select m.班级,m.考试科目,m.考试时间,(select count(班级) from m where m.考生成绩!<60 group by 班级)/(select count(班级) from m group by 班级)
from (select * from s INNER JOIN p ON s.学号=p.学号) AS m
group by m.班级
---round(0.23,2)
==0.23, --2为精度
from (select * from s INNER JOIN p ON s.学号=p.学号) AS m
group by m.班级
---round(0.23,2)
==0.23, --2为精度
from (select * from s INNER JOIN p ON s.学号=p.学号) AS m
group by m.班级
from s inner join p
group by s.考生班级,p.考试科目,p.考试时间
没有语法错误,但结果不对!我的程序有什么问题吗???