Write a view with function in oracle

Question

Dear all,
I have a table named borders, contains borders of some countries.
and then i made a view, to have symmetric  data , meaning if i have a record  {ch,DE} then i should have { DE,ch}.
then i want another  view, preferably with the help of functions , to show me these results, the first view should be used , not the main table , to create this view.
de,fr,1
de,pl,1
de,ru,2
de,lu,2
de,lu,3
it means between these countries, we have these amount of bordes, but we just want to see these up to 3 borders, not more.
thank you for you answers.
im using oracle 10 g and linux ubuntu 12.
First i have a table,illustrating the countries
{code}
--  File created - Sunday-November-24-2013 
--  DDL for Table BORDERS
  CREATE TABLE "borders" ("COUNTRY1" CHAR(2), "COUNTRY2" CHAR(2), "LENGTH" NUMBER)
REM INSERTING into borders
SET DEFINE OFF;
Insert into borders (COUNTRY1,COUNTRY2,LENGTH) values ('de','fr',381);
Insert into borders (COUNTRY1,COUNTRY2,LENGTH) values ('de','ch',494);
Insert into borders (COUNTRY1,COUNTRY2,LENGTH) values ('de','pl',148);
Insert into borders (COUNTRY1,COUNTRY2,LENGTH) values ('ch','fr',608);
Insert into borders (COUNTRY1,COUNTRY2,LENGTH) values ('ch','it',318);
Insert into borders (COUNTRY1,COUNTRY2,LENGTH) values ('ch','li',240);
Insert into borders (COUNTRY1,COUNTRY2,LENGTH) values ('it','si',306);
Insert into borders (COUNTRY1,COUNTRY2,LENGTH) values ('it','sm',584);
Insert into borders (COUNTRY1,COUNTRY2,LENGTH) values ('fr','lu',549);
Insert into borders (COUNTRY1,COUNTRY2,LENGTH) values ('fr','de',1000);
Insert into borders (COUNTRY1,COUNTRY2,LENGTH) values ('pl','ru',628);
Insert into borders (COUNTRY1,COUNTRY2,LENGTH) values ('pl','sk',126);
Insert into borders (COUNTRY1,COUNTRY2,LENGTH) values ('ru','ua',1800);
{code}
and then i have a view to have symmetric data :
{code}
SELECT B.COUNTRY1 , B.COUNTRY2
  FROM BORDERS B
  UNION
  SELECT B.COUNTRY2 , B.COUNTRY1
  FROM BORDERS B
{code}

Answer 1

Something like this will be a good starting point...
col path format A60
> with t as (
select country1, country2, level lvl , length , SYS_CONNECT_BY_PATH(country2, '/') "Path"from borders
start with country1 = 'de' connect by nocycle country1 = prior country2  )
select * from t  where lvl < 4 ;
COUNTRY1 COUNTRY2        LVL     LENGTH Path                                                      
de       ch                1        494 /ch                                                         
ch       fr                2        608 /ch/fr                                                      
fr       de                3       1000 /ch/fr/de                                                   
fr       lu                3        549 /ch/fr/lu                                                   
ch       it                2        318 /ch/it                                                      
it       si                3        306 /ch/it/si                                                   
it       sm                3        584 /ch/it/sm                                                   
ch       li                2        240 /ch/li                                                      
de       fr                1        381 /fr                                                         
fr       de                2       1000 /fr/de                                                      
de       ch                3        494 /fr/de/ch                                                   
de       pl                3        148 /fr/de/pl                                                   
fr       lu                2        549 /fr/lu                                                      
de       pl                1        148 /pl                                                         
pl       ru                2        628 /pl/ru                                                      
ru       ua                3       1800 /pl/ru/ua                                                   
pl       sk                2        126 /pl/sk                                                      
17 rows selected
VR,
Sudhakar