includes/db/DatabasePostgres.php

   1 <?php
   2 /**
   3  * This is the Postgres database abstraction layer.
   4  *
   5  * @file
   6  * @ingroup Database
   7  */
   8
   9 class PostgresField implements Field {
  10         private $name, $tablename, $type, $nullable, $max_length, $deferred, $deferrable, $conname;
  11
  12         /**
  13          * @param $db DatabaseBase
  14          * @param  $table
  15          * @param  $field
  16          * @return null|PostgresField
  17          */
  18         static function fromText( $db, $table, $field ) {
  19                 global $wgDBmwschema;
  20
  21                 $q = <<<SQL
  22 SELECT
  23  attnotnull, attlen, COALESCE(conname, '') AS conname,
  24  COALESCE(condeferred, 'f') AS deferred,
  25  COALESCE(condeferrable, 'f') AS deferrable,
  26  CASE WHEN typname = 'int2' THEN 'smallint'
  27   WHEN typname = 'int4' THEN 'integer'
  28   WHEN typname = 'int8' THEN 'bigint'
  29   WHEN typname = 'bpchar' THEN 'char'
  30  ELSE typname END AS typname
  31 FROM pg_class c
  32 JOIN pg_namespace n ON (n.oid = c.relnamespace)
  33 JOIN pg_attribute a ON (a.attrelid = c.oid)
  34 JOIN pg_type t ON (t.oid = a.atttypid)
  35 LEFT JOIN pg_constraint o ON (o.conrelid = c.oid AND a.attnum = ANY(o.conkey) AND o.contype = 'f')
  36 WHERE relkind = 'r'
  37 AND nspname=%s
  38 AND relname=%s
  39 AND attname=%s;
  40 SQL;
  41
  42                 $table = $db->tableName( $table, 'raw' );
  43                 $res = $db->query(
  44                         sprintf( $q,
  45                                 $db->addQuotes( $wgDBmwschema ),
  46                                 $db->addQuotes( $table ),
  47                                 $db->addQuotes( $field )
  48                         )
  49                 );
  50                 $row = $db->fetchObject( $res );
  51                 if ( !$row ) {
  52                         return null;
  53                 }
  54                 $n = new PostgresField;
  55                 $n->type = $row->typname;
  56                 $n->nullable = ( $row->attnotnull == 'f' );
  57                 $n->name = $field;
  58                 $n->tablename = $table;
  59                 $n->max_length = $row->attlen;
  60                 $n->deferrable = ( $row->deferrable == 't' );
  61                 $n->deferred = ( $row->deferred == 't' );
  62                 $n->conname = $row->conname;
  63                 return $n;
  64         }
  65
  66         function name() {
  67                 return $this->name;
  68         }
  69
  70         function tableName() {
  71                 return $this->tablename;
  72         }
  73
  74         function type() {
  75                 return $this->type;
  76         }
  77
  78         function isNullable() {
  79                 return $this->nullable;
  80         }
  81
  82         function maxLength() {
  83                 return $this->max_length;
  84         }
  85
  86         function is_deferrable() {
  87                 return $this->deferrable;
  88         }
  89
  90         function is_deferred() {
  91                 return $this->deferred;
  92         }
  93
  94         function conname() {
  95                 return $this->conname;
  96         }
  97
  98 }
  99
 100 /**
 101  * @ingroup Database
 102  */
 103 class DatabasePostgres extends DatabaseBase {
 104         var $mInsertId = null;
 105         var $mLastResult = null;
 106         var $numeric_version = null;
 107         var $mAffectedRows = null;
 108
 109         function getType() {
 110                 return 'postgres';
 111         }
 112
 113         function cascadingDeletes() {
 114                 return true;
 115         }
 116         function cleanupTriggers() {
 117                 return true;
 118         }
 119         function strictIPs() {
 120                 return true;
 121         }
 122         function realTimestamps() {
 123                 return true;
 124         }
 125         function implicitGroupby() {
 126                 return false;
 127         }
 128         function implicitOrderby() {
 129                 return false;
 130         }
 131         function searchableIPs() {
 132                 return true;
 133         }
 134         function functionalIndexes() {
 135                 return true;
 136         }
 137
 138         function hasConstraint( $name ) {
 139                 global $wgDBmwschema;
 140                 $SQL = "SELECT 1 FROM pg_catalog.pg_constraint c, pg_catalog.pg_namespace n WHERE c.connamespace = n.oid AND conname = '" .
 141                                 pg_escape_string( $this->mConn, $name ) . "' AND n.nspname = '" . pg_escape_string( $this->mConn, $wgDBmwschema ) ."'";
 142                 $res = $this->doQuery( $SQL );
 143                 return $this->numRows( $res );
 144         }
 145
 146         /**
 147          * Usually aborts on failure
 148          */
 149         function open( $server, $user, $password, $dbName ) {
 150                 # Test for Postgres support, to avoid suppressed fatal error
 151                 if ( !function_exists( 'pg_connect' ) ) {
 152                         throw new DBConnectionError( $this, "Postgres functions missing, have you compiled PHP with the --with-pgsql option?\n (Note: if you recently installed PHP, you may need to restart your webserver and database)\n" );
 153                 }
 154
 155                 global $wgDBport;
 156
 157                 if ( !strlen( $user ) ) { # e.g. the class is being loaded
 158                         return;
 159                 }
 160
 161                 $this->close();
 162                 $this->mServer = $server;
 163                 $port = $wgDBport;
 164                 $this->mUser = $user;
 165                 $this->mPassword = $password;
 166                 $this->mDBname = $dbName;
 167
 168                 $connectVars = array(
 169                         'dbname' => $dbName,
 170                         'user' => $user,
 171                         'password' => $password
 172                 );
 173                 if ( $server != false && $server != '' ) {
 174                         $connectVars['host'] = $server;
 175                 }
 176                 if ( $port != false && $port != '' ) {
 177                         $connectVars['port'] = $port;
 178                 }
 179                 $connectString = $this->makeConnectionString( $connectVars, PGSQL_CONNECT_FORCE_NEW );
 180
 181                 $this->installErrorHandler();
 182                 $this->mConn = pg_connect( $connectString );
 183                 $phpError = $this->restoreErrorHandler();
 184
 185                 if ( !$this->mConn ) {
 186                         wfDebug( "DB connection error\n" );
 187                         wfDebug( "Server: $server, Database: $dbName, User: $user, Password: " . substr( $password, 0, 3 ) . "...\n" );
 188                         wfDebug( $this->lastError() . "\n" );
 189                         throw new DBConnectionError( $this, str_replace( "\n", ' ', $phpError ) );
 190                 }
 191
 192                 $this->mOpened = true;
 193
 194                 global $wgCommandLineMode;
 195                 # If called from the command-line (e.g. importDump), only show errors
 196                 if ( $wgCommandLineMode ) {
 197                         $this->doQuery( "SET client_min_messages = 'ERROR'" );
 198                 }
 199
 200                 $this->query( "SET client_encoding='UTF8'", __METHOD__ );
 201                 $this->query( "SET datestyle = 'ISO, YMD'", __METHOD__ );
 202                 $this->query( "SET timezone = 'GMT'", __METHOD__ );
 203                 $this->query( "SET standard_conforming_strings = on", __METHOD__ );
 204
 205                 global $wgDBmwschema;
 206                 if ( $this->schemaExists( $wgDBmwschema ) ) {
 207                         $safeschema = $this->addIdentifierQuotes( $wgDBmwschema );
 208                         $this->doQuery( "SET search_path = $safeschema" );
 209                 } else {
 210                         $this->doQuery( "SET search_path = public" );
 211                 }
 212
 213                 return $this->mConn;
 214         }
 215
 216         /**
 217          * Postgres doesn't support selectDB in the same way MySQL does. So if the
 218          * DB name doesn't match the open connection, open a new one
 219          * @return
 220          */
 221         function selectDB( $db ) {
 222                 if ( $this->mDBname !== $db ) {
 223                         return (bool)$this->open( $this->mServer, $this->mUser, $this->mPassword, $db );
 224                 } else {
 225                         return true;
 226                 }
 227         }
 228
 229         function makeConnectionString( $vars ) {
 230                 $s = '';
 231                 foreach ( $vars as $name => $value ) {
 232                         $s .= "$name='" . str_replace( "'", "\\'", $value ) . "' ";
 233                 }
 234                 return $s;
 235         }
 236
 237         /**
 238          * Closes a database connection, if it is open
 239          * Returns success, true if already closed
 240          */
 241         function close() {
 242                 $this->mOpened = false;
 243                 if ( $this->mConn ) {
 244                         return pg_close( $this->mConn );
 245                 } else {
 246                         return true;
 247                 }
 248         }
 249
 250         protected function doQuery( $sql ) {
 251                 if ( function_exists( 'mb_convert_encoding' ) ) {
 252                         $sql = mb_convert_encoding( $sql, 'UTF-8' );
 253                 }
 254                 $this->mLastResult = pg_query( $this->mConn, $sql );
 255                 $this->mAffectedRows = null; // use pg_affected_rows(mLastResult)
 256                 return $this->mLastResult;
 257         }
 258
 259         function queryIgnore( $sql, $fname = 'DatabasePostgres::queryIgnore' ) {
 260                 return $this->query( $sql, $fname, true );
 261         }
 262
 263         function freeResult( $res ) {
 264                 if ( $res instanceof ResultWrapper ) {
 265                         $res = $res->result;
 266                 }
 267                 wfSuppressWarnings();
 268                 $ok = pg_free_result( $res );
 269                 wfRestoreWarnings();
 270                 if ( !$ok ) {
 271                         throw new DBUnexpectedError( $this, "Unable to free Postgres result\n" );
 272                 }
 273         }
 274
 275         function fetchObject( $res ) {
 276                 if ( $res instanceof ResultWrapper ) {
 277                         $res = $res->result;
 278                 }
 279                 wfSuppressWarnings();
 280                 $row = pg_fetch_object( $res );
 281                 wfRestoreWarnings();
 282                 # @todo FIXME: HACK HACK HACK HACK debug
 283
 284                 # @todo hashar: not sure if the following test really trigger if the object
 285                 #          fetching failed.
 286                 if( pg_last_error( $this->mConn ) ) {
 287                         throw new DBUnexpectedError( $this, 'SQL error: ' . htmlspecialchars( pg_last_error( $this->mConn ) ) );
 288                 }
 289                 return $row;
 290         }
 291
 292         function fetchRow( $res ) {
 293                 if ( $res instanceof ResultWrapper ) {
 294                         $res = $res->result;
 295                 }
 296                 wfSuppressWarnings();
 297                 $row = pg_fetch_array( $res );
 298                 wfRestoreWarnings();
 299                 if( pg_last_error( $this->mConn ) ) {
 300                         throw new DBUnexpectedError( $this, 'SQL error: ' . htmlspecialchars( pg_last_error( $this->mConn ) ) );
 301                 }
 302                 return $row;
 303         }
 304
 305         function numRows( $res ) {
 306                 if ( $res instanceof ResultWrapper ) {
 307                         $res = $res->result;
 308                 }
 309                 wfSuppressWarnings();
 310                 $n = pg_num_rows( $res );
 311                 wfRestoreWarnings();
 312                 if( pg_last_error( $this->mConn ) ) {
 313                         throw new DBUnexpectedError( $this, 'SQL error: ' . htmlspecialchars( pg_last_error( $this->mConn ) ) );
 314                 }
 315                 return $n;
 316         }
 317
 318         function numFields( $res ) {
 319                 if ( $res instanceof ResultWrapper ) {
 320                         $res = $res->result;
 321                 }
 322                 return pg_num_fields( $res );
 323         }
 324
 325         function fieldName( $res, $n ) {
 326                 if ( $res instanceof ResultWrapper ) {
 327                         $res = $res->result;
 328                 }
 329                 return pg_field_name( $res, $n );
 330         }
 331
 332         /**
 333          * This must be called after nextSequenceVal
 334          */
 335         function insertId() {
 336                 return $this->mInsertId;
 337         }
 338
 339         function dataSeek( $res, $row ) {
 340                 if ( $res instanceof ResultWrapper ) {
 341                         $res = $res->result;
 342                 }
 343                 return pg_result_seek( $res, $row );
 344         }
 345
 346         function lastError() {
 347                 if ( $this->mConn ) {
 348                         return pg_last_error();
 349                 } else {
 350                         return 'No database connection';
 351                 }
 352         }
 353         function lastErrno() {
 354                 return pg_last_error() ? 1 : 0;
 355         }
 356
 357         function affectedRows() {
 358                 if ( !is_null( $this->mAffectedRows ) ) {
 359                         // Forced result for simulated queries
 360                         return $this->mAffectedRows;
 361                 }
 362                 if( empty( $this->mLastResult ) ) {
 363                         return 0;
 364                 }
 365                 return pg_affected_rows( $this->mLastResult );
 366         }
 367
 368         /**
 369          * Estimate rows in dataset
 370          * Returns estimated count, based on EXPLAIN output
 371          * This is not necessarily an accurate estimate, so use sparingly
 372          * Returns -1 if count cannot be found
 373          * Takes same arguments as Database::select()
 374          */
 375         function estimateRowCount( $table, $vars = '*', $conds='', $fname = 'DatabasePostgres::estimateRowCount', $options = array() ) {
 376                 $options['EXPLAIN'] = true;
 377                 $res = $this->select( $table, $vars, $conds, $fname, $options );
 378                 $rows = -1;
 379                 if ( $res ) {
 380                         $row = $this->fetchRow( $res );
 381                         $count = array();
 382                         if( preg_match( '/rows=(\d+)/', $row[0], $count ) ) {
 383                                 $rows = $count[1];
 384                         }
 385                 }
 386                 return $rows;
 387         }
 388
 389         /**
 390          * Returns information about an index
 391          * If errors are explicitly ignored, returns NULL on failure
 392          */
 393         function indexInfo( $table, $index, $fname = 'DatabasePostgres::indexInfo' ) {
 394                 $sql = "SELECT indexname FROM pg_indexes WHERE tablename='$table'";
 395                 $res = $this->query( $sql, $fname );
 396                 if ( !$res ) {
 397                         return null;
 398                 }
 399                 foreach ( $res as $row ) {
 400                         if ( $row->indexname == $this->indexName( $index ) ) {
 401                                 return $row;
 402                         }
 403                 }
 404                 return false;
 405         }
 406
 407         function indexUnique( $table, $index, $fname = 'DatabasePostgres::indexUnique' ) {
 408                 $sql = "SELECT indexname FROM pg_indexes WHERE tablename='{$table}'".
 409                         " AND indexdef LIKE 'CREATE UNIQUE%(" .
 410                         $this->strencode( $this->indexName( $index ) ) .
 411                         ")'";
 412                 $res = $this->query( $sql, $fname );
 413                 if ( !$res ) {
 414                         return null;
 415                 }
 416                 foreach ( $res as $row ) {
 417                         return true;
 418                 }
 419                 return false;
 420         }
 421
 422         /**
 423          * INSERT wrapper, inserts an array into a table
 424          *
 425          * $args may be a single associative array, or an array of these with numeric keys,
 426          * for multi-row insert (Postgres version 8.2 and above only).
 427          *
 428          * @param $table   String: Name of the table to insert to.
 429          * @param $args    Array: Items to insert into the table.
 430          * @param $fname   String: Name of the function, for profiling
 431          * @param $options String or Array. Valid options: IGNORE
 432          *
 433          * @return bool Success of insert operation. IGNORE always returns true.
 434          */
 435         function insert( $table, $args, $fname = 'DatabasePostgres::insert', $options = array() ) {
 436                 if ( !count( $args ) ) {
 437                         return true;
 438                 }
 439
 440                 $table = $this->tableName( $table );
 441                 if (! isset( $this->numeric_version ) ) {
 442                         $this->getServerVersion();
 443                 }
 444
 445                 if ( !is_array( $options ) ) {
 446                         $options = array( $options );
 447                 }
 448
 449                 if ( isset( $args[0] ) && is_array( $args[0] ) ) {
 450                         $multi = true;
 451                         $keys = array_keys( $args[0] );
 452                 } else {
 453                         $multi = false;
 454                         $keys = array_keys( $args );
 455                 }
 456
 457                 // If IGNORE is set, we use savepoints to emulate mysql's behavior
 458                 $ignore = in_array( 'IGNORE', $options ) ? 'mw' : '';
 459
 460                 // If we are not in a transaction, we need to be for savepoint trickery
 461                 $didbegin = 0;
 462                 if ( $ignore ) {
 463                         if ( !$this->mTrxLevel ) {
 464                                 $this->begin();
 465                                 $didbegin = 1;
 466                         }
 467                         $olde = error_reporting( 0 );
 468                         // For future use, we may want to track the number of actual inserts
 469                         // Right now, insert (all writes) simply return true/false
 470                         $numrowsinserted = 0;
 471                 }
 472
 473                 $sql = "INSERT INTO $table (" . implode( ',', $keys ) . ') VALUES ';
 474
 475                 if ( $multi ) {
 476                         if ( $this->numeric_version >= 8.2 && !$ignore ) {
 477                                 $first = true;
 478                                 foreach ( $args as $row ) {
 479                                         if ( $first ) {
 480                                                 $first = false;
 481                                         } else {
 482                                                 $sql .= ',';
 483                                         }
 484                                         $sql .= '(' . $this->makeList( $row ) . ')';
 485                                 }
 486                                 $res = (bool)$this->query( $sql, $fname, $ignore );
 487                         } else {
 488                                 $res = true;
 489                                 $origsql = $sql;
 490                                 foreach ( $args as $row ) {
 491                                         $tempsql = $origsql;
 492                                         $tempsql .= '(' . $this->makeList( $row ) . ')';
 493
 494                                         if ( $ignore ) {
 495                                                 pg_query( $this->mConn, "SAVEPOINT $ignore" );
 496                                         }
 497
 498                                         $tempres = (bool)$this->query( $tempsql, $fname, $ignore );
 499
 500                                         if ( $ignore ) {
 501                                                 $bar = pg_last_error();
 502                                                 if ( $bar != false ) {
 503                                                         pg_query( $this->mConn, "ROLLBACK TO $ignore" );
 504                                                 } else {
 505                                                         pg_query( $this->mConn, "RELEASE $ignore" );
 506                                                         $numrowsinserted++;
 507                                                 }
 508                                         }
 509
 510                                         // If any of them fail, we fail overall for this function call
 511                                         // Note that this will be ignored if IGNORE is set
 512                                         if ( !$tempres ) {
 513                                                 $res = false;
 514                                         }
 515                                 }
 516                         }
 517                 } else {
 518                         // Not multi, just a lone insert
 519                         if ( $ignore ) {
 520                                 pg_query($this->mConn, "SAVEPOINT $ignore");
 521                         }
 522
 523                         $sql .= '(' . $this->makeList( $args ) . ')';
 524                         $res = (bool)$this->query( $sql, $fname, $ignore );
 525                         if ( $ignore ) {
 526                                 $bar = pg_last_error();
 527                                 if ( $bar != false ) {
 528                                         pg_query( $this->mConn, "ROLLBACK TO $ignore" );
 529                                 } else {
 530                                         pg_query( $this->mConn, "RELEASE $ignore" );
 531                                         $numrowsinserted++;
 532                                 }
 533                         }
 534                 }
 535                 if ( $ignore ) {
 536                         $olde = error_reporting( $olde );
 537                         if ( $didbegin ) {
 538                                 $this->commit();
 539                         }
 540
 541                         // Set the affected row count for the whole operation
 542                         $this->mAffectedRows = $numrowsinserted;
 543
 544                         // IGNORE always returns true
 545                         return true;
 546                 }
 547
 548                 return $res;
 549         }
 550
 551         /**
 552          * INSERT SELECT wrapper
 553          * $varMap must be an associative array of the form array( 'dest1' => 'source1', ...)
 554          * Source items may be literals rather then field names, but strings should be quoted with Database::addQuotes()
 555          * $conds may be "*" to copy the whole table
 556          * srcTable may be an array of tables.
 557          * @todo FIXME: Implement this a little better (seperate select/insert)?
 558          */
 559         function insertSelect( $destTable, $srcTable, $varMap, $conds, $fname = 'DatabasePostgres::insertSelect',
 560                 $insertOptions = array(), $selectOptions = array() )
 561         {
 562                 $destTable = $this->tableName( $destTable );
 563
 564                 // If IGNORE is set, we use savepoints to emulate mysql's behavior
 565                 $ignore = in_array( 'IGNORE', $insertOptions ) ? 'mw' : '';
 566
 567                 if( is_array( $insertOptions ) ) {
 568                         $insertOptions = implode( ' ', $insertOptions ); // FIXME: This is unused
 569                 }
 570                 if( !is_array( $selectOptions ) ) {
 571                         $selectOptions = array( $selectOptions );
 572                 }
 573                 list( $startOpts, $useIndex, $tailOpts ) = $this->makeSelectOptions( $selectOptions );
 574                 if( is_array( $srcTable ) ) {
 575                         $srcTable = implode( ',', array_map( array( &$this, 'tableName' ), $srcTable ) );
 576                 } else {
 577                         $srcTable = $this->tableName( $srcTable );
 578                 }
 579
 580                 // If we are not in a transaction, we need to be for savepoint trickery
 581                 $didbegin = 0;
 582                 if ( $ignore ) {
 583                         if( !$this->mTrxLevel ) {
 584                                 $this->begin();
 585                                 $didbegin = 1;
 586                         }
 587                         $olde = error_reporting( 0 );
 588                         $numrowsinserted = 0;
 589                         pg_query( $this->mConn, "SAVEPOINT $ignore");
 590                 }
 591
 592                 $sql = "INSERT INTO $destTable (" . implode( ',', array_keys( $varMap ) ) . ')' .
 593                                 " SELECT $startOpts " . implode( ',', $varMap ) .
 594                                 " FROM $srcTable $useIndex";
 595
 596                 if ( $conds != '*' ) {
 597                         $sql .= ' WHERE ' . $this->makeList( $conds, LIST_AND );
 598                 }
 599
 600                 $sql .= " $tailOpts";
 601
 602                 $res = (bool)$this->query( $sql, $fname, $ignore );
 603                 if( $ignore ) {
 604                         $bar = pg_last_error();
 605                         if( $bar != false ) {
 606                                 pg_query( $this->mConn, "ROLLBACK TO $ignore" );
 607                         } else {
 608                                 pg_query( $this->mConn, "RELEASE $ignore" );
 609                                 $numrowsinserted++;
 610                         }
 611                         $olde = error_reporting( $olde );
 612                         if( $didbegin ) {
 613                                 $this->commit();
 614                         }
 615
 616                         // Set the affected row count for the whole operation
 617                         $this->mAffectedRows = $numrowsinserted;
 618
 619                         // IGNORE always returns true
 620                         return true;
 621                 }
 622
 623                 return $res;
 624         }
 625
 626         function tableName( $name, $format = 'quoted' ) {
 627                 global $wgSharedDB, $wgSharedTables, $wgDBmwschema;
 628                 # Skip quoted tablenames.
 629                 if ( $this->isQuotedIdentifier( $name ) ) {
 630                         return $name;
 631                 }
 632                 # Lets test for any bits of text that should never show up in a table
 633                 # name. Basically anything like JOIN or ON which are actually part of
 634                 # SQL queries, but may end up inside of the table value to combine
 635                 # sql. Such as how the API is doing.
 636                 # Note that we use a whitespace test rather than a \b test to avoid
 637                 # any remote case where a word like on may be inside of a table name
 638                 # surrounded by symbols which may be considered word breaks.
 639                 if ( preg_match( '/(^|\s)(DISTINCT|JOIN|ON|AS)(\s|$)/i', $name ) !== 0 ) {
 640                         return $name;
 641                 }
 642                 # Extract the database prefix, if any and quote it
 643                 $dbDetails = explode( '.', $name, 2 );
 644                 if ( isset( $dbDetails[1] ) ) {
 645                         $schema = '"' . $dbDetails[0] . '".';
 646                         $table  = $dbDetails [1];
 647                 } else {
 648                         $schema = "\"{$wgDBmwschema}\"."; # keep old schema, but quote it.
 649                         $table = $dbDetails[0];
 650                 }
 651                 if ( $format != 'quoted' ) {
 652                         switch( $name ) {
 653                                 case 'user':
 654                                         return 'mwuser';
 655                                 case 'text':
 656                                         return 'pagecontent';
 657                                 default:
 658                                         return $table;
 659                         }
 660                 }
 661
 662                 # during installation wgDBmwschema is not set, so we would end up quering
 663                 # ""."table" => error. Erase the first part if wgDBmwschema is empty
 664                 if ( $schema == "\"\"." ) {
 665                         $schema = "";
 666                 }
 667                 if ( isset( $wgSharedDB ) # We have a shared database (=> schema)
 668                   && isset( $wgSharedTables )
 669                   && is_array( $wgSharedTables )
 670                   && in_array( $table, $wgSharedTables ) ) { # A shared table is selected
 671                         $schema = "\"{$wgSharedDB}\".";
 672                 }
 673                 switch ( $table ) {
 674                         case 'user':
 675                                 $table = "{$schema}\"mwuser\"";
 676                                 break;
 677                         case 'text':
 678                                 $table = "{$schema}\"pagecontent\"";
 679                                 break;
 680                         default:
 681                                 $table = "{$schema}\"$table\"";
 682                                 break;
 683                 }
 684                 return $table;
 685         }
 686
 687         /**
 688          * Return the next in a sequence, save the value for retrieval via insertId()
 689          */
 690         function nextSequenceValue( $seqName ) {
 691                 $safeseq = str_replace( "'", "''", $seqName );
 692                 $res = $this->query( "SELECT nextval('$safeseq')" );
 693                 $row = $this->fetchRow( $res );
 694                 $this->mInsertId = $row[0];
 695                 return $this->mInsertId;
 696         }
 697
 698         /**
 699          * Return the current value of a sequence. Assumes it has been nextval'ed in this session.
 700          */
 701         function currentSequenceValue( $seqName ) {
 702                 $safeseq = str_replace( "'", "''", $seqName );
 703                 $res = $this->query( "SELECT currval('$safeseq')" );
 704                 $row = $this->fetchRow( $res );
 705                 $currval = $row[0];
 706                 return $currval;
 707         }
 708
 709         # Returns the size of a text field, or -1 for "unlimited"
 710         function textFieldSize( $table, $field ) {
 711                 $table = $this->tableName( $table );
 712                 $sql = "SELECT t.typname as ftype,a.atttypmod as size
 713                         FROM pg_class c, pg_attribute a, pg_type t
 714                         WHERE relname='$table' AND a.attrelid=c.oid AND
 715                                 a.atttypid=t.oid and a.attname='$field'";
 716                 $res =$this->query( $sql );
 717                 $row = $this->fetchObject( $res );
 718                 if ( $row->ftype == 'varchar' ) {
 719                         $size = $row->size - 4;
 720                 } else {
 721                         $size = $row->size;
 722                 }
 723                 return $size;
 724         }
 725
 726         function limitResult( $sql, $limit, $offset = false ) {
 727                 return "$sql LIMIT $limit " . ( is_numeric( $offset ) ? " OFFSET {$offset} " : '' );
 728         }
 729
 730         function wasDeadlock() {
 731                 return $this->lastErrno() == '40P01';
 732         }
 733
 734         function duplicateTableStructure( $oldName, $newName, $temporary = false, $fname = 'DatabasePostgres::duplicateTableStructure' ) {
 735                 $newName = $this->addIdentifierQuotes( $newName );
 736                 $oldName = $this->addIdentifierQuotes( $oldName );
 737                 return $this->query( 'CREATE ' . ( $temporary ? 'TEMPORARY ' : '' ) . " TABLE $newName (LIKE $oldName INCLUDING DEFAULTS)", $fname );
 738         }
 739
 740         function listTables( $prefix = null, $fname = 'DatabasePostgres::listTables' ) {
 741                 global $wgDBmwschema;
 742                 $eschema = $this->addQuotes( $wgDBmwschema );
 743                 $result = $this->query( "SELECT tablename FROM pg_tables WHERE schemaname = $eschema", $fname );
 744
 745                 $endArray = array();
 746
 747                 foreach( $result as $table ) {
 748                         $vars = get_object_vars($table);
 749                         $table = array_pop( $vars );
 750                         if( !$prefix || strpos( $table, $prefix ) === 0 ) {
 751                                 $endArray[] = $table;
 752                         }
 753                 }
 754
 755                 return $endArray;
 756         }
 757
 758         function timestamp( $ts = 0 ) {
 759                 return wfTimestamp( TS_POSTGRES, $ts );
 760         }
 761
 762         /**
 763          * Return aggregated value function call
 764          */
 765         function aggregateValue( $valuedata, $valuename = 'value' ) {
 766                 return $valuedata;
 767         }
 768
 769         /**
 770          * @return string wikitext of a link to the server software's web site
 771          */
 772         public static function getSoftwareLink() {
 773                 return '[http://www.postgresql.org/ PostgreSQL]';
 774         }
 775
 776         /**
 777          * @return string Version information from the database
 778          */
 779         function getServerVersion() {
 780                 if ( !isset( $this->numeric_version ) ) {
 781                         $versionInfo = pg_version( $this->mConn );
 782                         if ( version_compare( $versionInfo['client'], '7.4.0', 'lt' ) ) {
 783                                 // Old client, abort install
 784                                 $this->numeric_version = '7.3 or earlier';
 785                         } elseif ( isset( $versionInfo['server'] ) ) {
 786                                 // Normal client
 787                                 $this->numeric_version = $versionInfo['server'];
 788                         } else {
 789                                 // Bug 16937: broken pgsql extension from PHP<5.3
 790                                 $this->numeric_version = pg_parameter_status( $this->mConn, 'server_version' );
 791                         }
 792                 }
 793                 return $this->numeric_version;
 794         }
 795
 796         /**
 797          * Query whether a given relation exists (in the given schema, or the
 798          * default mw one if not given)
 799          */
 800         function relationExists( $table, $types, $schema = false ) {
 801                 global $wgDBmwschema;
 802                 if ( !is_array( $types ) ) {
 803                         $types = array( $types );
 804                 }
 805                 if ( !$schema ) {
 806                         $schema = $wgDBmwschema;
 807                 }
 808                 $table = $this->tableName( $table, 'raw' );
 809                 $etable = $this->addQuotes( $table );
 810                 $eschema = $this->addQuotes( $schema );
 811                 $SQL = "SELECT 1 FROM pg_catalog.pg_class c, pg_catalog.pg_namespace n "
 812                         . "WHERE c.relnamespace = n.oid AND c.relname = $etable AND n.nspname = $eschema "
 813                         . "AND c.relkind IN ('" . implode( "','", $types ) . "')";
 814                 $res = $this->query( $SQL );
 815                 $count = $res ? $res->numRows() : 0;
 816                 return (bool)$count;
 817         }
 818
 819         /**
 820          * For backward compatibility, this function checks both tables and
 821          * views.
 822          */
 823         function tableExists( $table, $fname = __METHOD__, $schema = false ) {
 824                 return $this->relationExists( $table, array( 'r', 'v' ), $schema );
 825         }
 826
 827         function sequenceExists( $sequence, $schema = false ) {
 828                 return $this->relationExists( $sequence, 'S', $schema );
 829         }
 830
 831         function triggerExists( $table, $trigger ) {
 832                 global $wgDBmwschema;
 833
 834                 $q = <<<SQL
 835         SELECT 1 FROM pg_class, pg_namespace, pg_trigger
 836                 WHERE relnamespace=pg_namespace.oid AND relkind='r'
 837                           AND tgrelid=pg_class.oid
 838                           AND nspname=%s AND relname=%s AND tgname=%s
 839 SQL;
 840                 $res = $this->query(
 841                         sprintf(
 842                                 $q,
 843                                 $this->addQuotes( $wgDBmwschema ),
 844                                 $this->addQuotes( $table ),
 845                                 $this->addQuotes( $trigger )
 846                         )
 847                 );
 848                 if ( !$res ) {
 849                         return null;
 850                 }
 851                 $rows = $res->numRows();
 852                 return $rows;
 853         }
 854
 855         function ruleExists( $table, $rule ) {
 856                 global $wgDBmwschema;
 857                 $exists = $this->selectField( 'pg_rules', 'rulename',
 858                         array(
 859                                 'rulename' => $rule,
 860                                 'tablename' => $table,
 861                                 'schemaname' => $wgDBmwschema
 862                         )
 863                 );
 864                 return $exists === $rule;
 865         }
 866
 867         function constraintExists( $table, $constraint ) {
 868                 global $wgDBmwschema;
 869                 $SQL = sprintf( "SELECT 1 FROM information_schema.table_constraints ".
 870                            "WHERE constraint_schema = %s AND table_name = %s AND constraint_name = %s",
 871                         $this->addQuotes( $wgDBmwschema ),
 872                         $this->addQuotes( $table ),
 873                         $this->addQuotes( $constraint )
 874                 );
 875                 $res = $this->query( $SQL );
 876                 if ( !$res ) {
 877                         return null;
 878                 }
 879                 $rows = $res->numRows();
 880                 return $rows;
 881         }
 882
 883         /**
 884          * Query whether a given schema exists. Returns true if it does, false if it doesn't.
 885          */
 886         function schemaExists( $schema ) {
 887                 $exists = $this->selectField( '"pg_catalog"."pg_namespace"', 1,
 888                         array( 'nspname' => $schema ), __METHOD__ );
 889                 return (bool)$exists;
 890         }
 891
 892         /**
 893          * Returns true if a given role (i.e. user) exists, false otherwise.
 894          */
 895         function roleExists( $roleName ) {
 896                 $exists = $this->selectField( '"pg_catalog"."pg_roles"', 1,
 897                         array( 'rolname' => $roleName ), __METHOD__ );
 898                 return (bool)$exists;
 899         }
 900
 901         function fieldInfo( $table, $field ) {
 902                 return PostgresField::fromText( $this, $table, $field );
 903         }
 904
 905         /**
 906          * pg_field_type() wrapper
 907          */
 908         function fieldType( $res, $index ) {
 909                 if ( $res instanceof ResultWrapper ) {
 910                         $res = $res->result;
 911                 }
 912                 return pg_field_type( $res, $index );
 913         }
 914
 915         /* Not even sure why this is used in the main codebase... */
 916         function limitResultForUpdate( $sql, $num ) {
 917                 return $sql;
 918         }
 919
 920         /**
 921          * @param $b
 922          * @return Blob
 923          */
 924         function encodeBlob( $b ) {
 925                 return new Blob( pg_escape_bytea( $this->mConn, $b ) );
 926         }
 927
 928         function decodeBlob( $b ) {
 929                 if ( $b instanceof Blob ) {
 930                         $b = $b->fetch();
 931                 }
 932                 return pg_unescape_bytea( $b );
 933         }
 934
 935         function strencode( $s ) { # Should not be called by us
 936                 return pg_escape_string( $this->mConn, $s );
 937         }
 938
 939         /**
 940          * @param $s null|bool|Blob
 941          * @return int|string
 942          */
 943         function addQuotes( $s ) {
 944                 if ( is_null( $s ) ) {
 945                         return 'NULL';
 946                 } elseif ( is_bool( $s ) ) {
 947                         return intval( $s );
 948                 } elseif ( $s instanceof Blob ) {
 949                         return "'" . $s->fetch( $s ) . "'";
 950                 }
 951                 return "'" . pg_escape_string( $this->mConn, $s ) . "'";
 952         }
 953
 954         /**
 955          * Postgres specific version of replaceVars.
 956          * Calls the parent version in Database.php
 957          *
 958          * @private
 959          *
 960          * @param $ins String: SQL string, read from a stream (usually tables.sql)
 961          *
 962          * @return string SQL string
 963          */
 964         protected function replaceVars( $ins ) {
 965                 $ins = parent::replaceVars( $ins );
 966
 967                 if ( $this->numeric_version >= 8.3 ) {
 968                         // Thanks for not providing backwards-compatibility, 8.3
 969                         $ins = preg_replace( "/to_tsvector\s*\(\s*'default'\s*,/", 'to_tsvector(', $ins );
 970                 }
 971
 972                 if ( $this->numeric_version <= 8.1 ) { // Our minimum version
 973                         $ins = str_replace( 'USING gin', 'USING gist', $ins );
 974                 }
 975
 976                 return $ins;
 977         }
 978
 979         /**
 980          * Various select options
 981          *
 982          * @private
 983          *
 984          * @param $options Array: an associative array of options to be turned into
 985          *              an SQL query, valid keys are listed in the function.
 986          * @return array
 987          */
 988         function makeSelectOptions( $options ) {
 989                 $preLimitTail = $postLimitTail = '';
 990                 $startOpts = $useIndex = '';
 991
 992                 $noKeyOptions = array();
 993                 foreach ( $options as $key => $option ) {
 994                         if ( is_numeric( $key ) ) {
 995                                 $noKeyOptions[$option] = true;
 996                         }
 997                 }
 998
 999                 if ( isset( $options['GROUP BY'] ) ) {
1000                         $gb = is_array( $options['GROUP BY'] )
1001                                 ? implode( ',', $options['GROUP BY'] )
1002                                 : $options['GROUP BY'];
1003                         $preLimitTail .= " GROUP BY {$gb}";
1004                 }
1005
1006                 if ( isset( $options['HAVING'] ) ) {
1007                         $preLimitTail .= " HAVING {$options['HAVING']}";
1008                 }
1009
1010                 if ( isset( $options['ORDER BY'] ) ) {
1011                         $ob = is_array( $options['ORDER BY'] )
1012                                 ? implode( ',', $options['ORDER BY'] )
1013                                 : $options['ORDER BY'];
1014                         $preLimitTail .= " ORDER BY {$ob}";
1015                 }
1016
1017                 //if ( isset( $options['LIMIT'] ) ) {
1018                 //      $tailOpts .= $this->limitResult( '', $options['LIMIT'],
1019                 //              isset( $options['OFFSET'] ) ? $options['OFFSET']
1020                 //              : false );
1021                 //}
1022
1023                 if ( isset( $noKeyOptions['FOR UPDATE'] ) ) {
1024                         $postLimitTail .= ' FOR UPDATE';
1025                 }
1026                 if ( isset( $noKeyOptions['LOCK IN SHARE MODE'] ) ) {
1027                         $postLimitTail .= ' LOCK IN SHARE MODE';
1028                 }
1029                 if ( isset( $noKeyOptions['DISTINCT'] ) || isset( $noKeyOptions['DISTINCTROW'] ) ) {
1030                         $startOpts .= 'DISTINCT';
1031                 }
1032
1033                 return array( $startOpts, $useIndex, $preLimitTail, $postLimitTail );
1034         }
1035
1036         function setFakeMaster( $enabled = true ) {}
1037
1038         function getDBname() {
1039                 return $this->mDBname;
1040         }
1041
1042         function getServer() {
1043                 return $this->mServer;
1044         }
1045
1046         function buildConcat( $stringList ) {
1047                 return implode( ' || ', $stringList );
1048         }
1049
1050         public function getSearchEngine() {
1051                 return 'SearchPostgres';
1052         }
1053
1054         protected function streamStatementEnd( &$sql, &$newLine ) {
1055                 # Allow dollar quoting for function declarations
1056                 if ( substr( $newLine, 0, 4 ) == '$mw$' ) {
1057                         if ( $this->delimiter ) {
1058                                 $this->delimiter = false;
1059                         }
1060                         else {
1061                                 $this->delimiter = ';';
1062                         }
1063                 }
1064                 return parent::streamStatementEnd( $sql, $newLine );
1065         }
1066 } // end DatabasePostgres class