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:
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
In this section, ...