Xtykutl

I have this query to read out my custom post type dealers.

<?php

return array(

    'post_type' => 'deckmatedealers',

    'post_status' => 'publish',

     'posts_per_page' => 999,

    'meta_key'          => 'land',

    'orderby'           => 'meta_value',

    'order'             => 'ASC'

);

He picks up all dealers with customfield "country" and shows them sorted at the time of adding. I want them to be sorted on my customfield "province". The dealers come from different countries and only the Netherlands has provinces. I want the query to be sorted based on provinces. If I change my query to the following:

<?php

return array(

    'post_type' => 'deckmatedealers',

    'post_status' => 'publish',

     'posts_per_page' => 999,

    'meta_key'          => 'provincie',

    'orderby'           => 'meta_value',

    'order'             => 'ASC'

);

Then the results are sorted by province, but he does not show all other countries that do not have a province.

How can I create a query that picks up the dealers from all countries and the dealers who have a customfield province sort the dealers by province? In this case only dealers with country Netherlands have provinces.