Core Data in Objective-C, 3rd Edition

Doing Bulk Updates

Doing a bulk update isn’t a common event in most application life cycles. Selecting a large number of emails, or a large number of news items, and marking them as read is a common example of doing a bulk update. Although these situations do occur, they are unusual and shouldn’t be considered a core function of the application. Bulk updates are generally used to get us out of a coding or design “corner.”

In our recipes application, we’re going to use the bulk update API to change the values of some of our recipes on the first launch after a migration. When we migrate the application to the fourth version, we’ll add a Boolean to indicate whether it’s a favorite recipe; the default for all recipes is NO. Once the migration is ...