public function actionDelete($id, $act)
 {
     $connection = Yii::$app->getDb();
     $meeting = \backend\models\MeetingSchedules::find()->where(['id' => $id])->all();
     if ($meeting) {
         foreach ($meeting as $row) {
             $olattend = $row['ol_attendee_id'];
             $attend = $row['attendee_id'];
             $meeting = $row['meeting_id'];
         }
     }
     if ($act == "ol") {
         $sql = "update meeting_schedules set ol_attendee_id=NULL where id='{$id}'";
         $command = $connection->createCommand($sql);
         $result = $command->execute();
     } else {
         $sql = "update meeting_schedules set attendee_id=NULL where id='{$id}'";
         $command = $connection->createCommand($sql);
         $result = $command->execute();
     }
     if ($olattend == NULL && $attend == NULL) {
         $this->findModel($id)->delete();
     }
     return $this->redirect(['index', 'meeting_id' => $meeting]);
 }
 /**
  * Creates data provider instance with search query applied
  *
  * @param array $params
  *
  * @return ActiveDataProvider
  */
 public function searchAttendees($params)
 {
     $query = MeetingSchedules::find();
     // 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
         return $dataProvider;
     }
     // grid filtering conditions
     $query->andFilterWhere(['id' => $this->id, 'congress_id' => $this->congress_id, 'meeting_id' => $this->meeting_id, 'attendee_id' => $this->attendee_id, 'ol_attendee_id' => $this->ol_attendee_id, 'state_rule' => $this->state_rule, 'consultant' => $this->consultant]);
     $query->andWhere('attendee_id is not null');
     return $dataProvider;
 }