一、建表
CREATE TABLE Student(
Sno CHAR(3) PRIMARY KEY COMMENT "学号（主码）",
Sname CHAR(8) NOT NULL COMMENT "学生姓名",
Ssex CHAR(2) COMMENT "学生性别",
Sbirthday DATETIME COMMENT "学生出生年月",
Class CHAR(5) COMMENT "学生所在班级"
)
CREATE TABLE Course(
Cno CHAR(5) PRIMARY KEY COMMENT "课程号（主码）",
Cname VARCHAR(10) NOT NULL COMMENT "课程名称",
Tno CHAR(3) NOT NULL COMMENT "教工编号（外码）"
)
CREATE TABLE Score(
Sno CHAR(3) COMMENT "学号（外码）",
Cno CHAR(5) COMMENT "课程号（外码）",
Degree DECIMAL(4,1) COMMENT "成绩",
-- primary key(Sno,Cno),
FOREIGN KEY(Sno) REFERENCES Student(Sno),
FOREIGN KEY(Cno) REFERENCES Course(Cno)
)
CREATE TABLE Teacher(
Tno CHAR(3) PRIMARY KEY COMMENT "教工编号（主码）",
Tname CHAR(4) NOT NULL COMMENT "教工姓名",
Tsex CHAR(2) NOT NULL COMMENT "教工性别",
Tbirthday DATETIME COMMENT "教工出生年月",
Prof CHAR(6) COMMENT "职称",
Depart VARCHAR(10) COMMENT "教工所在部门"
)
INSERT INTO Student VALUES ('108','曾华','男','1977-09-01','95033');
INSERT INTO Student VALUES ('105','匡明','男','1975-10-02','95031');
INSERT INTO Student VALUES ('107','王丽','女','1976-01-23','95033');
INSERT INTO Student VALUES ('101','李军','男','1976-02-20','95033');
INSERT INTO Student VALUES ('109','王芳','女','1975-02-10','95031');
INSERT INTO Student VALUES ('103','陆君','男','1974-06-03','95031');
INSERT INTO Course VALUES ('3-105','计算机导论','825'),
('3-245','操作系统','804'),
('6-166 ','数字电路','856'),
('9-888','高等数学','831')
INSERT INTO Score VALUES ('103','3-245',86),
('105','3-245',75),
('109','3-245',68),
('103','3-105',92),
('105','3-105',88),
('109','3-105',76),
('101','3-105',64),
('107','3-105',91),
('108','3-105',78)
INSERT INTO Teacher VALUES('804','李诚','男','1958-12-02','副教授','计算机系'),
('856','张旭','男','1969-03-12','讲师','电子工程系'),
('825','王萍','女','1972-05-05','助教','计算机系'),
('831','刘冰','女','1977-08-14','助教','电子工程系')
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二、练习
1、查询Student表中的所有记录的Sname、Ssex和Class列。
SELECT Sname,Ssex,Class
FROM student
2、 查询教师所有的单位即不重复的Depart列。
SELECT DISTINCT Depart
FROM teacher
3、 查询Student表的所有记录。
SELECT *
FROM `student`
4、 查询Score表中成绩在60到80之间的所有记录。
SELECT *
FROM Score
WHERE Degree BETWEEN 60 AND 80
5、 查询Score表中成绩为85，86或88的记录。
SELECT *
FROM Score
WHERE Degree IN (85,86,88)
6、 查询Student表中“95031”班或性别为“女”的同学记录。
SELECT *
FROM student
WHERE Class="95031" OR Ssex="女"
7、 以Class降序查询Student表的所有记录。
SELECT *
FROM Student
ORDER BY Class DESC
8、 以Cno升序、Degree降序查询Score表的所有记录。
SELECT *
FROM score
ORDER BY Cno,Degree DESC
9、 查询“95031”班的学生人数。
SELECT COUNT(Class)
FROM Student
GROUP BY Class
HAVING Class=95031
10、 查询Score表中的最高分的学生学号和课程号。（子查询或者排序）
SELECT st.sno,sc.cno,degree
FROM student st JOIN score sc
ON st.sno=sc.sno
ORDER BY Degree DESC
LIMIT 1
11、 查询每门课的平均成绩。
SELECT cno,AVG(IFNULL(degree,0))
FROM score
GROUP BY cno
12、 查询Score表中至少有5名学生选修的并以3开头的课程的平均分数。
SELECT sc.cno,AVG(IFNULL(sc.degree,0))
FROM student st JOIN score sc
ON st.sno=sc.sno
GROUP BY sc.cno
HAVING COUNT(sc.cno)>=5 AND sc.cno LIKE "3%"
13、 查询分数大于70，小于90的Sno列。
SELECT sc.sno
FROM student st JOIN score sc
ON st.sno=sc.sno
WHERE degree>70 AND degree<90
14、 查询所有学生的Sname、Cno和Degree列。
SELECT st.sname,cno,degree
FROM student st JOIN score sc
ON st.sno=sc.sno
15、 查询所有学生的Sno、Cname和Degree列。
SELECT st.sno,cno,degree
FROM student st JOIN score sc
ON st.sno=sc.sno
16、 查询所有学生的Sname、Cname和Degree列。
SELECT st.sname,cname,degree
FROM student st JOIN score sc
ON st.sno=sc.sno
JOIN course co
ON sc.cno=co.cno
17、 查询“95033”班学生的平均分。
SELECT AVG(IFNULL(degree,0)) 平均分
FROM student st JOIN score sc
ON st.sno=sc.sno
GROUP BY class
HAVING class="95033"
18、 假设使用如下命令建立了一个grade表：
CREATE TABLE grade(
low INT(3),
upp INT(3),
ranks CHAR(1)
)
INSERT INTO grade VALUES(90,100,'A');
INSERT INTO grade VALUES(80,89,'B');
INSERT INTO grade VALUES(70,79,'C');
INSERT INTO grade VALUES(60,69,'D');
INSERT INTO grade VALUES(0,59,'E');
现查询所有同学的Sno、Cno和ranks列。
SELECT Sno,Cno,ranks
FROM score t1,(
SELECT low,upp,ranks
FROM grade
)t2
WHERE degree BETWEEN t2.low AND t2.upp
19、 查询选修“3-105”课程的成绩高于“109”号同学成绩的所有同学的记录。
SELECT *
FROM student st JOIN score sc
ON st.sno=sc.sno
WHERE sc.cno="3-105" AND degree > ALL(
SELECT degree
FROM student st JOIN score sc
ON st.sno=sc.sno
WHERE st.sno="109"
)
20、查询score中选学多门课程的同学中分数为非最高分成绩的记录。
SELECT t1.sno,t2.cno,t2.degree
FROM score t2,(
SELECT sno,MAX(degree) degree
FROM score
GROUP BY sno
HAVING COUNT(sno)>1
)t1
WHERE t1.sno=t2.sno AND t2.degree<t1.degree
21、查询成绩高于学号为“109”、课程号为“3-105”的成绩的所有记录。
SELECT st.*,sc.cno,degree
FROM student st JOIN score sc
ON st.sno=sc.sno
WHERE degree>(
SELECT degree
FROM score
WHERE cno='3-105' AND sno=109
)
22、查询和学号为108的同学同年出生的所有学生的Sno、Sname和Sbirthday列。
SELECT sno,sname,Sbirthday
FROM student
WHERE YEAR(sbirthday)=(
SELECT YEAR(sbirthday)
FROM student
WHERE sno=108
)
23、查询“张旭“教师任课的学生成绩。
SELECT st.*,sc.degree
FROM student st JOIN score sc
ON st.sno=sc.sno
JOIN course co
ON sc.cno=co.cno
JOIN teacher te
ON co.tno=te.tno
WHERE te.tname='张旭'
24、查询选修某课程的同学人数多于5人的教师姓名。
SELECT te.tname
FROM teacher te,course co,score sc,student st
WHERE te.tno=co.tno AND co.cno=sc.cno AND sc.sno=st.sno
GROUP BY te.tno
HAVING COUNT(st.sno)>5
25、查询95033班和95031班全体学生的记录。
SELECT *
FROM student
WHERE class IN(95033,95031)
26、 查询存在有85分以上成绩的课程Cno.
SELECT co.cno
FROM course co JOIN score sc
ON co.cno = sc.cno
WHERE degree>85
27、查询出“计算机系“教师所教课程的成绩表。
SELECT *
FROM teacher te JOIN course co
ON te.tno=co.tno
JOIN score sc
co.cno=sc.cno
WHERE cname='计算机系'
28、查询“计算机系”与“电子工程系“不同职称的教师的Tname和Prof。
SELECT tname,prof
FROM teacher
WHERE prof NOT IN (
SELECT prof
FROM teacher
WHERE depart IN ('计算机系','电子工程系')
)
29、查询选修编号为“3-105“课程且成绩至少高于选修编号为“3-245”的同学的Cno、Sno和Degree,
并按Degree从高到低次序排序。
SELECT st.sno,sc.cno,sc.degree
FROM(
SELECT sno,cno,degree
FROM score
WHERE cno='3-105' AND degree>(
SELECT MAX(degree)
FROM score
WHERE cno='3-245'
)
)sc
JOIN student st
ON sc.sno=st.sno
30、查询选修编号为“3-105”且成绩高于选修编号为“3-245”课程的同学的Cno、Sno和Degree.
SELECT st.sno,sc.cno,sc.degree
FROM(
SELECT sno,cno,degree
FROM score
WHERE cno='3-105' AND degree>(
SELECT MAX(degree)
FROM score
WHERE cno='3-245'
)
)sc
JOIN student st
ON sc.sno=st.sno
31、 查询所有教师和同学的name、sex和birthday.
SELECT sname NAME, ssex sex,sbirthday birthday
FROM student
UNION
SELECT tname NAME, tsex sex,tbirthday birthday
FROM teacher
-- 下面结果和上面的查询结果是一样的，这是因为union查询只会使用第一个查询的字段名
SELECT sname NAME, ssex sex,sbirthday birthday
FROM student
UNION
SELECT tname, tsex,tbirthday
FROM teacher
32、查询所有“女”教师和“女”同学的name、sex和birthday.
SELECT sname NAME,ssex sex,sbirthday birthday
FROM student
WHERE ssex='女'
UNION
SELECT tname,tsex,tbirthday birthday
FROM teacher
WHERE tsex='女'
33、 查询成绩比该课程平均成绩低的同学的成绩表。
SELECT s2.*
FROM (
SELECT AVG(IFNULL(degree,0)) avg_score
FROM score
)s1,score s2
WHERE s1.avg_score>s2.degree
34、查询所有任课教师的Tname和Depart.
SELECT tname,depart
FROM teacher
35 、 查询所有未讲课的教师的Tname和Depart.
SELECT tname,depart
FROM teacher te
WHERE NOT EXISTS(
SELECT 1
FROM course co
WHERE te.tno=co.tno
)
36、查询至少有2名男生的班号。
SELECT class
FROM student
GROUP BY ssex
HAVING COUNT(ssex)>1
37、查询Student表中不姓“王”的同学记录。
SELECT *
FROM student
WHERE sname NOT LIKE '王%'
38、查询Student表中每个学生的姓名和年龄。
SELECT sname,YEAR(NOW())-YEAR(sbirthday) age
FROM student
39、查询Student表中最大和最小的Sbirthday日期值。
SELECT MAX(sbirthday),MIN(sbirthday)
FROM student
40、以班号和年龄从大到小的顺序查询Student表中的全部记录。
SELECT st1.*,st2.age
FROM student st1 JOIN (
SELECT sno,YEAR(NOW())-YEAR(sbirthday) age
FROM student
)st2
ON st1.sno=st2.sno
ORDER BY class DESC,st2.age DESC
41、查询“男”教师及其所上的课程。
SELECT te.*,co.cno,co.cname
FROM teacher te JOIN course co
ON te.tno=co.tno
WHERE te.tsex='男'
42、查询最高分同学的Sno、Cno和Degree列。
SELECT sno,cno,MAX(degree)
FROM score
43、查询和“李军”同性别的所有同学的Sname.
SELECT sname
FROM student s1,(
SELECT ssex
FROM student
WHERE sname='李军'
)s2
WHERE s1.ssex=s2.ssex
44、查询和“李军”同性别并同班的同学Sname.
SELECT sname
FROM student s1,(
SELECT ssex,class
FROM student
WHERE sname='李军'
)s2
WHERE s1.ssex=s2.ssex AND s1.class=s2.class
45、查询所有选修“计算机导论”课程的“男”同学的成绩表。
SELECT st.sname,st.ssex,degree
FROM student st JOIN score sc
ON st.sno=sc.sno
JOIN course co
ON sc.cno=co.cno
WHERE co.cname='计算机导论' AND st.ssex='男'
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