Issue in EF, mapping fragment,no default value and is not nullable

Question

I am developing MVC 3 Applicaiton.

I have Model first approch.

I have Company Entity(Abstract). Lead and Customer is inherited from the company entity.

When I tried to validate the model, Its gives an errror.

Error 41 Error 3023: Problem in mapping fragments starting at line 70:Column Companies.Status in table Companies must be mapped: It has no default value and is not nullable.

Here is the mapping of tables.

And Here is the EDMX code in HTML View.

<?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>

Whats is the issue ?

Answer 1

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.