从Laravel Controller中的不同标签删除2行

Question

So, i have 2 tables named 'topics' and 'posts'.

Topics is for the main content of the thread and posts for its reply.

So, i want to if the user delete its topic, then its following reply/post should also be deleted.

Here is my delete form:

{!! Form::open(['action' => ['TopicController@destroy', $topic->id], 'method' => 'POST', 'class' => 'pull-right']) !!}
    {{ Form::hidden('_method', 'DELETE') }}
    {{ Form::submit('Delete', ['class' => 'btn btn-danger']) }}
{!! Form::close() !!}

and here is controller:

$topic = Topic::find($id);
$post = Post::where('topic_id', $id)->get();
$topic->delete();
$post->delete();
return redirect('/')->with('Success', 'Post Removed');

But it is giving error:

BadMethodCallException
Method delete does not exist.

What is did wrong here??

Answer 1

Use cascade deleting.

From the docs :

You may also specify the desired action for the "on delete" and "on update" properties of the constraint

Define a foreign key constraint in posts table migration:

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

Recreate the table and all posts related to the topic will be automatically deleted on topic deletion.

https://laravel.com/docs/5.5/migrations#foreign-key-constraints

Answer 2

More info at the Docs

Topic::destroy($id);
Post::where('topic_id', $id)->delete();
return redirect('/')->with('Success', 'Post Removed');

Answer 3

您应该在主题，帖子和回复模型中使用关系，以显示例如每个回复都属于一个帖子。