.. _alembic.ddl.toplevel:

=============
DDL Internals
=============

These are some of the constructs used to generate migration
instructions.  The APIs here build off of the :class:`sqlalchemy.schema.DDLElement`
and :ref:`sqlalchemy.ext.compiler_toplevel` systems.

For programmatic usage of Alembic's migration directives, the easiest
route is to use the higher level functions given by :ref:`alembic.operations.toplevel`.

.. automodule:: alembic.ddl
    :members:
    :undoc-members:

.. automodule:: alembic.ddl.base
    :members:
    :undoc-members:

.. automodule:: alembic.ddl.impl
    :members:
    :undoc-members:

MySQL
=============

.. automodule:: alembic.ddl.mysql
    :members:
    :undoc-members:
    :show-inheritance:

MS-SQL
=============

.. automodule:: alembic.ddl.mssql
    :members:
    :undoc-members:
    :show-inheritance:

Postgresql
=============

.. automodule:: alembic.ddl.postgresql
    :members:
    :undoc-members:
    :show-inheritance:

SQLite
=============

.. automodule:: alembic.ddl.sqlite
    :members:
    :undoc-members:
    :show-inheritance: