.. changelog::
:version: 2.1.0b3
- :include_notes_from: unreleased_21
+ :released: June 27, 2026
+
+ .. change::
+ :tags: usecase, orm
+ :tickets: 10610
+
+ The ``populate_existing`` execution option is now honored when passed in the
+ :paramref:`.Session.get.execution_options` dict by the method
+ :meth:`.Session.get` and analogous in other session kinds. The current
+ :paramref:`.Session.get.populate_existing` parameter will takes precedence if
+ specified, overriding the value of the execution options.
+
+ .. change::
+ :tags: feature, orm
+ :tickets: 11450
+
+ Added :paramref:`.selectinload.chunksize` parameter to :func:`.selectinload`
+ allowing users to configure the number of primary keys sent per IN clause
+ when loading relationships. Pull request courtesy bekapono.
+
+ .. change::
+ :tags: feature, sqlite
+ :tickets: 13260
+
+ Added :class:`_sqlite.JSONB` type for SQLite's binary JSON storage
+ format, available as of SQLite version 3.45.0. Values are stored via
+ the ``jsonb()`` SQL function and retrieved via ``json()``, while the
+ Python-side behavior remains identical to :class:`_sqlite.JSON`.
+ Pull request courtesy Shamil Abdulaev.
+
+ .. seealso::
+
+ :class:`_sqlite.JSONB`
+
+ .. change::
+ :tags: postgresql, usecase
+ :tickets: 13268
+
+ Changed the default backslash escape value in the PostgreSQL dialect to
+ ``False`` to align it with the default value of
+ ``standard_conforming_strings=on``. This change should not affect most users
+ since the value is set at driver initialization on first connect.
+
+ .. change::
+ :tags: bug, orm
+ :tickets: 13291
+
+ Fixed issue where the declarative class registry would not consider
+ class-level :class:`.MetaData` objects set on abstract mixin classes when
+ resolving string-based table references in :func:`.relationship`
+ configurations. The registry now uses the same metadata resolution logic
+ as table creation, first checking for a class-specific ``metadata``
+ attribute before falling back to :attr:`.registry.metadata`.
+
+ .. change::
+ :tags: bug, orm
+ :tickets: 13293
+
+ Fixed issue where the :meth:`_engine.Result.unique` filter was not properly
+ validated against the :meth:`_engine.Result.yield_per` method when both
+ were called as methods on the result object, such as
+ ``result.unique().yield_per(N)`` or ``result.yield_per(N).unique()``. The
+ uniquing filter was previously only checked when ``yield_per`` was set via
+ :paramref:`_engine.Connection.execution_options.yield_per`. Since these two
+ features are fundamentally incompatible for ORM results, an
+ :class:`.InvalidRequestError` is now raised in all cases.
+
+ .. change::
+ :tags: orm, usecase
+ :tickets: 13309
+
+ Updated the attribute :attr:`_orm.ORMExecuteState.user_defined_options` to
+ include options that were added to the statement before calling
+ :meth:`.Select.with_only_columns` or :meth:`_orm.Query.with_entities`.
+
+ .. change::
+ :tags: bug, orm
+ :tickets: 13333
+
+ A warning is now emitted when a Declarative attribute name is named
+ ``metadata`` or ``registry``. Previously, no warning was emitted for
+ ``registry``, and using the name ``metadata`` would raise an
+ InvalidRequestError. Since these names can be used for attributes
+ that are mapped as backrefs or using imperative mappings, usage
+ under Declarative has been relaxed for ``metadata`` but also warns
+ for both names as they may have unintended interactions with the
+ Declarative reserved names.
+
+ .. change::
+ :tags: usecase, orm, performance
+ :tickets: 13339
+
+ Optimized :func:`_orm.selectinload` to skip the ``.unique()`` call on inner
+ result sets when no nested :func:`_orm.joinedload` on a collection is
+ present. The uniquing pass is only required when a joined eager load
+ inflates rows due to a one-to-many or many-to-many JOIN; in the common case
+ of a leaf selectin load, rows are already unique by construction and the
+ per-row hashing overhead can be avoided. As a side effect, ``yield_per``
+ set in a ``do_orm_execute`` event for a :func:`_orm.selectinload`
+ relationship load no longer raises ``InvalidRequestError`` when no nested
+ collection joinedload is in effect, since ``.unique()`` is no longer called
+ in that path. Pull request courtesy Oliver Parker.
+
+ .. change::
+ :tags: bug, sql
+ :tickets: 13343
+
+ Fixed issue where negation of comparison expressions involving
+ ``func.any()``, ``func.all()``, and ``func.some()`` SQL functions would
+ incorrectly flip the comparison operator (e.g. ``=`` to ``!=``) rather
+ than wrapping the expression with ``NOT``. These functions are now
+ registered as collection aggregate functions that prevent operator
+ flipping on negation, consistent with the behavior of the standalone
+ :func:`_expression.any_` and :func:`_expression.all_` constructs.
+
+ .. change::
+ :tags: usecase, orm
+ :tickets: 13346
+
+ Session level :paramref:`_orm.Session.execution_options` now take
+ effect for Core level SQL emitted by unit of work operations, in
+ addition to their existing use within ORM statement executions.
+ This is to provide for Core options such as
+ :paramref:`_engine.Connection.execution_options.schema_translate_map`
+ to be applicable to a :class:`.Session` overall.
+
+ .. seealso::
+
+ :ref:`change_13346`
+
+ .. change::
+ :tags: engine, reflection
+ :tickets: 13350
+
+ Removed the legacy ``include_columns`` key from the dictionary returned
+ by the index reflection methods of some dialects.
+ This information is now part of the ``dialect_options`` dictionary under the key
+ ``{dialect_name}_include``, such as ``postgresql_include`` or ``mssql_include``.
+
+ .. change::
+ :tags: performance, orm
+ :tickets: 13363
+
+ ORM result row fetching now processes rows as plain tuples rather than
+ constructing :class:`.Row` objects, as ORM loaders use position-based
+ access and do not require the :class:`.Row` interface. :class:`.Row`
+ construction is still used when engine-level debug logging is enabled so
+ that individual rows can be logged. Benchmarks show a 3-16% improvement in
+ ORM entity load times depending on query shape. Pull request courtesy
+ Oliver Parker.
+
+ .. change::
+ :tags: performance, orm
+ :tickets: 13363
+
+ Improved performance of :func:`_orm.selectinload` and
+ :func:`_orm.subqueryload` result handling:
+
+ * in selectinloader, the primary key columns used to correlate related
+ rows are now selected directly rather than being wrapped in a
+ :class:`.Bundle`, and are read from positional slices of each result
+ row. This removes the per-row :class:`.Row` construction that the
+ :class:`.Bundle` introduced, including for the common single-column
+ primary key case.
+
+ * removed use of ``groupby()`` + ``lambda`` against :class:`.Row` objects
+ in subqueryloader; rows are converted to plain tuples and the result
+ lists are built via ``append()``.
+
+ * many-to-one selectinload reads foreign key values directly from the
+ parent instance dictionary when present, falling back to attribute-level
+ access only for expired or deferred attributes.
+
+ Pull request courtesy Oliver Parker.
+
+ .. change::
+ :tags: bug, engine
+ :tickets: 13381
+
+ Expanded try/except error handling to encompass the
+ :meth:`_events.ConnectionEvents.before_cursor_execute` and
+ :meth:`_events.ConnectionEvents.after_cursor_execute` event hooks, so that
+ exceptions raised within these hooks, including ``BaseException``
+ subclasses such as ``asyncio.CancelledError``, are properly handled via the
+ error handling path used for DBAPI errors. This ensures proper connection
+ invalidation and pool notification when exit-type exceptions are raised in
+ event hooks. As part of this change, DBAPI errors raised from within these
+ event hooks will now be wrapped as SQLAlchemy exceptions.
+
+ .. seealso::
+
+ :ref:`change_13381`
+
+ .. change::
+ :tags: bug, mysql
+ :tickets: 13393
+
+ Improved the regular expression used to parse index ``COMMENT`` clauses
+ in MySQL ``SHOW CREATE TABLE`` reflection to use an unambiguous
+ single-quoted-string pattern; the previous pattern was theoretically
+ subject to backtracking on malformed input, though such input is not
+ producible by MySQL itself. Fix courtesy of Javid Khan.
+
+ .. change::
+ :tags: orm, performance
+ :tickets: 5987
+
+ The :func:`.selectinload` loader strategy now selects the ``omit_join``
+ optimization for many-to-many non-self-referential relationships, reducing
+ the number of joins in the secondary SELECT by selecting from the secondary
+ table directly rather than joining back to the parent entity. ``omit_join``
+ is enabled automatically when the join condition determines that the
+ secondary table's foreign keys fully cover the parent's primary key. As
+ always, ``omit_join`` can be disabled by setting
+ :paramref:`.relationship.omit_join` to ``False``. Pull request courtesy
+ bekapono.
+
+ .. change::
+ :tags: bug, orm
+ :tickets: 8068
+
+ Fixed issue where the declarative class resolver would not consider
+ the :paramref:`.MetaData.schema` default schema when resolving a
+ string table name for the :paramref:`.relationship.secondary` parameter
+ as well as within string-based
+ :paramref:`.relationship.primaryjoin` and
+ :paramref:`.relationship.secondaryjoin` expressions. The resolution now
+ matches the behavior of :class:`.ForeignKey`, where an unqualified
+ table name is implicitly resolved under the default schema. A
+ deprecation warning is emitted when an unqualified name resolves to a
+ :data:`.BLANK_SCHEMA` table in a :class:`.MetaData` that has a default
+ schema set, as this implicit resolution will change in a future version.
+
+ .. change::
+ :tags: usecase, sql
+ :tickets: 8130
+
+ Added :meth:`_sql.Delete.using`, allowing explicit FROM expressions such as
+ joins to be rendered in backend-specific multiple-table DELETE forms
+ including MySQL/MariaDB ``DELETE .. USING``. Pull request courtesy
+ cjc0013.
+
+ .. seealso::
+
+ :ref:`change_8130`
+
+ .. change::
+ :tags: performance, mssql, reflection
+ :tickets: 8430
+
+ Implemented native multi-table reflection methods for the SQL Server
+ dialect, providing :meth:`.MSDialect.get_multi_columns`,
+ :meth:`.MSDialect.get_multi_pk_constraint`,
+ :meth:`.MSDialect.get_multi_foreign_keys`,
+ :meth:`.MSDialect.get_multi_indexes` and
+ :meth:`.MSDialect.get_multi_table_comment`. Previously the SQL Server
+ dialect relied on the default dialect default implementation
+ which calls the per-table methods in a loop; the new implementations
+ issue a single bulk query per object type against the ``sys.*``
+ catalog views, avoiding the per-table round trips. The single-table
+ reflection methods are now thin wrappers over the multi-table ones,
+ matching the pattern used by the PostgreSQL and Oracle dialects.
+ Pull request courtesy Gaurav Sharma.
.. changelog::
:version: 2.1.0b2
projects / thirdparty / sqlalchemy / sqlalchemy.git / commitdiff
