3 * @defgroup Database Database
7 * This file deals with database interface functions
8 * and query specifics/optimisations
11 /** Number of times to re-try an operation in case of deadlock */
12 define( 'DEADLOCK_TRIES', 4 );
13 /** Minimum time to wait before retry, in microseconds */
14 define( 'DEADLOCK_DELAY_MIN', 500000 );
15 /** Maximum time to wait before retry */
16 define( 'DEADLOCK_DELAY_MAX', 1500000 );
19 * Base interface for all DBMS-specific code. At a bare minimum, all of the
20 * following must be implemented to support MediaWiki
25 interface DatabaseType
{
27 * Get the type of the DBMS, as it appears in $wgDBtype.
34 * Open a connection to the database. Usually aborts on failure
36 * @param $server String: database server host
37 * @param $user String: database user name
38 * @param $password String: database user password
39 * @param $dbName String: database name
41 * @throws DBConnectionError
43 function open( $server, $user, $password, $dbName );
46 * Fetch the next row from the given result object, in object form.
47 * Fields can be retrieved with $row->fieldname, with fields acting like
50 * @param $res SQL result object as returned from DatabaseBase::query(), etc.
52 * @throws DBUnexpectedError Thrown if the database returns an error
54 function fetchObject( $res );
57 * Fetch the next row from the given result object, in associative array
58 * form. Fields are retrieved with $row['fieldname'].
60 * @param $res ResultWrapper result object as returned from DatabaseBase::query(), etc.
62 * @throws DBUnexpectedError Thrown if the database returns an error
64 function fetchRow( $res );
67 * Get the number of rows in a result object
69 * @param $res Mixed: A SQL result
72 function numRows( $res );
75 * Get the number of fields in a result object
76 * @see http://www.php.net/mysql_num_fields
78 * @param $res Mixed: A SQL result
81 function numFields( $res );
84 * Get a field name in a result object
85 * @see http://www.php.net/mysql_field_name
87 * @param $res Mixed: A SQL result
91 function fieldName( $res, $n );
94 * Get the inserted value of an auto-increment row
96 * The value inserted should be fetched from nextSequenceValue()
99 * $id = $dbw->nextSequenceValue('page_page_id_seq');
100 * $dbw->insert('page',array('page_id' => $id));
101 * $id = $dbw->insertId();
108 * Change the position of the cursor in a result object
109 * @see http://www.php.net/mysql_data_seek
111 * @param $res Mixed: A SQL result
112 * @param $row Mixed: Either MySQL row or ResultWrapper
114 function dataSeek( $res, $row );
117 * Get the last error number
118 * @see http://www.php.net/mysql_errno
122 function lastErrno();
125 * Get a description of the last error
126 * @see http://www.php.net/mysql_error
130 function lastError();
133 * mysql_fetch_field() wrapper
134 * Returns false if the field doesn't exist
136 * @param $table string: table name
137 * @param $field string: field name
141 function fieldInfo( $table, $field );
144 * Get information about an index into an object
145 * @param $table string: Table name
146 * @param $index string: Index name
147 * @param $fname string: Calling function name
148 * @return Mixed: Database-specific index description class or false if the index does not exist
150 function indexInfo( $table, $index, $fname = 'Database::indexInfo' );
153 * Get the number of rows affected by the last write query
154 * @see http://www.php.net/mysql_affected_rows
158 function affectedRows();
161 * Wrapper for addslashes()
163 * @param $s string: to be slashed.
164 * @return string: slashed string.
166 function strencode( $s );
169 * Returns a wikitext link to the DB's website, e.g.,
170 * return "[http://www.mysql.com/ MySQL]";
171 * Should at least contain plain text, if for some reason
172 * your database has no website.
174 * @return string: wikitext of a link to the server software's web site
176 static function getSoftwareLink();
179 * A string describing the current software version, like from
180 * mysql_get_server_info().
182 * @return string: Version information from the database server.
184 function getServerVersion();
187 * A string describing the current software version, and possibly
188 * other details in a user-friendly way. Will be listed on Special:Version, etc.
189 * Use getServerVersion() to get machine-friendly information.
191 * @return string: Version information from the database server
193 function getServerInfo();
197 * Database abstraction object
200 abstract class DatabaseBase
implements DatabaseType
{
202 # ------------------------------------------------------------------------------
204 # ------------------------------------------------------------------------------
206 protected $mLastQuery = '';
207 protected $mDoneWrites = false;
208 protected $mPHPError = false;
210 protected $mServer, $mUser, $mPassword, $mDBname;
215 protected $mConn = null;
216 protected $mOpened = false;
218 protected $mTablePrefix;
220 protected $mTrxLevel = 0;
221 protected $mErrorCount = 0;
222 protected $mLBInfo = array();
223 protected $mFakeSlaveLag = null, $mFakeMaster = false;
224 protected $mDefaultBigSelects = null;
225 protected $mSchemaVars = false;
227 protected $preparedArgs;
229 # ------------------------------------------------------------------------------
231 # ------------------------------------------------------------------------------
232 # These optionally set a variable and return the previous state
235 * A string describing the current software version, and possibly
236 * other details in a user-friendly way. Will be listed on Special:Version, etc.
237 * Use getServerVersion() to get machine-friendly information.
239 * @return string: Version information from the database server
241 public function getServerInfo() {
242 return $this->getServerVersion();
246 * Boolean, controls output of large amounts of debug information.
247 * @param $debug bool|null
248 * - true to enable debugging
249 * - false to disable debugging
250 * - omitted or null to do nothing
252 * @return The previous value of the flag
254 function debug( $debug = null ) {
255 return wfSetBit( $this->mFlags
, DBO_DEBUG
, $debug );
259 * Turns buffering of SQL result sets on (true) or off (false). Default is
262 * Unbuffered queries are very troublesome in MySQL:
264 * - If another query is executed while the first query is being read
265 * out, the first query is killed. This means you can't call normal
266 * MediaWiki functions while you are reading an unbuffered query result
267 * from a normal wfGetDB() connection.
269 * - Unbuffered queries cause the MySQL server to use large amounts of
270 * memory and to hold broad locks which block other queries.
272 * If you want to limit client-side memory, it's almost always better to
273 * split up queries into batches using a LIMIT clause than to switch off
276 * @param $buffer null|bool
278 * @return The previous value of the flag
280 function bufferResults( $buffer = null ) {
281 if ( is_null( $buffer ) ) {
282 return !(bool)( $this->mFlags
& DBO_NOBUFFER
);
284 return !wfSetBit( $this->mFlags
, DBO_NOBUFFER
, !$buffer );
289 * Turns on (false) or off (true) the automatic generation and sending
290 * of a "we're sorry, but there has been a database error" page on
291 * database errors. Default is on (false). When turned off, the
292 * code should use lastErrno() and lastError() to handle the
293 * situation as appropriate.
295 * @param $ignoreErrors bool|null
297 * @return The previous value of the flag.
299 function ignoreErrors( $ignoreErrors = null ) {
300 return wfSetBit( $this->mFlags
, DBO_IGNORE
, $ignoreErrors );
304 * Gets or sets the current transaction level.
306 * Historically, transactions were allowed to be "nested". This is no
307 * longer supported, so this function really only returns a boolean.
309 * @param $level An integer (0 or 1), or omitted to leave it unchanged.
310 * @return The previous value
312 function trxLevel( $level = null ) {
313 return wfSetVar( $this->mTrxLevel
, $level );
317 * Get/set the number of errors logged. Only useful when errors are ignored
318 * @param $count The count to set, or omitted to leave it unchanged.
319 * @return The error count
321 function errorCount( $count = null ) {
322 return wfSetVar( $this->mErrorCount
, $count );
326 * Get/set the table prefix.
327 * @param $prefix The table prefix to set, or omitted to leave it unchanged.
328 * @return The previous table prefix.
330 function tablePrefix( $prefix = null ) {
331 return wfSetVar( $this->mTablePrefix
, $prefix );
335 * Get properties passed down from the server info array of the load
338 * @param $name string The entry of the info array to get, or null to get the
341 * @return LoadBalancer|null
343 function getLBInfo( $name = null ) {
344 if ( is_null( $name ) ) {
345 return $this->mLBInfo
;
347 if ( array_key_exists( $name, $this->mLBInfo
) ) {
348 return $this->mLBInfo
[$name];
356 * Set the LB info array, or a member of it. If called with one parameter,
357 * the LB info array is set to that parameter. If it is called with two
358 * parameters, the member with the given name is set to the given value.
363 function setLBInfo( $name, $value = null ) {
364 if ( is_null( $value ) ) {
365 $this->mLBInfo
= $name;
367 $this->mLBInfo
[$name] = $value;
372 * Set lag time in seconds for a fake slave
376 function setFakeSlaveLag( $lag ) {
377 $this->mFakeSlaveLag
= $lag;
381 * Make this connection a fake master
383 * @param $enabled bool
385 function setFakeMaster( $enabled = true ) {
386 $this->mFakeMaster
= $enabled;
390 * Returns true if this database supports (and uses) cascading deletes
394 function cascadingDeletes() {
399 * Returns true if this database supports (and uses) triggers (e.g. on the page table)
403 function cleanupTriggers() {
408 * Returns true if this database is strict about what can be put into an IP field.
409 * Specifically, it uses a NULL value instead of an empty string.
413 function strictIPs() {
418 * Returns true if this database uses timestamps rather than integers
422 function realTimestamps() {
427 * Returns true if this database does an implicit sort when doing GROUP BY
431 function implicitGroupby() {
436 * Returns true if this database does an implicit order by when the column has an index
437 * For example: SELECT page_title FROM page LIMIT 1
441 function implicitOrderby() {
446 * Returns true if this database requires that SELECT DISTINCT queries require that all
447 ORDER BY expressions occur in the SELECT list per the SQL92 standard
451 function standardSelectDistinct() {
456 * Returns true if this database can do a native search on IP columns
457 * e.g. this works as expected: .. WHERE rc_ip = '127.42.12.102/32';
461 function searchableIPs() {
466 * Returns true if this database can use functional indexes
470 function functionalIndexes() {
475 * Return the last query that went through DatabaseBase::query()
478 function lastQuery() {
479 return $this->mLastQuery
;
483 * Returns true if the connection may have been used for write queries.
484 * Should return true if unsure.
488 function doneWrites() {
489 return $this->mDoneWrites
;
493 * Is a connection to the database open?
497 return $this->mOpened
;
501 * Set a flag for this connection
503 * @param $flag Integer: DBO_* constants from Defines.php:
504 * - DBO_DEBUG: output some debug info (same as debug())
505 * - DBO_NOBUFFER: don't buffer results (inverse of bufferResults())
506 * - DBO_IGNORE: ignore errors (same as ignoreErrors())
507 * - DBO_TRX: automatically start transactions
508 * - DBO_DEFAULT: automatically sets DBO_TRX if not in command line mode
509 * and removes it in command line mode
510 * - DBO_PERSISTENT: use persistant database connection
512 function setFlag( $flag ) {
513 $this->mFlags |
= $flag;
517 * Clear a flag for this connection
519 * @param $flag: same as setFlag()'s $flag param
521 function clearFlag( $flag ) {
522 $this->mFlags
&= ~
$flag;
526 * Returns a boolean whether the flag $flag is set for this connection
528 * @param $flag: same as setFlag()'s $flag param
531 function getFlag( $flag ) {
532 return !!( $this->mFlags
& $flag );
536 * General read-only accessor
538 * @param $name string
542 function getProperty( $name ) {
549 function getWikiID() {
550 if ( $this->mTablePrefix
) {
551 return "{$this->mDBname}-{$this->mTablePrefix}";
553 return $this->mDBname
;
558 * Return a path to the DBMS-specific schema file, otherwise default to tables.sql
562 public function getSchemaPath() {
564 if ( file_exists( "$IP/maintenance/" . $this->getType() . "/tables.sql" ) ) {
565 return "$IP/maintenance/" . $this->getType() . "/tables.sql";
567 return "$IP/maintenance/tables.sql";
571 # ------------------------------------------------------------------------------
573 # ------------------------------------------------------------------------------
577 * @param $server String: database server host
578 * @param $user String: database user name
579 * @param $password String: database user password
580 * @param $dbName String: database name
582 * @param $tablePrefix String: database table prefixes. By default use the prefix gave in LocalSettings.php
584 function __construct( $server = false, $user = false, $password = false, $dbName = false,
585 $flags = 0, $tablePrefix = 'get from global'
587 global $wgDBprefix, $wgCommandLineMode;
589 $this->mFlags
= $flags;
591 if ( $this->mFlags
& DBO_DEFAULT
) {
592 if ( $wgCommandLineMode ) {
593 $this->mFlags
&= ~DBO_TRX
;
595 $this->mFlags |
= DBO_TRX
;
599 /** Get the default table prefix*/
600 if ( $tablePrefix == 'get from global' ) {
601 $this->mTablePrefix
= $wgDBprefix;
603 $this->mTablePrefix
= $tablePrefix;
607 $this->open( $server, $user, $password, $dbName );
612 * Called by unserialize. Needed to reopen DB connection, which
613 * is not saved by serialize.
615 public function __wakeup() {
616 if ( $this->isOpen() ) {
617 $this->open( $this->mServer
, $this->mUser
,
618 $this->mPassword
, $this->mDBname
);
623 * Same as new DatabaseMysql( ... ), kept for backward compatibility
624 * @deprecated since 1.17
626 * @return DatabaseMysql
628 static function newFromParams( $server, $user, $password, $dbName, $flags = 0 ) {
629 wfDeprecated( __METHOD__
);
630 return new DatabaseMysql( $server, $user, $password, $dbName, $flags );
634 * Given a DB type, construct the name of the appropriate child class of
635 * DatabaseBase. This is designed to replace all of the manual stuff like:
636 * $class = 'Database' . ucfirst( strtolower( $type ) );
637 * as well as validate against the canonical list of DB types we have
639 * This factory function is mostly useful for when you need to connect to a
640 * database other than the MediaWiki default (such as for external auth,
641 * an extension, et cetera). Do not use this to connect to the MediaWiki
642 * database. Example uses in core:
643 * @see LoadBalancer::reallyOpenConnection()
644 * @see ExternalUser_MediaWiki::initFromCond()
645 * @see ForeignDBRepo::getMasterDB()
646 * @see WebInstaller_DBConnect::execute()
648 * @param $dbType String A possible DB type
649 * @param $p Array An array of options to pass to the constructor.
650 * Valid options are: host, user, password, dbname, flags, tablePrefix
651 * @return DatabaseBase subclass or null
653 public final static function factory( $dbType, $p = array() ) {
654 $canonicalDBTypes = array(
655 'mysql', 'postgres', 'sqlite', 'oracle', 'mssql', 'ibm_db2'
657 $dbType = strtolower( $dbType );
659 if( in_array( $dbType, $canonicalDBTypes ) ) {
660 $class = 'Database' . ucfirst( $dbType );
662 isset( $p['host'] ) ?
$p['host'] : false,
663 isset( $p['user'] ) ?
$p['user'] : false,
664 isset( $p['password'] ) ?
$p['password'] : false,
665 isset( $p['dbname'] ) ?
$p['dbname'] : false,
666 isset( $p['flags'] ) ?
$p['flags'] : 0,
667 isset( $p['tablePrefix'] ) ?
$p['tablePrefix'] : 'get from global'
674 protected function installErrorHandler() {
675 $this->mPHPError
= false;
676 $this->htmlErrors
= ini_set( 'html_errors', '0' );
677 set_error_handler( array( $this, 'connectionErrorHandler' ) );
681 * @return bool|string
683 protected function restoreErrorHandler() {
684 restore_error_handler();
685 if ( $this->htmlErrors
!== false ) {
686 ini_set( 'html_errors', $this->htmlErrors
);
688 if ( $this->mPHPError
) {
689 $error = preg_replace( '!\[<a.*</a>\]!', '', $this->mPHPError
);
690 $error = preg_replace( '!^.*?:(.*)$!', '$1', $error );
697 protected function connectionErrorHandler( $errno, $errstr ) {
698 $this->mPHPError
= $errstr;
702 * Closes a database connection.
703 * if it is open : commits any open transactions
705 * @return Bool operation success. true if already closed.
708 # Stub, should probably be overridden
713 * @param $error String: fallback error message, used if none is given by DB
715 function reportConnectionError( $error = 'Unknown error' ) {
716 $myError = $this->lastError();
722 throw new DBConnectionError( $this, $error );
726 * The DBMS-dependent part of query()
728 * @param $sql String: SQL query.
729 * @return ResultWrapper Result object to feed to fetchObject, fetchRow, ...; or false on failure
731 protected abstract function doQuery( $sql );
734 * Determine whether a query writes to the DB.
735 * Should return true if unsure.
741 function isWriteQuery( $sql ) {
742 return !preg_match( '/^(?:SELECT|BEGIN|COMMIT|SET|SHOW|\(SELECT)\b/i', $sql );
746 * Run an SQL query and return the result. Normally throws a DBQueryError
747 * on failure. If errors are ignored, returns false instead.
749 * In new code, the query wrappers select(), insert(), update(), delete(),
750 * etc. should be used where possible, since they give much better DBMS
751 * independence and automatically quote or validate user input in a variety
752 * of contexts. This function is generally only useful for queries which are
753 * explicitly DBMS-dependent and are unsupported by the query wrappers, such
756 * However, the query wrappers themselves should call this function.
758 * @param $sql String: SQL query
759 * @param $fname String: Name of the calling function, for profiling/SHOW PROCESSLIST
760 * comment (you can use __METHOD__ or add some extra info)
761 * @param $tempIgnore Boolean: Whether to avoid throwing an exception on errors...
762 * maybe best to catch the exception instead?
763 * @return boolean|ResultWrapper. true for a successful write query, ResultWrapper object
764 * for a successful read query, or false on failure if $tempIgnore set
765 * @throws DBQueryError Thrown when the database returns an error of any kind
767 public function query( $sql, $fname = '', $tempIgnore = false ) {
768 $isMaster = !is_null( $this->getLBInfo( 'master' ) );
769 if ( !Profiler
::instance()->isStub() ) {
770 # generalizeSQL will probably cut down the query to reasonable
771 # logging size most of the time. The substr is really just a sanity check.
774 $queryProf = 'query-m: ' . substr( DatabaseBase
::generalizeSQL( $sql ), 0, 255 );
775 $totalProf = 'DatabaseBase::query-master';
777 $queryProf = 'query: ' . substr( DatabaseBase
::generalizeSQL( $sql ), 0, 255 );
778 $totalProf = 'DatabaseBase::query';
781 wfProfileIn( $totalProf );
782 wfProfileIn( $queryProf );
785 $this->mLastQuery
= $sql;
786 if ( !$this->mDoneWrites
&& $this->isWriteQuery( $sql ) ) {
787 # Set a flag indicating that writes have been done
788 wfDebug( __METHOD__
. ": Writes done: $sql\n" );
789 $this->mDoneWrites
= true;
792 # Add a comment for easy SHOW PROCESSLIST interpretation
794 if ( is_object( $wgUser ) && $wgUser->isItemLoaded( 'name' ) ) {
795 $userName = $wgUser->getName();
796 if ( mb_strlen( $userName ) > 15 ) {
797 $userName = mb_substr( $userName, 0, 15 ) . '...';
799 $userName = str_replace( '/', '', $userName );
803 $commentedSql = preg_replace( '/\s/', " /* $fname $userName */ ", $sql, 1 );
805 # If DBO_TRX is set, start a transaction
806 if ( ( $this->mFlags
& DBO_TRX
) && !$this->trxLevel() &&
807 $sql != 'BEGIN' && $sql != 'COMMIT' && $sql != 'ROLLBACK' ) {
808 # avoid establishing transactions for SHOW and SET statements too -
809 # that would delay transaction initializations to once connection
810 # is really used by application
811 $sqlstart = substr( $sql, 0, 10 ); // very much worth it, benchmark certified(tm)
812 if ( strpos( $sqlstart, "SHOW " ) !== 0 and strpos( $sqlstart, "SET " ) !== 0 )
816 if ( $this->debug() ) {
820 $sqlx = substr( $commentedSql, 0, 500 );
821 $sqlx = strtr( $sqlx, "\t\n", ' ' );
824 wfDebug( "Query $cnt (master): $sqlx\n" );
826 wfDebug( "Query $cnt (slave): $sqlx\n" );
830 if ( istainted( $sql ) & TC_MYSQL
) {
831 throw new MWException( 'Tainted query found' );
834 # Do the query and handle errors
835 $ret = $this->doQuery( $commentedSql );
837 # Try reconnecting if the connection was lost
838 if ( false === $ret && $this->wasErrorReissuable() ) {
839 # Transaction is gone, like it or not
840 $this->mTrxLevel
= 0;
841 wfDebug( "Connection lost, reconnecting...\n" );
843 if ( $this->ping() ) {
844 wfDebug( "Reconnected\n" );
845 $sqlx = substr( $commentedSql, 0, 500 );
846 $sqlx = strtr( $sqlx, "\t\n", ' ' );
847 global $wgRequestTime;
848 $elapsed = round( microtime( true ) - $wgRequestTime, 3 );
849 if ( $elapsed < 300 ) {
850 # Not a database error to lose a transaction after a minute or two
851 wfLogDBError( "Connection lost and reconnected after {$elapsed}s, query: $sqlx\n" );
853 $ret = $this->doQuery( $commentedSql );
855 wfDebug( "Failed\n" );
859 if ( false === $ret ) {
860 $this->reportQueryError( $this->lastError(), $this->lastErrno(), $sql, $fname, $tempIgnore );
863 if ( !Profiler
::instance()->isStub() ) {
864 wfProfileOut( $queryProf );
865 wfProfileOut( $totalProf );
868 return $this->resultObject( $ret );
872 * Report a query error. Log the error, and if neither the object ignore
873 * flag nor the $tempIgnore flag is set, throw a DBQueryError.
875 * @param $error String
876 * @param $errno Integer
878 * @param $fname String
879 * @param $tempIgnore Boolean
881 function reportQueryError( $error, $errno, $sql, $fname, $tempIgnore = false ) {
882 # Ignore errors during error handling to avoid infinite recursion
883 $ignore = $this->ignoreErrors( true );
884 ++
$this->mErrorCount
;
886 if ( $ignore ||
$tempIgnore ) {
887 wfDebug( "SQL ERROR (ignored): $error\n" );
888 $this->ignoreErrors( $ignore );
890 $sql1line = str_replace( "\n", "\\n", $sql );
891 wfLogDBError( "$fname\t{$this->mServer}\t$errno\t$error\t$sql1line\n" );
892 wfDebug( "SQL ERROR: " . $error . "\n" );
893 throw new DBQueryError( $this, $error, $errno, $sql, $fname );
898 * Intended to be compatible with the PEAR::DB wrapper functions.
899 * http://pear.php.net/manual/en/package.database.db.intro-execute.php
901 * ? = scalar value, quoted as necessary
902 * ! = raw SQL bit (a function for instance)
903 * & = filename; reads the file and inserts as a blob
904 * (we don't use this though...)
906 * This function should not be used directly by new code outside of the
907 * database classes. The query wrapper functions (select() etc.) should be
911 * @param $func string
915 function prepare( $sql, $func = 'DatabaseBase::prepare' ) {
916 /* MySQL doesn't support prepared statements (yet), so just
917 pack up the query for reference. We'll manually replace
919 return array( 'query' => $sql, 'func' => $func );
923 * Free a prepared query, generated by prepare().
925 function freePrepared( $prepared ) {
926 /* No-op by default */
930 * Execute a prepared query with the various arguments
931 * @param $prepared String: the prepared sql
932 * @param $args Mixed: Either an array here, or put scalars as varargs
934 * @return ResultWrapper
936 function execute( $prepared, $args = null ) {
937 if ( !is_array( $args ) ) {
939 $args = func_get_args();
940 array_shift( $args );
943 $sql = $this->fillPrepared( $prepared['query'], $args );
945 return $this->query( $sql, $prepared['func'] );
949 * Prepare & execute an SQL statement, quoting and inserting arguments
950 * in the appropriate places.
952 * This function should not be used directly by new code outside of the
953 * database classes. The query wrapper functions (select() etc.) should be
956 * @param $query String
959 * @return ResultWrapper
961 function safeQuery( $query, $args = null ) {
962 $prepared = $this->prepare( $query, 'DatabaseBase::safeQuery' );
964 if ( !is_array( $args ) ) {
966 $args = func_get_args();
967 array_shift( $args );
970 $retval = $this->execute( $prepared, $args );
971 $this->freePrepared( $prepared );
977 * For faking prepared SQL statements on DBs that don't support
979 * @param $preparedQuery String: a 'preparable' SQL statement
980 * @param $args Array of arguments to fill it with
981 * @return string executable SQL
983 function fillPrepared( $preparedQuery, $args ) {
985 $this->preparedArgs
=& $args;
987 return preg_replace_callback( '/(\\\\[?!&]|[?!&])/',
988 array( &$this, 'fillPreparedArg' ), $preparedQuery );
992 * preg_callback func for fillPrepared()
993 * The arguments should be in $this->preparedArgs and must not be touched
994 * while we're doing this.
996 * @param $matches Array
999 function fillPreparedArg( $matches ) {
1000 switch( $matches[1] ) {
1001 case '\\?': return '?';
1002 case '\\!': return '!';
1003 case '\\&': return '&';
1006 list( /* $n */ , $arg ) = each( $this->preparedArgs
);
1008 switch( $matches[1] ) {
1009 case '?': return $this->addQuotes( $arg );
1010 case '!': return $arg;
1012 # return $this->addQuotes( file_get_contents( $arg ) );
1013 throw new DBUnexpectedError( $this, '& mode is not implemented. If it\'s really needed, uncomment the line above.' );
1015 throw new DBUnexpectedError( $this, 'Received invalid match. This should never happen!' );
1020 * Free a result object returned by query() or select(). It's usually not
1021 * necessary to call this, just use unset() or let the variable holding
1022 * the result object go out of scope.
1024 * @param $res Mixed: A SQL result
1026 function freeResult( $res ) {
1030 * Simple UPDATE wrapper.
1031 * Usually throws a DBQueryError on failure.
1032 * If errors are explicitly ignored, returns success
1034 * This function exists for historical reasons, DatabaseBase::update() has a more standard
1035 * calling convention and feature set
1037 * @param $table string
1041 * @param $fname string
1045 function set( $table, $var, $value, $cond, $fname = 'DatabaseBase::set' ) {
1046 $table = $this->tableName( $table );
1047 $sql = "UPDATE $table SET $var = '" .
1048 $this->strencode( $value ) . "' WHERE ($cond)";
1050 return (bool)$this->query( $sql, $fname );
1054 * A SELECT wrapper which returns a single field from a single result row.
1056 * Usually throws a DBQueryError on failure. If errors are explicitly
1057 * ignored, returns false on failure.
1059 * If no result rows are returned from the query, false is returned.
1061 * @param $table string|array Table name. See DatabaseBase::select() for details.
1062 * @param $var string The field name to select. This must be a valid SQL
1063 * fragment: do not use unvalidated user input.
1064 * @param $cond string|array The condition array. See DatabaseBase::select() for details.
1065 * @param $fname string The function name of the caller.
1066 * @param $options string|array The query options. See DatabaseBase::select() for details.
1068 * @return false|mixed The value from the field, or false on failure.
1070 function selectField( $table, $var, $cond = '', $fname = 'DatabaseBase::selectField',
1071 $options = array() )
1073 if ( !is_array( $options ) ) {
1074 $options = array( $options );
1077 $options['LIMIT'] = 1;
1079 $res = $this->select( $table, $var, $cond, $fname, $options );
1081 if ( $res === false ||
!$this->numRows( $res ) ) {
1085 $row = $this->fetchRow( $res );
1087 if ( $row !== false ) {
1088 return reset( $row );
1095 * Returns an optional USE INDEX clause to go after the table, and a
1096 * string to go at the end of the query.
1098 * @param $options Array: associative array of options to be turned into
1099 * an SQL query, valid keys are listed in the function.
1101 * @see DatabaseBase::select()
1103 function makeSelectOptions( $options ) {
1104 $preLimitTail = $postLimitTail = '';
1107 $noKeyOptions = array();
1109 foreach ( $options as $key => $option ) {
1110 if ( is_numeric( $key ) ) {
1111 $noKeyOptions[$option] = true;
1115 if ( isset( $options['GROUP BY'] ) ) {
1116 $gb = is_array( $options['GROUP BY'] )
1117 ?
implode( ',', $options['GROUP BY'] )
1118 : $options['GROUP BY'];
1119 $preLimitTail .= " GROUP BY {$gb}";
1122 if ( isset( $options['HAVING'] ) ) {
1123 $preLimitTail .= " HAVING {$options['HAVING']}";
1126 if ( isset( $options['ORDER BY'] ) ) {
1127 $ob = is_array( $options['ORDER BY'] )
1128 ?
implode( ',', $options['ORDER BY'] )
1129 : $options['ORDER BY'];
1130 $preLimitTail .= " ORDER BY {$ob}";
1133 // if (isset($options['LIMIT'])) {
1134 // $tailOpts .= $this->limitResult('', $options['LIMIT'],
1135 // isset($options['OFFSET']) ? $options['OFFSET']
1139 if ( isset( $noKeyOptions['FOR UPDATE'] ) ) {
1140 $postLimitTail .= ' FOR UPDATE';
1143 if ( isset( $noKeyOptions['LOCK IN SHARE MODE'] ) ) {
1144 $postLimitTail .= ' LOCK IN SHARE MODE';
1147 if ( isset( $noKeyOptions['DISTINCT'] ) ||
isset( $noKeyOptions['DISTINCTROW'] ) ) {
1148 $startOpts .= 'DISTINCT';
1151 # Various MySQL extensions
1152 if ( isset( $noKeyOptions['STRAIGHT_JOIN'] ) ) {
1153 $startOpts .= ' /*! STRAIGHT_JOIN */';
1156 if ( isset( $noKeyOptions['HIGH_PRIORITY'] ) ) {
1157 $startOpts .= ' HIGH_PRIORITY';
1160 if ( isset( $noKeyOptions['SQL_BIG_RESULT'] ) ) {
1161 $startOpts .= ' SQL_BIG_RESULT';
1164 if ( isset( $noKeyOptions['SQL_BUFFER_RESULT'] ) ) {
1165 $startOpts .= ' SQL_BUFFER_RESULT';
1168 if ( isset( $noKeyOptions['SQL_SMALL_RESULT'] ) ) {
1169 $startOpts .= ' SQL_SMALL_RESULT';
1172 if ( isset( $noKeyOptions['SQL_CALC_FOUND_ROWS'] ) ) {
1173 $startOpts .= ' SQL_CALC_FOUND_ROWS';
1176 if ( isset( $noKeyOptions['SQL_CACHE'] ) ) {
1177 $startOpts .= ' SQL_CACHE';
1180 if ( isset( $noKeyOptions['SQL_NO_CACHE'] ) ) {
1181 $startOpts .= ' SQL_NO_CACHE';
1184 if ( isset( $options['USE INDEX'] ) && ! is_array( $options['USE INDEX'] ) ) {
1185 $useIndex = $this->useIndexClause( $options['USE INDEX'] );
1190 return array( $startOpts, $useIndex, $preLimitTail, $postLimitTail );
1194 * Execute a SELECT query constructed using the various parameters provided.
1195 * See below for full details of the parameters.
1197 * @param $table String|Array Table name
1198 * @param $vars String|Array Field names
1199 * @param $conds String|Array Conditions
1200 * @param $fname String Caller function name
1201 * @param $options Array Query options
1202 * @param $join_conds Array Join conditions
1204 * @param $table string|array
1206 * May be either an array of table names, or a single string holding a table
1207 * name. If an array is given, table aliases can be specified, for example:
1209 * array( 'a' => 'user' )
1211 * This includes the user table in the query, with the alias "a" available
1212 * for use in field names (e.g. a.user_name).
1214 * All of the table names given here are automatically run through
1215 * DatabaseBase::tableName(), which causes the table prefix (if any) to be
1216 * added, and various other table name mappings to be performed.
1219 * @param $vars string|array
1221 * May be either a field name or an array of field names. The field names
1222 * here are complete fragments of SQL, for direct inclusion into the SELECT
1223 * query. Expressions and aliases may be specified as in SQL, for example:
1225 * array( 'MAX(rev_id) AS maxrev' )
1227 * If an expression is given, care must be taken to ensure that it is
1231 * @param $conds string|array
1233 * May be either a string containing a single condition, or an array of
1234 * conditions. If an array is given, the conditions constructed from each
1235 * element are combined with AND.
1237 * Array elements may take one of two forms:
1239 * - Elements with a numeric key are interpreted as raw SQL fragments.
1240 * - Elements with a string key are interpreted as equality conditions,
1241 * where the key is the field name.
1242 * - If the value of such an array element is a scalar (such as a
1243 * string), it will be treated as data and thus quoted appropriately.
1244 * If it is null, an IS NULL clause will be added.
1245 * - If the value is an array, an IN(...) clause will be constructed,
1246 * such that the field name may match any of the elements in the
1247 * array. The elements of the array will be quoted.
1248 * - If the field name ends with "!", this is taken as a flag which
1249 * inverts the comparison, allowing NOT IN clauses to be constructed,
1250 * for example: array( 'user_id!' => array( 1, 2, 3 ) )
1252 * Note that expressions are often DBMS-dependent in their syntax.
1253 * DBMS-independent wrappers are provided for constructing several types of
1254 * expression commonly used in condition queries. See:
1255 * - DatabaseBase::buildLike()
1256 * - DatabaseBase::conditional()
1259 * @param $options string|array
1261 * Optional: Array of query options. Boolean options are specified by
1262 * including them in the array as a string value with a numeric key, for
1265 * array( 'FOR UPDATE' )
1267 * The supported options are:
1269 * - OFFSET: Skip this many rows at the start of the result set. OFFSET
1270 * with LIMIT can theoretically be used for paging through a result set,
1271 * but this is discouraged in MediaWiki for performance reasons.
1273 * - LIMIT: Integer: return at most this many rows. The rows are sorted
1274 * and then the first rows are taken until the limit is reached. LIMIT
1275 * is applied to a result set after OFFSET.
1277 * - FOR UPDATE: Boolean: lock the returned rows so that they can't be
1278 * changed until the next COMMIT.
1280 * - DISTINCT: Boolean: return only unique result rows.
1282 * - GROUP BY: May be either an SQL fragment string naming a field or
1283 * expression to group by, or an array of such SQL fragments.
1285 * - HAVING: A string containing a HAVING clause.
1287 * - ORDER BY: May be either an SQL fragment giving a field name or
1288 * expression to order by, or an array of such SQL fragments.
1290 * - USE INDEX: This may be either a string giving the index name to use
1291 * for the query, or an array. If it is an associative array, each key
1292 * gives the table name (or alias), each value gives the index name to
1293 * use for that table. All strings are SQL fragments and so should be
1294 * validated by the caller.
1296 * - EXPLAIN: In MySQL, this causes an EXPLAIN SELECT query to be run,
1297 * instead of SELECT.
1299 * And also the following boolean MySQL extensions, see the MySQL manual
1300 * for documentation:
1302 * - LOCK IN SHARE MODE
1306 * - SQL_BUFFER_RESULT
1307 * - SQL_SMALL_RESULT
1308 * - SQL_CALC_FOUND_ROWS
1313 * @param $join_conds string|array
1315 * Optional associative array of table-specific join conditions. In the
1316 * most common case, this is unnecessary, since the join condition can be
1317 * in $conds. However, it is useful for doing a LEFT JOIN.
1319 * The key of the array contains the table name or alias. The value is an
1320 * array with two elements, numbered 0 and 1. The first gives the type of
1321 * join, the second is an SQL fragment giving the join condition for that
1322 * table. For example:
1324 * array( 'page' => array('LEFT JOIN','page_latest=rev_id') )
1326 * @return ResultWrapper. If the query returned no rows, a ResultWrapper
1327 * with no rows in it will be returned. If there was a query error, a
1328 * DBQueryError exception will be thrown, except if the "ignore errors"
1329 * option was set, in which case false will be returned.
1331 function select( $table, $vars, $conds = '', $fname = 'DatabaseBase::select',
1332 $options = array(), $join_conds = array() ) {
1333 $sql = $this->selectSQLText( $table, $vars, $conds, $fname, $options, $join_conds );
1335 return $this->query( $sql, $fname );
1339 * The equivalent of DatabaseBase::select() except that the constructed SQL
1340 * is returned, instead of being immediately executed.
1342 * @param $table string|array Table name
1343 * @param $vars string|array Field names
1344 * @param $conds string|array Conditions
1345 * @param $fname string Caller function name
1346 * @param $options string|array Query options
1347 * @param $join_conds string|array Join conditions
1349 * @return SQL query string.
1350 * @see DatabaseBase::select()
1352 function selectSQLText( $table, $vars, $conds = '', $fname = 'DatabaseBase::select', $options = array(), $join_conds = array() ) {
1353 if ( is_array( $vars ) ) {
1354 $vars = implode( ',', $vars );
1357 $options = (array)$options;
1359 if ( is_array( $table ) ) {
1360 $useIndex = ( isset( $options['USE INDEX'] ) && is_array( $options['USE INDEX'] ) )
1361 ?
$options['USE INDEX']
1363 if ( count( $join_conds ) ||
count( $useIndex ) ) {
1365 $this->tableNamesWithUseIndexOrJOIN( $table, $useIndex, $join_conds );
1367 $from = ' FROM ' . implode( ',', $this->tableNamesWithAlias( $table ) );
1369 } elseif ( $table != '' ) {
1370 if ( $table[0] == ' ' ) {
1371 $from = ' FROM ' . $table;
1373 $from = ' FROM ' . $this->tableName( $table );
1379 list( $startOpts, $useIndex, $preLimitTail, $postLimitTail ) = $this->makeSelectOptions( $options );
1381 if ( !empty( $conds ) ) {
1382 if ( is_array( $conds ) ) {
1383 $conds = $this->makeList( $conds, LIST_AND
);
1385 $sql = "SELECT $startOpts $vars $from $useIndex WHERE $conds $preLimitTail";
1387 $sql = "SELECT $startOpts $vars $from $useIndex $preLimitTail";
1390 if ( isset( $options['LIMIT'] ) ) {
1391 $sql = $this->limitResult( $sql, $options['LIMIT'],
1392 isset( $options['OFFSET'] ) ?
$options['OFFSET'] : false );
1394 $sql = "$sql $postLimitTail";
1396 if ( isset( $options['EXPLAIN'] ) ) {
1397 $sql = 'EXPLAIN ' . $sql;
1404 * Single row SELECT wrapper. Equivalent to DatabaseBase::select(), except
1405 * that a single row object is returned. If the query returns no rows,
1406 * false is returned.
1408 * @param $table string|array Table name
1409 * @param $vars string|array Field names
1410 * @param $conds|array Conditions
1411 * @param $fname string Caller function name
1412 * @param $options string|array Query options
1413 * @param $join_conds array|string Join conditions
1415 * @return ResultWrapper|bool
1417 function selectRow( $table, $vars, $conds, $fname = 'DatabaseBase::selectRow',
1418 $options = array(), $join_conds = array() )
1420 $options['LIMIT'] = 1;
1421 $res = $this->select( $table, $vars, $conds, $fname, $options, $join_conds );
1423 if ( $res === false ) {
1427 if ( !$this->numRows( $res ) ) {
1431 $obj = $this->fetchObject( $res );
1437 * Estimate rows in dataset.
1439 * MySQL allows you to estimate the number of rows that would be returned
1440 * by a SELECT query, using EXPLAIN SELECT. The estimate is provided using
1441 * index cardinality statistics, and is notoriously inaccurate, especially
1442 * when large numbers of rows have recently been added or deleted.
1444 * For DBMSs that don't support fast result size estimation, this function
1445 * will actually perform the SELECT COUNT(*).
1447 * Takes the same arguments as DatabaseBase::select().
1449 * @param $table String: table name
1450 * @param Array|string $vars : unused
1451 * @param Array|string $conds : filters on the table
1452 * @param $fname String: function name for profiling
1453 * @param $options Array: options for select
1454 * @return Integer: row count
1456 public function estimateRowCount( $table, $vars = '*', $conds = '',
1457 $fname = 'DatabaseBase::estimateRowCount', $options = array() )
1460 $res = $this->select ( $table, 'COUNT(*) AS rowcount', $conds, $fname, $options );
1463 $row = $this->fetchRow( $res );
1464 $rows = ( isset( $row['rowcount'] ) ) ?
$row['rowcount'] : 0;
1471 * Removes most variables from an SQL query and replaces them with X or N for numbers.
1472 * It's only slightly flawed. Don't use for anything important.
1474 * @param $sql String A SQL Query
1478 static function generalizeSQL( $sql ) {
1479 # This does the same as the regexp below would do, but in such a way
1480 # as to avoid crashing php on some large strings.
1481 # $sql = preg_replace ( "/'([^\\\\']|\\\\.)*'|\"([^\\\\\"]|\\\\.)*\"/", "'X'", $sql);
1483 $sql = str_replace ( "\\\\", '', $sql );
1484 $sql = str_replace ( "\\'", '', $sql );
1485 $sql = str_replace ( "\\\"", '', $sql );
1486 $sql = preg_replace ( "/'.*'/s", "'X'", $sql );
1487 $sql = preg_replace ( '/".*"/s', "'X'", $sql );
1489 # All newlines, tabs, etc replaced by single space
1490 $sql = preg_replace ( '/\s+/', ' ', $sql );
1493 $sql = preg_replace ( '/-?[0-9]+/s', 'N', $sql );
1499 * Determines whether a field exists in a table
1501 * @param $table String: table name
1502 * @param $field String: filed to check on that table
1503 * @param $fname String: calling function name (optional)
1504 * @return Boolean: whether $table has filed $field
1506 function fieldExists( $table, $field, $fname = 'DatabaseBase::fieldExists' ) {
1507 $info = $this->fieldInfo( $table, $field );
1513 * Determines whether an index exists
1514 * Usually throws a DBQueryError on failure
1515 * If errors are explicitly ignored, returns NULL on failure
1519 * @param $fname string
1523 function indexExists( $table, $index, $fname = 'DatabaseBase::indexExists' ) {
1524 $info = $this->indexInfo( $table, $index, $fname );
1525 if ( is_null( $info ) ) {
1528 return $info !== false;
1533 * Query whether a given table exists
1535 * @param $table string
1539 function tableExists( $table ) {
1540 $table = $this->tableName( $table );
1541 $old = $this->ignoreErrors( true );
1542 $res = $this->query( "SELECT 1 FROM $table LIMIT 1", __METHOD__
);
1543 $this->ignoreErrors( $old );
1550 * mysql_field_type() wrapper
1552 function fieldType( $res, $index ) {
1553 if ( $res instanceof ResultWrapper
) {
1554 $res = $res->result
;
1557 return mysql_field_type( $res, $index );
1561 * Determines if a given index is unique
1563 * @param $table string
1564 * @param $index string
1568 function indexUnique( $table, $index ) {
1569 $indexInfo = $this->indexInfo( $table, $index );
1571 if ( !$indexInfo ) {
1575 return !$indexInfo[0]->Non_unique
;
1579 * Helper for DatabaseBase::insert().
1581 * @param $options array
1584 function makeInsertOptions( $options ) {
1585 return implode( ' ', $options );
1589 * INSERT wrapper, inserts an array into a table.
1593 * - A single associative array. The array keys are the field names, and
1594 * the values are the values to insert. The values are treated as data
1595 * and will be quoted appropriately. If NULL is inserted, this will be
1596 * converted to a database NULL.
1597 * - An array with numeric keys, holding a list of associative arrays.
1598 * This causes a multi-row INSERT on DBMSs that support it. The keys in
1599 * each subarray must be identical to each other, and in the same order.
1601 * Usually throws a DBQueryError on failure. If errors are explicitly ignored,
1604 * $options is an array of options, with boolean options encoded as values
1605 * with numeric keys, in the same style as $options in
1606 * DatabaseBase::select(). Supported options are:
1608 * - IGNORE: Boolean: if present, duplicate key errors are ignored, and
1609 * any rows which cause duplicate key errors are not inserted. It's
1610 * possible to determine how many rows were successfully inserted using
1611 * DatabaseBase::affectedRows().
1613 * @param $table String Table name. This will be passed through
1614 * DatabaseBase::tableName().
1615 * @param $a Array of rows to insert
1616 * @param $fname String Calling function name (use __METHOD__) for logs/profiling
1617 * @param $options Array of options
1621 function insert( $table, $a, $fname = 'DatabaseBase::insert', $options = array() ) {
1622 # No rows to insert, easy just return now
1623 if ( !count( $a ) ) {
1627 $table = $this->tableName( $table );
1629 if ( !is_array( $options ) ) {
1630 $options = array( $options );
1633 $options = $this->makeInsertOptions( $options );
1635 if ( isset( $a[0] ) && is_array( $a[0] ) ) {
1637 $keys = array_keys( $a[0] );
1640 $keys = array_keys( $a );
1643 $sql = 'INSERT ' . $options .
1644 " INTO $table (" . implode( ',', $keys ) . ') VALUES ';
1648 foreach ( $a as $row ) {
1654 $sql .= '(' . $this->makeList( $row ) . ')';
1657 $sql .= '(' . $this->makeList( $a ) . ')';
1660 return (bool)$this->query( $sql, $fname );
1664 * Make UPDATE options for the DatabaseBase::update function
1666 * @param $options Array: The options passed to DatabaseBase::update
1669 function makeUpdateOptions( $options ) {
1670 if ( !is_array( $options ) ) {
1671 $options = array( $options );
1676 if ( in_array( 'LOW_PRIORITY', $options ) ) {
1677 $opts[] = $this->lowPriorityOption();
1680 if ( in_array( 'IGNORE', $options ) ) {
1684 return implode( ' ', $opts );
1688 * UPDATE wrapper. Takes a condition array and a SET array.
1690 * @param $table String name of the table to UPDATE. This will be passed through
1691 * DatabaseBase::tableName().
1693 * @param $values Array: An array of values to SET. For each array element,
1694 * the key gives the field name, and the value gives the data
1695 * to set that field to. The data will be quoted by
1696 * DatabaseBase::addQuotes().
1698 * @param $conds Array: An array of conditions (WHERE). See
1699 * DatabaseBase::select() for the details of the format of
1700 * condition arrays. Use '*' to update all rows.
1702 * @param $fname String: The function name of the caller (from __METHOD__),
1703 * for logging and profiling.
1705 * @param $options Array: An array of UPDATE options, can be:
1706 * - IGNORE: Ignore unique key conflicts
1707 * - LOW_PRIORITY: MySQL-specific, see MySQL manual.
1710 function update( $table, $values, $conds, $fname = 'DatabaseBase::update', $options = array() ) {
1711 $table = $this->tableName( $table );
1712 $opts = $this->makeUpdateOptions( $options );
1713 $sql = "UPDATE $opts $table SET " . $this->makeList( $values, LIST_SET
);
1715 if ( $conds !== array() && $conds !== '*' ) {
1716 $sql .= " WHERE " . $this->makeList( $conds, LIST_AND
);
1719 return $this->query( $sql, $fname );
1723 * Makes an encoded list of strings from an array
1724 * @param $a Array containing the data
1725 * @param $mode int Constant
1726 * - LIST_COMMA: comma separated, no field names
1727 * - LIST_AND: ANDed WHERE clause (without the WHERE). See
1728 * the documentation for $conds in DatabaseBase::select().
1729 * - LIST_OR: ORed WHERE clause (without the WHERE)
1730 * - LIST_SET: comma separated with field names, like a SET clause
1731 * - LIST_NAMES: comma separated field names
1735 function makeList( $a, $mode = LIST_COMMA
) {
1736 if ( !is_array( $a ) ) {
1737 throw new DBUnexpectedError( $this, 'DatabaseBase::makeList called with incorrect parameters' );
1743 foreach ( $a as $field => $value ) {
1745 if ( $mode == LIST_AND
) {
1747 } elseif ( $mode == LIST_OR
) {
1756 if ( ( $mode == LIST_AND ||
$mode == LIST_OR
) && is_numeric( $field ) ) {
1757 $list .= "($value)";
1758 } elseif ( ( $mode == LIST_SET
) && is_numeric( $field ) ) {
1760 } elseif ( ( $mode == LIST_AND ||
$mode == LIST_OR
) && is_array( $value ) ) {
1761 if ( count( $value ) == 0 ) {
1762 throw new MWException( __METHOD__
. ': empty input' );
1763 } elseif ( count( $value ) == 1 ) {
1764 // Special-case single values, as IN isn't terribly efficient
1765 // Don't necessarily assume the single key is 0; we don't
1766 // enforce linear numeric ordering on other arrays here.
1767 $value = array_values( $value );
1768 $list .= $field . " = " . $this->addQuotes( $value[0] );
1770 $list .= $field . " IN (" . $this->makeList( $value ) . ") ";
1772 } elseif ( $value === null ) {
1773 if ( $mode == LIST_AND ||
$mode == LIST_OR
) {
1774 $list .= "$field IS ";
1775 } elseif ( $mode == LIST_SET
) {
1776 $list .= "$field = ";
1780 if ( $mode == LIST_AND ||
$mode == LIST_OR ||
$mode == LIST_SET
) {
1781 $list .= "$field = ";
1783 $list .= $mode == LIST_NAMES ?
$value : $this->addQuotes( $value );
1791 * Build a partial where clause from a 2-d array such as used for LinkBatch.
1792 * The keys on each level may be either integers or strings.
1794 * @param $data Array: organized as 2-d
1795 * array(baseKeyVal => array(subKeyVal => <ignored>, ...), ...)
1796 * @param $baseKey String: field name to match the base-level keys to (eg 'pl_namespace')
1797 * @param $subKey String: field name to match the sub-level keys to (eg 'pl_title')
1798 * @return Mixed: string SQL fragment, or false if no items in array.
1800 function makeWhereFrom2d( $data, $baseKey, $subKey ) {
1803 foreach ( $data as $base => $sub ) {
1804 if ( count( $sub ) ) {
1805 $conds[] = $this->makeList(
1806 array( $baseKey => $base, $subKey => array_keys( $sub ) ),
1812 return $this->makeList( $conds, LIST_OR
);
1814 // Nothing to search for...
1820 * Bitwise operations
1827 function bitNot( $field ) {
1833 * @param $fieldRight
1836 function bitAnd( $fieldLeft, $fieldRight ) {
1837 return "($fieldLeft & $fieldRight)";
1842 * @param $fieldRight
1845 function bitOr( $fieldLeft, $fieldRight ) {
1846 return "($fieldLeft | $fieldRight)";
1850 * Change the current database
1852 * @todo Explain what exactly will fail if this is not overridden.
1856 * @return bool Success or failure
1858 function selectDB( $db ) {
1859 # Stub. Shouldn't cause serious problems if it's not overridden, but
1860 # if your database engine supports a concept similar to MySQL's
1861 # databases you may as well.
1862 $this->mDBname
= $db;
1867 * Get the current DB name
1869 function getDBname() {
1870 return $this->mDBname
;
1874 * Get the server hostname or IP address
1876 function getServer() {
1877 return $this->mServer
;
1881 * Format a table name ready for use in constructing an SQL query
1883 * This does two important things: it quotes the table names to clean them up,
1884 * and it adds a table prefix if only given a table name with no quotes.
1886 * All functions of this object which require a table name call this function
1887 * themselves. Pass the canonical name to such functions. This is only needed
1888 * when calling query() directly.
1890 * @param $name String: database table name
1891 * @param $format String One of:
1892 * quoted - Automatically pass the table name through addIdentifierQuotes()
1893 * so that it can be used in a query.
1894 * raw - Do not add identifier quotes to the table name
1895 * @return String: full database name
1897 function tableName( $name, $format = 'quoted' ) {
1898 global $wgSharedDB, $wgSharedPrefix, $wgSharedTables;
1899 # Skip the entire process when we have a string quoted on both ends.
1900 # Note that we check the end so that we will still quote any use of
1901 # use of `database`.table. But won't break things if someone wants
1902 # to query a database table with a dot in the name.
1903 if ( $this->isQuotedIdentifier( $name ) ) {
1907 # Lets test for any bits of text that should never show up in a table
1908 # name. Basically anything like JOIN or ON which are actually part of
1909 # SQL queries, but may end up inside of the table value to combine
1910 # sql. Such as how the API is doing.
1911 # Note that we use a whitespace test rather than a \b test to avoid
1912 # any remote case where a word like on may be inside of a table name
1913 # surrounded by symbols which may be considered word breaks.
1914 if ( preg_match( '/(^|\s)(DISTINCT|JOIN|ON|AS)(\s|$)/i', $name ) !== 0 ) {
1918 # Split database and table into proper variables.
1919 # We reverse the explode so that database.table and table both output
1920 # the correct table.
1921 $dbDetails = array_reverse( explode( '.', $name, 2 ) );
1922 if ( isset( $dbDetails[1] ) ) {
1923 list( $table, $database ) = $dbDetails;
1925 list( $table ) = $dbDetails;
1927 $prefix = $this->mTablePrefix
; # Default prefix
1929 # A database name has been specified in input. We don't want any
1931 if ( isset( $database ) ) {
1935 # Note that we use the long format because php will complain in in_array if
1936 # the input is not an array, and will complain in is_array if it is not set.
1937 if ( !isset( $database ) # Don't use shared database if pre selected.
1938 && isset( $wgSharedDB ) # We have a shared database
1939 && !$this->isQuotedIdentifier( $table ) # Paranoia check to prevent shared tables listing '`table`'
1940 && isset( $wgSharedTables )
1941 && is_array( $wgSharedTables )
1942 && in_array( $table, $wgSharedTables ) ) { # A shared table is selected
1943 $database = $wgSharedDB;
1944 $prefix = isset( $wgSharedPrefix ) ?
$wgSharedPrefix : $prefix;
1947 # Quote the $database and $table and apply the prefix if not quoted.
1948 if ( isset( $database ) ) {
1949 $database = ( $format == 'quoted' ||
$this->isQuotedIdentifier( $database ) ?
$database : $this->addIdentifierQuotes( $database ) );
1952 $table = "{$prefix}{$table}";
1953 if ( $format == 'quoted' && !$this->isQuotedIdentifier( $table ) ) {
1954 $table = $this->addIdentifierQuotes( "{$table}" );
1957 # Merge our database and table into our final table name.
1958 $tableName = ( isset( $database ) ?
"{$database}.{$table}" : "{$table}" );
1964 * Fetch a number of table names into an array
1965 * This is handy when you need to construct SQL for joins
1968 * extract($dbr->tableNames('user','watchlist'));
1969 * $sql = "SELECT wl_namespace,wl_title FROM $watchlist,$user
1970 * WHERE wl_user=user_id AND wl_user=$nameWithQuotes";
1974 public function tableNames() {
1975 $inArray = func_get_args();
1978 foreach ( $inArray as $name ) {
1979 $retVal[$name] = $this->tableName( $name );
1986 * Fetch a number of table names into an zero-indexed numerical array
1987 * This is handy when you need to construct SQL for joins
1990 * list( $user, $watchlist ) = $dbr->tableNamesN('user','watchlist');
1991 * $sql = "SELECT wl_namespace,wl_title FROM $watchlist,$user
1992 * WHERE wl_user=user_id AND wl_user=$nameWithQuotes";
1996 public function tableNamesN() {
1997 $inArray = func_get_args();
2000 foreach ( $inArray as $name ) {
2001 $retVal[] = $this->tableName( $name );
2008 * Get an aliased table name
2009 * e.g. tableName AS newTableName
2011 * @param $name string Table name, see tableName()
2012 * @param $alias string|bool Alias (optional)
2013 * @return string SQL name for aliased table. Will not alias a table to its own name
2015 public function tableNameWithAlias( $name, $alias = false ) {
2016 if ( !$alias ||
$alias == $name ) {
2017 return $this->tableName( $name );
2019 return $this->tableName( $name ) . ' ' . $this->addIdentifierQuotes( $alias );
2024 * Gets an array of aliased table names
2026 * @param $tables array( [alias] => table )
2027 * @return array of strings, see tableNameWithAlias()
2029 public function tableNamesWithAlias( $tables ) {
2031 foreach ( $tables as $alias => $table ) {
2032 if ( is_numeric( $alias ) ) {
2035 $retval[] = $this->tableNameWithAlias( $table, $alias );
2041 * Get the aliased table name clause for a FROM clause
2042 * which might have a JOIN and/or USE INDEX clause
2044 * @param $tables array ( [alias] => table )
2045 * @param $use_index array Same as for select()
2046 * @param $join_conds array Same as for select()
2049 protected function tableNamesWithUseIndexOrJOIN(
2050 $tables, $use_index = array(), $join_conds = array()
2054 $use_index = (array)$use_index;
2055 $join_conds = (array)$join_conds;
2057 foreach ( $tables as $alias => $table ) {
2058 if ( !is_string( $alias ) ) {
2059 // No alias? Set it equal to the table name
2062 // Is there a JOIN clause for this table?
2063 if ( isset( $join_conds[$alias] ) ) {
2064 list( $joinType, $conds ) = $join_conds[$alias];
2065 $tableClause = $joinType;
2066 $tableClause .= ' ' . $this->tableNameWithAlias( $table, $alias );
2067 if ( isset( $use_index[$alias] ) ) { // has USE INDEX?
2068 $use = $this->useIndexClause( implode( ',', (array)$use_index[$alias] ) );
2070 $tableClause .= ' ' . $use;
2073 $on = $this->makeList( (array)$conds, LIST_AND
);
2075 $tableClause .= ' ON (' . $on . ')';
2078 $retJOIN[] = $tableClause;
2079 // Is there an INDEX clause for this table?
2080 } elseif ( isset( $use_index[$alias] ) ) {
2081 $tableClause = $this->tableNameWithAlias( $table, $alias );
2082 $tableClause .= ' ' . $this->useIndexClause(
2083 implode( ',', (array)$use_index[$alias] ) );
2085 $ret[] = $tableClause;
2087 $tableClause = $this->tableNameWithAlias( $table, $alias );
2089 $ret[] = $tableClause;
2093 // We can't separate explicit JOIN clauses with ',', use ' ' for those
2094 $straightJoins = !empty( $ret ) ?
implode( ',', $ret ) : "";
2095 $otherJoins = !empty( $retJOIN ) ?
implode( ' ', $retJOIN ) : "";
2097 // Compile our final table clause
2098 return implode( ' ', array( $straightJoins, $otherJoins ) );
2102 * Get the name of an index in a given table
2108 function indexName( $index ) {
2109 // Backwards-compatibility hack
2111 'ar_usertext_timestamp' => 'usertext_timestamp',
2112 'un_user_id' => 'user_id',
2113 'un_user_ip' => 'user_ip',
2116 if ( isset( $renamed[$index] ) ) {
2117 return $renamed[$index];
2124 * If it's a string, adds quotes and backslashes
2125 * Otherwise returns as-is
2131 function addQuotes( $s ) {
2132 if ( $s === null ) {
2135 # This will also quote numeric values. This should be harmless,
2136 # and protects against weird problems that occur when they really
2137 # _are_ strings such as article titles and string->number->string
2138 # conversion is not 1:1.
2139 return "'" . $this->strencode( $s ) . "'";
2144 * Quotes an identifier using `backticks` or "double quotes" depending on the database type.
2145 * MySQL uses `backticks` while basically everything else uses double quotes.
2146 * Since MySQL is the odd one out here the double quotes are our generic
2147 * and we implement backticks in DatabaseMysql.
2153 public function addIdentifierQuotes( $s ) {
2154 return '"' . str_replace( '"', '""', $s ) . '"';
2158 * Returns if the given identifier looks quoted or not according to
2159 * the database convention for quoting identifiers .
2161 * @param $name string
2165 public function isQuotedIdentifier( $name ) {
2166 return $name[0] == '"' && substr( $name, -1, 1 ) == '"';
2170 * Backwards compatibility, identifier quoting originated in DatabasePostgres
2171 * which used quote_ident which does not follow our naming conventions
2172 * was renamed to addIdentifierQuotes.
2173 * @deprecated since 1.18 use addIdentifierQuotes
2179 function quote_ident( $s ) {
2180 wfDeprecated( __METHOD__
);
2181 return $this->addIdentifierQuotes( $s );
2185 * Escape string for safe LIKE usage.
2186 * WARNING: you should almost never use this function directly,
2187 * instead use buildLike() that escapes everything automatically
2188 * @deprecated since 1.17, warnings in 1.17, removed in ???
2194 public function escapeLike( $s ) {
2195 wfDeprecated( __METHOD__
);
2196 return $this->escapeLikeInternal( $s );
2203 protected function escapeLikeInternal( $s ) {
2204 $s = str_replace( '\\', '\\\\', $s );
2205 $s = $this->strencode( $s );
2206 $s = str_replace( array( '%', '_' ), array( '\%', '\_' ), $s );
2212 * LIKE statement wrapper, receives a variable-length argument list with parts of pattern to match
2213 * containing either string literals that will be escaped or tokens returned by anyChar() or anyString().
2214 * Alternatively, the function could be provided with an array of aforementioned parameters.
2216 * Example: $dbr->buildLike( 'My_page_title/', $dbr->anyString() ) returns a LIKE clause that searches
2217 * for subpages of 'My page title'.
2218 * Alternatively: $pattern = array( 'My_page_title/', $dbr->anyString() ); $query .= $dbr->buildLike( $pattern );
2221 * @return String: fully built LIKE statement
2223 function buildLike() {
2224 $params = func_get_args();
2226 if ( count( $params ) > 0 && is_array( $params[0] ) ) {
2227 $params = $params[0];
2232 foreach ( $params as $value ) {
2233 if ( $value instanceof LikeMatch
) {
2234 $s .= $value->toString();
2236 $s .= $this->escapeLikeInternal( $value );
2240 return " LIKE '" . $s . "' ";
2244 * Returns a token for buildLike() that denotes a '_' to be used in a LIKE query
2248 function anyChar() {
2249 return new LikeMatch( '_' );
2253 * Returns a token for buildLike() that denotes a '%' to be used in a LIKE query
2257 function anyString() {
2258 return new LikeMatch( '%' );
2262 * Returns an appropriately quoted sequence value for inserting a new row.
2263 * MySQL has autoincrement fields, so this is just NULL. But the PostgreSQL
2264 * subclass will return an integer, and save the value for insertId()
2266 function nextSequenceValue( $seqName ) {
2271 * USE INDEX clause. Unlikely to be useful for anything but MySQL. This
2272 * is only needed because a) MySQL must be as efficient as possible due to
2273 * its use on Wikipedia, and b) MySQL 4.0 is kind of dumb sometimes about
2274 * which index to pick. Anyway, other databases might have different
2275 * indexes on a given table. So don't bother overriding this unless you're
2278 function useIndexClause( $index ) {
2283 * REPLACE query wrapper.
2285 * REPLACE is a very handy MySQL extension, which functions like an INSERT
2286 * except that when there is a duplicate key error, the old row is deleted
2287 * and the new row is inserted in its place.
2289 * We simulate this with standard SQL with a DELETE followed by INSERT. To
2290 * perform the delete, we need to know what the unique indexes are so that
2291 * we know how to find the conflicting rows.
2293 * It may be more efficient to leave off unique indexes which are unlikely
2294 * to collide. However if you do this, you run the risk of encountering
2295 * errors which wouldn't have occurred in MySQL.
2297 * @param $table String: The table to replace the row(s) in.
2298 * @param $rows array Can be either a single row to insert, or multiple rows,
2299 * in the same format as for DatabaseBase::insert()
2300 * @param $uniqueIndexes array is an array of indexes. Each element may be either
2301 * a field name or an array of field names
2302 * @param $fname String: Calling function name (use __METHOD__) for logs/profiling
2304 function replace( $table, $uniqueIndexes, $rows, $fname = 'DatabaseBase::replace' ) {
2305 $quotedTable = $this->tableName( $table );
2307 if ( count( $rows ) == 0 ) {
2312 if ( !is_array( reset( $rows ) ) ) {
2313 $rows = array( $rows );
2316 foreach( $rows as $row ) {
2317 # Delete rows which collide
2318 if ( $uniqueIndexes ) {
2319 $sql = "DELETE FROM $quotedTable WHERE ";
2321 foreach ( $uniqueIndexes as $index ) {
2328 if ( is_array( $index ) ) {
2330 foreach ( $index as $col ) {
2336 $sql .= $col . '=' . $this->addQuotes( $row[$col] );
2339 $sql .= $index . '=' . $this->addQuotes( $row[$index] );
2343 $this->query( $sql, $fname );
2346 # Now insert the row
2347 $this->insert( $table, $row );
2352 * REPLACE query wrapper for MySQL and SQLite, which have a native REPLACE
2355 * @param $table Table name
2356 * @param $rows Rows to insert
2357 * @param $fname Caller function name
2359 * @return ResultWrapper
2361 protected function nativeReplace( $table, $rows, $fname ) {
2362 $table = $this->tableName( $table );
2365 if ( !is_array( reset( $rows ) ) ) {
2366 $rows = array( $rows );
2369 $sql = "REPLACE INTO $table (" . implode( ',', array_keys( $rows[0] ) ) . ') VALUES ';
2372 foreach ( $rows as $row ) {
2379 $sql .= '(' . $this->makeList( $row ) . ')';
2382 return $this->query( $sql, $fname );
2386 * DELETE where the condition is a join.
2388 * MySQL overrides this to use a multi-table DELETE syntax, in other databases
2389 * we use sub-selects
2391 * For safety, an empty $conds will not delete everything. If you want to
2392 * delete all rows where the join condition matches, set $conds='*'.
2394 * DO NOT put the join condition in $conds.
2396 * @param $delTable String: The table to delete from.
2397 * @param $joinTable String: The other table.
2398 * @param $delVar String: The variable to join on, in the first table.
2399 * @param $joinVar String: The variable to join on, in the second table.
2400 * @param $conds Array: Condition array of field names mapped to variables,
2401 * ANDed together in the WHERE clause
2402 * @param $fname String: Calling function name (use __METHOD__) for
2405 function deleteJoin( $delTable, $joinTable, $delVar, $joinVar, $conds,
2406 $fname = 'DatabaseBase::deleteJoin' )
2409 throw new DBUnexpectedError( $this,
2410 'DatabaseBase::deleteJoin() called with empty $conds' );
2413 $delTable = $this->tableName( $delTable );
2414 $joinTable = $this->tableName( $joinTable );
2415 $sql = "DELETE FROM $delTable WHERE $delVar IN (SELECT $joinVar FROM $joinTable ";
2416 if ( $conds != '*' ) {
2417 $sql .= 'WHERE ' . $this->makeList( $conds, LIST_AND
);
2421 $this->query( $sql, $fname );
2425 * Returns the size of a text field, or -1 for "unlimited"
2427 * @param $table string
2428 * @param $field string
2432 function textFieldSize( $table, $field ) {
2433 $table = $this->tableName( $table );
2434 $sql = "SHOW COLUMNS FROM $table LIKE \"$field\";";
2435 $res = $this->query( $sql, 'DatabaseBase::textFieldSize' );
2436 $row = $this->fetchObject( $res );
2440 if ( preg_match( '/\((.*)\)/', $row->Type
, $m ) ) {
2450 * A string to insert into queries to show that they're low-priority, like
2451 * MySQL's LOW_PRIORITY. If no such feature exists, return an empty
2452 * string and nothing bad should happen.
2454 * @return string Returns the text of the low priority option if it is
2455 * supported, or a blank string otherwise
2457 function lowPriorityOption() {
2462 * DELETE query wrapper.
2464 * @param $table Array Table name
2465 * @param $conds String|Array of conditions. See $conds in DatabaseBase::select() for
2466 * the format. Use $conds == "*" to delete all rows
2467 * @param $fname String name of the calling function
2471 function delete( $table, $conds, $fname = 'DatabaseBase::delete' ) {
2473 throw new DBUnexpectedError( $this, 'DatabaseBase::delete() called with no conditions' );
2476 $table = $this->tableName( $table );
2477 $sql = "DELETE FROM $table";
2479 if ( $conds != '*' ) {
2480 $sql .= ' WHERE ' . $this->makeList( $conds, LIST_AND
);
2483 return $this->query( $sql, $fname );
2487 * INSERT SELECT wrapper. Takes data from a SELECT query and inserts it
2488 * into another table.
2490 * @param $destTable string The table name to insert into
2491 * @param $srcTable string|array May be either a table name, or an array of table names
2492 * to include in a join.
2494 * @param $varMap array must be an associative array of the form
2495 * array( 'dest1' => 'source1', ...). Source items may be literals
2496 * rather than field names, but strings should be quoted with
2497 * DatabaseBase::addQuotes()
2499 * @param $conds array Condition array. See $conds in DatabaseBase::select() for
2500 * the details of the format of condition arrays. May be "*" to copy the
2503 * @param $fname string The function name of the caller, from __METHOD__
2505 * @param $insertOptions array Options for the INSERT part of the query, see
2506 * DatabaseBase::insert() for details.
2507 * @param $selectOptions array Options for the SELECT part of the query, see
2508 * DatabaseBase::select() for details.
2510 * @return ResultWrapper
2512 function insertSelect( $destTable, $srcTable, $varMap, $conds,
2513 $fname = 'DatabaseBase::insertSelect',
2514 $insertOptions = array(), $selectOptions = array() )
2516 $destTable = $this->tableName( $destTable );
2518 if ( is_array( $insertOptions ) ) {
2519 $insertOptions = implode( ' ', $insertOptions );
2522 if ( !is_array( $selectOptions ) ) {
2523 $selectOptions = array( $selectOptions );
2526 list( $startOpts, $useIndex, $tailOpts ) = $this->makeSelectOptions( $selectOptions );
2528 if ( is_array( $srcTable ) ) {
2529 $srcTable = implode( ',', array_map( array( &$this, 'tableName' ), $srcTable ) );
2531 $srcTable = $this->tableName( $srcTable );
2534 $sql = "INSERT $insertOptions INTO $destTable (" . implode( ',', array_keys( $varMap ) ) . ')' .
2535 " SELECT $startOpts " . implode( ',', $varMap ) .
2536 " FROM $srcTable $useIndex ";
2538 if ( $conds != '*' ) {
2539 $sql .= ' WHERE ' . $this->makeList( $conds, LIST_AND
);
2542 $sql .= " $tailOpts";
2544 return $this->query( $sql, $fname );
2548 * Construct a LIMIT query with optional offset. This is used for query
2549 * pages. The SQL should be adjusted so that only the first $limit rows
2550 * are returned. If $offset is provided as well, then the first $offset
2551 * rows should be discarded, and the next $limit rows should be returned.
2552 * If the result of the query is not ordered, then the rows to be returned
2553 * are theoretically arbitrary.
2555 * $sql is expected to be a SELECT, if that makes a difference. For
2556 * UPDATE, limitResultForUpdate should be used.
2558 * The version provided by default works in MySQL and SQLite. It will very
2559 * likely need to be overridden for most other DBMSes.
2561 * @param $sql String SQL query we will append the limit too
2562 * @param $limit Integer the SQL limit
2563 * @param $offset Integer|false the SQL offset (default false)
2567 function limitResult( $sql, $limit, $offset = false ) {
2568 if ( !is_numeric( $limit ) ) {
2569 throw new DBUnexpectedError( $this, "Invalid non-numeric limit passed to limitResult()\n" );
2572 return "$sql LIMIT "
2573 . ( ( is_numeric( $offset ) && $offset != 0 ) ?
"{$offset}," : "" )
2582 function limitResultForUpdate( $sql, $num ) {
2583 return $this->limitResult( $sql, $num, 0 );
2587 * Returns true if current database backend supports ORDER BY or LIMIT for separate subqueries
2588 * within the UNION construct.
2591 function unionSupportsOrderAndLimit() {
2592 return true; // True for almost every DB supported
2596 * Construct a UNION query
2597 * This is used for providing overload point for other DB abstractions
2598 * not compatible with the MySQL syntax.
2599 * @param $sqls Array: SQL statements to combine
2600 * @param $all Boolean: use UNION ALL
2601 * @return String: SQL fragment
2603 function unionQueries( $sqls, $all ) {
2604 $glue = $all ?
') UNION ALL (' : ') UNION (';
2605 return '(' . implode( $glue, $sqls ) . ')';
2609 * Returns an SQL expression for a simple conditional. This doesn't need
2610 * to be overridden unless CASE isn't supported in your DBMS.
2612 * @param $cond String: SQL expression which will result in a boolean value
2613 * @param $trueVal String: SQL expression to return if true
2614 * @param $falseVal String: SQL expression to return if false
2615 * @return String: SQL fragment
2617 function conditional( $cond, $trueVal, $falseVal ) {
2618 return " (CASE WHEN $cond THEN $trueVal ELSE $falseVal END) ";
2622 * Returns a comand for str_replace function in SQL query.
2623 * Uses REPLACE() in MySQL
2625 * @param $orig String: column to modify
2626 * @param $old String: column to seek
2627 * @param $new String: column to replace with
2631 function strreplace( $orig, $old, $new ) {
2632 return "REPLACE({$orig}, {$old}, {$new})";
2636 * Determines if the last failure was due to a deadlock
2641 function wasDeadlock() {
2646 * Determines if the last query error was something that should be dealt
2647 * with by pinging the connection and reissuing the query.
2652 function wasErrorReissuable() {
2657 * Determines if the last failure was due to the database being read-only.
2662 function wasReadOnlyError() {
2667 * Perform a deadlock-prone transaction.
2669 * This function invokes a callback function to perform a set of write
2670 * queries. If a deadlock occurs during the processing, the transaction
2671 * will be rolled back and the callback function will be called again.
2674 * $dbw->deadlockLoop( callback, ... );
2676 * Extra arguments are passed through to the specified callback function.
2678 * Returns whatever the callback function returned on its successful,
2679 * iteration, or false on error, for example if the retry limit was
2684 function deadlockLoop() {
2685 $myFname = 'DatabaseBase::deadlockLoop';
2688 $args = func_get_args();
2689 $function = array_shift( $args );
2690 $oldIgnore = $this->ignoreErrors( true );
2691 $tries = DEADLOCK_TRIES
;
2693 if ( is_array( $function ) ) {
2694 $fname = $function[0];
2700 $retVal = call_user_func_array( $function, $args );
2701 $error = $this->lastError();
2702 $errno = $this->lastErrno();
2703 $sql = $this->lastQuery();
2706 if ( $this->wasDeadlock() ) {
2708 usleep( mt_rand( DEADLOCK_DELAY_MIN
, DEADLOCK_DELAY_MAX
) );
2710 $this->reportQueryError( $error, $errno, $sql, $fname );
2713 } while ( $this->wasDeadlock() && --$tries > 0 );
2715 $this->ignoreErrors( $oldIgnore );
2717 if ( $tries <= 0 ) {
2718 $this->rollback( $myFname );
2719 $this->reportQueryError( $error, $errno, $sql, $fname );
2722 $this->commit( $myFname );
2728 * Wait for the slave to catch up to a given master position.
2730 * @param $pos DBMasterPos object
2731 * @param $timeout Integer: the maximum number of seconds to wait for
2734 * @return An integer: zero if the slave was past that position already,
2735 * greater than zero if we waited for some period of time, less than
2736 * zero if we timed out.
2738 function masterPosWait( DBMasterPos
$pos, $timeout ) {
2739 $fname = 'DatabaseBase::masterPosWait';
2740 wfProfileIn( $fname );
2742 if ( !is_null( $this->mFakeSlaveLag
) ) {
2743 $wait = intval( ( $pos->pos
- microtime( true ) +
$this->mFakeSlaveLag
) * 1e6
);
2745 if ( $wait > $timeout * 1e6
) {
2746 wfDebug( "Fake slave timed out waiting for $pos ($wait us)\n" );
2747 wfProfileOut( $fname );
2749 } elseif ( $wait > 0 ) {
2750 wfDebug( "Fake slave waiting $wait us\n" );
2752 wfProfileOut( $fname );
2755 wfDebug( "Fake slave up to date ($wait us)\n" );
2756 wfProfileOut( $fname );
2761 wfProfileOut( $fname );
2763 # Real waits are implemented in the subclass.
2768 * Get the replication position of this slave
2770 * @return DBMasterPos, or false if this is not a slave.
2772 function getSlavePos() {
2773 if ( !is_null( $this->mFakeSlaveLag
) ) {
2774 $pos = new MySQLMasterPos( 'fake', microtime( true ) - $this->mFakeSlaveLag
);
2775 wfDebug( __METHOD__
. ": fake slave pos = $pos\n" );
2784 * Get the position of this master
2786 * @return DBMasterPos, or false if this is not a master
2788 function getMasterPos() {
2789 if ( $this->mFakeMaster
) {
2790 return new MySQLMasterPos( 'fake', microtime( true ) );
2797 * Begin a transaction, committing any previously open transaction
2799 * @param $fname string
2801 function begin( $fname = 'DatabaseBase::begin' ) {
2802 $this->query( 'BEGIN', $fname );
2803 $this->mTrxLevel
= 1;
2809 * @param $fname string
2811 function commit( $fname = 'DatabaseBase::commit' ) {
2812 if ( $this->mTrxLevel
) {
2813 $this->query( 'COMMIT', $fname );
2814 $this->mTrxLevel
= 0;
2819 * Rollback a transaction.
2820 * No-op on non-transactional databases.
2822 * @param $fname string
2824 function rollback( $fname = 'DatabaseBase::rollback' ) {
2825 if ( $this->mTrxLevel
) {
2826 $this->query( 'ROLLBACK', $fname, true );
2827 $this->mTrxLevel
= 0;
2832 * Creates a new table with structure copied from existing table
2833 * Note that unlike most database abstraction functions, this function does not
2834 * automatically append database prefix, because it works at a lower
2835 * abstraction level.
2836 * The table names passed to this function shall not be quoted (this
2837 * function calls addIdentifierQuotes when needed).
2839 * @param $oldName String: name of table whose structure should be copied
2840 * @param $newName String: name of table to be created
2841 * @param $temporary Boolean: whether the new table should be temporary
2842 * @param $fname String: calling function name
2843 * @return Boolean: true if operation was successful
2845 function duplicateTableStructure( $oldName, $newName, $temporary = false,
2846 $fname = 'DatabaseBase::duplicateTableStructure' )
2848 throw new MWException(
2849 'DatabaseBase::duplicateTableStructure is not implemented in descendant class' );
2853 * List all tables on the database
2855 * @param $prefix Only show tables with this prefix, e.g. mw_
2856 * @param $fname String: calling function name
2858 function listTables( $prefix = null, $fname = 'DatabaseBase::listTables' ) {
2859 throw new MWException( 'DatabaseBase::listTables is not implemented in descendant class' );
2863 * Convert a timestamp in one of the formats accepted by wfTimestamp()
2864 * to the format used for inserting into timestamp fields in this DBMS.
2866 * The result is unquoted, and needs to be passed through addQuotes()
2867 * before it can be included in raw SQL.
2869 * @param $ts string|int
2873 function timestamp( $ts = 0 ) {
2874 return wfTimestamp( TS_MW
, $ts );
2878 * Convert a timestamp in one of the formats accepted by wfTimestamp()
2879 * to the format used for inserting into timestamp fields in this DBMS. If
2880 * NULL is input, it is passed through, allowing NULL values to be inserted
2881 * into timestamp fields.
2883 * The result is unquoted, and needs to be passed through addQuotes()
2884 * before it can be included in raw SQL.
2886 * @param $ts string|int
2890 function timestampOrNull( $ts = null ) {
2891 if ( is_null( $ts ) ) {
2894 return $this->timestamp( $ts );
2899 * Take the result from a query, and wrap it in a ResultWrapper if
2900 * necessary. Boolean values are passed through as is, to indicate success
2901 * of write queries or failure.
2903 * Once upon a time, DatabaseBase::query() returned a bare MySQL result
2904 * resource, and it was necessary to call this function to convert it to
2905 * a wrapper. Nowadays, raw database objects are never exposed to external
2906 * callers, so this is unnecessary in external code. For compatibility with
2907 * old code, ResultWrapper objects are passed through unaltered.
2909 * @param $result bool|ResultWrapper
2911 * @param bool|ResultWrapper
2913 function resultObject( $result ) {
2914 if ( empty( $result ) ) {
2916 } elseif ( $result instanceof ResultWrapper
) {
2918 } elseif ( $result === true ) {
2919 // Successful write query
2922 return new ResultWrapper( $this, $result );
2927 * Return aggregated value alias
2930 * @param $valuename string
2934 function aggregateValue ( $valuedata, $valuename = 'value' ) {
2939 * Ping the server and try to reconnect if it there is no connection
2941 * @return bool Success or failure
2944 # Stub. Not essential to override.
2949 * Get slave lag. Currently supported only by MySQL.
2951 * Note that this function will generate a fatal error on many
2952 * installations. Most callers should use LoadBalancer::safeGetLag()
2955 * @return Database replication lag in seconds
2958 return intval( $this->mFakeSlaveLag
);
2962 * Return the maximum number of items allowed in a list, or 0 for unlimited.
2966 function maxListLen() {
2971 * Some DBMSs have a special format for inserting into blob fields, they
2972 * don't allow simple quoted strings to be inserted. To insert into such
2973 * a field, pass the data through this function before passing it to
2974 * DatabaseBase::insert().
2976 function encodeBlob( $b ) {
2981 * Some DBMSs return a special placeholder object representing blob fields
2982 * in result objects. Pass the object through this function to return the
2985 function decodeBlob( $b ) {
2990 * Override database's default connection timeout. May be useful for very
2991 * long batch queries such as full-wiki dumps, where a single query reads
2992 * out over hours or days. May or may not be necessary for non-MySQL
2993 * databases. For most purposes, leaving it as a no-op should be fine.
2995 * @param $timeout Integer in seconds
2997 public function setTimeout( $timeout ) {}
3000 * Read and execute SQL commands from a file.
3002 * Returns true on success, error string or exception on failure (depending
3003 * on object's error ignore settings).
3005 * @param $filename String: File name to open
3006 * @param $lineCallback Callback: Optional function called before reading each line
3007 * @param $resultCallback Callback: Optional function called for each MySQL result
3008 * @param $fname String: Calling function name or false if name should be
3009 * generated dynamically using $filename
3011 function sourceFile( $filename, $lineCallback = false, $resultCallback = false, $fname = false ) {
3012 wfSuppressWarnings();
3013 $fp = fopen( $filename, 'r' );
3014 wfRestoreWarnings();
3016 if ( false === $fp ) {
3017 throw new MWException( "Could not open \"{$filename}\".\n" );
3021 $fname = __METHOD__
. "( $filename )";
3025 $error = $this->sourceStream( $fp, $lineCallback, $resultCallback, $fname );
3027 catch ( MWException
$e ) {
3038 * Get the full path of a patch file. Originally based on archive()
3039 * from updaters.inc. Keep in mind this always returns a patch, as
3040 * it fails back to MySQL if no DB-specific patch can be found
3042 * @param $patch String The name of the patch, like patch-something.sql
3043 * @return String Full path to patch file
3045 public function patchPath( $patch ) {
3048 $dbType = $this->getType();
3049 if ( file_exists( "$IP/maintenance/$dbType/archives/$patch" ) ) {
3050 return "$IP/maintenance/$dbType/archives/$patch";
3052 return "$IP/maintenance/archives/$patch";
3057 * Set variables to be used in sourceFile/sourceStream, in preference to the
3058 * ones in $GLOBALS. If an array is set here, $GLOBALS will not be used at
3059 * all. If it's set to false, $GLOBALS will be used.
3061 * @param $vars False, or array mapping variable name to value.
3063 function setSchemaVars( $vars ) {
3064 $this->mSchemaVars
= $vars;
3068 * Read and execute commands from an open file handle.
3070 * Returns true on success, error string or exception on failure (depending
3071 * on object's error ignore settings).
3073 * @param $fp Resource: File handle
3074 * @param $lineCallback Callback: Optional function called before reading each line
3075 * @param $resultCallback Callback: Optional function called for each MySQL result
3076 * @param $fname String: Calling function name
3078 function sourceStream( $fp, $lineCallback = false, $resultCallback = false,
3079 $fname = 'DatabaseBase::sourceStream' )
3083 $dollarquote = false;
3085 while ( ! feof( $fp ) ) {
3086 if ( $lineCallback ) {
3087 call_user_func( $lineCallback );
3090 $line = trim( fgets( $fp ) );
3091 $sl = strlen( $line ) - 1;
3097 if ( '-' == $line[0] && '-' == $line[1] ) {
3101 # # Allow dollar quoting for function declarations
3102 if ( substr( $line, 0, 4 ) == '$mw$' ) {
3103 if ( $dollarquote ) {
3104 $dollarquote = false;
3108 $dollarquote = true;
3111 elseif ( !$dollarquote ) {
3112 if ( ';' == $line[$sl] && ( $sl < 2 ||
';' != $line[$sl - 1] ) ) {
3114 $line = substr( $line, 0, $sl );
3125 $cmd = str_replace( ';;', ";", $cmd );
3126 $cmd = $this->replaceVars( $cmd );
3127 $res = $this->query( $cmd, $fname );
3129 if ( $resultCallback ) {
3130 call_user_func( $resultCallback, $res, $this );
3133 if ( false === $res ) {
3134 $err = $this->lastError();
3135 return "Query \"{$cmd}\" failed with error code \"$err\".\n";
3147 * Database independent variable replacement. Replaces a set of variables
3148 * in an SQL statement with their contents as given by $this->getSchemaVars().
3150 * Supports '{$var}' `{$var}` and / *$var* / (without the spaces) style variables.
3152 * - '{$var}' should be used for text and is passed through the database's
3154 * - `{$var}` should be used for identifiers (eg: table and database names),
3155 * it is passed through the database's addIdentifierQuotes method which
3156 * can be overridden if the database uses something other than backticks.
3157 * - / *$var* / is just encoded, besides traditional table prefix and
3158 * table options its use should be avoided.
3160 * @param $ins String: SQL statement to replace variables in
3161 * @return String The new SQL statement with variables replaced
3163 protected function replaceSchemaVars( $ins ) {
3164 $vars = $this->getSchemaVars();
3165 foreach ( $vars as $var => $value ) {
3167 $ins = str_replace( '\'{$' . $var . '}\'', $this->addQuotes( $value ), $ins );
3169 $ins = str_replace( '`{$' . $var . '}`', $this->addIdentifierQuotes( $value ), $ins );
3171 $ins = str_replace( '/*$' . $var . '*/', $this->strencode( $value ) , $ins );
3177 * Replace variables in sourced SQL
3179 * @param $ins string
3183 protected function replaceVars( $ins ) {
3184 $ins = $this->replaceSchemaVars( $ins );
3187 $ins = preg_replace_callback( '!/\*(?:\$wgDBprefix|_)\*/([a-zA-Z_0-9]*)!',
3188 array( $this, 'tableNameCallback' ), $ins );
3191 $ins = preg_replace_callback( '!/\*i\*/([a-zA-Z_0-9]*)!',
3192 array( $this, 'indexNameCallback' ), $ins );
3198 * Get schema variables. If none have been set via setSchemaVars(), then
3199 * use some defaults from the current object.
3201 protected function getSchemaVars() {
3202 if ( $this->mSchemaVars
) {
3203 return $this->mSchemaVars
;
3205 return $this->getDefaultSchemaVars();
3210 * Get schema variables to use if none have been set via setSchemaVars().
3212 * Override this in derived classes to provide variables for tables.sql
3213 * and SQL patch files.
3217 protected function getDefaultSchemaVars() {
3222 * Table name callback
3224 * @param $matches array
3228 protected function tableNameCallback( $matches ) {
3229 return $this->tableName( $matches[1] );
3233 * Index name callback
3235 * @param $matches array
3239 protected function indexNameCallback( $matches ) {
3240 return $this->indexName( $matches[1] );
3244 * Build a concatenation list to feed into a SQL query
3245 * @param $stringList Array: list of raw SQL expressions; caller is responsible for any quoting
3248 function buildConcat( $stringList ) {
3249 return 'CONCAT(' . implode( ',', $stringList ) . ')';
3253 * Acquire a named lock
3255 * Abstracted from Filestore::lock() so child classes can implement for
3258 * @param $lockName String: name of lock to aquire
3259 * @param $method String: name of method calling us
3260 * @param $timeout Integer: timeout
3263 public function lock( $lockName, $method, $timeout = 5 ) {
3270 * @param $lockName String: Name of lock to release
3271 * @param $method String: Name of method calling us
3273 * @return Returns 1 if the lock was released, 0 if the lock was not established
3274 * by this thread (in which case the lock is not released), and NULL if the named
3275 * lock did not exist
3277 public function unlock( $lockName, $method ) {
3282 * Lock specific tables
3284 * @param $read Array of tables to lock for read access
3285 * @param $write Array of tables to lock for write access
3286 * @param $method String name of caller
3287 * @param $lowPriority bool Whether to indicate writes to be LOW PRIORITY
3291 public function lockTables( $read, $write, $method, $lowPriority = true ) {
3296 * Unlock specific tables
3298 * @param $method String the caller
3302 public function unlockTables( $method ) {
3308 * @param $tableName string
3309 * @param $fName string
3310 * @return bool|ResultWrapper
3312 public function dropTable( $tableName, $fName = 'DatabaseBase::dropTable' ) {
3313 if( !$this->tableExists( $tableName ) ) {
3316 $sql = "DROP TABLE " . $this->tableName( $tableName );
3317 if( $this->cascadingDeletes() ) {
3320 return $this->query( $sql, $fName );
3324 * Get search engine class. All subclasses of this need to implement this
3325 * if they wish to use searching.
3329 public function getSearchEngine() {
3330 return 'SearchEngineDummy';
3334 * Find out when 'infinity' is. Most DBMSes support this. This is a special
3335 * keyword for timestamps in PostgreSQL, and works with CHAR(14) as well
3336 * because "i" sorts after all numbers.
3340 public function getInfinity() {
3345 * Encode an expiry time
3347 * @param $expiry String: timestamp for expiry, or the 'infinity' string
3350 public function encodeExpiry( $expiry ) {
3351 if ( $expiry == '' ||
$expiry == $this->getInfinity() ) {
3352 return $this->getInfinity();
3354 return $this->timestamp( $expiry );
3359 * Allow or deny "big selects" for this session only. This is done by setting
3360 * the sql_big_selects session variable.
3362 * This is a MySQL-specific feature.
3364 * @param $value Mixed: true for allow, false for deny, or "default" to
3365 * restore the initial value
3367 public function setBigSelects( $value = true ) {