create table tableA ( EMPNO int)
create table tableB ( EMPNO int)
insert into tableA values (1)
insert into tableA values (2)
insert into tableA values (3)
insert into tableA values (4)
insert into tableA values (5)
insert into tableB values (1)
insert into tableB values (2)
insert into tableB values (3)
insert into tableB values (4)
insert into tableB values (7)
-- A 테이블에만 존재하는 항목
select A.EMPNO
from tableA A left outer join tableB B on A.EMPNO=B.EMPNO
where B.EMPNO is null
-- B 테이블에만 존재하는 항목
select B.EMPNO
from tableA A right outer join tableB B on A.EMPNO=B.EMPNO
where A.EMPNO is null
-- A, B 테이블에 서로 없는것을 동시에
select A.EMPNO
from tableA A left outer join tableB B on A.EMPNO=B.EMPNO
where B.EMPNO is null
UNION ALL
select B.EMPNO
from tableA A right outer join tableB B on A.EMPNO=B.EMPNO
where A.EMPNO is null
-- 다른 방법으로 (A, B 테이블에 서로 없는것을 동시에)
select isnull(A.EMPNO,B.EMPNO)
from tableA A full outer join tableB B on A.EMPNO=B.EMPNO
where B.EMPNO is null or A.EMPNO is null
<출처: 네이버지식IN, 식물신 답변>
