- update to 1.7.7:
* Fixed issue where using :meth:`.Operations.create_table` in conjunction
with a :class:`.CheckConstraint` that referred to table-bound
:class:`.Column` objects rather than string expressions would be added to
the parent table potentially multiple times, resulting in an incorrect DDL
sequence. Pull request courtesy Nicolas CANIART.
* The ``logging.fileConfig()`` line in ``env.py`` templates, which is used
to setup Python logging for the migration run, is now conditional on
:attr:`.Config.config_file_name` not being ``None``. Otherwise, the line
is skipped as there is no default logging configuration present.
* Fixed bug where an :meth:`.Operations.alter_column` operation would change
a "NOT NULL" column to "NULL" by emitting an ALTER COLUMN statement that
did not specify "NOT NULL". (In the absence of "NOT NULL" T-SQL was
implicitly assuming "NULL"). An :meth:`.Operations.alter_column` operation
that specifies :paramref:`.Operations.alter_column.type` should also
specify include either :paramref:`.Operations.alter_column.nullable` or
:paramref:`.Operations.alter_column.existing_nullable` to inform Alembic as
to whether the emitted DDL should include "NULL" or "NOT NULL"; a warning
is now emitted if this is missing under this scenario.