Renaming CoreData classes while allowing App updates

I have made the mistake when starting the coding an iPhone App of not adding a prefix to my classnames, and as such have a conflict (A CoreData class called Category). The project build fine until the recent update of Xcode, and only now I realize the mistake.

Is it possible to rename CoreData classes while keeping a working system after update? If I add a new version t开发者_运维技巧o the Datamodel and rename the class, the App updates, but it seems that the old table is deleted and a new (empty) one created. Obviously all the links subsequently are broken. I would like to maintain the data while making the change.

In Java EE you can overrule the table name if I remember correctly, and as such I could stick to the old class name to name the table. Is there any such possibility with CoreData?

Thanks in advance! I have to find a way to update the DB without all the Apps out in the field breaking.

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Actually, it i documented quite well by Apple:

If you rename an entity or property, you can set the renaming identifier in the destination model to the name of the corresponding property or entity in the source model. You typically set the renaming identifier using the Xcode Data Modeling tool, (for either an NSEntityDescription or an NSPropertyDescription object). In Xcode, the renaming identifier is in the User Info pane of the Detail Pane, below the version hash modifier (see The Browser View in Xcode Tools for Core Data). (Mac OS X Developer Library )

But actually for me it seems to work just to change the Classname and leave the rest of the model alone.