Django Rest Framework 预取数据

Question

我想尽量减少获取数据的查询数量。我有 3 个模型：

class SubCategory(models.Model):
    game = models.ForeignKey(Game, verbose_name=_("Gra"), on_delete=models.CASCADE)
    name = models.CharField(verbose_name=_("Nazwa"), max_length=40)
    ...

class GameTask(CloneModel):
    game = models.ForeignKey(Game, verbose_name='Gra', related_name='tasks', on_delete=models.CASCADE)
    name = models.CharField(verbose_name='Nazwa', max_length=200)
    subcategory = models.ForeignKey(SubCategory, verbose_name=_("Podkategoria"), on_delete=models.SET_NULL, blank=True, null=True)

class TaskLevel(CloneModel):
    name = models.CharField(max_length=50)
    master_task = models.ForeignKey(GameTask, related_name='sub_levels', on_delete=models.CASCADE)

我的子类别视图如下所示：

class SubCategoryList(ListAPIView, PermissionMixin):
    permission_classes = (permissions.IsAuthenticated,)
    serializer_class = SubCategorySerializer

    def get_queryset(self):
        return SubCategory.objects.filter(game=self.get_game()).order_by("slug")

和我的 SubCategorySerializer：

class SubCategorySerializer(serializers.ModelSerializer):
    developments = SubCategoryDevelopmentSerializer(many=True, read_only=True)
    in_progress = serializers.SerializerMethodField()

        class Meta:
        model = SubCategory
        fields = ("id", "name", "slug", "description", "image", "developments", "in_progress")

    def get_in_progress(self, obj: SubCategory):
        user = self.context["request"].user
        subcategory_tasks = obj.gametask_set.all()
        // rest of the logic

我想要实现的就是仅返回与 TaskLevel 模型相关的任务 master_task。我正在尝试使用

subcategory_tasks = obj.gametask_set.all().prefetch_related("sub_levels")

，但查询量是相同的。有人能给我任何提示如何解决这个问题吗？