cppconn resultsetmetadata get columns count,get column name,resultset get value

//Model/mysqlhelper.h
#ifndef __mysqlhelper_h__
#define __mysqlhelper_h__
#include <chrono>
#include <ctime>
#include <fstream>
#include <iomanip>
#include <iostream>
#include <sstream>
#include <thread>
#include <unistd.h>
#include <uuid/uuid.h>
#include <mysql/mysql.h>
#include <cppconn/connection.h>
#include <cppconn/driver.h>
#include <cppconn/exception.h>
#include <cppconn/metadata.h>
#include <cppconn/parameter_metadata.h>
#include <cppconn/prepared_statement.h>
#include <cppconn/resultset.h>
#include <cppconn/resultset_metadata.h>

using namespace std;
using namespace std::chrono;

class mysqlhelper
{
public: 　

      string get_time_now();

      void mysqlreaddemo();

};

#endif

//model/mysqlhelper.cpp
#include "model/mysqlhelper.h"

string mysqlhelper::get_time_now()

{

chrono::time_point now = system_clock::now();

chrono::microseconds ms = duration_cast<milliseconds>(now.time_since_epoch()) % 1000;

time_t rawTime = system_clock::to_time_t(now);

struct tm tmInfo = *localtime(&rawTime);

stringstream ss;

ss << std::put_time(&tmInfo, "%Y%m%d%H%M%S") << std::setfill('0') << std::setw(3) << ms.count();

string dtStr = ss.str();

ss.str(std::string());

return dtStr;

}

void mysqlhelper::mysqlreaddemo()
{
    try
    {
        sql::Driver *driver;
        sql::Connection *conn;
        sql::ResultSet *res;
        sql::Statement *stmt;
        sql::PreparedStatement *pstmt;
        sql::ResultSetMetaData *resMetaData;
        driver = get_driver_instance();
        conn = driver->connect("tcp://127.0.0.1:3306", "username", "password");
        conn->setSchema("db");
        stmt = conn->createStatement();
        res = stmt->executeQuery("select Idx,Id,Author,Comment,Content,Name,Title from Book");
        resMetaData=res->getMetaData();
        unsigned int columnsCount= resMetaData->getColumnCount();
        while (res->next())
        {
            for(int i=1;i<columnsCount;i++)
             { 
                cout<<resMetaData->getColumnName(i).asStdString()<<":"<<res->getString(i)<<",";
             }
             cout<<resMetaData->getColumnName(columnsCount).asStdString()<<":"<<res->getString(columnsCount);
             cout<<endl<<endl;
        }
        delete res;
        delete stmt;
        delete conn;
    }
    catch (const sql::SQLException &e)
    {
        std::cerr << e.what() << '\n';
        cout<<e.getErrorCode()<<endl<<e.getSQLState()<<endl<<e.getSQLStateCStr()<<endl;
    }
    cout<<get_time_now()<<",finished in "<<__FUNCTION__<<","<<__LINE__<<endl;
}


//main.cpp
#include "model/mysqlhelper.h"

void mysqlreaddemo()
{
    mysqlhelper mh;
    mh.mysqlreaddemo();
}

int main(int args, char **argv)
{
    mysqlreaddemo();
}

 

 

Compile

g++ -g -std=c++2a -I. *.cpp ./model/*.cpp -o h1 -luuid -ljsoncpp -lmysqlcppconn

 

 

 

 

Run

./h1

 

 

 

 

Query from mysql table

select Idx,Id,Author,Comment,Content,Name,Title from Book;