:released: September 16, 2024

.. change::

:tags: bug, orm, typing

:tickets: 11820

Fixed issue where it was not possible to use ``typing.Literal`` with

``Mapped[]`` on Python 3.8 and 3.9. Pull request courtesy Frazer McLean.

.. change::

:tags: bug, sqlite, regression

:tickets: 11840

The changes made for SQLite CHECK constraint reflection in versions 2.0.33

and 2.0.34 , :ticket:`11832` and :ticket:`11677`, have now been fully

reverted, as users continued to identify existing use cases that stopped

working after this change. For the moment, because SQLite does not

provide any consistent way of delivering information about CHECK

constraints, SQLAlchemy is limited in what CHECK constraint syntaxes can be

reflected, including that a CHECK constraint must be stated all on a

single, independent line (or inline on a column definition) without

newlines, tabs in the constraint definition or unusual characters in the

constraint name. Overall, reflection for SQLite is tailored towards being

able to reflect CREATE TABLE statements that were originally created by

SQLAlchemy DDL constructs. Long term work on a DDL parser that does not

rely upon regular expressions may eventually improve upon this situation.

A wide range of additional cross-dialect CHECK constraint reflection tests

have been added as it was also a bug that these changes did not trip any

existing tests.

.. change::

:tags: orm, bug

:tickets: 11849

Fixed issue in ORM evaluator where two datatypes being evaluated with the

SQL concatenator operator would not be checked for

:class:`.UnevaluatableError` based on their datatype; this missed the case

of :class:`_postgresql.JSONB` values being used in a concatenate operation

which is supported by PostgreSQL as well as how SQLAlchemy renders the SQL

for this operation, but does not work at the Python level. By implementing

:class:`.UnevaluatableError` for this combination, ORM update statements

will now fall back to "expire" when a concatenated JSON value used in a SET

clause is to be synchronized to a Python object.

.. change::

:tags: bug, orm

:tickets: 11853

An warning is emitted if :func:`_orm.joinedload` or

:func:`_orm.subqueryload` are used as a top level option against a

statement that is not a SELECT statement, such as with an

``insert().returning()``. There are no JOINs in INSERT statements nor is

there a "subquery" that can be repurposed for subquery eager loading, and

for UPDATE/DELETE joinedload does not support these either, so it is never

appropriate for this use to pass silently.

.. change::

:tags: bug, orm

:tickets: 11855

Fixed issue where using loader options such as :func:`_orm.selectinload`

with additional criteria in combination with ORM DML such as

:func:`_sql.insert` with RETURNING would not correctly set up internal

contexts required for caching to work correctly, leading to incorrect

results.

.. change::

:tags: bug, mysql

:tickets: 11870

Fixed issue in mariadbconnector dialect where query string arguments that

weren't checked integer or boolean arguments would be ignored, such as

string arguments like ``unix_socket``, etc. As part of this change, the

argument parsing for particular elements such as ``client_flags``,

``compress``, ``local_infile`` has been made more consistent across all

MySQL / MariaDB dialect which accept each argument. Pull request courtesy

Tobias Alex-Petersen.

release = "2.0.35"

release_date = "September 16, 2024"