I would like to select all categories of my blog with count and date of create. I know that I have to convert post_date to specific month and then group my select by month(date) and category. However I don't know how to get all categories via SQL. Here is example for one post. I get only basic information but nothing about category.
$querystr = " SELECT distinct $wpdb->posts.* FROM $wpdb->posts, $wpdb->postmeta WHERE $wpdb->posts.post_status = 'publish' AND $wpdb->posts.post_type = 'post' AND $wpdb->posts.post_date < NOW() AND $wpdb->posts.ID = 1 ORDER BY $wpdb->posts.post_date DESC "; $res = $wpdb->get_results($querystr, OBJECT);
The chellenge is to get category of posts via this query. I need to this that way because as a result I need to make an array of: date (as moth and year, format YYYYMM), category, count(*).