public ResultSet runUpdate2(String sql) {
        ResultSet rs=null;
        try {
            stat.executeUpdate(sql,stat.RETURN_GENERATED_KEYS);
            rs=stat.getGeneratedKeys();
        } catch (SQLException ex) {
            Logger.getLogger(SQLHelper.class.getName()).log(Level.SEVERE, null, ex);
        }
        return rs;
    }