diff --git a/comment/views/oj.py b/comment/views/oj.py
index d2272ba..c3e5047 100644
--- a/comment/views/oj.py
+++ b/comment/views/oj.py
@@ -1,15 +1,15 @@
-from django.db.models import Avg, Count
-from django.db.models.functions import Round
-
-from account.decorators import login_required
+from django.db.models import Avg, Count
+from django.db.models.functions import Round
+
+from account.decorators import login_required
 from comment.models import Comment
 from comment.serializers import CommentSerializer, CreateCommentSerializer
 from problem.models import Problem
-from submission.models import JudgeStatus, Submission
-from utils.api import AsyncAPIView
-from utils.api.api import validate_serializer
-from utils.async_helpers import async_cache_delete, async_cache_get, async_cache_set
-from utils.constants import CacheKey
+from submission.models import JudgeStatus, Submission
+from utils.api import AsyncAPIView
+from utils.api.api import validate_serializer
+from utils.async_helpers import async_cache_delete, async_cache_get, async_cache_set
+from utils.constants import CacheKey
 
 
 class CommentAPI(AsyncAPIView):
@@ -48,8 +48,8 @@ class CommentAPI(AsyncAPIView):
             comprehensive_rating=data["comprehensive_rating"],
             content=data["content"],
         )
-        await async_cache_delete(f"{CacheKey.comment_stats}:{problem.id}")
-        return self.success()
+        await async_cache_delete(f"{CacheKey.comment_stats}:{problem.id}")
+        return self.success()
 
     @login_required
     async def get(self, request):
@@ -58,25 +58,22 @@ class CommentAPI(AsyncAPIView):
             Comment.objects.select_related("problem")
             .filter(user=request.user, problem_id=problem_id)
             .afirst()
-        )
-        if comment:
-            return self.success(await self.async_serialize_data(CommentSerializer, comment))
-        else:
-            return self.success()
+        )
+        if comment:
+            return self.success(await self.async_serialize_data(CommentSerializer, comment))
+        else:
+            return self.success()
 
 
 class CommentStatisticsAPI(AsyncAPIView):
     async def get(self, request):
-        problem_id = request.GET.get("problem_id")
-        cache_key = f"{CacheKey.comment_stats}:{problem_id}"
-        cached = await async_cache_get(cache_key)
-        if cached is not None:
-            return self.success(cached)
+        problem_id = request.GET.get("problem_id")
+        cache_key = f"{CacheKey.comment_stats}:{problem_id}"
+        cached = await async_cache_get(cache_key)
+        if cached is not None:
+            return self.success(cached)
 
-        from asgiref.sync import sync_to_async
-        agg = await sync_to_async(
-            Comment.objects.filter(problem_id=problem_id).aggregate
-        )(
+        agg = await Comment.objects.filter(problem_id=problem_id).aaggregate(
             count=Count("id"),
             description=Round(Avg("description_rating"), 2),
             difficulty=Round(Avg("difficulty_rating"), 2),
@@ -90,5 +87,5 @@ class CommentStatisticsAPI(AsyncAPIView):
             "difficulty": agg["difficulty"],
             "comprehensive": agg["comprehensive"],
         }}
-        await async_cache_set(cache_key, data, 3600)
-        return self.success(data)
+        await async_cache_set(cache_key, data, 3600)
+        return self.success(data)