C# EF更新实体相关表正在插入而不是更新

我有一个对象，我正试图使用EntityFramework5更新它

检索现有对象并更新字段后，它将正确更新基本对象“coach”，但无法更新Address对象，而是再次插入它，而不是使用新的主键更新它，即使已将现有主键传递给它以供再次使用

感谢您的帮助

下面是代码的简化版本：

using (AltairEntities context = new AltairEntities())
                    {
                        dtlCoach coach = context.dtlCoaches.FirstOrDefault(x => x.CoachID == coachId);
                        coach.Name = "Bob";
                        coach.Description = "sample";
                        coach.dtlCoachAddresses.Add(PrepareAddress(coach.dtlCoachAddresses.First().CoachAddressID));
                        context.Database.Connection.Open();
                        context.Entry(coach).State = EntityState.Modified;
                        context.SaveChanges();
                    }

public static dtlCoachAddress PrepareAddress(int existingId)
        {
            dtlCoachAddress newAddress = new dtlCoachAddress();
            try
            {
                newAddress.CoachAddressID = existingId;
                newAddress.AddressLine1 = "Line 1";
                newAddress.AddressLine2 = "Line 2";

                return newAddress;
            }
            catch (Exception ex)
            {
                throw ex;
            }
        }

更新： 因此，我发现，如果我将dtlCoach实体内部的现有dtlCoachAddress实体作为参数馈送到PrepareAddress函数中，而不是将对象声明为新对象，那么它会正确更新。

---

如果我传递所有相同的参数，那么实体中的dtlCoachAddress对象和从new定义的dtlCoachAddress对象之间有什么区别？但是这两个定义了对象是否被插入或更新？

我不确定您在实体中是如何安排PK和FK的。所以这个解决方案有几个假设

再次更新以匹配OPs方法。

using (AltairEntities context = new AltairEntities())
{
    dtlCoach coach = context.dtlCoaches.FirstOrDefault(x => x.CoachID == coachId);
    coach.Name = "Bob";
    coach.Description = "sample";
    //coach.dtlCoachAddresses.Add(PrepareAddress(coach.dtlCoachAddresses.First().CoachAddressID));
    //context.Database.Connection.Open();
    //context.Entry(coach).State = EntityState.Modified;

    var address = context.dtlCoachAddresses.FirstOrDefault(a => a.CoachAddressID == coachId);       
    if(address != null)
   {
     address.AddressLine1 = "Line 1";
     address.AddressLine2 = "Line 2";                                   
   }     
    context.SaveChanges();
}

/*This function is not required
public static dtlCoachAddress PrepareAddress(int existingId)
{
using (AltairEntities context = new AltairEntities())
{
var address = context.dtlCoachAddresses.FirstOrDefault(a => a.CoachAddressID == coachId);       
 if(address != null)
 {
     address.AddressLine1 = "Line 1";
     address.AddressLine2 = "Line 2";
     context.SaveChanges();//update an existing address.                             
 }
}
catch (Exception ex)
{
throw ex;
}
}*/

---

因此，为了简化您的问题，

coach

得到了正确的更新。该实体没有任何问题。您还需要添加新的

地址

。然后将其引用回

coach

。但这不起作用。是吗？我想更新地址，而不是添加新地址，并保留对coach的引用。我想从地址表中获取地址，而不是创建新对象，然后将其分配给coach。嗨，Tarik，这是简化版的代码。在上面的场景中，您的解决方案听起来最简单，但在我更复杂的场景中却帮不了我。如果传递相同的主键，则现有上下文的DlcocachAddress与从新上下文创建的DtlocachAddress之间有什么区别@TarikCoachAddressID属于Address对象，包含CoachID的外键，以1-N关系链接回coach对象。dtlCoach表对dtlCoachAddress表有一个约束，因此dtlCoachAddress对象可以从dtlCoach对象获得@科萨拉-w@Nick这是否意味着

address.coachaddress==coach.CoachID

？否，地址还包含名为Coach_ID的外键，该外键用作Coach表的约束。这意味着1 coach-多地址关系@科萨拉-w@Nick好啊那么，如何仅通过使用

CoachID

找到要更新的地址呢。如果按

CoachID

进行筛选，结果可能有多个地址。如果查看我放置的示例代码，它将使用dtlCoachAddress.First（）从coach实体中获取第一个地址记录@科萨拉-w