oracle查询日期语句有哪些？

alter session set NLS_DATE_FORMAT='YYYY-MM-DD HH24:MI:SS'

select sysdate from dual;

select trunc(sysdate) from dual;

select trunc(sysdate) + 0.99999 from dual;

select trunc(sysdate) + 1/24 from dual;

select trunc(sysdate) + 7/24 from dual;

select trunc(sysdate+1) from dual;

select trunc(sysdate)+1 from dual;

select trunc(sysdate,'mm') from dual;

select trunc(add_months(sysdate,1),'mm') from dual;

select last_day(sysdate) from dual;     

select last_day(trunc(sysdate)) from dual;

select trunc(last_day(sysdate)) from dual;

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

select trunc(sysdate,'yyyy')+ rn -1 date0

from

(select rownum rn from all_objects

where rownum<366);

SELECT TO_CHAR(SYSDATE,'DDD') FROM DUAL;

select add_months(sysdate,24) from dual;

select decode(to_char(last_day(trunc(sysdate,'y')+31),'dd'),'29','闰年','平年') from dual;

select decode(to_char(last_day(trunc(add_months(sysdate,24),'y')+31),'dd'),'29','闰年','平年') from dual;

select ceil(to_number(to_char(sysdate,'mm'))/3) from dual;

select to_char(sysdate, 'Q') from dual;