Skip to main content

Migrations

Migrations exist at two levels:

1) Collection document migrations (__v)​

Use collection.addMigration(...) to transform stored documents from an older __v to the current schema version when they are read.

Good for:

  • renaming fields
  • changing shapes
  • adding defaults

2) Database schema migrations (schemaVersion)​

The database stores a schemaVersion string in its metadata file.

db.getSchemaVersion()​

getSchemaVersion(): string

db.setSchemaVersion(v)​

setSchemaVersion(v: string): void

Writable mode only.

db.migrate(from, to, fn)​

migrate(from: string, to: string, fn: (db: LioranDB) => Promise<void>): void

Registers a step; after fn finishes, the DB schema version is updated to to.

db.applyMigrations(targetVersion)​

applyMigrations(targetVersion: string): Promise<void>

Applies registered migrations up to the latest registered version.