JOIN query for retrieving the last post from specific categories

Hello to everyone!

I have the following code for WordPress:

SELECT terms.*, posts.ID as post_ID
FROM wp_terms terms
JOIN wp_term_taxonomy term_taxonomy
    ON terms.term_id = term_taxonomy.term_id
JOIN wp_term_relationships term_relationships
    ON ( term_relationships.term_taxonomy_id = term_taxonomy.term_taxonomy_id
        AND term_taxonomy.taxonomy = 'category' )
JOIN wp_posts posts
    ON ( posts.ID = term_relationships.object_id
        AND posts.post_type='post'
        AND posts.post_status='publish')
WHERE terms.term_id=19 OR terms.term_id=20 OR terms.term_id=21 OR terms.term_id=22
GROUP BY terms.term_id
ORDER BY posts.post_modified_gmt DESC

I want to retrieve the last post from specific categories. But it returns the first post of each category. What am I doing wrong?