declare @t table (id int)
insert into @t
select 1 union all
select 2 union all
select 3 union all
select 4 union all
select 5

select id,ltrim(id*100/(select count(1) from @t))+'%' as 计算  from @t
/*
id          计算
----------- -------------
1           20%
2           40%
3           60%
4           80%
5           100%
*/

------解决方案--------------------
SQL code

declare @t table (数量 int)
insert into @t
select 100 union all
select 200 union all
select 300 union all
select 400

select *,(select sum(数量) from @t where 数量<=t.数量) as 合计 from @t t
/*
数量          合计
----------- -----------
100         100
200         300
300         600
400         1000
*/