How to get the administrator role id to assign new permissions?

Question

In my module I'm creating new permissions that I want by default also assigned to the Drupal admin user.

I know how to assign new permissions to a role, but I don't know how to get the Drupal administrator role id. In the database the rid for administrator is 3, but can I rely on that being always the case? I'm using Drupal 7.

Answer 1

unless you install Drupal in your custom installation profile and modify the administrator role there, the rid or administrator will be always 3.
Or you could just do a db_query() on role table to return the rid of administrator as:

$result = db_query("SELECT rid FROM {role} where name like :id",array(':id' => 'administrator'));
$admin_rid = $result->fetchField(0);

Answer 2

Consider that the administrator role may have a different name than administrator or may have a different role ID.

Drupal 7 has a configuration available at Account Settings page: Administrator role

The value is stored in variable named user_admin_role.

$admin_rid = variable_get('user_admin_role');

After getting the role ID, you can do pretty much anything you need with it.