How to show comments on specific posts - php

Question

I have an application that where users can post announcements and comment on posts. My problem is that whenever a comment is posted, It shows up on every announcement post. How can I post comments so that they show up on that specific post?
I have 2 database tables: "announcement: id, name, announcementTitle, announcement, image" and "comment: id, post_id, name, comment" with foreign key attached to comment.
Here is my home.php where the announcements and comments are echoed
<div class="container">
<div class="mx-auto">
<?php
if (isset($_SESSION['username'])) {
echo'
<h1 style="text-decoration:underline">Post an announcement</h1>
<form method="post" action="announcement.php" enctype="multipart/form-data">
<input type="text" name="announcementTitle" placeholder="Enter Subject"><br>
<textarea name="announcementBox" rows="5" cols="40" placeholder="Enter Announcement"></textarea><br>
<input type="file" name="image" accept="image/jpeg">
<button name="announcement">Submit</button>
</form>';
}
$query = "SELECT * FROM announcement ORDER BY id DESC";
$result = mysqli_query($con,$query);
while ($row = mysqli_fetch_array($result)) {
echo '<div class="row" style="color:black;background-color:white;border-radius:5px;padding:10px;margin-top:10px;margin-bottom:70px">';
echo '<div class="column" style="width:100%;border:5px">';
if (isset($_SESSION['username'])) {
echo '<form method="post" action="announcement.php">';
echo "Posted by " .$row["name"]. " click X to delete:";
echo '<input type="hidden" name="postID" value="'.$row['id'].'">';
echo '<button name="delete" style="float:right">X</button>';
echo '</form>';
}
echo $row['announcementTitle'].'<br>';
echo $row['announcement'].'<br>';
echo '<img width="20%" src="data:image;base64,'.$row['image'].'"alt="Image" style="padding-top:10px">';
echo'
<form method="post" action="comment.php">
<textarea name="commentbox" rows="2" cols="50" placeholder="Leave a Comment"></textarea><br>
<button name="comment">Submit</button>
</form>';
echo "Comments:<p><p>";
echo " <p>";
$find_comment = "SELECT * FROM comment ORDER BY id DESC";
$res = mysqli_query($con,$find_comment);
while ($row = mysqli_fetch_array($res)) {
echo '<input type="hidden" name="postID" value="'.$row['post_id'].'">';
$comment_name = $row['name'];
$comment = $row['comment'];
echo "$comment_name: $comment<p>";
}
if(isset($_GET['error'])) {
echo "<p>100 Character Limit";
}
echo '</div></div>';
}
?>
</div>
</div>
Here is comment.php where comments are put in the database
<?php
session_start();
$con = mysqli_connect('localhost', 'root', 'Arv5n321');
mysqli_select_db($con, 'userregistration');
$namee = '';
$comment = '';
$comment_length = strlen($comment);
if($comment_length > 100) {
header("location: home.php?error=1");
}else {
$que = "SELECT * FROM announcement";
$res = mysqli_query($con,$que);
while ($row = mysqli_fetch_array($res)) {
$post_id = $row['id'];
}
$namee = $_SESSION['username'];
$comment = $_POST['commentbox'];
$query = "INSERT INTO comment(post_id,name,comment) VALUES('$post_id','$namee','$comment')";
$result = mysqli_query($con, $query);
if ($result) {
header("location:home.php?success=submitted");
} else {
header("location:home.php?error=couldnotsubmit");
}
}
?>
Here is announcement.php where announcements are put in the database
<?php
session_start();
//$con = mysqli_connect('freedb.tech', 'freedbtech_arvindra', 'Arv5n321', 'freedbtech_remote') or die(mysqli_error($con));
$con = mysqli_connect('localhost', 'root', 'Arv5n321', 'userregistration') or die(mysqli_error($con));
if (isset($_POST['announcement'])) {
$image = $_FILES['image']['tmp_name'];
$name = $_FILES['image']['name'];
$image = base64_encode(file_get_contents(addslashes($image)));
date_default_timezone_set("America/New_York");
$title = $_POST['announcementTitle']." (<b>".date("m/d/Y")." ".date("h:i:sa")."</b>)";
$paragraph = $_POST['announcementBox'];
if (empty($paragraph)||empty($title)) {
header('location:home.php?error=fillintheblanks');
}else{
$nam = $_SESSION['username'];
$query = "insert into announcement(name,announcementTitle,announcement,image) values('$nam','$title','$paragraph','$image')";
$result = mysqli_query($con, $query);
if ($result) {
header("location:home.php?success=submitted");
} else {
header("location:home.php?error=couldnotsubmit");
}
}
}else if (isset($_POST['delete'])){
$query = "delete from announcement where id='".$_POST['postID']."';";
$result = mysqli_query($con,$query);
if ($result) {
header('location:home.php?success=deleted');
} else {
header('location:home.php?error=couldnotdelete');
}
}
else {
header('location:home.php');
}
I am a little new to PHP so any help is good.