[Programmers] 연도 별 평균 미세먼지 농도 조회하기
정답
-- AIR_POLLUTION: LOCATION1, LOCATION2, YM, PM_VAL1, PM_VAL2
SELECT
YEAR(YM) AS 'YEAR',
ROUND(AVG(PM_VAL1), 2) AS 'PM10',
ROUND(AVG(PM_VAL2), 2) AS 'PM2.5'
FROM AIR_POLLUTION
WHERE (LOCATION1 = '경기도' AND LOCATION2 = '수원')
GROUP BY YEAR(YM)
ORDER BY 1;
✅ Point
WHERE > GROUP
순으로ROUND
로 반올림