I have two tables - the first one is called 'users' and the second one is called 'buy_courses'.
I am trying to select all users those user_name is not in buy_courses. I tried something like -
$users = DB::table('users')
->rightjoin('buy_courses', 'users.user_name', '=', 'buy_courses.user_name')
->get();
It returns all users, whose user_name is in 'buy_courses', when I am using '<>', then I'm getting all users. What should be the right query?

