| From: | "David G(dot) Johnston" <david(dot)g(dot)johnston(at)gmail(dot)com> |
|---|---|
| To: | Philipp Kraus <philipp(dot)kraus(at)tu-clausthal(dot)de> |
| Cc: | Adrian Klaver <adrian(dot)klaver(at)aklaver(dot)com>, "pgsql-general(at)postgresql(dot)org" <pgsql-general(at)postgresql(dot)org> |
| Subject: | Re: sql function with empty row |
| Date: | 2018-05-16 20:35:43 |
| Message-ID: | CAKFQuwbJN0N-AnGQfyTzLaAjbE5+-euMehtPH92rnt-eKmNqeA@mail.gmail.com |
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| Lists: | pgsql-general |
On Wed, May 16, 2018 at 11:49 AM, Philipp Kraus <
philipp(dot)kraus(at)tu-clausthal(dot)de> wrote:
> I have tested it on my data and it works also, but that is a little bit
> confusing, because imho setof is >= 0 rows and
> without setof it is [0,1].
Without setof it will always return exactly 1 row, never 0. This is a
feature as returning zero rows is problematic in many ways; a 0-row result
in a select-list will cause that row to be removed from the result when is
most cases people would rather be told whatever they were trying to compute
for the row simply didn't compute - via a NULL.
David J.
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