Re: UNIQUE not honoured for NULL - Mailing list pgsql-bugs

Gaetano Mendola wrote:
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> Bruno Wolff III wrote:
>
> | On Mon, Jul 12, 2004 at 14:47:34 +0200,
> |   Gaetano Mendola <mendola@bigfoot.com> wrote:
> |
> |>As someone says NULL = NULL is false
> |
> |
> | As someone else pointed out, NULL = NULL is NULL which is not TRUE.
>
> Yes, that it's better.

Still not precise.

NULL = NULL
     is NULL (which is neither TRUE nor FALSE)

while
(NULL = NULL) IS NULL
      is TRUE...


Regards,
Andreas