Sybase怎么求百分数啊 求帮忙

[吹疯鸡]

大神们 帮我下 小弟菜鸟小白 刚接触


这个图sno是学生号 cno是课程号 score 得分 现在想求各个科目的及格率并且按正序排列
代码如下

create table sc2(
sno varchar(10),
cno varchar(10),
score numeric(4,2)
)

insert into sc2 values ('s001','c001',78.9)
insert into sc2 values ('s002','c001',80.9)
insert into sc2 values ('s003','c001',81.9)
insert into sc2 values ('s004','c001',60.9)
insert into sc2 values ('s001','c002',82.9)
insert into sc2 values ('s002','c002',72.9)
insert into sc2 values ('s003','c002',81.9)
insert into sc2 values ('s001','c003',59.9)

[wwxxjj]

select c.cno, a.cno/b.cno from sc2 c , (select cno,count(cno) as cno from sc2 where score>60 group by cno ) a, (select cno,count(cno) as cno from sc2 group by cno ) b where a.cno=c.cno and c.cno=b.cno