我正在尝试完成mysqli程序原始应用程序。除了仅更新，一切都正常。这是更新代码。请让我知道怎么了？当我单击编辑并保存我的新更新数据并在index.php上显示表格时，它给了我旧数据而不是更新数据
first update.php
<?php
include('config/connect.php');
$fname = $country ='';
$id = $_GET['id'];
if(isset( $_POST['update'] )){
$fname = $_POST['name'];
$country = $_POST['country'];
$sql = "UPDATE userdata
SET name='$fname', country='$country' WHERE id='$id' ";
if( mysqli_query($conn, $sql) ) {
header('Location: index.php');
} else {
echo "error"
}
}
$sql = "SELECT * FROM userdata WHERE id='$id' ";
$result = mysqli_query($conn, $sql);
$data = mysqli_fetch_assoc($result);
?>
<!DOCTYPE html>
<html>
<?php include('templates/header.php'); ?>
<section class="addsection">
<h4 class="text-center">update Your Data</h4>
<form class="form" action="index.php" method="POST">
<div class="form-group">
<label>Name</label>
<input type="text" name="name" class="form-control" value="<?php echo htmlspecialchars($fname) ?>">
</div>
<div class="form-group">
<label>Country</label>
<input type="text" name="country" class="form-control" value="<?php echo htmlspecialchars($country) ?>">
</div>
<div class="text-center">
<input type="submit" name="update" value="EDIT">
</div>
</form>
</section>
</html>
然后index.php
<?php
include('config/connect.php');
// select all from the table and order them
$sql = 'SELECT * FROM userdata ORDER BY id ASC';
// get the data
$data = mysqli_query($conn, $sql);
// make the gotten data in array
$users = mysqli_fetch_all($data, MYSQLI_ASSOC);
?>
<!DOCTYPE html>
<html>
<?php include('templates/header.php'); ?>
<div class="container">
<section class="tabledata">
<table class="table table-hover table-dark">
<thead>
<tr>
<th>ID</th>
<th>Name</th>
<th>Country</th>
<th>Update</th>
</tr>
</thead>
<tbody>
<?php foreach($users as $user): ?>
<tr>
<td><?php echo htmlspecialchars($user['id']); ?></td>
<td><?php echo htmlspecialchars($user['fname']); ?></td>
<td><?php echo htmlspecialchars($user['country']); ?></td>
<td>
<a href="update.php?id=<?php echo $user['id'] ;?>">Edit</a>
</td>
</tr>
<?php endforeach; ?>
</tbody>
</table>
</section>
</div>
</html>
表格正在提交给index.php，而不是update.php。应该是：
<form class="form" action="update.php?id=<?php echo $id; ?>" method="POST">