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, $conname;
  11
  12         static function fromText($db, $table, $field) {
  13         global $wgDBmwschema;
  14
  15                 $q = <<<SQL
  16 SELECT
  17  attnotnull, attlen, COALESCE(conname, '') AS conname,
  18  COALESCE(condeferred, 'f') AS deferred,
  19  COALESCE(condeferrable, 'f') AS deferrable,
  20  CASE WHEN typname = 'int2' THEN 'smallint'
  21   WHEN typname = 'int4' THEN 'integer'
  22   WHEN typname = 'int8' THEN 'bigint'
  23   WHEN typname = 'bpchar' THEN 'char'
  24  ELSE typname END AS typname
  25 FROM pg_class c
  26 JOIN pg_namespace n ON (n.oid = c.relnamespace)
  27 JOIN pg_attribute a ON (a.attrelid = c.oid)
  28 JOIN pg_type t ON (t.oid = a.atttypid)
  29 LEFT JOIN pg_constraint o ON (o.conrelid = c.oid AND a.attnum = ANY(o.conkey) AND o.contype = 'f')
  30 WHERE relkind = 'r'
  31 AND nspname=%s
  32 AND relname=%s
  33 AND attname=%s;
  34 SQL;
  35
  36                 $table = $db->tableName( $table );
  37                 $res = $db->query(
  38                         sprintf( $q,
  39                                 $db->addQuotes( $wgDBmwschema ),
  40                                 $db->addQuotes( $table ),
  41                                 $db->addQuotes( $field )
  42                         )
  43                 );
  44                 $row = $db->fetchObject( $res );
  45                 if ( !$row ) {
  46                         return null;
  47                 }
  48                 $n = new PostgresField;
  49                 $n->type = $row->typname;
  50                 $n->nullable = ( $row->attnotnull == 'f' );
  51                 $n->name = $field;
  52                 $n->tablename = $table;
  53                 $n->max_length = $row->attlen;
  54                 $n->deferrable = ( $row->deferrable == 't' );
  55                 $n->deferred = ( $row->deferred == 't' );
  56                 $n->conname = $row->conname;
  57                 return $n;
  58         }
  59
  60         function name() {
  61                 return $this->name;
  62         }
  63
  64         function tableName() {
  65                 return $this->tablename;
  66         }
  67
  68         function type() {
  69                 return $this->type;
  70         }
  71
  72         function isNullable() {
  73                 return $this->nullable;
  74         }
  75
  76         function maxLength() {
  77                 return $this->max_length;
  78         }
  79
  80         function is_deferrable() {
  81                 return $this->deferrable;
  82         }
  83
  84         function is_deferred() {
  85                 return $this->deferred;
  86         }
  87
  88         function conname() {
  89                 return $this->conname;
  90         }
  91
  92 }
  93
  94 /**
  95  * @ingroup Database
  96  */
  97 class DatabasePostgres extends DatabaseBase {
  98         var $mInsertId = null;
  99         var $mLastResult = null;
 100         var $numeric_version = null;
 101         var $mAffectedRows = null;
 102
 103         function getType() {
 104                 return 'postgres';
 105         }
 106
 107         function cascadingDeletes() {
 108                 return true;
 109         }
 110         function cleanupTriggers() {
 111                 return true;
 112         }
 113         function strictIPs() {
 114                 return true;
 115         }
 116         function realTimestamps() {
 117                 return true;
 118         }
 119         function implicitGroupby() {
 120                 return false;
 121         }
 122         function implicitOrderby() {
 123                 return false;
 124         }
 125         function searchableIPs() {
 126                 return true;
 127         }
 128         function functionalIndexes() {
 129                 return true;
 130         }
 131
 132         function hasConstraint( $name ) {
 133                 global $wgDBmwschema;
 134                 $SQL = "SELECT 1 FROM pg_catalog.pg_constraint c, pg_catalog.pg_namespace n WHERE c.connamespace = n.oid AND conname = '" .
 135                                 pg_escape_string( $this->mConn, $name ) . "' AND n.nspname = '" . pg_escape_string( $this->mConn, $wgDBmwschema ) ."'";
 136                 $res = $this->doQuery( $SQL );
 137                 return $this->numRows( $res );
 138         }
 139
 140         /**
 141          * Usually aborts on failure
 142          */
 143         function open( $server, $user, $password, $dbName ) {
 144                 # Test for Postgres support, to avoid suppressed fatal error
 145                 if ( !function_exists( 'pg_connect' ) ) {
 146                         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" );
 147                 }
 148
 149                 global $wgDBport;
 150
 151                 if ( !strlen( $user ) ) { # e.g. the class is being loaded
 152                         return;
 153                 }
 154
 155                 $this->close();
 156                 $this->mServer = $server;
 157                 $this->mPort = $port = $wgDBport;
 158                 $this->mUser = $user;
 159                 $this->mPassword = $password;
 160                 $this->mDBname = $dbName;
 161
 162                 $connectVars = array(
 163                         'dbname' => $dbName,
 164                         'user' => $user,
 165                         'password' => $password
 166                 );
 167                 if ( $server != false && $server != '' ) {
 168                         $connectVars['host'] = $server;
 169                 }
 170                 if ( $port != false && $port != '' ) {
 171                         $connectVars['port'] = $port;
 172                 }
 173                 $connectString = $this->makeConnectionString( $connectVars, PGSQL_CONNECT_FORCE_NEW );
 174
 175                 $this->installErrorHandler();
 176                 $this->mConn = pg_connect( $connectString );
 177                 $phpError = $this->restoreErrorHandler();
 178
 179                 if ( !$this->mConn ) {
 180                         wfDebug( "DB connection error\n" );
 181                         wfDebug( "Server: $server, Database: $dbName, User: $user, Password: " . substr( $password, 0, 3 ) . "...\n" );
 182                         wfDebug( $this->lastError() . "\n" );
 183                         throw new DBConnectionError( $this, $phpError );
 184                 }
 185
 186                 $this->mOpened = true;
 187
 188                 global $wgCommandLineMode;
 189                 # If called from the command-line (e.g. importDump), only show errors
 190                 if ( $wgCommandLineMode ) {
 191                         $this->doQuery( "SET client_min_messages = 'ERROR'" );
 192                 }
 193
 194                 $this->doQuery( "SET client_encoding='UTF8'" );
 195
 196                 global $wgDBmwschema;
 197                 if ( isset( $wgDBmwschema )
 198                         && $wgDBmwschema !== 'mediawiki'
 199                         && preg_match( '/^\w+$/', $wgDBmwschema )
 200                 ) {
 201                         $safeschema = $this->addIdentifierQuotes( $wgDBmwschema );
 202                         $this->doQuery( "SET search_path = $safeschema, public" );
 203                 }
 204
 205                 return $this->mConn;
 206         }
 207
 208         function makeConnectionString( $vars ) {
 209                 $s = '';
 210                 foreach ( $vars as $name => $value ) {
 211                         $s .= "$name='" . str_replace( "'", "\\'", $value ) . "' ";
 212                 }
 213                 return $s;
 214         }
 215
 216
 217         function initial_setup( $superuser, $password, $dbName ) {
 218                 // If this is the initial connection, setup the schema stuff and possibly create the user
 219                 global $wgDBname, $wgDBuser, $wgDBpassword, $wgDBmwschema, $wgDBts2schema;
 220
 221                 $safeuser = $this->addIdentifierQuotes( $wgDBuser );
 222                 // Are we connecting as a superuser for the first time?
 223                 if ( $superuser ) {
 224                         // Are we really a superuser? Check out our rights
 225                         $SQL = "SELECT
 226                       CASE WHEN usesuper IS TRUE THEN
 227                       CASE WHEN usecreatedb IS TRUE THEN 3 ELSE 1 END
 228                       ELSE CASE WHEN usecreatedb IS TRUE THEN 2 ELSE 0 END
 229                     END AS rights
 230                     FROM pg_catalog.pg_user WHERE usename = " . $this->addQuotes( $superuser );
 231                         $rows = $this->numRows( $res = $this->doQuery( $SQL ) );
 232                         if ( !$rows ) {
 233                                 print '<li>ERROR: Could not read permissions for user "' . htmlspecialchars( $superuser ) . "\"</li>\n";
 234                                 dieout( );
 235                         }
 236                         $perms = pg_fetch_result( $res, 0, 0 );
 237
 238                         $SQL = "SELECT 1 FROM pg_catalog.pg_user WHERE usename = " . $this->addQuotes( $wgDBuser );
 239                         $rows = $this->numRows( $this->doQuery( $SQL ) );
 240                         if ( $rows ) {
 241                                 print '<li>User "' . htmlspecialchars( $wgDBuser ) . '" already exists, skipping account creation.</li>';
 242                         } else {
 243                                 if ( $perms != 1 && $perms != 3 ) {
 244                                         print '<li>ERROR: the user "' . htmlspecialchars( $superuser ) . '" cannot create other users. ';
 245                                         print 'Please use a different Postgres user.</li>';
 246                                         dieout( );
 247                                 }
 248                                 print '<li>Creating user <b>' . htmlspecialchars( $wgDBuser ) . '</b>...';
 249                                 $safepass = $this->addQuotes( $wgDBpassword );
 250                                 $SQL = "CREATE USER $safeuser NOCREATEDB PASSWORD $safepass";
 251                                 $this->doQuery( $SQL );
 252                                 print "OK</li>\n";
 253                         }
 254                         // User now exists, check out the database
 255                         if ( $dbName != $wgDBname ) {
 256                                 $SQL = "SELECT 1 FROM pg_catalog.pg_database WHERE datname = " . $this->addQuotes( $wgDBname );
 257                                 $rows = $this->numRows( $this->doQuery( $SQL ) );
 258                                 if ( $rows ) {
 259                                         print '<li>Database "' . htmlspecialchars( $wgDBname ) . '" already exists, skipping database creation.</li>';
 260                                 } else {
 261                                         if ( $perms < 1 ) {
 262                                                 print '<li>ERROR: the user "' . htmlspecialchars( $superuser ) . '" cannot create databases. ';
 263                                                 print 'Please use a different Postgres user.</li>';
 264                                                 dieout( );
 265                                         }
 266                                         print '<li>Creating database <b>' . htmlspecialchars( $wgDBname ) . '</b>...';
 267                                         $safename = $this->addIdentifierQuotes( $wgDBname );
 268                                         $SQL = "CREATE DATABASE $safename OWNER $safeuser ";
 269                                         $this->doQuery( $SQL );
 270                                         print "OK</li>\n";
 271                                         // Hopefully tsearch2 and plpgsql are in template1...
 272                                 }
 273
 274                                 // Reconnect to check out tsearch2 rights for this user
 275                                 print '<li>Connecting to "' . htmlspecialchars( $wgDBname ) . '" as superuser "' .
 276                                         htmlspecialchars( $superuser ) . '" to check rights...';
 277
 278                                 $connectVars = array();
 279                                 if ( $this->mServer != false && $this->mServer != '' ) {
 280                                         $connectVars['host'] = $this->mServer;
 281                                 }
 282                                 if ( $this->mPort != false && $this->mPort != '' ) {
 283                                         $connectVars['port'] = $this->mPort;
 284                                 }
 285                                 $connectVars['dbname'] = $wgDBname;
 286                                 $connectVars['user'] = $superuser;
 287                                 $connectVars['password'] = $password;
 288
 289                                 @$this->mConn = pg_connect( $this->makeConnectionString( $connectVars ) );
 290                                 if ( !$this->mConn ) {
 291                                         print "<b>FAILED TO CONNECT!</b></li>";
 292                                         dieout( );
 293                                 }
 294                                 print "OK</li>\n";
 295                         }
 296
 297                         // Setup the schema for this user if needed
 298                         $result = $this->schemaExists( $wgDBmwschema );
 299                         $safeschema = $this->addIdentifierQuotes( $wgDBmwschema );
 300                         if ( !$result ) {
 301                                 print '<li>Creating schema <b>' . htmlspecialchars( $wgDBmwschema ) . '</b> ...';
 302                                 $result = $this->doQuery( "CREATE SCHEMA $safeschema AUTHORIZATION $safeuser" );
 303                                 if ( !$result ) {
 304                                         print "<b>FAILED</b>.</li>\n";
 305                                         dieout( );
 306                                 }
 307                                 print "OK</li>\n";
 308                         } else {
 309                                 print "<li>Schema already exists, explicitly granting rights...\n";
 310                                 $safeschema2 = $this->addQuotes( $wgDBmwschema );
 311                                 $SQL = "SELECT 'GRANT ALL ON '||pg_catalog.quote_ident(relname)||' TO $safeuser;'\n".
 312                                         "FROM pg_catalog.pg_class p, pg_catalog.pg_namespace n\n".
 313                                         "WHERE relnamespace = n.oid AND n.nspname = $safeschema2\n".
 314                                         "AND p.relkind IN ('r','S','v')\n";
 315                                 $SQL .= "UNION\n";
 316                                 $SQL .= "SELECT 'GRANT ALL ON FUNCTION '||pg_catalog.quote_ident(proname)||'('||\n".
 317                                         "pg_catalog.oidvectortypes(p.proargtypes)||') TO $safeuser;'\n".
 318                                         "FROM pg_catalog.pg_proc p, pg_catalog.pg_namespace n\n".
 319                                         "WHERE p.pronamespace = n.oid AND n.nspname = $safeschema2";
 320                                 $res = $this->doQuery( $SQL );
 321                                 if ( !$res ) {
 322                                         print "<b>FAILED</b>. Could not set rights for the user.</li>\n";
 323                                         dieout( );
 324                                 }
 325                                 $this->doQuery( "SET search_path = $safeschema" );
 326                                 $rows = $this->numRows( $res );
 327                                 while ( $rows ) {
 328                                         $rows--;
 329                                         $this->doQuery( pg_fetch_result( $res, $rows, 0 ) );
 330                                 }
 331                                 print "OK</li>";
 332                         }
 333
 334                         // Install plpgsql if needed
 335                         $this->setup_plpgsql();
 336
 337                         return true; // Reconnect as regular user
 338
 339                 } // end superuser
 340
 341                 if ( !defined( 'POSTGRES_SEARCHPATH' ) ) {
 342                         // Install plpgsql if needed
 343                         $this->setup_plpgsql();
 344
 345                         // Does the schema already exist? Who owns it?
 346                         $result = $this->schemaExists( $wgDBmwschema );
 347                         if ( !$result ) {
 348                                 print '<li>Creating schema <b>' . htmlspecialchars( $wgDBmwschema ) . '</b> ...';
 349                                 error_reporting( 0 );
 350                                 $safeschema = $this->addIdentifierQuotes( $wgDBmwschema );
 351                                 $result = $this->doQuery( "CREATE SCHEMA $safeschema" );
 352                                 error_reporting( E_ALL );
 353                                 if ( !$result ) {
 354                                         print '<b>FAILED</b>. The user "' . htmlspecialchars( $wgDBuser ) .
 355                                                 '" must be able to access the schema. '.
 356                                                 'You can try making them the owner of the database, or try creating the schema with a '.
 357                                                 'different user, and then grant access to the "' .
 358                                                 htmlspecialchars( $wgDBuser ) . "\" user.</li>\n";
 359                                         dieout( );
 360                                 }
 361                                 print "OK</li>\n";
 362                         } elseif ( $result != $wgDBuser ) {
 363                                 print '<li>Schema "' . htmlspecialchars( $wgDBmwschema ) . '" exists but is not owned by "' .
 364                                         htmlspecialchars( $wgDBuser ) . "\". Not ideal.</li>\n";
 365                         } else {
 366                                 print '<li>Schema "' . htmlspecialchars( $wgDBmwschema ) . '" exists and is owned by "' .
 367                                         htmlspecialchars( $wgDBuser ) . "\". Excellent.</li>\n";
 368                         }
 369
 370                         // Always return GMT time to accomodate the existing integer-based timestamp assumption
 371                         print "<li>Setting the timezone to GMT for user \"" . htmlspecialchars( $wgDBuser ) . '" ...';
 372                         $SQL = "ALTER USER $safeuser SET timezone = 'GMT'";
 373                         $result = pg_query( $this->mConn, $SQL );
 374                         if ( !$result ) {
 375                                 print "<b>FAILED</b>.</li>\n";
 376                                 dieout( );
 377                         }
 378                         print "OK</li>\n";
 379                         // Set for the rest of this session
 380                         $SQL = "SET timezone = 'GMT'";
 381                         $result = pg_query( $this->mConn, $SQL );
 382                         if ( !$result ) {
 383                                 print "<li>Failed to set timezone</li>\n";
 384                                 dieout( );
 385                         }
 386
 387                         print '<li>Setting the datestyle to ISO, YMD for user "' . htmlspecialchars( $wgDBuser ) . '" ...';
 388                         $SQL = "ALTER USER $safeuser SET datestyle = 'ISO, YMD'";
 389                         $result = pg_query( $this->mConn, $SQL );
 390                         if ( !$result ) {
 391                                 print "<b>FAILED</b>.</li>\n";
 392                                 dieout( );
 393                         }
 394                         print "OK</li>\n";
 395                         // Set for the rest of this session
 396                         $SQL = "SET datestyle = 'ISO, YMD'";
 397                         $result = pg_query( $this->mConn, $SQL );
 398                         if ( !$result ) {
 399                                 print "<li>Failed to set datestyle</li>\n";
 400                                 dieout( );
 401                         }
 402
 403                         // Fix up the search paths if needed
 404                         print '<li>Setting the search path for user "' . htmlspecialchars( $wgDBuser ) . '" ...';
 405                         $path = $this->addIdentifierQuotes( $wgDBmwschema );
 406                         if ( $wgDBts2schema !== $wgDBmwschema ) {
 407                                 $path .= ', '. $this->addIdentifierQuotes( $wgDBts2schema );
 408                         }
 409                         if ( $wgDBmwschema !== 'public' && $wgDBts2schema !== 'public' ) {
 410                                 $path .= ', public';
 411                         }
 412                         $SQL = "ALTER USER $safeuser SET search_path = $path";
 413                         $result = pg_query( $this->mConn, $SQL );
 414                         if ( !$result ) {
 415                                 print "<b>FAILED</b>.</li>\n";
 416                                 dieout( );
 417                         }
 418                         print "OK</li>\n";
 419                         // Set for the rest of this session
 420                         $SQL = "SET search_path = $path";
 421                         $result = pg_query( $this->mConn, $SQL );
 422                         if ( !$result ) {
 423                                 print "<li>Failed to set search_path</li>\n";
 424                                 dieout( );
 425                         }
 426                         define( 'POSTGRES_SEARCHPATH', $path );
 427                 }
 428         }
 429
 430         /**
 431          * Closes a database connection, if it is open
 432          * Returns success, true if already closed
 433          */
 434         function close() {
 435                 $this->mOpened = false;
 436                 if ( $this->mConn ) {
 437                         return pg_close( $this->mConn );
 438                 } else {
 439                         return true;
 440                 }
 441         }
 442
 443         function doQuery( $sql ) {
 444                 if ( function_exists( 'mb_convert_encoding' ) ) {
 445                         $sql = mb_convert_encoding( $sql, 'UTF-8' );
 446                 }
 447                 $this->mLastResult = pg_query( $this->mConn, $sql );
 448                 $this->mAffectedRows = null; // use pg_affected_rows(mLastResult)
 449                 return $this->mLastResult;
 450         }
 451
 452         function queryIgnore( $sql, $fname = 'DatabasePostgres::queryIgnore' ) {
 453                 return $this->query( $sql, $fname, true );
 454         }
 455
 456         function freeResult( $res ) {
 457                 if ( $res instanceof ResultWrapper ) {
 458                         $res = $res->result;
 459                 }
 460                 if ( !@pg_free_result( $res ) ) {
 461                         throw new DBUnexpectedError( $this, "Unable to free Postgres result\n" );
 462                 }
 463         }
 464
 465         function fetchObject( $res ) {
 466                 if ( $res instanceof ResultWrapper ) {
 467                         $res = $res->result;
 468                 }
 469                 @$row = pg_fetch_object( $res );
 470                 # FIXME: HACK HACK HACK HACK debug
 471
 472                 # TODO:
 473                 # hashar : not sure if the following test really trigger if the object
 474                 #          fetching failed.
 475                 if( pg_last_error( $this->mConn ) ) {
 476                         throw new DBUnexpectedError( $this, 'SQL error: ' . htmlspecialchars( pg_last_error( $this->mConn ) ) );
 477                 }
 478                 return $row;
 479         }
 480
 481         function fetchRow( $res ) {
 482                 if ( $res instanceof ResultWrapper ) {
 483                         $res = $res->result;
 484                 }
 485                 @$row = pg_fetch_array( $res );
 486                 if( pg_last_error( $this->mConn ) ) {
 487                         throw new DBUnexpectedError( $this, 'SQL error: ' . htmlspecialchars( pg_last_error( $this->mConn ) ) );
 488                 }
 489                 return $row;
 490         }
 491
 492         function numRows( $res ) {
 493                 if ( $res instanceof ResultWrapper ) {
 494                         $res = $res->result;
 495                 }
 496                 @$n = pg_num_rows( $res );
 497                 if( pg_last_error( $this->mConn ) ) {
 498                         throw new DBUnexpectedError( $this, 'SQL error: ' . htmlspecialchars( pg_last_error( $this->mConn ) ) );
 499                 }
 500                 return $n;
 501         }
 502
 503         function numFields( $res ) {
 504                 if ( $res instanceof ResultWrapper ) {
 505                         $res = $res->result;
 506                 }
 507                 return pg_num_fields( $res );
 508         }
 509
 510         function fieldName( $res, $n ) {
 511                 if ( $res instanceof ResultWrapper ) {
 512                         $res = $res->result;
 513                 }
 514                 return pg_field_name( $res, $n );
 515         }
 516
 517         /**
 518          * This must be called after nextSequenceVal
 519          */
 520         function insertId() {
 521                 return $this->mInsertId;
 522         }
 523
 524         function dataSeek( $res, $row ) {
 525                 if ( $res instanceof ResultWrapper ) {
 526                         $res = $res->result;
 527                 }
 528                 return pg_result_seek( $res, $row );
 529         }
 530
 531         function lastError() {
 532                 if ( $this->mConn ) {
 533                         return pg_last_error();
 534                 } else {
 535                         return 'No database connection';
 536                 }
 537         }
 538         function lastErrno() {
 539                 return pg_last_error() ? 1 : 0;
 540         }
 541
 542         function affectedRows() {
 543                 if ( !is_null( $this->mAffectedRows ) ) {
 544                         // Forced result for simulated queries
 545                         return $this->mAffectedRows;
 546                 }
 547                 if( empty( $this->mLastResult ) ) {
 548                         return 0;
 549                 }
 550                 return pg_affected_rows( $this->mLastResult );
 551         }
 552
 553         /**
 554          * Estimate rows in dataset
 555          * Returns estimated count, based on EXPLAIN output
 556          * This is not necessarily an accurate estimate, so use sparingly
 557          * Returns -1 if count cannot be found
 558          * Takes same arguments as Database::select()
 559          */
 560         function estimateRowCount( $table, $vars = '*', $conds='', $fname = 'DatabasePostgres::estimateRowCount', $options = array() ) {
 561                 $options['EXPLAIN'] = true;
 562                 $res = $this->select( $table, $vars, $conds, $fname, $options );
 563                 $rows = -1;
 564                 if ( $res ) {
 565                         $row = $this->fetchRow( $res );
 566                         $count = array();
 567                         if( preg_match( '/rows=(\d+)/', $row[0], $count ) ) {
 568                                 $rows = $count[1];
 569                         }
 570                 }
 571                 return $rows;
 572         }
 573
 574         /**
 575          * Returns information about an index
 576          * If errors are explicitly ignored, returns NULL on failure
 577          */
 578         function indexInfo( $table, $index, $fname = 'DatabasePostgres::indexInfo' ) {
 579                 $sql = "SELECT indexname FROM pg_indexes WHERE tablename='$table'";
 580                 $res = $this->query( $sql, $fname );
 581                 if ( !$res ) {
 582                         return null;
 583                 }
 584                 foreach ( $res as $row ) {
 585                         if ( $row->indexname == $this->indexName( $index ) ) {
 586                                 return $row;
 587                         }
 588                 }
 589                 return false;
 590         }
 591
 592         function indexUnique( $table, $index, $fname = 'DatabasePostgres::indexUnique' ) {
 593                 $sql = "SELECT indexname FROM pg_indexes WHERE tablename='{$table}'".
 594                         " AND indexdef LIKE 'CREATE UNIQUE%(" .
 595                         $this->strencode( $this->indexName( $index ) ) .
 596                         ")'";
 597                 $res = $this->query( $sql, $fname );
 598                 if ( !$res ) {
 599                         return null;
 600                 }
 601                 foreach ( $res as $row ) {
 602                         return true;
 603                 }
 604                 return false;
 605         }
 606
 607         /**
 608          * INSERT wrapper, inserts an array into a table
 609          *
 610          * $args may be a single associative array, or an array of these with numeric keys,
 611          * for multi-row insert (Postgres version 8.2 and above only).
 612          *
 613          * @param $table   String: Name of the table to insert to.
 614          * @param $args    Array: Items to insert into the table.
 615          * @param $fname   String: Name of the function, for profiling
 616          * @param $options String or Array. Valid options: IGNORE
 617          *
 618          * @return bool Success of insert operation. IGNORE always returns true.
 619          */
 620         function insert( $table, $args, $fname = 'DatabasePostgres::insert', $options = array() ) {
 621                 if ( !count( $args ) ) {
 622                         return true;
 623                 }
 624
 625                 $table = $this->tableName( $table );
 626                 if (! isset( $this->numeric_version ) ) {
 627                         $this->getServerVersion();
 628                 }
 629
 630                 if ( !is_array( $options ) ) {
 631                         $options = array( $options );
 632                 }
 633
 634                 if ( isset( $args[0] ) && is_array( $args[0] ) ) {
 635                         $multi = true;
 636                         $keys = array_keys( $args[0] );
 637                 } else {
 638                         $multi = false;
 639                         $keys = array_keys( $args );
 640                 }
 641
 642                 // If IGNORE is set, we use savepoints to emulate mysql's behavior
 643                 $ignore = in_array( 'IGNORE', $options ) ? 'mw' : '';
 644
 645                 // If we are not in a transaction, we need to be for savepoint trickery
 646                 $didbegin = 0;
 647                 if ( $ignore ) {
 648                         if ( !$this->mTrxLevel ) {
 649                                 $this->begin();
 650                                 $didbegin = 1;
 651                         }
 652                         $olde = error_reporting( 0 );
 653                         // For future use, we may want to track the number of actual inserts
 654                         // Right now, insert (all writes) simply return true/false
 655                         $numrowsinserted = 0;
 656                 }
 657
 658                 $sql = "INSERT INTO $table (" . implode( ',', $keys ) . ') VALUES ';
 659
 660                 if ( $multi ) {
 661                         if ( $this->numeric_version >= 8.2 && !$ignore ) {
 662                                 $first = true;
 663                                 foreach ( $args as $row ) {
 664                                         if ( $first ) {
 665                                                 $first = false;
 666                                         } else {
 667                                                 $sql .= ',';
 668                                         }
 669                                         $sql .= '(' . $this->makeList( $row ) . ')';
 670                                 }
 671                                 $res = (bool)$this->query( $sql, $fname, $ignore );
 672                         } else {
 673                                 $res = true;
 674                                 $origsql = $sql;
 675                                 foreach ( $args as $row ) {
 676                                         $tempsql = $origsql;
 677                                         $tempsql .= '(' . $this->makeList( $row ) . ')';
 678
 679                                         if ( $ignore ) {
 680                                                 pg_query( $this->mConn, "SAVEPOINT $ignore" );
 681                                         }
 682
 683                                         $tempres = (bool)$this->query( $tempsql, $fname, $ignore );
 684
 685                                         if ( $ignore ) {
 686                                                 $bar = pg_last_error();
 687                                                 if ( $bar != false ) {
 688                                                         pg_query( $this->mConn, "ROLLBACK TO $ignore" );
 689                                                 } else {
 690                                                         pg_query( $this->mConn, "RELEASE $ignore" );
 691                                                         $numrowsinserted++;
 692                                                 }
 693                                         }
 694
 695                                         // If any of them fail, we fail overall for this function call
 696                                         // Note that this will be ignored if IGNORE is set
 697                                         if ( !$tempres ) {
 698                                                 $res = false;
 699                                         }
 700                                 }
 701                         }
 702                 } else {
 703                         // Not multi, just a lone insert
 704                         if ( $ignore ) {
 705                                 pg_query($this->mConn, "SAVEPOINT $ignore");
 706                         }
 707
 708                         $sql .= '(' . $this->makeList( $args ) . ')';
 709                         $res = (bool)$this->query( $sql, $fname, $ignore );
 710                         if ( $ignore ) {
 711                                 $bar = pg_last_error();
 712                                 if ( $bar != false ) {
 713                                         pg_query( $this->mConn, "ROLLBACK TO $ignore" );
 714                                 } else {
 715                                         pg_query( $this->mConn, "RELEASE $ignore" );
 716                                         $numrowsinserted++;
 717                                 }
 718                         }
 719                 }
 720                 if ( $ignore ) {
 721                         $olde = error_reporting( $olde );
 722                         if ( $didbegin ) {
 723                                 $this->commit();
 724                         }
 725
 726                         // Set the affected row count for the whole operation
 727                         $this->mAffectedRows = $numrowsinserted;
 728
 729                         // IGNORE always returns true
 730                         return true;
 731                 }
 732
 733                 return $res;
 734         }
 735
 736         /**
 737          * INSERT SELECT wrapper
 738          * $varMap must be an associative array of the form array( 'dest1' => 'source1', ...)
 739          * Source items may be literals rather then field names, but strings should be quoted with Database::addQuotes()
 740          * $conds may be "*" to copy the whole table
 741          * srcTable may be an array of tables.
 742          * @todo FIXME: implement this a little better (seperate select/insert)?
 743          */
 744         function insertSelect( $destTable, $srcTable, $varMap, $conds, $fname = 'DatabasePostgres::insertSelect',
 745                 $insertOptions = array(), $selectOptions = array() )
 746         {
 747                 $destTable = $this->tableName( $destTable );
 748
 749                 // If IGNORE is set, we use savepoints to emulate mysql's behavior
 750                 $ignore = in_array( 'IGNORE', $insertOptions ) ? 'mw' : '';
 751
 752                 if( is_array( $insertOptions ) ) {
 753                         $insertOptions = implode( ' ', $insertOptions );
 754                 }
 755                 if( !is_array( $selectOptions ) ) {
 756                         $selectOptions = array( $selectOptions );
 757                 }
 758                 list( $startOpts, $useIndex, $tailOpts ) = $this->makeSelectOptions( $selectOptions );
 759                 if( is_array( $srcTable ) ) {
 760                         $srcTable = implode( ',', array_map( array( &$this, 'tableName' ), $srcTable ) );
 761                 } else {
 762                         $srcTable = $this->tableName( $srcTable );
 763                 }
 764
 765                 // If we are not in a transaction, we need to be for savepoint trickery
 766                 $didbegin = 0;
 767                 if ( $ignore ) {
 768                         if( !$this->mTrxLevel ) {
 769                                 $this->begin();
 770                                 $didbegin = 1;
 771                         }
 772                         $olde = error_reporting( 0 );
 773                         $numrowsinserted = 0;
 774                         pg_query( $this->mConn, "SAVEPOINT $ignore");
 775                 }
 776
 777                 $sql = "INSERT INTO $destTable (" . implode( ',', array_keys( $varMap ) ) . ')' .
 778                                 " SELECT $startOpts " . implode( ',', $varMap ) .
 779                                 " FROM $srcTable $useIndex";
 780
 781                 if ( $conds != '*' ) {
 782                         $sql .= ' WHERE ' . $this->makeList( $conds, LIST_AND );
 783                 }
 784
 785                 $sql .= " $tailOpts";
 786
 787                 $res = (bool)$this->query( $sql, $fname, $ignore );
 788                 if( $ignore ) {
 789                         $bar = pg_last_error();
 790                         if( $bar != false ) {
 791                                 pg_query( $this->mConn, "ROLLBACK TO $ignore" );
 792                         } else {
 793                                 pg_query( $this->mConn, "RELEASE $ignore" );
 794                                 $numrowsinserted++;
 795                         }
 796                         $olde = error_reporting( $olde );
 797                         if( $didbegin ) {
 798                                 $this->commit();
 799                         }
 800
 801                         // Set the affected row count for the whole operation
 802                         $this->mAffectedRows = $numrowsinserted;
 803
 804                         // IGNORE always returns true
 805                         return true;
 806                 }
 807
 808                 return $res;
 809         }
 810
 811         function tableName( $name ) {
 812                 # Replace reserved words with better ones
 813                 switch( $name ) {
 814                         case 'user':
 815                                 return 'mwuser';
 816                         case 'text':
 817                                 return 'pagecontent';
 818                         default:
 819                                 return $name;
 820                 }
 821         }
 822
 823         /**
 824          * Return the next in a sequence, save the value for retrieval via insertId()
 825          */
 826         function nextSequenceValue( $seqName ) {
 827                 $safeseq = str_replace( "'", "''", $seqName );
 828                 $res = $this->query( "SELECT nextval('$safeseq')" );
 829                 $row = $this->fetchRow( $res );
 830                 $this->mInsertId = $row[0];
 831                 return $this->mInsertId;
 832         }
 833
 834         /**
 835          * Return the current value of a sequence. Assumes it has been nextval'ed in this session.
 836          */
 837         function currentSequenceValue( $seqName ) {
 838                 $safeseq = str_replace( "'", "''", $seqName );
 839                 $res = $this->query( "SELECT currval('$safeseq')" );
 840                 $row = $this->fetchRow( $res );
 841                 $currval = $row[0];
 842                 return $currval;
 843         }
 844
 845         /**
 846          * REPLACE query wrapper
 847          * Postgres simulates this with a DELETE followed by INSERT
 848          * $row is the row to insert, an associative array
 849          * $uniqueIndexes is an array of indexes. Each element may be either a
 850          * field name or an array of field names
 851          *
 852          * It may be more efficient to leave off unique indexes which are unlikely to collide.
 853          * However if you do this, you run the risk of encountering errors which wouldn't have
 854          * occurred in MySQL
 855          */
 856         function replace( $table, $uniqueIndexes, $rows, $fname = 'DatabasePostgres::replace' ) {
 857                 $table = $this->tableName( $table );
 858
 859                 if ( count( $rows ) == 0 ) {
 860                         return;
 861                 }
 862
 863                 # Single row case
 864                 if ( !is_array( reset( $rows ) ) ) {
 865                         $rows = array( $rows );
 866                 }
 867
 868                 foreach( $rows as $row ) {
 869                         # Delete rows which collide
 870                         if ( $uniqueIndexes ) {
 871                                 $sql = "DELETE FROM $table WHERE ";
 872                                 $first = true;
 873                                 foreach ( $uniqueIndexes as $index ) {
 874                                         if ( $first ) {
 875                                                 $first = false;
 876                                                 $sql .= '(';
 877                                         } else {
 878                                                 $sql .= ') OR (';
 879                                         }
 880                                         if ( is_array( $index ) ) {
 881                                                 $first2 = true;
 882                                                 foreach ( $index as $col ) {
 883                                                         if ( $first2 ) {
 884                                                                 $first2 = false;
 885                                                         } else {
 886                                                                 $sql .= ' AND ';
 887                                                         }
 888                                                         $sql .= $col.'=' . $this->addQuotes( $row[$col] );
 889                                                 }
 890                                         } else {
 891                                                 $sql .= $index.'=' . $this->addQuotes( $row[$index] );
 892                                         }
 893                                 }
 894                                 $sql .= ')';
 895                                 $this->query( $sql, $fname );
 896                         }
 897
 898                         # Now insert the row
 899                         $sql = "INSERT INTO $table (" . $this->makeList( array_keys( $row ), LIST_NAMES ) .') VALUES (' .
 900                                 $this->makeList( $row, LIST_COMMA ) . ')';
 901                         $this->query( $sql, $fname );
 902                 }
 903         }
 904
 905         # DELETE where the condition is a join
 906         function deleteJoin( $delTable, $joinTable, $delVar, $joinVar, $conds, $fname = 'DatabasePostgres::deleteJoin' ) {
 907                 if ( !$conds ) {
 908                         throw new DBUnexpectedError( $this, 'DatabasePostgres::deleteJoin() called with empty $conds' );
 909                 }
 910
 911                 $delTable = $this->tableName( $delTable );
 912                 $joinTable = $this->tableName( $joinTable );
 913                 $sql = "DELETE FROM $delTable WHERE $delVar IN (SELECT $joinVar FROM $joinTable ";
 914                 if ( $conds != '*' ) {
 915                         $sql .= 'WHERE ' . $this->makeList( $conds, LIST_AND );
 916                 }
 917                 $sql .= ')';
 918
 919                 $this->query( $sql, $fname );
 920         }
 921
 922         # Returns the size of a text field, or -1 for "unlimited"
 923         function textFieldSize( $table, $field ) {
 924                 $table = $this->tableName( $table );
 925                 $sql = "SELECT t.typname as ftype,a.atttypmod as size
 926                         FROM pg_class c, pg_attribute a, pg_type t
 927                         WHERE relname='$table' AND a.attrelid=c.oid AND
 928                                 a.atttypid=t.oid and a.attname='$field'";
 929                 $res =$this->query( $sql );
 930                 $row = $this->fetchObject( $res );
 931                 if ( $row->ftype == 'varchar' ) {
 932                         $size = $row->size - 4;
 933                 } else {
 934                         $size = $row->size;
 935                 }
 936                 return $size;
 937         }
 938
 939         function limitResult( $sql, $limit, $offset = false ) {
 940                 return "$sql LIMIT $limit " . ( is_numeric( $offset ) ? " OFFSET {$offset} " : '' );
 941         }
 942
 943         function wasDeadlock() {
 944                 return $this->lastErrno() == '40P01';
 945         }
 946
 947         function duplicateTableStructure( $oldName, $newName, $temporary = false, $fname = 'DatabasePostgres::duplicateTableStructure' ) {
 948                 return $this->query( 'CREATE ' . ( $temporary ? 'TEMPORARY ' : '' ) . " TABLE $newName (LIKE $oldName INCLUDING DEFAULTS)", $fname );
 949         }
 950
 951         function timestamp( $ts = 0 ) {
 952                 return wfTimestamp( TS_POSTGRES, $ts );
 953         }
 954
 955         /**
 956          * Return aggregated value function call
 957          */
 958         function aggregateValue( $valuedata, $valuename = 'value' ) {
 959                 return $valuedata;
 960         }
 961
 962         function reportQueryError( $error, $errno, $sql, $fname, $tempIgnore = false ) {
 963                 // Ignore errors during error handling to avoid infinite recursion
 964                 $ignore = $this->ignoreErrors( true );
 965                 $this->mErrorCount++;
 966
 967                 if ( $ignore || $tempIgnore ) {
 968                         wfDebug( "SQL ERROR (ignored): $error\n" );
 969                         $this->ignoreErrors( $ignore );
 970                 } else {
 971                         $message = "A database error has occurred.  Did you forget to run maintenance/update.php after upgrading?  See: http://www.mediawiki.org/wiki/Manual:Upgrading#Run_the_update_script\n" .
 972                                 "Query: $sql\n" .
 973                                 "Function: $fname\n" .
 974                                 "Error: $errno $error\n";
 975                         throw new DBUnexpectedError( $this, $message );
 976                 }
 977         }
 978
 979         /**
 980          * @return string wikitext of a link to the server software's web site
 981          */
 982         public static function getSoftwareLink() {
 983                 return '[http://www.postgresql.org/ PostgreSQL]';
 984         }
 985
 986         /**
 987          * @return string Version information from the database
 988          */
 989         function getServerVersion() {
 990                 if ( !isset( $this->numeric_version ) ) {
 991                         $versionInfo = pg_version( $this->mConn );
 992                         if ( version_compare( $versionInfo['client'], '7.4.0', 'lt' ) ) {
 993                                 // Old client, abort install
 994                                 $this->numeric_version = '7.3 or earlier';
 995                         } elseif ( isset( $versionInfo['server'] ) ) {
 996                                 // Normal client
 997                                 $this->numeric_version = $versionInfo['server'];
 998                         } else {
 999                                 // Bug 16937: broken pgsql extension from PHP<5.3
1000                                 $this->numeric_version = pg_parameter_status( $this->mConn, 'server_version' );
1001                         }
1002                 }
1003                 return $this->numeric_version;
1004         }
1005
1006         /**
1007          * Query whether a given relation exists (in the given schema, or the
1008          * default mw one if not given)
1009          */
1010         function relationExists( $table, $types, $schema = false ) {
1011                 global $wgDBmwschema;
1012                 if ( !is_array( $types ) ) {
1013                         $types = array( $types );
1014                 }
1015                 if ( !$schema ) {
1016                         $schema = $wgDBmwschema;
1017                 }
1018                 $table = $this->tableName( $table );
1019                 $etable = $this->addQuotes( $table );
1020                 $eschema = $this->addQuotes( $schema );
1021                 $SQL = "SELECT 1 FROM pg_catalog.pg_class c, pg_catalog.pg_namespace n "
1022                         . "WHERE c.relnamespace = n.oid AND c.relname = $etable AND n.nspname = $eschema "
1023                         . "AND c.relkind IN ('" . implode( "','", $types ) . "')";
1024                 $res = $this->query( $SQL );
1025                 $count = $res ? $res->numRows() : 0;
1026                 return (bool)$count;
1027         }
1028
1029         /**
1030          * For backward compatibility, this function checks both tables and
1031          * views.
1032          */
1033         function tableExists( $table, $schema = false ) {
1034                 return $this->relationExists( $table, array( 'r', 'v' ), $schema );
1035         }
1036
1037         function sequenceExists( $sequence, $schema = false ) {
1038                 return $this->relationExists( $sequence, 'S', $schema );
1039         }
1040
1041         function triggerExists( $table, $trigger ) {
1042                 global $wgDBmwschema;
1043
1044                 $q = <<<SQL
1045         SELECT 1 FROM pg_class, pg_namespace, pg_trigger
1046                 WHERE relnamespace=pg_namespace.oid AND relkind='r'
1047                       AND tgrelid=pg_class.oid
1048                       AND nspname=%s AND relname=%s AND tgname=%s
1049 SQL;
1050                 $res = $this->query(
1051                         sprintf(
1052                                 $q,
1053                                 $this->addQuotes( $wgDBmwschema ),
1054                                 $this->addQuotes( $table ),
1055                                 $this->addQuotes( $trigger )
1056                         )
1057                 );
1058                 if ( !$res ) {
1059                         return null;
1060                 }
1061                 $rows = $res->numRows();
1062                 return $rows;
1063         }
1064
1065         function ruleExists( $table, $rule ) {
1066                 global $wgDBmwschema;
1067                 $exists = $this->selectField( 'pg_rules', 'rulename',
1068                         array(
1069                                 'rulename' => $rule,
1070                                 'tablename' => $table,
1071                                 'schemaname' => $wgDBmwschema
1072                         )
1073                 );
1074                 return $exists === $rule;
1075         }
1076
1077         function constraintExists( $table, $constraint ) {
1078                 global $wgDBmwschema;
1079                 $SQL = sprintf( "SELECT 1 FROM information_schema.table_constraints ".
1080                            "WHERE constraint_schema = %s AND table_name = %s AND constraint_name = %s",
1081                         $this->addQuotes( $wgDBmwschema ),
1082                         $this->addQuotes( $table ),
1083                         $this->addQuotes( $constraint )
1084                 );
1085                 $res = $this->query( $SQL );
1086                 if ( !$res ) {
1087                         return null;
1088                 }
1089                 $rows = $res->numRows();
1090                 return $rows;
1091         }
1092
1093         /**
1094          * Query whether a given schema exists. Returns the name of the owner
1095          */
1096         function schemaExists( $schema ) {
1097                 $eschema = str_replace( "'", "''", $schema );
1098                 $SQL = "SELECT rolname FROM pg_catalog.pg_namespace n, pg_catalog.pg_roles r "
1099                                 ."WHERE n.nspowner=r.oid AND n.nspname = '$eschema'";
1100                 $res = $this->query( $SQL );
1101                 if ( $res && $res->numRows() ) {
1102                         $row = $res->fetchObject();
1103                         $owner = $row->rolname;
1104                 } else {
1105                         $owner = false;
1106                 }
1107                 return $owner;
1108         }
1109
1110         function fieldInfo( $table, $field ) {
1111                 return PostgresField::fromText( $this, $table, $field );
1112         }
1113
1114         /**
1115          * pg_field_type() wrapper
1116          */
1117         function fieldType( $res, $index ) {
1118                 if ( $res instanceof ResultWrapper ) {
1119                         $res = $res->result;
1120                 }
1121                 return pg_field_type( $res, $index );
1122         }
1123
1124         /* Not even sure why this is used in the main codebase... */
1125         function limitResultForUpdate( $sql, $num ) {
1126                 return $sql;
1127         }
1128
1129         function encodeBlob( $b ) {
1130                 return new Blob( pg_escape_bytea( $this->mConn, $b ) );
1131         }
1132
1133         function decodeBlob( $b ) {
1134                 if ( $b instanceof Blob ) {
1135                         $b = $b->fetch();
1136                 }
1137                 return pg_unescape_bytea( $b );
1138         }
1139
1140         function strencode( $s ) { # Should not be called by us
1141                 return pg_escape_string( $this->mConn, $s );
1142         }
1143
1144         function addQuotes( $s ) {
1145                 if ( is_null( $s ) ) {
1146                         return 'NULL';
1147                 } elseif ( is_bool( $s ) ) {
1148                         return intval( $s );
1149                 } elseif ( $s instanceof Blob ) {
1150                         return "'" . $s->fetch( $s ) . "'";
1151                 }
1152                 return "'" . pg_escape_string( $this->mConn, $s ) . "'";
1153         }
1154
1155         /**
1156          * Postgres specific version of replaceVars.
1157          * Calls the parent version in Database.php
1158          *
1159          * @private
1160          *
1161          * @param $ins String: SQL string, read from a stream (usually tables.sql)
1162          *
1163          * @return string SQL string
1164          */
1165         protected function replaceVars( $ins ) {
1166                 $ins = parent::replaceVars( $ins );
1167
1168                 if ( $this->numeric_version >= 8.3 ) {
1169                         // Thanks for not providing backwards-compatibility, 8.3
1170                         $ins = preg_replace( "/to_tsvector\s*\(\s*'default'\s*,/", 'to_tsvector(', $ins );
1171                 }
1172
1173                 if ( $this->numeric_version <= 8.1 ) { // Our minimum version
1174                         $ins = str_replace( 'USING gin', 'USING gist', $ins );
1175                 }
1176
1177                 return $ins;
1178         }
1179
1180         /**
1181          * Various select options
1182          *
1183          * @private
1184          *
1185          * @param $options Array: an associative array of options to be turned into
1186          *              an SQL query, valid keys are listed in the function.
1187          * @return array
1188          */
1189         function makeSelectOptions( $options ) {
1190                 $preLimitTail = $postLimitTail = '';
1191                 $startOpts = $useIndex = '';
1192
1193                 $noKeyOptions = array();
1194                 foreach ( $options as $key => $option ) {
1195                         if ( is_numeric( $key ) ) {
1196                                 $noKeyOptions[$option] = true;
1197                         }
1198                 }
1199
1200                 if ( isset( $options['GROUP BY'] ) ) {
1201                         $preLimitTail .= ' GROUP BY ' . $options['GROUP BY'];
1202                 }
1203                 if ( isset( $options['HAVING'] ) ) {
1204                         $preLimitTail .= " HAVING {$options['HAVING']}";
1205                 }
1206                 if ( isset( $options['ORDER BY'] ) ) {
1207                         $preLimitTail .= ' ORDER BY ' . $options['ORDER BY'];
1208                 }
1209
1210                 //if ( isset( $options['LIMIT'] ) ) {
1211                 //      $tailOpts .= $this->limitResult( '', $options['LIMIT'],
1212                 //              isset( $options['OFFSET'] ) ? $options['OFFSET']
1213                 //              : false );
1214                 //}
1215
1216                 if ( isset( $noKeyOptions['FOR UPDATE'] ) ) {
1217                         $postLimitTail .= ' FOR UPDATE';
1218                 }
1219                 if ( isset( $noKeyOptions['LOCK IN SHARE MODE'] ) ) {
1220                         $postLimitTail .= ' LOCK IN SHARE MODE';
1221                 }
1222                 if ( isset( $noKeyOptions['DISTINCT'] ) || isset( $noKeyOptions['DISTINCTROW'] ) ) {
1223                         $startOpts .= 'DISTINCT';
1224                 }
1225
1226                 return array( $startOpts, $useIndex, $preLimitTail, $postLimitTail );
1227         }
1228
1229         function setFakeMaster( $enabled = true ) {}
1230
1231         function getDBname() {
1232                 return $this->mDBname;
1233         }
1234
1235         function getServer() {
1236                 return $this->mServer;
1237         }
1238
1239         function buildConcat( $stringList ) {
1240                 return implode( ' || ', $stringList );
1241         }
1242
1243         public function getSearchEngine() {
1244                 return 'SearchPostgres';
1245         }
1246 } // end DatabasePostgres class