我怎样才能得到它的年龄是最大在他的年级

Question

我如何能得到谁的年龄最大在他的等级名称的名称

表信息：

mysql> select * from stu; 
+----+------+------+-------+ 
| id | name | age | grade | 
+----+------+------+-------+ 
| 1 | a | 11 |  1 | 
| 2 | b | 12 |  1 | 
| 3 | c | 13 |  1 | 
| 4 | d | 11 |  2 | 
| 5 | e | 12 |  2 | 
| 6 | f | 13 |  2 | 
+----+------+------+-------+ 
6 rows in set (0.00 sec) 

mysql> describe stu; 
+-------+---------+------+-----+---------+----------------+ 
| Field | Type | Null | Key | Default | Extra   | 
+-------+---------+------+-----+---------+----------------+ 
| id | int(11) | NO | PRI | NULL | auto_increment | 
| name | char(1) | YES |  | NULL |    | 
| age | int(11) | YES |  | NULL |    | 
| grade | int(11) | YES |  | NULL |    | 
+-------+---------+------+-----+---------+----------------+ 
4 rows in set (0.00 sec) 

这样我可以得到

最大年龄和年级，但我怎么能得到这个年龄的名字是他的成绩最高。

mysql> select max(age),grade from stu group by grade; 
+----------+-------+ 
| max(age) | grade | 
+----------+-------+ 
|  13 |  1 | 
|  13 |  2 | 
+----------+-------+ 
2 rows in set (0.00 sec) 

Answer 1

你可以试试这个：

SELECT A.* 
FROM STU A 
INNER JOIN (SELECT MAX(AGE) AS MAX_AGE,GRADE FROM STU GROUP BY GRADE) B ON A.GRADE = B.GRADE AND A.AGE= B.MAX_AGE 

Answer 2

试试这个：

select max(name), max(age),grade from stu 
group by grade