Home >Backend Development >PHP Tutorial >PHP implements three-level cascading drop-down box, _PHP tutorial

PHP implements three-level cascading drop-down box, _PHP tutorial

WBOYOriginal: 2016-07-12 08:53:55863browse

php implements three-level cascading drop-down box,

This is the information I found on the Internet about php implementing three-level cascading drop-down box. Share it with everyone and let us make progress together. , the specific content is as follows

index.php:

<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312">
<title>Ajax联动菜单</title>
<script language="javascript" type="text/javascript" src="aa.js"></script>
</head>
<body>
<form>
<label>
<select name="sel" id="sel" onChange="showMenu(this.value);">
 <option>一级分类</option>
<&#63;php
$conn = mysql_connect('localhost', 'root', '') or die('Could not connect: ' . mysql_error());
mysql_select_db('fitment', $conn) or die ('Can\'t use database : ' . mysql_error());
mysql_query("set names 'gb2312'");
$str = "SELECT * FROM `fitment_sort` where supid = '0' ORDER BY `id` ASC";
$result = mysql_query($str) or die("Invalid query: " . mysql_error());
if($result)   while ($arr = mysql_fetch_array($result)){
    echo <<<EOD
<option value={$arr["id"]}>{$arr["name"]}</option>
EOD; }
mysql_close($conn);
&#63;>
</select>
</label>
<label>
<select name="sel2" id="sel2" onChange="showMenu2(this.value)">
 <option>二级分类</option>
 </select>
</label>
<label>
<select name="sel3" id="sel3">
 <option>三级分类</option>
</select>
</label>
</form>
<input type=button value="send value" onClick="alert(document.getElementByIdx_x_xx_x_xx('sel').options[document.getElementByIdx_x_xx_x_xx('sel').selectedIndex].text + '-' + document.getElementByIdx_x_xx_x_xx('sel2').options[document.getElementByIdx_x_xx_x_xx('sel2').selectedIndex].text + '-' + document.getElementByIdx_x_xx_x_xx('sel3').options[document.getElementByIdx_x_xx_x_xx('sel3').selectedIndex].text)">
</body>
</html>

aa.js

<!--
var xmlHttp
var xmlHttp2
//函数showMenu(str) - 功能函数1
function showMenu(str) xmlHttp=GetXmlHttpObject()    //调用GetXmlHttpObject()函数，创建XMLHttpRequest对象
if (xmlHttp==null)        //如果创建失败，则 alert ("Browser does not support HTTP Request")
 return 
var url="get2.php"        //定义url , 其主要读取数据库
url=url+"&#63;q="+str
url=url+"&sid="+Math.random()  //Math对象的random方法，取随机数
xmlHttp.onreadystatechange=stateChanged //设置当XMLHttpRequest对象xmlHttp状态改变时调用的函数,注意函数名后不要添加小括号
xmlHttp.open("GET",url,true)  //使用XMLHttpRequest对象的open()方法 , 创建HTTP请求
xmlHttp.send(null)        //使用XMLHttpRequest对象的open()方法 , 发送HTTP请求
}
//函数showMenu(str) - 功能函数1
function showMenu2(str)
{
xmlHttp2=GetXmlHttpObject()    //调用GetXmlHttpObject()函数，创建XMLHttpRequest对象
if (xmlHttp2==null)        //如果创建失败，则 alert ("Browser does not support HTTP Request")
 return 
var url="get2.php"        //定义url , 其主要读取数据库
url=url+"&#63;q2="+str
url=url+"&sid="+Math.random()  //Math对象的random方法，取随机数
xmlHttp2.onreadystatechange=stateChanged2 //设置当XMLHttpRequest对象xmlHttp状态改变时调用的函数,注意函数名后不要添加小括号
xmlHttp2.open("GET",url,true)  //使用XMLHttpRequest对象的open()方法 , 创建HTTP请求
xmlHttp2.send(null)        //使用XMLHttpRequest对象的open()方法 , 发送HTTP请求
}
//函数BuildSel() , 根据返回的的字串 , 重新构建新的下拉菜单控件Select - 功能函数2
function BuildSel(str,sel)   //先清空原来的数据.
  sel.options.length=0;   var arrstr = new Array();   arrstr = str.split(",");
  if(str.length>0)      //循环
    for(var i=0;i<arrstr.length;i++)       var subarrstr=new Array();       subarrstr=arrstr[i].split("|");
      sel.options.add(new Option(subarrstr[1],subarrstr[0]));     sel.options[0].selected=true; }
//函数stateChanged() - 响应HTTP请求状态变化
function stateChanged() //判断XMLHttpRequest对象的readyState属性值是否为4,如果为4表示异步调用完成(注意:异步调用完成 不代表 异步调用成功)
if (xmlHttp.readyState==4 || xmlHttp.readyState=="complete") //如果异步调用成功 --> XMLHttpRequest对象的status属性值为200 , html文件在本地运行,则xmlHttp.status的返回值为0,故应该加上xmlHttp.status==0
 if(xmlHttp.status==200 || xmlHttp.status==0)     //调用文档对象模型DOM的getElementById()方法查找html文件中的标签txtHint ,
     //innerHTML为IE浏览器中的属性,可以用来更改标签间文本的内容 ,
     //xmlHttp.responseText , 通过XMLHttpRequest的responseText属性来获取数据 responseText,结果为字符串;responseXML,结果为XML形式
//     document.getElementByIdx_x_xx_x_xx("txtHint").innerHTML=xmlHttp.responseText
     BuildSel(xmlHttp.responseText,document.getElementsByTagName_r("*").sel2)
     showMenu2(document.getElementsByTagName_r("*").sel2.value); }
}
//函数stateChanged() - 响应HTTP请求状态变化
function stateChanged2() //判断XMLHttpRequest对象的readyState属性值是否为4,如果为4表示异步调用完成(注意:异步调用完成 不代表 异步调用成功)
if (xmlHttp2.readyState==4 || xmlHttp2.readyState=="complete") //如果异步调用成功 --> XMLHttpRequest对象的status属性值为200 , html文件在本地运行,则xmlHttp.status的返回值为0,故应该加上xmlHttp.status==0
 if(xmlHttp2.status==200 || xmlHttp2.status==0)     //调用文档对象模型DOM的getElementById()方法查找html文件中的标签txtHint ,
     //innerHTML为IE浏览器中的属性,可以用来更改标签间文本的内容 ,
     //xmlHttp.responseText , 通过XMLHttpRequest的responseText属性来获取数据 responseText,结果为字符串;responseXML,结果为XML形式
//     document.getElementByIdx_x_xx_x_xx("txtHint").innerHTML=xmlHttp.responseText
     BuildSel(xmlHttp2.responseText,document.getElementsByTagName_r("*").sel3) }
}
//函数GetXmlHttpObject() - 创建XMLHttpRequest对象,即创建一个异步调用对象
function GetXmlHttpObject() var xmlHttp=null;
try // Firefox, Opera 8.0+, Safari
 xmlHttp=new XMLHttpRequest(); catch (e) //Internet Explorer
 try  xmlHttp=new ActiveXObject("Msxml2.XMLHTTP"); catch (e)  xmlHttp=new ActiveXObject("Microsoft.XMLHTTP"); }
return xmlHttp; -->

get2.php

<&#63;php header('Content-Type:text/html;charset=GB2312'); $conn = mysql_connect('localhost', 'root', '') or die('Could not connect: ' . mysql_error());
mysql_select_db('fitment', $conn) or die ('Can\'t use database : ' . mysql_error());
mysql_query("set names 'gb2312'");
//如果传递过来q
if($_GET["q"]){
$strs = "SELECT * FROM fitment_sort WHERE supid=' ".$_GET["q"]."' ";
//echo $str;
$results = mysql_query($strs) or die("Invalid query: " . mysql_error());
if($results)   while ($arrs = mysql_fetch_array($results)){
    $strings .= $arrs["id"]."|".$arrs["name"].",";   }
  echo substr($strings,0,strlen($strings)-1); }
//如果传递过来q2
if($_GET["q2"]){
$str = "SELECT * FROM fitment_sort WHERE supid= '".$_GET["q2"]."'";
//echo $str;
$result = mysql_query($str) or die("Invalid query: " . mysql_error());
if($result)   while ($arr = mysql_fetch_array($result)){
    $string .= $arr["id"]."|".$arr["name"].",";   }   echo substr($string,0,strlen($string)-1); }
mysql_close($conn);
&#63;>

The above is the relevant code for implementing three-level cascading drop-down boxes in PHP. I hope it will be helpful for everyone to learn PHP programming.

Statement：

The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn

Previous article：ThinkPHP Detailed tutorial on connecting to Oracle database, thinkphporacle_PHP tutorialNext article：ThinkPHP Detailed tutorial on connecting to Oracle database, thinkphporacle_PHP tutorial

See more

PHP implements three-level cascading drop-down box, _PHP tutorial

php implements three-level cascading drop-down box,

Related articles