LPAD, SUBSTR, REPLACE, TO_CHAR, TO_DATE

TO_CHAR와 TO_DATE의 차이

SELECT FIRST_NAME || ' ' || LAST_NAME AS 이름 , TO_CHAR(HIRE_DATE, 'YYYY"년"MM"월"DD"일"') , SUBSTR(HIRE_DATE, 1, 2) FROM EMPLOYEES WHERE TO_CHAR(HIRE_DATE, 'YYYY') LIKE '2002' OR TO_CHAR(HIRE_DATE, 'YYYY') LIKE '2004';

 

SELECT FIRST_NAME || ' ' || LAST_NAME AS 이름 , LPAD(SUBSTR(HIRE_DATE, 1, 2), 4,'20') || '년' || REPLACE(SUBSTR(HIRE_DATE, 3, 4),'/','') || '월' || SUBSTR(HIRE_DATE, 7, 8) || '일' AS 년도 , HIRE_DATE FROM EMPLOYEES WHERE SUBSTR(HIRE_DATE, 1, 2) IN ('02', '04'); --WHERE SUBSTR(HIRE_DATE, 1, 2) LIKE '02' -- 02/01/24 --OR SUBSTR(HIRE_DATE, 1, 2) LIKE '04';