This is my simplified example of how to run RAW SELECT, get result and access the values.
$res = DB::select('
select count(id) as c
from prices p
where p.type in (2,3)
');
if ($res[0]->c > 10)
{
throw new Exception('WOW');
}
If you want only run sql script with no return resutl use this
DB::statement('ALTER TABLE products MODIFY COLUMN physical tinyint(1) AFTER points;');
Tested in laravel 5.1