2.1 Changelog

2.1.0b1

no release date

orm

• [orm] [feature]

  The relationship.back_populates argument to relationship() may now be passed as a Python callable, which resolves to either the direct linked ORM attribute, or a string value as before. ORM attributes are also accepted directly by relationship.back_populates. This change allows type checkers and IDEs to confirm the argument for relationship.back_populates is valid. Thanks to Priyanshu Parikh for the help on suggesting and helping to implement this feature.

  See also

  ORM Relationship allows callable for back_populates

  References: #10050

• [orm] [change]

  Removed legacy signatures dating back to 0.9 release from the SessionEvents.after_bulk_update() and SessionEvents.after_bulk_delete().

  References: #10721

• [orm] [bug]

  Revised the set “binary” operators for the association proxy set() interface to correctly raise TypeError for invalid use of the |, &, ^, and - operators, as well as the in-place mutation versions of these methods, to match the behavior of standard Python set() as well as SQLAlchemy ORM’s “intstrumented” set implementation.

  References: #11349

schema

• [schema]

  Deprecate Oracle only parameters Sequence.order, Identity.order and Identity.on_null. They should be configured using the dialect kwargs oracle_order and oracle_on_null.

  References: #10247

typing

• [typing] [feature]

  The Row object now no longer makes use of an intermediary Tuple in order to represent its individual element types; instead, the individual element types are present directly, via new PEP 646 integration, now available in more recent versions of Mypy. Mypy 1.7 or greater is now required for statements, results and rows to be correctly typed. Pull request courtesy Yurii Karabas.

  See also

  Row now represents individual column types directly without Tuple

  References: #10635

asyncio

• [asyncio] [change]

  Adapted all asyncio dialects, including aiosqlite, aiomysql, asyncmy, psycopg, asyncpg to use the generic asyncio connection adapter first added in #6521 for the aioodbc DBAPI, allowing these dialects to take advantage of a common framework.

  References: #10415

• [asyncio] [change]

  Added an initialize step to the import of sqlalchemy.ext.asyncio so that greenlet will be imported only when the asyncio extension is first imported. Alternatively, the greenlet library is still imported lazily on first use to support use case that don’t make direct use of the SQLAlchemy asyncio extension.

  References: #10296

• [asyncio] [change]

  Removed the compatibility async_fallback mode for async dialects, since it’s no longer used by SQLAlchemy tests. Also removed the internal function await_fallback() and renamed the internal function await_only() to await_(). No change is expected to user code.

mariadb

• [mariadb] [usecase]

  Modified the MariaDB dialect so that when using the Uuid datatype with MariaDB >= 10.7, leaving the Uuid.native_uuid parameter at its default of True, the native UUID datatype will be rendered in DDL and used for database communication, rather than CHAR(32) (the non-native UUID type) as was the case previously. This is a behavioral change since 2.0, where the generic Uuid datatype delivered CHAR(32) for all MySQL and MariaDB variants. Support for all major DBAPIs is implemented including support for less common “insertmanyvalues” scenarios where UUID values are generated in different ways for primary keys. Thanks much to Volodymyr Kochetkov for delivering the PR.

  References: #10339

misc

• [change] [installation]

  Python 3.8 or above is now required; support for Python 3.7 is dropped as this version is EOL.

  References: #10357

• [change] [installation]

  The greenlet dependency used for asyncio support no longer installs by default. This dependency does not publish wheel files for every architecture and is not needed for applications that aren’t using asyncio features. Use the sqlalchemy[asyncio] install target to include this dependency.

  See also

  Asyncio “greenlet” dependency no longer installs by default

  References: #10197

• [change] [setup]

  Updated the setup manifest definition to use PEP 621-compliant pyproject.toml. Also updated the extra install dependency to comply with PEP-685. Thanks for the help of Matt Oberle and KOLANICH on this change.