handle non-mapped mixins for with_loader_criteria reduce

special handling is needed for a with_loader_criteria()
against a non-mapped mixin class.  added that to test
coverage

Fixes: #8109
Change-Id: Ia599361c8faab008e92095eb4607d02820f590d5

1 files changed, 10 insertions, 0 deletions

diff --git a/lib/sqlalchemy/testing/pickleable.py b/lib/sqlalchemy/testing/pickleable.py
index c14c681f6..4206e3041 100644
--- a/lib/sqlalchemy/testing/pickleable.py
+++ b/lib/sqlalchemy/testing/pickleable.py
@@ -14,6 +14,8 @@ unpickling.
 from __future__ import annotations
 
 from . import fixtures
+from ..schema import Column
+from ..types import String
 
 
 class User(fixtures.ComparableEntity):
@@ -55,6 +57,14 @@ class Screen:
         self.parent = parent
 
 
+class Mixin:
+    email_address = Column(String)
+
+
+class AddressWMixin(Mixin, fixtures.ComparableEntity):
+    pass
+
+
 class Foo:
     def __init__(self, moredata, stuff="im stuff"):
         self.data = "im data"