c++ - 解析 S3Select 输出 AWS 开发工具包 C++

Question

我有以下代码片段。

#include <aws/core/Aws.h>
#include <aws/core/utils/logging/LogLevel.h>
#include <aws/s3/S3Client.h>
#include <aws/s3/S3Errors.h>
#include <aws/s3/model/SelectObjectContentRequest.h>
#include <aws/s3/model/InputSerialization.h>
#include <aws/s3/model/ExpressionType.h>
#include <aws/s3/model/ParquetInput.h>
#include <iostream>
using namespace Aws;

int main()
{
    //The Aws::SDKOptions struct contains SDK configuration options.
    //An instance of Aws::SDKOptions is passed to the Aws::InitAPI and
    //Aws::ShutdownAPI methods.  The same instance should be sent to both methods.
    SDKOptions options;
    options.loggingOptions.logLevel = Utils::Logging::LogLevel::Trace;
    Aws::InitAPI(options);

    Aws::Client::ClientConfiguration cfg;

    Aws::String region = "eu-west-1";
    cfg.region = region;


    S3::S3Client client(cfg,
            Aws::Client::AWSAuthV4Signer::PayloadSigningPolicy::Never,
            false);


    S3::Model::SelectObjectContentRequest request;
    request.SetBucket("my-bucket");
    request.SetKey("parquet_file.parquet");
    request.SetExpressionType(S3::Model::ExpressionType::SQL);
    request.SetExpression("SELECT * FROM s3object s LIMIT 5");

    S3::Model::InputSerialization inputSerialization;
    S3::Model::ParquetInput parquetInput;
    inputSerialization.SetParquet(parquetInput);
    request.SetInputSerialization(inputSerialization);

    S3::Model::OutputSerialization outputSerialization;
    S3::Model::CSVOutput csvOutput;
    outputSerialization.SetCSV(csvOutput);
    request.SetOutputSerialization(outputSerialization);

    auto s3_select_outcome =
        client.SelectObjectContent(request);
    if (s3_select_outcome.IsSuccess()) {
        std::cout << "Success" << std::endl;
    }
    else {
        std::cout << "Failed with error: " << s3_select_outcome.GetError() << std::endl;
    }

    //Before the application terminates, the SDK must be shut down.
    ShutdownAPI(options);
    return 0;
}

然而，正如这里所见，结果是 type Model::SelectObjectContentOutcome。通过遵循此处的文档，这包括一个Aws::NoResult，虽然有一个GetResult方法，但没有实际的方法来获取或解析结果。程序返回Success意味着请求实际上应该返回一些东西。有谁知道如何做到这一点？谢谢！

标签： c++amazon-web-servicesamazon-s3amazon-s3-select