custom field - ACF Post Object meta-query by title not ID

I'm trying to query a post type (intervention) via a post object field (intervention_country) by the title (of the related custom post type - country).

Something like:

$wp_query = new WP_Query();
$wp_query->query(  array (
    'post_type' => 'intervention',
    'meta_query' => array(
        array(
            'key' => 'intervention_country',
            'value' => 'country_selected',
            'compare' => '=='
        )
     )
));

Can this be done? From other questions it looks like I have to give an ID but I would like to query using the title of the CPT (country) instead as given by `'country_selected' above

I'm trying to query a post type (intervention) via a post object field (intervention_country) by the title (of the related custom post type - country).

Something like:

$wp_query = new WP_Query();
$wp_query->query(  array (
    'post_type' => 'intervention',
    'meta_query' => array(
        array(
            'key' => 'intervention_country',
            'value' => 'country_selected',
            'compare' => '=='
        )
     )
));

Can this be done? From other questions it looks like I have to give an ID but I would like to query using the title of the CPT (country) instead as given by `'country_selected' above

• wp-query
• custom-field

Share Improve this question edited Nov 25, 2018 at 9:05 Krzysiek Dróżdż 25.6k99 gold badges5353 silver badges7474 bronze badges asked Nov 25, 2018 at 9:00 user142553user142553 2122 silver badges99 bronze badges

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1 Answer 1

Sorted by: Reset to default 0

It can be done, but it won't be so easy. Post Object is stored as an ID, so you can't use meta query to search by post title in such case... There are few ways of solving that problem:

1. Use acf/save_post action to save title of given post object as another meta value:

// Add this to your functions.php
function save_intervention_country_name ( $post_id ) {
    $country_id = get_field( 'intervention_country', $post_id );
    if ( $country_id ) {
        update_post_meta( $post_id, 'intervention_country_name', get_post_field( 'post_title', $country_id ) );
    }
}
add_action( 'acf/save_post', 'save_intervention_country_name', 20 );

And then you can search using intervention_country_name field:

$wp_query->query(  array (
    'post_type' => 'intervention',
    'meta_query' => array(
        array(
            'key' => 'intervention_country_name',
            'value' => <COUNTRY NAME>,
            'compare' => '=='
        )
     )
));

2. Use posts_where and posts_join filters to modify SQL query.

You'll have to add a JOIN statement to join your post object field with posts table, and then add where searching by title.

3. Modify your form in such way, that it does the search by ID not by name.

So if there is a select field, then fill its values with IDs. Or if you can't do that, you always can get the country first and then use its ID:

$country = get_page_by_title( <COUNTRY_NAME>, OBJECT, <COUNTRY_POST_TYPE> );
if ( $country ) {
    $wp_query->query(  array (
        'post_type' => 'intervention',
        'meta_query' => array(
            array(
                'key' => 'intervention_country',
                'value' => $country->ID,
                'compare' => '=='
            )
         )
    ));
}