CoreData - fetch code swift3

Question

below is not working throwing an error , please help how to write a code for fetching data from Users entity.

attached screenenter image description here

Answer 1

Grabbing appDelegate object and context

let appDelegate = UIApplication.shared.delegate as! AppDelegate
let context = appDelegate.persistentContainer.viewContext

Adding a record in Core Data

let user = NSEntityDescription.insertNewObject(forEntityName: "UsersClass", into: context) as! UsersClass
user.userName = "Rajan"
appDelegate.saveContext()

Fetching

let fetchRequest:NSFetchRequest<UsersClass> = UsersClass.fetchRequest()

And then execute this request

do {
    let searchResults = try context.fetch(fetchRequest)
    for trans in searchResults {
        print(trans.username!)
    }
}
catch {
    //Handle error
}

UsersClass+CoreDataProperties.swift

import Foundation
import CoreData

extension UsersClass {

    @nonobjc public class func fetchRequest() -> NSFetchRequest<UsersClass> {
        return NSFetchRequest<UsersClass>(entityName: "UsersClass");
    }

    @NSManaged public var userName: String?

}

Here is the Sample which I made.