public function prepareDataProvider()
{
    /* @var $modelClass yiidbActiveRecord */
    $modelClass = $this->modelClass;

    $query = $modelClass::find()
        ->where('published=1')
        ->select([
            'id',
            'city_id',
            'city_district_id',
            'seller_net_id',
            'name',
            'address',
            'type',
        ]);

    // filters
    if ($city_id = Yii::$app->request->getQueryParam('city_id'))
        $query->andWhere('city_id = :city_id',[':city_id'=>$city_id]);
    if ($city_district_id = Yii::$app->request->getQueryParam('city_district_id'))
        $query->andWhere('city_district_id = :city_district_id',[':city_district_id'=>$city_district_id]);
    $city_name = Yii::$app->request->getQueryParam('name');
    if ($city_name && mb_strlen($city_name) >= Yii::$app->params['minSearchChars'])
        $query->andWhere(['LIKE' ,'name',strtr($city_name,['%'=>'%', '_'=>'_', '\'=>'\\']).'%', false]);

    return new ActiveDataProvider([
        'query' => $query
    ]);
}

/**
 * Creates data provider instance with search query applied
 *
 * @param array $params
 *
 * @return ActiveDataProvider
 */
public function search($params)
{
    $query = Location::find();
    $dataProvider = new ActiveDataProvider([
        'query' => $query,
    ]);

    $this->load($params);

    if (!$this->validate()) {
        // uncomment the following line if you do not want to any records when validation fails
        // $query->where('0=1');
        return $dataProvider;
    }

    $query->joinWith(array('client','address'));

    $query->andFilterWhere([
        'id' => $this->id,
    ]);

    $query->andFilterWhere(['like', 'name', $this->name])
          ->andFilterWhere(['like', 'd_client.name', $this->client_id])
          ->orFilterWhere(['like','d_address.address1',$this->address_id])
          ->orFilterWhere(['like','d_address.address2',$this->address_id])
          ->orFilterWhere(['like','d_address.address3',$this->address_id]);

    return $dataProvider;
}