Horde_Rdo_Query::_orderBy PHP Method

    protected function _orderBy(&$sql, &$bindParams)
    {
        if ($this->sortby) {
            $sql .= ' ORDER BY';
            foreach ($this->sortby as $sort) {
                if (strpos($sort, '@') !== false) {
                    list($rel, $field) = explode('@', $sort);
                    if (!isset($this->relationships[$rel])) {
                        continue;
                    }
                    $sql .= ' ' . $this->relationships[$rel]['tableAlias'] . '.' . $field . ',';
                } else {
                    $sql .= " {$sort},";
                }
            }
            $sql = substr($sql, 0, -1);
        }
    }