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我正在开发 MVC 3 应用程序。

我有模型优先的方法。

我有公司实体（摘要）。Lead 和 Customer 继承自公司实体。

当我试图验证模型时，它给出了一个错误。

错误 41 错误 3023：从第 70 行开始映射片段时出现问题：必须映射表 Companies 中的列 Companies.Status：它没有默认值且不可为空。

这是表的映射。

在此处输入图像描述

这是 HTML 视图中的 EDMX 代码。

<?xml version="1.0" encoding="utf-8"?>
<edmx:Edmx Version="2.0" xmlns:edmx="http://schemas.microsoft.com/ado/2008/10/edmx">
  <!-- EF Runtime content -->
  <edmx:Runtime>
    <!-- SSDL content -->
    <edmx:StorageModels>
    <Schema Namespace="Model1.Store" Alias="Self" Provider="System.Data.SqlClient" ProviderManifestToken="2008" xmlns="http://schemas.microsoft.com/ado/2009/02/edm/ssdl" xmlns:store="http://schemas.microsoft.com/ado/2007/12/edm/EntityStoreSchemaGenerator">
    <EntityContainer Name="Model1StoreContainer">

        <EntitySet Name="Companies" EntityType="Model1.Store.Companies" store:Type="Tables" Schema="dbo" />

    </EntityContainer>

    <EntityType Name="Companies">
        <Key>
            <PropertyRef Name="Id" />
        </Key>
        <Property Name="Id" Type="int" StoreGeneratedPattern="Identity" Nullable="false" />
        <Property Name="Name" Type="nvarchar(max)" Nullable="false" />
        <Property Name="Status" Type="nvarchar(max)" Nullable="false" />
        <Property Name="__Disc__" Type="nvarchar" MaxLength="Max" Nullable="false" />
    </EntityType>
</Schema></edmx:StorageModels>
    <!-- CSDL content -->
    <edmx:ConceptualModels>
      <Schema xmlns="http://schemas.microsoft.com/ado/2008/09/edm" xmlns:cg="http://schemas.microsoft.com/ado/2006/04/codegeneration" xmlns:store="http://schemas.microsoft.com/ado/2007/12/edm/EntityStoreSchemaGenerator" Namespace="Model1" Alias="Self" xmlns:annotation="http://schemas.microsoft.com/ado/2009/02/edm/annotation">
        <EntityContainer Name="Model1Container" annotation:LazyLoadingEnabled="true">
          <EntitySet Name="Companies" EntityType="Model1.Company" />
          </EntityContainer>
        <EntityType Name="Company" Abstract="true">
          <Key>
            <PropertyRef Name="Id" />
          </Key>
          <Property Type="Int32" Name="Id" Nullable="false" annotation:StoreGeneratedPattern="Identity" />
          <Property Type="String" Name="Name" Nullable="false" />
        </EntityType>
        <EntityType Name="Lead" BaseType="Model1.Company" >
          <Property Type="String" Name="Status" Nullable="false" />
        </EntityType>
      </Schema>
    </edmx:ConceptualModels>
    <!-- C-S mapping content -->
    <edmx:Mappings>
    <Mapping Space="C-S" xmlns="http://schemas.microsoft.com/ado/2008/09/mapping/cs">
    <EntityContainerMapping StorageEntityContainer="Model1StoreContainer" CdmEntityContainer="Model1Container">
        <EntitySetMapping Name="Companies">
            <EntityTypeMapping TypeName="IsTypeOf(Model1.Company)">
                <MappingFragment StoreEntitySet="Companies">
                    <ScalarProperty Name="Id" ColumnName="Id" />
                    <ScalarProperty Name="Name" ColumnName="Name" />
                    <Condition ColumnName="__Disc__" Value="Company" />
                </MappingFragment>
            </EntityTypeMapping>
            <EntityTypeMapping TypeName="Model1.Lead">
                <MappingFragment StoreEntitySet="Companies">
                    <ScalarProperty Name="Id" ColumnName="Id" />
                    <ScalarProperty Name="Name" ColumnName="Name" />
                    <ScalarProperty Name="Status" ColumnName="Status" />
                    <Condition ColumnName="__Disc__" Value="Lead" />
                </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/2008/10/edmx">
    <edmx:Connection>
      <DesignerInfoPropertySet>
        <DesignerProperty Name="MetadataArtifactProcessing" Value="EmbedInOutputAssembly" />
      </DesignerInfoPropertySet>
    </edmx:Connection>
    <edmx:Options>
      <DesignerInfoPropertySet>
        <DesignerProperty Name="ValidateOnBuild" Value="true" />
        <DesignerProperty Name="EnablePluralization" Value="True" />
        <DesignerProperty Name="DatabaseGenerationWorkflow" Value="$(VSEFTools)\DBGen\Generate T-SQL Via T4 (TPH).xaml" />
      </DesignerInfoPropertySet>
    </edmx:Options>
    <!-- Diagram content (shape and connector positions) -->
    <edmx:Diagrams>
      <Diagram Name="Model1" >
        <EntityTypeShape EntityType="Model1.Company" Width="1.5" PointX="2.375" PointY="0.875" Height="1.2636116536458335" />
        <EntityTypeShape EntityType="Model1.Lead" Width="1.5" PointX="3.375" PointY="2.625" Height="1.0992643229166665" />
        <InheritanceConnector EntityType="Model1.Lead" >
          <ConnectorPoint PointX="3.125" PointY="2.1386116536458335" />
          <ConnectorPoint PointX="3.125" PointY="2.325" />
          <ConnectorPoint PointX="4.125" PointY="2.325" />
          <ConnectorPoint PointX="4.125" PointY="2.625" />
        </InheritanceConnector>
        </Diagram>
    </edmx:Diagrams>
  </edmx:Designer>
</edmx:Edmx>

有什么问题？

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2 回答 2

9

Put the DefaultValue attribute on the SSDL Status property. It would look like this (I used the empty string): 

<Property Name="Status" Type="nvarchar(max)" Nullable="false" DefaultValue=""/>

Since the base entity is abstract you won't be able to create entities of this type so this DefaultValue will not really be used but it should make EF stop complaining.

于 2012-10-08T17:58:25.937 回答
0

在您的存储模型中，Company.Status 列不允许空值。

由于从 Company 继承的所有实体（Lead 实体除外）都不会设置 Status 属性，因此您需要在 Companies.Status 列中允许 null 或设置用于其他实体的默认值。

于 2012-10-08T13:49:06.147 回答