全外联结
SELECT e.ename,d.dname, d.deptno
FROM emp e
FULL OUTER JOIN dept d
ON e.deptno = d.deptno;
如果是9i以下版本
select
select e.ename,d.dname, d.deptno
from emp e, dept d
where e.deptno = d.deptno(+)
union all
select
select e.ename,d.dname, d.deptno
from emp e, dept d
where e.deptno(+) = d.deptno where e.deptno is null
;