Convert Systemdate

1. SYSTEMDATE를 날짜로 변환(CONVERT SYSTEMDATE TO DATE)
2. DATE를 SYSTEMDATE로 변환(CONVERT DATE TO SYSTEMDATE)

 

-- SYSTEMDATE 날짜로 변환(CONVERT SYSTEMDATE TO DATE)
SELECT TO_CHAR(TO_TIMESTAMP('1970-01-01 09:00:00.0','YYYY-MM-DD HH24:MI:SS.FF3') + NUMTODSINTERVAL(1655254800000/1000, 'SECOND') ,'YYYY-MM-DD HH24:MI:SS') 
  FROM DUAL
;
 
-- DATE 날짜로 변환(CONVERT DATE TO SYSTEMDATE)
SELECT (CAST(SYS_EXTRACT_UTC(TO_TIMESTAMP('2022-06-15 10:00:00','YYYY-MM-DD HH24:MI:SS')) as date) - TO_DATE('1970-01-01 00:00:00' ,'YYYY-MM-DD HH24:MI:SS'))*86400000
  FROM DUAL
;