연습문제#2

SELECT ename, SUBSTR(hiredate, 1, 5) as "입사일" FROM employee;

SELECT ename, hiredate FROM employee WHERE SUBSTR(hiredate, 4, 2)='04';

SELECT ename, eno FROM employee WHERE MOD(eno,2)=0;

SELECT hiredate, TO_CHAR(hiredate, 'YY-MM DAY') FROM employee;

SELECT ROUND(SYSDATE-TO_DATE('13/01/01')) FROM dual;

SELECT manager, nvl(manager,'0') FROM employee;

SELECT job, salary, DECODE(job, 'ANALYST', salary+200, 'SALESMAN', salary+180, 'MANAGER', salary+150, 'CLERK', salary+100, salary) as 급여인상 FROM employee;