ios - 如何使用 Swift 打印 DynamoDB 查询结果

Question

在对 DynamoDB 表进行查询后，我试图打印查询结果。稍后我会在表格中显示它，但现在我只想确保它正常工作。查询有效并且没有任何错误。我认为它与我不理解的分页功能有关。我尝试阅读文档，但对我没有帮助。

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

    queryExpression.keyConditionExpression = "#userId = :userId AND #genre < :genre"
    queryExpression.filterExpression = "#author > :author"
    queryExpression.expressionAttributeNames = [
        "#userId": "userId",
        "#genre": "genre",
        "#author": "author",
    ]
    queryExpression.expressionAttributeValues = [
        ":userId": AWSIdentityManager.defaultIdentityManager().identityId!,
        ":genre": "fiction",
        ":author": "Taylor",
    ]

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


let completionHandler = {(response: AWSDynamoDBPaginatedOutput?, error: NSError?) -> Void in
    if let error = error {
        var errorMessage = "Failed to retrieve items. \(error.localizedDescription)"
        if (error.domain == AWSServiceErrorDomain && error.code == AWSServiceErrorType.AccessDeniedException.rawValue) {
            errorMessage = "Access denied. You are not allowed to perform this operation."
        }
    }else {


        print("I did it" )
        print(response)


    }
}

Answer 1

AWSDynamoDBPaginatedOutput 有一个名为 items 的属性.您应该打印出数组的内容。