Fetched Properties v Relationships (Core Data - iPhone)

Question

I\'m a new iPhone developer (of about 4 months or so) who is starting to look at Core Data.

In the \"Beginning iPhone 3 Development\" book by Dave Mark it

Answer 1

From the "Core Data Programming Guide", fetched properties represent "weak, one-way relationships". They simply allow you to define the value of a property with a fetch predicate rather than modeling it directly like a relationship.

One major difference is that fetched properties are not live or dynamic like direct relationships. You must explicitly keep fetched properties up-to-date by manually refreshing the object containing the fetched property when changes occur in your object graph that will affect the value of the fetched property.