oracle特殊時間查詢

--the first day

select trunc(sysdate,'q') from dual

-- 過去了多少天

select floor(sysdate- trunc(sysdate ,'q')+1) from dual

--乙個季度多少天

1. select last_day(to_date(to_char(sysdate,'yyyy-')||lpad(floor(to_number(to_char(sysdate,'mm'))/3)*3+3,2,'0')|| '-01','yyyy-mm-dd'))-

to_date(to_char(sysdate,'yyyy-')||lpad(floor(to_number(to_char(sysdate,'mm'))/3)*3+1,2,'0')||'-01','yyyy-mm-dd')+1

from dual

2.add_months(trunc(sysdate,'q'),3)-1-to_date(to_char(trunc(sysdate,'q'),'yyyy-mm-dd'),'yyyy-mm-dd')+1

--剩餘多少天

select last_day(to_date(to_char(sysdate,'yyyy-')||lpad(floor(to_number(to_char(sysdate,'mm'))/3)*3+3,2,'0')|| '-01','yyyy-mm-dd'))-

to_date(to_char(sysdate,'yyyy-')||lpad(floor(to_number(to_char(sysdate,'mm'))/3)*3+1,2,'0')||'-01','yyyy-mm-dd')+1 -

(floor(sysdate-

trunc(sysdate ,'q')+1))

from dual

--得到下月一日的日期

select add_months(trunc(to_date('2010-01-05','yyyy-mm-dd'), 'mm'), -1), from dual;

select to_date(to_char(add_months(trunc(sysdate, 'mm'), -1),'yyyy-mm')||'-'||to_char(sysdate,'dd'),'yyyy-mm-dd') from dual;