[SQL] Cursor names in a self-nested function

[Kidd, David M]

Hi,

I am trying to write a function that contains a cursor and iteratively calls 
itself.

It is along the lines of,

CREATE FUNCTON test(id integer) RETURNS TEXT AS
$BODY$
DECLARE
  mycursor CURSOR FOR SELECT * FROM myfunction(id);
  newid INTEGER;
  out = TEXT;
BEGIN
  out := '';
  OPEN mycursor;
  LOOP
    FETCH my_cursor INTO newid;
    out := out || test (newid);
  END LOOP;
  RETURN out;
END;
 $BODY$
LANGUAGE 'plpgsql' VOLATILE

This returns an ERROR stating that "mycursor" is already in use.

I understand this occurs because cursor names must be unique across, as well as 
within, functions.

So, my question is whether there is a way I can dynamically declare a cursor 
name, for example by appending a incremental number or guid to make the name 
unique?
Just trying to concatenate two passed arguments in the DECLARE statement 
unsurprisingly fails.

Any other solutions are of cause welcome.

Many thanks,

 - David



David M. Kidd

Research Associate
Center for Population Biology
Silwood Park Campus
Imperial College London
0207 594 2470