跪求sql大神 这个sql怎么写 mysql数据库

类似于：http://www.cnblogs.com/guwei4037/p/4635015.html

select id,name,age,class from student group by class order by id limit 2

select a.id,a.name,a.age,a.class
from
(select row_number() over (partition by class order by name)num,id,name,age,class
from student
)a where a.num in(1,2)

可以按这张表就这样写入数据库。读取的时候按class来循环读取，每读取一次的结果去前两位就行了‘