How to delete spam comments from wordpress
Once you put a blog up you will be the target of many link spammers looking for link juice. You can add a series of plugins to prevent them from clogging your database
but if you’re lazy like me you can delete them once in a while using a simple sql query:
DELETE FROM wp_comments WHERE comment_approved=0;
This deletes all unapproved comments, not necessarily all of them being spam.