SELECT
 SUBSTR(a.name,1,41) AS Name,
 a.path,
 a.date, a.time,
 IF (b.size IS NULL,a.size / 1073741824,b.size / 1073741824) AS 'Size (G)',
 count(a.name) AS Count
FROM movie_ls_l AS a
LEFT JOIN movie_du_sb AS b
  ON (a.name = b.name
  AND a.system = b.system
  AND a.path = b.path)
GROUP BY a.name, 'Size (G)'
ORDER BY a.date DESC, a.time DESC;