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
(cherry picked from commit 0e4c4d7efc)
Mike Bayer
a6387b0df8