Problem with the Edit and Delete for my Forum page - php

Question

My code is not appropriately editing or deleting my comments. I put my code through a syntax checker and that doesn't seem to be the problem. I have tried going through all the articles I could find and even tried multiple different methods but nothing seems to be working.
The issue is that I keep getting this error
Notice: Undefined index: id in C:\Users\Owner\Desktop\xampp\htdocs\FinalSite\edit.php on line 5
and when I click on edit the boxes will be filled with text like
Title:
<br /><b>Notice</b>: Trying to access array offset on value of type null in <b>C:\Users\Owner\Desktop\xampp\htdocs\FinalSite\edit.php</b> on line <b>20</b><br />
and Comment:
<br /><b>Notice</b>: Trying to access array offset on value of type null in <b>C:\Users\Owner\Desktop\xampp\htdocs\FinalSite\edit.php</b> on line <b>24</b><br />
I have tried multiple different ways to define id but to no avail. I have looked and implemented all the solutions I could find on StackOverflow but with no luck.
This is what I used to create the comments table:
CREATE TABLE IF NOT EXISTS `comments` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`page_id` int(11) NOT NULL,
`parent_id` int(11) NOT NULL DEFAULT '-1',
`name` varchar(255) NOT NULL,
`content` text NOT NULL,
`submit_date` datetime NOT NULL DEFAULT CURRENT_TIMESTAMP,
PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=4 DEFAULT CHARSET=utf8;
This is my code:
//This is the comments.php:
<?php
// Update the details below with your MySQL details
$DATABASE_HOST = 'localhost';
$DATABASE_USER = 'root';
$DATABASE_PASS = '';
$DATABASE_NAME = 'database_name';
try {
$pdo = new PDO('mysql:host=' . $DATABASE_HOST . ';dbname=' . $DATABASE_NAME . ';charset=utf8', $DATABASE_USER, $DATABASE_PASS);
} catch (PDOException $exception) {
// If there is an error with the connection, stop the script and display the error
exit('Failed to connect to database!');
}
// Below function will convert datetime to time elapsed string
function time_elapsed_string($datetime, $full = false) {
$now = new DateTime;
$ago = new DateTime($datetime);
$diff = $now->diff($ago);
$diff->w = floor($diff->d / 7);
$diff->d -= $diff->w * 7;
$string = array('y' => 'year', 'm' => 'month', 'w' => 'week', 'd' => 'day', 'h' => 'hour', 'i' => 'minute', 's' => 'second');
foreach ($string as $k => &$v) {
if ($diff->$k) {
$v = $diff->$k . ' ' . $v . ($diff->$k > 1 ? 's' : '');
} else {
unset($string[$k]);
}
}
if (!$full) $string = array_slice($string, 0, 1);
return $string ? implode(', ', $string) . ' ago' : 'just now';
}
// This function will populate the comments and comments replies using a loop
function show_comments($comments, $parent_id = -1) {
$html = '';
if ($parent_id != -1) {
// If the comments are replies sort them by the "submit_date" column
array_multisort(array_column($comments, 'submit_date'), SORT_ASC, $comments);
}
// Iterate the comments using the foreach loop
foreach ($comments as $comment) {
if ($comment['parent_id'] == $parent_id) {
// Add the comment to the $html variable
$html .= '
<div class="comment">
<div>
<h3 class="name">' . htmlspecialchars($comment['name'], ENT_QUOTES) . '</h3>
<span class="date">' . time_elapsed_string($comment['submit_date']) . '</span>
</div>
<p class="content">' . nl2br(htmlspecialchars($comment['content'], ENT_QUOTES)) . '</p>
<a class="reply_comment_btn" href="#" data-comment-id="' . $comment['id'] . '">Reply</a>
<a href=edit.php>edit</a>
<a href=delete_confirm.php>delete</a>
' . show_write_comment_form($comment['id']) . '
<div class="replies">
' . show_comments($comments, $comment['id']) . '
</div>
</div>
';
}
}
return $html;
}
// This function is the template for the write comment form
function show_write_comment_form($parent_id = -1) {
$html = '
<div class="write_comment" data-comment-id="' . $parent_id . '">
<form>
<input name="parent_id" type="hidden" value="' . $parent_id . '">
<input name="name" type="text" placeholder="Your Name" required>
<textarea name="content" placeholder="Write your comment here..." required></textarea>
<button type="submit">Submit Comment</button>
</form>
</div>
';
return $html;
}
// Page ID needs to exist, this is used to determine which comments are for which page
if (isset($_GET['page_id'])) {
// Check if the submitted form variables exist
if (isset($_POST['name'], $_POST['content'])) {
// POST variables exist, insert a new comment into the MySQL comments table (user submitted form)
$stmt = $pdo->prepare('INSERT INTO comments (page_id, parent_id, name, content, submit_date) VALUES (?,?,?,?,?)');
$stmt->execute([ $_GET['page_id'], $_POST['parent_id'], $_POST['name'], $_POST['content'], date('Y-m-d H:i:s') ]);
exit('Your comment has been submitted! Please reload the page to view your comment.');
}
// Get all comments by the Page ID ordered by the submit date
$stmt = $pdo->prepare('SELECT * FROM comments WHERE page_id = ? ORDER BY submit_date DESC');
$stmt->execute([ $_GET['page_id'] ]);
$comments = $stmt->fetchAll(PDO::FETCH_ASSOC);
// Get the total number of comments
$stmt = $pdo->prepare('SELECT COUNT(*) AS total_comments FROM comments WHERE page_id = ?');
$stmt->execute([ $_GET['page_id'] ]);
$comments_info = $stmt->fetch(PDO::FETCH_ASSOC);}
else {
exit('No page ID specified!');
}
?>
<div class="comment_header">
<span class="total"><?=$comments_info['total_comments']?> comments</span>
Write Comment
</div>
<?php
if($_SESSION['is_open'] = TRUE){
echo show_write_comment_form();
}else{
echo "Please login to post.";
echo "</br>";
}
if($_SESSION['is_open'] = TRUE){
echo show_comments($comments);
}else{
echo "Please login to see others comments.";
}
?>
//This is the edit.php:
<?php
// connect to SQL
require_once('includes/mysqli_connect.php');
#data preparation for the query
$id = intval($_GET["id"]);
# selects title and description fields from database
$sql = "SELECT * FROM comments WHERE id= '$'";
$result = mysqli_query($dbc,$sql) or die(mysqli_connect_error());
# retrieved by using $row['col_name']
$row = mysqli_fetch_array($result);
?>
<h3>Edit</h3>
<form action=<?="save_edit.php?id='$id'"?>enctype="multipart/form-data" method="post" name="myForm" >
<table>
<tr>
<td><b>Title</b></td>
<td><input type="text" size="70" maxlength="100" name="name" value="<?php $row['name'] ?>"></td>
</tr>
<tr>
<td><b>Description</b></td>
<td><textarea cols="80" rows="18" name="content"><?php $row['content']; ?></textarea></td>
</tr>
</table>
<input type="hidden" name="id" value="<?php $id; ?>" />
<input name="enter" type="submit" value="Edit">
</form>
//This is the save_edit.php:
<?php
require_once('includes/mysqli_connect.php');
#data preparation for the query
$id = intval($_POST["id"]);
foreach ($_POST as $key => $value) $_POST[$key] = mysqli_real_escape_string($value);
$sql = "UPDATE comments SET
name='$_POST[name]',
content='$_POST[content]',
WHERE id=$id";
if (mysqli_error()) {
die('Error: ' . mysqli_error());
}
mysqli_close($dbc);
header ("location: index.html");
?>
//This is the delete.php:
<?php
require_once('includes/mysqli_connect.php');
$id = $_GET['comments_id'];
if($_SESSION['is_open'] = TRUE) {
session_start();
echo "Welcome | " . $_SESSION['user_name'] . "!";
$query = "DELETE FROM comments WHERE id=$id";
$result = mysqli_query($dbc, $query);
if($result){
echo "<br>The selected comment has been deleted.";
} else{
echo"<br>The selected comment could not be deleted.";
}
}else {
echo "login please";
header("Location: login.php");
}
echo "<p><a href=index.html>Go back to the main page</a></p>";
mysqli_close($dbc);
?>
If you are wondering about the is_open that is how I confirm that the user is logged in before allowing them to access the forum.

Answer 1

In your "save_edit.php" file you are not doing anything with the SQL query. With mysqli should look something like this: $dbc->query($sql)