<table class="table table-bordered table-hover">
    <thead>
        <tr>
            <th>ID</th>
            <th>Avatar<th>
            <th>Username</th>
            <th>Full name</th>
            <th>Email</th>
            <th>Registered on</th>
            <th>Role</th>
        </tr>
    </thead>
    <tbody>
        <?php
            $sql = "SELECT id, username, email, firstname, lastname, registration_date, role, avatar FROM users ORDER BY id DESC";
            $query = mysqli_query($connection, $sql);
            if(!$query) {
                echo "Cannot get users from the database. " . mysqli_error($connection);
            }

            while($row = mysqli_fetch_assoc($query)) {
                $id = $row['id'];
                $username = $row['username'];
                $email = $row['email'];
                $firstname = $row['firstname'];
                $lastname = $row['lastname'];
                $date = $row['registration_date'];
                $role = $row['role'];
                $avatar = $row['avatar'];
                ?>
                <tr>
                    <td><?= $id ?></td>
                    <td><img class="img-responsive" style="max-width: 65px; max-height: 65px;" src="../images/<?= $avatar ?>"></td>
                    <td><?= $username ?></td>
                    <td><?= $firstname . " " . $lastname ?></td>
                    <td><?= $email ?></td>
                    <td><?= $date ?></td>
                    <td><?= $role ?></td>
                    <td><a href="users.php?source=update_user&amp;user_id=<?= $id ?>">Update</a></td>
                    <td><a href="users.php?delete_user=<?= $id ?>">Delete</a></td>
                </tr>
        <?php
            }
        ?>
    </tbody>
</table>

<?php

if(isset($_GET['delete_user'])) {
    $user_id = $_GET['delete_user'];

    $sql = "DELETE FROM users WHERE id = " . $post_id;
    $query = mysqli_query($connection, $sql);
    if(!$query) {
        echo 'Cannot remove user from the database. ' . mysqli_error($connection);
    }
    header("Location: users.php");
}

?>