Oracle11g 选择其他表中不存在的记录

我想得到x中表A中不存在的所有值

我尝试了以下返回空白的查询

select x.num from 
(
   select '888888' as num from dual union all
   select '111111' as num from dual
) x 
left outer join TableA a on (a.number = x.num)
where a.number is null


select x.num
FROM
(
    select '888888' as num from dual union all
    select '111111' as num from dual
) x
where x.num not in
(
    select a.number from TableA a where x.num = a.number
)

表格

| TableA.number |
-------------
  111111
  333333

预期结果是在这种情况下只返回“888888”

我不明白为什么这不起作用，我哪里做错了？

试试这个

with cte as
(
   select '888888' as num from dual union all
   select '111111' as num from dual
)  
select cte.num 
from cte
left join TableA a on (a.number = cte.num)
where a.number is null