From: | "D(dot) Dante Lorenso" <dante(at)lorenso(dot)com> |
---|---|
To: | pgsql-general(at)postgresql(dot)org |
Subject: | Re: Need efficient way to do comparison with NULL as an option |
Date: | 2008-01-05 04:15:47 |
Message-ID: | 477F0473.6040309@lorenso.com |
Views: | Raw Message | Whole Thread | Download mbox | Resend email |
Thread: | |
Lists: | pgsql-general |
D. Dante Lorenso wrote:
> I'm looking for an operator that will compare NULL with NULL and
> evaluate as TRUE.
> I have a BIGINT column which might contain NULL values. I want to pass
> a value to compare with that column in my WHERE clause. If the value
> I'm comparing is 0, I want it to match the NULL values. Here is a
> sample query that I currently use:
> SELECT *
> FROM mytable
> WHERE (col IS NULL AND NULLIF(?, 0) IS NULL) OR col = ?;
> The '?' placeholders used in the query will receive the same value which
> might be any one of the following: NULL, 0, 1, 2, 3, etc.
> What I'd really like is an operator that will compare NULL with NULL and
> evaluate as TRUE. Does that exist?
Is this the answer?
SELECT *
FROM mytable
WHERE col IS NOT DISTINCT FROM NULLIF(?, 0);
-- Dante
From | Date | Subject | |
---|---|---|---|
Next Message | Tom Lane | 2008-01-05 04:19:41 | Re: Need efficient way to do comparison with NULL as an option |
Previous Message | Greg Smith | 2008-01-05 04:09:31 | Re: Performance problem. Could it be related to 8.3-beta4? |