NHibernate的。如何在一次保存操作中保存图形？

Question

我有两张桌子的基地：

  

dbo.AEntity＆amp; dbo.BEntity

public class AEntity : EntityBase
{
    public virtual BEntity BClass { get; set; }
    public virtual string SomeAString { get; set; }
}

public class BEntity : EntityBase
{
    public virtual string SomeBString { get; set; }
}

这是我的映射：

public class AMap : ClassMap<AEntity>
{
    public AMap()
    {

        Table("AEntity");
        Map(x => x.CreateDate);
        Map(x => x.UpdateDate);
        Map(x => x.Deleted);
        Id(x => x.Id).GeneratedBy.GuidComb();
        HasOne(x => x.BClass).ForeignKey("BEntity_Id").Fetch.Join().Cascade.All();
    }
}

public class BMap : ClassMap<BEntity>
{
    public BMap()
    {
        Table("BEntity");
        Map(x => x.CreateDate);
        Map(x => x.UpdateDate);
        Map(x => x.Deleted);
        Id(x => x.Id).GeneratedBy.GuidComb();
    }
}

问题是当我保存图表时，BClass_Id为空。

我做错了什么？

CREATE TABLE [dbo].[AEntity] (
[Id]          UNIQUEIDENTIFIER NOT NULL,
[SomeAString] NVARCHAR (MAX)   NULL,
[CreateDate]  DATETIME         NOT NULL,
[UpdateDate]  DATETIME         NULL,
[Deleted]     BIT              NOT NULL,
[BClass_Id]   UNIQUEIDENTIFIER NULL,
CONSTRAINT [PK_dbo.AEntity] PRIMARY KEY CLUSTERED ([Id] ASC),
CONSTRAINT [FK_dbo.AEntity_dbo.BEntity_BClass_Id] FOREIGN KEY ([BClass_Id]) REFERENCES [dbo].[BEntity] ([Id]));

创建非集群索引[IX_BClass_Id] ON [dbo]。[AEntity]（[BClass_Id] ASC）;