public function beforeSave()
 {
     $r = parent::beforeSave();
     //Issue #2846
     if (empty($this->id)) {
         unset($this->id);
     }
     if (!$this->create_time) {
         $this->create_time = time();
     }
     $this->update_time = time();
     $this->user_ip = $_SERVER['REMOTE_ADDR'];
     return $r;
 }