《数据库》实验报告2

2、列出同时选修了'数学’和'数据库’的学生学号、姓名；

select student.sno,sname

from student,sc

where cno in (select cno from course

where cname='数学')and sc.sno=student.sno

intersect

select student.sno,sname

from student,sc

where cno in (select cno from course

where cname='数据库')and sc.sno=student.sno

3、查询缺少成绩的所有学生的详细情况；

select * from student,sc where Grade is null and student.sno=sc.sno

查询缺少成绩的所有学生的学号姓名；

select student.sno sname from student,sc where Grade is null and student.sno=sc.sno

4、查询与'李勇’ 年龄相同的所有学生的信息；

select * from student

where sage =(select sage from student where sname='李勇') and sname <> '李勇’

查询与'杨磊’年龄不相同的所有学生的信息；

select * from student

where sage <>(select sage from student where sname='杨磊')

7、按照“学号，姓名，所在院系，不及格课程门数”的顺序列出学生有课程不及格的情况。

select student.sno,sname,sdept,count(grade) 不及格门数 from student,sc

where  student.sno=sc.sno and grade<60 group by student.sno,sname,sdept

9、查询只被一名学生选修的课程的课程号；

select cno from sc group by Cno having COUNT(sno)=1