查询成绩在60分以上的学生的信息及其选课的课程号和成绩
A: select student.*,cid,grade from student,sc where student.sid=sc.sid and grade>=60
B: select * from student,sc where student.sid=sc.sid where grade>=60
C: select * from student,sc where student.sid=sc.sid where student.sid=sc.sid
D: select * from student,course where grade>=60
A: select student.*,cid,grade from student,sc where student.sid=sc.sid and grade>=60
B: select * from student,sc where student.sid=sc.sid where grade>=60
C: select * from student,sc where student.sid=sc.sid where student.sid=sc.sid
D: select * from student,course where grade>=60
举一反三
- 查询学生的学号，姓名，选修课程号和课程成绩 A: select sid,sname,cid,grade from student,sc where student.sid=sc.sid B: select * from student,sc where student.sid=sc.sid C: select sid,sname,cid,cname from student,course D: select sid,sname,cid,cname from student,sc
- 按照学号进行分组，统计学生的平均成绩（） A: select sid, avg(grade) from student group by cid B: select sid, avg(grade) from student group by sid C: select sid, avg(grade) from sc group by sid D: select sid, avg(grade) from sc group by cid
- 按照学号进行分组，统计学生的平均成绩，且平均分按降序排列 A: select sid, avg(grade) from sc group by sid order by avg(grade) desc B: select sid, avg(grade) from sc group by cid order by avg(grade) desc C: select sid, avg(grade) from student group by sid order by avg(grade) desc D: select sid, avg(grade) from student group by cid order by avg(grade)
- 查询选修了a001号课程且成绩在60分以上的所有学生 A: select * from course where cid=’a001’ and grade>=60 B: select * from student where cid=’a001’ and grade>=60 C: select * from sc where cid=’a001’ D: select * from sc where cid=’a001’ and grade>=60
- 查询每个学生的学号、姓名、选修的课程名及成绩，下列（)的操作是正确的。 A: select student,sno,sname,grade from student,sc where student.sno=sc.sno and sc.cno=course.cno B: select student,sno,sname,grade from student,sc,cource where student.sno=sc.sno C: select student,sno,sname,grade from student,sc,cource where sc.cno=course.cno D: select student,sno,sname,grade from student,sc,cource where student.sno=sc.sno and sc.cno=course.cno