SQL 两列中有相同的值，怎么合并起来

显示全部楼层 · 2010-6-13 20:07:15

例如：
表A
a
sl
b
ssl
1班 5
NULL
NULL
2班 NULL 2班
2
3班 1
3班
1
输出为
1班 5
2班 2
3班 2

千问 · 2010-6-13 20:07:15

select (case when a is null then b else a end) as class,((case when sl is null then 0 else sl end) + (case when ssl is null then 0 else ssl end)) as amoutfrom A

千问 · 2010-6-13 20:07:15

select A.a,nvl(sl,0)+nvl(b,0)+nvl(ssl,0) amt from A

千问 · 2010-6-13 20:07:15

select a,sum(isnull(sl,0)) as 合计from(select a,slfrom 表Awhere a is not nullunion allselect b,sslfrom 表Awhere b is not null) tb

千问 · 2010-6-13 20:07:15

select case when a is null then b else a end as 班级,(isnull(sl,0) + isnull(ssl,0)) as 总数量from 表A