select concat('4', to_char(02, '09')) from dual;
select concat('4', to_char(02)) from dual;
select 4 || '02' from dual;
为什么结果不一样呢,我想用to_char达到select 4 || '02' from dual;的效果怎么弄呀
select concat('4', to_char(02)) from dual;
select 4 || '02' from dual;
为什么结果不一样呢,我想用to_char达到select 4 || '02' from dual;的效果怎么弄呀
select concat('4', trim(to_char(02, '09'))) from dual;