questions about cursors

[Anton Andreev <fn30762(at)fmi(dot)uni-sofia(dot)bg>]

Hi,

I am trying to use cursors and I am really frustrated already. Do  I 
need to install an extension?

1. Problem number one is that what ever I use in front of the fetch 
command it is not being accepted, it gives a syntax error. If I use a 
number ,"all" or "forward" it gives an error again?????????? I want to 
do something like the code below:

CREATE OR REPLACE FUNCTION database_correction()
 RETURNS double precision AS
$BODY$
DECLARE
   mycursor CURSOR FOR select distinct(fund_id) from 
"NAV_values_bfb_history";
   iterator integer;

BEGIN
open mycursor;

FETCH mycursor INTO iterator;

--fetch next  from  mycursor  --gives  an error

WHILE (FETCH next from mycursor) LOOP
   -- some computations here
END LOOP;

CLOSE mycursor;
END;

2. What is the right way to check that the cursor has ended. In 
sqlserver there is a variable "@@fetch_status". I have to make here some 
comparison in the while clause, but I am not sure what it should be. I 
could not find a single example for cursor in a loop.

I will greatly appreciate any help, pgsql is my database of choice.

Cheers,
Anton