How to create a loop that will display one post and stop?

Question

I am trying to create a part on my wordpress theme that will only display one featured post. I have installed this plugin - https://wordpress.org/plugins/featured-post/ .

I know I am supposed to integrate <?php query_posts($query_string."&featured=yes"); somewhere into the loop to output the featured post. I tried modifying the code from my existing loop that displays regular posts but the results show the featured post repeated many times.

This is the loop I am trying to use that displays the featured post but repeats it a ton of times. How can I get it to only display once?

<?php 
if ( have_posts() ) {
    while ( have_posts() ) {
        the_post();

        query_posts($query_string . "&featured=yes");

        the_author();

        if ( has_post_thumbnail() ) {
            the_post_thumbnail('thumbnail');    
        }
?> 

<a href="<?php the_permalink(); ?>"><?php the_title(); ?></a>
<?php the_excerpt();?>  
<a href="<?php the_permalink(); ?>"> Read More.... </a>   


<?php
    } // end while
} // end if                      
?>

Answer 1

query_posts() can alter the WP query even when it is executed and it should be placed at least before you start the loop i.e. have_posts(). Currently you are placing it after setting up post data i.e. the_post(). Which is resulting in unexpected behavior.

Example:

global $query_string; //Get current query arguments
query_posts($query_string."&featured=yes");

if (have_posts()) {
    while (have_posts()) {
        the_post(); ?>    

        <? php the_author(); ?>

        <? php
        if (has_post_thumbnail()) {
            the_post_thumbnail('thumbnail');
        } ?>

        <a href = "<?php the_permalink(); ?>"><?php the_title(); ?></a> 
        <?php the_excerpt(); ?> 
        <a href = "<?php the_permalink(); ?>"> Read More.... </a>   


        <?php
    } // end while
} // end if

NOTE: query_posts() is not recommended please ask plugin support to provide alternative way to use their plugin!

Answer 2

I have just simplified my code. Add a custom field with name "_featured" with Yes and No Radio Button and add dummy 5 posts and from which make one post to be featured to Yes and then use below code to display featured post.

$args = array(
    'posts_per_page' => 5,
    'post_status' => 'publish',
    'post_type' => 'post',
    'meta_query' => array(
       array(
           'key' => '_featured',
           'value' => 'yes'
       )
    )
);

$the_query = new WP_Query( $args );
// The Loop
if ( $the_query->have_posts() ) {
    echo '<ul>';
    while ( $the_query->have_posts() ) {
        $the_query->the_post();
        echo '<li>' . get_the_title() . '</li>';
    }
    echo '</ul>';
} else {
    // no posts found
}
/* Restore original Post Data */
wp_reset_postdata();

Hope this helps!