Question

我有2个模型Onlinelearning和Onlinelearningreviews与HAS MANY关系。我想获得Onlinelearningreviews模型的特定属性。

在线学习属性：ID, Title, URL, Description, GradeAge

Onlinelearningreviews属性：ID, OnlinelearningID, Rating, Comments

模型在线学习：

public function getOnlinelearningreviews()
{
    return $this->hasMany(Onlinelearningreviews::className(), ['OnlineLearningID' => 'ID']);
}

模型在线学习评论：

 public function getOnlineLearning()
 {
        return $this->hasOne(Onlinelearning::className(), ['ID' => 'OnlineLearningID']);
 }

我想获得Title, URL, Description, GradeAge and Rating属性。

以下作品：

Onlinelearning::find()->select(['Title','URL','Description','GradeAge'])->with('onlinelearningreviews')->asArray()->all();

但是当我指定评级时，它会给我错误

Onlinelearning::find()->select(['Title','URL','Description','GradeAge','onlinelearningreviews.Rating'])->with('onlinelearningreviews')->asArray()->all();

如何从Onlinelearningreviews模型中仅获取评级属性？我不想要其他属性。

Onlinelearning::find()->with(['onlinelearningreviews'])->asArray()->all()打印：

 Array
    (
        [0] => Array
            (
                [ID] => 1
                [Title] => Udemy
                [URL] => http://www.google.com
                [Description] => Lorem Ipsum is simply dummy text of the printing and typesetting industry.
                [GradeAge] => 2nd to 5th Grade
                [AddedOn] => 2015-03-20 00:00:00
                [LastModifiedOn] => 2015-03-20 00:00:00
                [onlinelearningreviews] => Array
                    (
                        [0] => Array
                            (
                                [ID] => 1
                                [ParentID] => 1
                                [OnlineLearningID] => 1
                                [Rating] => 3.5
                                [PositiveComments] => It is a long established fact that a reader will be distracted by the readable content of a page when looking at its layout. .
                                [NegativeComments] => 
                                [AddedOn] => 
                                [LastModifiedOn] => 
                            )

                        [1] => Array
                            (
                                [ID] => 2
                                [ParentID] => 1
                                [OnlineLearningID] => 1
                                [Rating] => 3.5
                                [PositiveComments] => It is a long established fact that a reader will be distracted by the readable content of a page when looking at its layout. 
                                [NegativeComments] => 
                                [AddedOn] => 
                                [LastModifiedOn] => 
                            )

                    )

            )
)

和

Onlinelearning::find()
        ->select(['Title','URL','Description','GradeAge'])
        ->with([
            'onlinelearningreviews' => function ($query) {
                /* @var $query yii\db\ActiveQuery */

                $query->select('Rating');
            },
        ])
        ->asArray()
        ->all();

打印：

Array
(
    [0] => Array
        (
            [Title] => Udemy
            [URL] => http://www.google.com
            [Description] => Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book. It has survived not only five centuries, but also the leap into electronic typesetting, remaining essentially unchanged. It was popularised in the 1960s with the release of Letraset sheets containing Lorem Ipsum passages, and more recently with desktop publishing software like Aldus PageMaker including versions of Lorem Ipsum.
            [GradeAge] => 2nd to 5th Grade
            [onlinelearningreviews] => Array
                (
                )

        )
)

Answer 1

可能是这样的：

Onlinelearning::find()
    ->select(['Title','URL','Description','GradeAge'])
    ->with([
        'onlinelearningreviews' => function ($query) {
            /* @var $query \yii\db\ActiveQuery */

            $query->select('Rating');
        },
    ])
    ->asArray()
    ->all();

请参阅official docs，了解如何在with()中自定义关系查询。

如果您想从Onlinelearning模型中选择所有属性，可以省略select部分：

->select(['Title','URL','Description','GradeAge'])

<强>更新

似乎您应该在两个模型中包含连接属性：

->select(['ID', 'Title','URL','Description','GradeAge'])

和

$query->select(['OnlinelearningID', 'Rating']);

否则将抛出关于Undefinex index的异常。

Yii2获取关系模型的特定属性

1 个答案: