计算两个日期相差的天数、月数

1.天数 

select Maturity,'2007/10/16' curdate,(TO_DATE('2007/10/16','YYYY/MM/DD') -TO_DATE(Maturity,'YYYY/MM/DD'))  from business_duebill where Maturity<'2007/10/16';

 

2.月数

SELECT MONTHS_BETWEEN('20-JAN-07','13-MAY-07') FROM DUAL