Fwd: SQL Null

Hello,

I offer a small correction to the Postgresql documentation at
https://www.postgresql.org/docs/9.1/static/functions-comparison.html as
regards not using the operator = with the Null state:

"The null value represents an unknown value"

As SQL null is a state, not a value, the reason not to use the operator is
that querying the null state returns no value. So, a more accurate sentence
might be:

"The null state usually represents an unknown value".

Thanks,

Alex

---------- Forwarded message ----------
From: "Josh Berkus" <josh(at)agliodbs(dot)com>
Date: 12 Oct 2016 6:04 p.m.
Subject: Re: SQL Null
To: "Alex Lydiate" <alexlydiate(at)gmail(dot)com>
Cc:

On 10/12/2016 09:50 AM, Alex Lydiate wrote:
> It's not a question, it is a suggestion as that this little piece of
> documentation is incorrect, as regards not using the operator = with the
> Null state:
>
> "The null value represents an unknown value, and it is not known whether
> two unknown values are equal"
>
> As SQL null is a state, not a value, the reason not to use the operator
> is that querying the null state returns no value. So, a more accurate
> sentence might be:
>
> "The null state usually represents an unknown value, and it is not known
> whether two unknown values are equal".

That seems fine.

Please send this suggested correction to the pgsql-docs(at)postgresql(dot)org
mailing list.

--
--
Josh Berkus
Red Hat OSAS
(any opinions are my own)