合并来自不同查询的两个虚拟表

Question

我有两个 SQL 查询。一个人退还为游泳赛事支付给公司的所有款项 另一个获得所有座位付款（与第一个分开）。

第一个有一个虚拟表结构 carnivalId, buildingCode, TotalRaces, TotalIncome

第二个是 carnivalId, SeatCosts

我想将它们组合到一个表中，以便查询以以下格式返回 carnivalId, buildingCode, TotalRaces, TotalIncome, SeatCosts

我研究了 UNION，但它似乎不是正确的方法，因为这两个查询具有不同的返回结构。

我尝试在 carnivalId 上使用内部连接来连接两者，但它只是错误 -

SELECT c.carnivalId, c.buildingCode, COUNT(r.raceId) as TotalRaces, SUM(p.amountPaid) as TotalIncome
FROM Carnival c, Race r, Payment p, Entry e
WHERE r.carnivalId = c.carnivalId
AND e.raceId = r.raceId
AND p.payId = e.payId
INNER JOIN (SELECT c.carnivalId, SUM(s.seatsBought*st.seatCost)
    FROM Carnival c, SeatsAvailable s, SeatType st
    WHERE carnivalId = c.carnivalId
    AND st.seatType = s.seatType
    GROUP BY c.carnivalId, c.buildingCode) SeatingCosts ON c.carnivalId = SeatingCosts.carnivalId
GROUP BY c.carnivalId, c.buildingCode;

我也尝试将两个查询合并为一个，但它使所有返回的值完全错误（看起来它将第一个中的所有值乘以seatsBought结果中的行数

SELECT c.carnivalId, c.buildingCode, COUNT(r.raceId) as TotalRaces, SUM(p.amountPaid) as TotalIncome, SUM(s.seatsBought*st.seatCost) as SeatCosts
FROM Carnival c, Race r, Payment p, Entry e, SeatsAvailable s, SeatType st
WHERE r.carnivalId = c.carnivalId
AND e.raceId = r.raceId
AND p.payId = e.payId
AND s.carnivalId = c.carnivalId
AND st.seatType = s.seatType
GROUP BY c.carnivalId, c.buildingCode;

第一个查询 -

SELECT c.carnivalId, c.buildingCode, COUNT(r.raceId) as TotalRaces, SUM(p.amountPaid) as TotalIncome
FROM Carnival c, Race r, Payment p, Entry e
WHERE r.carnivalId = c.carnivalId
AND e.raceId = r.raceId
AND p.payId = e.payId
GROUP BY c.carnivalId, c.buildingCode;

第二次查询——

SELECT c.carnivalId, SUM(s.seatsBought*st.seatCost) as SeatCosts
FROM Carnival c, SeatsAvailable s, SeatType st
WHERE s.carnivalId = c.carnivalId
AND st.seatType = s.seatType
GROUP BY c.carnivalId, c.buildingCode;

Answer 1

你应该加入聚合的结果，例如使用你的查询作为子查询，而不是加入分解的行

SELECT t1.carnivalId
      , t1.buildingCode
      , t1.TotalRaces
      , t1.TotalIncome
      , t2.SeatCosts 
  FROM (

    SELECT c.carnivalId
      , c.buildingCode
      , COUNT(r.raceId) as TotalRaces
      , SUM(p.amountPaid) as TotalIncome
    FROM Carnival c
    INNER JOIN Race r ON r.carnivalId = c.carnivalId
    INNER JOIN Entry e ON e.raceId = r.raceId
    INNER JOIN Payment p ON p.payId = e.payId
    GROUP BY c.carnivalId, c.buildingCode
 ) t1 
INNER JOIN (
  SELECT c.carnivalId
    , SUM(s.seatsBought*st.seatCost) as SeatCosts
  FROM Carnival c
  INNER JOIN SeatsAvailable s ON s.carnivalId = c.carnivalId
  INNER JOIN  SeatType st ON st.seatType = s.seatType
  WHERE s.carnivalId = c.carnivalId
  GROUP BY c.carnivalId, c.buildingCode
) t2 ON t1.carnivalId = t2.carnivalId 
    

并且您应该使用基于 JOIN 显式子句的显式连接语法，并避免基于 where 子句的旧（1992 年之前）隐式连接语法。