如何将字段添加到Realm数据库的模式？

我正在寻求为我的Realm数据库方案添加另一个属性（箭头指向），同时学习如何使用迁移功能 .

class FeesPaid: Object {
    dynamic var fileNumber = ""
    dynamic var forMonth = ""
    dynamic var amount: Float = 0.0
    dynamic var balance: Float = 0.0   <-------
    dynamic var date = ""
}

我一直在按照Realm.io的说明进行操作，并且已经将代码复制到第一个块中并将其放入我的"application(application:didFinishLaunchingWithOptions:)"函数中，该函数位于"AppDelegate.swift"文件中 .

let config = Realm.Configuration(
   // Set the new schema version. This must be greater than the previously used
   // version (if you've never set a schema version before, the version is 0).
   schemaVersion: 1,

   // Set the block which will be called automatically when opening a Realm with
   // a schema version lower than the one set above
   migrationBlock: { migration, oldSchemaVersion in
      // We haven’t migrated anything yet, so oldSchemaVersion == 0
      if (oldSchemaVersion < 1) {
          // Nothing to do!
          // Realm will automatically detect new properties and removed properties
          // And will update the schema on disk automatically
      }
   }
)

// Tell Realm to use this new configuration object for the default Realm
Realm.Configuration.defaultConfiguration = config

// Now that we've told Realm how to handle the schema change, opening the file
// will automatically perform the migration
let clients = try! Realm()

Realm网站上此块下方的声明指出：
"At the very minimum all we need to do is to update the version with an empty block to indicate that the schema has been upgraded (automatically) by Realm."
（上述if语句中的注释似乎支持此声明无需其他任何操作 . ）

然而，当我运行我的应用程序时，我不断收到错误：

fatal error: 'try!' expression unexpectedly raised an error: Error Domain=io.realm Code=0 "Migration is required for object type 'FeesPaid' due to the following errors:
- Property 'balance' has been added to latest object model." UserInfo={NSLocalizedDescription=Migration is required for object type 'FeesPaid' due to the following errors:
- Property 'balance' has been added to latest object model.}: file /Library/Caches/com.apple.xbs/Sources/swiftlang/swiftlang-700.1.101.15/src/swift/stdlib/public/core/ErrorType.swift, line 50

那么我做错了什么？

我不需要枚举或预先填写新字段中的任何值 . 我只需要在我的方案中使用新字段 .