6. Migrations#

Damat's migration system (@damatjs/orm-migration) is module-aware: each module owns a migrations/ folder, and applied migrations are tracked per module so modules can be added and migrated independently. The damat-orm CLI drives it.

bun run db:create add_users        # generate a migration from model changes
bun run db:migrate                 # apply all pending migrations
bun run db:status                  # what's applied vs pending

Those scripts map to the damat-orm commands (migrate:create, migrate:up, migrate:status, migrate:list). Generation diffs your current models against a snapshot and emits SQL via @damatjs/orm-processor.

Applied migrations are recorded in a tracking table so re-running migrate:up is safe and idempotent.

When authoring a standalone module you drive the same per-module system through damat module instead of damat-orm — no damat.config.ts required, scoped to the module's own models and migrations/ folder:

damat module migration:create   # diff this module's models -> a SQL migration
damat module migration:run       # apply this module's migrations to DATABASE_URL
damat module migration:status    # show this module's applied vs pending migrations

migration:run and migration:status read DATABASE_URL from the module's .env, connect, and operate only on this module — migrations stay tracked under the module's name, so migration:run is idempotent. See Authoring a module.