Fixed #7105 -- Fixed dates() queries in light of model inheritance.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@7763 bcc190cf-cafb-0310-a4f2-bffc1f526a37

2 files changed, 6 insertions, 4 deletions

diff --git a/django/db/models/query.py b/django/db/models/query.py
index 2e9752288e..eff4c57a7c 100644
--- a/django/db/models/query.py
+++ b/django/db/models/query.py
@@ -688,7 +688,7 @@ class DateQuerySet(QuerySet):
         """
         self.query = self.query.clone(klass=sql.DateQuery, setup=True)
         self.query.select = []
-        self.query.add_date_select(self._field.column, self._kind, self._order)
+        self.query.add_date_select(self._field, self._kind, self._order)
         if self._field.null:
             self.query.add_filter(('%s__isnull' % self._field.name, False))
 
diff --git a/django/db/models/sql/subqueries.py b/django/db/models/sql/subqueries.py
index 28436abede..0bb741d706 100644
--- a/django/db/models/sql/subqueries.py
+++ b/django/db/models/sql/subqueries.py
@@ -357,12 +357,14 @@ class DateQuery(Query):
                     date = typecast_timestamp(str(date))
                 yield date
 
-    def add_date_select(self, column, lookup_type, order='ASC'):
+    def add_date_select(self, field, lookup_type, order='ASC'):
         """
         Converts the query into a date extraction query.
         """
-        alias = self.join((None, self.model._meta.db_table, None, None))
-        select = Date((alias, column), lookup_type,
+        result = self.setup_joins([field.name], self.get_meta(),
+                self.get_initial_alias(), False)
+        alias = result[3][-1]
+        select = Date((alias, field.column), lookup_type,
                 self.connection.ops.date_trunc_sql)
         self.select = [select]
         self.select_fields = [None]