Fixed #14707 -- Relax the protections on aggregate naming collisions when a ValuesQuerySet removes the colliding name. Thanks to Andy McKay for the report.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@15223 bcc190cf-cafb-0310-a4f2-bffc1f526a37

django/db/models/query.py

@@ -620,18 +620,19 @@ class QuerySet(object):
         """
         for arg in args:
             if arg.default_alias in kwargs:
-                raise ValueError("The %s named annotation conflicts with the "
+                raise ValueError("The named annotation '%s' conflicts with the "
                                  "default name for another annotation."
                                  % arg.default_alias)
             kwargs[arg.default_alias] = arg
 
+        names = getattr(self, '_fields', None)
+        if names is None:
             names = set(self.model._meta.get_all_field_names())
         for aggregate in kwargs:
             if aggregate in names:
-                raise ValueError("The %s annotation conflicts with a field on "
+                raise ValueError("The annotation '%s' conflicts with a field on "
                     "the model." % aggregate)
 
-
         obj = self._clone()
 
         obj._setup_aggregate_query(kwargs.keys())

tests/regressiontests/aggregation_regress/tests.py

@@ -474,6 +474,28 @@ class AggregationTests(TestCase):
         # Regression for #11256 - providing an aggregate name that conflicts with an m2m name on the model raises ValueError
         self.assertRaises(ValueError, Author.objects.annotate, friends=Count('friends'))
 
+    def test_values_queryset_non_conflict(self):
+        # Regression for #14707 -- If you're using a values query set, some potential conflicts are avoided.
+
+        # age is a field on Author, so it shouldn't be allowed as an aggregate.
+        # But age isn't included in the ValuesQuerySet, so it is.
+        results = Author.objects.values('name').annotate(age=Count('book_contact_set'))
+        self.assertEquals(len(results), 9)
+        self.assertEquals(results[0]['name'], u'Adrian Holovaty')
+        self.assertEquals(results[0]['age'], 1)
+
+        # Same problem, but aggregating over m2m fields
+        results = Author.objects.values('name').annotate(age=Avg('friends__age'))
+        self.assertEquals(len(results), 9)
+        self.assertEquals(results[0]['name'], u'Adrian Holovaty')
+        self.assertEquals(results[0]['age'], 32.0)
+
+        # Same problem, but colliding with an m2m field
+        results = Author.objects.values('name').annotate(friends=Count('friends'))
+        self.assertEquals(len(results), 9)
+        self.assertEquals(results[0]['name'], u'Adrian Holovaty')
+        self.assertEquals(results[0]['friends'], 2)
+
     def test_reverse_relation_name_conflict(self):
         # Regression for #11256 - providing an aggregate name that conflicts with a reverse-related name on the model raises ValueError
         self.assertRaises(ValueError, Author.objects.annotate, book_contact_set=Avg('friends__age'))