表结构脚本：
CREATE TABLE `student_grade` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`name` varchar(64) DEFAULT NULL,
`grade` int(11) DEFAULT NULL,
`subject` varchar(64) DEFAULT NULL,
PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=10 DEFAULT CHARSET=utf8;
表数据：
--方法1：
SELECT
s.*
FROM
student_grade s
WHERE
s.grade = (
SELECT
MAX(grade)
FROM
student_grade
WHERE
NAME = s.`name`
ORDER BY
`name`
)
--方法2：
SELECT
s.*
FROM
student_grade s,
(
SELECT
`name`,
MAX(grade) grade
FROM
student_grade
GROUP BY
`name`
) b
WHERE
s. `name` = b.`name` AND s.grade = b.grade
--方法
SELECT
s.*
FROM
student_grade s
INNER JOIN (
SELECT
`name`,
MAX(grade) grade
FROM
student_grade
GROUP BY
`name`
) b ON s. NAME = b. NAME
AND s.grade = b.grade