How to open comments

I am trying to open the comments on my blog. I used the MySQL query:

UPDATE wp_posts SET comment_status = 'open', ping_status = 'open' WHERE comment_status = 'closed';

When I log out of my blog and try to comment it still says that I need to be logged in to comment. do I need to do anything to the comments.php code on my blog as well? Any help on this would be greatly appreciated