alembic-migrate

alembic-migrate is a framework-independent fork of flask-migrate.

Installation

To install, run pip install alembic-migrate

Usage

Create the following file structure:

model/
  ├── __init__.py
  ├── base.py
  ├── book.py 

Then declare your SQLAlchemy Base and connection string in model/base.py. Note: the connection string doesn't need to match your app's DB connection, it's only used for migrations.

# model/base.py
from sqlalchemy.ext.declarative import declarative_base

Base = declarative_base()

def get_base():
    return {'base': Base, 'sqlalchemy_url': 'sqlite:///demo.db'}

Let's add a model in model/book.py:

from .base import Base
from sqlalchemy import Integer, String, Column

class Book(Base):
    __tablename__ = 'books'
    name = Column(String, primary_key=True)
    year = Column(Integer)

Now cd .. so that you are out of the model package and run:

• alembic-db init to setup the template
• alembic-db migrate to create a migration

You can also check out the example folder in this repo.

Configuring base module

The base module contains get_base() -> dict. By default model.base is used but you can change the environment variable:

export ALEMBIC_BASE="my_model.base"

Customize model import logic

By default, all *.py files in the same package as the base will be loaded. However if you want to split your models in subpackages or have custom logic you should implement import_models inside your base module.

def import_models():
   from . import car, book
   from .sub import other_models

def get_base():
    return ...