题解 | #商品交易(网易校招笔试真题)#

1. 先对trans表中每个商品的购买数量的求和。
2. 将trans表与goods表用商品id进行连接。
3. 利用where语句进行筛选，并用id进行排序。

select g.id, g.name, g.weight,a.total
from goods g join (
            select t.goods_id, sum(t.count) as total
            from trans t 
            group by t.goods_id
                 ) a 
            on g.id = a.goods_id
where g.weight < 50
and a.total > 20
order by id