[solvesql/SQLite] 미세먼지 수치의 계절간 차이

문제 요약
1. 기간을 4개의 계절로 구분
2. pm10의 중앙값, 평균 계산

풀이

SELECT CASE WHEN measured_at >= '2022-03-01' AND measured_at <= '2022-05-31' THEN 'spring'
           WHEN measured_at >= '2022-06-01' AND measured_at <= '2022-08-31' THEN 'summer'
           WHEN measured_at >= '2022-09-01' AND measured_at <= '2022-11-30' THEN 'autumn'
           ELSE 'winter'
      END AS season
      , MEDIAN(pm10) pm10_median
      , ROUND(AVG(pm10),2) pm10_average
FROM measurements
GROUP BY season