函数得到年底

Question

如题，date是‘2010-01-31’，如何写函数取得‘2009-12-31’，多谢！

Answer 1

select last_day(to_date(to_char(sysdate,'yyyy')||'-12','yyyy-mm')) from dual;

Answer 2

select last_day(to_date(to_char(sysdate,'yyyy')-1||'-12','yyyy-mm')) from dual;
LAST_DAY(TO_DATE(TO_CHAR(SYSDA
2009-12-31

Answer 3

select last_day(to_date(to_char(sysdate,'yyyy')||'-12','yyyy-mm')) from dual;

Answer 4

select last_day(to_date(to_char(sysdate,'yyyy')-1||'-12','yyyy-mm')) from dual;

Answer 5

select  trunc(add_months(to_date('20100131,'YYYYMMDD'),12),'YYYY')-1 from dual;

Answer 6

SQL> select last_day(to_date(to_char(sysdate,'yyyy')||'-12','yyyy-mm')) from dual; 
LAST_DAY(TO_DATE(TO_CHAR(SYSDA
------------------------------
2010-12-31

Answer 7

select add_months(date'2010-01-31',-1) from dual;

Answer 8

SQL> select last_day(to_date(to_char(to_date('2010-01-31','yyyy-mm-dd'),'yyyy')-1||'-12','yyyy-mm'))
 from dual;LAST_DAY(TO_DA
--------------
31-12月-09

Answer 9

select add_months(trunc(sysdate, 'year'), 12) - 1 from dual;

Answer 10

 select to_date('2010-01-01','yyyy-mm-dd')-1 "date" from dual;

Answer 11

select add_months(to_date('2010-01-31','yyyy-mm-dd'),-1) "date" from dual;    date
------------------
   2009-12-31