programmers SQL : 우유와 요거트가 담긴 장바구니

Summer/Winter Coding(2019)

우유와 요거트가 담긴 장바구니

데이터 분석 팀에서는 우유(Milk)와 요거트(Yogurt)를 동시에 구입한 장바구니가 있는지 알아보려 합니다. 우유와 요거트를 동시에 구입한 장바구니의 아이디를 조회하는 SQL 문을 작성해주세요. 이때 결과는 장바구니의 아이디 순으로 나와야 합니다.

JOIN

1

SELECT CART_ID
FROM (SELECT DISTINCT CART_ID
      FROM CART_PRODUCTS
      WHERE NAME = 'Yogurt') AS Y JOIN 
     (SELECT DISTINCT CART_ID
      FROM CART_PRODUCTS
      WHERE NAME = 'Milk') AS M
      USING(CART_ID)
ORDER BY CART_ID ;

2

SELECT DISTINCT A.CART_ID
FROM CART_PRODUCTS AS A JOIN CART_PRODUCTS AS B
USING(CART_ID)
WHERE A.NAME = 'Milk' AND B.NAME = 'Yogurt'

AND

SELECT DISTINCT A.CART_ID
FROM CART_PRODUCTS AS A, CART_PRODUCTS AS B
WHERE A.CART_ID = B.CART_ID
AND A.NAME = 'Milk' **AND** B.NAME = 'Yogurt'
ORDER BY A.CART_ID;

SUBQUERY

SELECT DISTINCT CART_ID
FROM CART_PRODUCTS
WHERE NAME LIKE 'Milk' AND CART_ID IN (SELECT CART_ID
									   FROM CART_PRODUCTS
									   WHERE NAME LIKE 'Yogurt');

DECODE

SELECT CART_ID
FROM   (SELECT CART_ID, DECODE(NAME, 'Milk', 1, 'Yogurt', 1, 0) AS CNT
        FROM   CART_PRODUCTS
        GROUP BY CART_ID, NAME)
GROUP BY CART_ID
HAVING SUM(CNT) > 1
ORDER BY CART_ID