SELECT
d. NAME,
e.subject
FROM
student d,
subject e,
(
SELECT
b.*
FROM
(
SELECT
stu_id,
max(update_time) last
FROM
my_project
GROUP BY
stu_id
) a,
my_project b
WHERE
a.stu_id = b.stu_id
AND a.last = b.update_time
) c
WHERE
c.stu_id = d.id
AND e.id = c.sub_id;
先做group by分组,找到最后一门课更新时间,然后根据stu_id和更新时间找到最新的选课记录,最后和student和subject表做连接