Date: Tue, 27 Jul 2021 08:38:05 +0200
From: hubert depesz lubaczewski <depesz@depesz.com>
Sender: depesz@depesz.com
To: Nicolas Mitchell <mitchelln@posteo.net>
Cc: pgsql-novice@lists.postgresql.org
Subject: Re: Trigger function
Message-ID: <20210727063805.GA28983@depesz.com>
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On Mon, Jul 26, 2021 at 03:17:12PM +0000, Nicolas Mitchell wrote:
> I am looking at whether functions can help me automate creating a new object
> when a new host is added.
> 
> I can do this manually with the following code:
> 
> WITH object_id AS
> (INSERT INTO public.object (type)
> VALUES (
> 	( SELECT obtype.id
>       FROM public.obtype
>       WHERE obtype.name LIKE 'host'
>       )
> )
> RETURNING id)
> INSERT INTO host (name, domain, object)
> VALUES ('gary', 1000001, (SELECT * FROM object_id));
> 
> I have a number of questions but I would like to begin by asking whether
> this a candidate for a trigger function on table ‘host’, triggered before an
> insert?

*after* insert, not *before*.
But other than that yes.

If I might suggest:
https://www.depesz.com/2012/11/14/how-i-learned-to-stop-worrying-and-love-the-triggers/

depesz