php - 删除laravel中的一行时删除所有关系

Question

我有帖子、评论和通知表

每个帖子都有很多评论

每条评论都有许多通知

每个帖子都有许多通知

class Post extends Model
{

    public function notifications() {
        return $this->morphOne(Notification::class, 'to');
    }

    public function comments() {
        return $this->hasMany(Comment::class, 'post_id');
    }

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

        static::deleting(function($post) {
            $post->comments()->delete();
            $post->notifications()->delete();
        });
    } 
}

class Comment extends Model
{
    public function notifications() {
        return $this->morphOne(Notification::class, 'to');
    }

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

        static::deleting(function($comment) {
            $comment->notifications()->delete();
        });
    }
}

当我删除帖子时，我也应该删除通知和评论，
但问题是当我删除评论时，通知不会随之删除，
当我直接删除评论时，它们会被删除，但是当我删除帖子时，我需要删除评论的通知!

Answer 1

Laravel 不会实例化它删除的相关模型，这就是为什么直接删除评论时会删除通知，而删除帖子删除评论时则不会。删除帖子时，您必须实例化评论才能使其正常工作。

class Post extends Model {
    
    public function notifications() {
        return $this->morphOne(Notification::class, 'to');
    }
    
    public function comments() {
        return $this->hasMany(Comment::class, 'post_id');
    }
    
    public static function boot() {
        parent::boot();
    
        static::deleting(function($post) {
            // here you could instantiate each related Comment
            // in this way the boot function in the Comment model will be called
            $post->comments->each(function($comment) {
                // and then the static::deleting method when you delete each one
                $comment->delete();
            });
            $post->notifications()->delete();
        });
    } 
}

只是为了记录，我在评论中添加了我们讨论的内容，因为它可以为遇到相同问题的其他人提供服务，并且在评论中可能会被忽视。归功于 OP @Mahmoud Ben Jabir。

But if the post has 100 comments It will execute 100 query to delete them ! I will Figure out how to delete with minimum queries...

I already have onDelete on comments, but the notifications are polymorphic so it won't work on them...

The solution I will use is:
1- Get Ids of Comments that are related to the Post.
2- Delete from Notifications where type IS Comment AND id in (ids).
3- Delete Comments related to the Post.
4- Delete The Notifications Related to the Post
5- Delete The Post.

public static function boot() {
    parent::boot();
    static::deleting(function($post) {
        // 1- Get Ids of Comments that are related to the Post. 
        $ids = $post->comments()->pluck('id'); 
        // 2- Delete from Notifications where type IS Comment AND id in (ids). 
        Notification::where('entity_type', 'App\Comment')->whereIn('entity_id', $ids)->delete(); 
        // 3- Delete Comments related to the Post. 
        $post->comments()->delete();
        // 4- Delete The Notifications Related to the Post 
        $post->notifications()->delete();
    });
    // 5- Delete The Post.
}