시작일 이벤트 갯수

select EVT_STRT_DT, count(EVT_STRT_DT) from table group by EVT_STRT_DT;

종료일 이벤트 갯수는 위에서 날짜 컬러만 바꾸어 주시면

날짜의 범위 검색까지 하시려면

select EVT_STRT_DT, count(EVT_STRT_DT) from table

where to_date('20140601', 'yyyymmdd') < EVT_STRT_DT  and

to_date('20140731', 'yyyymmdd') >= EVT_STRT_DT group by EVT_STRT_DT;

WITH t AS
(
SELECT '0001' evt_id, '개교기념일' evt_nm, '14/05/15' evt_strt_dt, '14/05/15' evt_end_dt FROM dual
UNION ALL SELECT '0002', '방학'      , '14/06/21', '14/07/30' FROM dual
UNION ALL SELECT '0003', '중간고사'  , '14/04/20', '14/05/03' FROM dual
UNION ALL SELECT '0004', '기말고사'  , '14/06/15', '14/06/20' FROM dual
UNION ALL SELECT '0005', '학부모회의', '14/06/16', '14/06/16' FROM dual
)
SELECT b.dt
     , COUNT(*) cnt
     , wm_concat(evt_nm) events
  FROM t a
     , (-- 기준일자
        SELECT TO_CHAR(sdt + LEVEL - 1, 'rr/mm/dd') dt
          FROM (SELECT TO_DATE('20140601', 'yyyymmdd') sdt
                     , TO_DATE('20140630', 'yyyymmdd') edt
                  FROM dual)
         CONNECT BY LEVEL <= edt - sdt + 1
        ) b
 WHERE b.dt BETWEEN a.evt_strt_dt AND a.evt_end_dt
 GROUP BY b.dt
 ORDER BY b.dt
;