Как получить из базы только уникальные данные?

select one from 
   (select data_id as one, lead(data_id, 1, data_id - 1) 
      over(order by data_id) as two from tos) as table
 where  one <> two

select one from 
   (select data_id as one, lead(data_id, 1, data_id - 1) 
      over(order by id) as two from tos) as table
 where  one <> two