From 365db5970268fb007af832812bb519256c3858ba Mon Sep 17 00:00:00 2001
From: Szabo Zoltan <szabozoltan69@gmail.com>
Date: Fri, 12 Jun 2026 11:21:00 +0200
Subject: [PATCH] Fix per-assesment n+1 query issue

---
 per/drf_views.py   | 34 ++++++++++++++++++++++++++++++++--
 per/serializers.py |  7 +++++++
 2 files changed, 39 insertions(+), 2 deletions(-)

diff --git a/per/drf_views.py b/per/drf_views.py
index 003d9a55a..b60736383 100644
--- a/per/drf_views.py
+++ b/per/drf_views.py
@@ -690,7 +690,22 @@ class FormAssessmentViewSet(viewsets.ModelViewSet):
     ordering_fields = "__all__"
 
     def get_queryset(self):
-        return PerAssessment.objects.select_related("overview")
+        return PerAssessment.objects.select_related("overview", "overview__country").prefetch_related(
+            Prefetch(
+                "area_responses",
+                queryset=AreaResponse.objects.select_related("area").prefetch_related(
+                    Prefetch(
+                        "component_response",
+                        queryset=FormComponentResponse.objects.select_related("component", "rating").prefetch_related(
+                            Prefetch(
+                                "question_responses",
+                                queryset=FormComponentQuestionAndAnswer.objects.select_related("question"),
+                            )
+                        ),
+                    )
+                ),
+            )
+        )
 
 
 class PublicFormAssessmentViewSet(viewsets.ReadOnlyModelViewSet):
@@ -698,7 +713,22 @@ class PublicFormAssessmentViewSet(viewsets.ReadOnlyModelViewSet):
     ordering_fields = "__all__"
 
     def get_queryset(self):
-        return PerAssessment.objects.select_related("overview")
+        return PerAssessment.objects.select_related("overview", "overview__country").prefetch_related(
+            Prefetch(
+                "area_responses",
+                queryset=AreaResponse.objects.select_related("area").prefetch_related(
+                    Prefetch(
+                        "component_response",
+                        queryset=FormComponentResponse.objects.select_related("component", "rating").prefetch_related(
+                            Prefetch(
+                                "question_responses",
+                                queryset=FormComponentQuestionAndAnswer.objects.select_related("question"),
+                            )
+                        ),
+                    )
+                ),
+            )
+        )
 
 
 # Consolidated public endpoints (map-data, assessments-processed, dashboard-data)
diff --git a/per/serializers.py b/per/serializers.py
index 92200e664..cb2882110 100644
--- a/per/serializers.py
+++ b/per/serializers.py
@@ -811,6 +811,13 @@ class PerAssessmentSerializer(
 ):
     area_responses = AreaResponseSerializer(many=True, required=False)
 
+    def __init__(self, *args, **kwargs):
+        super().__init__(*args, **kwargs)
+        overview_field = self.fields.get("overview")
+        if overview_field is not None and hasattr(overview_field, "queryset"):
+            # Avoid N+1 in overview choice labels, since Overview.__str__ touches country.
+            overview_field.queryset = Overview.objects.select_related("country")
+
     class Meta:
         model = PerAssessment
         fields = "__all__"