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 callable
235 protected $trxIdleCallbacks = 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;
277 # ------------------------------------------------------------------------------
279 # ------------------------------------------------------------------------------
280 # These optionally set a variable and return the previous state
283 * A string describing the current software version, and possibly
284 * other details in a user-friendly way. Will be listed on Special:Version, etc.
285 * Use getServerVersion() to get machine-friendly information.
287 * @return string: Version information from the database server
289 public function getServerInfo() {
290 return $this->getServerVersion();
294 * @return string: command delimiter used by this database engine
296 public function getDelimiter() {
297 return $this->delimiter
;
301 * Boolean, controls output of large amounts of debug information.
302 * @param $debug bool|null
303 * - true to enable debugging
304 * - false to disable debugging
305 * - omitted or null to do nothing
307 * @return bool|null previous value of the flag
309 public function debug( $debug = null ) {
310 return wfSetBit( $this->mFlags
, DBO_DEBUG
, $debug );
314 * Turns buffering of SQL result sets on (true) or off (false). Default is
317 * Unbuffered queries are very troublesome in MySQL:
319 * - If another query is executed while the first query is being read
320 * out, the first query is killed. This means you can't call normal
321 * MediaWiki functions while you are reading an unbuffered query result
322 * from a normal wfGetDB() connection.
324 * - Unbuffered queries cause the MySQL server to use large amounts of
325 * memory and to hold broad locks which block other queries.
327 * If you want to limit client-side memory, it's almost always better to
328 * split up queries into batches using a LIMIT clause than to switch off
331 * @param $buffer null|bool
333 * @return null|bool The previous value of the flag
335 public function bufferResults( $buffer = null ) {
336 if ( is_null( $buffer ) ) {
337 return !(bool)( $this->mFlags
& DBO_NOBUFFER
);
339 return !wfSetBit( $this->mFlags
, DBO_NOBUFFER
, !$buffer );
344 * Turns on (false) or off (true) the automatic generation and sending
345 * of a "we're sorry, but there has been a database error" page on
346 * database errors. Default is on (false). When turned off, the
347 * code should use lastErrno() and lastError() to handle the
348 * situation as appropriate.
350 * @param $ignoreErrors bool|null
352 * @return bool The previous value of the flag.
354 public function ignoreErrors( $ignoreErrors = null ) {
355 return wfSetBit( $this->mFlags
, DBO_IGNORE
, $ignoreErrors );
359 * Gets or sets the current transaction level.
361 * Historically, transactions were allowed to be "nested". This is no
362 * longer supported, so this function really only returns a boolean.
364 * @param $level int An integer (0 or 1), or omitted to leave it unchanged.
365 * @return int The previous value
367 public function trxLevel( $level = null ) {
368 return wfSetVar( $this->mTrxLevel
, $level );
372 * Get/set the number of errors logged. Only useful when errors are ignored
373 * @param $count int The count to set, or omitted to leave it unchanged.
374 * @return int The error count
376 public function errorCount( $count = null ) {
377 return wfSetVar( $this->mErrorCount
, $count );
381 * Get/set the table prefix.
382 * @param $prefix string The table prefix to set, or omitted to leave it unchanged.
383 * @return string The previous table prefix.
385 public function tablePrefix( $prefix = null ) {
386 return wfSetVar( $this->mTablePrefix
, $prefix );
390 * Get properties passed down from the server info array of the load
393 * @param $name string The entry of the info array to get, or null to get the
396 * @return LoadBalancer|null
398 public function getLBInfo( $name = null ) {
399 if ( is_null( $name ) ) {
400 return $this->mLBInfo
;
402 if ( array_key_exists( $name, $this->mLBInfo
) ) {
403 return $this->mLBInfo
[$name];
411 * Set the LB info array, or a member of it. If called with one parameter,
412 * the LB info array is set to that parameter. If it is called with two
413 * parameters, the member with the given name is set to the given value.
418 public function setLBInfo( $name, $value = null ) {
419 if ( is_null( $value ) ) {
420 $this->mLBInfo
= $name;
422 $this->mLBInfo
[$name] = $value;
427 * Set lag time in seconds for a fake slave
431 public function setFakeSlaveLag( $lag ) {
432 $this->mFakeSlaveLag
= $lag;
436 * Make this connection a fake master
438 * @param $enabled bool
440 public function setFakeMaster( $enabled = true ) {
441 $this->mFakeMaster
= $enabled;
445 * Returns true if this database supports (and uses) cascading deletes
449 public function cascadingDeletes() {
454 * Returns true if this database supports (and uses) triggers (e.g. on the page table)
458 public function cleanupTriggers() {
463 * Returns true if this database is strict about what can be put into an IP field.
464 * Specifically, it uses a NULL value instead of an empty string.
468 public function strictIPs() {
473 * Returns true if this database uses timestamps rather than integers
477 public function realTimestamps() {
482 * Returns true if this database does an implicit sort when doing GROUP BY
486 public function implicitGroupby() {
491 * Returns true if this database does an implicit order by when the column has an index
492 * For example: SELECT page_title FROM page LIMIT 1
496 public function implicitOrderby() {
501 * Returns true if this database can do a native search on IP columns
502 * e.g. this works as expected: .. WHERE rc_ip = '127.42.12.102/32';
506 public function searchableIPs() {
511 * Returns true if this database can use functional indexes
515 public function functionalIndexes() {
520 * Return the last query that went through DatabaseBase::query()
523 public function lastQuery() {
524 return $this->mLastQuery
;
528 * Returns true if the connection may have been used for write queries.
529 * Should return true if unsure.
533 public function doneWrites() {
534 return $this->mDoneWrites
;
538 * Is a connection to the database open?
541 public function isOpen() {
542 return $this->mOpened
;
546 * Set a flag for this connection
548 * @param $flag Integer: DBO_* constants from Defines.php:
549 * - DBO_DEBUG: output some debug info (same as debug())
550 * - DBO_NOBUFFER: don't buffer results (inverse of bufferResults())
551 * - DBO_IGNORE: ignore errors (same as ignoreErrors())
552 * - DBO_TRX: automatically start transactions
553 * - DBO_DEFAULT: automatically sets DBO_TRX if not in command line mode
554 * and removes it in command line mode
555 * - DBO_PERSISTENT: use persistant database connection
557 public function setFlag( $flag ) {
558 global $wgDebugDBTransactions;
559 $this->mFlags |
= $flag;
560 if ( ( $flag & DBO_TRX
) & $wgDebugDBTransactions ) {
561 wfDebug("Implicit transactions are now disabled.\n");
566 * Clear a flag for this connection
568 * @param $flag: same as setFlag()'s $flag param
570 public function clearFlag( $flag ) {
571 global $wgDebugDBTransactions;
572 $this->mFlags
&= ~
$flag;
573 if ( ( $flag & DBO_TRX
) && $wgDebugDBTransactions ) {
574 wfDebug("Implicit transactions are now disabled.\n");
579 * Returns a boolean whether the flag $flag is set for this connection
581 * @param $flag: same as setFlag()'s $flag param
584 public function getFlag( $flag ) {
585 return !!( $this->mFlags
& $flag );
589 * General read-only accessor
591 * @param $name string
595 public function getProperty( $name ) {
602 public function getWikiID() {
603 if ( $this->mTablePrefix
) {
604 return "{$this->mDBname}-{$this->mTablePrefix}";
606 return $this->mDBname
;
611 * Return a path to the DBMS-specific schema file, otherwise default to tables.sql
615 public function getSchemaPath() {
617 if ( file_exists( "$IP/maintenance/" . $this->getType() . "/tables.sql" ) ) {
618 return "$IP/maintenance/" . $this->getType() . "/tables.sql";
620 return "$IP/maintenance/tables.sql";
624 # ------------------------------------------------------------------------------
626 # ------------------------------------------------------------------------------
630 * @param $server String: database server host
631 * @param $user String: database user name
632 * @param $password String: database user password
633 * @param $dbName String: database name
635 * @param $tablePrefix String: database table prefixes. By default use the prefix gave in LocalSettings.php
637 function __construct( $server = false, $user = false, $password = false, $dbName = false,
638 $flags = 0, $tablePrefix = 'get from global'
640 global $wgDBprefix, $wgCommandLineMode, $wgDebugDBTransactions;
642 $this->mFlags
= $flags;
644 if ( $this->mFlags
& DBO_DEFAULT
) {
645 if ( $wgCommandLineMode ) {
646 $this->mFlags
&= ~DBO_TRX
;
647 if ( $wgDebugDBTransactions ) {
648 wfDebug("Implicit transaction open disabled.\n");
651 $this->mFlags |
= DBO_TRX
;
652 if ( $wgDebugDBTransactions ) {
653 wfDebug("Implicit transaction open enabled.\n");
658 /** Get the default table prefix*/
659 if ( $tablePrefix == 'get from global' ) {
660 $this->mTablePrefix
= $wgDBprefix;
662 $this->mTablePrefix
= $tablePrefix;
666 $this->open( $server, $user, $password, $dbName );
671 * Called by serialize. Throw an exception when DB connection is serialized.
672 * This causes problems on some database engines because the connection is
673 * not restored on unserialize.
675 public function __sleep() {
676 throw new MWException( 'Database serialization may cause problems, since the connection is not restored on wakeup.' );
680 * Given a DB type, construct the name of the appropriate child class of
681 * DatabaseBase. This is designed to replace all of the manual stuff like:
682 * $class = 'Database' . ucfirst( strtolower( $type ) );
683 * as well as validate against the canonical list of DB types we have
685 * This factory function is mostly useful for when you need to connect to a
686 * database other than the MediaWiki default (such as for external auth,
687 * an extension, et cetera). Do not use this to connect to the MediaWiki
688 * database. Example uses in core:
689 * @see LoadBalancer::reallyOpenConnection()
690 * @see ExternalUser_MediaWiki::initFromCond()
691 * @see ForeignDBRepo::getMasterDB()
692 * @see WebInstaller_DBConnect::execute()
696 * @param $dbType String A possible DB type
697 * @param $p Array An array of options to pass to the constructor.
698 * Valid options are: host, user, password, dbname, flags, tablePrefix
699 * @return DatabaseBase subclass or null
701 public final static function factory( $dbType, $p = array() ) {
702 $canonicalDBTypes = array(
703 'mysql', 'postgres', 'sqlite', 'oracle', 'mssql', 'ibm_db2'
705 $dbType = strtolower( $dbType );
706 $class = 'Database' . ucfirst( $dbType );
708 if( in_array( $dbType, $canonicalDBTypes ) ||
( class_exists( $class ) && is_subclass_of( $class, 'DatabaseBase' ) ) ) {
710 isset( $p['host'] ) ?
$p['host'] : false,
711 isset( $p['user'] ) ?
$p['user'] : false,
712 isset( $p['password'] ) ?
$p['password'] : false,
713 isset( $p['dbname'] ) ?
$p['dbname'] : false,
714 isset( $p['flags'] ) ?
$p['flags'] : 0,
715 isset( $p['tablePrefix'] ) ?
$p['tablePrefix'] : 'get from global'
722 protected function installErrorHandler() {
723 $this->mPHPError
= false;
724 $this->htmlErrors
= ini_set( 'html_errors', '0' );
725 set_error_handler( array( $this, 'connectionErrorHandler' ) );
729 * @return bool|string
731 protected function restoreErrorHandler() {
732 restore_error_handler();
733 if ( $this->htmlErrors
!== false ) {
734 ini_set( 'html_errors', $this->htmlErrors
);
736 if ( $this->mPHPError
) {
737 $error = preg_replace( '!\[<a.*</a>\]!', '', $this->mPHPError
);
738 $error = preg_replace( '!^.*?:\s?(.*)$!', '$1', $error );
749 protected function connectionErrorHandler( $errno, $errstr ) {
750 $this->mPHPError
= $errstr;
754 * Closes a database connection.
755 * if it is open : commits any open transactions
757 * @return Bool operation success. true if already closed.
759 public function close() {
760 $this->mOpened
= false;
761 if ( $this->mConn
) {
762 if ( $this->trxLevel() ) {
763 if ( !$this->mTrxAutomatic
) {
764 wfWarn( "Transaction still in progress (from {$this->mTrxFname}), " .
765 " performing implicit commit before closing connection!" );
768 $this->commit( __METHOD__
, 'flush' );
771 $ret = $this->closeConnection();
772 $this->mConn
= false;
780 * Closes underlying database connection
782 * @return bool: Whether connection was closed successfully
784 protected abstract function closeConnection();
787 * @param $error String: fallback error message, used if none is given by DB
788 * @throws DBConnectionError
790 function reportConnectionError( $error = 'Unknown error' ) {
791 $myError = $this->lastError();
797 throw new DBConnectionError( $this, $error );
801 * The DBMS-dependent part of query()
803 * @param $sql String: SQL query.
804 * @return ResultWrapper Result object to feed to fetchObject, fetchRow, ...; or false on failure
806 protected abstract function doQuery( $sql );
809 * Determine whether a query writes to the DB.
810 * Should return true if unsure.
816 public function isWriteQuery( $sql ) {
817 return !preg_match( '/^(?:SELECT|BEGIN|ROLLBACK|COMMIT|SET|SHOW|EXPLAIN|\(SELECT)\b/i', $sql );
821 * Run an SQL query and return the result. Normally throws a DBQueryError
822 * on failure. If errors are ignored, returns false instead.
824 * In new code, the query wrappers select(), insert(), update(), delete(),
825 * etc. should be used where possible, since they give much better DBMS
826 * independence and automatically quote or validate user input in a variety
827 * of contexts. This function is generally only useful for queries which are
828 * explicitly DBMS-dependent and are unsupported by the query wrappers, such
831 * However, the query wrappers themselves should call this function.
833 * @param $sql String: SQL query
834 * @param $fname String: Name of the calling function, for profiling/SHOW PROCESSLIST
835 * comment (you can use __METHOD__ or add some extra info)
836 * @param $tempIgnore Boolean: Whether to avoid throwing an exception on errors...
837 * maybe best to catch the exception instead?
838 * @throws MWException
839 * @return boolean|ResultWrapper. true for a successful write query, ResultWrapper object
840 * for a successful read query, or false on failure if $tempIgnore set
842 public function query( $sql, $fname = '', $tempIgnore = false ) {
843 $isMaster = !is_null( $this->getLBInfo( 'master' ) );
844 if ( !Profiler
::instance()->isStub() ) {
845 # generalizeSQL will probably cut down the query to reasonable
846 # logging size most of the time. The substr is really just a sanity check.
849 $queryProf = 'query-m: ' . substr( DatabaseBase
::generalizeSQL( $sql ), 0, 255 );
850 $totalProf = 'DatabaseBase::query-master';
852 $queryProf = 'query: ' . substr( DatabaseBase
::generalizeSQL( $sql ), 0, 255 );
853 $totalProf = 'DatabaseBase::query';
856 wfProfileIn( $totalProf );
857 wfProfileIn( $queryProf );
860 $this->mLastQuery
= $sql;
861 if ( !$this->mDoneWrites
&& $this->isWriteQuery( $sql ) ) {
862 # Set a flag indicating that writes have been done
863 wfDebug( __METHOD__
. ": Writes done: $sql\n" );
864 $this->mDoneWrites
= true;
867 # Add a comment for easy SHOW PROCESSLIST interpretation
869 if ( is_object( $wgUser ) && $wgUser->isItemLoaded( 'name' ) ) {
870 $userName = $wgUser->getName();
871 if ( mb_strlen( $userName ) > 15 ) {
872 $userName = mb_substr( $userName, 0, 15 ) . '...';
874 $userName = str_replace( '/', '', $userName );
878 $commentedSql = preg_replace( '/\s/', " /* $fname $userName */ ", $sql, 1 );
880 # If DBO_TRX is set, start a transaction
881 if ( ( $this->mFlags
& DBO_TRX
) && !$this->mTrxLevel
&&
882 $sql != 'BEGIN' && $sql != 'COMMIT' && $sql != 'ROLLBACK' )
884 # Avoid establishing transactions for SHOW and SET statements too -
885 # that would delay transaction initializations to once connection
886 # is really used by application
887 $sqlstart = substr( $sql, 0, 10 ); // very much worth it, benchmark certified(tm)
888 if ( strpos( $sqlstart, "SHOW " ) !== 0 && strpos( $sqlstart, "SET " ) !== 0 ) {
889 global $wgDebugDBTransactions;
890 if ( $wgDebugDBTransactions ) {
891 wfDebug("Implicit transaction start.\n");
893 $this->begin( __METHOD__
. " ($fname)" );
894 $this->mTrxAutomatic
= true;
898 # Keep track of whether the transaction has write queries pending
899 if ( $this->mTrxLevel
&& !$this->mTrxDoneWrites
&& $this->isWriteQuery( $sql ) ) {
900 $this->mTrxDoneWrites
= true;
903 if ( $this->debug() ) {
907 $sqlx = substr( $commentedSql, 0, 500 );
908 $sqlx = strtr( $sqlx, "\t\n", ' ' );
910 $master = $isMaster ?
'master' : 'slave';
911 wfDebug( "Query {$this->mDBname} ($cnt) ($master): $sqlx\n" );
914 if ( istainted( $sql ) & TC_MYSQL
) {
915 throw new MWException( 'Tainted query found' );
918 $queryId = MWDebug
::query( $sql, $fname, $isMaster );
920 # Do the query and handle errors
921 $ret = $this->doQuery( $commentedSql );
923 MWDebug
::queryTime( $queryId );
925 # Try reconnecting if the connection was lost
926 if ( false === $ret && $this->wasErrorReissuable() ) {
927 # Transaction is gone, like it or not
928 $this->mTrxLevel
= 0;
929 $this->trxIdleCallbacks
= array(); // cancel
930 wfDebug( "Connection lost, reconnecting...\n" );
932 if ( $this->ping() ) {
933 wfDebug( "Reconnected\n" );
934 $sqlx = substr( $commentedSql, 0, 500 );
935 $sqlx = strtr( $sqlx, "\t\n", ' ' );
936 global $wgRequestTime;
937 $elapsed = round( microtime( true ) - $wgRequestTime, 3 );
938 if ( $elapsed < 300 ) {
939 # Not a database error to lose a transaction after a minute or two
940 wfLogDBError( "Connection lost and reconnected after {$elapsed}s, query: $sqlx\n" );
942 $ret = $this->doQuery( $commentedSql );
944 wfDebug( "Failed\n" );
948 if ( false === $ret ) {
949 $this->reportQueryError( $this->lastError(), $this->lastErrno(), $sql, $fname, $tempIgnore );
952 if ( !Profiler
::instance()->isStub() ) {
953 wfProfileOut( $queryProf );
954 wfProfileOut( $totalProf );
957 return $this->resultObject( $ret );
961 * Report a query error. Log the error, and if neither the object ignore
962 * flag nor the $tempIgnore flag is set, throw a DBQueryError.
964 * @param $error String
965 * @param $errno Integer
967 * @param $fname String
968 * @param $tempIgnore Boolean
969 * @throws DBQueryError
971 public function reportQueryError( $error, $errno, $sql, $fname, $tempIgnore = false ) {
972 # Ignore errors during error handling to avoid infinite recursion
973 $ignore = $this->ignoreErrors( true );
974 ++
$this->mErrorCount
;
976 if ( $ignore ||
$tempIgnore ) {
977 wfDebug( "SQL ERROR (ignored): $error\n" );
978 $this->ignoreErrors( $ignore );
980 $sql1line = str_replace( "\n", "\\n", $sql );
981 wfLogDBError( "$fname\t{$this->mServer}\t$errno\t$error\t$sql1line\n" );
982 wfDebug( "SQL ERROR: " . $error . "\n" );
983 throw new DBQueryError( $this, $error, $errno, $sql, $fname );
988 * Intended to be compatible with the PEAR::DB wrapper functions.
989 * http://pear.php.net/manual/en/package.database.db.intro-execute.php
991 * ? = scalar value, quoted as necessary
992 * ! = raw SQL bit (a function for instance)
993 * & = filename; reads the file and inserts as a blob
994 * (we don't use this though...)
997 * @param $func string
1001 protected function prepare( $sql, $func = 'DatabaseBase::prepare' ) {
1002 /* MySQL doesn't support prepared statements (yet), so just
1003 pack up the query for reference. We'll manually replace
1005 return array( 'query' => $sql, 'func' => $func );
1009 * Free a prepared query, generated by prepare().
1012 protected function freePrepared( $prepared ) {
1013 /* No-op by default */
1017 * Execute a prepared query with the various arguments
1018 * @param $prepared String: the prepared sql
1019 * @param $args Mixed: Either an array here, or put scalars as varargs
1021 * @return ResultWrapper
1023 public function execute( $prepared, $args = null ) {
1024 if ( !is_array( $args ) ) {
1026 $args = func_get_args();
1027 array_shift( $args );
1030 $sql = $this->fillPrepared( $prepared['query'], $args );
1032 return $this->query( $sql, $prepared['func'] );
1036 * For faking prepared SQL statements on DBs that don't support it directly.
1038 * @param $preparedQuery String: a 'preparable' SQL statement
1039 * @param $args Array of arguments to fill it with
1040 * @return string executable SQL
1042 public function fillPrepared( $preparedQuery, $args ) {
1044 $this->preparedArgs
=& $args;
1046 return preg_replace_callback( '/(\\\\[?!&]|[?!&])/',
1047 array( &$this, 'fillPreparedArg' ), $preparedQuery );
1051 * preg_callback func for fillPrepared()
1052 * The arguments should be in $this->preparedArgs and must not be touched
1053 * while we're doing this.
1055 * @param $matches Array
1056 * @throws DBUnexpectedError
1059 protected function fillPreparedArg( $matches ) {
1060 switch( $matches[1] ) {
1061 case '\\?': return '?';
1062 case '\\!': return '!';
1063 case '\\&': return '&';
1066 list( /* $n */ , $arg ) = each( $this->preparedArgs
);
1068 switch( $matches[1] ) {
1069 case '?': return $this->addQuotes( $arg );
1070 case '!': return $arg;
1072 # return $this->addQuotes( file_get_contents( $arg ) );
1073 throw new DBUnexpectedError( $this, '& mode is not implemented. If it\'s really needed, uncomment the line above.' );
1075 throw new DBUnexpectedError( $this, 'Received invalid match. This should never happen!' );
1080 * Free a result object returned by query() or select(). It's usually not
1081 * necessary to call this, just use unset() or let the variable holding
1082 * the result object go out of scope.
1084 * @param $res Mixed: A SQL result
1086 public function freeResult( $res ) {}
1089 * A SELECT wrapper which returns a single field from a single result row.
1091 * Usually throws a DBQueryError on failure. If errors are explicitly
1092 * ignored, returns false on failure.
1094 * If no result rows are returned from the query, false is returned.
1096 * @param $table string|array Table name. See DatabaseBase::select() for details.
1097 * @param $var string The field name to select. This must be a valid SQL
1098 * fragment: do not use unvalidated user input.
1099 * @param $cond string|array The condition array. See DatabaseBase::select() for details.
1100 * @param $fname string The function name of the caller.
1101 * @param $options string|array The query options. See DatabaseBase::select() for details.
1103 * @return bool|mixed The value from the field, or false on failure.
1105 public function selectField( $table, $var, $cond = '', $fname = 'DatabaseBase::selectField',
1106 $options = array() )
1108 if ( !is_array( $options ) ) {
1109 $options = array( $options );
1112 $options['LIMIT'] = 1;
1114 $res = $this->select( $table, $var, $cond, $fname, $options );
1116 if ( $res === false ||
!$this->numRows( $res ) ) {
1120 $row = $this->fetchRow( $res );
1122 if ( $row !== false ) {
1123 return reset( $row );
1130 * Returns an optional USE INDEX clause to go after the table, and a
1131 * string to go at the end of the query.
1133 * @param $options Array: associative array of options to be turned into
1134 * an SQL query, valid keys are listed in the function.
1136 * @see DatabaseBase::select()
1138 public function makeSelectOptions( $options ) {
1139 $preLimitTail = $postLimitTail = '';
1142 $noKeyOptions = array();
1144 foreach ( $options as $key => $option ) {
1145 if ( is_numeric( $key ) ) {
1146 $noKeyOptions[$option] = true;
1150 if ( isset( $options['GROUP BY'] ) ) {
1151 $gb = is_array( $options['GROUP BY'] )
1152 ?
implode( ',', $options['GROUP BY'] )
1153 : $options['GROUP BY'];
1154 $preLimitTail .= " GROUP BY {$gb}";
1157 if ( isset( $options['HAVING'] ) ) {
1158 $having = is_array( $options['HAVING'] )
1159 ?
$this->makeList( $options['HAVING'], LIST_AND
)
1160 : $options['HAVING'];
1161 $preLimitTail .= " HAVING {$having}";
1164 if ( isset( $options['ORDER BY'] ) ) {
1165 $ob = is_array( $options['ORDER BY'] )
1166 ?
implode( ',', $options['ORDER BY'] )
1167 : $options['ORDER BY'];
1168 $preLimitTail .= " ORDER BY {$ob}";
1171 // if (isset($options['LIMIT'])) {
1172 // $tailOpts .= $this->limitResult('', $options['LIMIT'],
1173 // isset($options['OFFSET']) ? $options['OFFSET']
1177 if ( isset( $noKeyOptions['FOR UPDATE'] ) ) {
1178 $postLimitTail .= ' FOR UPDATE';
1181 if ( isset( $noKeyOptions['LOCK IN SHARE MODE'] ) ) {
1182 $postLimitTail .= ' LOCK IN SHARE MODE';
1185 if ( isset( $noKeyOptions['DISTINCT'] ) ||
isset( $noKeyOptions['DISTINCTROW'] ) ) {
1186 $startOpts .= 'DISTINCT';
1189 # Various MySQL extensions
1190 if ( isset( $noKeyOptions['STRAIGHT_JOIN'] ) ) {
1191 $startOpts .= ' /*! STRAIGHT_JOIN */';
1194 if ( isset( $noKeyOptions['HIGH_PRIORITY'] ) ) {
1195 $startOpts .= ' HIGH_PRIORITY';
1198 if ( isset( $noKeyOptions['SQL_BIG_RESULT'] ) ) {
1199 $startOpts .= ' SQL_BIG_RESULT';
1202 if ( isset( $noKeyOptions['SQL_BUFFER_RESULT'] ) ) {
1203 $startOpts .= ' SQL_BUFFER_RESULT';
1206 if ( isset( $noKeyOptions['SQL_SMALL_RESULT'] ) ) {
1207 $startOpts .= ' SQL_SMALL_RESULT';
1210 if ( isset( $noKeyOptions['SQL_CALC_FOUND_ROWS'] ) ) {
1211 $startOpts .= ' SQL_CALC_FOUND_ROWS';
1214 if ( isset( $noKeyOptions['SQL_CACHE'] ) ) {
1215 $startOpts .= ' SQL_CACHE';
1218 if ( isset( $noKeyOptions['SQL_NO_CACHE'] ) ) {
1219 $startOpts .= ' SQL_NO_CACHE';
1222 if ( isset( $options['USE INDEX'] ) && ! is_array( $options['USE INDEX'] ) ) {
1223 $useIndex = $this->useIndexClause( $options['USE INDEX'] );
1228 return array( $startOpts, $useIndex, $preLimitTail, $postLimitTail );
1232 * Execute a SELECT query constructed using the various parameters provided.
1233 * See below for full details of the parameters.
1235 * @param $table String|Array Table name
1236 * @param $vars String|Array Field names
1237 * @param $conds String|Array Conditions
1238 * @param $fname String Caller function name
1239 * @param $options Array Query options
1240 * @param $join_conds Array Join conditions
1242 * @param $table string|array
1244 * May be either an array of table names, or a single string holding a table
1245 * name. If an array is given, table aliases can be specified, for example:
1247 * array( 'a' => 'user' )
1249 * This includes the user table in the query, with the alias "a" available
1250 * for use in field names (e.g. a.user_name).
1252 * All of the table names given here are automatically run through
1253 * DatabaseBase::tableName(), which causes the table prefix (if any) to be
1254 * added, and various other table name mappings to be performed.
1257 * @param $vars string|array
1259 * May be either a field name or an array of field names. The field names
1260 * can be complete fragments of SQL, for direct inclusion into the SELECT
1261 * query. If an array is given, field aliases can be specified, for example:
1263 * array( 'maxrev' => 'MAX(rev_id)' )
1265 * This includes an expression with the alias "maxrev" in the query.
1267 * If an expression is given, care must be taken to ensure that it is
1271 * @param $conds string|array
1273 * May be either a string containing a single condition, or an array of
1274 * conditions. If an array is given, the conditions constructed from each
1275 * element are combined with AND.
1277 * Array elements may take one of two forms:
1279 * - Elements with a numeric key are interpreted as raw SQL fragments.
1280 * - Elements with a string key are interpreted as equality conditions,
1281 * where the key is the field name.
1282 * - If the value of such an array element is a scalar (such as a
1283 * string), it will be treated as data and thus quoted appropriately.
1284 * If it is null, an IS NULL clause will be added.
1285 * - If the value is an array, an IN(...) clause will be constructed,
1286 * such that the field name may match any of the elements in the
1287 * array. The elements of the array will be quoted.
1289 * Note that expressions are often DBMS-dependent in their syntax.
1290 * DBMS-independent wrappers are provided for constructing several types of
1291 * expression commonly used in condition queries. See:
1292 * - DatabaseBase::buildLike()
1293 * - DatabaseBase::conditional()
1296 * @param $options string|array
1298 * Optional: Array of query options. Boolean options are specified by
1299 * including them in the array as a string value with a numeric key, for
1302 * array( 'FOR UPDATE' )
1304 * The supported options are:
1306 * - OFFSET: Skip this many rows at the start of the result set. OFFSET
1307 * with LIMIT can theoretically be used for paging through a result set,
1308 * but this is discouraged in MediaWiki for performance reasons.
1310 * - LIMIT: Integer: return at most this many rows. The rows are sorted
1311 * and then the first rows are taken until the limit is reached. LIMIT
1312 * is applied to a result set after OFFSET.
1314 * - FOR UPDATE: Boolean: lock the returned rows so that they can't be
1315 * changed until the next COMMIT.
1317 * - DISTINCT: Boolean: return only unique result rows.
1319 * - GROUP BY: May be either an SQL fragment string naming a field or
1320 * expression to group by, or an array of such SQL fragments.
1322 * - HAVING: May be either an string containing a HAVING clause or an array of
1323 * conditions building the HAVING clause. If an array is given, the conditions
1324 * constructed from each element are combined with AND.
1326 * - ORDER BY: May be either an SQL fragment giving a field name or
1327 * expression to order by, or an array of such SQL fragments.
1329 * - USE INDEX: This may be either a string giving the index name to use
1330 * for the query, or an array. If it is an associative array, each key
1331 * gives the table name (or alias), each value gives the index name to
1332 * use for that table. All strings are SQL fragments and so should be
1333 * validated by the caller.
1335 * - EXPLAIN: In MySQL, this causes an EXPLAIN SELECT query to be run,
1336 * instead of SELECT.
1338 * And also the following boolean MySQL extensions, see the MySQL manual
1339 * for documentation:
1341 * - LOCK IN SHARE MODE
1345 * - SQL_BUFFER_RESULT
1346 * - SQL_SMALL_RESULT
1347 * - SQL_CALC_FOUND_ROWS
1352 * @param $join_conds string|array
1354 * Optional associative array of table-specific join conditions. In the
1355 * most common case, this is unnecessary, since the join condition can be
1356 * in $conds. However, it is useful for doing a LEFT JOIN.
1358 * The key of the array contains the table name or alias. The value is an
1359 * array with two elements, numbered 0 and 1. The first gives the type of
1360 * join, the second is an SQL fragment giving the join condition for that
1361 * table. For example:
1363 * array( 'page' => array('LEFT JOIN','page_latest=rev_id') )
1365 * @return ResultWrapper. If the query returned no rows, a ResultWrapper
1366 * with no rows in it will be returned. If there was a query error, a
1367 * DBQueryError exception will be thrown, except if the "ignore errors"
1368 * option was set, in which case false will be returned.
1370 public function select( $table, $vars, $conds = '', $fname = 'DatabaseBase::select',
1371 $options = array(), $join_conds = array() ) {
1372 $sql = $this->selectSQLText( $table, $vars, $conds, $fname, $options, $join_conds );
1374 return $this->query( $sql, $fname );
1378 * The equivalent of DatabaseBase::select() except that the constructed SQL
1379 * is returned, instead of being immediately executed. This can be useful for
1380 * doing UNION queries, where the SQL text of each query is needed. In general,
1381 * however, callers outside of Database classes should just use select().
1383 * @param $table string|array Table name
1384 * @param $vars string|array Field names
1385 * @param $conds string|array Conditions
1386 * @param $fname string Caller function name
1387 * @param $options string|array Query options
1388 * @param $join_conds string|array Join conditions
1390 * @return string SQL query string.
1391 * @see DatabaseBase::select()
1393 public function selectSQLText( $table, $vars, $conds = '', $fname = 'DatabaseBase::select',
1394 $options = array(), $join_conds = array() )
1396 if ( is_array( $vars ) ) {
1397 $vars = implode( ',', $this->fieldNamesWithAlias( $vars ) );
1400 $options = (array)$options;
1402 if ( is_array( $table ) ) {
1403 $useIndex = ( isset( $options['USE INDEX'] ) && is_array( $options['USE INDEX'] ) )
1404 ?
$options['USE INDEX']
1406 if ( count( $join_conds ) ||
count( $useIndex ) ) {
1408 $this->tableNamesWithUseIndexOrJOIN( $table, $useIndex, $join_conds );
1410 $from = ' FROM ' . implode( ',', $this->tableNamesWithAlias( $table ) );
1412 } elseif ( $table != '' ) {
1413 if ( $table[0] == ' ' ) {
1414 $from = ' FROM ' . $table;
1416 $from = ' FROM ' . $this->tableName( $table );
1422 list( $startOpts, $useIndex, $preLimitTail, $postLimitTail ) = $this->makeSelectOptions( $options );
1424 if ( !empty( $conds ) ) {
1425 if ( is_array( $conds ) ) {
1426 $conds = $this->makeList( $conds, LIST_AND
);
1428 $sql = "SELECT $startOpts $vars $from $useIndex WHERE $conds $preLimitTail";
1430 $sql = "SELECT $startOpts $vars $from $useIndex $preLimitTail";
1433 if ( isset( $options['LIMIT'] ) ) {
1434 $sql = $this->limitResult( $sql, $options['LIMIT'],
1435 isset( $options['OFFSET'] ) ?
$options['OFFSET'] : false );
1437 $sql = "$sql $postLimitTail";
1439 if ( isset( $options['EXPLAIN'] ) ) {
1440 $sql = 'EXPLAIN ' . $sql;
1447 * Single row SELECT wrapper. Equivalent to DatabaseBase::select(), except
1448 * that a single row object is returned. If the query returns no rows,
1449 * false is returned.
1451 * @param $table string|array Table name
1452 * @param $vars string|array Field names
1453 * @param $conds array Conditions
1454 * @param $fname string Caller function name
1455 * @param $options string|array Query options
1456 * @param $join_conds array|string Join conditions
1458 * @return object|bool
1460 public function selectRow( $table, $vars, $conds, $fname = 'DatabaseBase::selectRow',
1461 $options = array(), $join_conds = array() )
1463 $options = (array)$options;
1464 $options['LIMIT'] = 1;
1465 $res = $this->select( $table, $vars, $conds, $fname, $options, $join_conds );
1467 if ( $res === false ) {
1471 if ( !$this->numRows( $res ) ) {
1475 $obj = $this->fetchObject( $res );
1481 * Estimate rows in dataset.
1483 * MySQL allows you to estimate the number of rows that would be returned
1484 * by a SELECT query, using EXPLAIN SELECT. The estimate is provided using
1485 * index cardinality statistics, and is notoriously inaccurate, especially
1486 * when large numbers of rows have recently been added or deleted.
1488 * For DBMSs that don't support fast result size estimation, this function
1489 * will actually perform the SELECT COUNT(*).
1491 * Takes the same arguments as DatabaseBase::select().
1493 * @param $table String: table name
1494 * @param Array|string $vars : unused
1495 * @param Array|string $conds : filters on the table
1496 * @param $fname String: function name for profiling
1497 * @param $options Array: options for select
1498 * @return Integer: row count
1500 public function estimateRowCount( $table, $vars = '*', $conds = '',
1501 $fname = 'DatabaseBase::estimateRowCount', $options = array() )
1504 $res = $this->select( $table, array( 'rowcount' => 'COUNT(*)' ), $conds, $fname, $options );
1507 $row = $this->fetchRow( $res );
1508 $rows = ( isset( $row['rowcount'] ) ) ?
$row['rowcount'] : 0;
1515 * Removes most variables from an SQL query and replaces them with X or N for numbers.
1516 * It's only slightly flawed. Don't use for anything important.
1518 * @param $sql String A SQL Query
1522 static function generalizeSQL( $sql ) {
1523 # This does the same as the regexp below would do, but in such a way
1524 # as to avoid crashing php on some large strings.
1525 # $sql = preg_replace ( "/'([^\\\\']|\\\\.)*'|\"([^\\\\\"]|\\\\.)*\"/", "'X'", $sql);
1527 $sql = str_replace ( "\\\\", '', $sql );
1528 $sql = str_replace ( "\\'", '', $sql );
1529 $sql = str_replace ( "\\\"", '', $sql );
1530 $sql = preg_replace ( "/'.*'/s", "'X'", $sql );
1531 $sql = preg_replace ( '/".*"/s', "'X'", $sql );
1533 # All newlines, tabs, etc replaced by single space
1534 $sql = preg_replace ( '/\s+/', ' ', $sql );
1537 $sql = preg_replace ( '/-?[0-9]+/s', 'N', $sql );
1543 * Determines whether a field exists in a table
1545 * @param $table String: table name
1546 * @param $field String: filed to check on that table
1547 * @param $fname String: calling function name (optional)
1548 * @return Boolean: whether $table has filed $field
1550 public function fieldExists( $table, $field, $fname = 'DatabaseBase::fieldExists' ) {
1551 $info = $this->fieldInfo( $table, $field );
1557 * Determines whether an index exists
1558 * Usually throws a DBQueryError on failure
1559 * If errors are explicitly ignored, returns NULL on failure
1563 * @param $fname string
1567 public function indexExists( $table, $index, $fname = 'DatabaseBase::indexExists' ) {
1568 $info = $this->indexInfo( $table, $index, $fname );
1569 if ( is_null( $info ) ) {
1572 return $info !== false;
1577 * Query whether a given table exists
1579 * @param $table string
1580 * @param $fname string
1584 public function tableExists( $table, $fname = __METHOD__
) {
1585 $table = $this->tableName( $table );
1586 $old = $this->ignoreErrors( true );
1587 $res = $this->query( "SELECT 1 FROM $table LIMIT 1", $fname );
1588 $this->ignoreErrors( $old );
1594 * mysql_field_type() wrapper
1599 public function fieldType( $res, $index ) {
1600 if ( $res instanceof ResultWrapper
) {
1601 $res = $res->result
;
1604 return mysql_field_type( $res, $index );
1608 * Determines if a given index is unique
1610 * @param $table string
1611 * @param $index string
1615 public function indexUnique( $table, $index ) {
1616 $indexInfo = $this->indexInfo( $table, $index );
1618 if ( !$indexInfo ) {
1622 return !$indexInfo[0]->Non_unique
;
1626 * Helper for DatabaseBase::insert().
1628 * @param $options array
1631 protected function makeInsertOptions( $options ) {
1632 return implode( ' ', $options );
1636 * INSERT wrapper, inserts an array into a table.
1640 * - A single associative array. The array keys are the field names, and
1641 * the values are the values to insert. The values are treated as data
1642 * and will be quoted appropriately. If NULL is inserted, this will be
1643 * converted to a database NULL.
1644 * - An array with numeric keys, holding a list of associative arrays.
1645 * This causes a multi-row INSERT on DBMSs that support it. The keys in
1646 * each subarray must be identical to each other, and in the same order.
1648 * Usually throws a DBQueryError on failure. If errors are explicitly ignored,
1651 * $options is an array of options, with boolean options encoded as values
1652 * with numeric keys, in the same style as $options in
1653 * DatabaseBase::select(). Supported options are:
1655 * - IGNORE: Boolean: if present, duplicate key errors are ignored, and
1656 * any rows which cause duplicate key errors are not inserted. It's
1657 * possible to determine how many rows were successfully inserted using
1658 * DatabaseBase::affectedRows().
1660 * @param $table String Table name. This will be passed through
1661 * DatabaseBase::tableName().
1662 * @param $a Array of rows to insert
1663 * @param $fname String Calling function name (use __METHOD__) for logs/profiling
1664 * @param $options Array of options
1668 public function insert( $table, $a, $fname = 'DatabaseBase::insert', $options = array() ) {
1669 # No rows to insert, easy just return now
1670 if ( !count( $a ) ) {
1674 $table = $this->tableName( $table );
1676 if ( !is_array( $options ) ) {
1677 $options = array( $options );
1680 $options = $this->makeInsertOptions( $options );
1682 if ( isset( $a[0] ) && is_array( $a[0] ) ) {
1684 $keys = array_keys( $a[0] );
1687 $keys = array_keys( $a );
1690 $sql = 'INSERT ' . $options .
1691 " INTO $table (" . implode( ',', $keys ) . ') VALUES ';
1695 foreach ( $a as $row ) {
1701 $sql .= '(' . $this->makeList( $row ) . ')';
1704 $sql .= '(' . $this->makeList( $a ) . ')';
1707 return (bool)$this->query( $sql, $fname );
1711 * Make UPDATE options for the DatabaseBase::update function
1713 * @param $options Array: The options passed to DatabaseBase::update
1716 protected function makeUpdateOptions( $options ) {
1717 if ( !is_array( $options ) ) {
1718 $options = array( $options );
1723 if ( in_array( 'LOW_PRIORITY', $options ) ) {
1724 $opts[] = $this->lowPriorityOption();
1727 if ( in_array( 'IGNORE', $options ) ) {
1731 return implode( ' ', $opts );
1735 * UPDATE wrapper. Takes a condition array and a SET array.
1737 * @param $table String name of the table to UPDATE. This will be passed through
1738 * DatabaseBase::tableName().
1740 * @param $values Array: An array of values to SET. For each array element,
1741 * the key gives the field name, and the value gives the data
1742 * to set that field to. The data will be quoted by
1743 * DatabaseBase::addQuotes().
1745 * @param $conds Array: An array of conditions (WHERE). See
1746 * DatabaseBase::select() for the details of the format of
1747 * condition arrays. Use '*' to update all rows.
1749 * @param $fname String: The function name of the caller (from __METHOD__),
1750 * for logging and profiling.
1752 * @param $options Array: An array of UPDATE options, can be:
1753 * - IGNORE: Ignore unique key conflicts
1754 * - LOW_PRIORITY: MySQL-specific, see MySQL manual.
1757 function update( $table, $values, $conds, $fname = 'DatabaseBase::update', $options = array() ) {
1758 $table = $this->tableName( $table );
1759 $opts = $this->makeUpdateOptions( $options );
1760 $sql = "UPDATE $opts $table SET " . $this->makeList( $values, LIST_SET
);
1762 if ( $conds !== array() && $conds !== '*' ) {
1763 $sql .= " WHERE " . $this->makeList( $conds, LIST_AND
);
1766 return $this->query( $sql, $fname );
1770 * Makes an encoded list of strings from an array
1771 * @param $a Array containing the data
1772 * @param int $mode Constant
1773 * - LIST_COMMA: comma separated, no field names
1774 * - LIST_AND: ANDed WHERE clause (without the WHERE). See
1775 * the documentation for $conds in DatabaseBase::select().
1776 * - LIST_OR: ORed WHERE clause (without the WHERE)
1777 * - LIST_SET: comma separated with field names, like a SET clause
1778 * - LIST_NAMES: comma separated field names
1780 * @throws MWException|DBUnexpectedError
1783 public function makeList( $a, $mode = LIST_COMMA
) {
1784 if ( !is_array( $a ) ) {
1785 throw new DBUnexpectedError( $this, 'DatabaseBase::makeList called with incorrect parameters' );
1791 foreach ( $a as $field => $value ) {
1793 if ( $mode == LIST_AND
) {
1795 } elseif ( $mode == LIST_OR
) {
1804 if ( ( $mode == LIST_AND ||
$mode == LIST_OR
) && is_numeric( $field ) ) {
1805 $list .= "($value)";
1806 } elseif ( ( $mode == LIST_SET
) && is_numeric( $field ) ) {
1808 } elseif ( ( $mode == LIST_AND ||
$mode == LIST_OR
) && is_array( $value ) ) {
1809 if ( count( $value ) == 0 ) {
1810 throw new MWException( __METHOD__
. ": empty input for field $field" );
1811 } elseif ( count( $value ) == 1 ) {
1812 // Special-case single values, as IN isn't terribly efficient
1813 // Don't necessarily assume the single key is 0; we don't
1814 // enforce linear numeric ordering on other arrays here.
1815 $value = array_values( $value );
1816 $list .= $field . " = " . $this->addQuotes( $value[0] );
1818 $list .= $field . " IN (" . $this->makeList( $value ) . ") ";
1820 } elseif ( $value === null ) {
1821 if ( $mode == LIST_AND ||
$mode == LIST_OR
) {
1822 $list .= "$field IS ";
1823 } elseif ( $mode == LIST_SET
) {
1824 $list .= "$field = ";
1828 if ( $mode == LIST_AND ||
$mode == LIST_OR ||
$mode == LIST_SET
) {
1829 $list .= "$field = ";
1831 $list .= $mode == LIST_NAMES ?
$value : $this->addQuotes( $value );
1839 * Build a partial where clause from a 2-d array such as used for LinkBatch.
1840 * The keys on each level may be either integers or strings.
1842 * @param $data Array: organized as 2-d
1843 * array(baseKeyVal => array(subKeyVal => [ignored], ...), ...)
1844 * @param $baseKey String: field name to match the base-level keys to (eg 'pl_namespace')
1845 * @param $subKey String: field name to match the sub-level keys to (eg 'pl_title')
1846 * @return Mixed: string SQL fragment, or false if no items in array.
1848 public function makeWhereFrom2d( $data, $baseKey, $subKey ) {
1851 foreach ( $data as $base => $sub ) {
1852 if ( count( $sub ) ) {
1853 $conds[] = $this->makeList(
1854 array( $baseKey => $base, $subKey => array_keys( $sub ) ),
1860 return $this->makeList( $conds, LIST_OR
);
1862 // Nothing to search for...
1868 * Return aggregated value alias
1871 * @param $valuename string
1875 public function aggregateValue( $valuedata, $valuename = 'value' ) {
1883 public function bitNot( $field ) {
1889 * @param $fieldRight
1892 public function bitAnd( $fieldLeft, $fieldRight ) {
1893 return "($fieldLeft & $fieldRight)";
1898 * @param $fieldRight
1901 public function bitOr( $fieldLeft, $fieldRight ) {
1902 return "($fieldLeft | $fieldRight)";
1906 * Build a concatenation list to feed into a SQL query
1907 * @param $stringList Array: list of raw SQL expressions; caller is responsible for any quoting
1910 public function buildConcat( $stringList ) {
1911 return 'CONCAT(' . implode( ',', $stringList ) . ')';
1915 * Change the current database
1917 * @todo Explain what exactly will fail if this is not overridden.
1921 * @return bool Success or failure
1923 public function selectDB( $db ) {
1924 # Stub. Shouldn't cause serious problems if it's not overridden, but
1925 # if your database engine supports a concept similar to MySQL's
1926 # databases you may as well.
1927 $this->mDBname
= $db;
1932 * Get the current DB name
1934 public function getDBname() {
1935 return $this->mDBname
;
1939 * Get the server hostname or IP address
1941 public function getServer() {
1942 return $this->mServer
;
1946 * Format a table name ready for use in constructing an SQL query
1948 * This does two important things: it quotes the table names to clean them up,
1949 * and it adds a table prefix if only given a table name with no quotes.
1951 * All functions of this object which require a table name call this function
1952 * themselves. Pass the canonical name to such functions. This is only needed
1953 * when calling query() directly.
1955 * @param $name String: database table name
1956 * @param $format String One of:
1957 * quoted - Automatically pass the table name through addIdentifierQuotes()
1958 * so that it can be used in a query.
1959 * raw - Do not add identifier quotes to the table name
1960 * @return String: full database name
1962 public function tableName( $name, $format = 'quoted' ) {
1963 global $wgSharedDB, $wgSharedPrefix, $wgSharedTables;
1964 # Skip the entire process when we have a string quoted on both ends.
1965 # Note that we check the end so that we will still quote any use of
1966 # use of `database`.table. But won't break things if someone wants
1967 # to query a database table with a dot in the name.
1968 if ( $this->isQuotedIdentifier( $name ) ) {
1972 # Lets test for any bits of text that should never show up in a table
1973 # name. Basically anything like JOIN or ON which are actually part of
1974 # SQL queries, but may end up inside of the table value to combine
1975 # sql. Such as how the API is doing.
1976 # Note that we use a whitespace test rather than a \b test to avoid
1977 # any remote case where a word like on may be inside of a table name
1978 # surrounded by symbols which may be considered word breaks.
1979 if ( preg_match( '/(^|\s)(DISTINCT|JOIN|ON|AS)(\s|$)/i', $name ) !== 0 ) {
1983 # Split database and table into proper variables.
1984 # We reverse the explode so that database.table and table both output
1985 # the correct table.
1986 $dbDetails = explode( '.', $name, 2 );
1987 if ( count( $dbDetails ) == 2 ) {
1988 list( $database, $table ) = $dbDetails;
1989 # We don't want any prefix added in this case
1992 list( $table ) = $dbDetails;
1993 if ( $wgSharedDB !== null # We have a shared database
1994 && !$this->isQuotedIdentifier( $table ) # Paranoia check to prevent shared tables listing '`table`'
1995 && in_array( $table, $wgSharedTables ) # A shared table is selected
1997 $database = $wgSharedDB;
1998 $prefix = $wgSharedPrefix === null ?
$this->mTablePrefix
: $wgSharedPrefix;
2001 $prefix = $this->mTablePrefix
; # Default prefix
2005 # Quote $table and apply the prefix if not quoted.
2006 $tableName = "{$prefix}{$table}";
2007 if ( $format == 'quoted' && !$this->isQuotedIdentifier( $tableName ) ) {
2008 $tableName = $this->addIdentifierQuotes( $tableName );
2011 # Quote $database and merge it with the table name if needed
2012 if ( $database !== null ) {
2013 if ( $format == 'quoted' && !$this->isQuotedIdentifier( $database ) ) {
2014 $database = $this->addIdentifierQuotes( $database );
2016 $tableName = $database . '.' . $tableName;
2023 * Fetch a number of table names into an array
2024 * This is handy when you need to construct SQL for joins
2027 * extract($dbr->tableNames('user','watchlist'));
2028 * $sql = "SELECT wl_namespace,wl_title FROM $watchlist,$user
2029 * WHERE wl_user=user_id AND wl_user=$nameWithQuotes";
2033 public function tableNames() {
2034 $inArray = func_get_args();
2037 foreach ( $inArray as $name ) {
2038 $retVal[$name] = $this->tableName( $name );
2045 * Fetch a number of table names into an zero-indexed numerical array
2046 * This is handy when you need to construct SQL for joins
2049 * list( $user, $watchlist ) = $dbr->tableNamesN('user','watchlist');
2050 * $sql = "SELECT wl_namespace,wl_title FROM $watchlist,$user
2051 * WHERE wl_user=user_id AND wl_user=$nameWithQuotes";
2055 public function tableNamesN() {
2056 $inArray = func_get_args();
2059 foreach ( $inArray as $name ) {
2060 $retVal[] = $this->tableName( $name );
2067 * Get an aliased table name
2068 * e.g. tableName AS newTableName
2070 * @param $name string Table name, see tableName()
2071 * @param $alias string|bool Alias (optional)
2072 * @return string SQL name for aliased table. Will not alias a table to its own name
2074 public function tableNameWithAlias( $name, $alias = false ) {
2075 if ( !$alias ||
$alias == $name ) {
2076 return $this->tableName( $name );
2078 return $this->tableName( $name ) . ' ' . $this->addIdentifierQuotes( $alias );
2083 * Gets an array of aliased table names
2085 * @param $tables array( [alias] => table )
2086 * @return array of strings, see tableNameWithAlias()
2088 public function tableNamesWithAlias( $tables ) {
2090 foreach ( $tables as $alias => $table ) {
2091 if ( is_numeric( $alias ) ) {
2094 $retval[] = $this->tableNameWithAlias( $table, $alias );
2100 * Get an aliased field name
2101 * e.g. fieldName AS newFieldName
2103 * @param $name string Field name
2104 * @param $alias string|bool Alias (optional)
2105 * @return string SQL name for aliased field. Will not alias a field to its own name
2107 public function fieldNameWithAlias( $name, $alias = false ) {
2108 if ( !$alias ||
(string)$alias === (string)$name ) {
2111 return $name . ' AS ' . $alias; //PostgreSQL needs AS
2116 * Gets an array of aliased field names
2118 * @param $fields array( [alias] => field )
2119 * @return array of strings, see fieldNameWithAlias()
2121 public function fieldNamesWithAlias( $fields ) {
2123 foreach ( $fields as $alias => $field ) {
2124 if ( is_numeric( $alias ) ) {
2127 $retval[] = $this->fieldNameWithAlias( $field, $alias );
2133 * Get the aliased table name clause for a FROM clause
2134 * which might have a JOIN and/or USE INDEX clause
2136 * @param $tables array ( [alias] => table )
2137 * @param $use_index array Same as for select()
2138 * @param $join_conds array Same as for select()
2141 protected function tableNamesWithUseIndexOrJOIN(
2142 $tables, $use_index = array(), $join_conds = array()
2146 $use_index = (array)$use_index;
2147 $join_conds = (array)$join_conds;
2149 foreach ( $tables as $alias => $table ) {
2150 if ( !is_string( $alias ) ) {
2151 // No alias? Set it equal to the table name
2154 // Is there a JOIN clause for this table?
2155 if ( isset( $join_conds[$alias] ) ) {
2156 list( $joinType, $conds ) = $join_conds[$alias];
2157 $tableClause = $joinType;
2158 $tableClause .= ' ' . $this->tableNameWithAlias( $table, $alias );
2159 if ( isset( $use_index[$alias] ) ) { // has USE INDEX?
2160 $use = $this->useIndexClause( implode( ',', (array)$use_index[$alias] ) );
2162 $tableClause .= ' ' . $use;
2165 $on = $this->makeList( (array)$conds, LIST_AND
);
2167 $tableClause .= ' ON (' . $on . ')';
2170 $retJOIN[] = $tableClause;
2171 // Is there an INDEX clause for this table?
2172 } elseif ( isset( $use_index[$alias] ) ) {
2173 $tableClause = $this->tableNameWithAlias( $table, $alias );
2174 $tableClause .= ' ' . $this->useIndexClause(
2175 implode( ',', (array)$use_index[$alias] ) );
2177 $ret[] = $tableClause;
2179 $tableClause = $this->tableNameWithAlias( $table, $alias );
2181 $ret[] = $tableClause;
2185 // We can't separate explicit JOIN clauses with ',', use ' ' for those
2186 $straightJoins = !empty( $ret ) ?
implode( ',', $ret ) : "";
2187 $otherJoins = !empty( $retJOIN ) ?
implode( ' ', $retJOIN ) : "";
2189 // Compile our final table clause
2190 return implode( ' ', array( $straightJoins, $otherJoins ) );
2194 * Get the name of an index in a given table
2200 protected function indexName( $index ) {
2201 // Backwards-compatibility hack
2203 'ar_usertext_timestamp' => 'usertext_timestamp',
2204 'un_user_id' => 'user_id',
2205 'un_user_ip' => 'user_ip',
2208 if ( isset( $renamed[$index] ) ) {
2209 return $renamed[$index];
2216 * If it's a string, adds quotes and backslashes
2217 * Otherwise returns as-is
2223 public function addQuotes( $s ) {
2224 if ( $s === null ) {
2227 # This will also quote numeric values. This should be harmless,
2228 # and protects against weird problems that occur when they really
2229 # _are_ strings such as article titles and string->number->string
2230 # conversion is not 1:1.
2231 return "'" . $this->strencode( $s ) . "'";
2236 * Quotes an identifier using `backticks` or "double quotes" depending on the database type.
2237 * MySQL uses `backticks` while basically everything else uses double quotes.
2238 * Since MySQL is the odd one out here the double quotes are our generic
2239 * and we implement backticks in DatabaseMysql.
2245 public function addIdentifierQuotes( $s ) {
2246 return '"' . str_replace( '"', '""', $s ) . '"';
2250 * Returns if the given identifier looks quoted or not according to
2251 * the database convention for quoting identifiers .
2253 * @param $name string
2257 public function isQuotedIdentifier( $name ) {
2258 return $name[0] == '"' && substr( $name, -1, 1 ) == '"';
2265 protected function escapeLikeInternal( $s ) {
2266 $s = str_replace( '\\', '\\\\', $s );
2267 $s = $this->strencode( $s );
2268 $s = str_replace( array( '%', '_' ), array( '\%', '\_' ), $s );
2274 * LIKE statement wrapper, receives a variable-length argument list with parts of pattern to match
2275 * containing either string literals that will be escaped or tokens returned by anyChar() or anyString().
2276 * Alternatively, the function could be provided with an array of aforementioned parameters.
2278 * Example: $dbr->buildLike( 'My_page_title/', $dbr->anyString() ) returns a LIKE clause that searches
2279 * for subpages of 'My page title'.
2280 * Alternatively: $pattern = array( 'My_page_title/', $dbr->anyString() ); $query .= $dbr->buildLike( $pattern );
2283 * @return String: fully built LIKE statement
2285 public function buildLike() {
2286 $params = func_get_args();
2288 if ( count( $params ) > 0 && is_array( $params[0] ) ) {
2289 $params = $params[0];
2294 foreach ( $params as $value ) {
2295 if ( $value instanceof LikeMatch
) {
2296 $s .= $value->toString();
2298 $s .= $this->escapeLikeInternal( $value );
2302 return " LIKE '" . $s . "' ";
2306 * Returns a token for buildLike() that denotes a '_' to be used in a LIKE query
2310 public function anyChar() {
2311 return new LikeMatch( '_' );
2315 * Returns a token for buildLike() that denotes a '%' to be used in a LIKE query
2319 public function anyString() {
2320 return new LikeMatch( '%' );
2324 * Returns an appropriately quoted sequence value for inserting a new row.
2325 * MySQL has autoincrement fields, so this is just NULL. But the PostgreSQL
2326 * subclass will return an integer, and save the value for insertId()
2328 * Any implementation of this function should *not* involve reusing
2329 * sequence numbers created for rolled-back transactions.
2330 * See http://bugs.mysql.com/bug.php?id=30767 for details.
2331 * @param $seqName string
2334 public function nextSequenceValue( $seqName ) {
2339 * USE INDEX clause. Unlikely to be useful for anything but MySQL. This
2340 * is only needed because a) MySQL must be as efficient as possible due to
2341 * its use on Wikipedia, and b) MySQL 4.0 is kind of dumb sometimes about
2342 * which index to pick. Anyway, other databases might have different
2343 * indexes on a given table. So don't bother overriding this unless you're
2348 public function useIndexClause( $index ) {
2353 * REPLACE query wrapper.
2355 * REPLACE is a very handy MySQL extension, which functions like an INSERT
2356 * except that when there is a duplicate key error, the old row is deleted
2357 * and the new row is inserted in its place.
2359 * We simulate this with standard SQL with a DELETE followed by INSERT. To
2360 * perform the delete, we need to know what the unique indexes are so that
2361 * we know how to find the conflicting rows.
2363 * It may be more efficient to leave off unique indexes which are unlikely
2364 * to collide. However if you do this, you run the risk of encountering
2365 * errors which wouldn't have occurred in MySQL.
2367 * @param $table String: The table to replace the row(s) in.
2368 * @param $rows array Can be either a single row to insert, or multiple rows,
2369 * in the same format as for DatabaseBase::insert()
2370 * @param $uniqueIndexes array is an array of indexes. Each element may be either
2371 * a field name or an array of field names
2372 * @param $fname String: Calling function name (use __METHOD__) for logs/profiling
2374 public function replace( $table, $uniqueIndexes, $rows, $fname = 'DatabaseBase::replace' ) {
2375 $quotedTable = $this->tableName( $table );
2377 if ( count( $rows ) == 0 ) {
2382 if ( !is_array( reset( $rows ) ) ) {
2383 $rows = array( $rows );
2386 foreach( $rows as $row ) {
2387 # Delete rows which collide
2388 if ( $uniqueIndexes ) {
2389 $sql = "DELETE FROM $quotedTable WHERE ";
2391 foreach ( $uniqueIndexes as $index ) {
2398 if ( is_array( $index ) ) {
2400 foreach ( $index as $col ) {
2406 $sql .= $col . '=' . $this->addQuotes( $row[$col] );
2409 $sql .= $index . '=' . $this->addQuotes( $row[$index] );
2413 $this->query( $sql, $fname );
2416 # Now insert the row
2417 $this->insert( $table, $row );
2422 * REPLACE query wrapper for MySQL and SQLite, which have a native REPLACE
2425 * @param $table string Table name
2426 * @param $rows array Rows to insert
2427 * @param $fname string Caller function name
2429 * @return ResultWrapper
2431 protected function nativeReplace( $table, $rows, $fname ) {
2432 $table = $this->tableName( $table );
2435 if ( !is_array( reset( $rows ) ) ) {
2436 $rows = array( $rows );
2439 $sql = "REPLACE INTO $table (" . implode( ',', array_keys( $rows[0] ) ) . ') VALUES ';
2442 foreach ( $rows as $row ) {
2449 $sql .= '(' . $this->makeList( $row ) . ')';
2452 return $this->query( $sql, $fname );
2456 * DELETE where the condition is a join.
2458 * MySQL overrides this to use a multi-table DELETE syntax, in other databases
2459 * we use sub-selects
2461 * For safety, an empty $conds will not delete everything. If you want to
2462 * delete all rows where the join condition matches, set $conds='*'.
2464 * DO NOT put the join condition in $conds.
2466 * @param $delTable String: The table to delete from.
2467 * @param $joinTable String: The other table.
2468 * @param $delVar String: The variable to join on, in the first table.
2469 * @param $joinVar String: The variable to join on, in the second table.
2470 * @param $conds Array: Condition array of field names mapped to variables,
2471 * ANDed together in the WHERE clause
2472 * @param $fname String: Calling function name (use __METHOD__) for
2474 * @throws DBUnexpectedError
2476 public function deleteJoin( $delTable, $joinTable, $delVar, $joinVar, $conds,
2477 $fname = 'DatabaseBase::deleteJoin' )
2480 throw new DBUnexpectedError( $this,
2481 'DatabaseBase::deleteJoin() called with empty $conds' );
2484 $delTable = $this->tableName( $delTable );
2485 $joinTable = $this->tableName( $joinTable );
2486 $sql = "DELETE FROM $delTable WHERE $delVar IN (SELECT $joinVar FROM $joinTable ";
2487 if ( $conds != '*' ) {
2488 $sql .= 'WHERE ' . $this->makeList( $conds, LIST_AND
);
2492 $this->query( $sql, $fname );
2496 * Returns the size of a text field, or -1 for "unlimited"
2498 * @param $table string
2499 * @param $field string
2503 public function textFieldSize( $table, $field ) {
2504 $table = $this->tableName( $table );
2505 $sql = "SHOW COLUMNS FROM $table LIKE \"$field\";";
2506 $res = $this->query( $sql, 'DatabaseBase::textFieldSize' );
2507 $row = $this->fetchObject( $res );
2511 if ( preg_match( '/\((.*)\)/', $row->Type
, $m ) ) {
2521 * A string to insert into queries to show that they're low-priority, like
2522 * MySQL's LOW_PRIORITY. If no such feature exists, return an empty
2523 * string and nothing bad should happen.
2525 * @return string Returns the text of the low priority option if it is
2526 * supported, or a blank string otherwise
2528 public function lowPriorityOption() {
2533 * DELETE query wrapper.
2535 * @param $table Array Table name
2536 * @param $conds String|Array of conditions. See $conds in DatabaseBase::select() for
2537 * the format. Use $conds == "*" to delete all rows
2538 * @param $fname String name of the calling function
2540 * @throws DBUnexpectedError
2543 public function delete( $table, $conds, $fname = 'DatabaseBase::delete' ) {
2545 throw new DBUnexpectedError( $this, 'DatabaseBase::delete() called with no conditions' );
2548 $table = $this->tableName( $table );
2549 $sql = "DELETE FROM $table";
2551 if ( $conds != '*' ) {
2552 $sql .= ' WHERE ' . $this->makeList( $conds, LIST_AND
);
2555 return $this->query( $sql, $fname );
2559 * INSERT SELECT wrapper. Takes data from a SELECT query and inserts it
2560 * into another table.
2562 * @param $destTable string The table name to insert into
2563 * @param $srcTable string|array May be either a table name, or an array of table names
2564 * to include in a join.
2566 * @param $varMap array must be an associative array of the form
2567 * array( 'dest1' => 'source1', ...). Source items may be literals
2568 * rather than field names, but strings should be quoted with
2569 * DatabaseBase::addQuotes()
2571 * @param $conds array Condition array. See $conds in DatabaseBase::select() for
2572 * the details of the format of condition arrays. May be "*" to copy the
2575 * @param $fname string The function name of the caller, from __METHOD__
2577 * @param $insertOptions array Options for the INSERT part of the query, see
2578 * DatabaseBase::insert() for details.
2579 * @param $selectOptions array Options for the SELECT part of the query, see
2580 * DatabaseBase::select() for details.
2582 * @return ResultWrapper
2584 public function insertSelect( $destTable, $srcTable, $varMap, $conds,
2585 $fname = 'DatabaseBase::insertSelect',
2586 $insertOptions = array(), $selectOptions = array() )
2588 $destTable = $this->tableName( $destTable );
2590 if ( is_array( $insertOptions ) ) {
2591 $insertOptions = implode( ' ', $insertOptions );
2594 if ( !is_array( $selectOptions ) ) {
2595 $selectOptions = array( $selectOptions );
2598 list( $startOpts, $useIndex, $tailOpts ) = $this->makeSelectOptions( $selectOptions );
2600 if ( is_array( $srcTable ) ) {
2601 $srcTable = implode( ',', array_map( array( &$this, 'tableName' ), $srcTable ) );
2603 $srcTable = $this->tableName( $srcTable );
2606 $sql = "INSERT $insertOptions INTO $destTable (" . implode( ',', array_keys( $varMap ) ) . ')' .
2607 " SELECT $startOpts " . implode( ',', $varMap ) .
2608 " FROM $srcTable $useIndex ";
2610 if ( $conds != '*' ) {
2611 if ( is_array( $conds ) ) {
2612 $conds = $this->makeList( $conds, LIST_AND
);
2614 $sql .= " WHERE $conds";
2617 $sql .= " $tailOpts";
2619 return $this->query( $sql, $fname );
2623 * Construct a LIMIT query with optional offset. This is used for query
2624 * pages. The SQL should be adjusted so that only the first $limit rows
2625 * are returned. If $offset is provided as well, then the first $offset
2626 * rows should be discarded, and the next $limit rows should be returned.
2627 * If the result of the query is not ordered, then the rows to be returned
2628 * are theoretically arbitrary.
2630 * $sql is expected to be a SELECT, if that makes a difference.
2632 * The version provided by default works in MySQL and SQLite. It will very
2633 * likely need to be overridden for most other DBMSes.
2635 * @param $sql String SQL query we will append the limit too
2636 * @param $limit Integer the SQL limit
2637 * @param $offset Integer|bool the SQL offset (default false)
2639 * @throws DBUnexpectedError
2642 public function limitResult( $sql, $limit, $offset = false ) {
2643 if ( !is_numeric( $limit ) ) {
2644 throw new DBUnexpectedError( $this, "Invalid non-numeric limit passed to limitResult()\n" );
2646 return "$sql LIMIT "
2647 . ( ( is_numeric( $offset ) && $offset != 0 ) ?
"{$offset}," : "" )
2652 * Returns true if current database backend supports ORDER BY or LIMIT for separate subqueries
2653 * within the UNION construct.
2656 public function unionSupportsOrderAndLimit() {
2657 return true; // True for almost every DB supported
2661 * Construct a UNION query
2662 * This is used for providing overload point for other DB abstractions
2663 * not compatible with the MySQL syntax.
2664 * @param $sqls Array: SQL statements to combine
2665 * @param $all Boolean: use UNION ALL
2666 * @return String: SQL fragment
2668 public function unionQueries( $sqls, $all ) {
2669 $glue = $all ?
') UNION ALL (' : ') UNION (';
2670 return '(' . implode( $glue, $sqls ) . ')';
2674 * Returns an SQL expression for a simple conditional. This doesn't need
2675 * to be overridden unless CASE isn't supported in your DBMS.
2677 * @param $cond string|array SQL expression which will result in a boolean value
2678 * @param $trueVal String: SQL expression to return if true
2679 * @param $falseVal String: SQL expression to return if false
2680 * @return String: SQL fragment
2682 public function conditional( $cond, $trueVal, $falseVal ) {
2683 if ( is_array( $cond ) ) {
2684 $cond = $this->makeList( $cond, LIST_AND
);
2686 return " (CASE WHEN $cond THEN $trueVal ELSE $falseVal END) ";
2690 * Returns a comand for str_replace function in SQL query.
2691 * Uses REPLACE() in MySQL
2693 * @param $orig String: column to modify
2694 * @param $old String: column to seek
2695 * @param $new String: column to replace with
2699 public function strreplace( $orig, $old, $new ) {
2700 return "REPLACE({$orig}, {$old}, {$new})";
2704 * Determines how long the server has been up
2709 public function getServerUptime() {
2714 * Determines if the last failure was due to a deadlock
2719 public function wasDeadlock() {
2724 * Determines if the last failure was due to a lock timeout
2729 public function wasLockTimeout() {
2734 * Determines if the last query error was something that should be dealt
2735 * with by pinging the connection and reissuing the query.
2740 public function wasErrorReissuable() {
2745 * Determines if the last failure was due to the database being read-only.
2750 public function wasReadOnlyError() {
2755 * Perform a deadlock-prone transaction.
2757 * This function invokes a callback function to perform a set of write
2758 * queries. If a deadlock occurs during the processing, the transaction
2759 * will be rolled back and the callback function will be called again.
2762 * $dbw->deadlockLoop( callback, ... );
2764 * Extra arguments are passed through to the specified callback function.
2766 * Returns whatever the callback function returned on its successful,
2767 * iteration, or false on error, for example if the retry limit was
2772 public function deadlockLoop() {
2773 $this->begin( __METHOD__
);
2774 $args = func_get_args();
2775 $function = array_shift( $args );
2776 $oldIgnore = $this->ignoreErrors( true );
2777 $tries = DEADLOCK_TRIES
;
2779 if ( is_array( $function ) ) {
2780 $fname = $function[0];
2786 $retVal = call_user_func_array( $function, $args );
2787 $error = $this->lastError();
2788 $errno = $this->lastErrno();
2789 $sql = $this->lastQuery();
2792 if ( $this->wasDeadlock() ) {
2794 usleep( mt_rand( DEADLOCK_DELAY_MIN
, DEADLOCK_DELAY_MAX
) );
2796 $this->reportQueryError( $error, $errno, $sql, $fname );
2799 } while ( $this->wasDeadlock() && --$tries > 0 );
2801 $this->ignoreErrors( $oldIgnore );
2803 if ( $tries <= 0 ) {
2804 $this->rollback( __METHOD__
);
2805 $this->reportQueryError( $error, $errno, $sql, $fname );
2808 $this->commit( __METHOD__
);
2814 * Wait for the slave to catch up to a given master position.
2816 * @param $pos DBMasterPos object
2817 * @param $timeout Integer: the maximum number of seconds to wait for
2820 * @return integer: zero if the slave was past that position already,
2821 * greater than zero if we waited for some period of time, less than
2822 * zero if we timed out.
2824 public function masterPosWait( DBMasterPos
$pos, $timeout ) {
2825 wfProfileIn( __METHOD__
);
2827 if ( !is_null( $this->mFakeSlaveLag
) ) {
2828 $wait = intval( ( $pos->pos
- microtime( true ) +
$this->mFakeSlaveLag
) * 1e6
);
2830 if ( $wait > $timeout * 1e6
) {
2831 wfDebug( "Fake slave timed out waiting for $pos ($wait us)\n" );
2832 wfProfileOut( __METHOD__
);
2834 } elseif ( $wait > 0 ) {
2835 wfDebug( "Fake slave waiting $wait us\n" );
2837 wfProfileOut( __METHOD__
);
2840 wfDebug( "Fake slave up to date ($wait us)\n" );
2841 wfProfileOut( __METHOD__
);
2846 wfProfileOut( __METHOD__
);
2848 # Real waits are implemented in the subclass.
2853 * Get the replication position of this slave
2855 * @return DBMasterPos, or false if this is not a slave.
2857 public function getSlavePos() {
2858 if ( !is_null( $this->mFakeSlaveLag
) ) {
2859 $pos = new MySQLMasterPos( 'fake', microtime( true ) - $this->mFakeSlaveLag
);
2860 wfDebug( __METHOD__
. ": fake slave pos = $pos\n" );
2869 * Get the position of this master
2871 * @return DBMasterPos, or false if this is not a master
2873 public function getMasterPos() {
2874 if ( $this->mFakeMaster
) {
2875 return new MySQLMasterPos( 'fake', microtime( true ) );
2882 * Run an anonymous function as soon as there is no transaction pending.
2883 * If there is a transaction and it is rolled back, then the callback is cancelled.
2884 * Callbacks must commit any transactions that they begin.
2886 * This is useful for updates to different systems or separate transactions are needed.
2890 * @param Closure $callback
2892 final public function onTransactionIdle( Closure
$callback ) {
2893 if ( $this->mTrxLevel
) {
2894 $this->trxIdleCallbacks
[] = $callback;
2901 * Actually run the "on transaction idle" callbacks.
2905 protected function runOnTransactionIdleCallbacks() {
2906 $e = null; // last exception
2907 do { // callbacks may add callbacks :)
2908 $callbacks = $this->trxIdleCallbacks
;
2909 $this->trxIdleCallbacks
= array(); // recursion guard
2910 foreach ( $callbacks as $callback ) {
2913 } catch ( Exception
$e ) {}
2915 } while ( count( $this->trxIdleCallbacks
) );
2917 if ( $e instanceof Exception
) {
2918 throw $e; // re-throw any last exception
2923 * Begin a transaction. If a transaction is already in progress, that transaction will be committed before the
2924 * new transaction is started.
2926 * Note that when the DBO_TRX flag is set (which is usually the case for web requests, but not for maintenance scripts),
2927 * any previous database query will have started a transaction automatically.
2929 * Nesting of transactions is not supported. Attempts to nest transactions will cause a warning, unless the current
2930 * transaction was started automatically because of the DBO_TRX flag.
2932 * @param $fname string
2934 final public function begin( $fname = 'DatabaseBase::begin' ) {
2935 global $wgDebugDBTransactions;
2937 if ( $this->mTrxLevel
) { // implicit commit
2938 if ( !$this->mTrxAutomatic
) {
2939 // We want to warn about inadvertently nested begin/commit pairs, but not about auto-committing
2940 // implicit transactions that were started by query() because DBO_TRX was set.
2942 wfWarn( "$fname: Transaction already in progress (from {$this->mTrxFname}), " .
2943 " performing implicit commit!" );
2945 // if the transaction was automatic and has done write operations,
2946 // log it if $wgDebugDBTransactions is enabled.
2948 if ( $this->mTrxDoneWrites
&& $wgDebugDBTransactions ) {
2949 wfDebug( "$fname: Automatic transaction with writes in progress (from {$this->mTrxFname}), " .
2950 " performing implicit commit!\n" );
2954 $this->doCommit( $fname );
2955 $this->runOnTransactionIdleCallbacks();
2958 $this->doBegin( $fname );
2959 $this->mTrxFname
= $fname;
2960 $this->mTrxDoneWrites
= false;
2961 $this->mTrxAutomatic
= false;
2965 * Issues the BEGIN command to the database server.
2967 * @see DatabaseBase::begin()
2968 * @param type $fname
2970 protected function doBegin( $fname ) {
2971 $this->query( 'BEGIN', $fname );
2972 $this->mTrxLevel
= 1;
2976 * Commits a transaction previously started using begin().
2977 * If no transaction is in progress, a warning is issued.
2979 * Nesting of transactions is not supported.
2981 * @param $fname string
2982 * @param $flush String Flush flag, set to 'flush' to disable warnings about explicitly committing implicit
2983 * transactions, or calling commit when no transaction is in progress.
2984 * This will silently break any ongoing explicit transaction. Only set the flush flag if you are sure
2985 * that it is safe to ignore these warnings in your context.
2987 final public function commit( $fname = 'DatabaseBase::commit', $flush = '' ) {
2988 if ( $flush != 'flush' ) {
2989 if ( !$this->mTrxLevel
) {
2990 wfWarn( "$fname: No transaction to commit, something got out of sync!" );
2991 } elseif( $this->mTrxAutomatic
) {
2992 wfWarn( "$fname: Explicit commit of implicit transaction. Something may be out of sync!" );
2995 if ( !$this->mTrxLevel
) {
2996 return; // nothing to do
2997 } elseif( !$this->mTrxAutomatic
) {
2998 wfWarn( "$fname: Flushing an explicit transaction, getting out of sync!" );
3002 $this->doCommit( $fname );
3003 $this->runOnTransactionIdleCallbacks();
3007 * Issues the COMMIT command to the database server.
3009 * @see DatabaseBase::commit()
3010 * @param type $fname
3012 protected function doCommit( $fname ) {
3013 if ( $this->mTrxLevel
) {
3014 $this->query( 'COMMIT', $fname );
3015 $this->mTrxLevel
= 0;
3020 * Rollback a transaction previously started using begin().
3021 * If no transaction is in progress, a warning is issued.
3023 * No-op on non-transactional databases.
3025 * @param $fname string
3027 final public function rollback( $fname = 'DatabaseBase::rollback' ) {
3028 if ( !$this->mTrxLevel
) {
3029 wfWarn( "$fname: No transaction to rollback, something got out of sync!" );
3031 $this->doRollback( $fname );
3032 $this->trxIdleCallbacks
= array(); // cancel
3036 * Issues the ROLLBACK command to the database server.
3038 * @see DatabaseBase::rollback()
3039 * @param type $fname
3041 protected function doRollback( $fname ) {
3042 if ( $this->mTrxLevel
) {
3043 $this->query( 'ROLLBACK', $fname, true );
3044 $this->mTrxLevel
= 0;
3049 * Creates a new table with structure copied from existing table
3050 * Note that unlike most database abstraction functions, this function does not
3051 * automatically append database prefix, because it works at a lower
3052 * abstraction level.
3053 * The table names passed to this function shall not be quoted (this
3054 * function calls addIdentifierQuotes when needed).
3056 * @param $oldName String: name of table whose structure should be copied
3057 * @param $newName String: name of table to be created
3058 * @param $temporary Boolean: whether the new table should be temporary
3059 * @param $fname String: calling function name
3060 * @throws MWException
3061 * @return Boolean: true if operation was successful
3063 public function duplicateTableStructure( $oldName, $newName, $temporary = false,
3064 $fname = 'DatabaseBase::duplicateTableStructure' )
3066 throw new MWException(
3067 'DatabaseBase::duplicateTableStructure is not implemented in descendant class' );
3071 * List all tables on the database
3073 * @param $prefix string Only show tables with this prefix, e.g. mw_
3074 * @param $fname String: calling function name
3075 * @throws MWException
3077 function listTables( $prefix = null, $fname = 'DatabaseBase::listTables' ) {
3078 throw new MWException( 'DatabaseBase::listTables is not implemented in descendant class' );
3082 * Convert a timestamp in one of the formats accepted by wfTimestamp()
3083 * to the format used for inserting into timestamp fields in this DBMS.
3085 * The result is unquoted, and needs to be passed through addQuotes()
3086 * before it can be included in raw SQL.
3088 * @param $ts string|int
3092 public function timestamp( $ts = 0 ) {
3093 return wfTimestamp( TS_MW
, $ts );
3097 * Convert a timestamp in one of the formats accepted by wfTimestamp()
3098 * to the format used for inserting into timestamp fields in this DBMS. If
3099 * NULL is input, it is passed through, allowing NULL values to be inserted
3100 * into timestamp fields.
3102 * The result is unquoted, and needs to be passed through addQuotes()
3103 * before it can be included in raw SQL.
3105 * @param $ts string|int
3109 public function timestampOrNull( $ts = null ) {
3110 if ( is_null( $ts ) ) {
3113 return $this->timestamp( $ts );
3118 * Take the result from a query, and wrap it in a ResultWrapper if
3119 * necessary. Boolean values are passed through as is, to indicate success
3120 * of write queries or failure.
3122 * Once upon a time, DatabaseBase::query() returned a bare MySQL result
3123 * resource, and it was necessary to call this function to convert it to
3124 * a wrapper. Nowadays, raw database objects are never exposed to external
3125 * callers, so this is unnecessary in external code. For compatibility with
3126 * old code, ResultWrapper objects are passed through unaltered.
3128 * @param $result bool|ResultWrapper
3130 * @return bool|ResultWrapper
3132 public function resultObject( $result ) {
3133 if ( empty( $result ) ) {
3135 } elseif ( $result instanceof ResultWrapper
) {
3137 } elseif ( $result === true ) {
3138 // Successful write query
3141 return new ResultWrapper( $this, $result );
3146 * Ping the server and try to reconnect if it there is no connection
3148 * @return bool Success or failure
3150 public function ping() {
3151 # Stub. Not essential to override.
3156 * Get slave lag. Currently supported only by MySQL.
3158 * Note that this function will generate a fatal error on many
3159 * installations. Most callers should use LoadBalancer::safeGetLag()
3162 * @return int Database replication lag in seconds
3164 public function getLag() {
3165 return intval( $this->mFakeSlaveLag
);
3169 * Return the maximum number of items allowed in a list, or 0 for unlimited.
3173 function maxListLen() {
3178 * Some DBMSs have a special format for inserting into blob fields, they
3179 * don't allow simple quoted strings to be inserted. To insert into such
3180 * a field, pass the data through this function before passing it to
3181 * DatabaseBase::insert().
3185 public function encodeBlob( $b ) {
3190 * Some DBMSs return a special placeholder object representing blob fields
3191 * in result objects. Pass the object through this function to return the
3196 public function decodeBlob( $b ) {
3201 * Override database's default behavior. $options include:
3202 * 'connTimeout' : Set the connection timeout value in seconds.
3203 * May be useful for very long batch queries such as
3204 * full-wiki dumps, where a single query reads out over
3207 * @param $options Array
3210 public function setSessionOptions( array $options ) {}
3213 * Read and execute SQL commands from a file.
3215 * Returns true on success, error string or exception on failure (depending
3216 * on object's error ignore settings).
3218 * @param $filename String: File name to open
3219 * @param bool|callable $lineCallback Optional function called before reading each line
3220 * @param bool|callable $resultCallback Optional function called for each MySQL result
3221 * @param bool|string $fname Calling function name or false if name should be
3222 * generated dynamically using $filename
3223 * @throws MWException
3224 * @return bool|string
3226 public function sourceFile(
3227 $filename, $lineCallback = false, $resultCallback = false, $fname = false
3229 wfSuppressWarnings();
3230 $fp = fopen( $filename, 'r' );
3231 wfRestoreWarnings();
3233 if ( false === $fp ) {
3234 throw new MWException( "Could not open \"{$filename}\".\n" );
3238 $fname = __METHOD__
. "( $filename )";
3242 $error = $this->sourceStream( $fp, $lineCallback, $resultCallback, $fname );
3244 catch ( MWException
$e ) {
3255 * Get the full path of a patch file. Originally based on archive()
3256 * from updaters.inc. Keep in mind this always returns a patch, as
3257 * it fails back to MySQL if no DB-specific patch can be found
3259 * @param $patch String The name of the patch, like patch-something.sql
3260 * @return String Full path to patch file
3262 public function patchPath( $patch ) {
3265 $dbType = $this->getType();
3266 if ( file_exists( "$IP/maintenance/$dbType/archives/$patch" ) ) {
3267 return "$IP/maintenance/$dbType/archives/$patch";
3269 return "$IP/maintenance/archives/$patch";
3274 * Set variables to be used in sourceFile/sourceStream, in preference to the
3275 * ones in $GLOBALS. If an array is set here, $GLOBALS will not be used at
3276 * all. If it's set to false, $GLOBALS will be used.
3278 * @param $vars bool|array mapping variable name to value.
3280 public function setSchemaVars( $vars ) {
3281 $this->mSchemaVars
= $vars;
3285 * Read and execute commands from an open file handle.
3287 * Returns true on success, error string or exception on failure (depending
3288 * on object's error ignore settings).
3290 * @param $fp Resource: File handle
3291 * @param $lineCallback Callback: Optional function called before reading each line
3292 * @param $resultCallback Callback: Optional function called for each MySQL result
3293 * @param $fname String: Calling function name
3294 * @param $inputCallback Callback: Optional function called for each complete line (ended with ;) sent
3295 * @return bool|string
3297 public function sourceStream( $fp, $lineCallback = false, $resultCallback = false,
3298 $fname = 'DatabaseBase::sourceStream', $inputCallback = false )
3302 while ( !feof( $fp ) ) {
3303 if ( $lineCallback ) {
3304 call_user_func( $lineCallback );
3307 $line = trim( fgets( $fp ) );
3309 if ( $line == '' ) {
3313 if ( '-' == $line[0] && '-' == $line[1] ) {
3321 $done = $this->streamStatementEnd( $cmd, $line );
3325 if ( $done ||
feof( $fp ) ) {
3326 $cmd = $this->replaceVars( $cmd );
3327 if ( $inputCallback ) {
3328 call_user_func( $inputCallback, $cmd );
3330 $res = $this->query( $cmd, $fname );
3332 if ( $resultCallback ) {
3333 call_user_func( $resultCallback, $res, $this );
3336 if ( false === $res ) {
3337 $err = $this->lastError();
3338 return "Query \"{$cmd}\" failed with error code \"$err\".\n";
3349 * Called by sourceStream() to check if we've reached a statement end
3351 * @param $sql String SQL assembled so far
3352 * @param $newLine String New line about to be added to $sql
3353 * @return Bool Whether $newLine contains end of the statement
3355 public function streamStatementEnd( &$sql, &$newLine ) {
3356 if ( $this->delimiter
) {
3358 $newLine = preg_replace( '/' . preg_quote( $this->delimiter
, '/' ) . '$/', '', $newLine );
3359 if ( $newLine != $prev ) {
3367 * Database independent variable replacement. Replaces a set of variables
3368 * in an SQL statement with their contents as given by $this->getSchemaVars().
3370 * Supports '{$var}' `{$var}` and / *$var* / (without the spaces) style variables.
3372 * - '{$var}' should be used for text and is passed through the database's
3374 * - `{$var}` should be used for identifiers (eg: table and database names),
3375 * it is passed through the database's addIdentifierQuotes method which
3376 * can be overridden if the database uses something other than backticks.
3377 * - / *$var* / is just encoded, besides traditional table prefix and
3378 * table options its use should be avoided.
3380 * @param $ins String: SQL statement to replace variables in
3381 * @return String The new SQL statement with variables replaced
3383 protected function replaceSchemaVars( $ins ) {
3384 $vars = $this->getSchemaVars();
3385 foreach ( $vars as $var => $value ) {
3387 $ins = str_replace( '\'{$' . $var . '}\'', $this->addQuotes( $value ), $ins );
3389 $ins = str_replace( '`{$' . $var . '}`', $this->addIdentifierQuotes( $value ), $ins );
3391 $ins = str_replace( '/*$' . $var . '*/', $this->strencode( $value ) , $ins );
3397 * Replace variables in sourced SQL
3399 * @param $ins string
3403 protected function replaceVars( $ins ) {
3404 $ins = $this->replaceSchemaVars( $ins );
3407 $ins = preg_replace_callback( '!/\*(?:\$wgDBprefix|_)\*/([a-zA-Z_0-9]*)!',
3408 array( $this, 'tableNameCallback' ), $ins );
3411 $ins = preg_replace_callback( '!/\*i\*/([a-zA-Z_0-9]*)!',
3412 array( $this, 'indexNameCallback' ), $ins );
3418 * Get schema variables. If none have been set via setSchemaVars(), then
3419 * use some defaults from the current object.
3423 protected function getSchemaVars() {
3424 if ( $this->mSchemaVars
) {
3425 return $this->mSchemaVars
;
3427 return $this->getDefaultSchemaVars();
3432 * Get schema variables to use if none have been set via setSchemaVars().
3434 * Override this in derived classes to provide variables for tables.sql
3435 * and SQL patch files.
3439 protected function getDefaultSchemaVars() {
3444 * Table name callback
3446 * @param $matches array
3450 protected function tableNameCallback( $matches ) {
3451 return $this->tableName( $matches[1] );
3455 * Index name callback
3457 * @param $matches array
3461 protected function indexNameCallback( $matches ) {
3462 return $this->indexName( $matches[1] );
3466 * Check to see if a named lock is available. This is non-blocking.
3468 * @param $lockName String: name of lock to poll
3469 * @param $method String: name of method calling us
3473 public function lockIsFree( $lockName, $method ) {
3478 * Acquire a named lock
3480 * Abstracted from Filestore::lock() so child classes can implement for
3483 * @param $lockName String: name of lock to aquire
3484 * @param $method String: name of method calling us
3485 * @param $timeout Integer: timeout
3488 public function lock( $lockName, $method, $timeout = 5 ) {
3495 * @param $lockName String: Name of lock to release
3496 * @param $method String: Name of method calling us
3498 * @return int Returns 1 if the lock was released, 0 if the lock was not established
3499 * by this thread (in which case the lock is not released), and NULL if the named
3500 * lock did not exist
3502 public function unlock( $lockName, $method ) {
3507 * Lock specific tables
3509 * @param $read Array of tables to lock for read access
3510 * @param $write Array of tables to lock for write access
3511 * @param $method String name of caller
3512 * @param $lowPriority bool Whether to indicate writes to be LOW PRIORITY
3516 public function lockTables( $read, $write, $method, $lowPriority = true ) {
3521 * Unlock specific tables
3523 * @param $method String the caller
3527 public function unlockTables( $method ) {
3533 * @param $tableName string
3534 * @param $fName string
3535 * @return bool|ResultWrapper
3538 public function dropTable( $tableName, $fName = 'DatabaseBase::dropTable' ) {
3539 if( !$this->tableExists( $tableName, $fName ) ) {
3542 $sql = "DROP TABLE " . $this->tableName( $tableName );
3543 if( $this->cascadingDeletes() ) {
3546 return $this->query( $sql, $fName );
3550 * Get search engine class. All subclasses of this need to implement this
3551 * if they wish to use searching.
3555 public function getSearchEngine() {
3556 return 'SearchEngineDummy';
3560 * Find out when 'infinity' is. Most DBMSes support this. This is a special
3561 * keyword for timestamps in PostgreSQL, and works with CHAR(14) as well
3562 * because "i" sorts after all numbers.
3566 public function getInfinity() {
3571 * Encode an expiry time into the DBMS dependent format
3573 * @param $expiry String: timestamp for expiry, or the 'infinity' string
3576 public function encodeExpiry( $expiry ) {
3577 return ( $expiry == '' ||
$expiry == 'infinity' ||
$expiry == $this->getInfinity() )
3578 ?
$this->getInfinity()
3579 : $this->timestamp( $expiry );
3583 * Decode an expiry time into a DBMS independent format
3585 * @param $expiry String: DB timestamp field value for expiry
3586 * @param $format integer: TS_* constant, defaults to TS_MW
3589 public function decodeExpiry( $expiry, $format = TS_MW
) {
3590 return ( $expiry == '' ||
$expiry == $this->getInfinity() )
3592 : wfTimestamp( $format, $expiry );
3596 * Allow or deny "big selects" for this session only. This is done by setting
3597 * the sql_big_selects session variable.
3599 * This is a MySQL-specific feature.
3601 * @param $value Mixed: true for allow, false for deny, or "default" to
3602 * restore the initial value
3604 public function setBigSelects( $value = true ) {
3611 public function __toString() {
3612 return (string)$this->mConn
;