A function written in PHP to recursively implement unlimited classification and generate drop-down lists

/*—————————————————— */
//– 递归实现无限分类生成下拉列表函数
//– $tpl->assign('sort_list',createSortOptions ());
//– $tpl->assign('sort_list',createSortOptions ($sort_id));
/*—————————————————— */
function createSortOptions ($selected=0,$parent_id=0,$n=-1)
{
global $db;
$sql = "SELECT * FROM `@__article_sort` WHERE `parent_id` = '{$parent_id}'";
$options = ";
static $i = 0;
if ($i == 0)
{
$options .= 'if ($row['sort_id'] == $selected)
{
$options .=' selected ';
}
$options .=">".str_repeat(' ',$n*3).$row['sort_name']."n";
$options .=createSortOptions ($selected,$row['sort_id'],$n);
}
}
return $options;
}
?>