Add new datafile or tempfile to space

ALTER DATABASE TEMPFILE 'D:\DATA\ORACLE\xxx_HOME\ORADATA\MIG_TEMP01.DBF' OFFLINE;

select file#,status,name from v$tempfile;
select file#,status,name from v$datafile;

alter tablespace MIG_TEMP drop tempfile 2;

alter tablespace MIG_TEMP add tempfile 'D:\DATA\ORACLE\xxx_HOME\ORADATA\MIG_TEMP01.DBF' size 10M;
alter tablespace MIG_TEMP add tempfile 'D:\DATA\ORACLE\xxx_HOME\ORADATA\MIG_TEMP02.DBF' size 10M;

ALTER DATABASE TEMPFILE 'D:\DATA\ORACLE\xxx_HOME\ORADATA\MIG_TEMP01.DBF' ONLINE;
ALTER DATABASE TEMPFILE 'D:\DATA\ORACLE\xxx_HOME\ORADATA\MIG_TEMP02.DBF' ONLINE;


ALTER DATABASE 
  TEMPFILE 'D:\DATA\ORACLE\xxx_HOME\ORADATA\MIG_TEMP01.DBF'
  AUTOEXTEND ON
  NEXT 100M
  MAXSIZE UNLIMITED;