数据库原理与应用教程(第三版)第四章课后习题答案 下载本文

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1. SELECT *

FROM Student 结果:

2. SELECT Sname 姓名,Sage 年龄

FROM Student

WHERE Sdept='计算机系' 结果:

3. SELECT Sno 学号,Cno 课程号,Grade 成绩

FROM SC

WHERE Grade BETWEEN 70 AND 80

4. SELECT Sname 姓名,Sage 年龄

FROM Student

WHERE Sdept='计算机系' AND Sage>=18 AND Sage<=20 AND Ssex='男'

5. SELECT MAX(Grade) 最高分数

FROM SC

WHERE Cno='c01'

6. SELECT MAX(Sage) 最大年龄,MIN(Sage) 最小年龄

FROM Student

WHERE Sdept='计算机系'

7. SELECT Sdept 系名,COUNT(*) 学生人数

FROM Student GROUP BY Sdept

8. SELECT Cname 课程名,COUNT(*) 选课门数,MAX(Grade) 最高分

FROM Course,SC GROUP BY Cname

9. SELECT Sno 学号,COUNT(*) 选课门数,SUM(Grade) 总成绩

FROM SC GROUP BY Sno

ORDER BY'选课门数' ASC

10. SELECT Sno 学号,SUM(Grade) 总成绩

FROM SC GROUP BY Sno

HAVING SUM(Grade)>200

10.

CREAT TABLE BOOK(

Snobook nchar(6) PRIMARY KEY, Snamebook nvarchar(30) NBOT NULL, Writer char(10) NOT NULL, Time smalldatetime, Price numeric(3,1) )

CREAT TABLE BOOKSHOP(

Snoshop nchar(6) PRIMARY KEY, Snameshop nvarchar(30) NOT NULL, Tel char(8)CHECK(Tel =0 AND Tel <=9), Place nchar(40), Snoemail char(6) )

CREAT TABLE BOOKSELL( Snobook nchar(6) NOT NULL,