wiki.techinc.nl/includes/DatabasePostgreSQL.php
2006-06-06 23:07:26 +00:00

443 lines
12 KiB
PHP

<?php
/**
* This is PostgreSQL database abstraction layer.
*
* As it includes more generic version for DB functions,
* than MySQL ones, some of them should be moved to parent
* Database class.
*
* STATUS: Working PG implementation of MediaWiki
* TODO: Installer support
*
* @package MediaWiki
*/
/**
* Depends on database
*/
require_once( 'Database.php' );
/**
*
* @package MediaWiki
*/
class DatabasePgsql extends Database {
var $mInsertId = NULL;
var $mLastResult = NULL;
function DatabasePgsql($server = false, $user = false, $password = false, $dbName = false,
$failFunction = false, $flags = 0, $tablePrefix = 'get from global' )
{
Database::Database( $server, $user, $password, $dbName, $failFunction, $flags, $tablePrefix );
}
/* static */ function newFromParams( $server = false, $user = false, $password = false, $dbName = false,
$failFunction = false, $flags = 0, $tablePrefix = 'get from global' )
{
return new DatabasePgsql( $server, $user, $password, $dbName, $failFunction, $flags, $tablePrefix );
}
/**
* Usually aborts on failure
* If the failFunction is set to a non-zero integer, returns success
*/
function open( $server, $user, $password, $dbName ) {
# Test for PostgreSQL support, to avoid suppressed fatal error
if ( !function_exists( 'pg_connect' ) ) {
throw new DBConnectionError( $this, "PostgreSQL functions missing, have you compiled PHP with the --with-pgsql option?\n" );
}
global $wgDBschema;
$this->close();
$this->mServer = $server;
$this->mUser = $user;
$this->mPassword = $password;
$this->mDBname = $dbName;
$this->mSchemas = array($wgDBschema,'public');
$success = false;
if ( '' != $dbName ) {
# start a database connection
$hstring="";
if ($server!=false && $server!="") {
$hstring="host=$server ";
}
@$this->mConn = pg_connect("$hstring dbname=$dbName user=$user password=$password");
if ( $this->mConn == false ) {
wfDebug( "DB connection error\n" );
wfDebug( "Server: $server, Database: $dbName, User: $user, Password: " . substr( $password, 0, 3 ) . "...\n" );
wfDebug( $this->lastError()."\n" );
} else {
$this->setSchema();
$this->mOpened = true;
}
}
return $this->mConn;
}
/**
* Closes a database connection, if it is open
* Returns success, true if already closed
*/
function close() {
$this->mOpened = false;
if ( $this->mConn ) {
return pg_close( $this->mConn );
} else {
return true;
}
}
function doQuery( $sql ) {
return $this->mLastResult=pg_query( $this->mConn , $sql);
}
function queryIgnore( $sql, $fname = '' ) {
return $this->query( $sql, $fname, true );
}
function freeResult( $res ) {
if ( !@pg_free_result( $res ) ) {
throw new DBUnexpectedError($this, "Unable to free PostgreSQL result\n" );
}
}
function fetchObject( $res ) {
@$row = pg_fetch_object( $res );
# FIXME: HACK HACK HACK HACK debug
# TODO:
# hashar : not sure if the following test really trigger if the object
# fetching failled.
if( pg_last_error($this->mConn) ) {
throw new DBUnexpectedError($this, 'SQL error: ' . htmlspecialchars( pg_last_error($this->mConn) ) );
}
return $row;
}
function fetchRow( $res ) {
@$row = pg_fetch_array( $res );
if( pg_last_error($this->mConn) ) {
throw new DBUnexpectedError($this, 'SQL error: ' . htmlspecialchars( pg_last_error($this->mConn) ) );
}
return $row;
}
function numRows( $res ) {
@$n = pg_num_rows( $res );
if( pg_last_error($this->mConn) ) {
throw new DBUnexpectedError($this, 'SQL error: ' . htmlspecialchars( pg_last_error($this->mConn) ) );
}
return $n;
}
function numFields( $res ) { return pg_num_fields( $res ); }
function fieldName( $res, $n ) { return pg_field_name( $res, $n ); }
/**
* This must be called after nextSequenceVal
*/
function insertId() {
return $this->mInsertId;
}
function dataSeek( $res, $row ) { return pg_result_seek( $res, $row ); }
function lastError() { return pg_last_error(); }
function lastErrno() { return 1; }
function affectedRows() {
return pg_affected_rows( $this->mLastResult );
}
/**
* Returns information about an index
* If errors are explicitly ignored, returns NULL on failure
*/
function indexInfo( $table, $index, $fname = 'Database::indexExists' ) {
$sql = "SELECT indexname FROM pg_indexes WHERE tablename='$table'";
$res = $this->query( $sql, $fname );
if ( !$res ) {
return NULL;
}
while ( $row = $this->fetchObject( $res ) ) {
if ( $row->Key_name == $index ) {
return $row;
}
}
return false;
}
function indexUnique ($table, $index, $fname = 'Database::indexUnique' ) {
$sql = "SELECT indexname FROM pg_indexes WHERE tablename='{$table}'".
" AND indexdef LIKE 'CREATE UNIQUE%({$index})'";
$res = $this->query( $sql, $fname );
if ( !$res )
return NULL;
while ($row = $this->fetchObject( $res ))
return true;
return false;
}
function fieldInfo( $table, $field ) {
throw new DBUnexpectedError($this, 'Database::fieldInfo() error : mysql_fetch_field() not implemented for postgre' );
/*
$res = $this->query( "SELECT * FROM '$table' LIMIT 1" );
$n = pg_num_fields( $res );
for( $i = 0; $i < $n; $i++ ) {
// FIXME
throw new DBUnexpectedError($this, "Database::fieldInfo() error : mysql_fetch_field() not implemented for postgre" );
$meta = mysql_fetch_field( $res, $i );
if( $field == $meta->name ) {
return $meta;
}
}
return false;*/
}
function insert( $table, $a, $fname = 'Database::insert', $options = array() ) {
# PostgreSQL doesn't support options
# We have a go at faking one of them
# TODO: DELAYED, LOW_PRIORITY
if ( !is_array($options))
$options = array($options);
if ( in_array( 'IGNORE', $options ) )
$oldIgnore = $this->ignoreErrors( true );
# IGNORE is performed using single-row inserts, ignoring errors in each
# FIXME: need some way to distiguish between key collision and other types of error
$oldIgnore = $this->ignoreErrors( true );
if ( !is_array( reset( $a ) ) ) {
$a = array( $a );
}
foreach ( $a as $row ) {
parent::insert( $table, $row, $fname, array() );
}
$this->ignoreErrors( $oldIgnore );
$retVal = true;
if ( in_array( 'IGNORE', $options ) )
$this->ignoreErrors( $oldIgnore );
return $retVal;
}
function tableName( $name ) {
# First run any transformations from the parent object
$name = parent::tableName( $name );
# Replace backticks into double quotes
$name = strtr($name,'`','"');
# Now quote PG reserved keywords
switch( $name ) {
case 'user':
case 'old':
case 'group':
return '"' . $name . '"';
default:
return $name;
}
}
function strencode( $s ) {
return pg_escape_string( $s );
}
/**
* Return the next in a sequence, save the value for retrieval via insertId()
*/
function nextSequenceValue( $seqName ) {
$value = $this->selectField(''," nextval('" . $seqName . "')");
$this->mInsertId = $value;
return $value;
}
/**
* USE INDEX clause
* PostgreSQL doesn't have them and returns ""
*/
function useIndexClause( $index ) {
return '';
}
# REPLACE query wrapper
# PostgreSQL simulates this with a DELETE followed by INSERT
# $row is the row to insert, an associative array
# $uniqueIndexes is an array of indexes. Each element may be either a
# field name or an array of field names
#
# It may be more efficient to leave off unique indexes which are unlikely to collide.
# However if you do this, you run the risk of encountering errors which wouldn't have
# occurred in MySQL
function replace( $table, $uniqueIndexes, $rows, $fname = 'Database::replace' ) {
$table = $this->tableName( $table );
if (count($rows)==0) {
return;
}
# Single row case
if ( !is_array( reset( $rows ) ) ) {
$rows = array( $rows );
}
foreach( $rows as $row ) {
# Delete rows which collide
if ( $uniqueIndexes ) {
$sql = "DELETE FROM $table WHERE ";
$first = true;
foreach ( $uniqueIndexes as $index ) {
if ( $first ) {
$first = false;
$sql .= "(";
} else {
$sql .= ') OR (';
}
if ( is_array( $index ) ) {
$first2 = true;
foreach ( $index as $col ) {
if ( $first2 ) {
$first2 = false;
} else {
$sql .= ' AND ';
}
$sql .= $col.'=' . $this->addQuotes( $row[$col] );
}
} else {
$sql .= $index.'=' . $this->addQuotes( $row[$index] );
}
}
$sql .= ')';
$this->query( $sql, $fname );
}
# Now insert the row
$sql = "INSERT INTO $table (" . $this->makeList( array_keys( $row ), LIST_NAMES ) .') VALUES (' .
$this->makeList( $row, LIST_COMMA ) . ')';
$this->query( $sql, $fname );
}
}
# DELETE where the condition is a join
function deleteJoin( $delTable, $joinTable, $delVar, $joinVar, $conds, $fname = "Database::deleteJoin" ) {
if ( !$conds ) {
throw new DBUnexpectedError($this, 'Database::deleteJoin() called with empty $conds' );
}
$delTable = $this->tableName( $delTable );
$joinTable = $this->tableName( $joinTable );
$sql = "DELETE FROM $delTable WHERE $delVar IN (SELECT $joinVar FROM $joinTable ";
if ( $conds != '*' ) {
$sql .= 'WHERE ' . $this->makeList( $conds, LIST_AND );
}
$sql .= ')';
$this->query( $sql, $fname );
}
# Returns the size of a text field, or -1 for "unlimited"
function textFieldSize( $table, $field ) {
$table = $this->tableName( $table );
$sql = "SELECT t.typname as ftype,a.atttypmod as size
FROM pg_class c, pg_attribute a, pg_type t
WHERE relname='$table' AND a.attrelid=c.oid AND
a.atttypid=t.oid and a.attname='$field'";
$res =$this->query($sql);
$row=$this->fetchObject($res);
if ($row->ftype=="varchar") {
$size=$row->size-4;
} else {
$size=$row->size;
}
$this->freeResult( $res );
return $size;
}
function lowPriorityOption() {
return '';
}
function limitResult($sql, $limit,$offset) {
return "$sql LIMIT $limit ".(is_numeric($offset)?" OFFSET {$offset} ":"");
}
/**
* Returns an SQL expression for a simple conditional.
* Uses CASE on PostgreSQL.
*
* @param string $cond SQL expression which will result in a boolean value
* @param string $trueVal SQL expression to return if true
* @param string $falseVal SQL expression to return if false
* @return string SQL fragment
*/
function conditional( $cond, $trueVal, $falseVal ) {
return " (CASE WHEN $cond THEN $trueVal ELSE $falseVal END) ";
}
# FIXME: actually detecting deadlocks might be nice
function wasDeadlock() {
return false;
}
# Return DB-style timestamp used for MySQL schema
function timestamp( $ts=0 ) {
return wfTimestamp(TS_DB,$ts);
}
/**
* Return aggregated value function call
*/
function aggregateValue ($valuedata,$valuename='value') {
return $valuedata;
}
function reportQueryError( $error, $errno, $sql, $fname, $tempIgnore = false ) {
$message = "A database error has occurred\n" .
"Query: $sql\n" .
"Function: $fname\n" .
"Error: $errno $error\n";
throw new DBUnexpectedError($this, $message);
}
/**
* @return string wikitext of a link to the server software's web site
*/
function getSoftwareLink() {
return "[http://www.postgresql.org/ PostgreSQL]";
}
/**
* @return string Version information from the database
*/
function getServerVersion() {
$res = $this->query( "SELECT version()" );
$row = $this->fetchRow( $res );
$version = $row[0];
$this->freeResult( $res );
return $version;
}
function setSchema($schema=false) {
$schemas=$this->mSchemas;
if ($schema) { array_unshift($schemas,$schema); }
$searchpath=$this->makeList($schemas,LIST_NAMES);
$this->query("SET search_path = $searchpath");
}
}
/**
* Just an alias.
* @package MediaWiki
*/
class DatabasePostgreSQL extends DatabasePgsql {
}
?>