SQL多行字段分组有关问题

select * from tb t where col2=(select max(col1) from tb where col1=t.col1)
------解决方案--------------------
SQL code
declare @表 table (id int,c1 int,c2 varchar(2),c3 varchar(2))insert into @表select 1,5,'发','人' union allselect 1,6,'哈','与' union allselect 1,7,'一','放' union allselect 2,5,'虾','你' union allselect 2,6,'屁','股' union allselect 2,8,'怕','爬' union allselect 8,5,'富','阿' union allselect 8,7,'倒','萨' union allselect 8,8,'但','怕'select * from @表 twhere c1=(select max(c1) from @表 where id=t.id) order by 1/*id          c1          c2   c3----------- ----------- ---- ----1           7           一    放2           8           怕    爬8           8           但    怕*/
------解决方案--------------------
SELECT id, MAX(name)
FROM tb
GROUP BY id
HAVING COUNT(*) = 1
------解决方案--------------------
SQL code
select *from tb twhere not exists(select 1 from tb where col1=t.col1 and col2>t.col2)