select wp_posts. *
from wp_posts
left join wp_postmeta on ( wp_posts.id = wp_postmeta.post_id )
where 1=1
and wp_posts.post_date < now()
group by wp_posts.id
order by wp_posts.post_date desc
limit 0, 30;

code from this topic:

SELECT g.group_id, COUNT(m.member_id) AS members
FROM groups AS g
LEFT JOIN group_members AS m USING(group_id)
GROUP BY g.group_id
HAVING members > 4