0
我在PHP中失去會話變量時遇到了很多麻煩。我發現了很多很好的信息，但在這種情況下沒有任何幫助。這裏是我的PHP文件：PHP會話變量在移動到頁面後丟失
首先，util.php。它包含在每個文件的頂部。它有session_start（）命令和MySQL連接字符串：
<?php
session_start();
$connect=mysqli_connect("localhost","mysql","mypassword","mydb");
if(mysqli_connect_errno()){
echo 'Failed to connect to database ' . mysqli_connect_error();
}
?>
接下來，show_variables.php。它將所有會話變量轉儲到屏幕上：
<?php
echo date('H:i:s');
echo "<br/><p>Session Variables:</p>";
foreach ($_SESSION as $key=>$val)
echo $key." ".$val."<br/>";
echo session_name();
?>
現在第一頁，index.php。頁面頂部從數據庫表中抽取員工姓名。正文提供一個包含員工姓名和兩個角色的表單。該頁面將根據所選角色重定向。
<?php
include "util.php";
$query=mysqli_query($connect,"select * from staff");
while ($row = mysqli_fetch_array($query)){
$staff_select .= '<option value="'.$row[id].'">'.$row[name_first].' '.$row[name_last].'</option>';
}
?>
<html>
<head>
<title>Restaurant Order Tracking</title>
<link href="./css/style.css" rel="stylesheet" type="text/css">
<script language="javascript" type="text/javascript">
function start_shift(){
var e_select = document.selector.employee_select;
var name = e_select.options[e_select.selectedIndex].value;
var r_select = document.selector.role_select;
var role = r_select.options[r_select.selectedIndex].value;
alert("Ok, " + name + ". You're a " + role + " today. Let's get to work.");
if(role == "server"){location = "./server/server.php?id=" + name};
if(role == "foodprep"){location = "foodprep.php?id=" + name};
}
</script>
</head>
<body>
<div id="header">
<h1>Welcome To The Restaurant Order Tracker</h1>
</div>
<div id="middle">
<p>Now get to work !</p>
<form name="selector">
<p>Select your employee:</p>
<select name="employee_select">
<?php
echo $staff_select;
?>
</select>
<p>Select your role for today</p>
<select name="role_select">
<option value="server">Server</option>
<option value="foodprep">Food Prep</option>
</select>
<br/>
<input type="button" value="Start Shift" onclick="start_shift()"/>
</form>
<?php include "show_variables.php";?>
</div>
</body>
</html>
此頁面正常工作。在這裏選擇服務器會導致「server.php」。以下是該文件：
<?php
include "../util.php";
$_SESSION['id']=$id=$_GET['id'];
$_SESSION['foo']="fubar";
$query = mysqli_query($connect,"select name_first, name_last from staff where id = $id");
while($row = mysqli_fetch_array($query)){
$_SESSION['name'] = $row['name_first'].' '.$row['name_last'];
}
?>
<html>
<head>
<Title>Server Interface</Title>
<link href="../css/style.css" rel="stylesheet" type="text/css">
<script language="JavaScript" type="text/javascript">
function update(target){
var ajaxRequest;
ajaxRequest = new XMLHttpRequest();
ajaxRequest.onreadystatechange = function(){
if(ajaxRequest.readyState == 4){
var middleDisplay = document.getElementById('middle');
middleDisplay.innerHTML = ajaxRequest.responseText;
}
}
ajaxRequest.open("GET", target, true);
ajaxRequest.send(null);
}
</script>
</head>
<body>
<div id="header">
<p>Server Interface</p>
<p>Server Name: <?php echo $_SESSION['name'] ?> </p>
<form action="../logout.php" method="post">
<input type="submit" value="Logout">
</form>
</div>
<div id="middle">
<?php include "stage1.php" ?>
</div>
</body>
</html>
本頁設置了三個變量：id，name和foo。正如所料，show_variable.php具有以下的輸出：
19:54:34
Session Variables:
id 2
foo fubar
name Dave Smith
PHPSESSID
還有一個包括中間DIV stage1.php。這是那個文件：
<br/>
<form name="selector">
<input type="button" value="Start a new order" name="new_order" onclick = "update('new_order.php')" />
<input type="button" value="View your open orders" name="view_order" onclick="update('view_order.php')" />
</form>
<?php include "../show_variables.php"; ?>
到目前爲止，這麼好。有一些AJAX可以改變中間格，這很好。如果用戶選擇「開始新訂單」，AJAX會將new_order.php放入中間div。以下是文件：
<?php
include "../util.php";
$query=mysqli_query($connect,"select * from loc");
while ($row = mysqli_fetch_array($query)){
$table_select .= '<option value="'.$row[id].'">'.$row[description].'</option>';
}
echo "<br/>
<form name = 'new_order'>
<label>Enter the table number for this order</label>
<select name = 'table_select'>
$table_select
</select>
<br/>
<input type='button' value='Start New Order' onclick=\"update('enter_order.php?table=' + document.new_order.table_select[document.new_order.table_select.selectedIndex].value)\" />
<br/>
<input type='button' value='Cancel New Order' onclick=\"update('stage1.php')\" />
</form>
<a href= "stage1.php">Go back to stage 1 via link</a>
"
?>
<?php include "../show_variables.php"; ?>
該頁面還顯示了正確的會話變量：
19:55:27
Session Variables:
id 2
foo fubar
name Dave Smith
PHPSESSID
但在那之後，所有的變量消失。如果用戶點擊「取消新訂單」，AJAX腳本再次用stage1.php填充中間div。會話變量不再存在：
19:59:12
Session Variables:
PHPSESSID
這不能是stage1.php文件中的拼寫錯誤。完全相同的代碼在一次查看中具有會話變量，但在另一次查看時會丟失它們。 我想也許AJAX搞砸了我，所以我添加了href到new_order.php。沒有任何AJAX/JavaScript就直接進入了stage1.php。但變數再次失去了。
我嘗試手動輸入網址。 我瀏覽到http://www.mysite.com/server/server.php?id=1。會話變量顯示正確。 我打開一個新標籤並瀏覽到http://www.mysite.com/server/server.php（沒有獲得）。會話變量存在且設置相同。 我打開另一個選項卡並瀏覽至http://www.mysite.com/server/stage1.php。會話變量不存在。
請注意，每個文件都通過util.php文件具有session_start（）命令。還要注意這是一個開發服務器。我的網站是唯一的會話。有任何想法嗎？
結帳一些意見的文件在在session_start（）。聽起來像你適合那裏的條目之一：http://us2.php.net/manual/en/function.session-start.php – Zarathuztra