3 * @defgroup Database Database
5 * This file deals with database interface functions
6 * and query specifics/optimisations.
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
18 * You should have received a copy of the GNU General Public License along
19 * with this program; if not, write to the Free Software Foundation, Inc.,
20 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
21 * http://www.gnu.org/copyleft/gpl.html
27 /** Number of times to re-try an operation in case of deadlock */
28 define( 'DEADLOCK_TRIES', 4 );
29 /** Minimum time to wait before retry, in microseconds */
30 define( 'DEADLOCK_DELAY_MIN', 500000 );
31 /** Maximum time to wait before retry */
32 define( 'DEADLOCK_DELAY_MAX', 1500000 );
35 * Base interface for all DBMS-specific code. At a bare minimum, all of the
36 * following must be implemented to support MediaWiki
41 interface DatabaseType
{
43 * Get the type of the DBMS, as it appears in $wgDBtype.
50 * Open a connection to the database. Usually aborts on failure
52 * @param string $server database server host
53 * @param string $user database user name
54 * @param string $password database user password
55 * @param string $dbName database name
57 * @throws DBConnectionError
59 function open( $server, $user, $password, $dbName );
62 * Fetch the next row from the given result object, in object form.
63 * Fields can be retrieved with $row->fieldname, with fields acting like
65 * If no more rows are available, false is returned.
67 * @param $res ResultWrapper|object as returned from DatabaseBase::query(), etc.
69 * @throws DBUnexpectedError Thrown if the database returns an error
71 function fetchObject( $res );
74 * Fetch the next row from the given result object, in associative array
75 * form. Fields are retrieved with $row['fieldname'].
76 * If no more rows are available, false is returned.
78 * @param $res ResultWrapper result object as returned from DatabaseBase::query(), etc.
80 * @throws DBUnexpectedError Thrown if the database returns an error
82 function fetchRow( $res );
85 * Get the number of rows in a result object
87 * @param $res Mixed: A SQL result
90 function numRows( $res );
93 * Get the number of fields in a result object
94 * @see http://www.php.net/mysql_num_fields
96 * @param $res Mixed: A SQL result
99 function numFields( $res );
102 * Get a field name in a result object
103 * @see http://www.php.net/mysql_field_name
105 * @param $res Mixed: A SQL result
109 function fieldName( $res, $n );
112 * Get the inserted value of an auto-increment row
114 * The value inserted should be fetched from nextSequenceValue()
117 * $id = $dbw->nextSequenceValue( 'page_page_id_seq' );
118 * $dbw->insert( 'page', array( 'page_id' => $id ) );
119 * $id = $dbw->insertId();
126 * Change the position of the cursor in a result object
127 * @see http://www.php.net/mysql_data_seek
129 * @param $res Mixed: A SQL result
130 * @param $row Mixed: Either MySQL row or ResultWrapper
132 function dataSeek( $res, $row );
135 * Get the last error number
136 * @see http://www.php.net/mysql_errno
140 function lastErrno();
143 * Get a description of the last error
144 * @see http://www.php.net/mysql_error
148 function lastError();
151 * mysql_fetch_field() wrapper
152 * Returns false if the field doesn't exist
154 * @param string $table table name
155 * @param string $field field name
159 function fieldInfo( $table, $field );
162 * Get information about an index into an object
163 * @param string $table Table name
164 * @param string $index Index name
165 * @param string $fname Calling function name
166 * @return Mixed: Database-specific index description class or false if the index does not exist
168 function indexInfo( $table, $index, $fname = 'Database::indexInfo' );
171 * Get the number of rows affected by the last write query
172 * @see http://www.php.net/mysql_affected_rows
176 function affectedRows();
179 * Wrapper for addslashes()
181 * @param string $s to be slashed.
182 * @return string: slashed string.
184 function strencode( $s );
187 * Returns a wikitext link to the DB's website, e.g.,
188 * return "[http://www.mysql.com/ MySQL]";
189 * Should at least contain plain text, if for some reason
190 * your database has no website.
192 * @return string: wikitext of a link to the server software's web site
194 static function getSoftwareLink();
197 * A string describing the current software version, like from
198 * mysql_get_server_info().
200 * @return string: Version information from the database server.
202 function getServerVersion();
205 * A string describing the current software version, and possibly
206 * other details in a user-friendly way. Will be listed on Special:Version, etc.
207 * Use getServerVersion() to get machine-friendly information.
209 * @return string: Version information from the database server
211 function getServerInfo();
215 * Database abstraction object
218 abstract class DatabaseBase
implements DatabaseType
{
220 # ------------------------------------------------------------------------------
222 # ------------------------------------------------------------------------------
224 protected $mLastQuery = '';
225 protected $mDoneWrites = false;
226 protected $mPHPError = false;
228 protected $mServer, $mUser, $mPassword, $mDBname;
230 protected $mConn = null;
231 protected $mOpened = false;
235 * @var array of Closure
237 protected $mTrxIdleCallbacks = array();
239 protected $mTablePrefix;
241 protected $mTrxLevel = 0;
242 protected $mErrorCount = 0;
243 protected $mLBInfo = array();
244 protected $mFakeSlaveLag = null, $mFakeMaster = false;
245 protected $mDefaultBigSelects = null;
246 protected $mSchemaVars = false;
248 protected $preparedArgs;
250 protected $htmlErrors;
252 protected $delimiter = ';';
255 * Remembers the function name given for starting the most recent transaction via begin().
256 * Used to provide additional context for error reporting.
259 * @see DatabaseBase::mTrxLevel
261 private $mTrxFname = null;
264 * Record if possible write queries were done in the last transaction started
267 * @see DatabaseBase::mTrxLevel
269 private $mTrxDoneWrites = false;
272 * Record if the current transaction was started implicitly due to DBO_TRX being set.
275 * @see DatabaseBase::mTrxLevel
277 private $mTrxAutomatic = false;
281 * @var file handle for upgrade
283 protected $fileHandle = null;
285 # ------------------------------------------------------------------------------
287 # ------------------------------------------------------------------------------
288 # These optionally set a variable and return the previous state
291 * A string describing the current software version, and possibly
292 * other details in a user-friendly way. Will be listed on Special:Version, etc.
293 * Use getServerVersion() to get machine-friendly information.
295 * @return string: Version information from the database server
297 public function getServerInfo() {
298 return $this->getServerVersion();
302 * @return string: command delimiter used by this database engine
304 public function getDelimiter() {
305 return $this->delimiter
;
309 * Boolean, controls output of large amounts of debug information.
310 * @param $debug bool|null
311 * - true to enable debugging
312 * - false to disable debugging
313 * - omitted or null to do nothing
315 * @return bool|null previous value of the flag
317 public function debug( $debug = null ) {
318 return wfSetBit( $this->mFlags
, DBO_DEBUG
, $debug );
322 * Turns buffering of SQL result sets on (true) or off (false). Default is
325 * Unbuffered queries are very troublesome in MySQL:
327 * - If another query is executed while the first query is being read
328 * out, the first query is killed. This means you can't call normal
329 * MediaWiki functions while you are reading an unbuffered query result
330 * from a normal wfGetDB() connection.
332 * - Unbuffered queries cause the MySQL server to use large amounts of
333 * memory and to hold broad locks which block other queries.
335 * If you want to limit client-side memory, it's almost always better to
336 * split up queries into batches using a LIMIT clause than to switch off
339 * @param $buffer null|bool
341 * @return null|bool The previous value of the flag
343 public function bufferResults( $buffer = null ) {
344 if ( is_null( $buffer ) ) {
345 return !(bool)( $this->mFlags
& DBO_NOBUFFER
);
347 return !wfSetBit( $this->mFlags
, DBO_NOBUFFER
, !$buffer );
352 * Turns on (false) or off (true) the automatic generation and sending
353 * of a "we're sorry, but there has been a database error" page on
354 * database errors. Default is on (false). When turned off, the
355 * code should use lastErrno() and lastError() to handle the
356 * situation as appropriate.
358 * @param $ignoreErrors bool|null
360 * @return bool The previous value of the flag.
362 public function ignoreErrors( $ignoreErrors = null ) {
363 return wfSetBit( $this->mFlags
, DBO_IGNORE
, $ignoreErrors );
367 * Gets or sets the current transaction level.
369 * Historically, transactions were allowed to be "nested". This is no
370 * longer supported, so this function really only returns a boolean.
372 * @param int $level An integer (0 or 1), or omitted to leave it unchanged.
373 * @return int The previous value
375 public function trxLevel( $level = null ) {
376 return wfSetVar( $this->mTrxLevel
, $level );
380 * Get/set the number of errors logged. Only useful when errors are ignored
381 * @param int $count The count to set, or omitted to leave it unchanged.
382 * @return int The error count
384 public function errorCount( $count = null ) {
385 return wfSetVar( $this->mErrorCount
, $count );
389 * Get/set the table prefix.
390 * @param string $prefix The table prefix to set, or omitted to leave it unchanged.
391 * @return string The previous table prefix.
393 public function tablePrefix( $prefix = null ) {
394 return wfSetVar( $this->mTablePrefix
, $prefix );
398 * Set the filehandle to copy write statements to.
400 * @param $fh filehandle
402 public function setFileHandle( $fh ) {
403 $this->fileHandle
= $fh;
407 * Get properties passed down from the server info array of the load
410 * @param string $name The entry of the info array to get, or null to get the
413 * @return LoadBalancer|null
415 public function getLBInfo( $name = null ) {
416 if ( is_null( $name ) ) {
417 return $this->mLBInfo
;
419 if ( array_key_exists( $name, $this->mLBInfo
) ) {
420 return $this->mLBInfo
[$name];
428 * Set the LB info array, or a member of it. If called with one parameter,
429 * the LB info array is set to that parameter. If it is called with two
430 * parameters, the member with the given name is set to the given value.
435 public function setLBInfo( $name, $value = null ) {
436 if ( is_null( $value ) ) {
437 $this->mLBInfo
= $name;
439 $this->mLBInfo
[$name] = $value;
444 * Set lag time in seconds for a fake slave
448 public function setFakeSlaveLag( $lag ) {
449 $this->mFakeSlaveLag
= $lag;
453 * Make this connection a fake master
455 * @param $enabled bool
457 public function setFakeMaster( $enabled = true ) {
458 $this->mFakeMaster
= $enabled;
462 * Returns true if this database supports (and uses) cascading deletes
466 public function cascadingDeletes() {
471 * Returns true if this database supports (and uses) triggers (e.g. on the page table)
475 public function cleanupTriggers() {
480 * Returns true if this database is strict about what can be put into an IP field.
481 * Specifically, it uses a NULL value instead of an empty string.
485 public function strictIPs() {
490 * Returns true if this database uses timestamps rather than integers
494 public function realTimestamps() {
499 * Returns true if this database does an implicit sort when doing GROUP BY
503 public function implicitGroupby() {
508 * Returns true if this database does an implicit order by when the column has an index
509 * For example: SELECT page_title FROM page LIMIT 1
513 public function implicitOrderby() {
518 * Returns true if this database can do a native search on IP columns
519 * e.g. this works as expected: .. WHERE rc_ip = '127.42.12.102/32';
523 public function searchableIPs() {
528 * Returns true if this database can use functional indexes
532 public function functionalIndexes() {
537 * Return the last query that went through DatabaseBase::query()
540 public function lastQuery() {
541 return $this->mLastQuery
;
545 * Returns true if the connection may have been used for write queries.
546 * Should return true if unsure.
550 public function doneWrites() {
551 return $this->mDoneWrites
;
555 * Returns true if there is a transaction open with possible write
556 * queries or transaction idle callbacks waiting on it to finish.
560 public function writesOrCallbacksPending() {
561 return $this->mTrxLevel
&& ( $this->mTrxDoneWrites ||
$this->mTrxIdleCallbacks
);
565 * Is a connection to the database open?
568 public function isOpen() {
569 return $this->mOpened
;
573 * Set a flag for this connection
575 * @param $flag Integer: DBO_* constants from Defines.php:
576 * - DBO_DEBUG: output some debug info (same as debug())
577 * - DBO_NOBUFFER: don't buffer results (inverse of bufferResults())
578 * - DBO_IGNORE: ignore errors (same as ignoreErrors())
579 * - DBO_TRX: automatically start transactions
580 * - DBO_DEFAULT: automatically sets DBO_TRX if not in command line mode
581 * and removes it in command line mode
582 * - DBO_PERSISTENT: use persistant database connection
584 public function setFlag( $flag ) {
585 global $wgDebugDBTransactions;
586 $this->mFlags |
= $flag;
587 if ( ( $flag & DBO_TRX
) & $wgDebugDBTransactions ) {
588 wfDebug( "Implicit transactions are now disabled.\n" );
593 * Clear a flag for this connection
595 * @param $flag: same as setFlag()'s $flag param
597 public function clearFlag( $flag ) {
598 global $wgDebugDBTransactions;
599 $this->mFlags
&= ~
$flag;
600 if ( ( $flag & DBO_TRX
) && $wgDebugDBTransactions ) {
601 wfDebug( "Implicit transactions are now disabled.\n" );
606 * Returns a boolean whether the flag $flag is set for this connection
608 * @param $flag: same as setFlag()'s $flag param
611 public function getFlag( $flag ) {
612 return !!( $this->mFlags
& $flag );
616 * General read-only accessor
618 * @param $name string
622 public function getProperty( $name ) {
629 public function getWikiID() {
630 if ( $this->mTablePrefix
) {
631 return "{$this->mDBname}-{$this->mTablePrefix}";
633 return $this->mDBname
;
638 * Return a path to the DBMS-specific schema file, otherwise default to tables.sql
642 public function getSchemaPath() {
644 if ( file_exists( "$IP/maintenance/" . $this->getType() . "/tables.sql" ) ) {
645 return "$IP/maintenance/" . $this->getType() . "/tables.sql";
647 return "$IP/maintenance/tables.sql";
651 # ------------------------------------------------------------------------------
653 # ------------------------------------------------------------------------------
657 * @param string $server database server host
658 * @param string $user database user name
659 * @param string $password database user password
660 * @param string $dbName database name
662 * @param string $tablePrefix database table prefixes. By default use the prefix gave in LocalSettings.php
664 function __construct( $server = false, $user = false, $password = false, $dbName = false,
665 $flags = 0, $tablePrefix = 'get from global'
667 global $wgDBprefix, $wgCommandLineMode, $wgDebugDBTransactions;
669 $this->mFlags
= $flags;
671 if ( $this->mFlags
& DBO_DEFAULT
) {
672 if ( $wgCommandLineMode ) {
673 $this->mFlags
&= ~DBO_TRX
;
674 if ( $wgDebugDBTransactions ) {
675 wfDebug( "Implicit transaction open disabled.\n" );
678 $this->mFlags |
= DBO_TRX
;
679 if ( $wgDebugDBTransactions ) {
680 wfDebug( "Implicit transaction open enabled.\n" );
685 /** Get the default table prefix*/
686 if ( $tablePrefix == 'get from global' ) {
687 $this->mTablePrefix
= $wgDBprefix;
689 $this->mTablePrefix
= $tablePrefix;
693 $this->open( $server, $user, $password, $dbName );
698 * Called by serialize. Throw an exception when DB connection is serialized.
699 * This causes problems on some database engines because the connection is
700 * not restored on unserialize.
702 public function __sleep() {
703 throw new MWException( 'Database serialization may cause problems, since the connection is not restored on wakeup.' );
707 * Given a DB type, construct the name of the appropriate child class of
708 * DatabaseBase. This is designed to replace all of the manual stuff like:
709 * $class = 'Database' . ucfirst( strtolower( $type ) );
710 * as well as validate against the canonical list of DB types we have
712 * This factory function is mostly useful for when you need to connect to a
713 * database other than the MediaWiki default (such as for external auth,
714 * an extension, et cetera). Do not use this to connect to the MediaWiki
715 * database. Example uses in core:
716 * @see LoadBalancer::reallyOpenConnection()
717 * @see ExternalUser_MediaWiki::initFromCond()
718 * @see ForeignDBRepo::getMasterDB()
719 * @see WebInstaller_DBConnect::execute()
723 * @param string $dbType A possible DB type
724 * @param array $p An array of options to pass to the constructor.
725 * Valid options are: host, user, password, dbname, flags, tablePrefix
726 * @return DatabaseBase subclass or null
728 final public static function factory( $dbType, $p = array() ) {
729 $canonicalDBTypes = array(
730 'mysql', 'postgres', 'sqlite', 'oracle', 'mssql'
732 $dbType = strtolower( $dbType );
733 $class = 'Database' . ucfirst( $dbType );
735 if( in_array( $dbType, $canonicalDBTypes ) ||
( class_exists( $class ) && is_subclass_of( $class, 'DatabaseBase' ) ) ) {
737 isset( $p['host'] ) ?
$p['host'] : false,
738 isset( $p['user'] ) ?
$p['user'] : false,
739 isset( $p['password'] ) ?
$p['password'] : false,
740 isset( $p['dbname'] ) ?
$p['dbname'] : false,
741 isset( $p['flags'] ) ?
$p['flags'] : 0,
742 isset( $p['tablePrefix'] ) ?
$p['tablePrefix'] : 'get from global'
749 protected function installErrorHandler() {
750 $this->mPHPError
= false;
751 $this->htmlErrors
= ini_set( 'html_errors', '0' );
752 set_error_handler( array( $this, 'connectionErrorHandler' ) );
756 * @return bool|string
758 protected function restoreErrorHandler() {
759 restore_error_handler();
760 if ( $this->htmlErrors
!== false ) {
761 ini_set( 'html_errors', $this->htmlErrors
);
763 if ( $this->mPHPError
) {
764 $error = preg_replace( '!\[<a.*</a>\]!', '', $this->mPHPError
);
765 $error = preg_replace( '!^.*?:\s?(.*)$!', '$1', $error );
776 protected function connectionErrorHandler( $errno, $errstr ) {
777 $this->mPHPError
= $errstr;
781 * Closes a database connection.
782 * if it is open : commits any open transactions
784 * @throws MWException
785 * @return Bool operation success. true if already closed.
787 public function close() {
788 if ( count( $this->mTrxIdleCallbacks
) ) { // sanity
789 throw new MWException( "Transaction idle callbacks still pending." );
791 $this->mOpened
= false;
792 if ( $this->mConn
) {
793 if ( $this->trxLevel() ) {
794 if ( !$this->mTrxAutomatic
) {
795 wfWarn( "Transaction still in progress (from {$this->mTrxFname}), " .
796 " performing implicit commit before closing connection!" );
799 $this->commit( __METHOD__
, 'flush' );
802 $ret = $this->closeConnection();
803 $this->mConn
= false;
811 * Closes underlying database connection
813 * @return bool: Whether connection was closed successfully
815 abstract protected function closeConnection();
818 * @param string $error fallback error message, used if none is given by DB
819 * @throws DBConnectionError
821 function reportConnectionError( $error = 'Unknown error' ) {
822 $myError = $this->lastError();
828 throw new DBConnectionError( $this, $error );
832 * The DBMS-dependent part of query()
834 * @param $sql String: SQL query.
835 * @return ResultWrapper Result object to feed to fetchObject, fetchRow, ...; or false on failure
837 abstract protected function doQuery( $sql );
840 * Determine whether a query writes to the DB.
841 * Should return true if unsure.
847 public function isWriteQuery( $sql ) {
848 return !preg_match( '/^(?:SELECT|BEGIN|ROLLBACK|COMMIT|SET|SHOW|EXPLAIN|\(SELECT)\b/i', $sql );
852 * Run an SQL query and return the result. Normally throws a DBQueryError
853 * on failure. If errors are ignored, returns false instead.
855 * In new code, the query wrappers select(), insert(), update(), delete(),
856 * etc. should be used where possible, since they give much better DBMS
857 * independence and automatically quote or validate user input in a variety
858 * of contexts. This function is generally only useful for queries which are
859 * explicitly DBMS-dependent and are unsupported by the query wrappers, such
862 * However, the query wrappers themselves should call this function.
864 * @param $sql String: SQL query
865 * @param $fname String: Name of the calling function, for profiling/SHOW PROCESSLIST
866 * comment (you can use __METHOD__ or add some extra info)
867 * @param $tempIgnore Boolean: Whether to avoid throwing an exception on errors...
868 * maybe best to catch the exception instead?
869 * @throws MWException
870 * @return boolean|ResultWrapper. true for a successful write query, ResultWrapper object
871 * for a successful read query, or false on failure if $tempIgnore set
873 public function query( $sql, $fname = '', $tempIgnore = false ) {
874 $isMaster = !is_null( $this->getLBInfo( 'master' ) );
875 if ( !Profiler
::instance()->isStub() ) {
876 # generalizeSQL will probably cut down the query to reasonable
877 # logging size most of the time. The substr is really just a sanity check.
880 $queryProf = 'query-m: ' . substr( DatabaseBase
::generalizeSQL( $sql ), 0, 255 );
881 $totalProf = 'DatabaseBase::query-master';
883 $queryProf = 'query: ' . substr( DatabaseBase
::generalizeSQL( $sql ), 0, 255 );
884 $totalProf = 'DatabaseBase::query';
887 wfProfileIn( $totalProf );
888 wfProfileIn( $queryProf );
891 $this->mLastQuery
= $sql;
892 if ( !$this->mDoneWrites
&& $this->isWriteQuery( $sql ) ) {
893 # Set a flag indicating that writes have been done
894 wfDebug( __METHOD__
. ": Writes done: $sql\n" );
895 $this->mDoneWrites
= true;
898 # Add a comment for easy SHOW PROCESSLIST interpretation
900 if ( is_object( $wgUser ) && $wgUser->isItemLoaded( 'name' ) ) {
901 $userName = $wgUser->getName();
902 if ( mb_strlen( $userName ) > 15 ) {
903 $userName = mb_substr( $userName, 0, 15 ) . '...';
905 $userName = str_replace( '/', '', $userName );
910 // Add trace comment to the begin of the sql string, right after the operator.
911 // Or, for one-word queries (like "BEGIN" or COMMIT") add it to the end (bug 42598)
912 $commentedSql = preg_replace( '/\s|$/', " /* $fname $userName */ ", $sql, 1 );
914 # If DBO_TRX is set, start a transaction
915 if ( ( $this->mFlags
& DBO_TRX
) && !$this->mTrxLevel
&&
916 $sql != 'BEGIN' && $sql != 'COMMIT' && $sql != 'ROLLBACK' )
918 # Avoid establishing transactions for SHOW and SET statements too -
919 # that would delay transaction initializations to once connection
920 # is really used by application
921 $sqlstart = substr( $sql, 0, 10 ); // very much worth it, benchmark certified(tm)
922 if ( strpos( $sqlstart, "SHOW " ) !== 0 && strpos( $sqlstart, "SET " ) !== 0 ) {
923 global $wgDebugDBTransactions;
924 if ( $wgDebugDBTransactions ) {
925 wfDebug( "Implicit transaction start.\n" );
927 $this->begin( __METHOD__
. " ($fname)" );
928 $this->mTrxAutomatic
= true;
932 # Keep track of whether the transaction has write queries pending
933 if ( $this->mTrxLevel
&& !$this->mTrxDoneWrites
&& $this->isWriteQuery( $sql ) ) {
934 $this->mTrxDoneWrites
= true;
937 if ( $this->debug() ) {
941 $sqlx = substr( $commentedSql, 0, 500 );
942 $sqlx = strtr( $sqlx, "\t\n", ' ' );
944 $master = $isMaster ?
'master' : 'slave';
945 wfDebug( "Query {$this->mDBname} ($cnt) ($master): $sqlx\n" );
948 if ( istainted( $sql ) & TC_MYSQL
) {
949 throw new MWException( 'Tainted query found' );
952 $queryId = MWDebug
::query( $sql, $fname, $isMaster );
954 # Do the query and handle errors
955 $ret = $this->doQuery( $commentedSql );
957 MWDebug
::queryTime( $queryId );
959 # Try reconnecting if the connection was lost
960 if ( false === $ret && $this->wasErrorReissuable() ) {
961 # Transaction is gone, like it or not
962 $this->mTrxLevel
= 0;
963 $this->mTrxIdleCallbacks
= array(); // cancel
964 wfDebug( "Connection lost, reconnecting...\n" );
966 if ( $this->ping() ) {
967 wfDebug( "Reconnected\n" );
968 $sqlx = substr( $commentedSql, 0, 500 );
969 $sqlx = strtr( $sqlx, "\t\n", ' ' );
970 global $wgRequestTime;
971 $elapsed = round( microtime( true ) - $wgRequestTime, 3 );
972 if ( $elapsed < 300 ) {
973 # Not a database error to lose a transaction after a minute or two
974 wfLogDBError( "Connection lost and reconnected after {$elapsed}s, query: $sqlx\n" );
976 $ret = $this->doQuery( $commentedSql );
978 wfDebug( "Failed\n" );
982 if ( false === $ret ) {
983 $this->reportQueryError( $this->lastError(), $this->lastErrno(), $sql, $fname, $tempIgnore );
986 if ( !Profiler
::instance()->isStub() ) {
987 wfProfileOut( $queryProf );
988 wfProfileOut( $totalProf );
991 return $this->resultObject( $ret );
995 * Report a query error. Log the error, and if neither the object ignore
996 * flag nor the $tempIgnore flag is set, throw a DBQueryError.
998 * @param $error String
999 * @param $errno Integer
1000 * @param $sql String
1001 * @param $fname String
1002 * @param $tempIgnore Boolean
1003 * @throws DBQueryError
1005 public function reportQueryError( $error, $errno, $sql, $fname, $tempIgnore = false ) {
1006 # Ignore errors during error handling to avoid infinite recursion
1007 $ignore = $this->ignoreErrors( true );
1008 ++
$this->mErrorCount
;
1010 if ( $ignore ||
$tempIgnore ) {
1011 wfDebug( "SQL ERROR (ignored): $error\n" );
1012 $this->ignoreErrors( $ignore );
1014 $sql1line = str_replace( "\n", "\\n", $sql );
1015 wfLogDBError( "$fname\t{$this->mServer}\t$errno\t$error\t$sql1line\n" );
1016 wfDebug( "SQL ERROR: " . $error . "\n" );
1017 throw new DBQueryError( $this, $error, $errno, $sql, $fname );
1022 * Intended to be compatible with the PEAR::DB wrapper functions.
1023 * http://pear.php.net/manual/en/package.database.db.intro-execute.php
1025 * ? = scalar value, quoted as necessary
1026 * ! = raw SQL bit (a function for instance)
1027 * & = filename; reads the file and inserts as a blob
1028 * (we don't use this though...)
1030 * @param $sql string
1031 * @param $func string
1035 protected function prepare( $sql, $func = 'DatabaseBase::prepare' ) {
1036 /* MySQL doesn't support prepared statements (yet), so just
1037 pack up the query for reference. We'll manually replace
1039 return array( 'query' => $sql, 'func' => $func );
1043 * Free a prepared query, generated by prepare().
1046 protected function freePrepared( $prepared ) {
1047 /* No-op by default */
1051 * Execute a prepared query with the various arguments
1052 * @param string $prepared the prepared sql
1053 * @param $args Mixed: Either an array here, or put scalars as varargs
1055 * @return ResultWrapper
1057 public function execute( $prepared, $args = null ) {
1058 if ( !is_array( $args ) ) {
1060 $args = func_get_args();
1061 array_shift( $args );
1064 $sql = $this->fillPrepared( $prepared['query'], $args );
1066 return $this->query( $sql, $prepared['func'] );
1070 * For faking prepared SQL statements on DBs that don't support it directly.
1072 * @param string $preparedQuery a 'preparable' SQL statement
1073 * @param array $args of arguments to fill it with
1074 * @return string executable SQL
1076 public function fillPrepared( $preparedQuery, $args ) {
1078 $this->preparedArgs
=& $args;
1080 return preg_replace_callback( '/(\\\\[?!&]|[?!&])/',
1081 array( &$this, 'fillPreparedArg' ), $preparedQuery );
1085 * preg_callback func for fillPrepared()
1086 * The arguments should be in $this->preparedArgs and must not be touched
1087 * while we're doing this.
1089 * @param $matches Array
1090 * @throws DBUnexpectedError
1093 protected function fillPreparedArg( $matches ) {
1094 switch( $matches[1] ) {
1095 case '\\?': return '?';
1096 case '\\!': return '!';
1097 case '\\&': return '&';
1100 list( /* $n */, $arg ) = each( $this->preparedArgs
);
1102 switch( $matches[1] ) {
1103 case '?': return $this->addQuotes( $arg );
1104 case '!': return $arg;
1106 # return $this->addQuotes( file_get_contents( $arg ) );
1107 throw new DBUnexpectedError( $this, '& mode is not implemented. If it\'s really needed, uncomment the line above.' );
1109 throw new DBUnexpectedError( $this, 'Received invalid match. This should never happen!' );
1114 * Free a result object returned by query() or select(). It's usually not
1115 * necessary to call this, just use unset() or let the variable holding
1116 * the result object go out of scope.
1118 * @param $res Mixed: A SQL result
1120 public function freeResult( $res ) {}
1123 * A SELECT wrapper which returns a single field from a single result row.
1125 * Usually throws a DBQueryError on failure. If errors are explicitly
1126 * ignored, returns false on failure.
1128 * If no result rows are returned from the query, false is returned.
1130 * @param string|array $table Table name. See DatabaseBase::select() for details.
1131 * @param string $var The field name to select. This must be a valid SQL
1132 * fragment: do not use unvalidated user input.
1133 * @param string|array $cond The condition array. See DatabaseBase::select() for details.
1134 * @param string $fname The function name of the caller.
1135 * @param string|array $options The query options. See DatabaseBase::select() for details.
1137 * @return bool|mixed The value from the field, or false on failure.
1139 public function selectField( $table, $var, $cond = '', $fname = 'DatabaseBase::selectField',
1140 $options = array() )
1142 if ( !is_array( $options ) ) {
1143 $options = array( $options );
1146 $options['LIMIT'] = 1;
1148 $res = $this->select( $table, $var, $cond, $fname, $options );
1150 if ( $res === false ||
!$this->numRows( $res ) ) {
1154 $row = $this->fetchRow( $res );
1156 if ( $row !== false ) {
1157 return reset( $row );
1164 * Returns an optional USE INDEX clause to go after the table, and a
1165 * string to go at the end of the query.
1167 * @param array $options associative array of options to be turned into
1168 * an SQL query, valid keys are listed in the function.
1170 * @see DatabaseBase::select()
1172 public function makeSelectOptions( $options ) {
1173 $preLimitTail = $postLimitTail = '';
1176 $noKeyOptions = array();
1178 foreach ( $options as $key => $option ) {
1179 if ( is_numeric( $key ) ) {
1180 $noKeyOptions[$option] = true;
1184 $preLimitTail .= $this->makeGroupByWithHaving( $options );
1186 $preLimitTail .= $this->makeOrderBy( $options );
1188 // if (isset($options['LIMIT'])) {
1189 // $tailOpts .= $this->limitResult('', $options['LIMIT'],
1190 // isset($options['OFFSET']) ? $options['OFFSET']
1194 if ( isset( $noKeyOptions['FOR UPDATE'] ) ) {
1195 $postLimitTail .= ' FOR UPDATE';
1198 if ( isset( $noKeyOptions['LOCK IN SHARE MODE'] ) ) {
1199 $postLimitTail .= ' LOCK IN SHARE MODE';
1202 if ( isset( $noKeyOptions['DISTINCT'] ) ||
isset( $noKeyOptions['DISTINCTROW'] ) ) {
1203 $startOpts .= 'DISTINCT';
1206 # Various MySQL extensions
1207 if ( isset( $noKeyOptions['STRAIGHT_JOIN'] ) ) {
1208 $startOpts .= ' /*! STRAIGHT_JOIN */';
1211 if ( isset( $noKeyOptions['HIGH_PRIORITY'] ) ) {
1212 $startOpts .= ' HIGH_PRIORITY';
1215 if ( isset( $noKeyOptions['SQL_BIG_RESULT'] ) ) {
1216 $startOpts .= ' SQL_BIG_RESULT';
1219 if ( isset( $noKeyOptions['SQL_BUFFER_RESULT'] ) ) {
1220 $startOpts .= ' SQL_BUFFER_RESULT';
1223 if ( isset( $noKeyOptions['SQL_SMALL_RESULT'] ) ) {
1224 $startOpts .= ' SQL_SMALL_RESULT';
1227 if ( isset( $noKeyOptions['SQL_CALC_FOUND_ROWS'] ) ) {
1228 $startOpts .= ' SQL_CALC_FOUND_ROWS';
1231 if ( isset( $noKeyOptions['SQL_CACHE'] ) ) {
1232 $startOpts .= ' SQL_CACHE';
1235 if ( isset( $noKeyOptions['SQL_NO_CACHE'] ) ) {
1236 $startOpts .= ' SQL_NO_CACHE';
1239 if ( isset( $options['USE INDEX'] ) && ! is_array( $options['USE INDEX'] ) ) {
1240 $useIndex = $this->useIndexClause( $options['USE INDEX'] );
1245 return array( $startOpts, $useIndex, $preLimitTail, $postLimitTail );
1249 * Returns an optional GROUP BY with an optional HAVING
1251 * @param array $options associative array of options
1253 * @see DatabaseBase::select()
1256 public function makeGroupByWithHaving( $options ) {
1258 if ( isset( $options['GROUP BY'] ) ) {
1259 $gb = is_array( $options['GROUP BY'] )
1260 ?
implode( ',', $options['GROUP BY'] )
1261 : $options['GROUP BY'];
1262 $sql .= ' GROUP BY ' . $gb;
1264 if ( isset( $options['HAVING'] ) ) {
1265 $having = is_array( $options['HAVING'] )
1266 ?
$this->makeList( $options['HAVING'], LIST_AND
)
1267 : $options['HAVING'];
1268 $sql .= ' HAVING ' . $having;
1274 * Returns an optional ORDER BY
1276 * @param array $options associative array of options
1278 * @see DatabaseBase::select()
1281 public function makeOrderBy( $options ) {
1282 if ( isset( $options['ORDER BY'] ) ) {
1283 $ob = is_array( $options['ORDER BY'] )
1284 ?
implode( ',', $options['ORDER BY'] )
1285 : $options['ORDER BY'];
1286 return ' ORDER BY ' . $ob;
1292 * Execute a SELECT query constructed using the various parameters provided.
1293 * See below for full details of the parameters.
1295 * @param string|array $table Table name
1296 * @param string|array $vars Field names
1297 * @param string|array $conds Conditions
1298 * @param string $fname Caller function name
1299 * @param array $options Query options
1300 * @param $join_conds Array Join conditions
1302 * @param $table string|array
1304 * May be either an array of table names, or a single string holding a table
1305 * name. If an array is given, table aliases can be specified, for example:
1307 * array( 'a' => 'user' )
1309 * This includes the user table in the query, with the alias "a" available
1310 * for use in field names (e.g. a.user_name).
1312 * All of the table names given here are automatically run through
1313 * DatabaseBase::tableName(), which causes the table prefix (if any) to be
1314 * added, and various other table name mappings to be performed.
1317 * @param $vars string|array
1319 * May be either a field name or an array of field names. The field names
1320 * can be complete fragments of SQL, for direct inclusion into the SELECT
1321 * query. If an array is given, field aliases can be specified, for example:
1323 * array( 'maxrev' => 'MAX(rev_id)' )
1325 * This includes an expression with the alias "maxrev" in the query.
1327 * If an expression is given, care must be taken to ensure that it is
1331 * @param $conds string|array
1333 * May be either a string containing a single condition, or an array of
1334 * conditions. If an array is given, the conditions constructed from each
1335 * element are combined with AND.
1337 * Array elements may take one of two forms:
1339 * - Elements with a numeric key are interpreted as raw SQL fragments.
1340 * - Elements with a string key are interpreted as equality conditions,
1341 * where the key is the field name.
1342 * - If the value of such an array element is a scalar (such as a
1343 * string), it will be treated as data and thus quoted appropriately.
1344 * If it is null, an IS NULL clause will be added.
1345 * - If the value is an array, an IN(...) clause will be constructed,
1346 * such that the field name may match any of the elements in the
1347 * array. The elements of the array will be quoted.
1349 * Note that expressions are often DBMS-dependent in their syntax.
1350 * DBMS-independent wrappers are provided for constructing several types of
1351 * expression commonly used in condition queries. See:
1352 * - DatabaseBase::buildLike()
1353 * - DatabaseBase::conditional()
1356 * @param $options string|array
1358 * Optional: Array of query options. Boolean options are specified by
1359 * including them in the array as a string value with a numeric key, for
1362 * array( 'FOR UPDATE' )
1364 * The supported options are:
1366 * - OFFSET: Skip this many rows at the start of the result set. OFFSET
1367 * with LIMIT can theoretically be used for paging through a result set,
1368 * but this is discouraged in MediaWiki for performance reasons.
1370 * - LIMIT: Integer: return at most this many rows. The rows are sorted
1371 * and then the first rows are taken until the limit is reached. LIMIT
1372 * is applied to a result set after OFFSET.
1374 * - FOR UPDATE: Boolean: lock the returned rows so that they can't be
1375 * changed until the next COMMIT.
1377 * - DISTINCT: Boolean: return only unique result rows.
1379 * - GROUP BY: May be either an SQL fragment string naming a field or
1380 * expression to group by, or an array of such SQL fragments.
1382 * - HAVING: May be either an string containing a HAVING clause or an array of
1383 * conditions building the HAVING clause. If an array is given, the conditions
1384 * constructed from each element are combined with AND.
1386 * - ORDER BY: May be either an SQL fragment giving a field name or
1387 * expression to order by, or an array of such SQL fragments.
1389 * - USE INDEX: This may be either a string giving the index name to use
1390 * for the query, or an array. If it is an associative array, each key
1391 * gives the table name (or alias), each value gives the index name to
1392 * use for that table. All strings are SQL fragments and so should be
1393 * validated by the caller.
1395 * - EXPLAIN: In MySQL, this causes an EXPLAIN SELECT query to be run,
1396 * instead of SELECT.
1398 * And also the following boolean MySQL extensions, see the MySQL manual
1399 * for documentation:
1401 * - LOCK IN SHARE MODE
1405 * - SQL_BUFFER_RESULT
1406 * - SQL_SMALL_RESULT
1407 * - SQL_CALC_FOUND_ROWS
1412 * @param $join_conds string|array
1414 * Optional associative array of table-specific join conditions. In the
1415 * most common case, this is unnecessary, since the join condition can be
1416 * in $conds. However, it is useful for doing a LEFT JOIN.
1418 * The key of the array contains the table name or alias. The value is an
1419 * array with two elements, numbered 0 and 1. The first gives the type of
1420 * join, the second is an SQL fragment giving the join condition for that
1421 * table. For example:
1423 * array( 'page' => array( 'LEFT JOIN', 'page_latest=rev_id' ) )
1425 * @return ResultWrapper. If the query returned no rows, a ResultWrapper
1426 * with no rows in it will be returned. If there was a query error, a
1427 * DBQueryError exception will be thrown, except if the "ignore errors"
1428 * option was set, in which case false will be returned.
1430 public function select( $table, $vars, $conds = '', $fname = 'DatabaseBase::select',
1431 $options = array(), $join_conds = array() ) {
1432 $sql = $this->selectSQLText( $table, $vars, $conds, $fname, $options, $join_conds );
1434 return $this->query( $sql, $fname );
1438 * The equivalent of DatabaseBase::select() except that the constructed SQL
1439 * is returned, instead of being immediately executed. This can be useful for
1440 * doing UNION queries, where the SQL text of each query is needed. In general,
1441 * however, callers outside of Database classes should just use select().
1443 * @param string|array $table Table name
1444 * @param string|array $vars Field names
1445 * @param string|array $conds Conditions
1446 * @param string $fname Caller function name
1447 * @param string|array $options Query options
1448 * @param $join_conds string|array Join conditions
1450 * @return string SQL query string.
1451 * @see DatabaseBase::select()
1453 public function selectSQLText( $table, $vars, $conds = '', $fname = 'DatabaseBase::select',
1454 $options = array(), $join_conds = array() )
1456 if ( is_array( $vars ) ) {
1457 $vars = implode( ',', $this->fieldNamesWithAlias( $vars ) );
1460 $options = (array)$options;
1462 if ( is_array( $table ) ) {
1463 $useIndex = ( isset( $options['USE INDEX'] ) && is_array( $options['USE INDEX'] ) )
1464 ?
$options['USE INDEX']
1466 if ( count( $join_conds ) ||
count( $useIndex ) ) {
1468 $this->tableNamesWithUseIndexOrJOIN( $table, $useIndex, $join_conds );
1470 $from = ' FROM ' . implode( ',', $this->tableNamesWithAlias( $table ) );
1472 } elseif ( $table != '' ) {
1473 if ( $table[0] == ' ' ) {
1474 $from = ' FROM ' . $table;
1476 $from = ' FROM ' . $this->tableName( $table );
1482 list( $startOpts, $useIndex, $preLimitTail, $postLimitTail ) = $this->makeSelectOptions( $options );
1484 if ( !empty( $conds ) ) {
1485 if ( is_array( $conds ) ) {
1486 $conds = $this->makeList( $conds, LIST_AND
);
1488 $sql = "SELECT $startOpts $vars $from $useIndex WHERE $conds $preLimitTail";
1490 $sql = "SELECT $startOpts $vars $from $useIndex $preLimitTail";
1493 if ( isset( $options['LIMIT'] ) ) {
1494 $sql = $this->limitResult( $sql, $options['LIMIT'],
1495 isset( $options['OFFSET'] ) ?
$options['OFFSET'] : false );
1497 $sql = "$sql $postLimitTail";
1499 if ( isset( $options['EXPLAIN'] ) ) {
1500 $sql = 'EXPLAIN ' . $sql;
1507 * Single row SELECT wrapper. Equivalent to DatabaseBase::select(), except
1508 * that a single row object is returned. If the query returns no rows,
1509 * false is returned.
1511 * @param string|array $table Table name
1512 * @param string|array $vars Field names
1513 * @param array $conds Conditions
1514 * @param string $fname Caller function name
1515 * @param string|array $options Query options
1516 * @param $join_conds array|string Join conditions
1518 * @return object|bool
1520 public function selectRow( $table, $vars, $conds, $fname = 'DatabaseBase::selectRow',
1521 $options = array(), $join_conds = array() )
1523 $options = (array)$options;
1524 $options['LIMIT'] = 1;
1525 $res = $this->select( $table, $vars, $conds, $fname, $options, $join_conds );
1527 if ( $res === false ) {
1531 if ( !$this->numRows( $res ) ) {
1535 $obj = $this->fetchObject( $res );
1541 * Estimate rows in dataset.
1543 * MySQL allows you to estimate the number of rows that would be returned
1544 * by a SELECT query, using EXPLAIN SELECT. The estimate is provided using
1545 * index cardinality statistics, and is notoriously inaccurate, especially
1546 * when large numbers of rows have recently been added or deleted.
1548 * For DBMSs that don't support fast result size estimation, this function
1549 * will actually perform the SELECT COUNT(*).
1551 * Takes the same arguments as DatabaseBase::select().
1553 * @param string $table table name
1554 * @param array|string $vars : unused
1555 * @param array|string $conds : filters on the table
1556 * @param string $fname function name for profiling
1557 * @param array $options options for select
1558 * @return Integer: row count
1560 public function estimateRowCount( $table, $vars = '*', $conds = '',
1561 $fname = 'DatabaseBase::estimateRowCount', $options = array() )
1564 $res = $this->select( $table, array( 'rowcount' => 'COUNT(*)' ), $conds, $fname, $options );
1567 $row = $this->fetchRow( $res );
1568 $rows = ( isset( $row['rowcount'] ) ) ?
$row['rowcount'] : 0;
1575 * Removes most variables from an SQL query and replaces them with X or N for numbers.
1576 * It's only slightly flawed. Don't use for anything important.
1578 * @param string $sql A SQL Query
1582 static function generalizeSQL( $sql ) {
1583 # This does the same as the regexp below would do, but in such a way
1584 # as to avoid crashing php on some large strings.
1585 # $sql = preg_replace ( "/'([^\\\\']|\\\\.)*'|\"([^\\\\\"]|\\\\.)*\"/", "'X'", $sql);
1587 $sql = str_replace ( "\\\\", '', $sql );
1588 $sql = str_replace ( "\\'", '', $sql );
1589 $sql = str_replace ( "\\\"", '', $sql );
1590 $sql = preg_replace ( "/'.*'/s", "'X'", $sql );
1591 $sql = preg_replace ( '/".*"/s', "'X'", $sql );
1593 # All newlines, tabs, etc replaced by single space
1594 $sql = preg_replace ( '/\s+/', ' ', $sql );
1597 $sql = preg_replace ( '/-?[0-9]+/s', 'N', $sql );
1603 * Determines whether a field exists in a table
1605 * @param string $table table name
1606 * @param string $field filed to check on that table
1607 * @param string $fname calling function name (optional)
1608 * @return Boolean: whether $table has filed $field
1610 public function fieldExists( $table, $field, $fname = 'DatabaseBase::fieldExists' ) {
1611 $info = $this->fieldInfo( $table, $field );
1617 * Determines whether an index exists
1618 * Usually throws a DBQueryError on failure
1619 * If errors are explicitly ignored, returns NULL on failure
1623 * @param $fname string
1627 public function indexExists( $table, $index, $fname = 'DatabaseBase::indexExists' ) {
1628 if( !$this->tableExists( $table ) ) {
1632 $info = $this->indexInfo( $table, $index, $fname );
1633 if ( is_null( $info ) ) {
1636 return $info !== false;
1641 * Query whether a given table exists
1643 * @param $table string
1644 * @param $fname string
1648 public function tableExists( $table, $fname = __METHOD__
) {
1649 $table = $this->tableName( $table );
1650 $old = $this->ignoreErrors( true );
1651 $res = $this->query( "SELECT 1 FROM $table LIMIT 1", $fname );
1652 $this->ignoreErrors( $old );
1658 * mysql_field_type() wrapper
1663 public function fieldType( $res, $index ) {
1664 if ( $res instanceof ResultWrapper
) {
1665 $res = $res->result
;
1668 return mysql_field_type( $res, $index );
1672 * Determines if a given index is unique
1674 * @param $table string
1675 * @param $index string
1679 public function indexUnique( $table, $index ) {
1680 $indexInfo = $this->indexInfo( $table, $index );
1682 if ( !$indexInfo ) {
1686 return !$indexInfo[0]->Non_unique
;
1690 * Helper for DatabaseBase::insert().
1692 * @param $options array
1695 protected function makeInsertOptions( $options ) {
1696 return implode( ' ', $options );
1700 * INSERT wrapper, inserts an array into a table.
1704 * - A single associative array. The array keys are the field names, and
1705 * the values are the values to insert. The values are treated as data
1706 * and will be quoted appropriately. If NULL is inserted, this will be
1707 * converted to a database NULL.
1708 * - An array with numeric keys, holding a list of associative arrays.
1709 * This causes a multi-row INSERT on DBMSs that support it. The keys in
1710 * each subarray must be identical to each other, and in the same order.
1712 * Usually throws a DBQueryError on failure. If errors are explicitly ignored,
1715 * $options is an array of options, with boolean options encoded as values
1716 * with numeric keys, in the same style as $options in
1717 * DatabaseBase::select(). Supported options are:
1719 * - IGNORE: Boolean: if present, duplicate key errors are ignored, and
1720 * any rows which cause duplicate key errors are not inserted. It's
1721 * possible to determine how many rows were successfully inserted using
1722 * DatabaseBase::affectedRows().
1724 * @param $table String Table name. This will be passed through
1725 * DatabaseBase::tableName().
1726 * @param $a Array of rows to insert
1727 * @param $fname String Calling function name (use __METHOD__) for logs/profiling
1728 * @param array $options of options
1732 public function insert( $table, $a, $fname = 'DatabaseBase::insert', $options = array() ) {
1733 # No rows to insert, easy just return now
1734 if ( !count( $a ) ) {
1738 $table = $this->tableName( $table );
1740 if ( !is_array( $options ) ) {
1741 $options = array( $options );
1745 if ( isset( $options['fileHandle'] ) ) {
1746 $fh = $options['fileHandle'];
1748 $options = $this->makeInsertOptions( $options );
1750 if ( isset( $a[0] ) && is_array( $a[0] ) ) {
1752 $keys = array_keys( $a[0] );
1755 $keys = array_keys( $a );
1758 $sql = 'INSERT ' . $options .
1759 " INTO $table (" . implode( ',', $keys ) . ') VALUES ';
1763 foreach ( $a as $row ) {
1769 $sql .= '(' . $this->makeList( $row ) . ')';
1772 $sql .= '(' . $this->makeList( $a ) . ')';
1775 if ( $fh !== null && false === fwrite( $fh, $sql ) ) {
1777 } elseif ( $fh !== null ) {
1781 return (bool)$this->query( $sql, $fname );
1785 * Make UPDATE options for the DatabaseBase::update function
1787 * @param array $options The options passed to DatabaseBase::update
1790 protected function makeUpdateOptions( $options ) {
1791 if ( !is_array( $options ) ) {
1792 $options = array( $options );
1797 if ( in_array( 'LOW_PRIORITY', $options ) ) {
1798 $opts[] = $this->lowPriorityOption();
1801 if ( in_array( 'IGNORE', $options ) ) {
1805 return implode( ' ', $opts );
1809 * UPDATE wrapper. Takes a condition array and a SET array.
1811 * @param $table String name of the table to UPDATE. This will be passed through
1812 * DatabaseBase::tableName().
1814 * @param array $values An array of values to SET. For each array element,
1815 * the key gives the field name, and the value gives the data
1816 * to set that field to. The data will be quoted by
1817 * DatabaseBase::addQuotes().
1819 * @param $conds Array: An array of conditions (WHERE). See
1820 * DatabaseBase::select() for the details of the format of
1821 * condition arrays. Use '*' to update all rows.
1823 * @param $fname String: The function name of the caller (from __METHOD__),
1824 * for logging and profiling.
1826 * @param array $options An array of UPDATE options, can be:
1827 * - IGNORE: Ignore unique key conflicts
1828 * - LOW_PRIORITY: MySQL-specific, see MySQL manual.
1831 function update( $table, $values, $conds, $fname = 'DatabaseBase::update', $options = array() ) {
1832 $table = $this->tableName( $table );
1833 $opts = $this->makeUpdateOptions( $options );
1834 $sql = "UPDATE $opts $table SET " . $this->makeList( $values, LIST_SET
);
1836 if ( $conds !== array() && $conds !== '*' ) {
1837 $sql .= " WHERE " . $this->makeList( $conds, LIST_AND
);
1840 return $this->query( $sql, $fname );
1844 * Makes an encoded list of strings from an array
1845 * @param array $a containing the data
1846 * @param int $mode Constant
1847 * - LIST_COMMA: comma separated, no field names
1848 * - LIST_AND: ANDed WHERE clause (without the WHERE). See
1849 * the documentation for $conds in DatabaseBase::select().
1850 * - LIST_OR: ORed WHERE clause (without the WHERE)
1851 * - LIST_SET: comma separated with field names, like a SET clause
1852 * - LIST_NAMES: comma separated field names
1854 * @throws MWException|DBUnexpectedError
1857 public function makeList( $a, $mode = LIST_COMMA
) {
1858 if ( !is_array( $a ) ) {
1859 throw new DBUnexpectedError( $this, 'DatabaseBase::makeList called with incorrect parameters' );
1865 foreach ( $a as $field => $value ) {
1867 if ( $mode == LIST_AND
) {
1869 } elseif ( $mode == LIST_OR
) {
1878 if ( ( $mode == LIST_AND ||
$mode == LIST_OR
) && is_numeric( $field ) ) {
1879 $list .= "($value)";
1880 } elseif ( ( $mode == LIST_SET
) && is_numeric( $field ) ) {
1882 } elseif ( ( $mode == LIST_AND ||
$mode == LIST_OR
) && is_array( $value ) ) {
1883 if ( count( $value ) == 0 ) {
1884 throw new MWException( __METHOD__
. ": empty input for field $field" );
1885 } elseif ( count( $value ) == 1 ) {
1886 // Special-case single values, as IN isn't terribly efficient
1887 // Don't necessarily assume the single key is 0; we don't
1888 // enforce linear numeric ordering on other arrays here.
1889 $value = array_values( $value );
1890 $list .= $field . " = " . $this->addQuotes( $value[0] );
1892 $list .= $field . " IN (" . $this->makeList( $value ) . ") ";
1894 } elseif ( $value === null ) {
1895 if ( $mode == LIST_AND ||
$mode == LIST_OR
) {
1896 $list .= "$field IS ";
1897 } elseif ( $mode == LIST_SET
) {
1898 $list .= "$field = ";
1902 if ( $mode == LIST_AND ||
$mode == LIST_OR ||
$mode == LIST_SET
) {
1903 $list .= "$field = ";
1905 $list .= $mode == LIST_NAMES ?
$value : $this->addQuotes( $value );
1913 * Build a partial where clause from a 2-d array such as used for LinkBatch.
1914 * The keys on each level may be either integers or strings.
1916 * @param array $data organized as 2-d
1917 * array(baseKeyVal => array(subKeyVal => [ignored], ...), ...)
1918 * @param string $baseKey field name to match the base-level keys to (eg 'pl_namespace')
1919 * @param string $subKey field name to match the sub-level keys to (eg 'pl_title')
1920 * @return Mixed: string SQL fragment, or false if no items in array.
1922 public function makeWhereFrom2d( $data, $baseKey, $subKey ) {
1925 foreach ( $data as $base => $sub ) {
1926 if ( count( $sub ) ) {
1927 $conds[] = $this->makeList(
1928 array( $baseKey => $base, $subKey => array_keys( $sub ) ),
1934 return $this->makeList( $conds, LIST_OR
);
1936 // Nothing to search for...
1942 * Return aggregated value alias
1945 * @param $valuename string
1949 public function aggregateValue( $valuedata, $valuename = 'value' ) {
1957 public function bitNot( $field ) {
1963 * @param $fieldRight
1966 public function bitAnd( $fieldLeft, $fieldRight ) {
1967 return "($fieldLeft & $fieldRight)";
1972 * @param $fieldRight
1975 public function bitOr( $fieldLeft, $fieldRight ) {
1976 return "($fieldLeft | $fieldRight)";
1980 * Build a concatenation list to feed into a SQL query
1981 * @param array $stringList list of raw SQL expressions; caller is responsible for any quoting
1984 public function buildConcat( $stringList ) {
1985 return 'CONCAT(' . implode( ',', $stringList ) . ')';
1989 * Change the current database
1991 * @todo Explain what exactly will fail if this is not overridden.
1995 * @return bool Success or failure
1997 public function selectDB( $db ) {
1998 # Stub. Shouldn't cause serious problems if it's not overridden, but
1999 # if your database engine supports a concept similar to MySQL's
2000 # databases you may as well.
2001 $this->mDBname
= $db;
2006 * Get the current DB name
2008 public function getDBname() {
2009 return $this->mDBname
;
2013 * Get the server hostname or IP address
2015 public function getServer() {
2016 return $this->mServer
;
2020 * Format a table name ready for use in constructing an SQL query
2022 * This does two important things: it quotes the table names to clean them up,
2023 * and it adds a table prefix if only given a table name with no quotes.
2025 * All functions of this object which require a table name call this function
2026 * themselves. Pass the canonical name to such functions. This is only needed
2027 * when calling query() directly.
2029 * @param string $name database table name
2030 * @param string $format One of:
2031 * quoted - Automatically pass the table name through addIdentifierQuotes()
2032 * so that it can be used in a query.
2033 * raw - Do not add identifier quotes to the table name
2034 * @return String: full database name
2036 public function tableName( $name, $format = 'quoted' ) {
2037 global $wgSharedDB, $wgSharedPrefix, $wgSharedTables;
2038 # Skip the entire process when we have a string quoted on both ends.
2039 # Note that we check the end so that we will still quote any use of
2040 # use of `database`.table. But won't break things if someone wants
2041 # to query a database table with a dot in the name.
2042 if ( $this->isQuotedIdentifier( $name ) ) {
2046 # Lets test for any bits of text that should never show up in a table
2047 # name. Basically anything like JOIN or ON which are actually part of
2048 # SQL queries, but may end up inside of the table value to combine
2049 # sql. Such as how the API is doing.
2050 # Note that we use a whitespace test rather than a \b test to avoid
2051 # any remote case where a word like on may be inside of a table name
2052 # surrounded by symbols which may be considered word breaks.
2053 if ( preg_match( '/(^|\s)(DISTINCT|JOIN|ON|AS)(\s|$)/i', $name ) !== 0 ) {
2057 # Split database and table into proper variables.
2058 # We reverse the explode so that database.table and table both output
2059 # the correct table.
2060 $dbDetails = explode( '.', $name, 2 );
2061 if ( count( $dbDetails ) == 2 ) {
2062 list( $database, $table ) = $dbDetails;
2063 # We don't want any prefix added in this case
2066 list( $table ) = $dbDetails;
2067 if ( $wgSharedDB !== null # We have a shared database
2068 && !$this->isQuotedIdentifier( $table ) # Paranoia check to prevent shared tables listing '`table`'
2069 && in_array( $table, $wgSharedTables ) # A shared table is selected
2071 $database = $wgSharedDB;
2072 $prefix = $wgSharedPrefix === null ?
$this->mTablePrefix
: $wgSharedPrefix;
2075 $prefix = $this->mTablePrefix
; # Default prefix
2079 # Quote $table and apply the prefix if not quoted.
2080 $tableName = "{$prefix}{$table}";
2081 if ( $format == 'quoted' && !$this->isQuotedIdentifier( $tableName ) ) {
2082 $tableName = $this->addIdentifierQuotes( $tableName );
2085 # Quote $database and merge it with the table name if needed
2086 if ( $database !== null ) {
2087 if ( $format == 'quoted' && !$this->isQuotedIdentifier( $database ) ) {
2088 $database = $this->addIdentifierQuotes( $database );
2090 $tableName = $database . '.' . $tableName;
2097 * Fetch a number of table names into an array
2098 * This is handy when you need to construct SQL for joins
2101 * extract( $dbr->tableNames( 'user', 'watchlist' ) );
2102 * $sql = "SELECT wl_namespace,wl_title FROM $watchlist,$user
2103 * WHERE wl_user=user_id AND wl_user=$nameWithQuotes";
2107 public function tableNames() {
2108 $inArray = func_get_args();
2111 foreach ( $inArray as $name ) {
2112 $retVal[$name] = $this->tableName( $name );
2119 * Fetch a number of table names into an zero-indexed numerical array
2120 * This is handy when you need to construct SQL for joins
2123 * list( $user, $watchlist ) = $dbr->tableNamesN( 'user', 'watchlist' );
2124 * $sql = "SELECT wl_namespace,wl_title FROM $watchlist,$user
2125 * WHERE wl_user=user_id AND wl_user=$nameWithQuotes";
2129 public function tableNamesN() {
2130 $inArray = func_get_args();
2133 foreach ( $inArray as $name ) {
2134 $retVal[] = $this->tableName( $name );
2141 * Get an aliased table name
2142 * e.g. tableName AS newTableName
2144 * @param string $name Table name, see tableName()
2145 * @param string|bool $alias Alias (optional)
2146 * @return string SQL name for aliased table. Will not alias a table to its own name
2148 public function tableNameWithAlias( $name, $alias = false ) {
2149 if ( !$alias ||
$alias == $name ) {
2150 return $this->tableName( $name );
2152 return $this->tableName( $name ) . ' ' . $this->addIdentifierQuotes( $alias );
2157 * Gets an array of aliased table names
2159 * @param $tables array( [alias] => table )
2160 * @return array of strings, see tableNameWithAlias()
2162 public function tableNamesWithAlias( $tables ) {
2164 foreach ( $tables as $alias => $table ) {
2165 if ( is_numeric( $alias ) ) {
2168 $retval[] = $this->tableNameWithAlias( $table, $alias );
2174 * Get an aliased field name
2175 * e.g. fieldName AS newFieldName
2177 * @param string $name Field name
2178 * @param string|bool $alias Alias (optional)
2179 * @return string SQL name for aliased field. Will not alias a field to its own name
2181 public function fieldNameWithAlias( $name, $alias = false ) {
2182 if ( !$alias ||
(string)$alias === (string)$name ) {
2185 return $name . ' AS ' . $alias; //PostgreSQL needs AS
2190 * Gets an array of aliased field names
2192 * @param $fields array( [alias] => field )
2193 * @return array of strings, see fieldNameWithAlias()
2195 public function fieldNamesWithAlias( $fields ) {
2197 foreach ( $fields as $alias => $field ) {
2198 if ( is_numeric( $alias ) ) {
2201 $retval[] = $this->fieldNameWithAlias( $field, $alias );
2207 * Get the aliased table name clause for a FROM clause
2208 * which might have a JOIN and/or USE INDEX clause
2210 * @param array $tables ( [alias] => table )
2211 * @param $use_index array Same as for select()
2212 * @param $join_conds array Same as for select()
2215 protected function tableNamesWithUseIndexOrJOIN(
2216 $tables, $use_index = array(), $join_conds = array()
2220 $use_index = (array)$use_index;
2221 $join_conds = (array)$join_conds;
2223 foreach ( $tables as $alias => $table ) {
2224 if ( !is_string( $alias ) ) {
2225 // No alias? Set it equal to the table name
2228 // Is there a JOIN clause for this table?
2229 if ( isset( $join_conds[$alias] ) ) {
2230 list( $joinType, $conds ) = $join_conds[$alias];
2231 $tableClause = $joinType;
2232 $tableClause .= ' ' . $this->tableNameWithAlias( $table, $alias );
2233 if ( isset( $use_index[$alias] ) ) { // has USE INDEX?
2234 $use = $this->useIndexClause( implode( ',', (array)$use_index[$alias] ) );
2236 $tableClause .= ' ' . $use;
2239 $on = $this->makeList( (array)$conds, LIST_AND
);
2241 $tableClause .= ' ON (' . $on . ')';
2244 $retJOIN[] = $tableClause;
2245 // Is there an INDEX clause for this table?
2246 } elseif ( isset( $use_index[$alias] ) ) {
2247 $tableClause = $this->tableNameWithAlias( $table, $alias );
2248 $tableClause .= ' ' . $this->useIndexClause(
2249 implode( ',', (array)$use_index[$alias] ) );
2251 $ret[] = $tableClause;
2253 $tableClause = $this->tableNameWithAlias( $table, $alias );
2255 $ret[] = $tableClause;
2259 // We can't separate explicit JOIN clauses with ',', use ' ' for those
2260 $straightJoins = !empty( $ret ) ?
implode( ',', $ret ) : "";
2261 $otherJoins = !empty( $retJOIN ) ?
implode( ' ', $retJOIN ) : "";
2263 // Compile our final table clause
2264 return implode( ' ', array( $straightJoins, $otherJoins ) );
2268 * Get the name of an index in a given table
2274 protected function indexName( $index ) {
2275 // Backwards-compatibility hack
2277 'ar_usertext_timestamp' => 'usertext_timestamp',
2278 'un_user_id' => 'user_id',
2279 'un_user_ip' => 'user_ip',
2282 if ( isset( $renamed[$index] ) ) {
2283 return $renamed[$index];
2290 * If it's a string, adds quotes and backslashes
2291 * Otherwise returns as-is
2297 public function addQuotes( $s ) {
2298 if ( $s === null ) {
2301 # This will also quote numeric values. This should be harmless,
2302 # and protects against weird problems that occur when they really
2303 # _are_ strings such as article titles and string->number->string
2304 # conversion is not 1:1.
2305 return "'" . $this->strencode( $s ) . "'";
2310 * Quotes an identifier using `backticks` or "double quotes" depending on the database type.
2311 * MySQL uses `backticks` while basically everything else uses double quotes.
2312 * Since MySQL is the odd one out here the double quotes are our generic
2313 * and we implement backticks in DatabaseMysql.
2319 public function addIdentifierQuotes( $s ) {
2320 return '"' . str_replace( '"', '""', $s ) . '"';
2324 * Returns if the given identifier looks quoted or not according to
2325 * the database convention for quoting identifiers .
2327 * @param $name string
2331 public function isQuotedIdentifier( $name ) {
2332 return $name[0] == '"' && substr( $name, -1, 1 ) == '"';
2339 protected function escapeLikeInternal( $s ) {
2340 $s = str_replace( '\\', '\\\\', $s );
2341 $s = $this->strencode( $s );
2342 $s = str_replace( array( '%', '_' ), array( '\%', '\_' ), $s );
2348 * LIKE statement wrapper, receives a variable-length argument list with parts of pattern to match
2349 * containing either string literals that will be escaped or tokens returned by anyChar() or anyString().
2350 * Alternatively, the function could be provided with an array of aforementioned parameters.
2352 * Example: $dbr->buildLike( 'My_page_title/', $dbr->anyString() ) returns a LIKE clause that searches
2353 * for subpages of 'My page title'.
2354 * Alternatively: $pattern = array( 'My_page_title/', $dbr->anyString() ); $query .= $dbr->buildLike( $pattern );
2357 * @return String: fully built LIKE statement
2359 public function buildLike() {
2360 $params = func_get_args();
2362 if ( count( $params ) > 0 && is_array( $params[0] ) ) {
2363 $params = $params[0];
2368 foreach ( $params as $value ) {
2369 if ( $value instanceof LikeMatch
) {
2370 $s .= $value->toString();
2372 $s .= $this->escapeLikeInternal( $value );
2376 return " LIKE '" . $s . "' ";
2380 * Returns a token for buildLike() that denotes a '_' to be used in a LIKE query
2384 public function anyChar() {
2385 return new LikeMatch( '_' );
2389 * Returns a token for buildLike() that denotes a '%' to be used in a LIKE query
2393 public function anyString() {
2394 return new LikeMatch( '%' );
2398 * Returns an appropriately quoted sequence value for inserting a new row.
2399 * MySQL has autoincrement fields, so this is just NULL. But the PostgreSQL
2400 * subclass will return an integer, and save the value for insertId()
2402 * Any implementation of this function should *not* involve reusing
2403 * sequence numbers created for rolled-back transactions.
2404 * See http://bugs.mysql.com/bug.php?id=30767 for details.
2405 * @param $seqName string
2408 public function nextSequenceValue( $seqName ) {
2413 * USE INDEX clause. Unlikely to be useful for anything but MySQL. This
2414 * is only needed because a) MySQL must be as efficient as possible due to
2415 * its use on Wikipedia, and b) MySQL 4.0 is kind of dumb sometimes about
2416 * which index to pick. Anyway, other databases might have different
2417 * indexes on a given table. So don't bother overriding this unless you're
2422 public function useIndexClause( $index ) {
2427 * REPLACE query wrapper.
2429 * REPLACE is a very handy MySQL extension, which functions like an INSERT
2430 * except that when there is a duplicate key error, the old row is deleted
2431 * and the new row is inserted in its place.
2433 * We simulate this with standard SQL with a DELETE followed by INSERT. To
2434 * perform the delete, we need to know what the unique indexes are so that
2435 * we know how to find the conflicting rows.
2437 * It may be more efficient to leave off unique indexes which are unlikely
2438 * to collide. However if you do this, you run the risk of encountering
2439 * errors which wouldn't have occurred in MySQL.
2441 * @param string $table The table to replace the row(s) in.
2442 * @param array $rows Can be either a single row to insert, or multiple rows,
2443 * in the same format as for DatabaseBase::insert()
2444 * @param array $uniqueIndexes is an array of indexes. Each element may be either
2445 * a field name or an array of field names
2446 * @param string $fname Calling function name (use __METHOD__) for logs/profiling
2448 public function replace( $table, $uniqueIndexes, $rows, $fname = 'DatabaseBase::replace' ) {
2449 $quotedTable = $this->tableName( $table );
2451 if ( count( $rows ) == 0 ) {
2456 if ( !is_array( reset( $rows ) ) ) {
2457 $rows = array( $rows );
2460 foreach( $rows as $row ) {
2461 # Delete rows which collide
2462 if ( $uniqueIndexes ) {
2463 $sql = "DELETE FROM $quotedTable WHERE ";
2465 foreach ( $uniqueIndexes as $index ) {
2472 if ( is_array( $index ) ) {
2474 foreach ( $index as $col ) {
2480 $sql .= $col . '=' . $this->addQuotes( $row[$col] );
2483 $sql .= $index . '=' . $this->addQuotes( $row[$index] );
2487 $this->query( $sql, $fname );
2490 # Now insert the row
2491 $this->insert( $table, $row, $fname );
2496 * REPLACE query wrapper for MySQL and SQLite, which have a native REPLACE
2499 * @param string $table Table name
2500 * @param array $rows Rows to insert
2501 * @param string $fname Caller function name
2503 * @return ResultWrapper
2505 protected function nativeReplace( $table, $rows, $fname ) {
2506 $table = $this->tableName( $table );
2509 if ( !is_array( reset( $rows ) ) ) {
2510 $rows = array( $rows );
2513 $sql = "REPLACE INTO $table (" . implode( ',', array_keys( $rows[0] ) ) . ') VALUES ';
2516 foreach ( $rows as $row ) {
2523 $sql .= '(' . $this->makeList( $row ) . ')';
2526 return $this->query( $sql, $fname );
2530 * DELETE where the condition is a join.
2532 * MySQL overrides this to use a multi-table DELETE syntax, in other databases
2533 * we use sub-selects
2535 * For safety, an empty $conds will not delete everything. If you want to
2536 * delete all rows where the join condition matches, set $conds='*'.
2538 * DO NOT put the join condition in $conds.
2540 * @param $delTable String: The table to delete from.
2541 * @param $joinTable String: The other table.
2542 * @param $delVar String: The variable to join on, in the first table.
2543 * @param $joinVar String: The variable to join on, in the second table.
2544 * @param $conds Array: Condition array of field names mapped to variables,
2545 * ANDed together in the WHERE clause
2546 * @param $fname String: Calling function name (use __METHOD__) for
2548 * @throws DBUnexpectedError
2550 public function deleteJoin( $delTable, $joinTable, $delVar, $joinVar, $conds,
2551 $fname = 'DatabaseBase::deleteJoin' )
2554 throw new DBUnexpectedError( $this,
2555 'DatabaseBase::deleteJoin() called with empty $conds' );
2558 $delTable = $this->tableName( $delTable );
2559 $joinTable = $this->tableName( $joinTable );
2560 $sql = "DELETE FROM $delTable WHERE $delVar IN (SELECT $joinVar FROM $joinTable ";
2561 if ( $conds != '*' ) {
2562 $sql .= 'WHERE ' . $this->makeList( $conds, LIST_AND
);
2566 $this->query( $sql, $fname );
2570 * Returns the size of a text field, or -1 for "unlimited"
2572 * @param $table string
2573 * @param $field string
2577 public function textFieldSize( $table, $field ) {
2578 $table = $this->tableName( $table );
2579 $sql = "SHOW COLUMNS FROM $table LIKE \"$field\";";
2580 $res = $this->query( $sql, 'DatabaseBase::textFieldSize' );
2581 $row = $this->fetchObject( $res );
2585 if ( preg_match( '/\((.*)\)/', $row->Type
, $m ) ) {
2595 * A string to insert into queries to show that they're low-priority, like
2596 * MySQL's LOW_PRIORITY. If no such feature exists, return an empty
2597 * string and nothing bad should happen.
2599 * @return string Returns the text of the low priority option if it is
2600 * supported, or a blank string otherwise
2602 public function lowPriorityOption() {
2607 * DELETE query wrapper.
2609 * @param array $table Table name
2610 * @param string|array $conds of conditions. See $conds in DatabaseBase::select() for
2611 * the format. Use $conds == "*" to delete all rows
2612 * @param string $fname name of the calling function
2614 * @throws DBUnexpectedError
2615 * @return bool|ResultWrapper
2617 public function delete( $table, $conds, $fname = 'DatabaseBase::delete' ) {
2619 throw new DBUnexpectedError( $this, 'DatabaseBase::delete() called with no conditions' );
2622 $table = $this->tableName( $table );
2623 $sql = "DELETE FROM $table";
2625 if ( $conds != '*' ) {
2626 $sql .= ' WHERE ' . $this->makeList( $conds, LIST_AND
);
2629 return $this->query( $sql, $fname );
2633 * INSERT SELECT wrapper. Takes data from a SELECT query and inserts it
2634 * into another table.
2636 * @param string $destTable The table name to insert into
2637 * @param string|array $srcTable May be either a table name, or an array of table names
2638 * to include in a join.
2640 * @param array $varMap must be an associative array of the form
2641 * array( 'dest1' => 'source1', ...). Source items may be literals
2642 * rather than field names, but strings should be quoted with
2643 * DatabaseBase::addQuotes()
2645 * @param array $conds Condition array. See $conds in DatabaseBase::select() for
2646 * the details of the format of condition arrays. May be "*" to copy the
2649 * @param string $fname The function name of the caller, from __METHOD__
2651 * @param array $insertOptions Options for the INSERT part of the query, see
2652 * DatabaseBase::insert() for details.
2653 * @param array $selectOptions Options for the SELECT part of the query, see
2654 * DatabaseBase::select() for details.
2656 * @return ResultWrapper
2658 public function insertSelect( $destTable, $srcTable, $varMap, $conds,
2659 $fname = 'DatabaseBase::insertSelect',
2660 $insertOptions = array(), $selectOptions = array() )
2662 $destTable = $this->tableName( $destTable );
2664 if ( is_array( $insertOptions ) ) {
2665 $insertOptions = implode( ' ', $insertOptions );
2668 if ( !is_array( $selectOptions ) ) {
2669 $selectOptions = array( $selectOptions );
2672 list( $startOpts, $useIndex, $tailOpts ) = $this->makeSelectOptions( $selectOptions );
2674 if ( is_array( $srcTable ) ) {
2675 $srcTable = implode( ',', array_map( array( &$this, 'tableName' ), $srcTable ) );
2677 $srcTable = $this->tableName( $srcTable );
2680 $sql = "INSERT $insertOptions INTO $destTable (" . implode( ',', array_keys( $varMap ) ) . ')' .
2681 " SELECT $startOpts " . implode( ',', $varMap ) .
2682 " FROM $srcTable $useIndex ";
2684 if ( $conds != '*' ) {
2685 if ( is_array( $conds ) ) {
2686 $conds = $this->makeList( $conds, LIST_AND
);
2688 $sql .= " WHERE $conds";
2691 $sql .= " $tailOpts";
2693 return $this->query( $sql, $fname );
2697 * Construct a LIMIT query with optional offset. This is used for query
2698 * pages. The SQL should be adjusted so that only the first $limit rows
2699 * are returned. If $offset is provided as well, then the first $offset
2700 * rows should be discarded, and the next $limit rows should be returned.
2701 * If the result of the query is not ordered, then the rows to be returned
2702 * are theoretically arbitrary.
2704 * $sql is expected to be a SELECT, if that makes a difference.
2706 * The version provided by default works in MySQL and SQLite. It will very
2707 * likely need to be overridden for most other DBMSes.
2709 * @param string $sql SQL query we will append the limit too
2710 * @param $limit Integer the SQL limit
2711 * @param $offset Integer|bool the SQL offset (default false)
2713 * @throws DBUnexpectedError
2716 public function limitResult( $sql, $limit, $offset = false ) {
2717 if ( !is_numeric( $limit ) ) {
2718 throw new DBUnexpectedError( $this, "Invalid non-numeric limit passed to limitResult()\n" );
2720 return "$sql LIMIT "
2721 . ( ( is_numeric( $offset ) && $offset != 0 ) ?
"{$offset}," : "" )
2726 * Returns true if current database backend supports ORDER BY or LIMIT for separate subqueries
2727 * within the UNION construct.
2730 public function unionSupportsOrderAndLimit() {
2731 return true; // True for almost every DB supported
2735 * Construct a UNION query
2736 * This is used for providing overload point for other DB abstractions
2737 * not compatible with the MySQL syntax.
2738 * @param array $sqls SQL statements to combine
2739 * @param $all Boolean: use UNION ALL
2740 * @return String: SQL fragment
2742 public function unionQueries( $sqls, $all ) {
2743 $glue = $all ?
') UNION ALL (' : ') UNION (';
2744 return '(' . implode( $glue, $sqls ) . ')';
2748 * Returns an SQL expression for a simple conditional. This doesn't need
2749 * to be overridden unless CASE isn't supported in your DBMS.
2751 * @param string|array $cond SQL expression which will result in a boolean value
2752 * @param string $trueVal SQL expression to return if true
2753 * @param string $falseVal SQL expression to return if false
2754 * @return String: SQL fragment
2756 public function conditional( $cond, $trueVal, $falseVal ) {
2757 if ( is_array( $cond ) ) {
2758 $cond = $this->makeList( $cond, LIST_AND
);
2760 return " (CASE WHEN $cond THEN $trueVal ELSE $falseVal END) ";
2764 * Returns a comand for str_replace function in SQL query.
2765 * Uses REPLACE() in MySQL
2767 * @param string $orig column to modify
2768 * @param string $old column to seek
2769 * @param string $new column to replace with
2773 public function strreplace( $orig, $old, $new ) {
2774 return "REPLACE({$orig}, {$old}, {$new})";
2778 * Determines how long the server has been up
2783 public function getServerUptime() {
2788 * Determines if the last failure was due to a deadlock
2793 public function wasDeadlock() {
2798 * Determines if the last failure was due to a lock timeout
2803 public function wasLockTimeout() {
2808 * Determines if the last query error was something that should be dealt
2809 * with by pinging the connection and reissuing the query.
2814 public function wasErrorReissuable() {
2819 * Determines if the last failure was due to the database being read-only.
2824 public function wasReadOnlyError() {
2829 * Perform a deadlock-prone transaction.
2831 * This function invokes a callback function to perform a set of write
2832 * queries. If a deadlock occurs during the processing, the transaction
2833 * will be rolled back and the callback function will be called again.
2836 * $dbw->deadlockLoop( callback, ... );
2838 * Extra arguments are passed through to the specified callback function.
2840 * Returns whatever the callback function returned on its successful,
2841 * iteration, or false on error, for example if the retry limit was
2846 public function deadlockLoop() {
2847 $this->begin( __METHOD__
);
2848 $args = func_get_args();
2849 $function = array_shift( $args );
2850 $oldIgnore = $this->ignoreErrors( true );
2851 $tries = DEADLOCK_TRIES
;
2853 if ( is_array( $function ) ) {
2854 $fname = $function[0];
2860 $retVal = call_user_func_array( $function, $args );
2861 $error = $this->lastError();
2862 $errno = $this->lastErrno();
2863 $sql = $this->lastQuery();
2866 if ( $this->wasDeadlock() ) {
2868 usleep( mt_rand( DEADLOCK_DELAY_MIN
, DEADLOCK_DELAY_MAX
) );
2870 $this->reportQueryError( $error, $errno, $sql, $fname );
2873 } while ( $this->wasDeadlock() && --$tries > 0 );
2875 $this->ignoreErrors( $oldIgnore );
2877 if ( $tries <= 0 ) {
2878 $this->rollback( __METHOD__
);
2879 $this->reportQueryError( $error, $errno, $sql, $fname );
2882 $this->commit( __METHOD__
);
2888 * Wait for the slave to catch up to a given master position.
2890 * @param $pos DBMasterPos object
2891 * @param $timeout Integer: the maximum number of seconds to wait for
2894 * @return integer: zero if the slave was past that position already,
2895 * greater than zero if we waited for some period of time, less than
2896 * zero if we timed out.
2898 public function masterPosWait( DBMasterPos
$pos, $timeout ) {
2899 wfProfileIn( __METHOD__
);
2901 if ( !is_null( $this->mFakeSlaveLag
) ) {
2902 $wait = intval( ( $pos->pos
- microtime( true ) +
$this->mFakeSlaveLag
) * 1e6
);
2904 if ( $wait > $timeout * 1e6
) {
2905 wfDebug( "Fake slave timed out waiting for $pos ($wait us)\n" );
2906 wfProfileOut( __METHOD__
);
2908 } elseif ( $wait > 0 ) {
2909 wfDebug( "Fake slave waiting $wait us\n" );
2911 wfProfileOut( __METHOD__
);
2914 wfDebug( "Fake slave up to date ($wait us)\n" );
2915 wfProfileOut( __METHOD__
);
2920 wfProfileOut( __METHOD__
);
2922 # Real waits are implemented in the subclass.
2927 * Get the replication position of this slave
2929 * @return DBMasterPos, or false if this is not a slave.
2931 public function getSlavePos() {
2932 if ( !is_null( $this->mFakeSlaveLag
) ) {
2933 $pos = new MySQLMasterPos( 'fake', microtime( true ) - $this->mFakeSlaveLag
);
2934 wfDebug( __METHOD__
. ": fake slave pos = $pos\n" );
2943 * Get the position of this master
2945 * @return DBMasterPos, or false if this is not a master
2947 public function getMasterPos() {
2948 if ( $this->mFakeMaster
) {
2949 return new MySQLMasterPos( 'fake', microtime( true ) );
2956 * Run an anonymous function as soon as there is no transaction pending.
2957 * If there is a transaction and it is rolled back, then the callback is cancelled.
2958 * Callbacks must commit any transactions that they begin.
2960 * This is useful for updates to different systems or separate transactions are needed.
2964 * @param Closure $callback
2966 final public function onTransactionIdle( Closure
$callback ) {
2967 if ( $this->mTrxLevel
) {
2968 $this->mTrxIdleCallbacks
[] = $callback;
2975 * Actually run the "on transaction idle" callbacks.
2979 protected function runOnTransactionIdleCallbacks() {
2980 $autoTrx = $this->getFlag( DBO_TRX
); // automatic begin() enabled?
2982 $e = null; // last exception
2983 do { // callbacks may add callbacks :)
2984 $callbacks = $this->mTrxIdleCallbacks
;
2985 $this->mTrxIdleCallbacks
= array(); // recursion guard
2986 foreach ( $callbacks as $callback ) {
2988 $this->clearFlag( DBO_TRX
); // make each query its own transaction
2990 $this->setFlag( $autoTrx ? DBO_TRX
: 0 ); // restore automatic begin()
2991 } catch ( Exception
$e ) {}
2993 } while ( count( $this->mTrxIdleCallbacks
) );
2995 if ( $e instanceof Exception
) {
2996 throw $e; // re-throw any last exception
3001 * Begin a transaction. If a transaction is already in progress, that transaction will be committed before the
3002 * new transaction is started.
3004 * Note that when the DBO_TRX flag is set (which is usually the case for web requests, but not for maintenance scripts),
3005 * any previous database query will have started a transaction automatically.
3007 * Nesting of transactions is not supported. Attempts to nest transactions will cause a warning, unless the current
3008 * transaction was started automatically because of the DBO_TRX flag.
3010 * @param $fname string
3012 final public function begin( $fname = 'DatabaseBase::begin' ) {
3013 global $wgDebugDBTransactions;
3015 if ( $this->mTrxLevel
) { // implicit commit
3016 if ( !$this->mTrxAutomatic
) {
3017 // We want to warn about inadvertently nested begin/commit pairs, but not about
3018 // auto-committing implicit transactions that were started by query() via DBO_TRX
3019 $msg = "$fname: Transaction already in progress (from {$this->mTrxFname}), " .
3020 " performing implicit commit!";
3022 wfLogDBError( $msg );
3024 // if the transaction was automatic and has done write operations,
3025 // log it if $wgDebugDBTransactions is enabled.
3026 if ( $this->mTrxDoneWrites
&& $wgDebugDBTransactions ) {
3027 wfDebug( "$fname: Automatic transaction with writes in progress" .
3028 " (from {$this->mTrxFname}), performing implicit commit!\n" );
3032 $this->doCommit( $fname );
3033 $this->runOnTransactionIdleCallbacks();
3036 $this->doBegin( $fname );
3037 $this->mTrxFname
= $fname;
3038 $this->mTrxDoneWrites
= false;
3039 $this->mTrxAutomatic
= false;
3043 * Issues the BEGIN command to the database server.
3045 * @see DatabaseBase::begin()
3046 * @param type $fname
3048 protected function doBegin( $fname ) {
3049 $this->query( 'BEGIN', $fname );
3050 $this->mTrxLevel
= 1;
3054 * Commits a transaction previously started using begin().
3055 * If no transaction is in progress, a warning is issued.
3057 * Nesting of transactions is not supported.
3059 * @param $fname string
3060 * @param string $flush Flush flag, set to 'flush' to disable warnings about explicitly committing implicit
3061 * transactions, or calling commit when no transaction is in progress.
3062 * This will silently break any ongoing explicit transaction. Only set the flush flag if you are sure
3063 * that it is safe to ignore these warnings in your context.
3065 final public function commit( $fname = 'DatabaseBase::commit', $flush = '' ) {
3066 if ( $flush != 'flush' ) {
3067 if ( !$this->mTrxLevel
) {
3068 wfWarn( "$fname: No transaction to commit, something got out of sync!" );
3069 } elseif( $this->mTrxAutomatic
) {
3070 wfWarn( "$fname: Explicit commit of implicit transaction. Something may be out of sync!" );
3073 if ( !$this->mTrxLevel
) {
3074 return; // nothing to do
3075 } elseif( !$this->mTrxAutomatic
) {
3076 wfWarn( "$fname: Flushing an explicit transaction, getting out of sync!" );
3080 $this->doCommit( $fname );
3081 $this->runOnTransactionIdleCallbacks();
3085 * Issues the COMMIT command to the database server.
3087 * @see DatabaseBase::commit()
3088 * @param type $fname
3090 protected function doCommit( $fname ) {
3091 if ( $this->mTrxLevel
) {
3092 $this->query( 'COMMIT', $fname );
3093 $this->mTrxLevel
= 0;
3098 * Rollback a transaction previously started using begin().
3099 * If no transaction is in progress, a warning is issued.
3101 * No-op on non-transactional databases.
3103 * @param $fname string
3105 final public function rollback( $fname = 'DatabaseBase::rollback' ) {
3106 if ( !$this->mTrxLevel
) {
3107 wfWarn( "$fname: No transaction to rollback, something got out of sync!" );
3109 $this->doRollback( $fname );
3110 $this->mTrxIdleCallbacks
= array(); // cancel
3114 * Issues the ROLLBACK command to the database server.
3116 * @see DatabaseBase::rollback()
3117 * @param type $fname
3119 protected function doRollback( $fname ) {
3120 if ( $this->mTrxLevel
) {
3121 $this->query( 'ROLLBACK', $fname, true );
3122 $this->mTrxLevel
= 0;
3127 * Creates a new table with structure copied from existing table
3128 * Note that unlike most database abstraction functions, this function does not
3129 * automatically append database prefix, because it works at a lower
3130 * abstraction level.
3131 * The table names passed to this function shall not be quoted (this
3132 * function calls addIdentifierQuotes when needed).
3134 * @param string $oldName name of table whose structure should be copied
3135 * @param string $newName name of table to be created
3136 * @param $temporary Boolean: whether the new table should be temporary
3137 * @param string $fname calling function name
3138 * @throws MWException
3139 * @return Boolean: true if operation was successful
3141 public function duplicateTableStructure( $oldName, $newName, $temporary = false,
3142 $fname = 'DatabaseBase::duplicateTableStructure' )
3144 throw new MWException(
3145 'DatabaseBase::duplicateTableStructure is not implemented in descendant class' );
3149 * List all tables on the database
3151 * @param string $prefix Only show tables with this prefix, e.g. mw_
3152 * @param string $fname calling function name
3153 * @throws MWException
3155 function listTables( $prefix = null, $fname = 'DatabaseBase::listTables' ) {
3156 throw new MWException( 'DatabaseBase::listTables is not implemented in descendant class' );
3160 * Convert a timestamp in one of the formats accepted by wfTimestamp()
3161 * to the format used for inserting into timestamp fields in this DBMS.
3163 * The result is unquoted, and needs to be passed through addQuotes()
3164 * before it can be included in raw SQL.
3166 * @param $ts string|int
3170 public function timestamp( $ts = 0 ) {
3171 return wfTimestamp( TS_MW
, $ts );
3175 * Convert a timestamp in one of the formats accepted by wfTimestamp()
3176 * to the format used for inserting into timestamp fields in this DBMS. If
3177 * NULL is input, it is passed through, allowing NULL values to be inserted
3178 * into timestamp fields.
3180 * The result is unquoted, and needs to be passed through addQuotes()
3181 * before it can be included in raw SQL.
3183 * @param $ts string|int
3187 public function timestampOrNull( $ts = null ) {
3188 if ( is_null( $ts ) ) {
3191 return $this->timestamp( $ts );
3196 * Take the result from a query, and wrap it in a ResultWrapper if
3197 * necessary. Boolean values are passed through as is, to indicate success
3198 * of write queries or failure.
3200 * Once upon a time, DatabaseBase::query() returned a bare MySQL result
3201 * resource, and it was necessary to call this function to convert it to
3202 * a wrapper. Nowadays, raw database objects are never exposed to external
3203 * callers, so this is unnecessary in external code. For compatibility with
3204 * old code, ResultWrapper objects are passed through unaltered.
3206 * @param $result bool|ResultWrapper
3208 * @return bool|ResultWrapper
3210 public function resultObject( $result ) {
3211 if ( empty( $result ) ) {
3213 } elseif ( $result instanceof ResultWrapper
) {
3215 } elseif ( $result === true ) {
3216 // Successful write query
3219 return new ResultWrapper( $this, $result );
3224 * Ping the server and try to reconnect if it there is no connection
3226 * @return bool Success or failure
3228 public function ping() {
3229 # Stub. Not essential to override.
3234 * Get slave lag. Currently supported only by MySQL.
3236 * Note that this function will generate a fatal error on many
3237 * installations. Most callers should use LoadBalancer::safeGetLag()
3240 * @return int Database replication lag in seconds
3242 public function getLag() {
3243 return intval( $this->mFakeSlaveLag
);
3247 * Return the maximum number of items allowed in a list, or 0 for unlimited.
3251 function maxListLen() {
3256 * Some DBMSs have a special format for inserting into blob fields, they
3257 * don't allow simple quoted strings to be inserted. To insert into such
3258 * a field, pass the data through this function before passing it to
3259 * DatabaseBase::insert().
3263 public function encodeBlob( $b ) {
3268 * Some DBMSs return a special placeholder object representing blob fields
3269 * in result objects. Pass the object through this function to return the
3274 public function decodeBlob( $b ) {
3279 * Override database's default behavior. $options include:
3280 * 'connTimeout' : Set the connection timeout value in seconds.
3281 * May be useful for very long batch queries such as
3282 * full-wiki dumps, where a single query reads out over
3285 * @param $options Array
3288 public function setSessionOptions( array $options ) {}
3291 * Read and execute SQL commands from a file.
3293 * Returns true on success, error string or exception on failure (depending
3294 * on object's error ignore settings).
3296 * @param string $filename File name to open
3297 * @param bool|callable $lineCallback Optional function called before reading each line
3298 * @param bool|callable $resultCallback Optional function called for each MySQL result
3299 * @param bool|string $fname Calling function name or false if name should be
3300 * generated dynamically using $filename
3301 * @param bool|callable $inputCallback Callback: Optional function called for each complete line sent
3302 * @throws MWException
3303 * @throws Exception|MWException
3304 * @return bool|string
3306 public function sourceFile(
3307 $filename, $lineCallback = false, $resultCallback = false, $fname = false, $inputCallback = false
3309 wfSuppressWarnings();
3310 $fp = fopen( $filename, 'r' );
3311 wfRestoreWarnings();
3313 if ( false === $fp ) {
3314 throw new MWException( "Could not open \"{$filename}\".\n" );
3318 $fname = __METHOD__
. "( $filename )";
3322 $error = $this->sourceStream( $fp, $lineCallback, $resultCallback, $fname, $inputCallback );
3324 catch ( MWException
$e ) {
3335 * Get the full path of a patch file. Originally based on archive()
3336 * from updaters.inc. Keep in mind this always returns a patch, as
3337 * it fails back to MySQL if no DB-specific patch can be found
3339 * @param string $patch The name of the patch, like patch-something.sql
3340 * @return String Full path to patch file
3342 public function patchPath( $patch ) {
3345 $dbType = $this->getType();
3346 if ( file_exists( "$IP/maintenance/$dbType/archives/$patch" ) ) {
3347 return "$IP/maintenance/$dbType/archives/$patch";
3349 return "$IP/maintenance/archives/$patch";
3354 * Set variables to be used in sourceFile/sourceStream, in preference to the
3355 * ones in $GLOBALS. If an array is set here, $GLOBALS will not be used at
3356 * all. If it's set to false, $GLOBALS will be used.
3358 * @param bool|array $vars mapping variable name to value.
3360 public function setSchemaVars( $vars ) {
3361 $this->mSchemaVars
= $vars;
3365 * Read and execute commands from an open file handle.
3367 * Returns true on success, error string or exception on failure (depending
3368 * on object's error ignore settings).
3370 * @param $fp Resource: File handle
3371 * @param $lineCallback Callback: Optional function called before reading each query
3372 * @param $resultCallback Callback: Optional function called for each MySQL result
3373 * @param string $fname Calling function name
3374 * @param $inputCallback Callback: Optional function called for each complete query sent
3375 * @return bool|string
3377 public function sourceStream( $fp, $lineCallback = false, $resultCallback = false,
3378 $fname = 'DatabaseBase::sourceStream', $inputCallback = false )
3382 while ( !feof( $fp ) ) {
3383 if ( $lineCallback ) {
3384 call_user_func( $lineCallback );
3387 $line = trim( fgets( $fp ) );
3389 if ( $line == '' ) {
3393 if ( '-' == $line[0] && '-' == $line[1] ) {
3401 $done = $this->streamStatementEnd( $cmd, $line );
3405 if ( $done ||
feof( $fp ) ) {
3406 $cmd = $this->replaceVars( $cmd );
3408 if ( ( $inputCallback && call_user_func( $inputCallback, $cmd ) ) ||
!$inputCallback ) {
3409 $res = $this->query( $cmd, $fname );
3411 if ( $resultCallback ) {
3412 call_user_func( $resultCallback, $res, $this );
3415 if ( false === $res ) {
3416 $err = $this->lastError();
3417 return "Query \"{$cmd}\" failed with error code \"$err\".\n";
3428 * Called by sourceStream() to check if we've reached a statement end
3430 * @param string $sql SQL assembled so far
3431 * @param string $newLine New line about to be added to $sql
3432 * @return Bool Whether $newLine contains end of the statement
3434 public function streamStatementEnd( &$sql, &$newLine ) {
3435 if ( $this->delimiter
) {
3437 $newLine = preg_replace( '/' . preg_quote( $this->delimiter
, '/' ) . '$/', '', $newLine );
3438 if ( $newLine != $prev ) {
3446 * Database independent variable replacement. Replaces a set of variables
3447 * in an SQL statement with their contents as given by $this->getSchemaVars().
3449 * Supports '{$var}' `{$var}` and / *$var* / (without the spaces) style variables.
3451 * - '{$var}' should be used for text and is passed through the database's
3453 * - `{$var}` should be used for identifiers (eg: table and database names),
3454 * it is passed through the database's addIdentifierQuotes method which
3455 * can be overridden if the database uses something other than backticks.
3456 * - / *$var* / is just encoded, besides traditional table prefix and
3457 * table options its use should be avoided.
3459 * @param string $ins SQL statement to replace variables in
3460 * @return String The new SQL statement with variables replaced
3462 protected function replaceSchemaVars( $ins ) {
3463 $vars = $this->getSchemaVars();
3464 foreach ( $vars as $var => $value ) {
3466 $ins = str_replace( '\'{$' . $var . '}\'', $this->addQuotes( $value ), $ins );
3468 $ins = str_replace( '`{$' . $var . '}`', $this->addIdentifierQuotes( $value ), $ins );
3470 $ins = str_replace( '/*$' . $var . '*/', $this->strencode( $value ), $ins );
3476 * Replace variables in sourced SQL
3478 * @param $ins string
3482 protected function replaceVars( $ins ) {
3483 $ins = $this->replaceSchemaVars( $ins );
3486 $ins = preg_replace_callback( '!/\*(?:\$wgDBprefix|_)\*/([a-zA-Z_0-9]*)!',
3487 array( $this, 'tableNameCallback' ), $ins );
3490 $ins = preg_replace_callback( '!/\*i\*/([a-zA-Z_0-9]*)!',
3491 array( $this, 'indexNameCallback' ), $ins );
3497 * Get schema variables. If none have been set via setSchemaVars(), then
3498 * use some defaults from the current object.
3502 protected function getSchemaVars() {
3503 if ( $this->mSchemaVars
) {
3504 return $this->mSchemaVars
;
3506 return $this->getDefaultSchemaVars();
3511 * Get schema variables to use if none have been set via setSchemaVars().
3513 * Override this in derived classes to provide variables for tables.sql
3514 * and SQL patch files.
3518 protected function getDefaultSchemaVars() {
3523 * Table name callback
3525 * @param $matches array
3529 protected function tableNameCallback( $matches ) {
3530 return $this->tableName( $matches[1] );
3534 * Index name callback
3536 * @param $matches array
3540 protected function indexNameCallback( $matches ) {
3541 return $this->indexName( $matches[1] );
3545 * Check to see if a named lock is available. This is non-blocking.
3547 * @param string $lockName name of lock to poll
3548 * @param string $method name of method calling us
3552 public function lockIsFree( $lockName, $method ) {
3557 * Acquire a named lock
3559 * Abstracted from Filestore::lock() so child classes can implement for
3562 * @param string $lockName name of lock to aquire
3563 * @param string $method name of method calling us
3564 * @param $timeout Integer: timeout
3567 public function lock( $lockName, $method, $timeout = 5 ) {
3574 * @param string $lockName Name of lock to release
3575 * @param string $method Name of method calling us
3577 * @return int Returns 1 if the lock was released, 0 if the lock was not established
3578 * by this thread (in which case the lock is not released), and NULL if the named
3579 * lock did not exist
3581 public function unlock( $lockName, $method ) {
3586 * Lock specific tables
3588 * @param array $read of tables to lock for read access
3589 * @param array $write of tables to lock for write access
3590 * @param string $method name of caller
3591 * @param bool $lowPriority Whether to indicate writes to be LOW PRIORITY
3595 public function lockTables( $read, $write, $method, $lowPriority = true ) {
3600 * Unlock specific tables
3602 * @param string $method the caller
3606 public function unlockTables( $method ) {
3612 * @param $tableName string
3613 * @param $fName string
3614 * @return bool|ResultWrapper
3617 public function dropTable( $tableName, $fName = 'DatabaseBase::dropTable' ) {
3618 if( !$this->tableExists( $tableName, $fName ) ) {
3621 $sql = "DROP TABLE " . $this->tableName( $tableName );
3622 if( $this->cascadingDeletes() ) {
3625 return $this->query( $sql, $fName );
3629 * Get search engine class. All subclasses of this need to implement this
3630 * if they wish to use searching.
3634 public function getSearchEngine() {
3635 return 'SearchEngineDummy';
3639 * Find out when 'infinity' is. Most DBMSes support this. This is a special
3640 * keyword for timestamps in PostgreSQL, and works with CHAR(14) as well
3641 * because "i" sorts after all numbers.
3645 public function getInfinity() {
3650 * Encode an expiry time into the DBMS dependent format
3652 * @param string $expiry timestamp for expiry, or the 'infinity' string
3655 public function encodeExpiry( $expiry ) {
3656 return ( $expiry == '' ||
$expiry == 'infinity' ||
$expiry == $this->getInfinity() )
3657 ?
$this->getInfinity()
3658 : $this->timestamp( $expiry );
3662 * Decode an expiry time into a DBMS independent format
3664 * @param string $expiry DB timestamp field value for expiry
3665 * @param $format integer: TS_* constant, defaults to TS_MW
3668 public function decodeExpiry( $expiry, $format = TS_MW
) {
3669 return ( $expiry == '' ||
$expiry == $this->getInfinity() )
3671 : wfTimestamp( $format, $expiry );
3675 * Allow or deny "big selects" for this session only. This is done by setting
3676 * the sql_big_selects session variable.
3678 * This is a MySQL-specific feature.
3680 * @param $value Mixed: true for allow, false for deny, or "default" to
3681 * restore the initial value
3683 public function setBigSelects( $value = true ) {
3690 public function __toString() {
3691 return (string)$this->mConn
;
3694 public function __destruct() {
3695 if ( count( $this->mTrxIdleCallbacks
) ) { // sanity
3696 trigger_error( "Transaction idle callbacks still pending." );