Home Forums Front-end Issues Reverse Relationship Query Reply To: Reverse Relationship Query

  • Well, If I needed I’d go directly to the database, only because it would mean a lot less queries to do and would be a lot faster. This is quick to illustrate the queries. On the other hand, I don’t think that prepare can handle the ‘IN’ clause, at least I have never found anything that gives any adequate solution.

    global $wpdb;
    // 1. get all the post ID's of doctors
    $query = 'SELECT ID
              FROM '.$wpdb->posts.'
              WHERE post_type = "doctor"
                AND post_status = "publish"';
    $ids = $wpdb->get_col($query);
    // 2. get the relationship field for all of the above posts
    $query = 'SELECT meta_value
              FROM '.$wpdb->postmeta.'
              WHERE post_id IN ("'.implode('", "', $ids).'")
                AND meta_key = "my_relationship"'; // or whatever the field name is
    $list = $wpdb->get_col($query);
    // 3. get list of unique locations
    $location_ids = array()
    for ($i=0; $<count($list); $i++) {
      $value = maybe_unserialize($list[$i]);
      if (is_array($value)) {
        for ($j=0; $j<count($value); $j++) {
          if (!in_array($value[$j], $location_ids)) {
            $location_ids = intval($value[$j]);
        } // end for j
      } // end if array
    } // end for i
    // 4. query locations
    $args = array(
      'post_type' => 'location',
      'posts_per_page' => -1,
      'post__in' => $location_ids
    $locations = new WP_Query($args);