Oracle里not in 与 null 原创

in/not in在判断NULL时用的与=/<>一样的方式，即必须用is null来判断，否则始终为失败。

所有与null的操作（+，-，*，/，比较）返回的结果都是null

复制收展Javaselect 'true'
from DUAL;

select 'true'
from DUAL where 1 not in (2, null);

select 'true'
from DUAL where null not in (2, null);

select 'true'
from DUAL where null in (2, null);

select 'true'
from DUAL where 1 in (2, null);

select 'true'
from DUAL where  null = null;
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