SQL先按名字分组再按日期排序

select client，ID，taskdate from 表名
order by client, ID DESC, taskdate

select client，ID，taskdate from 表名
order by client, taskdate DESC, ID

select client，ID，taskdate from 表名 order BY client asc,taskdate,ID desc（如果让client为降序的话order by改成group by,asc改成desc,ID要升序desc改成asc）