1.4.36

Released: April 26, 2022

orm

• [orm] [bug] [regression] Fixed regression where the change made for #7861, released in version 1.4.33, that brought the Insert construct to be partially recognized as an ORM-enabled statement did not properly transfer the correct mapper / mapped table state to the Session, causing the Session.get_bind() method to fail for a Session that was bound to engines and/or connections using the Session.binds parameter.

  References: #7936

orm declarative

• [orm] [declarative] [bug] Modified the DeclarativeMeta metaclass to pass cls.__dict__ into the declarative scanning process to look for attributes, rather than the separate dictionary passed to the type's __init__() method. This allows user-defined base classes that add attributes within an __init_subclass__() to work as expected, as __init_subclass__() can only affect the cls.__dict__ itself and not the other dictionary. This is technically a regression from 1.3 where __dict__ was being used.

  References: #7900

engine

• [engine] [bug] Fixed a memory leak in the C extensions which could occur when calling upon named members of Row when the member does not exist under Python 3; in particular this could occur during NumPy transformations when it attempts to call members such as .__array__, but the issue was surrounding any AttributeError thrown by the Row object. This issue does not apply to version 2.0 which has already transitioned to Cython. Thanks much to Sebastian Berg for identifying the problem.

  References: #7875

• [engine] [bug] Added a warning regarding a bug which exists in the Result.columns() method when passing 0 for the index in conjunction with a Result that will return a single ORM entity, which indicates that the current behavior of Result.columns() is broken in this case as the Result object will yield scalar values and not Row objects. The issue will be fixed in 2.0, which would be a backwards-incompatible change for code that relies on the current broken behavior. Code which wants to receive a collection of scalar values should use the Result.scalars() method, which will return a new ScalarResult object that yields non-row scalar objects.

  References: #7953

schema

• [schema] [bug] Fixed bug where ForeignKeyConstraint naming conventions using the referred_column_0 naming convention key would not work if the foreign key constraint were set up as a ForeignKey object rather than an explicit ForeignKeyConstraint object. As this change makes use of a backport of some fixes from version 2.0, an additional little-known feature that has likely been broken for many years is also fixed which is that a ForeignKey object may refer to a referred table by name of the table alone without using a column name, if the name of the referent column is the same as that of the referred column.

  The referred_column_0 naming convention key was previously not tested with the ForeignKey object, only ForeignKeyConstraint, and this bug reveals that the feature has never worked correctly unless ForeignKeyConstraint is used for all FK constraints. This bug traces back to the original introduction of the feature introduced for #3989.

  References: #7958

asyncio

• [asyncio] [bug] Repaired handling of contextvar.ContextVar objects inside of async adapted event handlers. Previously, values applied to a ContextVar would not be propagated in the specific case of calling upon awaitables inside of non-awaitable code.

  References: #7937

postgresql

• [postgresql] [bug] Fixed bug in ARRAY datatype in combination with Enum on PostgreSQL where using the .any() or .all() methods to render SQL ANY() or ALL(), given members of the Python enumeration as arguments, would produce a type adaptation failure on all drivers.

  References: #6515

• [postgresql] [bug] Implemented _postgresql.UUID.python_type attribute for the PostgreSQL _postgresql.UUID type object. The attribute will return either str or uuid.UUID based on the _postgresql.UUID.as_uuid parameter setting. Previously, this attribute was unimplemented. Pull request courtesy Alex Grönholm.

  References: #7943

• [postgresql] [bug] Fixed an issue in the psycopg2 dialect when using the create_engine.pool_pre_ping parameter which would cause user-configured AUTOCOMMIT isolation level to be inadvertently reset by the "ping" handler.

  References: #7930

mysql

• [mysql] [bug] [regression] Fixed a regression in the untested MySQL PyODBC dialect caused by the fix for #7518 in version 1.4.32 where an argument was being propagated incorrectly upon first connect, leading to a TypeError.

  References: #7871

tests

• [tests] [bug] For third party dialects, repaired a missing requirement for the SimpleUpdateDeleteTest suite test which was not checking for a working "rowcount" function on the target dialect.

  References: #7919