Edit File: commands.txt
.. _alembic.command.toplevel: ========= Commands ========= .. note:: this section discusses the **internal API of Alembic** as regards its command invocation system. This section is only useful for developers who wish to extend the capabilities of Alembic. For documentation on using Alembic commands, please see :doc:`/tutorial`. Alembic commands are all represented by functions in the :ref:`alembic.command.toplevel` package. They all accept the same style of usage, being sent the :class:`.Config` object as the first argument. Commands can be run programmatically, by first constructing a :class:`.Config` object, as in:: from alembic.config import Config from alembic import command alembic_cfg = Config("/path/to/yourapp/alembic.ini") command.upgrade(alembic_cfg, "head") In many cases, and perhaps more often than not, an application will wish to call upon a series of Alembic commands and/or other features. It is usually a good idea to link multiple commands along a single connection and transaction, if feasible. This can be achieved using the :attr:`.Config.attributes` dictionary in order to share a connection:: with engine.begin() as connection: alembic_cfg.attributes['connection'] = connection command.upgrade(alembic_cfg, "head") This recipe requires that ``env.py`` consumes this connection argument; see the example in :ref:`connection_sharing` for details. To write small API functions that make direct use of database and script directory information, rather than just running one of the built-in commands, use the :class:`.ScriptDirectory` and :class:`.MigrationContext` classes directly. .. automodule:: alembic.command :members: