Mysql学生课程表SQL面试集合

 

现有如下2个表，根据要求写出SQL语句。

student表：编号(sid)，姓名(sname)，性别(sex)

course表：编号(sid)，科目(subject)，成绩(score)

 

 问题1：查询出所有科目总成绩最高的学生姓名及总成绩

方式一）：

1 select s.sid,s.sname,sum(c.score) as z
2 from course c
3 left join student s
4 on c.sid = s.sid
5 group by c.sid,s.sname
6 order by z desc 
7 limit 1

 

方式二）：

 1 SELECT
 2     sname
 3 FROM
 4     student
 5 WHERE
 6     sid IN (
 7         SELECT
 8             sid
 9         FROM
10             (
11                 SELECT
12                     sid,
13                     sum(score) AS z
14                 FROM
15                     grade
16                 GROUP BY
17                     sid
18                 ORDER BY
19                     z DESC
20                 LIMIT 1
21             ) AS qw
22     )
23 UNION
24     (
25         SELECT
26             sum(score) AS z
27         FROM
28             grade
29         GROUP BY
30             sid
31         ORDER BY
32             z DESC
33         LIMIT 1
34     )