order by ordering expression changed to empty string when creatin view with union

create table if not exists t1 (t1col1 int, t1col2 int,t1col3 int );

create table if not exists t2 (t2col1 int, t2col2 int, t2col3 int);

create or replace view t_view as 

select t1col1,t1col2,t1col3 from t1

union all

select t2col1,t2col2,t2col3 from t2

order by 2,3;

show create view t_view;

CREATE ALGORITHM=UNDEFINED DEFINER=`marclang`@`10.45.53.%` SQL SECURITY DEFINER VIEW `t_view` AS select `t1`.`t1col1` AS `t1col1`,`t1`.`t1col2` AS `t1col2`,`t1`.`t1col3` AS `t1col3` from `t1` union all select `t2`.`t2col1` AS `t2col1`,`t2`.`t2col2` AS `t2col2`,`t2`.`t2col3` AS `t2col3` from `t2` order by '',''