nested category

tree_menu.php

<?
$con = mysql_connect('localhost', 'root', '') or die('Erro ao conectar no banco de dados.');
$base = mysql_select_db('test');

// listando as categorias
$sql_tree = "SELECT node.category_id, CONCAT( REPEAT( '_', (COUNT(parent.name) - 1) ), node.name) AS name
             FROM nested_category AS node,
                    nested_category AS parent
             WHERE node.lft BETWEEN parent.lft AND parent.rgt
             GROUP BY node.name
             ORDER BY node.lft";
$exe_tree = mysql_query($sql_tree, $con) or die(mysql_error());
$num_tree = mysql_num_rows($exe_tree);
if ($num_tree > 0){
    echo "<ul>";
    while ($reg_tree = mysql_fetch_array($exe_tree, MYSQLI_ASSOC)){
        $n_level = substr_count($reg_tree['name'], "_");
        echo "<li>".$reg_tree['category_id']." - ".$reg_tree['name']." - ".$n_level."</li>";  
    }
    echo "</ul>";
}
?>