# 번외, [ORACLE] SQL JOIN. 없는 데이터도 조인해서 출력하고 싶어 !

EMP (사원테이블) 

EMPNO	ENAME	DEPTNO
2200	JAMES	10
2211	WESTBROOK	20
2222	CURRY	30

DEPT (부서테이블)

DEPTNO	DNAME	LOC
10	PFW	LACKERS
20	SFW	ROCKETS
30	SG	WARRIORS
40	CENTER	CELTICS

두 테이블의 DEPTNO 를 이용하여 조인해서 출력 시 (40번 부서도 출력한다)

SELECT DEPT.DEPTNO, DNAME, COUNT(EMP.EMPNO)

    FROM EMP, DEPT

   WHERE EMP.DEPTNO(+) = DEPT.DEPTNO

  GROUP BY DEPT.DEPTNO, DNAME

   ORDER BY DEPT.DEPTNO ;

ANSI JOIN ( right outer join )  사용

SELECT DEPT.DEPTNO, DNAME, COUNT(EMP.EMPNO)

    FROM EMP RIGHT OUTER JOIN DEPT

   ON EMP.DEPTNO = DEPT.DEPTNO

  GROUP BY DEPT.DEPTNO, DNAME

   ORDER BY DEPT.DEPTNO ;