1. Sales 부서에서 입사일의 평균은? SELECT ROUND((AVG(TO_NUMBER(TO_CHAR(HIRE_DATE,'YYYY')))),0 ) AS "입사년도", ROUND((AVG(TO_NUMBER(TO_CHAR(HIRE_DATE,'MM')))),0 ) AS "월", ROUND((AVG(TO_NUMBER(TO_CHAR(HIRE_DATE,'DD')))),0 ) AS "일" FROM EMPLOYEES E, DEPARTMENTS D WHERE E.DEPARTMENT_ID = D.DEPARTMENT_ID AND DEPARTMENT_NAME = 'Sales'; 2. ASIA에서 DEPARTMENT_NAME이 IT Support 인 사원의 이름을 출력 SELECT DEPARTMENT_NAME,FIRST_..
