Book Image

Core Data iOS Essentials

By : Bintu Harwani, B. M. Harwani
Book Image

Core Data iOS Essentials

By: Bintu Harwani, B. M. Harwani

Overview of this book

Core Data is the essential ingredient in data driven iOS apps. It's used for storing, retrieving, and manipulating application data in databases, XML, and binary formats. It's an essential component for iPhone, iPod Touch, and iPad apps.Core Data Essentials provides a clear, readable guide to the most useful aspects of Core Data. Built around a realistic example app, the book showcases the most important aspects of Core Data development in the context of a complete, functioning app written in Objective C.The book starts with a tour of how the app works. Then you'll see how to easily display data using the Table View. You'll learn how to develop an appropriate data model that fits the needs of your app, then implement that model as updatable data objects. You'll see how to update data and build relationships between objects and learn how Core Data can work with search, and how to provide your users with friendly data editing features.
Table of Contents (19 chapters)
Core Data iOS Essentials
About the Author
About the Reviewers

Establishing a relationship between the Customer and the Product entities

In our Data Model, we have to establish relationships in two directions: one in the forward direction from the Customer to the Product entity and the other in the backward direction from the Product to the Customer entity.

Setting a relationship from the Customer entity to the Product entity

As a customer can purchase several products, the relationship from the Customer entity to the Product entity will be of the one to many type. To add the relationship, follow the given steps:

  1. 1. Select the Customer entity (in the Xcode's data model editor) in the Entity pane and from the Attributes pane select the + (plus button) to add an attribute (the relationship is stored in the form of an attribute in the Data Model).

  2. 2. From the menu that pops up, select the Add Relationship option. Specify the name of the relationship as product.

  3. 3. From the Destination drop-down list, select the Product entity (to declare that the relationship...