例子：
在表中有两个字段：id_no (varchar) , in_date (datetime) ，把in_date相同的记录的in_date依次累加1秒， 使in_date没有相同的记录。
以下为原始的数据:
id_no in_date
5791 2003-9-1 14:42:02
5792 2003-9-1 14:42:02
5794 2003-9-1 14:42:02
5795 2003-9-1 14:42:03
5796 2003-9-1 14:42:03
5797 2003-9-1 14:42:03
5831 2003-9-1 14:42:04
5832 2003-9-1 14:42:14
5833 2003-9-1 14:42:14
结果为：
id_no in_date
5791 2003-9-1 14:42:02
5792 2003-9-1 14:42:03
5794 2003-9-1 14:42:04
5795 2003-9-1 14:42:05
5796 2003-9-1 14:42:06
5797 2003-9-1 14:42:07
5831 2003-9-1 14:42:08
5832 2003-9-1 14:42:14
5833 2003-9-1 14:42:15
处理的方法：
--建立测试环境
create table a(id_no varchar(8),in_date datetime)
go
insert into a select '5791','2003-9-1 14:42:02'
union all select '5792','2003-9-1 14:42:02'
union all select '5794','2003-9-1 14:42:02'
union all select '5795','2003-9-1 14:42:03'
union all select '5796','2003-9-1 14:42:03'
union all select '5797','2003-9-1 14:42:03'
union all select '5831','2003-9-1 14:42:04'
union all select '5832','2003-9-1 14:42:04'
union all select '5833','2003-9-1 14:42:04'
union all select '5734','2003-9-1 14:42:02'
union all select '6792','2003-9-1 14:42:22'
union all select '6794','2003-9-1 14:42:22'
union all select '6795','2003-9-1 14:42:23'
union all select '6796','2003-9-1 14:42:23'
union all select '6797','2003-9-1 14:42:23'
union all select '6831','2003-9-1 14:42:34'
union all select '6832','2003-9-1 14:42:34'
union all select '6833','2003-9-1 14:42:54'
union all select '6734','2003-9-1 14:42:22'
go
--生成临时表，按照in_date排序
select * into # from a order by in_date
--相同的时间，加一秒。加完了不带重复的
declare @date1 datetime,@date2 datetime,@date datetime
update #
set @date=case when @date1=in_date or @date2>=in_date
then dateadd(s,1,@date2) else in_date end,
@date1=in_date,
@date2=@date,
in_date=@date
--更新到基本表中去
update a set a.in_date=b.in_date from
a a join # b on a.id_no=b.id_no
select * from a
drop table #,a
