数据库练习题

-- 学生表
CREATE TABLE student(
    sno VARCHAR(20) NOT NULL PRIMARY KEY,
    sname VARCHAR(20) NOT NULL,
    ssex VARCHAR(20) NOT NULL,
    sbirthday DATE,
    class VARCHAR(20)
)
-- 教师表
CREATE TABLE teacher(
    tno VARCHAR(20) NOT NULL PRIMARY KEY,
    tname VARCHAR(20) NOT NULL,
    tsex VARCHAR(20) NOT NULL,
    tbirthday DATE,
    prof VARCHAR(20),
    depart VARCHAR(20) NOT NULL

)

-- 课程表
CREATE TABLE course(
    cno VARCHAR(20)  PRIMARY KEY NOT NULL ,
    cname VARCHAR(20) NOT NULL,
    tno VARCHAR(20) NOT NULL ,
    CONSTRAINT course_teacher_fk FOREIGN KEY(tno)
    REFERENCES teacher(tno)
    
)
-- 成绩表
CREATE TABLE score(
    sno VARCHAR(20) NOT NULL,
    CONSTRAINT score_student_fk FOREIGN KEY(sno)
    REFERENCES student(sno),
    cno VARCHAR(20) NOT NULL ,
    CONSTRAINT score_course_fk FOREIGN KEY(cno)
    REFERENCES course(cno),
    degree DECIMAL(4,1) 
    
)
-- student
INSERT INTO student VALUES(‘108‘,‘曾华‘,‘男‘,‘19770901‘,‘95033‘);
INSERT INTO student VALUES(‘105‘,‘匡明‘,‘男‘,‘19751002‘,‘95031‘);
INSERT INTO student VALUES(‘107‘,‘王丽‘,‘女‘,‘19760123‘,‘95033‘);
INSERT INTO student VALUES(‘101‘,‘李军‘,‘男‘,‘19760220‘,‘95033‘);
INSERT INTO student VALUES(‘109‘,‘王芳‘,‘女‘,‘19750210‘,‘95031‘);
INSERT INTO student VALUES(‘103‘,‘陆君‘,‘男‘,‘19740603‘,‘95031‘);
SELECT * FROM student;
-- teacher 
INSERT INTO teacher VALUES(‘804‘,‘李诚‘,‘男‘,‘19581202‘,‘副教授‘,‘计算机系‘);
INSERT INTO teacher VALUES(‘856‘,‘张旭‘,‘男‘,‘19690312‘,‘讲师‘,‘电子工程系‘);
INSERT INTO teacher VALUES(‘825‘,‘王萍‘,‘女‘,‘19720505‘,‘助教‘,‘计算机系‘);
INSERT INTO teacher VALUES(‘831‘,‘刘冰‘,‘女‘,‘19770814‘,‘助教‘,‘电子工程系‘);
SELECT * FROM teacher;
-- course
INSERT INTO course VALUES(‘3-105‘,‘计算机导论‘,‘825‘);
INSERT INTO course VALUES(‘3-245‘,‘操作系统‘,‘804‘);
INSERT INTO course VALUES(‘6-166‘,‘数字电路‘,‘856‘);
INSERT INTO course VALUES(‘9-888‘,‘高等数学‘,‘831‘);
DELETE FROM student;
DELETE FROM teacher;
DELETE FROM course;
DELETE FROM score;
SELECT * FROM course;
-- score
INSERT INTO score VALUES(‘103‘,‘3-245‘,86);
INSERT INTO score VALUES(‘105‘,‘3-245‘,75);
INSERT INTO score VALUES(‘109‘,‘3-245‘,68);
INSERT INTO score VALUES(‘103‘,‘3-105‘,92);
INSERT INTO score VALUES(‘105‘,‘3-105‘,88);
INSERT INTO score VALUES(‘109‘,‘3-105‘,76);
INSERT INTO score VALUES(‘101‘,‘3-105‘,64);
INSERT INTO score VALUES(‘107‘,‘3-105‘,91);
INSERT INTO score VALUES(‘108‘,‘3-105‘,78);
INSERT INTO score VALUES(‘101‘,‘6-166‘,85);
INSERT INTO score VALUES(‘107‘,‘6-166‘,79);
INSERT INTO score VALUES(‘108‘,‘6-166‘,81);
SELECT * FROM score;

-- 1
SELECT sname,ssex,class FROM student ;
-- 2
SELECT DISTINCT depart FROM teacher;
-- 3
SELECT * FROM student;
-- 4
SELECT * FROM score WHERE degree BETWEEN 60 AND 80;
-- 5
SELECT * FROM score WHERE degree IN( 85,86,88);
-- 6
SELECT * FROM student WHERE class=‘95031‘ OR ssex=‘女‘;
-- 7
SELECT * FROM student ORDER BY class DESC ;
-- 8
SELECT * FROM score ORDER BY cno ASC,degree DESC;
-- 9
SELECT COUNT(*)AS 学生人数 FROM student WHERE class=‘95031‘;
-- 10
SELECT sno AS 学生学号 ,cno AS 课程号 FROM score WHERE degree =(SELECT MAX(degree) FROM score);
-- 11
SELECT cno,AVG(degree) AS 平均成绩 FROM score   GROUP BY cno;
-- 12
SELECT cno,AVG(degree) AS 平均分数 FROM score WHERE cno LIKE ‘3%‘ GROUP BY cno HAVING COUNT(cno)>=5  ;
-- 13
SELECT sno FROM score WHERE degree BETWEEN 70 AND 90;
-- 14
SELECT sname,cno,degree FROM score JOIN student ON 
    student.`sno`=score.`sno`;
-- 15
SELECT sno,cname,degree FROM score JOIN course ON
    score.`cno`= course.`cno`;
-- 16
SELECT sname,cname,degree FROM score JOIN student ON
    student.`sno`=score.`sno`
    JOIN course ON 
    score.`cno`= course.`cno`;
-- 17
SELECT AVG(degree) AS 平均分 FROM score WHERE sno IN(SELECT sno FROM student WHERE class=‘95033‘);
-- 18
SELECT * FROM student JOIN score ON student.`sno`= score.`sno`
    WHERE cno =‘3-105‘ 
    AND degree>(SELECT degree FROM score WHERE sno =‘109‘ AND cno=‘3-105‘);
-- 20
-- 第一种
SELECT * FROM score a
    WHERE sno IN(SELECT sno FROM score GROUP BY sno HAVING COUNT(sno)>1 )
     AND degree not in (SELECT MAX(degree) FROM score b 
                where a.`cno`=b.`cno` );
-- 第二种
SELECT * FROM score a
    WHERE sno IN(SELECT sno FROM score GROUP BY sno HAVING COUNT(sno)>1 )
    and degree NOT IN (SELECT MAX(degree) FROM score 
            where sno in(SELECT sno FROM score 
                GROUP BY sno HAVING COUNT(sno)>1)
    
    
-- 21

SELECT * FROM student JOIN score ON student.`sno`= score.`sno`
    WHERE cno =‘3-105‘ 
    AND degree>(SELECT degree FROM score WHERE sno =‘109‘AND cno =‘3-105‘);
-- 22
SELECT sno,sname,sbirthday FROM student WHERE 
    LEFT(sbirthday,4) = (SELECT LEFT(sbirthday,4) FROM student WHERE sno =‘108‘);
-- 23
SELECT sname AS 姓名,degree AS 学生成绩 FROM student 
    JOIN score ON student.`sno`= score.`sno`
    WHERE cno=( SELECT cno FROM course  
            JOIN teacher ON course.`tno`= teacher.`tno`
            WHERE tname =‘张旭‘)
-- 23.1

SELECT sname AS 姓名,degree AS 学生成绩 FROM student 
    JOIN score ON student.`sno`= score.`sno`
    WHERE cno =(SELECT cno FROM course WHERE cname =‘计算机导论‘);
-- 23.2
SELECT cname AS 课程名称 FROM course
    JOIN teacher ON course.`tno`=teacher.`tno`
    WHERE  tname =‘李诚‘;
-- 23.3

SELECT depart FROM teacher 
    WHERE tno=(SELECT tno FROM course WHERE cname =‘高等数学‘);
-- 24
SELECT tname AS 教师姓名 FROM teacher JOIN course ON teacher.`tno`=course.`tno`
    WHERE cno =(SELECT cno FROM score GROUP BY cno
            HAVING COUNT(cno)>5);
-- 25
SELECT score.sno,sname,ssex,sbirthday,class,score.cno,degree,cname,tname FROM student 
    JOIN score ON student.`sno`=score.`sno`
    JOIN course ON score.`cno` =course.`cno`
    JOIN teacher ON course.`tno`=teacher.`tno`
    WHERE class =‘95033‘OR class =‘95031‘;
      
-- 26
SELECT DISTINCT (score.`cno`) FROM course JOIN score ON score.`cno` =course.`cno`
    WHERE  degree >85
-- 27
SELECT score.* FROM score 
    JOIN course ON score.`cno` =course.`cno`
    JOIN teacher ON course.`tno`=teacher.`tno`
    WHERE  depart = ‘计算机系‘
    
-- 28
-- 29

SELECT cno,sno,degree FROM score 
    WHERE cno =‘3-105‘ AND 
    degree>ANY(SELECT degree FROM score WHERE cno=‘3-245‘)
    ORDER BY degree DESC;
-- 30
SELECT cno,sno,degree FROM score 
    WHERE cno =‘3-105‘ AND 
    degree>ALL(SELECT degree FROM score WHERE cno=‘3-245‘)
-- 31
SELECT sname AS NAME,ssex AS sex,sbirthday AS birthday FROM student 
    UNION    
SELECT tname,tsex,tbirthday FROM teacher    
-- 32
SELECT sname AS NAME,ssex AS sex,sbirthday AS birthday FROM student
    WHERE ssex=‘女‘
UNION    
SELECT tname,tsex,tbirthday FROM teacher
    WHERE tsex=‘女‘
-- 33
-- 方法一
SELECT * FROM score 
    WHERE cno=‘3-105‘
        AND degree <(SELECT AVG(degree)FROM score GROUP BY cno HAVING cno=‘3-105‘)
       OR cno=‘3-245‘
        AND degree <(SELECT AVG(degree)FROM score GROUP BY cno HAVING cno=‘3-245‘)
       OR cno=‘6-166‘
        AND degree <(SELECT AVG(degree)FROM score GROUP BY cno HAVING cno=‘6-166‘)


-- 方法二
select * from score a
    where degree<(SELECT AVG(degree)FROM score b
        where a.cno=b.cno);
        
    

-- 34
SELECT tname,depart FROM teacher 
    WHERE tno IN(SELECT DISTINCT (course.tno) FROM score 
            JOIN course ON score.`cno`=course.`cno` );

-- 35
SELECT tname,depart FROM teacher 
    WHERE tno  NOT IN(SELECT DISTINCT (course.tno) FROM score 
             JOIN course ON score.`cno`=course.`cno` );

-- 36
SELECT class AS 班号 FROM student 
    WHERE ssex =‘男‘GROUP BY class HAVING COUNT(*)>=2 

-- 37
SELECT * FROM student WHERE sname  NOT LIKE ‘王%‘

-- 38
SELECT sname AS 姓名,YEAR(NOW())-YEAR(sbirthday) AS 年龄 FROM student
-- 39
SELECT MAX(sbirthday),MIN(sbirthday) FROM student;

-- 40
SELECT * FROM student ORDER BY class DESC,sbirthday ;
-- 41
SELECT tname AS 教师名,cname AS 课程名 FROM teacher 
    JOIN course ON teacher.`tno`=course.`tno`
    WHERE tsex =‘男‘
-- 42
SELECT sno,cno,degree FROM score 
    WHERE degree=(SELECT MAX(degree) FROM score )
-- 43
SELECT sname FROM student 
    WHERE ssex= (SELECT ssex FROM student WHERE sname =‘李军‘)
        AND sname NOT IN(‘李军‘)
-- 44
SELECT sname FROM student 
    WHERE ssex= (SELECT ssex FROM student WHERE sname =‘李军‘)
        AND sname NOT IN(‘李军‘)
        AND class=(SELECT class FROM student WHERE sname =‘李军‘)
        
-- 45
SELECT *FROM score     
    WHERE cno =(SELECT cno FROM course WHERE cname =‘计算机导论‘)
        AND sno IN(SELECT sno FROM student WHERE ssex =‘男‘)