How to Do a Lightweight CoreData Migration in Swift

Question

I am attempting my first lightweight CoreData migration. I read two guides on lightweight migrations. Both add code to a CoreDataStack class, modifying variables like NSPersiste

Answer 1

The migration options need to be used in the call that added the persistent store to the persistent store coordinator. You will easily find this line of code by doing a search for addPersistentStoreWithType.

try coordinator!.addPersistentStoreWithType(
     NSSQLiteStoreType, configuration: nil, URL: url, options: mOptions)

Most likely your Core Data stack is in the AppDelegate class, but regardless where it is, this is where you have to add the migration options.