Re: NOT IN (NULL) ?
| От | Pavel Stehule |
|---|---|
| Тема | Re: NOT IN (NULL) ? |
| Дата | |
| Msg-id | AANLkTi=WCJqVnH_oi5J4kph-R7R3LEedcUck5=Dm7BP+@mail.gmail.com обсуждение исходный текст |
| Ответ на | Re: NOT IN (NULL) ? ("Paul" <magamos@mail.ru>) |
| Список | pgsql-general |
2010/10/31 Paul <magamos@mail.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@postgresql.org) > To make changes to your subscription: > http://www.postgresql.org/mailpref/pgsql-general >
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