C++ query data from mysql and limit page via key word 'limit startIndex,interval'

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//Util.h
#ifndef Util_H
#define Util_H
#include <chrono>
#include <ctime>
#include <fstream>
#include <functional>
#include <future>
#include <iostream>
#include <random>
#include <sstream>
#include <thread>
#include <unistd.h>
#include <uuid/uuid.h>
#include <vector>
#include "mysql_connection.h"
#include <cppconn/driver.h>
#include <cppconn/resultset.h>
#include <cppconn/exception.h>
#include <cppconn/statement.h>
#include <cppconn/prepared_statement.h>

using namespace std;

class Util
{
public:
    void mysqlSelectLimitPage(int interval);
};

#endif

//Util.cpp
#include "Model/Util.h"
void Util::mysqlSelectLimitPage(int interval)
{
    try
    {
        sql::Driver *dvr;
        sql::Connection *conn;
        sql::Statement *stmt;
        sql::ResultSet *res;
        sql::PreparedStatement *pStmt;

        dvr = get_driver_instance();
        conn = dvr->connect("tcp://127.0.0.1:3306", "root", "password);
        conn->setSchema("db");

        stmt = conn->createStatement();
        res = stmt->executeQuery("select count(*) from Book;");
        int rowsCount = -1;
        while (res->next())
        {
            rowsCount = res->getInt(1);
            cout << "rowsCount=" << rowsCount << endl;
        }

        int startIndex = 0;
        int loops = rowsCount / interval;
        int remainder = rowsCount % interval;

        stringstream sqlSS;

        for (int i = 0; i <= loops+1; i++)
        {
            sqlSS << "select Idx from Book limit ";
            sqlSS << startIndex << "," << interval << ";" << endl; 
            res = stmt->executeQuery(sqlSS.str());
            if (res->rowsCount() > 0)
            {
                cout << endl << "SQL=" << sqlSS.str();
                while (res->next())
                {
                    cout << res->getInt(1) << "\t";
                }
                cout << endl << "Loop=" << i << endl;
                startIndex += interval;
                sqlSS = stringstream();
            }
        }

        delete res;
        delete stmt;
        delete conn;
    }
    catch (sql::SQLException &e)
    {
        std::cerr << e.what() << '\n';
        cout << e.getErrorCode() << endl;
        cout << e.getSQLState() << endl;
    }
}

//main.cpp
#include "Model/Util.h"
void mysqlLimitPage28(int interval);


int main(int args, char **argv)
{
    mysqlLimitPage28(atoi(argv[1]));
}

void mysqlLimitPage28(int interval)
{
    Util ul;
    ul.mysqlSelectLimitPage(interval);
}

Compile

g++ -std=c++2a -I. *.cpp ./Model/*.cpp -o h1 -luuid -lpthread -lmysqlcppconn;

Execute

./h1 100;

Make  a summary,coding in for loop and the startIndex should incremente by interval,the interval is fixed.

select Idx from Book limit startIndex,interval;

the startIndex=startIndex+interval;

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