SQL 关于sum的问题

declare @count int
select @count=count(*) from dbo.Orders
select  top 3 OrderID,Freight,其它总汇 from Orders,(select sum(Freight) as 其它总汇 from  (select top (@count-3) OrderID,Freight from Orders order by Freight asc ) as temptable) as sumother order by Freight desc

declare @count int,
@departsum float
select @count=count(*) from dbo.Orders
select @departsum=sum(Freight) from (select top (@count-3) OrderID,Freight from Orders order by Freight asc) as tablepart
if object_id('tempdb..#tabletmep') is not null
drop table #tabletmep
select  top 3 OrderID,Freight into #tabletmep from dbo.Orders order by Freight desc
insert #tabletmep values(@departsum)
select * from #tabletmep order by freight desc