DB Migration Generator

DB Migration Generator

Prerequisites & Dependencies

• Node.js 18+ with prisma or typeorm, or Python 3.10+ with alembic, matching the project ORM
• Existing ORM setup: schema.prisma, TypeORM DataSource config, or alembic.ini plus env.py
• DATABASE_URL pointing to a dev database that mirrors the current production schema

Execution Steps

1. Sync the dev database to the last applied migration so the diff is computed against the true current state.
2. Apply model changes (edit schema.prisma, TypeORM entities, or SQLAlchemy models).
3. Auto-generate a descriptively named migration using the ORM diff engine (e.g., add_user_email_index).
4. Read the generated SQL before applying: flag destructive operations (column drops, type changes, table locks on large tables) for manual review.
5. Apply the migration to the dev database and verify the resulting schema (prisma db pull, alembic current, or information_schema inspection).
6. Test the rollback path (alembic downgrade -1, TypeORM migration:revert) and document any irreversible steps for ops sign-off.

# Prisma
npx prisma migrate dev --name add_user_email_index
npx prisma migrate status

# TypeORM
npx typeorm migration:generate -d src/data-source.ts src/migrations/AddUserEmailIndex
npx typeorm migration:run -d src/data-source.ts

# Alembic
alembic revision --autogenerate -m "add user email index"
alembic upgrade head
alembic downgrade -1