recreate table t1(id int, x int);

recreate table t2(evt char(3), new_id int, new_x int, old_id int, old_x int);
recreate table t2log(evt char(3), affected_rows int);
commit;

set term ^;
create trigger t1_aiud after insert or update or delete on t1 as
    declare rc int;
begin
    if (inserting) then
        begin
            insert into t2(evt, new_id, new_x) values ('ins', new.id, new.x);
            insert into t2log(evt, affected_rows) values('ins', row_count);
        end
    else if (updating) then
        begin
            update t2 set 
                evt='upd', 
                old_id = old.id, old_x = old.x, 
                new_id = new.id, new_x = new.x
            where new_id = old.id;

            insert into t2log(evt, affected_rows) values('upd', row_count);
             --rc = row_count;
            --insert into t2log(evt, affected_rows) values('upd', :rc); 
        end
    else
        begin
            update t2 set evt='del', old_x = old.x, new_id = null, new_x = null
            where new_id = old.id;
            insert into t2log(evt, affected_rows) values('del', row_count);
        end
end
^
set term ;^
commit;

insert into t1 values(1, 100);
update t1 set id=2, x=200 where id=1;
delete from t1 where id=2;

select * from t2;

select * from t2log;