I want to select all Users which are not members of a Group with id=6

Question

My tables

1. users

id	name
Cell 1	Cell 2
Cell 3	Cell 4

2. group

id	name
Cell 1	Cell 2
Cell 3	Cell 4

3. group_users

id	user_id	group_id
Cell 1	Cell 2	Cell 4
Cell 3	Cell 4	Cell 6

// All users which are members of group
public function users()
{
    return $this->belongsToMany(User::class);
}

// All groups user belong to
public function groups()
{
    return $this->belongsToMany(Group::class);
}

This is what I have tried to do. I think the problem is that I have to make the $users an array of ids that were fetched and I'm unable to do that. Please help

public function show(Group $group)
{
    //Fetching all members of the group
    $users = $group->users()->get()

    return Inertia::render('Clients/Show', [
            'users' => Group::whereNotIn('id', $users)->get()
    ]);
}

Answer 1

If you want to select users who don't have a relation, you can use whereDoesntHave:

$users = User
    ::whereDoesntHave('groups', fn($query) => $query->where('id', 1))
    ->get();

In this case I'm querying for all users who dont have a group with id 1 linked.

Answer 2

public function show(Group $group)
{
    //Fetching all members of the group
    $exceptId = $group->users()->pluck('users.id');

    return Inertia::render('Clients/Show', [
            //Here it will fetch all users except those with ids matching $exceptId array
            'users' => Group::whereNotIn('id', $exceptId)->get(),
    ]);
}