| From: | Pavel Stehule <pavel(dot)stehule(at)gmail(dot)com> |
|---|---|
| To: | Paul <magamos(at)mail(dot)ru> |
| Cc: | pgsql-general(at)postgresql(dot)org |
| Subject: | Re: NOT IN (NULL) ? |
| Date: | 2010-10-31 17:08:16 |
| Message-ID: | AANLkTi=WCJqVnH_oi5J4kph-R7R3LEedcUck5=Dm7BP+@mail.gmail.com |
| Views: | Whole Thread | Raw Message | Download mbox | Resend email |
| Thread: | |
| Lists: | pgsql-general |
2010/10/31 Paul <magamos(at)mail(dot)ru>:
> Tom,
>
> Sunday, October 31, 2010, 9:42:27 PM, you wrote:
>
> TL> Because the SQL standard says so.
>
> But there is not such thing in PostgreSQL as empty set as "IN ()" that must be
> false, because nothing element may be found in empty set.
> And I thought that instead of "IN ()" I could use "IN (NULL)", but I
> was failed and result was NULL and not FALSE. :(
>
(NULL) isn't empty set. Empty set can be
(SELECT 1 WHERE false)
Regards
Pavel
> --
> Paul
>
>
> --
> Sent via pgsql-general mailing list (pgsql-general(at)postgresql(dot)org)
> To make changes to your subscription:
> http://www.postgresql.org/mailpref/pgsql-general
>
| From | Date | Subject | |
|---|---|---|---|
| Next Message | Tom Lane | 2010-10-31 17:19:14 | Re: NOT IN (NULL) ? |
| Previous Message | Paul | 2010-10-31 16:53:46 | Re: NOT IN (NULL) ? |