//how to update current user role in custom user column inside wpdb.
//update must effect only the current user
global $wpdb;
$user_Tag = $current_user->ID; //ID hook
$push_status = 'customer'; // custom string
if(current_user_can('customer') ) {$wpdb->update( 'wpdb_table_name', array( 'wpdb_role_column' =>$push_status), array( 'wpdb_id_column' => $user_Tag ), array( '%s' ));
}