Cocoa Programming for Mac OS X, Third Edition

Chapter 30. Core Data Relationships

It is time to delve a bit deeper into Core Data. In Chapter 11, you dealt with a single entity (Car). In most applications, you will have multiple entities and relationships between them. Core Data supports to-one relationships and unordered to-many relationships.

This exercise will have two entities: Employee and Department. An employee will work for one department. A department will have a set of employees. A department will also have one employee (chosen from its set) who will be a manager. Thus, there are three relationships, as shown in Figure 30.1.

Figure 30.1. The Data Model

Edit the Model

In this section, ...