use builder for query

app/Http/Controllers/HeadquartersDashboard/CumulativeVoiceRatingStatsController.php

@@ -13,25 +13,22 @@ class CumulativeVoiceRatingStatsController extends Controller
     public function index(Request $request): JsonResponse
     {
         $query = DB::table('country_voice_rating_reports')->selectRaw("
-                SELECT
                 province_id,
                 province_name,
                 SUM(message_quality_ok) as message_quality_ok,
                 SUM(message_format_ok) as message_format_ok,
                 SUM(message_quality_nok) as message_quality_nok,
                 SUM(message_format_nok) as message_format_nok
-            GROUP BY province_id, province_name
-
-            UNION ALL
-
-            SELECT
+            ")
+            ->groupBy('province_id', 'province_name')
+            ->unionAll(DB::table('country_voice_rating_reports')->selectRaw("
                 0 as province_id,
                 'کشوری' as province_name,
                 SUM(message_quality_ok),
                 SUM(message_format_ok),
                 SUM(message_quality_nok),
                 SUM(message_format_nok)
-        ");
+            "));
 
         return response()->json(
             DataTableFacade::run(