SELECT date_available,
      COUNT(DISTINCT id) nb_elements,
      COUNT(DISTINCT category_id) nb_cats
  FROM phpwebgallery_images INNER JOIN phpwebgallery_image_category AS ic ON id=image_id
  WHERE 1 = 1
  GROUP BY date_available
  ORDER BY date_available DESC
  LIMIT 0,5
;
[mysql error 1146] Table 'royalfig.phpwebgallery_images' doesn't exist