Yii2:如何在Yii2上删除带有关系3的表

Question

我有以下表格，我想点击删除在Pak按钮，可以删除所有3个表的关系。

我怎样才能做到这一点呢？

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

将约束与innoDB引擎一起使用

如果您使用的是InnoDB，并且正确地添加了约束on delete cascade并在模型中定义了相应的关系，那么您就不必担心其他表中的相关记录，只需在Pak中找到该模型并将其删除即可。

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，则可以覆盖Pak的ActiveRecord模型中的beforeDelete()，并在Church中移除Pak模型的所有子行，然后覆盖Church中的beforeDelete()以删除Member模型中的所有子行，并从中返回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']);
}

以及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 ();
}

在你的actionDelete()中只需找到模型并调用delete

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

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

还有一篇关于在父模型here中实现recursiveDelete()方法的很好的文章。

Answer 2

下面的代码可能会帮助你解决问题。

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]);
}