SELECT c.id_cat as cat,c.name, count(p.category) as nbre_post,p.crea_date
FROM frm_category as c
LEFT OUTER JOIN frm_post as p ON (c.id_cat = p.category)
WHERE c.id_parent=0
GROUP BY c.id_cat,c.name
ORDER BY c.id_cat,p.crea_date DESC;