实体框架-实体映射问题

I have two tables: Address and Contact which are joined on contactID (in Contact). Both of these tables have entities in my Entity data model (EF 4.0) and I do not wan't to modify them.

我确实想创建一个新实体,其中包含来自两个实体的信息。

到目前为止我所做的:

在CSDL:

<EntityContainer...>
    <EntitySet Name="AddressTest" EntityType="WebGearsModel.Test" />
    <EntitySet Name="ContactTest" EntityType="WebGearsModel.Test" />
</EntityContainer>

<EntityType Name="Test">
  <Key>
    <PropertyRef Name="addressID" />
  </Key>
  <Property Type="Int32" Name="addressID" Nullable="false" annotation:StoreGeneratedPattern="Identity"  />
  <Property Type="Int32" Name="contactID" Nullable="false"  />
  <Property Type="String" Name="firstName" Nullable="false" MaxLength="30" FixedLength="false" Unicode="false" />
  <Property Type="String" Name="emailAddress" Nullable="false" MaxLength="150" FixedLength="false" Unicode="false" />
</EntityType>

在我的C-S映射中:

<EntitySetMapping Name="AddressTest">
  <EntityTypeMapping TypeName="WebGearsModel.Test">
    <MappingFragment StoreEntitySet="Address">
      <ScalarProperty Name="addressID" ColumnName="addressID" />
      <ScalarProperty Name="contactID" ColumnName="contactID" />
      <ScalarProperty Name="firstName" ColumnName="firstName" />
    </MappingFragment>
  </EntityTypeMapping>
</EntitySetMapping>

<EntitySetMapping Name="ContactTest">
  <EntityTypeMapping TypeName="WebGearsModel.Test">
    <MappingFragment StoreEntitySet="Contact">
      <ScalarProperty Name="contactID" ColumnName="contactID" />
      <ScalarProperty Name="emailAddress" ColumnName="emailAddress" />
    </MappingFragment>
  </EntityTypeMapping>
</EntitySetMapping>

我收到的错误是:

开始映射片段时出现问题 在第150行:必须为指定映射 所有键属性 (contacttest.addressID)的 EntitySet联系人测试。

当联系人实体中不存在地址ID时,如何从该实体映射该地址ID?我想我需要某种联系,但我不确定该怎么做…记住,我不想修改我现有的地址和联系人实体。