Question

SQL中怎么写能得到这一行减去上一行的值，循环处理多行~多谢

求 上下列的差值！

Answer 1

select a.value-b.value from (select row_number() over (order by 字段) xh,value from t1) a,
(select row_number() over (order by 字段) xh,value from t2) b where a.xh=b.xh-1

Answer 2

create table biao22 ( a int)

insert biao22 select '10'

insert biao22 select '9'

insert biao22 select '20'

insert biao22 select '25'

insert biao22 select '18'

insert biao22 select '7'

select * from biao22

create table #A ( id int identity(1,1), a int)

insert into #a(a)
select * from biao22

declare @a int
declare @b int

select @a=min(id) from #a

select @b=max(id) from #a

while (@a<@b)

begin

select t1.a-t2.a from #a t1,#a t2 where t1.id=t2.id+1 and t1.id=@a

set @a=@a+1

end