mysql - 按日期月份分组多个表

Question

所以我有 3 个表，名为:
支出 - 记录支出
Directv - 记录电视 channel 的订阅付款
销售额 - 记录销售额
我必须计算每个月的营业额、销售总额、总费用和 Directv

    Spending
    id|Amount|dateSpd
    1 |2000  |2018-10-05
    3 |3000  |2018-11-06

    Directv
    id|Amount|dateTv
    1 |50    |2018-10-05

    Sales
    id|customer|quantity|price|dateSales
    1 |Marc    |2       |500  |2018-10-05
    2 |Kevin   |3       |1500 |2018-10-05
    5 |Angel   |2       |500  |2018-11-07

我希望得到例如

turnover | Spending | sales | DirecTv | month | year
  5500   | 3000     | 2000  | 50      | 10     |2018
   1000  | 2000     | 500   | 0       | 11     |2018

我在获取它时遇到一些问题， 我的疑问:

--to get total amount of sales
select sum(sl.price) , month(sl.date) , year(sl.date) from sales sl GROUP by year(sl.date) , month(sl.date)

--for directtv
select sum(dv.amount) , month(dv.date) , year(dv.date) from directtv dv GROUP by year(dv.date) , month(dv.date)

--for turnover
SELECT sum(sl.quantity*sl.price) , month(sl.date) FROM sales sl GROUP by year(sl.date), month(sl.date) 

但是如何使用连接按日期对所有 SQL 查询进行分组
有人可以帮助我或给我任何提示吗？预先感谢您

Answer 1

您可以使用union all组合表中的数据，然后进行聚合。

我怀疑你想要这样的东西:

select year(dte), month(dte),
       sum(spending) as spending, sum(directtv) as directtv,
       sum(price*quantity) as turnover
from ((select datesp as dte, amount as spending, 0 as directtv, 0 as price, 0 as quantity
       from spending
      ) union all
      (select datetv as dte, 0 as spending, amount as directtv, 0 as price, 0 as quantity
       from directtv
      ) union all
      (select datesales as dte, 0 as spending, 0 as directtv, price, quantity
       from sales
      )
     ) x
group by year(dte), month(dte) ;

这并不完全是您查询中的内容，但考虑到您提供的数据，它是有意义的。