实体中的属性在swift4中产生nil值

Question

我在xcdatamodeld中有一个包含3个实体的快捷项目：Access，CustomerInfo和User。我试图在用户中单独保存dateEndSubscription。当我尝试保存dateEndSubscription时，它提供了空值。

我的代码有什么错误？
我的代码在这里：

import UIKit
import SwiftyJSON
import CoreData

class DataManager: NSObject {

static let sharedInstance = DataManager()

func loadUser() -> User? {
    let users = loadEntity(name: Entity.User)
    if let user = users.first as? User {
        return user
    }
    return nil
}
//this for deleteuser
func deleteUser() {
    deleteEntity(entityName: Entity.User)
}

func saveUser(userInfo:JSON, handler: @escaping (Bool) -> Void) {
    deleteEntity(entityName: Entity.User)
    deleteEntity(entityName: Entity.Access)

    let entity = createEntity(withName:Entity.User)

    let info = userInfo.dictionaryValue
    let userId = (info[API.Id]?.stringValue ?? "").trimmingCharacters(in: .whitespacesAndNewlines)
    let dateEnd = (info[API.DateEnd]?.stringValue ?? "").trimmingCharacters(in: .whitespacesAndNewlines)
      // this produces with no value.
    let type = (info[API.UserType]?.stringValue ?? "").trimmingCharacters(in: .whitespacesAndNewlines)

    let cyberAccount = (info[API.CyberAccount]?.stringValue ?? "").trimmingCharacters(in: .whitespacesAndNewlines)
    let product = (info[API.Product]?.stringValue ?? "").trimmingCharacters(in: .whitespacesAndNewlines)

    let user = User(entity: entity, insertInto: context)
    user.setValue(userId, forKey:API.Id)
    user.setValue(dateEnd, forKey: API.DateEnd)
    user.setValue(type, forKey:API.UserType)
    user.setValue(cyberAccount, forKey:API.CyberAccount)
    user.setValue(product, forKey:API.Product)

    let accessInfo = info[API.Access]!
    saveUserAccess(accessInfo: accessInfo)


    handler(save)
}
 //this for saving useraccess
func saveUserAccess(accessInfo:JSON) -> Void {
    let entity = createEntity(withName:Entity.Access)

    let info = accessInfo.dictionaryValue

    let photo = (info[API.Photo]?.stringValue ?? "").trimmingCharacters(in: .whitespacesAndNewlines)
    let chat = (info[API.Chat]?.stringValue ?? "").trimmingCharacters(in: .whitespacesAndNewlines)
    let product = (info[API.Product]?.stringValue ?? "").trimmingCharacters(in: .whitespacesAndNewlines)
    let profile = (info[API.Profile]?.stringValue ?? "").trimmingCharacters(in: .whitespacesAndNewlines)
    let curve = (info[API.Curve]?.stringValue ?? "").trimmingCharacters(in: .whitespacesAndNewlines)
    let weeks = (info[API.Weeks]?.stringValue ?? "").trimmingCharacters(in: .whitespacesAndNewlines)
    let recipe = (info[API.Recipe]?.stringValue ?? "").trimmingCharacters(in: .whitespacesAndNewlines)
    let shopping = (info[API.Shopping]?.stringValue ?? "").trimmingCharacters(in: .whitespacesAndNewlines)
    let rdv = (info[API.RDV]?.stringValue ?? "").trimmingCharacters(in: .whitespacesAndNewlines)

    let userAccess = User(entity: entity, insertInto: context)
    userAccess.setValue(photo, forKey:API.Photo)
    userAccess.setValue(chat, forKey:API.Chat)
    userAccess.setValue(product, forKey:API.Product)
    userAccess.setValue(profile, forKey:API.Profile)
    userAccess.setValue(curve, forKey:API.Curve)
    userAccess.setValue(weeks, forKey:API.Weeks)
    userAccess.setValue(recipe, forKey:API.Recipe)
    userAccess.setValue(shopping, forKey:API.Shopping)
    userAccess.setValue(rdv, forKey:API.RDV)
}
// This for saving customer info
func saveCustomerInformation(customerInfo: JSON, handler: @escaping (Bool) -> Void) {

    let entity = createEntity(withName:Entity.CustomerInfo)

    let info = customerInfo.dictionaryValue

    let userId = (info[API.Id]?.stringValue ?? "").trimmingCharacters(in: .whitespacesAndNewlines)
    let type = (info[API.UserType]?.stringValue ?? "").trimmingCharacters(in: .whitespacesAndNewlines)
    let cyberAccount = (info[API.CyberAccount]?.stringValue ?? "").trimmingCharacters(in: .whitespacesAndNewlines)
    let product = (info[API.Product]?.stringValue ?? "").trimmingCharacters(in: .whitespacesAndNewlines)
    let dateEnd = (info[API.DateEnd]?.stringValue ?? "").trimmingCharacters(in: .whitespacesAndNewlines)

  print("Butwal",dateEnd)

    let user = User(entity: entity, insertInto: context)
    user.setValue(userId, forKey:API.Id)
    user.setValue(type, forKey:API.UserType)
    user.setValue(cyberAccount, forKey:API.CyberAccount)
    user.setValue(product, forKey:API.Product)
    user.setValue(dateEnd, forKey: API.DateEnd)
  print("Butwal1",dateEnd)

    let accessInfo = info[API.Access]!
    saveUserAccess(accessInfo: accessInfo)


    handler(save)
}

//MARK: Load and Save Objects for Key
func loadObject(forKey key:String) -> Any? {
    let userDefaults = UserDefaults.standard
    guard let object = userDefaults.object(forKey: key) else {
        return nil
    }

    return object as AnyObject
}

func saveObject(object:Any, forKey key:String) {
    let userDefaults = UserDefaults.standard
    userDefaults.set(object, forKey: key)
    userDefaults.synchronize()
}

private func loadEntity(name : String) -> [Any] {
    let fetchRequest = NSFetchRequest<NSFetchRequestResult>(entityName:name)
    let objects = try! context.fetch(fetchRequest)
    return objects
}

// MARK: Delete Entities
private func deleteEntity(entityName name:String) {
    let request = NSFetchRequest<NSFetchRequestResult>(entityName: name)
    let deleteRequest = NSBatchDeleteRequest(fetchRequest: request)
    deleteRequest.resultType = .resultTypeObjectIDs

    do {
        let result = try context.execute(deleteRequest) as? NSBatchDeleteResult
        guard let objectIDs = result?.result as? [NSManagedObjectID] else { return }
        let changes = [NSUpdatedObjectsKey: objectIDs]
        NSManagedObjectContext.mergeChanges(fromRemoteContextSave: changes, into: [context])
    }
    catch {
        fatalError("Failed to execute request: \(error)")
    }
}

private func createEntity(withName name:String) -> NSEntityDescription {
    return NSEntityDescription.entity(forEntityName: name, in: context)!
}

private var context: NSManagedObjectContext {
    return CoreDataManager.sharedInstance.context
}



private var save: Bool {
    return CoreDataManager.sharedInstance.saveContext(rollBackOnError: true)
}
}

struct API {
       static let DateEnd      = "dateEndSubscription"
         }

Here are the screenshots for the data model of coredata. I have included all 3 entities with their relationships and inverse. 

我需要来自服务器的dateEndSubscription值。但是，当我解析时，它不返回任何值。我还在用户实体中创建了dateEndSubscription属性。