Prevent a query from duplicating

Question

Trying to show featured posts on home using catID,but it is being duplicated. Is there any way to prevent it from duplicating:

<?php
 query_posts("posts_per_page=1&cat=1");
if ( have_posts() ) while ( have_posts() ) : the_post(); ?>
<h2><a href="<?php the_permalink(); ?>"><?php the_title(); ?></a></h2>
    <?php the_post_thumbnail(); ?>
<p><?php the_excerpt(); ?></p>
<p><a href="<?php the_permalink(); ?>">continue reading</a></p>
<?php endwhile; ?> <?php wp_reset_query(); ?>

Answer 1

Try to use wp_query instead of query_posts

Answer 2

Before I start, you should never make use of query_posts unless your intention is to break almost everything on your page :-)

Note: This function isn't meant to be used by plugins or themes. As explained later, there are better, more performant options to alter the main query. query_posts() is overly simplistic and problematic way to modify main query of a page by replacing it with new instance of the query. It is inefficient (re-runs SQL queries) and will outright fail in some circumstances (especially often when dealing with posts pagination).

To accomplish this, you should use WP_Query, and the post__not_in parameter. You must first get an array of the all the post ID's on the page, and then use that to exclude those posts in your query

You can try something like this on your page

$post_ids = wp_pluck_list($wp_query->posts, 'ID'); 
$args = array(
    'posts_per_page' => 1,
    'cat'            => 1,
    'post__not_in'   => $post_ids
);
$q = new WP_Query($args);

if ($q->have_posts()) {
    while($q->have_posts()) {
    $q->the_post();

       //Your loop

    }
    wp_reset_postdata();
}