按日期月份多個表分組

Question

所以我有3個表：
支出 -記錄支出
Directv-記錄電視頻道的訂閱付款
銷售 -記錄銷售
而且我必須計算每個月的營業額，總銷售額，總費用和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

我想舉個例子

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

我有一些問題要解決，我的查詢是：

--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) 

但是如何將所有帶有聯接的SQL查詢按日期分組
有人可以幫助我或給我任何提示嗎？ 先感謝您

Answer 1

您可以使用union all合並表中的數據，然后進行匯總。

我懷疑您想要這樣的東西：

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) ;

這與查詢中的內容不完全相同，但是鑒於您提供的數據，這才有意義。