Yii2:对 GridView 中的关系计数列进行排序

Still the same result without the topicCount set in the Grid view. I show my TagSearch model, TagController and views/tag/index view file below:

标签搜索

<?php

namespace commonmodels;

use Yii;
use yiiaseModel;
use yiidataActiveDataProvider;
use commonmodelsTag;

/**
 * TagSearch represents the model behind the search form about `commonmodelsTag`.
 */
class TagSearch extends Tag
{

    public $topicCount;

    /**
     * @inheritdoc
     */
    public function rules()
    {
        return [
            [['id', 'topicCount'], 'integer'],
            [['name', 'created_at', 'updated_at', 'topicCount'], '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 $params
     *
     * @return ActiveDataProvider
     */
    public function search($params)
    {
        $query = Tag::find();

        $dataProvider = new ActiveDataProvider([
            'query' => $query->from("tags")->select(["tags.*","(select count(topic_tags.id) from topic_tags where topic_tags.tag_id=tags.id) topicCount"])->groupBy("tags.id"),
        ]);

        $this->load($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,
            'topicCount' => $this->topicCount,
            'created_at' => $this->created_at,
            'updated_at' => $this->updated_at,
        ]);

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

        return $dataProvider;
    }
}

标签模型

<?php

namespace commonmodels;

use Yii;

/**
 * This is the model class for table "tags".
 *
 * @property integer $id
 * @property integer $topicCount
 * @property string $name
 * @property string $created_at
 * @property string $updated_at
 */
class Tag extends yiidbActiveRecord
{

    public $topicCount;

    /**
     * @inheritdoc
     */
    public static function tableName()
    {
        return 'tags';
    }

    /**
     * @inheritdoc
     */
    public function rules()
    {
        return [
            [['topicCount'], 'integer'],
            [['name'], 'string'],
            [['created_at', 'updated_at'], 'required'],
            [['created_at', 'updated_at'], 'safe']
        ];
    }

    /**
     * @inheritdoc
     */
    public function attributeLabels()
    {
        return [
            'id' => 'ID',
            'name' => 'Name',
            'topicCount' => 'TC',
            'created_at' => 'Created At',
            'updated_at' => 'Updated At',
        ];
    }

}

标签控制器

public function actionIndex()
{

    $searchModel = new TagSearch();
    $myModels = $searchModel->search([]);

    return $this->render('index', [
        'dataProvider' => $myModels,
    ]);
}

标签/索引

<?= GridView::widget([
    'dataProvider' => $dataProvider,
    'columns' => [
        'id',
        'name',
        'topicCount',
        'created_at',
        'updated_at',
        ['class' => 'yiigridActionColumn','template' => '{view}',],
    ],
]); ?>

我错过了什么?

推荐答案

于是解决了这个维基:

由于在我的情况下我不使用 SUM('amount')，我更改为以下内容并且工作正常:

public function getTopicCount() 
{
    return $this->hasMany(TopicTag::className(), ["tag_id" => "id"])->count();

}

    $query = Tag::find();
    $subQuery = TopicTag::find()->select('tag_id, COUNT(tag_id) as topic_count')->groupBy('tag_id');        
    $query->leftJoin(["topicSum" => $subQuery], '"topicSum".tag_id = id');

exception 'PDOException' with message 'SQLSTATE[42P01]: Undefined table: 7 ERROR:  missing FROM-clause entry for table "topicsum"

SELECT COUNT(*) FROM "tags" 
LEFT JOIN (SELECT "tag_id", COUNT(*) as topic_count FROM "topic_tags" GROUP BY "tag_id") "topicSum" 
ON "topicSum".tag_id = id