帮忙写一下这个sql语句?

[dongxsoft]

表结构如下：
id
Macid
Value
HappenTime
在表中求出：

Macid, Max(Value) as 最大值, HappenTime as 最大值对应时刻,
Min(Value) as 最小值,HappenTime as 最小值对应时刻

那位高手帮忙给一下写法，或思路

[wangxl430]

select macid,value as 最大值,happentime as 最大值对应时刻
from biao
where biao.value=(select max(value) from biao)

另外一个一样
access2000是可以的，不知你用的是什么。

[wangxl430]

如果你的意思是最大值和最小值都放在同一条纪录中的话
我看可能不行吧，放在两条纪录中肯定没问题。
用
union
select macid,value as 最小值,happentime as 最小值对应时刻
from biao
where biao.value=(select min(value) from biao)

[wangxl430]

或者直接or (biao.value=(select min(value) from biao)

[longlongge]

select macid, max(value) as 最大值,happentime as 最大值对应时刻 from biao

select macid, min(value) as 最小值,happentime as 最小值对应时刻 from biao

[dejoy]

用以下语句
select macid,max(value) as 最大值,happentime as 最大值对应时刻,value as 最小值,happentime as 最小值对应时刻
from biao
where biao.value in (select max(value) from biao union select min(value))
group by value

[3yugui]

这样ok吗？？？

[dejoy]

错了，重贴，用以下语句
select macid,max(value) as 最大值,happentime as 最大值对应时刻,value as 最小值,happentime as 最小值对应时刻
from biao
where biao.value in (select max(value) from biao a union select min(b.value) from biao b)
group by value

[dejoy]

select macid,
(select max(value) from biao tmp1 ) as 最大值,
(select happentime from biao tmp2 where value=(select max(value) from biao tm1 )) as 最大值对应时刻,
(select min(value) from biao tmp3 ) as 最小值,
(select happentime from biao tmp4 where value=(select min(value) from biao tm2)) as 最小值对应时刻
from biao

不过没什么效率

[dongxsoft]

to dejoy(燕青) ( )
这样是不是效率很低，不过这到是我要的答案，因为我还要用macid分组以及限定查询时间段，哇，这样不累死才怪。
有没有更好一点的办法

[blazingfire]

select macid, max(value) as 最大值,
(Select min(value) from biao) as 最小值,happentime as 最大值对应时刻 ,
(Select happentime from biao where value=min(value))as 最小值对应时刻
from biao

[dongxsoft]

我用临时表解决