Migrating your database with Go migrate

Database migrations can be executed seamlessly using the Migrate tool. This allows developers to track and apply changes to their databases over time while ensuring consistency in the application's database schema.

You can install Go migrate at https://github.com/golang-migrate/migrate.

To get started, first, create a new migration file using the migrate create command, specify the file extension as SQL, and provide the directory path and a timestamp format for the new file:

migrate create -ext sql -dir meta/migrations/ -format "20060102150405"

To set up a connection to your database, use the export command to set an environment variable (MY_DATABASE in this case) with your database's connection string. Here, we are connecting to a MySQL database:

export MY_DATABASE='mysql://root:password@tcp/mydatabase'

If your database is in a Kubernetes pod, you can create a port forwarding rule to make it accessible locally:

kubectl port-forward svc/mariadb 3306:3306

Now, you can check your current migration version using:

migrate -database $MY_DATABASE -path meta/migrations version

In case your migration's state becomes out of sync, you can force a migration to a particular version using the force command in Migrate:

migrate -database $MY_DATABASE -path meta/migrations force 20230719122330

If you wish to roll back the last migration (i.e., go down one level), use the down command:

migrate -database $MY_DATABASE -path meta/migrations down 1

To apply the migrations (i.e., go up), use the up command:

migrate -database $MY_DATABASE -path meta/migrations up 1

If you wish to apply all migrations, simply drop the number:

migrate -database $MY_DATABASE -path meta/migrations up