How to search display_name column when using WP_User_Query

Question

I'm using WP_User_Query to bring back a list of users. According to this article, I can focus the query on particular columns (I'm assuming in the wp_users table) using the search_columns param.

My query:

$args = array(
    'search' => 'Rami',
    'search_columns' => array( 'user_login', 'user_email', 'display_name' ),
);
$user_query = new WP_User_Query( $args );

My aim is to have my query look in the display_name column but that doesn't seem to be working. Interestingly, display_name isn't a mentioned column in the article example but it is definitely a column in the wp_users table.

How can I search the display_name column when using WP_User_Query?

Answer 1

You can try this:

/**
 * Add support for the "display_name" search column in WP_User_Query
 * 
 * @see http://wordpress.stackexchange.com/a/166369/26350
 */
add_filter( 'user_search_columns', function( $search_columns ) {
    $search_columns[] = 'display_name';
    return $search_columns;
} );

where we use the user_search_columns filter to modify the available search columns.

So what fields can we use with this filter? Here's the list of all the fields in the wp_users table:

x ID
x user_login
  user_pass
x user_nicename
x user_email
x user_url
  user_registered
  user_activation_key
  user_status
  display_name

where I've marked the default search columns with an x.

Answer 2

According to the codex, display_name isn't supported.

You could use the pre_user_query filter.

function henry_display_name_find( $query ) {
    global $wpdb;

    /* you don't say where the name comes from - this assumes a $_POST field */
    $display_name = $_POST['display_name'];

    $use_like_syntax = false;

    if ( $use_like_syntax = true ) {
        $query->query_where .= $wpdb->prepare( " AND $wpdb->users.display_name LIKE %s", '%' . like_escape( $display_name ) . '%' );
    } else {
        $query->query_where .= $wpdb->prepare( " AND $wpdb->users.display_name = %s", $display_name );
    }
}
add_action( 'pre_user_query', 'henry_display_name_find' );

You'll probably want to add and remove the filter in a function.