fixes issues with patient annotate + distinct not implemented for csv…

… export (#1999)

* fixes issues with annotate + distinct not implemented for csv export

* fixes #1998

* fix typo

care/facility/api/viewsets/patient.py

@@ -406,6 +406,14 @@ def get_serializer_class(self):
         else:
             return self.serializer_class
 
+    def filter_queryset(self, queryset: QuerySet) -> QuerySet:
+        if self.action == "list" and settings.CSV_REQUEST_PARAMETER in self.request.GET:
+            for backend in (PatientDRYFilter, filters.DjangoFilterBackend):
+                queryset = backend().filter_queryset(self.request, queryset, self)
+            return queryset.filter(last_consultation__discharge_date__isnull=True)
+
+        return super().filter_queryset(queryset)
+
     def list(self, request, *args, **kwargs):
         """
         Patient List