def addAttendee(name, seminar, paid): # Fetch the number of places left cursor.execute('select places_left' ' from Seminars' ' where ID=%s' % (seminar),) (places_left, )=cursor.fetchone() # If there are no places left, raise exception if places_left==0: raise ValueError,'Out of room:#%i' %(seminar,) # Add a row to the Attendees table cursor.execute("insert into Attendees " "values (?,?,?)", (name, seminar, paid) ) # Decrease the places_left count of the selected # seminar cursor.execute("update Seminars set " "places_left=%i where ID=%s" % (places_left-1, seminar) ) # Commit the changes db.commit()