Solve n+1 problem while getting orders list of a user

backend/api/orders_serializers.py

@@ -1,6 +1,7 @@
 import json
 import re
 
+from django.db.models import Prefetch
 from rest_framework import serializers
 
 from .products_serializers import ProductPresentSerializer
@@ -92,24 +93,17 @@ class Meta:
         )
         model = Order
 
-    # TODO: commented code doesn't reduce DB hits
     @classmethod
     def setup_eager_loading(cls, queryset):
         """Perform necessary eager loading of orders data."""
-        return queryset.select_related("user")
-        # ).prefetch_related(
-        #     Prefetch(
-        #         "products",
-        #         queryset=Product.objects.select_related(
-        #             "category", "subcategory", "producer"
-        #         ).prefetch_related(
-        #             "components",
-        #             "tags",
-        #             "promotions",
-        #             "reviews",
-        #         ),
-        #     )
-        # )
+        return queryset.select_related("user").prefetch_related(
+            Prefetch(
+                "orders",
+                queryset=OrderProduct.objects.select_related(
+                    "product__category"
+                ).prefetch_related("product__promotions"),
+            )
+        )
 
 
 class OrderGetAnonSerializer(serializers.ModelSerializer):

backend/api/orders_views.py

@@ -273,7 +273,6 @@ def retrieve(self, request, **kwargs):
     def list(self, request, **kwargs):
         if self.request.user.is_authenticated:
             queryset = self.get_queryset().filter(user=self.request.user)
-            # TODO: need to solve n+1 problem
             serializer = self.get_serializer(queryset, many=True)
             logger.info("The user's order list was successfully received.")
             return Response(serializer.data, status=status.HTTP_200_OK)