Javascript 基于另一个';s使用变量/函数选择
我有两个从数据库上的SQL查询生成的下拉列表。它们是:Javascript 基于另一个';s使用变量/函数选择,javascript,php,ajax,html-select,forms,Javascript,Php,Ajax,Html Select,Forms,我有两个从数据库上的SQL查询生成的下拉列表。它们是: <?php $conn = new mysqli('localhost', 'root', '', 'Rosters') or die ('Cannot connect to db'); $result = $conn->query("SELECT City, Name FROM Teams"); echo "<select name='Teams'>"; while ($row = $result->
<?php
$conn = new mysqli('localhost', 'root', '', 'Rosters')
or die ('Cannot connect to db');
$result = $conn->query("SELECT City, Name FROM Teams");
echo "<select name='Teams'>";
while ($row = $result->fetch_assoc()) {
unset($city, $team);
$city = $row['City'];
$name = $row['Name'];
$fullname = $city." ".$name;
echo '<option value="'.$fullname.'">'.$fullname.'</option>';
}
echo "</select>";
?>
及
第一个是NHL中的团队列表。第二张是该队球员的名单。我试图使第二个选项在第一个选项更改时更新(基于“选项”的“值”)。要使其工作,需要更新第二段代码中的$team变量。既然PHP是服务器端的,不能动态更新,我该怎么做呢?即使使用AJAX,答案似乎也不明显。我使用的方法完全是有缺陷的吗?您必须在第一个下拉列表的更改中使用ajax,并从ajax调用php文件,将数据从php文件返回到ajax并在第二个下拉列表中显示。首先,编写一个onchange事件处理程序,它使用ajax将“team”选项发送到服务器端,然后编写一个php来接收“team”选项,从数据库中检索播放器信息,然后将数据重新格式化为XML或json格式,发送到客户端 最后,编写一个javascript函数来解析服务器端响应并更新网页 这是解决问题的逻辑流程。你可以去谷歌搜索上面的关键字来获取示例代码 下面是一个简单的示例代码: HTML文件内容:
<html>
<head>
<title>PHP/Ajax update 2nd drop down box base on 1st drop down box value</title>
<script src="http://code.jquery.com/jquery-latest.js"></script>
<script language=javascript>
function updateData(v)
{
var value=v.options[v.selectedIndex].value;
$("#number").empty(); //empty "digit" drop down box
if (value!="") //Ensure no empty value is submitted to server side
{
jQuery.post("getResult.php","type="+value,updateNumber);
}
}
function updateNumber(data)
{
var numberData=jQuery.trim(data).split("\n");//split server side response by "\n"
var number=document.getElementById("number");
for (i=0;i<numberData.length;i++)
{
value=numberData[i].split("-")[0];//get value from server response
text=numberData[i].split("-")[1]; //get text from server response
option=new Option(text,value); //for better IE compatibility
number.options[i]=option;
}
}
</script>
</head>
<body>
<h1>PHP/Ajax update 2nd drop down box base on 1st drop down box value Demo</h1>
No number type
<select id=type name="type" onchange="updateData(this)">
<option value="">Please select</option>
<option value="1">Odd No.</option>
<option value="0">Even No.</option>
</select>
Number
<select id="number" name="number">
</select>
</body>
</html>
基于第一个下拉框值的PHP/Ajax更新第二个下拉框
函数更新数据(v)
{
var value=v.options[v.selectedIndex].value;
$(“#number”).empty();//空的“数字”下拉框
if(value!=“”)//确保没有向服务器端提交空值
{
jQuery.post(“getResult.php”,“type=“+value,updateEnumber”);
}
}
函数updateEnumber(数据)
{
var numberData=jQuery.trim(data.split(“\n”);//按“\n”拆分服务器端响应
var编号=document.getElementById(“编号”);
对于(i=0;我知道第一步是进行更改:(例如)。第二部分是我迷路的地方。我在这方面是一个完全的初学者,我找不到任何不让我感到困惑的东西。哦,好吧,我会继续找。“第二部分”是指“将数据发送到服务器端”或“将响应发送到客户端”或“解析服务器端响应并更新网页”?“解析服务器端响应并更新网页”“。你完全不知道我在那里。你的服务器端响应数据格式是什么?你能使用jquery吗?你的服务器端响应是什么?你能提供一个例子吗?问题是这两个都应该在启动时显示,并且在每次更改选择时都应该更新。我需要刷新这部分代码(第二个PHP代码段),但我不知道如何做到这一点,老实说,AJAX让我害怕,因为我是这种编程的初学者。。。
<html>
<head>
<title>PHP/Ajax update 2nd drop down box base on 1st drop down box value</title>
<script src="http://code.jquery.com/jquery-latest.js"></script>
<script language=javascript>
function updateData(v)
{
var value=v.options[v.selectedIndex].value;
$("#number").empty(); //empty "digit" drop down box
if (value!="") //Ensure no empty value is submitted to server side
{
jQuery.post("getResult.php","type="+value,updateNumber);
}
}
function updateNumber(data)
{
var numberData=jQuery.trim(data).split("\n");//split server side response by "\n"
var number=document.getElementById("number");
for (i=0;i<numberData.length;i++)
{
value=numberData[i].split("-")[0];//get value from server response
text=numberData[i].split("-")[1]; //get text from server response
option=new Option(text,value); //for better IE compatibility
number.options[i]=option;
}
}
</script>
</head>
<body>
<h1>PHP/Ajax update 2nd drop down box base on 1st drop down box value Demo</h1>
No number type
<select id=type name="type" onchange="updateData(this)">
<option value="">Please select</option>
<option value="1">Odd No.</option>
<option value="0">Even No.</option>
</select>
Number
<select id="number" name="number">
</select>
</body>
</html>
<?php
$type=htmlspecialchars($_POST["type"]);
if ($type=="1")
{
echo "1-one\n";//Ends-with \n for client side getting data from server side response
echo "3-three\n";//Ends-with \n for client side getting data from server side response
echo "5-five\n";//Ends-with \n for client side getting data from server side response
echo "7-seven\n";//Ends-with \n for client side getting data from server side response
}
else
{
if ($type=="0")
{ echo "2-two\n";//Ends-with \n for client side getting data from server side response
echo "4-four\n";//Ends-with \n for client side getting data from server side response
echo "6-six\n";//Ends-with \n for client side getting data from server side response
echo "8-eight\n";//Ends-with \n for client side getting data from server side response
}
}
?>