group by 显示所有数据

select open_id ,max(id)  id  from table group by open_id  通过openId分组,并拿到id最大的那一个open_id数据

要获得所有字段的数据,需要做一个自关联

 

select *

from (select open_id ,max(id)  id  from table group by open_id) a i

nner join table

on a.open_id = table.open_id

and a.id = table.id