[SQL문제풀기] 서울숲 요일별 대기오염도 계산하기

문제

solvesql.com

https://solvesql.com/problems/weekday-stats-airpollution/

SQLite

내가 작성한 정답

select case strftime('%w',measured_at) when '0' then '일요일' 
                                       when '1' then '월요일'
                                       when '2' then '화요일'
                                       when '3' then '수요일'
                                       when '4' then '목요일'
                                       when '5' then '금요일'
                                       when '6' then '토요일'  end weekday,
        round(avg(no2),4) no2, round(avg(o3),4) o3,
        round(avg(co),4) co, round(avg(so2),4) so2,
        round(avg(pm10),4) pm10, round(avg(pm2_5),4) pm2_5
from measurements
group by weekday
order by case weekday when '월요일' then 1
                      when '화요일' then 2
                      when '수요일' then 3 
                      when '목요일' then 4
                      when '금요일' then 5
                      when '토요일' then 6
                      when '일요일' then 7 end asc;