Build & Record

22/11/05 -조인 주말과제 1.select e.EMPLOYEE_ID, e.FIRST_NAME, nvl(e2.FIRST_NAME, '관리자 없음' from EMPLOYEES e, EMPLOYEES e2 where e.EMPLOYEE_ID = e2.manager_id and e.FIRST_NAME like '_t%'; 2.select d.department_name, round(avg(e.salary),0) from employees e, DEPARTMENTS d where e.DEPARTMENT_ID = d.DEPARTMENT_ID and e.salary >= 5000 group by d.department_name order by avg(e.salary) desc; 3.select e.first_n..

자체 조인, 외부 조인을 알아야 풀 수 있는 문제 SQL> SELECT D.DEPTNO, D.DNAME, E.EMPNO, E.ENAME, E.MGR, E.SAL, E.DEPTNO, 2 S.LOSAL, S.HISAL, S.GRADE, E2.EMPNO AS MGR_EMPNO, E2.ENAME AS MGR_ENAME 3 FROM EMP E, DEPT D, SALGRADE S, EMP E2 4 WHERE E.DEPTNO(+) = D.DEPTNO 5 AND E.SAL BETWEEN S.LOSAL(+) AND S.HISAL(+) 6 AND E.MGR = E2.EMPNO(+) 7 ORDER BY D.DEPTNO, E.EMPNO; DEPTNO DNAME EMPNO ENAME MGR SAL DEPTNO LOSAL HIS..