CloudKit如何查询和获取数据？

Question

我是 Swift 的新手，本周才开始学习 CloudKit 的 iOS 应用程序项目。

数据库正常，我可以在数据库中添加记录和查找记录。

我运行向 CloudKit 发送查询并访问与查询相关的数据时遇到问题。

CloudKit 数据具有唯一标识符，因此搜索是针对这些标识符之一（因此查询应该只 return 一条记录）。然后我试图从该记录中获取三条信息 - "UPC"、"foodName" 和 "Ingredients"（所有字符串）

这是执行查询并尝试获取数据的代码部分。

let publicDatabase = CKContainer.defaultContainer().publicCloudDatabase

let predicate = NSPredicate(format: "UPC = %@", subStr)

let query = CKQuery(recordType: "Food", predicate: predicate)

publicDatabase.performQuery(query, inZoneWithID: nil,
                    completionHandler: ({results, error in

       if (error != nil) {
           dispatch_async(dispatch_get_main_queue()) {
                     print("CloudKit Error")
                            }
                        } else {
        if results!.count > 0 {

            var record = results as! CKRecord

            dispatch_async(dispatch_get_main_queue()) {

            print("UPC Found")
            let cloudUPC = record.objectForKey("UPC") as! CKAsset
            print("UPC from CloudKit \(cloudUPC)")

                }
            } else {
               dispatch_async(dispatch_get_main_queue()) {
                                    print("UPC Not Found")
                                }
                            }
                        }
                    }))

崩溃发生在此时

 var record = results as! CKRecord

and returns "EXC_Breakpoint(code = 1, subcode - 0x10047b7c)

关于如何解决这个问题有什么建议吗？

谢谢

Answer 1

谢谢rmaddy的建议。

这就是我修复代码的方式

let publicDatabase = CKContainer.defaultContainer().publicCloudDatabase

let predicate = NSPredicate(format: "UPC = %@", subStr)

let query = CKQuery(recordType: "Food", predicate: predicate)

publicDatabase.performQuery(query, inZoneWithID: nil,
                completionHandler: ({results, error in

                    if (error != nil) {
                        dispatch_async(dispatch_get_main_queue()) {
                            print("Cloud Error")
                        }
                    } else {
                        if results!.count > 0 {


          dispatch_async(dispatch_get_main_queue()) {


         for entry in results! {
         let cloudUPC = entry["UPC"] as? String
         print("UPC from CloudKit \(cloudUPC)")

         let cloudFoodName = entry["foodName"] as? String
         print("Name from CloudKit \(cloudFoodName)")

         let cloudIngredients = entry["Ingredients"] as? String
         print("Ingredients from CloudKit \(cloudIngredients)")

          }
        } else {
           dispatch_async(dispatch_get_main_queue()) {
                                print("UPC Not Found")
                            }
                        }
                    }
                }))

Answer 2

您需要先对记录中的项目编写 for 循环，然后打印每个 UPC 像那样：

for item in record {
print(item["UPC"]
print(item["foodName"]
}

CloudKit如何查询和获取数据？

How do I query and obtain data from CloudKit?

ios

swift

cloudkit