select STUDENTS.stno, STUDENTS.name, count(distinct cno) as noc from STUDENTS, GRADES where STUDENTS.stno = GRADES.stno group by STUDENTS.stno, STUDENTS.name order by count(distinct cno) desc;
select STUDENTS.stno, STUDENTS.name, count(distinct cno) as noc from STUDENTS, GRADES where STUDENTS.stno = GRADES.stno group by STUDENTS.stno, STUDENTS.name order by count(distinct cno) desc;