1.4.45

Released: December 10, 2022

orm

• [orm] [bug] Fixed bug where _orm.Session.merge() would fail to preserve the
  current loaded contents of relationship attributes that were indicated with
  the _orm.relationship.viewonly parameter, thus defeating
  strategies that use _orm.Session.merge() to pull fully loaded objects
  from caches and other similar techniques. In a related change, fixed issue
  where an object that contains a loaded relationship that was nonetheless
  configured as lazy='raise' on the mapping would fail when passed to
  _orm.Session.merge(); checks for "raise" are now suspended within
  the merge process assuming the _orm.Session.merge.load
  parameter remains at its default of True.

  Overall, this is a behavioral adjustment to a change introduced in the 1.4
  series as of #4994, which took "merge" out of the set of cascades
  applied by default to "viewonly" relationships. As "viewonly" relationships
  aren't persisted under any circumstances, allowing their contents to
  transfer during "merge" does not impact the persistence behavior of the
  target object. This allows _orm.Session.merge() to correctly suit one
  of its use cases, that of adding objects to a Session that were
  loaded elsewhere, often for the purposes of restoring from a cache.

  References: #8862

• [orm] [bug] Fixed issues in _orm.with_expression() where expressions that were
  composed of columns that were referenced from the enclosing SELECT would
  not render correct SQL in some contexts, in the case where the expression
  had a label name that matched the attribute which used
  _orm.query_expression(), even when _orm.query_expression() had
  no default expression. For the moment, if the _orm.query_expression()
  does have a default expression, that label name is still used for that
  default, and an additional label with the same name will continue to be
  ignored. Overall, this case is pretty thorny so further adjustments might
  be warranted.

  References: #8881

engine

• [engine] [bug] Fixed issue where _engine.Result.freeze() method would not work for
  textual SQL using either _sql.text() or
  _engine.Connection.exec_driver_sql().

  References: #8963

sql

• [sql] [usecase] An informative re-raise is now thrown in the case where any "literal
  bindparam" render operation fails, indicating the value itself and
  the datatype in use, to assist in debugging when literal params
  are being rendered in a statement.

  References: #8800

• [sql] [bug] Fixed a series of issues regarding the position and sometimes the identity
  of rendered bound parameters, such as those used for SQLite, asyncpg,
  MySQL, Oracle and others. Some compiled forms would not maintain the order
  of parameters correctly, such as the PostgreSQL regexp_replace()
  function, the "nesting" feature of the CTE construct first
  introduced in #4123, and selectable tables formed by using the
  FunctionElement.column_valued() method with Oracle.

  References: #8827

asyncio

• [asyncio] [bug] Removed non-functional merge() method from
  _asyncio.AsyncResult. This method has never worked and was
  included with _asyncio.AsyncResult in error.

  References: #8952

postgresql

• [postgresql] [bug] Made an adjustment to how the PostgreSQL dialect considers column types
  when it reflects columns from a table, to accommodate for alternative
  backends which may return NULL from the PG format_type() function.

  References: #8748

sqlite

• [sqlite] [usecase] Added support for the SQLite backend to reflect the "DEFERRABLE" and
  "INITIALLY" keywords which may be present on a foreign key construct. Pull
  request courtesy Michael Gorven.

  References: #8903

• [sqlite] [usecase] Added support for reflection of expression-oriented WHERE criteria included
  in indexes on the SQLite dialect, in a manner similar to that of the
  PostgreSQL dialect. Pull request courtesy Tobias Pfeiffer.

  References: #8804

• [sqlite] [bug] Backported a fix for SQLite reflection of unique constraints in attached
  schemas, released in 2.0 as a small part of #4379. Previously,
  unique constraints in attached schemas would be ignored by SQLite
  reflection. Pull request courtesy Michael Gorven.

  References: #8866

oracle

• [oracle] [bug] Continued fixes for Oracle fix #8708 released in 1.4.43 where
  bound parameter names that start with underscores, which are disallowed by
  Oracle, were still not being properly escaped in all circumstances.

  References: #8708

• [oracle] [bug] Fixed issue in Oracle compiler where the syntax for
  FunctionElement.column_valued() was incorrect, rendering the name
  COLUMN_VALUE without qualifying the source table correctly.

  References: #8945