Is there a way for me to get a pseudo-ID of a post from the category it belongs to? Let's say I have these posts post_id | post_title | post_cat --------+------------+--------- 0 | a post | cat1 1 | a post1 | cat2 2 | a post2 | cat1 3 | a post3 | cat2 ... 57 | a post57 | cat2 I want the posts from cat2 and the posts' ids to be relative to the category they were posted in. Something like post_id | post_title | post_cat | cat_post_id --------+------------+----------+-------- 1 | a post1 | cat2 | 1 3 | a post3 | cat2 | 2 57 | a post57 | cat2 | 3