Question

给出表格：

parts (part_id, part_desc, type_id, car_id)
types (type_id, type_name)
cars (car_id, car_model, car_make)

我想找到汽车的id，型号和品牌，这些汽车的零件属于制造'本田'和模型'思域'的所有类型的零件。也就是说，如果Honda Civic的类型为A,B,C，那么它会找到所有属于A和B以及C的汽车。

我不确定如何执行此操作，但我设法为A或B或C

执行此操作

SELECT DISTINCT c.car_id, c.car_model, c.car_make
FROM cars c, parts p
WHERE c.car_id= p.car_id AND p.type_id IN (
       SELECT p.type_id FROM cars c, parts p
       WHERE a.car_id = p.car_id
       AND a.car_model = 'Civic' 
       AND a.car_make = 'Honda'
)

如果内部查询获得本田思域的所有类型的部件，但如果它们只有A,B,C中的一个而不是全部，那么IN（）子句将匹配汽车。

我希望避免使用ALL和ANY集合运算符。另外A,B,C就是一个例子，不应该在字面上用它在答案中硬编码。子查询的结果将是未知的。

Answer 1

with t as ( -- first find out all the type_id belonging to Honda civic
select distinct p.type_id
  from cars c
      ,parts p
 where c.car_model = 'Civic' 
   and c.car_make = 'Honda'
   and c.car_id = p.car_id
)  
,c as ( -- find which car has which part types
select distinct
       c.car_id
      ,c.car_make
      ,c.car_model
      ,t.type_id
  from t
      ,parts p
      ,cars  c
 where t.type_id = p.type_id
   and p.car_id = c.car_id
)
-- the number of the records in c for each car meeting conditions must be equal to 
-- the number of part types
select c.car_id
      ,c.car_make
      ,c.car_model
  from c
 group
    by c.car_id
      ,c.car_make
      ,c.car_model
having count(0) = (select count(0) from t)

Answer 2

为避免像“所有”这样的词语，请使用两个否定来重新表达问题：
你想要的是本田思域没有类型的汽车，但这辆车没有。

SELECT *
FROM cars
WHERE NOT EXISTS (SELECT 1
                  FROM types CivicTypes
                  JOIN parts CivicParts USING (type_id)
                  WHERE car_id = (SELECT car_id
                                  FROM cars
                                  WHERE car_make = 'Honda'
                                    AND car_model = 'Civic')
                    AND NOT EXISTS (SELECT 1
                                    FROM types JOIN parts USING (type_id)
                                    WHERE type_id = CivicTypes.type_id
                                      AND car_id = cars.car_id)
                 )

查找使用相同零件类型的所有汽车

2 个答案: