Question

我是实体框架的新手，这种行为让我感到困惑：

    [Table("ClinicProfile")]
    public class ClinicProfile
    {
        [Key]
        [DatabaseGeneratedAttribute(DatabaseGeneratedOption.Identity)]
        public int Id { get; set; }

        [ForeignKey("ContactData")]
        public int ContactDataId { get; set; }
        public ContactData ContactData { get; set; }
    }

    [Table("ContactData")]
    public class ContactData
    {
         [Key]
         [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
         public int Id { get; set; }

         ...
    }

插入新实体时，一切正常 - ContactData保存到表中并分配了外键：

clinicProfile.ContactData = contactData;
SharedContext.Current.Entry(clinicProfile).State = EntityState.Added;
SharedContext.Current.SaveChanges();

但是当我尝试更新此实体时，ContactData无法获得更新。

clinicProfile.ContactData = contactData;
SharedContext.Current.Entry(clinicProfile).State = EntityState.Modified;
SharedContext.Current.SaveChanges();

我是否必须将ContactData标记为已修改？或者我只是做错了什么？

EDIT-2 - 答案

如果contactData是数据库中的新对象，则使用此代码，并使用新的对象ID。

clinicProfile.ContactData = contactData;
SharedContext.Current.Entry(clinicProfile).State = EntityState.Modified;
SharedContext.Current.SaveChanges();

如果您只想更新旧的contactData，使用此代码是正确的：

SharedContext.Current.Entry(contactData).State = EntityState.Modified;
SharedContext.Current.SaveChanges();

编辑 - 扩展代码快照

来自MVC控制器的代码，从页面回发。参数＆＃34; clinicProfile＆＃34;和＆＃34; contactData＆＃34;，＆＃34; adressData＆＃34;包含有效的ID。

        [HttpPost]
        [ValidateAntiForgeryToken]
        public ActionResult Modify(ClinicProfile clinicProfile, ContactData contactData, AdressData adressData)
        {
            ViewBag.Id = clinicProfile.Id;

            if (ModelState.IsValid)
            {
                if (clinicProfile.Id != 0)
                {
                    clinicProfile.ContactData = contactData;
                    clinicProfile.AdressData = adressData;
                    clinicProfile.AdressDataComposed = adressData.ComposeData();
                    clinicProfile.ContactDataComposed = contactData.ComposeData();

                    SharedContext.Current.Entry(clinicProfile).State = EntityState.Modified;
                    SharedContext.Current.SaveChanges();

                    Config.SaveClinicPhoto(clinicProfile.ClinicImageUpload, clinicProfile.Id);
                    Config.SaveClinicPreviewPhoto(clinicProfile.ClinicImageUpload, clinicProfile.Id);

                    return View(new ClinicProfileComposite { AdressData = adressData, ClinicProfile = clinicProfile, ContactData = contactData });
                }

                {
                    clinicProfile.ContactData = contactData;
                    clinicProfile.AdressData = adressData;
                    clinicProfile.AdressDataComposed = adressData.ComposeData();
                    clinicProfile.ContactDataComposed = contactData.ComposeData();

                    SharedContext.Current.Entry(clinicProfile).State = EntityState.Added;
                    SharedContext.Current.SaveChanges();

                    Config.SaveClinicPhoto(clinicProfile.ClinicImageUpload, clinicProfile.Id);
                    Config.SaveClinicPreviewPhoto(clinicProfile.ClinicImageUpload, clinicProfile.Id);

                    return RedirectToAction("Info", new { id = clinicProfile.Id });
                }
            }

            ViewBag.Id = clinicProfile.Id;
            return View(new ClinicProfileComposite { AdressData = adressData, ClinicProfile = clinicProfile, ContactData = contactData });
        }

Answer 1

你刚才错放了外键属性

 [Table("ClinicProfile")]
    public class ClinicProfile
    {
        [Key]
        [DatabaseGeneratedAttribute(DatabaseGeneratedOption.Identity)]
        public int Id { get; set; }

        //[ForeignKey("ContactData")] here the wrong place
        public int ContactDataId { get; set; }
        [ForeignKey("ContactDataId")] // here the correct place
        public ContactData ContactData { get; set; }
    }

    [Table("ContactData")]
    public class ContactData
    {
         [Key]
         [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
         public int Id { get; set; }

         ...
    }

当您想要设置外键数据时，可以设置ContactDataId值或从Database中检索ContactData作为对象并在ClinicProfile中设置它

// according to your data posted later

[HttpPost]
        [ValidateAntiForgeryToken]
        public ActionResult Modify(ClinicProfile clinicProfile, ContactData contactData, AdressData adressData)
        {
            ViewBag.Id = clinicProfile.Id;

            if (ModelState.IsValid)
            {
                if (clinicProfile.Id != 0)
                {
                    // here you want to tell the SharedContext to attach the contactData to the clinicProfile 
                    // you need to retrieve the lastVersion of contactData from db
                    var currentContactData=SharedContext.Current.ContactData.Single(t=>t.Id=contactData.Id);
                    // update the changed data in the currentContactData
                    clinicProfile.ContactData =currentContactData;  // instead of contactData;
                    clinicProfile.AdressData = adressData;
                    clinicProfile.AdressDataComposed = adressData.ComposeData();
                    clinicProfile.ContactDataComposed = contactData.ComposeData();

                    SharedContext.Current.Entry(clinicProfile).State = EntityState.Modified;
                    SharedContext.Current.SaveChanges();

                    Config.SaveClinicPhoto(clinicProfile.ClinicImageUpload, clinicProfile.Id);
                    Config.SaveClinicPreviewPhoto(clinicProfile.ClinicImageUpload, clinicProfile.Id);

                    return View(new ClinicProfileComposite { AdressData = adressData, ClinicProfile = clinicProfile, ContactData = contactData });
                }

                {
                    clinicProfile.ContactData = contactData;
                    clinicProfile.AdressData = adressData;
                    clinicProfile.AdressDataComposed = adressData.ComposeData();
                    clinicProfile.ContactDataComposed = contactData.ComposeData();

                    SharedContext.Current.Entry(clinicProfile).State = EntityState.Added;
                    SharedContext.Current.SaveChanges();

                    Config.SaveClinicPhoto(clinicProfile.ClinicImageUpload, clinicProfile.Id);
                    Config.SaveClinicPreviewPhoto(clinicProfile.ClinicImageUpload, clinicProfile.Id);

                    return RedirectToAction("Info", new { id = clinicProfile.Id });
                }
            }

            ViewBag.Id = clinicProfile.Id;
            return View(new ClinicProfileComposite { AdressData = adressData, ClinicProfile = clinicProfile, ContactData = contactData });
        }

//作为评论讨论的结果

如果您想更新contactData，您需要通过将其状态设置为已修改来告诉上下文contactData已被修改，正如您在上一篇文章中所提到的，如果您进行以下操作，它将起作用：

SharedContext.Current.Entry（clinicProfile）.State = EntityState.Modified; SharedContext.Current.Entry（contactData）.State = EntityState.Modified; SharedContext.Current.SaveChanges（）;

希望这会对你有所帮助

Answer 2

更新时只需设置ContactDataId

clinicProfile.ContactData = contactData;
clinicProfile.ContactDataId = contactData.Id;
SharedContext.Current.Entry(clinicProfile).State = EntityState.Modified;
SharedContext.Current.SaveChanges();

Answer 3

如果你设置为现有的ClinicProfile新的ContactData，你应该首先将新的ContactData保存到db，第二次使用新的ContactDataId获取新的Id和第三次更新ClinicProfile。

clinicProfile.ContactDataId = newContactData.Id;
SharedContext.Current.Entry(clinicProfile).State = EntityState.Modified;
SharedContext.Current.SaveChanges();

如果要更新现有的ContactData属性，则应仅保存它。

SharedContext.Current.Entry(existingContactData).State = EntityState.Modified;
SharedContext.Current.SaveChanges();

实体框架不更新外键对象

3 个答案: