无限分类原理

<?php

mysql_connect("localhost","root","root");

mysql_select_db("test");

mysql_query("set names gb2312");

function select($fid,$kong){

$query=mysql_query("select *
from class where class_id_father='$fid' order by class_id
asc");//------------------------------------ 查询$fid的儿子分类

while($arr=mysql_fetch_array($query)){

echo
"<option
value=\"".$arr[class_id]."\">";

for($i=0;$i<$kong;$i++){//------------------------------------根据$kong输出选项前面的空格.$kong控制子父分类的缩进

echo
"  ";

}

$he=$kong;

$kong++;

echo
"┗".$arr[class_name];

echo
"</option>";

select($arr[class_id],$kong);//------------------------------------递归查询此类的儿子分类

$kong=$he;//------------------------------------同级的儿子分类查询完后做这句，将$kong还原到此同级分类前使用的值

}

}

if($_POST['add']!=""){

if(mysql_query("insert into
class (class_name,class_id_father) values
('$_POST[class_name]','$_POST[class_id]')"))

echo
"<script>alert('恭喜，分类添加成功！！');window.location.href='./wxfl.php';</script>";

}

?>

<form name="form_class" action=""
method="post">

添加分类  

<select name="class_id"
style="width:200px;">

<option
vlaue="0"
selected="selected">顶层分类</option>

<?php
select(0,0); ?>

</select>

  

<input
type="text" name="class_name" />

  

<input
type="submit" name="add" value="添加分类">

</form>

<?php

function
all($fid,$kong){//------------------------------------------------------------以下为输出列表，和上面的有一点不同，但原理都一样

$query=mysql_query("select *
from class where class_id_father='$fid' order by class_id
asc");

while($arr=mysql_fetch_array($query)){

for($i=0;$i<$kong;$i++){

echo
"  ";

}

$he=$kong;

$kong++;

echo
"┗".$arr[class_name]."  <a
href='?id=".$arr[class_id]."'>修改</a>  <a
href='?id=".$arr[class_id]."'>删除</a><hr>";

all($arr[class_id],$kong);

$kong=$he;

}

}

all(0,0);

?>