dotclaude/rules/database.md

paths

paths
**/migrations/** **/migrate/** **/db/migrate/** **/alembic/** **/alembic/versions/** **/prisma/migrations/** **/drizzle/** **/knex/migrations/** **/sequelize/migrations/** **/typeorm/migrations/** **/flyway/** **/liquibase/**

Database Migrations

• Never modify an existing migration — always create a new migration for changes. Existing migrations may have already run in production.
• Every migration must be reversible — implement both up/forward and down/rollback.
• Test migrations in both directions before committing.
• Migration filenames are ordered by timestamp prefix — new migrations go at the end.
• Never use raw SQL when the ORM/migration tool provides a method for the operation.
• Never seed production data in migration files — use dedicated seed files.
• Never drop columns or tables without first confirming the data is no longer needed.
• Add indexes in their own migration, not bundled with schema changes — easier to rollback independently.