学生表 Student
create table Student(Sid varchar(6), Sname varchar(10), Sage datetime, Ssex varchar(10));
insert into Student values('01' , '赵雷' , '1990-01-01' , '男');
insert into Student values('02' , '钱电' , '1990-12-21' , '男');
insert into Student values('03' , '孙风' , '1990-05-20' , '男');
insert into Student values('04' , '李云' , '1990-08-06' , '男');
insert into Student values('05' , '周梅' , '1991-12-01' , '女');
insert into Student values('06' , '吴兰' , '1992-03-01' , '女');
insert into Student values('07' , '郑竹' , '1989-07-01' , '女');
insert into Student values('08' , '王菊' , '1990-01-20' , '女')成绩表 SC
create table SC(Sid varchar(10), Cid varchar(10), score decimal(18,1));
insert into SC values('01' , '01' , 80);
insert into SC values('01' , '02' , 90);
insert into SC values('01' , '03' , 99);
insert into SC values('02' , '01' , 70);
insert into SC values('02' , '02' , 60);
insert into SC values('02' , '03' , 80);
insert into SC values('03' , '01' , 80);
insert into SC values('03' , '02' , 80);
insert into SC values('03' , '03' , 80);
insert into SC values('04' , '01' , 50);
insert into SC values('04' , '02' , 30);
insert into SC values('04' , '03' , 20);
insert into SC values('05' , '01' , 76);
insert into SC values('05' , '02' , 87);
insert into SC values('06' , '01' , 31);
insert into SC values('06' , '03' , 34);
insert into SC values('07' , '02' , 89);
insert into SC values('07' , '03' , 98)
课程表 Course
create table Course(Cid varchar(10),Cname varchar(10),Tid varchar(10));
insert into Course values('01' , '语文' , '02');
insert into Course values('02' , '数学' , '01');
insert into Course values('03' , '英语' , '03')教师表 Teacher
create table Teacher(Tid varchar(10),Tname varchar(10));
insert into Teacher values('01' , '张三');
insert into Teacher values('02' , '李四');
insert into Teacher values('03' , '王五')
1. 查询" 01 "课程比" 02 "课程成绩高的学生的信息及课程分数
with A as
(select sid, cid, score from sc where cid = 01),
B as
(select sid, cid, score from sc where cid = 02),
C as
(select a.sid, a.score as score_01, b.score as score_02
from A a
left join B b
on a.sid = b.sid
and a.score > b.score)
select t1.*, c.score_01, c.score_02
from Student t1
left join C c
on t1.sid = c.sid
where c.score_01 > c.score_02select s.*, a.score as score_01, b.score as score_02
from student s,
(select sid, score from sc where cid=01) a,
(select sid, score from sc where cid=02) b
where a.sid = b.sid and a.score > b.score and s.sid = a.sid
+------+--------+---------------------+------+----------+----------+
| Sid | Sname | Sage | Ssex | score_01 | score_02 |
+------+--------+---------------------+------+----------+----------+
| 02 | 钱电 | 1990-12-21 00:00:00 | 男 | 70.0 | 60.0 |
| 04 | 李云 | 1990-08-06 00:00:00 | 男 | 50.0 | 30.0 |
+------+--------+---------------------+------+----------+----------+2. 查询平均成绩大于等于 60 分的同学的学生编号和学生姓名和平均成绩
with A as
(select SID,round(avg(score),2) as AVG_SCORE from sc group by SID having avg(score)>60)
select
b.SID,
b.sname,
a.AVG_SCORE
from student b
right join A a on b.sid = a.sid
+------+--------+-----------+
| sid | sname | avg_score |
+------+--------+-----------+
| 01 | 赵雷 | 89.67 |
| 02 | 钱电 | 70 |
| 03 | 孙风 | 80 |
| 05 | 周梅 | 81.5 |
| 07 | 郑竹 | 93.5 |
+------+--------+-----------+3. 查询在 SC 表存在成绩的学生信息
with A as (select distinct SID from SC )
select b.* from A a left join student b on a.sid = b.sid;select * from student where sid in (select sid from sc where score is not null);
+------+--------+---------------------+------+
| Sid | Sname | Sage | Ssex |
+------+--------+---------------------+------+
| 01 | 赵雷 | 1990-01-01 00:00:00 | 男 |
| 02 | 钱电 | 1990-12-21 00:00:00 | 男 |
| 03 | 孙风 | 1990-05-20 00:00:00 | 男 |
| 04 | 李云 | 1990-08-06 00:00:00 | 男 |
| 05 | 周梅 | 1991-12-01 00:00:00 | 女 |
| 06 | 吴兰 | 1992-03-01 00:00:00 | 女 |
| 07 | 郑竹 | 1989-07-01 00:00:00 | 女 |
+------+--------+---------------------+------+4. 查询所有同学的学生编号、学生姓名、选课总数、所有课程的总成绩(没成绩的显示为 null )
select a.sid, a.sname, COUNT(b.cid) as 选课总数, SUM(b.score) as 总成绩
from student a
left join sc b
on a.sid = b.sid
group by a.sid, a.sname
order by a.sid
+------+--------+--------------+-----------+
| sid | sname | 选课总数 | 总成绩 |
+------+--------+--------------+-----------+
| 01 | 赵雷 | 3 | 269 |
| 02 | 钱电 | 3 | 210 |
| 03 | 孙风 | 3 | 240 |
| 04 | 李云 | 3 | 100 |
| 05 | 周梅 | 2 | 163 |
| 06 | 吴兰 | 2 | 65 |
| 07 | 郑竹 | 2 | 187 |
| 08 | 王菊 | 0 | NULL |
+------+--------+--------------+-----------+5. 查有成绩的学生信息,并显示每门课的成绩
select a.sid,
a.sname,
COUNT(b.cid) as 选课总数,
SUM(b.score) as 总成绩,
SUM(case when cid = 01 then score else null end) as score_01,
SUM(case when cid = 02 then score else null end) as score_02,
SUM(case when cid = 03 then score else null end) as score_03
from student a, sc b
where a.sid = b.sid
group by a.sid, a.sname
order by a.sid+------+--------+--------------+-----------+----------+----------+----------+
| sid | sname | 选课总数 | 总成绩 | score_01 | score_02 | score_03 |
+------+--------+--------------+-----------+----------+----------+----------+
| 01 | 赵雷 | 3 | 269.0 | 80.0 | 90.0 | 99.0 |
| 02 | 钱电 | 3 | 210.0 | 70.0 | 60.0 | 80.0 |
| 03 | 孙风 | 3 | 240.0 | 80.0 | 80.0 | 80.0 |
| 04 | 李云 | 3 | 100.0 | 50.0 | 30.0 | 20.0 |
| 05 | 周梅 | 2 | 163.0 | 76.0 | 87.0 | NULL |
| 06 | 吴兰 | 2 | 65.0 | 31.0 | NULL | 34.0 |
| 07 | 郑竹 | 2 | 187.0 | NULL | 89.0 | 98.0 |
+------+--------+--------------+-----------+----------+----------+----------+6. 查询「李」姓老师的数量
select count(*) from Teacher where TNAME like '李%';+----------+
| count(*) |
+----------+
| 1 |
+----------+7. 查询学过「张三」老师授课的同学的信息
select a.*
from student a
left join SC b
on a.sid = b.sid
left join Course c
on b.cid = c.cid
left join Teacher d
on c.tid = d.tid
where d.tname = '张三';select *
from student
where sid in (select sid
from sc, course, teacher
where sc.cid = course.cid
and course.tid = teacher.tid
and tname = '张三')
order by SID;+------+--------+---------------------+------+
| Sid | Sname | Sage | Ssex |
+------+--------+---------------------+------+
| 01 | 赵雷 | 1990-01-01 00:00:00 | 男 |
| 02 | 钱电 | 1990-12-21 00:00:00 | 男 |
| 03 | 孙风 | 1990-05-20 00:00:00 | 男 |
| 04 | 李云 | 1990-08-06 00:00:00 | 男 |
| 05 | 周梅 | 1991-12-01 00:00:00 | 女 |
| 07 | 郑竹 | 1989-07-01 00:00:00 | 女 |
+------+--------+---------------------+------+8. 查询没有学全所有课程的同学的信息
with A as
(select sid from SC group by sid having count(cid) < 3)
select * from student right join A on student.sid = A.sid
select *
from student
where sid in (select sid from sc group by sid having count(cid) < 3);+------+--------+---------------------+------+
| Sid | Sname | Sage | Ssex |
+------+--------+---------------------+------+
| 05 | 周梅 | 1991-12-01 00:00:00 | 女 |
| 06 | 吴兰 | 1992-03-01 00:00:00 | 女 |
| 07 | 郑竹 | 1989-07-01 00:00:00 | 女 |
+------+--------+---------------------+------+9. 查询和" 01 "号的同学学习的课程完全相同的其他同学的信息
select * from student where sid in (
select B.sid
from
(select sid,
sum(case when cid=01 then 1 else 0 end) as course_01,
sum(case when cid=02 then 1 else 0 end) as course_02,
sum(case when cid=03 then 1 else 0 end) as course_03
from sc where sid = 01 group by sid) A,
(select sid,
sum(case when cid=01 then 1 else 0 end) as course_01,
sum(case when cid=02 then 1 else 0 end) as course_02,
sum(case when cid=03 then 1 else 0 end) as course_03
from sc where sid != 01 group by sid) B
where A.course_01=B.course_01 and A.course_02=B.course_02 and A.course_03=B.course_03
)select * from Student
where Sid in(
select Sid from SC
where Cid in (select Cid from SC where Sid = '01') and Sid <>'01'
group by Sid
having COUNT(Cid)>=3
)+------+--------+---------------------+------+
| Sid | Sname | Sage | Ssex |
+------+--------+---------------------+------+
| 02 | 钱电 | 1990-12-21 00:00:00 | 男 |
| 03 | 孙风 | 1990-05-20 00:00:00 | 男 |
| 04 | 李云 | 1990-08-06 00:00:00 | 男 |
+------+--------+---------------------+------+10. 查询至少有一门课与学号为" 01 "的同学所学相同的同学的信息
select * from Student where Sid in(
select distinct Sid from SC where Cid in(
select Cid from SC where Sid='01'
)
)+------+--------+---------------------+------+
| Sid | Sname | Sage | Ssex |
+------+--------+---------------------+------+
| 01 | 赵雷 | 1990-01-01 00:00:00 | 男 |
| 02 | 钱电 | 1990-12-21 00:00:00 | 男 |
| 03 | 孙风 | 1990-05-20 00:00:00 | 男 |
| 04 | 李云 | 1990-08-06 00:00:00 | 男 |
| 05 | 周梅 | 1991-12-01 00:00:00 | 女 |
| 06 | 吴兰 | 1992-03-01 00:00:00 | 女 |
| 07 | 郑竹 | 1989-07-01 00:00:00 | 女 |
+------+--------+---------------------+------+11. 查询没学过"张三"老师讲授的任一门课程的学生姓名
select sname
from student
where sname not in (select s.sname
from student s, course c, teacher t, sc
where s.sid = sc.sid
and sc.cid = c.cid
and c.tid = t.tid
and t.tname = '张三')+--------+
| sname |
+--------+
| 吴兰 |
| 王菊 |
+--------+12. 查询两门及其以上不及格课程的同学的学号，姓名及其平均成绩
select s.sid,s.sname,avg(score)
from student s, sc
where s.sid = sc.sid
and score < 60
group by s.sid,s.sname
having count(score) >= 2+------+--------+------------+
| sid | sname | avg(score) |
+------+--------+------------+
| 04 | 李云 | 33.33333 |
| 06 | 吴兰 | 32.50000 |
+------+--------+------------+13. 检索" 01 "课程分数小于 60，按分数降序排列的学生信息
select s.*, score
from student s, sc
where cid = 01
and score < 60
and s.sid = sc.sid
order by score descwith A as
(select *
from sc
where cid = 1
and score < 60)
select b.*, A.score
from student B
right join A
on a.sid = b.sid
order by a.score desc+------+--------+---------------------+------+-------+
| Sid | Sname | Sage | Ssex | score |
+------+--------+---------------------+------+-------+
| 04 | 李云 | 1990-08-06 00:00:00 | 男 | 50.0 |
| 06 | 吴兰 | 1992-03-01 00:00:00 | 女 | 31.0 |
+------+--------+---------------------+------+-------+14. 按平均成绩从高到低显示所有学生的所有课程的成绩以及平均成绩
select sid,
sum(case when cid=01 then score else null end) as score_01,
sum(case when cid=02 then score else null end) as score_02,
sum(case when cid=03 then score else null end) as score_03,
round(avg(score),2)
from sc group by sid
order by avg(score) desc+------+----------+----------+----------+------------+
| sid | score_01 | score_02 | score_03 | avg(score) |
+------+----------+----------+----------+------------+
| 07 | NULL | 89.0 | 98.0 | 93.50000 |
| 01 | 80.0 | 90.0 | 99.0 | 89.66667 |
| 05 | 76.0 | 87.0 | NULL | 81.50000 |
| 03 | 80.0 | 80.0 | 80.0 | 80.00000 |
| 02 | 70.0 | 60.0 | 80.0 | 70.00000 |
| 04 | 50.0 | 30.0 | 20.0 | 33.33333 |
| 06 | 31.0 | NULL | 34.0 | 32.50000 |
+------+----------+----------+----------+------------+15、查询各科成绩最高分、最低分和平均分，以如下形式显示：课程 ID，课程 name，最高分，最低分，平均分，及格率，中等率，优良率，优秀率(及格为>=60，中等为：70-80，优良为：80-90，优秀为：>=90）。
要求输出课程号和选修人数，查询结果按人数降序排列，若人数相同，按课程号升序排列
select c.cid as 课程号, c.cname as 课程名称, count(*) as 选修人数,
max(score) as 最高分, min(score) as 最低分, avg(score) as 平均分,
sum(case when score >= 60 then 1 else 0 end)/count(*) as 及格率,
sum(case when score >= 70 and score < 80 then 1 else 0 end)/count(*) as 中等率,
sum(case when score >= 80 and score < 90 then 1 else 0 end)/count(*) as 优良率,
sum(case when score >= 90 then 1 else 0 end)/count(*) as 优秀率
from sc, course c
where c.cid = sc.cid
group by c.cid,c.cname
order by count(*) desc, c.cid asc+-----------+--------------+--------------+-----------+-----------+-----------+-----------+-----------+-----------+-----------+
| 课程号 | 课程名称 | 选修人数 | 最高分 | 最低分 | 平均分 | 及格率 | 中等率 | 优良率 | 优秀率 |
+-----------+--------------+--------------+-----------+-----------+-----------+-----------+-----------+-----------+-----------+
| 01 | 语文 | 6 | 80.0 | 31.0 | 64.50000 | 0.6667 | 0.3333 | 0.3333 | 0.0000 |
| 02 | 数学 | 6 | 90.0 | 30.0 | 72.66667 | 0.8333 | 0.0000 | 0.5000 | 0.1667 |
| 03 | 英语 | 6 | 99.0 | 20.0 | 68.50000 | 0.6667 | 0.0000 | 0.3333 | 0.3333 |
+-----------+--------------+--------------+-----------+-----------+-----------+-----------+-----------+-----------+-----------+16. 按平均成绩进行排序，显示总排名和各科排名，Score 重复时合并名次
select s.*, rank_01, rank_02, rank_03, rank_total
from student s
left join (select sid, dense_rank() over(partition by cid order by score desc) as rank_01 from sc where cid=01) A on s.sid=A.sid
left join (select sid, dense_rank() over(partition by cid order by score desc) as rank_02 from sc where cid=02) B on s.sid=B.sid
left join (select sid, dense_rank() over(partition by cid order by score desc) as rank_03 from sc where cid=03) C on s.sid=C.sid
left join (select sid, dense_rank() over(order by avg(score) desc) as rank_total from sc group by sid) D on s.sid=D.sid
order by rank_total asc+------+--------+---------------------+------+---------+---------+---------+------------+
| Sid | Sname | Sage | Ssex | rank_01 | rank_02 | rank_03 | rank_total |
+------+--------+---------------------+------+---------+---------+---------+------------+
| 08 | 王菊 | 1990-01-20 00:00:00 | 女 | NULL | NULL | NULL | NULL |
| 07 | 郑竹 | 1989-07-01 00:00:00 | 女 | NULL | 2 | 2 | 1 |
| 01 | 赵雷 | 1990-01-01 00:00:00 | 男 | 1 | 1 | 1 | 2 |
| 05 | 周梅 | 1991-12-01 00:00:00 | 女 | 2 | 3 | NULL | 3 |
| 03 | 孙风 | 1990-05-20 00:00:00 | 男 | 1 | 4 | 3 | 4 |
| 02 | 钱电 | 1990-12-21 00:00:00 | 男 | 3 | 5 | 3 | 5 |
| 04 | 李云 | 1990-08-06 00:00:00 | 男 | 4 | 6 | 5 | 6 |
| 06 | 吴兰 | 1992-03-01 00:00:00 | 女 | 5 | NULL | 4 | 7 |
+------+--------+---------------------+------+---------+---------+---------+------------+17. 统计各科成绩各分数段人数：课程编号，课程名称，[100-85]，[85-70]，[70-60]，[60-0] 及所占百分比
select c.cid as 课程编号, c.cname as 课程名称, A.*
from course c,
(select cid,
sum(case when score >= 85 then 1 else 0 end)/count(*) as Percent_100_85,
sum(case when score >= 70 and score < 85 then 1 else 0 end)/count(*) as Percent_85_70,
sum(case when score >= 60 and score < 70 then 1 else 0 end)/count(*) as Percent_70_60,
sum(case when score < 60 then 1 else 0 end)/count(*) as Percent_60_0
from sc group by cid) A
where c.cid = A.cid+--------------+--------------+------+--------+--------+--------+--------+
| 课程编号 | 课程名称 | cid | 100_85 | 85_70 | 70_60 | 60_0 |
+--------------+--------------+------+--------+--------+--------+--------+
| 01 | 语文 | 01 | 0.0000 | 0.6667 | 0.0000 | 0.3333 |
| 02 | 数学 | 02 | 0.5000 | 0.1667 | 0.1667 | 0.1667 |
| 03 | 英语 | 03 | 0.3333 | 0.3333 | 0.0000 | 0.3333 |
+--------------+--------------+------+--------+--------+--------+--------+18. 查询各科成绩前三名的记录
select cid, score
from sc a
where (select count(1)
from sc b
where a.cid = b.cid
and a.score < b.score) < 3
order by cid, score desc;| Cid | score |
+------+-------+
| 01 | 80.0 |
| 01 | 80.0 |
| 01 | 76.0 |
| 02 | 90.0 |
| 02 | 89.0 |
| 02 | 87.0 |
| 03 | 99.0 |
| 03 | 98.0 |
| 03 | 80.0 |
| 03 | 80.0 |
+------+-------+19. 查询出只选修两门课程的学生学号和姓名
select s.sid, s.sname, count(cid)
from student s, sc
where s.sid = sc.sid
group by s.sid, s.sname
having count(cid)=2+------+--------+------------+
| sid | sname | count(cid) |
+------+--------+------------+
| 05 | 周梅 | 2 |
| 06 | 吴兰 | 2 |
| 07 | 郑竹 | 2 |
+------+--------+------------+20. 查询名字中含有「风」字的学生信息
select * from student where sname like '%风%'+------+--------+---------------------+------+
| Sid | Sname | Sage | Ssex |
+------+--------+---------------------+------+
| 03 | 孙风 | 1990-05-20 00:00:00 | 男 |
+------+--------+---------------------+------+21. 查询 1990 年出生的学生名单
select * from student where substr(sage,0,4) = '1990';+------+--------+------------+------+
| Sid | Sname | Sage | Ssex |
+------+--------+------------+------+
| 01 | 赵雷 | 1990-01-01 | 男 |
| 02 | 钱电 | 1990-12-21 | 男 |
| 03 | 孙风 | 1990-05-20 | 男 |
| 04 | 李云 | 1990-08-06 | 男 |
| 08 | 王菊 | 1990-01-20 | 女 |
+------+--------+------------+------+22. 成绩不重复，查询选修「张三」老师所授课程的学生中，成绩最高的学生信息及其成绩
select
a.*,b.score
from student A,SC B,Course C,Teacher D
where a.sid = b.sid
and b.cid = c.cid
and c.tid = d.tid
and d.tname = '张三'
and rownum<2
order by b.score+------+--------+---------------------+------+-------+
| Sid | Sname | Sage | Ssex | score |
+------+--------+---------------------+------+-------+
| 01 | 赵雷 | 1990-01-01 00:00:00 | 男 | 90.0 |
+------+--------+---------------------+------+-------+23. 查询各学生的年龄，只按年份来算
select
sname,
to_char(sysdate, 'yyyy') - substr(sage, 0, 4) as age
from student+--------+------+
| sname | age |
+--------+------+
| 赵雷 | 28 |
| 钱电 | 28 |
| 孙风 | 28 |
| 李云 | 28 |
| 周梅 | 27 |
| 吴兰 | 26 |
| 郑竹 | 29 |
| 王菊 | 28 |
+--------+------+-----持续完善更新-----