Zope.sqlalchemy

----------------

- Add ``mark_changed`` and ``join_transaction`` methods to
``ZopeTransactionEvents``.
(`46 <https://github.com/zopefoundation/zope.sqlalchemy/issues/46>`_)

- Reduce DeprecationWarnings with SQLAlchemy 1.4 and require at least
SQLAlchemy >= 0.9.
(`54 <https://github.com/zopefoundation/zope.sqlalchemy/issues/54>`_)

- Add support for SQLAlchemy 1.4.
(`58 <https://github.com/zopefoundation/zope.sqlalchemy/issues/58>`_)

- Prevent using an SQLAlchemy 1.4 version with broken flush support.
(`57 <https://github.com/zopefoundation/zope.sqlalchemy/issues/57>`_)

----------------

* ``.datamanager.register()`` now returns the ``ZopeTransactionEvents``
instance which was used to register the events. This allows to change its
parameters afterwards.
(`40 <https://github.com/zopefoundation/zope.sqlalchemy/pull/40>`_)

* Add preliminary support for Python 3.9a3.

----------------

**Breaking Changes**

* Drop support for Python 3.4.

* Add support for Python 3.7 and 3.8.

* Fix deprecation warnings for the event system. We already used it in general
but still leveraged the old extension mechanism in some places.
(`31 <https://github.com/zopefoundation/zope.sqlalchemy/issues/31>`_)

To make things clearer we renamed the ``ZopeTransactionExtension`` class
to ``ZopeTransactionEvents``. Existing code using the 'register' version
stays compatible.

----------------

* Add support to MySQL using pymysql.

----------------

* Add support for Python 3.4 up to 3.6.

* Support SQLAlchemy 1.2.

* Drop support for Python 2.6, 3.2 and 3.3.

* Drop support for transaction < 1.6.0.

* Fix hazard that could cause SQLAlchemy session not to be committed when
transaction is committed in rare situations.
(`23 <https://github.com/zopefoundation/zope.sqlalchemy/pull/23>`_)

------------------

* Support SQLAlchemy 1.1.
(`15 <https://github.com/zopefoundation/zope.sqlalchemy/issues/15>`_)