SQL - 組合兩個查詢

Question

我有兩個我想要結合的查詢。

查詢1 - 這告訴我庫存中的所有車輛。 含義不在所有權表中：

SELECT VEHICLE.*
FROM VEHICLE
WHERE NOT EXISTS
(SELECT NULL FROM OWNERSHIP WHERE VEHICLE.VEH_ID= OWNERSHIP.VEH_ID);

查詢2 - 這個告訴我哪個車是每個品牌的最高價格。

SELECT B.BRAND_ID, B.BRAND_NAME, M.MODEL_NAME, C.CLASS_NAME, V.VEH_ID, V.VEH_YEAR, V.VEH_PRICE

FROM (((VEHICLE AS V INNER JOIN CLASS AS C ON V.CLASS_ID = C.CLASS_ID) 
INNER JOIN MODEL AS M ON M.MODEL_ID = V.MODEL_ID) 
INNER JOIN BRAND AS B ON B.BRAND_ID = M.BRAND_ID) 
INNER JOIN (SELECT M.BRAND_ID, MAX(V.VEH_PRICE) AS VEH_PRICE FROM VEHICLE AS V 
INNER JOIN MODEL AS M ON M.MODEL_ID = V.MODEL_ID GROUP BY M.BRAND_ID) 

AS derived ON (v.VEH_PRICE = derived.VEH_PRICE) AND (b.BRAND_ID = derived.BRAND_ID)
ORDER BY 7 DESC;

我意識到，確定哪些車輛是最昂貴的車輛，如果它們已經由客戶擁有則無關緊要。 由於第一個查詢告訴我們哪些可用，我將如何將這兩個結合起來？

Answer 1

我無法測試您的查詢，但認為這是您正在尋找的：

SELECT
  B.BRAND_ID,
  B.BRAND_NAME,
  M.MODEL_NAME,
  C.CLASS_NAME,
  V.VEH_ID,
  V.VEH_YEAR,
  V.VEH_PRICE
FROM 
  (((VEHICLE AS V INNER JOIN CLASS AS C ON V.CLASS_ID = C.CLASS_ID) 
    INNER JOIN MODEL AS M ON M.MODEL_ID = V.MODEL_ID) 
   INNER JOIN BRAND AS B ON B.BRAND_ID = M.BRAND_ID) 
  INNER JOIN (SELECT M.BRAND_ID, MAX(V.VEH_PRICE) AS VEH_PRICE
              FROM VEHICLE AS V
                   INNER JOIN MODEL AS M
                   ON M.MODEL_ID = V.MODEL_ID
              WHERE
                NOT EXISTS
                  (SELECT NULL FROM OWNERSHIP
                   WHERE V.VEH_ID=OWNERSHIP.VEH_ID)
              GROUP BY M.BRAND_ID) AS derived
  ON (v.VEH_PRICE = derived.VEH_PRICE)
  AND (b.BRAND_ID = derived.BRAND_ID)
WHERE
  NOT EXISTS
  (SELECT NULL FROM OWNERSHIP
   WHERE V.VEH_ID=OWNERSHIP.VEH_ID)
ORDER BY 7 DESC;

您必須排除子查詢中已經擁有的汽車，您可以在其中計算每個品牌的最高價格，也可以在外部查詢中排除與擁有所有者的汽車最大價格相同的自有汽車。

我還建議在子查詢和外部查詢中再添加一個帶有OWNERSHIP的LEFT JOIN，而不是使用NOT EXISTS子句，並且只采用OWNERSHIP.VEH_ID為空的行。