How to merge these two post queries?

Question

How can I consolidate the queries below... ?

Query 1: Any posts with the "Topic" taxonomy term, eg. "Music"

Query 2: Any posts attached to a "Company" taxonomy term, eg. "Spotify", which itself has the above "Topic" term, eg. "Music" (via meta field 'org_topics').

The result should be all "Music"-related posts, whether it is a post directly tagged with that Topic or a post whose attached Company has that Topic.

Query 1, regular:

  $paged = ( get_query_var( 'paged' ) ) ? get_query_var( 'paged' ) : 1;
  $query_args = array(
  // pagination
    'nopaging' => false,
    'posts_per_page' => 81,
    'paged' => $paged,
    // order
    'order_by' => 'date',
    'order'   => 'DESC',
    // posts
    'post_type' => 'any',
    // taxonomies
    'tax_query' => array(
      'relation' => 'AND',
      array(
        'taxonomy' => 'topic',
        'field'    => 'slug',
        'terms'    => 'music,
        'include_children' => false,
      ),
   ),
  );
  global $query_posts;
  $query_posts = new WP_Query($query_args);
  wp_reset_postdata();

Query 2, more complex:

I already have a custom function (get_posts_with_extras) which does this query in isolation.

It calls a prior custom function (get_terms_with_extras) which first gets a list of terms with matching meta. We use that to generate an array of term IDs to pre-set in WP_Query.

$post_results = get_posts_with_tax_and_meta('any', 'company', array('org_topics'=>$queried_object->term_id), 81);

.

function get_posts_with_tax_and_meta(          // Get these posts...
   $post_type,                                 // 1. Get posts of this post type                        eg. 'viewpoint'
   $taxonomy,                                  // 2. But only those with this taxonomy                  eg. 'company'
   $tax_meta,                                  // 3. And the taxonomy term has this meta                eg. array('tags'=>'Marketing'),
   $num_posts=6,                               // 4. Return this many posts                             eg. 6
   $tax_and_term=null,                         // 5. Constrain by a second taxonomy and term            eg. array('format'=>'oped'),
   $offset                                     // 6. Offset posts by this number of posts               eg. 4
   // $paged                                   // 7. Pagination page
) {

  /*  1. First, get the Taxonomy Terms' IDs */
  // These are the relevant Taxonomy Term objects

  $terms_list = get_terms_with_extras(
     $taxonomy,                                // 1. Get terms in the specified taxonomy                eg. 'company'
     array(key($tax_meta)=>reset($tax_meta)),  // 2. Which also have these meta fields                  eg. array('tags'=>'media')
     $post_type,                               // 3. And also have posts of the specified type          eg. 'viewpoint'
     '',                                       // 4. But those posts must have this taxonomy and term   eg. array('format'=>'oped')
     'name',                                   // 5. Order by value, corresponds to get_terms order_by  eg. 'name'
     'asc'                                     // 6. Order direction, corresponds to get_terms order    eg. 'asc'
                                               // 7. Limit term result, corresponds to get_terms number eg. 16
 );


  // But we only want the Terms' IDs (to pass to the query below)...
  $terms_list_ids = array();
  foreach ($terms_list  as $term_single) {
       array_push($terms_list_ids, $term_single->term_id);
  }

  if ( !empty($tax_and_term) ) {
     $tax_and_term_query[] = array(
     'taxonomy' => key($tax_and_term),
     'field' => 'slug',
     'terms' => reset($tax_and_term),
     );
   } else {
     $tax_and_term_query[] = null;
   }


  /* 2. Get the Posts with those Terms */
  // Query posts
  global $paged;
  $paged = ( get_query_var( 'paged' ) ) ? get_query_var( 'paged' ) : 1;
  $query_args = array(
  // pagination
    'nopaging' => false,
    'posts_per_page' => $num_posts,
    'paged' => $paged,
    // order
    'order_by' => 'date',
    'order'   => 'DESC',
    // posts
    'post_type' => $post_type,
    'offset' => $offset,
    // taxonomies
    'tax_query' => array(
      'relation' => 'AND',
      array(
        'taxonomy' => $taxonomy,
        'field'    => 'id',
        'terms'    => $terms_list_ids,
        'include_children' => false,
      ),
      $tax_and_term_query,
   ),
  );
  global $the_post_results; // Make it available everywhere
  // Get the posts and return them to whatever called this...
  $the_post_results = new WP_Query($query_args);
  wp_reset_postdata();
  return $the_post_results;


}

This second query works fine in isolation.

What I don't understand is how to combine these two.

Is the right approach to perform the two queries and then combine at the end somehow? (I have tried a couple of array merging techniques, but the resulting query seems to become unstuck).

Or is there a way to make a single, more efficient query?

Answer 1

The answer is "take the array from the tax_query argument in the first query, insert it into the second and change the relation to OR".

In other words, to use a single query with the following in the arguments ...

(As stated before, $terms_list_ids was already generated; it contains the IDs of Company terms which have meta that matches the current Topic term).

Credit for the answer goes to a Reddit user.

  // taxonomies
  'tax_query' => array(
    'relation' => 'OR',
    // Posts related to a Company with this Topic...
    array(
      'taxonomy' => 'company',
      'field'    => 'id',
      'terms'    => $terms_list_ids,
      'include_children' => true, // <<< IMPORTANT
    ),
    // Or...
    // Posts with this Topic directly...
    array(
      'taxonomy' => 'topic',
      'field'    => 'slug',
      'terms'    => $topic_term->slug,
      'include_children' => false,
    ),
 ),