createOrUpdate in laravel does not work

I want do update or create functionality its not working at all here is my code please suggest

foreach($ProfileRequest as $fieldname=>$value){


            ProfileRequest::updateOrCreate(['sm_id' => $uid, 'field_name' => $fieldname],
                        [
                        'sm_id' => $uid,
                        'field_name' => $fieldname,
                        'value' => $value
                        ]);
          }

via Manish Jakhmola