问题描述
我很难按定义为模型标签"上的关系 getter 的topicCount"进行排序.一个主题可以有很多标签，并且希望按照包含该标签的主题的数量对标签进行排序.
I'm having hard time to sort by the 'topicCount' which is defined as a relational getter on a model 'Tag'. A Topic can have a lots of Tag, and wish to sort the Tags by how many Topics containing that Tag.
在我的模型/Tag.php 中:
In my models/Tag.php:
public function getTopicCount()
{
return TopicTag::find()->where(['tag_id' => $this->id])->count();
}
在我的 views/tag/index.php 中:
And in my views/tag/index.php:
<?= GridView::widget([
'dataProvider' => $dataProvider,
'columns' => [
'id',
'name',
[
'attribute'=>'topicCount',
'value' => 'topicCount',
],
'created_at',
['class' => 'yiigridActionColumn','template' => '{view}',],
],
]); ?>
在我的控制器/TagController.php 中:
And in my controllers/TagController.php:
public function actionIndex()
{
$dataProvider = new ActiveDataProvider([
'query' => Tag::find(),
'sort'=> [
'defaultOrder' => ['id'=>SORT_DESC],
'attributes' => ['id','topicCount'],
],
'pagination' => [
'pageSize' => 100,
],
]);
return $this->render('index', [
'dataProvider' => $dataProvider,
]);
}
在我的模型/TagSearch.php 中:
And in my models/TagSearch.php:
<?php
namespace commonmodels;
use Yii;
/**
* This is the model class for table "tags".
*
* @property integer $id
* @property string $name
* @property string $created_at
* @property string $updated_at
*/
class TagSearch extends Tag
{
public $topicCount;
/**
* @inheritdoc
*/
public function rules()
{
return [
[['topicCount'], 'safe']
];
}
public function search($params)
{
// create ActiveQuery
$query = Tag::find();
$query->joinWith(['topicCount']);
$dataProvider = new ActiveDataProvider([
'query' => $query,
]);
$dataProvider->sort->attributes['topicCount'] = [
'asc' => ['topicCount' => SORT_ASC],
'desc' => ['topicCount' => SORT_DESC],
];
if (!($this->load($params) && $this->validate())) {
return $dataProvider;
}
$query->andFilterWhere([
//... other searched attributes here
])
->andFilterWhere(['=', 'topicCount', $this->topicCount]);
return $dataProvider;
}
}
在索引视图中，我可以看到正确的 topicCount:
And in the index view I can see the correct topicCount:
但是在单击 topicCount 列时出现错误:
but on clicking the topicCount column I get the error:
带有消息SQLSTATE[42703]"的异常PDOException":未定义的列:7 错误:topicCount"列不存在第 1 行:SELECT * FROM "tags" ORDER BY "topicCount" LIMIT 100
感谢您的指导...！
按照 Lucas 的建议，我在 $dataProvider 中设置了 dataProvider 查询，如下所示:
Following Lucas' advice, I've set my dataProvider query in my $dataProvider like this:
'query' => $query->select(['tags.*','(select count(topic_tags.id) from topic_tags where topic_tags.tag_id=tags.id) topicCount'])->groupBy('tags.id'),
我得到了错误:
带有消息SQLSTATE[42P01]"的异常PDOException":未定义的表:7 错误:缺少表标签"的 FROM 子句条目
所以我改写成这样:
'query' => $query->from('tags')->leftJoin('topic_tags','topic_tags.tag_id = tags.id')->select(['tags.*','(select count(topic_tags.id) from topic_tags where topic_tags.tag_id=tags.id) topicCount'])->groupBy('tags.id'),
现在我得到了结果:
显然没有设置 topicCount 列，所以当我尝试按它排序时，它返回错误:
apparently the topicCount column is not set, so when I try to sort by it, it returns the error:
带有消息SQLSTATE[42703]"的异常PDOException":未定义的列:7 错误:topicCount"列不存在
但是当我直接在数据库上尝试 SQL 时，它工作正常:
but when I try the SQL directly on the DB, it works fine:
所以我想问题在于 Yii 处理别名topicCount"的方式?
so I suppose the problem is in the way Yii handles the alias 'topicCount'?
在网格视图中没有设置 topicCount 的情况下仍然是相同的结果.我在下面展示了我的 TagSearch 模型、TagController 和 views/tag/index 视图文件:
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:
Since in my case I don't use SUM('amount'), I changed to the following and works perfectly:
标签模型:
public function getTopicCount()
{
return $this->hasMany(TopicTag::className(), ["tag_id" => "id"])->count();
}
标签搜索模型:
$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');
刚生成的SQL遇到问题:
Just encountered a problem with the generated SQL:
exception 'PDOException' with message 'SQLSTATE[42P01]: Undefined table: 7 ERROR: missing FROM-clause entry for table "topicsum"
这可能是 Postgres 特有的问题，不得不安排代码，使生成的 SQL 变成这样:
This might be a Postgres-specific issue, had to arrange the code so that the generated SQL becomes like this:
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
注意"topicSum".tag_id 部分的双引号.
希望这对在 Yii2 上使用 Postgres 的人有所帮助.
Hope this might be of help for someone using Postgres on Yii2.
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