Display a query with multiple post types and same relationship on a single page

I am creating a client portal were my clients can maintain their projects and leave feedback in WordPress. I have two custom post types called “Clients” and “Projects” and they each pull information from one another in the backend. When I create a client it automatically generates its postID to a drop down menu on the projects post type were I can assign a client to a project.

What I am trying to accomplish is by displaying all projects that are associated with the selected client on a single page on the front end. The single page will be the client portal, which is generated by the client post type.

I can’t seems to display the associated post. Here is my code for single.php which will be displaying the projects on the clients portal.

 <?php 
    $paged = (get_query_var('paged')) ? get_query_var('paged') : 1;
      $loop = new WP_Query( array(
         'post_type'      => array( 'projects'),
         'posts_per_page' => -1,
         'paged'          => $paged,
         'meta_query' => array(
              array(
                 'key'     => 'a_client', // name of custom field
                 'value'   => '"' . get_the_ID() . '"', 
                 'compare' => 'LIKE'
             )
          )                 
     )); 
 ?> 

Below is the code I am using to assign a client to a projects in the admin panel of projects. This script displays any client that I created in the client page and display their names in a drop down menu.

 add_action( 'add_meta_boxes', 'add_clients_custom_metabox' );
    function add_clients_custom_metabox() {
 add_meta_box( 'custom-metabox', __( 'Clients' ), 'clients_custom_metabox', 'projects', 'side', 'high' );
 }

 function clients_custom_metabox($post) {
     global $post,$current_user;
     //remember the current $post object
        $real_post = $post;
     //get curent user info (we need the ID)
       get_currentuserinfo();
     //create nonce
       echo '<input type="hidden" name="clients_meta_box_nonce" value="',       wp_create_nonce(basename(__FILE__)), '" />';
     //get saved meta
       $selected = get_post_meta( $post->ID, 'a_clients', true );
    //create a query for all of the user clients posts
       $clients_query = new WP_Query();
       $clients_query->query(array(
           'post_type'      => 'client_portal',
           'posts_per_page' => -1,
           'author'         => $current_user->ID));
    if ($clients_query->have_posts()){
          echo '<select name="a_clients" id="a_clients">';
      //loop over all post and add them to the select dropdown
          echo '<option>Assign a client</option>';
          while ($clients_query->have_posts()){
     $clients_query->the_post();
          echo '<option value="'.$post->ID.'" ';
                if ( $post->ID == $selected){
          echo 'selected="selected"';
               }
          echo '>'.$post->post_title .'</option>';
               }
          echo '<select>';
               }
     //reset the query and the $post to its real value
        wp_reset_query();
        $post = $real_post;
             }
    //hook to save the post meta
          add_action( 'save_post', 'save_clients_custom_metabox' );
    // Process the custom metabox fields
        function save_clients_custom_metabox( $post_id ) {
            global $post;
   // verify nonce
    if (!wp_verify_nonce($_POST['clients_meta_box_nonce'], basename(__FILE__))) {
        return $post_id;
   }
  // check autosave
     if (defined('DOING_AUTOSAVE') && DOING_AUTOSAVE) {
     return $post_id;
  }
 // check permissions
 if ('events' == $_POST['post_type']) {
 if (!current_user_can('edit_page', $post_id)) {
return $post_id;
 }
} elseif (!current_user_can('edit_post', $post_id)) {
return $post_id;
 }
if( $_POST ) {
 $old = get_post_meta($post_id, 'a_clients', true);
 $new = $_POST['a_clients'];
if ($new && $new != $old){
 update_post_meta($post_id, 'a_clients', $new);
}
 }
  }

Full code for single.php http://pastebin.com/na7djwsq

Register Post Type I am using
Project post type is called => projects
Clients post type is called => client_portal

You’re setting the post meta as a_clients, but the query is looking for a_client.

update_post_meta($post_id, 'a_clients', $new);

'key' => 'a_client'

Those need to be the same. Since updating the query means you won’t have to go updating posts again, I suggest updating the key of the meta_query to a_clients.