Swift 在迁移期间添加和删除Realm.Object
我正在进行迁移,这需要从领域中删除对象,并用不同的类型替换它们 简而言之,我以前只有一个类型,现在正在创建层次结构,因此BaseItem现在需要是DerivedItem 我不确定实现这一目标的最佳方式 下面是我要尝试的:Swift 在迁移期间添加和删除Realm.Object,swift,migration,realm,Swift,Migration,Realm,我正在进行迁移,这需要从领域中删除对象,并用不同的类型替换它们 简而言之,我以前只有一个类型,现在正在创建层次结构,因此BaseItem现在需要是DerivedItem 我不确定实现这一目标的最佳方式 下面是我要尝试的: setSchemaVersion(kSchemaVersion, Realm.defaultPath, { migration, oldSchemaVersion in if oldSchemaVersion == 0 { let realm = Rea
setSchemaVersion(kSchemaVersion, Realm.defaultPath, { migration, oldSchemaVersion in
if oldSchemaVersion == 0 {
let realm = Realm()
realm.write({ () -> Void in
old = oldObject!
if old["type"] as! Int == 1 {
let textItem = TextItem()
textItem.text = old["text"] as! String
copyBaseItemCommon(old, textItem)
realm.add(textItem)
realm.delete(newObject!)
}
})
这些是添加和删除的方式吗
更新:
尝试此操作后,代码在第3行出现死锁:let realm=realm()
有人知道这种迁移的技术是什么吗?您使用的是更新的领域吗 根据文件 你应该这样做>>
let realm = Realm()
realm.write
{
realm.add(theObject)
realm.delete(theObject)
}
希望有帮助 下载领域时,您有一个示例项目。打开它,您将看到一个迁移演示 这是他们进行迁移的方式:
let migrationBlock: MigrationBlock = { migration, oldSchemaVersion in
if oldSchemaVersion < 1 {
migration.enumerate(Person.className()) { oldObject, newObject in
if oldSchemaVersion < 1 {
// combine name fields into a single field
let firstName = oldObject!["firstName"] as! String
let lastName = oldObject!["lastName"] as! String
newObject?["fullName"] = "\(firstName) \(lastName)"
}
}
}
}
setDefaultRealmSchemaVersion(1, migrationBlock)
/**
Create an `Object` of type `className` in the Realm being migrated.
:param: className The name of the `Object` class to create.
:param: object The object used to populate the object. This can be any key/value coding
compliant object, or a JSON object such as those returned from the methods in
`NSJSONSerialization`, or an `Array` with one object for each persisted
property. An exception will be thrown if any required properties are not
present and no default is set.
:returns: The created object.
*/
func create(className: String, value: AnyObject = default) -> RealmSwift.MigrationObject
/**
Delete an object from a Realm during a migration. This can be called within
`enumerate(_:block:)`.
:param: object Object to be deleted from the Realm being migrated.
*/
func delete(object: RealmSwift.MigrationObject)
在迁移块中使用它们,如下所示migration.create(“TextItem”,oldObject!)
请记住,在迁移过程中,您使用的是
迁移
对象,而不是领域。不幸的是,我发现在迁移过程中尝试更新领域会导致死锁。看来这是不可能的。谢谢!不知怎么的,我完全忘了看迁移类。