组合两个选择状态sql

Question

我有以下数据库：

我想获得所有市场的总利润。这是购买的总价格 - 您为员工支付的工资总数。

所以我有这样的疑问： 我得到每个市场的所有购买总和

SELECT
    Markets.Title,
    SUM(Purchase.TotalPrice) sum
FROM Purchase
INNER JOIN Employees ON Purchase.Employee_ID = Employees.Employee_ID
INNER JOIN Markets ON Employees.Market_ID = Markets.Market_ID
GROUP BY Markets.Title

在另一个查询中，我获得了工资支付市场总额：

SELECT
    Markets.Title,
    SUM(Employees.Salary) sum
FROM Employees
INNER JOIN Markets ON Employees.Market_ID = Markets.Market_ID
GROUP BY Markets.Title

但我很困惑如何结合这些查询以获得每个市场的利润（所有订单的总和 - 所有工资的总和）。 任何人都可以帮助我吗？

Answer 1

SELECT
      m.Title
    , e.TotalSalary
    , e.TotalPrice
FROM dbo.Markets m
JOIN (
    SELECT
          e.Market_ID
        , TotalSalary = SUM(e.Salary)
        , TotalPrice = SUM(p.TotalPrice)
    FROM dbo.Employees e
    JOIN (
        SELECT Employee_ID, TotalPrice = SUM(TotalPrice)
        FROM dbo.Purchase
        GROUP BY Employee_ID
    ) p ON p.Employee_ID = e.Employee_ID
    GROUP BY e.Market_ID
) e ON e.Market_ID = m.Market_ID

Answer 2

像.........

这样的东西

SELECT SUB_Q.Title, SUM(SUB_Q.Tot) FROM 
(
  SELECT Markets.Title, sum(Purchase.TotalPrice) as Tot
  FROM Purchase 
  INNER JOIN Employees ON Purchase.Employee_ID = Employees.Employee_ID 
  INNER JOIN Markets ON Employees.Market_ID = Markets.Market_ID
  GROUP BY Markets.Title
  UNION ALL
  SELECT Markets.Title, sum(Employees.Salary) as Tot
  FROM Employees 
  INNER JOIN Markets ON Employees.Market_ID = Markets.Market_ID
  GROUP BY Markets.Title
) SUB_Q
GROUP BY SUB_Q.Title

Answer 3

只需在两个SELECT

之间添加UNION关键字

有关UNION的详细信息，请参阅此处：https://msdn.microsoft.com/fr-fr/library/ms180026%28v=sql.120%29.aspx