public function insert(UserLogin $ul)
 {
     $query = "SELECT * FROM `user_login` WHERE `username`='" . $ul->getUsername() . "' AND `password`=MD5('" . $ul->getPassword() . "')";
     $this->con->openConnection();
     $result = $this->con->executeRawQuery($query);
     if (mysqli_num_rows($result) == 0) {
         $query = "INSERT INTO `user_login`(`user_iduser`, `username`, `password`, `status`, `user_type_iduser_type`) VALUES ('" . $ul->getUserIduser() . "', '" . $ul->getUsername() . "', MD5('" . $ul->getPassword() . "'), '" . $ul->getStatus() . "', '" . $ul->getUserTypeIduserType() . "')";
         $this->con->executeRawQuery($query);
         $this->con->closeConnection();
         return true;
     } else {
         return false;
     }
 }