Structure and Analysis of edmx Files (3)

The Entity Designer of Visual Studio 2008 stores its data in an XML file with the extension .edmx. In the first part of this series I covered the Storage Model, the second part dealt with the Conceptual Model.

This part covers the Mappings section with regard to C# mappings. The Mapping section uses the xmlns:cs namespace

• xmlns:cs=”urn:schemas-microsoft-com:windows:storage:mapping:CS”

For tables and views, the mapping section defines the mappings from database object to C# class (EntitySets and EntityTypes), along with their scalar properties:

    <edmx:Mappings>
      <cs:Mapping Space="C-S" >
        <cs:EntityContainerMapping
            StorageEntityContainer="MyNamespaceEntitiesStoreContainer"
            CdmEntityContainer="MyEntities">
          <cs:EntitySetMapping Name="TableFooSet">
            <cs:EntityTypeMapping TypeName="IsTypeOf(My.Namespace.Entities.TableFoo)">
              <cs:MappingFragment StoreEntitySet="TABLEFOO">
                <cs:ScalarProperty Name="ID" ColumnName="ID" />
                <cs:ScalarProperty Name="Name" ColumnName="NAME" />
              </cs:MappingFragment>
            </cs:EntityTypeMapping>
          </cs:EntitySetMapping> 

          <cs:AssociationSetMapping Name="FK_TABLEFOO_TABLEBAR"
            TypeName="My.Namespace.Entities.FK_TABLEFOO_TABLEBAR"
            StoreEntitySet="TABLEFOO">
            <cs:EndProperty Name="TABLEFOO">
              <cs:ScalarProperty Name="ID" ColumnName="ID" />
            </cs:EndProperty>
            <cs:EndProperty Name="TableBar">
              <cs:ScalarProperty Name="ID" ColumnName="BAR_ID" />
            </cs:EndProperty>
            <cs:Condition ColumnName="BAR_ID" IsNull="false" />
          </cs:AssociationSetMapping>

          <cs:FunctionImportMapping FunctionImportName="SPBarFromFoo"
            FunctionName="My.Namespace.Entities.Store.SP_BAR_FROM_FOO" />

End of Mapping section, end of Runtime declarations

        </cs:EntityContainerMapping>
      </cs:Mapping>
    </edmx:Mappings>
  </edmx:Runtime>

The rest of the edmx file contains the edmx:Designer section with layout information (shapes, connectors).