Eloquent - Many To Many, users-topics delete all topics by user id

Question

Given Eloquent Many To Many relationship:

Migration:

class Topics extends Migration
{
    public function up()
    {
        Schema::create('topics', function(Blueprint $table) {
            $table->increments('id');
            $table->string('name');
        });

        Schema::create('topic_user', function(Blueprint $table) {
            $table->integer('user_id')->unsigned();
            $table->foreign('user_id')->references('id')->on('users');
            $table->integer('topic_id')->unsigned();
            $table->foreign('topic_id')->references('id')->on('topics');
        });
    }
}

Model:

class User extends Model
{
    public function topics()
    {
        return $this->belongsToMany('App\Topic', 'topic_user');
    }
}

I'm wondering how can I delete all topics by given user, currently my code looks like this:

Auth::user()->topics()->delete();

But I'm getting exception:

ERROR: missing FROM-clause entry for table "topic_user" LINE 1: delete from "topics" where "topic_user"."user_id" = $1 ^ (SQL: delete from "topics" where "topic_user"."user_id" = 6)

What I'm doing wrong?

Answer 1

That's pretty simple:

Auth::user()->topics()->detach();