trigger question - Mailing list pgsql-general

From Furesz Peter
Subject trigger question
Date
Msg-id 001001c73994$c72ee1f0$0202fea9@bixerverintel
Whole thread Raw
Responses Re: trigger question  ("A. Kretschmer" <andreas.kretschmer@schollglas.com>)
Re: trigger question  ("Lenorovitz, Joel" <Joel.Lenorovitz@usap.gov>)
List pgsql-general
Hello,

I have a table named foobar  and I don't want to allow from DELETE or UPDATE
its rows.

I have a table as described below:
foobar(foobar_id, value, is_deleted);

I don't want to allow directly delete or modify the table's rows. I plan to
make an on before update or delete trigger and
on delete action I update the actual row is_deleted flag, on UPDATE action I
also update the is_deleted flag and I insert a new row with the new values.
Everything is ok, but when I capture the delete action I am execute an
update what triggering the trigger again and I got an unwanted row.

CREATE TRIGGER "tr_foobar" BEFORE UPDATE OR DELETE  ON "public"."foobar" FOR
EACH ROW
EXECUTE PROCEDURE "public"."tr_foobar_func"();

BEGIN
  IF TG_OP='DELETE' THEN
     UPDATE foobar SET is_deleted=TRUE WHERE foobar_id=OLD.foobar;
     RETURN NULL;
  ELSEIF TG_OP='UPDATE' THEN
     INSERT INTO foobar(value) VALUES(NEW.value);
     NEW.is_deleted=TRUE;
     NEW.value=OLD.value;
     RETURN NEW;
  END IF;
END;

What is the right solution for this situation. Thank you for the help!



pgsql-general by date:

Previous
From: "Filip Rembiałkowski"
Date:
Subject: Re: Coercion in PGSQL?
Next
From: "Vinesh, Raghavan"
Date:
Subject: Installation of PostgreSQL Service under admin account