1.4.41

Released: September 6, 2022

orm

• [orm] [bug] [events] Fixed event listening issue where event listeners added to a superclass would be lost if a subclass were created which then had its own listeners associated. The practical example is that of the sessionmaker class created after events have been associated with the _orm.Session class.

  References: #8467

• [orm] [bug] Hardened the cache key strategy for the _orm.aliased() and _orm.with_polymorphic() constructs. While no issue involving actual statements being cached can easily be demonstrated (if at all), these two constructs were not including enough of what makes them unique in their cache keys for caching on the aliased construct alone to be accurate.

  References: #8401

• [orm] [bug] [regression] Fixed regression appearing in the 1.4 series where a joined-inheritance query placed as a subquery within an enclosing query for that same entity would fail to render the JOIN correctly for the inner query. The issue manifested in two different ways prior and subsequent to version 1.4.18 (related issue #6595), in one case rendering JOIN twice, in the other losing the JOIN entirely. To resolve, the conditions under which "polymorphic loading" are applied have been scaled back to not be invoked for simple joined inheritance queries.

  References: #8456

• [orm] [bug] Fixed issue in sqlalchemy.ext.mutable extension where collection links to the parent object would be lost if the object were merged with Session.merge() while also passing Session.merge.load as False.

  References: #8446

• [orm] [bug] Fixed issue involving _orm.with_loader_criteria() where a closure variable used as bound parameter value within the lambda would not carry forward correctly into additional relationship loaders such as _orm.selectinload() and _orm.lazyload() after the statement were cached, using the stale originally-cached value instead.

  References: #8399

sql

• [sql] [bug] Fixed issue where use of the _sql.table() construct, passing a string for the _sql.table.schema parameter, would fail to take the "schema" string into account when producing a cache key, thus leading to caching collisions if multiple, same-named _sql.table() constructs with different schemas were used.

  References: #8441

asyncio

• [asyncio] [bug] Integrated support for asyncpg's terminate() method call for cases where the connection pool is recycling a possibly timed-out connection, where a connection is being garbage collected that wasn't gracefully closed, as well as when the connection has been invalidated. This allows asyncpg to abandon the connection without waiting for a response that may incur long timeouts.

  References: #8419

mssql

• [mssql] [bug] [regression] Fixed regression caused by the fix for #8231 released in 1.4.40 where connection would fail if the user did not have permission to query the dm_exec_sessions or dm_pdw_nodes_exec_sessions system views when trying to determine the current transaction isolation level.

  References: #8475