How do I empty a specific meta_value for all users in PHP

Question

I've been able to successfully empty the meta_value for a specific meta_key. The problem is that a new meta_key will be created for all users in the database. I do not want all users to have the meta_key created in the database unless it already exist.

I think perhaps if I set 'guest_list_venue_names' as a variable and check if it exist I can use an IF statement? I'm new to PHP so any insight would be helpful.

$wp_user_query = new WP_User_Query(array('role' => 'Subscriber'));

$users = $wp_user_query->get_results();

if (!empty($users)) {


    foreach ($users as $user)
    {
        update_user_meta( $user->id, 'guest_list_venue', ''); 
        update_user_meta( $user->id, 'guest_list_venue_names', ''); 
    }
}

Answer 1

You could specify the meta key in the user query so the results you're getting back are only for users who have an existing field.

For reference WP_User_Query custom field(user meta) params.

$args = array(
    'role' => 'Subscriber',
    'meta_query' => array(
        array(
            'key' => 'old_meta_key_name',
            'compare' => 'EXISTS'
        )
    ),
);
$users_with_meta = new WP_User_Query( $args );
$users = $users_with_meta->get_results();

Answer 2

my friend. You should use the get_user_meta() function to check if there is meta in the user table or not. If there is, replace the meta value.

$meta = get_user_meta($user->id,
'guest_list_venue')
if(! empty($meta)){
   update_user_meta( $user->id, 'guest_list_venue', 'value');
}