public function index()
 {
     $competitiongroups = Competitiongroup::orderBy('date', 'desc')->paginate(6);
     $competitiongroup_in_entry = Competitiongroup::where('entry_closed', '=', 0)->get();
     $in_entry = [];
     foreach ($competitiongroup_in_entry as $comp) {
         $already_in = Result::where('competitiongroup_id', '=', $comp->id)->first();
         if ($already_in) {
             $in_entry[] = $already_in->competitiongroup_id;
         }
     }
     return view('backend.competitiongroups.index', compact('competitiongroups', 'in_entry'));
 }