存储过程+游标

declare @str varchar(8000)
declare @currentValue numeric(12)
declare @previousValue numeric(12)

 

declare @currentTime datetime
declare @previousTime datetime

 

set @str = ''

 

declare mycur cursor for
select S_value, timestamp  from  sj where S1 = @code order by TimeStamp

open mycur
fetch next from mycur into @previousValue, @previousTime

while @@FETCH_STATUS = 0
begin
    fetch next from mycur into @currentValue, @currentTime

 
  set @str = @str + ltrim(rtrim(str(@currentValue - @previousValue,15,0))) + '  '
  set @previousValue = @currentValue 

  set @previousTime = @currentTime 

end
close mycur

deallocate mycur

select @str
GO