foo.sql

SELECT 
	s.article_id, 
	a.category,
	DATE(s.date_created) AS date_c, 
	COUNT(s.article_id) AS count 
FROM 
	warehouse_stockunit AS s, 
	warehouse_article AS a
WHERE
	s.article_id = a.id
GROUP BY 
	s.article_id, 
	date_c 
ORDER BY 
	date_c DESC