create table #tab(aa int,bb nvarchar(10),cc int,dd int) 
insert into #tab(aa,bb,cc,dd) select 1,'b',1,12  
insert into #tab(aa,bb,cc,dd) select 2,'c',1,20  
insert into #tab(aa,bb,cc,dd) select 3,'b',2,20  
insert into #tab(aa,bb,cc,dd) select 4,'d',1,30  
insert into #tab(aa,bb,cc,dd) select 5,'a',1,40  
insert into #tab(aa,bb,cc,dd) select 6,'d',2,10  
insert into #tab(aa,bb,cc,dd) select 7,'d',3,12  
insert into #tab(aa,bb,cc,dd) select 8,'c',2,-11  
insert into #tab(aa,bb,cc,dd) select 9,'a',2,12  
insert into #tab(aa,bb,cc,dd) select 10,'b',3,-10  
insert into #tab(aa,bb,cc,dd) select 11,'d',4,-10  
select * from #tab order by bb,aa

declare @aa int
declare @bb varchar(10)
declare @dd int
declare curdel cursor static for
select aa,bb,dd from #tab where dd < 0
open curdel
fetch next from curdel into @aa,@bb,@dd
while @@fetch_status = 0
begin
    update #tab set dd = dd + @dd where bb = @bb and aa = (select max(aa) from #tab where bb= @bb and aa < @aa)
    delete from #tab where bb = @bb and aa = @aa
    fetch next from curdel into @aa,@bb,@dd
end
close curdel
deallocate curdel
select * from #tab order by bb ,aa
drop table #tab

create table tb1(aa int,bb nvarchar(10),cc int,dd int) 
insert into tb1 select 1,'b',1,12  
insert into tb1 select 2,'c',1,20  
insert into tb1 select 3,'b',2,20  
insert into tb1 select 4,'d',1,30  
insert into tb1 select 5,'a',1,40  
insert into tb1 select 6,'d',2,10  
insert into tb1 select 7,'d',3,12  
insert into tb1 select 8,'c',2,-11  
insert into tb1 select 9,'a',2,12  
insert into tb1 select 10,'b',3,-10  
insert into tb1 select 11,'d',4,-10  

select * from 
(
  select aa,bb,cc,dd = case when dd > 0 then isnull((select top 1 dd from tb1 where bb = t.bb and cc = t.cc + 1 and dd < 0 order by cc desc),0) + dd else dd end from tb1 t 
) m
where dd >= 0 
order by bb, cc

drop table tb1

/*
aa          bb         cc          dd          
----------- ---------- ----------- ----------- 
5           a          1           40
9           a          2           12
1           b          1           12
3           b          2           10
2           c          1           9
4           d          1           30
6           d          2           10
7           d          3           2

（所影响的行数为 8 行）
*/