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 $server String: database server host
53 * @param $user String: database user name
54 * @param $password String: database user password
55 * @param $dbName String: 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
66 * @param $res ResultWrapper|object as returned from DatabaseBase::query(), etc.
68 * @throws DBUnexpectedError Thrown if the database returns an error
70 function fetchObject( $res );
73 * Fetch the next row from the given result object, in associative array
74 * form. Fields are retrieved with $row['fieldname'].
76 * @param $res ResultWrapper result object as returned from DatabaseBase::query(), etc.
78 * @throws DBUnexpectedError Thrown if the database returns an error
80 function fetchRow( $res );
83 * Get the number of rows in a result object
85 * @param $res Mixed: A SQL result
88 function numRows( $res );
91 * Get the number of fields in a result object
92 * @see http://www.php.net/mysql_num_fields
94 * @param $res Mixed: A SQL result
97 function numFields( $res );
100 * Get a field name in a result object
101 * @see http://www.php.net/mysql_field_name
103 * @param $res Mixed: A SQL result
107 function fieldName( $res, $n );
110 * Get the inserted value of an auto-increment row
112 * The value inserted should be fetched from nextSequenceValue()
115 * $id = $dbw->nextSequenceValue( 'page_page_id_seq' );
116 * $dbw->insert( 'page', array( 'page_id' => $id ) );
117 * $id = $dbw->insertId();
124 * Change the position of the cursor in a result object
125 * @see http://www.php.net/mysql_data_seek
127 * @param $res Mixed: A SQL result
128 * @param $row Mixed: Either MySQL row or ResultWrapper
130 function dataSeek( $res, $row );
133 * Get the last error number
134 * @see http://www.php.net/mysql_errno
138 function lastErrno();
141 * Get a description of the last error
142 * @see http://www.php.net/mysql_error
146 function lastError();
149 * mysql_fetch_field() wrapper
150 * Returns false if the field doesn't exist
152 * @param $table string: table name
153 * @param $field string: field name
157 function fieldInfo( $table, $field );
160 * Get information about an index into an object
161 * @param $table string: Table name
162 * @param $index string: Index name
163 * @param $fname string: Calling function name
164 * @return Mixed: Database-specific index description class or false if the index does not exist
166 function indexInfo( $table, $index, $fname = 'Database::indexInfo' );
169 * Get the number of rows affected by the last write query
170 * @see http://www.php.net/mysql_affected_rows
174 function affectedRows();
177 * Wrapper for addslashes()
179 * @param $s string: to be slashed.
180 * @return string: slashed string.
182 function strencode( $s );
185 * Returns a wikitext link to the DB's website, e.g.,
186 * return "[http://www.mysql.com/ MySQL]";
187 * Should at least contain plain text, if for some reason
188 * your database has no website.
190 * @return string: wikitext of a link to the server software's web site
192 static function getSoftwareLink();
195 * A string describing the current software version, like from
196 * mysql_get_server_info().
198 * @return string: Version information from the database server.
200 function getServerVersion();
203 * A string describing the current software version, and possibly
204 * other details in a user-friendly way. Will be listed on Special:Version, etc.
205 * Use getServerVersion() to get machine-friendly information.
207 * @return string: Version information from the database server
209 function getServerInfo();
213 * Database abstraction object
216 abstract class DatabaseBase
implements DatabaseType
{
218 # ------------------------------------------------------------------------------
220 # ------------------------------------------------------------------------------
222 protected $mLastQuery = '';
223 protected $mDoneWrites = false;
224 protected $mPHPError = false;
226 protected $mServer, $mUser, $mPassword, $mDBname;
228 protected $mConn = null;
229 protected $mOpened = false;
233 * @var array of Closure
235 protected $mTrxIdleCallbacks = array();
237 protected $mTablePrefix;
239 protected $mTrxLevel = 0;
240 protected $mErrorCount = 0;
241 protected $mLBInfo = array();
242 protected $mFakeSlaveLag = null, $mFakeMaster = false;
243 protected $mDefaultBigSelects = null;
244 protected $mSchemaVars = false;
246 protected $preparedArgs;
248 protected $htmlErrors;
250 protected $delimiter = ';';
253 * Remembers the function name given for starting the most recent transaction via begin().
254 * Used to provide additional context for error reporting.
257 * @see DatabaseBase::mTrxLevel
259 private $mTrxFname = null;
262 * Record if possible write queries were done in the last transaction started
265 * @see DatabaseBase::mTrxLevel
267 private $mTrxDoneWrites = false;
270 * Record if the current transaction was started implicitly due to DBO_TRX being set.
273 * @see DatabaseBase::mTrxLevel
275 private $mTrxAutomatic = false;
279 * @var file handle for upgrade
281 protected $fileHandle = null;
284 # ------------------------------------------------------------------------------
286 # ------------------------------------------------------------------------------
287 # These optionally set a variable and return the previous state
290 * A string describing the current software version, and possibly
291 * other details in a user-friendly way. Will be listed on Special:Version, etc.
292 * Use getServerVersion() to get machine-friendly information.
294 * @return string: Version information from the database server
296 public function getServerInfo() {
297 return $this->getServerVersion();
301 * @return string: command delimiter used by this database engine
303 public function getDelimiter() {
304 return $this->delimiter
;
308 * Boolean, controls output of large amounts of debug information.
309 * @param $debug bool|null
310 * - true to enable debugging
311 * - false to disable debugging
312 * - omitted or null to do nothing
314 * @return bool|null previous value of the flag
316 public function debug( $debug = null ) {
317 return wfSetBit( $this->mFlags
, DBO_DEBUG
, $debug );
321 * Turns buffering of SQL result sets on (true) or off (false). Default is
324 * Unbuffered queries are very troublesome in MySQL:
326 * - If another query is executed while the first query is being read
327 * out, the first query is killed. This means you can't call normal
328 * MediaWiki functions while you are reading an unbuffered query result
329 * from a normal wfGetDB() connection.
331 * - Unbuffered queries cause the MySQL server to use large amounts of
332 * memory and to hold broad locks which block other queries.
334 * If you want to limit client-side memory, it's almost always better to
335 * split up queries into batches using a LIMIT clause than to switch off
338 * @param $buffer null|bool
340 * @return null|bool The previous value of the flag
342 public function bufferResults( $buffer = null ) {
343 if ( is_null( $buffer ) ) {
344 return !(bool)( $this->mFlags
& DBO_NOBUFFER
);
346 return !wfSetBit( $this->mFlags
, DBO_NOBUFFER
, !$buffer );
351 * Turns on (false) or off (true) the automatic generation and sending
352 * of a "we're sorry, but there has been a database error" page on
353 * database errors. Default is on (false). When turned off, the
354 * code should use lastErrno() and lastError() to handle the
355 * situation as appropriate.
357 * @param $ignoreErrors bool|null
359 * @return bool The previous value of the flag.
361 public function ignoreErrors( $ignoreErrors = null ) {
362 return wfSetBit( $this->mFlags
, DBO_IGNORE
, $ignoreErrors );
366 * Gets or sets the current transaction level.
368 * Historically, transactions were allowed to be "nested". This is no
369 * longer supported, so this function really only returns a boolean.
371 * @param $level int An integer (0 or 1), or omitted to leave it unchanged.
372 * @return int The previous value
374 public function trxLevel( $level = null ) {
375 return wfSetVar( $this->mTrxLevel
, $level );
379 * Get/set the number of errors logged. Only useful when errors are ignored
380 * @param $count int The count to set, or omitted to leave it unchanged.
381 * @return int The error count
383 public function errorCount( $count = null ) {
384 return wfSetVar( $this->mErrorCount
, $count );
388 * Get/set the table prefix.
389 * @param $prefix string The table prefix to set, or omitted to leave it unchanged.
390 * @return string The previous table prefix.
392 public function tablePrefix( $prefix = null ) {
393 return wfSetVar( $this->mTablePrefix
, $prefix );
397 * Set the filehandle to copy write statements to.
399 * @param $fh filehandle
401 public function setFileHandle( $fh ) {
402 $this->fileHandle
= $fh;
406 * Get properties passed down from the server info array of the load
409 * @param $name string The entry of the info array to get, or null to get the
412 * @return LoadBalancer|null
414 public function getLBInfo( $name = null ) {
415 if ( is_null( $name ) ) {
416 return $this->mLBInfo
;
418 if ( array_key_exists( $name, $this->mLBInfo
) ) {
419 return $this->mLBInfo
[$name];
427 * Set the LB info array, or a member of it. If called with one parameter,
428 * the LB info array is set to that parameter. If it is called with two
429 * parameters, the member with the given name is set to the given value.
434 public function setLBInfo( $name, $value = null ) {
435 if ( is_null( $value ) ) {
436 $this->mLBInfo
= $name;
438 $this->mLBInfo
[$name] = $value;
443 * Set lag time in seconds for a fake slave
447 public function setFakeSlaveLag( $lag ) {
448 $this->mFakeSlaveLag
= $lag;
452 * Make this connection a fake master
454 * @param $enabled bool
456 public function setFakeMaster( $enabled = true ) {
457 $this->mFakeMaster
= $enabled;
461 * Returns true if this database supports (and uses) cascading deletes
465 public function cascadingDeletes() {
470 * Returns true if this database supports (and uses) triggers (e.g. on the page table)
474 public function cleanupTriggers() {
479 * Returns true if this database is strict about what can be put into an IP field.
480 * Specifically, it uses a NULL value instead of an empty string.
484 public function strictIPs() {
489 * Returns true if this database uses timestamps rather than integers
493 public function realTimestamps() {
498 * Returns true if this database does an implicit sort when doing GROUP BY
502 public function implicitGroupby() {
507 * Returns true if this database does an implicit order by when the column has an index
508 * For example: SELECT page_title FROM page LIMIT 1
512 public function implicitOrderby() {
517 * Returns true if this database can do a native search on IP columns
518 * e.g. this works as expected: .. WHERE rc_ip = '127.42.12.102/32';
522 public function searchableIPs() {
527 * Returns true if this database can use functional indexes
531 public function functionalIndexes() {
536 * Return the last query that went through DatabaseBase::query()
539 public function lastQuery() {
540 return $this->mLastQuery
;
544 * Returns true if the connection may have been used for write queries.
545 * Should return true if unsure.
549 public function doneWrites() {
550 return $this->mDoneWrites
;
554 * Returns true if there is a transaction open with possible write
555 * queries or transaction idle callbacks waiting on it to finish.
559 public function writesOrCallbacksPending() {
560 return $this->mTrxLevel
&& ( $this->mTrxDoneWrites ||
$this->mTrxIdleCallbacks
);
564 * Is a connection to the database open?
567 public function isOpen() {
568 return $this->mOpened
;
572 * Set a flag for this connection
574 * @param $flag Integer: DBO_* constants from Defines.php:
575 * - DBO_DEBUG: output some debug info (same as debug())
576 * - DBO_NOBUFFER: don't buffer results (inverse of bufferResults())
577 * - DBO_IGNORE: ignore errors (same as ignoreErrors())
578 * - DBO_TRX: automatically start transactions
579 * - DBO_DEFAULT: automatically sets DBO_TRX if not in command line mode
580 * and removes it in command line mode
581 * - DBO_PERSISTENT: use persistant database connection
583 public function setFlag( $flag ) {
584 global $wgDebugDBTransactions;
585 $this->mFlags |
= $flag;
586 if ( ( $flag & DBO_TRX
) & $wgDebugDBTransactions ) {
587 wfDebug( "Implicit transactions are now disabled.\n" );
592 * Clear a flag for this connection
594 * @param $flag: same as setFlag()'s $flag param
596 public function clearFlag( $flag ) {
597 global $wgDebugDBTransactions;
598 $this->mFlags
&= ~
$flag;
599 if ( ( $flag & DBO_TRX
) && $wgDebugDBTransactions ) {
600 wfDebug( "Implicit transactions are now disabled.\n" );
605 * Returns a boolean whether the flag $flag is set for this connection
607 * @param $flag: same as setFlag()'s $flag param
610 public function getFlag( $flag ) {
611 return !!( $this->mFlags
& $flag );
615 * General read-only accessor
617 * @param $name string
621 public function getProperty( $name ) {
628 public function getWikiID() {
629 if ( $this->mTablePrefix
) {
630 return "{$this->mDBname}-{$this->mTablePrefix}";
632 return $this->mDBname
;
637 * Return a path to the DBMS-specific schema file, otherwise default to tables.sql
641 public function getSchemaPath() {
643 if ( file_exists( "$IP/maintenance/" . $this->getType() . "/tables.sql" ) ) {
644 return "$IP/maintenance/" . $this->getType() . "/tables.sql";
646 return "$IP/maintenance/tables.sql";
650 # ------------------------------------------------------------------------------
652 # ------------------------------------------------------------------------------
656 * @param $server String: database server host
657 * @param $user String: database user name
658 * @param $password String: database user password
659 * @param $dbName String: database name
661 * @param $tablePrefix String: database table prefixes. By default use the prefix gave in LocalSettings.php
663 function __construct( $server = false, $user = false, $password = false, $dbName = false,
664 $flags = 0, $tablePrefix = 'get from global'
666 global $wgDBprefix, $wgCommandLineMode, $wgDebugDBTransactions;
668 $this->mFlags
= $flags;
670 if ( $this->mFlags
& DBO_DEFAULT
) {
671 if ( $wgCommandLineMode ) {
672 $this->mFlags
&= ~DBO_TRX
;
673 if ( $wgDebugDBTransactions ) {
674 wfDebug( "Implicit transaction open disabled.\n" );
677 $this->mFlags |
= DBO_TRX
;
678 if ( $wgDebugDBTransactions ) {
679 wfDebug( "Implicit transaction open enabled.\n" );
684 /** Get the default table prefix*/
685 if ( $tablePrefix == 'get from global' ) {
686 $this->mTablePrefix
= $wgDBprefix;
688 $this->mTablePrefix
= $tablePrefix;
692 $this->open( $server, $user, $password, $dbName );
697 * Called by serialize. Throw an exception when DB connection is serialized.
698 * This causes problems on some database engines because the connection is
699 * not restored on unserialize.
701 public function __sleep() {
702 throw new MWException( 'Database serialization may cause problems, since the connection is not restored on wakeup.' );
706 * Given a DB type, construct the name of the appropriate child class of
707 * DatabaseBase. This is designed to replace all of the manual stuff like:
708 * $class = 'Database' . ucfirst( strtolower( $type ) );
709 * as well as validate against the canonical list of DB types we have
711 * This factory function is mostly useful for when you need to connect to a
712 * database other than the MediaWiki default (such as for external auth,
713 * an extension, et cetera). Do not use this to connect to the MediaWiki
714 * database. Example uses in core:
715 * @see LoadBalancer::reallyOpenConnection()
716 * @see ExternalUser_MediaWiki::initFromCond()
717 * @see ForeignDBRepo::getMasterDB()
718 * @see WebInstaller_DBConnect::execute()
722 * @param $dbType String A possible DB type
723 * @param $p Array An array of options to pass to the constructor.
724 * Valid options are: host, user, password, dbname, flags, tablePrefix
725 * @return DatabaseBase subclass or null
727 final public static function factory( $dbType, $p = array() ) {
728 $canonicalDBTypes = array(
729 'mysql', 'postgres', 'sqlite', 'oracle', 'mssql', 'ibm_db2'
731 $dbType = strtolower( $dbType );
732 $class = 'Database' . ucfirst( $dbType );
734 if( in_array( $dbType, $canonicalDBTypes ) ||
( class_exists( $class ) && is_subclass_of( $class, 'DatabaseBase' ) ) ) {
736 isset( $p['host'] ) ?
$p['host'] : false,
737 isset( $p['user'] ) ?
$p['user'] : false,
738 isset( $p['password'] ) ?
$p['password'] : false,
739 isset( $p['dbname'] ) ?
$p['dbname'] : false,
740 isset( $p['flags'] ) ?
$p['flags'] : 0,
741 isset( $p['tablePrefix'] ) ?
$p['tablePrefix'] : 'get from global'
748 protected function installErrorHandler() {
749 $this->mPHPError
= false;
750 $this->htmlErrors
= ini_set( 'html_errors', '0' );
751 set_error_handler( array( $this, 'connectionErrorHandler' ) );
755 * @return bool|string
757 protected function restoreErrorHandler() {
758 restore_error_handler();
759 if ( $this->htmlErrors
!== false ) {
760 ini_set( 'html_errors', $this->htmlErrors
);
762 if ( $this->mPHPError
) {
763 $error = preg_replace( '!\[<a.*</a>\]!', '', $this->mPHPError
);
764 $error = preg_replace( '!^.*?:\s?(.*)$!', '$1', $error );
775 protected function connectionErrorHandler( $errno, $errstr ) {
776 $this->mPHPError
= $errstr;
780 * Closes a database connection.
781 * if it is open : commits any open transactions
783 * @throws MWException
784 * @return Bool operation success. true if already closed.
786 public function close() {
787 if ( count( $this->mTrxIdleCallbacks
) ) { // sanity
788 throw new MWException( "Transaction idle callbacks still pending." );
790 $this->mOpened
= false;
791 if ( $this->mConn
) {
792 if ( $this->trxLevel() ) {
793 if ( !$this->mTrxAutomatic
) {
794 wfWarn( "Transaction still in progress (from {$this->mTrxFname}), " .
795 " performing implicit commit before closing connection!" );
798 $this->commit( __METHOD__
, 'flush' );
801 $ret = $this->closeConnection();
802 $this->mConn
= false;
810 * Closes underlying database connection
812 * @return bool: Whether connection was closed successfully
814 abstract protected function closeConnection();
817 * @param $error String: fallback error message, used if none is given by DB
818 * @throws DBConnectionError
820 function reportConnectionError( $error = 'Unknown error' ) {
821 $myError = $this->lastError();
827 throw new DBConnectionError( $this, $error );
831 * The DBMS-dependent part of query()
833 * @param $sql String: SQL query.
834 * @return ResultWrapper Result object to feed to fetchObject, fetchRow, ...; or false on failure
836 abstract protected function doQuery( $sql );
839 * Determine whether a query writes to the DB.
840 * Should return true if unsure.
846 public function isWriteQuery( $sql ) {
847 return !preg_match( '/^(?:SELECT|BEGIN|ROLLBACK|COMMIT|SET|SHOW|EXPLAIN|\(SELECT)\b/i', $sql );
851 * Run an SQL query and return the result. Normally throws a DBQueryError
852 * on failure. If errors are ignored, returns false instead.
854 * In new code, the query wrappers select(), insert(), update(), delete(),
855 * etc. should be used where possible, since they give much better DBMS
856 * independence and automatically quote or validate user input in a variety
857 * of contexts. This function is generally only useful for queries which are
858 * explicitly DBMS-dependent and are unsupported by the query wrappers, such
861 * However, the query wrappers themselves should call this function.
863 * @param $sql String: SQL query
864 * @param $fname String: Name of the calling function, for profiling/SHOW PROCESSLIST
865 * comment (you can use __METHOD__ or add some extra info)
866 * @param $tempIgnore Boolean: Whether to avoid throwing an exception on errors...
867 * maybe best to catch the exception instead?
868 * @throws MWException
869 * @return boolean|ResultWrapper. true for a successful write query, ResultWrapper object
870 * for a successful read query, or false on failure if $tempIgnore set
872 public function query( $sql, $fname = '', $tempIgnore = false ) {
873 $isMaster = !is_null( $this->getLBInfo( 'master' ) );
874 if ( !Profiler
::instance()->isStub() ) {
875 # generalizeSQL will probably cut down the query to reasonable
876 # logging size most of the time. The substr is really just a sanity check.
879 $queryProf = 'query-m: ' . substr( DatabaseBase
::generalizeSQL( $sql ), 0, 255 );
880 $totalProf = 'DatabaseBase::query-master';
882 $queryProf = 'query: ' . substr( DatabaseBase
::generalizeSQL( $sql ), 0, 255 );
883 $totalProf = 'DatabaseBase::query';
886 wfProfileIn( $totalProf );
887 wfProfileIn( $queryProf );
890 $this->mLastQuery
= $sql;
891 if ( !$this->mDoneWrites
&& $this->isWriteQuery( $sql ) ) {
892 # Set a flag indicating that writes have been done
893 wfDebug( __METHOD__
. ": Writes done: $sql\n" );
894 $this->mDoneWrites
= true;
897 # Add a comment for easy SHOW PROCESSLIST interpretation
899 if ( is_object( $wgUser ) && $wgUser->isItemLoaded( 'name' ) ) {
900 $userName = $wgUser->getName();
901 if ( mb_strlen( $userName ) > 15 ) {
902 $userName = mb_substr( $userName, 0, 15 ) . '...';
904 $userName = str_replace( '/', '', $userName );
909 // Add trace comment to the begin of the sql string, right after the operator.
910 // Or, for one-word queries (like "BEGIN" or COMMIT") add it to the end (bug 42598)
911 $commentedSql = preg_replace( '/\s|$/', " /* $fname $userName */ ", $sql, 1 );
913 # If DBO_TRX is set, start a transaction
914 if ( ( $this->mFlags
& DBO_TRX
) && !$this->mTrxLevel
&&
915 $sql != 'BEGIN' && $sql != 'COMMIT' && $sql != 'ROLLBACK' )
917 # Avoid establishing transactions for SHOW and SET statements too -
918 # that would delay transaction initializations to once connection
919 # is really used by application
920 $sqlstart = substr( $sql, 0, 10 ); // very much worth it, benchmark certified(tm)
921 if ( strpos( $sqlstart, "SHOW " ) !== 0 && strpos( $sqlstart, "SET " ) !== 0 ) {
922 global $wgDebugDBTransactions;
923 if ( $wgDebugDBTransactions ) {
924 wfDebug( "Implicit transaction start.\n" );
926 $this->begin( __METHOD__
. " ($fname)" );
927 $this->mTrxAutomatic
= true;
931 # Keep track of whether the transaction has write queries pending
932 if ( $this->mTrxLevel
&& !$this->mTrxDoneWrites
&& $this->isWriteQuery( $sql ) ) {
933 $this->mTrxDoneWrites
= true;
936 if ( $this->debug() ) {
940 $sqlx = substr( $commentedSql, 0, 500 );
941 $sqlx = strtr( $sqlx, "\t\n", ' ' );
943 $master = $isMaster ?
'master' : 'slave';
944 wfDebug( "Query {$this->mDBname} ($cnt) ($master): $sqlx\n" );
947 if ( istainted( $sql ) & TC_MYSQL
) {
948 throw new MWException( 'Tainted query found' );
951 $queryId = MWDebug
::query( $sql, $fname, $isMaster );
953 # Do the query and handle errors
954 $ret = $this->doQuery( $commentedSql );
956 MWDebug
::queryTime( $queryId );
958 # Try reconnecting if the connection was lost
959 if ( false === $ret && $this->wasErrorReissuable() ) {
960 # Transaction is gone, like it or not
961 $this->mTrxLevel
= 0;
962 $this->mTrxIdleCallbacks
= array(); // cancel
963 wfDebug( "Connection lost, reconnecting...\n" );
965 if ( $this->ping() ) {
966 wfDebug( "Reconnected\n" );
967 $sqlx = substr( $commentedSql, 0, 500 );
968 $sqlx = strtr( $sqlx, "\t\n", ' ' );
969 global $wgRequestTime;
970 $elapsed = round( microtime( true ) - $wgRequestTime, 3 );
971 if ( $elapsed < 300 ) {
972 # Not a database error to lose a transaction after a minute or two
973 wfLogDBError( "Connection lost and reconnected after {$elapsed}s, query: $sqlx\n" );
975 $ret = $this->doQuery( $commentedSql );
977 wfDebug( "Failed\n" );
981 if ( false === $ret ) {
982 $this->reportQueryError( $this->lastError(), $this->lastErrno(), $sql, $fname, $tempIgnore );
985 if ( !Profiler
::instance()->isStub() ) {
986 wfProfileOut( $queryProf );
987 wfProfileOut( $totalProf );
990 return $this->resultObject( $ret );
994 * Report a query error. Log the error, and if neither the object ignore
995 * flag nor the $tempIgnore flag is set, throw a DBQueryError.
997 * @param $error String
998 * @param $errno Integer
1000 * @param $fname String
1001 * @param $tempIgnore Boolean
1002 * @throws DBQueryError
1004 public function reportQueryError( $error, $errno, $sql, $fname, $tempIgnore = false ) {
1005 # Ignore errors during error handling to avoid infinite recursion
1006 $ignore = $this->ignoreErrors( true );
1007 ++
$this->mErrorCount
;
1009 if ( $ignore ||
$tempIgnore ) {
1010 wfDebug( "SQL ERROR (ignored): $error\n" );
1011 $this->ignoreErrors( $ignore );
1013 $sql1line = str_replace( "\n", "\\n", $sql );
1014 wfLogDBError( "$fname\t{$this->mServer}\t$errno\t$error\t$sql1line\n" );
1015 wfDebug( "SQL ERROR: " . $error . "\n" );
1016 throw new DBQueryError( $this, $error, $errno, $sql, $fname );
1021 * Intended to be compatible with the PEAR::DB wrapper functions.
1022 * http://pear.php.net/manual/en/package.database.db.intro-execute.php
1024 * ? = scalar value, quoted as necessary
1025 * ! = raw SQL bit (a function for instance)
1026 * & = filename; reads the file and inserts as a blob
1027 * (we don't use this though...)
1029 * @param $sql string
1030 * @param $func string
1034 protected function prepare( $sql, $func = 'DatabaseBase::prepare' ) {
1035 /* MySQL doesn't support prepared statements (yet), so just
1036 pack up the query for reference. We'll manually replace
1038 return array( 'query' => $sql, 'func' => $func );
1042 * Free a prepared query, generated by prepare().
1045 protected function freePrepared( $prepared ) {
1046 /* No-op by default */
1050 * Execute a prepared query with the various arguments
1051 * @param $prepared String: the prepared sql
1052 * @param $args Mixed: Either an array here, or put scalars as varargs
1054 * @return ResultWrapper
1056 public function execute( $prepared, $args = null ) {
1057 if ( !is_array( $args ) ) {
1059 $args = func_get_args();
1060 array_shift( $args );
1063 $sql = $this->fillPrepared( $prepared['query'], $args );
1065 return $this->query( $sql, $prepared['func'] );
1069 * For faking prepared SQL statements on DBs that don't support it directly.
1071 * @param $preparedQuery String: a 'preparable' SQL statement
1072 * @param $args Array of arguments to fill it with
1073 * @return string executable SQL
1075 public function fillPrepared( $preparedQuery, $args ) {
1077 $this->preparedArgs
=& $args;
1079 return preg_replace_callback( '/(\\\\[?!&]|[?!&])/',
1080 array( &$this, 'fillPreparedArg' ), $preparedQuery );
1084 * preg_callback func for fillPrepared()
1085 * The arguments should be in $this->preparedArgs and must not be touched
1086 * while we're doing this.
1088 * @param $matches Array
1089 * @throws DBUnexpectedError
1092 protected function fillPreparedArg( $matches ) {
1093 switch( $matches[1] ) {
1094 case '\\?': return '?';
1095 case '\\!': return '!';
1096 case '\\&': return '&';
1099 list( /* $n */, $arg ) = each( $this->preparedArgs
);
1101 switch( $matches[1] ) {
1102 case '?': return $this->addQuotes( $arg );
1103 case '!': return $arg;
1105 # return $this->addQuotes( file_get_contents( $arg ) );
1106 throw new DBUnexpectedError( $this, '& mode is not implemented. If it\'s really needed, uncomment the line above.' );
1108 throw new DBUnexpectedError( $this, 'Received invalid match. This should never happen!' );
1113 * Free a result object returned by query() or select(). It's usually not
1114 * necessary to call this, just use unset() or let the variable holding
1115 * the result object go out of scope.
1117 * @param $res Mixed: A SQL result
1119 public function freeResult( $res ) {}
1122 * A SELECT wrapper which returns a single field from a single result row.
1124 * Usually throws a DBQueryError on failure. If errors are explicitly
1125 * ignored, returns false on failure.
1127 * If no result rows are returned from the query, false is returned.
1129 * @param $table string|array Table name. See DatabaseBase::select() for details.
1130 * @param $var string The field name to select. This must be a valid SQL
1131 * fragment: do not use unvalidated user input.
1132 * @param $cond string|array The condition array. See DatabaseBase::select() for details.
1133 * @param $fname string The function name of the caller.
1134 * @param $options string|array The query options. See DatabaseBase::select() for details.
1136 * @return bool|mixed The value from the field, or false on failure.
1138 public function selectField( $table, $var, $cond = '', $fname = 'DatabaseBase::selectField',
1139 $options = array() )
1141 if ( !is_array( $options ) ) {
1142 $options = array( $options );
1145 $options['LIMIT'] = 1;
1147 $res = $this->select( $table, $var, $cond, $fname, $options );
1149 if ( $res === false ||
!$this->numRows( $res ) ) {
1153 $row = $this->fetchRow( $res );
1155 if ( $row !== false ) {
1156 return reset( $row );
1163 * Returns an optional USE INDEX clause to go after the table, and a
1164 * string to go at the end of the query.
1166 * @param $options Array: associative array of options to be turned into
1167 * an SQL query, valid keys are listed in the function.
1169 * @see DatabaseBase::select()
1171 public function makeSelectOptions( $options ) {
1172 $preLimitTail = $postLimitTail = '';
1175 $noKeyOptions = array();
1177 foreach ( $options as $key => $option ) {
1178 if ( is_numeric( $key ) ) {
1179 $noKeyOptions[$option] = true;
1183 $preLimitTail .= $this->makeGroupByWithHaving( $options );
1185 $preLimitTail .= $this->makeOrderBy( $options );
1187 // if (isset($options['LIMIT'])) {
1188 // $tailOpts .= $this->limitResult('', $options['LIMIT'],
1189 // isset($options['OFFSET']) ? $options['OFFSET']
1193 if ( isset( $noKeyOptions['FOR UPDATE'] ) ) {
1194 $postLimitTail .= ' FOR UPDATE';
1197 if ( isset( $noKeyOptions['LOCK IN SHARE MODE'] ) ) {
1198 $postLimitTail .= ' LOCK IN SHARE MODE';
1201 if ( isset( $noKeyOptions['DISTINCT'] ) ||
isset( $noKeyOptions['DISTINCTROW'] ) ) {
1202 $startOpts .= 'DISTINCT';
1205 # Various MySQL extensions
1206 if ( isset( $noKeyOptions['STRAIGHT_JOIN'] ) ) {
1207 $startOpts .= ' /*! STRAIGHT_JOIN */';
1210 if ( isset( $noKeyOptions['HIGH_PRIORITY'] ) ) {
1211 $startOpts .= ' HIGH_PRIORITY';
1214 if ( isset( $noKeyOptions['SQL_BIG_RESULT'] ) ) {
1215 $startOpts .= ' SQL_BIG_RESULT';
1218 if ( isset( $noKeyOptions['SQL_BUFFER_RESULT'] ) ) {
1219 $startOpts .= ' SQL_BUFFER_RESULT';
1222 if ( isset( $noKeyOptions['SQL_SMALL_RESULT'] ) ) {
1223 $startOpts .= ' SQL_SMALL_RESULT';
1226 if ( isset( $noKeyOptions['SQL_CALC_FOUND_ROWS'] ) ) {
1227 $startOpts .= ' SQL_CALC_FOUND_ROWS';
1230 if ( isset( $noKeyOptions['SQL_CACHE'] ) ) {
1231 $startOpts .= ' SQL_CACHE';
1234 if ( isset( $noKeyOptions['SQL_NO_CACHE'] ) ) {
1235 $startOpts .= ' SQL_NO_CACHE';
1238 if ( isset( $options['USE INDEX'] ) && ! is_array( $options['USE INDEX'] ) ) {
1239 $useIndex = $this->useIndexClause( $options['USE INDEX'] );
1244 return array( $startOpts, $useIndex, $preLimitTail, $postLimitTail );
1248 * Returns an optional GROUP BY with an optional HAVING
1250 * @param $options Array: associative array of options
1252 * @see DatabaseBase::select()
1255 public function makeGroupByWithHaving( $options ) {
1257 if ( isset( $options['GROUP BY'] ) ) {
1258 $gb = is_array( $options['GROUP BY'] )
1259 ?
implode( ',', $options['GROUP BY'] )
1260 : $options['GROUP BY'];
1261 $sql .= ' GROUP BY ' . $gb;
1263 if ( isset( $options['HAVING'] ) ) {
1264 $having = is_array( $options['HAVING'] )
1265 ?
$this->makeList( $options['HAVING'], LIST_AND
)
1266 : $options['HAVING'];
1267 $sql .= ' HAVING ' . $having;
1273 * Returns an optional ORDER BY
1275 * @param $options Array: associative array of options
1277 * @see DatabaseBase::select()
1280 public function makeOrderBy( $options ) {
1281 if ( isset( $options['ORDER BY'] ) ) {
1282 $ob = is_array( $options['ORDER BY'] )
1283 ?
implode( ',', $options['ORDER BY'] )
1284 : $options['ORDER BY'];
1285 return ' ORDER BY ' . $ob;
1291 * Execute a SELECT query constructed using the various parameters provided.
1292 * See below for full details of the parameters.
1294 * @param $table String|Array Table name
1295 * @param $vars String|Array Field names
1296 * @param $conds String|Array Conditions
1297 * @param $fname String Caller function name
1298 * @param $options Array Query options
1299 * @param $join_conds Array Join conditions
1301 * @param $table string|array
1303 * May be either an array of table names, or a single string holding a table
1304 * name. If an array is given, table aliases can be specified, for example:
1306 * array( 'a' => 'user' )
1308 * This includes the user table in the query, with the alias "a" available
1309 * for use in field names (e.g. a.user_name).
1311 * All of the table names given here are automatically run through
1312 * DatabaseBase::tableName(), which causes the table prefix (if any) to be
1313 * added, and various other table name mappings to be performed.
1316 * @param $vars string|array
1318 * May be either a field name or an array of field names. The field names
1319 * can be complete fragments of SQL, for direct inclusion into the SELECT
1320 * query. If an array is given, field aliases can be specified, for example:
1322 * array( 'maxrev' => 'MAX(rev_id)' )
1324 * This includes an expression with the alias "maxrev" in the query.
1326 * If an expression is given, care must be taken to ensure that it is
1330 * @param $conds string|array
1332 * May be either a string containing a single condition, or an array of
1333 * conditions. If an array is given, the conditions constructed from each
1334 * element are combined with AND.
1336 * Array elements may take one of two forms:
1338 * - Elements with a numeric key are interpreted as raw SQL fragments.
1339 * - Elements with a string key are interpreted as equality conditions,
1340 * where the key is the field name.
1341 * - If the value of such an array element is a scalar (such as a
1342 * string), it will be treated as data and thus quoted appropriately.
1343 * If it is null, an IS NULL clause will be added.
1344 * - If the value is an array, an IN(...) clause will be constructed,
1345 * such that the field name may match any of the elements in the
1346 * array. The elements of the array will be quoted.
1348 * Note that expressions are often DBMS-dependent in their syntax.
1349 * DBMS-independent wrappers are provided for constructing several types of
1350 * expression commonly used in condition queries. See:
1351 * - DatabaseBase::buildLike()
1352 * - DatabaseBase::conditional()
1355 * @param $options string|array
1357 * Optional: Array of query options. Boolean options are specified by
1358 * including them in the array as a string value with a numeric key, for
1361 * array( 'FOR UPDATE' )
1363 * The supported options are:
1365 * - OFFSET: Skip this many rows at the start of the result set. OFFSET
1366 * with LIMIT can theoretically be used for paging through a result set,
1367 * but this is discouraged in MediaWiki for performance reasons.
1369 * - LIMIT: Integer: return at most this many rows. The rows are sorted
1370 * and then the first rows are taken until the limit is reached. LIMIT
1371 * is applied to a result set after OFFSET.
1373 * - FOR UPDATE: Boolean: lock the returned rows so that they can't be
1374 * changed until the next COMMIT.
1376 * - DISTINCT: Boolean: return only unique result rows.
1378 * - GROUP BY: May be either an SQL fragment string naming a field or
1379 * expression to group by, or an array of such SQL fragments.
1381 * - HAVING: May be either an string containing a HAVING clause or an array of
1382 * conditions building the HAVING clause. If an array is given, the conditions
1383 * constructed from each element are combined with AND.
1385 * - ORDER BY: May be either an SQL fragment giving a field name or
1386 * expression to order by, or an array of such SQL fragments.
1388 * - USE INDEX: This may be either a string giving the index name to use
1389 * for the query, or an array. If it is an associative array, each key
1390 * gives the table name (or alias), each value gives the index name to
1391 * use for that table. All strings are SQL fragments and so should be
1392 * validated by the caller.
1394 * - EXPLAIN: In MySQL, this causes an EXPLAIN SELECT query to be run,
1395 * instead of SELECT.
1397 * And also the following boolean MySQL extensions, see the MySQL manual
1398 * for documentation:
1400 * - LOCK IN SHARE MODE
1404 * - SQL_BUFFER_RESULT
1405 * - SQL_SMALL_RESULT
1406 * - SQL_CALC_FOUND_ROWS
1411 * @param $join_conds string|array
1413 * Optional associative array of table-specific join conditions. In the
1414 * most common case, this is unnecessary, since the join condition can be
1415 * in $conds. However, it is useful for doing a LEFT JOIN.
1417 * The key of the array contains the table name or alias. The value is an
1418 * array with two elements, numbered 0 and 1. The first gives the type of
1419 * join, the second is an SQL fragment giving the join condition for that
1420 * table. For example:
1422 * array( 'page' => array( 'LEFT JOIN', 'page_latest=rev_id' ) )
1424 * @return ResultWrapper. If the query returned no rows, a ResultWrapper
1425 * with no rows in it will be returned. If there was a query error, a
1426 * DBQueryError exception will be thrown, except if the "ignore errors"
1427 * option was set, in which case false will be returned.
1429 public function select( $table, $vars, $conds = '', $fname = 'DatabaseBase::select',
1430 $options = array(), $join_conds = array() ) {
1431 $sql = $this->selectSQLText( $table, $vars, $conds, $fname, $options, $join_conds );
1433 return $this->query( $sql, $fname );
1437 * The equivalent of DatabaseBase::select() except that the constructed SQL
1438 * is returned, instead of being immediately executed. This can be useful for
1439 * doing UNION queries, where the SQL text of each query is needed. In general,
1440 * however, callers outside of Database classes should just use select().
1442 * @param $table string|array Table name
1443 * @param $vars string|array Field names
1444 * @param $conds string|array Conditions
1445 * @param $fname string Caller function name
1446 * @param $options string|array Query options
1447 * @param $join_conds string|array Join conditions
1449 * @return string SQL query string.
1450 * @see DatabaseBase::select()
1452 public function selectSQLText( $table, $vars, $conds = '', $fname = 'DatabaseBase::select',
1453 $options = array(), $join_conds = array() )
1455 if ( is_array( $vars ) ) {
1456 $vars = implode( ',', $this->fieldNamesWithAlias( $vars ) );
1459 $options = (array)$options;
1461 if ( is_array( $table ) ) {
1462 $useIndex = ( isset( $options['USE INDEX'] ) && is_array( $options['USE INDEX'] ) )
1463 ?
$options['USE INDEX']
1465 if ( count( $join_conds ) ||
count( $useIndex ) ) {
1467 $this->tableNamesWithUseIndexOrJOIN( $table, $useIndex, $join_conds );
1469 $from = ' FROM ' . implode( ',', $this->tableNamesWithAlias( $table ) );
1471 } elseif ( $table != '' ) {
1472 if ( $table[0] == ' ' ) {
1473 $from = ' FROM ' . $table;
1475 $from = ' FROM ' . $this->tableName( $table );
1481 list( $startOpts, $useIndex, $preLimitTail, $postLimitTail ) = $this->makeSelectOptions( $options );
1483 if ( !empty( $conds ) ) {
1484 if ( is_array( $conds ) ) {
1485 $conds = $this->makeList( $conds, LIST_AND
);
1487 $sql = "SELECT $startOpts $vars $from $useIndex WHERE $conds $preLimitTail";
1489 $sql = "SELECT $startOpts $vars $from $useIndex $preLimitTail";
1492 if ( isset( $options['LIMIT'] ) ) {
1493 $sql = $this->limitResult( $sql, $options['LIMIT'],
1494 isset( $options['OFFSET'] ) ?
$options['OFFSET'] : false );
1496 $sql = "$sql $postLimitTail";
1498 if ( isset( $options['EXPLAIN'] ) ) {
1499 $sql = 'EXPLAIN ' . $sql;
1506 * Single row SELECT wrapper. Equivalent to DatabaseBase::select(), except
1507 * that a single row object is returned. If the query returns no rows,
1508 * false is returned.
1510 * @param $table string|array Table name
1511 * @param $vars string|array Field names
1512 * @param $conds array Conditions
1513 * @param $fname string Caller function name
1514 * @param $options string|array Query options
1515 * @param $join_conds array|string Join conditions
1517 * @return object|bool
1519 public function selectRow( $table, $vars, $conds, $fname = 'DatabaseBase::selectRow',
1520 $options = array(), $join_conds = array() )
1522 $options = (array)$options;
1523 $options['LIMIT'] = 1;
1524 $res = $this->select( $table, $vars, $conds, $fname, $options, $join_conds );
1526 if ( $res === false ) {
1530 if ( !$this->numRows( $res ) ) {
1534 $obj = $this->fetchObject( $res );
1540 * Estimate rows in dataset.
1542 * MySQL allows you to estimate the number of rows that would be returned
1543 * by a SELECT query, using EXPLAIN SELECT. The estimate is provided using
1544 * index cardinality statistics, and is notoriously inaccurate, especially
1545 * when large numbers of rows have recently been added or deleted.
1547 * For DBMSs that don't support fast result size estimation, this function
1548 * will actually perform the SELECT COUNT(*).
1550 * Takes the same arguments as DatabaseBase::select().
1552 * @param $table String: table name
1553 * @param Array|string $vars : unused
1554 * @param Array|string $conds : filters on the table
1555 * @param $fname String: function name for profiling
1556 * @param $options Array: options for select
1557 * @return Integer: row count
1559 public function estimateRowCount( $table, $vars = '*', $conds = '',
1560 $fname = 'DatabaseBase::estimateRowCount', $options = array() )
1563 $res = $this->select( $table, array( 'rowcount' => 'COUNT(*)' ), $conds, $fname, $options );
1566 $row = $this->fetchRow( $res );
1567 $rows = ( isset( $row['rowcount'] ) ) ?
$row['rowcount'] : 0;
1574 * Removes most variables from an SQL query and replaces them with X or N for numbers.
1575 * It's only slightly flawed. Don't use for anything important.
1577 * @param $sql String A SQL Query
1581 static function generalizeSQL( $sql ) {
1582 # This does the same as the regexp below would do, but in such a way
1583 # as to avoid crashing php on some large strings.
1584 # $sql = preg_replace ( "/'([^\\\\']|\\\\.)*'|\"([^\\\\\"]|\\\\.)*\"/", "'X'", $sql);
1586 $sql = str_replace ( "\\\\", '', $sql );
1587 $sql = str_replace ( "\\'", '', $sql );
1588 $sql = str_replace ( "\\\"", '', $sql );
1589 $sql = preg_replace ( "/'.*'/s", "'X'", $sql );
1590 $sql = preg_replace ( '/".*"/s', "'X'", $sql );
1592 # All newlines, tabs, etc replaced by single space
1593 $sql = preg_replace ( '/\s+/', ' ', $sql );
1596 $sql = preg_replace ( '/-?[0-9]+/s', 'N', $sql );
1602 * Determines whether a field exists in a table
1604 * @param $table String: table name
1605 * @param $field String: filed to check on that table
1606 * @param $fname String: calling function name (optional)
1607 * @return Boolean: whether $table has filed $field
1609 public function fieldExists( $table, $field, $fname = 'DatabaseBase::fieldExists' ) {
1610 $info = $this->fieldInfo( $table, $field );
1616 * Determines whether an index exists
1617 * Usually throws a DBQueryError on failure
1618 * If errors are explicitly ignored, returns NULL on failure
1622 * @param $fname string
1626 public function indexExists( $table, $index, $fname = 'DatabaseBase::indexExists' ) {
1627 if( !$this->tableExists( $table ) ) {
1631 $info = $this->indexInfo( $table, $index, $fname );
1632 if ( is_null( $info ) ) {
1635 return $info !== false;
1640 * Query whether a given table exists
1642 * @param $table string
1643 * @param $fname string
1647 public function tableExists( $table, $fname = __METHOD__
) {
1648 $table = $this->tableName( $table );
1649 $old = $this->ignoreErrors( true );
1650 $res = $this->query( "SELECT 1 FROM $table LIMIT 1", $fname );
1651 $this->ignoreErrors( $old );
1657 * mysql_field_type() wrapper
1662 public function fieldType( $res, $index ) {
1663 if ( $res instanceof ResultWrapper
) {
1664 $res = $res->result
;
1667 return mysql_field_type( $res, $index );
1671 * Determines if a given index is unique
1673 * @param $table string
1674 * @param $index string
1678 public function indexUnique( $table, $index ) {
1679 $indexInfo = $this->indexInfo( $table, $index );
1681 if ( !$indexInfo ) {
1685 return !$indexInfo[0]->Non_unique
;
1689 * Helper for DatabaseBase::insert().
1691 * @param $options array
1694 protected function makeInsertOptions( $options ) {
1695 return implode( ' ', $options );
1699 * INSERT wrapper, inserts an array into a table.
1703 * - A single associative array. The array keys are the field names, and
1704 * the values are the values to insert. The values are treated as data
1705 * and will be quoted appropriately. If NULL is inserted, this will be
1706 * converted to a database NULL.
1707 * - An array with numeric keys, holding a list of associative arrays.
1708 * This causes a multi-row INSERT on DBMSs that support it. The keys in
1709 * each subarray must be identical to each other, and in the same order.
1711 * Usually throws a DBQueryError on failure. If errors are explicitly ignored,
1714 * $options is an array of options, with boolean options encoded as values
1715 * with numeric keys, in the same style as $options in
1716 * DatabaseBase::select(). Supported options are:
1718 * - IGNORE: Boolean: if present, duplicate key errors are ignored, and
1719 * any rows which cause duplicate key errors are not inserted. It's
1720 * possible to determine how many rows were successfully inserted using
1721 * DatabaseBase::affectedRows().
1723 * @param $table String Table name. This will be passed through
1724 * DatabaseBase::tableName().
1725 * @param $a Array of rows to insert
1726 * @param $fname String Calling function name (use __METHOD__) for logs/profiling
1727 * @param $options Array of options
1731 public function insert( $table, $a, $fname = 'DatabaseBase::insert', $options = array() ) {
1732 # No rows to insert, easy just return now
1733 if ( !count( $a ) ) {
1737 $table = $this->tableName( $table );
1739 if ( !is_array( $options ) ) {
1740 $options = array( $options );
1744 if ( isset( $options['fileHandle'] ) ) {
1745 $fh = $options['fileHandle'];
1747 $options = $this->makeInsertOptions( $options );
1749 if ( isset( $a[0] ) && is_array( $a[0] ) ) {
1751 $keys = array_keys( $a[0] );
1754 $keys = array_keys( $a );
1757 $sql = 'INSERT ' . $options .
1758 " INTO $table (" . implode( ',', $keys ) . ') VALUES ';
1762 foreach ( $a as $row ) {
1768 $sql .= '(' . $this->makeList( $row ) . ')';
1771 $sql .= '(' . $this->makeList( $a ) . ')';
1774 if ( $fh !== null && false === fwrite( $fh, $sql ) ) {
1776 } elseif ( $fh !== null ) {
1780 return (bool)$this->query( $sql, $fname );
1784 * Make UPDATE options for the DatabaseBase::update function
1786 * @param $options Array: The options passed to DatabaseBase::update
1789 protected function makeUpdateOptions( $options ) {
1790 if ( !is_array( $options ) ) {
1791 $options = array( $options );
1796 if ( in_array( 'LOW_PRIORITY', $options ) ) {
1797 $opts[] = $this->lowPriorityOption();
1800 if ( in_array( 'IGNORE', $options ) ) {
1804 return implode( ' ', $opts );
1808 * UPDATE wrapper. Takes a condition array and a SET array.
1810 * @param $table String name of the table to UPDATE. This will be passed through
1811 * DatabaseBase::tableName().
1813 * @param $values Array: An array of values to SET. For each array element,
1814 * the key gives the field name, and the value gives the data
1815 * to set that field to. The data will be quoted by
1816 * DatabaseBase::addQuotes().
1818 * @param $conds Array: An array of conditions (WHERE). See
1819 * DatabaseBase::select() for the details of the format of
1820 * condition arrays. Use '*' to update all rows.
1822 * @param $fname String: The function name of the caller (from __METHOD__),
1823 * for logging and profiling.
1825 * @param $options Array: An array of UPDATE options, can be:
1826 * - IGNORE: Ignore unique key conflicts
1827 * - LOW_PRIORITY: MySQL-specific, see MySQL manual.
1830 function update( $table, $values, $conds, $fname = 'DatabaseBase::update', $options = array() ) {
1831 $table = $this->tableName( $table );
1832 $opts = $this->makeUpdateOptions( $options );
1833 $sql = "UPDATE $opts $table SET " . $this->makeList( $values, LIST_SET
);
1835 if ( $conds !== array() && $conds !== '*' ) {
1836 $sql .= " WHERE " . $this->makeList( $conds, LIST_AND
);
1839 return $this->query( $sql, $fname );
1843 * Makes an encoded list of strings from an array
1844 * @param $a Array containing the data
1845 * @param int $mode Constant
1846 * - LIST_COMMA: comma separated, no field names
1847 * - LIST_AND: ANDed WHERE clause (without the WHERE). See
1848 * the documentation for $conds in DatabaseBase::select().
1849 * - LIST_OR: ORed WHERE clause (without the WHERE)
1850 * - LIST_SET: comma separated with field names, like a SET clause
1851 * - LIST_NAMES: comma separated field names
1853 * @throws MWException|DBUnexpectedError
1856 public function makeList( $a, $mode = LIST_COMMA
) {
1857 if ( !is_array( $a ) ) {
1858 throw new DBUnexpectedError( $this, 'DatabaseBase::makeList called with incorrect parameters' );
1864 foreach ( $a as $field => $value ) {
1866 if ( $mode == LIST_AND
) {
1868 } elseif ( $mode == LIST_OR
) {
1877 if ( ( $mode == LIST_AND ||
$mode == LIST_OR
) && is_numeric( $field ) ) {
1878 $list .= "($value)";
1879 } elseif ( ( $mode == LIST_SET
) && is_numeric( $field ) ) {
1881 } elseif ( ( $mode == LIST_AND ||
$mode == LIST_OR
) && is_array( $value ) ) {
1882 if ( count( $value ) == 0 ) {
1883 throw new MWException( __METHOD__
. ": empty input for field $field" );
1884 } elseif ( count( $value ) == 1 ) {
1885 // Special-case single values, as IN isn't terribly efficient
1886 // Don't necessarily assume the single key is 0; we don't
1887 // enforce linear numeric ordering on other arrays here.
1888 $value = array_values( $value );
1889 $list .= $field . " = " . $this->addQuotes( $value[0] );
1891 $list .= $field . " IN (" . $this->makeList( $value ) . ") ";
1893 } elseif ( $value === null ) {
1894 if ( $mode == LIST_AND ||
$mode == LIST_OR
) {
1895 $list .= "$field IS ";
1896 } elseif ( $mode == LIST_SET
) {
1897 $list .= "$field = ";
1901 if ( $mode == LIST_AND ||
$mode == LIST_OR ||
$mode == LIST_SET
) {
1902 $list .= "$field = ";
1904 $list .= $mode == LIST_NAMES ?
$value : $this->addQuotes( $value );
1912 * Build a partial where clause from a 2-d array such as used for LinkBatch.
1913 * The keys on each level may be either integers or strings.
1915 * @param $data Array: organized as 2-d
1916 * array(baseKeyVal => array(subKeyVal => [ignored], ...), ...)
1917 * @param $baseKey String: field name to match the base-level keys to (eg 'pl_namespace')
1918 * @param $subKey String: field name to match the sub-level keys to (eg 'pl_title')
1919 * @return Mixed: string SQL fragment, or false if no items in array.
1921 public function makeWhereFrom2d( $data, $baseKey, $subKey ) {
1924 foreach ( $data as $base => $sub ) {
1925 if ( count( $sub ) ) {
1926 $conds[] = $this->makeList(
1927 array( $baseKey => $base, $subKey => array_keys( $sub ) ),
1933 return $this->makeList( $conds, LIST_OR
);
1935 // Nothing to search for...
1941 * Return aggregated value alias
1944 * @param $valuename string
1948 public function aggregateValue( $valuedata, $valuename = 'value' ) {
1956 public function bitNot( $field ) {
1962 * @param $fieldRight
1965 public function bitAnd( $fieldLeft, $fieldRight ) {
1966 return "($fieldLeft & $fieldRight)";
1971 * @param $fieldRight
1974 public function bitOr( $fieldLeft, $fieldRight ) {
1975 return "($fieldLeft | $fieldRight)";
1979 * Build a concatenation list to feed into a SQL query
1980 * @param $stringList Array: list of raw SQL expressions; caller is responsible for any quoting
1983 public function buildConcat( $stringList ) {
1984 return 'CONCAT(' . implode( ',', $stringList ) . ')';
1988 * Change the current database
1990 * @todo Explain what exactly will fail if this is not overridden.
1994 * @return bool Success or failure
1996 public function selectDB( $db ) {
1997 # Stub. Shouldn't cause serious problems if it's not overridden, but
1998 # if your database engine supports a concept similar to MySQL's
1999 # databases you may as well.
2000 $this->mDBname
= $db;
2005 * Get the current DB name
2007 public function getDBname() {
2008 return $this->mDBname
;
2012 * Get the server hostname or IP address
2014 public function getServer() {
2015 return $this->mServer
;
2019 * Format a table name ready for use in constructing an SQL query
2021 * This does two important things: it quotes the table names to clean them up,
2022 * and it adds a table prefix if only given a table name with no quotes.
2024 * All functions of this object which require a table name call this function
2025 * themselves. Pass the canonical name to such functions. This is only needed
2026 * when calling query() directly.
2028 * @param $name String: database table name
2029 * @param $format String One of:
2030 * quoted - Automatically pass the table name through addIdentifierQuotes()
2031 * so that it can be used in a query.
2032 * raw - Do not add identifier quotes to the table name
2033 * @return String: full database name
2035 public function tableName( $name, $format = 'quoted' ) {
2036 global $wgSharedDB, $wgSharedPrefix, $wgSharedTables;
2037 # Skip the entire process when we have a string quoted on both ends.
2038 # Note that we check the end so that we will still quote any use of
2039 # use of `database`.table. But won't break things if someone wants
2040 # to query a database table with a dot in the name.
2041 if ( $this->isQuotedIdentifier( $name ) ) {
2045 # Lets test for any bits of text that should never show up in a table
2046 # name. Basically anything like JOIN or ON which are actually part of
2047 # SQL queries, but may end up inside of the table value to combine
2048 # sql. Such as how the API is doing.
2049 # Note that we use a whitespace test rather than a \b test to avoid
2050 # any remote case where a word like on may be inside of a table name
2051 # surrounded by symbols which may be considered word breaks.
2052 if ( preg_match( '/(^|\s)(DISTINCT|JOIN|ON|AS)(\s|$)/i', $name ) !== 0 ) {
2056 # Split database and table into proper variables.
2057 # We reverse the explode so that database.table and table both output
2058 # the correct table.
2059 $dbDetails = explode( '.', $name, 2 );
2060 if ( count( $dbDetails ) == 2 ) {
2061 list( $database, $table ) = $dbDetails;
2062 # We don't want any prefix added in this case
2065 list( $table ) = $dbDetails;
2066 if ( $wgSharedDB !== null # We have a shared database
2067 && !$this->isQuotedIdentifier( $table ) # Paranoia check to prevent shared tables listing '`table`'
2068 && in_array( $table, $wgSharedTables ) # A shared table is selected
2070 $database = $wgSharedDB;
2071 $prefix = $wgSharedPrefix === null ?
$this->mTablePrefix
: $wgSharedPrefix;
2074 $prefix = $this->mTablePrefix
; # Default prefix
2078 # Quote $table and apply the prefix if not quoted.
2079 $tableName = "{$prefix}{$table}";
2080 if ( $format == 'quoted' && !$this->isQuotedIdentifier( $tableName ) ) {
2081 $tableName = $this->addIdentifierQuotes( $tableName );
2084 # Quote $database and merge it with the table name if needed
2085 if ( $database !== null ) {
2086 if ( $format == 'quoted' && !$this->isQuotedIdentifier( $database ) ) {
2087 $database = $this->addIdentifierQuotes( $database );
2089 $tableName = $database . '.' . $tableName;
2096 * Fetch a number of table names into an array
2097 * This is handy when you need to construct SQL for joins
2100 * extract( $dbr->tableNames( 'user', 'watchlist' ) );
2101 * $sql = "SELECT wl_namespace,wl_title FROM $watchlist,$user
2102 * WHERE wl_user=user_id AND wl_user=$nameWithQuotes";
2106 public function tableNames() {
2107 $inArray = func_get_args();
2110 foreach ( $inArray as $name ) {
2111 $retVal[$name] = $this->tableName( $name );
2118 * Fetch a number of table names into an zero-indexed numerical array
2119 * This is handy when you need to construct SQL for joins
2122 * list( $user, $watchlist ) = $dbr->tableNamesN( 'user', 'watchlist' );
2123 * $sql = "SELECT wl_namespace,wl_title FROM $watchlist,$user
2124 * WHERE wl_user=user_id AND wl_user=$nameWithQuotes";
2128 public function tableNamesN() {
2129 $inArray = func_get_args();
2132 foreach ( $inArray as $name ) {
2133 $retVal[] = $this->tableName( $name );
2140 * Get an aliased table name
2141 * e.g. tableName AS newTableName
2143 * @param $name string Table name, see tableName()
2144 * @param $alias string|bool Alias (optional)
2145 * @return string SQL name for aliased table. Will not alias a table to its own name
2147 public function tableNameWithAlias( $name, $alias = false ) {
2148 if ( !$alias ||
$alias == $name ) {
2149 return $this->tableName( $name );
2151 return $this->tableName( $name ) . ' ' . $this->addIdentifierQuotes( $alias );
2156 * Gets an array of aliased table names
2158 * @param $tables array( [alias] => table )
2159 * @return array of strings, see tableNameWithAlias()
2161 public function tableNamesWithAlias( $tables ) {
2163 foreach ( $tables as $alias => $table ) {
2164 if ( is_numeric( $alias ) ) {
2167 $retval[] = $this->tableNameWithAlias( $table, $alias );
2173 * Get an aliased field name
2174 * e.g. fieldName AS newFieldName
2176 * @param $name string Field name
2177 * @param $alias string|bool Alias (optional)
2178 * @return string SQL name for aliased field. Will not alias a field to its own name
2180 public function fieldNameWithAlias( $name, $alias = false ) {
2181 if ( !$alias ||
(string)$alias === (string)$name ) {
2184 return $name . ' AS ' . $alias; //PostgreSQL needs AS
2189 * Gets an array of aliased field names
2191 * @param $fields array( [alias] => field )
2192 * @return array of strings, see fieldNameWithAlias()
2194 public function fieldNamesWithAlias( $fields ) {
2196 foreach ( $fields as $alias => $field ) {
2197 if ( is_numeric( $alias ) ) {
2200 $retval[] = $this->fieldNameWithAlias( $field, $alias );
2206 * Get the aliased table name clause for a FROM clause
2207 * which might have a JOIN and/or USE INDEX clause
2209 * @param $tables array ( [alias] => table )
2210 * @param $use_index array Same as for select()
2211 * @param $join_conds array Same as for select()
2214 protected function tableNamesWithUseIndexOrJOIN(
2215 $tables, $use_index = array(), $join_conds = array()
2219 $use_index = (array)$use_index;
2220 $join_conds = (array)$join_conds;
2222 foreach ( $tables as $alias => $table ) {
2223 if ( !is_string( $alias ) ) {
2224 // No alias? Set it equal to the table name
2227 // Is there a JOIN clause for this table?
2228 if ( isset( $join_conds[$alias] ) ) {
2229 list( $joinType, $conds ) = $join_conds[$alias];
2230 $tableClause = $joinType;
2231 $tableClause .= ' ' . $this->tableNameWithAlias( $table, $alias );
2232 if ( isset( $use_index[$alias] ) ) { // has USE INDEX?
2233 $use = $this->useIndexClause( implode( ',', (array)$use_index[$alias] ) );
2235 $tableClause .= ' ' . $use;
2238 $on = $this->makeList( (array)$conds, LIST_AND
);
2240 $tableClause .= ' ON (' . $on . ')';
2243 $retJOIN[] = $tableClause;
2244 // Is there an INDEX clause for this table?
2245 } elseif ( isset( $use_index[$alias] ) ) {
2246 $tableClause = $this->tableNameWithAlias( $table, $alias );
2247 $tableClause .= ' ' . $this->useIndexClause(
2248 implode( ',', (array)$use_index[$alias] ) );
2250 $ret[] = $tableClause;
2252 $tableClause = $this->tableNameWithAlias( $table, $alias );
2254 $ret[] = $tableClause;
2258 // We can't separate explicit JOIN clauses with ',', use ' ' for those
2259 $straightJoins = !empty( $ret ) ?
implode( ',', $ret ) : "";
2260 $otherJoins = !empty( $retJOIN ) ?
implode( ' ', $retJOIN ) : "";
2262 // Compile our final table clause
2263 return implode( ' ', array( $straightJoins, $otherJoins ) );
2267 * Get the name of an index in a given table
2273 protected function indexName( $index ) {
2274 // Backwards-compatibility hack
2276 'ar_usertext_timestamp' => 'usertext_timestamp',
2277 'un_user_id' => 'user_id',
2278 'un_user_ip' => 'user_ip',
2281 if ( isset( $renamed[$index] ) ) {
2282 return $renamed[$index];
2289 * If it's a string, adds quotes and backslashes
2290 * Otherwise returns as-is
2296 public function addQuotes( $s ) {
2297 if ( $s === null ) {
2300 # This will also quote numeric values. This should be harmless,
2301 # and protects against weird problems that occur when they really
2302 # _are_ strings such as article titles and string->number->string
2303 # conversion is not 1:1.
2304 return "'" . $this->strencode( $s ) . "'";
2309 * Quotes an identifier using `backticks` or "double quotes" depending on the database type.
2310 * MySQL uses `backticks` while basically everything else uses double quotes.
2311 * Since MySQL is the odd one out here the double quotes are our generic
2312 * and we implement backticks in DatabaseMysql.
2318 public function addIdentifierQuotes( $s ) {
2319 return '"' . str_replace( '"', '""', $s ) . '"';
2323 * Returns if the given identifier looks quoted or not according to
2324 * the database convention for quoting identifiers .
2326 * @param $name string
2330 public function isQuotedIdentifier( $name ) {
2331 return $name[0] == '"' && substr( $name, -1, 1 ) == '"';
2338 protected function escapeLikeInternal( $s ) {
2339 $s = str_replace( '\\', '\\\\', $s );
2340 $s = $this->strencode( $s );
2341 $s = str_replace( array( '%', '_' ), array( '\%', '\_' ), $s );
2347 * LIKE statement wrapper, receives a variable-length argument list with parts of pattern to match
2348 * containing either string literals that will be escaped or tokens returned by anyChar() or anyString().
2349 * Alternatively, the function could be provided with an array of aforementioned parameters.
2351 * Example: $dbr->buildLike( 'My_page_title/', $dbr->anyString() ) returns a LIKE clause that searches
2352 * for subpages of 'My page title'.
2353 * Alternatively: $pattern = array( 'My_page_title/', $dbr->anyString() ); $query .= $dbr->buildLike( $pattern );
2356 * @return String: fully built LIKE statement
2358 public function buildLike() {
2359 $params = func_get_args();
2361 if ( count( $params ) > 0 && is_array( $params[0] ) ) {
2362 $params = $params[0];
2367 foreach ( $params as $value ) {
2368 if ( $value instanceof LikeMatch
) {
2369 $s .= $value->toString();
2371 $s .= $this->escapeLikeInternal( $value );
2375 return " LIKE '" . $s . "' ";
2379 * Returns a token for buildLike() that denotes a '_' to be used in a LIKE query
2383 public function anyChar() {
2384 return new LikeMatch( '_' );
2388 * Returns a token for buildLike() that denotes a '%' to be used in a LIKE query
2392 public function anyString() {
2393 return new LikeMatch( '%' );
2397 * Returns an appropriately quoted sequence value for inserting a new row.
2398 * MySQL has autoincrement fields, so this is just NULL. But the PostgreSQL
2399 * subclass will return an integer, and save the value for insertId()
2401 * Any implementation of this function should *not* involve reusing
2402 * sequence numbers created for rolled-back transactions.
2403 * See http://bugs.mysql.com/bug.php?id=30767 for details.
2404 * @param $seqName string
2407 public function nextSequenceValue( $seqName ) {
2412 * USE INDEX clause. Unlikely to be useful for anything but MySQL. This
2413 * is only needed because a) MySQL must be as efficient as possible due to
2414 * its use on Wikipedia, and b) MySQL 4.0 is kind of dumb sometimes about
2415 * which index to pick. Anyway, other databases might have different
2416 * indexes on a given table. So don't bother overriding this unless you're
2421 public function useIndexClause( $index ) {
2426 * REPLACE query wrapper.
2428 * REPLACE is a very handy MySQL extension, which functions like an INSERT
2429 * except that when there is a duplicate key error, the old row is deleted
2430 * and the new row is inserted in its place.
2432 * We simulate this with standard SQL with a DELETE followed by INSERT. To
2433 * perform the delete, we need to know what the unique indexes are so that
2434 * we know how to find the conflicting rows.
2436 * It may be more efficient to leave off unique indexes which are unlikely
2437 * to collide. However if you do this, you run the risk of encountering
2438 * errors which wouldn't have occurred in MySQL.
2440 * @param $table String: The table to replace the row(s) in.
2441 * @param $rows array Can be either a single row to insert, or multiple rows,
2442 * in the same format as for DatabaseBase::insert()
2443 * @param $uniqueIndexes array is an array of indexes. Each element may be either
2444 * a field name or an array of field names
2445 * @param $fname String: Calling function name (use __METHOD__) for logs/profiling
2447 public function replace( $table, $uniqueIndexes, $rows, $fname = 'DatabaseBase::replace' ) {
2448 $quotedTable = $this->tableName( $table );
2450 if ( count( $rows ) == 0 ) {
2455 if ( !is_array( reset( $rows ) ) ) {
2456 $rows = array( $rows );
2459 foreach( $rows as $row ) {
2460 # Delete rows which collide
2461 if ( $uniqueIndexes ) {
2462 $sql = "DELETE FROM $quotedTable WHERE ";
2464 foreach ( $uniqueIndexes as $index ) {
2471 if ( is_array( $index ) ) {
2473 foreach ( $index as $col ) {
2479 $sql .= $col . '=' . $this->addQuotes( $row[$col] );
2482 $sql .= $index . '=' . $this->addQuotes( $row[$index] );
2486 $this->query( $sql, $fname );
2489 # Now insert the row
2490 $this->insert( $table, $row );
2495 * REPLACE query wrapper for MySQL and SQLite, which have a native REPLACE
2498 * @param $table string Table name
2499 * @param $rows array Rows to insert
2500 * @param $fname string Caller function name
2502 * @return ResultWrapper
2504 protected function nativeReplace( $table, $rows, $fname ) {
2505 $table = $this->tableName( $table );
2508 if ( !is_array( reset( $rows ) ) ) {
2509 $rows = array( $rows );
2512 $sql = "REPLACE INTO $table (" . implode( ',', array_keys( $rows[0] ) ) . ') VALUES ';
2515 foreach ( $rows as $row ) {
2522 $sql .= '(' . $this->makeList( $row ) . ')';
2525 return $this->query( $sql, $fname );
2529 * DELETE where the condition is a join.
2531 * MySQL overrides this to use a multi-table DELETE syntax, in other databases
2532 * we use sub-selects
2534 * For safety, an empty $conds will not delete everything. If you want to
2535 * delete all rows where the join condition matches, set $conds='*'.
2537 * DO NOT put the join condition in $conds.
2539 * @param $delTable String: The table to delete from.
2540 * @param $joinTable String: The other table.
2541 * @param $delVar String: The variable to join on, in the first table.
2542 * @param $joinVar String: The variable to join on, in the second table.
2543 * @param $conds Array: Condition array of field names mapped to variables,
2544 * ANDed together in the WHERE clause
2545 * @param $fname String: Calling function name (use __METHOD__) for
2547 * @throws DBUnexpectedError
2549 public function deleteJoin( $delTable, $joinTable, $delVar, $joinVar, $conds,
2550 $fname = 'DatabaseBase::deleteJoin' )
2553 throw new DBUnexpectedError( $this,
2554 'DatabaseBase::deleteJoin() called with empty $conds' );
2557 $delTable = $this->tableName( $delTable );
2558 $joinTable = $this->tableName( $joinTable );
2559 $sql = "DELETE FROM $delTable WHERE $delVar IN (SELECT $joinVar FROM $joinTable ";
2560 if ( $conds != '*' ) {
2561 $sql .= 'WHERE ' . $this->makeList( $conds, LIST_AND
);
2565 $this->query( $sql, $fname );
2569 * Returns the size of a text field, or -1 for "unlimited"
2571 * @param $table string
2572 * @param $field string
2576 public function textFieldSize( $table, $field ) {
2577 $table = $this->tableName( $table );
2578 $sql = "SHOW COLUMNS FROM $table LIKE \"$field\";";
2579 $res = $this->query( $sql, 'DatabaseBase::textFieldSize' );
2580 $row = $this->fetchObject( $res );
2584 if ( preg_match( '/\((.*)\)/', $row->Type
, $m ) ) {
2594 * A string to insert into queries to show that they're low-priority, like
2595 * MySQL's LOW_PRIORITY. If no such feature exists, return an empty
2596 * string and nothing bad should happen.
2598 * @return string Returns the text of the low priority option if it is
2599 * supported, or a blank string otherwise
2601 public function lowPriorityOption() {
2606 * DELETE query wrapper.
2608 * @param $table Array Table name
2609 * @param $conds String|Array of conditions. See $conds in DatabaseBase::select() for
2610 * the format. Use $conds == "*" to delete all rows
2611 * @param $fname String name of the calling function
2613 * @throws DBUnexpectedError
2614 * @return bool|ResultWrapper
2616 public function delete( $table, $conds, $fname = 'DatabaseBase::delete' ) {
2618 throw new DBUnexpectedError( $this, 'DatabaseBase::delete() called with no conditions' );
2621 $table = $this->tableName( $table );
2622 $sql = "DELETE FROM $table";
2624 if ( $conds != '*' ) {
2625 $sql .= ' WHERE ' . $this->makeList( $conds, LIST_AND
);
2628 return $this->query( $sql, $fname );
2632 * INSERT SELECT wrapper. Takes data from a SELECT query and inserts it
2633 * into another table.
2635 * @param $destTable string The table name to insert into
2636 * @param $srcTable string|array May be either a table name, or an array of table names
2637 * to include in a join.
2639 * @param $varMap array must be an associative array of the form
2640 * array( 'dest1' => 'source1', ...). Source items may be literals
2641 * rather than field names, but strings should be quoted with
2642 * DatabaseBase::addQuotes()
2644 * @param $conds array Condition array. See $conds in DatabaseBase::select() for
2645 * the details of the format of condition arrays. May be "*" to copy the
2648 * @param $fname string The function name of the caller, from __METHOD__
2650 * @param $insertOptions array Options for the INSERT part of the query, see
2651 * DatabaseBase::insert() for details.
2652 * @param $selectOptions array Options for the SELECT part of the query, see
2653 * DatabaseBase::select() for details.
2655 * @return ResultWrapper
2657 public function insertSelect( $destTable, $srcTable, $varMap, $conds,
2658 $fname = 'DatabaseBase::insertSelect',
2659 $insertOptions = array(), $selectOptions = array() )
2661 $destTable = $this->tableName( $destTable );
2663 if ( is_array( $insertOptions ) ) {
2664 $insertOptions = implode( ' ', $insertOptions );
2667 if ( !is_array( $selectOptions ) ) {
2668 $selectOptions = array( $selectOptions );
2671 list( $startOpts, $useIndex, $tailOpts ) = $this->makeSelectOptions( $selectOptions );
2673 if ( is_array( $srcTable ) ) {
2674 $srcTable = implode( ',', array_map( array( &$this, 'tableName' ), $srcTable ) );
2676 $srcTable = $this->tableName( $srcTable );
2679 $sql = "INSERT $insertOptions INTO $destTable (" . implode( ',', array_keys( $varMap ) ) . ')' .
2680 " SELECT $startOpts " . implode( ',', $varMap ) .
2681 " FROM $srcTable $useIndex ";
2683 if ( $conds != '*' ) {
2684 if ( is_array( $conds ) ) {
2685 $conds = $this->makeList( $conds, LIST_AND
);
2687 $sql .= " WHERE $conds";
2690 $sql .= " $tailOpts";
2692 return $this->query( $sql, $fname );
2696 * Construct a LIMIT query with optional offset. This is used for query
2697 * pages. The SQL should be adjusted so that only the first $limit rows
2698 * are returned. If $offset is provided as well, then the first $offset
2699 * rows should be discarded, and the next $limit rows should be returned.
2700 * If the result of the query is not ordered, then the rows to be returned
2701 * are theoretically arbitrary.
2703 * $sql is expected to be a SELECT, if that makes a difference.
2705 * The version provided by default works in MySQL and SQLite. It will very
2706 * likely need to be overridden for most other DBMSes.
2708 * @param $sql String SQL query we will append the limit too
2709 * @param $limit Integer the SQL limit
2710 * @param $offset Integer|bool the SQL offset (default false)
2712 * @throws DBUnexpectedError
2715 public function limitResult( $sql, $limit, $offset = false ) {
2716 if ( !is_numeric( $limit ) ) {
2717 throw new DBUnexpectedError( $this, "Invalid non-numeric limit passed to limitResult()\n" );
2719 return "$sql LIMIT "
2720 . ( ( is_numeric( $offset ) && $offset != 0 ) ?
"{$offset}," : "" )
2725 * Returns true if current database backend supports ORDER BY or LIMIT for separate subqueries
2726 * within the UNION construct.
2729 public function unionSupportsOrderAndLimit() {
2730 return true; // True for almost every DB supported
2734 * Construct a UNION query
2735 * This is used for providing overload point for other DB abstractions
2736 * not compatible with the MySQL syntax.
2737 * @param $sqls Array: SQL statements to combine
2738 * @param $all Boolean: use UNION ALL
2739 * @return String: SQL fragment
2741 public function unionQueries( $sqls, $all ) {
2742 $glue = $all ?
') UNION ALL (' : ') UNION (';
2743 return '(' . implode( $glue, $sqls ) . ')';
2747 * Returns an SQL expression for a simple conditional. This doesn't need
2748 * to be overridden unless CASE isn't supported in your DBMS.
2750 * @param $cond string|array SQL expression which will result in a boolean value
2751 * @param $trueVal String: SQL expression to return if true
2752 * @param $falseVal String: SQL expression to return if false
2753 * @return String: SQL fragment
2755 public function conditional( $cond, $trueVal, $falseVal ) {
2756 if ( is_array( $cond ) ) {
2757 $cond = $this->makeList( $cond, LIST_AND
);
2759 return " (CASE WHEN $cond THEN $trueVal ELSE $falseVal END) ";
2763 * Returns a comand for str_replace function in SQL query.
2764 * Uses REPLACE() in MySQL
2766 * @param $orig String: column to modify
2767 * @param $old String: column to seek
2768 * @param $new String: column to replace with
2772 public function strreplace( $orig, $old, $new ) {
2773 return "REPLACE({$orig}, {$old}, {$new})";
2777 * Determines how long the server has been up
2782 public function getServerUptime() {
2787 * Determines if the last failure was due to a deadlock
2792 public function wasDeadlock() {
2797 * Determines if the last failure was due to a lock timeout
2802 public function wasLockTimeout() {
2807 * Determines if the last query error was something that should be dealt
2808 * with by pinging the connection and reissuing the query.
2813 public function wasErrorReissuable() {
2818 * Determines if the last failure was due to the database being read-only.
2823 public function wasReadOnlyError() {
2828 * Perform a deadlock-prone transaction.
2830 * This function invokes a callback function to perform a set of write
2831 * queries. If a deadlock occurs during the processing, the transaction
2832 * will be rolled back and the callback function will be called again.
2835 * $dbw->deadlockLoop( callback, ... );
2837 * Extra arguments are passed through to the specified callback function.
2839 * Returns whatever the callback function returned on its successful,
2840 * iteration, or false on error, for example if the retry limit was
2845 public function deadlockLoop() {
2846 $this->begin( __METHOD__
);
2847 $args = func_get_args();
2848 $function = array_shift( $args );
2849 $oldIgnore = $this->ignoreErrors( true );
2850 $tries = DEADLOCK_TRIES
;
2852 if ( is_array( $function ) ) {
2853 $fname = $function[0];
2859 $retVal = call_user_func_array( $function, $args );
2860 $error = $this->lastError();
2861 $errno = $this->lastErrno();
2862 $sql = $this->lastQuery();
2865 if ( $this->wasDeadlock() ) {
2867 usleep( mt_rand( DEADLOCK_DELAY_MIN
, DEADLOCK_DELAY_MAX
) );
2869 $this->reportQueryError( $error, $errno, $sql, $fname );
2872 } while ( $this->wasDeadlock() && --$tries > 0 );
2874 $this->ignoreErrors( $oldIgnore );
2876 if ( $tries <= 0 ) {
2877 $this->rollback( __METHOD__
);
2878 $this->reportQueryError( $error, $errno, $sql, $fname );
2881 $this->commit( __METHOD__
);
2887 * Wait for the slave to catch up to a given master position.
2889 * @param $pos DBMasterPos object
2890 * @param $timeout Integer: the maximum number of seconds to wait for
2893 * @return integer: zero if the slave was past that position already,
2894 * greater than zero if we waited for some period of time, less than
2895 * zero if we timed out.
2897 public function masterPosWait( DBMasterPos
$pos, $timeout ) {
2898 wfProfileIn( __METHOD__
);
2900 if ( !is_null( $this->mFakeSlaveLag
) ) {
2901 $wait = intval( ( $pos->pos
- microtime( true ) +
$this->mFakeSlaveLag
) * 1e6
);
2903 if ( $wait > $timeout * 1e6
) {
2904 wfDebug( "Fake slave timed out waiting for $pos ($wait us)\n" );
2905 wfProfileOut( __METHOD__
);
2907 } elseif ( $wait > 0 ) {
2908 wfDebug( "Fake slave waiting $wait us\n" );
2910 wfProfileOut( __METHOD__
);
2913 wfDebug( "Fake slave up to date ($wait us)\n" );
2914 wfProfileOut( __METHOD__
);
2919 wfProfileOut( __METHOD__
);
2921 # Real waits are implemented in the subclass.
2926 * Get the replication position of this slave
2928 * @return DBMasterPos, or false if this is not a slave.
2930 public function getSlavePos() {
2931 if ( !is_null( $this->mFakeSlaveLag
) ) {
2932 $pos = new MySQLMasterPos( 'fake', microtime( true ) - $this->mFakeSlaveLag
);
2933 wfDebug( __METHOD__
. ": fake slave pos = $pos\n" );
2942 * Get the position of this master
2944 * @return DBMasterPos, or false if this is not a master
2946 public function getMasterPos() {
2947 if ( $this->mFakeMaster
) {
2948 return new MySQLMasterPos( 'fake', microtime( true ) );
2955 * Run an anonymous function as soon as there is no transaction pending.
2956 * If there is a transaction and it is rolled back, then the callback is cancelled.
2957 * Callbacks must commit any transactions that they begin.
2959 * This is useful for updates to different systems or separate transactions are needed.
2963 * @param Closure $callback
2965 final public function onTransactionIdle( Closure
$callback ) {
2966 if ( $this->mTrxLevel
) {
2967 $this->mTrxIdleCallbacks
[] = $callback;
2974 * Actually run the "on transaction idle" callbacks.
2978 protected function runOnTransactionIdleCallbacks() {
2979 $autoTrx = $this->getFlag( DBO_TRX
); // automatic begin() enabled?
2981 $e = null; // last exception
2982 do { // callbacks may add callbacks :)
2983 $callbacks = $this->mTrxIdleCallbacks
;
2984 $this->mTrxIdleCallbacks
= array(); // recursion guard
2985 foreach ( $callbacks as $callback ) {
2987 $this->clearFlag( DBO_TRX
); // make each query its own transaction
2989 $this->setFlag( $autoTrx ? DBO_TRX
: 0 ); // restore automatic begin()
2990 } catch ( Exception
$e ) {}
2992 } while ( count( $this->mTrxIdleCallbacks
) );
2994 if ( $e instanceof Exception
) {
2995 throw $e; // re-throw any last exception
3000 * Begin a transaction. If a transaction is already in progress, that transaction will be committed before the
3001 * new transaction is started.
3003 * Note that when the DBO_TRX flag is set (which is usually the case for web requests, but not for maintenance scripts),
3004 * any previous database query will have started a transaction automatically.
3006 * Nesting of transactions is not supported. Attempts to nest transactions will cause a warning, unless the current
3007 * transaction was started automatically because of the DBO_TRX flag.
3009 * @param $fname string
3011 final public function begin( $fname = 'DatabaseBase::begin' ) {
3012 global $wgDebugDBTransactions;
3014 if ( $this->mTrxLevel
) { // implicit commit
3015 if ( !$this->mTrxAutomatic
) {
3016 // We want to warn about inadvertently nested begin/commit pairs, but not about
3017 // auto-committing implicit transactions that were started by query() via DBO_TRX
3018 $msg = "$fname: Transaction already in progress (from {$this->mTrxFname}), " .
3019 " performing implicit commit!";
3021 wfLogDBError( $msg );
3023 // if the transaction was automatic and has done write operations,
3024 // log it if $wgDebugDBTransactions is enabled.
3025 if ( $this->mTrxDoneWrites
&& $wgDebugDBTransactions ) {
3026 wfDebug( "$fname: Automatic transaction with writes in progress" .
3027 " (from {$this->mTrxFname}), performing implicit commit!\n" );
3031 $this->doCommit( $fname );
3032 $this->runOnTransactionIdleCallbacks();
3035 $this->doBegin( $fname );
3036 $this->mTrxFname
= $fname;
3037 $this->mTrxDoneWrites
= false;
3038 $this->mTrxAutomatic
= false;
3042 * Issues the BEGIN command to the database server.
3044 * @see DatabaseBase::begin()
3045 * @param type $fname
3047 protected function doBegin( $fname ) {
3048 $this->query( 'BEGIN', $fname );
3049 $this->mTrxLevel
= 1;
3053 * Commits a transaction previously started using begin().
3054 * If no transaction is in progress, a warning is issued.
3056 * Nesting of transactions is not supported.
3058 * @param $fname string
3059 * @param $flush String Flush flag, set to 'flush' to disable warnings about explicitly committing implicit
3060 * transactions, or calling commit when no transaction is in progress.
3061 * This will silently break any ongoing explicit transaction. Only set the flush flag if you are sure
3062 * that it is safe to ignore these warnings in your context.
3064 final public function commit( $fname = 'DatabaseBase::commit', $flush = '' ) {
3065 if ( $flush != 'flush' ) {
3066 if ( !$this->mTrxLevel
) {
3067 wfWarn( "$fname: No transaction to commit, something got out of sync!" );
3068 } elseif( $this->mTrxAutomatic
) {
3069 wfWarn( "$fname: Explicit commit of implicit transaction. Something may be out of sync!" );
3072 if ( !$this->mTrxLevel
) {
3073 return; // nothing to do
3074 } elseif( !$this->mTrxAutomatic
) {
3075 wfWarn( "$fname: Flushing an explicit transaction, getting out of sync!" );
3079 $this->doCommit( $fname );
3080 $this->runOnTransactionIdleCallbacks();
3084 * Issues the COMMIT command to the database server.
3086 * @see DatabaseBase::commit()
3087 * @param type $fname
3089 protected function doCommit( $fname ) {
3090 if ( $this->mTrxLevel
) {
3091 $this->query( 'COMMIT', $fname );
3092 $this->mTrxLevel
= 0;
3097 * Rollback a transaction previously started using begin().
3098 * If no transaction is in progress, a warning is issued.
3100 * No-op on non-transactional databases.
3102 * @param $fname string
3104 final public function rollback( $fname = 'DatabaseBase::rollback' ) {
3105 if ( !$this->mTrxLevel
) {
3106 wfWarn( "$fname: No transaction to rollback, something got out of sync!" );
3108 $this->doRollback( $fname );
3109 $this->mTrxIdleCallbacks
= array(); // cancel
3113 * Issues the ROLLBACK command to the database server.
3115 * @see DatabaseBase::rollback()
3116 * @param type $fname
3118 protected function doRollback( $fname ) {
3119 if ( $this->mTrxLevel
) {
3120 $this->query( 'ROLLBACK', $fname, true );
3121 $this->mTrxLevel
= 0;
3126 * Creates a new table with structure copied from existing table
3127 * Note that unlike most database abstraction functions, this function does not
3128 * automatically append database prefix, because it works at a lower
3129 * abstraction level.
3130 * The table names passed to this function shall not be quoted (this
3131 * function calls addIdentifierQuotes when needed).
3133 * @param $oldName String: name of table whose structure should be copied
3134 * @param $newName String: name of table to be created
3135 * @param $temporary Boolean: whether the new table should be temporary
3136 * @param $fname String: calling function name
3137 * @throws MWException
3138 * @return Boolean: true if operation was successful
3140 public function duplicateTableStructure( $oldName, $newName, $temporary = false,
3141 $fname = 'DatabaseBase::duplicateTableStructure' )
3143 throw new MWException(
3144 'DatabaseBase::duplicateTableStructure is not implemented in descendant class' );
3148 * List all tables on the database
3150 * @param $prefix string Only show tables with this prefix, e.g. mw_
3151 * @param $fname String: calling function name
3152 * @throws MWException
3154 function listTables( $prefix = null, $fname = 'DatabaseBase::listTables' ) {
3155 throw new MWException( 'DatabaseBase::listTables is not implemented in descendant class' );
3159 * Convert a timestamp in one of the formats accepted by wfTimestamp()
3160 * to the format used for inserting into timestamp fields in this DBMS.
3162 * The result is unquoted, and needs to be passed through addQuotes()
3163 * before it can be included in raw SQL.
3165 * @param $ts string|int
3169 public function timestamp( $ts = 0 ) {
3170 return wfTimestamp( TS_MW
, $ts );
3174 * Convert a timestamp in one of the formats accepted by wfTimestamp()
3175 * to the format used for inserting into timestamp fields in this DBMS. If
3176 * NULL is input, it is passed through, allowing NULL values to be inserted
3177 * into timestamp fields.
3179 * The result is unquoted, and needs to be passed through addQuotes()
3180 * before it can be included in raw SQL.
3182 * @param $ts string|int
3186 public function timestampOrNull( $ts = null ) {
3187 if ( is_null( $ts ) ) {
3190 return $this->timestamp( $ts );
3195 * Take the result from a query, and wrap it in a ResultWrapper if
3196 * necessary. Boolean values are passed through as is, to indicate success
3197 * of write queries or failure.
3199 * Once upon a time, DatabaseBase::query() returned a bare MySQL result
3200 * resource, and it was necessary to call this function to convert it to
3201 * a wrapper. Nowadays, raw database objects are never exposed to external
3202 * callers, so this is unnecessary in external code. For compatibility with
3203 * old code, ResultWrapper objects are passed through unaltered.
3205 * @param $result bool|ResultWrapper
3207 * @return bool|ResultWrapper
3209 public function resultObject( $result ) {
3210 if ( empty( $result ) ) {
3212 } elseif ( $result instanceof ResultWrapper
) {
3214 } elseif ( $result === true ) {
3215 // Successful write query
3218 return new ResultWrapper( $this, $result );
3223 * Ping the server and try to reconnect if it there is no connection
3225 * @return bool Success or failure
3227 public function ping() {
3228 # Stub. Not essential to override.
3233 * Get slave lag. Currently supported only by MySQL.
3235 * Note that this function will generate a fatal error on many
3236 * installations. Most callers should use LoadBalancer::safeGetLag()
3239 * @return int Database replication lag in seconds
3241 public function getLag() {
3242 return intval( $this->mFakeSlaveLag
);
3246 * Return the maximum number of items allowed in a list, or 0 for unlimited.
3250 function maxListLen() {
3255 * Some DBMSs have a special format for inserting into blob fields, they
3256 * don't allow simple quoted strings to be inserted. To insert into such
3257 * a field, pass the data through this function before passing it to
3258 * DatabaseBase::insert().
3262 public function encodeBlob( $b ) {
3267 * Some DBMSs return a special placeholder object representing blob fields
3268 * in result objects. Pass the object through this function to return the
3273 public function decodeBlob( $b ) {
3278 * Override database's default behavior. $options include:
3279 * 'connTimeout' : Set the connection timeout value in seconds.
3280 * May be useful for very long batch queries such as
3281 * full-wiki dumps, where a single query reads out over
3284 * @param $options Array
3287 public function setSessionOptions( array $options ) {}
3290 * Read and execute SQL commands from a file.
3292 * Returns true on success, error string or exception on failure (depending
3293 * on object's error ignore settings).
3295 * @param $filename String: File name to open
3296 * @param bool|callable $lineCallback Optional function called before reading each line
3297 * @param bool|callable $resultCallback Optional function called for each MySQL result
3298 * @param bool|string $fname Calling function name or false if name should be
3299 * generated dynamically using $filename
3300 * @param bool|callable $inputCallback Callback: Optional function called for each complete line sent
3301 * @throws MWException
3302 * @throws Exception|MWException
3303 * @return bool|string
3305 public function sourceFile(
3306 $filename, $lineCallback = false, $resultCallback = false, $fname = false, $inputCallback = false
3308 wfSuppressWarnings();
3309 $fp = fopen( $filename, 'r' );
3310 wfRestoreWarnings();
3312 if ( false === $fp ) {
3313 throw new MWException( "Could not open \"{$filename}\".\n" );
3317 $fname = __METHOD__
. "( $filename )";
3321 $error = $this->sourceStream( $fp, $lineCallback, $resultCallback, $fname, $inputCallback );
3323 catch ( MWException
$e ) {
3334 * Get the full path of a patch file. Originally based on archive()
3335 * from updaters.inc. Keep in mind this always returns a patch, as
3336 * it fails back to MySQL if no DB-specific patch can be found
3338 * @param $patch String The name of the patch, like patch-something.sql
3339 * @return String Full path to patch file
3341 public function patchPath( $patch ) {
3344 $dbType = $this->getType();
3345 if ( file_exists( "$IP/maintenance/$dbType/archives/$patch" ) ) {
3346 return "$IP/maintenance/$dbType/archives/$patch";
3348 return "$IP/maintenance/archives/$patch";
3353 * Set variables to be used in sourceFile/sourceStream, in preference to the
3354 * ones in $GLOBALS. If an array is set here, $GLOBALS will not be used at
3355 * all. If it's set to false, $GLOBALS will be used.
3357 * @param $vars bool|array mapping variable name to value.
3359 public function setSchemaVars( $vars ) {
3360 $this->mSchemaVars
= $vars;
3364 * Read and execute commands from an open file handle.
3366 * Returns true on success, error string or exception on failure (depending
3367 * on object's error ignore settings).
3369 * @param $fp Resource: File handle
3370 * @param $lineCallback Callback: Optional function called before reading each query
3371 * @param $resultCallback Callback: Optional function called for each MySQL result
3372 * @param $fname String: Calling function name
3373 * @param $inputCallback Callback: Optional function called for each complete query sent
3374 * @return bool|string
3376 public function sourceStream( $fp, $lineCallback = false, $resultCallback = false,
3377 $fname = 'DatabaseBase::sourceStream', $inputCallback = false )
3381 while ( !feof( $fp ) ) {
3382 if ( $lineCallback ) {
3383 call_user_func( $lineCallback );
3386 $line = trim( fgets( $fp ) );
3388 if ( $line == '' ) {
3392 if ( '-' == $line[0] && '-' == $line[1] ) {
3400 $done = $this->streamStatementEnd( $cmd, $line );
3404 if ( $done ||
feof( $fp ) ) {
3405 $cmd = $this->replaceVars( $cmd );
3407 if ( ( $inputCallback && call_user_func( $inputCallback, $cmd ) ) ||
!$inputCallback ) {
3408 $res = $this->query( $cmd, $fname );
3410 if ( $resultCallback ) {
3411 call_user_func( $resultCallback, $res, $this );
3414 if ( false === $res ) {
3415 $err = $this->lastError();
3416 return "Query \"{$cmd}\" failed with error code \"$err\".\n";
3427 * Called by sourceStream() to check if we've reached a statement end
3429 * @param $sql String SQL assembled so far
3430 * @param $newLine String New line about to be added to $sql
3431 * @return Bool Whether $newLine contains end of the statement
3433 public function streamStatementEnd( &$sql, &$newLine ) {
3434 if ( $this->delimiter
) {
3436 $newLine = preg_replace( '/' . preg_quote( $this->delimiter
, '/' ) . '$/', '', $newLine );
3437 if ( $newLine != $prev ) {
3445 * Database independent variable replacement. Replaces a set of variables
3446 * in an SQL statement with their contents as given by $this->getSchemaVars().
3448 * Supports '{$var}' `{$var}` and / *$var* / (without the spaces) style variables.
3450 * - '{$var}' should be used for text and is passed through the database's
3452 * - `{$var}` should be used for identifiers (eg: table and database names),
3453 * it is passed through the database's addIdentifierQuotes method which
3454 * can be overridden if the database uses something other than backticks.
3455 * - / *$var* / is just encoded, besides traditional table prefix and
3456 * table options its use should be avoided.
3458 * @param $ins String: SQL statement to replace variables in
3459 * @return String The new SQL statement with variables replaced
3461 protected function replaceSchemaVars( $ins ) {
3462 $vars = $this->getSchemaVars();
3463 foreach ( $vars as $var => $value ) {
3465 $ins = str_replace( '\'{$' . $var . '}\'', $this->addQuotes( $value ), $ins );
3467 $ins = str_replace( '`{$' . $var . '}`', $this->addIdentifierQuotes( $value ), $ins );
3469 $ins = str_replace( '/*$' . $var . '*/', $this->strencode( $value ), $ins );
3475 * Replace variables in sourced SQL
3477 * @param $ins string
3481 protected function replaceVars( $ins ) {
3482 $ins = $this->replaceSchemaVars( $ins );
3485 $ins = preg_replace_callback( '!/\*(?:\$wgDBprefix|_)\*/([a-zA-Z_0-9]*)!',
3486 array( $this, 'tableNameCallback' ), $ins );
3489 $ins = preg_replace_callback( '!/\*i\*/([a-zA-Z_0-9]*)!',
3490 array( $this, 'indexNameCallback' ), $ins );
3496 * Get schema variables. If none have been set via setSchemaVars(), then
3497 * use some defaults from the current object.
3501 protected function getSchemaVars() {
3502 if ( $this->mSchemaVars
) {
3503 return $this->mSchemaVars
;
3505 return $this->getDefaultSchemaVars();
3510 * Get schema variables to use if none have been set via setSchemaVars().
3512 * Override this in derived classes to provide variables for tables.sql
3513 * and SQL patch files.
3517 protected function getDefaultSchemaVars() {
3522 * Table name callback
3524 * @param $matches array
3528 protected function tableNameCallback( $matches ) {
3529 return $this->tableName( $matches[1] );
3533 * Index name callback
3535 * @param $matches array
3539 protected function indexNameCallback( $matches ) {
3540 return $this->indexName( $matches[1] );
3544 * Check to see if a named lock is available. This is non-blocking.
3546 * @param $lockName String: name of lock to poll
3547 * @param $method String: name of method calling us
3551 public function lockIsFree( $lockName, $method ) {
3556 * Acquire a named lock
3558 * Abstracted from Filestore::lock() so child classes can implement for
3561 * @param $lockName String: name of lock to aquire
3562 * @param $method String: name of method calling us
3563 * @param $timeout Integer: timeout
3566 public function lock( $lockName, $method, $timeout = 5 ) {
3573 * @param $lockName String: Name of lock to release
3574 * @param $method String: Name of method calling us
3576 * @return int Returns 1 if the lock was released, 0 if the lock was not established
3577 * by this thread (in which case the lock is not released), and NULL if the named
3578 * lock did not exist
3580 public function unlock( $lockName, $method ) {
3585 * Lock specific tables
3587 * @param $read Array of tables to lock for read access
3588 * @param $write Array of tables to lock for write access
3589 * @param $method String name of caller
3590 * @param $lowPriority bool Whether to indicate writes to be LOW PRIORITY
3594 public function lockTables( $read, $write, $method, $lowPriority = true ) {
3599 * Unlock specific tables
3601 * @param $method String the caller
3605 public function unlockTables( $method ) {
3611 * @param $tableName string
3612 * @param $fName string
3613 * @return bool|ResultWrapper
3616 public function dropTable( $tableName, $fName = 'DatabaseBase::dropTable' ) {
3617 if( !$this->tableExists( $tableName, $fName ) ) {
3620 $sql = "DROP TABLE " . $this->tableName( $tableName );
3621 if( $this->cascadingDeletes() ) {
3624 return $this->query( $sql, $fName );
3628 * Get search engine class. All subclasses of this need to implement this
3629 * if they wish to use searching.
3633 public function getSearchEngine() {
3634 return 'SearchEngineDummy';
3638 * Find out when 'infinity' is. Most DBMSes support this. This is a special
3639 * keyword for timestamps in PostgreSQL, and works with CHAR(14) as well
3640 * because "i" sorts after all numbers.
3644 public function getInfinity() {
3649 * Encode an expiry time into the DBMS dependent format
3651 * @param $expiry String: timestamp for expiry, or the 'infinity' string
3654 public function encodeExpiry( $expiry ) {
3655 return ( $expiry == '' ||
$expiry == 'infinity' ||
$expiry == $this->getInfinity() )
3656 ?
$this->getInfinity()
3657 : $this->timestamp( $expiry );
3661 * Decode an expiry time into a DBMS independent format
3663 * @param $expiry String: DB timestamp field value for expiry
3664 * @param $format integer: TS_* constant, defaults to TS_MW
3667 public function decodeExpiry( $expiry, $format = TS_MW
) {
3668 return ( $expiry == '' ||
$expiry == $this->getInfinity() )
3670 : wfTimestamp( $format, $expiry );
3674 * Allow or deny "big selects" for this session only. This is done by setting
3675 * the sql_big_selects session variable.
3677 * This is a MySQL-specific feature.
3679 * @param $value Mixed: true for allow, false for deny, or "default" to
3680 * restore the initial value
3682 public function setBigSelects( $value = true ) {
3689 public function __toString() {
3690 return (string)$this->mConn
;
3693 public function __destruct() {
3694 if ( count( $this->mTrxIdleCallbacks
) ) { // sanity
3695 trigger_error( "Transaction idle callbacks still pending." );