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| author | Mike Bayer <mike_mp@zzzcomputing.com> | 2021-05-12 09:26:03 -0400 |
|---|---|---|
| committer | Mike Bayer <mike_mp@zzzcomputing.com> | 2021-05-12 09:26:03 -0400 |
| commit | 71a858817cb8c11451ae577c61329f4239fab46b (patch) | |
| tree | 14fcd7fa0facf6f772280e0aea42d7124aeca509 /lib/sqlalchemy/orm/unitofwork.py | |
| parent | f6329060f1b2f5631deac3ca877c2ae19e3e6f36 (diff) | |
| download | sqlalchemy-71a858817cb8c11451ae577c61329f4239fab46b.tar.gz | |
Create new event for collection add w/o mutation
Fixed issue when using :paramref:`_orm.relationship.cascade_backrefs`
parameter set to ``False``, which per :ref:`change_5150` is set to become
the standard behavior in SQLAlchemy 2.0, where adding the item to a
collection that uniquifies, such as ``set`` or ``dict`` would fail to fire
a cascade event if the object were already associated in that collection
via the backref. This fix represents a fundamental change in the collection
mechanics by introducing a new event state which can fire off for a
collection mutation even if there is no net change on the collection; the
action is now suited using a new event hook
:meth:`_orm.AttributeEvents.append_wo_mutation`.
Fixes: #6471
Change-Id: Ic50413f7e62440dad33ab84838098ea62ff4e815
Diffstat (limited to 'lib/sqlalchemy/orm/unitofwork.py')
| -rw-r--r-- | lib/sqlalchemy/orm/unitofwork.py | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/lib/sqlalchemy/orm/unitofwork.py b/lib/sqlalchemy/orm/unitofwork.py index 77bbb4751..ae99da059 100644 --- a/lib/sqlalchemy/orm/unitofwork.py +++ b/lib/sqlalchemy/orm/unitofwork.py @@ -144,6 +144,7 @@ def track_cascade_events(descriptor, prop): sess.expunge(oldvalue) return newvalue + event.listen(descriptor, "append_wo_mutation", append, raw=True) event.listen(descriptor, "append", append, raw=True, retval=True) event.listen(descriptor, "remove", remove, raw=True, retval=True) event.listen(descriptor, "set", set_, raw=True, retval=True) |