현재 날짜 구하기 select current_date as today; 현재 날짜/시간 구하기 select now() as today; select current_timestamp as today; 하루 전/후 날짜 구하기 select date '2023-07-04' + integer '-1'; select now() + '-1 days'; select date '2023-07-04' + integer '1'; select now() + '1 days'; 일주일 전/후 날짜 구하기 select date '2023-07-04' + integer '-7'; select now() + '-1 week'; select date '2023-07-04' + integer '7'; select now() + '1 w..