private function orderBy($order) {
        if(is_array($order) && !empty(array_filter($order))) {
            $string = array();
            foreach($order as $fieldorder => $fieldvalue) {
                if(!empty($fieldorder) && !empty($fieldvalue)) {
                    $string[] = sprintf("`%s` %s", SafeString::makeSafe($fieldorder), strtoupper(SafeString::makeSafe($fieldvalue)));
                }
                elseif($fieldvalue === 'RAND()') {
                    $string[] = $fieldvalue;
                }
            }
            return sprintf(" ORDER BY %s", implode(", ", $string));
        }
        elseif($order == 'RAND()') {
            return " ORDER BY RAND()";
        }
        return false;
    }