[WordPress] 複数のタームを持つ投稿の関連記事を取得する

SQL
SELECT
    p2.*
FROM
    wp_posts p2
    INNER JOIN (
        SELECT
            p.ID
        FROM
            wp_posts p
            INNER JOIN wp_term_relationships tr
            ON p.ID = tr.object_id
            INNER JOIN wp_term_taxonomy tt
            ON tr.term_taxonomy_id = tt.term_taxonomy_id
        WHERE
            tt.term_id IN(4, 13, 21) -- 対象の投稿に紐づいたタームID
            AND p.post_type = 'post'
            AND p.post_status = 'publish'
            AND p.ID <> 1234 -- 対象の投稿を除外
        GROUP BY
            p.ID,
            p.menu_order
        ORDER BY
            COUNT(p.ID) DESC,
            p.menu_order
        LIMIT 6
    ) p3
    ON p2.ID = p3.ID
ORDER BY
    p2.menu_order

SQL
SELECT
    p2.*
FROM
    wp_posts p2
WHERE
    p2.ID IN (
        SELECT
            p.ID
        FROM
            wp_posts p
            INNER JOIN wp_term_relationships tr
            ON p.ID = tr.object_id
            INNER JOIN wp_term_taxonomy tt
            ON tr.term_taxonomy_id = tt.term_taxonomy_id
        WHERE
            tt.term_id IN(4, 13, 21) -- 対象の投稿に紐づいたタームID
            AND p.post_type = 'photo'
            AND p.post_status = 'publish'
            AND p.ID <> 1234 -- 対象の投稿を除外
        GROUP BY
            p.ID,
            p.menu_order
        ORDER BY
            COUNT(p.ID) DESC,
            p.menu_order
        LIMIT 6
    )
ORDER BY
    p2.menu_order