无法更新实体框架中的外键6 [英] Unable to update Foreign Key in Entity Framework 6

问题描述

这是我使用的代码：

我正在尝试对外键进行简单的更新，但脚本永远不会被发送。

  using（var db = new MyContext（））
 {
 db.Entry< Contact>（newContact） = EntityState.Modified; 
 newContact.ContactOwner = db.Person.Find（3）; 
 db.SaveChanges（）; 
} 
  

EF6更新了Persons表中的其余列，但不更新Person表中的Contact_Id。

个人实体：

  public class Person 
 {
 public int Id {get;组; } 
 public string Name {get;组; } 
 public List< Contact> ContactList {get;组; } 
} 
  

联系实体：

X-45454545 X- 20045 X-454545 X-454545 X-454545 X- 20045 CEEC X-组; }
public string Email {get;组; }
public string TelNo {get;组; }
public Person ContactOwner {get;组;
}

我在这里缺少什么？

请帮助！

解决方案

由于您正在与独立协会合作。您可以

• 从 ContactList 中添加和删除关系，但您需要从 Person 中检索。

    db.Entry（newContact ）.State = EntityState.Modified; 
   
   var p1 = db.Set< Person>（）。Include（p => p.ContactList）
   .FirstOrDefault（p => p.Id == 1）; 
   p1.ContactList.Remove（newContact）; 
   
   var p3 = db.Set< Person>（）。Include（p => p.ContactList）
   .FirstOrDefault（p => p.Id == 3）; 
   p3.ContactList.Add（newContact）; 
   
   db.SaveChanges（）; 
    




• 或者您可以使用断开连接的对象，但需要手动管理关系。 p>
  
  

    db.Entry（newContact）.State = EntityState.Modified; 
   
   var p1 = new Person {Id = 1}; X-454545 X-454545 X-454545 X- 20045 X-4545 X- 20045 X- 20045 X- 20045 X-4545 X-4545 
   var p3 = new Person {Id = 3}; CE X- 20045 X-454545 X-454545 X- 20045 X-454545 X- 20045 X- 20045 X-4545 X- 20045 X-454545 
   
   var manager =（（IObjectContextAdapter）db）.ObjectContext.ObjectStateManager; 
   manager.ChangeRelationshipState（newContact，p1，item => item.ContactOwner，
   EntityState.Deleted）; 
   manager.ChangeRelationshipState（newContact，p3，item => item.ContactOwner，
   EntityState.Added）; 
   
   db.SaveChanges（）; 
    

PS / p>

您可能需要重新考虑添加外键值，以便使一切更容易，只需提及Id即可更新外键。

有关详细信息，请参见此帖。 p>

I am trying to do a simple update to the foreign key but the script never get sent over.

Here is the code I am using:

using (var db = new MyContext())
{
      db.Entry<Contact>(newContact).State = EntityState.Modified;
      newContact.ContactOwner = db.Person.Find(3);
      db.SaveChanges();
}

EF6 update the rest of the column in the Persons table but it is not updating the Contact_Id in Persons table.

Person entity:

public class Person
{
    public int Id { get; set; }
    public string Name { get; set; }
    public List<Contact> ContactList { get; set; }
}

Contact entity:

public class Contact
{
    public int Id { get; set; }
    public string Email { get; set; }
    public string TelNo { get; set; }
    public Person ContactOwner { get; set; }
}

What am I missing here?

Please help!

解决方案

Since you are working with independent association. You can either

• Adding and removing the relationship from ContactList, but you need to retrieve from both Person.

  db.Entry(newContact).State = EntityState.Modified;
  
  var p1 = db.Set<Person>().Include(p => p.ContactList)
      .FirstOrDefault(p =>p.Id == 1);
  p1.ContactList.Remove(newContact);
  
  var p3 = db.Set<Person>().Include(p => p.ContactList)
      .FirstOrDefault(p => p.Id == 3);
  p3.ContactList.Add(newContact);
  
  db.SaveChanges();
  

• Or you can use disconnected object, but you need to manually manage the relationship.

  db.Entry(newContact).State = EntityState.Modified;
  
  var p1 = new Person { Id = 1 };
  db.Entry(p1).State = EntityState.Unchanged;
  var p3 = new Person { Id = 3 };
  db.Entry(p3).State = EntityState.Unchanged;
  
  var manager = ((IObjectContextAdapter)db).ObjectContext.ObjectStateManager;
  manager.ChangeRelationshipState(newContact, p1, item => item.ContactOwner,
       EntityState.Deleted);
  manager.ChangeRelationshipState(newContact, p3, item => item.ContactOwner,
       EntityState.Added);
  
  db.SaveChanges();
  

PS

You might need to reconsider adding foreign key value, to make everything easier, updating foreign key just by mentioning the Id.

See this post for more information.

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