쿼리 select * from hong_a; select * from hong_b; -- inner join SELECT a.emp_id, b.emp_id FROM hong_a a inner join hong_b b on a.emp_id = b.emp_id; -- natural join SELECT emp_id -- * 도 동일한 결과 FROM hong_a a natural join hong_b b ; -- right outer join SELECT a.emp_id, b.emp_id FROM hong_a a right outer join hong_b b on a.emp_id = b.emp_id; -- left outer join SELECT * FROM hong_a a left outer join hon..