Updating a filename's counter value failed each time

[Simpleton]

Hello again, something simple this time:

After a user selects a file from the form, that sleection of his can be 
found form reading the variable 'filename'

If the filename already exists in to the database i want to update its 
counter and that is what i'm trying to accomplish by:

-----------
if form.getvalue('filename'):
	cur.execute('''UPDATE files SET hits = hits + 1, host = %s, lastvisit = 
%s WHERE url = %s''', (host, lastvisit, filename) )
-----------

For some reason this never return any data, because for troubleshooting 
i have tried:

-----------------
data = cur.fetchone()

if data:
	print("something been returned out of this"_
----------------

Since for sure the filename the user selected is represented by a record 
inside 'files' table why its corresponding counter never seems to get 
updated?

Thank you.
-- 
What is now proved was at first only imagined!