使用 TPH 的实体框架的多重继承

Question

进一步回答这个问题： 具有多重抽象继承的实体框架 TPH 和 VS.2008 sp1 .net 3.5 c#

我决定添加组织和学校。组织（抽象）继承于党，学校（具体）继承于组织。

我收到错误：

Error   1   Error 3034: Problem in Mapping Fragments starting at lines 73, 93: Two entities with different keys are mapped to the same row. Ensure these two mapping fragments do not map two groups of entities with different keys to the same group of rows.
    C:\Users\xxx\Documents\Visual Studio 2008\Projects\TEST\TEST\Model1.edmx    74  29  TEST

我在 EF 的旅途中经常看到 3034 错误。但通常它们与导航属性有关。我在继承中没有看到这样的错误。

这是我的 edmx xml：

<?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="test_1Model.Store" Alias="Self"
          Provider="System.Data.SqlClient" ProviderManifestToken="2005"
          xmlns:store="http://schemas.microsoft.com/ado/2007/12/edm/EntityStoreSchemaGenerator"
          xmlns="http://schemas.microsoft.com/ado/2006/04/edm/ssdl">
                <EntityContainer Name="test_1ModelStoreContainer">
                    <EntitySet Name="Student" EntityType="test_1Model.Store.Student"
              store:Type="Tables" Schema="dbo" />
                </EntityContainer>
                <EntityType Name="Student">
                    <Key>
                        <PropertyRef Name="Id" />
                    </Key>
                    <Property Name="Id" Type="int" Nullable="false"
              StoreGeneratedPattern="Identity" />
                    <Property Name="PartyInfo" Type="varchar(max)" Nullable="false" />
                    <Property Name="PersonInfo" Type="varchar(max)" Nullable="true" />
                    <Property Name="StudInfo" Type="varchar(max)" Nullable="true" />
                    <Property Name="OrgInfo" Type="varchar(max)" Nullable="true" />
                    <Property Name="SchoolInfo" Type="varchar(max)" Nullable="true" />
                    <Property Name="TypeOfParty" Type="varchar(max)" Nullable="false" />
                </EntityType>
            </Schema>
        </edmx:StorageModels>
        <!-- CSDL content -->
        <edmx:ConceptualModels>
            <Schema Namespace="test_1Model" Alias="Self"
          xmlns="http://schemas.microsoft.com/ado/2006/04/edm">
                <EntityContainer Name="test_Entities">
                    <EntitySet Name="PartySet" EntityType="test_1Model.Party" />
                </EntityContainer>
                <EntityType Name="Party" Abstract="true">
                    <Key>
                        <PropertyRef Name="Id" />
                    </Key>
                    <Property Name="Id" Type="Int32" Nullable="false" />
                    <Property Name="PartyInfo" Type="String" Nullable="false"
              MaxLength="Max" Unicode="false" FixedLength="false" />
                </EntityType>
                <EntityType Name="Person" BaseType="test_1Model.Party" Abstract="true" >
                    <Property Name="PersonInfo" Type="String" Nullable="false" />
                </EntityType>
                <EntityType Name="Student" BaseType="test_1Model.Person" >
                    <Property Name="StudInfo" Type="String" Nullable="false" />
                </EntityType>
                <EntityType Name="Organization" BaseType="test_1Model.Party" Abstract="true" >
                    <Property Name="OrgInfo" Type="String" Nullable="false" />
                </EntityType>
                <EntityType Name="School" BaseType="test_1Model.Organization" >
                    <Property Name="SchoolInfo" Type="String" Nullable="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="test_1ModelStoreContainer"
            CdmEntityContainer="test_Entities">
                    <EntitySetMapping Name="PartySet">
                        <EntityTypeMapping TypeName="IsTypeOf(test_1Model.Party)">
                            <MappingFragment StoreEntitySet="Student">
                                <ScalarProperty Name="PartyInfo" ColumnName="PartyInfo" />
                                <ScalarProperty Name="Id" ColumnName="Id" />
                            </MappingFragment>
                        </EntityTypeMapping>
                        <EntityTypeMapping TypeName="IsTypeOf(test_1Model.Person)">
                            <MappingFragment StoreEntitySet="Student">
                                <ScalarProperty Name="Id" ColumnName="Id" />
                                <ScalarProperty Name="PersonInfo" ColumnName="PersonInfo" />
                            </MappingFragment>
                        </EntityTypeMapping>
                        <EntityTypeMapping TypeName="test_1Model.Student">
                            <MappingFragment StoreEntitySet="Student">
                                <ScalarProperty Name="Id" ColumnName="Id" />
                                <ScalarProperty Name="StudInfo" ColumnName="StudInfo" />
                                <ScalarProperty Name="PersonInfo" ColumnName="PersonInfo" />
                                <ScalarProperty Name="PartyInfo" ColumnName="PartyInfo" />
                                <Condition ColumnName="TypeOfParty" Value="STUDENT" />
                            </MappingFragment>
                        </EntityTypeMapping>
                        <EntityTypeMapping TypeName="IsTypeOf(test_1Model.Organization)">
                            <MappingFragment StoreEntitySet="Student">
                                <ScalarProperty Name="Id" ColumnName="Id" />
                                <ScalarProperty Name="OrgInfo" ColumnName="OrgInfo" />
                            </MappingFragment>
                        </EntityTypeMapping>
                        <EntityTypeMapping TypeName="test_1Model.School">
                            <MappingFragment StoreEntitySet="Student">
                                <ScalarProperty Name="Id" ColumnName="Id" />
                                <ScalarProperty Name="OrgInfo" ColumnName="OrgInfo" />
                                <ScalarProperty Name="PartyInfo" ColumnName="PartyInfo" />
                                <ScalarProperty Name="SchoolInfo" ColumnName="SchoolInfo" />
                                <Condition ColumnName="TypeOfParty" Value="SCHOOL" />
                            </MappingFragment>
                        </EntityTypeMapping>
                    </EntitySetMapping>
                </EntityContainerMapping>
            </Mapping>
        </edmx:Mappings>
    </edmx:Runtime>
    <!-- EF Designer content (DO NOT EDIT MANUALLY BELOW HERE) -->
    <edmx:Designer xmlns="http://schemas.microsoft.com/ado/2007/06/edmx">
        <edmx:Connection>
            <DesignerInfoPropertySet>
                <DesignerProperty Name="MetadataArtifactProcessing"
        Value="EmbedInOutputAssembly" />
            </DesignerInfoPropertySet>
        </edmx:Connection>
        <edmx:Options>
            <DesignerInfoPropertySet>
                <DesignerProperty Name="ValidateOnBuild" Value="true" />
            </DesignerInfoPropertySet>
        </edmx:Options>
        <!-- Diagram content (shape and connector positions) -->
        <edmx:Diagrams>
            <Diagram Name="SqlServer_Model" >
                <EntityTypeShape EntityType="test_1Model.Party" Width="1.5" PointX="1.25" PointY="3.25" Height="1.4033821614583326" />
                <InheritanceConnector EntityType="test_1Model.Person" ManuallyRouted="false">
                    <ConnectorPoint PointX="2" PointY="4.6533821614583326" />
                    <ConnectorPoint PointX="2" PointY="5.75" />
                </InheritanceConnector>
                <EntityTypeShape EntityType="test_1Model.Organization" Width="1.5" PointX="3.875" PointY="5.625" Height="1.2110807291666665" />
                <InheritanceConnector EntityType="test_1Model.Organization">
                    <ConnectorPoint PointX="2.75" PointY="3.9516910807291663" />
                    <ConnectorPoint PointX="4.625" PointY="3.9516910807291663" />
                    <ConnectorPoint PointX="4.625" PointY="5.625" />
                </InheritanceConnector>
                <EntityTypeShape EntityType="test_1Model.School" Width="1.5" PointX="3.875" PointY="7.875" Height="1.2110807291666657" />
                <InheritanceConnector EntityType="test_1Model.School">
                    <ConnectorPoint PointX="4.625" PointY="6.8360807291666665" />
                    <ConnectorPoint PointX="4.625" PointY="7.875" />
                </InheritanceConnector>
            </Diagram>
        </edmx:Diagrams>
    </edmx:Designer>
</edmx:Edmx>

Answer 1

我知道这个问题已经很老了，但我在最近的 EF 5.0（和 6.0.0-beta1）冒险中花了很长时间研究类似的问题，并且 这篇文章 引导我找到了一个有效的解决方案。感谢作者。

我有一个使用 TPH 映射的复杂层次结构：

• A1 - B1 - C1
• A1 - B1 - C2
• A1 - B2 - C3
• A1 - B2 - C4
• A1 - B2 - C5
• A1 - B2 - C6< /em> - D1 - E1
• A1 - B2 - C6 - D1 - E2
• A1 - B2< /em> - C6 - D1 - E3
• A1 - B2 - C6 - D2 - E4
• A1< /em> - B2 - C6 - D2 - E5
• A1 - B2 - C6 - D2 - E6
• A1 - B2 - C6 > - D3 - E7
• A1 - B2 - C6 - D3 - E8
• A1< /strong> - B2 - C6 - D3 > - E9

其中粗体表示抽象，斜体表示特定于该类（和子类）到同一表（当然）的附加映射。

基本上，解决方案是在表中创建 4 个鉴别器列，并将层次结构中的每个级别映射到不同的鉴别器列。请注意，B 级及以下级别的抽象类也需要映射并指定鉴别器值。

在这上面浪费了很多时间，TPH 的所有示例和文档似乎只涵盖了基础知识。在现实世界中，事情可能会变得更加复杂！

希望这对某人有帮助。

Answer 2

您似乎正在尝试进行每个层次结构表的映射（因为我在 SSDL 中只看到一个表），但我没有看到您在 CSDL 中设置了鉴别器映射。应该有一个条件节点，如下所示：

            <Condition ColumnName="NotificationType" Value="Announcement"/>

简而言之，如果您尝试使用每个层次结构映射一个表，您应该查看配置此操作的说明并遵循它们，因为您尚未完成所有步骤。

另一方面，如果您打算按类型映射表，那么当您从数据库更新时，您似乎错过了几个表。