Herself's Webtools

While there has been Much ado over nothing at Slashdot, to upgrade or not is the question now for WordPress users.

Myself I am holding off. All plugins that use categories are now broken. Why WordPress didn’t make things backwards compatible I am not sure? Until I, or someone else, re-writes the plugins I use that work with categories. I won’t be upgrading. ( I’m hoping to rewrite several this weekend. Check back next week. )
I strongly suggest you do a test upgrade on your home computer, test your plugins, template etc before upgrading on your webhost.

Old Tables:
wp_post2cat: post_id, category_id
wp_categories: cat_ID, cat_name

New Tables:
wp_term_relationship: object_id, term_taxonomy_id
wp_term_taxonomy: term_taxonomy_id, term_id, taxonomy, description, parent, count
wp_terms: term_id, name, slug, term_group

Before to get category names from a post you went from post2cat->category_id and matched it to wp_categories->cat_ID and grabbed the name.

Now to get category names from a post you go from wp_term_relationship->term_taxonomy_id and match it to wp_term_taxonomy->term_taxonomy_id and fetch term_id after which you must then go to wp_terms match term_id and fetch the name.

So dust off those MySQL books if you have plugins that need fixing.