SQL을 많이 선택하십시오.

Question

category_product 
--------------- 
id_category 
id_product 

product 
--------------- 
id_product 
id_manufacturer 

manufacturer 
--------------- 
id_manufacturer 
name 

id_category와 일치 할 때 제조업체의 모든 이름을 선택하도록 SQL 쿼리를 만드는 방법은 무엇입니까?

SELECT m.* 
FROM  category_product cp INNER JOIN 
      product p ON cp.id_product = p.id_product INNER JOIN 
      manufacturer m ON p.id_manufacturer = m.id_manufacturer 
WHERE  cp.id_category = <your_value> 

Answer 1

같은

Answer 2

시도 뭔가 그것은 테이블의 간단한 내부 조인 것 :

SELECT m.name, cp.id_category 
FROM manufacturer as m 
INNER JOIN product as p 
    ON m.id_manufacturer = p.id_manufacturer 
INNER JOIN category_product as cp 
    ON p.id_product = cp.id_product 
WHERE cp.id_category = 'some value' 

Answer 3

검색어없는 다음과 같이됩니다 조인 (

SELECT m.name 
FROM manufacturer as m, product as p, category_product as cp 
WHERE cp.id_category = <your value> 
     AND cp.id_product = p.id_product 
     AND p.id_manufacturer = m.id_manufacturer 

Answer 4

Select M.name 
From manufacturer M 
Where M.id_manufacturer in (Select P.id_manufacturer 
           From product P 
           Where P.id_product in (Select C.id_product 
                 From category_product C 
                 Where C.id_category = ?))