Query Posts Where Custom Field is NULL
To query posts where a specific custom field is null, use the snippet below:
$args = array(
'posts_per_page' => -1,
'post_type' => 'my_post_type', // change
'post_status' => 'publish',
'order' => 'DESC',
'orderby' => 'date',
'meta_query' => array(
'relation' => 'OR',
array(
'key' => 'my_custom_field', // change
'compare' => 'NOT EXISTS'
)
)
);
// Build Query
$query = new WP_Query($args);