select 
a.EMP_CODE        as CODE
,a.EMP_LAST_NAME  as SURNAME
,a.EMP_FIRST_NAME as NAME
from
 emp a,
(select 
 REPLACE(b.EMP_LAST_NAME,' ','')  as EMP_LAST_NAME
,REPLACE(b.EMP_FIRST_NAME,' ','') as EMP_FIRST_NAME
,count(*)
from
  emp b
 where
  b.VALID_FLG = '1'
 group by 
 REPLACE(b.EMP_LAST_NAME,' ','')
,REPLACE(b.EMP_FIRST_NAME,' ','')
having count(*) > 1
) b
where
  REPLACE(a.EMP_LAST_NAME,' ','') = REPLACE(b.EMP_LAST_NAME,' ','')
order by
  REPLACE(a.EMP_LAST_NAME,' ','')||REPLACE(a.EMP_FIRST_NAME,' ','')
 ,a.EMP_CODE