与NHibernate的关系

我使用两个表,EmployeeGroups和EmployeeGroups,如下所示。我忽略了下面大部分不相关的专栏。我正在努力绘制外键关系图。它是一个一对一的关系,不是EmployeeGroups表中的每个EmployeeId都存在于EmployeeGroups表中。我想知道如何在下面的映射文件中设置EmployeeId关系?

员工

CREATE TABLE [dbo].[Employees](
[EmployeeId] [int] IDENTITY(1,1) NOT NULL,
[ForeName] [nvarchar](20) COLLATE Latin1_General_CI_AI NOT NULL,
[SurName] [nvarchar](20) COLLATE Latin1_General_CI_AI NOT NULL,

CONSTRAINT [PK_Employees_1] PRIMARY KEY CLUSTERED 
(
    [EmployeeId] ASC
)WITH (IGNORE_DUP_KEY = OFF) ON [PRIMARY]
) ON [PRIMARY]

CREATE TABLE [dbo].[EmployeeGroups](
[GroupId] [int] NULL,
[EmployeeId] [int] NOT NULL,
[Active] [int] NULL,
 CONSTRAINT [PK_EmployeeGroups] PRIMARY KEY CLUSTERED 
(
    [EmployeeId] ASC
)WITH (IGNORE_DUP_KEY = OFF) ON [PRIMARY]
) ON [PRIMARY]

USE [DemoDEV]
GO
ALTER TABLE [dbo].[EmployeeGroups]  WITH CHECK ADD  CONSTRAINT     
[FK_EmployeeGroups_Employees] FOREIGN KEY([EmployeeId])
REFERENCES [dbo].[Employees] ([EmployeeId])

到目前为止我的员工映射文件

<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2">
<class name="AdaptiveMaintenance.Core.Domain.Employee, AdaptiveMaintenance.Core" table="Employees" lazy="false">
    <id name="ID" column="EmployeeId">
        <generator class="assigned" />
    </id>
    <property name="Forename" column="ForeName" not-null="true"/>
    <property name="Surname" column="SurName" not-null="true"/>

</class>
</hibernate-mapping>

<?xml version="1.0" encoding="utf-8" ?>
<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2">
  <class name="AdaptiveMaintenance.Core.Domain.EmployeeGroup, AdaptiveMaintenance.Core" table="EmployeeGroups" lazy="false">
      <id name="ID" column="EmployeeId">
      <generator class="foreign" />
    </id>

    <property name="Active" column="Active" />
</class>