Book Image

Core Data iOS Essentials

Book Image

Core Data iOS Essentials

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
Credits
About the Author
Acknowledgement
About the Reviewers
www.PacktPub.com
Preface
Appendix

Automatically updating the quantity of the product in the MasterProduct entity


The quantity sold to a customer is automatically deducted from the master product's quantity in hand. To see if the stock has been updated, first select the Master Product Information button from the toolbar at the bottom of the Main view — the first view of the application, we'll see the list of products stored in the MasterProduct entity. On selecting a master product, we'll see the page that displays the master product information. We will see that the quantity of the product is reduced by the quantity sold to the customer.

Let's complete the book with a small introduction of migrations and versioning. The concept of migrations and versioning is useful for us to understand in case we make some changes to our data model, that is, if we add or delete some attribute in any of the entities that we created in our application. Modification in the data model is usually required to meet future demands.