UPDATE `chv_stats` SET
stat_images = (SELECT IFNULL(COUNT(*),0) FROM `chv_images`),
stat_albums = (SELECT IFNULL(COUNT(*),0) FROM `chv_albums`),
stat_users = (SELECT IFNULL(COUNT(*),0) FROM `chv_users`),
stat_image_views = (SELECT IFNULL(SUM(image_views),0) FROM `chv_images`),
stat_disk_used = (SELECT IFNULL(SUM(image_size) + SUM(image_thumb_size) + SUM(image_medium_size),0) FROM `chv_images`)
WHERE stat_type = "total";