update.php

<?php
    include './connect.php';
    $id = $_GET ['update_id'];
    $sql = "Select * from `crud` where id=$id";
    $result = mysqli_query($con, $sql);
    $row = mysqli_fetch_row($result);
    // $name = $row['name'];
    // $email = $row['email'];
    // $mobile = $row['mobile'];
    // $password = $row['password'];

    if (isset($_POST['submit'])) {
        $name = $_POST['name'];
        $email = $_POST['email'];
        $mobile = $_POST['mobile'];
        $password = $_POST['password'];

        $sql = "update `crud` set id='$id', name='$name', email='$email', mobile='$mobile', password='$password' where id=$id";
        $result = mysqli_query($con, $sql);
        if ($result) {
            header('location:display.php');
        }
        else {
            die (mysqli_error($con));
        }
    }
?>

<!doctype html>
<html lang="en">
    <head>
        <meta charset="utf-8">
        <meta name="viewport" content="width=device-width, initial-scale=1">
        <title>PHP-CRUD</title>
        <link href="https://cdn.jsdelivr.net/npm/bootstrap@5.2.3/dist/css/bootstrap.min.css" rel="stylesheet">
    </head>
    <body>
        <div class="container my-5">
        <form method="post">
            <div class="mb-3">
                <label>Name</label>
                <input type="text" class="form-control" name="name" placeholder="Your name" required autocomplete="off">
            </div>
            <div class="mb-3">
                <label>Email</label>
                <input type="email" class="form-control" name="email" placeholder="Your email" required autocomplete="off">
            </div>
            <div class="mb-3">
                <label>Mobile</label>
                <input type="text" class="form-control" name="mobile" placeholder="Your mobile number" required autocomplete="off">
            </div>
            <div class="mb-3">
                <label>Password</label>
                <input type="password" class="form-control" name="password" placeholder="Your password" required autocomplete="off">
            </div>
            <button type="submit" class="btn btn-primary" name="submit">Update</button>
        </form>
        </div>
    </body>
</html>