Sort by date - Swift 3 - swift

Question

I have a func getData() which retrieves core data entity, and I want to sort them by date. How can I apply NSPredicate or Predicate to get the data from CoreData sorted by date?
My core data entity:
Entity: Expenses
Attributes:
amount
category
date
func getData() {
let context = appDelegate.persistentContainer.viewContext
do {
expenses = try context.fetch(Expenses.fetchRequest())
} catch {
print("Cannot fetch Expenses")
}
}

Answer 1

Predicates are for filtering your search results. To sort them you need to use an NSSortDescriptor. Assuming you have an attribute on your Expenses entity called date of type Date:
func getData() {
let context = appDelegate.persistentContainer.viewContext
let fetchRequest = NSFetchRequest<Expenses>(entityName: "Expenses")
let sort = NSSortDescriptor(key: #keyPath(Expenses.date), ascending: true)
fetchRequest.sortDescriptors = [sort]
do {
expenses = try context.fetch(fetchRequest)
} catch {
print("Cannot fetch Expenses")
}
}
EDIT: I should have mentioned that the sort selector is added in an array so that multiple sort descriptors can be added if needed. e.g. sort first by date, then by number of legs, then by volume, etc.

Answer 2

You need a sort descriptor to get all the objects in a specific order.
let sectionSortDescriptor = NSSortDescriptor(key: "date", ascending: true)
let sortDescriptors = [sectionSortDescriptor]
fetchRequest.sortDescriptors = sortDescriptors

Answer 3

My function to do a fetchRequest of data in Core Data and sort the results by date "timestamp" in descending order. "Ruta" is the name of the entity.
//Array of Ruta entity
rutas = [Ruta]()
func getData() {
let request = NSFetchRequest<NSFetchRequestResult>(entityName: "Ruta")
let sort = NSSortDescriptor(key: "timestamp", ascending: false)
request.sortDescriptors = [sort]
do {
rutas = try context.fetch(request) as! [Ruta]
} catch {
print("Fetching Failed")
}
}

Answer 4

In swift 4 or swift 5, you can use like
func sortlist(){
//1
guard let appDelegate =
UIApplication.shared.delegate as? AppDelegate else {
return
}
let managedContext =
appDelegate.persistentContainer.viewContext
//2
let fetchRequest =
NSFetchRequest<NSManagedObject>(entityName: "User")
let sort = NSSortDescriptor(key: "date", ascending: false)
fetchRequest.sortDescriptors = [sort]
//3
do {
let langugeCodes = try managedContext.fetch(fetchRequest)
for result in langugeCodes as [NSManagedObject] {
var username:String = result.value(forKey: "username")! as! String
print("username==>",username)
}
} catch let error as NSError {
print("Could not fetch. \(error), \(error.userInfo)")
}
}

Answer 5

To get data which are lastly added at first, need to set key of sort descriptor as ObjectId.
let sectionSortDescriptor = NSSortDescriptor(key: #keyPath(Entity.ObjectId)
ascending: false) fetchRequest.sortDescriptors = [sectionSortDescriptor]