select last_day(add_months(to_date(concat(to_char(sysdate,'yyyy'),'1231'),'yyyy-mm-dd'),-level))+1 dates from dual connect by level<=12;
2015年全年
select last_day(add_months(to_date('20141231','yyyy-mm-dd'),-level))+1 dates from dual connect by level<=12;
2014全年