CoreData: “Dangling reference to an invalid object.” error

Question

I\'m working on a Cocoa-Touch app, it uses CoreData and has some NSPersistentObject subclasses generated by the XCode model editor.

I\'ve noticed that recently, when

Answer 1

Let's say you have a table "recipes" and a child table "ingredients". You then create a one-to-many relation from recipe's to ingredients and also create an inverse relationship (one-to-one) from ingredients to recipes. It makes sense to specify a delete rule of "cascade" from the recipes table because if you delete a recipe the ingredient should also be deleted. However, if you specify "no action" in the delete rule on the one-to-one relationship in ingredients you will get the dangling reference error when you try to delete an ingredient. Change the delete rule on the one-to-one relationship to "nullify" and this should correct the problem.