SQL 經典練習

SQL 基礎練習

CREATE TABLE STUDENT
(SNO VARCHAR(3) NOT NULL, 
SNAME VARCHAR(4) NOT NULL,
SSEX VARCHAR(2) NOT NULL, 
SBIRTHDAY DATETIME,
CLASS VARCHAR(5))
go
CREATE TABLE COURSE
(CNO VARCHAR(5) NOT NULL, 
CNAME VARCHAR(10) NOT NULL, 
TNO VARCHAR(10) NOT NULL)
go
CREATE TABLE SCORE 
(SNO VARCHAR(3) NOT NULL, 
CNO VARCHAR(5) NOT NULL, 
DEGREE NUMERIC(10, 1) NOT NULL) 
go
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)

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' ,'操做系統' ,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');

題目：
一、 查詢Student表中的全部記錄的Sname、Ssex和Class列。
二、 查詢教師全部的單位即不重複的Depart列。
三、 查詢Student表的全部記錄。
四、 查詢Score表中成績在60到80之間的全部記錄。
五、 查詢Score表中成績爲85，86或88的記錄。
六、 查詢Student表中「95031」班或性別爲「女」的同窗記錄。
七、 以Class降序查詢Student表的全部記錄。
八、 以Cno升序、Degree降序查詢Score表的全部記錄。
九、 查詢「95031」班的學生人數。
十、查詢Score表中的最高分的學生學號和課程號。
十一、查詢‘3-105’號課程的平均分。
十二、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。
1三、查詢最低分大於70，最高分小於90的Sno列。
1四、查詢全部學生的Sname、Cno和Degree列。
1五、查詢全部學生的Sno、Cname和Degree列。
1六、查詢全部學生的Sname、Cname和Degree列。
1七、查詢「95033」班所選課程的平均分。
1八、假設使用以下命令創建了一個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;
現查詢全部同窗的Sno、Cno和rank列。
1九、查詢選修「3-105」課程的成績高於「109」號同窗成績的全部同窗的記錄。
20、查詢score中選學一門以上課程的同窗中分數爲非最高分紅績的記錄。
2一、查詢成績高於學號爲「109」、課程號爲「3-105」的成績的全部記錄。
2二、查詢和學號爲108的同窗同年出生的全部學生的Sno、Sname和Sbirthday列。
2三、查詢「張旭「教師任課的學生成績。
2四、查詢選修某課程的同窗人數多於5人的教師姓名。
2五、查詢95033班和95031班全體學生的記錄。
2六、查詢存在有85分以上成績的課程Cno.
2七、查詢出「計算機系「教師所教課程的成績表。
2八、查詢「計算機系」與「電子工程系「不一樣職稱的教師的Tname和Prof。
2九、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」的同窗的Cno、Sno和Degree,並按Degree從高到低次序排序。
30、查詢選修編號爲「3-105」且成績高於選修編號爲「3-245」課程的同窗的Cno、Sno和Degree.
3一、查詢全部教師和同窗的name、sex和birthday.
3二、查詢全部「女」教師和「女」同窗的name、sex和birthday.
3三、查詢成績比該課程平均成績低的同窗的成績表。
3四、查詢全部任課教師的Tname和Depart.
35  查詢全部未講課的教師的Tname和Depart. 
3六、查詢至少有2名男生的班號。
3七、查詢Student表中不姓「王」的同窗記錄。
3八、查詢Student表中每一個學生的姓名和年齡。
3九、查詢Student表中最大和最小的Sbirthday日期值。
40、以班號和年齡從大到小的順序查詢Student表中的所有記錄。
4一、查詢「男」教師及其所上的課程。
4二、查詢最高分同窗的Sno、Cno和Degree列。
4三、查詢和「李軍」同性別的全部同窗的Sname.
4四、查詢和「李軍」同性別並同班的同窗Sname.
4五、查詢全部選修「計算機導論」課程的「男」同窗的成績表
參考答案：
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(*) FROM STUDENT WHERE CLASS='95031';

10.SELECT SNO,CNO FROM SCORE WHERE DEGREE=(SELECT MAX(DEGREE) FROM SCORE);

SELECT SNO,CNO FROM SCORE ORDER BY DEGREE DESC LIMIT 1;

11.SELECT AVG(DEGREE) FROM SCORE WHERE CNO='3-105';

12.select avg(degree),cno
from score
where cno like '3%'
group by cno
having count(sno)>= 5;

13.SELECT SNO FROM SCORE GROUP BY SNO HAVING MIN(DEGREE)>70 AND MAX(DEGREE)<90;

14.SELECT A.SNAME,B.CNO,B.DEGREE FROM STUDENT AS A JOIN SCORE AS B ON A.SNO=B.SNO;

15.SELECT A.CNAME, B.SNO,B.DEGREE FROM COURSE AS A JOIN SCORE AS B ON A.CNO=B.CNO ;

16.SELECT A.SNAME,B.CNAME,C.DEGREE FROM STUDENT A JOIN (COURSE B,SCORE C)
ON A.SNO=C.SNO AND B.CNO =C.CNO;

17.SELECT AVG(A.DEGREE) FROM SCORE A JOIN STUDENT B ON A.SNO = B.SNO WHERE B.CLASS='95033';

18.SELECT A.SNO,A.CNO,B.RANK FROM SCORE A,GRADE B WHERE A.DEGREE BETWEEN B.LOW AND B.UPP 

ORDER BY RANK;

19.SELECT A.* FROM SCORE A JOIN SCORE B WHERE A.CNO='3-105' AND A.DEGREE>B.DEGREE AND 

B.SNO='109' AND B.CNO='3-105';
另外一解法：SELECT A.* FROM SCORE A  WHERE A.CNO='3-105' AND A.DEGREE>ALL(SELECT DEGREE FROM 

SCORE B WHERE B.SNO='109' AND B.CNO='3-105');

20.SELECT * FROM score s WHERE DEGREE<(SELECT MAX(DEGREE) FROM SCORE) GROUP BY SNO HAVING 

COUNT(SNO)>1 ORDER BY DEGREE ;

21.見19的第二種解法

22。SELECT SNO,SNAME,SBIRTHDAY FROM STUDENT WHERE YEAR(SBIRTHDAY)=(SELECT YEAR(SBIRTHDAY) 

FROM STUDENT WHERE SNO='108');
ORACLE:select x.cno,x.Sno,x.degree from score x,score y where x.degree>y.degree and 

y.sno='109'and y.cno='3-105';
select cno,sno,degree from score   where degree >(select degree from score where sno='109' 

and cno='3-105')

23.SELECT A.SNO,A.DEGREE FROM SCORE A JOIN (TEACHER B,COURSE C)
ON A.CNO=C.CNO AND B.TNO=C.TNO
WHERE B.TNAME='張旭';
另外一種解法：select cno,sno,degree from score where cno=(select x.cno from course x,teacher y 

where x.tno=y.tno and y.tname='張旭');
根據實際EXPLAIN此SELECT語句，第一個的掃描次數要小於第二個

24.SELECT A.TNAME FROM TEACHER A JOIN (COURSE B, SCORE C) ON (A.TNO=B.TNO AND B.CNO=C.CNO) 

GROUP BY C.CNO HAVING COUNT(C.CNO)>5;
另外一種解法：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);
實際測試1明顯優於2


25。select cno,sno,degree from score where cno=(select x.cno from course x,teacher y where 

x.tno=y.tno and y.tname='張旭');

26。SELECT CNO FROM SCORE GROUP BY CNO HAVING MAX(DEGREE)>85;
另外一種解法：select distinct cno from score where degree in (select degree from score where 

degree>85);

27。SELECT A.* FROM SCORE A JOIN (TEACHER B,COURSE C) ON A.CNO=C.CNO AND B.TNO=C.TNO
WHERE B.DEPART='計算機系';
另外一種解法：SELECT * from score where cno in (select a.cno from course a join teacher b on 

a.tno=b.tno and b.depart='計算機系');
此時2略好於1，在多鏈接的境況下性能會迅速降低

28。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。SELECT * FROM SCORE WHERE DEGREE>ANY(SELECT DEGREE FROM SCORE WHERE CNO='3-245') ORDER 

BY DEGREE DESC;

30。SELECT * FROM SCORE WHERE DEGREE>ALL(SELECT DEGREE FROM SCORE WHERE CNO='3-245') ORDER 

BY DEGREE DESC;

31.SELECT SNAME AS NAME, SSEX AS SEX, SBIRTHDAY AS BIRTHDAY FROM STUDENT
UNION
SELECT TNAME AS NAME, TSEX AS SEX, TBIRTHDAY AS BIRTHDAY FROM TEACHER;

32.SELECT SNAME AS NAME, SSEX AS SEX, SBIRTHDAY AS BIRTHDAY FROM STUDENT WHERE SSEX='女'
UNION
SELECT TNAME AS NAME, TSEX AS SEX, TBIRTHDAY AS BIRTHDAY FROM TEACHER WHERE TSEX='女';

33.SELECT A.* FROM SCORE A WHERE DEGREE<(SELECT AVG(DEGREE) FROM SCORE B WHERE A.CNO=B.CNO);
須注意********此題

34。解法一：SELECT A.TNAME,A.DEPART FROM TEACHER A JOIN COURSE B ON A.TNO=B.TNO;
解法二：select tname,depart from teacher a where exists
(select * from course b where a.tno=b.tno);
解法三：SELECT TNAME,DEPART FROM TEACHER WHERE TNO IN (SELECT TNO FROM COURSE);

實際分析，第一種揭發貌似更好，至少掃描次數最少。

35.解法一：SELECT TNAME,DEPART FROM TEACHER A LEFT JOIN COURSE B USING(TNO) WHERE ISNUL

(B.tno);
解法二：select tname,depart from teacher a where not exists
(select * from course b where a.tno=b.tno);
解法三：SELECT TNAME,DEPART FROM TEACHER WHERE TNO NOT IN (SELECT TNO FROM COURSE);
NOT IN的方法效率最差，其他兩種差很少

36.SELECT CLASS FROM STUDENT A WHERE SSEX='男' GROUP BY CLASS HAVING COUNT(SSEX)>1;

37.SELECT * FROM STUDENT A WHERE SNAME not like '王%';

38.SELECT SNAME,(YEAR(NOW())-YEAR(SBIRTHDAY)) AS AGE FROM STUDENT;

39.select sname,sbirthday as THEMAX from student where sbirthday =(select min(SBIRTHDAY) 

from student)
union
select sname,sbirthday as THEMIN from student where sbirthday =(select max(SBIRTHDAY) from 

student);

40.SELECT CLASS,(YEAR(NOW())-YEAR(SBIRTHDAY)) AS AGE FROM STUDENT ORDER BY CLASS DESC,AGE 

DESC;

41.SELECT A.TNAME,B.CNAME FROM TEACHER A JOIN COURSE B USING(TNO) WHERE A.TSEX='男';

42.SELECT A.* FROM SCORE A WHERE DEGREE=(SELECT MAX(DEGREE) FROM SCORE B );

43.SELECT SNAME FROM STUDENT A WHERE SSEX=(SELECT SSEX FROM STUDENT B WHERE B.SNAME='李軍');

44.SELECT SNAME FROM STUDENT A WHERE SSEX=(SELECT SSEX FROM STUDENT B WHERE B.SNAME='李軍' )
AND CLASS=(SELECT CLASS FROM STUDENT C WHERE c.SNAME='李軍');

45.解法一：SELECT A.* FROM SCORE A JOIN (STUDENT B,COURSE C) USING(sno,CNO) WHERE B.SSEX='男

' AND C.CNAME='計算機導論';
解法二：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');