DB::insert PHP Méthode

    public static function insert()
    {
        $args = func_get_args();
        return call_user_func_array(array(DB::getMDB(), 'insert'), $args);
    }

 public function save($POST)
 {
     $db = new DB();
     $ref = "TF" . date("dmyhis");
     //        for($i = 0; $i < count($POST); $i++){
     //            if(count($POST[$i]) > 1)
     //                $type = "radio";
     //            else
     //                $type = "text";
     //            $sql = "INSERT INTO forms (question, ref, user_id, type) VALUES ('". $POST[$i][0] ."','". $ref ."', '1','". $type ."')";
     //            $last_id = $db->insert($sql);
     //            for($j = 0; $j < count($POST[$i]); $j++){
     //                $sql = "INSERT INTO choices (form_id, choice) VALUES ('". $last_id . "', '". $POST[$i][$j] . "')";
     //                $db->insert($sql);
     //            }
     //        }
     $sql = "INSERT INTO topics (topic, create_dt) VALUES ('" . $POST["topic"] . "', now())";
     $last_topic_id = $db->insert($sql);
     for ($i = 0; $i < count($POST["data"]); $i++) {
         $last_from_id = 0;
         if (count($POST["data"][$i]) > 1) {
             $sql = "INSERT INTO froms (question) VALUES ('" . $POST["data"][$i][0] . "')";
             $last_from_id = $db->insert($sql);
         }
         $start = $last_from_id == 0 ? 0 : 1;
         for ($j = $start; $j < count($POST["data"][$i]); $j++) {
             $sql = "INSERT INTO questions (question, from_id, topic_id) VALUES ('" . $POST["data"][$i][$j] . "', '" . $last_from_id . "', '" . $last_topic_id . "')";
             $db->insert($sql);
         }
     }
     $response["status"] = 0;
     $response["msg"] = "Success";
     echo json_encode($response);
 }