Laravel中的SQL Server ON DELETE CASCADE错误 [英] SQL Server ON DELETE CASCADE Error In Laravel

问题描述

我正在使用Laravel Framework；我有多个连接的表，

I'm using Laravel Framework; I have multiple connected tables,

用户模式表:

 Schema::create('users', function (Blueprint $table) {
        $table->bigIncrements('id');
        $table->string('name');
        $table->string('email')->unique();
        $table->timestamp('email_verified_at')->nullable();
        $table->string('password');
        $table->rememberToken();
        $table->timestamps();
    });

文章模式表:

Schema::create('articles', function (Blueprint $table) {
        $table->bigIncrements('id');
        $table->unsignedBigInteger('user_id');
        $table->foreign('user_id')->references('id')->on('users')->onDelete('cascade');
        $table->string("title");
        $table->string("slug")->unique();
        $table->text("cover");
        $table->text("body");
        $table->boolean("status")->default(1);
        $table->timestamps();
    });

注释模式表:

        Schema::create('comments', function (Blueprint $table) {
        $table->bigIncrements('id');
        $table->unsignedBigInteger("user_id");
        $table->foreign("user_id")->references("id")->on("users")->onDelete('cascade');
        $table->unsignedBigInteger("article_id");
        $table->foreign("article_id")->references("id")->on("articles")->onDelete('cascade');
        $table->text("comment");
        $table->bigInteger("level");
        $table->boolean("status")->default(0);
        $table->timestamps();
    });

在注释表中，我有以下重要代码:

In the comments table I have this important code:

$table->unsignedBigInteger("user_id");
        $table->foreign("user_id")->references("id")->on("users")->onDelete('cascade');
        $table->unsignedBigInteger("article_id");
        $table->foreign("article_id")->references("id")->on("articles")->onDelete('cascade');

我想在删除文章或用户时希望在删除用户或文章时删除其注释，但这是SQL Server数据库中的错误.

I want to when I delete an article or user, I would like to have their comments deleted when a user or an article is deleted, But this is a mistake in the SQL Server database.

错误表SQL Server数据库:在此处输入图片描述

当我删除此方法时

-> onDelete('cascade');

->onDelete('cascade');

错误消失.

我绝对需要相应的方法.谁能指导我解决这个问题?

I definitely need to have the corresponding method. Can anyone guide me to solve this problem?

推荐答案

使用删除观察器代替，删除级联上的不是最好的选择.

Use a delete observer instead, on delete cascade is not the best thing to do.

在 User 模型中定义关系:

/**
 * @return \Illuminate\Database\Eloquent\Relations\HasMany
 */
public function articles()
{
    return $this->hasMany(Article::class, 'user_id');
}

然后实施 boot 方法以观察记录的删除

Then implement the boot method to observe the deletion of a record

protected static function boot() {
    parent::boot();

    static::deleting(function($user) {
        $user->articles()->delete();
    });
}

您可以使用相同的方法循环文章注释，或者使用 Article 和 Comment 模型

You can loop on articles comments in the same method or do the same thing you did here with Article and Comment models

在此处了解有关观察者的更多信息 https://laravel.com/docs/5.8/eloquent#观察者

Read more about observers here https://laravel.com/docs/5.8/eloquent#observers

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