public static function setCommentLike($id, $val)
 {
     $val = $val >= 0 ? 1 : -1;
     $rate = self::model()->findByAttributes(array('comment_id' => $id, 'user_id' => Yii::app()->user->id));
     $comment = BooksComments::model()->findByPk($id);
     if (empty($rate)) {
         $rate = new CommentLike();
         $rate->comment_id = $id;
         $rate->user_id = Yii::app()->user->id;
     } else {
         if ($rate->val == $val) {
             $rate->delete();
             if (!empty($comment)) {
                 $comment->updateRate();
             }
             return 0;
         }
     }
     $rate->val = $val;
     $rate->save();
     if (!empty($comment)) {
         $comment->updateRate();
     }
     return $val;
 }