sql - 查询计算一个月的利润

Question

我必须表：

收入：

| date | incomeAmount |

花费：

| date | expenseAmount |

我想使用以下方法总结我在特定月份的所有收入：MONTH(date) = ?

我还需要总结我在同一个月的所有费用

然后减去得到我当月的利润，输出表类似于：

| Month | TotalIncomes | TotalExpenses | Profit |

我怎样才能创建一个 SQL 查询来做到这一点？谢谢大家的帮助！

Answer 1

您可以加入聚合表。

SELECT A.Month, TotalIncomes, TotalExpenses, TotalIncomes-TotalExpenses AS Profit
FROM (MONTH(Date) AS Month, SUM(incomeAmount) AS TotalIncomes
      FROM Incomes 
      GROUP BY MONTH(Date)
      ) A 
INNER JOIN (
      MONTH(Date) AS Month, SUM(expenseAmount) AS TotalExpenses
      FROM Incomes 
      GROUP BY MONTH(Date)
      ) B
 ON A.Month = B.Month

Answer 2

SELECT I.Month AS Month,
       I.TotalIncomes AS TotalIncomes,
       E.TotalExpenses AS TotalExpenses,
       I.TotalIncomes - E.TotalExpenses AS Profit
  FROM ( SELECT EXTRACT(MONTH FROM DATE ) AS Month,
                SUM( I.incomeAmount ) AS TotalIncomes
           FROM Incomes
       )  I,
       (
         SELECT EXTRACT(MONTH FROM DATE ) AS Month,
                SUM( E.expenseAmount ) AS TotalExpenses
           FROM Expenses
       ) E
 WHERE I.Month = E.Month
;