From: Mike Bayer <mike_mp@zzzcomputing.com>
Date: Wed, 8 Jun 2022 15:54:46 +0000 (-0400)
Subject: add note re: pickling for loader criteria
X-Git-Tag: rel_2_0_0b1~260
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=258d07e478eab9ee385f36a5c5fd56c56bf7dfea;p=thirdparty%2Fsqlalchemy%2Fsqlalchemy.git

add note re: pickling for loader criteria

Change-Id: I75992af71ba08799a03995178a6e4612c9a7428a
References: #8108
---

diff --git a/lib/sqlalchemy/orm/_orm_constructors.py b/lib/sqlalchemy/orm/_orm_constructors.py
index e682828650..6ef0a647f2 100644
--- a/lib/sqlalchemy/orm/_orm_constructors.py
+++ b/lib/sqlalchemy/orm/_orm_constructors.py
@@ -724,11 +724,19 @@ def with_loader_criteria(
      accepts a target class as an argument, when the given class is
      a base with many different mapped subclasses.
 
+     .. note:: when the SQL expression is a lambda, **pickling is not
+        supported**.  Set
+        :paramref:`_orm.with_loader_criteria.propagate_to_loaders`
+        to ``False`` to prevent the object from being applied to instances.
+
     :param include_aliases: if True, apply the rule to :func:`_orm.aliased`
      constructs as well.
 
     :param propagate_to_loaders: defaults to True, apply to relationship
-     loaders such as lazy loaders.
+     loaders such as lazy loaders.   This indicates that the
+     option object itself including SQL expression is carried along with
+     each loaded instance.  Set to ``False`` to prevent the object from
+     being assigned to individual instances.
 
 
      .. seealso::