Laravel and pivot table to relate different model -

i'm wondering how, it's bit confusing.

i have fine belongs many relation between users , groups tables appropriate models of that.

but have table students, not users student students table maintain user_id field.

my question be: can use pivot table "group_user" relations between student , group model, in students table have "user_id" field? , how?

i tried

public function students() { return $this->belongstomany('student','group_user','group_id','user_id'); { 

but don't see way how tell eloquent not take students.id take students.user_id???

assuming these relations:

subject belongsto group group belongstomany user user hasone student 

you can this:

$subject = subject::find($someid); // of course multiple subject use eager loading: // $subjects = subject::with('group.users.student')->get();  $users = $subject->group->users; // related users  foreach ($users $user) {   $user->student; // null|student model }