From: Stephan Szabo <sszabo@megazone23.bigpanda.com>
To: Ian Burrell <ib@onsitetech.com>
Cc: pgsql-sql@postgresql.org
Subject: Re: Sorting by NULL values
Date: Tue, 4 Mar 2003 12:13:05 -0800 (PST)
Message-ID: <20030304120713.W55865-100000@megazone23.bigpanda.com> (raw)
In-Reply-To: <3E65023E.10404@onsitetech.com>
On Tue, 4 Mar 2003, Ian Burrell wrote:
> I am doing a query where I need to sort by a column that may be NULL
> because it is coming from an OUTER JOIN. I noticed a difference between
> PostgreSQL and other databases about where NULLs show up. It seems that
> with Postgres, NULLs are sorted after other values. Other databases
> sort them before.
> Is there any standard on how sorting NULLs work? Is there a way to
IIRC, they're either considered greater than or less than non-NULL values,
but the decision is up to the implementation.
> change Postgres's behavior? Is there a way to replace the NULLs with
> empty strings?
Coalesce should work.
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To: pgsql-sql@postgresql.org
Cc: sszabo@megazone23.bigpanda.com, ib@onsitetech.com
Subject: Re: Sorting by NULL values
In-Reply-To: <20030304120713.W55865-100000@megazone23.bigpanda.com>
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