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Re: How do I check for NULL

David G. Johnston <david.g.johnston@gmail.com>

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From: "David G. Johnston" <david.g.johnston@gmail.com>
To: Thiemo Kellner <thiemo@gelassene-pferde.biz>
Cc: pgsql-general@lists.postgresql.org
Date: 2025-12-09T17:29:17Z
Lists: pgsql-general 
On Tue, Dec 9, 2025 at 10:14 AM Thiemo Kellner <thiemo@gelassene-pferde.biz>
wrote:

> I feel, you meant to say, the subquery does not return any record which is
> not the same as returns NULL.
>

For a scalar subquery the final output of a zero-row query is the null
value.

David J.