fix

problemset/models.py

@@ -170,15 +170,15 @@ class ProblemSetProgress(models.Model):
         )
         self.total_problems_count = problemset_problems.count()
 
-        # 获取当前题单中所有题目的ID集合
-        current_problem_ids = {str(psp.problem.id) for psp in problemset_problems}
-        
+        # 获取当前题单中所有题目的ID集合（直接用 problem_id FK 字段，无需额外查询）
+        current_problem_ids = {str(psp.problem_id) for psp in problemset_problems}
+
         # 清理已删除题目的进度记录
         progress_detail_to_remove = []
         for problem_id in self.progress_detail.keys():
             if problem_id not in current_problem_ids:
                 progress_detail_to_remove.append(problem_id)
-        
+
         for problem_id in progress_detail_to_remove:
             del self.progress_detail[problem_id]
 
@@ -187,7 +187,7 @@ class ProblemSetProgress(models.Model):
         total_score = 0
 
         for psp in problemset_problems:
-            problem_id = str(psp.problem.id)
+            problem_id = str(psp.problem_id)
             if problem_id in self.progress_detail:
                 problem_progress = self.progress_detail[problem_id]
                 completed_count += 1

problemset/serializers.py

@@ -183,16 +183,18 @@ class ProblemSetProblemSerializer(serializers.ModelSerializer):
     def get_is_completed(self, obj):
         """获取当前用户是否已完成该题目"""
         request = self.context.get("request")
-        if request and request.user.is_authenticated:
+        if not (request and request.user.is_authenticated):
+            return False
+        # 优先使用 view 层预取的进度对象，避免 N+1
+        progress = self.context.get("user_progress")
+        if progress is None:
             try:
                 progress = ProblemSetProgress.objects.get(
                     problemset=obj.problemset, user=request.user
                 )
-                problem_id = str(obj.problem.id)
-                return problem_id in progress.progress_detail
             except ProblemSetProgress.DoesNotExist:
                 return False
-        return False
+        return str(obj.problem.id) in progress.progress_detail
 
 
 class AddProblemToSetSerializer(serializers.Serializer):

problemset/views/oj.py

@@ -137,11 +137,23 @@ class ProblemSetProblemAPI(APIView):
         except ProblemSet.DoesNotExist:
             return self.error("题单不存在")
 
-        problems = ProblemSetProblem.objects.filter(problemset=problem_set).order_by(
-            "order"
+        problems = (
+            ProblemSetProblem.objects.filter(problemset=problem_set)
+            .select_related("problem__created_by")
+            .prefetch_related("problem__tags")
+            .order_by("order")
         )
+        # 预取当前用户的题单进度，供 get_is_completed 使用，避免 N+1
+        user_progress = None
+        if request.user.is_authenticated:
+            try:
+                user_progress = ProblemSetProgress.objects.get(
+                    problemset=problem_set, user=request.user
+                )
+            except ProblemSetProgress.DoesNotExist:
+                pass
         serializer = ProblemSetProblemSerializer(
-            problems, many=True, context={"request": request}
+            problems, many=True, context={"request": request, "user_progress": user_progress}
         )
         return self.success(serializer.data)