高手请进，比较复杂

[casper1]

TABLE1:
ID MC AGE
1 A 5
2 A 7
3 A 8
4 A 5
5 B 1
6 B 3
7 C 4
8 C 3
9 C 3
通过select * from table t where age=(select min(age) from table where MC=t.MC ) 得到下面的结果(得到字段AGE（按MC分组）的最小值的记录)：
ID MC AGE
1 a 5
4 a 5
5 b 1
8 c 3
9 c 3
那要再通过怎么样才能得到下面的结果：（上面的结果集中取ID小的记录）
ID MC AGE
1 A 5
4 B 1
7 C 3

[csdyyr]

DECLARE @TB TABLE(ID INT,MC VARCHAR(1),AGE INT)
INSERT @TB
SELECT 1,  'A',  5 UNION ALL 
SELECT 2,  'A',  7 UNION ALL 
SELECT 3,  'A',  8 UNION ALL 
SELECT 4,  'A',  5 UNION ALL 
SELECT 5,  'B',  1 UNION ALL 
SELECT 6,  'B',  3 UNION ALL 
SELECT 7,  'C',  4 UNION ALL 
SELECT 8,  'C',  3 UNION ALL 
SELECT 9,  'C',  3


SELECT * FROM @TB AS A  WHERE NOT EXISTS(SELECT 1 FROM @TB WHERE MC=A.MC AND ID<A.ID)
/*
ID          MC   AGE         
----------- ---- ----------- 
1           A    5
5           B    1
7           C    4
*/

[playwarcraft]

select min(A.id) as ID,A.mc,A.age
from T A
inner join
(
select mc,min(age) as age
from t
group by mc
) B
on A.mc=B.mc and A.age=B.age
group by A.mc,A.age

[playwarcraft]

Create table  T (ID INT,MC VARCHAR(1),AGE INT)
INSERT T
SELECT 1,  'A',  5 UNION ALL 
SELECT 2,  'A',  7 UNION ALL 
SELECT 3,  'A',  8 UNION ALL 
SELECT 4,  'A',  5 UNION ALL 
SELECT 5,  'B',  1 UNION ALL 
SELECT 6,  'B',  3 UNION ALL 
SELECT 7,  'C',  4 UNION ALL 
SELECT 8,  'C',  3 UNION ALL 
SELECT 9,  'C',  3
Go
select min(A.id) as ID,A.mc,A.age 
from T A 
inner join 
( 
select mc,min(age) as age 
from t 
group by mc 
) B 
on A.mc=B.mc and A.age=B.age 
group by A.mc,A.age
/*
id     mc      age
-----------------------
1	A	5
5	B	1
8	C	3

*/
GO
drop table T

[sdhdy]

select * from table1 a where not exists(select 1 from table1 where  MC=a.MC and id<a.id)

[dawugui]

select ID ,MC, AGE from
(
  select *, px = (select count(1) from tb  where mc = t.mc and (age < t.age or (age=t.age and id < t.id))) + 1 from tb t
) m
where px = 1
order by mc

[dawugui]

create TABLE tb(ID INT,MC VARCHAR(1),AGE INT)
INSERT tb
SELECT 1,  'A',  5 UNION ALL 
SELECT 2,  'A',  7 UNION ALL 
SELECT 3,  'A',  8 UNION ALL 
SELECT 4,  'A',  5 UNION ALL 
SELECT 5,  'B',  1 UNION ALL 
SELECT 6,  'B',  3 UNION ALL 
SELECT 7,  'C',  4 UNION ALL 
SELECT 8,  'C',  3 UNION ALL 
SELECT 9,  'C',  3

select ID ,MC, AGE from
(
  select *, px = (select count(1) from tb  where mc = t.mc and (age < t.age or (age=t.age and id < t.id))) + 1 from tb t
) m
where px = 1
order by mc

drop table tb

/*
ID          MC   AGE         
----------- ---- ----------- 
1           A    5
5           B    1
8           C    3

（所影响的行数为 3 行）
*/