Database Schema Upgrades

Once your database has production data that should not be lost, you cannot follow the sequelize.sync approach of dropping the databases and recreating them with a new schema when you need to make changes.

There are multiple possible approaches to upgrading your database schema. Which one works best for you will depend on your specific requirements.

Using Migrations

Migrations are a way to version control your database schema, allowing you to easily upgrade and downgrade your database as your application evolves.

Sequelize provides @sequelize/cli, a Command Line Interface that can be used to create and run migrations. Head to the @sequelize/cli page for more information on how to write migrations.

Of course, you are free to use any other migration tool:

• Umzug is a great alternative that the Sequelize CLI uses under the hood.
• Third-party tools that can be used to help with migrations are also listed on the Third-Party Resources page.

Using a Database Diff Tool

You can use a database diff tool to compare the current database schema with the new schema you want to apply. One such tool is pg-diff.

In this approach, you would generate a diff as part of your release process and apply it to the database.