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| author | Mike Bayer <mike_mp@zzzcomputing.com> | 2020-09-02 14:47:03 -0400 |
|---|---|---|
| committer | Mike Bayer <mike_mp@zzzcomputing.com> | 2020-09-02 14:56:49 -0400 |
| commit | b050169600019ef249a8b315e7435c752623c900 (patch) | |
| tree | 32a8be7337a59bb99e0ec7d639cefec36eea14ca /lib/sqlalchemy/orm | |
| parent | 7439697ca3c8b07af79de6a146a15c34fc85d9d6 (diff) | |
| download | sqlalchemy-b050169600019ef249a8b315e7435c752623c900.tar.gz | |
Add caveat re: with_expression and already-loaded object
Adds a test for the populate_existing() behavior as well.
Fixes: #5553
Change-Id: Ib0db6227c3fec7d0065f2a7caa36b3fd94ef14fd
Diffstat (limited to 'lib/sqlalchemy/orm')
| -rw-r--r-- | lib/sqlalchemy/orm/strategy_options.py | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/lib/sqlalchemy/orm/strategy_options.py b/lib/sqlalchemy/orm/strategy_options.py index 6c6f0307d..53350cb8e 100644 --- a/lib/sqlalchemy/orm/strategy_options.py +++ b/lib/sqlalchemy/orm/strategy_options.py @@ -1682,6 +1682,12 @@ def with_expression(loadopt, key, expression): :param expr: SQL expression to be applied to the attribute. + .. note:: the target attribute is populated only if the target object + is **not currently loaded** in the current :class:`_orm.Session` + unless the :meth:`_orm.Query.populate_existing` method is used. + Please refer to :ref:`mapper_querytime_expression` for complete + usage details. + .. seealso:: :ref:`mapper_querytime_expression` |