2.0.51

Released: June 15, 2026

orm

• [orm] [bug] Fixed issue where _orm.subqueryload() combined with PropComparator.of_type() and PropComparator.and_() would silently drop the additional filter criteria, causing all related objects to be loaded instead of only those matching the filter. The LoaderCriteriaOption was being constructed against the base entity rather than the effective entity indicated by PropComparator.of_type(). Pull request courtesy Arya Rizky.

  References: #13207

• [orm] [bug] Fixed bug where a failure during tpc_prepare() within _orm.Session.commit() for a two-phase session would raise IllegalStateChangeError instead of the original database exception. The internal _prepare_impl() method's error handler was unable to invoke _orm.SessionTransaction.rollback() due to a state-change guard, preventing proper cleanup and masking the underlying error.

  References: #13356

engine

• [engine] [bug] Fixed issue where Result.freeze() would lose track of ambiguous column names present in the original CursorResult, causing key-based access on the thawed result to silently return a value instead of raising InvalidRequestError. The SimpleResultMetaData now accepts and propagates ambiguous key information so that frozen, thawed, and pickled results raise consistently for duplicate column names. Pull request courtesy Saurabh Kohli.

  References: #9427

sql

• [sql] [bug] Fixed issue where _sql.StatementLambdaElement would proxy attribute access through the cached "expected" expression rather than the resolved expression, causing stale closure-bound parameter values to be used when a lambda statement was extended with non-lambda criteria such as an additional .where() clause. Courtesy cjc0013.

  References: #10827

postgresql

• [postgresql] [bug] Repaired bug introduced in #13229 where a two-phase transaction recovery would not return the correct transaction identifier when generating the identifiers using the xid() method of the psycopg connection.

  References: #13355

• [postgresql] [bug] Fixed regular expression in the pure Python hstore result processor, used when use_native_hstore=False is set, which could hang on malformed hstore text containing unterminated quoted segments with backslashes. Pull request courtesy dxbjavid.

  References: #13370