当我尝试使用PHP脚本从phpmyadmin数据库中检索数据时，我使用了一个隐藏的文件并传递了＃34; user_id＆＃34;但后来我得到一个关于未定义变量的错误。代码如下。
而且我也希望在尝试大量解决方案之后使标题响应但没有运气。我已经尝试了使用这么多网站的所有可能的解决方案，但我无法使其发挥作用。
代码如下。
<?php
session_start();
include 'lib/dao.php';
include 'lib/model.php';
$d = new dao();
$m = new model();
extract($_POST);
if(!isset($_SESSION['user_id']))
{
header("location:login.php");
}
$q=$d->select("user","user_id='$user_id'");
$data=mysqli_fetch_array($q);
?>
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>Your Tracker</title>
<link rel="stylesheet" type="text/css" href="css/bootstrap.min.css"/>
<link rel="stylesheet" type="text/css" href="css/font_awesome/css/font-awesome.min.css"/>
<link rel="stylesheet" type="text/css" href="css/style.css"/>
<link rel="stylesheet" type="text/css" href="css/style1.css"/>
</head>
<body>
<div id="home" class="container">
<?php echo $data['$user_name']; ?>
<div class="row">
<div class="logo col-sm-6">
<img src="img/firefox.png" height="30px" width="30px" class="text-left">
</div>
<div class="main-menu col-sm-6 text-right">
<nav>
<ul>
<li><a href="logout.php">Log Out</a></li>
<li><a href="#contact">Contact Us</a></li>
<li><a href="#account">Account</a></li>
<li><a href="#home">Home</a></li>
</ul>
</nav>
</div>
</div>
</div>
<div style="background-color: #fff;" class="section-titlee text-center col-xs-12">
<h1>Personal <span>Details</span></h1><br>
<div>
<div class="text-left">
<h4 style="margin-left: 40px;">Add Your Personal Details</h4><br>
<form action="#" method="post" enctype="multipart/form-data">
<div class="form-group required">
<label class="col-sm-4 control-label" for="name">Name</label>
<div class="col-sm-6">
<input type="hidden" name="user_id" value="<?php echo $data['user_id']; ?>">
<input type="text" name="user_name" value="<?php echo $data['user_name']; ?>" placeholder="Name" id="user_name" class="form-control">
</div>
<div class="col-sm-2"></div>
</div>
<div class="form-group required">
<label class="col-sm-4 control-label" for="gender">Gender</label>
<div class="col-sm-6">
<div class="row">
<div class="col-sm-4">
Male<input type="radio" name="radio" value="male" id="male">
</div>
<div class="col-sm-4">
Female<input type="radio" name="radio" value="female" id="female">
</div>
<div class="col-sm-4">
Other<input type="radio" name="radio" value="other" id="other">
</div>
</div>
</div>
<div class="col-sm-2"></div>
</div>
<div class="form-group required">
<label class="col-sm-4 control-label" for="email">E-Mail</label>
<div class="col-sm-6">
<input type="email" name="email" value="<?php echo $data['user_email']; ?>" placeholder="E-Mail" id="input-email" class="form-control">
</div>
<div class="col-sm-2"></div>
</div>
<div class="form-group required">
<label class="col-sm-4 control-label" for="mobile">Mobile</label>
<div class="col-sm-6">
<input type="text" name="mobile" value="<?php echo $data['user_email']; ?>" placeholder="Mobile" id="mobile" class="form-control">
</div>
<div class="col-sm-2"></div>
</div>
<div class="text-center col-sm-12" style="margin-top: 10px;">
<input type="submit" class="btn-link" style="border-radius: 9px;border-color: blue;" name="update" id="update" value="Update">
</div>
</form>
</div>
<div class="col-sm-12">
<hr>
</div>
</div>
</div>
<div id="contact" class="footer section-titlee white text-center col-xs-12">
<h1 style="margin-left: 40px;margin-top: -25px;">Contact <span>Us</span></h1>
<div>
<div class="row">
<div class="col-lg-8 col-lg-offset-2 col-md-10 col-md-offset-1 col-xs-12">
<div class="row">
<div class="single-contact-info text-center col-sm-4 col-xs-12 mb-40">
<i class="fa fa-phone"></i>
<p>+91 7802969879</p>
</div>
<div class="single-contact-info text-center col-sm-4 col-xs-12 mb-40">
<i class="fa fa-google-wallet"></i>
<p>anami662@gmail.com</p>
</div>
<div class="single-contact-info text-center col-sm-4 col-xs-12 mb-40">
<i class="fa fa-map"></i>
<p>Ahemdabad,Gujarat.</p>
</div>
</div>
<div class="row mt-30">
<div class="contact-form">
<div>
<div id="msg"></div><br><br>
<form action="mail.php" method="post" enctype="multipart/form-data">
<div class="col-sm-6 col-xs-12">
<input type="text" id="name" name="name" placeholder="Name" >
<input type="email" id="email" name="email" placeholder="Email">
<input type="text" id="subject" name="subject" placeholder="Subject" >
</div>
<div class="col-sm-6 col-xs-12">
<textarea name="message" id="message" placeholder="Message"></textarea>
<input type="submit" id="submit" value="Submit">
</div>
</form>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
<!-- <script type="text/javascript">
function mailsend()
{
jQuery.ajax({
url:"mail.php",
data:{name: $('input#name').val(),email:$('input#email').val(),subject:$('input#subject').val(),message:$('textarea#message').val()},
type:"POST",
success:function(data){
$("#msg").html(data);}
});
}
</script> -->
<script type="text/javascript" href="css/jquery.min.js"></script>
<script type="text/javascript" href="css/bootstrap.min.js"></script>
</body>
</html>
答案 0 :(得分：0)
答案很简单，只需使用下面给出的代码并且所有错误消失。
<input type="hidden" name="user_id" value="<?php echo $_SESSION['user_id']; ?>">
<?php
extract($_POST);
$user_id=$_SESSION['user_id'];
$q=$d->select("user","user_id='$user_id'");
$data=mysqli_fetch_array($q); ?>