Q:

NOT EXISTS doesn't work

I have a table countries, and I want to display all the neighbouring countries to Sweden, and I got two problems.
My code is like this:
SELECT b.cntry_name
FROM countries as a
JOIN countries as b
ON ST_Distance(a.the_geom,b.the_geom)<10000
WHERE a.cntry_name='Sweden'
GROUP BY  b.cntry_name 

It returned a table looks like this:

I want to delete Sweden from this table, so I tried to use NOT EXISTS:
SELECT b.cntry_name
FROM countries as a
JOIN countries as b
ON ST_Distance(a.the_geom,b.the_geom)<10000
WHERE a.cntry_name='Sweden' AND NOT EXISTS(SELECT b.cntry_name FROM b WHERE b.cntry_name='Sweden')
GROUP BY b.cntry_name

However, this returned a blank webpage(I'm doing PostGIS online),which means there's something wrong in my code. 
So the first question is, how can I delete the row Sweden after the selection?
Same thing happened when I tried to add countries.svg after b.cntry_name:
SELECT b.cntry_name,countries.svg
FROM countries as a
JOIN countries as b
ON ST_Distance(a.the_geom,b.the_geom)<10000
WHERE a.cntry_name='Sweden'
GROUP BY  b.cntry_name 

This also returned a blank webpage. Any tips where I went wrong when tried to display svg?

A:

No need for NOT EXISTS:
SELECT b.cntry_name
FROM countries as a
JOIN countries as b
ON ST_Distance(a.the_geom,b.the_geom)<10000
WHERE a.cntry_name='Sweden'
  AND a.cntry_name <> b.cntry_name
--GROUP BY  b.cntry_name -- should work without GROUP BY

