使用外键约束的 FluentNHibernate 一对一

Question

好的，我有 2 个对象和一个外键。

第一个对象是。

    public class OutboundEmailMap : ClassMap<OutboundEmail>
{
    public OutboundEmailMap()
    {
        Table("OutboundEmail");

        Id(x => x.Id, "OutboundEmailId")
            .UnsavedValue(0)
            .GeneratedBy.Identity();

        Map(x => x.OutboundEmailGuid);
        Map(x => x.FromAccountName);
        Map(x => x.ToAccountName);
        Map(x => x.FromContactFirstName);
        Map(x => x.FromContactLastName);
        Map(x => x.ToContactFirstName);
        Map(x => x.ToContactLastName);
        Map(x => x.FromEmailAddress);
        Map(x => x.ToEmailAddress);
        Map(x => x.EmailTemplateID);
        Map(x => x.SentDate);
        Map(x => x.Subject);
        Map(x => x.XMLTokenDictionary);
        Map(x => x.IsFax);
        Map(x => x.TransmittalId);

        //References<Transmittal>(x => x.Transmittal)
        //    .Column("TransmittalID")
        //    .LazyLoad()
        //    .Cascade.None();

        HasOne<OutboundEmailStatus>(x => x.Status)
            .ForeignKey("FK_OutboundEmailStatus_OutboundEmail")
            .Cascade.None();
    }
}

第二类是

    public class OutboundEmailStatusMap : ClassMap<OutboundEmailStatus>
{
    public OutboundEmailStatusMap()
    {
        Table("OutboundEmailStatus");

        Id(x => x.Id, "OutboundEmailStatusID")
            .UnsavedValue(0)
            .GeneratedBy.Identity();

        References(x => x.OutboundEmail, "OutboundemailID");
        Map(x => x.EmailStatus, "EmailStatusID");
        Map(x => x.EmailStatusDate);
    }
}

外键是

USE [Mail]
GO

ALTER TABLE [dbo].[OutboundEmailStatus]  WITH CHECK ADD  CONSTRAINT   [FK_OutboundEmailStatus_OutboundEmail] FOREIGN KEY([OutboundEmailID])
REFERENCES [dbo].[OutboundEmail] ([OutboundEmailID])
GO

ALTER TABLE [dbo].[OutboundEmailStatus] CHECK CONSTRAINT [FK_OutboundEmailStatus_OutboundEmail]
GO

最后这是生成的查询

SELECT   top 20 this_.OutboundEmailId              as Outbound1_1_1_,
            this_.OutboundEmailGuid            as Outbound2_1_1_,
            this_.FromAccountName              as FromAcco3_1_1_,
            this_.ToAccountName                as ToAccoun4_1_1_,
            this_.FromContactFirstName         as FromCont5_1_1_,
            this_.FromContactLastName          as FromCont6_1_1_,
            this_.ToContactFirstName           as ToContac7_1_1_,
            this_.ToContactLastName            as ToContac8_1_1_,
            this_.FromEmailAddress             as FromEmai9_1_1_,
            this_.ToEmailAddress               as ToEmail10_1_1_,
            this_.EmailTemplateID              as EmailTe11_1_1_,
            this_.SentDate                     as SentDate1_1_,
            this_.Subject                      as Subject1_1_,
            this_.XMLTokenDictionary           as XMLToke14_1_1_,
            this_.IsFax                        as IsFax1_1_,
            this_.TransmittalId                as Transmi16_1_1_,
            outboundem2_.OutboundEmailStatusID as Outbound1_7_0_,
            outboundem2_.EmailStatusID         as EmailSta2_7_0_,
            outboundem2_.EmailStatusDate       as EmailSta3_7_0_,
            outboundem2_.OutboundemailID       as Outbound4_7_0_
FROM     OutboundEmail this_
     left outer join OutboundEmailStatus outboundem2_
       on this_.OutboundEmailId = outboundem2_.OutboundEmailStatusID
WHERE    this_.TransmittalId = '7789322e-acd6-4cb8-9c43-5bdaec52aa8a' /* @p0 */
ORDER BY this_.ToAccountName asc

所以问题如您所见，无论出于何种原因，它生成的查询都会尝试使用外键，尽管将外键连接到 OutboundEmailStatusID 而不是 OutboundEmailID

如果有人知道为什么会发生这种情况，或者有替代方法，请告诉我。

对我来说这真的很愚蠢，甚至发生这种事？！

Answer 1

根据设计，NHibernate 中的一对一是通过主键连接的关系。这是一种隐式关系，而不是显式关系，因为两个实体仅通过隐式约定关联，即如果两个键具有相同的值，则它们会关联。请参阅： NHibernate 一对一。

从你的数据库设计来看，你实际上有一个一对多-多对一的关系结构，而不是一对一的关系结构。您的领域模型可能将其表示为一对一，但底层它仍然是一对多；在数据库中，您的 OutboundEmail 可以有许多 OutboundEmailStatus，因为没有什么可以阻止多行具有相同的外键值。

就我个人而言，我会翻转它并将外键放在 OuboundEmail 上。这样，您的 OutboundEmail 将具有与 OutboundEmailStatus 的多对一关系。又名。一封电子邮件具有单一状态，但一个状态可以与多封电子邮件关联。