typing-extensions 4.13.0 possibly breaks ORM declarative codepaths that are deprecated in 2.0 #12473
Description
Describe the bug
Defining a simple custom type with the type syntax (es. type MyType = Literal["test1", "test2"]) and using it within a declarative model within a Mapped (e.g. Mapped[MyType]) fails with typing-extensions 4.13.0
I raised the same issue on typing_extensions and it seems something that needs to be fixed on SQLAlchemy side (just like pydantic had to fix it)
python/typing_extensions#560
Optional link from https://docs.sqlalchemy.org which documents the behavior that is expected
No response
SQLAlchemy Version in Use
2.0.39
DBAPI (i.e. the database driver)
psycopg(3) (but shouldn't matter)
Database Vendor and Major Version
Postgres 13 (but shouldn't matter)
Python Version
3.12.9
Operating system
Linux (Ubuntu)
To Reproduce
from typing import Literal
from sqlalchemy.orm import DeclarativeBase, Mapped, mapped_column
type MyType = Literal["test1", "test2"]
class Base(DeclarativeBase):
pass
class MyModel(Base):
__tablename__ = "my_model"
id: Mapped[int] = mapped_column(primary_key=True)
my_type: Mapped[MyType]Error
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "../lib/python3.12/site-packages/sqlalchemy/orm/decl_api.py", line 842, in __init_subclass__
_as_declarative(cls._sa_registry, cls, cls.__dict__)
File "../lib/python3.12/site-packages/sqlalchemy/orm/decl_base.py", line 244, in _as_declarative
return _MapperConfig.setup_mapping(registry, cls, dict_, None, {})
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "../lib/python3.12/site-packages/sqlalchemy/orm/decl_base.py", line 325, in setup_mapping
return _ClassScanMapperConfig(
^^^^^^^^^^^^^^^^^^^^^^^
File "../lib/python3.12/site-packages/sqlalchemy/orm/decl_base.py", line 572, in __init__
self._extract_mappable_attributes()
File "../lib/python3.12/site-packages/sqlalchemy/orm/decl_base.py", line 1568, in _extract_mappable_attributes
value.declarative_scan(
File "../lib/python3.12/site-packages/sqlalchemy/orm/properties.py", line 707, in declarative_scan
self._init_column_for_annotation(
File "../lib/python3.12/site-packages/sqlalchemy/orm/properties.py", line 871, in _init_column_for_annotation
raise sa_exc.ArgumentError(
sqlalchemy.exc.ArgumentError: Could not locate SQLAlchemy Core type for Python type MyType inside the 'my_type' attribute Mapped annotation
Additional context
It doesn't matter whether you add the type in the type_annotation_map within Base.