행열변환 (1) 썸네일형 리스트형 행열 변환2 (가로 -> 세로) SELECT MM , SUM(CASE WHEN YR=1998 THEN CNT ELSE 0 END) AS BEFOREYEAR , SUM(CASE WHEN YR=1999 THEN CNT ELSE 0 END) AS THISYEAR FROM (SELECT YEAR(HIRE_DATE) YR , MONTH(HIRE_DATE) AS MM , COUNT(*) AS CNT FROM EMPLOYEES WHERE YEAR(HIRE_DATE) IN ('1998', '1999') GROUP BY YEAR(HIRE_DATE), MONTH(HIRE_DATE) ) DS GROUP BY MM 이전 1 다음
