实体框架:在关联中使用非主键的替代解决方案

我知道实体框架不允许使用非主键作为外键关联从数据库生成模型。我可以手动修改EDMX吗?如果是的话,有人能给我提供一个例子或参考吗?如果没有,还有其他的可能性吗?

最简单的例子:

这是桌子的DDL。你会注意到我有一个从PersonType.TypeCode到Person.TypeCode的外键

CREATE TABLE [dbo].[PersonType](
    [PersonTypeId] [int] NOT NULL,
    [TypeCode] [varchar](10) NOT NULL,
    [TypeDesc] [varchar](max) NULL,
 CONSTRAINT [PK_PersonType] PRIMARY KEY CLUSTERED 
 ([PersonTypeId] ASC)
 CONSTRAINT [UK_PersonType] UNIQUE NONCLUSTERED 
 ([TypeCode] ASC)
)

CREATE TABLE [dbo].[Person](
    [PersonId] [int] NOT NULL,
    [TypeCode] [varchar](10) NOT NULL,
 CONSTRAINT [PK_Person] PRIMARY KEY CLUSTERED 
 ([PersonId] ASC)
)

ALTER TABLE [dbo].[Person]  WITH CHECK ADD  CONSTRAINT [FK_Person_PersonType] FOREIGN KEY([TypeCode])
REFERENCES [dbo].[PersonType] ([TypeCode])

ALTER TABLE [dbo].[Person] CHECK CONSTRAINT [FK_Person_PersonType]

<?xml version="1.0" encoding="utf-8"?>
<edmx:Edmx Version="1.0" xmlns:edmx="http://schemas.microsoft.com/ado/2007/06/edmx">
  <!-- EF Runtime content -->
  <edmx:Runtime>
    <!-- SSDL content -->
    <edmx:StorageModels>
      <Schema Namespace="testModel.Store" Alias="Self" Provider="System.Data.SqlClient" ProviderManifestToken="2008" xmlns:store="http://schemas.microsoft.com/ado/2007/12/edm/EntityStoreSchemaGenerator" xmlns="http://schemas.microsoft.com/ado/2006/04/edm/ssdl">
        <EntityContainer Name="testModelStoreContainer">
          <EntitySet Name="Person" EntityType="testModel.Store.Person" store:Type="Tables" Schema="dbo" />
          <EntitySet Name="PersonType" EntityType="testModel.Store.PersonType" store:Type="Tables" Schema="dbo" />
        </EntityContainer>
        <EntityType Name="Person">
          <Key>
            <PropertyRef Name="PersonId" />
          </Key>
          <Property Name="PersonId" Type="int" Nullable="false" />
          <Property Name="TypeCode" Type="varchar" Nullable="false" MaxLength="10" />
        </EntityType>
        <!--Errors Found During Generation:
      warning 6035: The relationship 'FK_Person_PersonType' has columns that are not part of the key of the table on the primary side of the relationship. The relationship was excluded.
      -->
        <EntityType Name="PersonType">
          <Key>
            <PropertyRef Name="PersonTypeId" />
          </Key>
          <Property Name="PersonTypeId" Type="int" Nullable="false" />
          <Property Name="TypeCode" Type="varchar" Nullable="false" MaxLength="10" />
          <Property Name="TypeDesc" Type="varchar(max)" />
        </EntityType>
      </Schema>
    </edmx:StorageModels>
    <!-- CSDL content -->
    <edmx:ConceptualModels>
      <Schema Namespace="testModel" Alias="Self" xmlns="http://schemas.microsoft.com/ado/2006/04/edm">
        <EntityContainer Name="testEntities">
          <EntitySet Name="People" EntityType="testModel.Person" />
          <EntitySet Name="PersonTypes" EntityType="testModel.PersonType" />
        </EntityContainer>
        <EntityType Name="Person">
          <Key>
            <PropertyRef Name="PersonId" />
          </Key>
          <Property Name="PersonId" Type="Int32" Nullable="false" />
          <Property Name="TypeCode" Type="String" Nullable="false" MaxLength="10" Unicode="false" FixedLength="false" />
        </EntityType>
        <EntityType Name="PersonType">
          <Key>
            <PropertyRef Name="PersonTypeId" />
          </Key>
          <Property Name="PersonTypeId" Type="Int32" Nullable="false" />
          <Property Name="TypeCode" Type="String" Nullable="false" MaxLength="10" Unicode="false" FixedLength="false" />
          <Property Name="TypeDesc" Type="String" MaxLength="Max" Unicode="false" FixedLength="false" />
        </EntityType>
      </Schema>
    </edmx:ConceptualModels>
    <!-- C-S mapping content -->
    <edmx:Mappings>
      <Mapping Space="C-S" xmlns="urn:schemas-microsoft-com:windows:storage:mapping:CS">
        <EntityContainerMapping StorageEntityContainer="testModelStoreContainer" CdmEntityContainer="testEntities">
          <EntitySetMapping Name="People"><EntityTypeMapping TypeName="testModel.Person"><MappingFragment StoreEntitySet="Person">
            <ScalarProperty Name="PersonId" ColumnName="PersonId" />
            <ScalarProperty Name="TypeCode" ColumnName="TypeCode" />
          </MappingFragment></EntityTypeMapping></EntitySetMapping>
          <EntitySetMapping Name="PersonTypes"><EntityTypeMapping TypeName="testModel.PersonType"><MappingFragment StoreEntitySet="PersonType">
            <ScalarProperty Name="PersonTypeId" ColumnName="PersonTypeId" />
            <ScalarProperty Name="TypeCode" ColumnName="TypeCode" />
            <ScalarProperty Name="TypeDesc" ColumnName="TypeDesc" />
          </MappingFragment></EntityTypeMapping></EntitySetMapping>
        </EntityContainerMapping>
      </Mapping>
    </edmx:Mappings>
  </edmx:Runtime>

我试图修改EDMX以在personType和Person之间创建导航属性,但没有成功。我想我可以手动创建一个关联。任何帮助都将不胜感激。