How to delete "" visits from database?

Hi at all,

I have now updated to the newest Version of piwik, so the Referrer Spam shall not be shown in my statistics from now.

But how I get rid of the whole spam entries from the last year of “”, “” in my database?
Is there a SQL Statement which I can enter in my phpmyadmin?

Thanks for your help.

I’ve updated a couple of old Piwiks and d’like to delete the referer-spam from database too…

I’d also like to know how to do this. In general, how to delete “wrong” entries from the database?