PHP pagination isn't working and I'm not sure why - php

Question

I feel like I ask a lot of questions.
Anyways, I'm writing pagination for some database entries, and it looks sound to me but it's only displaying the first 10 posts and nothing else when I click the links.
The whole shebang is right here:
<?php
$post_limit = 10;
$conn = new mysqli($servername, $username, $password, $dbname);
if ($conn->connect_error) {
die("failed to connect: " . $conn->connect_error);
}
$sql = "SELECT count(id) FROM $tablename";
$result = mysqli_query($conn, $sql);
if (!$result) {
echo "you fucked up";
} else {
echo $row["id"];
}
$row = mysqli_fetch_array($result, MYSQL_NUM);
$post_count = $row[0];
if(isset($_GET['page'])) {
$page = $_GET['page'] + 1;
$offset = $post_limit * $page;
} else {
$page = 0;
$offset = 0;
}
$post_left = $post_count - ($page * $post_limit);
$sql = "SELECT id, upvotes, downvotes, name, title, message, date, time FROM posts ORDER BY date DESC, time DESC LIMIT $offset, $post_limit";
$result = $conn->query($sql);
if ($result->num_rows > 0) {
while($row = $result->fetch_assoc()) {
echo "<br><div id='messageBar'>";
echo " ❖ </b>";
echo "Posted by <b>";
echo htmlspecialchars($row["name"]);
echo "</b> on ";
echo $row["date"];
echo " at ";
echo $row["time"];
if (!empty($row['title'])) {
echo " - <b>";
echo htmlspecialchars($row["title"]);
echo "</b>";
}
echo "<span style='float: right'>#";
echo $row["id"];
echo "</span>";
echo "</div><div id='messageContent'>";
echo htmlspecialchars($row["message"]);
echo "<br><br><span id='commentLink'><a class='commentLink' href='thread.php?id=$row[id]'>view thread </a></span>";
echo "<br></div><br><hr>";
}
} else {
echo "<br>";
echo "<center><i>it's dusty in here</i></center>";
echo "<br>";
}
if ($page > 0) {
$last = $page - 2;
echo "<a href='$_PHP_SELF?page = $last'>previous page</a> | ";
echo "<a href='$_PHP_SELF?page = $page'>next page</a>";
} else if ($page == 0) {
echo "<a href='$_PHP_SELF?page = $page'>next page</a>";
} else if ($post_left < $post_limit) {
$last = $page - 2;
echo "<a href='$_PHP_SELF?page = $last'>previous page</a>";
}
$conn->close();
?>
The link for the next page appears at the bottom, but clicking it takes you to the page you're already on with the same 10 most recent posts.
I am trying to learn PHP as I go, so I appreciate any help. Thank you!

Answer 1

Instead of using $_GET please use $_SESSION to manage a counter.
Every time you go in this page you increment the counter.
So, you have to do this on the top of the page:
if(isset($_SESSION['counter'])) {
$page = $_SESSION['counter'] + 1;
$offset = $post_limit * $page;
} else {
$page = 0;
$offset = 0;
$_SESSION['counter']=0;
}
Try this.
By the way there is Datatables which do what you're looking for.
P.S. If you don't start sessions in some other points in your code, please put session_start(); in the first page (e.g., login.php) otherwise put on this page.

Answer 2

Fixed. Problem was here:
if ($page > 0) {
$last = $page - 2;
echo "<a href='$_PHP_SELF?page = $last'>previous page</a> | ";
echo "<a href='$_PHP_SELF?page = $page'>next page</a>";
} else if ($page == 0) {
echo "<a href='$_PHP_SELF?page = $page'>next page</a>";
} else if ($post_left < $post_limit) {
$last = $page - 2;
echo "<a href='$_PHP_SELF?page = $last'>previous page</a>";
}
The URL I was linking to wasn't supposed to have spaces around the = sign. It's still buggy, but it works.