Wordpress: search users using 'first_name' and 'last_name'?

Question

UPDATE: I mean to search user in the Admin User Dashboard at /wp-admin/users.php

Is there a way to search users using 'first_name' and 'last_name'?

I found this plugin but not working at all: https://wordpress.org/plugins/full-name-search-in-wp-admin/

I also found this function, but neither is working in my site. Do I need to call the function with a hook/action?:

function search_users($search_term){

    global $wpdb;
    $the_users = $wpdb->get_results("SELECT DISTINCT $wpdb->users.* FROM $wpdb->users INNER JOIN $wpdb->usermeta um1 ON um1.user_id = $wpdb->users.ID JOIN $wpdb->usermeta um2 ON um2.user_id = $wpdb->users.ID WHERE (um1.meta_key = 'uRPhICRS_capabilities' AND um1.meta_value LIKE '%agent%') AND ((um2.meta_key = 'first_name' OR um2.meta_key = 'last_name') AND um2.meta_value LIKE '%".$search_term."%');");

    if(!empty($the_users)){
        return $the_users;
    }
    else{
        return false;
    }

}

Answer 1

Two Ways as follow:

1) If You want to check from the string match in either firstname or lastname, following will be work:

$users_query = new WP_User_Query(
  array(
    'meta_query' => array(
    'relation' => 'OR',
      array(
        'key' => 'first_name',
        'value' => $str,
        'compare' => 'LIKE'
      ),
    array(
        'key' => 'last_name',
        'value' => $str,
        'compare' => 'LIKE'
      )
    )
  )
 );

$users = $users_query->get_results();

2) If you want to check the user from username, user_nicename, user_email, firstname, or lastname use following code:

//search from the user table 
$users_query_table = new WP_User_Query(
  array(
    'search' => "*{$str}*",
    'search_columns' => array(
    'user_login',
    'user_nicename',
    'user_email',
  ),
) );
$users_via_table = $users_query_table->get_results();

//search from the usermeta
$users_query_meta = new WP_User_Query(
  array(
    'meta_query' => array(
    'relation' => 'OR',
      array(
        'key' => 'first_name',
        'value' => $str,
        'compare' => 'LIKE'
      ),
    array(
        'key' => 'last_name',
        'value' => $str,
        'compare' => 'LIKE'
      )
    )
  )
 );

$users_via_meta = $users_query_meta->get_results();

// Merge both result.. 
$combined_users = array_merge( $users_via_table, $users_via_meta );

// Get unique user
$users = array_unique( $combined_users, SORT_REGULAR );