2.0.46

Released: January 21, 2026

typing

• [typing] [bug] Fixed typing issues where ORM mapped classes and aliased entities could not be used as keys in result row mappings or as join targets in select statements. Patterns such as row._mapping[User], row._mapping[aliased(User)], row._mapping[with_polymorphic(...)] (rejected by both mypy and Pylance), and .join(aliased(User)) (rejected by Pylance) are documented and fully supported at runtime but were previously rejected by type checkers. The type definitions for _KeyType and _FromClauseArgument have been updated to accept these ORM entity types.

  References: #13075

postgresql

• [postgresql] [bug] Fixed issue where PostgreSQL JSONB operators _postgresql.JSONB.Comparator.path_match() and _postgresql.JSONB.Comparator.path_exists() were applying incorrect VARCHAR casts to the right-hand side operand when used with newer PostgreSQL drivers such as psycopg. The operators now indicate the right-hand type as JSONPATH, which currently results in no casting taking place, but is also compatible with explicit casts if the implementation were require it at a later point.

  References: #13059

• [postgresql] [bug] Fixed regression in PostgreSQL dialect where JSONB subscription syntax would generate incorrect SQL for cast() expressions returning JSONB, causing syntax errors. The dialect now properly wraps cast expressions in parentheses when using the [] subscription syntax, generating (CAST(...))[index] instead of CAST(...)[index] to comply with PostgreSQL syntax requirements. This extends the fix from #12778 which addressed the same issue for function calls.

  References: #13067

• [postgresql] [bug] Improved the foreign key reflection regular expression pattern used by the PostgreSQL dialect to be more permissive in matching identifier characters, allowing it to correctly handle unicode characters in table and column names. This change improves compatibility with PostgreSQL variants such as CockroachDB that may use different quoting patterns in combination with unicode characters in their identifiers. Pull request courtesy Gord Thompson.

mariadb

• [mariadb] [bug] Fixed the SQL compilation for the mariadb sequence "NOCYCLE" keyword that is to be emitted when the Sequence.cycle parameter is set to False on a Sequence. Pull request courtesy Diego Dupin.

  References: #13070

sqlite

• [sqlite] [bug] Fixed issue in the aiosqlite driver where SQLAlchemy's setting of aiosqlite's worker thread to "daemon" stopped working because the aiosqlite architecture moved the location of the worker thread in version 0.22.0. This "daemon" flag is necessary so that a program is able to exit if the SQLite connection itself was not explicitly closed, which is particularly likely with SQLAlchemy as it maintains SQLite connections in a connection pool. While it's perfectly fine to call AsyncEngine.dispose() before program exit, this is not historically or technically necessary for any driver of any known backend, since a primary feature of relational databases is durability. The change also implements support for "terminate" with aiosqlite when using version version 0.22.1 or greater, which implements a sync .stop() method.

  References: #13039

mssql

• [mssql] [usecase] Added support for the IF EXISTS clause when dropping indexes on SQL Server 2016 (13.x) and later versions. The DropIndex.if_exists parameter is now honored by the SQL Server dialect, allowing conditional index drops that will not raise an error if the index does not exist. Pull request courtesy Edgar Ramírez Mondragón.

  References: #13045