Professional iOS Database Application Programming, 2nd Edition

Chapter 6

Modeling Data in Xcode

WHAT’S IN THIS CHAPTER?

• Defining entities and their attributes
• Expressing the relationships between entities
• Creating fetched properties and fetch requests using the predicate builder
• Generating custom subclasses of NSManagedObject from your model

WROX.COM CODE DOWNLOADS FOR THIS CHAPTER

The wrox.com code downloads for this chapter are found at www.wrox.com/remtitle.cgi?isbn=1118391845 on the Download Code tab. The code is in the Chapter 6 download and individually named according to the names throughout the chapter.

In the previous chapter, you learned the fundamentals of working with Core Data. In this chapter, you explore the Xcode data modeling tool and discover how to create data models.

In this chapter, you learn how to use the Xcode data modeling tool to create your Core Data model. The tool is easy to use and can dramatically speed the development time of your next data-driven application. Think of the data modeling tool as Interface Builder for your data.

You can use the tool to model the entities and attributes that you will use in your application. You can also use the tool to define relationships between entities, create fetched properties, and even build fetch requests.

MODELING YOUR DATA

In Chapter 2, you learned about the importance of modeling your data before you begin work on your application. You saw how to use OmniGraffle to create Entity-Relationship Diagrams (ERDs). Then you explored how to turn those diagrams into an SQLite ...