Trigger error

sub_woofer <tqzelijah@yahoo.co.uk> writes:

IF (((TG_OP = 'INSERT') AND (new.subjects=TRUE)) OR ((TG_OP='UPDATE') AND
(new.subjects=TRUE) AND (old.subjects=FALSE))) THEN

You can't do that. Split the IF apart so that you don't touch NEW or
OLD in the same if-test that tries to determine if they're safe to
touch.

regards, tom lane

----- "sub_woofer" <tqzelijah@yahoo.co.uk> wrote:

Hi All

Its been some time since I did any work using triggers/pgsql and when
I did,
it was pretty much basic stuff. Ive now returned to developing apps
using
postgres and have run into an error when using a trigger that I wrote
a few
years back (which worked fine then) but doesnt seem to work anymore! I
must
have changed something (?) but can't remb what!

When I try to insert a record into a table called "stage" which should
then
fire my trigger i get the following error message:

org.postgresql.util.PSQLException: ERROR: record "old" is not assigned
yet
Detail: The tuple structure of a not-yet-assigned record is
indeterminate.

Here is the code for the trigger:-

CREATE OR REPLACE FUNCTION createstagesubjectlisting()
RETURNS "trigger" AS
$BODY$

Declare

Begin
IF (((TG_OP = 'INSERT') AND (new.subjects=TRUE)) OR ((TG_OP='UPDATE')
AND
(new.subjects=TRUE) AND (old.subjects=FALSE))) THEN

An INSERT tuple does not have OLD record. You might be running into problems with your parentheses and operator precedence. I usually find it easier to follow by doing the TG_OP in IF,ELSEIF:

IF TG_OP = 'INSERT'
ELSIF TG_OP = 'UPDATE'
ELSIF TG_OP ='DELETE'

with the appropriate statements nested in each .

Insert into subsperstage(stageid, subno) VALUES (new.stageid, 10);
Insert into subsperstage(stageid, subno) VALUES (new.stageid, 20);
Insert into subsperstage(stageid, subno) VALUES (new.stageid, 30);
Insert into subsperstage(stageid, subno) VALUES (new.stageid, 40);
Insert into subsperstage(stageid, subno) VALUES (new.stageid, 50);
Insert into subsperstage(stageid, subno) VALUES (new.stageid, 100);
Insert into subsperstage(stageid, subno) VALUES (new.stageid, 200);
Insert into subsperstage(stageid, subno) VALUES (new.stageid, 300);
Insert into subsperstage(stageid, subno) VALUES (new.stageid, 400);
Insert into subsperstage(stageid, subno) VALUES (new.stageid, 500);
Insert into subsperstage(stageid, subno) VALUES (new.stageid, 1000);
END IF;

IF ((TG_OP='UPDATE') AND (new.subjects=FALSE) AND (old.subjects=true))
THEN
DELETE FROM subsperstage where stageid=old.stageid;
end if;
Return NULL;

END;

$BODY$
LANGUAGE 'plpgsql' VOLATILE;
ALTER FUNCTION createstagesubjectlisting() OWNER TO postgres;

the trigger on table:

CREATE TRIGGER createstagesubjectlisting
AFTER INSERT OR UPDATE
ON stage
FOR EACH ROW
EXECUTE PROCEDURE createstagesubjectlisting();

Removing the trigger everything works fine - records get inserted into
my
stage table, but having the trigger results in no data being inserted
in my
stage table or the trigger being fired.

Any ideas???

Thanks in advance

t.

Adrian Klaver
aklaver@comcast.net

Hi Thank you both for your responses and apologies for the late reply!

Tom you were correct! :) I split the If statements into 2 for the old and
new tests and it all worked! :)

Thanks once again for all your help! :)

t.

Tom Lane-2 wrote:

sub_woofer <tqzelijah@yahoo.co.uk> writes:

IF (((TG_OP = 'INSERT') AND (new.subjects=TRUE)) OR ((TG_OP='UPDATE') AND
(new.subjects=TRUE) AND (old.subjects=FALSE))) THEN

You can't do that. Split the IF apart so that you don't touch NEW or
OLD in the same if-test that tries to determine if they're safe to
touch.

regards, tom lane

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