數據庫練習及答案

數據庫結構
創建四張表 分別存儲 學生信息 課程信息 分數 講師信息表 存儲相應數據
學生信息表 Student
字段名	字段類型	字段約束 / 含義
Sno	Varchar(3)	Not null  / 學員編號
Sname	Varchar(4)	Not null  / 學員姓名 
Ssex	Varchar(2)	Not null  / 性別
Sbirthday	Datetime	生日
Classnum	Varchar(5)	班級號

CREATE TABLE STUDENT
(
SNO VARCHAR(3) NOT NULL,
SNAME VARCHAR(4) NOT NULL,
SSEX VARCHAR(2) NOT NULL,
SBIRTHDAY DATETIME,
CLASS VARCHAR(5)
)
課程信息表 course
字段名	字段類型	字段約束 / 含義
Cno	Varchar(5)	Not null / 課程編號
Cname	Varchar(10)	Not null / 課程名稱
Tno	Varchar(10)	Not null / 授課老師編號


CREATE TABLE COURSE
(CNO VARCHAR(5) NOT NULL,
CNAME VARCHAR(10) NOT NULL,
TNO VARCHAR(10) NOT NULL)
成績表score
字段名	字段類型	字段約束 / 含義
Sno	Varchar(3)	Not null  / 學員編號
Cno	Varchar(5)	Not null  / 課程編號
Degree	Double(3,1)	Not null  / 分數

CREATE TABLE SCORE
(SNO VARCHAR(3) NOT NULL,
CNO VARCHAR(5) NOT NULL,
DEGREE NUMERIC(10, 1) NOT NULL)
講師表teacher
字段名	字段類型	字段約束 / 含義
Tno	Varchar(3)	Not null  / 講師編號
Tname	Varchar(4)	Not null  / 講師姓名
Tsex	Varchar(2)	Not null  / 講師性別
Tbirthday	Datetime	Not null  / 出生日期
Prof	Varchar(6)	等級
Depart	Varchar(10)	所屬院系

CREATE TABLE TEACHER
(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);

向表中存儲數據
INSERT INTO STUDENT (SNO,SNAME,SSEX,SBIRTHDAY,CLASS) VALUES (108 ,'曾華' ,'男' ,'1977-09-01',95033);
INSERT INTO STUDENT (SNO,SNAME,SSEX,SBIRTHDAY,CLASS) VALUES (105 ,'匡明' ,'男' ,'1975-10-02',95031);
INSERT INTO STUDENT (SNO,SNAME,SSEX,SBIRTHDAY,CLASS) VALUES (107 ,'王麗' ,'女' ,'1976-01-23',95033);
INSERT INTO STUDENT (SNO,SNAME,SSEX,SBIRTHDAY,CLASS) VALUES (101 ,'李軍' ,'男' ,'1976-02-20',95033);
INSERT INTO STUDENT (SNO,SNAME,SSEX,SBIRTHDAY,CLASS) VALUES (109 ,'王芳' ,'女' ,'1975-02-10',95031);
INSERT INTO STUDENT (SNO,SNAME,SSEX,SBIRTHDAY,CLASS) VALUES (103 ,'陸君' ,'男' ,'1974-06-03',95031);
GO
INSERT INTO COURSE(CNO,CNAME,TNO)VALUES ('3-105' ,'計算機導論',825);
INSERT INTO COURSE(CNO,CNAME,TNO)VALUES ('3-245' ,'操作系統' ,804);
INSERT INTO COURSE(CNO,CNAME,TNO)VALUES ('6-166' ,'數據電路' ,856);
INSERT INTO COURSE(CNO,CNAME,TNO)VALUES ('9-888' ,'高等數學' ,100);
GO
INSERT INTO SCORE(SNO,CNO,DEGREE)VALUES (103,'3-245',86);
INSERT INTO SCORE(SNO,CNO,DEGREE)VALUES (105,'3-245',75);
INSERT INTO SCORE(SNO,CNO,DEGREE)VALUES (109,'3-245',68);
INSERT INTO SCORE(SNO,CNO,DEGREE)VALUES (103,'3-105',92);
INSERT INTO SCORE(SNO,CNO,DEGREE)VALUES (105,'3-105',88);
INSERT INTO SCORE(SNO,CNO,DEGREE)VALUES (109,'3-105',76);
INSERT INTO SCORE(SNO,CNO,DEGREE)VALUES (101,'3-105',64);
INSERT INTO SCORE(SNO,CNO,DEGREE)VALUES (107,'3-105',91);
INSERT INTO SCORE(SNO,CNO,DEGREE)VALUES (108,'3-105',78);
INSERT INTO SCORE(SNO,CNO,DEGREE)VALUES (101,'6-166',85);
INSERT INTO SCORE(SNO,CNO,DEGREE)VALUES (107,'6-106',79);
INSERT INTO SCORE(SNO,CNO,DEGREE)VALUES (108,'6-166',81);
GO
INSERT INTO TEACHER(TNO,TNAME,TSEX,TBIRTHDAY,PROF,DEPART) 
VALUES (804,'李誠','男','1958-12-02','副教授','計算機系');
INSERT INTO TEACHER(TNO,TNAME,TSEX,TBIRTHDAY,PROF,DEPART) 
VALUES (856,'張旭','男','1969-03-12','講師','電子工程系');
INSERT INTO TEACHER(TNO,TNAME,TSEX,TBIRTHDAY,PROF,DEPART)
VALUES (825,'王萍','女','1972-05-05','助教','計算機系');
INSERT INTO TEACHER(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。

	select distinct Depart from teacher;

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 DEGREE from score where DEGREE >= 60 and DEGREE <= 80;
5、 查詢Score表中成績爲85，86或88的記錄。
	select DEGREE from score where DEGREE in (85, 86 , 88);
select DEGREE from score where DEGREE = 85 or DEGREE = 86 or DEGREE = 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。
select * from student order by CLASS desc;
8、 以Cno升序、Degree降序查詢Score表的所有記錄。
select * from score order by CNO asc, DEGREE desc ;
9、 查詢“95031”班的學生人數。
select count(1) from student where CLASS = '95031';
10、查詢Score表中的最高分的學生學號和課程號。
select SNO,CNO from score where DEGREE=(select max(SCORE.DEGREE) from score);
11、查詢‘3-105’號課程的平均分。
select avg(DEGREE) from score 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。
select avg(DEGREE) from score where (select count(1) from score where CNO like '3%') >= 5;
13、查詢最低分大於70，最高分小於90的Sno列。
select sno from score group by SNO having min(DEGREE) > 70 and max(DEGREE) < 90;
14、查詢所有學生的Sname、Cno和Degree列。
select SNAME,CNO,DEGREE from student,score where SCORE.SNO = STUDENT.SNO;
15、查詢所有學生的Sno、Cname和Degree列。
select SNAME,CNAME,DEGREE from score,student,course where STUDENT.SNO = SCORE.SNO and SCORE.CNO = COURSE.CNO;
16、查詢所有學生的Sname、Cname和Degree列。
select SNAME,CNAME,DEGREE from score,student,course where STUDENT.SNO = SCORE.SNO and SCORE.CNO = COURSE.CNO;
17、查詢“95033”班所選課程的平均分。
select avg(DEGREE) from score,course,student where STUDENT.SNO = SCORE.SNO and SCORE.CNO = COURSE.CNO
and CLASS='95033';
18、假設使用如下命令建立了一個grade表：

create table grade(low NUMERIC(3,0),upp NUMERIC(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。
SELECT SNO,CNO,rank FROM score,grade where DEGREE between low and upp;
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。
select * from score,course where SCORE.CNO = COURSE.CNO
                               and SCORE.CNO='3-105'
                               and  DEGREE > (select DEGREE from score where SNO = '109' and SCORE.CNO='3-105') ;

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。
select DEGREE,SNO,CNO
from SCORE
where SNO in (select SNO
              from SCORE
              group by SNO
              having count(CNO) > 1) and DEGREE < (select max(DEGREE)
                                                    from SCORE);
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。
同19題
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。
select SNO,SNAME,SBIRTHDAY from student where SBIRTHDAY = (select SBIRTHDAY from student where SNO='108');
23、查詢“張旭“教師任課的學生成績。
select STUDENT.SNO, SNAME, COURSE.CNO, CNAME,SCORE.DEGREE from course,score,student,teacher where TNAME='張旭'
                                                                       and COURSE.TNO = TEACHER.TNO
                                                                       and SCORE.CNO = COURSE.CNO
                                                                       and SCORE.SNO = STUDENT.SNO;
24、查詢選修某課程的同學人數多於5人的教師姓名。
select tname from teacher where tno in (select x.tno from course x,score y where x.CNO=y.CNO group by x.tno having count(x.tno)>5);
25、查詢95033班和95031班全體學生的記錄。
select * from student where CLASS='95033' or CLASS='95031';
26、查詢存在有85分以上成績的課程Cno.
select SCORE.CNO from course,score where SCORE.CNO=COURSE.CNO group by CNO having max(DEGREE) >= 85;
27、查詢出“計算機系“教師所教課程的成績表。
select x.CNO,x.SNO,x.DEGREE from score x,course y,teacher z where x.CNO=y.CNO
                                           and y.TNO=z.TNO
                                           and DEPART = '計算機系';
select * from score where cno in(select x.cno from course x,teacher y where y.tno=x.tno and y.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 teacher where depart='計算機系' and prof not in (select prof from teacher 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。
select * from score where cno='3-105' and degree>all (select degree from score 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 score where cno='3-105' and degree>all(select degree from score where cno='3-245');
31、查詢所有教師和同學的name、sex和birthday.
select tname,tsex,tbirthday from teacher union select sname,ssex,sbirthday from student;
32、查詢所有“女”教師和“女”同學的name、sex和birthday.
select tname,tsex,tbirthday from teacher where tsex='女' union select sname,ssex,sbirthday from student where ssex='女';
33、查詢成績比該課程平均成績低的同學的成績表。
select * from score x where DEGREE < (select avg(DEGREE) from score y where x.CNO = y.CNO);
34、查詢所有任課教師的Tname和Depart.
select tname,depart from teacher a where exists (select * from course b where a.tno=b.tno);
35 查詢所有未講課的教師的Tname和Depart. 
select tname,depart from teacher a where not exists (select * from course b where a.tno=b.tno);	
36、查詢至少有2名男生的班號。
select class from student where ssex='男'group by class having count(*)>=2;	
37、查詢Student表中不姓“王”的同學記錄。
select * from student where sname not like'王_';
38、查詢Student表中每個學生的姓名和年齡。
select SNAME,SBIRTHDAY from student;
39、查詢Student表中最大和最小的Sbirthday日期值。
select SBIRTHDAY from student where SBIRTHDAY in (select max(SBIRTHDAY) from student)
                                 or SBIRTHDAY in (select min(SBIRTHDAY) from student);
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 class,sname,sbirthday from student order by class desc,sbirthday;
41、查詢“男”教師及其所上的課程。
select x.tname,y.cname from teacher x,course y where x.tno=y.tno and x.tsex='男';
42、查詢最高分同學的Sno、Cno和Degree列。
select * from score where degree=(select max(degree)from score);
43、查詢和“李軍”同性別的所有同學的Sname.
select sname from student where ssex=(select ssex from student where sname='李軍');
44、查詢和“李軍”同性別並同班的同學Sname.
select sname from student where ssex=(select ssex from student where sname='李軍') and class=(select class from student where sname='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 * from score where sno in(select sno from student where ssex='男') and cno=(select cno from course where cname='計算機導論');