Question

对不起，标题有点令人费解！

我到处都有一点点搜索，但我不确定我是否正确地写出了正确的结果，或者我想做什么甚至是可能的......

基本上我想返回表中与另一个值匹配的所有值。我有桌子：

Table "Cars"               Table "Models"

Car_ID    Car              Car_ID    Model_ID    Model
-------------------        ----------------------------
1         Ford             1          14         Mustang
2         Fiat             1          21         Focus
3         Toyota           1          87         Escort
                           2          78         500
                           2          45         Punto
                           3          66         Aygo

如果我只搜索一个模型名称（例如Escort），我想要这些结果：

Car    Model_ID    Model
------------------------
Ford   14          Mustang
Ford   21          Focus
Ford   87          Escort

因此，搜索汽车模型将返回所有相同品牌的模型。

任何人都有任何想法？

Answer 1

这是你要找的吗？

SELECT c.Car, m.Model_ID, m.Model
FROM Models m
INNER JOIN Cars c ON c.Car_ID = M.Car_ID
WHERE m.Car_ID = (SELECT Car_ID FROM Models WHERE Model = 'Escort');

Answer 2

您可以使用此查询。如果有多个具有相同名称的模型，则此查询将返回所提供的模型名称的所有相应品牌中的所有模型。

SELECT c.Car, m.Model_ID, m.Model

FROM Models AS m_search

INNER JOIN Cars AS c
ON m_search.Car_ID = c.Car_ID

INNER JOIN Models AS m
ON c.Car_ID = m.Car_ID

WHERE m_search.Model = ?

PostgreSQL上的示例（因为MySQL不支持WITH）：

chris=$ WITH Cars (Car_ID, Car) AS (VALUES
    (1, 'Ford'),
    (2, 'Fiat'),
    (3, 'Toyota')
), Models (Car_ID, Model_ID, Model) AS (VALUES
    (1, 14, 'Mustang'),
    (1, 21, 'Focus'),
    (1, 87, 'Escort'),
    (2, 78, '500'),
    (2, 45, 'Punto'),
    (3, 66, 'Agyo')
)

SELECT c.Car, m.Model_ID, m.Model

FROM Models AS m_search

INNER JOIN Cars AS c
ON m_search.Car_ID = c.Car_ID

INNER JOIN Models AS m
ON c.Car_ID = m.Car_ID

WHERE m_search.Model = 'Escort';

 car  | model_id |  model
------+----------+---------
 Ford |       14 | Mustang
 Ford |       21 | Focus
 Ford |       87 | Escort
(3 rows)

Answer 3

试试这个：

 select c.Car, m.Model_ID, m.Model from Cars c, Models m where c.Car_ID=m.Car_ID 
and Car_ID in (select Car_ID from Models where  Model='Escort')

Answer 4

您可以使用子查询来检索模型的Car_ID：

select  *
from    Models m
join    Cars c
on      c.Car_ID = m.Car_ID
where   m.Car_ID = 
        (
        select  Car_ID
        from    Models
        where   Model = 'Mustang'
        )

Answer 5

根据您正在查看的表的大小，可以更有效地在子查询中获取信息，而不是使用“in”或连接。

select ( select car from cars where car_id = m.car_id ), model_id, model
  from models m
 where car_id = ( select car_id from from models where model = 'Escort' )

返回另一个表中与另一个链接值匹配的所有值

5 个答案: