Learn Cocoa on the Mac, Second Edition

Chapter    9

Core Data Relationships

The last chapter covered a lot of the basics about how Core Data works, but we worked with an extremely simple data model that contained just a single entity. In this chapter, we’re going to extend our data model to contain multiple entities and define relationships between those entities. We’ll also create a GUI that shows these relationships and lets us edit them. Along the way, we’ll catch our first glimpse of how Core Data deals with multiple, incompatible versions of our data model and how it can migrate a data store from one model version to the next.

We’ll do all of this while extending the MythBase project from Chapter 7 to include some data that’s often overlooked with discussing mythical heroes ...