declare @dt datetime
set @dt=getdate()
select top 1000 *,
(select datediff(ms,@dt,getdate())) as ms
from Table_1
declare @dt datetime
set @dt=getdate()
select top 1000 * from Table_1
union all
select datediff(ms,@dt,getdate()),null,null,null--要有跟表一样的列数和类型才能合并
