有四个表,一个用户表m_user(id,name),一个订单表m_order(id,user_id,amount),还有一些没用的表和字段,要求查出订单数量大于1的用户名和订单数量,按订单数量降序排列,请大伙帮我看看下面这个有啥问题 select m_user.name,sum(m_order.amount) total from m_user join m_order on m_user.id=m_order.user_id group by m_user.id having total>1 order by total desc,m_user.name asc