queryset-refactor: Added an order_by parameter to extra(). Refs #2076.

git-svn-id: http://code.djangoproject.com/svn/django/branches/queryset-refactor@6511 bcc190cf-cafb-0310-a4f2-bffc1f526a37

django/db/models/query.py

@@ -313,11 +313,10 @@ class _QuerySet(object):
         obj.query.distinct = true_or_false
         return obj
 
-    def extra(self, select=None, where=None, params=None, tables=None):
+    def extra(self, select=None, where=None, params=None, tables=None,
+            order_by=None):
         """
-        Add extra SQL fragments to the query. These are applied more or less
-        verbatim (no quoting, no alias renaming, etc), so care should be taken
-        when using extra() with other complex filters and combinations.
+        Add extra SQL fragments to the query.
         """
         assert self.query.can_filter(), \
                 "Cannot change a query once a slice has been taken"
@@ -330,6 +329,8 @@ class _QuerySet(object):
             clone.query.extra_params.extend(params)
         if tables:
             clone.query.extra_tables.extend(tables)
+        if order_by:
+            clone.query.extra_order_by.extend(order_by)
         return clone
 
     ###################

django/db/models/sql/query.py

@@ -378,9 +378,14 @@ class Query(object):
         for alias in self.tables:
             if not self.alias_map[alias][ALIAS_REFCOUNT]:
                 continue
-            name, alias, join_type, lhs, lhs_col, col = \
-                    self.alias_map[alias][ALIAS_JOIN]
-            alias_str = (alias != name and ' AS %s' % alias or '')
+            join = self.alias_map[alias][ALIAS_JOIN]
+            if join:
+                name, alias, join_type, lhs, lhs_col, col = join
+                alias_str = (alias != name and ' AS %s' % alias or '')
+            else:
+                join_type = None
+                alias_str = ''
+                name = alias
             if join_type:
                 result.append('%s %s%s ON (%s.%s = %s.%s)'
                         % (join_type, qn(name), alias_str, qn(lhs),
@@ -464,8 +469,8 @@ class Query(object):
 
     def find_ordering_name(self, name, opts, alias=None, default_order='ASC'):
         """
-        Returns the table alias (the name might not be unambiguous, the alias
-        will be) and column name for ordering by the given 'name' parameter.
+        Returns the table alias (the name might be ambiguous, the alias will
+        not be) and column name for ordering by the given 'name' parameter.
         The 'name' is of the form 'field1__field2__...__fieldN'.
         """
         name, order = get_order_dir(name, default_order)

tests/regressiontests/queries/models.py

@@ -289,6 +289,11 @@ Bug #2076
 >>> Author.objects.order_by('extra', '-name')
 [<Author: a2>, <Author: a1>, <Author: a4>, <Author: a3>]
 
+# Using remote model default ordering can span multiple models (in this case,
+# Cover is ordered by Item's default, which uses Note's default).
+>>> Cover.objects.all()
+[<Cover: first>, <Cover: second>]
+
 # If the remote model does not have a default ordering, we order by its 'id'
 # field.
 >>> Item.objects.order_by('creator', 'name')
@@ -300,8 +305,10 @@ Bug #2076
 >>> Ranking.objects.all().order_by('rank')
 [<Ranking: 1: a3>, <Ranking: 2: a2>, <Ranking: 3: a1>]
 
->>> Cover.objects.all()
-[<Cover: first>, <Cover: second>]
+# Ordering of extra() pieces is possible, too and you can mix extra fields and
+# model fields in the ordering.
+>>> Ranking.objects.extra(tables=['django_site'], order_by=['-django_site.id', 'rank'])
+[<Ranking: 1: a3>, <Ranking: 2: a2>, <Ranking: 3: a1>]
 
 Bugs #2874, #3002
 >>> qs = Item.objects.select_related().order_by('note__note', 'name')