database-migrations

name	database-migrations
description	Create, review, apply, squash, or validate shared PostgreSQL migrations in this monorepo. Use when changing `packages/db/src/schema.ts`, generating Drizzle migrations, adding backfills, or checking migration bootstrap behavior.

Shared PostgreSQL migrations

This skill covers shared PostgreSQL migrations only. It does not govern Durable Object SQLite or Wrangler migrations. Read packages/db/AGENTS.md first; it is canonical for shared PostgreSQL and Drizzle invariants. Use the git-rebase skill for migration conflicts during a rebase.

Workflow

1. Read packages/db/AGENTS.md and inspect relevant schema and migration files.
2. Change packages/db/src/schema.ts first.
3. Generate artifacts with pnpm drizzle generate.
4. Inspect generated SQL.
5. Review generated DDL for destructive operations and data loss. Prefer additive or staged schema changes. If generated DDL is unsafe, wrong, or too broad, correct the schema and regenerate. Do not hand-edit generated DDL, snapshots, or journal entries.
6. Append only intentional UPDATE or INSERT data backfills after generated DDL, separated with --> statement-breakpoint.
7. Apply migrations with pnpm drizzle migrate or run pnpm drizzle:verify-bootstrap when relevant.
8. Run pnpm format and targeted schema or migration checks.
9. Prefer one generated migration per unshipped feature branch. To squash migrations before shipping, remove the branch-local migration SQL, snapshots, and journal entries, then regenerate once from the current schema. Re-append intentional backfills afterward.

Keep generated artifacts generated. packages/db/AGENTS.md also covers shared-schema PII requirements and DB-backed timestamp serialization.