Display all posts in a custom post type, grouped by a custom taxonomy

Question

I’m working on a member page where I use a custom post type with a custom taxonomy. My custom post type is called member and my custom taxonomy is called member_groups.

I want to list all the members but group them together into their respective groups.

So to be clear, I’ve 35 members divided into 9 groups – so instead of making the same query nine times I want to do it once but group them together, so that Member1, Member4 and Member 11 is grouped together in one group, called “Marketing”.

I’m using WP_Query to retrieve all posts under post type member. I’ve tried different attempts but with no successful result.

How can I achieve that?

Answer 1

So, you might consider automating the multiple queries.

First, get the list of terms in your custom taxonomy, using get_terms():

<?php
$member_group_terms = get_terms( 'member_group' );
?>

Then, loop through each one, running a new query each time:

<?php
foreach ( $member_group_terms as $member_group_term ) {
    $member_group_query = new WP_Query( array(
        'post_type' => 'member',
        'tax_query' => array(
            array(
                'taxonomy' => 'member_group',
                'field' => 'slug',
                'terms' => array( $member_group_term->slug ),
                'operator' => 'IN'
            )
        )
    ) );
    ?>
    <h2><?php echo $member_group_term->name; ?></h2>
    <ul>
    <?php
    if ( $member_group_query->have_posts() ) : while ( $member_group_query->have_posts() ) : $member_group_query->the_post(); ?>
        <li><?php echo the_title(); ?></li>
    <?php endwhile; endif; ?>
    </ul>
    <?php
    // Reset things, for good measure
    $member_group_query = null;
    wp_reset_postdata();
}
?>

I can't see anything particularly wrong with this approach, though it may have a limited ability to scale (i.e. if you have hundreds or thousands of members, or member_group terms, you may see performance issues).

Answer 2

I found a solution by using a custom query and then grouping it with the term name:

SELECT * 
FROM wp_term_taxonomy AS cat_term_taxonomy
INNER JOIN wp_terms AS cat_terms ON cat_term_taxonomy.term_id = cat_terms.term_id
INNER JOIN wp_term_relationships AS cat_term_relationships ON cat_term_taxonomy.term_taxonomy_id = cat_term_relationships.term_taxonomy_id
INNER JOIN wp_posts AS cat_posts ON cat_term_relationships.object_id = cat_posts.ID
INNER JOIN wp_postmeta AS meta ON cat_posts.ID = meta.post_id
WHERE cat_posts.post_status =  'publish'
AND meta.meta_key =  'active'
AND meta.meta_value =  'active'
AND cat_posts.post_type =  'member'
AND cat_term_taxonomy.taxonomy =  'member_groups'

Then by just using a regular foreach query I can just extract the information I want.

But I'm still interested in another way if there is, maybe by using Wordpress' own functions.

Answer 3

even simpler:

$terms = get_terms('tax_name');
$posts = array();
foreach ( $terms as $term ) {
    $posts[$term->name] = get_posts(array( 'posts_per_page' => -1, 'post_type' => 'post_type', 'tax_name' => $term->name ));
}

Within the resultant $posts array, each tax term is the key to a nested array containing its posts.

Answer 4

I had this exact need, and Chip's solution worked, except for one thing: 'field' => 'slug' is required.

    foreach ( $service_categories as $category ) {
        $services = new WP_Query( 
            array(
                'post_type'     => 'service',
                'tax_query'     => array(
                    array(
                        'taxonomy'  => 'service_category',
                        'terms'     => array( $category->slug ),
                        'operator'  => 'IN',
                        'get'       => 'all',
                        'field'     => 'slug'
                    )
                )
            ) 
        ); ?>
        <h2><?php echo $category->slug; ?></h2>
        <?php if ( $services->have_posts() ) {  // loop stuff goes here ?>

I also needed the resulting display to be flat, so 'get' => 'all' is set here.

Hopefully this helps somebody else out.

Answer 5

I had to do this on a project years ago. Similar answer to djb, just with a bit more details. This will output all of your taxonomy names as an h3, with a bulleted list of each post title linked to their detail page.

<?php // Output all Taxonomies names with their respective items
$terms = get_terms('member_groups');
foreach( $terms as $term ):
?>                          
    <h3><?php echo $term->name; // Print the term name ?></h3>                          
    <ul>
      <?php                         
          $posts = get_posts(array(
            'post_type' => 'member',
            'taxonomy' => $term->taxonomy,
            'term' => $term->slug,                                  
            'nopaging' => true, // to show all posts in this taxonomy, could also use 'numberposts' => -1 instead
          ));
          foreach($posts as $post): // begin cycle through posts of this taxonmy
            setup_postdata($post); //set up post data for use in the loop (enables the_title(), etc without specifying a post ID)
      ?>        
          <li><a href="<?php the_permalink(); ?>"><?php the_title(); ?></a></li>    
        <?php endforeach; ?>
    </ul>                                                   
<?php endforeach; ?>

Answer 6

$query = new WP_Query( 
   array ( 
      'post_type' => 'member', 
      'orderby'   => 'meta_value', 
      'meta_key'  => 'member_group' 
   ) 
);

Then when you loop through this query you could just use an if along these lines (in php pseudocode)

$groupName = "";
$counter = 0;
if havePosts: while havePosts: thePost

if( $groupName != post->meta_value )
{
if ($counter > 0)
{
</ul>
}
<h1>A group name</h1>
<ul>
<li>member name</li>
}
else
{
<li>member name</li>
}

endwhile;endif

</ul>

I hope that helps. I think you were making this far more complicated than it needed to be.

More information: http://codex.wordpress.org/Class_Reference/WP_Query#Taxonomy_Parameters

Answer 7

Well, it's an old thread, but if someone passes by as I did, this might help. The idea is to modify the main query so we don't need to go the templates and generate new queries and loops...

PS: Yet to be tested in large dbs. It was satisfactory in my case.

function grouped_by_taxonomy_main_query( $query ) {

    if ( $query->is_home() && $query->is_main_query() ) { // Run only on the homepage

        $post_ids = array();

        $terms = get_terms('my_custom_taxonomy');

        foreach ( $terms as $term ) {
            $post_ids = array_merge( $post_ids, get_posts( array( 
                'posts_per_page' => 4, // as you wish...
                'post_type' => 'my_custom_post_type', // If needed... Default is posts
                'fields' => 'ids', // we only want the ids to use later in 'post__in'
                'tax_query' => array( array( 'taxonomy' => $term->taxonomy, 'field' => 'term_id', 'terms' => $term->term_id, )))) // getting posts in the current term
            );
        }

        $query->query_vars['post_type'] = 'my_custom_post_type'; // Again, if needed... Default is posts
        $query->query_vars['posts_per_page'] = 16; // If needed...
        $query->query_vars['post__in'] = $post_ids; // Filtering with the post ids we've obtained above
        $query->query_vars['orderby'] = 'post__in'; // Here we keep the order we generated in the terms loop
        $query->query_vars['ignore_sticky_posts'] = 1; // If you dont want your sticky posts to change the order

    }
}

// Hook my above function to the pre_get_posts action
add_action( 'pre_get_posts', 'grouped_by_taxonomy_main_query' );