EntityReference都有不匹配的EntityKey属性值？

Question

我试图说明，我创造了一些实体。当我尝试和添加问题的实体来设定（见下面的代码）我收到以下错误：

“对象不能被添加或连接，因为它的EntityReference具有不匹配的EntityKey此对象的的EntityKey属性值。”

我不知道是什么的EntityKey它指的是虽然。下面是代码，有可能是一个更好的方式来退出这个功能，以及：

public Internship CreateInternship(Internship internshipToCreate)
{
    try
    {
        Contact contactToCreate = new Contact();

        contactToCreate.Fax = internshipToCreate.contacts.Fax;
        contactToCreate.Extension = internshipToCreate.contacts.Extension;
        contactToCreate.FirstName = internshipToCreate.contacts.FirstName;
        contactToCreate.MiddleName = internshipToCreate.contacts.MiddleName;
        contactToCreate.LastName = internshipToCreate.contacts.LastName;
        contactToCreate.PhoneNumber = internshipToCreate.contacts.PhoneNumber;
        contactToCreate.StreetAddress = internshipToCreate.contacts.StreetAddress;
        contactToCreate.PostalCode = internshipToCreate.contacts.PostalCode;
        contactToCreate.ContactEmail = internshipToCreate.contacts.ContactEmail;

        contactToCreate.statesReference.EntityKey =
                    new EntityKey("InternshipEntities.StateSet", "ID", internshipToCreate.contacts.states.ID);
        contactToCreate.countriesReference.EntityKey =
                    new EntityKey("InternshipEntities.CountrySet", "ID", internshipToCreate.contacts.countries.ID);

        _internshipEntities.AddToContactSet(contactToCreate);
        _internshipEntities.SaveChanges();

        try
        {
            Availability availabilityToCreate = new Availability();

            availabilityToCreate.StartDate = internshipToCreate.availability.StartDate;
            availabilityToCreate.EndDate = internshipToCreate.availability.EndDate;
            availabilityToCreate.Negotiable = internshipToCreate.availability.Negotiable;

            _internshipEntities.AddToAvailabilitySet(availabilityToCreate);
            _internshipEntities.SaveChanges();

            try
            {
                internshipToCreate.contactsReference.EntityKey =
                    new EntityKey("InternshipEntities.ContactSet", "ID", contactToCreate.ID);
                internshipToCreate.availabilityReference.EntityKey =
                    new EntityKey("InternshipEntities.AvailabilitySet", "ID", availabilityToCreate.ID);
                internshipToCreate.classificationsReference.EntityKey =
                    new EntityKey("InternshipEntities.ClassificationSet", "ID", internshipToCreate.classifications.ID);
                internshipToCreate.educationReference.EntityKey =
                    new EntityKey("InternshipEntities.EducationSet", "ID", internshipToCreate.education.ID);

                _internshipEntities.AddToInternshipSet(internshipToCreate); //exception here
                _internshipEntities.SaveChanges();

                return internshipToCreate;
            }
            catch(Exception e)
            {
                throw e; 
            }
        }
        catch(Exception e)
        {
            throw e;
        }
    }
    catch(Exception e)
    {
        throw e;
    }

}

有是除了当我通过，所以我甚至不能确定哪个键是问题跟踪误差给出任何其他信息。

编辑：这里是结束了工作的版本：

using (TransactionScope scope = new TransactionScope())
{
    try
    {
        Contact contactToCreate = new Contact();
        Availability availabilityToCreate = new Availability();
        Internship i = new Internship();

        // Set the contact entity values;

        contactToCreate.Fax = internshipToCreate.contacts.Fax;
        //...
        //ommited for brevity
        //...
        contactToCreate.ContactEmail = internshipToCreate.contacts.ContactEmail;

        // Set the contact entity references to existing tables

        contactToCreate.statesReference.EntityKey =
                    new EntityKey("InternshipEntities.StateSet", "ID", internshipToCreate.contacts.states.ID);
        contactToCreate.countriesReference.EntityKey =
                    new EntityKey("InternshipEntities.CountrySet", "ID", internshipToCreate.contacts.countries.ID);

        // Add contact

        _internshipEntities.AddToContactSet(contactToCreate);

        // Set the availability entity values;

        availabilityToCreate.StartDate = internshipToCreate.availability.StartDate;
        availabilityToCreate.EndDate = internshipToCreate.availability.EndDate;
        availabilityToCreate.Negotiable = internshipToCreate.availability.Negotiable;

        // Add availability

        _internshipEntities.AddToAvailabilitySet(availabilityToCreate);

        //Add contact and availability entities to new internship entity

        i.contacts = contactToCreate;
        i.availability = availabilityToCreate;

        // Set internship entity values;

        i.UserID = internshipToCreate.UserID;
        //...
        //ommited for brevity
        //...
        i.Created = DateTime.Now;

        // Set the internship entity references to existing tables

        i.classificationsReference.EntityKey =
            new EntityKey("InternshipEntities.ClassificationSet", "ID", internshipToCreate.classifications.ID);
        i.educationReference.EntityKey =
            new EntityKey("InternshipEntities.EducationSet", "ID", internshipToCreate.education.ID);

        // Add internship and save

        _internshipEntities.AddToInternshipSet(i);
        _internshipEntities.SaveChanges();

        //commit transaction
        scope.Complete();

        return internshipToCreate;

    }
    catch (Exception e)
    {
        throw e;
    }
}

Answer 1

此代码是不是赚了很多道理给我。在两种情况下，你要通过的EntityKey时，你可以只分配一个对象引用。即，改变该：

internshipToCreate.contactsReference.EntityKey =
    new EntityKey("InternshipEntities.ContactSet", "ID", contactToCreate.ID);
internshipToCreate.availabilityReference.EntityKey =
    new EntityKey("InternshipEntities.AvailabilitySet", "ID", availabilityToCreate.ID);

...为：

internshipToCreate.contacts = contactToCreate;
internshipToCreate.availability = availabilityToCreate;

在其它两种情况下，你似乎尝试分配这已经在那里的对象的ID。这两条线，即使成功，在我看来，什么都不做：

internshipToCreate.classificationsReference.EntityKey =
    new EntityKey("InternshipEntities.ClassificationSet", "ID", internshipToCreate.classifications.ID);
internshipToCreate.educationReference.EntityKey =
    new EntityKey("InternshipEntities.EducationSet", "ID", internshipToCreate.education.ID);

所以，你可以摆脱他们。

当你做出这两个变化，会发生什么？

Answer 2

喂，

虽然我不知道是什么问题，我有一个建议。要传递到方法（internshipToCreate）实习对象用于这些值传送到其它实体（联系，可用性）的 你的方法的内部实例 ，然后其创建工作得很好。

也许你应该尝试做相同的实习？创建新实习对象，并通过从internshipToCreate对象把他们设置你把所有的值，比新创建的对象传递给_internshipEntities.AddToInternshipSet方法。

这可能是你设置你所需要的其他用途internshipToCreate对象的某些价值观，其中有些是实际造成的除外。

和，我不知道你的业务逻辑是什么，但是如果你把所有的一个事务中，因为这样可能会发生创建前两个实体，而第三个不是会更好一些。