[Backend Dependencies Update] Update alembic to 1.6.4

[pyup-bot]

This PR updates alembic from 1.2.1 to 1.6.4.

Changelog

1.6.4

:released: May 24, 2021

 .. change::
     :tags: bug, regression, op directives
     :tickets: 848

     Fixed regression caused by just fixed :ticket:`844` that scaled back the
     filter for ``unique=True/index=True`` too far such that these directives no
     longer worked for the ``op.create_table()`` op, this has been fixed.

.. changelog::

1.6.3

:released: May 21, 2021

 .. change::
     :tags: bug, regression, autogenerate
     :tickets: 844

     Fixed 1.6-series regression where ``UniqueConstraint`` and to a lesser
     extent ``Index`` objects would be doubled up in the generated model when
     the ``unique=True`` / ``index=True`` flags were used.

 .. change::
     :tags: bug, autogenerate
     :tickets: 839

     Fixed a bug where paths defined in post-write hook options
     would be wrongly escaped in non posix environment (Windows).

 .. change::
     :tags: bug, regression, versioning
     :tickets: 843

     Fixed regression where a revision file that contained its own down revision
     as a dependency would cause an endless loop in the traversal logic.

.. changelog::

1.6.2

:released: May 6, 2021

 .. change::
     :tags: bug, versioning, regression
     :tickets: 839

     Fixed additional regression nearly the same as that of :ticket:`838` just
     released in 1.6.1 but within a slightly different codepath, where "alembic
     downgrade head" (or equivalent) would fail instead of iterating no
     revisions.

.. changelog::

1.6.1

:released: May 6, 2021

 .. change::
     :tags: bug, versioning, regression
     :tickets: 838

     Fixed regression in new revisioning traversal where "alembic downgrade
     base" would fail if the database itself were clean and unversioned;
     additionally repairs the case where downgrade would fail if attempting
     to downgrade to the current head that is already present.

.. changelog::

1.6.0

:released: May 3, 2021

 .. change::
     :tags: bug, autogenerate
     :tickets: 803

     Refactored the implementation of :class:`.MigrateOperation` constructs such
     as :class:`.CreateIndexOp`, :class:`.CreateTableOp`, etc. so that they no
     longer rely upon maintaining a persistent version of each schema object
     internally; instead, the state variables of each operation object will be
     used to produce the corresponding construct when the operation is invoked.
     The rationale is so that environments which make use of
     operation-manipulation schemes such as those those discussed in
     :ref:`autogen_rewriter` are better supported, allowing end-user code to
     manipulate the public attributes of these objects which will then be
     expressed in the final output, an example is
     ``some_create_index_op.kw["postgresql_concurrently"] = True``.

     Previously, these objects when generated from autogenerate would typically
     hold onto the original, reflected element internally without honoring the
     other state variables of each construct, preventing the public API from
     working.



 .. change::
     :tags: bug, environment
     :tickets: 829

     Fixed regression caused by the SQLAlchemy 1.4/2.0 compatibility switch
     where calling ``.rollback()`` or ``.commit()`` explicitly within the
     ``context.begin_transaction()`` context manager would cause it to fail when
     the block ended, as it did not expect that the transaction was manually
     closed.

 .. change::
     :tags: bug, autogenerate
     :tickets: 827

     Improved the rendering of ``op.add_column()`` operations when adding
     multiple columns to an existing table, so that the order of these
     statements matches the order in which the columns were declared in the
     application's table metadata. Previously the added columns were being
     sorted alphabetically.


 .. change::
     :tags: feature, autogenerate
     :tickets: 819

     Fix the documentation regarding the default command-line argument position of
     the revision script filename within the post-write hook arguments. Implement a
     ``REVISION_SCRIPT_FILENAME`` token, enabling the position to be changed. Switch
     from ``str.split()`` to ``shlex.split()`` for more robust command-line argument
     parsing.

 .. change::
     :tags: feature
     :tickets: 822

     Implement a ``.cwd`` (current working directory) suboption for post-write hooks
     (of type ``console_scripts``). This is useful for tools like pre-commit, which
     rely on the working directory to locate the necessary config files. Add
     pre-commit as an example to the documentation. Minor change: rename some variables
     from ticket 819 to improve readability.

 .. change::
     :tags: bug, versioning
     :tickets: 765, 464

     The algorithm used for calculating downgrades/upgrades/iterating
     revisions has been rewritten, to resolve ongoing issues of branches
     not being handled consistently particularly within downgrade operations,
     as well as for overall clarity and maintainability.  This change includes
     that a deprecation warning is emitted if an ambiguous command such
     as "downgrade -1" when multiple heads are present is given.

     In particular, the change implements a long-requested use case of allowing
     downgrades of a single branch to a branchpoint.

     Huge thanks to Simon Bowly for their impressive efforts in successfully
     tackling this very difficult problem.

 .. change::
     :tags: bug, batch
     :tickets: 799

     Added missing ``batch_op.create_table_comment()``,
     ``batch_op.drop_table_comment()`` directives to batch ops.

.. changelog::

1.5.8

:released: March 23, 2021

 .. change::
     :tags: bug, environment
     :tickets: 816

     Fixed regression caused by SQLAlchemy 1.4 where the "alembic current"
     command would fail due to changes in the ``URL`` object.


.. changelog::

1.5.7

:released: March 11, 2021

 .. change::
     :tags: bug, autogenerate
     :tickets: 813

     Adjusted the recently added
     :paramref:`.EnvironmentContext.configure.include_name` hook to accommodate
     for additional object types such as "views" that don't have a parent table,
     to support third party recipes and extensions. Pull request courtesy Oliver
     Rice.

.. changelog::

1.5.6

:released: March 5, 2021

 .. change::
     :tags: bug, mssql, operations
     :tickets: 812

     Fixed bug where the "existing_type" parameter, which the MSSQL dialect
     requires in order to change the nullability of a column in the absence of
     also changing the column type, would cause an ALTER COLUMN operation to
     incorrectly render a second ALTER statement without the nullability if a
     new type were also present, as the MSSQL-specific contract did not
     anticipate all three of "nullability", "type_" and "existing_type" being
     sent at the same time.


 .. change::
     :tags: template
     :ticket: 805

     Add async template to Alembic to bootstrap environments that use
     async DBAPI. Updated the cookbook to include a migration guide
     on how to adapt an existing enviroment for use with DBAPI drivers.

.. changelog::

1.5.5

:released: February 20, 2021

 .. change::
     :tags: bug

     Adjusted the use of SQLAlchemy's ".copy()" internals to use "._copy()"
     for version 1.4.0, as this method is being renamed.

 .. change::
     :tags: bug, environment
     :tickets: 797

     Added new config file option ``prepend_sys_path``, which is a series of
     paths that will be prepended to sys.path; the default value in newly
     generated alembic.ini files is ".".  This fixes a long-standing issue
     where for some reason running the alembic command line would not place the
     local "." path in sys.path, meaning an application locally present in "."
     and importable through normal channels, e.g. python interpreter, pytest,
     etc. would not be located by Alembic, even though the ``env.py`` file is
     loaded relative to the current path when ``alembic.ini`` contains a
     relative path. To enable for existing installations, add the option to the
     alembic.ini file as follows::

        sys.path path, will be prepended to sys.path if present.
        defaults to the current working directory.
       prepend_sys_path = .

     .. seealso::

         :ref:`installation` - updated documentation reflecting that local
         installation of the project is not necessary if running the Alembic cli
         from the local path.


.. changelog::

1.5.4

:released: February 3, 2021

 .. change::
     :tags: bug, versioning
     :tickets: 789

     Fixed bug in versioning model where a downgrade across a revision with a
     dependency on another branch, yet an ancestor is also dependent on that
     branch, would produce an erroneous state in the alembic_version table,
     making upgrades impossible without manually repairing the table.

.. changelog::

1.5.3

:released: January 29, 2021

 .. change::
     :tags: bug, autogenerate
     :tickets: 786

     Changed the default ordering of "CREATE" and "DROP" statements indexes and
     unique constraints within the autogenerate process, so that for example in
     an upgrade() operation, a particular index or constraint that is to be
     replaced such as for a casing convention change will not produce any naming
     conflicts. For foreign key constraint objects, this is already how
     constraints are ordered, and for table objects, users would normally want
     to use :meth:`.Operations.rename_table` in any case.

 .. change::
     :tags: bug, autogenerate, mssql
     :tickets: 787

     Fixed assorted autogenerate issues with SQL Server:

     * ignore default reflected identity on primary_key columns
     * improve server default comparison

 .. change::
     :tags: bug, mysql, autogenerate
     :tickets: 788

     Fixed issue where autogenerate rendering of ``op.alter_column()`` would
     fail to include MySQL ``existing_nullable=False`` if the column were part
     of a primary key constraint within the table metadata.

.. changelog::

1.5.2

:released: January 20, 2021

 .. change::
     :tags: bug, versioning, regression
     :tickets: 784

     Fixed regression where new "loop detection" feature introduced in
     :ticket:`757` produced false positives for revision names that have
     overlapping substrings between revision number and down revision and/or
     dependency, if the downrev/dependency were not in sequence form.

 .. change::
     :tags: bug, environment
     :tickets: 782

     Fixed regression where Alembic would fail to create a transaction properly
     if the :class:`sqlalchemy.engine.Connection` were a so-called "branched"
     connection, that is, one where the ``.connect()`` method had been called to
     create a "sub" connection.

.. changelog::

1.5.1

:released: January 19, 2021

 .. change::
     :tags: bug, installation, commands
     :tickets: 780

     Fixed installation issue where the "templates" directory was not being
     installed, preventing commands like "list_templates" and "init" from
     working.

.. changelog::

1.5.0

:released: January 18, 2021

 .. change::
     :tags: usecase, operations
     :tickets: 730

     Added support for rendering of "identity" elements on
     :class:`.Column` objects, supported in SQLAlchemy via
     the :class:`.Identity` element introduced in version 1.4.

     Adding columns with identity is supported on PostgreSQL,
     MSSQL and Oracle. Changing the identity options or removing
     it is supported only on PostgreSQL and Oracle.

 .. change::
     :tags: changed, environment

     To accommodate SQLAlchemy 1.4 and 2.0, the migration model now no longer
     assumes that the SQLAlchemy Connection will autocommit an individual
     operation.   This essentially means that for databases that use
     non-transactional DDL (pysqlite current driver behavior, MySQL), there is
     still a BEGIN/COMMIT block that will surround each individual migration.
     Databases that support transactional DDL should continue to have the
     same flow, either per migration or per-entire run, depending on the
     value of the :paramref:`.Environment.configure.transaction_per_migration`
     flag.


 .. change::
     :tags: changed, environment

     A :class:`.CommandError` is raised if a ``sqlalchemy.engine.Engine`` is
     passed to the :meth:`.MigrationContext.configure` method instead of a
     ``sqlalchemy.engine.Connection`` object.  Previously, this would be a
     warning only.

 .. change::
     :tags: bug, operations
     :tickets: 753

     Modified the ``add_column()`` operation such that the ``Column`` object in
     use is shallow copied to a new instance if that ``Column`` is already
     attached to a ``table()`` or ``Table``. This accommodates for the change
     made in SQLAlchemy issue 5618 which prohibits a ``Column`` from being
     associated with multiple ``table()`` objects. This resumes support for
     using a ``Column`` inside of an Alembic operation that already refers to a
     parent ``table()`` or ``Table`` as well as allows operation objects just
     autogenerated to work.

 .. change::
     :tags: feature, autogenerate
     :tickets: 650

     Added new hook :paramref:`.EnvironmentContext.configure.include_name`,
     which complements the
     :paramref:`.EnvironmentContext.configure.include_object` hook by providing
     a means of preventing objects of a certain name from being autogenerated
     **before** the SQLAlchemy reflection process takes place, and notably
     includes explicit support for passing each schema name when
     :paramref:`.EnvironmentContext.configure.include_schemas` is set to True.
     This is most important especially for enviroments that make use of
     :paramref:`.EnvironmentContext.configure.include_schemas` where schemas are
     actually databases (e.g. MySQL) in order to prevent reflection sweeps of
     the entire server.

     .. seealso::

         :ref:`autogenerate_include_hooks` - new documentation section

 .. change::
     :tags: removed, autogenerate

     The long deprecated
     :paramref:`.EnvironmentContext.configure.include_symbol` hook is removed.
     The  :paramref:`.EnvironmentContext.configure.include_object`
     and  :paramref:`.EnvironmentContext.configure.include_name`
     hooks both achieve the goals of this hook.


 .. change::
     :tags: bug, autogenerate
     :tickets: 721

     Added rendering for the ``Table.prefixes`` element to autogenerate so that
     the rendered Python code includes these directives. Pull request courtesy
     Rodrigo Ce Moretto.

 .. change::
     :tags: bug, batch
     :tickets: 761

     Added missing "create comment" feature for columns that are altered in
     batch migrations.


 .. change::
     :tags: changed
     :tickets: 748

     Alembic 1.5.0 now supports **Python 2.7 and Python 3.6 and above**, as well
     as **SQLAlchemy 1.3.0 and above**.  Support is removed for Python 3
     versions prior to 3.6 and SQLAlchemy versions prior to the 1.3 series.

 .. change::
     :tags: bug, batch
     :tickets: 773

     Made an adjustment to the PostgreSQL dialect to allow it to work more
     effectively in batch mode, where a datatype like Boolean or non-native Enum
     that may have embedded rules to generate CHECK constraints will be more
     correctly handled in that these constraints usually will not have been
     generated on the PostgreSQL backend; previously it would inadvertently
     assume they existed unconditionally in a special PG-only "drop constraint"
     step.


 .. change::
     :tags: feature, versioning
     :tickets: 757

     The revision tree is now checked for cycles and loops between revision
     files when the revision environment is loaded up.  Scenarios such as a
     revision pointing to itself, or a revision that can reach itself via a
     loop, are handled and will raise the :class:`.CycleDetected` exception when
     the environment is loaded (expressed from the Alembic commandline as a
     failure message and nonzero return code). Previously, these situations were
     silently ignored up front, and the behavior of revision traversal would
     either be silently incorrect, or would produce errors such as
     :class:`.RangeNotAncestorError`.  Pull request courtesy Koichiro Den.


 .. change::
     :tags: usecase, commands

     Add ``__main__.py`` file to alembic package to support invocation
     with ``python -m alembic``.

 .. change::
     :tags: removed, commands

     Removed deprecated ``--head_only`` option to the ``alembic current``
     command

 .. change::
     :tags: removed, operations

     Removed legacy parameter names from operations, these have been emitting
     warnings since version 0.8.  In the case that legacy version files have not
     yet been updated, these can be modified directly in order to maintain
     compatibility:

     * :meth:`.Operations.drop_constraint` - "type" (use "type_") and "name"
       (use "constraint_name")

     * :meth:`.Operations.create_primary_key` - "cols" (use "columns") and
       "name" (use "constraint_name")

     * :meth:`.Operations.create_unique_constraint` - "name" (use
       "constraint_name"), "source" (use "table_name") and "local_cols" (use
       "columns")

     * :meth:`.Operations.batch_create_unique_constraint` - "name" (use
       "constraint_name")

     * :meth:`.Operations.create_foreign_key` - "name" (use "constraint_name"),
       "source" (use "source_table"), "referent" (use "referent_table")

     * :meth:`.Operations.batch_create_foreign_key` - "name" (use
       "constraint_name"), "referent" (use "referent_table")

     * :meth:`.Operations.create_check_constraint` - "name" (use
       "constraint_name"), "source" (use "table_name")

     * :meth:`.Operations.batch_create_check_constraint` - "name" (use
       "constraint_name")

     * :meth:`.Operations.create_index` - "name" (use "index_name")

     * :meth:`.Operations.drop_index` - "name" (use "index_name"), "tablename"
       (use "table_name")

     * :meth:`.Operations.batch_drop_index` - "name" (use "index_name"),

     * :meth:`.Operations.create_table` - "name" (use "table_name")

     * :meth:`.Operations.drop_table` - "name" (use "table_name")

     * :meth:`.Operations.alter_column` - "name" (use "new_column_name")



.. changelog::

1.4.3

:released: September 11, 2020

 .. change::
     :tags: bug, sqlite, batch
     :tickets: 711

     Added support to drop named CHECK constraints that are specified as part of
     a column, rather than table wide.  Previously, only constraints associated
     with the table were considered.

 .. change::
     :tags: bug, ops, mysql
     :tickets: 736

     Fixed issue where the MySQL dialect would not correctly render the server
     default of a column in an alter operation, if the operation were
     programmatically generated from an autogenerate pass as it would not
     accommodate for the full structure of the DefaultClause construct.

 .. change::
     :tags: bug, sqlite, batch
     :tickets: 697

     Fixed issue where the CAST applied to a JSON column when copying a SQLite
     table during batch mode would cause the data to be lost, as SQLite's CAST
     with JSON appears to convert the data to the value "0". The CAST is now
     skipped in a dialect-specific manner, including for JSON columns on SQLite.
     Pull request courtesy Sebastián Ramírez.

 .. change::
     :tags: bug, commands
     :tickets: 694

     The ``alembic current`` command no longer creates an ``alembic_version``
     table in the database if one does not exist already, returning no version
     as the current version. This allows checking for migrations in parallel
     without introducing race conditions.  Pull request courtesy Nikolay
     Edigaryev.


 .. change::
     :tags: bug, batch

     Fixed issue where columns in a foreign-key referenced table would be
     replaced with null-type columns during a batch operation; while this did
     not generally have any side effects, it could theoretically impact a batch
     operation that also targets that table directly and also would interfere
     with future changes to the ``.append_column()`` method to disallow implicit
     replacement of columns.

 .. change::
    :tags: bug, mssql
    :tickets: 716

    Fixed issue where the ``mssql_drop_foreign_key=True`` flag on
    ``op.drop_column`` would lead to incorrect syntax error due to a typo in the
    SQL emitted, same typo was present in the test as well so it was not
    detected. Pull request courtesy Oleg Shigorin.

.. changelog::

1.4.2

:released: March 19, 2020

 .. change::
     :tags: usecase, autogenerate
     :tickets: 669

     Adjusted autogen comparison to accommodate for backends that support
     computed column reflection, dependent on SQLAlchemy version 1.3.16 or
     higher. This emits a warning if the SQL expression inside of a
     :class:`.Computed` value changes between the metadata and the database, as
     these expressions can't be changed without dropping and recreating the
     column.


 .. change::
     :tags: bug, tests
     :tickets: 668

     Fixed an issue that prevented the test suite from running with the
     recently released py.test 5.4.0.


 .. change::
     :tags: bug, autogenerate, mysql
     :tickets: 671

     Fixed more false-positive failures produced by the new "compare type" logic
     first added in :ticket:`605`, particularly impacting MySQL string types
     regarding flags such as "charset" and "collation".

 .. change::
     :tags: bug, op directives, oracle
     :tickets: 670

     Fixed issue in Oracle backend where a table RENAME with a schema-qualified
     name would include the schema in the "to" portion, which is rejected by
     Oracle.


.. changelog::

1.4.1

:released: March 1, 2020

 .. change::
     :tags: bug, autogenerate
     :tickets: 661

     Fixed regression caused by the new "type comparison" logic introduced in
     1.4 as part of :ticket:`605` where comparisons of MySQL "unsigned integer"
     datatypes would produce false positives, as the regular expression logic
     was not correctly parsing the "unsigned" token when MySQL's default display
     width would be returned by the database.  Pull request courtesy Paul
     Becotte.

 .. change::
     :tags: bug, environment
     :tickets: 663

     Error message for "path doesn't exist" when loading up script environment
     now displays the absolute path.  Pull request courtesy Rowan Hart.

 .. change::
     :tags: bug, autogenerate
     :tickets: 654

     Fixed regression in 1.4.0 due to :ticket:`647` where unique constraint
     comparison with mixed case constraint names while not using a naming
     convention would produce false positives during autogenerate.

 .. change::
     :tags: bug, environment

     The check for matched rowcount when the alembic_version table is updated or
     deleted from is now conditional based on whether or not the dialect
     supports the concept of "rowcount" for UPDATE or DELETE rows matched.  Some
     third party dialects do not support this concept.  Pull request courtesy Ke
     Zhu.

 .. change::
     :tags: bug, operations
     :tickets: 655

     Fixed long-standing bug where an inline column CHECK constraint would not
     be rendered within an "ADD COLUMN" operation.  The DDL compiler is now
     consulted for inline constraints within the :meth:`.Operations.add_column`
     method as is done for regular CREATE TABLE operations.



.. changelog::

1.4.0

:released: February 4, 2020

 .. change::
     :tags: change

     The internal inspection routines no longer use SQLAlchemy's
     ``Inspector.from_engine()`` method, which is expected to be deprecated in
     1.4.  The ``inspect()`` function is now used.


 .. change::
     :tags: bug, autogenerate
     :tickets: 647

     Adjusted the unique constraint comparison logic in a similar manner as that
     of :ticket:`421` did for indexes in order to take into account SQLAlchemy's
     own truncation of long constraint names when a naming convention is in use.
     Without this step, a name that is truncated by SQLAlchemy based on a unique
     constraint naming convention or hardcoded name will not compare properly.


 .. change::
     :tags: feature, batch
     :tickets: 640

     Added new parameters :paramref:`.BatchOperations.add_column.insert_before`,
     :paramref:`.BatchOperations.add_column.insert_after` which provide for
     establishing the specific position in which a new column should be placed.
     Also added :paramref:`.Operations.batch_alter_table.partial_reordering`
     which allows the complete set of columns to be reordered when the new table
     is created.   Both operations apply only to when batch mode is recreating
     the whole table using ``recreate="always"``.  Thanks to Marcin Szymanski
     for assistance with the implementation.

 .. change::
     :tags: usecase, environment
     :tickets: 648

     Moved the use of the ``__file__`` attribute at the base of the Alembic
     package into the one place that it is specifically needed, which is when
     the config attempts to locate the template directory. This helps to allow
     Alembic to be fully importable in environments that are using Python
     memory-only import schemes.  Pull request courtesy layday.

 .. change::
     :tags: bug, autogenerate
     :tickets: 605

     A major rework of the "type comparison" logic is in place which changes the
     entire approach by which column datatypes are compared.  Types are now
     compared based on the DDL string generated by the metadata type vs. the
     datatype reflected from the database.  This means we compare types based on
     what would actually render and additionally if elements of the types change
     like string length, those changes are detected as well.  False positives
     like those generated between SQLAlchemy Boolean and MySQL TINYINT should
     also be resolved.   Thanks very much to Paul Becotte  for lots of hard work
     and patience on this one.

     .. seealso::

         :ref:`autogenerate_detects` - updated comments on type comparison

.. changelog::

1.3.3

:released: January 22, 2020

 .. change::
     :tags: bug, postgresql
     :tickets: 637

     Fixed issue where COMMENT directives for PostgreSQL failed to correctly
     include an explicit schema name, as well as correct quoting rules for
     schema, table, and column names.  Pull request courtesy Matthew Sills.

 .. change::
     :tags: usecase, operations
     :tickets: 624

     Added support for rendering of "computed" elements on :class:`.Column`
     objects, supported in SQLAlchemy via the new :class:`.Computed` element
     introduced in version 1.3.11. Pull request courtesy Federico Caselli.

     Note that there is currently no support for ALTER COLUMN to add, remove, or
     modify the "GENERATED ALWAYS AS" element from a column;  at least for
     PostgreSQL, it does not seem to be supported by the database. Additionally,
     SQLAlchemy does not currently reliably reflect the "GENERATED ALWAYS AS"
     phrase from an existing column, so there is also no autogenerate support
     for addition or removal of the :class:`.Computed` element to or from an
     existing column, there is only support for adding new columns that include
     the :class:`.Computed` element.  In the case that the :class:`.Computed`
     element is removed from the :class:`.Column` object in the table metadata,
     PostgreSQL and Oracle currently reflect the "GENERATED ALWAYS AS"
     expression as the "server default" which will produce an op that tries to
     drop the element as a default.

.. changelog::

1.3.2

:released: December 16, 2019

 .. change::
     :tags: bug, api, autogenerate
     :tickets: 635

     Fixed regression introduced by :ticket:`579` where server default rendering
     functions began to require a dialect implementation, however the
     :func:`.render_python_code` convenience function did not include one, thus
     causing the function to fail when used in a server default context.  The
     function now accepts a migration context argument and also creates one
     against the default dialect if one is not provided.


.. changelog::

1.3.1

:released: November 13, 2019

 .. change::
     :tags: bug, mssql
     :tickets: 621

     Fixed bug in MSSQL dialect where the drop constraint execution steps used
     to remove server default or implicit foreign key constraint failed to take
     into account the schema name of the target table.


.. changelog::

1.3.0

:released: October 31, 2019

 .. change::
     :tags: feature, command
     :tickets: 608

     Added support for ALEMBIC_CONFIG environment variable,
     refers to the location of the alembic configuration script
     in lieu of using the -c command line option.


 .. change::
     :tags: bug, autogenerate
     :tickets: 131

     Fixed bug in new Variant autogenerate where the order of the arguments to
     Variant were mistakenly reversed.

 .. change::
     :tags: change, compatibility

     Some internal modifications have been made to how the names of indexes and
     unique constraints work to make use of new functions added in SQLAlchemy
     1.4, so that SQLAlchemy has more flexibility over how naming conventions
     may be applied to these objects.

.. changelog::

Links

• PyPI: https://pypi.org/project/alembic
• Changelog: https://pyup.io/changelogs/alembic/
• Homepage: https://alembic.sqlalchemy.org
• Docs: https://pythonhosted.org/alembic/