[Plugin: Custom Field Template] Manual Related Post

Do you want this field to be a select list from which you can pick on related post?

Here’s some code for the field that goes in the template definition section:

[Related_Post_ID]
type = select
code = 0
hideKey = true
label = Related Post

The attribute code = 0 references the PHP code section further down the page. The following code should go in the PHP Code section, in the Code #0 box.

global $wpdb;
$items = $wpdb->get_results("SELECT ID, post_title
FROM $wpdb->posts
where post_type = 'post'
and post_status = 'publish'
order by post_date DESC");
$i = 0;
foreach ($items as $item) {
	$values[$i] = $item->ID;
	$valueLabel[$i] = $item->post_title;
	$i++;
}

If all goes well, this will give you a dropdown list of all your posts.