optimize db queries on /api/back/establishments/employees

apps/establishment/models.py

@@ -1063,6 +1063,15 @@ class EmployeeQuerySet(models.QuerySet):
     def with_extended_related(self):
         return self.prefetch_related('establishments')
 
+    def with_back_office_related(self):
+        return self.prefetch_related(
+            Prefetch('establishmentemployee_set',
+                     queryset=EstablishmentEmployee.objects.actual()
+                     .prefetch_related('establishment', 'position').order_by('-from_date'),
+                     to_attr='prefetched_establishment_employee'),
+            'awards'
+        )
+
 
 class Employee(BaseAttributes):
     """Employee model."""

apps/establishment/serializers/back.py

@@ -247,12 +247,18 @@ class EmployeeBackSerializers(serializers.ModelSerializer):
 
     def get_public_mark(self, obj):
         """Get last list actual public_mark"""
+        if hasattr(obj, 'prefetched_establishment_employee'):
+            return obj.prefetched_establishment_employee[0].establishment.public_mark if len(
+                obj.prefetched_establishment_employee) else None
         qs = self.get_qs(obj)
         if qs:
             return qs.public_mark
         return None
 
     def get_toque_number(self, obj):
+        if hasattr(obj, 'prefetched_establishment_employee'):
+            return obj.prefetched_establishment_employee[0].establishment.toque_number if len(
+                obj.prefetched_establishment_employee) else None
         qs = self.get_qs(obj)
         if qs:
             return qs.toque_number
@@ -260,6 +266,11 @@ class EmployeeBackSerializers(serializers.ModelSerializer):
 
     def get_positions(self, obj):
         """Get last list actual positions"""
+        if hasattr(obj, 'prefetched_establishment_employee'):
+            if not len(obj.prefetched_establishment_employee):
+                return []
+            return [PositionBackSerializer(ee.position).data for ee in obj.prefetched_establishment_employee]
+
         est_id = self.get_qs(obj)
 
         if not est_id:
@@ -275,6 +286,11 @@ class EmployeeBackSerializers(serializers.ModelSerializer):
 
     def get_establishment(self, obj):
         """Get last actual establishment"""
+        if hasattr(obj, 'prefetched_establishment_employee'):
+            return {
+                'id': obj.prefetched_establishment_employee[0].establishment.pk,
+                'slug': obj.prefetched_establishment_employee[0].establishment.slug,
+            } if len(obj.prefetched_establishment_employee) else None
         est = self.get_qs(obj)
 
         if not est:

apps/establishment/views/back.py

@@ -174,21 +174,14 @@ class EmployeeListCreateView(generics.ListCreateAPIView):
     permission_classes = (permissions.AllowAny,)
     filter_class = filters.EmployeeBackFilter
     serializer_class = serializers.EmployeeBackSerializers
-    queryset = models.Employee.objects.all().prefetch_related(
+    queryset = models.Employee.objects.all().with_back_office_related()
-        'establishmentemployee_set',
-        'establishmentemployee_set__establishment',
-        'awards',
-    )
 
 
 class EmployeesListSearchViews(generics.ListAPIView):
     """Employee search view"""
     pagination_class = None
     permission_classes = (permissions.AllowAny,)
-    queryset = models.Employee.objects.all().prefetch_related(
+    queryset = models.Employee.objects.all().with_back_office_related().select_related('photo')
-        'establishmentemployee_set',
-        'establishmentemployee_set__establishment',
-    ).select_related('photo')
     filter_class = filters.EmployeeBackSearchFilter
     serializer_class = serializers.EmployeeBackSerializers
 
@@ -207,7 +200,7 @@ class EstablishmentEmployeeListView(generics.ListCreateAPIView):
 class EmployeeRUDView(generics.RetrieveUpdateDestroyAPIView):
     """Employee RUD view."""
     serializer_class = serializers.EmployeeBackSerializers
-    queryset = models.Employee.objects.all()
+    queryset = models.Employee.objects.all().with_back_office_related()
 
 
 class EstablishmentTypeListCreateView(generics.ListCreateAPIView):