DELETE
FROM
 EMP
WHERE
 EMP.EMP_CODE =
  (SELECT
    EMP_tmp.EMP_CODE
   FROM
    EMP AS EMP_tmp,
    EMP_INVALID AS EMP_INVALID_tmp
   WHERE
    EMP_tmp.EMP_CODE = EMP_INVALID_tmp.EMP_CODE
   )
AND
 EMP.EMP_CODE != 
   (SELECT
    EMP_tmp2.EMP_CODE
   FROM
    EMP AS EMP_tmp2,
    EMP_INVALID AS EMP_INVALID_tmp2
   WHERE
    EMP_tmp2.EMP_CODE = EMP_INVALID_tmp2.EMP_CODE
   AND
    EMP_tmp2.USER_UPDATE_DATETIME > EMP_INVALID_tmp2.USER_UPDATE_DATETIME
   AND
    EMP_tmp2.VALID_FLG = '1'
   )
;