Rails Native Composite Primary Keys: A Complete Evolution from Rails 3 to Rails 8 | Saeloun Blog

Composite Primary Keys (CPKs) are one of those “real world engineering” features that frameworks eventually grow into. Many enterprise databases, analytics systems, geographic indexes, and ledger tables naturally model identity using more than one attribute. For years, Rails avoided this space and assumed a single integer column called id, and our applications were expected to adapt with Rails 8, this is finally changing. The framework now understands identity that is multi column, not just “one number per record”. .