[SQL문제풀기] 자동차 평균 대여 기간 구하기

문제

MYSQL

내가 작성한 오답

SELECT CAR_ID, ROUND(AVG(DATEDIFF(END_DATE,START_DATE)),1) AVERAGE_DURATION
FROM CAR_RENTAL_COMPANY_RENTAL_HISTORY
GROUP BY 1
HAVING AVG(DATEDIFF(END_DATE,START_DATE)) >= 7
ORDER BY 2 DESC, CAR_ID DESC

내가 작성한 정답

SELECT CAR_ID, ROUND(AVG(DATEDIFF(END_DATE,START_DATE)+1),1) AVERAGE_DURATION
FROM CAR_RENTAL_COMPANY_RENTAL_HISTORY
GROUP BY 1
HAVING AVG(DATEDIFF(END_DATE,START_DATE)+1) >= 7
ORDER BY 2 DESC, CAR_ID DESC

ORACLE

내가 작성한 오답

SELECT CAR_ID, ROUND(AVG((END_DATE-START_DATE)+1),1) AVERAGE_DURATION
FROM CAR_RENTAL_COMPANY_RENTAL_HISTORY
GROUP BY CAR_ID
HAVING ROUND(AVG((END_DATE-START_DATE)+1),1) >= 7
ORDER BY AVERAGE_DURATION DESC, CAR_ID DESC

 

내가 작성한 정답

SELECT CAR_ID, TO_CHAR(ROUND(AVG(END_DATE - START_DATE)+1, 1), 'FM999.0') AVERAGE_DURATION
FROM CAR_RENTAL_COMPANY_RENTAL_HISTORY
GROUP BY CAR_ID
HAVING ROUND(AVG(END_DATE - START_DATE)+1, 1) >= 7
ORDER BY ROUND(AVG(END_DATE - START_DATE)+1, 1) DESC, CAR_ID DESC;