with tb as
(
  select 组编码, max(序号) as 序号
  from T1
  group by 组编码
)
select T1.*
from T1
inner join tb on tb.组编码 = T1.组编码
and tb.序号 = T1.序号

------解决方案--------------------
select a.* from tb a left join tb b on a.组编码=b.组编码 and a.序号<b.序号 where b.组编码 is null

------解决方案--------------------
SQL code
select 
*
from 
(select *,row_number()over(partition by 组编码 order by 序号 desc)  as Row from T1 )as a
where a.Row=1

------解决方案--------------------
SQL code

1、
select * from tb a
 where not exists(select 1 from tb where 组编码=a.组编码 and 序号>a.序号)
2、
select * from tb a
where (select count(1) from tb where 组编码=a.组编码 and 序号>a.序号)=0
3、
select * from tb a
where 序号=(select max(序号)from tb where 组编码=a.组编码)order by 序号
4、
select * from tb 
where 序号=(select top 1 序号 from tb where 组编码=a.组编码 order by 序号 desc)
5、
select * from tb a where 序号!<all(select  序号 from tb where 组编码=a.组编码)
6、-- sql 2005 以上版本
select * from 
(select *,rn=row_number()over(partition by 组编码 order by 序号 desc) from tb )as a
where a.rn=1

------解决方案--------------------
SQL code


select 组编码,max(序号),名称,规格,单位,价格 from T1
group by 组编码,名称,规格,单位,价格