SQL) 헤비유저가 소유한 뭐시기

SELECT * 
FROM PLACES
WHERE HOST_ID IN (
    SELECT HOST_ID
    FROM PLACES
    GROUP BY HOST_ID
    HAVING COUNT(HOST_ID) >=2)
ORDER BY ID​

HOST_ID 중에서(IN) 다시 SELECT한다

HOST_ID 별로 GROUP 지은 다음에,

HAVING COUNT(HOST_ID) : 카운트를 해서, HOST_ID가 2개 이상인 것들을 다시 SELECT한다

 

마지막으로 ID별로 ORDER

우유 요거트 intersect

SELECT A.CART_ID FROM
(SELECT CART_ID FROM CART_PRODUCTS WHERE NAME = 'Milk') as A,
(SELECT CART_ID FROM CART_PRODUCTS WHERE NAME = 'Yogurt') as B
WHERE A.CART_ID = B.CART_ID