Fixed #10666 -- Corrected the handling of inherited fields with aggregate() and annotate(). Thanks to julienb for the report.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@10446 bcc190cf-cafb-0310-a4f2-bffc1f526a37

django/db/models/sql/query.py

@@ -1403,8 +1403,17 @@ class BaseQuery(object):
             field_name = field_list[0]
             col = field_name
             source = self.aggregates[field_name]
-        elif (len(field_list) > 1 or
-            field_list[0] not in [i.name for i in opts.fields]):
+        elif ((len(field_list) > 1) or
+            (field_list[0] not in [i.name for i in opts.fields]) or
+            self.group_by is None or
+            not is_summary):
+            # If:
+            #   - the field descriptor has more than one part (foo__bar), or
+            #   - the field descriptor is referencing an m2m/m2o field, or
+            #   - this is a reference to a model field (possibly inherited), or
+            #   - this is an annotation over a model field
+            # then we need to explore the joins that are required.
+
             field, source, opts, join_list, last, _ = self.setup_joins(
                 field_list, opts, self.get_initial_alias(), False)
 
@@ -1419,15 +1428,11 @@ class BaseQuery(object):
 
             col = (join_list[-1], col)
         else:
-            # Aggregate references a normal field
+            # The simplest cases. No joins required -
+            # just reference the provided column alias.
             field_name = field_list[0]
             source = opts.get_field(field_name)
-            if not (self.group_by is not None and is_summary):
-                # Only use a column alias if this is a
-                # standalone aggregate, or an annotation
-                col = (opts.db_table, source.column)
-            else:
-                col = field_name
+            col = field_name
 
         # Add the aggregate to the query
         alias = truncate_name(alias, self.connection.ops.max_name_length())
@@ -1659,7 +1664,6 @@ class BaseQuery(object):
             last.append(len(joins))
             if name == 'pk':
                 name = opts.pk.name
-
             try:
                 field, model, direct, m2m = opts.get_field_by_name(name)
             except FieldDoesNotExist:

tests/regressiontests/aggregation_regress/fixtures/initial_data.json

@@ -239,5 +239,19 @@
             "friends": [8],
             "name": "Stuart Russell"
         }
+    },
+    {
+        "pk": 5,
+        "model": "aggregation_regress.hardbackbook",
+        "fields": {
+            "weight": 4.5
+        }
+    },
+    {
+        "pk": 6,
+        "model": "aggregation_regress.hardbackbook",
+        "fields": {
+            "weight": 3.7
+        }
     }
 ]

tests/regressiontests/aggregation_regress/models.py

@@ -58,6 +58,12 @@ class Clues(models.Model):
     EntryID = models.ForeignKey(Entries, verbose_name='Entry', db_column = 'Entry ID')
     Clue = models.CharField(max_length=150)
 
+class HardbackBook(Book):
+    weight = models.FloatField()
+
+    def __unicode__(self):
+        return "%s (hardback): %s" % (self.name, self.weight)
+
 __test__ = {'API_TESTS': """
 >>> from django.core import management
 >>> from django.db.models import get_app, F
@@ -137,17 +143,17 @@ __test__ = {'API_TESTS': """
 >>> Book.objects.all().aggregate(num_authors=Count('foo'))
 Traceback (most recent call last):
 ...
-FieldError: Cannot resolve keyword 'foo' into field. Choices are: authors, contact, id, isbn, name, pages, price, pubdate, publisher, rating, store
+FieldError: Cannot resolve keyword 'foo' into field. Choices are: authors, contact, hardbackbook, id, isbn, name, pages, price, pubdate, publisher, rating, store
 
 >>> Book.objects.all().annotate(num_authors=Count('foo'))
 Traceback (most recent call last):
 ...
-FieldError: Cannot resolve keyword 'foo' into field. Choices are: authors, contact, id, isbn, name, pages, price, pubdate, publisher, rating, store
+FieldError: Cannot resolve keyword 'foo' into field. Choices are: authors, contact, hardbackbook, id, isbn, name, pages, price, pubdate, publisher, rating, store
 
 >>> Book.objects.all().annotate(num_authors=Count('authors__id')).aggregate(Max('foo'))
 Traceback (most recent call last):
 ...
-FieldError: Cannot resolve keyword 'foo' into field. Choices are: authors, contact, id, isbn, name, pages, price, pubdate, publisher, rating, store, num_authors
+FieldError: Cannot resolve keyword 'foo' into field. Choices are: authors, contact, hardbackbook, id, isbn, name, pages, price, pubdate, publisher, rating, store, num_authors
 
 # Old-style count aggregations can be mixed with new-style
 >>> Book.objects.annotate(num_authors=Count('authors')).count()
@@ -276,6 +282,22 @@ FieldError: Cannot resolve keyword 'foo' into field. Choices are: authors, conta
 
 >>> publishers
 [<Publisher: Apress>, <Publisher: Sams>]
+
+
+# Regression for 10666 - inherited fields work with annotations and aggregations
+>>> HardbackBook.objects.aggregate(n_pages=Sum('book_ptr__pages'))
+{'n_pages': 2078}
+
+>>> HardbackBook.objects.aggregate(n_pages=Sum('pages'))
+{'n_pages': 2078}
+
+>>> HardbackBook.objects.annotate(n_authors=Count('book_ptr__authors')).values('name','n_authors')
+[{'n_authors': 2, 'name': u'Artificial Intelligence: A Modern Approach'}, {'n_authors': 1, 'name': u'Paradigms of Artificial Intelligence Programming: Case Studies in Common Lisp'}]
+
+>>> HardbackBook.objects.annotate(n_authors=Count('authors')).values('name','n_authors')
+[{'n_authors': 2, 'name': u'Artificial Intelligence: A Modern Approach'}, {'n_authors': 1, 'name': u'Paradigms of Artificial Intelligence Programming: Case Studies in Common Lisp'}]
+
+
 """
 }