该操作无法完成.(可可错误133021.)+迅捷2

Question

我目前正在我的应用程序中使用核心数据.我有以下实体:通知(to-1),People(to-many).实体如下:

通知实体的架构

People实体的架构

People实体具有唯一约束,即字段id.基本上我将从人员(将保存在People实体中)接收通知(将保存在通知实体中).如果具有特定ID的人发送多个通知而不创建新通知(这将是重复的),我想更新People实体.

当我做上述操作时,我收到以下错误:

该操作无法完成.(可可错误133021.)

有人可以帮我解决这个问题.下面是我的代码和我试图保存的数据示例.

let entityNotification = NSEntityDescription.entityForName("Notification", inManagedObjectContext: self.managedContext)

    let newNotification = Notification(entity: entityNotification!, insertIntoManagedObjectContext: self.managedContext)

    newNotification.message = data["message"] as? String

    if let actor = data["actor"] as? [String : AnyObject]
    {
        let newPeople = NSEntityDescription.insertNewObjectForEntityForName("People", inManagedObjectContext: self.managedContext) as! People

        newPeople.id = actor["id"] as? Int
        newPeople.name = actor["name"] as? String

        newNotification.actor = newPeople
    }

    if let designator = data["designator"] as? [String : AnyObject]
    {
        let newPeople = NSEntityDescription.insertNewObjectForEntityForName("People", inManagedObjectContext: self.managedContext) as! People

        newPeople.id = designator["id"] as? Int
        newPeople.name = designator["name"] as? String

        newNotification.designator = newPeople
    }

    do
    {
        try newNotification.managedObjectContext?.save()
    }
    catch let error as NSError
    {
        print(error.localizedDescription)
    }

数据模型:

let notif = ["message" : "testing",
                 "actor" : ["id": 1, "name": "jim"],
                 "designator" : ["id": 2, "name": "dave"]]

    let notif1 = ["message" : "testing 1",
                 "actor" : ["id": 1, "name": "jim21"],
                 "designator" : ["id": 2, "name": "dave"]]

Answer 1

解决重复创建问题的传统方法是Person使用该标识进行获取请求并更新,而不是创建新的.测试将告诉你,这也许是你的最佳选择.

凭借独特的约束,核心数据可以为您进行合并,但您需要告诉它如何.目前它正在通过抛出错误来合并,这不是很有用.你需要mergePolicy在上下文中设置NSMergeByPropertyObjectTrumpMergePolicy,然后尝试一下,看看结果是否真的是你想要的......