我有3套下拉列表。当我选择最后一个下拉列表时，我正在尝试显示mysql表。所有示例仅显示一个下拉列表。非常感谢帮助!! 提前致谢。 ：）
这是我的ajax代码：
<script type="text/javascript">
function ajaxFunction()
{
var httpxml;
try
{
// Firefox, Opera 8.0+, Safari
httpxml=new XMLHttpRequest();
}
catch (e)
{
// Internet Explorer
try
{
httpxml=new ActiveXObject("Msxml2.XMLHTTP");
}
catch (e)
{
try
{
httpxml=new ActiveXObject("Microsoft.XMLHTTP");
}
catch (e)
{
alert("Your browser does not support AJAX!");
return false;
}
}
}
function stateChanged()
{
if(httpxml.readyState==4)
{
//alert(httpxml.responseText);
var myObject = JSON.parse(httpxml.responseText);
for(j=document.myForm.PTT.options.length-1;j>=0;j--)
{
document.myForm.PTT.remove(j);
}
var PTT1=myObject.value.PTT1; // ptt1 remove change to PTT only.
//var optn = document.createElement("OPTION");
//optn.text = 'Select PTT';
//optn.value = '';
document.myForm.PTT.options.add(optn);
for (i=0;i<myObject.PTT.length;i++)
{
var optn = document.createElement("OPTION");
optn.text = myObject.PTT[i];
optn.value = myObject.PTT[i];
document.myForm.PTT.options.add(optn);
if(optn.value==PTT1){
var k= i+1;
document.myForm.PTT.options[k].selected=true;
}
}
//////////////////////////
for(j=document.myForm.EXT.options.length-1;j>=0;j--)
{
document.myForm.EXT.remove(j);
}
var EXT1=myObject.value.EXT1;
//alert(city1);
for (i=0;i<myObject.EXT.length;i++)
{
var optn = document.createElement("OPTION");
optn.text = myObject.EXT[i];
optn.value = myObject.EXT[i];
document.myForm.EXT.options.add(optn);
if(optn.value==EXT1){
document.myForm.EXT.options[i].selected=true;
}
}
///////////////////////////
document.getElementById("txtHint").style.background='#00f040';
document.getElementById("txtHint").innerHTML='done';
//setTimeout("document.getElementById('txtHint').style.display='none'",3000)
}
}
var url="checking2.php";
var REGION=myForm.REGION.value;
if(choice != 's1'){
var PTT=myForm.PTT.value;
var EXT=myForm.EXT.value;
}else{
var PTT='';
var EXT='';
}
url=url+"?REGION="+REGION;
url=url+"&PTT="+PTT;
url=url+"&EXT="+EXT;
//url=url+"&id="+Math.random();
myForm.st.value=PTT;
//alert(url);
document.getElementById("txtHint2").innerHTML=url;
httpxml.onreadystatechange=stateChanged;
httpxml.open("GET",url,true);
httpxml.send(null);
document.getElementById("txtHint").innerHTML="Please Wait....";
document.getElementById("txtHint").style.background='#f1f1f1';
}
</script>
//这是html代码
<div id="txtHint" style="width : 100px;background-color: #cccc33;">Message area</div>
<br><br>
<form name="myForm" action='details.php' method='post'">
<input type=hidden name=st value=0>
<table width=500>
//use this function to collect the value of region from table.
<tr><td >
Select Region:<br><select name=REGION id='s1' onchange=ajaxFunction('s1');>
<option value=''>Select One</option>
<?Php
require "config2.php";// connection to database
$sql="select distinct REGION from all_exchangelist ";
foreach ($dbo->query($sql) as $row) {
echo "<option value=$row[REGION]>$row[REGION]</option>";
}
?>
</select>
</td><td ><select name=PTT onchange=ajaxFunction('s2')>
<option value=''>Select One</option></select></td>
<td ><select name=EXT onchange=ajaxFunction('s3')>
<option value=''>Select One</option></select></td>
</tr></tr>
<tr><td colspan=3><input type=submit value='Submit'></td></tr>
</form>
</table>
<br><br>
<div id="txtHint2"></div>
这是用于验证html和ajax代码：
<?Php
include "config2.php"; // connection details
error_reporting(0);// With this no error reporting will be there
//////////
/////////////////////////////////////////////////////////////////////////////
$REGION=$_GET['REGION'];//
$PTT1=$_GET['PTT'];
$EXT1=$_GET['EXT'];
///////////// Validate the inputs ////////////
if((strlen($REGION)) > 0 and (!ctype_alpha($REGION))){
echo "Data Error";
exit;
}
// Checking ptt variable (with space ) ///
if ((strlen($PTT1)) > 0 and ctype_alpha(str_replace(' ', '', $PTT1)) === false) {
echo "Data Error";
exit;
}
/////////// end of input validation //////
if(strlen($REGION) > 0){
$q_REGION="select distinct(PTT) from all_exchangelist where REGION = '$REGION'";
}else{
$q_REGION="select distinct(PTT) from all_exchangelist";
}
//echo $q_region;
$sth = $dbo->prepare($q_REGION);
$sth->execute();
$PTT = $sth->fetchAll(PDO::FETCH_COLUMN);
$q_PTT="select distinct(EXT) from all_exchangelist where ";
if(strlen($REGION) > 0){
$q_PTT= $q_PTT . " REGION = '$REGION' ";
}
if(strlen($PTT1) > 0){$q_PTT= $q_PTT . " and PTT='$PTT1'";}
$sth = $dbo->prepare($q_PTT);
$sth->execute();
$EXT = $sth->fetchAll(PDO::FETCH_COLUMN);
$main = array('PTT'=>$PTT,'EXT'=>$EXT,'value'=>array("PTT1"=>"$PTT1","EXT1"=>"$EXT1"));
echo json_encode($main);
?>
答案 0 :(得分：0)
@php_purest如果我改变编码变成这样？如何检索表？顺便说一下，我的连接速度很慢，所以我无法观看youtube。
<?php
require "config2.php"; // Your Database details
?>
<!doctype html public "-//w3c//dtd html 3.2//en">
<html>
<head>
<title></title>
<meta name="GENERATOR" content="Arachnophilia 4.0">
<meta name="FORMATTER" content="Arachnophilia 4.0">
<SCRIPT language=JavaScript>
function reload(form)
{
var value=form.REGION.options[form.REGION.options.selectedIndex].value;
self.location='threelist.php?REGION=' + value ;
}
function reload3(form)
{
var value=form.REGION.options[form.REGION.options.selectedIndex].value;
var value2=form.PTT.options[form.PTT.options.selectedIndex].value;
self.location='threelist.php?REGION=' + value + '&PTT=' + value2 ;
}
</script>
</head>
<body>
<?Php
///////// Getting the data from Mysql table for first list box//////////
$query2="SELECT DISTINCT REGION FROM all_exchangelist";
///////////// End of query for first list box////////////
/////// for second drop down list we will check if category is selected else we will display all the subcategory/////
$REGION=$_GET['REGION']; // This line is added to take care if your global variable is off
if(isset($PTT) and strlen($PTT) > 0)
{
$query="SELECT DISTINCT PTT FROM all_exchangelist where PTT=$REGION";
}else{$query="SELECT DISTINCT PTT FROM all_exchangelist"; }
////////// end of query for second subcategory drop down list box ///////////////////////////
/////// for Third drop down list we will check if sub category is selected else we will display all the subcategory3/////
$PTT=$_GET['PTT']; // This line is added to take care if your global variable is off
if(isset($EXT) and strlen($EXT) > 0){
$query3="SELECT DISTINCT EXT FROM all_exchangelist where EXT=$PTT";
}else{$query3="SELECT DISTINCT EXT FROM all_exchangelist"; }
////////// end of query for third subcategory drop down list box ///////////////////////////
echo "<form method=post name=f1 action='threelistcheck.php'>";
////////// Starting of first drop downlist /////////
echo "<select name='REGION' onchange=\"reload(this.form)\">
<option value=''>Select one</option>";
foreach ($dbo->query($query2) as $noticia2)
{
if($noticia2['REGION']==@$REGION)
{
echo "<option selected value='$noticia2[REGION]'>$noticia2[REGION]</option>"."<BR>";
}
else
{
echo "<option value='$noticia2[REGION]'>$noticia2[REGION]</option>";
}
}
echo "</select>";
////////////////// This will end the first drop down list ///////////
////////// Starting of second drop downlist /////////
echo "<select name='PTT' onchange=\"reload3(this.form)\">
<option value=''>Select one</option>";
foreach ($dbo->query($query) as $noticia)
{
if($noticia['PTT']==@$PTT)
{
echo "<option selected value='$noticia[PTT]'>$noticia[PTT]</option>"."<BR>";
}
else
{
echo "<option value='$noticia[PTT]'>$noticia[PTT]</option>";}
}
echo "</select>";
////////////////// This will end the second drop down list ///////////
////////// Starting of third drop downlist /////////
echo "<select name='EXT' ><option value=''>Select one</option>";
foreach ($dbo->query($query3) as $noticia)
{
echo "<option value='$noticia[EXT]'>$noticia[EXT]</option>";
}
echo "</select>";
////////////////// This will end the third drop down list ///////////
echo "<input type=submit value='Submit the form data'></form>";
?>
<br><br>
<a href=threelist.php>Reset and Try again</a>
</body>
</html>