20241001===========================================
-- Lv 2. 성분으로 구분한 아이스크림 총 주문량
SELECT INGREDIENT_TYPE, SUM(TOTAL_ORDER) AS TOTAL_ORDER
FROM FIRST_HALF A
LEFT JOIN ICECREAM_INFO B
ON A.FLAVOR = B.FLAVOR
GROUP BY B.INGREDIENT_TYPE
ORDER BY TOTAL_ORDER;
-- Lv 3. 오랜기간 보호한 동물 (1)
SELECT A.NAME,A.DATETIME
FROM ANIMAL_INS A
LEFT JOIN ANIMAL_OUTS B
ON A.ANIMAL_ID = B.ANIMAL_ID
WHERE B.ANIMAL_ID IS NULL
ORDER BY A.DATETIME
FETCH FIRST 3 ROWS ONLY;
-- Lv 3. 있었는데요 없었습니다
SELECT a.ANIMAL_ID, a.NAME
FROM ANIMAL_INS a
LEFT JOIN ANIMAL_OUTS b
ON a.ANIMAL_ID = b.ANIMAL_ID
WHERE a.DATETIME > b.DATETIME
ORDER BY a.DATETIME;