select * from (
select u.UYE_ID,
  (
    SELECT STRING_AGG (CONVERT(NVARCHAR(max),v.Kodu), ', ') AS csv 
    FROM [v_UyelerveMulkleri] v where v.UYE_ID=u.UYE_ID 
  ) as Mulkleri
from Uyeler u) z
where Mulkleri is not null