php - 如何从数据库调用 `id`？

Question

我创建了一个表单来将名称更新到数据库中，我在数据库中创建了两个表first_name和last_name，看一下这是我的代码:

$sql="
CREATE TABLE admin
(
id INT PRIMARY KEY AUTO_INCREMENT,
first_name VARCHAR(100),
last_name VARCHAR(100),
)";

现在我已经在这里创建了更新表单:

<div class="box">
    <h1 style="font-family: consolas">Change your name</h1><hr>
    <div id="change_name">
        <label><strong>Your current name: </strong></label>
        <?php
        include('change_setting_db.php');

        while($row = mysqli_fetch_array($result))
        {
            echo $row['first_name']." ".$row['last_name'];
        }
        ?><br><br>

        <form method="post" action="do_update_name.php">
        <label><strong>First name: </strong></label>
        <input type="text" name="first_name">
        <label><strong>Last name: </strong></label>
        <input type="text" name="last_name">
            <input type="submit" value="Submit">
        </form>

    </div>

</div>

这是我的 do_update_name.php 文件:

<?php
$firstname=$_POST['first_name'];
$lastname=$_POST['last_name'];
$id=$_GET['id'];

$con=mysqli_connect("localhost","root","Bhawanku", "members");
// Check connection
if (mysqli_connect_errno())
{
    echo "Failed to connect to MySQL: " . mysqli_connect_error();
}

$update =mysqli_query($con,"UPDATE admin SET first_name='$firstname' AND  last_name='$lastname' WHERE id='$id' ");
if($update){
    echo "Successfully created!!";
}
?>

现在的问题是，当我输入新名称并提交时，它显示错误:

Notice: Undefined index: id in C:\Users\Raj\PhpstormProjects\...\new do_update_name.php on line 4
Successfully created!!

Answer 1

<form method="post" action="do_update_name.php">
        <label><strong>First name: </strong></label>
        <input type="text" name="first_name">
        <label><strong>Last name: </strong></label>
        <input type="text" name="last_name">
            <input type="submit" value="Submit">
        </form>

这里必须添加ID，这样对方才能获取到$_GET参数['id']例如:

<form method="post" action="do_update_name.php?id=1">
        <label><strong>First name: </strong></label>
        <input type="text" name="first_name">
        <label><strong>Last name: </strong></label>
        <input type="text" name="last_name">
            <input type="submit" value="Submit">
        </form>