获取过去两年的今天时间：

SELECT last_day(ADD_MONTHS(ADD_MONTHS(sysdate,-12), ROWNUM - 1)) as monthlist

FROM DUAL

CONNECT BY ROWNUM <=

months_between(SYSDATE,

ADD_MONTHS(sysdate,-12)) + 1;

select extract(year from sysdate) from dual

union

select extract(year from sysdate) -1 from dual

union

select extract(year from sysdate) -2 from dual;

select add_months(sysdate,-12) from dual

union

select add_months(sysdate,-24) from dual ;

select last_day(to_date('201409','yyyymm')) from dual;