更新sql不适用于PHP的GET变量

Question

I have the following code to pass a variable id (primary key in meeting table) from viewMeeting.php to modifyMeeting.php

Under viewMeeting.php:

<a href="modifyfinalmeeting.php?id=<?php echo $id ?>"><?php echo $nameMeeting; ?></a>

Eg of URL: http://localhost/MyProject/modifyMeeting.php?id=1

Under modifyMeeting.php:

//get ID from URL 
if (isset($_GET['id'])) {
    $id =$_GET['id'];
}

if (isset($_POST['updatebtn'])) {
        $sql = 'UPDATE meeting SET nameMeeting = ?, venue = ? WHERE id = ?';
        if ($stmt = mysqli_prepare($link, $sql)) {
            // Bind variables to the prepared statement as parameters
            mysqli_stmt_bind_param($stmt, 'sss', $nameMeeting, $venue, $id);

            // Attempt to execute the prepared statement
            if (mysqli_stmt_execute($stmt)) {

                //Alert to redirect
                 echo ("<SCRIPT LANGUAGE='JavaScript'>
                 window.alert('Succesfully Updated')
                 window.location.href='viewfinalmeeting.php';
                 </SCRIPT>");
             } else {
                 echo "Something went wrong. Please try again later.";
             }
        }
}

<button type="submit" name="updatebtn" class="btn btn-primary">Update</button>

If i hardcode the variable for $id (eg: $id = 2), it will update the database.

However, currently it will show "Successful Updated" but not update the database to the corresponding $id from the GET variable.

I also tried the following method but it does not work as it shows undefined function:

$id = mysql_real_escape_string($_GET['id'])

Please, any help as to how to update the database will be greatly appreciated!

Answer 1

Problem

You are submitting the form from modifyMeeting.php page, so when it will go to the target page as mentioned in the tag it will not retain the $_GET['id'] variable as it will not be in the URL anymore. So your database will show value "undefined" for that id.

Solution

When you create the form on modifyMeeting.page, set the URL to contain the GET variable

Example

<form action="sample.php?id=<?php echo $_GET['id']; ?>" method="post">

Hope this helps.