题解 | #返回产品名称和每一项产品的总订单数#
返回产品名称和每一项产品的总订单数
https://www.nowcoder.com/practice/1c64fd9048364a58a8ffa541720359a4
本题承接上一题的思路,在联合查询表的基础上分组聚合,并按产品名称升序排列。
select prod_name,count(order_num) orders from ((select prod_name,order_num from Products t1 left join OrderItems t2 on t1.prod_id = t2.prod_id) union (select prod_name,order_num from Products t1 right join OrderItems t2 on t1.prod_id = t2.prod_id)) t // 使用联合查询得到去重后的合并表 group by prod_name // 按产品名称分组 order by prod_name asc // 按产品名称升序排列