includes/DatabasePostgres.php

   1 <?php
   2
   3 /**
   4  * This is PostgreSQL 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  * STATUS: Working PG implementation of MediaWiki
  11  * TODO: Installer support
  12  *
  13  * @package MediaWiki
  14  */
  15
  16 /**
  17  * Depends on database
  18  */
  19 require_once( 'Database.php' );
  20
  21 /**
  22  *
  23  * @package MediaWiki
  24  */
  25 class DatabasePostgres extends Database {
  26         var $mInsertId = NULL;
  27         var $mLastResult = NULL;
  28
  29         function DatabasePostgres($server = false, $user = false, $password = false, $dbName = false,
  30                 $failFunction = false, $flags = 0 )
  31         {
  32                 Database::__construct( $server, $user, $password, $dbName, $failFunction, $flags );
  33         }
  34
  35         static function newFromParams( $server = false, $user = false, $password = false, $dbName = false,
  36                 $failFunction = false, $flags = 0)
  37         {
  38                 return new DatabasePostgres( $server, $user, $password, $dbName, $failFunction, $flags );
  39         }
  40
  41         /**
  42          * Usually aborts on failure
  43          * If the failFunction is set to a non-zero integer, returns success
  44          */
  45         function open( $server, $user, $password, $dbName ) {
  46                 # Test for PostgreSQL support, to avoid suppressed fatal error
  47                 if ( !function_exists( 'pg_connect' ) ) {
  48                         throw new DBConnectionError( $this, "PostgreSQL functions missing, have you compiled PHP with the --with-pgsql option?\n" );
  49                 }
  50
  51                 global $wgDBschema;
  52
  53                 $this->close();
  54                 $this->mServer = $server;
  55                 $this->mUser = $user;
  56                 $this->mPassword = $password;
  57                 $this->mDBname = $dbName;
  58                 $this->mSchemas = array($wgDBschema,'public');
  59
  60                 $success = false;
  61
  62                 if ( '' != $dbName ) {
  63                         # start a database connection
  64                         $hstring="";
  65                         if ($server!=false && $server!="") {
  66                                 $hstring="host=$server ";
  67                         }
  68
  69                         @$this->mConn = pg_connect("$hstring dbname=$dbName user=$user password=$password");
  70                         if ( $this->mConn == false ) {
  71                                 wfDebug( "DB connection error\n" );
  72                                 wfDebug( "Server: $server, Database: $dbName, User: $user, Password: " . substr( $password, 0, 3 ) . "...\n" );
  73                                 wfDebug( $this->lastError()."\n" );
  74                         } else {
  75                                 $this->setSchema();
  76                                 $this->mOpened = true;
  77                         }
  78                 }
  79                 return $this->mConn;
  80         }
  81
  82         /**
  83          * Closes a database connection, if it is open
  84          * Returns success, true if already closed
  85          */
  86         function close() {
  87                 $this->mOpened = false;
  88                 if ( $this->mConn ) {
  89                         return pg_close( $this->mConn );
  90                 } else {
  91                         return true;
  92                 }
  93         }
  94
  95         function doQuery( $sql ) {
  96                 return $this->mLastResult=pg_query( $this->mConn , $sql);
  97         }
  98
  99         function queryIgnore( $sql, $fname = '' ) {
 100                 return $this->query( $sql, $fname, true );
 101         }
 102
 103         function freeResult( $res ) {
 104                 if ( !@pg_free_result( $res ) ) {
 105                         throw new DBUnexpectedError($this,  "Unable to free PostgreSQL result\n" );
 106                 }
 107         }
 108
 109         function fetchObject( $res ) {
 110                 @$row = pg_fetch_object( $res );
 111                 # FIXME: HACK HACK HACK HACK debug
 112
 113                 # TODO:
 114                 # hashar : not sure if the following test really trigger if the object
 115                 #          fetching failled.
 116                 if( pg_last_error($this->mConn) ) {
 117                         throw new DBUnexpectedError($this,  'SQL error: ' . htmlspecialchars( pg_last_error($this->mConn) ) );
 118                 }
 119                 return $row;
 120         }
 121
 122         function fetchRow( $res ) {
 123                 @$row = pg_fetch_array( $res );
 124                 if( pg_last_error($this->mConn) ) {
 125                         throw new DBUnexpectedError($this,  'SQL error: ' . htmlspecialchars( pg_last_error($this->mConn) ) );
 126                 }
 127                 return $row;
 128         }
 129
 130         function numRows( $res ) {
 131                 @$n = pg_num_rows( $res );
 132                 if( pg_last_error($this->mConn) ) {
 133                         throw new DBUnexpectedError($this,  'SQL error: ' . htmlspecialchars( pg_last_error($this->mConn) ) );
 134                 }
 135                 return $n;
 136         }
 137         function numFields( $res ) { return pg_num_fields( $res ); }
 138         function fieldName( $res, $n ) { return pg_field_name( $res, $n ); }
 139
 140         /**
 141          * This must be called after nextSequenceVal
 142          */
 143         function insertId() {
 144                 return $this->mInsertId;
 145         }
 146
 147         function dataSeek( $res, $row ) { return pg_result_seek( $res, $row ); }
 148         function lastError() {
 149                 if ( $this->mConn ) {
 150                         return pg_last_error();
 151                 }
 152                 else {
 153                         return "No database connection";
 154                 }
 155         }
 156         function lastErrno() { return 1; }
 157
 158         function affectedRows() {
 159                 return pg_affected_rows( $this->mLastResult );
 160         }
 161
 162         /**
 163          * Returns information about an index
 164          * If errors are explicitly ignored, returns NULL on failure
 165          */
 166         function indexInfo( $table, $index, $fname = 'Database::indexExists' ) {
 167                 $sql = "SELECT indexname FROM pg_indexes WHERE tablename='$table'";
 168                 $res = $this->query( $sql, $fname );
 169                 if ( !$res ) {
 170                         return NULL;
 171                 }
 172
 173                 while ( $row = $this->fetchObject( $res ) ) {
 174                         if ( $row->Key_name == $index ) {
 175                                 return $row;
 176                         }
 177                 }
 178                 return false;
 179         }
 180
 181         function indexUnique ($table, $index, $fname = 'Database::indexUnique' ) {
 182                 $sql = "SELECT indexname FROM pg_indexes WHERE tablename='{$table}'".
 183                         " AND indexdef LIKE 'CREATE UNIQUE%({$index})'";
 184                 $res = $this->query( $sql, $fname );
 185                 if ( !$res )
 186                         return NULL;
 187                 while ($row = $this->fetchObject( $res ))
 188                         return true;
 189                 return false;
 190
 191         }
 192
 193         function fieldInfo( $table, $field ) {
 194                 throw new DBUnexpectedError($this,  'Database::fieldInfo() error : mysql_fetch_field() not implemented for postgre' );
 195                 /*
 196                 $res = $this->query( "SELECT * FROM '$table' LIMIT 1" );
 197                 $n = pg_num_fields( $res );
 198                 for( $i = 0; $i < $n; $i++ ) {
 199                         // FIXME
 200                         throw new DBUnexpectedError($this,  "Database::fieldInfo() error : mysql_fetch_field() not implemented for postgre" );
 201                         $meta = mysql_fetch_field( $res, $i );
 202                         if( $field == $meta->name ) {
 203                                 return $meta;
 204                         }
 205                 }
 206                 return false;*/
 207         }
 208
 209         function insert( $table, $a, $fname = 'Database::insert', $options = array() ) {
 210                 # PostgreSQL doesn't support options
 211                 # We have a go at faking one of them
 212                 # TODO: DELAYED, LOW_PRIORITY
 213
 214                 if ( !is_array($options))
 215                         $options = array($options);
 216
 217                 if ( in_array( 'IGNORE', $options ) )
 218                         $oldIgnore = $this->ignoreErrors( true );
 219
 220                 # IGNORE is performed using single-row inserts, ignoring errors in each
 221                 # FIXME: need some way to distiguish between key collision and other types of error
 222                 $oldIgnore = $this->ignoreErrors( true );
 223                 if ( !is_array( reset( $a ) ) ) {
 224                         $a = array( $a );
 225                 }
 226                 foreach ( $a as $row ) {
 227                         parent::insert( $table, $row, $fname, array() );
 228                 }
 229                 $this->ignoreErrors( $oldIgnore );
 230                 $retVal = true;
 231
 232                 if ( in_array( 'IGNORE', $options ) )
 233                         $this->ignoreErrors( $oldIgnore );
 234
 235                 return $retVal;
 236         }
 237
 238         function tableName( $name ) {
 239                 # First run any transformations from the parent object
 240                 $name = parent::tableName( $name );
 241
 242                 # Replace backticks into double quotes
 243                 $name = strtr($name,'`','"');
 244
 245                 # Now quote PG reserved keywords
 246                 switch( $name ) {
 247                         case 'user':
 248                         case 'old':
 249                         case 'group':
 250                                 return '"' . $name . '"';
 251
 252                         default:
 253                                 return $name;
 254                 }
 255         }
 256
 257         function strencode( $s ) {
 258                 return pg_escape_string( $s );
 259         }
 260
 261         /**
 262          * Return the next in a sequence, save the value for retrieval via insertId()
 263          */
 264         function nextSequenceValue( $seqName ) {
 265                 $value = $this->selectField(''," nextval('" . $seqName . "')");
 266                 $this->mInsertId = $value;
 267                 return $value;
 268         }
 269
 270         /**
 271          * USE INDEX clause
 272          * PostgreSQL doesn't have them and returns ""
 273          */
 274         function useIndexClause( $index ) {
 275                 return '';
 276         }
 277
 278         # REPLACE query wrapper
 279         # PostgreSQL simulates this with a DELETE followed by INSERT
 280         # $row is the row to insert, an associative array
 281         # $uniqueIndexes is an array of indexes. Each element may be either a
 282         # field name or an array of field names
 283         #
 284         # It may be more efficient to leave off unique indexes which are unlikely to collide.
 285         # However if you do this, you run the risk of encountering errors which wouldn't have
 286         # occurred in MySQL
 287         function replace( $table, $uniqueIndexes, $rows, $fname = 'Database::replace' ) {
 288                 $table = $this->tableName( $table );
 289
 290                 if (count($rows)==0) {
 291                         return;
 292                 }
 293
 294                 # Single row case
 295                 if ( !is_array( reset( $rows ) ) ) {
 296                         $rows = array( $rows );
 297                 }
 298
 299                 foreach( $rows as $row ) {
 300                         # Delete rows which collide
 301                         if ( $uniqueIndexes ) {
 302                                 $sql = "DELETE FROM $table WHERE ";
 303                                 $first = true;
 304                                 foreach ( $uniqueIndexes as $index ) {
 305                                         if ( $first ) {
 306                                                 $first = false;
 307                                                 $sql .= "(";
 308                                         } else {
 309                                                 $sql .= ') OR (';
 310                                         }
 311                                         if ( is_array( $index ) ) {
 312                                                 $first2 = true;
 313                                                 foreach ( $index as $col ) {
 314                                                         if ( $first2 ) {
 315                                                                 $first2 = false;
 316                                                         } else {
 317                                                                 $sql .= ' AND ';
 318                                                         }
 319                                                         $sql .= $col.'=' . $this->addQuotes( $row[$col] );
 320                                                 }
 321                                         } else {
 322                                                 $sql .= $index.'=' . $this->addQuotes( $row[$index] );
 323                                         }
 324                                 }
 325                                 $sql .= ')';
 326                                 $this->query( $sql, $fname );
 327                         }
 328
 329                         # Now insert the row
 330                         $sql = "INSERT INTO $table (" . $this->makeList( array_keys( $row ), LIST_NAMES ) .') VALUES (' .
 331                                 $this->makeList( $row, LIST_COMMA ) . ')';
 332                         $this->query( $sql, $fname );
 333                 }
 334         }
 335
 336         # DELETE where the condition is a join
 337         function deleteJoin( $delTable, $joinTable, $delVar, $joinVar, $conds, $fname = "Database::deleteJoin" ) {
 338                 if ( !$conds ) {
 339                         throw new DBUnexpectedError($this,  'Database::deleteJoin() called with empty $conds' );
 340                 }
 341
 342                 $delTable = $this->tableName( $delTable );
 343                 $joinTable = $this->tableName( $joinTable );
 344                 $sql = "DELETE FROM $delTable WHERE $delVar IN (SELECT $joinVar FROM $joinTable ";
 345                 if ( $conds != '*' ) {
 346                         $sql .= 'WHERE ' . $this->makeList( $conds, LIST_AND );
 347                 }
 348                 $sql .= ')';
 349
 350                 $this->query( $sql, $fname );
 351         }
 352
 353         # Returns the size of a text field, or -1 for "unlimited"
 354         function textFieldSize( $table, $field ) {
 355                 $table = $this->tableName( $table );
 356                 $sql = "SELECT t.typname as ftype,a.atttypmod as size
 357                         FROM pg_class c, pg_attribute a, pg_type t
 358                         WHERE relname='$table' AND a.attrelid=c.oid AND
 359                                 a.atttypid=t.oid and a.attname='$field'";
 360                 $res =$this->query($sql);
 361                 $row=$this->fetchObject($res);
 362                 if ($row->ftype=="varchar") {
 363                         $size=$row->size-4;
 364                 } else {
 365                         $size=$row->size;
 366                 }
 367                 $this->freeResult( $res );
 368                 return $size;
 369         }
 370
 371         function lowPriorityOption() {
 372                 return '';
 373         }
 374
 375         function limitResult($sql, $limit,$offset) {
 376                 return "$sql LIMIT $limit ".(is_numeric($offset)?" OFFSET {$offset} ":"");
 377         }
 378
 379         /**
 380          * Returns an SQL expression for a simple conditional.
 381          * Uses CASE on PostgreSQL.
 382          *
 383          * @param string $cond SQL expression which will result in a boolean value
 384          * @param string $trueVal SQL expression to return if true
 385          * @param string $falseVal SQL expression to return if false
 386          * @return string SQL fragment
 387          */
 388         function conditional( $cond, $trueVal, $falseVal ) {
 389                 return " (CASE WHEN $cond THEN $trueVal ELSE $falseVal END) ";
 390         }
 391
 392         # FIXME: actually detecting deadlocks might be nice
 393         function wasDeadlock() {
 394                 return false;
 395         }
 396
 397         # Return DB-style timestamp used for MySQL schema
 398         function timestamp( $ts=0 ) {
 399                 return wfTimestamp(TS_DB,$ts);
 400         }
 401
 402         /**
 403          * Return aggregated value function call
 404          */
 405         function aggregateValue ($valuedata,$valuename='value') {
 406                 return $valuedata;
 407         }
 408
 409
 410         function reportQueryError( $error, $errno, $sql, $fname, $tempIgnore = false ) {
 411                 $message = "A database error has occurred\n" .
 412                         "Query: $sql\n" .
 413                         "Function: $fname\n" .
 414                         "Error: $errno $error\n";
 415                 throw new DBUnexpectedError($this, $message);
 416         }
 417
 418         /**
 419          * @return string wikitext of a link to the server software's web site
 420          */
 421         function getSoftwareLink() {
 422                 return "[http://www.postgresql.org/ PostgreSQL]";
 423         }
 424
 425         /**
 426          * @return string Version information from the database
 427          */
 428         function getServerVersion() {
 429                 $res = $this->query( "SELECT version()" );
 430                 $row = $this->fetchRow( $res );
 431                 $version = $row[0];
 432                 $this->freeResult( $res );
 433                 return $version;
 434         }
 435
 436         function setSchema($schema=false) {
 437                 $schemas=$this->mSchemas;
 438                 if ($schema) { array_unshift($schemas,$schema); }
 439                 $searchpath=$this->makeList($schemas,LIST_NAMES);
 440                 $this->query("SET search_path = $searchpath");
 441         }
 442 }
 443
 444 ?>