从数据透视表中检索单个列-Laravel 5

Question

I am using a pivot table genre_user to relate user to genre . table contains the following fields

id 
user_id 
genre_id

Following are the model definitions

User.php

public function genres() {
        return $this->belongsToMany('App\Genre');
    }

Genre.php

public function artists() {
        return $this->belongsToMany('App\User');
    }

I am getting the results as a collection when I use the following code

$user = auth()->user();
dd($user->genres);

I want to show the selected genres in a dropdown field of genres. Is it possible to get only the current users genre_id as an array from the pivot table without using a foreach loop.

Answer 1

I think what will help you achieve this behavior is the lists() method. Try something like

$user_genres = auth()->user()->genres()->lists('name','id');

If you are using Forms & HTML package you can just do

{!! Form::select('genres',$user_genres,null) !!}

And here is your dropdown

More info here (scroll down to "Retrieving A List Of Column Values")

Answer 2

A user should have one genre .

Therefore, your models should contain the following relations:

User.php

public function genre() {
    return $this->hasOne('App\Genre');
}

Genre.php

public function artists() {
    return $this->belongsToMany('App\User');
}