使用LEFT JOIN以天为单位的mysql组结果

Question

当有人购买物品时我有付款表我添加了1条带有金额和日期的记录

一些买家需要额外的服务项目（运输支持......） 所以我有服务价格和payment_id的服务表

我想要这样的结果

   date    -  Sum(payments)  -  Sum(services)
01-01-2016 -    200          -       100
02-01-2016 -    200          -       100
03-01-2016 -    100          -        0

我试过这个查询

SELECT DATE(FROM_UNIXTIME(date)),SUM(amount),SUM(price) 
FROM payments 
LEFT JOIN services ON payments.id = service.payment_id 
GROUP BY DATE(FROM_UNIXTIME(date))

但返回重复的值 提前谢谢

Answer 1

您需要使用连接两个表的子查询，并对每笔付款的价格求和。然后，您可以按日期对结果进行分组。

SELECT date, SUM(payments), SUM(services)
FROM (
    SELECT DATE(FROM_UNIXTIME(p.date)) AS date, p.amount AS payments, IFNULL(SUM(s.price), 0) AS services
    FROM payments AS p
    LEFT JOIN services AS s ON p.id = s.payment_id
    GROUP BY p.id
) AS subquery
GROUP BY date