3使用Ajax MySQL的Downs Downs链
[英]3 Drop Downs chain using ajax mysql
问题描述
I have 3 Pages Index.php findasset.php and findid.php. 
我有3页Index.php findasset.php和findid.php。 I have 2 dropdowns and the last value will be echo out to another part of the page. 我有2个下拉菜单，最后一个值将回显到页面的另一部分。 I am using ajax to query the other dropdowns and it is partially working. 我正在使用ajax来查询其他下拉菜单，并且它部分起作用。
Most of it is dynamic and working besides device_category_name='$cId' on the findid page which should be replaced with $category but I wanted to show code as a working model. 除了在findid页面上的device_category_name ='$ cId'之外，大多数代码都是动态的并且可以正常工作，应该将其替换为$ category，但我想将代码显示为有效的模型。 I think the original start of my problem is on findasset page $category= isset($_GET['category']); 我认为问题的最初开始是在findasset页上$ category = isset（$ _ GET ['category']）;
When I try to echo out the variable on findid it echoes a "1" and not the word 当我尝试在findid上回显变量时，它回显“ 1”而不是单词
The index page has a dropdown pulled from mysql database that is working just fine. 索引页面上有一个从mysql数据库中拉出的下拉列表，它运行正常。 I have tagged the code as best as I could describe. 正如我所描述的，我已将代码标记为最佳。 Here is partially Working example . 这是部分工作示例 。 If you select Category-Drawing then either of the Assets it works, but it is because of on the findid page the query is partically hard coded and I dont want it to be hardcoded. 如果选择Category-Drawing，则可以使用任何一种资产，但这是因为在findid页面上查询是部分硬编码的，因此我不希望对其进行硬编码。
I know, I am so close to getting this figured out but I am stuck. 我知道，我很想弄明白这一点，但我被困住了。 Could you help me out? 你能帮我吗？
Index.php Index.php
function getXMLHTTP() { //function to return the xml http object
var xmlhttp=false;
try{
xmlhttp=new XMLHttpRequest();
}
catch(e) {
try{
xmlhttp= new ActiveXObject("Microsoft.XMLHTTP");
}
catch(e){
try{
xmlhttp = new ActiveXObject("Msxml2.XMLHTTP");
}
catch(e1){
xmlhttp=false;
}
}
}
return xmlhttp;
}
function getcategory(category) {
var strURL="findasset.php?category="+category;
var req = getXMLHTTP();
if (req) {
req.onreadystatechange = function() {
if (req.readyState == 4) {
// only if "OK"
if (req.status == 200) {
document.getElementById('assetdiv').innerHTML=req.responseText;
} else {
alert("There was a problem while using XMLHTTP:\n" + req.statusText);
}
}
}
req.open("GET", strURL, true);
req.send(null);
}
}
function getid(category,asset) {
var strURL="findid.php?category="+category+"&asset="+asset;
var req = getXMLHTTP();
if (req) {
req.onreadystatechange = function() {
if (req.readyState == 4) {
// only if "OK"
if (req.status == 200) {
document.getElementById('iddiv').innerHTML=req.responseText;
} else {
alert("There was a problem while using XMLHTTP:\n" + req.statusText);
}
}
}
req.open("GET", strURL, true);
req.send(null);
}
}
</script>
</head>
<body>
<form method="post" action="" name="form1">
<table width="60%" border="0" cellspacing="0" cellpadding="0">
<tr>
<td width="150">Category</td>
<td width="150"><select name="category" onChange="getcategory(this.value)">
<?
require "config.php";// connection to database
$query = "SELECT DISTINCT device_category_name FROM fgen_structures ORDER BY device_category_name ASC";
$result = mysql_query($query);
while ($myrow = mysql_fetch_array($result))
{
echo "<option value='$myrow[device_category_name]'>$myrow[device_category_name]</option>";
}
?>
</select></td>
</tr>
<tr style="">
<td>Asset</td>
<td ><div id="assetdiv"><select name="asset" >
<option>Select Category First</option>
</select></div></td>
</tr>
<tr style="">
<td>ID</td>
<td ><div id="iddiv"></div></td>
</tr>
<tr>
<td> </td>
<td> </td>
</tr>
<tr>
<td> </td>
<td> </td>
</tr>
</table>
</form>
</body>
</html>
findasset.php findasset.php
$category= isset($_GET['category']);// Could be the Start of the PROBLEM
$cate=$_GET['category'];
require "config.php";// connection to database
$query="SELECT * FROM fgen_structures WHERE device_category_name='$cate'";
$result=mysql_query($query);
?>
<select name="asset" onchange="getid(<?=$category;?>,this.value)">
<option>Select State</option>
<? while($row=mysql_fetch_array($result)) { ?>
<option value=<? echo $row['device_type_name'];?>><? echo $row['device_type_name'];?></option>
<? } ?>
</select>
findid.php findid.php
<?
$category=isset($_GET['category']); // This is where I think the problem is as well!!!!
$asset=isset($_GET['asset']);
$cate=$_GET['category'];
$assets=$_GET['asset'];
$cId='Drawing'; //If Hard Coded works
require "config.php";// connection to database
$query="SELECT * FROM fgen_structures WHERE device_category_name='$cId' AND device_type_name='$assets'"; // Currently hardcoded with $cid and it works but I need it dynamic with $cate or $category
$result=mysql_query($query);
while($row=mysql_fetch_array($result)) {
echo $row['fgen_structure_id'];
//echo $category; // This displays a 1 ??
} ?>
1 个解决方案
解决方案1
0 2013-06-14 21:58:19
I think your problem is, you don't understand what "isset()" is doing: 我认为您的问题是，您不了解“ isset（）”在做什么：
$category=isset($_GET['category']);
http://php.net/isset determines weither a variable or an index exists (and is not NULL), the return value of isset is boolean, this mean either true or false. http://php.net/isset确定是否存在变量或索引（且不为NULL），isset的返回值为boolean，表示true或false。 In your case it seems to be true, because your echo shows an 1. 在您的情况下，这似乎是正确的，因为您的回声显示为1。
I think you try to do this: 我认为您尝试这样做：
$category=isset($_GET['category']) ? $_GET['category'] : null;
On the other hand, you have heavy security issues in your code 另一方面，您的代码中存在严重的安全性问题
$query="SELECT * FROM fgen_structures WHERE device_category_name='$cId' AND device_type_name='$assets'";
You can't just use $assets unfiltered. 您不能只使用未过滤的$ assets。 Please google for SQL Injection for more informations. 请谷歌的SQL注入更多的信息。
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