无限极分类

$host = 'localhost';  
$db_user = 'root';
$db_pass = 'root';
$db_name = 'mst';  //数据库
$link = mysqli_connect($host, $db_user, $db_pass, $db_name);
mysqli_query($link,"SET names UTF8");
header("Content-Type:text/html;charset=utf-8");

function tree($link,&$tree_list = array(),$pid = 1,$count=0){
    $count+=2;
    $result = mysqli_query($link,"SELECT * FROM tree WHERE parent_id = {$pid}");
    while ($row = mysqli_fetch_assoc($result)) {
        $row['count'] = $count;
        $row['name'] = str_repeat(' ',$count).'|-'.$row['name'];
        $tree_list[] = $row;
        tree($link,$tree_list,$row['id'],$count);
    }
    return $tree_list;
}
$values = tree($link);
echo '<select name = "parent_id" id="">';
 foreach ($values as $key => $value) {
    echo '<option value="'.$value['id'].'">'.$value['name'].'</option>';
 }
echo '</select>';

数据库：mst 数据库表：tree ；

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