Best practice in Unit Testing

I want to know is there any best practice in Unit Testing (C#/NUnit) to test solution like this: Imagine I have method GetOrderById(long orderId) in BLL (Business Logic Layer), which gives me an Order by it's Id :). So I need to write test that will call this method with hardcoded Id parameter, but for example var Id = 1; If there is no record with such id, test will fail

[Test]
public void GetOrderById() 
{
    //var id = ?

    Assert.DoesNotThrow(() => {
        _orderService.GetOrderById(id);
    });
}

I need some solution to make work any time, create temporary record maybe? or smth better solution..

any ideas?