oracle转换数字

oracle转换数字

 to_number(                                                                                                              ) as month_Id
                 to_char(trunc(                                                                        ),'yyyymm')
                                      to_date(                                                  ),'mm'    
                                                   to_char(                 ),'yyyymmdd'
                                                               rmr.time_id

to_number(to_char(trunc(to_date(to_char(rmr.time_id),'yyyymmdd'),'mm'),'yyyymm')) as month_Id