sql上期(月、季、年)上月月末,上季末,上年末(统计中常用到)
 
SELECT
current timestamp -day(current  date) days ,-- 上个月月末 ,能够知道跨年
 
/*
to_date('2013-02-23','yyyy-mm-dd') -day(current  date) days ,-- 上个月月末 ,能够知道跨年  www.2cto.com  
*/
 
CASE  WHEN  TO_CHAR('2012-06-22','Q') ='1' THEN  to_char(year('2012-12-01')-1)||'-12' 
when  TO_CHAR('2012-06-22','Q') ='2' THEN to_char(year('2012-06-22'))||'-3'
when  TO_CHAR('2012-01-01','Q') ='3' THEN to_char(year('2012-12-01'))||'-6'
when  TO_CHAR('2012-01-01','Q') ='4' THEN to_char(year('2012-12-01'))||'-9'
 END AS tt , -- 上个季月 能够知道跨年
 
current date - (month(current date) -1 ) month - day(current date) day  --上年年末
 
 from sysibm.sysdummy1;