Question

我有这个模型

public class Appointment
{

    [Key]
    public Guid Id { get; set; }

    public IEnumerable<Attendee> Attendees { get; set; }

    public DateTime StartDateTime { get; set; }
    public DateTime EndDateTime { get; set; }      
}

和参加者课程

public class Attendee
{
    public Guid AttendeeId { get; set; }

    public Guid AppointmentId { get; set; }
    public Appointment Appointment { get; set; }

    public string FirstName { get; set; }
    public string LastName { get; set; }
    public string Email { get; set; }

    public Boolean IsApproved { get; set; }
    public IEnumerable<Response> Responses { get; set; } 
}

和DbContext类

public class DatePickerDbContext : IdentityDbContext
{
    public DatePickerDbContext():base("DefaultConnection")
    {
    }
    protected override void OnModelCreating(DbModelBuilder modelBuilder)
    {
        base.OnModelCreating(modelBuilder);
        modelBuilder.Entity<IdentityUser>().ToTable("Users");
        modelBuilder.Entity<ApplicationUser>().ToTable("Users");
        modelBuilder.Entity<IdentityRole>().ToTable("Roles");
    }

    public DbSet<Appointment> Appointments { get; set; }

    public DbSet<Attendee> Attendees { get; set; }
}

现在当我在Appointments表上进行查询时，例如

_db.Appointments.Find(appointmentId);

不应该懒得加载所有与会者吗？

或者我在模特中遗漏了一些东西？

PS：

EntityFramework版本：6.0.2

Asp.Net MVC版本：5.1.0

Answer 1

要延迟加载相关的类，模型中的属性应该是virtual，它应该是ICollection，而不是IEnumerable：

public virtual ICollection<Attendee> Attendees { get; set; }

Answer 2

显然我应该改变

public IEnumerable<Attendee> Attendees { get; set; }

到

public virtual ICollection<Attendee> Attendees { get; set; }

PS：

简单地将其设置为虚拟IEnumerable<Attendee>对我来说不起作用，必须是虚拟的ICollection<Attendee>

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2 个答案: