在11g中
SQL> select count(*)
  2    from emp a, dept b, bonus c
  3   where a.deptno(+) = b.deptno
  4     and a.ename(+) = c.ename;
where a.deptno(+) = b.deptno
                   *
ERROR at line 3:
ORA-01417: a table may be outer joined to at most one other table

SQL>

在12C中
SQL> select count(*)
  2    from emp a, dept b, bonus c
  3   where a.deptno(+) = b.deptno
  4     and a.ename(+) = c.ename;
  COUNT(*)
----------
         0
SQL>