oracle 对日期处理

select sysdate from dual; --获取上个的最后一天 select last_day(add_months(sysdate,-1)) from dual; select to_date(add_months(last_day(add_months(sysdate,-1))+1,-1)) from dual; select trunc(sysdate),to_date(to_char(sysdate,'yyyy-mm-dd')||'23:59:59','YYYY-MM-DD HH24:MI:SS') from dual; select trunc(sysdate),'yyyy-mm-dd')||'00:00:01','YYYY-MM-DD HH24:MI:SS') from dual; ---获取上个月最后一天时间 select to_date(to_char( (select last_day(add_months(sysdate,-1)) from dual),'YYYY-MM-DD HH24:MI:SS') from dual; ---获取上个月第一天的时间 select to_date(to_char( (select to_date(add_months(last_day(add_months(sysdate,'YYYY-MM-DD HH24:MI:SS') from dual;