Sort user.php by last name

Hello friends
i’ve a problem in admin area exactly about user.php
i really need to order user list by last name.

In name list i see name + last name so
first of all i edited the code for split:

Line 338 adding array

	protected function get_sortable_columns() {
		$c = array(
			'username' => 'login',
			'lastname' => 'last_name',
			'name'     => 'first_name',
			'email'    => 'email',
		);

Line 469 split case name so i can see last name column

				switch ( $column_name ) {
					case 'username':
						$r .= "$avatar $edit";
						break;
					case 'lastname':
						$r .= "$user_object->last_name";
						break;
					case 'name':
						$r .= "$user_object->first_name";
						break;

So the problem is that if i click on last name sorting indicator the list change always sorting by username. why?
Can you help me please?

• This topic was modified 8 years, 7 months ago by Bluekid.