How do you update a CoreData entry that has already been saved in Swift?

Question

I\'m not sure what I\'m doing wrong here, but when I save the first time into coredata, it works just fine. When I try to overwrite that, it doesn\'t.

func t         


        

Answer 1

 var context:NSManagedObjectContext = appDel.managedObjectContext!

 var en = NSEntityDescription.entityForName("ENTITIES_NAME", inManagedObjectContext: context)

 let batchUpdateRequest = NSBatchUpdateRequest(entity: en!)
            batchUpdateRequest.resultType = NSBatchUpdateRequestResultType.UpdatedObjectIDsResultType
            batchUpdateRequest.propertiesToUpdate = ["OBJECT_KEY": "NEWVALUE"]
            var batchUpdateRequestError: NSError?
            context.executeRequest(batchUpdateRequest, error:&batchUpdateRequestError)
            if let error = batchUpdateRequestError {println("error")}

good luck

Answer 2

Swift 5

You can create a method that can work to both, include and update. Considering you have an entity created on CoreData with the name Users:

 var context: NSManagedObjectContext 
    let appDelegate = UIApplication.shared.delegate as! AppDelegate
    return appDelegate.persistentContainer.viewContext
 }

 let user: Users!

 let fetchUser: NSFetchRequest<Users> = Users.fetchRequest()
 fetchUser.predicate = NSPredicate(format: "id = %@", id as String)

 let results = try? context.fetch(fetchUser)

 if results?.count == 0 {
    // here you are inserting
    user = Users(context: context)
 } else {
    // here you are updating
    user = results?.first
 }

 user.id = id
 user.name = name
 ...


try context.save()