Re: [BUGS] (null) != (null) ?

Поиск
Список
Период
Сортировка
От Todd Vierling
Тема Re: [BUGS] (null) != (null) ?
Дата
Msg-id Pine.NEB.4.10.9910261040460.26623-100000@server.int.duh.org
обсуждение исходный текст
Ответ на Re: [BUGS] (null) != (null) ?  (Todd Vierling <tv@pobox.com>)
Ответы Re: [BUGS] (null) != (null) ?
Список pgsql-bugs
On Tue, 26 Oct 1999, Todd Vierling wrote:

: : NULL = NULL does not yield TRUE, it yields NULL.  For that matter,
: : NULL != NULL does not yield FALSE --- it yields NULL.  This is a
: : basic consequence of the semantics of NULL.

: It seems _extremely_ counter-intuitive, especially in cases where both
: fields are in fact the same type.

Although I did find a SQL92 document on the web in the amount of time this
took to copy back to me, and I see the clause about NULL <comp op>
<anything> being unknown.  Which, I imagine, means "implementation
dependent".

--
-- Todd Vierling (tv@pobox.com)


В списке pgsql-bugs по дате отправления:

Предыдущее
От: Todd Vierling
Дата:
Сообщение: Re: [BUGS] (null) != (null) ?
Следующее
От: Tom Lane
Дата:
Сообщение: Re: [BUGS] (null) != (null) ?