*)(void*));
void sqlite3_result_text16(sqlite3_context*, const void*, int n, void(*)(void*));
void sqlite3_result_text16be(sqlite3_context*, const void*, int n, void(*)(void*));
void sqlite3_result_text16le(sqlite3_context*, const void*, int n, void(*)(void*));
void sqlite3_result_value(sqlite3_context*, sqlite3_value*);
} {
User-defined functions invoke these routines in order to
set their return value. The sqlite3_result_value() routine is used
to return an exact copy of one of the arguments to the function.
The operation of these routines is very similar to the operation of
sqlite3_bind_blob() and its cousins. Refer to the documentation there
for additional information.
}
api {} {
int sqlite3_set_authorizer(
sqlite3*,
int (*xAuth)(void*,int,const char*,const char*,const char*,const char*),
void *pUserData
);
#define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */
#define SQLITE_CREATE_TABLE 2 /* Table Name NULL */
#define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */
#define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */
#define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */
#define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */
#define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */
#define SQLITE_CREATE_VIEW 8 /* View Name NULL */
#define SQLITE_DELETE 9 /* Table Name NULL */
#define SQLITE_DROP_INDEX 10 /* Index Name Table Name */
#define SQLITE_DROP_TABLE 11 /* Table Name NULL */
#define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */
#define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */
#define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */
#define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */
#define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */
#define SQLITE_DROP_VIEW 17 /* View Name NULL */
#define SQLITE_INSERT 18 /* Table Name NULL */
#define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */
#define SQLITE_READ 20 /* Table Name Column Name */
#define SQLITE_SELECT 21 /* NULL NULL */
#define SQLITE_TRANSACTION 22 /* NULL NULL */
#define SQLITE_UPDATE 23 /* Table Name Column Name */
#define SQLITE_ATTACH 24 /* Filename NULL */
#define SQLITE_DETACH 25 /* Database Name NULL */
#define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */
#define SQLITE_REINDEX 27 /* Index Name NULL */
#define SQLITE_ANALYZE 28 /* Table Name NULL */
#define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */
#define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */
#define SQLITE_FUNCTION 31 /* Function Name NULL */
#define SQLITE_DENY 1 /* Abort the SQL statement with an error */
#define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */
} {
This routine registers a callback with the SQLite library. The
callback is invoked by sqlite3_prepare() to authorize various
operations against the database. The callback should
return SQLITE_OK if access is allowed, SQLITE_DENY if the entire
SQL statement should be aborted with an error and SQLITE_IGNORE
if the operation should be treated as a no-op.
Each database connection have at most one authorizer registered
at a time one time. Each call
to sqlite3_set_authorizer() overrides the previous authorizer.
Setting the callback to NULL disables the authorizer.
The second argument to the access authorization function will be one
of the defined constants shown. These values signify what kind of operation
is to be authorized. The 3rd and 4th arguments to the authorization
function will be arguments or NULL depending on which of the
codes is used as the second argument. For example, if the the
2nd argument code is SQLITE_READ then the 3rd argument will be the name
of the table that is being read from and the 4th argument will be the
name of the column that is being read from. Or if the 2nd argument
is SQLITE_FUNCTION then the 3rd argument will be the name of the
function that is being invoked and the 4th argument will be NULL.
The 5th argument is the name
of the database ("main", "temp", etc.) where applicable. The 6th argument
is the name of the inner-most trigger or view that is responsible for
the access attempt or NULL if this access attempt is directly from
input SQL code.
The return value of the authorization function should be one of the
constants SQLITE_OK, SQLITE_DENY, or SQLITE_IGNORE. A return of
SQLITE_OK means that the operation is permitted and that
sqlite3_prepare() can proceed as normal.
A return of SQLITE_DENY means that the sqlite3_prepare()
should fail with an error. A return of SQLITE_IGNORE causes the
sqlite3_prepare() to continue as normal but the requested
operation is silently converted into a no-op. A return of SQLITE_IGNORE
in response to an SQLITE_READ or SQLITE_FUNCTION causes the column
being read or the function being invoked to return a NULL.
The intent of this routine is to allow applications to safely execute
user-entered SQL. An appropriate callback can deny the user-entered
SQL access certain operations (ex: anything that changes the database)
or to deny access to certain tables or columns within the database.
}
api {} {
int sqlite3_step(sqlite3_stmt*);
} {
After an SQL query has been prepared with a call to either
sqlite3_prepare() or sqlite3_prepare16(), then this function must be
called one or more times to execute the statement.
The return value will be either SQLITE_BUSY, SQLITE_DONE,
SQLITE_ROW, SQLITE_ERROR, or SQLITE_MISUSE.
SQLITE_BUSY means that the database engine attempted to open
a locked database and there is no busy callback registered.
Call sqlite3_step() again to retry the open.
SQLITE_DONE means that the statement has finished executing
successfully. sqlite3_step() should not be called again on this virtual
machine without first calling sqlite3_reset() to reset the virtual
machine back to its initial state.
If the SQL statement being executed returns any data, then
SQLITE_ROW is returned each time a new row of data is ready
for processing by the caller. The values may be accessed using
the sqlite3_column_*() functions. sqlite3_step()
is called again to retrieve the next row of data.
SQLITE_ERROR means that a run-time error (such as a constraint
violation) has occurred. sqlite3_step() should not be called again on
the VM. More information may be found by calling sqlite3_errmsg().
A more specific error code (example: SQLITE_INTERRUPT, SQLITE_SCHEMA,
SQLITE_CORRUPT, and so forth) can be obtained by calling
sqlite3_reset() on the prepared statement.
SQLITE_MISUSE means that the this routine was called inappropriately.
Perhaps it was called on a virtual machine that had already been
finalized or on one that had previously returned SQLITE_ERROR or
SQLITE_DONE. Or it could be the case that a database connection
is being used by a different thread than the one it was created it.
<b>Goofy Interface Alert:</b>
The sqlite3_step() API always returns a generic error code,
SQLITE_ERROR, following any error other than SQLITE_BUSY and SQLITE_MISUSE.
You must call sqlite3_reset() (or sqlite3_finalize()) in order to find
the specific error code that better describes the error. We admit that
this is a goofy design. Sqlite3_step() would be much easier to use if
it returned the specific error code directly. But we cannot change that
now without breaking backwards compatibility.
Note that there is never any harm in calling sqlite3_reset() after
getting back an SQLITE_ERROR from sqlite3_step(). Any API that can
be used after an sqlite3_step() can also be used after sqlite3_reset().
You may want to create a simple wrapper around sqlite3_step() to make
this easier. For example:
<blockquote><pre>
int less_goofy_sqlite3_step(sqlite3_stmt *pStatement){
int rc;
rc = sqlite3_step(pStatement);
if( rc==SQLITE_ERROR ){
rc = sqlite3_reset(pStatement);
}
return rc;
}
</pre></blockquote>
Simply substitute the less_goofy_sqlite3_step() call above for
the normal sqlite3_step() everywhere in your code, and you will
always get back the specific error code rather than a generic
SQLITE_ERROR error code.
}
api {} {
void *sqlite3_trace(sqlite3*, void(*xTrace)(void*,const char*), void*);
} {
Register a function that is called each time an SQL statement is evaluated.
The callback function is invoked on the first call to sqlite3_step() after
calls to sqlite3_prepare() or sqlite3_reset().
This function can be used (for example) to generate
a log file of all SQL executed against a database. This can be
useful when debugging an application that uses SQLite.
}
api {} {
void *sqlite3_user_data(sqlite3_context*);
} {
The pUserData argument to the sqlite3_create_function() and
sqlite3_create_function16() routines used to register user functions
is available to the implementation of the function using this
call.
}
api {} {
const void *sqlite3_value_blob(sqlite3_value*);
int sqlite3_value_bytes(sqlite3_value*);
int sqlite3_value_bytes16(sqlite3_value*);
double sqlite3_value_double(sqlite3_value*);
int sqlite3_value_int(sqlite3_value*);
long long int sqlite3_value_int64(sqlite3_value*);
const unsigned char *sqlite3_value_text(sqlite3_value*);
const void *sqlite3_value_text16(sqlite3_value*);
const void *sqlite3_value_text16be(sqlite3_value*);
const void *sqlite3_value_text16le(sqlite3_value*);
int sqlite3_value_type(sqlite3_value*);
} {
This group of routines returns information about arguments to
a user-defined function. Function implementations use these routines
to access their arguments. These routines are the same as the
sqlite3_column_... routines except that these routines take a single
sqlite3_value* pointer instead of an sqlite3_stmt* and an integer
column number.
See the documentation under sqlite3_column_blob for additional
information.
}
api {} {
int sqlite3_sleep(int);
} {
Sleep for a little while. The second parameter is the number of
miliseconds to sleep for.
If the operating system does not support sleep requests with
milisecond time resolution, then the time will be rounded up to
the nearest second. The number of miliseconds of sleep actually
requested from the operating system is returned.
}
api {} {
int sqlite3_expired(sqlite3_stmt*);
} {
Return TRUE (non-zero) if the statement supplied as an argument needs
to be recompiled. A statement needs to be recompiled whenever the
execution environment changes in a way that would alter the program
that sqlite3_prepare() generates. For example, if new functions or
collating sequences are registered or if an authorizer function is
added or changed.
}
api {} {
int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*);
} {
Move all bindings from the first prepared statement over to the second.
This routine is useful, for example, if the first prepared statement
fails with an SQLITE_SCHEMA error. The same SQL can be prepared into
the second prepared statement then all of the bindings transfered over
to the second statement before the first statement is finalized.
}
api {} {
int sqlite3_global_recover();
} {
This function used to be involved in recovering from out-of-memory
errors. But as of SQLite version 3.3.0, out-of-memory recovery is
automatic and this routine now does nothing. THe interface is retained
to avoid link errors with legacy code.
}
api {} {
int sqlite3_get_autocommit(sqlite3*);
} {
Test to see whether or not the database connection is in autocommit
mode. Return TRUE if it is and FALSE if not. Autocommit mode is on
by default. Autocommit is disabled by a BEGIN statement and reenabled
by the next COMMIT or ROLLBACK.
}
api {} {
int sqlite3_clear_bindings(sqlite3_stmt*);
} {
Set all the parameters in the compiled SQL statement back to NULL.
}
api {} {
sqlite3 *sqlite3_db_handle(sqlite3_stmt*);
} {
Return the sqlite3* database handle to which the prepared statement given
in the argument belongs. This is the same database handle that was
the first argument to the sqlite3_prepare() that was used to create
the statement in the first place.
}
api {} {
void *sqlite3_update_hook(
sqlite3*,
void(*)(void *,int ,char const *,char const *,sqlite_int64),
void*
);
} {
Register 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.
See also: sqlite3_commit_hook(), sqlite3_rollback_hook()
}
api {} {
void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*);
} {
Register a callback to be invoked whenever a transaction is rolled
back.
The new callback function overrides any existing rollback-hook
callback. If there was an existing callback, then it's pArg value
(the third argument to sqlite3_rollback_hook() when it was registered)
is returned. Otherwise, NULL is returned.
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
callback is not invoked if a transaction is automatically rolled
back because the database connection is closed.
}
api {} {
int sqlite3_enable_shared_cache(int);
} {
This routine enables or disables the sharing of the database cache
and schema data structures between 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 on a thread-by-thread basis.
Each call to this routine enables or disables cache sharing only for
connections created in the same thread in which this routine is called.
There is no mechanism for sharing cache between database connections
running in different threads.
Sharing must be disabled prior to shutting down a thread or else
the thread will leak memory. Call this routine with an argument of
0 to turn off sharing. Or use the sqlite3_thread_cleanup() API.
This routine must not be called when any database connections
are active in the current thread. Enabling or disabling shared
cache while there are active database connections will result
in memory corruption.
When the shared cache is enabled, the
following routines must always be called from the same thread:
sqlite3_open(), sqlite3_prepare(), sqlite3_step(), sqlite3_reset(),
sqlite3_finalize(), and sqlite3_close().
This is due to the fact that the shared cache makes use of
thread-specific storage so that it will be available for sharing
with other connections.
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 for backward compatibility.
}
api {} {
void sqlite3_thread_cleanup(void);
} {
This routine makes sure that all thread local storage used by SQLite
in the current thread has been deallocated. A thread can call this
routine prior to terminating in order to make sure there are no memory
leaks.
This routine is not strictly necessary. If cache sharing has been
disabled using sqlite3_enable_shared_cache() and if all database
connections have been closed and if SQLITE_ENABLE_MEMORY_MANAGMENT is
on and all memory has been freed, then the thread local storage will
already have been automatically deallocated. This routine is provided
as a convenience to the program who just wants to make sure that there
are no leaks.
}
api {} {
int sqlite3_release_memory(int N);
} {
This routine attempts to free at least N bytes of memory from the caches
of database connecions that were created in the same thread from which this
routine is called. The value returned is the number of bytes actually
freed.
This routine is only available if memory management has been enabled
by compiling with the SQLITE_ENABLE_MEMORY_MANAGMENT macro.
}
api {} {
void sqlite3_soft_heap_limit(int N);
} {
This routine sets the soft heap limit for the current thread to N.
If the total heap usage by SQLite in the current thread exceeds N,
then sqlite3_release_memory() is called to try to reduce the memory usage
below the soft limit.
Prior to shutting down a thread sqlite3_soft_heap_limit() must be set to
zero (the default) or else the thread will leak memory. Alternatively, use
the sqlite3_thread_cleanup() API.
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 exhaused.
The default value for the soft heap limit is zero.
SQLite makes a best effort to honor the soft heap limit. But if it
is unable to reduce memory usage below the soft limit, execution will
continue without error or notification. This is why the limit is
called a "soft" limit. It is advisory only.
This routine is only available if memory management has been enabled
by compiling with the SQLITE_ENABLE_MEMORY_MANAGMENT macro.
}
api {} {
void sqlite3_thread_cleanup(void);
} {
This routine ensures that a thread that has used SQLite in the past
has released any thread-local storage it might have allocated.
When the rest of the API is used properly, the cleanup of
thread-local storage should be completely automatic. You should
never really need to invoke this API. But it is provided to you
as a precaution and as a potential work-around for future
thread-releated memory-leaks.
}
set n 0
set i 0
foreach item $apilist {
set namelist [lindex $item 0]
foreach name $namelist {
set n_to_name($n) $name
set n_to_idx($n) $i
set name_to_idx($name) $i
incr n
}
incr i
}
set i 0
foreach name [lsort [array names name_to_idx]] {
set sname($i) $name
incr i
}
#parray n_to_name
#parray n_to_idx
#parray name_to_idx
#parray sname
incr n -1
puts {<table width="100%" cellpadding="5"><tr>}
set nrow [expr {($n+2)/3}]
set i 0
for {set j 0} {$j<3} {incr j} {
if {$j>0} {puts {<td width="10"></td>}}
puts {<td valign="top">}
set limit [expr {$i+$nrow}]
puts {<ul>}
while {$i<$limit && $i<$n} {
set name $sname($i)
if {[regexp {^sqlite} $name]} {set display $name} {set display <i>$name</i>}
puts "<li><a href=\"#$name\">$display</a></li>"
incr i
}
puts {</ul></td>}
}
puts "</table>"
puts "<!-- $n entries. $nrow rows in 3 columns -->"
proc resolve_name {ignore_list name} {
global name_to_idx
if {![info exists name_to_idx($name)] || [lsearch $ignore_list $name]>=0} {
return $name
} else {
return "<a href=\"#$name\">$name</a>"
}
}
foreach name [lsort [array names name_to_idx]] {
set i $name_to_idx($name)
if {[info exists done($i)]} continue
set done($i) 1
foreach {namelist prototype desc} [lindex $apilist $i] break
foreach name $namelist {
puts "<a name=\"$name\">"
}
puts "<p><hr></p>"
puts "<blockquote><pre>"
regsub "^( *\n)+" $prototype {} p2
regsub "(\n *)+\$" $p2 {} p3
puts $p3
puts "</pre></blockquote>"
regsub -all {\[} $desc {\[} desc
regsub -all {sqlite3_[a-z0-9_]+} $desc "\[resolve_name $name &\]" d2
foreach x $specialname {
regsub -all $x $d2 "\[resolve_name $name &\]" d2
}
regsub -all "\n( *\n)+" [subst $d2] "</p>\n\n<p>" d3
puts "<p>$d3</p>"
}
footer $rcsid
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