Laravel Pivot table id column

Question

In Laravel and Eloquent you can use ManyToMany-Relations with a pivot table. The problem in my case is the automatic ID of the pivot row. Can I change how the ID is generated? I want to use UUIDs for that matter.

For other Objects you can just implement this behaviour in the Model, but there is no model for pivot objects.

Did I miss something?

score 8 · Accepted Answer · answered Jul 03 '14 at 12:21

Yeah, wherever you are adding new records to the pivot table, either through attach() or sync(), you give it a key/value array of additional items to put into the pivot table as the second parameter.

So for example $user->roles()->attach($role, array('id' => $uuid));

If you are doing this, it might be useful to also make sure your id isn't set to auto increment.

It might also be important to note that a lot of people don't even have an id column on their pivot table because it's usually not required unless you plan on creating a model for it, or it contains some other foreign key for some reason besides the 2 it would usually have.

score 1 · Answer 2 · answered Jan 20 '20 at 18:55

I think creating Intermediate model does better job otherwise we will have to add primary uuid whenever we create new record.

use Webpatser\Uuid\Uuid;
use Illuminate\Database\Eloquent\Relations\Pivot;

class ProjectAssignee extends Pivot
{

    public $incrementing = false;
    protected $keyType = 'string';
    protected $primaryKey = 'id';
    protected $guarded = [];

    public static function boot()
    {
       parent::boot();
       self::creating(function ($model) {
           $model->id = (string) Uuid::generate(4);
       });
    }

}

Now we can create attach easily

Project::first()->assignees()->attach(Assignee::inRandomOrder()->take(5)->pluck('id')->toArray());

Don't forget to chain using method to tell relationship about intermediate table.

public function assignees(){return $this->belongsToMany(
  Assignee::class,
 'projects_assignees',
 'project_id',
 'assignee_id')
->using(ProjectAssignee::class);}

score 0 · Answer 3 · answered May 31 '20 at 19:23

Be careful here : id on a pivot table can cause confusion when doing a join, as it will end up on the same row as joined table's id, and can cause fairly nasty bugs, as the latter will override the former. If you really need one, at least change its name.

Laravel Pivot table id column

3 Answers3