php - Generate unique 4(may be greater) digit random code checking existence in database in laravel -

i creating pincode users in laravel while user register. pincode 4 digits long including characters , numbers. pincode must unique , uniqueness checked using database whether pincode assigned other user or not.

i trying laravel str_random() function not work uniqueness.

i trying process in laravel. can package provide functionality? if yes suggest name of package.

maybe this:

$validator = validator::make(     ['pin_code' => $random],     ['pin_code' => 'required|unique:users'] ); while($validator->fails()) {      // given data did not pass validation     // generate $random again      $validator = validator::make(        ['pin_code' => $random],        ['pin_code' => 'required|unique:users']     );  }