Question

我有以下迁移：

 public function up()
    {
        Schema::create('topics_to_subscriptions', function (Blueprint $table) {
            $table->engine = 'InnoDB';
            $table->integer('topic_id')->unsigned();
            $table->integer('subscription_id')->unsigned();

            $table->foreign('topic_id')->references('id')->on('topics')->onDelete('cascade');
            $table->foreign('subscription_id')->references('id')->on('subscriptions')->onDelete('cascade');
        });
    }

我的不足之处是，在使用onDelete('cascade')时，如果我删除订阅，则所有关联的TopicsToSubscriptions都将被删除。

当我运行App\Subscription::truncate();时，所有订阅都会从subscriptions表中正确删除，但不会从topics_to_subscriptions中删除任何数据。我做错了什么？

Answer 1

您不应该截断外键引用的表。我怀疑你的外键从未正确应用过。

https://laravel.com/docs/5.4/migrations#foreign-key-constraints

public function up()
{
    Schema::create('youtube_topics_to_subscriptions', function (Blueprint $table) {
        $table->engine = 'InnoDB';
        $table->integer('topic_id')->unsigned();
        $table->integer('youtube_subscription_id')->unsigned();

        $table->foreign('topic_id')->references('id')->on('youtube_topics')->onDelete('cascade');
        $table->foreign('youtube_subscription_id')->references('id')->on('youtube_subscriptions')->onDelete('cascade');
    });
}

onDelete（＆＃39; cascade＆＃39;）不删除数据透视表上的数据

1 个答案: