[PGS9.2] Date Type Formatting Function

/****************************************************************************************************************
-- Title : [PGS9.2] Date Type Formatting Function
-- Reference : www.postgresql.org
-- Key word : 날자 날짜 date type 데이터 타입 to_har
****************************************************************************************************************/

-- Formatting Functions
-- References : http://www.postgresql.org/docs/9.2/static/functions-formatting.html

Function	Return Type	Example
to_char(timestamp, text)	text	to_char(current_timestamp, 'HH12:MI:SS')
to_char(interval, text)	text	to_char(interval '15h 2m 12s', 'HH24:MI:SS')
to_char(int, text)	text	to_char(125, '999')
to_char(double precision, text)	text	to_char(125.8::real, '999D9')
to_char(numeric, text)	text	to_char(-125.8, '999D99S')
to_date(text, text)	date	to_date('05 Dec 2000', 'DD Mon YYYY')
to_number(text, text)	numeric	to_number('12,454.8-', '99G999D9S')
to_timestamp(text, text)	timestamp with time zone	to_timestamp('05 Dec 2000', 'DD Mon YYYY')
to_timestamp(double precision)	timestamp with time zone	to_timestamp(1284352323)

-- Sample

SELECT to_char(now(), 'YYYY-MM-DD HH24:MI:ss.ms');

SELECT to_char(now(), 'YYYYMMDD');