保存到核心数据 "ALL 或 ANY 运算符的左侧必须是 NSArray 或 NSSet

Question

当我尝试保存与核心数据的关系时，它会在标题中抛出上述错误。我基本上正在创建一个消息传递应用程序并附加数据模型。在尝试保存到其他关系时，这也是在做同样的事情。我可以一次保存所有数据模型，还是应该一次保存一个数据模型，然后在模型使用其常规属性保存后返回并添加关系。**数据模型视觉对象

static func save(sender: UserCD, message: String) -> Conversation? {
let convo: Conversation? = nil
guard let appDelegate = UIApplication.shared.delegate as? AppDelegate else {
return convo
}
if #available(iOS 10.0, *) {
let context = appDelegate.persistentContainer.viewContext
let now = Date()
let messageEntity = NSEntityDescription.entity(forEntityName: "Message", in: context)
let newMessage = NSManagedObject(entity: messageEntity!, insertInto: context) as! Message
let conversationEntity = NSEntityDescription.entity(forEntityName: "Conversation", in: context)
let newConvo = NSManagedObject(entity: conversationEntity!, insertInto: context) as! Conversation
newMessage.setValue(UUID().uuidString, forKey: "messageId")
newMessage.setValue(message, forKey: "text")
newMessage.setValue(now, forKey: "timestamp")
newMessage.setValue(sender, forKey: "sender")
newConvo.setValue(UUID().uuidString, forKey: "conversationId")
newConvo.setValue(now, forKey: "startDate")
newConvo.setValue(now, forKey: "lastMessageDate")
newConvo.addMessage(message: newMessage)
sender.addMessage(message: newMessage)
sender.addConversation(conversation: newConvo)
do {
try newMessage.managedObjectContext?.save()
try sender.managedObjectContext?.save()
try newConvo.managedObjectContext?.save()
return newConvo
} catch {
let saveError = error as NSError
print("Failed to save conversastion: (saveError.debugDescription)")
}
}
return convo
}

它在"newConvo.addMessage(message： newMessage("行上失败

@NSManaged public var messages: Message?
func addMessage(message: Message) {
let messages = self.mutableSetValue(forKey: "messages")
messages.add(message)
}

Answer 1

错误消息

ALL 或 ANY 运算符的左侧必须是 NSArray 或 NSSet

很清楚：

• 您声明messages为一对一关系Message。

• 方法addMessage的发送方必须是对多关系Set<Message>