to_char(xxx,'FM9999990.00') --保留两位小数,不足两位补0
select to_char(118.8,'FM9999990.00') from dual
---118.80
select to_char(118,'FM9999990.00') from dual
---118.00
select to_char(118.8,'FM9999990.00') from dual
---118.80
select to_char(118,'FM9999990.00') from dual
---118.00