Chapter 5. Preparing for Change: Migrations and Versioning
By the time you reached the end of Chapter 4, you mastered a great deal of the Core Data architecture and functionality. Together, we built a fully functioning, albeit somewhat simple, Core Data application. You've now got enough Core Data chops to build a solid app, send it to your testers, and then on to the App Store.
But what happens if you change your data model and send a new version of your application out to testers who already have the previous version? Consider our
SuperDB app. Let's say we decide to add a new attribute to the
Hero entity, make one of the existing, currently optional attributes required, and then add a new entity. Can we just send the program out to our users, ...