SQL연습-04함수(SCOTT)

SELECT EMPNO, 
    SUBSTR(To_char(EMPNO),1,2)||'**' Maksing_EMPNO,
    ENAME,
    RPAD(SUBSTR(ENAME,1,1),5,'#') MASKING_ENAME
    FROM EMP;
    
SELECT EMPNO, ENAME, SAL, TRUNC(SAL/21.5,2) DAY_PAY,
  ROUND(SAL/21.5/8,1) TIME_PAY FROM EMP;
  
SELECT EMPNO, ENAME, TO_CHAR(HIREDATE,'yyyy/MM/dd') HIREDATE, TO_CHAR(NEXT_DAY(HIREDATE,'월요일'),'yyyy-MM-dd') R_JOB,
  NVL(TO_CHAR(COMM),'N/A') COMM FROM EMP;
  
SELECT EMPNO, ENAME, MGR,
  CASE
  WHEN MGR IS NULL THEN '0000'
  WHEN MGR LIKE '78%' THEN '8888'
  WHEN MGR LIKE '77%' THEN '7777'
  WHEN MGR LIKE '76%' THEN '6666'
  WHEN MGR LIKE '75%' THEN '5555'
  ELSE TO_CHAR(MGR)
  END AS CHG_MGR
  FROM EMP;