题解 | #商品交易(网易校招笔试真题)#
商品交易(网易校招笔试真题)
http://www.nowcoder.com/practice/f257dfc1b55e42e19eec004aa3cb4174
法一：（窗口函数）
SELECT DISTINCT id,name,weight,total FROM
(SELECT goods.id,name,weight,SUM(count) over (partition by trans.goods_id) total
FROM goods JOIN trans ON goods.id=trans.goods_id) t1
WHERE weight<50 AND total>20
ORDER BY id
法二：给goods加一个total列即可。（这个方法就可以了，感觉我老开窗开习惯了，捂脸）
SELECT id,name,weight,total FROM goods
JOIN
(SELECT goods_id, SUM(count) total FROM trans GROUP BY goods_id) t1
ON goods.id=t1.goods_id
WHERE weight<50 AND total>20
ORDER BY id
