mysql循环获取结果集

do 
    {
        MYSQL_RES* res = mysql_store_result(con);
        if (i++ == 0)
        {
            MYSQL_ROW row;
            if (row = mysql_fetch_row(res))
            {
                int ret = atoi(row[0]);
                if (ret != 0)
                {
                    r = e_asc_errorcode::e_asc_errorcode_registe_already;
                }
                else
                {
                    ret_user_id = atoi(row[1]);
                }
            }
            else
            {
                r = e_asc_errorcode_unkown_error;
            }
        }
        mysql_free_result(res);
    } while (!mysql_next_result(con));