How to assign role with PHP in Drupal?

Question

I need to assign a kind of \"premium status\" to members that purchase an amount equal or greater than 100 € via PHP.

Conditional Actions are already set up (user = anon

Answer 1

for drupal 7:

     global $user; // Retrieve user object for currently logged in user.

  $role_name = 'test role'; // Name of role to add

  // Get RID of role
  $rid = db_query("SELECT r.rid FROM {role} r WHERE r.name = :rname", array(':rname' => $role_name))->fetchField();

  // Save the user object with the new role.
  if (!isset($user->roles[$rid])) {
    $roles = $user->roles + array($rid => $role_name);
    user_save($user, array('roles' => $roles));
  }

thanks rix.