public function up()
	{
		$transaction=$this->getDbConnection()->beginTransaction();
		try
		{
			if($this->safeUp()===false)
			{
				$transaction->rollback();
				return false;
			}
			$transaction->commit();
		}
		catch(Exception $e)
		{
			echo "Exception: ".$e->getMessage().' ('.$e->getFile().':'.$e->getLine().")\n";
			echo $e->getTraceAsString()."\n";
			$transaction->rollback();
			return false;
		}
	}