Walking through a mysql db

[Jeff Elkins]

I'm writing a small wxpython app to display and update a dataset. So far, I 
get the first record for display:

 try:
      cursor = conn.cursor ()
      cursor.execute ("SELECT * FROM dataset")
      item = cursor.fetchone ()

Now, how do I step through the dataset one row at a time?  My form has  'next' 
and 'back' buttons, and I'd like them to step forward or back, fetching the 
appropriate row in the table. I've tried setting cursor.rownumber by 
incrementing it prior to the fetchone() w/o effect.

Thanks for any pointers.

Jeff Elkins