保存和获取 CloudKit 引用

Posted 2023-02-24

【中文标题】保存和获取 CloudKit 引用

【英文标题】：Saving & Fetching CloudKit References

【发布时间】：2018-10-10 14:47:25

【问题描述】：

我在使用 CloudKit 参考创建时遇到问题。数据正在保存到 CloudKit 中，但它没有引用其父级（列表）。不知道我做错了什么，任何帮助将不胜感激！

保存方法

var list: CKRecord?
var item: CKRecord?    

@objc func save() 
    let name = nameTextField.text! as NSString

    //Fetch Private Database
    let privateDatabase = CKContainer.default().privateCloudDatabase

    if item == nil 
        //Create Record
        item = CKRecord(recordType: RecordTypeItems)

        //Initialization Reference
        guard let recordID = list?.recordID else  return 
        let listReference = CKRecord.Reference(recordID: recordID, action: .deleteSelf)

        item?.setObject(listReference, forKey: "list")
    

    item?.setObject(name, forKey: "name")

    //Save Record
    privateDatabase.save(item!)  (record, error) in
        DispatchQueue.main.sync 
            self.processResponse(record: record, error: error)
        
    

获取方法

var list: CKRecord!
var items = [CKRecord]()

private func fetchItems() 
    //Fetch Private Database
    let privateDatabase = CKContainer.default().privateCloudDatabase

    //Initialize Query
    guard let recordID = list?.recordID else  return 
    let reference = CKRecord.Reference(recordID: recordID, action: .deleteSelf)
    let query = CKQuery(recordType: RecordTypeItems, predicate: NSPredicate(format: "list == %@", [reference]))


    //Configure Query
    query.sortDescriptors = [NSSortDescriptor(key: "name", ascending: true)]

    //Peform Query
    privateDatabase.perform(query, inZoneWith: nil)  (records, error) in
        DispatchQueue.main.sync 
            self.processResponseForQuery(records: records, error: error)
        
    

【问题讨论】：

您的问题不清楚，但是您是否尝试过查看 CloudKit Web 仪表板以查看引用是否已成功保存到服务器上的项目记录中？

【参考方案1】：

您在哪里创建查询以检索引用列表的项目，谓词格式字符串中的列表引用是否应该在数组内？如果您创建项目的引用，如 item?.setObject(listReference, forKey: "list")，CloudKit 将推断 list 字段为单个 CKRecord.Reference，因此查询将是：

let query = CKQuery(recordType: RecordTypeItems, predicate: NSPredicate(format: "list == %@", reference))