Re: example of Create Function

Roberto (SmartBit) wrote:
(re: PostgreSQL 7.3 release)
> by the way, when does it will be done???
>

Can't say for sure, but I think beta testing is starting to wind down.

>
>      would I be able to change the value of field? like:
>           IF r_value < 0 THEN
>              r_value = r_value*-1;
>

Sure:

CREATE TABLE payments (r_date_payment TIMESTAMP, r_description VARCHAR(50),
r_value numeric (12,2));

INSERT INTO payments VALUES(CURRENT_TIMESTAMP, 'a', '12.50');
INSERT INTO payments VALUES(CURRENT_TIMESTAMP, 'b', '11.75');
INSERT INTO payments VALUES(CURRENT_TIMESTAMP, 'c', '-99.99');

CREATE OR REPLACE FUNCTION my_proc(TIMESTAMP)
RETURNS SETOF payments
AS '
DECLARE
    rec RECORD;
BEGIN
    FOR rec IN SELECT * FROM payments
    WHERE r_date_payment BETWEEN $1 AND CURRENT_TIMESTAMP LOOP
       IF rec.r_value < 0 THEN
           rec.r_value = rec.r_value*-1;
       END IF;
       RETURN NEXT rec; /* Each RETURN NEXT command returns a row */
    END LOOP;
    RETURN;
END;
' LANGUAGE 'plpgsql';

test=# select * from payments;
        r_date_payment       | r_description | r_value
----------------------------+---------------+---------
  2002-10-22 10:27:38.086554 | a             |   12.50
  2002-10-22 10:27:38.172964 | b             |   11.75
  2002-10-22 10:27:38.177543 | c             |  -99.99
(3 rows)

test=# SELECT * FROM my_proc('01/01/2002');
        r_date_payment       | r_description | r_value
----------------------------+---------------+---------
  2002-10-22 10:27:38.086554 | a             |   12.50
  2002-10-22 10:27:38.172964 | b             |   11.75
  2002-10-22 10:27:38.177543 | c             |   99.99
(3 rows)

Joe