Tern

This project is unmaintained. I'd recommend using [Flyway][https://flywaydb.org/].

Tern is a simple way to version control your database. It integrates with git (Support for more SCMs upcoming), and you can use it to distribute and manage schema changes across git branches, team members, and servers.

Quickstart

First, install tern:

$ pip install tern

Now, in the root of your repository, run the setup command.

$ tern setup models/
DBMS (Choose `postgres` or `sqlite`):  postgres
Host [localhost]:  
DB name:  tern
Username:  postgres
Password:  awesome
Running setup...  Done.

This will set up tern in your repository and store all the schema changes in the models/ directory. Now we can run the update command to get the most up-to-date version of the database.

$ tern update
Checking for downgrades...  0
Checking for upgrades...  0

Of course, that's not unexpected. We haven't done anything yet! Let's add a schema change. You'll notice a file in the repository root called setup.tern.sql. Open it up and add some SQL to it:

CREATE TABLE person (
  id SERIAL PRIMARY KEY,
  forename TEXT NOT NULL,
  surname TEXT NOT NULL
);

Now that we've told tern how to install this change, we need to tell it how to remove the change. Open up and edit teardown.tern.sql:

DROP TABLE person;

Let's make sure we did everything right:

$ tern test
Applying change...  Done.
Reversing change...  Done.
Everything looks good!

Now let's finally commit our SQL changes.

$ tern apply
$ tern update
Checking for downgrades...  0
Checking for upgrades...  1
Applying upgrades...  1/1
$ git commit