[SQL] 프로그래머스 [Level-2] 입양시각구하기(1)

<MySQL>

SELECT A.HOUR
     , A.COUNT
  FROM (
         SELECT DATE_FORMAT(DATETIME, '%Y-%m-%d %H:%i:%s') AS TOTAL_DATE
              , DATE_FORMAT(DATETIME, '%H') AS HOUR
              , COUNT(SUBSTR(DATETIME, 12, 2)) AS COUNT
           FROM ANIMAL_OUTS
       GROUP BY SUBSTR(DATETIME, 12, 2)
       ) A
 WHERE A.HOUR BETWEEN 9 AND 20
ORDER BY HOUR

<Oracle>

SELECT A.HOUR
     , A.COUNT
  FROM (
         SELECT TO_CHAR(DATETIME, 'HH24') AS HOUR
              , COUNT(TO_CHAR(DATETIME, 'HH24')) AS COUNT
           FROM ANIMAL_OUTS
       GROUP BY TO_CHAR(DATETIME, 'HH24')
       ) A
 WHERE A.HOUR BETWEEN 9 AND 20
ORDER BY HOUR

프로그래머스 입양시각구하기 SQL