快速提取AWS DynamoDB中的数据

Question

class ViewController: UIViewController {

@IBOutlet weak var NoSQLResultLabel: UILabel!

var teste : [AWSDynamoDBObjectModel]?

override func viewDidLoad() {
    super.viewDidLoad()

    query { (response, error) in
        if let erro = error {
            self.NoSQLResultLabel.text = String(erro)
            print("error: \(erro)")
        } else if response?.items.count == 0 {
            self.NoSQLResultLabel.text = String("0")
            print("No items")
        } else {
            self.NoSQLResultLabel.text = String(response!.items)
            print("success: \(response!.items)")
        }
    }

}

func query(completionHandler: (response: AWSDynamoDBPaginatedOutput?, error: NSError?) -> Void) {
    let objectMapper = AWSDynamoDBObjectMapper.defaultDynamoDBObjectMapper()
    let queryExpression = AWSDynamoDBQueryExpression()

    queryExpression.keyConditionExpression = "#userId = :userId"
    queryExpression.expressionAttributeNames = ["#userId": "userId",]
    queryExpression.expressionAttributeValues = [":userId": AWSIdentityManager.defaultIdentityManager().identityId!,]

    objectMapper.query(UserLocations.self, expression: queryExpression, completionHandler: {(response: AWSDynamoDBPaginatedOutput?, error: NSError?) -> Void in
        dispatch_async(dispatch_get_main_queue(), {
            completionHandler(response: response, error: error)
        })
    })
}

}

我创建了一个query函数以从数据库中提取数据，然后在viewDidLoad中将其调用。

当我运行模拟器时，它返回以下内容：

succeso: [<MySampleApp.UserLocations: 0x7fa25480f560> {
    "_lastModifiedDate" = "2016-10-01 14:27:05 +0000";
    "_latitude" = "37.33233141";
    "_longitude" = "-122.0312186";
    "_userId" = "us-east-1:be2dfccb-caac-4b45-bd36-6fa8964e78d9";
    "_userLocationID" = "sendBox-userLocationID-500000";
}]

现在我需要单独显示这些值

我尝试了这个：

print("sucesso: \\(response!.items["_userId"])")

对于它，返回_userId内的_userId

但是它显示了这个错误：

Cannot subscript a value of type [AWSDynamoDBObjectModel] with an index type String

谁能告诉我如何提取此数组的值？

Answer 1

要访问项目及其属性，您可以执行以下操作

let userLocation = response?.items[0] as! UserLocations
print("\(userLocation._userId!)")