更新触发器以更新到同一个表

create or replace trigger admin.patreg_paid_amt_temp
before UPDATE OF PAIDAMOUNT_TEMP ON admin.patient_registration
REFERENCING OLD AS OLD NEW AS NEW
For EACH ROW 
BEGIN
   if :new.PAIDAMOUNT_TEMP != :old.PAIDAMOUNT_TEMP
   then
       UPDATE admin.patient_registration d
        set d.PAID_AMOUNT = :new.PAIDAMOUNT_TEMP + d.DIFFERENCE ,
        d.PENDING = ABS(:new.PAIDAMOUNT_TEMP - d.DUES) 
       where d.PATIENT_ID = :new.PATIENT_ID;
   end if;
END;
create or replace trigger admin.patreg_paid_amt