[MS-SQL] datetime => second & second => datetime

datetime -> second SELECT DATEDIFF( S, '1970-01-01 09:00:00', datetime ) second -> datetime SELECT DATEADD( S, second, '1970-01-01 09:00:00' ) * 우리나라는 9시간을 더해주고 빼주는 처리를 해줘야하기.....