CloudKit --尽管delete工作，但未能用我自己的CKRecord.ID修改现有的CKRecord

Question

对于我将保存到CloudKit的每一条记录，我都会传入一个使用自己的UUID创建的CKRecord.ID，如下所示：

        let recordId = CKRecord.ID(recordName: myOwnUUID, zoneID: .default)
        let record = CKRecord(recordType: recordType, recordID: recordId)
        record.setValue(title, forKey: "title")
        ...

UUID是我的数据模型的一部分，不会对每个记录进行更改。

我能够成功地删除记录，再次传入相同的CKRecord.ID：

    func delete(_ item: MyItem, completion: @escaping (Result<Int, Error>) -> ()) {

        let myOwnUUID = item.id // this is the exact same UUID that I used to create/save the record the first time.
        let recordId = CKRecord.ID(recordName: myOwnUUID, zoneID: .default)

        ckDatabase.delete(withRecordID: recordId) { (recordId, error) in
            DispatchQueue.main.async {
                if let error = error {
                    completion(.failure(error))
                    return
                }
                guard recordId != nil else {
                    completion(.failure(CloudKitHelperError.castFailure))
                    return
                }
                completion(.success(0))
            }
        }
    }

所以，删除工作没有任何问题。

但是当我尝试修改记录时，我得到了错误："Server Record Changed". "record to insert already exists"

}>

下面是我的修改代码：

    func modify(_ item: MyItem, completion: @escaping (Result<Int, Error>) -> ()) {

        let myOwnUUID = item.id // this is the exact same UUID that I used to create/save the record the first time.
        let recordId = CKRecord.ID(recordName: myOwnUUID, zoneID: .default)

        let record = CKRecord(recordType: recordType, recordID: recordId)
        
        record.setObject(item.title as __CKRecordObjCValue, forKey: "title")

        let configuration = CKOperation.Configuration()
        configuration.timeoutIntervalForRequest = 10
        configuration.timeoutIntervalForResource = 10

        let operation = CKModifyRecordsOperation(recordsToSave: [record], recordIDsToDelete: nil)
        operation.configuration = configuration
        
        operation.modifyRecordsCompletionBlock = { (savedRecords, _, error) in
            DispatchQueue.main.async {
                if savedRecords != nil, error == nil {
                    completion(.success(0))
                }
                if let error = error {
                    completion(.failure(error))
                }
            }
        }
        
        ckDatabase.add(operation)
    }

顺便说一下，ckDatabase设置为：ckDatabase = CKContainer(identifier: "iCloud.com.xxx.yyy").privateCloudDatabase。

那么，为什么我不能使用我用来创建记录的CKRecord.ID来修改现有的记录呢？删除操作清楚地识别了它。

Answer 1

通常，您应该始终从后端获取CKRecord对象，而不是在内存中构造它。只有这样，cloudkit才会正确地初始化它。

首先给出这个记录的代码在哪里，而不是下面的代码？

let record = CKRecord(recordType: recordType, recordID: recordId)

可选地，检查记录保存策略。

见这个答案为您提供详细信息。