Question

Notice the nested subqueries. I know there’s a better way to make this happen with a JOIN. I just don’t have the expertise to figure it out.

SELECT DISTINCT pm.post_id 
FROM wp_3_postmeta pm
WHERE pm.meta_key LIKE 'member_categories_%_member_categories_name'
AND pm.meta_value IN(
    SELECT tt.term_taxonomy_id
    FROM wp_3_term_taxonomy tt
    WHERE tt.parent IN(
        SELECT tt.term_taxonomy_id
        FROM wp_3_term_taxonomy tt
        WHERE tt.parent = 33)
    OR tt.parent = 33
);

Thanks for your help!

Answer 1

This should do the trick for you

SELECT DISTINCT pm.post_id 
FROM wp_3_postmeta pm
     INNER JOIN wp_3_term_taxonomy tt ON pm.meta_value = tt.term_taxonomy_id
     LEFT JOIN wp_3_term_taxonomy tt2 ON tt.parent = tt2.term_taxonomy_id
WHERE pm.meta_key LIKE 'member_categories_%_member_categories_name'
   AND (tt.parent = 33 OR tt2.parent = 33)