public function searchRequest($params)
 {
     $query = DataRequest::find()->where(['!=', 'request_status', 4]);
     // add conditions that should always apply here
     $dataProvider = new ActiveDataProvider(['query' => $query]);
     $this->load($params);
     if (!$this->validate()) {
         // uncomment the following line if you do not want to return any records when validation fails
         // $query->where('0=1');
         return $dataProvider;
     }
     $query->andFilterWhere(['id' => $this->id, 'user_id' => $this->user_id, 'student_id' => $this->student_id, 'request_status' => $this->request_status, 'request_status' => $this->request_status, 'created_at' => $this->created_at, 'updated_at' => $this->updated_at]);
     //$query->andFilterWhere(['request_status', '!=', 4]);
     return $dataProvider;
 }