oracle中列出某月所有天的sql语句

select *
  from (select to_char(to_date(to_char(sysdate, 'yyyymm') || '01',
                               'yyyymmdd') + rownum - 1,
                       'yyyymmdd')
          from dual
         start with dummy = 'X'
        connect by dummy = dummy)
 where rownum < to_number(to_char(last_day(sysdate), 'dd')) + 1;