What do I have to do to get Core Data to automatically migrate models?

Question

I have read the documentation about automatic /lightweight migration for Core Data models - but I am having problems implementing it.

As I understand it the applicat

Answer 1

Grouchal's answer is perfect...but if you are still having the "Can't merge models with two different entities xxx" even after cleaning up the build several times...Your might have issues with how the managedObjectModel is being loaded...take at look at this one...which helped me fix it..

core data migration problems