Using Offset in Custom Post Type Query

Question

I'm using the following query for a custom post type:

<?php
             $posts = get_posts(array(
                'numberposts' => -1,
                'offset' => 20,
                'post_type' => 'faqs'

             ));


            if($posts)
            {

                foreach($posts as $post)
                {
                    echo '<li class="faq">
                        <p class="title"><a href="' . get_permalink($post->ID) . '">' . get_the_title($post->ID) . '</a></p></li>';
                        /*<h4 class="title"><a href="' . get_permalink($post->ID) . '">' . get_the_title($post->ID) . '</a></h4><p>' . get_the_excerpt($post->ID) . '</p></li>'; */
                }

            }
             wp_reset_query();
            ?>

Is there a reason as to why the offset parameter doesn't work? Perhaps I need to write an entirely different query altogether?

Answer 1

Reason of this behavior is pretty simple. First of all you have to know that get_posts uses WP_Query to get posts.

So let's look at WP_Query implementation. On line 1998 of query.php you can find:

if ( $q['posts_per_page'] == -1 ) {
    $q['nopaging'] = true;

Then on line 2544 of query.php you find:

if ( empty($q['nopaging']) && !$this->is_singular ) {
    $page = absint($q['paged']);
    if ( !$page )
        $page = 1;

    if ( empty($q['offset']) ) {
        $pgstrt = ($page - 1) * $q['posts_per_page'] . ', ';
    } else { // we're ignoring $page and using 'offset'
        $q['offset'] = absint($q['offset']);
        $pgstrt = $q['offset'] . ', ';
    }
    $limits = 'LIMIT ' . $pgstrt . $q['posts_per_page'];
}

It's the only part where LIMIT for posts is added. And, as you can see, it is added only if nopaging is not set. So if posts_per_page is set to -1, then paging part of SQL query is not added.

So what can you do to work it around? You can set numberofposts to some big positive number.

Answer 2

Set 'numberposts' value to a large positive number. With numberposts set to -1 it will return all the faqs ignoring the offset value.