Query with Relationship field

• mclambert

• July 7, 2016 at 11:58 pm

Hi,

I’ve a tourism website with 2 custom post type :
“Offre” (Holiday deals) and “Proposition” (Proposals for travelers)

A “Proposition” has some fields, one of them is a relationship field called ‘offre_liee’ which is linked to a post type “Offre”

I want to display only one “Proposition” which is linked to a specific “Offre” with the ID of it.

In a “Proposition” post, the field linked to an “Offre” is named “offre_liee”.

Here is the code :

$offre=get_post(21969);
$offre_id=$offre->ID;
var_dump($offre_id);

$favoris = get_posts(array(
			'post_type' => 'proposition',
			'numberposts' => -1,
			'meta_query' => array(
						array(
							'key' => 'offre_liee', 
							'value' => $offre_id, 
							'compare' => '='
						)
					)
					
				));

var_dump($favoris);

The first vardump works fine, it returns : the ID of the “Offre” : int(21969)

And unfortunately, the “var_dump($favoris);” return no result : array(0) { }

In the backoffice I can see that the “Offre” is properly linked to the “Proposition” with a Relation type field .
In ACF settings, I’ve tried with two options : “Term Object” and “Term ID”.

Anyone understand why the query return no result ?

Thank you for your help

• James

• July 8, 2016 at 2:56 pm

Hi @mclambert

That’s because the relationship field saves the data in the database as a serialized IDs. If you want to query it, I believe you should do it like this:

'meta_query' => array(
    array(
        'key' => 'offre_liee', 
        'value' => '"' . $offre_id . '"', 
        'compare' => 'LIKE'
    )
),

This page should give you more idea about it: https://www.advancedcustomfields.com/resources/querying-relationship-fields/.

I hope this helps 🙂

• mclambert

• July 9, 2016 at 12:16 am

Hi James

Thank you for your help, it works !

I’ve tried with an array of ID, it doesn’t work, it returns an empty array.

Here is what I’ve done, unfortunately it doesn’t work…
Do you have an idea ?

Thank you very much for your time.

<?php 

$preargs = array(
  'post_type'  => 'offres'
 );

$the_query = new WP_Query( $preargs ); 
$offres_id = array(); //added

while ( $the_query->have_posts() ) : $the_query->the_post();
 $offres_id[] = get_the_ID();
endwhile; 

// $arraydeidoffre RETURNS : array(7) { [0]=> int(25747) [1]=> int(25356) [2]=> int(24140) [3]=> int(23097) [4]=> int(23054) [5]=> int(22286) [6]=> int(12005) } 

$propositions = get_posts(array(
     'post_type' => 'proposition',
     'numberposts' => -1,
     'meta_query' => array(
      array(
       'key' => 'offre_liee', 
       'value' => $offres_id, 
       'compare' => 'IN'
      )
     )

    ));

var_dump($propositions);

?>

• James

• July 11, 2016 at 11:54 am

Hi @mclambert

I’m afraid you need to use multiple ‘meta_query’ values like this:

$meta_query = array('relation' => 'AND');
foreach( $offres_id as $the_id ) {
    $meta_query[] = array(
        'key' => 'offre_liee', 
        'value' => '"' . $the_id . '"', 
        'compare' => 'LIKE'
    );
}

Then you can use it like this:

'meta_query' => $meta_query,

This will create the query for all of the IDs you get. Unfortunately, I’m not sure regarding the performance if you have a lot of IDs.

I hope this helps 🙂