mysql recursive catalog tree

    $result = mysql_query("SELECT * FROM test");
    $arrs = array();

    while ($row = mysql_fetch_array($result, MYSQL_ASSOC)) {
        $arrs[] = $row;
    }

    function build_tree($arrs, $parent_id=0, $level=0) {
        foreach ($arrs as $arr) {
            echo str_repeat("-", $level).$arr['name'];
            if ($arr['parent_id'] == $parent_id) {
                build_tree($arrs, $arr['id'], $level+1);
            }
        }
    }

    build_tree($arrs);