Laravel外左连接

I have the following query for my users table. I have an additional pivot table for permissions and need to integrate this into my query.

$users = DB::table('users')
            ->join('locations', 'locations.id', '=', 'users.location_id')
            ->where('active', 1)
            ->get(array('users.fullname', 'users.email', 'permissions.granted'))

The pivot table consists of

user_persmission (table)

user_id, permission_id

permissions (table) id title

Simply, I need my array to have an additional field to indicate if this user has any permission set. It does not have to show the value, but only set 'granted' to 1 if a row exists.

Note: It is possible for a user to have no permissions as this is not mandatory, and equally they can have more than one permission.

I was thinking of a left outer join but very unsure how to build this into my existing query as it is a many-to-many relationship.