-- 코드를 입력하세요 with recursive timetable as ( select 0 as h union all select h + 1 from timetable where h < 23 ) select h, count(HOUR(DATETIME)) as count from timetable left outer join animal_outs on (h=HOUR(DATETIME)) GROUP BY h ORDER BY h # SELECT h, COUNT(HOUR(DATETIME)) AS 'COUNT' # FROM TIME LEFT OUTER JOIN ANIMAL_OUTS # ON (h=HOUR(DATETIME)) # GROUP BY h 대략 읽어보니 초기 설정값과 recursive할 쿼리를 union a..