$parents_str = implode(', ', $parents_arr);
$r = q("SELECT %s FROM `item` %s
WHERE %s AND `item`.`uid` = %d AND `item`.`parent` IN (%s)
$sql_extra
ORDER BY `parent` DESC, `gravity` ASC, `item`.`id` ASC ",
$parents_str = implode(', ', $parents_arr);
$r = q("SELECT %s FROM `item` %s
WHERE %s AND `item`.`uid` = %d AND `item`.`parent` IN (%s)
$sql_extra
ORDER BY `parent` DESC, `gravity` ASC, `item`.`id` ASC ",