题解 | 统计各等级会员用户下订单总额

select 
  u.vip,
IFNULL(sum(o.order_price), 0) as order_total
from uservip_tb u
left join order_tb o on u.user_id = o.user_id  
group by u.vip  
order by order_total desc

ifnull（null，0）如果是null就返回0