题解 | #返回产品名称和与之相关的订单号#
返回产品名称和与之相关的订单号
https://www.nowcoder.com/practice/c369a759436a4e8b80baa9c39e9adf18
select prod_name,order_num from Products p left join OrderItems o on p.prod_id=o.prod_id union select prod_name,order_num from Products p right join OrderItems o on p.prod_id=o.prod_id order by prod_name;
MySQL 没有outer join 所以要左右一起用， union 自动去重
