[programmers] 과일로 만든 아이스크림 고르기 (JOIN)

https://school.programmers.co.kr/learn/courses/30/lessons/133025

프로그래머스

SELECT A.FLAVOR 
FROM FIRST_HALF A, ICECREAM_INFO B
WHERE A.TOTAL_ORDER > 3000
    AND B.INGREDIENT_TYPE='fruit_based'
    AND A.FLAVOR = B.FLAVOR
ORDER BY A.TOTAL_ORDER DESC


SELECT A.FLAVOR 
FROM FIRST_HALF A 
    LEFT OUTER JOIN ICECREAM_INFO B
    ON A.FLAVOR = B.FLAVOR
WHERE A.TOTAL_ORDER > 3000 
    AND B.INGREDIENT_TYPE = 'fruit_based'

1. LEFT OUTER JOIN

혹시 INGREDIENT_TYPE 정의되지 않은 정보도 있을까봐 'OUTER' JOIN으로 진행.