mysqli_fetch_all() expects parameter 1 to be mysqli_result, boolean given [дубликат]

вот цикл:

<?php $posts = get_posts(); ?>
<?php foreach ($posts as $post) :?>
    <div class="post">
        <img src="<?=$post['image']?>" alt="image">
    </div>
<?php endforeach;?>

вот функция:

function get_posts(){
    global $link;
    $sql = "SELECT * FROM posts ORDER BY id DESC LIMIT";
    $result = mysqli_query($link, $sql);
    $posts = mysqli_fetch_all($result, 1);
    return $posts; 
}

выдаёт эту ошибку:

 mysqli_fetch_all() expects parameter 1 to be mysqli_result, boolean given