2.1.0b2

Released: April 16, 2026

orm

• [orm] [usecase] The metadata, type_annotation_map, or registry can now be
  set up in a declarative base also via a mixin class, not only by
  directly setting them on the subclass like before.
  The declarative class setup now uses getattr() to look for these
  attributes, instead of relying only on the class __dict__.

  References: #13198

sql

• [sql] [usecase] Added new parameter _sql.over.exclude to _sql.over() and
  related methods, enabling SQL standard frame exclusion clauses EXCLUDE CURRENT ROW, EXCLUDE GROUP, EXCLUDE TIES, EXCLUDE NO OTHERS
  in window functions. Pull request courtesy of Varun Chawla.

  References: #11671

• [sql] [usecase] The ColumnCollection class hierarchy has been refactored to allow
  column names such as add, remove, update, extend, and
  clear to be used without conflicts. ColumnCollection is now
  an abstract base class, with mutation operations moved to
  WriteableColumnCollection and DedupeColumnCollection
  subclasses. The ReadOnlyColumnCollection exposed as attributes
  such as Table.c no longer includes mutation methods that raised
  NotImplementedError, allowing these common column names to be
  accessed naturally, e.g. table.c.add, table.c.remove,
  table.c.update, etc.

• [sql] [bug] A warning is emitted when using the standalone _sql.distinct()
  function in a _sql.select() columns list outside of an aggregate
  function; this function is not intended as a replacement for the use of
  Select.distinct(). Pull request courtesy bekapono.

  References: #11526

• [sql] [bug] Improved the ability for TypeDecorator to produce a correct
  repr() for "schema" types such as Enum and Boolean.
  This is mostly to support the Alembic autogenerate use case so that custom
  types render with relevant arguments present. Improved the architecture
  used by TypeEngine to produce repr() strings to be more
  modular for compound types like TypeDecorator.

  References: #13140

schema

• [schema] [usecase] Most _sql.FromClause subclasses are now generic on
  _schema.TypedColumns subclasses, that can be used to type their
  _sql.FromClause.c collection.
  This applied to _schema.Table, _sql.Join,
  _sql.Subquery, _sql.CTE and more.

  References: #13085

• [schema] [bug] Amended the repr() output for Enum so that the
  MetaData is not shown in the output, as this interferes with
  Alembic-autogenerated forms of this type which should be inheriting the
  MetaData of the parent table in the migration script.

  References: #10604

typing

• [typing] [bug] Fixed issue in new PEP 646 support for result sets where an issue in the
  mypy type checker prevented "scalar" methods including
  Connection.scalar(), Result.scalar(),
  _orm.Session.scalar(), as well as async versions of these methods
  from applying the correct type to the scalar result value, when the columns
  in the originating _sql.select() were typed as Any. Pull request
  courtesy Yurii Karabas.

  References: #13091

• [typing] [bug] Improved typing of _sqltypes.JSON as well as dialect specific
  variants like _postgresql.JSON to include generic capabilities, so
  that the types may be parameterized to indicate any specific type of
  contents expected, e.g. JSONB[list[str]]().

  References: #13131

mssql

• [mssql] [feature] Added support for the mssql-python driver, Microsoft's official Python
  driver for SQL Server.

  References: #12869

oracle

• [oracle] [feature] Added support for the _sqltypes.JSON datatype when using the
  Oracle database with the oracledb dialect. JSON values are serialized and
  deserialized using configurable strategies that accommodate Oracle's native
  JSON type available as of Oracle 21c. Pull request courtesy Abdallah
  Alhadad.

  References: #10375