Feedback-ID: ia2694551:Fastmail
Date: Mon, 15 May 2023 13:15:54 +0200
From: Alvaro Herrera <alvherre@alvh.no-ip.org>
To: Nikhil Ingale <niks.bgm@gmail.com>
Cc: pgsql-admin@lists.postgresql.org
Subject: Re: how do I capture conflicting rows
Message-ID: <20230515111554.2a2q3hg2b4s5l7wh@alvherre.pgsql>
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Disposition: inline
Content-Transfer-Encoding: 8bit
In-Reply-To: 
 <CALXkTpx3iLuGRx1_4N6GJ85ptoW4n4XSdh3ChJLE-hrFGC982g@mail.gmail.com>
Archived-At: 
 <https://www.postgresql.org/message-id/20230515111554.2a2q3hg2b4s5l7wh%40alvherre.pgsql>
Precedence: bulk

On 2023-May-15, Nikhil Ingale wrote:

> Hi All,
> 
> The following query inserts the rows by ignoring the rows that has
> conflicts.
> 
> INSERT INTO test (id,name,age,branch) SELECT * FROM student ON CONFLICT DO
> NOTHING;
> 
> How do I capture the conflicting records to a file while non conflicting
> records are inserted to the table?

It sounds like you want a new feature:

INSERT INTO test (...) SELECT * FROM student
  ON CONFLICT EXECUTE FUNCTION do_your_stuff(excluded);

Sounds like it could be useful, but somebody would have to design it
fully and implement it.

Or maybe just

INSERT INTO test (...) SELECT * FROM student
  ON CONFLICT DO NOTHING RETURNING excluded.*;

-- 
Álvaro Herrera         PostgreSQL Developer  —  https://www.EnterpriseDB.com/
"Now I have my system running, not a byte was off the shelf;
It rarely breaks and when it does I fix the code myself.
It's stable, clean and elegant, and lightning fast as well,
And it doesn't cost a nickel, so Bill Gates can go to hell."