Question

我有一个类

中定义的领域数据库对象

class TPDailyRashifal: Object, Mappable {

    public required convenience init?(map: Map) {
      self.init()
      mapping(map: map)
    }

    dynamic var rashi: String = ""
    dynamic var rashiDetail: String = ""

    public func mapping(map: Map) {
      rashi       <- map["rashi"]
      rashiDetail <- map["rashifal"]
    }
    override static func primaryKey() -> String {
      return "rashi"
    }
}

我想在我的对象中添加这三个变量，如下所示

dynamic var date: String = ""
dynamic var fallIds: String = ""
dynamic var rating: Int = 0

我知道我的映射函数必须修改并添加以下内容。

    date        <- map["date"]
    fallIds     <- map["fallIds"]
    rating      <- map["rating"]

但我的

dynamic var rashi: String = ""

定义必须更改为

dynamic var rashi:  Int = 0

在我的Appdelegate，applicationDidFinishLaunchingWithOptions函数中，我写了

    Realm.Configuration.defaultConfiguration = Realm.Configuration(
        schemaVersion: 1,
        migrationBlock: { migration, oldSchemaVersion in
            if (oldSchemaVersion < 1) {
                print("Schema Version 0")
                // The enumerateObjects(ofType:_:) method iterates
                // over every Person object stored in the Realm file
                migration.enumerateObjects(ofType: TPDailyRashifal.className()) { oldObject, newObject in
                    // combine name fields into a single field
                    /*
                     To add these variables during migration
                     dynamic var date: String = ""
                     dynamic var fallIds: String = ""
                     dynamic var rating: Int = 0
                     */
                    let oldRashi = oldObject?["id"] as? Int
                 //   let newRashiId = 


                }
            }
    })

我很困惑，我应该在哪里开始在Realm对象中添加新变量。我已提到其他问题，但我无法赶上它们。

Answer 1

我相信你需要将你的“rashi”重命名为其他东西（假设在下面的例子中新的Int将是“rashi2”）。

migration.enumerateObjects(ofType: TPDailyRashifal.className()) { oldObject, newObject in
    newObject!["date"] = ""
    newObject!["fallIds"] = ""
    newObject!["rating"] = 0
    newObject!["rashi2"] = 0   // this version has a rashi2 (Int) instead of a rashi (String).
}

另请注意，如果需要通过string-to-int转换将旧rashi转换为rashi2，可以通过在此闭包中使用oldObject [“rashi”]来获取旧字符串，然后转换它并将rashi2设置为它而不是0。

Answer 2

Smarcat部分正确但后来我不得不做一些研究，现在就是。

    Realm.Configuration.defaultConfiguration = Realm.Configuration(
        schemaVersion: 1,
        migrationBlock: { migration, oldSchemaVersion in
            if (oldSchemaVersion < 1) {
                print("Schema Version 0")
                // The enumerateObjects(ofType:_:) method iterates
                // over every Person object stored in the Realm file
                migration.enumerateObjects(ofType: TPDailyRashifal.className()) { oldObject, newObject in
                    // combine name fields into a single field

                    newObject!["date"] = ""
                    newObject!["fallIds"] = ""
                    newObject!["rating"] = 0
                      newObject!["rashi2"] = 0
                }
                migration.renameProperty(onType: TPDailyRashifal.className(), from: "rashi", to: "rashi2")

            }
    })

我必须使用migration.renameProperty块将rashi重命名为rashi2。

领域数据库迁移，添加新对象并修改旧

2 个答案: