oracle获取周几以及每周对应得开始日期和结束日期

--获取近一年周的开始日期和结束日期，从星期日开始
select
'2014'||sunday.the_week,decode(sign(sunday.the_day-saturday.the_day),-1,sunday.the_day,sunday.the_day-7)
sunday,saturday.the_day saturday from
(select to_char(wwm,'WW') the_week,to_char(wwm,'D') the_daynum,wwm the_day from (select
trunc(to_date('2014-01-01','yyyy-mm-dd'), 'MM')+rownum-1 as wwm from user_objects where rownum < 366) where
to_char(wwm,'D')=1 ) sunday,
(select to_char(wwm,'WW') the_week,to_char(wwm,'D') the_daynum,wwm the_day  from (select
trunc(to_date('2014-01-01','yyyy-mm-dd'), 'MM')+rownum-1 as wwm from user_objects where rownum < 366) where
to_char(wwm,'D')=7 ) saturday
where sunday.the_week=saturday.the_week;


--获取近一年周的开始日期和结束日期，从星期一开始
select
'2014'||monday.the_week,decode(sign(monday.the_day-sunday.the_day),-1,monday.the_day,monday.the_day-6)
sunday,sunday.the_day sunday from
(select to_char(wwm,'WW') the_week,to_char(wwm,'D') the_daynum,wwm the_day from (select
trunc(to_date('2014-01-01','yyyy-mm-dd'), 'MM')+rownum-1 as wwm from user_objects where rownum < 366) where
to_char(wwm,'D')=1 ) monday,
(select to_char(wwm,'WW') the_week,to_char(wwm,'D') the_daynum,wwm+1 the_day  from (select
trunc(to_date('2014-01-01','yyyy-mm-dd'), 'MM')+rownum-1 as wwm from user_objects where rownum < 366) where
to_char(wwm,'D')=7 ) sunday
where monday.the_week=sunday.the_week;