How to pass timestamps to a function and retrieve resulting rows - postgresql

Question

I have created custom data type. In that I have given alias name of the one field. you will get that in body of the function below.
create type voucher as (
ori numeric, RECEIPT_NO numeric
, receipt_date timestamp with time zone, reg_no character varying
, patient_name character varying, tot_refund_bill_amount double precision
, username character varying );
Thea above statement completes successfully.
Then I want to create a function:
create or replace function billing.voucher_receipt (in_from_date timestamp with time zone, in_to_date timestamp with time zone)
returns setof voucher as $$
declare
out_put voucher%rowtype;
begin
return query(select C.receipt_no as ori ,A.RECEIPT_NO, receipt_date , A.reg_no, patient_name, tot_refund_bill_amount, username
from billing.tran_counter_receipt as a inner join mas_user as b on a.ent_by=b.uid AND cash_book='REFUND'
INNER JOIN billing.tran_BILL AS C ON C.REG_NO=A.REG_NO AND C.CASH_BOOK='GCASH' where receipt_date>=in_from_date and receipt_date<=in_to_date);
end;$$
LANGUAGE plpgsql
Executes without problem.
But when I call it with input like this:
select * from voucher_receipt ('2014-09-25 11:42:44.298346+05:30'
, '2014-09-29 11:03:47.573049+05:30')
it shows an error:
ERROR: function voucher_receipt(unknown, unknown) does not exist
LINE 1: select * from voucher_receipt ('2014-09-25 11:42:44.298346+0...
^
HINT: No function matches the given name and argument types. You might need to add explicit type casts.
Can any one help me out from this?

Answer 1

Explain error
You created your function in the schema billing with:
create or replace function billing.voucher_receipt( ...
Then you call without schema-qualification:
select * from voucher_receipt ( ...
This only works while your current setting for search_path includes the schema billing.
Better function
You don't need to create a composite type. Unless you need the same type in multiple places just use RETURNS TABLE to define the return type in the function:
CREATE OR REPLACE FUNCTION billing.voucher_receipt (_from timestamptz
, _to timestamptz)
RETURNS TABLE (
ori numeric
, receipt_no numeric
, receipt_date timestamptz
, reg_no varchar
, patient_name varchar
, tot_refund_bill_amount float8
, username varchar) AS
$func$
BEGIN
RETURN QUERY
SELECT b.receipt_no -- AS ori
, cr.RECEIPT_NO
, ??.receipt_date
, cr.reg_no
, ??.patient_name
, ??.tot_refund_bill_amount
, ??.username
FROM billing.tran_counter_receipt cr
JOIN billing.tran_bill b USING (reg_no)
JOIN mas_user u ON u.uid = cr.ent_by
WHERE ??.receipt_date >= _from
AND ??.receipt_date <= _to
AND b.CASH_BOOK = 'GCASH'
AND ??.cash_book = 'REFUND'
END
$func$ LANGUAGE plpgsql;
Notes
Don't call your parameters "date" while they are actually timestamptz.
RETURN QUERY does not require parentheses.
No need for DECLARE out_put voucher%rowtype; at all.
Your format was inconsistent and messy. That ruins readability and that's also where bugs can hide.
This could just as well be a simple SQL function.
Column names in RETURNS TABLE are visible in the function body almost everywhere. table-qualify columns in your query to avoid ambiguities (and errors). Replace all ??. I left in the code, where information was missing.
Output column names are superseded by names in the RETURNS declaration. So AS ori in the SELECT list is just documentation in this case.
Why schema-qualify billing.tran_bill but not mas_user?