How to remove all uncategorized posts.

I have got about 20,000 uncategorized posts I really need to get rid off.
Specially for the function have_posts() – it returns posts from this category as well so I want badly to remove it.

I can do so by going to the 1,000 pages showing each 20 results and delete em all from the uncategorized category but that doesn’t seem too smart.

How could I possibly with phpmyadmin execute a query in there or with php to delete every single post that is in the category uncategorized.

Thanks