sql - 不使用游标更新表格

Question

我有这样的数据

alt text http://img252.imageshack.us/img252/8518/data.png

我想根据 Id 更新 minP、maxP 和 agvP 列。我想要的结果是；

alt text http://img20.imageshack.us/img20/2029/updatedu.png

请帮忙。

Answer 1

尝试这样的事情:

update mt
set minp = a.minp,
maxp = a.maxp,
avgp = a.avgp
from mytable mt
join
(select id, min(price) as minp, max(price) as maxp, avg(price) as avgp
from mytable group by id) a on a.id = mt.id