验证表单传递的分类 [ 2.0 版本 ]

这里的表单验证需要传递value值,数据库根据value来确定分类,控制器的方法怎么验证category

  public function actionAdvice()
    {

        if (Request::isPost()){
            $res = new TradeAdvice();
            $res -> content = Request::post('content');
            $res -> category = Request::post('category');
            $res -> uid = Yii::$app->trade->id;
            $res -> add_time = time();
            $res ->save();
        }
        return $this-> render('advice');
    }