database-development - SKILL.md Agent Skill

name: database-development description: Database migrations and Drizzle ORM guidelines for the vm0 project

Database Development

Commands

cd turbo/packages/db

pnpm db:generate   # Generate migration from schema changes
pnpm db:migrate    # Run pending migrations
pnpm db:studio     # Open Drizzle Studio UI

Migration Workflows

Auto-Generated (simple changes)

# 1. Edit schema in src/schema/
# 2. Generate migration (auto-updates _journal.json and snapshot)
pnpm db:generate
# 3. Run locally
pnpm db:migrate

Custom SQL (renames, complex ALTER, data transforms)

Use drizzle-kit generate --custom to create an empty migration file managed by Drizzle. This auto-updates _journal.json and snapshot — never edit these manually.

# 1. Generate empty migration file
pnpm drizzle-kit generate --custom --name=rename_foo_to_bar
# 2. Write SQL in the generated file
# 3. Update schema file to match
# 4. Run locally
pnpm db:migrate

Data Migration Scripts (Clerk API)

When a data migration requires external API calls (e.g., reading from Clerk), it cannot be done in a SQL migration. These scripts live in:

turbo/packages/db/scripts/migrations/NNN-description/
├── backfill.ts   # (or sync.ts) — the migration script
└── README.md     # Usage, prerequisites, verification steps

Pure data transforms that only touch the database should use regular SQL migrations instead.

Convention

Numbered sequentially: 001-, 002-, etc. — never reuse numbers
Permanent: these scripts are historical records and MUST NOT be deleted, even after the migration is complete and the referenced tables/schemas no longer exist
Default dry-run: use parseArgs with --migrate flag; default mode is dry-run
Self-contained: each directory has its own README with usage instructions
Excluded from CI: completed scripts that reference deleted schemas are excluded from tsconfig.json and eslint.config.js to avoid build errors

Checklist

Before committing:

Schema file updated in src/schema/
Schema exported in src/index.ts (if new table)
Custom migrations created via drizzle-kit generate --custom (not manually)
pnpm db:migrate works locally
pnpm test passes