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Editorial Team
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Asked: 2026-06-18T03:28:06+00:00

I’ve got an iOS app which uses Core Data (SQLite on the backend). It

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I’ve got an iOS app which uses Core Data (SQLite on the backend). It only has one entity, ‘Item’. There is a SQLite file bundled with the app, with hundreds of items pre-added, so when the user downloads the app from the App Store it already has the data.

The only entity has a BOOL favorite attribute which the user can alter, used -of course- to check if an item is among the user favorite items.

I’m planning to publish an update of the app with more items pre-built in the app bundle (a new SQLite file), but I want to keep the user favorites. As well, in this version my Core Data model will suffer a few modifications (I need some new properties in the ‘Item’ entity). The new set of items is a superset of the old items (an item in the old version of the app shall be in the new version, always).

I’ve been struggling with this a lot and I can’t find a solution to this. I’m able to upgrade the data model introducing new properties into my entity while keeping the user favorites (performing a so-called lightweight migration, but then I’m not able to merge old and new items. On the other hand, I’m able to get the new pre-added items, but then the favorite-related data is discarded.

Any hint? Thank you all in advance

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1 Answer

  1. Editorial Team

    I finally managed to solve the problem.

    I’ve got two NSPersistentStoreCoordinators, two NSManagedObjectContexts and two NSManagedObjectModels in my app delegate: one set to use in the application (the updated one) and another set pointing to the old store. In my app delegate didFinishLaunchingWithOptions: method I load all the user’s favorites from the old store and save them into the new one. That’s the only point in the app where I touch the old store.

    Thank you all anyway!

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