How to get the number of posts from Relationship field – for "reverse" posts?

• danbo

• November 24, 2015 at 8:32 am

– I have custom post type “producers”.

– And i have custom post type “movies”.

– I have relationship field “movies_of_this_producer”.

On the page of edit/creation new post of custom post type “movies”

*I have this relationship field “movies_of_this_producer” on the page of edit/creation new post of custom post type “movies”.

So, to display a list of related posts of custom post type “movies” on a single post page (of custom post type “producers”) (single-produsers.php template) – I use Reverse Query (like in this tutorial: http://www.advancedcustomfields.com/resources/tutorials/querying-relationship-fields/). And it’s work correctly.

1) Now I need to display on the main page (index.php template) list of posts of custom post type “movies”, with number of related “producers” posts (related via relationship field “movies_of_this_producer”).

2) And now I need to display on the main page (index.php template) list of posts of custom post type “producers”, with number of related “movies” posts (related via relationship field “movies_of_this_producer”).

– To solve the problem number1 (display on the main page list of posts of custom post type “movies”, with number of related “producers” posts), I use this code (and it’s work correctly):

<?php
$TESTrel_movies = new WP_Query( array(
    'post_type' => 'movies',
    'post__not_in' => array($post->ID),
    'posts_per_page' => 5,
    'orderby' => 'meta_value_num',
    'order' => 'ASC',
    'meta_key' => 'movies_of_this_producer',
    'offset' => 0,
    ) );
?>

<?php if( $TESTrel_movies ): ?>
<div class="content_block_wrap two_columns_right col-md-6">
    <div class="content_block transparent_block_with_border">
        <div class="block_title">
            Title here
        </div>
        <ul>
            <?php
                while ( $TESTrel_movies->have_posts() ) :
            $TESTrel_movies->the_post();
            ?>
                <li class="content_item col-xs-12">
                    <a class="post_thumbnail" href="<?php echo get_permalink( $TESTrel_movies->ID ); ?>">
                        <?php echo get_the_post_thumbnail( $TESTrel_movies->ID, '90x60-thumb' ); ?>
                    </a>

                    <a href="<?php echo get_permalink( ); ?>"><?php echo get_the_title( ); ?></a>
                    
                    Number of related posts: <?php
                    echo $movie_count = count(get_field('movies_of_this_producer'));
                    ?>

                </li>
            <?php
            endwhile;
            ?>
        </ul>
    </div>
</div>
<?php endif; ?>

<?php
wp_reset_postdata();
?>

– However, if I use analogical code to solve the problem number2 (display on the main page list of posts of custom post type “producers”, with number of related “movies” posts) – it’s work incorrectly (as a result I get a list of “producers” posts, but the values of the number of related “movies” posts – equals zero). Here is this code (that I try to use, but it’s work incorrectly):

<?php
$TESTrel_producers = new WP_Query( array(
    'post_type' => 'producers',
    'post__not_in' => array($post->ID),
    'posts_per_page' => 5,
    'orderby' => 'meta_value_num',
    'order' => 'ASC',
    'meta_key' => 'movies_of_this_producer',
    'offset' => 0,
    ) );
?>

<?php if( $TESTrel_producers ): ?>
<div class="content_block_wrap two_columns_right col-md-6">
    <div class="content_block transparent_block_with_border">
        <div class="block_title">
            Title here
        </div>
        <ul>
            <?php
                while ( $TESTrel_producers->have_posts() ) :
            $TESTrel_producers->the_post();
            ?>
                <li class="content_item col-xs-12">
                    <a class="post_thumbnail" href="<?php echo get_permalink( $TESTrel_producers->ID ); ?>">
                        <?php echo get_the_post_thumbnail( $TESTrel_producers->ID, '90x60-thumb' ); ?>
                    </a>

                    <a href="<?php echo get_permalink( ); ?>"><?php echo get_the_title( ); ?></a>
                    
                    Number of related posts: <?php
                    echo $producer_count = count(get_field('movies_of_this_producer'));
                    ?>

                </li>
            <?php
            endwhile;
            ?>
        </ul>
    </div>
</div>
<?php endif; ?>

<?php
wp_reset_postdata();
?>

I think that in this case – may need to use some kind of “Reverse” way (because “producers” posts – have “reverse” relationship with “movies” posts via relationship field “movies_of_this_producer”), but I don’t know how to do it.

Question: How to display on the main page (index.php template) list of posts of custom post type “producers”, with number of related “movies” posts (related via relationship field “movies_of_this_producer”)? (*it’s a problem number2, described in this topic)

• James

• June 27, 2016 at 6:19 pm

Hi there,

You can achieve this by looking into this page: http://www.advancedcustomfields.com/resources/querying-relationship-fields/. On the last code example, you can see that you need to query the posts using get_posts(). It will be something like this:

<!-- TESTrel_producers -->    
<?php
$TESTrel_producers = new WP_Query( array(
    'post_type' => 'producers',
    'post__not_in' => array($post->ID),
    'posts_per_page' => 20,
    'orderby' => 'title', //change it if you want to order by something else
    'order' => 'ASC',
    'offset' => 0,
    ) );
?>

<?php if( $TESTrel_producers ): ?>
<div class="content_block_wrap two_columns_right col-md-6">
    <div class="content_block transparent_block_with_border">
        <div class="block_title">
            List of posts of custom post type “producers”, with number of related “movies” posts:
        </div>
        <ul>
            <?php
                while ( $TESTrel_producers->have_posts() ) :
            $TESTrel_producers->the_post();
            ?>

                <?php
                $the_movies = get_posts(array(
                    'post_type' => array( 'movies' ), // uncomment it if you only want to get the result from movies post type
                    'posts_per_page' => -1,
                    'meta_query' => array(
                        array(
                            'key' => 'movies_of_this_producer', // name of custom field
                            'value' => '"' . get_the_ID() . '"', // matches exaclty "123", not just 123. This prevents a match for "1234"
                            'compare' => 'LIKE'
                        )
                    )
                ));
                ?>

                <li class="content_item col-xs-12">
                    <a class="post_thumbnail" href="<?php echo get_permalink( $TESTrel_producers->ID ); ?>">
                        <?php echo get_the_post_thumbnail( $TESTrel_producers->ID, '90x60-thumb' ); ?>
                    </a>

                    <a href="<?php echo get_permalink( ); ?>"><?php echo get_the_title( ); ?></a>
                    
                    <span class="sm">Number of related posts:</span> <?php
                    echo $producer_count = count($the_movies);
                    ?>

                </li>
            <?php
            endwhile;
            ?>
        </ul>
    </div>
</div>
<?php endif; ?>

<?php
wp_reset_postdata();
?>
<!-- TESTrel_producers end -->

I hope that helps.