Oacle 은 지난 순서의 시작 시간 과 끝 시간의 실현 함 수 를 가 져 옵 니 다.

 
--          
create or replace function fd_lastxunstart(rq in date) return string is 
refstr varchar2(50); 
v_rq date; 
begin 
--         
v_rq := trunc(rq); 
select case decode(trunc((to_char(v_rq, 'dd') - 1) / 10), 
0, 
'  ', 
1, 
'  ', 
'  ') 
when '  ' then --         
to_char(add_months(v_rq, -1), 'yyyyMM') || '21' 
when '  ' then 
to_char(v_rq, 'yyyymm') || '01' else　 
to_char(v_rq, 'yyyymm') || '11' 
end 
into refstr 
from dual; 
return refstr; 
end fd_lastxunstart; 

--       ：        
select sysdate from dual; 
select fd_lastxunstart(sysdate) from dual; 
select fd_lastxunstart(to_date('20130305','yyyymmdd')) from dual; 
select fd_lastxunstart(to_date('20130311','yyyymmdd')) from dual; 
select fd_lastxunstart(to_date('20130325','yyyymmdd')) from dual; 

--      ： 2013/9/5 12:08:39、20130821、20130221、20130301、20130311 

----            
--         date     ，    varchar          
create or replace function fd_lastxunend(rq in date) return string is 
refstr varchar2(50); 
v_rq date; 
begin 
--         
v_rq := trunc(rq); 
select case decode(trunc((to_char(v_rq, 'dd') - 1) / 10), 
0, 
'  ', 
1, 
'  ', 
'  ') 
when '  ' then --        1  
--chr(39)        
to_char(last_day(add_months(v_rq, -1)) + 1 - 1 / 24 / 60 / 60, 
'yyyymmdd') 
when '  ' then 
to_char(v_rq, 'yyyymm') || '10' else　 
to_char(v_rq, 'yyyymm') || '20' 
end 
into refstr 
from dual; 
return refstr; 
end fd_lastxunend; 

--       ：        
select fd_lastxunend(sysdate) from dual; 
select fd_lastxunend(to_date('20130305','yyyymmdd')) from dual; 
select fd_lastxunend(to_date('20130311','yyyymmdd')) from dual; 
select fd_lastxunend(to_date('20130315','yyyymmdd')) from dual; 
select fd_lastxunend(to_date('20130221','yyyymmdd')) from dual; 

--    ：20130831、20130228、20130310、20130310、20130220 

--    1 / 24 / 60 / 60           
select last_day(add_months(trunc(sysdate), -1)) + 1 - 1 / 24 / 60 / 60 
from dual; 
select last_day(add_months(trunc(sysdate), -1)) from dual; 
select last_day(add_months(trunc(sysdate), -1)) + 1 from dual; 
--     ：2013/8/31 23:59:59、2013/8/31、2013/9/1