DevFoundry/.devfoundry/skills/db-schema-change.md

Skill: Database Schema Change

Purpose: Safely plan and execute schema changes across Access, SQLite, SQL Server, or Postgres.

Steps

1. Document the current schema (relevant tables/fields) in the spec.
2. Write the exact DDL/change statements for the target engine, following .devfoundry/rules/database-sql.md.
3. Identify all known dependent queries, views, or reports (check .devfoundry/references/data-dictionary.md).
4. Provide a rollback statement or backup step. For Access .mdb/.accdb files this is mandatory: before any structural change, copy the file with a timestamped suffix (e.g. copy "<path>.accdb" "<path>_backup_<YYYYMMDD-HHMM>.accdb" from a command prompt, or FileCopy in VBA/VB6) and confirm the copy exists and opens before proceeding. Record the exact backup command and path used in the spec's Implementation Plan.
5. Test the change in a non-production copy of the database before applying it live.