I am not sure from your wording if you hadn’t tried it with query argument or it didn’t work?
$the_query = new WP_Query(array( 'meta_key' => 'open', 'meta_value' => 'yes' ));
Custom Field Parameters in Codex.
I am not sure from your wording if you hadn’t tried it with query argument or it didn’t work?
$the_query = new WP_Query(array( 'meta_key' => 'open', 'meta_value' => 'yes' ));
Custom Field Parameters in Codex.