我有一个看起来像这样的表:
pk client value date
1 001 564 2012/5/1
2 002 245 2012/6/1
3 003 445 2012/6/6
4 001 845 2012/7/1
5 002 567 2012/8/1
6 001 123 2012/9/1
我知道这可以通过每组最大的n和自我加入来解决,但我无法搞清楚。
基本上这就是我想要的输出
client min(value) max(value) date_for_min(value) date_for_max(value)
001 123 845 2012/9/1 2012/7/1
002 245 567 2012/6/1 2012/8/1
003 445 445 2012/6/6 2012/6/6
棘手的部分是每个客户端只有一行具有最小/最大值,然后是其他列与最小/最大值一起。有什么想法吗?
答案 0 :(得分:1)
如果有一些最小值或最大值的行(对于同一个客户端),我已经给出了它们出现的最早日期:
select t1.client, t1.MinValue, t1.MaxValue, min(t2.date) as date_for_min_value, min(t3.date) as date_for_max_value
from (
select client, min(value) as MinValue, max(value) as MaxValue
from MyTable
group by client
) t1
inner join MyTable t2 on t1.client = t2.client and t1.MinValue = t2.Value
inner join MyTable t3 on t1.client = t3.client and t1.MaxValue = t3.Value
group by t1.client, t1.MinValue, t1.MaxValue
答案 1 :(得分:1)
您可以使用以下内容:
select distinct t1.client, t1.mnval, mindate.dt, t1.mxval, maxdate.dt
from
(
select min(value) mnval, max(value) mxVal, client
from yourtable
group by client
) t1
inner join yourtable t2
on t1.client = t2.client
inner join yourtable mindate
on t1.client = mindate.client
and t1.mnval = mindate.value
inner join yourtable maxdate
on t1.client = maxdate.client
and t1.mxVal = maxdate.value