[FEATURE]: Support data migrations independent of schema change

[gnarroway-bullish]

Describe what you want

Background

• At present, the migration mechanism seems to depend on changes to the schema.
• There may be situations where you want to use migrations to add / modify data in the DB (e.g. seed some data, change the format of some columns etc)
• This is quite simple in migration systems like liquibase where you can handwrite your migrations
• It is not clear how this can or should be achieved using drizzle

Workaround

• It is possible to make a dummy update to the schema, and add your data migration in the generated .sql
• This risks breaking some consistency in however drizzle is implemented

Desired state

• Provide a mechanism to be able to create data migrations, independent of any schema change
• This could be as simple as supported the creation of an empty migration file that the user populates with SQL manually
• Or another special file (like schema.ts) that takes a set of desired operations to apply, which are transformed into SQL by drizzle

[a7ul]

Wont this work for your case?

npx drizzle-kit generate --custom

More details here: https://orm.drizzle.team/kit-docs/commands#generate-migrations

[gnarroway-bullish]

Indeed, totally missed that option thanks :)