Subject: Re: trigger question
From: Larry Rosenman <ler@lerctr.org>
To: josh@agliodbs.com
Cc: pgsql-sql@postgresql.org
In-Reply-To: <200205161049.23148.josh@agliodbs.com>
References: <1021570694.95676.7.camel@ler-freebie.iadfw.net>
	<200205161049.23148.josh@agliodbs.com>
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Date: 16 May 2002 12:51:03 -0500
Message-Id: <1021571463.95676.11.camel@ler-freebie.iadfw.net>
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On Thu, 2002-05-16 at 12:49, Josh Berkus wrote:
> Larry,
> 
> > Is there a way in PL/pgSQL to have a trigger look at the fields in a
> > %ROWTYPE variable to look for changes? 
> > 
> > I'm looking to be able to log the fields that are different between old
> > and new in a trigger,  but don't want to have to list each field (It
> > changes, occasionally, but it changes).  I'd also like to add a
> > timestamp and flag field when I store the record in the log table. 
> > 
> > Am I just SOL, or is there a way to do this? (7.2.1, if it matters). 
> 
> I'm pretty sure there is a way to do what you want, and it's probably simpler 
> than you think.  
> 
> However, I need you to be more explicit, with examples.  I can't quite figure 
> out what is is you're trying to do.
> 

given the following table:
CREATE TABLE "networks" (
	"netblock" cidr,
	"router" integer,
	"interface" character varying(256),
	"dest_ip" inet,
	"mis_token" character(16),
	"assigned_date" date,
	"assigned_by" character varying(256),
	"justification_now" integer,
	"justification_1yr" integer,
	"cust_asn" integer,
	"comments" character varying(2048),
	"other_reference" character varying(256),
	"parent_asn" integer,
	"status" integer NOT NULL,
	"purpose" integer,
	"last_update_by" character varying(256),
	"last_update_at" timestamp with time zone,
	"customer_reference" integer,
	"natblock" cidr
);

I want to log the changes to it in a trigger.  Occasionally we add fields to it, so 
I'd like the trigger to know about them automatically.  I need to log old/new for just the fields
that change (and the netblock, which is the primary key). 

I realize I can build up the insert, but that seems to be the hard way. 


> -Josh Berkus
-- 
Larry Rosenman                     http://www.lerctr.org/~ler
Phone: +1 972-414-9812                 E-Mail: ler@lerctr.org
US Mail: 1905 Steamboat Springs Drive, Garland, TX 75044-6749