// Take the largest picture that is smaller or equal 640 pixels
$p = q("SELECT `scale` FROM `photo` WHERE `resource-id` = '%s' AND `height` <= 640 AND `width` <= 640 ORDER BY `resource-id`, `scale` LIMIT 1",
// Take the largest picture that is smaller or equal 640 pixels
$p = q("SELECT `scale` FROM `photo` WHERE `resource-id` = '%s' AND `height` <= 640 AND `width` <= 640 ORDER BY `resource-id`, `scale` LIMIT 1",