iPhone app store approval - coredata design change

I created an app, uploaded to app store and approved by app store as well. Its ready for download. The app is based on coredata. Now I changed the design of the app to add new functionality. Changes include addition of new attributes to current entities, deletion of few entities etc. Now, if I upload the app to app store, does it appro开发者_StackOverflow中文版ve or not? Do I have to put and Note saying that "Please uninstall old version and install new version?" Will my app be approved first of all or not.

If your app has already been available for downloads then this is an upgrade path for your app and you must have code in the next version to transition your data schema from the old version to the new.

Asking users to uninstall and reinstall the app will not be acceptable (nor should it be).

Core Data has the ability to migrate data from the old store to the new store. I would suggest reviewing Apple's documentation on this subject and optionally the Core Data book from The Pragmatic Programmers.

I would recommend both, but I am biased with regard to the book :)