register_migration migration registers a migration migration with the migration service so it can be executed with `run_all`.

register_migrations migrations registers migrations migrations with the migration service so it can be executed with `run_all`.

execute migrations runs all migrations migrations.

run_all () runs all migrations that have been registered.

pending_migrations () returns a list of migrations that need to be executed in order to have all migrations applied. The returned migration is a tuple (namespace, number) where namespace is the namespace of the migration and number is the number of pending migrations that need to be applied in order to achieve the desired schema version.

An empty list means that there are no pending migrations and that the database schema is up-to-date.