posts + categorie problem with child-child category

Hi.

I find a problem but didn’t have a solution. But i know now the problem and can solve it without child child categories.

The following problem with an example:

I have the categories:

AA (term_id: 1)
BB (term_id: 2)
-BBA (term_id: 3)
–BBAA (term_id: 4)
-BBB (term_id: 5)

I have a post with Category “AA” and “BBA”

So now i will show with shortcodes ultimate posts which are in the category AA and BBA. Tax Operator is AND.

Result: No posts found.

It takes me a while but i found the problem.

The final query for seraching the term_id looks like this:

SELECT term_id
FROM wp_XXXXX_term_taxonomy
WHERE taxonomy = 'category'
AND term_id IN (1,3,4)

The query wants to find posts with the child-child term_id: 4

So there is no post with the child-child term_id 4 and we have no results. If i delete the child-child category BBAA then then hole thing works. If you have more questions, please ask. I hope this report helps you and others to find a solution, if they ran into the same problem.