public function DeleteAll($obj)
	{
		$fms = $this->GetFieldMaps(get_class($obj));
		$pk = $obj->GetPrimaryKeyName();
		$table = $fms[$pk]->TableName;

		$sql = "delete from `$table`";
		$returnval = $this->DataAdapter->Execute($sql);
		$obj->OnDelete(); // fire OnDelete event
		return $returnval;

	}