select sname from s where not exists( select * from c where not exists ( select * from sc where c.cno=sc.cno and s.sno=sc.sno))
select c.sname from (select SNO,count(CNO) CNO from SC group by SN) a,(select distinct count(CNO) CNO from C) b,s where a.cn=b.cn AND a.SNO=c.SNO 如果还有学期之类的,在叫where条件吧
select * from s where not exists( select * from c where not exists (select * from sc where cno = c.cno and sno = s.sno))
select sname from s where not exist (select sno,cno from sc where not exists(select cno from c where sc.cno=c.cno))
not exists ( select * from sc where c.cno=sc.cno
and s.sno=sc.sno))
如果还有学期之类的,在叫where条件吧
from s
where not exists( select *
from c
where not exists (select *
from sc
where cno = c.cno
and sno = s.sno))