Set php variables in shortcode

I have created my page in .php and I am trying to set a variable depending on the user role but the code seems to just show up on the page.

the code is something like this inside php tags:

echo do_shortcode('[O_U user_role="myCustomUserGroup"] $var = $wpdb->get_results("query"); ?>[/O_U]');

https://wordpress.org/plugins/user-specific-content/