Caribou SQLite Migrations

Caribou is a small, simple SQLite database migrations library for Python, built primarily to manage the evolution of client side databases over multiple releases of an application.

Example

Here is a simple example illustrating how to use Caribou to manage your SQLite schema:

Create a Migration

Use Caribou's command line tool to create your first migration:

$ caribou create my_first_migration
created migration ./v20091115140758_my_first_migration.py

Edit Your Migration

Let's create a table with some data in the upgrade step and reverse the changes in the downgrade step.

"""
An example of a Caribou migration file.
"""

def upgrade(connection):
    # connection is a plain old sqlite3 database connection
    sql = """
        create table animals
        ( name     TEXT
        , status   TEXT
        ) """
    connection.execute(sql)

    animals = [ ('caribou', 'least concerned')
              , ('bengal tiger', 'threatened')
              , ('eastern elk', 'extinct')
              ]
    sql = 'insert into animals values (?, ?)'
    for name, status in animals:
        connection.execute(sql, [name, status])

    connection.commit()

def downgrade(connection):
    connection.execute('drop table animals')

Caribou migrations are flexible because they are plain Python files. Feel free to add logging, DDL transactions, anything at all.

Run Your Migration:

Caribou migrations can be run with the command line tool:

$ caribou upgrade db.sqlite .
upgrading db [db.sqlite] to most recent version
upgraded [db.sqlite] successfully to version [20091115140758]

# if you want to revert your changes, use the downgrade command:

$ caribou downgrade db.sqlite . 0
downgrading db [db.sqlite] to version [0]
downgraded [db.sqlite] successfully to version [0]

Since Caribou is built to manage client side SQLite databases, it can also be run programmatically from within your application:

"""
An example illustrating how to run a migration programmatically.
"""

import caribou

db = 'db.sqlite'
migrations_dir = '/path/to/migrations/dir'
version = '20091115140758'

# upgrade to most recent version
caribou.upgrade(db, migrations_dir)

# upgrade to a specific version
caribou.upgrade(db, migrations_dir, version)

# downgrade to a specific version
caribou.downgrade(db, migrations_dir, version)

Module-Based Migrations

When bundling your app with PyInstaller, Poetry, or similar tools, filesystem-based migration discovery may not work. You can pass a list of already-imported migration modules directly to upgrade() and downgrade():

import caribou
from myapp.migrations import v20240101120000_create_users, v20240215090000_add_scores

modules = [v20240101120000_create_users, v20240215090000_add_scores]

# upgrade using modules
caribou.upgrade("my.db", modules)

# downgrade using modules
caribou.downgrade("my.db", modules, "0")

Migration files use a v-prefix naming convention (v20240101120000_name.py) that is both importable as a Python module and sortable by version. The naming convention in versions 0.5 and below (20240101120000_name.py) continues to work for directory-based discovery.

To convert existing migrations to the new convention, simply add a v prefix to the filename (e.g. rename 20240101120000_name.py to v20240101120000_name.py).

That's it. You're rolling.

Installation

pip install caribou

Licence

Caribou is in the public domain.

Development

Things to know, before you start hacking Caribou:

Unit Tests

The unit test suite uses pytest and tox. To install and run:

uv sync
tox

Appendix

Haven't got enough?

• Additional Reading
• Additional Listening