Cant cout the result that what I want with MySQL and c++ - c++

Question

#include <iostream>
#include <Windows.h>
#include "jdbc/mysql_connection.h"
#include "jdbc/cppconn/driver.h"
#include "jdbc/cppconn/exception.h"
#include "jdbc/cppconn/resultset.h"
#include "jdbc/cppconn/statement.h"
#include "jdbc/cppconn/prepared_statement.h"
#ifdef _DEBUG
#pragma comment(lib, "debug/mysqlcppconn.lib")
#else
#pragma comment(lib, "mysqlcppconn.lib")
#endif
using namespace std;
std::string Utf8ToMultiByte(std::string utf8_str);
int main()
{
try
{
sql::Driver* driver;
sql::Connection* connection;
sql::Statement* statement;
sql::ResultSet* resultset;
driver = get_driver_instance();
connection = driver->connect("tcp://127.0.0.1:3306", "root", "");
if (connection == nullptr)
{
cout << "connect failed" << endl;
exit(-1);
}
connection->setSchema("logindata");
statement = connection->createStatement();
resultset = statement->executeQuery("insert into new_table(number, id, wincount, totalgameplay) values(4, 132, 232349, 123)");
resultset = statement->executeQuery("select * from new_table ");
for (;resultset->next();)
{
cout << resultset->getInt("id") << " : " <<
Utf8ToMultiByte(resultset->getString("wincount")) << " : " <<
Utf8ToMultiByte(resultset->getString("totalgameplay")) << endl;
}
delete resultset;
delete statement;
delete connection;
}
catch (sql::SQLException e)
{
cout << "# ERR: SQLException in " << __FILE__;
cout << "(" << __FUNCTION__ << ") on line " << __LINE__ << endl;
cout << "# ERR: " << e.what();
cout << " (MySQL error code: " << e.getErrorCode();
cout << ", SQLState: " << e.getSQLState() << " )" << endl;
}
return 0;
}
std::string Utf8ToMultiByte(std::string utf8_str)
{
std::string resultString; char* pszIn = new char[utf8_str.length() + 1];
strncpy_s(pszIn, utf8_str.length() + 1, utf8_str.c_str(), utf8_str.length());
int nLenOfUni = 0, nLenOfANSI = 0; wchar_t* uni_wchar = NULL;
char* pszOut = NULL;
// 1. utf8 Length
if ((nLenOfUni = MultiByteToWideChar(CP_UTF8, 0, pszIn, (int)strlen(pszIn), NULL, 0)) <= 0)
return nullptr;
uni_wchar = new wchar_t[nLenOfUni + 1];
memset(uni_wchar, 0x00, sizeof(wchar_t)*(nLenOfUni + 1));
// 2. utf8 --> unicode
nLenOfUni = MultiByteToWideChar(CP_UTF8, 0, pszIn, (int)strlen(pszIn), uni_wchar, nLenOfUni);
// 3. ANSI(multibyte) Length
if ((nLenOfANSI = WideCharToMultiByte(CP_ACP, 0, uni_wchar, nLenOfUni, NULL, 0, NULL, NULL)) <= 0)
{
delete[] uni_wchar; return 0;
}
pszOut = new char[nLenOfANSI + 1];
memset(pszOut, 0x00, sizeof(char)*(nLenOfANSI + 1));
// 4. unicode --> ANSI(multibyte)
nLenOfANSI = WideCharToMultiByte(CP_ACP, 0, uni_wchar, nLenOfUni, pszOut, nLenOfANSI, NULL, NULL);
pszOut[nLenOfANSI] = 0;
resultString = pszOut;
delete[] uni_wchar;
delete[] pszOut;
return resultString;
}
why I cant get result of table information?
does insert and select then cout is not proper process?
Also I try with PrepareStatement with above the select phrase. But I worked properly
I know that preparestatement and createstatement is different with dynamic parsing and static parsing. what is more efficient with adding information to database?