- Fixed bug in :meth:`.Update.return_defaults` which would cause all

insert-default holding columns not otherwise included in the SET
clause (such as primary key cols) to get rendered into the RETURNING
even though this is an UPDATE.

- Major fixes to the :paramref:`.Mapper.eager_defaults` flag, this
flag would not be honored correctly in the case that multiple
UPDATE statements were to be emitted, either as part of a flush
or a bulk update operation.  Additionally, RETURNING
would be emitted unnecessarily within update statements.

fixes #3609

1 files changed, 13 insertions, 1 deletions

diff --git a/lib/sqlalchemy/orm/mapper.py b/lib/sqlalchemy/orm/mapper.py
index 5ade4b966..95aa14a26 100644
--- a/lib/sqlalchemy/orm/mapper.py
+++ b/lib/sqlalchemy/orm/mapper.py
@@ -1970,12 +1970,24 @@ class Mapper(InspectionAttr):
             (
                 table,
                 frozenset([
-                    col for col in columns
+                    col.key for col in columns
                     if col.server_default is not None])
             )
             for table, columns in self._cols_by_table.items()
         )
 
+    @_memoized_configured_property
+    def _server_onupdate_default_cols(self):
+        return dict(
+            (
+                table,
+                frozenset([
+                    col.key for col in columns
+                    if col.server_onupdate is not None])
+            )
+            for table, columns in self._cols_by_table.items()
+        )
+
     @property
     def selectable(self):
         """The :func:`.select` construct this :class:`.Mapper` selects from