dao 获取表最大排序实现

public Long getMaxOrder(Long parentId) {
        Query query = this.getSession().createSQLQuery(
                "select max(ORDERID) from tbl_type where PARENTID =:parentId");
        query.setLong("parentId", parentId);
        List<Object> list = query.list();
        Long order = 0l;
        if (list != null && list.size() > 0) {
            if (list.get(0)!=null) {
                order = Long.parseLong(list.get(0).toString());
            }
        }
        if (order != null && order > 0) {
            return order + 1;
        } else {
            return 1l;
        }
}