Trigger to update triggering table

Hi!

I'm trying to create a trigger that retrieves information from the same table which activates the trigger.

CREATE TRIGGER bi_increment_calls BEFORE INSERT  ON medi_calls FOR EACH ROW
 BEGIN
    SELECT NVL(MAX(call_nr),0)+1

     INTO :new.call_nr
     FROM medi_calls
     WHERE tel_nr = :new.tel_nr AND
           prefix = :new.prefix;

ORA-04091: table KENNY.MEDI_CALLS is mutating, trigger/function may not see it
ORA-06512: at "KENNY.BI_INCREMENT_CALLS", line 2 ORA-04088: error during execution of trigger 'KENNY.BI_INCREMENT_CALLS'

There has to be a way to do this.. please help. :)

/Kenny
Received on Mon Aug 13 2001 - 13:35:05 CEST