includes/db/DatabaseMssql.php

   1 <?php
   2 /**
   3  * This is the MS SQL Server Native database abstraction layer.
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @file
  21  * @ingroup Database
  22  * @author Joel Penner <a-joelpe at microsoft dot com>
  23  * @author Chris Pucci <a-cpucci at microsoft dot com>
  24  * @author Ryan Biesemeyer <v-ryanbi at microsoft dot com>
  25  * @author Ryan Schmidt <skizzerz at gmail dot com>
  26  */
  27
  28 /**
  29  * @ingroup Database
  30  */
  31 class DatabaseMssql extends DatabaseBase {
  32         protected $mInsertId = null;
  33         protected $mLastResult = null;
  34         protected $mAffectedRows = null;
  35         protected $mSubqueryId = 0;
  36         protected $mScrollableCursor = true;
  37         protected $mPrepareStatements = true;
  38         protected $mBinaryColumnCache = null;
  39         protected $mBitColumnCache = null;
  40         protected $mIgnoreDupKeyErrors = false;
  41
  42         protected $mPort;
  43
  44         public function cascadingDeletes() {
  45                 return true;
  46         }
  47
  48         public function cleanupTriggers() {
  49                 return false;
  50         }
  51
  52         public function strictIPs() {
  53                 return false;
  54         }
  55
  56         public function realTimestamps() {
  57                 return false;
  58         }
  59
  60         public function implicitGroupby() {
  61                 return false;
  62         }
  63
  64         public function implicitOrderby() {
  65                 return false;
  66         }
  67
  68         public function functionalIndexes() {
  69                 return true;
  70         }
  71
  72         public function unionSupportsOrderAndLimit() {
  73                 return false;
  74         }
  75
  76         /**
  77          * Usually aborts on failure
  78          * @param string $server
  79          * @param string $user
  80          * @param string $password
  81          * @param string $dbName
  82          * @throws DBConnectionError
  83          * @return bool|DatabaseBase|null
  84          */
  85         public function open( $server, $user, $password, $dbName ) {
  86                 # Test for driver support, to avoid suppressed fatal error
  87                 if ( !function_exists( 'sqlsrv_connect' ) ) {
  88                         throw new DBConnectionError(
  89                                 $this,
  90                                 "Microsoft SQL Server Native (sqlsrv) functions missing.
  91                                 You can download the driver from: http://go.microsoft.com/fwlink/?LinkId=123470\n"
  92                         );
  93                 }
  94
  95                 global $wgDBport, $wgDBWindowsAuthentication;
  96
  97                 # e.g. the class is being loaded
  98                 if ( !strlen( $user ) ) {
  99                         return null;
 100                 }
 101
 102                 $this->close();
 103                 $this->mServer = $server;
 104                 $this->mPort = $wgDBport;
 105                 $this->mUser = $user;
 106                 $this->mPassword = $password;
 107                 $this->mDBname = $dbName;
 108
 109                 $connectionInfo = array();
 110
 111                 if ( $dbName ) {
 112                         $connectionInfo['Database'] = $dbName;
 113                 }
 114
 115                 // Decide which auth scenerio to use
 116                 // if we are using Windows auth, don't add credentials to $connectionInfo
 117                 if ( !$wgDBWindowsAuthentication ) {
 118                         $connectionInfo['UID'] = $user;
 119                         $connectionInfo['PWD'] = $password;
 120                 }
 121
 122                 wfSuppressWarnings();
 123                 $this->mConn = sqlsrv_connect( $server, $connectionInfo );
 124                 wfRestoreWarnings();
 125
 126                 if ( $this->mConn === false ) {
 127                         throw new DBConnectionError( $this, $this->lastError() );
 128                 }
 129
 130                 $this->mOpened = true;
 131
 132                 return $this->mConn;
 133         }
 134
 135         /**
 136          * Closes a database connection, if it is open
 137          * Returns success, true if already closed
 138          * @return bool
 139          */
 140         protected function closeConnection() {
 141                 return sqlsrv_close( $this->mConn );
 142         }
 143
 144         /**
 145          * @param bool|MssqlResultWrapper|resource $result
 146          * @return bool|MssqlResultWrapper
 147          */
 148         public function resultObject( $result ) {
 149                 if ( empty( $result ) ) {
 150                         return false;
 151                 } elseif ( $result instanceof MssqlResultWrapper ) {
 152                         return $result;
 153                 } elseif ( $result === true ) {
 154                         // Successful write query
 155                         return $result;
 156                 } else {
 157                         return new MssqlResultWrapper( $this, $result );
 158                 }
 159         }
 160
 161         /**
 162          * @param string $sql
 163          * @return bool|MssqlResult
 164          * @throws DBUnexpectedError
 165          */
 166         protected function doQuery( $sql ) {
 167                 if ( $this->debug() ) {
 168                         wfDebug( "SQL: [$sql]\n" );
 169                 }
 170                 $this->offset = 0;
 171
 172                 // several extensions seem to think that all databases support limits
 173                 // via LIMIT N after the WHERE clause well, MSSQL uses SELECT TOP N,
 174                 // so to catch any of those extensions we'll do a quick check for a
 175                 // LIMIT clause and pass $sql through $this->LimitToTopN() which parses
 176                 // the limit clause and passes the result to $this->limitResult();
 177                 if ( preg_match( '/\bLIMIT\s*/i', $sql ) ) {
 178                         // massage LIMIT -> TopN
 179                         $sql = $this->LimitToTopN( $sql );
 180                 }
 181
 182                 // MSSQL doesn't have EXTRACT(epoch FROM XXX)
 183                 if ( preg_match( '#\bEXTRACT\s*?\(\s*?EPOCH\s+FROM\b#i', $sql, $matches ) ) {
 184                         // This is same as UNIX_TIMESTAMP, we need to calc # of seconds from 1970
 185                         $sql = str_replace( $matches[0], "DATEDIFF(s,CONVERT(datetime,'1/1/1970'),", $sql );
 186                 }
 187
 188                 // perform query
 189
 190                 // SQLSRV_CURSOR_STATIC is slower than SQLSRV_CURSOR_CLIENT_BUFFERED (one of the two is
 191                 // needed if we want to be able to seek around the result set), however CLIENT_BUFFERED
 192                 // has a bug in the sqlsrv driver where wchar_t types (such as nvarchar) that are empty
 193                 // strings make php throw a fatal error "Severe error translating Unicode"
 194                 if ( $this->mScrollableCursor ) {
 195                         $scrollArr = array( 'Scrollable' => SQLSRV_CURSOR_STATIC );
 196                 } else {
 197                         $scrollArr = array();
 198                 }
 199
 200                 if ( $this->mPrepareStatements ) {
 201                         // we do prepare + execute so we can get its field metadata for later usage if desired
 202                         $stmt = sqlsrv_prepare( $this->mConn, $sql, array(), $scrollArr );
 203                         $success = sqlsrv_execute( $stmt );
 204                 } else {
 205                         $stmt = sqlsrv_query( $this->mConn, $sql, array(), $scrollArr );
 206                         $success = (bool)$stmt;
 207                 }
 208
 209                 if ( $this->mIgnoreDupKeyErrors ) {
 210                         // ignore duplicate key errors, but nothing else
 211                         // this emulates INSERT IGNORE in MySQL
 212                         if ( $success === false ) {
 213                                 $errors = sqlsrv_errors( SQLSRV_ERR_ERRORS );
 214                                 $success = true;
 215
 216                                 foreach ( $errors as $err ) {
 217                                         if ( $err['SQLSTATE'] == '23000' && $err['code'] == '2601' ) {
 218                                                 continue; // duplicate key error caused by unique index
 219                                         } elseif ( $err['SQLSTATE'] == '23000' && $err['code'] == '2627' ) {
 220                                                 continue; // duplicate key error caused by primary key
 221                                         } elseif ( $err['SQLSTATE'] == '01000' && $err['code'] == '3621' ) {
 222                                                 continue; // generic "the statement has been terminated" error
 223                                         }
 224
 225                                         $success = false; // getting here means we got an error we weren't expecting
 226                                         break;
 227                                 }
 228
 229                                 if ( $success ) {
 230                                         $this->mAffectedRows = 0;
 231                                         return $stmt;
 232                                 }
 233                         }
 234                 }
 235
 236                 if ( $success === false ) {
 237                         return false;
 238                 }
 239                 // remember number of rows affected
 240                 $this->mAffectedRows = sqlsrv_rows_affected( $stmt );
 241
 242                 return $stmt;
 243         }
 244
 245         public function freeResult( $res ) {
 246                 if ( $res instanceof ResultWrapper ) {
 247                         $res = $res->result;
 248                 }
 249
 250                 sqlsrv_free_stmt( $res );
 251         }
 252
 253         /**
 254          * @param MssqlResultWrapper $res
 255          * @return stdClass
 256          */
 257         public function fetchObject( $res ) {
 258                 // $res is expected to be an instance of MssqlResultWrapper here
 259                 return $res->fetchObject();
 260         }
 261
 262         /**
 263          * @param MssqlResultWrapper $res
 264          * @return array
 265          */
 266         public function fetchRow( $res ) {
 267                 return $res->fetchRow();
 268         }
 269
 270         /**
 271          * @param mixed $res
 272          * @return int
 273          */
 274         public function numRows( $res ) {
 275                 if ( $res instanceof ResultWrapper ) {
 276                         $res = $res->result;
 277                 }
 278
 279                 return sqlsrv_num_rows( $res );
 280         }
 281
 282         /**
 283          * @param mixed $res
 284          * @return int
 285          */
 286         public function numFields( $res ) {
 287                 if ( $res instanceof ResultWrapper ) {
 288                         $res = $res->result;
 289                 }
 290
 291                 return sqlsrv_num_fields( $res );
 292         }
 293
 294         /**
 295          * @param mixed $res
 296          * @param int $n
 297          * @return int
 298          */
 299         public function fieldName( $res, $n ) {
 300                 if ( $res instanceof ResultWrapper ) {
 301                         $res = $res->result;
 302                 }
 303
 304                 $metadata = sqlsrv_field_metadata( $res );
 305                 return $metadata[$n]['Name'];
 306         }
 307
 308         /**
 309          * This must be called after nextSequenceVal
 310          * @return int|null
 311          */
 312         public function insertId() {
 313                 return $this->mInsertId;
 314         }
 315
 316         /**
 317          * @param MssqlResultWrapper $res
 318          * @param int $row
 319          * @return bool
 320          */
 321         public function dataSeek( $res, $row ) {
 322                 return $res->seek( $row );
 323         }
 324
 325         /**
 326          * @return string
 327          */
 328         public function lastError() {
 329                 $strRet = '';
 330                 $retErrors = sqlsrv_errors( SQLSRV_ERR_ALL );
 331                 if ( $retErrors != null ) {
 332                         foreach ( $retErrors as $arrError ) {
 333                                 $strRet .= $this->formatError( $arrError ) . "\n";
 334                         }
 335                 } else {
 336                         $strRet = "No errors found";
 337                 }
 338
 339                 return $strRet;
 340         }
 341
 342         /**
 343          * @param array $err
 344          * @return string
 345          */
 346         private function formatError( $err ) {
 347                 return '[SQLSTATE ' . $err['SQLSTATE'] . '][Error Code ' . $err['code'] . ']' . $err['message'];
 348         }
 349
 350         /**
 351          * @return string
 352          */
 353         public function lastErrno() {
 354                 $err = sqlsrv_errors( SQLSRV_ERR_ALL );
 355                 if ( $err !== null && isset( $err[0] ) ) {
 356                         return $err[0]['code'];
 357                 } else {
 358                         return 0;
 359                 }
 360         }
 361
 362         /**
 363          * @return int
 364          */
 365         public function affectedRows() {
 366                 return $this->mAffectedRows;
 367         }
 368
 369         /**
 370          * SELECT wrapper
 371          *
 372          * @param mixed $table Array or string, table name(s) (prefix auto-added)
 373          * @param mixed $vars Array or string, field name(s) to be retrieved
 374          * @param mixed $conds Array or string, condition(s) for WHERE
 375          * @param string $fname Calling function name (use __METHOD__) for logs/profiling
 376          * @param array $options Associative array of options (e.g.
 377          *   array('GROUP BY' => 'page_title')), see Database::makeSelectOptions
 378          *   code for list of supported stuff
 379          * @param array $join_conds Associative array of table join conditions
 380          *   (optional) (e.g. array( 'page' => array('LEFT JOIN','page_latest=rev_id') )
 381          * @return mixed Database result resource (feed to Database::fetchObject
 382          *   or whatever), or false on failure
 383          */
 384         public function select( $table, $vars, $conds = '', $fname = __METHOD__,
 385                 $options = array(), $join_conds = array()
 386         ) {
 387                 $sql = $this->selectSQLText( $table, $vars, $conds, $fname, $options, $join_conds );
 388                 if ( isset( $options['EXPLAIN'] ) ) {
 389                         try {
 390                                 $this->mScrollableCursor = false;
 391                                 $this->mPrepareStatements = false;
 392                                 $this->query( "SET SHOWPLAN_ALL ON" );
 393                                 $ret = $this->query( $sql, $fname );
 394                                 $this->query( "SET SHOWPLAN_ALL OFF" );
 395                         } catch ( DBQueryError $dqe ) {
 396                                 if ( isset( $options['FOR COUNT'] ) ) {
 397                                         // likely don't have privs for SHOWPLAN, so run a select count instead
 398                                         $this->query( "SET SHOWPLAN_ALL OFF" );
 399                                         unset( $options['EXPLAIN'] );
 400                                         $ret = $this->select(
 401                                                 $table,
 402                                                 'COUNT(*) AS EstimateRows',
 403                                                 $conds,
 404                                                 $fname,
 405                                                 $options,
 406                                                 $join_conds
 407                                         );
 408                                 } else {
 409                                         // someone actually wanted the query plan instead of an est row count
 410                                         // let them know of the error
 411                                         $this->mScrollableCursor = true;
 412                                         $this->mPrepareStatements = true;
 413                                         throw $dqe;
 414                                 }
 415                         }
 416                         $this->mScrollableCursor = true;
 417                         $this->mPrepareStatements = true;
 418                         return $ret;
 419                 }
 420                 return $this->query( $sql, $fname );
 421         }
 422
 423         /**
 424          * SELECT wrapper
 425          *
 426          * @param mixed $table Array or string, table name(s) (prefix auto-added)
 427          * @param mixed $vars Array or string, field name(s) to be retrieved
 428          * @param mixed $conds Array or string, condition(s) for WHERE
 429          * @param string $fname Calling function name (use __METHOD__) for logs/profiling
 430          * @param array $options Associative array of options (e.g. array('GROUP BY' => 'page_title')),
 431          *   see Database::makeSelectOptions code for list of supported stuff
 432          * @param array $join_conds Associative array of table join conditions (optional)
 433          *    (e.g. array( 'page' => array('LEFT JOIN','page_latest=rev_id') )
 434          * @return string The SQL text
 435          */
 436         public function selectSQLText( $table, $vars, $conds = '', $fname = __METHOD__,
 437                 $options = array(), $join_conds = array()
 438         ) {
 439                 if ( isset( $options['EXPLAIN'] ) ) {
 440                         unset( $options['EXPLAIN'] );
 441                 }
 442
 443                 $sql = parent::selectSQLText( $table, $vars, $conds, $fname, $options, $join_conds );
 444
 445                 // try to rewrite aggregations of bit columns (currently MAX and MIN)
 446                 if ( strpos( $sql, 'MAX(' ) !== false || strpos( $sql, 'MIN(' ) !== false ) {
 447                         $bitColumns = array();
 448                         if ( is_array( $table ) ) {
 449                                 foreach ( $table as $t ) {
 450                                         $bitColumns += $this->getBitColumns( $this->tableName( $t ) );
 451                                 }
 452                         } else {
 453                                 $bitColumns = $this->getBitColumns( $this->tableName( $table ) );
 454                         }
 455
 456                         foreach ( $bitColumns as $col => $info ) {
 457                                 $replace = array(
 458                                         "MAX({$col})" => "MAX(CAST({$col} AS tinyint))",
 459                                         "MIN({$col})" => "MIN(CAST({$col} AS tinyint))",
 460                                 );
 461                                 $sql = str_replace( array_keys( $replace ), array_values( $replace ), $sql );
 462                         }
 463                 }
 464
 465                 return $sql;
 466         }
 467
 468         public function deleteJoin( $delTable, $joinTable, $delVar, $joinVar, $conds,
 469                 $fname = __METHOD__
 470         ) {
 471                 $this->mScrollableCursor = false;
 472                 try {
 473                         parent::deleteJoin( $delTable, $joinTable, $delVar, $joinVar, $conds, $fname );
 474                 } catch ( Exception $e ) {
 475                         $this->mScrollableCursor = true;
 476                         throw $e;
 477                 }
 478                 $this->mScrollableCursor = true;
 479         }
 480
 481         public function delete( $table, $conds, $fname = __METHOD__ ) {
 482                 $this->mScrollableCursor = false;
 483                 try {
 484                         parent::delete( $table, $conds, $fname );
 485                 } catch ( Exception $e ) {
 486                         $this->mScrollableCursor = true;
 487                         throw $e;
 488                 }
 489                 $this->mScrollableCursor = true;
 490         }
 491
 492         /**
 493          * Estimate rows in dataset
 494          * Returns estimated count, based on SHOWPLAN_ALL output
 495          * This is not necessarily an accurate estimate, so use sparingly
 496          * Returns -1 if count cannot be found
 497          * Takes same arguments as Database::select()
 498          * @param string $table
 499          * @param string $vars
 500          * @param string $conds
 501          * @param string $fname
 502          * @param array $options
 503          * @return int
 504          */
 505         public function estimateRowCount( $table, $vars = '*', $conds = '',
 506                 $fname = __METHOD__, $options = array()
 507         ) {
 508                 // http://msdn2.microsoft.com/en-us/library/aa259203.aspx
 509                 $options['EXPLAIN'] = true;
 510                 $options['FOR COUNT'] = true;
 511                 $res = $this->select( $table, $vars, $conds, $fname, $options );
 512
 513                 $rows = -1;
 514                 if ( $res ) {
 515                         $row = $this->fetchRow( $res );
 516
 517                         if ( isset( $row['EstimateRows'] ) ) {
 518                                 $rows = $row['EstimateRows'];
 519                         }
 520                 }
 521
 522                 return $rows;
 523         }
 524
 525         /**
 526          * Returns information about an index
 527          * If errors are explicitly ignored, returns NULL on failure
 528          * @param string $table
 529          * @param string $index
 530          * @param string $fname
 531          * @return array|bool|null
 532          */
 533         public function indexInfo( $table, $index, $fname = __METHOD__ ) {
 534                 # This does not return the same info as MYSQL would, but that's OK
 535                 # because MediaWiki never uses the returned value except to check for
 536                 # the existance of indexes.
 537                 $sql = "sp_helpindex '" . $table . "'";
 538                 $res = $this->query( $sql, $fname );
 539                 if ( !$res ) {
 540                         return null;
 541                 }
 542
 543                 $result = array();
 544                 foreach ( $res as $row ) {
 545                         if ( $row->index_name == $index ) {
 546                                 $row->Non_unique = !stristr( $row->index_description, "unique" );
 547                                 $cols = explode( ", ", $row->index_keys );
 548                                 foreach ( $cols as $col ) {
 549                                         $row->Column_name = trim( $col );
 550                                         $result[] = clone $row;
 551                                 }
 552                         } elseif ( $index == 'PRIMARY' && stristr( $row->index_description, 'PRIMARY' ) ) {
 553                                 $row->Non_unique = 0;
 554                                 $cols = explode( ", ", $row->index_keys );
 555                                 foreach ( $cols as $col ) {
 556                                         $row->Column_name = trim( $col );
 557                                         $result[] = clone $row;
 558                                 }
 559                         }
 560                 }
 561
 562                 return empty( $result ) ? false : $result;
 563         }
 564
 565         /**
 566          * INSERT wrapper, inserts an array into a table
 567          *
 568          * $arrToInsert may be a single associative array, or an array of these with numeric keys, for
 569          * multi-row insert.
 570          *
 571          * Usually aborts on failure
 572          * If errors are explicitly ignored, returns success
 573          * @param string $table
 574          * @param array $arrToInsert
 575          * @param string $fname
 576          * @param array $options
 577          * @throws DBQueryError
 578          * @return bool
 579          */
 580         public function insert( $table, $arrToInsert, $fname = __METHOD__, $options = array() ) {
 581                 # No rows to insert, easy just return now
 582                 if ( !count( $arrToInsert ) ) {
 583                         return true;
 584                 }
 585
 586                 if ( !is_array( $options ) ) {
 587                         $options = array( $options );
 588                 }
 589
 590                 $table = $this->tableName( $table );
 591
 592                 if ( !( isset( $arrToInsert[0] ) && is_array( $arrToInsert[0] ) ) ) { // Not multi row
 593                         $arrToInsert = array( 0 => $arrToInsert ); // make everything multi row compatible
 594                 }
 595
 596                 // We know the table we're inserting into, get its identity column
 597                 $identity = null;
 598                 // strip matching square brackets and the db/schema from table name
 599                 $tableRawArr = explode( '.', preg_replace( '#\[([^\]]*)\]#', '$1', $table ) );
 600                 $tableRaw = array_pop( $tableRawArr );
 601                 $res = $this->doQuery(
 602                         "SELECT NAME AS idColumn FROM SYS.IDENTITY_COLUMNS " .
 603                                 "WHERE OBJECT_NAME(OBJECT_ID)='{$tableRaw}'"
 604                 );
 605                 if ( $res && sqlsrv_has_rows( $res ) ) {
 606                         // There is an identity for this table.
 607                         $identityArr = sqlsrv_fetch_array( $res, SQLSRV_FETCH_ASSOC );
 608                         $identity = array_pop( $identityArr );
 609                 }
 610                 sqlsrv_free_stmt( $res );
 611
 612                 // Determine binary/varbinary fields so we can encode data as a hex string like 0xABCDEF
 613                 $binaryColumns = $this->getBinaryColumns( $table );
 614
 615                 // INSERT IGNORE is not supported by SQL Server
 616                 // remove IGNORE from options list and set ignore flag to true
 617                 if ( in_array( 'IGNORE', $options ) ) {
 618                         $options = array_diff( $options, array( 'IGNORE' ) );
 619                         $this->mIgnoreDupKeyErrors = true;
 620                 }
 621
 622                 foreach ( $arrToInsert as $a ) {
 623                         // start out with empty identity column, this is so we can return
 624                         // it as a result of the insert logic
 625                         $sqlPre = '';
 626                         $sqlPost = '';
 627                         $identityClause = '';
 628
 629                         // if we have an identity column
 630                         if ( $identity ) {
 631                                 // iterate through
 632                                 foreach ( $a as $k => $v ) {
 633                                         if ( $k == $identity ) {
 634                                                 if ( !is_null( $v ) ) {
 635                                                         // there is a value being passed to us,
 636                                                         // we need to turn on and off inserted identity
 637                                                         $sqlPre = "SET IDENTITY_INSERT $table ON;";
 638                                                         $sqlPost = ";SET IDENTITY_INSERT $table OFF;";
 639                                                 } else {
 640                                                         // we can't insert NULL into an identity column,
 641                                                         // so remove the column from the insert.
 642                                                         unset( $a[$k] );
 643                                                 }
 644                                         }
 645                                 }
 646
 647                                 // we want to output an identity column as result
 648                                 $identityClause = "OUTPUT INSERTED.$identity ";
 649                         }
 650
 651                         $keys = array_keys( $a );
 652
 653                         // Build the actual query
 654                         $sql = $sqlPre . 'INSERT ' . implode( ' ', $options ) .
 655                                 " INTO $table (" . implode( ',', $keys ) . ") $identityClause VALUES (";
 656
 657                         $first = true;
 658                         foreach ( $a as $key => $value ) {
 659                                 if ( isset( $binaryColumns[$key] ) ) {
 660                                         $value = new MssqlBlob( $value );
 661                                 }
 662                                 if ( $first ) {
 663                                         $first = false;
 664                                 } else {
 665                                         $sql .= ',';
 666                                 }
 667                                 if ( is_null( $value ) ) {
 668                                         $sql .= 'null';
 669                                 } elseif ( is_array( $value ) || is_object( $value ) ) {
 670                                         if ( is_object( $value ) && $value instanceof Blob ) {
 671                                                 $sql .= $this->addQuotes( $value );
 672                                         } else {
 673                                                 $sql .= $this->addQuotes( serialize( $value ) );
 674                                         }
 675                                 } else {
 676                                         $sql .= $this->addQuotes( $value );
 677                                 }
 678                         }
 679                         $sql .= ')' . $sqlPost;
 680
 681                         // Run the query
 682                         $this->mScrollableCursor = false;
 683                         try {
 684                                 $ret = $this->query( $sql );
 685                         } catch ( Exception $e ) {
 686                                 $this->mScrollableCursor = true;
 687                                 $this->mIgnoreDupKeyErrors = false;
 688                                 throw $e;
 689                         }
 690                         $this->mScrollableCursor = true;
 691
 692                         if ( !is_null( $identity ) ) {
 693                                 // then we want to get the identity column value we were assigned and save it off
 694                                 $row = $ret->fetchObject();
 695                                 if ( is_object( $row ) ) {
 696                                         $this->mInsertId = $row->$identity;
 697                                 }
 698                         }
 699                 }
 700                 $this->mIgnoreDupKeyErrors = false;
 701                 return $ret;
 702         }
 703
 704         /**
 705          * INSERT SELECT wrapper
 706          * $varMap must be an associative array of the form array( 'dest1' => 'source1', ...)
 707          * Source items may be literals rather than field names, but strings should
 708          * be quoted with Database::addQuotes().
 709          * @param string $destTable
 710          * @param array|string $srcTable May be an array of tables.
 711          * @param array $varMap
 712          * @param array $conds May be "*" to copy the whole table.
 713          * @param string $fname
 714          * @param array $insertOptions
 715          * @param array $selectOptions
 716          * @throws DBQueryError
 717          * @return null|ResultWrapper
 718          */
 719         public function insertSelect( $destTable, $srcTable, $varMap, $conds, $fname = __METHOD__,
 720                 $insertOptions = array(), $selectOptions = array()
 721         ) {
 722                 $this->mScrollableCursor = false;
 723                 try {
 724                         $ret = parent::insertSelect(
 725                                 $destTable,
 726                                 $srcTable,
 727                                 $varMap,
 728                                 $conds,
 729                                 $fname,
 730                                 $insertOptions,
 731                                 $selectOptions
 732                         );
 733                 } catch ( Exception $e ) {
 734                         $this->mScrollableCursor = true;
 735                         throw $e;
 736                 }
 737                 $this->mScrollableCursor = true;
 738
 739                 return $ret;
 740         }
 741
 742         /**
 743          * UPDATE wrapper. Takes a condition array and a SET array.
 744          *
 745          * @param string $table Name of the table to UPDATE. This will be passed through
 746          *                DatabaseBase::tableName().
 747          *
 748          * @param array $values An array of values to SET. For each array element,
 749          *                the key gives the field name, and the value gives the data
 750          *                to set that field to. The data will be quoted by
 751          *                DatabaseBase::addQuotes().
 752          *
 753          * @param array $conds An array of conditions (WHERE). See
 754          *                DatabaseBase::select() for the details of the format of
 755          *                condition arrays. Use '*' to update all rows.
 756          *
 757          * @param string $fname The function name of the caller (from __METHOD__),
 758          *                for logging and profiling.
 759          *
 760          * @param array $options An array of UPDATE options, can be:
 761          *                   - IGNORE: Ignore unique key conflicts
 762          *                   - LOW_PRIORITY: MySQL-specific, see MySQL manual.
 763          * @return bool
 764          */
 765         function update( $table, $values, $conds, $fname = __METHOD__, $options = array() ) {
 766                 $table = $this->tableName( $table );
 767                 $binaryColumns = $this->getBinaryColumns( $table );
 768
 769                 $opts = $this->makeUpdateOptions( $options );
 770                 $sql = "UPDATE $opts $table SET " . $this->makeList( $values, LIST_SET, $binaryColumns );
 771
 772                 if ( $conds !== array() && $conds !== '*' ) {
 773                         $sql .= " WHERE " . $this->makeList( $conds, LIST_AND, $binaryColumns );
 774                 }
 775
 776                 $this->mScrollableCursor = false;
 777                 try {
 778                         $ret = $this->query( $sql );
 779                 } catch ( Exception $e ) {
 780                         $this->mScrollableCursor = true;
 781                         throw $e;
 782                 }
 783                 $this->mScrollableCursor = true;
 784                 return true;
 785         }
 786
 787         /**
 788          * Makes an encoded list of strings from an array
 789          * @param array $a Containing the data
 790          * @param int $mode Constant
 791          *      - LIST_COMMA:          comma separated, no field names
 792          *      - LIST_AND:            ANDed WHERE clause (without the WHERE). See
 793          *        the documentation for $conds in DatabaseBase::select().
 794          *      - LIST_OR:             ORed WHERE clause (without the WHERE)
 795          *      - LIST_SET:            comma separated with field names, like a SET clause
 796          *      - LIST_NAMES:          comma separated field names
 797          * @param array $binaryColumns Contains a list of column names that are binary types
 798          *      This is a custom parameter only present for MS SQL.
 799          *
 800          * @throws MWException|DBUnexpectedError
 801          * @return string
 802          */
 803         public function makeList( $a, $mode = LIST_COMMA, $binaryColumns = array() ) {
 804                 if ( !is_array( $a ) ) {
 805                         throw new DBUnexpectedError( $this,
 806                                 'DatabaseBase::makeList called with incorrect parameters' );
 807                 }
 808
 809                 $first = true;
 810                 $list = '';
 811
 812                 foreach ( $a as $field => $value ) {
 813                         if ( $mode != LIST_NAMES && isset( $binaryColumns[$field] ) ) {
 814                                 if ( is_array( $value ) ) {
 815                                         foreach ( $value as &$v ) {
 816                                                 $v = new MssqlBlob( $v );
 817                                         }
 818                                 } else {
 819                                         $value = new MssqlBlob( $value );
 820                                 }
 821                         }
 822
 823                         if ( !$first ) {
 824                                 if ( $mode == LIST_AND ) {
 825                                         $list .= ' AND ';
 826                                 } elseif ( $mode == LIST_OR ) {
 827                                         $list .= ' OR ';
 828                                 } else {
 829                                         $list .= ',';
 830                                 }
 831                         } else {
 832                                 $first = false;
 833                         }
 834
 835                         if ( ( $mode == LIST_AND || $mode == LIST_OR ) && is_numeric( $field ) ) {
 836                                 $list .= "($value)";
 837                         } elseif ( ( $mode == LIST_SET ) && is_numeric( $field ) ) {
 838                                 $list .= "$value";
 839                         } elseif ( ( $mode == LIST_AND || $mode == LIST_OR ) && is_array( $value ) ) {
 840                                 if ( count( $value ) == 0 ) {
 841                                         throw new MWException( __METHOD__ . ": empty input for field $field" );
 842                                 } elseif ( count( $value ) == 1 ) {
 843                                         // Special-case single values, as IN isn't terribly efficient
 844                                         // Don't necessarily assume the single key is 0; we don't
 845                                         // enforce linear numeric ordering on other arrays here.
 846                                         $value = array_values( $value );
 847                                         $list .= $field . " = " . $this->addQuotes( $value[0] );
 848                                 } else {
 849                                         $list .= $field . " IN (" . $this->makeList( $value ) . ") ";
 850                                 }
 851                         } elseif ( $value === null ) {
 852                                 if ( $mode == LIST_AND || $mode == LIST_OR ) {
 853                                         $list .= "$field IS ";
 854                                 } elseif ( $mode == LIST_SET ) {
 855                                         $list .= "$field = ";
 856                                 }
 857                                 $list .= 'NULL';
 858                         } else {
 859                                 if ( $mode == LIST_AND || $mode == LIST_OR || $mode == LIST_SET ) {
 860                                         $list .= "$field = ";
 861                                 }
 862                                 $list .= $mode == LIST_NAMES ? $value : $this->addQuotes( $value );
 863                         }
 864                 }
 865
 866                 return $list;
 867         }
 868
 869         /**
 870          * @param string $table
 871          * @param string $field
 872          * @return int Returns the size of a text field, or -1 for "unlimited"
 873          */
 874         public function textFieldSize( $table, $field ) {
 875                 $table = $this->tableName( $table );
 876                 $sql = "SELECT CHARACTER_MAXIMUM_LENGTH,DATA_TYPE FROM INFORMATION_SCHEMA.Columns
 877                         WHERE TABLE_NAME = '$table' AND COLUMN_NAME = '$field'";
 878                 $res = $this->query( $sql );
 879                 $row = $this->fetchRow( $res );
 880                 $size = -1;
 881                 if ( strtolower( $row['DATA_TYPE'] ) != 'text' ) {
 882                         $size = $row['CHARACTER_MAXIMUM_LENGTH'];
 883                 }
 884
 885                 return $size;
 886         }
 887
 888         /**
 889          * Construct a LIMIT query with optional offset
 890          * This is used for query pages
 891          *
 892          * @param string $sql SQL query we will append the limit too
 893          * @param int $limit The SQL limit
 894          * @param bool|int $offset The SQL offset (default false)
 895          * @return array|string
 896          */
 897         public function limitResult( $sql, $limit, $offset = false ) {
 898                 if ( $offset === false || $offset == 0 ) {
 899                         if ( strpos( $sql, "SELECT" ) === false ) {
 900                                 return "TOP {$limit} " . $sql;
 901                         } else {
 902                                 return preg_replace( '/\bSELECT(\s+DISTINCT)?\b/Dsi',
 903                                         'SELECT$1 TOP ' . $limit, $sql, 1 );
 904                         }
 905                 } else {
 906                         // This one is fun, we need to pull out the select list as well as any ORDER BY clause
 907                         $select = $orderby = array();
 908                         $s1 = preg_match( '#SELECT\s+(.+?)\s+FROM#Dis', $sql, $select );
 909                         $s2 = preg_match( '#(ORDER BY\s+.+?)(\s*FOR XML .*)?$#Dis', $sql, $orderby );
 910                         $overOrder = $postOrder = '';
 911                         $first = $offset + 1;
 912                         $last = $offset + $limit;
 913                         $sub1 = 'sub_' . $this->mSubqueryId;
 914                         $sub2 = 'sub_' . ( $this->mSubqueryId + 1 );
 915                         $this->mSubqueryId += 2;
 916                         if ( !$s1 ) {
 917                                 // wat
 918                                 throw new DBUnexpectedError( $this, "Attempting to LIMIT a non-SELECT query\n" );
 919                         }
 920                         if ( !$s2 ) {
 921                                 // no ORDER BY
 922                                 $overOrder = 'ORDER BY (SELECT 1)';
 923                         } else {
 924                                 if ( !isset( $orderby[2] ) || !$orderby[2] ) {
 925                                         // don't need to strip it out if we're using a FOR XML clause
 926                                         $sql = str_replace( $orderby[1], '', $sql );
 927                                 }
 928                                 $overOrder = $orderby[1];
 929                                 $postOrder = ' ' . $overOrder;
 930                         }
 931                         $sql = "SELECT {$select[1]}
 932                                         FROM (
 933                                                 SELECT ROW_NUMBER() OVER({$overOrder}) AS rowNumber, *
 934                                                 FROM ({$sql}) {$sub1}
 935                                         ) {$sub2}
 936                                         WHERE rowNumber BETWEEN {$first} AND {$last}{$postOrder}";
 937
 938                         return $sql;
 939                 }
 940         }
 941
 942         /**
 943          * If there is a limit clause, parse it, strip it, and pass the remaining
 944          * SQL through limitResult() with the appropriate parameters. Not the
 945          * prettiest solution, but better than building a whole new parser. This
 946          * exists becase there are still too many extensions that don't use dynamic
 947          * sql generation.
 948          *
 949          * @param string $sql
 950          * @return array|mixed|string
 951          */
 952         public function LimitToTopN( $sql ) {
 953                 // Matches: LIMIT {[offset,] row_count | row_count OFFSET offset}
 954                 $pattern = '/\bLIMIT\s+((([0-9]+)\s*,\s*)?([0-9]+)(\s+OFFSET\s+([0-9]+))?)/i';
 955                 if ( preg_match( $pattern, $sql, $matches ) ) {
 956                         // row_count = $matches[4]
 957                         $row_count = $matches[4];
 958                         // offset = $matches[3] OR $matches[6]
 959                         $offset = $matches[3] or
 960                         $offset = $matches[6] or
 961                         $offset = false;
 962
 963                         // strip the matching LIMIT clause out
 964                         $sql = str_replace( $matches[0], '', $sql );
 965
 966                         return $this->limitResult( $sql, $row_count, $offset );
 967                 }
 968
 969                 return $sql;
 970         }
 971
 972         /**
 973          * @return string Wikitext of a link to the server software's web site
 974          */
 975         public function getSoftwareLink() {
 976                 return "[{{int:version-db-mssql-url}} MS SQL Server]";
 977         }
 978
 979         /**
 980          * @return string Version information from the database
 981          */
 982         public function getServerVersion() {
 983                 $server_info = sqlsrv_server_info( $this->mConn );
 984                 $version = 'Error';
 985                 if ( isset( $server_info['SQLServerVersion'] ) ) {
 986                         $version = $server_info['SQLServerVersion'];
 987                 }
 988
 989                 return $version;
 990         }
 991
 992         /**
 993          * @param string $table
 994          * @param string $fname
 995          * @return bool
 996          */
 997         public function tableExists( $table, $fname = __METHOD__ ) {
 998                 list( $db, $schema, $table ) = $this->tableName( $table, 'split' );
 999
1000                 if ( $db !== false ) {
1001                         // remote database
1002                         wfDebug( "Attempting to call tableExists on a remote table" );
1003                         return false;
1004                 }
1005
1006                 if ( $schema === false ) {
1007                         global $wgDBmwschema;
1008                         $schema = $wgDBmwschema;
1009                 }
1010
1011                 $res = $this->query( "SELECT 1 FROM INFORMATION_SCHEMA.TABLES
1012                         WHERE TABLE_TYPE = 'BASE TABLE'
1013                         AND TABLE_SCHEMA = '$schema' AND TABLE_NAME = '$table'" );
1014
1015                 if ( $res->numRows() ) {
1016                         return true;
1017                 } else {
1018                         return false;
1019                 }
1020         }
1021
1022         /**
1023          * Query whether a given column exists in the mediawiki schema
1024          * @param string $table
1025          * @param string $field
1026          * @param string $fname
1027          * @return bool
1028          */
1029         public function fieldExists( $table, $field, $fname = __METHOD__ ) {
1030                 list( $db, $schema, $table ) = $this->tableName( $table, 'split' );
1031
1032                 if ( $db !== false ) {
1033                         // remote database
1034                         wfDebug( "Attempting to call fieldExists on a remote table" );
1035                         return false;
1036                 }
1037
1038                 $res = $this->query( "SELECT 1 FROM INFORMATION_SCHEMA.COLUMNS
1039                         WHERE TABLE_SCHEMA = '$schema' AND TABLE_NAME = '$table' AND COLUMN_NAME = '$field'" );
1040
1041                 if ( $res->numRows() ) {
1042                         return true;
1043                 } else {
1044                         return false;
1045                 }
1046         }
1047
1048         public function fieldInfo( $table, $field ) {
1049                 list( $db, $schema, $table ) = $this->tableName( $table, 'split' );
1050
1051                 if ( $db !== false ) {
1052                         // remote database
1053                         wfDebug( "Attempting to call fieldInfo on a remote table" );
1054                         return false;
1055                 }
1056
1057                 $res = $this->query( "SELECT * FROM INFORMATION_SCHEMA.COLUMNS
1058                         WHERE TABLE_SCHEMA = '$schema' AND TABLE_NAME = '$table' AND COLUMN_NAME = '$field'" );
1059
1060                 $meta = $res->fetchRow();
1061                 if ( $meta ) {
1062                         return new MssqlField( $meta );
1063                 }
1064
1065                 return false;
1066         }
1067
1068         /**
1069          * Begin a transaction, committing any previously open transaction
1070          * @param string $fname
1071          */
1072         protected function doBegin( $fname = __METHOD__ ) {
1073                 sqlsrv_begin_transaction( $this->mConn );
1074                 $this->mTrxLevel = 1;
1075         }
1076
1077         /**
1078          * End a transaction
1079          * @param string $fname
1080          */
1081         protected function doCommit( $fname = __METHOD__ ) {
1082                 sqlsrv_commit( $this->mConn );
1083                 $this->mTrxLevel = 0;
1084         }
1085
1086         /**
1087          * Rollback a transaction.
1088          * No-op on non-transactional databases.
1089          * @param string $fname
1090          */
1091         protected function doRollback( $fname = __METHOD__ ) {
1092                 sqlsrv_rollback( $this->mConn );
1093                 $this->mTrxLevel = 0;
1094         }
1095
1096         /**
1097          * Escapes a identifier for use inm SQL.
1098          * Throws an exception if it is invalid.
1099          * Reference: http://msdn.microsoft.com/en-us/library/aa224033%28v=SQL.80%29.aspx
1100          * @param string $identifier
1101          * @throws MWException
1102          * @return string
1103          */
1104         private function escapeIdentifier( $identifier ) {
1105                 if ( strlen( $identifier ) == 0 ) {
1106                         throw new MWException( "An identifier must not be empty" );
1107                 }
1108                 if ( strlen( $identifier ) > 128 ) {
1109                         throw new MWException( "The identifier '$identifier' is too long (max. 128)" );
1110                 }
1111                 if ( ( strpos( $identifier, '[' ) !== false )
1112                         || ( strpos( $identifier, ']' ) !== false )
1113                 ) {
1114                         // It may be allowed if you quoted with double quotation marks, but
1115                         // that would break if QUOTED_IDENTIFIER is OFF
1116                         throw new MWException( "Square brackets are not allowed in '$identifier'" );
1117                 }
1118
1119                 return "[$identifier]";
1120         }
1121
1122         /**
1123          * @param string $s
1124          * @return string
1125          */
1126         public function strencode( $s ) { # Should not be called by us
1127                 return str_replace( "'", "''", $s );
1128         }
1129
1130         /**
1131          * @param string $s
1132          * @return string
1133          */
1134         public function addQuotes( $s ) {
1135                 if ( $s instanceof MssqlBlob ) {
1136                         return $s->fetch();
1137                 } elseif ( $s instanceof Blob ) {
1138                         // this shouldn't really ever be called, but it's here if needed
1139                         // (and will quite possibly make the SQL error out)
1140                         $blob = new MssqlBlob( $s->fetch() );
1141                         return $blob->fetch();
1142                 } else {
1143                         if ( is_bool( $s ) ) {
1144                                 $s = $s ? 1 : 0;
1145                         }
1146                         return parent::addQuotes( $s );
1147                 }
1148         }
1149
1150         /**
1151          * @param string $s
1152          * @return string
1153          */
1154         public function addIdentifierQuotes( $s ) {
1155                 // http://msdn.microsoft.com/en-us/library/aa223962.aspx
1156                 return '[' . $s . ']';
1157         }
1158
1159         /**
1160          * @param string $name
1161          * @return bool
1162          */
1163         public function isQuotedIdentifier( $name ) {
1164                 return strlen( $name ) && $name[0] == '[' && substr( $name, -1, 1 ) == ']';
1165         }
1166
1167         /**
1168          * @param string $db
1169          * @return bool
1170          */
1171         public function selectDB( $db ) {
1172                 try {
1173                         $this->mDBname = $db;
1174                         $this->query( "USE $db" );
1175                         return true;
1176                 } catch ( Exception $e ) {
1177                         return false;
1178                 }
1179         }
1180
1181         /**
1182          * @param array $options An associative array of options to be turned into
1183          *   an SQL query, valid keys are listed in the function.
1184          * @return array
1185          */
1186         public function makeSelectOptions( $options ) {
1187                 $tailOpts = '';
1188                 $startOpts = '';
1189
1190                 $noKeyOptions = array();
1191                 foreach ( $options as $key => $option ) {
1192                         if ( is_numeric( $key ) ) {
1193                                 $noKeyOptions[$option] = true;
1194                         }
1195                 }
1196
1197                 $tailOpts .= $this->makeGroupByWithHaving( $options );
1198
1199                 $tailOpts .= $this->makeOrderBy( $options );
1200
1201                 if ( isset( $noKeyOptions['DISTINCT'] ) || isset( $noKeyOptions['DISTINCTROW'] ) ) {
1202                         $startOpts .= 'DISTINCT';
1203                 }
1204
1205                 if ( isset( $noKeyOptions['FOR XML'] ) ) {
1206                         // used in group concat field emulation
1207                         $tailOpts .= " FOR XML PATH('')";
1208                 }
1209
1210                 // we want this to be compatible with the output of parent::makeSelectOptions()
1211                 return array( $startOpts, '', $tailOpts, '' );
1212         }
1213
1214         /**
1215          * Get the type of the DBMS, as it appears in $wgDBtype.
1216          * @return string
1217          */
1218         public function getType() {
1219                 return 'mssql';
1220         }
1221
1222         /**
1223          * @param array $stringList
1224          * @return string
1225          */
1226         public function buildConcat( $stringList ) {
1227                 return implode( ' + ', $stringList );
1228         }
1229
1230         /**
1231          * Build a GROUP_CONCAT or equivalent statement for a query.
1232          * MS SQL doesn't have GROUP_CONCAT so we emulate it with other stuff (and boy is it nasty)
1233          *
1234          * This is useful for combining a field for several rows into a single string.
1235          * NULL values will not appear in the output, duplicated values will appear,
1236          * and the resulting delimiter-separated values have no defined sort order.
1237          * Code using the results may need to use the PHP unique() or sort() methods.
1238          *
1239          * @param string $delim Glue to bind the results together
1240          * @param string|array $table Table name
1241          * @param string $field Field name
1242          * @param string|array $conds Conditions
1243          * @param string|array $join_conds Join conditions
1244          * @return string SQL text
1245          * @since 1.23
1246          */
1247         public function buildGroupConcatField( $delim, $table, $field, $conds = '',
1248                 $join_conds = array()
1249         ) {
1250                 $gcsq = 'gcsq_' . $this->mSubqueryId;
1251                 $this->mSubqueryId++;
1252
1253                 $delimLen = strlen( $delim );
1254                 $fld = "{$field} + {$this->addQuotes( $delim )}";
1255                 $sql = "(SELECT LEFT({$field}, LEN({$field}) - {$delimLen}) FROM ("
1256                         . $this->selectSQLText( $table, $fld, $conds, null, array( 'FOR XML' ), $join_conds )
1257                         . ") {$gcsq} ({$field}))";
1258
1259                 return $sql;
1260         }
1261
1262         /**
1263          * @return string
1264          */
1265         public function getSearchEngine() {
1266                 return "SearchMssql";
1267         }
1268
1269         /**
1270          * Returns an associative array for fields that are of type varbinary, binary, or image
1271          * $table can be either a raw table name or passed through tableName() first
1272          * @param string $table
1273          * @return array
1274          */
1275         private function getBinaryColumns( $table ) {
1276                 $tableRawArr = explode( '.', preg_replace( '#\[([^\]]*)\]#', '$1', $table ) );
1277                 $tableRaw = array_pop( $tableRawArr );
1278
1279                 if ( $this->mBinaryColumnCache === null ) {
1280                         $this->populateColumnCaches();
1281                 }
1282
1283                 return isset( $this->mBinaryColumnCache[$tableRaw] )
1284                         ? $this->mBinaryColumnCache[$tableRaw]
1285                         : array();
1286         }
1287
1288         /**
1289          * @param string $table
1290          * @return array
1291          */
1292         private function getBitColumns( $table ) {
1293                 $tableRawArr = explode( '.', preg_replace( '#\[([^\]]*)\]#', '$1', $table ) );
1294                 $tableRaw = array_pop( $tableRawArr );
1295
1296                 if ( $this->mBitColumnCache === null ) {
1297                         $this->populateColumnCaches();
1298                 }
1299
1300                 return isset( $this->mBitColumnCache[$tableRaw] )
1301                         ? $this->mBitColumnCache[$tableRaw]
1302                         : array();
1303         }
1304
1305         private function populateColumnCaches() {
1306                 $res = $this->select( 'INFORMATION_SCHEMA.COLUMNS', '*',
1307                         array(
1308                                 'TABLE_CATALOG' => $this->mDBname,
1309                                 'TABLE_SCHEMA' => $this->mSchema,
1310                                 'DATA_TYPE' => array( 'varbinary', 'binary', 'image', 'bit' )
1311                         ) );
1312
1313                 $this->mBinaryColumnCache = array();
1314                 $this->mBitColumnCache = array();
1315                 foreach ( $res as $row ) {
1316                         if ( $row->DATA_TYPE == 'bit' ) {
1317                                 $this->mBitColumnCache[$row->TABLE_NAME][$row->COLUMN_NAME] = $row;
1318                         } else {
1319                                 $this->mBinaryColumnCache[$row->TABLE_NAME][$row->COLUMN_NAME] = $row;
1320                         }
1321                 }
1322         }
1323
1324         /**
1325          * @param string $name
1326          * @param string $format
1327          * @return string
1328          */
1329         function tableName( $name, $format = 'quoted' ) {
1330                 # Replace reserved words with better ones
1331                 switch ( $name ) {
1332                         case 'user':
1333                                 return $this->realTableName( 'mwuser', $format );
1334                         default:
1335                                 return $this->realTableName( $name, $format );
1336                 }
1337         }
1338
1339         /**
1340          * call this instead of tableName() in the updater when renaming tables
1341          * @param string $name
1342          * @param string $format One of quoted, raw, or split
1343          * @return string
1344          */
1345         function realTableName( $name, $format = 'quoted' ) {
1346                 $table = parent::tableName( $name, $format );
1347                 if ( $format == 'split' ) {
1348                         // Used internally, we want the schema split off from the table name and returned
1349                         // as a list with 3 elements (database, schema, table)
1350                         $table = explode( '.', $table );
1351                         while ( count( $table ) < 3 ) {
1352                                 array_unshift( $table, false );
1353                         }
1354                 }
1355                 return $table;
1356         }
1357
1358         /**
1359          * Called in the installer and updater.
1360          * Probably doesn't need to be called anywhere else in the codebase.
1361          * @param bool|null $value
1362          * @return bool|null
1363          */
1364         public function prepareStatements( $value = null ) {
1365                 return wfSetVar( $this->mPrepareStatements, $value );
1366         }
1367
1368         /**
1369          * Called in the installer and updater.
1370          * Probably doesn't need to be called anywhere else in the codebase.
1371          * @param bool|null $value
1372          * @return bool|null
1373          */
1374         public function scrollableCursor( $value = null ) {
1375                 return wfSetVar( $this->mScrollableCursor, $value );
1376         }
1377 } // end DatabaseMssql class
1378
1379 /**
1380  * Utility class.
1381  *
1382  * @ingroup Database
1383  */
1384 class MssqlField implements Field {
1385         private $name, $tableName, $default, $max_length, $nullable, $type;
1386
1387         function __construct( $info ) {
1388                 $this->name = $info['COLUMN_NAME'];
1389                 $this->tableName = $info['TABLE_NAME'];
1390                 $this->default = $info['COLUMN_DEFAULT'];
1391                 $this->max_length = $info['CHARACTER_MAXIMUM_LENGTH'];
1392                 $this->nullable = !( strtolower( $info['IS_NULLABLE'] ) == 'no' );
1393                 $this->type = $info['DATA_TYPE'];
1394         }
1395
1396         function name() {
1397                 return $this->name;
1398         }
1399
1400         function tableName() {
1401                 return $this->tableName;
1402         }
1403
1404         function defaultValue() {
1405                 return $this->default;
1406         }
1407
1408         function maxLength() {
1409                 return $this->max_length;
1410         }
1411
1412         function isNullable() {
1413                 return $this->nullable;
1414         }
1415
1416         function type() {
1417                 return $this->type;
1418         }
1419 }
1420
1421 class MssqlBlob extends Blob {
1422         public function __construct( $data ) {
1423                 if ( $data instanceof MssqlBlob ) {
1424                         return $data;
1425                 } elseif ( $data instanceof Blob ) {
1426                         $this->mData = $data->fetch();
1427                 } elseif ( is_array( $data ) && is_object( $data ) ) {
1428                         $this->mData = serialize( $data );
1429                 } else {
1430                         $this->mData = $data;
1431                 }
1432         }
1433
1434         /**
1435          * Returns an unquoted hex representation of a binary string
1436          * for insertion into varbinary-type fields
1437          * @return string
1438          */
1439         public function fetch() {
1440                 if ( $this->mData === null ) {
1441                         return 'null';
1442                 }
1443
1444                 $ret = '0x';
1445                 $dataLength = strlen( $this->mData );
1446                 for ( $i = 0; $i < $dataLength; $i++ ) {
1447                         $ret .= bin2hex( pack( 'C', ord( $this->mData[$i] ) ) );
1448                 }
1449
1450                 return $ret;
1451         }
1452 }
1453
1454 class MssqlResultWrapper extends ResultWrapper {
1455         private $mSeekTo = null;
1456
1457         /**
1458          * @return stdClass|bool
1459          */
1460         public function fetchObject() {
1461                 $res = $this->result;
1462
1463                 if ( $this->mSeekTo !== null ) {
1464                         $result = sqlsrv_fetch_object( $res, 'stdClass', array(),
1465                                 SQLSRV_SCROLL_ABSOLUTE, $this->mSeekTo );
1466                         $this->mSeekTo = null;
1467                 } else {
1468                         $result = sqlsrv_fetch_object( $res );
1469                 }
1470
1471                 // MediaWiki expects us to return boolean false when there are no more rows instead of null
1472                 if ( $result === null ) {
1473                         return false;
1474                 }
1475
1476                 return $result;
1477         }
1478
1479         /**
1480          * @return array|bool
1481          */
1482         public function fetchRow() {
1483                 $res = $this->result;
1484
1485                 if ( $this->mSeekTo !== null ) {
1486                         $result = sqlsrv_fetch_array( $res, SQLSRV_FETCH_BOTH,
1487                                 SQLSRV_SCROLL_ABSOLUTE, $this->mSeekTo );
1488                         $this->mSeekTo = null;
1489                 } else {
1490                         $result = sqlsrv_fetch_array( $res );
1491                 }
1492
1493                 // MediaWiki expects us to return boolean false when there are no more rows instead of null
1494                 if ( $result === null ) {
1495                         return false;
1496                 }
1497
1498                 return $result;
1499         }
1500
1501         /**
1502          * @param int $row
1503          * @return bool
1504          */
1505         public function seek( $row ) {
1506                 $res = $this->result;
1507
1508                 // check bounds
1509                 $numRows = $this->db->numRows( $res );
1510                 $row = intval( $row );
1511
1512                 if ( $numRows === 0 ) {
1513                         return false;
1514                 } elseif ( $row < 0 || $row > $numRows - 1 ) {
1515                         return false;
1516                 }
1517
1518                 // Unlike MySQL, the seek actually happens on the next access
1519                 $this->mSeekTo = $row;
1520                 return true;
1521         }
1522 }