SQL练习题

学生表 Student
create table Student(SId varchar(10),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' , '1990-12-20' , '男');
insert into Student values('04' , '李云' , '1990-12-06' , '男');
insert into Student values('05' , '周梅' , '1991-12-01' , '女');
insert into Student values('06' , '吴兰' , '1992-01-01' , '女');
insert into Student values('07' , '郑竹' , '1989-01-01' , '女');
insert into Student values('09' , '张三' , '2017-12-20' , '女');
insert into Student values('10' , '李四' , '2017-12-25' , '女');
insert into Student values('11' , '李四' , '2012-06-06' , '女');
insert into Student values('12' , '赵六' , '2013-06-13' , '女');
insert into Student values('13' , '孙七' , '2014-06-01' , '女');
科目表 Course
create table Course(CId varchar(10),Cname nvarchar(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');
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);

 

1. 查询" 01 "课程比" 02 "课程成绩高的学生的信息及课程分数

   select * from student right join (select t1.sid, class1, class2 from(select sid, score as class1 from sc where sc.cid = '01') as t1, (select sid, score as class2 from sc where sc.cid = '02') as t2where t1.sid = t2.sid and t1.class1 > t2.class2
   ) r 
   on student.sid = r.sid;

   

2. 查询同时存在" 01 "课程和" 02 "课程的情况

   select * from 
   (select * from sc where sc.cid = '01') as t1
   left join 
   (select * from sc where sc.cid = '02') as t2
   on t1.sid = t2.sid;

   

3. 查询存在" 01 "课程但可能不存在" 02 "课程的情况(不存在时显示为 null )

   select * from sc
   where sc.sid not in (select sid from sc where sc.cid = '01'
   ) 
   and sc.cid = '02';

   

4. 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

   select student.sid, sname, ss 
   from student, (select sid, avg(score) as ss from sc  group by sid having avg(score) > 60
   ) as r
   where student.sid = r.sid;

   

5. 查询在 SC 表存在成绩的学生信息

   select distinct student.*
   from student, sc
   where student.sid = sc.sid;

   

6. 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 s.sid, s.sname,r.coursenumber,r.scoresum
   from (select student.sid,student.sname from student
   ) s 
   left join (select sc.sid, sum(sc.score) as scoresum, count(sc.cid) as coursenumberfrom sc group by sc.sid
   ) r on s.sid = r.sid;

   

7. 查有成绩的学生信息

   select * from student
   where student.sid in (select sc.sid from sc
   );

   

8. 查询「李」姓老师的数量

   select count(*)
   from teacher
   where tname like '李%';

   

9. 查询学过「张三」老师授课的同学的信息

   select student.* from student,teacher,course,sc
   where student.sid = sc.sid and course.cid=sc.cid and course.tid = teacher.tid and tname = '张三';

   

10. 查询没有学全所有课程的同学的信息

    select * from student
    where student.sid not in (select sc.sid from scgroup by sc.sidhaving count(sc.cid)= (select count(cid) from course)
    );

    

11. 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 student.sid in (select sc.sid from sc where sc.cid in(select sc.cid from sc where sc.sid = '01')
    );

    

12. 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

    with course01 as (select cid from sc where sid = '01'
    )select distinct s.*
    from student s
    join sc on s.sid = sc.sid
    where s.sid != '01'  
    and not exists (select cid from course01exceptselect cid from sc where sid = s.sid
    )
    and not exists (select cid from sc where sid = s.sidexceptselect cid from course01
    );

    

13. 查询没学过"张三"老师讲授的任一门课程的学生姓名

    select * from student
    where student.sid not in(select sc.sid from sc,course,teacher wheresc.cid = course.cidand course.tid = teacher.tidand teacher.tname= "张三"
    );

    

14. 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 student.SId, student.Sname,b.avg
    from student RIGHT JOIN
    (select sid, AVG(score) as avg from scwhere sid in (select sid from sc where score<60 GROUP BY sid HAVING count(score)>1)GROUP BY sid) b on student.sid=b.sid;

    

15. 检索" 01 "课程分数小于 60，按分数降序排列的学生信息

    select student.*, sc.score 
    from student
    join sc on student.sid = sc.sid
    where sc.score < 60and sc.cid = '01'
    order by sc.score desc;

    

16. 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 *  from sc 
    left join (select sid,avg(score) as avscore from sc group by sid)r 
    on sc.sid = r.sid
    order by avscore desc;

    

17. 查询各科成绩最高分、最低分和平均分：

    select c.cid as '课程编号',c.cname as '课程名称',max(sc.score) as '最高分',min(sc.score) as '最低分',cast(avg(sc.score) as decimal(10,1)) as '平均分'
    from course c
    join sc on c.cid = sc.cid
    group by c.cid, c.cname
    order by c.cid;

    

18. 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 sc.cid,max(sc.score) as 最高分,min(sc.score) as 最低分,avg(sc.score) as 平均分,count(*) as 选修人数,sum(case when sc.score >= 60 then 1 else 0 end) / count(*) as 及格率,sum(case when sc.score >= 70 and sc.score < 80 then 1 else 0 end) / count(*) as 中等率,sum(case when sc.score >= 80 and sc.score < 90 then 1 else 0 end) / count(*) as 优良率,sum(case when sc.score >= 90 then 1 else 0 end) / count(*) as 优秀率
    from sc
    group by sc.cid
    order by count(*) desc, sc.cid asc;

    

19. 按各科成绩进行排序，并显示排名， Score 重复时保留名次空缺

    selectc.cname as '课程名称',s.sname as '学生姓名',sc.score as '分数',dense_rank() over (partition by sc.cid order by sc.score desc) as '排名'
    fromsc
    joinstudent s on sc.sid = s.sid
    joincourse c on sc.cid = c.cid
    order bysc.cid,sc.score desc;

    

20. 按各科成绩进行排序，并显示排名， Score 重复时合并名次

    selectc.cname as '课程名称',s.sname as '学生姓名',sc.score as '分数',rank() over (partition by sc.cid order by sc.score desc) as '排名'
    fromsc
    joinstudent s on sc.sid = s.sid
    joincourse c on sc.cid = c.cid
    order bysc.cid,sc.score desc;

    

21. 查询学生的总成绩，并进行排名，总分重复时保留名次空缺

    with student_total_score as (select s.sid,s.sname,sum(sc.score) as total_scorefrom student sjoin sc on s.sid = sc.sidgroup by s.sid, s.sname
    )select sid as '学号',sname as '学生姓名',total_score as '总成绩',dense_rank() over (order by total_score desc) as '排名'
    from student_total_score
    order by total_score desc;

    

22. 查询学生的总成绩，并进行排名，总分重复时不保留名次空缺

    with student_total as (selects.sid,s.sname,sum(sc.score) as total_scorefromstudent sleft joinsc on s.sid = sc.sidgroup bys.sid, s.sname
    )selectsid as '学号',sname as '学生姓名',total_score as '总成绩',row_number() over (order by total_score desc) as '排名'
    fromstudent_total
    wheretotal_score is not null
    order bytotal_score desc;

    

23. 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

    selectcourse.cname,course.cid,sum(case when sc.score <= 100 and sc.score > 85 then 1 else 0 end) as "[100-85]",sum(case when sc.score <= 85 and sc.score > 70 then 1 else 0 end) as "[85-70]",sum(case when sc.score <= 70 and sc.score > 60 then 1 else 0 end) as "[70-60]",sum(case when sc.score <= 60 and sc.score > 0 then 1 else 0 end) as "[60-0]"
    fromsc
    left joincourse on sc.cid = course.cid
    group bycourse.cid,course.cname
    order bycourse.cid;

    

24. 查询各科成绩前三名的记录

    select * from sc
    where (
    select count(*) from sc as a 
    where sc.cid = a.cid and sc.score<a.score 
    )< 3
    order by cid asc, sc.score desc;

    

25. 查询每门课程被选修的学生数

    select cid, count(sid) from sc 
    group by cid;

    

26. 查询出只选修两门课程的学生学号和姓名

    select student.sid, student.sname from student
    where student.sid in
    (select sc.sid from sc
    group by sc.sid
    having count(sc.cid)=2
    );

    

27. 查询男生、女生人数

    select ssex, count(*) from student
    group by ssex;

    

28. 查询名字中含有「风」字的学生信息

    select *
    from student 
    where student.sname like '%风%';

    

29. 查询同名同性学生名单，并统计同名人数

    select sname, count(*) from student
    group by sname
    having count(*)>1;

    

30. 查询 1990 年出生的学生名单

    select *
    from student
    where year(sage) = 1990;

    

31. 查询每门课程的平均成绩，结果按平均成绩降序排列，平均成绩相同时，按课程编号升序排列

    selectsc.cid,course.cname,avg(sc.score) as average
    fromsc
    joincourse on sc.cid = course.cid
    group bysc.cid,course.cname
    order byaverage desc,sc.cid asc;

    

32. 查询平均成绩大于等于 85 的所有学生的学号、姓名和平均成绩

    selectstudent.sid,student.sname,avg(sc.score) as aver
    fromstudent
    joinsc on student.sid = sc.sid
    group bystudent.sid,student.sname
    havingavg(sc.score) > 85
    order byaver desc;

    

33. 查询课程名称为「数学」，且分数低于 60 的学生姓名和分数

    select student.sname, sc.score from student, sc, course
    where student.sid = sc.sid
    and course.cid = sc.cid
    and course.cname = "数学"
    and sc.score < 60;

    

34. 查询所有学生的课程及分数情况（存在学生没成绩，没选课的情况）

    select student.sname, cid, score from student
    left join sc
    on student.sid = sc.sid;

    

35. 查询任何一门课程成绩在 70 分以上的姓名、课程名称和分数

    select student.sname, course.cname,sc.score from student,course,sc
    where sc.score>70
    and student.sid = sc.sid
    and sc.cid = course.cid;

    

36. 查询不及格的课程

    select cid from sc
    where score< 60
    group by cid;

    

37. 查询课程编号为 01 且课程成绩在 80 分以上的学生的学号和姓名

    select student.sid,student.sname 
    from student,sc
    where cid="01"
    and score>=80
    and student.sid = sc.sid;

    

38. 求每门课程的学生人数

    selectsc.cid,count(*) as 学生人数
    fromsc
    group bysc.cid
    order bysc.cid;

    

39. 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

    with zhang_san_courses as (select c.cidfrom course cjoin teacher t on c.tid = t.tidwhere t.tname = '张三'
    ),
    top_score as (select max(sc.score) as max_scorefrom scjoin zhang_san_courses z on sc.cid = z.cid
    )
    select s.sid as '学号',s.sname as '学生姓名',s.sage as '出生日期',s.ssex as '性别',sc.score as '成绩',c.cname as '课程名称'
    from student s
    join sc on s.sid = sc.sid
    join zhang_san_courses z on sc.cid = z.cid
    join course c on z.cid = c.cid
    join top_score ts on sc.score = ts.max_score;

    

40. 成绩有重复的情况下，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 student.*, sc.score, sc.cid from student, teacher, course,sc 
    where teacher.tid = course.tid
    and sc.sid = student.sid
    and sc.cid = course.cid
    and teacher.tname = "张三"
    and sc.score = (select Max(sc.score) from sc,student, teacher, coursewhere teacher.tid = course.tidand sc.sid = student.sidand sc.cid = course.cidand teacher.tname = "张三"
    );

    

41. 查询不同课程成绩相同的学生的学生编号、课程编号、学生成绩

    selects.sid as '学生编号',s.sname as '学生姓名',sc1.cid as '课程编号1',c1.cname as '课程名称1',sc2.cid as '课程编号2',c2.cname as '课程名称2',sc1.score as '相同成绩'
    fromsc sc1
    joinsc sc2 on sc1.sid = sc2.sidand sc1.cid < sc2.cidand sc1.score = sc2.score
    joinstudent s on sc1.sid = s.sid
    joincourse c1 on sc1.cid = c1.cid
    joincourse c2 on sc2.cid = c2.cid
    order bys.sid,sc1.score;

    

42. 查询每门功成绩最好的前两名

    select a.sid,a.cid,a.score from sc as a 
    left join sc as b 
    on a.cid = b.cid and a.score<b.score
    group by a.cid, a.sid
    having count(b.cid)<2
    order by a.cid;

43. 统计每门课程的学生选修人数（超过 5 人的课程才统计）。

    select sc.cid, count(sid) as cc from sc
    group by cid
    having cc >5;

    

44.  检索至少选修两门课程的学生学号

    select sid, count(cid) as cc from sc
    group by sid
    having cc>=2;

    

45. 查询选修了全部课程的学生信息

    selectstudent.*
    fromstudent
    joinsc on student.sid = sc.sid
    group bystudent.sid,student.sname,student.sage,student.ssex
    havingcount(*) = (select count(distinct cid) from course);

    

46. 查询各学生的年龄，只按年份来算

    selectsid as '学号',sname as '姓名',ssex as '性别',year(sage) as '出生年份',year(curdate()) - year(sage) as '年龄(按年份计算)'
    fromstudent
    order bysid;

    

47. 按照出生日期来算，当前月日 < 出生年月的月日则，年龄减一

    select student.SId as 学生编号,student.Sname  as  学生姓名,
    TIMESTAMPDIFF(YEAR,student.Sage,CURDATE()) as 学生年龄
    from student;

    

48. 查询本周过生日的学生

    select *
    from student
    where weekofyear(sage) = weekofyear(curdate());

    

49. 查询下周过生日的学生

    selectsid as '学号',sname as '姓名',ssex as '性别',sage as '生日'
    fromstudent
    wheredate_format(sage, '%m-%d') betweendate_format(date_add(curdate(), interval 1 day), '%m-%d') anddate_format(date_add(curdate(), interval 7 day), '%m-%d');

    

50. 查询本月过生日的学生

    select *
    from student
    where month(sage) = month(curdate());

    

51. 查询下月过生日的学生

    selectsid as '学号',sname as '姓名',ssex as '性别',sage as '生日',date_format(sage, '%m-%d') as '生日(月日)'
    fromstudent
    wheremonth(sage) = if(month(curdate()) = 12, 1, month(curdate()) + 1);