What is a NSFetchRequest?
NSFetchRequest is use to access the existing data. The fetching of objects from Core Data is one of the most powerful features of this framework. It defines criteria to search/query/retrieve data from the cache (NSManagedObjectContext) or persistent store.
What is predicate in CoreData?
A CoreData predicate has a simple format attribute == value which is very similar to aContact.uniqueId! == contactIdentifierString : var contactIdentifierString = “” func userSelectedContact(contactIdentifier: String) { let context = (UIApplication.shared.delegate as!
What is NSManagedObjectContext?
An object space to manipulate and track changes to managed objects. iOS 3.0+
What is NSEntityDescription in Swift?
You usually define entities in a Managed object modelusing the data modeling tool in Xcode. Like the other major modeling classes, NSEntityDescription provides you with a user dictionary in which you can store any application-specific information related to the entity.
How to use variable value in nspredicate?
As it is relatively time consuming for the app to parse the format string of the NSPredicate, we should try to reduce creating multiple NSPredicate and reuse similar NSPredicate as much as possible. We can use variable value in NSPredicate denoted by $ sign, and substitute its value by calling withSubstitutionVariables method.
What are some examples of predicates in Entity Framework?
Examples (Entity’s property…) Say for a predicate which select Person that have a name “Asriel” and 50 money : The format is “name == %@ AND money == %i”.
What are predicates in core data?
Put simply, a predicate is a filter: you specify the criteria you want to match, and Core Data will ensure that only matching objects get returned. The best way to learn about predicates is by example, so I’ve created three examples below that demonstrate various different filters.
Is nspredicate hard to use?
NSPredicate uses syntax that is new to you so you might find it a bit daunting at first, but it really isn’t very hard once you have a few examples to work from, and it does offer a huge amount of power to your apps. SPONSORED Realm is a fast, Swifty alternative to SQLite and Core Data that simplifies local data storage.