asp.net-mvc - LINQ to SQL - 填充集合属性的子属性

Question

我在 ASP.NET MVC4 项目中使用 Code First 和 LINQ to SQL。在下面的查询中，我试图填充 PatientView.Appointments.ScheduledBy，但它返回 null。我尝试添加 .Include("Appointments.ScheduledBy")，但 Appointments.ScheduledBy 继续返回 null。

如何修改 LINQ to SQL 表达式以填充 ScheduledBy？

这是我的 LINQ to SQL（Id 是操作的参数）

var q = from p in context.Patients.Include("Appointments.ScheduledBy")
        where p.Id == Id
        select new PatientView
        {
             Patient = p,
             Appointments = p.Appointments.OrderByDescending(a => a.ScheduledFor)
        };
PatientView pv = q.Single();

PatientView 是视图的视图模型。Appointments 属性确实被填充，但 Appointments 的 ScheduledBy 属性为空。

public class PatientView
{
    public Patient Patient { get; set; }
    public IEnumerable<Appointment> Appointments { get; set; }
}

public class Patient
{
    public int Id { get; set; }
    public string Number { get; set; }
    public string FirstName { get; set; }
    public string LastName { get; set; }
    public List<Appointment> Appointments { get; set; }
}

public class Appointment
{
    public int Id { get; set; }
    public Patient Patient { get; set; }
    public Employee ScheduledBy { get; set; }
    public DateTime ScheduledFor { get; set; }
}

public class Employee
{
    public int Id { get; set; }
    public string Email { get; set; }
    public string FirstName { get; set; }
    public string LastName { get; set; }
}