오라클 집합 연산자중에 차집합 minus를 사용하시면 됩니다.

select * from table1

minus

select * from table2

with t1 as (
select '서울' city, '8011' code from dual union all
select '서울'     , '8012'      from dual union all
select '서울'     , '8013'      from dual union all
select '경기'     , '8012'      from dual union all
select '경기'     , '8013'      from dual union all
select '경기'     , '8014'      from dual
),   t2 as (
select '서울' city, '8011' code from dual union all
select '서울'     , '8012'      from dual union all
select '경기'     , '8012'      from dual
)
select a.*
  from t1 a
 where not exists ( select ''
                      from t2 b
                     where a.city = b.city
                       and a.code = b.code
                  )

SELECT t1.*
  FROM t1, t2
 WHERE t1.city = t2.city(+)
   AND t1.code = t2.code(+)
   AND t2.city IS NULL
;

SELECT *
  FROM t1
 WHERE (city, code) NOT IN (SELECT city, code FROM t2)
;

댓글 주신 모든 분들 감사합니다~ 덕분에 잘 해결 되었어요!!!