Flask-Alembic 1.2

Installation

Install releases from PyPI:

pip install Flask-Alembic

Install the latest code from BitBucket:

pip install https://bitbucket.org/davidism/flask-alembic/get/default.tar.gz

Basic Usage

You’ve created a Flask application and some models with Flask-SQLAlchemy. Now start using Flask-Alembic:

from flask_alembic import Alembic

# Intialize the extension
alembic = Alembic()
alembic.init_app(app)

# Auto-generate a migration
alembic.revision('making changes')

# Upgrade the database
alembic.upgrade()

# Access the internals
environment_context = alembic.env

Commands are included for Click and Flask-Script:

$ ./manage.py db revision "making changes"
$ ./manage.py db upgrade

Differences from Alembic core

• Configuration is taken from Flask instead of alembic.ini.

• The migrations are stored directly in the migrations folder instead of the versions folder.

• The extension provides the migration environment instead of env.py.

• Does not (currently) support offline migrations.

Differences from Flask-Migrate

Flask-Migrate is a simple wrapper around the existing Alembic commands. It associates the Flask-SQLAlchemy database with Alembic, and wraps the Alembic commands with Flask-Script. It still requires the standard Alembic file structure, does not integrate with Flask configuration, and does not expose the Alembic internals.

TODO

• See if db.session can be used rather than establishing new connections.

• Support multiple databases though Flask-SQLAlchemy’s binds.

• Support offline migrations.