Insert and Delete from an Entity using Core Data in Swift

import Foundation
import CoreData
import UIKit

class UserInfoServices:UserInfoProtocol{
    
    //Insert values in User Info table
    func insertUserInfoData()->UserInfo {
     
        let managedObjectContext = (UIApplication.sharedApplication().delegate as! AppDelegate).managedObjectContext
        let newItem = NSEntityDescription.insertNewObjectForEntityForName("UserInfo", inManagedObjectContext: managedObjectContext!) as! UserInfo
        newItem.userId="1"
        newItem.name="Demo User"
        
        var error: NSError?
        if !managedObjectContext!.save(&error) {
            println("Could not save \(error), \(error?.userInfo)")
        }
        return newItem
    }
    
    //Delete values from User Info table
    func deleteUserInfoData() {
        let appDelegate =
        UIApplication.sharedApplication().delegate as! AppDelegate
        let managedContext = appDelegate.managedObjectContext!
        let fetchRequest = NSFetchRequest(entityName: "UserInfo")
        fetchRequest.includesPropertyValues = false // Only fetch the managedObjectID (not the full object structure)
        if let fetchResults = managedContext.executeFetchRequest(fetchRequest, error: nil) as? [UserInfo] {
            for result in fetchResults {
                managedContext.deleteObject(result)
            }
        }
        var err: NSError?
        if !managedContext.save(&err) {
            println("User Info deleteData - Error : \(err!.localizedDescription)")
            abort()
        } else {
            println("User Info deleteData - Success")
        }
    }
    
}