2.0.20

Released: August 15, 2023

orm

• [orm] [usecase] Implemented the "RETURNING '*'" use case for ORM enabled DML statements.
  This will render in as many cases as possible and return the unfiltered
  result set, however is not supported for multi-parameter "ORM bulk INSERT"
  statements that have specific column rendering requirements.

  References: #10192

• [orm] [bug] Fixed fundamental issue which prevented some forms of ORM "annotations"
  from taking place for subqueries which made use of _sql.Select.join()
  against a relationship target. These annotations are used whenever a
  subquery is used in special situations such as within
  _orm.PropComparator.and_() and other ORM-specific scenarios.

  This change is also backported to: 1.4.50

  References: #10223

• [orm] [bug] Fixed fundamental issue which prevented some forms of ORM "annotations"
  from taking place for subqueries which made use of _sql.Select.join()
  against a relationship target. These annotations are used whenever a
  subquery is used in special situations such as within
  _orm.PropComparator.and_() and other ORM-specific scenarios.

  This change is also backported to: 1.4.50

  References: #10223

• [orm] [bug] Fixed issue where the ORM's generation of a SELECT from a joined
  inheritance model with same-named columns in superclass and subclass would
  somehow not send the correct list of column names to the CTE
  construct, when the RECURSIVE column list were generated.

  References: #10169

• [orm] [bug] Fixed fairly major issue where execution options passed to
  _orm.Session.execute(), as well as execution options local to the ORM
  executed statement itself, would not be propagated along to eager loaders
  such as that of _orm.selectinload(), _orm.immediateload(), and
  _orm.subqueryload(), making it impossible to do things such as
  disabling the cache for a single statement or using
  schema_translate_map for a single statement, as well as the use of
  user-custom execution options. A change has been made where all
  user-facing execution options present for _orm.Session.execute() will
  be propagated along to additional loaders.

  As part of this change, the warning for "excessively deep" eager loaders
  leading to caching being disabled can be silenced on a per-statement
  basis by sending execution_options={"compiled_cache": None} to
  _orm.Session.execute(), which will disable caching for the full
  series of statements within that scope.

  References: #10231

• [orm] [bug] Fixed issue where internal cloning used by the ORM for expressions like
  _orm.relationship.Comparator.any() to produce correlated EXISTS
  constructs would interfere with the "cartesian product warning" feature of
  the SQL compiler, leading the SQL compiler to warn when all elements of the
  statement were correctly joined.

  References: #10124

• [orm] [bug] Fixed issue where the lazy="immediateload" loader strategy would place
  an internal loading token into the ORM mapped attribute under circumstances
  where the load should not occur, such as in a recursive self-referential
  load. As part of this change, the lazy="immediateload" strategy now
  honors the _orm.relationship.join_depth parameter for
  self-referential eager loads in the same way as that of other eager
  loaders, where leaving it unset or set at zero will lead to a
  self-referential immediateload not occurring, setting it to a value of one
  or greater will immediateload up until that given depth.

  References: #10139

• [orm] [bug] Fixed issue where dictionary-based collections such as
  _orm.attribute_keyed_dict() did not fully pickle/unpickle correctly,
  leading to issues when attempting to mutate such a collection after
  unpickling.

  References: #10175

• [orm] [bug] Fixed issue where chaining _orm.load_only() or other wildcard use of
  _orm.defer() from another eager loader using a _orm.aliased()
  against a joined inheritance subclass would fail to take effect for columns
  local to the superclass.

  References: #10125

• [orm] [bug] Fixed issue where an ORM-enabled _sql.select() construct would not
  render any CTEs added only via the _sql.Select.add_cte() method that
  were not otherwise referenced in the statement.

  References: #10167

examples

• [examples] [bug] The dogpile_caching examples have been updated for 2.0 style queries.
  Within the "caching query" logic itself there is one conditional added to
  differentiate between Query and select() when performing an
  invalidation operation.

engine

• [engine] [bug] Fixed critical issue where setting
  _sa.create_engine.isolation_level to AUTOCOMMIT (as opposed
  to using the _engine.Engine.execution_options() method) would fail to
  restore "autocommit" to a pooled connection if an alternate isolation level
  were temporarily selected using
  _engine.Connection.execution_options.isolation_level.

  References: #10147

sql

• [sql] [bug] Fixed issue where unpickling of a _schema.Column or other
  _sql.ColumnElement would fail to restore the correct "comparator"
  object, which is used to generate SQL expressions specific to the type
  object.

  This change is also backported to: 1.4.50

  References: #10213

• [sql] [bug] Fixed issue where unpickling of a _schema.Column or other
  _sql.ColumnElement would fail to restore the correct "comparator"
  object, which is used to generate SQL expressions specific to the type
  object.

  This change is also backported to: 1.4.50

  References: #10213

typing

• [typing] [usecase] Added new typing only utility functions Nullable() and
  NotNullable() to type a column or ORM class as, respectively,
  nullable or not nullable.
  These function are no-op at runtime, returning the input unchanged.

  References: #10173

• [typing] [bug] Typing improvements:

  -   `CursorResult` is returned for some forms of
      `_orm.Session.execute()` where DML without RETURNING is used
  
  -   fixed type for `_orm.Query.with_for_update.of` parameter within
      `_orm.Query.with_for_update()`
  
  -   improvements to `_DMLColumnArgument` type used by some DML methods to
      pass column expressions
  
  -   Add overload to `_sql.literal()` so that it is inferred that the
      return type is `BindParameter[NullType]` where
      `_sql.literal.type_` param is None
  
  -   Add overloads to `_sql.ColumnElement.op()` so that the inferred
      type when `_sql.ColumnElement.op.return_type` is not provided
      is `Callable[[Any], BinaryExpression[Any]]`
  
  -   Add missing overload to `_sql.ColumnElement.__add__()`
  

  Pull request courtesy Mehdi Gmira.

  References: #9185

• [typing] [bug] Fixed issue in _orm.Session and _asyncio.AsyncSession
  methods such as _orm.Session.connection() where the
  _orm.Session.connection.execution_options parameter were
  hardcoded to an internal type that is not user-facing.

  References: #10182

asyncio

• [asyncio] [usecase] Added new methods _asyncio.AsyncConnection.aclose() as a synonym for
  _asyncio.AsyncConnection.close() and
  _asyncio.AsyncSession.aclose() as a synonym for
  _asyncio.AsyncSession.close() to the
  _asyncio.AsyncConnection and _asyncio.AsyncSession
  objects, to provide compatibility with Python standard library
  @contextlib.aclosing construct. Pull request courtesy Grigoriev Semyon.

  References: #9698

mysql

• [mysql] [usecase] Updated aiomysql dialect since the dialect appears to be maintained again.
  Re-added to the ci testing using version 0.2.0.

  This change is also backported to: 1.4.50