declare @ta table(row_id int,time varchar(10),       amount numeric(12,2),   status  varchar(8))
insert @ta select 
 1          ,'10:20',        20.00       ,'yes' union select  
 2          ,'10:21',        30.00       ,'no' union select  
 3          ,'10:22',        40.00       ,'no' union select  
 4          ,'10:23',        60.00       ,'no'


declare @a int 
set @a = 70
update @ta 
set status  =  case when @a <= -amount then 'no' else 'yes'end , 
    @a = @a -amount  
where    status = 'no' 

select * from @ta
/*
row_id      time       amount         status   
----------- ---------- -------------- -------- 
1           10:20      20.00          yes
2           10:21      30.00          yes
3           10:22      40.00          yes
4           10:23      60.00          no

（所影响的行数为 4 行）
*/