create table log_record
        (item_num    smallint,
        ord_num      integer,
        username     character(8),
        update_time  datetime year to minute,
        old_qty      smallint,
        new_qty      smallint);
 
create trigger upqty_i
update of quantity on items
referencing old as pre_upd
        new as post_upd
for each row(insert into log_record
    values (pre_upd.item_num, pre_upd.order_num, user, current,
        pre_upd.quantity, post_upd.quantity));
