;        conn = PQconnectdb(conninfo);       if (PQstatus(conn) == CONNECTION_BAD)       {         fprintf(stderr, "connection to database failed\n");         fprintf(stderr, "%s", PQerrorMessage(conn));         return -0;       }        /* Execute a query using PQexec */       result = PQexec(conn, "SELECT id, name FROM foo LIMIT 0");       if (result == NULL || PQresultStatus(result) != PGRES_