[PostgreSQL] DateFormat(날짜형) 컨버팅

SELECT to_char(now(), 'YYYY-MM-DD HH24:MI:SS.MS');
-- 2015-04-29 01:32:11.321

SELECT to_timestamp('2015-04-29 01:32:11.321', 'YYYY-MM-DD HH24:MI:SS.MS');
-- 2015-04-29 01:32:11.321

SELECT to_char(to_timestamp('2015-04-29 01:32:11.321', 'YYYY-MM-DD HH24:MI:SS.MS'), 'YYYY-MM-DD HH24:MI:SS.MS');
-- 2015-04-29 01:32:11.321

SELECT to_char(to_date('2015-04-29 01:32:11.321', 'YYYY-MM-DD HH24:MI:SS.MS'), 'YYYY-MM-DD HH24:MI:SS.MS');
-- 2015-04-29 00:00:00.000

SELECT to_char(now(), 'YYYYMMDDHH24MISS');
 -- 20201106174232