SQL-JOIN

조인 (INNER JOIN)

SELECT a.empno
     , a.ename
     , a.deptno
     , b.dname
  FROM emp a
 INNER JOIN dept b
    ON a.deptno = b.deptno
 WHERE a.job = 'MANAGER'

SELECT a.empno
     , a.ename
     , a.deptno
     , b.dname
  FROM emp a
     , dept b
 WHERE a.job = 'MANAGER'
   AND a.deptno = b.deptno

아우터 조인 (LEFT OUTER JOIN)

아우터 조인 (RIGHT OUTER JOIN)
크로스 조인 (CROSS JOIN)
풀 아우터 조인 (FULL OUTER JOIN)

참고링크 : https://gent.tistory.com/469