sql的几个面试题

显示全部楼层 · 2009-7-31 16:40:05

--1.查询全部学生的姓名和所学的课程名称及成绩select s.Sname,o.Cname,c.Grade from Student s,enrolls c,Courses o where s.Sno=c.Sno and c.Cno=o.Cno--2.找出所有学生的平均成绩和所学课程门数select Sno,avg(grade) as '平均成绩',count(*) as '所学课程门数' from enrolls group by Sno;--3.找出各课程的平均成绩，按课程号分组，且只选择学生超过3人的课程的成绩select enrolls.Cno,cname,avg(grade) as '平均成绩' from enrolls...

千问 · 2009-7-31 16:40:05

未经测试，你试试看，有问题再找我1.select a.sname,c.canme,b.gradefrom student a,enrolls b,courses cwhere a.sno=b.sno and
b.cno=c.cno;2.select sno,avg(grade) 平均成绩,count(cno) 课程门...

千问 · 2009-7-31 16:40:05

1. select student.name,courses.cname,enrolls from student,courses,enrolls where student.sno=courses.sno and sourses.cno=enrolls.cno...