从Laravel中的另一个表中过滤表中的用户

I am new to Laravel. I want to filter users from a table.

1) First table 'users' Users table

2) Second table 'requests' Requests table

3) My controller

  public function search() 
  {

            $my_id= Auth::User()->id;
            $my_gender= Auth::User()->gender;


            $users = DB::table('users')
                      ->join('personal_info', 'users.id', '=', 'personal_info.user_id')
                      ->join('user_about', 'users.id', '=', 'user_about.user_id');
                                         ->join('requests', 'users.id', '=', 'requests.request_to_id');

            $users =  $users ->whereNotIn('users.id', [$my_id]);
            $users =  $users ->whereNotIn('users.gender', [$my_gender]);
            $users =  $users ->whereNotIn('requests.request_to_id', ['users.id']);
            $users =  $users ->paginate(7);

            return view('search',compact('users'));
     }

4) Users is my primary table , it is combined with two other table and also with requests table , I want filter users (users.id) who are present in (requests.request_to_id) . And I get blank screen nothing get.

After call to database like you do in this example:

DB::table('requests')
                   ->where('request_by_id', '=', $my_id)
                   ->value('request_to_id');

You must add ->get() to the end of query, to get value from database.