DB Migrations

What are DB migrations?

Database migrations are a way to update database structure (migrate) to a new one or roll back to previous one. For example when citizenos-api code change requires a change in DB structure, these changes can be easily applied and reverted on an existing database. You can think of it as database versioning.

How to use Citizen OS DB migrations?

Citizen OS API uses Sequelize ORM and their standard migrations system.

Please read before going any further:

• http://docs.sequelizejs.com/manual/tutorial/migrations.html

Shortcuts

There are some shortcuts described in package.json:

• dbstatus - Migration status. Runs Sequelize db:migrate:status.
• dbmigrate - Run migration. Runs Sequelize db:migrate.
• dbrollback - Roll back migration. Runs Sequelize db:migrate:undo.

These are used as any other NPM script - npm run <command>.

How migrations are created?

Please read before going any further:

• http://docs.sequelizejs.com/manual/tutorial/migrations.html

RULES:

• Any change in the model has to be described as a migration.
• You have to test that migration and rollback works.