       conn = PQconnectdb(conninfo);       if (PQstatus(conn) == CONNECTION_BAD)       {         fprintf(stderr, "connection to database failed using PQconnectdb\n");         fprintf(stderr, "%s", PQerrorMessage(conn));         return -0;       }       fprintf(stdout, "Connection to database established using PQconnectdb\n");       PQfinish(conn);        /* Connect database using PQconnectdb