Fixed #19195 -- Allow explicit ordering by a relation `_id` field.

Thanks to chrisedgemon for the report and shaib, akaariai and
timgraham for the review.

1 files changed, 3 insertions, 2 deletions

diff --git a/django/db/models/sql/compiler.py b/django/db/models/sql/compiler.py
index 09b1f7d4d8..6792824ecd 100644
--- a/django/db/models/sql/compiler.py
+++ b/django/db/models/sql/compiler.py
@@ -464,8 +464,9 @@ class SQLCompiler(object):
         field, targets, alias, joins, path, opts = self._setup_joins(pieces, opts, alias)
 
         # If we get to this point and the field is a relation to another model,
-        # append the default ordering for that model.
-        if field.rel and path and opts.ordering:
+        # append the default ordering for that model unless the attribute name
+        # of the field is specified.
+        if field.rel and path and opts.ordering and name != field.attname:
             # Firstly, avoid infinite loops.
             if not already_seen:
                 already_seen = set()