Query posts by custom fields (object post)

Question

As described in ACF documentation, here is the way to find all posts where a custom field called ‘color’ has a value of ‘red’.

$posts = get_posts(array(
    'numberposts'   => -1,
    'post_type'     => 'post',
    'meta_key'      => 'color',
    'meta_value'    => 'red'
));

But in my case, I need to find all posts where the ID of an object post custom field has a certain ID.

How should I proceed to handle meta_value as an object, and targeting its ID key?

Answer 1

If you use Post Object field type, then it is stored as ID in custom field. So this should do the trick:

$posts = get_posts(array(
    'numberposts'   => -1,
    'post_type'     => 'post',
    'meta_key'      => '<FIELD_NAME>',
    'meta_value'    => <POST_ID>
));

PS. You should use 'posts_per_page' instead of 'numberposts' (which is deprecated).