Php 使用更新按钮更新MySQL字段

我正在尝试更新MySQL表中显示的所有字段。删除功能目前可以工作，但是我没有得到任何更新功能的输出。我觉得我错过了一些非常基本的东西。欢迎您的任何意见

    <form action="" method="post">
    <?php
    $con = mysqli_connect($host,$username,$password,$dbname);
    if (mysqli_connect_errno())
    {
    echo "Failed to connect to MySQL: " . mysqli_connect_error();
    }
    $query = mysqli_query($con,"SELECT * FROM customers");
    while($row = mysqli_fetch_array($query))
    {
    echo "<tr>";
    echo "<td><input type=\"text\" name=\"FirstName\" value=\"" . htmlspecialchars($row['FirstName'], ENT_QUOTES, 'UTF-8') . "\"></td>";
    echo "<td><input type=\"text\" name=\"LastName\" value=\"" . htmlspecialchars($row['LastName'], ENT_QUOTES, 'UTF-8') . "\"></td>";
    echo "<td>" . htmlspecialchars($row['email'], ENT_QUOTES, 'UTF-8') . "</td>";   
    echo "<td>" . htmlspecialchars($row['address'], ENT_QUOTES, 'UTF-8') . "</td>"; 
    echo "<td>" . htmlspecialchars($row['phone'], ENT_QUOTES, 'UTF-8') . "</td>"; 
    echo "<td>" . htmlspecialchars($row['product'], ENT_QUOTES, 'UTF-8') . "</td>";
    echo "<td>" . htmlspecialchars($row['firmware'], ENT_QUOTES, 'UTF-8') . "</td>"; 
    echo "<td>" . htmlspecialchars($row['purchase_date'], ENT_QUOTES, 'UTF-8') . "</td>"; 
    echo '<td align="center"><input type="hidden" name="email" value="';
    echo htmlspecialchars($row['email'], ENT_QUOTES, 'UTF-8');
    echo '"><input type="submit" name="delete" value="X"> </td>';
    echo "</tr>";
    echo '<tr><td colspan="9"><input type="hidden" name="email" value="';
    echo htmlspecialchars($row['email'], ENT_QUOTES, 'UTF-8'); 
    echo '"><input type="submit" name="edit" value="Update"></td></tr>';
    }
    echo "</table>";

?>

<?php
if(isset($_POST['delete'])) {
    $email = $_POST['email'];
    $delete = "DELETE FROM customers WHERE email = '$email'";
    if ($con->query($delete) === TRUE) {
        echo "Record deleted successfully";
    } else {
        echo "Error deleting record: " . $con->error;
}
if (isset($_POST['edit'])) {

    $email = $_POST['email'];
    $FirstName = $_POST['FirstName'];
    $LastName = $_POST['LastName'];
    $edit = "UPDATE customers SET Firstname = '$FirstName', LastName = '$LastName' WHERE email = '$email'";
    if ($con->query($edit) === TRUE) {
    echo $edit;
        echo "Record updated successfully";
        } else {
        echo $edit;
        echo "Error updating record: " . $con->error;
}
}
$conn->close(); 
}  
?>
</form>

在
conn
试试这个：

<form action="" method="post">
<?php
$conn = mysqli_connect($host,$username,$password,$dbname);
if (mysqli_connect_errno())
{
echo "Failed to connect to MySQL: " . mysqli_connect_error();
}
// $query = mysqli_query($conn,"SELECT * FROM customers");
$query = $conn->query("SELECT * FROM customers");
while($row = $query->fetch_assoc())
{
echo "<tr>";
echo "<td><input type=\"text\" name=\"FirstName\" value=\"" . htmlspecialchars($row['FirstName'], ENT_QUOTES, 'UTF-8') . "\"></td>";
echo "<td><input type=\"text\" name=\"LastName\" value=\"" . htmlspecialchars($row['LastName'], ENT_QUOTES, 'UTF-8') . "\"></td>";
echo "<td>" . htmlspecialchars($row['email'], ENT_QUOTES, 'UTF-8') . "</td>";   
echo "<td>" . htmlspecialchars($row['address'], ENT_QUOTES, 'UTF-8') . "</td>"; 
echo "<td>" . htmlspecialchars($row['phone'], ENT_QUOTES, 'UTF-8') . "</td>"; 
echo "<td>" . htmlspecialchars($row['product'], ENT_QUOTES, 'UTF-8') . "</td>";
echo "<td>" . htmlspecialchars($row['firmware'], ENT_QUOTES, 'UTF-8') . "</td>"; 
echo "<td>" . htmlspecialchars($row['purchase_date'], ENT_QUOTES, 'UTF-8') . "</td>"; 
echo '<td align="center"><input type="hidden" name="email" value="';
echo htmlspecialchars($row['email'], ENT_QUOTES, 'UTF-8');
echo '"><input type="submit" name="delete" value="X"> </td>';
echo "</tr>";
echo '<tr><td colspan="9"><input type="hidden" name="email" value="';
echo htmlspecialchars($row['email'], ENT_QUOTES, 'UTF-8'); 
echo '"><input type="submit" name="edit" value="Update"></td></tr>';
}
echo "</table>";

?>

<?php
if(isset($_POST['delete'])) {
$email = $_POST['email'];
$delete = "DELETE FROM customers WHERE email = '$email'";
if ($conn->query($delete) === TRUE) {
    echo "Record deleted successfully";
} else {
    echo "Error deleting record: " . $conn->error;
}
if (isset($_POST['edit'])) {

$email = $_POST['email'];
$FirstName = $_POST['FirstName'];
$LastName = $_POST['LastName'];
$edit = "UPDATE customers SET Firstname = '$FirstName', LastName = '$LastName' WHERE email = '$email'";
if ($conn->query($edit) === TRUE) {
echo $edit;
    echo "Record updated successfully";
    } else {
    echo $edit;
    echo "Error updating record: " . $conn->error;
}
}
$conn->close(); 
}  
?>
</form>


你的隐藏值和提交都有相同的name属性。很好！更新了值，仍然没有得到任何输出/更改。用您现在使用的更新您的代码。我在下面发布了一个答案。感谢您的反馈。我更新了while循环，但是我仍然没有得到$edit.Changed w/更新代码的任何更改或回显。仍然没有数据库更新。请在php文件的开头尝试此操作<代码>ini\U集合（“显示错误”，1）
ini\u集（'display\u startup\u errors'，1）
ini\u集（'default\u charset'，'utf-8'）错误报告（-1）对底部的if构造执行
var\u dump
。添加
或模具（$conn->error）
在
$conn->query
的末尾将结果粘贴到此处注意：未定义变量：在第2行的/var/www/project/view_customers.php中编辑NULL注意：未定义变量：在第3行的/var/www/project/view_customers.php中发送电子邮件NULL注意：未定义变量：在第4行的/var/www/project/view_customers.php中的FirstName变量：第5行的/var/www/project/view_customers.php中的LastName NULL string（6）“Update”您是否修复了此问题？我修复了，但我只是从头开始。找不到错误，重新编码比继续查找花费的时间更少！谢谢