fix: Fix time filtering of relationships on MySQL

Resolves #31

people/views/network.py

@@ -2,15 +2,18 @@
 Views for displaying networks of :class:`People` and :class:`Relationship`s.
 """
 
+import logging
+
 from django.contrib.auth.mixins import LoginRequiredMixin
 from django.db.models import Q
 from django.forms import ValidationError
 from django.utils import timezone
 from django.views.generic import FormView
 
-
 from people import forms, models, serializers
 
+logger = logging.getLogger(__name__)  # pylint: disable=invalid-name
+
 
 class NetworkView(LoginRequiredMixin, FormView):
     """
@@ -47,35 +50,45 @@ class NetworkView(LoginRequiredMixin, FormView):
         if not at_date:
             at_date = timezone.now().date()
 
+        # Filter on timestamp__date doesn't seem to work on MySQL
+        # To compare datetimes we need at_date to be midnight at
+        # the *end* of the day in question - so add one day here
+        at_date += timezone.timedelta(days=1)
+
         relationship_answerset_set = models.RelationshipAnswerSet.objects.filter(
-            Q(replaced_timestamp__date__gte=at_date) | Q(replaced_timestamp__isnull=True),
-            timestamp__date__lte=at_date
-        )
+            Q(replaced_timestamp__gte=at_date)
+            | Q(replaced_timestamp__isnull=True),
+            timestamp__lte=at_date)
+
+        logger.info('Found %d relationship answer sets for %s',
+                    relationship_answerset_set.count(), at_date)
 
         # Filter answers to relationship questions
         for field, values in form.cleaned_data.items():
             if field.startswith('question_') and values:
                 relationship_answerset_set = relationship_answerset_set.filter(
-                    question_answers__in=values
-                )
+                    question_answers__in=values)
+
+        logger.info('Found %d relationship answer sets matching filters',
+                    relationship_answerset_set.count())
 
         context['person_set'] = serializers.PersonSerializer(
-            models.Person.objects.all(),
-            many=True
-        ).data
+            models.Person.objects.all(), many=True).data
 
         context['relationship_set'] = serializers.RelationshipSerializer(
             models.Relationship.objects.filter(
-                pk__in=relationship_answerset_set.values_list('relationship', flat=True)
-            ),
-            many=True
-        ).data
+                pk__in=relationship_answerset_set.values_list('relationship',
+                                                              flat=True)),
+            many=True).data
+
+        logger.info('Found %d distinct relationships matching filters',
+                    len(context['relationship_set']))
 
         return context
 
     def form_valid(self, form):
         try:
             return self.render_to_response(self.get_context_data())
-        
+
         except ValidationError:
             return self.form_invalid(form)