$dataProvider = new ActiveDataProvider([

            'query' => $query,                  // 如何来取得数据

            'pagination' => ['pageSize'=>5],    // pagination 用于分页

            'sort'  => [                        // sort 用于排序

                'defaultOrder' => [

                    'id' => SORT_DESC,          // defaultOrder 指定默认排序字段

                ],

                'attributes' => ['id','title'], // attribute 指定那几个字段可以用来排序

            ],

        ]);

  echo $query ->createCommand()->getRawSql();

$dataProvider->query->each() //获取 $dataProvider 所有记录;

$dataProvider->getModels() // 获取当前页的数据，以数组的方式返回

use yii\db\Pagination;

$dataProvider = $searchModel->search(\Yii::$app->request->getQueryParams());

$dataProvider->setPagination(new Pagination([

     'defaultPageSize' => 10000,

     'pageSizeLimit' => [1, 10000]

]));

<?php

namespace organize\models;

use Yii;

use yii\base\Model;

use standard\models\Country;

use organize\models\User;

use yii\db\Expression;

use yii\data\SqlDataProvider;

class CountrySearch extends Country

{

    /**

     * @inheritdoc

     */

    public function rules()

    {

        return [

            [['country_id', 'created_at', 'updated_at', 'is_delete'], 'integer'],

            [[ 'country_name','remarks'], 'safe'],

        ];

    }

    /**

     * @inheritdoc

     */

    public function scenarios()

    {

        // bypass scenarios() implementation in the parent class

        return Model::scenarios();

    }

    /**

     * Creates data provider instance with search query applied

     *

     * @param array $params

     *

     * @return SqlDataProvider

     */

    public function search($params)

    {

        $query = self::find()

            ->select(['country_id AS unique_id','country_name','created_at'])

            ->addSelect(new Expression("'country' AS table_name"));  // 查询一个常量

        $this->load($params);

        // grid filtering conditions

        $query->andFilterWhere([

            'country_id' => $this->country_id,

            'created_at' => $this->created_at,

            'updated_at' => $this->updated_at,

            'is_delete' => $this->is_delete,

        ]);

        $query->andFilterWhere(['like', 'country_name', $this->country_name])

            ->andFilterWhere(['like', 'remarks', $this->remarks]);

        $query->from('standard.country');  // 有多个库名的时候使用

        $userQuery = User::find();

        $userQuery->innerJoin('organize.org_auth_assignment','org_user.id=org_auth_assignment.user_id')

            ->select(['id AS unique_id','realname','sex','dept_id','mobile','email','qq','org_auth_assignment.name as role','org_user.created_at'])

            ->addSelect(new Expression("'org_user' AS table_name"));

        $userQuery->andFilterWhere(['like', 'realname', $this->realname])

            ->andFilterWhere(['like', 'sex', $this->sex])

            ->andFilterWhere(['=', 'org_auth_assignment.name', $this->role])

            ->andFilterWhere(['like', 'mobile', $this->mobile])

            ->andFilterWhere(['like', 'email', $this->email])

            ->andFilterWhere(['like', 'qq', $this->qq]);

        $userQuery->from('organize.org_user');

        $query->union($userQuery,true);  // 联合查询

        $sql = $query->createCommand()->rawSql;  // 生成一条不带分页的 sql

        $dataProvider = new SqlDataProvider([

            'sql' => $sql,

            'totalCount' => $query->count(),

            'sort' => false,

            'pagination' => [

                'pageSize' => 20,

            ],

        ]);

        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;

        }

        //echo $query->createCommand()->getRawSql();

        return $dataProvider;

    }

}

// 最后的 $dataProvider 渲染到页面后，用 ArrayHelper() 即可获取对应的值