protected function findPrimaryKey($table,$indices)
	{
		$indices=implode(', ',preg_split('/\s+/',$indices));
		$sql=<<<EOD
SELECT attnum, attname FROM pg_catalog.pg_attribute WHERE
	attrelid=(
		SELECT oid FROM pg_catalog.pg_class WHERE relname=:table AND relnamespace=(
			SELECT oid FROM pg_catalog.pg_namespace WHERE nspname=:schema
		)
	)
	AND attnum IN ({$indices})
EOD;
		$command=$this->getDbConnection()->createCommand($sql);
		$command->bindValue(':table',$table->name);
		$command->bindValue(':schema',$table->schemaName);
		foreach($command->queryAll() as $row)
		{
			$name=$row['attname'];
			if(isset($table->columns[$name]))
			{
				$table->columns[$name]->isPrimaryKey=true;
				if($table->primaryKey===null)
					$table->primaryKey=$name;
				elseif(is_string($table->primaryKey))
					$table->primaryKey=array($table->primaryKey,$name);
				else
					$table->primaryKey[]=$name;
			}
		}
	}