我一直在开发一个php脚本，可以从我的博客中删除文章。但现在，每个人都可以删除每个人的帖子，如果他们登录。我想限制这对作者的帖子，所以他们只能删除自己的帖子。我怎样才能做到这一点？
我的index.php是这样的：

<script  language ="JavaScript" type="text/javascript">
    function delpost(id, title) {
        if (confirm("Are you sure you want to delete '" + title + "'")) {
            window.location.href = 'index.php?delpost=' + id;
        }
    }
</script>
<?php
    try {
        $author = $_SESSION['author'];
        $stmt = $db->query('SELECT postID, postTitle,postAlttext, postDesc, postDate, postAlttext, postImage, author FROM blog_posts ORDER BY postID DESC');
        while ($row = $stmt->fetch()) {
            echo '<span style="float: right"><a href="edit-post.php?id='.$row['postID'].'"><i class="material-icons" style="font-size:36px;color:black">border_color</i></a></span>';?>
        <a href="javascript:delpost('<?php echo $row['postID'];?>','<?php echo $row['postTitle'];?>')"><i class="material-icons" style="font-size:36px;color:red">delete</i></a>