includes/DatabasePostgres.php

   1 <?php
   2
   3 /**
   4  * This is Postgres database abstraction layer.
   5  *
   6  * As it includes more generic version for DB functions,
   7  * than MySQL ones, some of them should be moved to parent
   8  * Database class.
   9  *
  10  * @package MediaWiki
  11  */
  12
  13 /**
  14  * Depends on database
  15  */
  16 require_once( 'Database.php' );
  17
  18 class DatabasePostgres extends Database {
  19         var $mInsertId = NULL;
  20         var $mLastResult = NULL;
  21
  22         function DatabasePostgres($server = false, $user = false, $password = false, $dbName = false,
  23                 $failFunction = false, $flags = 0 )
  24         {
  25
  26                 global $wgOut, $wgDBprefix, $wgCommandLineMode;
  27                 # Can't get a reference if it hasn't been set yet
  28                 if ( !isset( $wgOut ) ) {
  29                         $wgOut = NULL;
  30                 }
  31                 $this->mOut =& $wgOut;
  32                 $this->mFailFunction = $failFunction;
  33                 $this->mCascadingDeletes = true;
  34                 $this->mCleanupTriggers = true;
  35                 $this->mStrictIPs = true;
  36                 $this->mFlags = $flags;
  37                 $this->open( $server, $user, $password, $dbName);
  38
  39         }
  40
  41         static function newFromParams( $server = false, $user = false, $password = false, $dbName = false,
  42                 $failFunction = false, $flags = 0)
  43         {
  44                 return new DatabasePostgres( $server, $user, $password, $dbName, $failFunction, $flags );
  45         }
  46
  47         /**
  48          * Usually aborts on failure
  49          * If the failFunction is set to a non-zero integer, returns success
  50          */
  51         function open( $server, $user, $password, $dbName ) {
  52                 # Test for Postgres support, to avoid suppressed fatal error
  53                 if ( !function_exists( 'pg_connect' ) ) {
  54                         throw new DBConnectionError( $this, "Postgres functions missing, have you compiled PHP with the --with-pgsql option?\n" );
  55                 }
  56
  57
  58                 global $wgDBport;
  59
  60                 $this->close();
  61                 $this->mServer = $server;
  62                 $port = $wgDBport;
  63                 $this->mUser = $user;
  64                 $this->mPassword = $password;
  65                 $this->mDBname = $dbName;
  66
  67                 $success = false;
  68                 $hstring="";
  69                 if ($server!=false && $server!="") {
  70                         $hstring="host=$server ";
  71                 }
  72                 if ($port!=false && $port!="") {
  73                         $hstring .= "port=$port ";
  74                 }
  75
  76                 if (!strlen($user)) { ## e.g. the class is being loaded
  77                         return;
  78                 }
  79
  80                 error_reporting( E_ALL );
  81                 @$this->mConn = pg_connect("$hstring dbname=$dbName user=$user password=$password");
  82
  83                 if ( $this->mConn == false ) {
  84                         wfDebug( "DB connection error\n" );
  85                         wfDebug( "Server: $server, Database: $dbName, User: $user, Password: " . substr( $password, 0, 3 ) . "...\n" );
  86                         wfDebug( $this->lastError()."\n" );
  87                         return false;
  88                 }
  89
  90                 $this->mOpened = true;
  91                 ## If this is the initial connection, setup the schema stuff and possibly create the user
  92                 if (defined('MEDIAWIKI_INSTALL')) {
  93                         global $wgDBname, $wgDBuser, $wgDBpass, $wgDBsuperuser, $wgDBmwschema, $wgDBts2schema;
  94                         print "OK</li>\n";
  95
  96                         $safeuser = $this->quote_ident($wgDBuser);
  97                         ## Are we connecting as a superuser for the first time?
  98                         if ($wgDBsuperuser) {
  99                                 ## Are we really a superuser? Check out our rights
 100                                 $SQL = "SELECT
 101                                                 CASE WHEN usesuper IS TRUE THEN
 102                                                         CASE WHEN usecreatedb IS TRUE THEN 3 ELSE 1 END
 103                                                         ELSE CASE WHEN usecreatedb IS TRUE THEN 2 ELSE 0 END
 104                         END AS rights
 105                                                 FROM pg_catalog.pg_user WHERE usename = " . $this->addQuotes($wgDBsuperuser);
 106                                 $rows = $this->numRows($res = $this->doQuery($SQL));
 107                                 if (!$rows) {
 108                                         print "<li>ERROR: Could not read permissions for user \"$wgDBsuperuser\"</li>\n";
 109                                         dieout('</ul>');
 110                                 }
 111                                 $perms = pg_fetch_result($res, 0, 0);
 112
 113                                 $SQL = "SELECT 1 FROM pg_catalog.pg_user WHERE usename = " . $this->addQuotes($wgDBuser);
 114                                 $rows = $this->numRows($this->doQuery($SQL));
 115                                 if ($rows) {
 116                                         print "<li>User \"$wgDBuser\" already exists, skipping account creation.</li>";
 117                                 }
 118                                 else {
 119                                         if ($perms != 1 and $perms != 3) {
 120                                                 print "<li>ERROR: the user \"$wgDBsuperuser\" cannot create other users. ";
 121                                                 print 'Please use a different Postgres user.</li>';
 122                                                 dieout('</ul>');
 123                                         }
 124                                         print "<li>Creating user <b>$wgDBuser</b>...";
 125                                         $safepass = $this->addQuotes($wgDBpass);
 126                                         $SQL = "CREATE USER $safeuser NOCREATEDB PASSWORD $safepass";
 127                                         $this->doQuery($SQL);
 128                                         print "OK</li>\n";
 129                                 }
 130                                 ## User now exists, check out the database
 131                                 if ($dbName != $wgDBname) {
 132                                         $SQL = "SELECT 1 FROM pg_catalog.pg_database WHERE datname = " . $this->addQuotes($wgDBname);
 133                                         $rows = $this->numRows($this->doQuery($SQL));
 134                                         if ($rows) {
 135                                                 print "<li>Database \"$wgDBname\" already exists, skipping database creation.</li>";
 136                                         }
 137                                         else {
 138                                                 if ($perms < 2) {
 139                                                         print "<li>ERROR: the user \"$wgDBsuperuser\" cannot create databases. ";
 140                                                         print 'Please use a different Postgres user.</li>';
 141                                                         dieout('</ul>');
 142                                                 }
 143                                                 print "<li>Creating database <b>$wgDBname</b>...";
 144                                                 $safename = $this->quote_ident($wgDBname);
 145                                                 $SQL = "CREATE DATABASE $safename OWNER $safeuser ";
 146                                                 $this->doQuery($SQL);
 147                                                 print "OK</li>\n";
 148                                                 ## Hopefully tsearch2 and plpgsql are in template1...
 149                                         }
 150
 151                                         ## Reconnect to check out tsearch2 rights for this user
 152                                         print "<li>Connecting to \"$wgDBname\" as superuser \"$wgDBsuperuser\" to check rights...";
 153                                         @$this->mConn = pg_connect("$hstring dbname=$wgDBname user=$user password=$password");
 154                                         if ( $this->mConn == false ) {
 155                                                 print "<b>FAILED TO CONNECT!</b></li>";
 156                                                 dieout("</ul>");
 157                                         }
 158                                         print "OK</li>\n";
 159                                 }
 160
 161                                 ## Tsearch2 checks
 162                                 print "<li>Checking that tsearch2 is installed in the database \"$wgDBname\"...";
 163                                 if (! $this->tableExists("pg_ts_cfg", $wgDBts2schema)) {
 164                                         print "<b>FAILED</b>. tsearch2 must be installed in the database \"$wgDBname\".";
 165                                         print "Please see 'http://www.devx.com/opensource/Article/21674/0/page/2'>this article</a>";
 166                                         print " for instructions or ask on #postgresql on irc.freenode.net</li>\n";
 167                                         dieout("</ul>");
 168                                 }
 169                                 print "OK</li>\n";
 170                                 print "<li>Ensuring that user \"$wgDBuser\" has select rights on the tsearch2 tables...";
 171                                 foreach (array('cfg','cfgmap','dict','parser') as $table) {
 172                                         $SQL = "GRANT SELECT ON pg_ts_$table TO $safeuser";
 173                                         $this->doQuery($SQL);
 174                                 }
 175                                 print "OK</li>\n";
 176
 177
 178                                 ## Setup the schema for this user if needed
 179                                 $result = $this->schemaExists($wgDBmwschema);
 180                                 $safeschema = $this->quote_ident($wgDBmwschema);
 181                                 if (!$result) {
 182                                         print "<li>Creating schema <b>$wgDBmwschema</b> ...";
 183                                         $result = $this->doQuery("CREATE SCHEMA $safeschema AUTHORIZATION $safeuser");
 184                                         if (!$result) {
 185                                                 print "<b>FAILED</b>.</li>\n";
 186                                                 dieout("</ul>");
 187                                         }
 188                                         print "OK</li>\n";
 189                                 }
 190                                 else {
 191                                         print "<li>Schema already exists, explicitly granting rights...\n";
 192                                         $safeschema2 = $this->addQuotes($wgDBmwschema);
 193                                         $SQL = "SELECT 'GRANT ALL ON '||pg_catalog.quote_ident(relname)||' TO $safeuser;'\n".
 194                                                         "FROM pg_catalog.pg_class p, pg_catalog.pg_namespace n\n".
 195                                                         "WHERE relnamespace = n.oid AND n.nspname = $safeschema2\n".
 196                                                         "AND p.relkind IN ('r','S','v')\n";
 197                                         $SQL .= "UNION\n";
 198                                         $SQL .= "SELECT 'GRANT ALL ON FUNCTION '||pg_catalog.quote_ident(proname)||'('||\n".
 199                                                         "pg_catalog.oidvectortypes(p.proargtypes)||') TO $safeuser;'\n".
 200                                                         "FROM pg_catalog.pg_proc p, pg_catalog.pg_namespace n\n".
 201                                                         "WHERE p.pronamespace = n.oid AND n.nspname = $safeschema2";
 202                                         $res = $this->doQuery($SQL);
 203                                         if (!$res) {
 204                                                 print "<b>FAILED</b>. Could not set rights for the user.</li>\n";
 205                                                 dieout("</ul>");
 206                                         }
 207                                         $this->doQuery("SET search_path = $safeschema");
 208                                         $rows = $this->numRows($res);
 209                                         while ($rows) {
 210                                                 $rows--;
 211                                                 $this->doQuery(pg_fetch_result($res, $rows, 0));
 212                                         }
 213                                         print "OK</li>";
 214                                 }
 215
 216                                 $wgDBsuperuser = '';
 217                                 return true; ## Reconnect as regular user
 218                         }
 219
 220                 if (!defined('POSTGRES_SEARCHPATH')) {
 221
 222                         ## Do we have the basic tsearch2 table?
 223                         print "<li>Checking for tsearch2 in the schema \"$wgDBts2schema\"...";
 224                         if (! $this->tableExists("pg_ts_dict", $wgDBts2schema)) {
 225                                 print "<b>FAILED</b>. Make sure tsearch2 is installed. See <a href=";
 226                                 print "'http://www.devx.com/opensource/Article/21674/0/page/2'>this article</a>";
 227                                 print " for instructions.</li>\n";
 228                                 dieout("</ul>");
 229                         }
 230                         print "OK</li>\n";
 231
 232                         ## Does this user have the rights to the tsearch2 tables?
 233                         print "<li>Checking tsearch2 permissions...";
 234                         $SQL = "SELECT 1 FROM $wgDBts2schema.pg_ts_cfg";
 235                         error_reporting( 0 );
 236                         $res = $this->doQuery($SQL);
 237                         error_reporting( E_ALL );
 238                         if (!$res) {
 239                                 print "<b>FAILED</b>. Make sure that the user \"$wgDBuser\" has SELECT access to the tsearch2 tables</li>\n";
 240                                 dieout("</ul>");
 241                         }
 242                         print "OK</li>";
 243
 244                         ## Do we have plpgsql installed?
 245                         print "<li>Checking for Pl/Pgsql ...";
 246                         $SQL = "SELECT 1 FROM pg_catalog.pg_language WHERE lanname = 'plpgsql'";
 247                         $rows = $this->numRows($this->doQuery($SQL));
 248                         if ($rows < 1) {
 249                                 print "<b>FAILED</b>. Make sure the language plpgsql is installed for the database <tt>$wgDBname</tt></li>";
 250                                 dieout("</ul>");
 251                         }
 252                         print "OK</li>\n";
 253
 254                         ## Does the schema already exist? Who owns it?
 255                         $result = $this->schemaExists($wgDBmwschema);
 256                         if (!$result) {
 257                                 print "<li>Creating schema <b>$wgDBmwschema</b> ...";
 258                                 $result = $this->doQuery("CREATE SCHEMA $wgDBmwschema");
 259                                 if (!$result) {
 260                                         print "<b>FAILED</b>.</li>\n";
 261                                         dieout("</ul>");
 262                                 }
 263                                 print "OK</li>\n";
 264                         }
 265                         else if ($result != $user) {
 266                                 print "<li>Schema \"$wgDBmwschema\" exists but is not owned by \"$user\". Not ideal.</li>\n";
 267                         }
 268                         else {
 269                                 print "<li>Schema \"$wgDBmwschema\" exists and is owned by \"$user\". Excellent.</li>\n";
 270                         }
 271
 272                         ## Fix up the search paths if needed
 273                         print "<li>Setting the search path for user \"$user\" ...";
 274                         $path = $this->quote_ident($wgDBmwschema);
 275                         if ($wgDBts2schema !== $wgDBmwschema)
 276                                 $path .= ", ". $this->quote_ident($wgDBts2schema);
 277                         if ($wgDBmwschema !== 'public' and $wgDBts2schema !== 'public')
 278                                 $path .= ", public";
 279                         $SQL = "ALTER USER $safeuser SET search_path = $path";
 280                         $result = pg_query($this->mConn, $SQL);
 281                         if (!$result) {
 282                                 print "<b>FAILED</b>.</li>\n";
 283                                 dieout("</ul>");
 284                         }
 285                         print "OK</li>\n";
 286                         ## Set for the rest of this session
 287                         $SQL = "SET search_path = $path";
 288                         $result = pg_query($this->mConn, $SQL);
 289                         if (!$result) {
 290                                 print "<li>Failed to set search_path</li>\n";
 291                                 dieout("</ul>");
 292                         }
 293                         define( "POSTGRES_SEARCHPATH", $path );
 294                 }}
 295
 296                 return $this->mConn;
 297         }
 298
 299         /**
 300          * Closes a database connection, if it is open
 301          * Returns success, true if already closed
 302          */
 303         function close() {
 304                 $this->mOpened = false;
 305                 if ( $this->mConn ) {
 306                         return pg_close( $this->mConn );
 307                 } else {
 308                         return true;
 309                 }
 310         }
 311
 312         function doQuery( $sql ) {
 313                 return $this->mLastResult=pg_query( $this->mConn , $sql);
 314         }
 315
 316         function queryIgnore( $sql, $fname = '' ) {
 317                 return $this->query( $sql, $fname, true );
 318         }
 319
 320         function freeResult( $res ) {
 321                 if ( !@pg_free_result( $res ) ) {
 322                         throw new DBUnexpectedError($this,  "Unable to free Postgres result\n" );
 323                 }
 324         }
 325
 326         function fetchObject( $res ) {
 327                 @$row = pg_fetch_object( $res );
 328                 # FIXME: HACK HACK HACK HACK debug
 329
 330                 # TODO:
 331                 # hashar : not sure if the following test really trigger if the object
 332                 #          fetching failled.
 333                 if( pg_last_error($this->mConn) ) {
 334                         throw new DBUnexpectedError($this,  'SQL error: ' . htmlspecialchars( pg_last_error($this->mConn) ) );
 335                 }
 336                 return $row;
 337         }
 338
 339         function fetchRow( $res ) {
 340                 @$row = pg_fetch_array( $res );
 341                 if( pg_last_error($this->mConn) ) {
 342                         throw new DBUnexpectedError($this,  'SQL error: ' . htmlspecialchars( pg_last_error($this->mConn) ) );
 343                 }
 344                 return $row;
 345         }
 346
 347         function numRows( $res ) {
 348                 @$n = pg_num_rows( $res );
 349                 if( pg_last_error($this->mConn) ) {
 350                         throw new DBUnexpectedError($this,  'SQL error: ' . htmlspecialchars( pg_last_error($this->mConn) ) );
 351                 }
 352                 return $n;
 353         }
 354         function numFields( $res ) { return pg_num_fields( $res ); }
 355         function fieldName( $res, $n ) { return pg_field_name( $res, $n ); }
 356
 357         /**
 358          * This must be called after nextSequenceVal
 359          */
 360         function insertId() {
 361                 return $this->mInsertId;
 362         }
 363
 364         function dataSeek( $res, $row ) { return pg_result_seek( $res, $row ); }
 365         function lastError() {
 366                 if ( $this->mConn ) {
 367                         return pg_last_error();
 368                 }
 369                 else {
 370                         return "No database connection";
 371                 }
 372         }
 373         function lastErrno() {
 374                 return pg_last_error() ? 1 : 0;
 375         }
 376
 377         function affectedRows() {
 378                 return pg_affected_rows( $this->mLastResult );
 379         }
 380
 381         /**
 382          * Returns information about an index
 383          * If errors are explicitly ignored, returns NULL on failure
 384          */
 385         function indexInfo( $table, $index, $fname = 'Database::indexExists' ) {
 386                 $sql = "SELECT indexname FROM pg_indexes WHERE tablename='$table'";
 387                 $res = $this->query( $sql, $fname );
 388                 if ( !$res ) {
 389                         return NULL;
 390                 }
 391
 392                 while ( $row = $this->fetchObject( $res ) ) {
 393                         if ( $row->indexname == $index ) {
 394                                 return $row;
 395                         }
 396                 }
 397                 return false;
 398         }
 399
 400         function indexUnique ($table, $index, $fname = 'Database::indexUnique' ) {
 401                 $sql = "SELECT indexname FROM pg_indexes WHERE tablename='{$table}'".
 402                         " AND indexdef LIKE 'CREATE UNIQUE%({$index})'";
 403                 $res = $this->query( $sql, $fname );
 404                 if ( !$res )
 405                         return NULL;
 406                 while ($row = $this->fetchObject( $res ))
 407                         return true;
 408                 return false;
 409
 410         }
 411
 412         function insert( $table, $a, $fname = 'Database::insert', $options = array() ) {
 413                 # Postgres doesn't support options
 414                 # We have a go at faking one of them
 415                 # TODO: DELAYED, LOW_PRIORITY
 416
 417                 if ( !is_array($options))
 418                         $options = array($options);
 419
 420                 if ( in_array( 'IGNORE', $options ) )
 421                         $oldIgnore = $this->ignoreErrors( true );
 422
 423                 # IGNORE is performed using single-row inserts, ignoring errors in each
 424                 # FIXME: need some way to distiguish between key collision and other types of error
 425                 $oldIgnore = $this->ignoreErrors( true );
 426                 if ( !is_array( reset( $a ) ) ) {
 427                         $a = array( $a );
 428                 }
 429                 foreach ( $a as $row ) {
 430                         parent::insert( $table, $row, $fname, array() );
 431                 }
 432                 $this->ignoreErrors( $oldIgnore );
 433                 $retVal = true;
 434
 435                 if ( in_array( 'IGNORE', $options ) )
 436                         $this->ignoreErrors( $oldIgnore );
 437
 438                 return $retVal;
 439         }
 440
 441         function tableName( $name ) {
 442                 # Replace reserved words with better ones
 443                 switch( $name ) {
 444                         case 'user':
 445                                 return 'mwuser';
 446                         case 'text':
 447                                 return 'pagecontent';
 448                         default:
 449                                 return $name;
 450                 }
 451         }
 452
 453         /**
 454          * Return the next in a sequence, save the value for retrieval via insertId()
 455          */
 456         function nextSequenceValue( $seqName ) {
 457                 $safeseq = preg_replace( "/'/", "''", $seqName );
 458                 $res = $this->query( "SELECT nextval('$safeseq')" );
 459                 $row = $this->fetchRow( $res );
 460                 $this->mInsertId = $row[0];
 461                 $this->freeResult( $res );
 462                 return $this->mInsertId;
 463         }
 464
 465         /**
 466          * Postgres does not have a "USE INDEX" clause, so return an empty string
 467          */
 468         function useIndexClause( $index ) {
 469                 return '';
 470         }
 471
 472         # REPLACE query wrapper
 473         # Postgres simulates this with a DELETE followed by INSERT
 474         # $row is the row to insert, an associative array
 475         # $uniqueIndexes is an array of indexes. Each element may be either a
 476         # field name or an array of field names
 477         #
 478         # It may be more efficient to leave off unique indexes which are unlikely to collide.
 479         # However if you do this, you run the risk of encountering errors which wouldn't have
 480         # occurred in MySQL
 481         function replace( $table, $uniqueIndexes, $rows, $fname = 'Database::replace' ) {
 482                 $table = $this->tableName( $table );
 483
 484                 if (count($rows)==0) {
 485                         return;
 486                 }
 487
 488                 # Single row case
 489                 if ( !is_array( reset( $rows ) ) ) {
 490                         $rows = array( $rows );
 491                 }
 492
 493                 foreach( $rows as $row ) {
 494                         # Delete rows which collide
 495                         if ( $uniqueIndexes ) {
 496                                 $sql = "DELETE FROM $table WHERE ";
 497                                 $first = true;
 498                                 foreach ( $uniqueIndexes as $index ) {
 499                                         if ( $first ) {
 500                                                 $first = false;
 501                                                 $sql .= "(";
 502                                         } else {
 503                                                 $sql .= ') OR (';
 504                                         }
 505                                         if ( is_array( $index ) ) {
 506                                                 $first2 = true;
 507                                                 foreach ( $index as $col ) {
 508                                                         if ( $first2 ) {
 509                                                                 $first2 = false;
 510                                                         } else {
 511                                                                 $sql .= ' AND ';
 512                                                         }
 513                                                         $sql .= $col.'=' . $this->addQuotes( $row[$col] );
 514                                                 }
 515                                         } else {
 516                                                 $sql .= $index.'=' . $this->addQuotes( $row[$index] );
 517                                         }
 518                                 }
 519                                 $sql .= ')';
 520                                 $this->query( $sql, $fname );
 521                         }
 522
 523                         # Now insert the row
 524                         $sql = "INSERT INTO $table (" . $this->makeList( array_keys( $row ), LIST_NAMES ) .') VALUES (' .
 525                                 $this->makeList( $row, LIST_COMMA ) . ')';
 526                         $this->query( $sql, $fname );
 527                 }
 528         }
 529
 530         # DELETE where the condition is a join
 531         function deleteJoin( $delTable, $joinTable, $delVar, $joinVar, $conds, $fname = "Database::deleteJoin" ) {
 532                 if ( !$conds ) {
 533                         throw new DBUnexpectedError($this,  'Database::deleteJoin() called with empty $conds' );
 534                 }
 535
 536                 $delTable = $this->tableName( $delTable );
 537                 $joinTable = $this->tableName( $joinTable );
 538                 $sql = "DELETE FROM $delTable WHERE $delVar IN (SELECT $joinVar FROM $joinTable ";
 539                 if ( $conds != '*' ) {
 540                         $sql .= 'WHERE ' . $this->makeList( $conds, LIST_AND );
 541                 }
 542                 $sql .= ')';
 543
 544                 $this->query( $sql, $fname );
 545         }
 546
 547         # Returns the size of a text field, or -1 for "unlimited"
 548         function textFieldSize( $table, $field ) {
 549                 $table = $this->tableName( $table );
 550                 $sql = "SELECT t.typname as ftype,a.atttypmod as size
 551                         FROM pg_class c, pg_attribute a, pg_type t
 552                         WHERE relname='$table' AND a.attrelid=c.oid AND
 553                                 a.atttypid=t.oid and a.attname='$field'";
 554                 $res =$this->query($sql);
 555                 $row=$this->fetchObject($res);
 556                 if ($row->ftype=="varchar") {
 557                         $size=$row->size-4;
 558                 } else {
 559                         $size=$row->size;
 560                 }
 561                 $this->freeResult( $res );
 562                 return $size;
 563         }
 564
 565         function lowPriorityOption() {
 566                 return '';
 567         }
 568
 569         function limitResult($sql, $limit,$offset) {
 570                 return "$sql LIMIT $limit ".(is_numeric($offset)?" OFFSET {$offset} ":"");
 571         }
 572
 573         /**
 574          * Returns an SQL expression for a simple conditional.
 575          * Uses CASE on Postgres
 576          *
 577          * @param string $cond SQL expression which will result in a boolean value
 578          * @param string $trueVal SQL expression to return if true
 579          * @param string $falseVal SQL expression to return if false
 580          * @return string SQL fragment
 581          */
 582         function conditional( $cond, $trueVal, $falseVal ) {
 583                 return " (CASE WHEN $cond THEN $trueVal ELSE $falseVal END) ";
 584         }
 585
 586         # FIXME: actually detecting deadlocks might be nice
 587         function wasDeadlock() {
 588                 return false;
 589         }
 590
 591         function timestamp( $ts=0 ) {
 592                 return wfTimestamp(TS_POSTGRES,$ts);
 593         }
 594
 595         /**
 596          * Return aggregated value function call
 597          */
 598         function aggregateValue ($valuedata,$valuename='value') {
 599                 return $valuedata;
 600         }
 601
 602
 603         function reportQueryError( $error, $errno, $sql, $fname, $tempIgnore = false ) {
 604                 $message = "A database error has occurred\n" .
 605                         "Query: $sql\n" .
 606                         "Function: $fname\n" .
 607                         "Error: $errno $error\n";
 608                 throw new DBUnexpectedError($this, $message);
 609         }
 610
 611         /**
 612          * @return string wikitext of a link to the server software's web site
 613          */
 614         function getSoftwareLink() {
 615                 return "[http://www.postgresql.org/ PostgreSQL]";
 616         }
 617
 618         /**
 619          * @return string Version information from the database
 620          */
 621         function getServerVersion() {
 622                 $res = $this->query( "SELECT version()" );
 623                 $row = $this->fetchRow( $res );
 624                 $version = $row[0];
 625                 $this->freeResult( $res );
 626                 return $version;
 627         }
 628
 629
 630         /**
 631          * Query whether a given table exists (in the given schema, or the default mw one if not given)
 632          */
 633         function tableExists( $table, $schema = false ) {
 634                 global $wgDBmwschema;
 635                 if (! $schema )
 636                         $schema = $wgDBmwschema;
 637                 $etable = preg_replace("/'/", "''", $table);
 638                 $eschema = preg_replace("/'/", "''", $schema);
 639                 $SQL = "SELECT 1 FROM pg_catalog.pg_class c, pg_catalog.pg_namespace n "
 640                         . "WHERE c.relnamespace = n.oid AND c.relname = '$etable' AND n.nspname = '$eschema'";
 641                 $res = $this->query( $SQL );
 642                 $count = $res ? pg_num_rows($res) : 0;
 643                 if ($res)
 644                         $this->freeResult( $res );
 645                 return $count;
 646         }
 647
 648
 649         /**
 650          * Query whether a given schema exists. Returns the name of the owner
 651          */
 652         function schemaExists( $schema ) {
 653                 $eschema = preg_replace("/'/", "''", $schema);
 654                 $SQL = "SELECT rolname FROM pg_catalog.pg_namespace n, pg_catalog.pg_roles r "
 655                                 ."WHERE n.nspowner=r.oid AND n.nspname = '$eschema'";
 656                 $res = $this->query( $SQL );
 657                 $owner = $res ? pg_num_rows($res) ? pg_fetch_result($res, 0, 0) : false : false;
 658                 if ($res)
 659                         $this->freeResult($res);
 660                 return $owner;
 661         }
 662
 663         /**
 664          * Query whether a given column exists in the mediawiki schema
 665          */
 666         function fieldExists( $table, $field ) {
 667                 global $wgDBmwschema;
 668                 $etable = preg_replace("/'/", "''", $table);
 669                 $eschema = preg_replace("/'/", "''", $wgDBmwschema);
 670                 $ecol = preg_replace("/'/", "''", $field);
 671                 $SQL = "SELECT 1 FROM pg_catalog.pg_class c, pg_catalog.pg_namespace n, pg_catalog.pg_attribute a "
 672                         . "WHERE c.relnamespace = n.oid AND c.relname = '$etable' AND n.nspname = '$eschema' "
 673                         . "AND a.attrelid = c.oid AND a.attname = '$ecol'";
 674                 $res = $this->query( $SQL );
 675                 $count = $res ? pg_num_rows($res) : 0;
 676                 if ($res)
 677                         $this->freeResult( $res );
 678                 return $count;
 679         }
 680
 681         function fieldInfo( $table, $field ) {
 682                 $res = $this->query( "SELECT $field FROM $table LIMIT 1" );
 683                 $type = pg_field_type( $res, 0 );
 684                 return $type;
 685         }
 686
 687         function begin( $fname = 'DatabasePostgrs::begin' ) {
 688                 $this->query( 'BEGIN', $fname );
 689                 $this->mTrxLevel = 1;
 690         }
 691         function immediateCommit( $fname = 'DatabasePostgres::immediateCommit' ) {
 692                 return true;
 693         }
 694         function commit( $fname = 'DatabasePostgres::commit' ) {
 695                 $this->query( 'COMMIT', $fname );
 696                 $this->mTrxLevel = 0;
 697         }
 698
 699         /* Not even sure why this is used in the main codebase... */
 700         function limitResultForUpdate($sql, $num) {
 701                 return $sql;
 702         }
 703
 704         function setup_database() {
 705                 global $wgVersion, $wgDBmwschema, $wgDBts2schema, $wgDBport;
 706
 707                 dbsource( "../maintenance/postgres/tables.sql", $this);
 708
 709                 ## Update version information
 710                 $mwv = $this->addQuotes($wgVersion);
 711                 $pgv = $this->addQuotes($this->getServerVersion());
 712                 $pgu = $this->addQuotes($this->mUser);
 713                 $mws = $this->addQuotes($wgDBmwschema);
 714                 $tss = $this->addQuotes($wgDBts2schema);
 715                 $pgp = $this->addQuotes($wgDBport);
 716                 $dbn = $this->addQuotes($this->mDBname);
 717
 718                 $SQL = "UPDATE mediawiki_version SET mw_version=$mwv, pg_version=$pgv, pg_user=$pgu, ".
 719                                 "mw_schema = $mws, ts2_schema = $tss, pg_port=$pgp, pg_dbname=$dbn ".
 720                                 "WHERE type = 'Creation'";
 721                 $this->query($SQL);
 722
 723                 ## Avoid the non-standard "REPLACE INTO" syntax
 724                 $f = fopen( "../maintenance/interwiki.sql", 'r' );
 725                 if ($f == false ) {
 726                         dieout( "<li>Could not find the interwiki.sql file");
 727                 }
 728                 ## We simply assume it is already empty as we have just created it
 729                 $SQL = "INSERT INTO interwiki(iw_prefix,iw_url,iw_local) VALUES ";
 730                 while ( ! feof( $f ) ) {
 731                         $line = fgets($f,1024);
 732                         if (!preg_match("/^\s*(\(.+?),(\d)\)/", $line, $matches)) {
 733                                 continue;
 734                         }
 735                         $yesno = $matches[2]; ## ? "'true'" : "'false'";
 736                         $this->query("$SQL $matches[1],$matches[2])");
 737                 }
 738                 print " (table interwiki successfully populated)...\n";
 739         }
 740
 741         function encodeBlob($b) {
 742                 return array('bytea',pg_escape_bytea($b));
 743         }
 744         function decodeBlob($b) {
 745                 return pg_unescape_bytea( $b );
 746         }
 747
 748         function strencode( $s ) { ## Should not be called by us
 749                 return pg_escape_string( $s );
 750         }
 751
 752         function addQuotes( $s ) {
 753                 if ( is_null( $s ) ) {
 754                         return 'NULL';
 755                 } else if (is_array( $s )) { ## Assume it is bytea data
 756                         return "E'$s[1]'";
 757                 }
 758                 return "'" . pg_escape_string($s) . "'";
 759                 return "E'" . pg_escape_string($s) . "'";
 760         }
 761
 762         function quote_ident( $s ) {
 763                 return '"' . preg_replace( '/"/', '""', $s) . '"';
 764         }
 765
 766 }
 767
 768 ?>