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

To follow up on Santthosh's answer, figured I'd post the code snippet right here instead. You need to create your managedObjectModel with initWithContentsOfURL: instead of mergedModelFromBundles: otherwise you'll get error:

Can't merge models with two different entities XXX and XXX

If your Model file is named "Model", here's how you create the managedObjectModel:

NSString *path = [[NSBundle mainBundle] pathForResource:@"Model" ofType:@"momd"];
NSURL *momURL = [NSURL fileURLWithPath:path];
managedObjectModel = [[NSManagedObjectModel alloc] initWithContentsOfURL:momURL]; 

Credit to this blog post.