可以利用开源软件 rapidCsv 读入csv文件，然后用MultithreadedTableWriter接口写入数据，示例代码如下：

#include "MultithreadedTableWriter.h"
#include "DolphinDB.h"
#include "Util.h"
#include "rapidcsv.h"
#include <string>
#include <vector>
#include <thread>

using namespace std;
using namespace dolphindb;

Constant *createDateTime(string str) {
	int year, month, day, hour, minute, second;
	year = atoi(str.substr(0, 4).c_str());
	month = atoi(str.substr(5, 2).c_str());
	day = atoi(str.substr(8, 2).c_str());
	hour = atoi(str.substr(11, 2).c_str());
	minute = atoi(str.substr(14, 2).c_str());
	second = atoi(str.substr(17, 2).c_str());
	return Util::createDateTime(year, month, day, hour, minute, second);
}

int main(int argc, char *argv[]) {
	DBConnection::initialize();
	DBConnection conn;
	string host = "127.0.0.1";
	int port = 8848;
	string userId = "admin";
	string password = "123456";

	string path = "d:/data/devices_big/devices_big_readings.csv";

	try {
		vector<COMPRESS_METHOD> compress;
		compress.push_back(COMPRESS_DELTA);
		compress.push_back(COMPRESS_LZ4);
		compress.push_back(COMPRESS_DELTA);
		compress.push_back(COMPRESS_LZ4);
		compress.push_back(COMPRESS_LZ4);
		compress.push_back(COMPRESS_LZ4);
		compress.push_back(COMPRESS_LZ4);
		compress.push_back(COMPRESS_LZ4);
		compress.push_back(COMPRESS_LZ4);
		compress.push_back(COMPRESS_DELTA);
		compress.push_back(COMPRESS_DELTA);
		compress.push_back(COMPRESS_LZ4);
		compress.push_back(COMPRESS_LZ4);

		MultithreadedTableWriter writer("127.0.0.1", 8848, "admin", "123456", "dfs://iot", "readings",
			false, false, NULL, 10000, 1, 10, "device_id", &compress);

		rapidcsv::Document doc(path, rapidcsv::LabelParams(-1, -1));
		std::vector<string> time = doc.GetColumn<string>(0);
		std::vector<string> device_id = doc.GetColumn<string>(1);
		std::vector<int> battery_level = doc.GetColumn<int>(2);
		std::vector<string> battery_status = doc.GetColumn<string>(3);
		std::vector<double> battery_temperature = doc.GetColumn<double>(4);
		std::vector<string> bssid = doc.GetColumn<string>(5);
		std::vector<double> cpu_avg_1min = doc.GetColumn<double>(6);
		std::vector<double> cpu_avg_5min = doc.GetColumn<double>(7);
		std::vector<double> cpu_avg_15min = doc.GetColumn<double>(8);
		std::vector<long long> mem_free = doc.GetColumn<long long>(9);
		std::vector<long long> mem_used = doc.GetColumn<long long>(10);
		std::vector<int> rssi = doc.GetColumn<int>(11);
		std::vector<string> ssid = doc.GetColumn<string>(12);

		int rowNum = time.size();

		ErrorCodeInfo errorInfo;

		long long startTime = Util::getEpochTime();
		
		for (int i = 0; i < rowNum; i++) {
			if (writer.insert(errorInfo, 
				createDateTime(time[i]),
				device_id[i],
				battery_level[i],
				battery_status[i],
				battery_temperature[i],
				bssid[i],
				cpu_avg_1min[i],
				cpu_avg_5min[i],
				cpu_avg_15min[i],
				mem_free[i],
				mem_used[i],
				(short)rssi[i],
				ssid[i]
				) == false) {
				//此处不会执行到
				cout << "insert failed: " << errorInfo.errorInfo << endl;
				break;
			}
				
		}
		//检查目前MTW的状态
		MultithreadedTableWriter::Status status;
		writer.getStatus(status);
		if (status.hasError()) {
			cout << "error in writing: " << status.errorInfo << endl;
		}
		writer.waitForThreadCompletion();
		//再次检查完成后的MTW状态
		writer.getStatus(status);
		if (status.hasError()) {
			cout << "error after write complete: " << status.errorInfo << endl;
			//获取未写入的数据
			std::vector<std::vector<ConstantSP>*> unwrittenData;
			writer.getUnwrittenData(unwrittenData);
			cout << "unwriterdata length " << unwrittenData.size() << endl;
		}
			   		 
		cout << "Insert Time " << Util::getEpochTime() - startTime << " ms" << endl;
		//检查最后写入结果
		cout << conn.run("select count(*) from pt")->getString() << endl;


	}
	catch (std::exception &e) {
		cerr << "Failed to insert table, with exception: " << e.what() << endl;
	}



}