C++ sqlite- Error- what(): basic_string::_S_construct null not valid

I have a sqlite table SiteCode having following schema:

    CREATE TABLE SiteCode(
    ID INTEGER PRIMARY KEY,
    Code TEXT(3) UNIQUE NOT NULL DEFAULT 0);

The values in SiteCode are as follows:

   ID             Code      
----------      ----------
    7              789       
    8              78        
    9              785       
    10             998 

Following is the header file to access it using C++

DBAccess1.h

#ifndef LIB_DBAccess1_HH
#define LIB_DBAccess1_HH
using namespace std;

class sqliteDB {

private:
    int rc;
    char *zErrMsg;
    sqlite3 *db;
    const char *sql;
    sqlite3_stmt * stmt5;
    list<string> Site_Code_list;
public:
    //=================================XX====================================XX====================================//
                                   //=====SITE-CODE=====//                                   
                                //=====GET FUNCTION=====//
list<string> GET_Site_Code(const char* CodeB)
{
    int CodeA;

    list<string> Site_Code_list;

    int rc = sqlite3_open("/DBsqlite3/empdbv3.db", &db);

        if (rc != SQLITE_OK) {      
            cerr << "Cannot open database [ " << sqlite3_errmsg(db) << " ]" << endl;        
            sqlite3_close(db);      
        }

        sql = "SELECT Code FROM SiteCode WHERE ID= @ID;";

        rc = sqlite3_prepare_v2(db, sql, -1, &stmt5, 0);

        if(SQLITE_OK != rc) {
            cerr << "Failed to PREPARE SELECT statement for SiteCode Table [ " << sqlite3_errmsg(db) << " ]" << endl;
            sqlite3_finalize(stmt5);
            sqlite3_close(db);
            exit(1);
        }
        else {
            int Code_x = sqlite3_bind_parameter_index(stmt5, "@ID");

            char* buffer1=const_cast<char*>(CodeB);  //converting const char* to char*

            cout<<"Buffer1="<<buffer1<<endl;
            CodeA=atoi(buffer1);  //Converting char* to int
            cout<<"CodeA="<<CodeA<<endl;

            if(isdigit(CodeA)!= 0) {
                cout<<"\nPlease enter only digits\n"<<endl;
            }
            else {
                if((CodeA >= 000) && (CodeA <= 998)) {
                    sqlite3_bind_int(stmt5, Code_x, CodeA);
                    cout<<"Binding done successfully"<<endl;
                }
                else {
                    cout<< "Valid ID Should be between 000 to 998\n" <<endl;
                }
            }//else loop of (isdigit) ends here
        }//else loop of (cin.fail) ends here


    int column = sqlite3_column_count(stmt5);

    for(int i = 0; i < column; i++)
    {       
        cout << "Columns=" << column << endl;
        Site_Code_list.push_back(string((const char *) sqlite3_column_text(stmt5, i)));   // ORIGIN OF ERROR LINE-AS PER ME
        cout<<"Pushed back in List"<<endl;              
    }

    if(sqlite3_step(stmt5)==SQLITE_DONE) {
        cout<<"\nRecord fetching completed"<< endl;
    } 
    else {
        cout<<"\nERROR while fetching record from the SiteCode table[ " << sqlite3_errmsg(db) << " ]" << endl;
    }

    sqlite3_finalize(stmt5);
    sqlite3_close(db);

    return Site_Code_list; 
}

//=================================XX====================================XX====================================//

The main file is main.cpp

#include <iostream>
#include <sqlite3.h>
#include <stdlib.h>
#include <list>
#include <iterator>
#include <algorithm>
#include <cstring>
#include <unistd.h>
#include <string>
#include <cstdio>
#include <sstream>
#include <cctype>
#include <cstdlib>

#include "DBAccess1.h"
//#include "Check_Individual_Function1.h"

using namespace std ;

int main()
{

sqliteDB object1;

const char* value1 = "10";

object1.GET_Site_Code(value1);

cout << "\n\nAll the statement were executed properly\n\n";

return 0;
}

when i execute the program i get the following results with error:

Buffer1=10
CodeA=10
Binding done successfully
Columns=1
terminate called after throwing an instance of 'std::logic_error'
what():  basic_string::_S_construct null not valid
Aborted (core dumped)

As per my understanding, I believe the error is because I am returning a NULL string from the function GET_Site_Code. So I conclude that no data is getting pushed into the LIST- Site_Code_list.

As per my understanding, the line Site_Code_list.push_back(string((const char *) sqlite3_column_text(stmt5, i))); is the problem.

How do i solve it or how do I approach? Kindly Help.