Laravel 4: Where Not Exists

Question

I need my model to return only those records from one table where a matching record does not exist in another table. I was thinking that the solution might be with Query Sco

Answer 1

Something like

A::whereNotExists(function($query)
            {
                $query->select(DB::raw(1))
                      ->from('B')
                      ->whereRaw('A.id = B.id');
            })
            ->get();