iOS - Core Data relation tutorial

iOS 의 Core Data 에서 relation 의 개념을 명쾌하게 설명한 글을 발견하였다. :)

Core Data on iOS 5 Tutorial: How To Work with Relations and Predicates

http://www.raywenderlich.com/14742/core-data-on-ios-5-tutorial-how-to-work-with-relations-and-predicates