杭电数据库概论月A卷

select sname from student

where sdept=‘数学’and sname like ‘王%’ order by sage;

2. 查询每个班级每门课程的选课人数和平均分； select clno,cno,count(*) 选课人数,avg(grade) 平均分 from student,sc where =

group by clno,cno;

3.查询李爽同学没选修的课程名； SELECT cname FROM course WHERE NOT EXISTS (SELECT * FROM sc WHERE cno= AND sno=

(SELECT sno FROM student WHERE sname='李爽'));

此题可有多种答案

4. 把对表Course的查询权限及对Ccredit字段的更新权限授予用户张三;

GRANT SELECT ,UPDATE(Ccredit) ON course TO 张三;

5. 将01311班全体学生成绩置空； UPDATE sc

SET grade=NULL WHERE sno IN

(SELECT sno FROM student WHERE clno='01311');