From: Terry Lee Tucker <terry@esc1.com>
Organization: Enhanced Solutions Computing
To: pgsql-sql@postgresql.org
Subject: Re: Simple plpgsql question
Date: Fri, 14 Apr 2006 05:03:10 -0400
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On Thursday 13 April 2006 11:38 pm, "Todd Kennedy" <todd.kennedy@gmail.com> 
thus communicated:
--> Hi,
-->
--> I have, what I hope to be, a simple question about plpgsql.
-->
--> I have a trigger on a table right now that updates a count everytime
--> that a new record is entered into a database (or removed).
-->
--> What I'd also like to do is have it create a new row in a different
--> table using the automatically assigned id as a reference, but I'm
--> unsure of how to obtain the id of the newly created row in the first
--> table.
-->
--> Example:
--> CREATE TABLE system_info (
--> id serial PRIMARY KEY,
--> name varchar(255),
--> value varchar(255)
--> );
--> INSERT INTO system_info (name,value) VALUES ('total_users','0');
-->
--> CREATE TABLE master (
--> id serial PRIMARY KEY,
--> name varchar(32) NOT NULL CHECK ( name <> ''),
--> UNIQUE(name)
--> );
-->
--> CREATE TABLE slave (
--> id serial PRIMARY KEY,
--> master_id integer REFERENCES master (id),
--> additional_info text
--> );
-->
--> CREATE OR REPLACE FUNCTION update_users() RETURNS trigger AS $$
--> BEGIN
-->     IF TG_OP = 'DELETE' THEN
-->         UPDATE system_info SET value=(value::integer)-1 WHERE name =
--> 'total_users'
-->         RETURN OLD;
-->     ELSEIF TG_OP = 'INSERT' THEN
-->         UPDATE system_info SET value=(value::integer)+1 WHERE name =
--> 'total_users';
--> 	INSERT INTO slave (master_id) VALUES (THIS IS WHAT I NEED TO KNOW);
-->         RETURN NEW;
-->     END IF;
-->     RETURN NULL;
--> END;
--> $$ LANGUAGE plpgsql;
-->
--> CREATE TRIGGER update_users AFTER INSERT OR DELETE ON master
-->     FOR EACH ROW EXECUTE PROCEDURE update_users();
-->
-->
--> The part I need to know is the INSERT INTO statement in the procedure.
-->
--> Any help would be great.
-->
--> Thanks!
-->
--> ---------------------------(end of broadcast)---------------------------
--> TIP 4: Have you searched our list archives?
-->
-->                http://archives.postgresql.org
-->

INSERT INTO slave (master_id) VALUES (new.id);

The buffer NEW contains all the "new" data.