Display current ranking of post as a number in post title

Question

I have a page where people can rank stuff. My posts are ordered by the current ranking which is stored as a meta key in post meta.

Now i want to add the current ranking spot within the title of the single post page.

I found this code which is working fine with adding the ranking number according to post date:

    class MY_Post_Numbers {

    private $count = 0;
    private $posts = array();

    public function display_count() {
        $this->init(); // prevent unnecessary queries
        $id = get_the_ID();
        echo sprintf( '<div class="post-counter">Post number<span class="num">%s</span><span class="slash">/</span><span class="total">%s</span></div>', $this->posts[$id], $this->count );
    }

    private function init() {
        if ( $this->count )
            return;
        global $wpdb;       
        $posts = $wpdb->get_col( "SELECT ID FROM $wpdb->posts WHERE post_status = 'publish' AND post_type = 'post' ORDER BY post_date " ); // can add or change order if you want 
        $this->count = count($posts);

        foreach ( $posts as $key => $value ) {
            $this->posts[$value] = $key + 1;
        }
        unset($posts);
    }

}
$GLOBALS['my_post_numbers'] = new MY_Post_Numbers;

function my_post_number() {
    $GLOBALS['my_post_numbers']->display_count();
}

Now i only need to make it work with my meta key value instead of order by post_date

$posts = $wpdb->get_col( "SELECT ID FROM $wpdb->posts WHERE post_status = 'publish' AND post_type = 'post' ORDER BY post_date " );

Can someone help me changing this line so i can order by my ranking meta value?

The meta value is a decimal number like e.g. 3.745 .

Kinda lost right now already tried a lot with this but nothing worked yet

Answer 1

Could make it work already :)

     class MY_Post_Numbers {

    private $count = 0;
    private $posts = array();

    public function display_count() {
        $this->init(); // prevent unnecessary queries
        $id = get_the_ID();
        echo sprintf( '<div class="post-counter">Post number<span class="num">%s</span><span class="slash">/</span><span class="total">%s</span></div>', $this->posts[$id], $this->count );
    }

    private function init() {
        if ( $this->count )
            return;
        global $wpdb;       
        $posts = $wpdb->get_col( "SELECT $wpdb->posts.ID
                FROM $wpdb->posts
                left join $wpdb->postmeta ON ($wpdb->posts.ID = $wpdb->postmeta.post_id)
                WHERE $wpdb->posts.post_status = 'publish'
                AND $wpdb->posts.post_type = 'hp_listing'
                AND $wpdb->postmeta.meta_key = 'hp_rating'
                ORDER BY ($wpdb->postmeta.meta_value + 0) DESC");
        $this->count = count($posts);

        foreach ( $posts as $key => $value ) {
            $this->posts[$value] = $key + 1;
        }
        unset($posts);
    }

}
$GLOBALS['my_post_numbers'] = new MY_Post_Numbers;

function my_post_number() {
    $GLOBALS['my_post_numbers']->display_count();
}

with

<?php my_post_number(); ?>

it's possible to use in template file if anyone else is interested