From: Mike Bayer <mike_mp@zzzcomputing.com>
Date: Tue, 2 Jan 2024 16:36:20 +0000 (-0500)
Subject: force uselist=False for all collection class not present
X-Git-Tag: rel_2_0_25~9
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=2ce6010c924e963dcd9245b99e583611be5fb061;p=thirdparty%2Fsqlalchemy%2Fsqlalchemy.git

force uselist=False for all collection class not present

Fixed issue where ORM Annotated Declarative would mis-interpret the left
hand side of a relationship without any collection specified as
uselist=True if the left type were given as a class and not a string,
without using future-style annotations.

Fixes: #10815
Change-Id: I85daccec03f7e6ea3b49eb07c06e0f85e361a1c0
(cherry picked from commit c1139c2e5d2f14738798d3c0deb876286014c808)
---

diff --git a/doc/build/changelog/unreleased_20/10815.rst b/doc/build/changelog/unreleased_20/10815.rst
new file mode 100644
index 0000000000..2240764aeb
--- /dev/null
+++ b/doc/build/changelog/unreleased_20/10815.rst
@@ -0,0 +1,8 @@
+.. change::
+    :tags: bug, orm
+    :tickets: 10815
+
+    Fixed issue where ORM Annotated Declarative would mis-interpret the left
+    hand side of a relationship without any collection specified as
+    uselist=True if the left type were given as a class and not a string,
+    without using future-style annotations.
diff --git a/lib/sqlalchemy/orm/relationships.py b/lib/sqlalchemy/orm/relationships.py
index b19d23b277..bcdd79cb75 100644
--- a/lib/sqlalchemy/orm/relationships.py
+++ b/lib/sqlalchemy/orm/relationships.py
@@ -1814,15 +1814,12 @@ class RelationshipProperty(
                 argument, originating_module
             )
 
-            # we don't allow the collection class to be a
-            # __forward_arg__ right now, so if we see a forward arg here,
-            # we know there was no collection class either
-            if (
-                self.collection_class is None
-                and not is_write_only
-                and not is_dynamic
-            ):
-                self.uselist = False
+        if (
+            self.collection_class is None
+            and not is_write_only
+            and not is_dynamic
+        ):
+            self.uselist = False
 
         # ticket #8759
         # if a lead argument was given to relationship(), like
diff --git a/test/orm/declarative/test_tm_future_annotations_sync.py b/test/orm/declarative/test_tm_future_annotations_sync.py
index e64834b39d..e2a442767a 100644
--- a/test/orm/declarative/test_tm_future_annotations_sync.py
+++ b/test/orm/declarative/test_tm_future_annotations_sync.py
@@ -2750,7 +2750,7 @@ class RelationshipLHSTest(fixtures.TestBase, testing.AssertsCompiledSQL):
         is_false(B.__mapper__.attrs["a"].uselist)
         is_false(B.__mapper__.attrs["a_warg"].uselist)
 
-    def test_one_to_one_example(self, decl_base: Type[DeclarativeBase]):
+    def test_one_to_one_example_quoted(self, decl_base: Type[DeclarativeBase]):
         """test example in the relationship docs will derive uselist=False
         correctly"""
 
@@ -2774,6 +2774,32 @@ class RelationshipLHSTest(fixtures.TestBase, testing.AssertsCompiledSQL):
         is_(p1.child, c1)
         is_(c1.parent, p1)
 
+    def test_one_to_one_example_non_quoted(
+        self, decl_base: Type[DeclarativeBase]
+    ):
+        """test example in the relationship docs will derive uselist=False
+        correctly"""
+
+        class Child(decl_base):
+            __tablename__ = "child"
+
+            id: Mapped[int] = mapped_column(primary_key=True)
+            parent_id: Mapped[int] = mapped_column(ForeignKey("parent.id"))
+            parent: Mapped["Parent"] = relationship(back_populates="child")
+
+        class Parent(decl_base):
+            __tablename__ = "parent"
+
+            id: Mapped[int] = mapped_column(primary_key=True)
+            child: Mapped[Child] = relationship(  # noqa: F821
+                back_populates="parent"
+            )
+
+        c1 = Child()
+        p1 = Parent(child=c1)
+        is_(p1.child, c1)
+        is_(c1.parent, p1)
+
     def test_collection_class_dict_no_collection(self, decl_base):
         class A(decl_base):
             __tablename__ = "a"
diff --git a/test/orm/declarative/test_typed_mapping.py b/test/orm/declarative/test_typed_mapping.py
index 44327324ca..0f1bb452d5 100644
--- a/test/orm/declarative/test_typed_mapping.py
+++ b/test/orm/declarative/test_typed_mapping.py
@@ -2741,7 +2741,7 @@ class RelationshipLHSTest(fixtures.TestBase, testing.AssertsCompiledSQL):
         is_false(B.__mapper__.attrs["a"].uselist)
         is_false(B.__mapper__.attrs["a_warg"].uselist)
 
-    def test_one_to_one_example(self, decl_base: Type[DeclarativeBase]):
+    def test_one_to_one_example_quoted(self, decl_base: Type[DeclarativeBase]):
         """test example in the relationship docs will derive uselist=False
         correctly"""
 
@@ -2765,6 +2765,32 @@ class RelationshipLHSTest(fixtures.TestBase, testing.AssertsCompiledSQL):
         is_(p1.child, c1)
         is_(c1.parent, p1)
 
+    def test_one_to_one_example_non_quoted(
+        self, decl_base: Type[DeclarativeBase]
+    ):
+        """test example in the relationship docs will derive uselist=False
+        correctly"""
+
+        class Child(decl_base):
+            __tablename__ = "child"
+
+            id: Mapped[int] = mapped_column(primary_key=True)
+            parent_id: Mapped[int] = mapped_column(ForeignKey("parent.id"))
+            parent: Mapped["Parent"] = relationship(back_populates="child")
+
+        class Parent(decl_base):
+            __tablename__ = "parent"
+
+            id: Mapped[int] = mapped_column(primary_key=True)
+            child: Mapped[Child] = relationship(  # noqa: F821
+                back_populates="parent"
+            )
+
+        c1 = Child()
+        p1 = Parent(child=c1)
+        is_(p1.child, c1)
+        is_(c1.parent, p1)
+
     def test_collection_class_dict_no_collection(self, decl_base):
         class A(decl_base):
             __tablename__ = "a"