题目描述：

要求写一个SQL查询，对于所有产品，返回每个产品的产品名称，以及全部发票累计的总应缴款项、总已支付金额、总已取消金额、总已退款金额。
查询结果按 product_name 排序
示例：

方法1:
主要思路：解题链接汇总

select p.name as name,
        ifnull(sum(i.rest),0) as rest,
        ifnull(sum(i.paid),0) as paid,
        ifnull(sum(i.canceled),0) as canceled,
        ifnull(sum(i.refunded),0) as refunded
from Product as p left join Invoice as i on p.product_id=i.product_id
group by p.name
order by p.name