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| 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)
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> select max(name), max(age),grade from stu group by grade; +-----------+----------+-------+ | max(name) | max(age) | grade | +-----------+----------+-------+ | c | 13 | 1 | | f | 13 | 2 | +-----------+----------+-------+ 2 rows in set (0.01 sec)
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