1.3.14

Released: March 10, 2020

general

• [general] [bug] [py3k] Applied an explicit "cause" to most if not all internally raised exceptions
  that are raised from within an internal exception catch, to avoid
  misleading stacktraces that suggest an error within the handling of an
  exception. While it would be preferable to suppress the internally caught
  exception in the way that the __suppress_context__ attribute would,
  there does not as yet seem to be a way to do this without suppressing an
  enclosing user constructed context, so for now it exposes the internally
  caught exception as the cause so that full information about the context
  of the error is maintained.

  References: #4849

orm

• [orm] [bug] Fixed regression caused in 1.3.13 by #5056 where a refactor of the
  ORM path registry system made it such that a path could no longer be
  compared to an empty tuple, which can occur in a particular kind of joined
  eager loading path. The "empty tuple" use case has been resolved so that
  the path registry is compared to a path registry in all cases; the
  PathRegistry object itself now implements __eq__() and
  __ne__() methods which will take place for all equality comparisons and
  continue to succeed in the not anticipated case that a non-
  PathRegistry object is compared, while emitting a warning that
  this object should not be the subject of the comparison.

  References: #5110

• [orm] [bug] Setting a relationship to viewonly=True which is also the target of a
  back_populates or backref configuration will now emit a warning and
  eventually be disallowed. back_populates refers specifically to mutation
  of an attribute or collection, which is disallowed when the attribute is
  subject to viewonly=True. The viewonly attribute is not subject to
  persistence behaviors which means it will not reflect correct results
  when it is locally mutated.

  References: #5149

• [orm] [bug] Fixed an additional regression in the same area as that of #5080
  introduced in 1.3.0b3 via #4468 where the ability to create a
  joined option across a with_polymorphic() into a relationship
  against the base class of that with_polymorphic, and then further into
  regular mapped relationships would fail as the base class component would
  not add itself to the load path in a way that could be located by the
  loader strategy. The changes applied in #5080 have been further
  refined to also accommodate this scenario.

  References: #5121

• [orm] [usecase] Added a new flag InstanceEvents.restore_load_context and
  SessionEvents.restore_load_context which apply to the
  InstanceEvents.load(), InstanceEvents.refresh(), and
  SessionEvents.loaded_as_persistent() events, which when set will
  restore the "load context" of the object after the event hook has been
  called. This ensures that the object remains within the "loader context"
  of the load operation that is already ongoing, rather than the object being
  transferred to a new load context due to refresh operations which may have
  occurred in the event. A warning is now emitted when this condition occurs,
  which recommends use of the flag to resolve this case. The flag is
  "opt-in" so that there is no risk introduced to existing applications.

  The change additionally adds support for the raw=True flag to
  session lifecycle events.

  References: #5129

engine

• [engine] [bug] Expanded the scope of cursor/connection cleanup when a statement is
  executed to include when the result object fails to be constructed, or an
  after_cursor_execute() event raises an error, or autocommit / autoclose
  fails. This allows the DBAPI cursor to be cleaned up on failure and for
  connectionless execution allows the connection to be closed out and
  returned to the connection pool, where previously it waiting until garbage
  collection would trigger a pool return.

  References: #5182

sql

• [sql] [bug] [postgresql] Fixed bug where a CTE of an INSERT/UPDATE/DELETE that also uses RETURNING
  could then not be SELECTed from directly, as the internal state of the
  compiler would try to treat the outer SELECT as a DELETE statement itself
  and access nonexistent state.

  References: #5181

postgresql

• [postgresql] [bug] Fixed issue where the "schema_translate_map" feature would not work with a
  PostgreSQL native enumeration type (i.e. Enum,
  postgresql.ENUM) in that while the "CREATE TYPE" statement would
  be emitted with the correct schema, the schema would not be rendered in
  the CREATE TABLE statement at the point at which the enumeration was
  referenced.

  References: #5158

• [postgresql] [bug] [reflection] Fixed bug where PostgreSQL reflection of CHECK constraints would fail to
  parse the constraint if the SQL text contained newline characters. The
  regular expression has been adjusted to accommodate for this case. Pull
  request courtesy Eric Borczuk.

  References: #5170

mysql

• [mysql] [bug] Fixed issue in MySQL mysql.Insert.on_duplicate_key_update() construct
  where using a SQL function or other composed expression for a column argument
  would not properly render the VALUES keyword surrounding the column
  itself.

  References: #5173

mssql

• [mssql] [bug] Fixed issue where the mssql.DATETIMEOFFSET type would not
  accommodate for the None value, introduced as part of the series of
  fixes for this type first introduced in #4983, #5045.
  Additionally, added support for passing a backend-specific date formatted
  string through this type, as is typically allowed for date/time types on
  most other DBAPIs.

  References: #5132

oracle

• [oracle] [bug] Fixed a reflection bug where table comments could only be retrieved for
  tables actually owned by the user but not for tables visible to the user
  but owned by someone else. Pull request courtesy Dave Hirschfeld.

  References: #5146

misc

• [bug] [performance] Revised an internal change to the test system added as a result of
  #5085 where a testing-related module per dialect would be loaded
  unconditionally upon making use of that dialect, pulling in SQLAlchemy's
  testing framework as well as the ORM into the module import space. This
  would only impact initial startup time and memory to a modest extent,
  however it's best that these additional modules aren't reverse-dependent on
  straight Core usage.

  References: #5180

• [bug] [installation] Vendored the inspect.formatannotation function inside of
  sqlalchemy.util.compat, which is needed for the vendored version of
  inspect.formatargspec. The function is not documented in cPython and
  is not guaranteed to be available in future Python versions.

  References: #5138

• [ext] [usecase] Added keyword arguments to the MutableList.sort() function so that a
  key function as well as the "reverse" keyword argument can be provided.

  References: #5114