# SQLAlchemy rel_2_1_0rc1 — 2.1.0rc1

- Product: SQLAlchemy (https://whatsnew.fyi/product/sqlalchemy)
- Vendor: SQLAlchemy
- Date: 2026-08-31
- Version: rel_2_1_0rc1
- Original notes: https://github.com/sqlalchemy/sqlalchemy/releases/tag/rel_2_1_0rc1
- Permalink: https://whatsnew.fyi/product/sqlalchemy/releases/rel-2-1-0rc1
- Labels: Pre-release

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#### 2.1.0rc1

Released: August 31, 2026
##### platform


-   **[platform] [change]** Python 3.11 or above is now required; support for Python 3.10 is dropped,
    in addition to the drop of versions Python 3.9, 3.8 and 3.7 introduced
    in 2.1.0b1.   Python 3.10 reaches EOL in October of 2026, so dropping
    support now gives the SQLAlchemy 2.1 series an extra year of space to
    remain on current Python versions.

-   **[platform] [bug]** Python 3.15 support has been added and tested, including minimal changes
    for full compatibility.
    
    This change is also **backported** to: 2.0.52
    
    References: [#13477](https://www.sqlalchemy.org/trac/ticket/13477)

##### orm


-   **[orm] [usecase]** Improved the error message raised when a `Session` is used
    inside a context manager after the transaction has been rolled back due
    to an exception. The `InvalidRequestError` now includes the original
    exception that triggered the rollback, making it clearer why the
    transaction is no longer active. Pull request courtesy Ilan Keshet.
    
    References: [#11297](https://www.sqlalchemy.org/trac/ticket/11297)

-   **[orm] [usecase]** Improved error messages raised when ORM loader strategy options cannot be
    applied to a query.  Messages now render the offending option in a
    user-friendly form such as `joinedload(User.orders)` rather than exposing
    internal class and path representations, and the "does not apply to root
    entities" message now includes the option that triggered the error.  The
    same user-friendly rendering is also applied to the "conflicting loader
    strategy" message and to the `of_type()` representation in "does not
    link" messages.  Originating pull request courtesy Jan Vollmer.
    
    References: [#12398](https://www.sqlalchemy.org/trac/ticket/12398)

-   **[orm] [usecase]** Python source generated at runtime is now compiled against a descriptive
    filename which is registered with the `linecache` module, so that
    generated functions appearing on a stack trace render with their source
    rather than as an opaque `File "<string>"` frame.  This allows tools
    like `pdb` and `inspect.getsource()` to work with these generated
    source blocks as well.  The new feature is applied to the instrumentation
    applied to an ORM object's `__init__` method, as well as throughout
    SQLAlchemy functions that are internally instrumented.
    
    References: [#13505](https://www.sqlalchemy.org/trac/ticket/13505)

-   **[orm] [usecase]** When a subclass overrides a `_orm.validates()` method using the
    same method name as the parent class, only the subclass validator is
    now invoked for instances of the subclass.  The subclass validator
    may call `super()` to also invoke the parent class validator.
    Previously, the parent validator was always used regardless of
    whether the subclass provided an override.  Pull request courtesy
    Indivar Mishra.
    
    References: [#2943](https://www.sqlalchemy.org/trac/ticket/2943)

-   **[orm] [bug]** Fixed a result-column misalignment bug in ORM-enabled UPDATE statements
    where `synchronize_session="fetch"` is in use, either explicitly or
    because the statement uses constructs such as CTEs that implicitly select
    for it.  Columns in rows returned by `.returning()` could be returned
    under incorrect keys (e.g. `row[SomeClass.a]` returning the value of
    a different column), a problem most likely to manifest under concurrent
    workloads.  ORM DELETE statements were not affected.
    
    This change is also **backported** to: 2.0.52
    
    References: [#13439](https://www.sqlalchemy.org/trac/ticket/13439)

-   **[orm] [bug]** Fixed bug where a failed `_orm.Session.bulk_insert_mappings()`,
    `_orm.Session.bulk_update_mappings()` or
    `_orm.Session.bulk_save_objects()` call could leave the
    `_orm.Session` permanently in a "flushing" state, such as when the
    transaction could not be begun because a p

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