–>title:生成測試數據
–>author:wufeng4552
–>date :2009-09-21 15:08:41
declare @t table([col1] int,[col2] int,[col3] int,[col4] int,[col5] int,[col6] int,[col7] int)
insert @t
select 1,10,20,30,40,50,60 union all
select 2,60,30,45,20,52,85 union all
select 3,87,56,65,41,14,21
–方法1
select [col1],
max([col2])maxcol
from
(select [col1],[col2] from @t
union all
select [col1],[col3] from @t
union all
select [col1],[col4] from @t
union all
select [col1],[col5] from @t
union all
select [col1],[col6] from @t
union all
select [col1],[col7] from @t
)t
where [col2] between 20 and 60 –條件限制
group by [col1]
/*
col1 maxcol
———– ———–
1 60
2 60
3 56
(3 個資料列受到影響)
*/
–方法2
select [col1],
(select max([col2])from
(
select [col2]
union all select [col3]
union all select [col4]
union all select [col5]
union all select [col6]
union all select [col7]
)t
where [col2] between 20 and 60) as maxcol –指定查詢範圍
from @t
/*
(3 個資料列受到影響)
col1 maxcol
———– ———–
1 60
2 60
3 56
*/