Core data: any way to fetch multiple entities?

I had to deal with this issue as well. Wanted to be able to search multiple entities but avoid inheritance that results in hierarchy of objects all stored in a single core data class and the performance issues that may result.

I opted for creating a concrete Searchable object that stores searchable terms common among the objects I want to search against. This object was added to each of the classes I wanted to search for:

Person.Searchable
Employee.Searchable
Department.Searchable

Searchable has fields such at searchTerm and to many relationships with each of the objects I need to search for. And a displayName so that the information can be shown to the user without having to query/load any other table.

Core Data queries are executed against Searchable so you only query a single entity.

Example:

Person { firstName = Joe, lastName = Jackson } -> searchable { term = joejackson, displayName = Joe Jackson, type = person }
Employee { firstName = Joe, lastName = Smith } -> searchable { term = joesmith, displayName = Joe Smith, type = employee }
Group { name = Joe’s Development Team } -> searchable { term = joesdevelopmentteam, displayName = Joe’s Development Team, type = group }

Now you can list and search for Person, Employee, Department all separate tables using their Searchable member using a single Fetched Request Controller.

What you're trying to do is accomplished by defining entity inheritance in your model, where "DisplayableObject" would be an abstract class defined as the parent of "Cheese" and "Pirate".

Then you can perform a fetch request on the "DisplayableObject" entity and it will retrieve both entities' objects.

Take a look into this article in the apple documentation: https://developer.apple.com/library/ios/documentation/Cocoa/Conceptual/CoreData/KeyConcepts.html