相关子查询写SQL语句

查询被一个以上的学生选修的课程号 三个表，student(sno,sname,sdept)，sc(sno,cno,),c(cno,cname)

select cname from c where cno in (select cno from sc group by cno having count(cno)>0);

试试这~

SELECt cno FROM sc GROUP BY cno HAVINg COUNT(SNO)>1

应该是这样的，你试下看看！

谢谢！

SELECt cno,sno FROM SC GROUP BY sno HAVINg COUNT(cno)>1

Select cno From (Select cno,sno,count(sno) x From sc group by cno,sno) a where a.x > 1