Declare a variable of temporary table in stored procedure in PL/pgSQL - postgresql

Question

I receive this error to begin with:
ERROR: syntax error at or near "conference"
LINE 19: FOR conference IN conferenceset
Here's the function:
CREATE OR REPLACE FUNCTION due_payments_to_suppliers_previous_month()
RETURNS TABLE(supplier varchar,due_amount numeric)
AS $$
DECLARE
BEGIN
CREATE TABLE conferenceset AS -- temporary table, so I can store the result set
SELECT
conference.conference_supplier_id,
conference.id AS conferenceid,
conference.price_per_person,
0 AS participants_count,
400 AS deduction_per_participant,
0 AS total_amount
FROM Conference WHERE --- date_start has to be from the month before
date_start >= date_trunc('month', current_date - interval '1' month)
AND
date_start < date_trunc('month', current_date);
FOR conference IN conferenceset
LOOP
---fill up the count_participants column for the conference
conference.participants_count :=
SELECT COUNT(*)
FROM participant_conference JOIN conferenceset
ON participant_conference.conference_id = conferenceset.conferenceid;
---calculate the total amount for that conference
conference.total_amount := somerec.participants_count*(conference.price_per_person-conference.deduction_per_participant);
END LOOP;
----we still don't have the name of the suppliers of these conferences
CREATE TABLE finalresultset AS -- temporary table again
SELECT conference_supplier.name, conferenceset.total_amount
FROM conferenceset JOIN conference_supplier
ON conferenceset.conference_supplier_id = conference_supplier.id
----we have conference records with their amounts and suppliers' names scattered all over this set
----return the result with the suppliers' names extracted and their total amounts calculated
FOR finalrecord IN (SELECT name,SUM(total_amount) AS amount FROM finalresultset GROUP BY name)
LOOP
supplier:=finalrecord.name;
due_amount:=finalrecord.amount;
RETURN NEXT;
END LOOP;
END; $$
LANGUAGE 'plpgsql';
I don't know how and where to declare the variables that I need for the two FOR loops that I have: conference as type conferenceset and finalrecord whose type I'm not even sure of.
I guess nested blocks will be needed as well. It's my first stored procedure and I need help.
Thank you.

Answer 1

CREATE OR REPLACE FUNCTION due_payments_to_suppliers_previous_month()
RETURNS TABLE(supplier varchar,due_amount numeric)
AS $$
DECLARE
conference record;
finalrecord record;
BEGIN
CREATE TABLE conferenceset AS -- temporary table, so I can store the result set
SELECT
conference.conference_supplier_id,
conference.id AS conferenceid,
conference.price_per_person,
0 AS participants_count,
400 AS deduction_per_participant,
0 AS total_amount
FROM Conference WHERE --- date_start has to be from the month before
date_start >= date_trunc('month', current_date - interval '1' month)
AND
date_start < date_trunc('month', current_date);
FOR conference IN (select * from conferenceset)
LOOP
---fill up the count_participants column for the conference
conference.participants_count = (
SELECT COUNT(*)
FROM participant_conference JOIN conferenceset
ON participant_conference.conference_id = conferenceset.conferenceid
);
---calculate the total amount for that conference
conference.total_amount = somerec.participants_count*(conference.price_per_person-conference.deduction_per_participant);
END LOOP;
----we still don't have the name of the suppliers of these conferences
CREATE TABLE finalresultset AS -- temporary table again
SELECT conference_supplier.name, conferenceset.total_amount
FROM conferenceset JOIN conference_supplier
ON conferenceset.conference_supplier_id = conference_supplier.id
----we have conference records with their amounts and suppliers' names scattered all over this set
----return the result with the suppliers' names extracted and their total amounts calculated
FOR finalrecord IN (SELECT name,SUM(total_amount) AS amount FROM finalresultset GROUP BY name)
LOOP
supplier = finalrecord.name;
due_amount = finalrecord.amount;
RETURN NEXT;
END LOOP;
END; $$
LANGUAGE 'plpgsql';