SQL - DQL : DATA QUERY LANGUAGE SELECT - DML : DATA MANIPULATION LANGUAGE INSERT UPDATE DELETE - DDL : DATA DEFINITION LANGUAGE CREATE ALTER DROP - TCL : TRANSACTION CONTROL LANGUAGE COMMIT ROLLBACK - DCL : DATA CONTROL LANGUAGE GRANT REVOKE * NVL(NULL, 치환하고 싶은 데이터) * TO_CHAR(DATE 타입, 날짜 형식) * 날짜 처리 - SYSDATE - SYSTIMESTAMP * UPPER() * LOWER() * LIKE '%', '_' * IS NULL * IS NOT NULL * DESC * DIS..