Updating a filename's counter value failed each time

[Jens Thoms Toerring]

Νίκος <support at superhost.gr> wrote:
> On 17/6/2013 8:54 μμ, Jens Thoms Toerring wrote:
> > Also take care to check the filename you insert - a malicous
> > user might cobble together a file name that is actually a SQL
> > statement and then do nasty things to your database. I.e. never
> > insert values you received from a user without checking them.

> Yes in generally user iput validation is needed always, but here here 
> the filename being selected is from an html table list of filenames.

> But i take it you eman that someone might tried it to pass a bogus 
> "filename" value from the url like:

> http://superhost.gr/cgi-bin/files.py?filename="Select....."

> Si that what you mean?

Well, you neer wrote where this filename is coming from.
so all I could assume was that the user can enter a more
or less random file name. If he only can select one from
a list you put together there's probably less of a problem.

> But the comma inside the execute statement doesn't protect me from such 
> actions opposed when i was using a substitute operator?

> > I would guess because you forgot the uotes around string
> > values in your SQL statement which thus wasn't executed.

> i tried you suggestions:

> cur.execute('''UPDATE files SET hits = hits + 1, host = %s, lastvisit = 
> %s WHERE url = "%s"''', (host, lastvisit, filename) )

> seems the same as:

> cur.execute('''UPDATE files SET hits = hits + 1, host = %s, lastvisit = 
> %s WHERE url = %s''', (host, lastvisit, filename) )

> since everything is tripled quoted already what would the difference be 
> in "%s" opposed to plain %s ?

As I wrote you need *single* quotes around strings in
SQL statements. Double quotes won't do - this is SQL
and not Python so you're dealing with a different lan-
guage and thus different rules apply. The triple single
quotes are seen by Python, but SQL needs its own.

                        Regards, Jens
-- 
  \   Jens Thoms Toerring  ___      jt at toerring.de
   \__________________________      http://toerring.de