Renumbering Categories in WordPress Blogs

There are some situations you may want to manually change (or hack) the category numbers of your WordPress.org blog. Here is how.

Supose you have posts category named “Wine” with ID 15 and you want it to become 1015. You probably already have some posts categorized as “Wine” too and you want to make the number change reflect in their metainformation.

You’ll have to execute some SQL commands in 2 tables: wp_categories and wp_post2cat. Have access to WordPress.org blog MySQL database with PHPMyAdmin or even the plain mysql command and execute this steps.

1. Don’t trust your eyes or memory because if you forget something or mistype a number, you will make a mess in your blog database. Write in a paper a note for yourself with the category name, previous ID and new desired ID:

   Wine: 15 ➔ 1015

2. Change the category number from 15 to 1015 in the master categories table:

   UPDATE wp_categories SET cat_ID=1015 WHERE cat_ID=15 LIMIT 1;

3. Renumber all posts categorized as 15 (old Wine category number) to 1015 (new category number) in the posts metadata table:

   UPDATE wp_post2cat SET category_id=1015 WHERE category_id=15;

4. WordPress.org also uses the same wp_categories table to classify the links on your blogroll (or sidebar), so you’ll have to change the records associated with the Wine category too, if some:

   UPDATE wp_link2cat SET category_id=1015 WHERE category_id=15;

There is no visual change for the readers of your blog, everything will look the same. This is only for you, if you want to organize categories in ranges while WordPress.org naturally creates them in a sequence.