어떻게 중첩 된 mysql 쿼리 속도를 향상시킬 수 있습니까?

Question

나는 같은 쿼리를 수행하는 동안 MySQL 서버에서 빠른 응답을 검색하는 어려움을 조금 보내고있어 : 훨씬 더 빨리 제공 응답 다른 쿼리 방법이 있다면

select distinct(products.id) as product_id,products.title as product_name, (select count(id) from stock where stock.available='0' and stock.product_id=products.id) as none, 
(select count(id) from stock where stock.available='1' and stock.product_id=products.id) as available, 
(select count(id) from stock where stock.available='2' and stock.product_id=products.id) as staged, 
(select count(id) from stock where stock.available='3' and stock.product_id=products.id) as departed, 
(select count(id) from stock where stock.available='4' and stock.product_id=products.id) as delivered 
from products,stock where products.id=stock.product_id; 

내가 궁금합니다. 고맙습니다 이런

Answer 1

뭔가 :-) :

SELECT 
    P.id as product_id, 
    P.title as product_name, 
    SUM(CASE WHEN S.available = 0 THEN 1 ELSE 0 END) as none, 
    SUM(CASE WHEN S.available = 1 THEN 1 ELSE 0 END) as available, 
    SUM(CASE WHEN S.available = 2 THEN 1 ELSE 0 END) as staged, 
    SUM(CASE WHEN S.available = 3 THEN 1 ELSE 0 END) as departed, 
    SUM(CASE WHEN S.available = 4 THEN 1 ELSE 0 END) as delivered 
FROM products P 
     JOIN stock S 
      ON P.id = S.product_id 
    GROUP BY P.id, 
      P.title