CREATE TABLE students
(sno VARCHAR(3) NOT NULL,
sname VARCHAR(4) NOT NULL,
ssex VARCHAR(2) NOT NULL,
sbirthday DATETIME,
class VARCHAR(5));
CREATE TABLE courses
(cno VARCHAR(5) NOT NULL,
cname VARCHAR(10) NOT NULL,
tno VARCHAR(10) NOT NULL);
CREATE TABLE scores
(sno VARCHAR(3) NOT NULL,
cno VARCHAR(5) NOT NULL,
degree NUMERIC(10, 1) NOT NULL);
CREATE TABLE teachers
(tno VARCHAR(3) NOT NULL,
tname VARCHAR(4) NOT NULL, tsex VARCHAR(2) NOT NULL,
tbirthday DATETIME NOT NULL, prof VARCHAR(6),
depart VARCHAR(10) NOT NULL);
INSERT INTO STUDENTS (SNO,SNAME,SSEX,SBIRTHDAY,CLASS) VALUES (108 ,‘曾華’ ,‘男’ ,‘1977-09-01’,95033);
INSERT INTO STUDENTS (SNO,SNAME,SSEX,SBIRTHDAY,CLASS) VALUES (105 ,‘匡明’ ,‘男’ ,‘1975-10-02’,95031);
INSERT INTO STUDENTS (SNO,SNAME,SSEX,SBIRTHDAY,CLASS) VALUES (107 ,‘王麗’ ,‘女’ ,‘1976-01-23’,95033);
INSERT INTO STUDENTS (SNO,SNAME,SSEX,SBIRTHDAY,CLASS) VALUES (101 ,‘李軍’ ,‘男’ ,‘1976-02-20’,95033);
INSERT INTO STUDENTS (SNO,SNAME,SSEX,SBIRTHDAY,CLASS) VALUES (109 ,‘王芳’ ,‘女’ ,‘1975-02-10’,95031);
INSERT INTO STUDENTS (SNO,SNAME,SSEX,SBIRTHDAY,CLASS) VALUES (103 ,‘陸君’ ,‘男’ ,‘1974-06-03’,95031);
INSERT INTO COURSES(CNO,CNAME,TNO)VALUES (‘3-105’ ,‘計算機導論’,825);
INSERT INTO COURSES(CNO,CNAME,TNO)VALUES (‘3-245’ ,‘操作系統’ ,804);
INSERT INTO COURSES(CNO,CNAME,TNO)VALUES (‘6-166’ ,‘數據電路’ ,856);
INSERT INTO COURSES(CNO,CNAME,TNO)VALUES (‘9-888’ ,‘高等數學’ ,100);
INSERT INTO SCORES(SNO,CNO,DEGREE)VALUES (103,‘3-245’,86);
INSERT INTO SCORES(SNO,CNO,DEGREE)VALUES (105,‘3-245’,75);
INSERT INTO SCORES(SNO,CNO,DEGREE)VALUES (109,‘3-245’,68);
INSERT INTO SCORES(SNO,CNO,DEGREE)VALUES (103,‘3-105’,92);
INSERT INTO SCORES(SNO,CNO,DEGREE)VALUES (105,‘3-105’,88);
INSERT INTO SCORES(SNO,CNO,DEGREE)VALUES (109,‘3-105’,76);
INSERT INTO SCORES(SNO,CNO,DEGREE)VALUES (101,‘3-105’,64);
INSERT INTO SCORES(SNO,CNO,DEGREE)VALUES (107,‘3-105’,91);
INSERT INTO SCORES(SNO,CNO,DEGREE)VALUES (108,‘3-105’,78);
INSERT INTO SCORES(SNO,CNO,DEGREE)VALUES (101,‘6-166’,85);
INSERT INTO SCORES(SNO,CNO,DEGREE)VALUES (107,‘6-106’,79);
INSERT INTO SCORES(SNO,CNO,DEGREE)VALUES (108,‘6-166’,81);
INSERT INTO TEACHERS(TNO,TNAME,TSEX,TBIRTHDAY,PROF,DEPART) VALUES (804,‘李誠’,‘男’,‘1958-12-02’,‘副教授’,‘計算機系’);
INSERT INTO TEACHERS(TNO,TNAME,TSEX,TBIRTHDAY,PROF,DEPART) VALUES (856,‘張旭’,‘男’,‘1969-03-12’,‘講師’,‘電子工程系’);
INSERT INTO TEACHERS(TNO,TNAME,TSEX,TBIRTHDAY,PROF,DEPART) VALUES (825,‘王萍’,‘女’,‘1972-05-05’,‘助教’,‘計算機系’);
INSERT INTO TEACHERS(TNO,TNAME,TSEX,TBIRTHDAY,PROF,DEPART) VALUES (831,‘劉冰’,‘女’,‘1977-08-14’,‘助教’,‘電子工程系’);
1、 查詢Student表中的所有記錄的Sname、Ssex和Class列。
select Sname, Ssex, Class from Student;
2、 查詢教師所有的單位即不重複的Depart列。
去重
select distinct depart from teachers
3、 查詢Student表的所有記錄。
select * from Student
4、 查詢Score表中成績在60到80之間的所有記錄。
select * from Scores where degree between 60 and 80;
5、 查詢Score表中成績爲85，86或88的記錄。
select * from Scores where degree = 85 or degree = 86 or degree = 88;
改爲
select * from Scores where degree in (85, 86, 88);
6、 查詢Student表中“95031”班或性別爲“女”的同學記錄。
select * from Student where class = “95031” or Ssex = “女”;
7、 以Class降序查詢Student表的所有記錄。
降序
select * from Student order by Class desc;
8、 以Cno升序、Degree降序查詢Score表的所有記錄。
以某升序以某降序
select * from Score order by Cno, Degree desc;
9、 查詢“95031”班的學生人數。
select count from students where class = “95031”;
10、查詢Score表中的最高分的學生學號和課程號。
分數最高
select sno, cno from Score order by Degree limit 1;
11、查詢‘3-105’號課程的平均分。
平均值
select avg(degree) from scores where cno = “3-105”;
12、查詢Score表中至少有5名學生選修的並以3開頭的課程的平均分數。
錯誤：
select avg(degree) from score where cno begin with “3” and count(sno) >= 5;
範例：
select cno, avg(degree) from score where cno like “3%” group by cno having count(sno) >= 5;
13、查詢最低分大於70，最高分小於90的Sno列。
select sno from scores group by sno having max(degree) < 90 and min(degree) > 70;
14、查詢所有學生的Sname、Cno和Degree列。
select sname, cno, degree from students join in scores where students.sno = scores.sno;
範例：
select sname, cno, degree from students inner join scores on (students.sno = scores.sno) order by sname;
15、查詢所有學生的Sno、Cname和Degree列。
select sno,cname,degree from scores inner join courses on (scores.cno = courses.cno) order by sno;
16、查詢所有學生的Sname、Cname和Degree列。
多表關聯
select sname,cname,degree
from students inner join scores
on (students.sno = scores.sno) inner join courses
on (courses.cno = scores.cno) order by sname;
17、查詢“95033”班所選課程的平均分。
錯誤：
select cno avg(scores) from students inner join scores on (students.sno = scores.sno) group by cno where class = “95033”;
範例：
select cname avg(degree)
from students inner join scores
on (students.sno = scores.sno) inner join courses
on (courses.cno = scores.con) where class = “95033”
group by courses.cno
order by cname;
18、假設使用如下命令建立了一個grade表：
create table grade(low number(3,0),upp number(3),rank 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’);
commit;
現查詢所有同學的Sno、Cno和rank列。
區間調教關聯：
select sno, cno, rank
from scores inner join grade
on (scores.degree >= grade.low and scores.degree <= grade.upp)
order by sno;
19、查詢選修“3-105”課程的成績高於“109”號同學成績的所有同學的記錄。
錯誤：
select * from
students inner join scores
on (students.sno = scores.sno)
where cno = “3-105” and degree > (select degree from scores where sno = “109”);
範例：
select s1.sno, s1.degree from
scores as s1 inner join scores as s2
on (s1.cno = s2.cno and s1.degree > s2.degree)
where s1.cno = “3-105” and s2.sno = “109”
order by s1.sno;
20、查詢score中選學一門以上課程的同學中分數爲非最高分成績的記錄。
有疑問
select * from scores
group by sno
where count() > 1 and degree != max(degree)
21、查詢成績高於學號爲“109”、課程號爲“3-105”的成績的所有記錄。
有疑問
select s1.sno, s1.cno, s1.degree
from scores as s1 inner join scores as s2
on (s1.degree > s2.degree)
where s2.sno = “109” and s2.cno = “3-105”;
22、查詢和學號爲108的同學同年出生的所有學生的Sno、Sname和Sbirthday列。
同年出生：
select s1.sno, s1.sname, s1.sbirthday
from students as s1 inner join students as s2
on (year(s1.sbirthday) = year(s2.sbirthday))
where s2.sno = “108”;
23、查詢“張旭“教師任課的學生成績。
select * from scores as s inner join courses as c
on (s.cno = c.cno) inner join teachers as t
on (t.tno = c.tno)
where t.tname = “張旭”
Order by sno;
24、查詢選修某課程的同學人數多於5人的教師姓名。
select distinct tname
from teachers as t inner join courses as c
on (t.tno = c.tno) inner join scores as s
on (c.cno = s.cno)
where c.cno in (select cno from scores group by (sno) having
count(sno) > 5);
範例：
select distinct tname
from scores inner join courses
on (scores.cno = courses.cno) inner join teachers
on (courses.tno = teachers.tno)
where courses.cno in (
select cno from scores
group by (cno) having count(sno)>5);
25、查詢95033班和95031班全體學生的記錄。
select * from students where class in (“95033”,“95031”) order by class;
26、查詢存在有85分以上成績的課程Cno.
錯誤：
select distinct cno from scores group by cno having max(degree) > 85;
範例：
select distinct cno from scores where degree > 85;
27、查詢出“計算機系“教師所教課程的成績表。
select t.tname,c.cname,s.sno,s.degree from scores as s inner join courses as c
on (s.cno = c.cno) inner join teachers as t
on (c.tno = t.tno)
where t.depart = “計算機系”;
範例：
select from teachers as t inner join courses as c
on (t.tno = c.tno) inner join scores as s
on (c.cno = s.cno) inner join students as st
on (s.sno = st.sno)
where t.depart = “計算機系”;
28、查詢“計算機系”與“電子工程系“不同職稱的教師的Tname和Prof。
select tname, prof from teachers where depart in (“計算機系”, “電子工程系”);
範例：
select tname, prof from teachers
where depart = “計算機系” and prof not in (
select distinct prof from teachers where depart = “電子工程系”);
29、查詢選修編號爲“3-105“課程且成績至少高於選修編號爲“3-245”的同學的Cno、Sno和Degree,並按Degree從高到低次序排序。
範例：
select cno, sno, degree from scores where cno = “3-105” and degree > any(
select degree from scores where cno = “3-245”) order by degree desc;
30、查詢選修編號爲“3-105”且成績高於選修編號爲“3-245”課程的同學的Cno、Sno和Degree.
select * from scores as s1 inner join scores as s2
on (s1.degree > s2.degree)
範例：
select * from scores where cno = “3-105” and degree > all(select degree from scores where cno = “3-204”)
31、查詢所有教師和同學的name、sex和birthday.
範例：
select sname, ssex, sbirthday from students union select tname, tsex, tbirthday from teachers;
32、查詢所有“女”教師和“女”同學的name、sex和birthday.
select sname, ssex, sbirthday from students where ssex = “女” union select tname, tsex, tbirthday from teachers where tsex = “女”;
33、查詢成績比該課程平均成績低的同學的成績表。
錯誤：
select * from scores where degree < (select avg(degree) from scores group by cno)
範例：
select s1.* from scores as s1 inner join (select
cno,avg(degree) as aDegree from scores group by (cno)) s2
on (s1.cno = s2.cno and s1.degree < s2.aDegree);
34、查詢所有任課教師的Tname和Depart.
select tname, depart from teachers where tno in (select tno from courses);
35 查詢所有未講課的教師的Tname和Depart.
select tname, depart from teachers where tno not in (select tno from courses);
36、查詢至少有2名男生的班號。
select count(ssex) as css, class from students group by (class) where count
範例：
select class, count(1) as boyCount from students
where ssex = “男”
group by class
having boyCount >= 2;
37、查詢Student表中不姓“王”的同學記錄。
select * from students where sname not like “王%”;
38、查詢Student表中每個學生的姓名和年齡。
範例：
select sname, year(now())-year(sbirthday) as sage from students;
39、查詢Student表中最大和最小的Sbirthday日期值。
範例：
select max(sbirthday), min(sbirthday) from students;
40、以班號和年齡從大到小的順序查詢Student表中的全部記錄。
select * from students order by class desc, sbirthday asc;
41、查詢“男”教師及其所上的課程。
select t.tname, c.cname from teachers as t inner join courses as c
on (teachers.tno = courses.tno) where t.tsex = “男”;
42、查詢最高分同學的Sno、Cno和Degree列。
select sno, cno, max(degree) from scores group by (cno);
範例：
select * from scores group by (cno) having degree = max(degree);
43、查詢和“李軍”同性別的所有同學的Sname.
select sname from students where ssex = (select ssex from students where sname = “李軍”);
範例：
select s1.sname from students as s1 inner join students as s2
on (s1.ssex = s2.ssex) where s2.sname = “李軍”;
44、查詢和“李軍”同性別並同班的同學Sname.
select s1.sname from students as s1 inner join students as s2
on (s1.ssex = s2.ssex and s1.class = s2.class)
where s2.name = “李軍”;
45、查詢所有選修“計算機導論”課程的“男”同學的成績表
select st.sname, c.cname, s.degree from courses as c inner join scores as s
on (c.cno = s.cno) inner join students as st
on (s.sno = st.sno)
where c.cname = “計算機導論” and st.ssex = “男”；
範例：
select * from scores
where sno in (select sno from students where ssex = “男”)
and cno in (select cno from courses where cname = “計算機導論”);