$f = DB_DataObject::Factory('Events');
$f->selectAdd();
$f->selectAdd("on_id, on_table, min(id) as min_id, max(id) as max_id, count(*) as mm");
$f = DB_DataObject::Factory('Events');
$f->selectAdd();
$f->selectAdd("on_id, on_table, min(id) as min_id, max(id) as max_id, count(*) as mm");