本文介绍了在领域迁移期间创建领域对象的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!
问题描述
您能够在迁移期间创建领域对象吗?我想提取现有领域对象的一部分,并使用该数据创建一个新对象,但是迁移总是挂断.这是我的迁移代码
Are you able to create a realm Object during a migration? I am wanting to extract part of an existing realm object and create a new object with that data, but the migration always hangs up. Here is my migration code
private class var migrationBlock: MigrationBlock { return { migration, oldSchemaVersion in if oldSchemaVersion < 1 { print("Shema Version 0") migration.enumerate(Transaction.className(), { (oldObject, newObject) -> Void in let oldDate = oldObject!["date"] as! NSDate let newTransactionDate = TransactionDate() newTransactionDate.date = oldDate try! Realm.getRealm().write { Realm.getRealm().add(newTransactionDate, update: true) } newObject!["_date"] = newTransactionDate }) } } }推荐答案
您可以在迁移过程中使用Migration.create(_:value:)创建对象.
You can use Migration.create(_:value:) to create object during migration.
realm.io/docs/swift/latest/api/Classes/Migration.html#/s:FC10RealmSwift9Migration6createFS0_FTSS5valuePSs9AnyObject__CS_13DynamicObject
它返回MigrationObject的实例.因此,您应该使用下标为属性分配一个值.
It returns MigrationObject's instance. So you should use subscripting to assign a value to its property.
let oldDate = oldObject!["date"] as! NSDate let newTransactionDate = migration.create(TransactionDate.className()) newTransactionDate["date"] = oldDate newObject!["_date"] = newTransactionDate更多推荐
在领域迁移期间创建领域对象
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