I have four entities, when creating an object with a form I need to select an entity's name so that object belongs to that entity by selecting the name. When I set this form up using a picker, it's grayed out and can't select a name. What do you need to do to make that available?

I've tried googling this and the responses are quite dated. The iOS App Dev Tutorials from developer.apple's website, which is the most recent info on the subject, goes the File System route. Is one better than the other? Are you losing out on anything by not using Core Data? Is it perfectly fine to use the File System for data persistence? What are your thoughts?

I need help with this topic please. I'm interested in the three column layout version. Column one I want my list of Core Data Entities, Column two I want a list of my Core Data Entity's ListView items, and for Column three I want the detail view of the selected list view item. Any help on figuring out the best way to accomplish this would be much appreciated. Thanks