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


The concept of migrations and versioning is related to the problems that are caused when we make some changes in our data model. Like if we add or delete some attribute(s) from an existing Entity or add one more Entity to our data model. In that case, our new version of application will crash when launched because of the simple fact that the existing data in the persistent store on the iPhone will be unusable in the new version of our application.

This problem can be corrected at our end by selecting Reset Content and Settings option from the iPhone simulator menu or by uninstalling the application from the iPhone and re-installing it. Consequently, the CoreData will create a new persistent store on the basis of the new Data model when the application is launched. But the problem occurs at the client's end, who has the older application, and a new version of the application is sent to them. They cannot uninstall and re-install the application as they will lose their existing data...