Welcome to Alembic’s documentation! # Alembic is a lightweight database migration tool for usage with the SQLAlchemy Database Toolkit for Python.

As the alembic.ini file includes a subset of options that are specific to the organization and production of Python code within the local environment, these specific options may alternatively be placed in the …

Alembic is developed by Mike Bayer, and is part of the SQLAlchemy project. User issues, discussion of potential bugs and features are most easily discussed using GitHub Discussions.

Using this API is also optional; we can just as well make any kind of Python function that we would invoke from our migration scripts. However, using this API gives us operations built directly into the …

The vast majority of user issues with Alembic centers on the topic of what kinds of changes autogenerate can and cannot detect reliably, as well as how it renders Python code for what it does …

Currently, alembic.op is a real Python module, populated with individual proxies for each method on Operations, so symbols can be imported safely from the alembic.op namespace.

Alembic’s internal API has many public integration points that can be used to extend Alembic’s functionality as well as to re-use its functionality in new ways.

Within env.py, the instantiated EnvironmentContext is made available via a special proxy module called alembic.context. That is, you can import alembic.context like a regular Python module, and each …

Alembic commands are all represented by functions in the Commands package. They all accept the same style of usage, being sent the Config object as the first argument.

A major capability of Alembic is to generate migrations as SQL scripts, instead of running them against the database - this is also referred to as offline mode.