WITH t AS ( SELECT 'www.oracleclub.com' str FROM dual UNION ALL SELECT 'oracleclub.com' FROM dual UNION ALL SELECT 'gurubee.net' FROM dual UNION ALL SELECT 'www.gurubee.net' FROM dual ) -- 1. Update 하기 전에 우선 Select 구문을 만들어 보세요. SELECT str , REPLACE(str, 'oracleclub.com', 'gurubee.net') new_str FROM t WHERE INSTR(str, 'oracleclub.com') > 0 ; -- 2. Update UPDATE t SET str = REPLACE(str, 'oracleclub.com', 'gurubee.net') WHERE INSTR(str, 'oracleclub.com') > 0 ;