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;
231 protected $mConn = null;
232 protected $mOpened = false;
234 protected $mTablePrefix;
236 protected $mTrxLevel = 0;
237 protected $mErrorCount = 0;
238 protected $mLBInfo = array();
239 protected $mFakeSlaveLag = null, $mFakeMaster = false;
240 protected $mDefaultBigSelects = null;
241 protected $mSchemaVars = false;
243 protected $preparedArgs;
245 protected $htmlErrors;
247 protected $delimiter = ';';
249 # ------------------------------------------------------------------------------
251 # ------------------------------------------------------------------------------
252 # These optionally set a variable and return the previous state
255 * A string describing the current software version, and possibly
256 * other details in a user-friendly way. Will be listed on Special:Version, etc.
257 * Use getServerVersion() to get machine-friendly information.
259 * @return string: Version information from the database server
261 public function getServerInfo() {
262 return $this->getServerVersion();
266 * Boolean, controls output of large amounts of debug information.
267 * @param $debug bool|null
268 * - true to enable debugging
269 * - false to disable debugging
270 * - omitted or null to do nothing
272 * @return bool|null previous value of the flag
274 public function debug( $debug = null ) {
275 return wfSetBit( $this->mFlags
, DBO_DEBUG
, $debug );
279 * Turns buffering of SQL result sets on (true) or off (false). Default is
282 * Unbuffered queries are very troublesome in MySQL:
284 * - If another query is executed while the first query is being read
285 * out, the first query is killed. This means you can't call normal
286 * MediaWiki functions while you are reading an unbuffered query result
287 * from a normal wfGetDB() connection.
289 * - Unbuffered queries cause the MySQL server to use large amounts of
290 * memory and to hold broad locks which block other queries.
292 * If you want to limit client-side memory, it's almost always better to
293 * split up queries into batches using a LIMIT clause than to switch off
296 * @param $buffer null|bool
298 * @return null|bool The previous value of the flag
300 public function bufferResults( $buffer = null ) {
301 if ( is_null( $buffer ) ) {
302 return !(bool)( $this->mFlags
& DBO_NOBUFFER
);
304 return !wfSetBit( $this->mFlags
, DBO_NOBUFFER
, !$buffer );
309 * Turns on (false) or off (true) the automatic generation and sending
310 * of a "we're sorry, but there has been a database error" page on
311 * database errors. Default is on (false). When turned off, the
312 * code should use lastErrno() and lastError() to handle the
313 * situation as appropriate.
315 * @param $ignoreErrors bool|null
317 * @return bool The previous value of the flag.
319 public function ignoreErrors( $ignoreErrors = null ) {
320 return wfSetBit( $this->mFlags
, DBO_IGNORE
, $ignoreErrors );
324 * Gets or sets the current transaction level.
326 * Historically, transactions were allowed to be "nested". This is no
327 * longer supported, so this function really only returns a boolean.
329 * @param $level int An integer (0 or 1), or omitted to leave it unchanged.
330 * @return int The previous value
332 public function trxLevel( $level = null ) {
333 return wfSetVar( $this->mTrxLevel
, $level );
337 * Get/set the number of errors logged. Only useful when errors are ignored
338 * @param $count int The count to set, or omitted to leave it unchanged.
339 * @return int The error count
341 public function errorCount( $count = null ) {
342 return wfSetVar( $this->mErrorCount
, $count );
346 * Get/set the table prefix.
347 * @param $prefix string The table prefix to set, or omitted to leave it unchanged.
348 * @return string The previous table prefix.
350 public function tablePrefix( $prefix = null ) {
351 return wfSetVar( $this->mTablePrefix
, $prefix );
355 * Get properties passed down from the server info array of the load
358 * @param $name string The entry of the info array to get, or null to get the
361 * @return LoadBalancer|null
363 public function getLBInfo( $name = null ) {
364 if ( is_null( $name ) ) {
365 return $this->mLBInfo
;
367 if ( array_key_exists( $name, $this->mLBInfo
) ) {
368 return $this->mLBInfo
[$name];
376 * Set the LB info array, or a member of it. If called with one parameter,
377 * the LB info array is set to that parameter. If it is called with two
378 * parameters, the member with the given name is set to the given value.
383 public function setLBInfo( $name, $value = null ) {
384 if ( is_null( $value ) ) {
385 $this->mLBInfo
= $name;
387 $this->mLBInfo
[$name] = $value;
392 * Set lag time in seconds for a fake slave
396 public function setFakeSlaveLag( $lag ) {
397 $this->mFakeSlaveLag
= $lag;
401 * Make this connection a fake master
403 * @param $enabled bool
405 public function setFakeMaster( $enabled = true ) {
406 $this->mFakeMaster
= $enabled;
410 * Returns true if this database supports (and uses) cascading deletes
414 public function cascadingDeletes() {
419 * Returns true if this database supports (and uses) triggers (e.g. on the page table)
423 public function cleanupTriggers() {
428 * Returns true if this database is strict about what can be put into an IP field.
429 * Specifically, it uses a NULL value instead of an empty string.
433 public function strictIPs() {
438 * Returns true if this database uses timestamps rather than integers
442 public function realTimestamps() {
447 * Returns true if this database does an implicit sort when doing GROUP BY
451 public function implicitGroupby() {
456 * Returns true if this database does an implicit order by when the column has an index
457 * For example: SELECT page_title FROM page LIMIT 1
461 public function implicitOrderby() {
466 * Returns true if this database can do a native search on IP columns
467 * e.g. this works as expected: .. WHERE rc_ip = '127.42.12.102/32';
471 public function searchableIPs() {
476 * Returns true if this database can use functional indexes
480 public function functionalIndexes() {
485 * Return the last query that went through DatabaseBase::query()
488 public function lastQuery() {
489 return $this->mLastQuery
;
493 * Returns true if the connection may have been used for write queries.
494 * Should return true if unsure.
498 public function doneWrites() {
499 return $this->mDoneWrites
;
503 * Is a connection to the database open?
506 public function isOpen() {
507 return $this->mOpened
;
511 * Set a flag for this connection
513 * @param $flag Integer: DBO_* constants from Defines.php:
514 * - DBO_DEBUG: output some debug info (same as debug())
515 * - DBO_NOBUFFER: don't buffer results (inverse of bufferResults())
516 * - DBO_IGNORE: ignore errors (same as ignoreErrors())
517 * - DBO_TRX: automatically start transactions
518 * - DBO_DEFAULT: automatically sets DBO_TRX if not in command line mode
519 * and removes it in command line mode
520 * - DBO_PERSISTENT: use persistant database connection
522 public function setFlag( $flag ) {
523 global $wgDebugDBTransactions;
524 $this->mFlags |
= $flag;
525 if ( ( $flag & DBO_TRX
) & $wgDebugDBTransactions ) {
526 wfDebug("Implicit transactions are now disabled.\n");
531 * Clear a flag for this connection
533 * @param $flag: same as setFlag()'s $flag param
535 public function clearFlag( $flag ) {
536 global $wgDebugDBTransactions;
537 $this->mFlags
&= ~
$flag;
538 if ( ( $flag & DBO_TRX
) && $wgDebugDBTransactions ) {
539 wfDebug("Implicit transactions are now disabled.\n");
544 * Returns a boolean whether the flag $flag is set for this connection
546 * @param $flag: same as setFlag()'s $flag param
549 public function getFlag( $flag ) {
550 return !!( $this->mFlags
& $flag );
554 * General read-only accessor
556 * @param $name string
560 public function getProperty( $name ) {
567 public function getWikiID() {
568 if ( $this->mTablePrefix
) {
569 return "{$this->mDBname}-{$this->mTablePrefix}";
571 return $this->mDBname
;
576 * Return a path to the DBMS-specific schema file, otherwise default to tables.sql
580 public function getSchemaPath() {
582 if ( file_exists( "$IP/maintenance/" . $this->getType() . "/tables.sql" ) ) {
583 return "$IP/maintenance/" . $this->getType() . "/tables.sql";
585 return "$IP/maintenance/tables.sql";
589 # ------------------------------------------------------------------------------
591 # ------------------------------------------------------------------------------
595 * @param $server String: database server host
596 * @param $user String: database user name
597 * @param $password String: database user password
598 * @param $dbName String: database name
600 * @param $tablePrefix String: database table prefixes. By default use the prefix gave in LocalSettings.php
602 function __construct( $server = false, $user = false, $password = false, $dbName = false,
603 $flags = 0, $tablePrefix = 'get from global'
605 global $wgDBprefix, $wgCommandLineMode, $wgDebugDBTransactions;
607 $this->mFlags
= $flags;
609 if ( $this->mFlags
& DBO_DEFAULT
) {
610 if ( $wgCommandLineMode ) {
611 $this->mFlags
&= ~DBO_TRX
;
612 if ( $wgDebugDBTransactions ) {
613 wfDebug("Implicit transaction open disabled.\n");
616 $this->mFlags |
= DBO_TRX
;
617 if ( $wgDebugDBTransactions ) {
618 wfDebug("Implicit transaction open enabled.\n");
623 /** Get the default table prefix*/
624 if ( $tablePrefix == 'get from global' ) {
625 $this->mTablePrefix
= $wgDBprefix;
627 $this->mTablePrefix
= $tablePrefix;
631 $this->open( $server, $user, $password, $dbName );
636 * Called by serialize. Throw an exception when DB connection is serialized.
637 * This causes problems on some database engines because the connection is
638 * not restored on unserialize.
640 public function __sleep() {
641 throw new MWException( 'Database serialization may cause problems, since the connection is not restored on wakeup.' );
645 * Given a DB type, construct the name of the appropriate child class of
646 * DatabaseBase. This is designed to replace all of the manual stuff like:
647 * $class = 'Database' . ucfirst( strtolower( $type ) );
648 * as well as validate against the canonical list of DB types we have
650 * This factory function is mostly useful for when you need to connect to a
651 * database other than the MediaWiki default (such as for external auth,
652 * an extension, et cetera). Do not use this to connect to the MediaWiki
653 * database. Example uses in core:
654 * @see LoadBalancer::reallyOpenConnection()
655 * @see ExternalUser_MediaWiki::initFromCond()
656 * @see ForeignDBRepo::getMasterDB()
657 * @see WebInstaller_DBConnect::execute()
661 * @param $dbType String A possible DB type
662 * @param $p Array An array of options to pass to the constructor.
663 * Valid options are: host, user, password, dbname, flags, tablePrefix
664 * @return DatabaseBase subclass or null
666 public final static function factory( $dbType, $p = array() ) {
667 $canonicalDBTypes = array(
668 'mysql', 'postgres', 'sqlite', 'oracle', 'mssql', 'ibm_db2'
670 $dbType = strtolower( $dbType );
671 $class = 'Database' . ucfirst( $dbType );
673 if( in_array( $dbType, $canonicalDBTypes ) ||
( class_exists( $class ) && is_subclass_of( $class, 'DatabaseBase' ) ) ) {
675 isset( $p['host'] ) ?
$p['host'] : false,
676 isset( $p['user'] ) ?
$p['user'] : false,
677 isset( $p['password'] ) ?
$p['password'] : false,
678 isset( $p['dbname'] ) ?
$p['dbname'] : false,
679 isset( $p['flags'] ) ?
$p['flags'] : 0,
680 isset( $p['tablePrefix'] ) ?
$p['tablePrefix'] : 'get from global'
687 protected function installErrorHandler() {
688 $this->mPHPError
= false;
689 $this->htmlErrors
= ini_set( 'html_errors', '0' );
690 set_error_handler( array( $this, 'connectionErrorHandler' ) );
694 * @return bool|string
696 protected function restoreErrorHandler() {
697 restore_error_handler();
698 if ( $this->htmlErrors
!== false ) {
699 ini_set( 'html_errors', $this->htmlErrors
);
701 if ( $this->mPHPError
) {
702 $error = preg_replace( '!\[<a.*</a>\]!', '', $this->mPHPError
);
703 $error = preg_replace( '!^.*?:\s?(.*)$!', '$1', $error );
714 protected function connectionErrorHandler( $errno, $errstr ) {
715 $this->mPHPError
= $errstr;
719 * Closes a database connection.
720 * if it is open : commits any open transactions
722 * @return Bool operation success. true if already closed.
724 public function close() {
725 $this->mOpened
= false;
726 if ( $this->mConn
) {
727 if ( $this->trxLevel() ) {
728 $this->commit( __METHOD__
);
730 $ret = $this->closeConnection();
731 $this->mConn
= false;
739 * Closes underlying database connection
741 * @return bool: Whether connection was closed successfully
743 protected abstract function closeConnection();
746 * @param $error String: fallback error message, used if none is given by DB
748 function reportConnectionError( $error = 'Unknown error' ) {
749 $myError = $this->lastError();
755 throw new DBConnectionError( $this, $error );
759 * The DBMS-dependent part of query()
761 * @param $sql String: SQL query.
762 * @return ResultWrapper Result object to feed to fetchObject, fetchRow, ...; or false on failure
764 protected abstract function doQuery( $sql );
767 * Determine whether a query writes to the DB.
768 * Should return true if unsure.
774 public function isWriteQuery( $sql ) {
775 return !preg_match( '/^(?:SELECT|BEGIN|ROLLBACK|COMMIT|SET|SHOW|EXPLAIN|\(SELECT)\b/i', $sql );
779 * Run an SQL query and return the result. Normally throws a DBQueryError
780 * on failure. If errors are ignored, returns false instead.
782 * In new code, the query wrappers select(), insert(), update(), delete(),
783 * etc. should be used where possible, since they give much better DBMS
784 * independence and automatically quote or validate user input in a variety
785 * of contexts. This function is generally only useful for queries which are
786 * explicitly DBMS-dependent and are unsupported by the query wrappers, such
789 * However, the query wrappers themselves should call this function.
791 * @param $sql String: SQL query
792 * @param $fname String: Name of the calling function, for profiling/SHOW PROCESSLIST
793 * comment (you can use __METHOD__ or add some extra info)
794 * @param $tempIgnore Boolean: Whether to avoid throwing an exception on errors...
795 * maybe best to catch the exception instead?
796 * @return boolean|ResultWrapper. true for a successful write query, ResultWrapper object
797 * for a successful read query, or false on failure if $tempIgnore set
798 * @throws DBQueryError Thrown when the database returns an error of any kind
800 public function query( $sql, $fname = '', $tempIgnore = false ) {
801 $isMaster = !is_null( $this->getLBInfo( 'master' ) );
802 if ( !Profiler
::instance()->isStub() ) {
803 # generalizeSQL will probably cut down the query to reasonable
804 # logging size most of the time. The substr is really just a sanity check.
807 $queryProf = 'query-m: ' . substr( DatabaseBase
::generalizeSQL( $sql ), 0, 255 );
808 $totalProf = 'DatabaseBase::query-master';
810 $queryProf = 'query: ' . substr( DatabaseBase
::generalizeSQL( $sql ), 0, 255 );
811 $totalProf = 'DatabaseBase::query';
814 wfProfileIn( $totalProf );
815 wfProfileIn( $queryProf );
818 $this->mLastQuery
= $sql;
819 if ( !$this->mDoneWrites
&& $this->isWriteQuery( $sql ) ) {
820 # Set a flag indicating that writes have been done
821 wfDebug( __METHOD__
. ": Writes done: $sql\n" );
822 $this->mDoneWrites
= true;
825 # Add a comment for easy SHOW PROCESSLIST interpretation
827 if ( is_object( $wgUser ) && $wgUser->isItemLoaded( 'name' ) ) {
828 $userName = $wgUser->getName();
829 if ( mb_strlen( $userName ) > 15 ) {
830 $userName = mb_substr( $userName, 0, 15 ) . '...';
832 $userName = str_replace( '/', '', $userName );
836 $commentedSql = preg_replace( '/\s/', " /* $fname $userName */ ", $sql, 1 );
838 # If DBO_TRX is set, start a transaction
839 if ( ( $this->mFlags
& DBO_TRX
) && !$this->trxLevel() &&
840 $sql != 'BEGIN' && $sql != 'COMMIT' && $sql != 'ROLLBACK' ) {
841 # avoid establishing transactions for SHOW and SET statements too -
842 # that would delay transaction initializations to once connection
843 # is really used by application
844 $sqlstart = substr( $sql, 0, 10 ); // very much worth it, benchmark certified(tm)
845 if ( strpos( $sqlstart, "SHOW " ) !== 0 && strpos( $sqlstart, "SET " ) !== 0 ) {
846 global $wgDebugDBTransactions;
847 if ( $wgDebugDBTransactions ) {
848 wfDebug("Implicit transaction start.\n");
850 $this->begin( __METHOD__
. " ($fname)" );
854 if ( $this->debug() ) {
858 $sqlx = substr( $commentedSql, 0, 500 );
859 $sqlx = strtr( $sqlx, "\t\n", ' ' );
861 $master = $isMaster ?
'master' : 'slave';
862 wfDebug( "Query {$this->mDBname} ($cnt) ($master): $sqlx\n" );
865 if ( istainted( $sql ) & TC_MYSQL
) {
866 throw new MWException( 'Tainted query found' );
869 $queryId = MWDebug
::query( $sql, $fname, $isMaster );
871 # Do the query and handle errors
872 $ret = $this->doQuery( $commentedSql );
874 MWDebug
::queryTime( $queryId );
876 # Try reconnecting if the connection was lost
877 if ( false === $ret && $this->wasErrorReissuable() ) {
878 # Transaction is gone, like it or not
879 $this->mTrxLevel
= 0;
880 wfDebug( "Connection lost, reconnecting...\n" );
882 if ( $this->ping() ) {
883 wfDebug( "Reconnected\n" );
884 $sqlx = substr( $commentedSql, 0, 500 );
885 $sqlx = strtr( $sqlx, "\t\n", ' ' );
886 global $wgRequestTime;
887 $elapsed = round( microtime( true ) - $wgRequestTime, 3 );
888 if ( $elapsed < 300 ) {
889 # Not a database error to lose a transaction after a minute or two
890 wfLogDBError( "Connection lost and reconnected after {$elapsed}s, query: $sqlx\n" );
892 $ret = $this->doQuery( $commentedSql );
894 wfDebug( "Failed\n" );
898 if ( false === $ret ) {
899 $this->reportQueryError( $this->lastError(), $this->lastErrno(), $sql, $fname, $tempIgnore );
902 if ( !Profiler
::instance()->isStub() ) {
903 wfProfileOut( $queryProf );
904 wfProfileOut( $totalProf );
907 return $this->resultObject( $ret );
911 * Report a query error. Log the error, and if neither the object ignore
912 * flag nor the $tempIgnore flag is set, throw a DBQueryError.
914 * @param $error String
915 * @param $errno Integer
917 * @param $fname String
918 * @param $tempIgnore Boolean
920 public function reportQueryError( $error, $errno, $sql, $fname, $tempIgnore = false ) {
921 # Ignore errors during error handling to avoid infinite recursion
922 $ignore = $this->ignoreErrors( true );
923 ++
$this->mErrorCount
;
925 if ( $ignore ||
$tempIgnore ) {
926 wfDebug( "SQL ERROR (ignored): $error\n" );
927 $this->ignoreErrors( $ignore );
929 $sql1line = str_replace( "\n", "\\n", $sql );
930 wfLogDBError( "$fname\t{$this->mServer}\t$errno\t$error\t$sql1line\n" );
931 wfDebug( "SQL ERROR: " . $error . "\n" );
932 throw new DBQueryError( $this, $error, $errno, $sql, $fname );
937 * Intended to be compatible with the PEAR::DB wrapper functions.
938 * http://pear.php.net/manual/en/package.database.db.intro-execute.php
940 * ? = scalar value, quoted as necessary
941 * ! = raw SQL bit (a function for instance)
942 * & = filename; reads the file and inserts as a blob
943 * (we don't use this though...)
946 * @param $func string
950 protected function prepare( $sql, $func = 'DatabaseBase::prepare' ) {
951 /* MySQL doesn't support prepared statements (yet), so just
952 pack up the query for reference. We'll manually replace
954 return array( 'query' => $sql, 'func' => $func );
958 * Free a prepared query, generated by prepare().
961 protected function freePrepared( $prepared ) {
962 /* No-op by default */
966 * Execute a prepared query with the various arguments
967 * @param $prepared String: the prepared sql
968 * @param $args Mixed: Either an array here, or put scalars as varargs
970 * @return ResultWrapper
972 public function execute( $prepared, $args = null ) {
973 if ( !is_array( $args ) ) {
975 $args = func_get_args();
976 array_shift( $args );
979 $sql = $this->fillPrepared( $prepared['query'], $args );
981 return $this->query( $sql, $prepared['func'] );
985 * For faking prepared SQL statements on DBs that don't support it directly.
987 * @param $preparedQuery String: a 'preparable' SQL statement
988 * @param $args Array of arguments to fill it with
989 * @return string executable SQL
991 public function fillPrepared( $preparedQuery, $args ) {
993 $this->preparedArgs
=& $args;
995 return preg_replace_callback( '/(\\\\[?!&]|[?!&])/',
996 array( &$this, 'fillPreparedArg' ), $preparedQuery );
1000 * preg_callback func for fillPrepared()
1001 * The arguments should be in $this->preparedArgs and must not be touched
1002 * while we're doing this.
1004 * @param $matches Array
1007 protected function fillPreparedArg( $matches ) {
1008 switch( $matches[1] ) {
1009 case '\\?': return '?';
1010 case '\\!': return '!';
1011 case '\\&': return '&';
1014 list( /* $n */ , $arg ) = each( $this->preparedArgs
);
1016 switch( $matches[1] ) {
1017 case '?': return $this->addQuotes( $arg );
1018 case '!': return $arg;
1020 # return $this->addQuotes( file_get_contents( $arg ) );
1021 throw new DBUnexpectedError( $this, '& mode is not implemented. If it\'s really needed, uncomment the line above.' );
1023 throw new DBUnexpectedError( $this, 'Received invalid match. This should never happen!' );
1028 * Free a result object returned by query() or select(). It's usually not
1029 * necessary to call this, just use unset() or let the variable holding
1030 * the result object go out of scope.
1032 * @param $res Mixed: A SQL result
1034 public function freeResult( $res ) {}
1037 * A SELECT wrapper which returns a single field from a single result row.
1039 * Usually throws a DBQueryError on failure. If errors are explicitly
1040 * ignored, returns false on failure.
1042 * If no result rows are returned from the query, false is returned.
1044 * @param $table string|array Table name. See DatabaseBase::select() for details.
1045 * @param $var string The field name to select. This must be a valid SQL
1046 * fragment: do not use unvalidated user input.
1047 * @param $cond string|array The condition array. See DatabaseBase::select() for details.
1048 * @param $fname string The function name of the caller.
1049 * @param $options string|array The query options. See DatabaseBase::select() for details.
1051 * @return bool|mixed The value from the field, or false on failure.
1053 public function selectField( $table, $var, $cond = '', $fname = 'DatabaseBase::selectField',
1054 $options = array() )
1056 if ( !is_array( $options ) ) {
1057 $options = array( $options );
1060 $options['LIMIT'] = 1;
1062 $res = $this->select( $table, $var, $cond, $fname, $options );
1064 if ( $res === false ||
!$this->numRows( $res ) ) {
1068 $row = $this->fetchRow( $res );
1070 if ( $row !== false ) {
1071 return reset( $row );
1078 * Returns an optional USE INDEX clause to go after the table, and a
1079 * string to go at the end of the query.
1081 * @param $options Array: associative array of options to be turned into
1082 * an SQL query, valid keys are listed in the function.
1084 * @see DatabaseBase::select()
1086 public function makeSelectOptions( $options ) {
1087 $preLimitTail = $postLimitTail = '';
1090 $noKeyOptions = array();
1092 foreach ( $options as $key => $option ) {
1093 if ( is_numeric( $key ) ) {
1094 $noKeyOptions[$option] = true;
1098 if ( isset( $options['GROUP BY'] ) ) {
1099 $gb = is_array( $options['GROUP BY'] )
1100 ?
implode( ',', $options['GROUP BY'] )
1101 : $options['GROUP BY'];
1102 $preLimitTail .= " GROUP BY {$gb}";
1105 if ( isset( $options['HAVING'] ) ) {
1106 $preLimitTail .= " HAVING {$options['HAVING']}";
1109 if ( isset( $options['ORDER BY'] ) ) {
1110 $ob = is_array( $options['ORDER BY'] )
1111 ?
implode( ',', $options['ORDER BY'] )
1112 : $options['ORDER BY'];
1113 $preLimitTail .= " ORDER BY {$ob}";
1116 // if (isset($options['LIMIT'])) {
1117 // $tailOpts .= $this->limitResult('', $options['LIMIT'],
1118 // isset($options['OFFSET']) ? $options['OFFSET']
1122 if ( isset( $noKeyOptions['FOR UPDATE'] ) ) {
1123 $postLimitTail .= ' FOR UPDATE';
1126 if ( isset( $noKeyOptions['LOCK IN SHARE MODE'] ) ) {
1127 $postLimitTail .= ' LOCK IN SHARE MODE';
1130 if ( isset( $noKeyOptions['DISTINCT'] ) ||
isset( $noKeyOptions['DISTINCTROW'] ) ) {
1131 $startOpts .= 'DISTINCT';
1134 # Various MySQL extensions
1135 if ( isset( $noKeyOptions['STRAIGHT_JOIN'] ) ) {
1136 $startOpts .= ' /*! STRAIGHT_JOIN */';
1139 if ( isset( $noKeyOptions['HIGH_PRIORITY'] ) ) {
1140 $startOpts .= ' HIGH_PRIORITY';
1143 if ( isset( $noKeyOptions['SQL_BIG_RESULT'] ) ) {
1144 $startOpts .= ' SQL_BIG_RESULT';
1147 if ( isset( $noKeyOptions['SQL_BUFFER_RESULT'] ) ) {
1148 $startOpts .= ' SQL_BUFFER_RESULT';
1151 if ( isset( $noKeyOptions['SQL_SMALL_RESULT'] ) ) {
1152 $startOpts .= ' SQL_SMALL_RESULT';
1155 if ( isset( $noKeyOptions['SQL_CALC_FOUND_ROWS'] ) ) {
1156 $startOpts .= ' SQL_CALC_FOUND_ROWS';
1159 if ( isset( $noKeyOptions['SQL_CACHE'] ) ) {
1160 $startOpts .= ' SQL_CACHE';
1163 if ( isset( $noKeyOptions['SQL_NO_CACHE'] ) ) {
1164 $startOpts .= ' SQL_NO_CACHE';
1167 if ( isset( $options['USE INDEX'] ) && ! is_array( $options['USE INDEX'] ) ) {
1168 $useIndex = $this->useIndexClause( $options['USE INDEX'] );
1173 return array( $startOpts, $useIndex, $preLimitTail, $postLimitTail );
1177 * Execute a SELECT query constructed using the various parameters provided.
1178 * See below for full details of the parameters.
1180 * @param $table String|Array Table name
1181 * @param $vars String|Array Field names
1182 * @param $conds String|Array Conditions
1183 * @param $fname String Caller function name
1184 * @param $options Array Query options
1185 * @param $join_conds Array Join conditions
1187 * @param $table string|array
1189 * May be either an array of table names, or a single string holding a table
1190 * name. If an array is given, table aliases can be specified, for example:
1192 * array( 'a' => 'user' )
1194 * This includes the user table in the query, with the alias "a" available
1195 * for use in field names (e.g. a.user_name).
1197 * All of the table names given here are automatically run through
1198 * DatabaseBase::tableName(), which causes the table prefix (if any) to be
1199 * added, and various other table name mappings to be performed.
1202 * @param $vars string|array
1204 * May be either a field name or an array of field names. The field names
1205 * can be complete fragments of SQL, for direct inclusion into the SELECT
1206 * query. If an array is given, field aliases can be specified, for example:
1208 * array( 'maxrev' => 'MAX(rev_id)' )
1210 * This includes an expression with the alias "maxrev" in the query.
1212 * If an expression is given, care must be taken to ensure that it is
1216 * @param $conds string|array
1218 * May be either a string containing a single condition, or an array of
1219 * conditions. If an array is given, the conditions constructed from each
1220 * element are combined with AND.
1222 * Array elements may take one of two forms:
1224 * - Elements with a numeric key are interpreted as raw SQL fragments.
1225 * - Elements with a string key are interpreted as equality conditions,
1226 * where the key is the field name.
1227 * - If the value of such an array element is a scalar (such as a
1228 * string), it will be treated as data and thus quoted appropriately.
1229 * If it is null, an IS NULL clause will be added.
1230 * - If the value is an array, an IN(...) clause will be constructed,
1231 * such that the field name may match any of the elements in the
1232 * array. The elements of the array will be quoted.
1234 * Note that expressions are often DBMS-dependent in their syntax.
1235 * DBMS-independent wrappers are provided for constructing several types of
1236 * expression commonly used in condition queries. See:
1237 * - DatabaseBase::buildLike()
1238 * - DatabaseBase::conditional()
1241 * @param $options string|array
1243 * Optional: Array of query options. Boolean options are specified by
1244 * including them in the array as a string value with a numeric key, for
1247 * array( 'FOR UPDATE' )
1249 * The supported options are:
1251 * - OFFSET: Skip this many rows at the start of the result set. OFFSET
1252 * with LIMIT can theoretically be used for paging through a result set,
1253 * but this is discouraged in MediaWiki for performance reasons.
1255 * - LIMIT: Integer: return at most this many rows. The rows are sorted
1256 * and then the first rows are taken until the limit is reached. LIMIT
1257 * is applied to a result set after OFFSET.
1259 * - FOR UPDATE: Boolean: lock the returned rows so that they can't be
1260 * changed until the next COMMIT.
1262 * - DISTINCT: Boolean: return only unique result rows.
1264 * - GROUP BY: May be either an SQL fragment string naming a field or
1265 * expression to group by, or an array of such SQL fragments.
1267 * - HAVING: A string containing a HAVING clause.
1269 * - ORDER BY: May be either an SQL fragment giving a field name or
1270 * expression to order by, or an array of such SQL fragments.
1272 * - USE INDEX: This may be either a string giving the index name to use
1273 * for the query, or an array. If it is an associative array, each key
1274 * gives the table name (or alias), each value gives the index name to
1275 * use for that table. All strings are SQL fragments and so should be
1276 * validated by the caller.
1278 * - EXPLAIN: In MySQL, this causes an EXPLAIN SELECT query to be run,
1279 * instead of SELECT.
1281 * And also the following boolean MySQL extensions, see the MySQL manual
1282 * for documentation:
1284 * - LOCK IN SHARE MODE
1288 * - SQL_BUFFER_RESULT
1289 * - SQL_SMALL_RESULT
1290 * - SQL_CALC_FOUND_ROWS
1295 * @param $join_conds string|array
1297 * Optional associative array of table-specific join conditions. In the
1298 * most common case, this is unnecessary, since the join condition can be
1299 * in $conds. However, it is useful for doing a LEFT JOIN.
1301 * The key of the array contains the table name or alias. The value is an
1302 * array with two elements, numbered 0 and 1. The first gives the type of
1303 * join, the second is an SQL fragment giving the join condition for that
1304 * table. For example:
1306 * array( 'page' => array('LEFT JOIN','page_latest=rev_id') )
1308 * @return ResultWrapper. If the query returned no rows, a ResultWrapper
1309 * with no rows in it will be returned. If there was a query error, a
1310 * DBQueryError exception will be thrown, except if the "ignore errors"
1311 * option was set, in which case false will be returned.
1313 public function select( $table, $vars, $conds = '', $fname = 'DatabaseBase::select',
1314 $options = array(), $join_conds = array() ) {
1315 $sql = $this->selectSQLText( $table, $vars, $conds, $fname, $options, $join_conds );
1317 return $this->query( $sql, $fname );
1321 * The equivalent of DatabaseBase::select() except that the constructed SQL
1322 * is returned, instead of being immediately executed. This can be useful for
1323 * doing UNION queries, where the SQL text of each query is needed. In general,
1324 * however, callers outside of Database classes should just use select().
1326 * @param $table string|array Table name
1327 * @param $vars string|array Field names
1328 * @param $conds string|array Conditions
1329 * @param $fname string Caller function name
1330 * @param $options string|array Query options
1331 * @param $join_conds string|array Join conditions
1333 * @return string SQL query string.
1334 * @see DatabaseBase::select()
1336 public function selectSQLText( $table, $vars, $conds = '', $fname = 'DatabaseBase::select',
1337 $options = array(), $join_conds = array() )
1339 if ( is_array( $vars ) ) {
1340 $vars = implode( ',', $this->fieldNamesWithAlias( $vars ) );
1343 $options = (array)$options;
1345 if ( is_array( $table ) ) {
1346 $useIndex = ( isset( $options['USE INDEX'] ) && is_array( $options['USE INDEX'] ) )
1347 ?
$options['USE INDEX']
1349 if ( count( $join_conds ) ||
count( $useIndex ) ) {
1351 $this->tableNamesWithUseIndexOrJOIN( $table, $useIndex, $join_conds );
1353 $from = ' FROM ' . implode( ',', $this->tableNamesWithAlias( $table ) );
1355 } elseif ( $table != '' ) {
1356 if ( $table[0] == ' ' ) {
1357 $from = ' FROM ' . $table;
1359 $from = ' FROM ' . $this->tableName( $table );
1365 list( $startOpts, $useIndex, $preLimitTail, $postLimitTail ) = $this->makeSelectOptions( $options );
1367 if ( !empty( $conds ) ) {
1368 if ( is_array( $conds ) ) {
1369 $conds = $this->makeList( $conds, LIST_AND
);
1371 $sql = "SELECT $startOpts $vars $from $useIndex WHERE $conds $preLimitTail";
1373 $sql = "SELECT $startOpts $vars $from $useIndex $preLimitTail";
1376 if ( isset( $options['LIMIT'] ) ) {
1377 $sql = $this->limitResult( $sql, $options['LIMIT'],
1378 isset( $options['OFFSET'] ) ?
$options['OFFSET'] : false );
1380 $sql = "$sql $postLimitTail";
1382 if ( isset( $options['EXPLAIN'] ) ) {
1383 $sql = 'EXPLAIN ' . $sql;
1390 * Single row SELECT wrapper. Equivalent to DatabaseBase::select(), except
1391 * that a single row object is returned. If the query returns no rows,
1392 * false is returned.
1394 * @param $table string|array Table name
1395 * @param $vars string|array Field names
1396 * @param $conds array Conditions
1397 * @param $fname string Caller function name
1398 * @param $options string|array Query options
1399 * @param $join_conds array|string Join conditions
1401 * @return object|bool
1403 public function selectRow( $table, $vars, $conds, $fname = 'DatabaseBase::selectRow',
1404 $options = array(), $join_conds = array() )
1406 $options = (array)$options;
1407 $options['LIMIT'] = 1;
1408 $res = $this->select( $table, $vars, $conds, $fname, $options, $join_conds );
1410 if ( $res === false ) {
1414 if ( !$this->numRows( $res ) ) {
1418 $obj = $this->fetchObject( $res );
1424 * Estimate rows in dataset.
1426 * MySQL allows you to estimate the number of rows that would be returned
1427 * by a SELECT query, using EXPLAIN SELECT. The estimate is provided using
1428 * index cardinality statistics, and is notoriously inaccurate, especially
1429 * when large numbers of rows have recently been added or deleted.
1431 * For DBMSs that don't support fast result size estimation, this function
1432 * will actually perform the SELECT COUNT(*).
1434 * Takes the same arguments as DatabaseBase::select().
1436 * @param $table String: table name
1437 * @param Array|string $vars : unused
1438 * @param Array|string $conds : filters on the table
1439 * @param $fname String: function name for profiling
1440 * @param $options Array: options for select
1441 * @return Integer: row count
1443 public function estimateRowCount( $table, $vars = '*', $conds = '',
1444 $fname = 'DatabaseBase::estimateRowCount', $options = array() )
1447 $res = $this->select( $table, array( 'rowcount' => 'COUNT(*)' ), $conds, $fname, $options );
1450 $row = $this->fetchRow( $res );
1451 $rows = ( isset( $row['rowcount'] ) ) ?
$row['rowcount'] : 0;
1458 * Removes most variables from an SQL query and replaces them with X or N for numbers.
1459 * It's only slightly flawed. Don't use for anything important.
1461 * @param $sql String A SQL Query
1465 static function generalizeSQL( $sql ) {
1466 # This does the same as the regexp below would do, but in such a way
1467 # as to avoid crashing php on some large strings.
1468 # $sql = preg_replace ( "/'([^\\\\']|\\\\.)*'|\"([^\\\\\"]|\\\\.)*\"/", "'X'", $sql);
1470 $sql = str_replace ( "\\\\", '', $sql );
1471 $sql = str_replace ( "\\'", '', $sql );
1472 $sql = str_replace ( "\\\"", '', $sql );
1473 $sql = preg_replace ( "/'.*'/s", "'X'", $sql );
1474 $sql = preg_replace ( '/".*"/s', "'X'", $sql );
1476 # All newlines, tabs, etc replaced by single space
1477 $sql = preg_replace ( '/\s+/', ' ', $sql );
1480 $sql = preg_replace ( '/-?[0-9]+/s', 'N', $sql );
1486 * Determines whether a field exists in a table
1488 * @param $table String: table name
1489 * @param $field String: filed to check on that table
1490 * @param $fname String: calling function name (optional)
1491 * @return Boolean: whether $table has filed $field
1493 public function fieldExists( $table, $field, $fname = 'DatabaseBase::fieldExists' ) {
1494 $info = $this->fieldInfo( $table, $field );
1500 * Determines whether an index exists
1501 * Usually throws a DBQueryError on failure
1502 * If errors are explicitly ignored, returns NULL on failure
1506 * @param $fname string
1510 public function indexExists( $table, $index, $fname = 'DatabaseBase::indexExists' ) {
1511 $info = $this->indexInfo( $table, $index, $fname );
1512 if ( is_null( $info ) ) {
1515 return $info !== false;
1520 * Query whether a given table exists
1522 * @param $table string
1523 * @param $fname string
1527 public function tableExists( $table, $fname = __METHOD__
) {
1528 $table = $this->tableName( $table );
1529 $old = $this->ignoreErrors( true );
1530 $res = $this->query( "SELECT 1 FROM $table LIMIT 1", $fname );
1531 $this->ignoreErrors( $old );
1537 * mysql_field_type() wrapper
1542 public function fieldType( $res, $index ) {
1543 if ( $res instanceof ResultWrapper
) {
1544 $res = $res->result
;
1547 return mysql_field_type( $res, $index );
1551 * Determines if a given index is unique
1553 * @param $table string
1554 * @param $index string
1558 public function indexUnique( $table, $index ) {
1559 $indexInfo = $this->indexInfo( $table, $index );
1561 if ( !$indexInfo ) {
1565 return !$indexInfo[0]->Non_unique
;
1569 * Helper for DatabaseBase::insert().
1571 * @param $options array
1574 protected function makeInsertOptions( $options ) {
1575 return implode( ' ', $options );
1579 * INSERT wrapper, inserts an array into a table.
1583 * - A single associative array. The array keys are the field names, and
1584 * the values are the values to insert. The values are treated as data
1585 * and will be quoted appropriately. If NULL is inserted, this will be
1586 * converted to a database NULL.
1587 * - An array with numeric keys, holding a list of associative arrays.
1588 * This causes a multi-row INSERT on DBMSs that support it. The keys in
1589 * each subarray must be identical to each other, and in the same order.
1591 * Usually throws a DBQueryError on failure. If errors are explicitly ignored,
1594 * $options is an array of options, with boolean options encoded as values
1595 * with numeric keys, in the same style as $options in
1596 * DatabaseBase::select(). Supported options are:
1598 * - IGNORE: Boolean: if present, duplicate key errors are ignored, and
1599 * any rows which cause duplicate key errors are not inserted. It's
1600 * possible to determine how many rows were successfully inserted using
1601 * DatabaseBase::affectedRows().
1603 * @param $table String Table name. This will be passed through
1604 * DatabaseBase::tableName().
1605 * @param $a Array of rows to insert
1606 * @param $fname String Calling function name (use __METHOD__) for logs/profiling
1607 * @param $options Array of options
1611 public function insert( $table, $a, $fname = 'DatabaseBase::insert', $options = array() ) {
1612 # No rows to insert, easy just return now
1613 if ( !count( $a ) ) {
1617 $table = $this->tableName( $table );
1619 if ( !is_array( $options ) ) {
1620 $options = array( $options );
1623 $options = $this->makeInsertOptions( $options );
1625 if ( isset( $a[0] ) && is_array( $a[0] ) ) {
1627 $keys = array_keys( $a[0] );
1630 $keys = array_keys( $a );
1633 $sql = 'INSERT ' . $options .
1634 " INTO $table (" . implode( ',', $keys ) . ') VALUES ';
1638 foreach ( $a as $row ) {
1644 $sql .= '(' . $this->makeList( $row ) . ')';
1647 $sql .= '(' . $this->makeList( $a ) . ')';
1650 return (bool)$this->query( $sql, $fname );
1654 * Make UPDATE options for the DatabaseBase::update function
1656 * @param $options Array: The options passed to DatabaseBase::update
1659 protected function makeUpdateOptions( $options ) {
1660 if ( !is_array( $options ) ) {
1661 $options = array( $options );
1666 if ( in_array( 'LOW_PRIORITY', $options ) ) {
1667 $opts[] = $this->lowPriorityOption();
1670 if ( in_array( 'IGNORE', $options ) ) {
1674 return implode( ' ', $opts );
1678 * UPDATE wrapper. Takes a condition array and a SET array.
1680 * @param $table String name of the table to UPDATE. This will be passed through
1681 * DatabaseBase::tableName().
1683 * @param $values Array: An array of values to SET. For each array element,
1684 * the key gives the field name, and the value gives the data
1685 * to set that field to. The data will be quoted by
1686 * DatabaseBase::addQuotes().
1688 * @param $conds Array: An array of conditions (WHERE). See
1689 * DatabaseBase::select() for the details of the format of
1690 * condition arrays. Use '*' to update all rows.
1692 * @param $fname String: The function name of the caller (from __METHOD__),
1693 * for logging and profiling.
1695 * @param $options Array: An array of UPDATE options, can be:
1696 * - IGNORE: Ignore unique key conflicts
1697 * - LOW_PRIORITY: MySQL-specific, see MySQL manual.
1700 function update( $table, $values, $conds, $fname = 'DatabaseBase::update', $options = array() ) {
1701 $table = $this->tableName( $table );
1702 $opts = $this->makeUpdateOptions( $options );
1703 $sql = "UPDATE $opts $table SET " . $this->makeList( $values, LIST_SET
);
1705 if ( $conds !== array() && $conds !== '*' ) {
1706 $sql .= " WHERE " . $this->makeList( $conds, LIST_AND
);
1709 return $this->query( $sql, $fname );
1713 * Makes an encoded list of strings from an array
1714 * @param $a Array containing the data
1715 * @param $mode int Constant
1716 * - LIST_COMMA: comma separated, no field names
1717 * - LIST_AND: ANDed WHERE clause (without the WHERE). See
1718 * the documentation for $conds in DatabaseBase::select().
1719 * - LIST_OR: ORed WHERE clause (without the WHERE)
1720 * - LIST_SET: comma separated with field names, like a SET clause
1721 * - LIST_NAMES: comma separated field names
1725 public function makeList( $a, $mode = LIST_COMMA
) {
1726 if ( !is_array( $a ) ) {
1727 throw new DBUnexpectedError( $this, 'DatabaseBase::makeList called with incorrect parameters' );
1733 foreach ( $a as $field => $value ) {
1735 if ( $mode == LIST_AND
) {
1737 } elseif ( $mode == LIST_OR
) {
1746 if ( ( $mode == LIST_AND ||
$mode == LIST_OR
) && is_numeric( $field ) ) {
1747 $list .= "($value)";
1748 } elseif ( ( $mode == LIST_SET
) && is_numeric( $field ) ) {
1750 } elseif ( ( $mode == LIST_AND ||
$mode == LIST_OR
) && is_array( $value ) ) {
1751 if ( count( $value ) == 0 ) {
1752 throw new MWException( __METHOD__
. ': empty input' );
1753 } elseif ( count( $value ) == 1 ) {
1754 // Special-case single values, as IN isn't terribly efficient
1755 // Don't necessarily assume the single key is 0; we don't
1756 // enforce linear numeric ordering on other arrays here.
1757 $value = array_values( $value );
1758 $list .= $field . " = " . $this->addQuotes( $value[0] );
1760 $list .= $field . " IN (" . $this->makeList( $value ) . ") ";
1762 } elseif ( $value === null ) {
1763 if ( $mode == LIST_AND ||
$mode == LIST_OR
) {
1764 $list .= "$field IS ";
1765 } elseif ( $mode == LIST_SET
) {
1766 $list .= "$field = ";
1770 if ( $mode == LIST_AND ||
$mode == LIST_OR ||
$mode == LIST_SET
) {
1771 $list .= "$field = ";
1773 $list .= $mode == LIST_NAMES ?
$value : $this->addQuotes( $value );
1781 * Build a partial where clause from a 2-d array such as used for LinkBatch.
1782 * The keys on each level may be either integers or strings.
1784 * @param $data Array: organized as 2-d
1785 * array(baseKeyVal => array(subKeyVal => [ignored], ...), ...)
1786 * @param $baseKey String: field name to match the base-level keys to (eg 'pl_namespace')
1787 * @param $subKey String: field name to match the sub-level keys to (eg 'pl_title')
1788 * @return Mixed: string SQL fragment, or false if no items in array.
1790 public function makeWhereFrom2d( $data, $baseKey, $subKey ) {
1793 foreach ( $data as $base => $sub ) {
1794 if ( count( $sub ) ) {
1795 $conds[] = $this->makeList(
1796 array( $baseKey => $base, $subKey => array_keys( $sub ) ),
1802 return $this->makeList( $conds, LIST_OR
);
1804 // Nothing to search for...
1810 * Return aggregated value alias
1813 * @param $valuename string
1817 public function aggregateValue( $valuedata, $valuename = 'value' ) {
1825 public function bitNot( $field ) {
1831 * @param $fieldRight
1834 public function bitAnd( $fieldLeft, $fieldRight ) {
1835 return "($fieldLeft & $fieldRight)";
1840 * @param $fieldRight
1843 public function bitOr( $fieldLeft, $fieldRight ) {
1844 return "($fieldLeft | $fieldRight)";
1848 * Build a concatenation list to feed into a SQL query
1849 * @param $stringList Array: list of raw SQL expressions; caller is responsible for any quoting
1852 public function buildConcat( $stringList ) {
1853 return 'CONCAT(' . implode( ',', $stringList ) . ')';
1857 * Change the current database
1859 * @todo Explain what exactly will fail if this is not overridden.
1863 * @return bool Success or failure
1865 public function selectDB( $db ) {
1866 # Stub. Shouldn't cause serious problems if it's not overridden, but
1867 # if your database engine supports a concept similar to MySQL's
1868 # databases you may as well.
1869 $this->mDBname
= $db;
1874 * Get the current DB name
1876 public function getDBname() {
1877 return $this->mDBname
;
1881 * Get the server hostname or IP address
1883 public function getServer() {
1884 return $this->mServer
;
1888 * Format a table name ready for use in constructing an SQL query
1890 * This does two important things: it quotes the table names to clean them up,
1891 * and it adds a table prefix if only given a table name with no quotes.
1893 * All functions of this object which require a table name call this function
1894 * themselves. Pass the canonical name to such functions. This is only needed
1895 * when calling query() directly.
1897 * @param $name String: database table name
1898 * @param $format String One of:
1899 * quoted - Automatically pass the table name through addIdentifierQuotes()
1900 * so that it can be used in a query.
1901 * raw - Do not add identifier quotes to the table name
1902 * @return String: full database name
1904 public function tableName( $name, $format = 'quoted' ) {
1905 global $wgSharedDB, $wgSharedPrefix, $wgSharedTables;
1906 # Skip the entire process when we have a string quoted on both ends.
1907 # Note that we check the end so that we will still quote any use of
1908 # use of `database`.table. But won't break things if someone wants
1909 # to query a database table with a dot in the name.
1910 if ( $this->isQuotedIdentifier( $name ) ) {
1914 # Lets test for any bits of text that should never show up in a table
1915 # name. Basically anything like JOIN or ON which are actually part of
1916 # SQL queries, but may end up inside of the table value to combine
1917 # sql. Such as how the API is doing.
1918 # Note that we use a whitespace test rather than a \b test to avoid
1919 # any remote case where a word like on may be inside of a table name
1920 # surrounded by symbols which may be considered word breaks.
1921 if ( preg_match( '/(^|\s)(DISTINCT|JOIN|ON|AS)(\s|$)/i', $name ) !== 0 ) {
1925 # Split database and table into proper variables.
1926 # We reverse the explode so that database.table and table both output
1927 # the correct table.
1928 $dbDetails = array_reverse( explode( '.', $name, 2 ) );
1929 if ( isset( $dbDetails[1] ) ) {
1930 list( $table, $database ) = $dbDetails;
1932 list( $table ) = $dbDetails;
1934 $prefix = $this->mTablePrefix
; # Default prefix
1936 # A database name has been specified in input. We don't want any
1938 if ( isset( $database ) ) {
1942 # Note that we use the long format because php will complain in in_array if
1943 # the input is not an array, and will complain in is_array if it is not set.
1944 if ( !isset( $database ) # Don't use shared database if pre selected.
1945 && isset( $wgSharedDB ) # We have a shared database
1946 && !$this->isQuotedIdentifier( $table ) # Paranoia check to prevent shared tables listing '`table`'
1947 && isset( $wgSharedTables )
1948 && is_array( $wgSharedTables )
1949 && in_array( $table, $wgSharedTables ) ) { # A shared table is selected
1950 $database = $wgSharedDB;
1951 $prefix = isset( $wgSharedPrefix ) ?
$wgSharedPrefix : $prefix;
1954 # Quote the $database and $table and apply the prefix if not quoted.
1955 if ( isset( $database ) ) {
1956 if ( $format == 'quoted' && !$this->isQuotedIdentifier( $database ) ) {
1957 $database = $this->addIdentifierQuotes( $database );
1961 $table = "{$prefix}{$table}";
1962 if ( $format == 'quoted' && !$this->isQuotedIdentifier( $table ) ) {
1963 $table = $this->addIdentifierQuotes( "{$table}" );
1966 # Merge our database and table into our final table name.
1967 $tableName = ( isset( $database ) ?
"{$database}.{$table}" : "{$table}" );
1973 * Fetch a number of table names into an array
1974 * This is handy when you need to construct SQL for joins
1977 * extract($dbr->tableNames('user','watchlist'));
1978 * $sql = "SELECT wl_namespace,wl_title FROM $watchlist,$user
1979 * WHERE wl_user=user_id AND wl_user=$nameWithQuotes";
1983 public function tableNames() {
1984 $inArray = func_get_args();
1987 foreach ( $inArray as $name ) {
1988 $retVal[$name] = $this->tableName( $name );
1995 * Fetch a number of table names into an zero-indexed numerical array
1996 * This is handy when you need to construct SQL for joins
1999 * list( $user, $watchlist ) = $dbr->tableNamesN('user','watchlist');
2000 * $sql = "SELECT wl_namespace,wl_title FROM $watchlist,$user
2001 * WHERE wl_user=user_id AND wl_user=$nameWithQuotes";
2005 public function tableNamesN() {
2006 $inArray = func_get_args();
2009 foreach ( $inArray as $name ) {
2010 $retVal[] = $this->tableName( $name );
2017 * Get an aliased table name
2018 * e.g. tableName AS newTableName
2020 * @param $name string Table name, see tableName()
2021 * @param $alias string|bool Alias (optional)
2022 * @return string SQL name for aliased table. Will not alias a table to its own name
2024 public function tableNameWithAlias( $name, $alias = false ) {
2025 if ( !$alias ||
$alias == $name ) {
2026 return $this->tableName( $name );
2028 return $this->tableName( $name ) . ' ' . $this->addIdentifierQuotes( $alias );
2033 * Gets an array of aliased table names
2035 * @param $tables array( [alias] => table )
2036 * @return array of strings, see tableNameWithAlias()
2038 public function tableNamesWithAlias( $tables ) {
2040 foreach ( $tables as $alias => $table ) {
2041 if ( is_numeric( $alias ) ) {
2044 $retval[] = $this->tableNameWithAlias( $table, $alias );
2050 * Get an aliased field name
2051 * e.g. fieldName AS newFieldName
2053 * @param $name string Field name
2054 * @param $alias string|bool Alias (optional)
2055 * @return string SQL name for aliased field. Will not alias a field to its own name
2057 public function fieldNameWithAlias( $name, $alias = false ) {
2058 if ( !$alias ||
(string)$alias === (string)$name ) {
2061 return $name . ' AS ' . $alias; //PostgreSQL needs AS
2066 * Gets an array of aliased field names
2068 * @param $fields array( [alias] => field )
2069 * @return array of strings, see fieldNameWithAlias()
2071 public function fieldNamesWithAlias( $fields ) {
2073 foreach ( $fields as $alias => $field ) {
2074 if ( is_numeric( $alias ) ) {
2077 $retval[] = $this->fieldNameWithAlias( $field, $alias );
2083 * Get the aliased table name clause for a FROM clause
2084 * which might have a JOIN and/or USE INDEX clause
2086 * @param $tables array ( [alias] => table )
2087 * @param $use_index array Same as for select()
2088 * @param $join_conds array Same as for select()
2091 protected function tableNamesWithUseIndexOrJOIN(
2092 $tables, $use_index = array(), $join_conds = array()
2096 $use_index = (array)$use_index;
2097 $join_conds = (array)$join_conds;
2099 foreach ( $tables as $alias => $table ) {
2100 if ( !is_string( $alias ) ) {
2101 // No alias? Set it equal to the table name
2104 // Is there a JOIN clause for this table?
2105 if ( isset( $join_conds[$alias] ) ) {
2106 list( $joinType, $conds ) = $join_conds[$alias];
2107 $tableClause = $joinType;
2108 $tableClause .= ' ' . $this->tableNameWithAlias( $table, $alias );
2109 if ( isset( $use_index[$alias] ) ) { // has USE INDEX?
2110 $use = $this->useIndexClause( implode( ',', (array)$use_index[$alias] ) );
2112 $tableClause .= ' ' . $use;
2115 $on = $this->makeList( (array)$conds, LIST_AND
);
2117 $tableClause .= ' ON (' . $on . ')';
2120 $retJOIN[] = $tableClause;
2121 // Is there an INDEX clause for this table?
2122 } elseif ( isset( $use_index[$alias] ) ) {
2123 $tableClause = $this->tableNameWithAlias( $table, $alias );
2124 $tableClause .= ' ' . $this->useIndexClause(
2125 implode( ',', (array)$use_index[$alias] ) );
2127 $ret[] = $tableClause;
2129 $tableClause = $this->tableNameWithAlias( $table, $alias );
2131 $ret[] = $tableClause;
2135 // We can't separate explicit JOIN clauses with ',', use ' ' for those
2136 $straightJoins = !empty( $ret ) ?
implode( ',', $ret ) : "";
2137 $otherJoins = !empty( $retJOIN ) ?
implode( ' ', $retJOIN ) : "";
2139 // Compile our final table clause
2140 return implode( ' ', array( $straightJoins, $otherJoins ) );
2144 * Get the name of an index in a given table
2150 protected function indexName( $index ) {
2151 // Backwards-compatibility hack
2153 'ar_usertext_timestamp' => 'usertext_timestamp',
2154 'un_user_id' => 'user_id',
2155 'un_user_ip' => 'user_ip',
2158 if ( isset( $renamed[$index] ) ) {
2159 return $renamed[$index];
2166 * If it's a string, adds quotes and backslashes
2167 * Otherwise returns as-is
2173 public function addQuotes( $s ) {
2174 if ( $s === null ) {
2177 # This will also quote numeric values. This should be harmless,
2178 # and protects against weird problems that occur when they really
2179 # _are_ strings such as article titles and string->number->string
2180 # conversion is not 1:1.
2181 return "'" . $this->strencode( $s ) . "'";
2186 * Quotes an identifier using `backticks` or "double quotes" depending on the database type.
2187 * MySQL uses `backticks` while basically everything else uses double quotes.
2188 * Since MySQL is the odd one out here the double quotes are our generic
2189 * and we implement backticks in DatabaseMysql.
2195 public function addIdentifierQuotes( $s ) {
2196 return '"' . str_replace( '"', '""', $s ) . '"';
2200 * Returns if the given identifier looks quoted or not according to
2201 * the database convention for quoting identifiers .
2203 * @param $name string
2207 public function isQuotedIdentifier( $name ) {
2208 return $name[0] == '"' && substr( $name, -1, 1 ) == '"';
2215 protected function escapeLikeInternal( $s ) {
2216 $s = str_replace( '\\', '\\\\', $s );
2217 $s = $this->strencode( $s );
2218 $s = str_replace( array( '%', '_' ), array( '\%', '\_' ), $s );
2224 * LIKE statement wrapper, receives a variable-length argument list with parts of pattern to match
2225 * containing either string literals that will be escaped or tokens returned by anyChar() or anyString().
2226 * Alternatively, the function could be provided with an array of aforementioned parameters.
2228 * Example: $dbr->buildLike( 'My_page_title/', $dbr->anyString() ) returns a LIKE clause that searches
2229 * for subpages of 'My page title'.
2230 * Alternatively: $pattern = array( 'My_page_title/', $dbr->anyString() ); $query .= $dbr->buildLike( $pattern );
2233 * @return String: fully built LIKE statement
2235 public function buildLike() {
2236 $params = func_get_args();
2238 if ( count( $params ) > 0 && is_array( $params[0] ) ) {
2239 $params = $params[0];
2244 foreach ( $params as $value ) {
2245 if ( $value instanceof LikeMatch
) {
2246 $s .= $value->toString();
2248 $s .= $this->escapeLikeInternal( $value );
2252 return " LIKE '" . $s . "' ";
2256 * Returns a token for buildLike() that denotes a '_' to be used in a LIKE query
2260 public function anyChar() {
2261 return new LikeMatch( '_' );
2265 * Returns a token for buildLike() that denotes a '%' to be used in a LIKE query
2269 public function anyString() {
2270 return new LikeMatch( '%' );
2274 * Returns an appropriately quoted sequence value for inserting a new row.
2275 * MySQL has autoincrement fields, so this is just NULL. But the PostgreSQL
2276 * subclass will return an integer, and save the value for insertId()
2278 * Any implementation of this function should *not* involve reusing
2279 * sequence numbers created for rolled-back transactions.
2280 * See http://bugs.mysql.com/bug.php?id=30767 for details.
2281 * @param $seqName string
2284 public function nextSequenceValue( $seqName ) {
2289 * USE INDEX clause. Unlikely to be useful for anything but MySQL. This
2290 * is only needed because a) MySQL must be as efficient as possible due to
2291 * its use on Wikipedia, and b) MySQL 4.0 is kind of dumb sometimes about
2292 * which index to pick. Anyway, other databases might have different
2293 * indexes on a given table. So don't bother overriding this unless you're
2298 public function useIndexClause( $index ) {
2303 * REPLACE query wrapper.
2305 * REPLACE is a very handy MySQL extension, which functions like an INSERT
2306 * except that when there is a duplicate key error, the old row is deleted
2307 * and the new row is inserted in its place.
2309 * We simulate this with standard SQL with a DELETE followed by INSERT. To
2310 * perform the delete, we need to know what the unique indexes are so that
2311 * we know how to find the conflicting rows.
2313 * It may be more efficient to leave off unique indexes which are unlikely
2314 * to collide. However if you do this, you run the risk of encountering
2315 * errors which wouldn't have occurred in MySQL.
2317 * @param $table String: The table to replace the row(s) in.
2318 * @param $rows array Can be either a single row to insert, or multiple rows,
2319 * in the same format as for DatabaseBase::insert()
2320 * @param $uniqueIndexes array is an array of indexes. Each element may be either
2321 * a field name or an array of field names
2322 * @param $fname String: Calling function name (use __METHOD__) for logs/profiling
2324 public function replace( $table, $uniqueIndexes, $rows, $fname = 'DatabaseBase::replace' ) {
2325 $quotedTable = $this->tableName( $table );
2327 if ( count( $rows ) == 0 ) {
2332 if ( !is_array( reset( $rows ) ) ) {
2333 $rows = array( $rows );
2336 foreach( $rows as $row ) {
2337 # Delete rows which collide
2338 if ( $uniqueIndexes ) {
2339 $sql = "DELETE FROM $quotedTable WHERE ";
2341 foreach ( $uniqueIndexes as $index ) {
2348 if ( is_array( $index ) ) {
2350 foreach ( $index as $col ) {
2356 $sql .= $col . '=' . $this->addQuotes( $row[$col] );
2359 $sql .= $index . '=' . $this->addQuotes( $row[$index] );
2363 $this->query( $sql, $fname );
2366 # Now insert the row
2367 $this->insert( $table, $row );
2372 * REPLACE query wrapper for MySQL and SQLite, which have a native REPLACE
2375 * @param $table string Table name
2376 * @param $rows array Rows to insert
2377 * @param $fname string Caller function name
2379 * @return ResultWrapper
2381 protected function nativeReplace( $table, $rows, $fname ) {
2382 $table = $this->tableName( $table );
2385 if ( !is_array( reset( $rows ) ) ) {
2386 $rows = array( $rows );
2389 $sql = "REPLACE INTO $table (" . implode( ',', array_keys( $rows[0] ) ) . ') VALUES ';
2392 foreach ( $rows as $row ) {
2399 $sql .= '(' . $this->makeList( $row ) . ')';
2402 return $this->query( $sql, $fname );
2406 * DELETE where the condition is a join.
2408 * MySQL overrides this to use a multi-table DELETE syntax, in other databases
2409 * we use sub-selects
2411 * For safety, an empty $conds will not delete everything. If you want to
2412 * delete all rows where the join condition matches, set $conds='*'.
2414 * DO NOT put the join condition in $conds.
2416 * @param $delTable String: The table to delete from.
2417 * @param $joinTable String: The other table.
2418 * @param $delVar String: The variable to join on, in the first table.
2419 * @param $joinVar String: The variable to join on, in the second table.
2420 * @param $conds Array: Condition array of field names mapped to variables,
2421 * ANDed together in the WHERE clause
2422 * @param $fname String: Calling function name (use __METHOD__) for
2425 public function deleteJoin( $delTable, $joinTable, $delVar, $joinVar, $conds,
2426 $fname = 'DatabaseBase::deleteJoin' )
2429 throw new DBUnexpectedError( $this,
2430 'DatabaseBase::deleteJoin() called with empty $conds' );
2433 $delTable = $this->tableName( $delTable );
2434 $joinTable = $this->tableName( $joinTable );
2435 $sql = "DELETE FROM $delTable WHERE $delVar IN (SELECT $joinVar FROM $joinTable ";
2436 if ( $conds != '*' ) {
2437 $sql .= 'WHERE ' . $this->makeList( $conds, LIST_AND
);
2441 $this->query( $sql, $fname );
2445 * Returns the size of a text field, or -1 for "unlimited"
2447 * @param $table string
2448 * @param $field string
2452 public function textFieldSize( $table, $field ) {
2453 $table = $this->tableName( $table );
2454 $sql = "SHOW COLUMNS FROM $table LIKE \"$field\";";
2455 $res = $this->query( $sql, 'DatabaseBase::textFieldSize' );
2456 $row = $this->fetchObject( $res );
2460 if ( preg_match( '/\((.*)\)/', $row->Type
, $m ) ) {
2470 * A string to insert into queries to show that they're low-priority, like
2471 * MySQL's LOW_PRIORITY. If no such feature exists, return an empty
2472 * string and nothing bad should happen.
2474 * @return string Returns the text of the low priority option if it is
2475 * supported, or a blank string otherwise
2477 public function lowPriorityOption() {
2482 * DELETE query wrapper.
2484 * @param $table Array Table name
2485 * @param $conds String|Array of conditions. See $conds in DatabaseBase::select() for
2486 * the format. Use $conds == "*" to delete all rows
2487 * @param $fname String name of the calling function
2491 public function delete( $table, $conds, $fname = 'DatabaseBase::delete' ) {
2493 throw new DBUnexpectedError( $this, 'DatabaseBase::delete() called with no conditions' );
2496 $table = $this->tableName( $table );
2497 $sql = "DELETE FROM $table";
2499 if ( $conds != '*' ) {
2500 $sql .= ' WHERE ' . $this->makeList( $conds, LIST_AND
);
2503 return $this->query( $sql, $fname );
2507 * INSERT SELECT wrapper. Takes data from a SELECT query and inserts it
2508 * into another table.
2510 * @param $destTable string The table name to insert into
2511 * @param $srcTable string|array May be either a table name, or an array of table names
2512 * to include in a join.
2514 * @param $varMap array must be an associative array of the form
2515 * array( 'dest1' => 'source1', ...). Source items may be literals
2516 * rather than field names, but strings should be quoted with
2517 * DatabaseBase::addQuotes()
2519 * @param $conds array Condition array. See $conds in DatabaseBase::select() for
2520 * the details of the format of condition arrays. May be "*" to copy the
2523 * @param $fname string The function name of the caller, from __METHOD__
2525 * @param $insertOptions array Options for the INSERT part of the query, see
2526 * DatabaseBase::insert() for details.
2527 * @param $selectOptions array Options for the SELECT part of the query, see
2528 * DatabaseBase::select() for details.
2530 * @return ResultWrapper
2532 public function insertSelect( $destTable, $srcTable, $varMap, $conds,
2533 $fname = 'DatabaseBase::insertSelect',
2534 $insertOptions = array(), $selectOptions = array() )
2536 $destTable = $this->tableName( $destTable );
2538 if ( is_array( $insertOptions ) ) {
2539 $insertOptions = implode( ' ', $insertOptions );
2542 if ( !is_array( $selectOptions ) ) {
2543 $selectOptions = array( $selectOptions );
2546 list( $startOpts, $useIndex, $tailOpts ) = $this->makeSelectOptions( $selectOptions );
2548 if ( is_array( $srcTable ) ) {
2549 $srcTable = implode( ',', array_map( array( &$this, 'tableName' ), $srcTable ) );
2551 $srcTable = $this->tableName( $srcTable );
2554 $sql = "INSERT $insertOptions INTO $destTable (" . implode( ',', array_keys( $varMap ) ) . ')' .
2555 " SELECT $startOpts " . implode( ',', $varMap ) .
2556 " FROM $srcTable $useIndex ";
2558 if ( $conds != '*' ) {
2559 if ( is_array( $conds ) ) {
2560 $conds = $this->makeList( $conds, LIST_AND
);
2562 $sql .= " WHERE $conds";
2565 $sql .= " $tailOpts";
2567 return $this->query( $sql, $fname );
2571 * Construct a LIMIT query with optional offset. This is used for query
2572 * pages. The SQL should be adjusted so that only the first $limit rows
2573 * are returned. If $offset is provided as well, then the first $offset
2574 * rows should be discarded, and the next $limit rows should be returned.
2575 * If the result of the query is not ordered, then the rows to be returned
2576 * are theoretically arbitrary.
2578 * $sql is expected to be a SELECT, if that makes a difference.
2580 * The version provided by default works in MySQL and SQLite. It will very
2581 * likely need to be overridden for most other DBMSes.
2583 * @param $sql String SQL query we will append the limit too
2584 * @param $limit Integer the SQL limit
2585 * @param $offset Integer|bool the SQL offset (default false)
2589 public function limitResult( $sql, $limit, $offset = false ) {
2590 if ( !is_numeric( $limit ) ) {
2591 throw new DBUnexpectedError( $this, "Invalid non-numeric limit passed to limitResult()\n" );
2593 return "$sql LIMIT "
2594 . ( ( is_numeric( $offset ) && $offset != 0 ) ?
"{$offset}," : "" )
2599 * Returns true if current database backend supports ORDER BY or LIMIT for separate subqueries
2600 * within the UNION construct.
2603 public function unionSupportsOrderAndLimit() {
2604 return true; // True for almost every DB supported
2608 * Construct a UNION query
2609 * This is used for providing overload point for other DB abstractions
2610 * not compatible with the MySQL syntax.
2611 * @param $sqls Array: SQL statements to combine
2612 * @param $all Boolean: use UNION ALL
2613 * @return String: SQL fragment
2615 public function unionQueries( $sqls, $all ) {
2616 $glue = $all ?
') UNION ALL (' : ') UNION (';
2617 return '(' . implode( $glue, $sqls ) . ')';
2621 * Returns an SQL expression for a simple conditional. This doesn't need
2622 * to be overridden unless CASE isn't supported in your DBMS.
2624 * @param $cond String: SQL expression which will result in a boolean value
2625 * @param $trueVal String: SQL expression to return if true
2626 * @param $falseVal String: SQL expression to return if false
2627 * @return String: SQL fragment
2629 public function conditional( $cond, $trueVal, $falseVal ) {
2630 return " (CASE WHEN $cond THEN $trueVal ELSE $falseVal END) ";
2634 * Returns a comand for str_replace function in SQL query.
2635 * Uses REPLACE() in MySQL
2637 * @param $orig String: column to modify
2638 * @param $old String: column to seek
2639 * @param $new String: column to replace with
2643 public function strreplace( $orig, $old, $new ) {
2644 return "REPLACE({$orig}, {$old}, {$new})";
2648 * Determines how long the server has been up
2653 public function getServerUptime() {
2658 * Determines if the last failure was due to a deadlock
2663 public function wasDeadlock() {
2668 * Determines if the last failure was due to a lock timeout
2673 public function wasLockTimeout() {
2678 * Determines if the last query error was something that should be dealt
2679 * with by pinging the connection and reissuing the query.
2684 public function wasErrorReissuable() {
2689 * Determines if the last failure was due to the database being read-only.
2694 public function wasReadOnlyError() {
2699 * Perform a deadlock-prone transaction.
2701 * This function invokes a callback function to perform a set of write
2702 * queries. If a deadlock occurs during the processing, the transaction
2703 * will be rolled back and the callback function will be called again.
2706 * $dbw->deadlockLoop( callback, ... );
2708 * Extra arguments are passed through to the specified callback function.
2710 * Returns whatever the callback function returned on its successful,
2711 * iteration, or false on error, for example if the retry limit was
2716 public function deadlockLoop() {
2717 $this->begin( __METHOD__
);
2718 $args = func_get_args();
2719 $function = array_shift( $args );
2720 $oldIgnore = $this->ignoreErrors( true );
2721 $tries = DEADLOCK_TRIES
;
2723 if ( is_array( $function ) ) {
2724 $fname = $function[0];
2730 $retVal = call_user_func_array( $function, $args );
2731 $error = $this->lastError();
2732 $errno = $this->lastErrno();
2733 $sql = $this->lastQuery();
2736 if ( $this->wasDeadlock() ) {
2738 usleep( mt_rand( DEADLOCK_DELAY_MIN
, DEADLOCK_DELAY_MAX
) );
2740 $this->reportQueryError( $error, $errno, $sql, $fname );
2743 } while ( $this->wasDeadlock() && --$tries > 0 );
2745 $this->ignoreErrors( $oldIgnore );
2747 if ( $tries <= 0 ) {
2748 $this->rollback( __METHOD__
);
2749 $this->reportQueryError( $error, $errno, $sql, $fname );
2752 $this->commit( __METHOD__
);
2758 * Wait for the slave to catch up to a given master position.
2760 * @param $pos DBMasterPos object
2761 * @param $timeout Integer: the maximum number of seconds to wait for
2764 * @return integer: zero if the slave was past that position already,
2765 * greater than zero if we waited for some period of time, less than
2766 * zero if we timed out.
2768 public function masterPosWait( DBMasterPos
$pos, $timeout ) {
2769 wfProfileIn( __METHOD__
);
2771 if ( !is_null( $this->mFakeSlaveLag
) ) {
2772 $wait = intval( ( $pos->pos
- microtime( true ) +
$this->mFakeSlaveLag
) * 1e6
);
2774 if ( $wait > $timeout * 1e6
) {
2775 wfDebug( "Fake slave timed out waiting for $pos ($wait us)\n" );
2776 wfProfileOut( __METHOD__
);
2778 } elseif ( $wait > 0 ) {
2779 wfDebug( "Fake slave waiting $wait us\n" );
2781 wfProfileOut( __METHOD__
);
2784 wfDebug( "Fake slave up to date ($wait us)\n" );
2785 wfProfileOut( __METHOD__
);
2790 wfProfileOut( __METHOD__
);
2792 # Real waits are implemented in the subclass.
2797 * Get the replication position of this slave
2799 * @return DBMasterPos, or false if this is not a slave.
2801 public function getSlavePos() {
2802 if ( !is_null( $this->mFakeSlaveLag
) ) {
2803 $pos = new MySQLMasterPos( 'fake', microtime( true ) - $this->mFakeSlaveLag
);
2804 wfDebug( __METHOD__
. ": fake slave pos = $pos\n" );
2813 * Get the position of this master
2815 * @return DBMasterPos, or false if this is not a master
2817 public function getMasterPos() {
2818 if ( $this->mFakeMaster
) {
2819 return new MySQLMasterPos( 'fake', microtime( true ) );
2826 * Begin a transaction
2828 * @param $fname string
2830 public function begin( $fname = 'DatabaseBase::begin' ) {
2831 $this->query( 'BEGIN', $fname );
2832 $this->mTrxLevel
= 1;
2838 * @param $fname string
2840 public function commit( $fname = 'DatabaseBase::commit' ) {
2841 if ( $this->mTrxLevel
) {
2842 $this->query( 'COMMIT', $fname );
2843 $this->mTrxLevel
= 0;
2848 * Rollback a transaction.
2849 * No-op on non-transactional databases.
2851 * @param $fname string
2853 public function rollback( $fname = 'DatabaseBase::rollback' ) {
2854 if ( $this->mTrxLevel
) {
2855 $this->query( 'ROLLBACK', $fname, true );
2856 $this->mTrxLevel
= 0;
2861 * Creates a new table with structure copied from existing table
2862 * Note that unlike most database abstraction functions, this function does not
2863 * automatically append database prefix, because it works at a lower
2864 * abstraction level.
2865 * The table names passed to this function shall not be quoted (this
2866 * function calls addIdentifierQuotes when needed).
2868 * @param $oldName String: name of table whose structure should be copied
2869 * @param $newName String: name of table to be created
2870 * @param $temporary Boolean: whether the new table should be temporary
2871 * @param $fname String: calling function name
2872 * @return Boolean: true if operation was successful
2874 public function duplicateTableStructure( $oldName, $newName, $temporary = false,
2875 $fname = 'DatabaseBase::duplicateTableStructure' )
2877 throw new MWException(
2878 'DatabaseBase::duplicateTableStructure is not implemented in descendant class' );
2882 * List all tables on the database
2884 * @param $prefix string Only show tables with this prefix, e.g. mw_
2885 * @param $fname String: calling function name
2887 function listTables( $prefix = null, $fname = 'DatabaseBase::listTables' ) {
2888 throw new MWException( 'DatabaseBase::listTables is not implemented in descendant class' );
2892 * Convert a timestamp in one of the formats accepted by wfTimestamp()
2893 * to the format used for inserting into timestamp fields in this DBMS.
2895 * The result is unquoted, and needs to be passed through addQuotes()
2896 * before it can be included in raw SQL.
2898 * @param $ts string|int
2902 public function timestamp( $ts = 0 ) {
2903 return wfTimestamp( TS_MW
, $ts );
2907 * Convert a timestamp in one of the formats accepted by wfTimestamp()
2908 * to the format used for inserting into timestamp fields in this DBMS. If
2909 * NULL is input, it is passed through, allowing NULL values to be inserted
2910 * into timestamp fields.
2912 * The result is unquoted, and needs to be passed through addQuotes()
2913 * before it can be included in raw SQL.
2915 * @param $ts string|int
2919 public function timestampOrNull( $ts = null ) {
2920 if ( is_null( $ts ) ) {
2923 return $this->timestamp( $ts );
2928 * Take the result from a query, and wrap it in a ResultWrapper if
2929 * necessary. Boolean values are passed through as is, to indicate success
2930 * of write queries or failure.
2932 * Once upon a time, DatabaseBase::query() returned a bare MySQL result
2933 * resource, and it was necessary to call this function to convert it to
2934 * a wrapper. Nowadays, raw database objects are never exposed to external
2935 * callers, so this is unnecessary in external code. For compatibility with
2936 * old code, ResultWrapper objects are passed through unaltered.
2938 * @param $result bool|ResultWrapper
2940 * @return bool|ResultWrapper
2942 public function resultObject( $result ) {
2943 if ( empty( $result ) ) {
2945 } elseif ( $result instanceof ResultWrapper
) {
2947 } elseif ( $result === true ) {
2948 // Successful write query
2951 return new ResultWrapper( $this, $result );
2956 * Ping the server and try to reconnect if it there is no connection
2958 * @return bool Success or failure
2960 public function ping() {
2961 # Stub. Not essential to override.
2966 * Get slave lag. Currently supported only by MySQL.
2968 * Note that this function will generate a fatal error on many
2969 * installations. Most callers should use LoadBalancer::safeGetLag()
2972 * @return int Database replication lag in seconds
2974 public function getLag() {
2975 return intval( $this->mFakeSlaveLag
);
2979 * Return the maximum number of items allowed in a list, or 0 for unlimited.
2983 function maxListLen() {
2988 * Some DBMSs have a special format for inserting into blob fields, they
2989 * don't allow simple quoted strings to be inserted. To insert into such
2990 * a field, pass the data through this function before passing it to
2991 * DatabaseBase::insert().
2995 public function encodeBlob( $b ) {
3000 * Some DBMSs return a special placeholder object representing blob fields
3001 * in result objects. Pass the object through this function to return the
3006 public function decodeBlob( $b ) {
3011 * Override database's default behavior. $options include:
3012 * 'connTimeout' : Set the connection timeout value in seconds.
3013 * May be useful for very long batch queries such as
3014 * full-wiki dumps, where a single query reads out over
3017 * @param $options Array
3020 public function setSessionOptions( array $options ) {}
3023 * Read and execute SQL commands from a file.
3025 * Returns true on success, error string or exception on failure (depending
3026 * on object's error ignore settings).
3028 * @param $filename String: File name to open
3029 * @param $lineCallback Callback: Optional function called before reading each line
3030 * @param $resultCallback Callback: Optional function called for each MySQL result
3031 * @param $fname String: Calling function name or false if name should be
3032 * generated dynamically using $filename
3033 * @return bool|string
3035 public function sourceFile(
3036 $filename, $lineCallback = false, $resultCallback = false, $fname = false
3038 wfSuppressWarnings();
3039 $fp = fopen( $filename, 'r' );
3040 wfRestoreWarnings();
3042 if ( false === $fp ) {
3043 throw new MWException( "Could not open \"{$filename}\".\n" );
3047 $fname = __METHOD__
. "( $filename )";
3051 $error = $this->sourceStream( $fp, $lineCallback, $resultCallback, $fname );
3053 catch ( MWException
$e ) {
3064 * Get the full path of a patch file. Originally based on archive()
3065 * from updaters.inc. Keep in mind this always returns a patch, as
3066 * it fails back to MySQL if no DB-specific patch can be found
3068 * @param $patch String The name of the patch, like patch-something.sql
3069 * @return String Full path to patch file
3071 public function patchPath( $patch ) {
3074 $dbType = $this->getType();
3075 if ( file_exists( "$IP/maintenance/$dbType/archives/$patch" ) ) {
3076 return "$IP/maintenance/$dbType/archives/$patch";
3078 return "$IP/maintenance/archives/$patch";
3083 * Set variables to be used in sourceFile/sourceStream, in preference to the
3084 * ones in $GLOBALS. If an array is set here, $GLOBALS will not be used at
3085 * all. If it's set to false, $GLOBALS will be used.
3087 * @param $vars bool|array mapping variable name to value.
3089 public function setSchemaVars( $vars ) {
3090 $this->mSchemaVars
= $vars;
3094 * Read and execute commands from an open file handle.
3096 * Returns true on success, error string or exception on failure (depending
3097 * on object's error ignore settings).
3099 * @param $fp Resource: File handle
3100 * @param $lineCallback Callback: Optional function called before reading each line
3101 * @param $resultCallback Callback: Optional function called for each MySQL result
3102 * @param $fname String: Calling function name
3103 * @param $inputCallback Callback: Optional function called for each complete line (ended with ;) sent
3104 * @return bool|string
3106 public function sourceStream( $fp, $lineCallback = false, $resultCallback = false,
3107 $fname = 'DatabaseBase::sourceStream', $inputCallback = false )
3111 while ( !feof( $fp ) ) {
3112 if ( $lineCallback ) {
3113 call_user_func( $lineCallback );
3116 $line = trim( fgets( $fp ) );
3118 if ( $line == '' ) {
3122 if ( '-' == $line[0] && '-' == $line[1] ) {
3130 $done = $this->streamStatementEnd( $cmd, $line );
3134 if ( $done ||
feof( $fp ) ) {
3135 $cmd = $this->replaceVars( $cmd );
3136 if ( $inputCallback ) {
3137 call_user_func( $inputCallback, $cmd );
3139 $res = $this->query( $cmd, $fname );
3141 if ( $resultCallback ) {
3142 call_user_func( $resultCallback, $res, $this );
3145 if ( false === $res ) {
3146 $err = $this->lastError();
3147 return "Query \"{$cmd}\" failed with error code \"$err\".\n";
3158 * Called by sourceStream() to check if we've reached a statement end
3160 * @param $sql String SQL assembled so far
3161 * @param $newLine String New line about to be added to $sql
3162 * @return Bool Whether $newLine contains end of the statement
3164 public function streamStatementEnd( &$sql, &$newLine ) {
3165 if ( $this->delimiter
) {
3167 $newLine = preg_replace( '/' . preg_quote( $this->delimiter
, '/' ) . '$/', '', $newLine );
3168 if ( $newLine != $prev ) {
3176 * Database independent variable replacement. Replaces a set of variables
3177 * in an SQL statement with their contents as given by $this->getSchemaVars().
3179 * Supports '{$var}' `{$var}` and / *$var* / (without the spaces) style variables.
3181 * - '{$var}' should be used for text and is passed through the database's
3183 * - `{$var}` should be used for identifiers (eg: table and database names),
3184 * it is passed through the database's addIdentifierQuotes method which
3185 * can be overridden if the database uses something other than backticks.
3186 * - / *$var* / is just encoded, besides traditional table prefix and
3187 * table options its use should be avoided.
3189 * @param $ins String: SQL statement to replace variables in
3190 * @return String The new SQL statement with variables replaced
3192 protected function replaceSchemaVars( $ins ) {
3193 $vars = $this->getSchemaVars();
3194 foreach ( $vars as $var => $value ) {
3196 $ins = str_replace( '\'{$' . $var . '}\'', $this->addQuotes( $value ), $ins );
3198 $ins = str_replace( '`{$' . $var . '}`', $this->addIdentifierQuotes( $value ), $ins );
3200 $ins = str_replace( '/*$' . $var . '*/', $this->strencode( $value ) , $ins );
3206 * Replace variables in sourced SQL
3208 * @param $ins string
3212 protected function replaceVars( $ins ) {
3213 $ins = $this->replaceSchemaVars( $ins );
3216 $ins = preg_replace_callback( '!/\*(?:\$wgDBprefix|_)\*/([a-zA-Z_0-9]*)!',
3217 array( $this, 'tableNameCallback' ), $ins );
3220 $ins = preg_replace_callback( '!/\*i\*/([a-zA-Z_0-9]*)!',
3221 array( $this, 'indexNameCallback' ), $ins );
3227 * Get schema variables. If none have been set via setSchemaVars(), then
3228 * use some defaults from the current object.
3232 protected function getSchemaVars() {
3233 if ( $this->mSchemaVars
) {
3234 return $this->mSchemaVars
;
3236 return $this->getDefaultSchemaVars();
3241 * Get schema variables to use if none have been set via setSchemaVars().
3243 * Override this in derived classes to provide variables for tables.sql
3244 * and SQL patch files.
3248 protected function getDefaultSchemaVars() {
3253 * Table name callback
3255 * @param $matches array
3259 protected function tableNameCallback( $matches ) {
3260 return $this->tableName( $matches[1] );
3264 * Index name callback
3266 * @param $matches array
3270 protected function indexNameCallback( $matches ) {
3271 return $this->indexName( $matches[1] );
3275 * Check to see if a named lock is available. This is non-blocking.
3277 * @param $lockName String: name of lock to poll
3278 * @param $method String: name of method calling us
3282 public function lockIsFree( $lockName, $method ) {
3287 * Acquire a named lock
3289 * Abstracted from Filestore::lock() so child classes can implement for
3292 * @param $lockName String: name of lock to aquire
3293 * @param $method String: name of method calling us
3294 * @param $timeout Integer: timeout
3297 public function lock( $lockName, $method, $timeout = 5 ) {
3304 * @param $lockName String: Name of lock to release
3305 * @param $method String: Name of method calling us
3307 * @return int Returns 1 if the lock was released, 0 if the lock was not established
3308 * by this thread (in which case the lock is not released), and NULL if the named
3309 * lock did not exist
3311 public function unlock( $lockName, $method ) {
3316 * Lock specific tables
3318 * @param $read Array of tables to lock for read access
3319 * @param $write Array of tables to lock for write access
3320 * @param $method String name of caller
3321 * @param $lowPriority bool Whether to indicate writes to be LOW PRIORITY
3325 public function lockTables( $read, $write, $method, $lowPriority = true ) {
3330 * Unlock specific tables
3332 * @param $method String the caller
3336 public function unlockTables( $method ) {
3342 * @param $tableName string
3343 * @param $fName string
3344 * @return bool|ResultWrapper
3347 public function dropTable( $tableName, $fName = 'DatabaseBase::dropTable' ) {
3348 if( !$this->tableExists( $tableName, $fName ) ) {
3351 $sql = "DROP TABLE " . $this->tableName( $tableName );
3352 if( $this->cascadingDeletes() ) {
3355 return $this->query( $sql, $fName );
3359 * Get search engine class. All subclasses of this need to implement this
3360 * if they wish to use searching.
3364 public function getSearchEngine() {
3365 return 'SearchEngineDummy';
3369 * Find out when 'infinity' is. Most DBMSes support this. This is a special
3370 * keyword for timestamps in PostgreSQL, and works with CHAR(14) as well
3371 * because "i" sorts after all numbers.
3375 public function getInfinity() {
3380 * Encode an expiry time into the DBMS dependent format
3382 * @param $expiry String: timestamp for expiry, or the 'infinity' string
3385 public function encodeExpiry( $expiry ) {
3386 return ( $expiry == '' ||
$expiry == 'infinity' ||
$expiry == $this->getInfinity() )
3387 ?
$this->getInfinity()
3388 : $this->timestamp( $expiry );
3392 * Decode an expiry time into a DBMS independent format
3394 * @param $expiry String: DB timestamp field value for expiry
3395 * @param $format integer: TS_* constant, defaults to TS_MW
3398 public function decodeExpiry( $expiry, $format = TS_MW
) {
3399 return ( $expiry == '' ||
$expiry == $this->getInfinity() )
3401 : wfTimestamp( $format, $expiry );
3405 * Allow or deny "big selects" for this session only. This is done by setting
3406 * the sql_big_selects session variable.
3408 * This is a MySQL-specific feature.
3410 * @param $value Mixed: true for allow, false for deny, or "default" to
3411 * restore the initial value
3413 public function setBigSelects( $value = true ) {
3420 public function __toString() {
3421 return (string)$this->mConn
;