1.
SELECT
id,
gname,
price AS 原价,
price * 0.5 AS 五折价格,
num,
description
FROM
goods
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2.
SELECT
sum(price) AS 所有商品价格的和,
sum(price) / sum(num) AS 所有商品平均价格
FROM
goods作者: binggn 时间: 2017-2-22 15:29
第2个应该是:
SELECT
sum(price) AS 所有商品价格的和,
sum(price) / count(num) AS 所有商品平均价格
FROM
goods