如何在Swift for Realm模型中设置主键 [英] How to set primary key in Swift for Realm model

问题描述

我在一个新的iOS Swift项目中使用Realm。我正在使用Xcode 6.0.1与iOS SDK 8.0和Realm 0.85.0

I'm using Realm in a new iOS Swift project. I'm using Xcode 6.0.1 with iOS SDK 8.0 and Realm 0.85.0

我正在尝试使用新的Realm主键功能，所以我可以做一个 addOrUpdateObject 。

I'm trying to use the new Realm primary key feature so I can do an addOrUpdateObject.

以下是一个示例模型：

import Foundation
import Realm

class Foo: RLMObject {
    dynamic var id = 0
    dynamic var title = ""

    func primaryKey() -> Int {
        return id
    }
}

以及我如何我试图添加/更新一个新对象：

And how I'm trying to add/update a new object:

let foo = Foo()
foo.title = titleField.text
foo.id = 1

// Get the default Realm
let realm = RLMRealm.defaultRealm()

// Add to the Realm inside a transaction
realm.beginWriteTransaction()
realm.addOrUpdateObject(foo)
realm.commitWriteTransaction()

我收到此错误：

RLMExecption'，原因：''Foo'没有主键，不能更新

RLMExecption', reason: ''Foo' does not have a primary key and can not be updated

以下是主键上的文档。我可能没有正确设置：
http://realm.io/docs/cocoa/0.85.0/api/Classes/RLMObject.html#//api/name/primaryKey

Here are the docs on the primary key. I'm probably not setting it correctly: http://realm.io/docs/cocoa/0.85.0/api/Classes/RLMObject.html#//api/name/primaryKey

最新文档现在在这里：
https://realm.io/docs/objc/latest/api/Classes/RLMObject.html#//api/name/primaryKey

Latest docs are here now: https://realm.io/docs/objc/latest/api/Classes/RLMObject.html#//api/name/primaryKey

推荐答案

primaryKey 需要是一个类函数，它返回作为主键的属性的名称，而不是实例方法返回主键的值。

primaryKey needs to be a class function which returns the name of the property which is the primary key, not an instance method which returns the value of the primary key.

class Foo: RLMObject {
    dynamic var id = 0
    dynamic var title = ""

    override class func primaryKey() -> String? {
        return "id"
    }
}

这篇关于如何在Swift for Realm模型中设置主键的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！