public function order($query)
    {
        $clause = '';

        if (!empty($query->order)) {
            $clause = 'ORDER BY ';
            $list = array();
            foreach ($query->order as $order) {
                $columns = AnDomainQueryHelper::parseColumns($query, $order['column']);
                foreach ($columns as $column) {
                    $list[] = $column.' '.$order['direction'];
                }
            }

            $clause .= implode(' , ', $list);
        }

        return $clause;
    }