Trigger

Hi,

I'd like to make a trigger on a table which shall check, on any update and insert
if the sum of all values of a specific column is below 100 i did it like this:

but if i do an update i get the error "trigger is not allowed to see the data because it the data is
just being modified" .. can i solve this problem with a "trigger" ? the trigger has to read the same data
in the table, but is not allowed to do so... any idea ?

declare
 var_gewichtung number;
begin

    select nvl(sum(GEWICHTUNG),0) into var_gewichtung from PORTFOLIOZUSAMMENSETZUNG
     WHERE ID_PORTFOLIO = :new.id_portfolio;

   if var_gewichtung + :new.gewichtung > 100 then      var_gewichtung := 100 - var_gewichtung;     raise_application_error(-20000, 'Die Summe aller Gewichtungen zu diesem Portfolio ist größer als 100. Bitte geben Sie einen Wert <= ' || var_gewichtung || ' ein.');

   end if;

end; Received on Fri Nov 09 2001 - 11:09:05 CST