| 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 |
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| 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
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