如何使用代码优先实体框架获取完整的对象4.1 [英] How to Get Full Object with Code First Entity Framework 4.1

问题描述

我正在尝试以JSON的形式返回完全深入的对象（填写所有外键关系） >以下是获取对象的调用：

  public ActionResult GetAll（）
 {
 return Json （ppEFContext.Orders，JsonRequestBehavior.AllowGet）; 
} 
  

这里是Order对象本身：

  public class Order 
 {
 public int Id {get;组; } 
 
 public Patient Patient {get;组; } 
 
 public CertificationPeriod CertificationPeriod {get;组; } 
 
 public Agency Agency {get;组; } 
 
公共诊断PrimaryDiagnosis {get;组; } 
 
 public OrderApprovalStatus ApprovalStatus {get;组; } 
 
 public User Approver {get;组; } 
 
 public User Submitter {get;组; } 
 
 public DateTime ApprovalDate {get;组; } 
 
 public DateTime SubmittedDate {get;组; } 
 public Boolean IsDeprecated {get;组; 
} 
  

我还没有找到使用EF 4.1注释的好资源。如果你能建议一个好的，那就有答案，你可以给我链接，这对我来说足够了。

问候，

Guido

更新

我根据Saxman添加了虚拟关键字，现在
处理循环引用
错误问题。

解决方案

在相关实体之前添加 virtual 关键字：

  public class Order 
 {
 public int Id {get;组; } 
 
 public virtual患者病人{get;组; } 
 
 public virtual CertificationPeriod CertificationPeriod {get;组; } 
 
 public virtual Agency Agency {get;组; } 
 
 public virtual Diagnosis PrimaryDiagnosis {get;组; } 
 
 public virtual OrderApprovalStatus ApprovalStatus {get;组; } 
 
 public virtual User Approver {get;组; } 
 
 public virtual User Submitter {get;组; } 
 
 public DateTime ApprovalDate {get;组; } 
 
 public DateTime SubmittedDate {get;组; } 
 public Boolean IsDeprecated {get;组; } 
} 
  

你可能会得到一个一个循环引用如果您的对象具有彼此的引用，则会在序列化对象... 时检测到错误。在这种情况下，您将需要创建一个 ViewModel 或类似的东西来克服这个问题。或使用LINQ来投射匿名对象。

I am trying to return as JSON the fully deep object (with all of the foreign key relationships filled in) but I am getting nulls for all the referenced objects.

Here is the call to get the object:

    public ActionResult GetAll()
    {
        return Json(ppEFContext.Orders, JsonRequestBehavior.AllowGet);
    }

And here is the Order object itself:

public class Order
{
    public int Id { get; set; }

    public Patient Patient { get; set; }

    public CertificationPeriod CertificationPeriod { get; set; }

    public Agency Agency { get; set; }

    public Diagnosis PrimaryDiagnosis { get; set; }

    public OrderApprovalStatus ApprovalStatus { get; set; }

    public User Approver { get; set; }

    public User Submitter { get; set; }

    public DateTime ApprovalDate { get; set; }

    public DateTime SubmittedDate { get; set; }
    public Boolean IsDeprecated { get; set; }
}

I have not yet found a good resource on using EF 4.1 Annotations. If you could suggest a good one, that has the answer, you could give me the link and that would be enough of an answer for me!

Regards,

Guido

Update

I added the virtual keyword as per Saxman and am now dealing with the circular reference error issue.

解决方案

Add the virtual keyword before your related entities:

public class Order
{
    public int Id { get; set; }

    public virtual Patient Patient { get; set; }

    public virtual CertificationPeriod CertificationPeriod { get; set; }

    public virtual Agency Agency { get; set; }

    public virtual Diagnosis PrimaryDiagnosis { get; set; }

    public virtual OrderApprovalStatus ApprovalStatus { get; set; }

    public virtual User Approver { get; set; }

    public virtual User Submitter { get; set; }

    public DateTime ApprovalDate { get; set; }

    public DateTime SubmittedDate { get; set; }
    public Boolean IsDeprecated { get; set; }
}

You might end up with a A circular reference was detected while serializing an object... error if your objects have references of each other. In that case, you will need to create a ViewModel or something similar to overcome this problem. Or use LINQ to project an anonymous object.

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