How do you query posts from more than one author in Wordpress?

Question

How do you query posts from more than one author in Wordpress?

something like: query_posts('author=9,10&post_status=publish&orderby=date')

This is not working though.

Answer 1

The query_posts() function was only meant to support querying one author at a time. If you want to display multiple authors, I suggest trying one of the following:

1. Create your own custom query to include multiple author IDs. You can use $wpdb->query() to run just about any SQL statement on the database, so you can definitely get a list of all posts by multiple authors, it just takes more work.
2. The second option is to group your posts by author and run a separate WordPress loop for each author ID. This breaks your content up somewhat, but you could preface each section with a short author bio. There's example code on this site.

Answer 2

According to this documentation there is no official support: http://codex.wordpress.org/Function_Reference/query_posts - under "Author Parameters" heading.

However, digging into the source code reveals otherwise: http://wordpress.taragana.net/nav.html?wp-includes/classes.php.html#query_posts.

$author_array = preg_split('/[,\s]+/', $q['author']);
for ($i = 1; $i < (count($author_array)); $i = $i + 1) {
    $whichauthor .= ' '.$andor.' post_author '.$eq.' '.intval($author_array[$i]);
}
$whichauthor .= ')';

To see if your comma-separated list is being used correctly I would go ahead and start throwing debug lines into the WP_Query::get_posts() function. For example, what is the final value of $whichauthor?

Answer 3

This slightly different loop will work mutliple times on a page or post with a different query parameters:

<?php $my_query = new WP_Query('author=9&post_status=publish&orderby=date'); ?>
<?php while ($my_query->have_posts()) : $my_query->the_post(); ?>
<a href="<?php the_permalink() ?>" title="<?php the_title(); ?>">
<?php the_title(); ?></a>
<?php endwhile; ?>

Answer 4

I think this is the right way to do it :

function yclads_posts_where_followed_authors($where) { global $wpdb;

$authors_ids = array(0,1,2,3);//array of authors IDs

if (count($authors_ids) > 0) {
    $where .= ' AND ' . $wpdb->posts . '.post_author IN(' . implode (',', $authors_ids) . ') ';
}else {
    $where .= ' AND 1=2'; //do not return results
}
return $where;

}

add_filter('posts_where', 'posts_where_filter_authors');