-- 建表
create table t1(
    b int,
    i int,
    o int,
    e int,
    d datetime default getdate()
)

-- 插入数据
insert into t1 
select 100,10,20,null,'2008-07-01' union all
select null,20,30,null,'2008-07-02' union all
select null,50,20,null,'2008-07-03' union all
select null,50,20,null,'2008-07-04'  

-- 存储过程
create procedure prDoSomething
as
declare @b int,
    @i int,
    @o int,
    @e int,
    @d datetime
declare cur cursor for
select b,i,o,d from t1
open cur
fetch next from cur into @b,@i,@o,@d
while(@@fetch_status = 0)
begin
    update t1 set e = @b + @i - @o where d = @d
    update t1 set b = @b + @i - @o where d = (select min(d) from t1 where d > @d)
    fetch next from cur into @b,@i,@o,@d
end
close cur
deallocate cur

-- 执行procedure
exec prDoSomething

-- 查询
select * from t1

-- 清理 
drop table t1
drop procedure prDoSomething

b           i           o           e           d                     
----------- ----------- ----------- ----------- -----------------------
100         10          20          90          2008-07-01 00:00:00.000
90          20          30          80          2008-07-02 00:00:00.000
80          50          20          110         2008-07-03 00:00:00.000
110         50          20          140         2008-07-04 00:00:00.000

（所影响的行数为 4 行）