"implicit combining column" warning not emitting for two columns from two different aliases against same parent table

Describe the bug

Description

The following code yields a strange result. I'm expecting bar_1, bar_2, and bar_3 to be mapped as CompositeBar(value_1="a", value_2="b"), CompositeBar(value_1="c", value_2="d"), and CompositeBar(value_1="e", value_2="f") respectively, but actually it ended up with every CompositeBar being CompositeBar(value_1="e", value_2="f") as if it got mapped to bar_alias_3 and the rest were ignored.

BTW the reason why I didn't use relationships here is that the actual code I'm working on has more complex mappings like the composite instance gets mapped to both the table that corresponds to the containing class, and the table that it refers to.

Optional link from https://docs.sqlalchemy.org which documents the behavior that is expected

No response

SQLAlchemy Version in Use

2.0.25

DBAPI (i.e. the database driver)

sqlite3 module

Database Vendor and Major Version

SQLite 2.6.0

Python Version

3.8.16

Operating system

macOS

To Reproduce

import dataclasses

import sqlalchemy as sa
from sqlalchemy import orm


class Base(orm.MappedAsDataclass, orm.DeclarativeBase):
    pass


class Bar(Base):
    __tablename__ = "bar"

    id: orm.Mapped[int] = sa.Column(sa.Integer, primary_key=True)
    value_1: orm.Mapped[str] = sa.Column(sa.String, nullable=False)
    value_2: orm.Mapped[str] = sa.Column(sa.String, nullable=False)


@dataclasses.dataclass
class CompositeBar:
    value_1: str
    value_2: str


foo_table = sa.Table(
    "foo",
    Base.metadata,
    sa.Column("id", sa.Integer, primary_key=True),
    sa.Column("bar_1_id", sa.Integer, sa.ForeignKey(Bar.id), nullable=False),
    sa.Column("bar_2_id", sa.Integer, sa.ForeignKey(Bar.id), nullable=False),
    sa.Column("bar_3_id", sa.Integer, sa.ForeignKey(Bar.id), nullable=False),
)
bar_alias_1 = orm.aliased(Bar)
bar_alias_2 = orm.aliased(Bar)
bar_alias_3 = orm.aliased(Bar)


class Foo(Base):
    __table__ = foo_table.outerjoin(
        bar_alias_1,
        foo_table.c.bar_1_id == bar_alias_1.id
    ).outerjoin(
        bar_alias_2,
        foo_table.c.bar_2_id == bar_alias_2.id
    ).outerjoin(
        bar_alias_3,
        foo_table.c.bar_3_id == bar_alias_3.id
    )

    id: orm.Mapped[int] = orm.column_property(foo_table.c.id)
    _bar_1_id: orm.Mapped[int] = orm.column_property(foo_table.c.bar_1_id, bar_alias_1.id)
    _bar_2_id: orm.Mapped[int] = orm.column_property(foo_table.c.bar_2_id, bar_alias_2.id)
    _bar_3_id: orm.Mapped[int] = orm.column_property(foo_table.c.bar_3_id, bar_alias_3.id)
    bar_1: orm.Mapped[CompositeBar] = orm.composite(CompositeBar, bar_alias_1.value_1, bar_alias_1.value_2)
    bar_2: orm.Mapped[CompositeBar] = orm.composite(CompositeBar, bar_alias_2.value_1, bar_alias_2.value_2)
    bar_3: orm.Mapped[CompositeBar] = orm.composite(CompositeBar, bar_alias_3.value_1, bar_alias_3.value_2)


engine = sa.create_engine("sqlite:///")
Base.metadata.create_all(bind=engine)

with orm.Session(bind=engine) as session:
    bar_1 = Bar(id=1, value_1="a", value_2="b")
    bar_2 = Bar(id=2, value_1="c", value_2="d")
    bar_3 = Bar(id=3, value_1="e", value_2="f")
    session.add_all([bar_1, bar_2, bar_3])
    session.flush()
    session.execute(sa.insert(foo_table).values([{"id": 1, "bar_1_id": bar_1.id, "bar_2_id": bar_2.id, "bar_3_id": bar_3.id}]))
    foo = session.execute(sa.select(Foo).where(Foo.id == 1)).scalar()
    print(foo)

Error

Actual result:

Foo(id=1, _bar_1_id=1, _bar_2_id=2, _bar_3_id=3, bar_1=CompositeBar(value_1='e', value_2='f'), bar_2=CompositeBar(value_1='e', value_2='f'), bar_3=CompositeBar(value_1='e', value_2='f'))

Expected:

Foo(id=1, _bar_1_id=1, _bar_2_id=2, _bar_3_id=3, bar_1=CompositeBar(value_1='a', value_2='b'), bar_2=CompositeBar(value_1='c', value_2='d'), bar_3=CompositeBar(value_1='e', value_2='f'))

Additional context

No response

Start by running the supplied Python reproduction with SQLite, then trace the SQLAlchemy ORM mappings using orm.composite, column_property, and the three aliased Bar objects. No repository files or tests are named in the issue. Done when the three composite values match the expected output and the implicit combining-column warning behavior is corrected.