php+mysql不用递归实现的无限级分类实例(非递归)

<?php   $sql=”SELECT * FROM tree order by path”;  $result=$nbs->Query($sql);  while($rows=$nbs->fetch_array($result)){    if(substr_count($rows['path'],',')>2){      for($i=0;$i<(substr_count($rows['path'],',')-2);$i++)        echo ‘ ‘;    }    echo $rows['class_name'].'<br>';  }  ?>  $conn = mysql_connect ( 'localhost', 'root', 'root' );mysql_select_db ( 'wanggou123', $conn );mysql_query ( 'set names UTF8' );$sql = "select id,concat(catpath,'-',id) as abspath,name from category order by abspath"; $query = mysql_query ( $sql );while ( $row=mysql_fetch_array($query)) {  /**  * 第一种展示方法*//*$space = str_repeat ( '    ', count ( explode ( '-', $row ['abspath'] ) ) - 1 );echo $space . $row ['name'] . '';*//** 第二种展示方法*/$space = str_repeat ( '――', count ( explode ( '-', $row ['abspath'] ) ) - 1 );$option .= '' . $space . $row ['name'] . '<Br>';}echo $option;exit();echo '<select name="opt">' . $option . '</select>';