sequential query in C++ ????

[max]

I cannot write a code that make two query in cascade:

-I use PgTransaction(dbname)
-I use dbname.ExecTuplesOk("my query 1")

and this is working good, than i do another one:

- dbname.ExecTuplesOk("my query 2")

and this time it doesn't work at all!

Maybe i have to clear the query result but i can't find out how to do!

here is my code:

#include <iostream>
#include <iomanip>
#include "libpq++.h"
int main() {
const char* dbname = "dbname=river";
PgTransaction data(dbname);
int res = data.ExecTuplesOk("select * from pippo");
int res = data.ExecTuplesOk("select * from pluto");
}