Thread: how to use a cursor for update?

Hi all,

I'm trying to create a stored procedure using a cursor to udate a
table this is my code:


CREATE OR REPLACE FUNCTION test_select() RETURNS void AS
$BODY$

DECLARE
    cur CURSOR FOR SELECT *
               FROM zone
           WHERE patient = '4595'
           FOR UPDATE;
    var1 record;
    var2 record;
BEGIN
    OPEN cur;

    FETCH  cur INTO var1;

    FETCH cur INTO var2;

    UPDATE zone SET end_period = var1.end_period WHERE CURRENT OF cur;

END;
$BODY$
LANGUAGE 'plpgsql';


When i try to execute this code i get a :

ERROR:  cursor "cur" is not a simply updatable scan of table "zone"
CONTEXT:  SQL statement "UPDATE zone SET end_period =  $1  WHERE
CURRENT OF  $2 "
PL/pgSQL function "test_select" line 16 at SQL statement

How can i use that cursor for update?

Tnx in advance!

=?ISO-8859-1?Q?nicola_zandon=E0?= <nick.zando@gmail.com> writes:
> When i try to execute this code i get a :

> ERROR:  cursor "cur" is not a simply updatable scan of table "zone"
> CONTEXT:  SQL statement "UPDATE zone SET end_period =  $1  WHERE
> CURRENT OF  $2 "
> PL/pgSQL function "test_select" line 16 at SQL statement

The example works for me, using a simple definition of the "zone"
table.  Maybe your "zone" is not a table but a complicated view?

Or it could be a bug that's been fixed.  What PG version are you using?

            regards, tom lane