Yii2：如何删除 Yii2 上的关系 3 表

Question

我有以下表格，我想在Pak 上单击删除按钮，该按钮可以删除所有 3 个表格关系。

我怎样才能做到这一点？

table Pak : id_pak, pak_name/////
table Church : id_church, church_name, id_pak/////
table Member : id_member, name_member, id_church////

public function actionDelete($id)
{
    $this->findModel($id);
    $select = Church::find()
            ->select('church_name')
            ->where(['id_pak' => $id])
            ->all();

    $a3 = Church::find()
        ->select('id_church')
        ->where(['id_pak' => $id])
        ->all();

    $select2 = Member::find()
            ->select('member_name')
            ->where(['id_church'=> $a3])
            ->all();
    Church::find()->where(['id_pak' => $id])->one()->delete();
    Pak::find()->where(['id_pak' =>$id])->one()->delete();
    Member::find()->where(['id_church'=> $a3])->one()->delete();
    return $this->redirect(['index','select'=>$select,'select2'=>$select2]);
}

Answer 1

以下代码可以帮助您解决问题。

public function actionDelete($id)
{
    $select = Church::find()
            ->select('church_name')
            ->where(['id_pak' => $id])
            ->all();

    $a3 = Church::find()
        ->select('id_church')
        ->where(['id_pak' => $id])
        ->all();

    $select2 = Member::find()
            ->select('member_name')
            ->where(['id_church'=> $a3])
            ->all();

    // ---------- start ---------------
    $park = Park::find()->where(['id_pak' => $id])->one();
    if ( $park->delete() ){
        Pak::deleteAll('id_pak = :id', [':id' => $id]);
        foreach ($a3 as $value) {
            Member::deleteAll('id_church = :id', [':id' => $value->id_church ]);
        }
    }
    // ---------- end ---------------

    return $this->redirect(['index','select'=>$select,'select2'=>$select2]);
}

Answer 2

在 innoDB 引擎中使用约束

如果你使用 InnoDB 并且已经正确添加了约束 on delete cascade 并且在模型中定义了各自的关系，你不需要担心其他表中的相关记录你只需要在 @ 中找到模型987654323@并删除。

public function actionDelete($id)
{
    $this->findModel($id)->delete();

    return $this->redirect(['index']);
}

protected function findModel( $id ) {
    if ( ($model = Pak::findOne ( $id )) !== null ) {
        return $model;
    }

    throw new NotFoundHttpException ( 'The requested page does not exist.' );
}

手动删除

或者，如果您不使用 innoDB 或出于任何原因不使用约束，那么您可以覆盖 Pak 的 ActiveRecord 模型中的 beforeDelete() 并删除 Church 中 Pak 模型的所有子行并在Church 中覆盖beforeDelete() 以删除Member 模型中的所有子行并从那里返回true 以继续删除Pak 模型中的实际记录

我假设您在Pak 模型中定义了以下关系

public function getChurch(){
    return $this->hasOne(Church::className(), ['id_pak'=>'id_pak']);
}

Church 模型中的以下内容

public function getMember(){
    return $this->hasOne(Member::className(),['id_church'=>'id_church']);
}

然后覆盖Pak模型中的beforeDelete()

public function beforeDelete() {
    $this->church->delete();
    return parent::beforeDelete ();
}

并覆盖 Church 模型中的 beforeDelete()

public function beforeDelete() {
    $this->member->delete();
    return parent::beforeDelete ();
}

在您的actionDelete() 中找到模型并调用删除

public function actionDelete($id)
{
    $this->findModel($id)->delete();

    return $this->redirect(['index']);
}

还有一篇很好的文章介绍了在父模型here 中实现recursiveDelete() 方法。