zt:使用复杂类型定义模型(实体框架)

实体数据模型 (EDM) 中的复杂类型是具有内部结构但没有键属性的数据类型。复杂类型用于实现具有其自己的内部属性的属性。实体或复杂类型可能具有声明为复杂类型的属性。

复杂类型以类似于实体类型的语法声明。主要差别在于复杂类型不包括键属性的声明,但对于实体则包括此声明。在映射规范中,复杂类型映射为复杂属性。

实现复杂属性

  1. 在 Visual Studio 中创建类库类型的项目,然后添加对 System.Data.EntitySystem.Runtime.Serialization 的引用。

  2. 向项目中添加新的实体数据模型模板。

  3. 实现概念架构设计语言 (CSDL) 架构并将其添加到由 EDM 模板提供的 CSDL 文件中。此架构包含 CCustomer 实体及其使用复杂类型 CAddressAddress 属性的声明。以下示例代码中显示了完整的架构。

  4. 对第 2 步中创建的概念架构运行 edmgen.exe 以创建对象代码。

  5. 实现存储架构定义语言 (SSDL) 架构并将其添加到由 EDM 模板提供的 SSDL 文件中。在此架构中,复杂类型数据与包含实体存储在同一个表中,如以下存储架构设计语言 (SSDL) 元数据中所示。以下示例代码中显示了完整的架构。

  6. 实现映射规范语言 (MSL) 架构并将其添加到由 EDM 模板提供的 MSL 文件中。以下映射架构将 Address 的映射显示为复杂属性。以下示例代码中显示了完整的映射规范。

示例

以下 XML 中连续显示了三个所需的架构。在该代码之后提供了一个脚本,可以用于创建此示例中用于存储的数据库。

    <Schema Namespace="CustomerComplexAddress"
        Alias="Self"
        xmlns="http://schemas.microsoft.com/ado/2006/04/edm">

        <EntityContainer Name="CustomerComplexAddressContext">
          <EntitySet Name="CCustomers" EntityType="CustomerComplexAddress.CCustomer" />
        </EntityContainer>

        <EntityType Name="CCustomer">
          <Key>
            <PropertyRef Name="CustomerId" />
          </Key>
          <Property Name="CustomerId" Type="Int32" Nullable="false" />
          <Property Name="CompanyName" Type="String" />
          <Property Name="ContactName" Type="String" />
          <Property Name="ContactTitle" Type="String" />
          <Property Name="Address" Type="Self.CAddress" Nullable="false" />
        </EntityType>

        <ComplexType Name="CAddress">
          <Property Name="StreetAddress" Type="String" />
          <Property Name="City" Type="String" />
          <Property Name="Region" Type="String" />
          <Property Name="PostalCode" Type="String" />
          <Property Name="Country" Type="String" />
          <Property Name="Phone" Type="String" />
          <Property Name="Fax" Type="String" />
        </ComplexType>
    </Schema>

    <Schema Namespace="CustomerComplexAddress.Store"
        Alias="Self" Provider="System.Data.SqlClient"
        ProviderManifestToken="2005"
        xmlns="http://schemas.microsoft.com/ado/2006/04/edm/ssdl">

        <EntityContainer Name="dbo">
          <EntitySet Name="SCustomer" EntityType="CustomerComplexAddress.Store.SCustomer" />
        </EntityContainer>

        <EntityType Name="SCustomer">
          <Key>
            <PropertyRef Name="CustomerId" />
          </Key>
          <Property Name="CustomerId" Type="int" Nullable="false" />
          <Property Name="CompanyName" Type="nvarchar" MaxLength="50" />
          <Property Name="ContactName" Type="nvarchar" MaxLength="50" />
          <Property Name="ContactTitle" Type="nvarchar" MaxLength="50" />
          <Property Name="Address" Type="nvarchar" MaxLength="50" />
          <Property Name="City" Type="nvarchar" MaxLength="50" />
          <Property Name="Region" Type="nvarchar" MaxLength="50" />
          <Property Name="PostalCode" Type="nvarchar" MaxLength="50" />
          <Property Name="Country" Type="nvarchar" MaxLength="50" />
          <Property Name="Phone" Type="nvarchar" MaxLength="50" />
          <Property Name="Fax" Type="nvarchar" MaxLength="50" />
        </EntityType>
    </Schema>

    <Mapping Space="C-S"
        xmlns="urn:schemas-microsoft-com:windows:storage:mapping:CS">

        <EntityContainerMapping StorageEntityContainer="dbo"
                  CdmEntityContainer="CustomerComplexAddressContext">

          <EntitySetMapping Name="CCustomers">
            <EntityTypeMapping
                 TypeName="CustomerComplexAddress.CCustomer">
              <MappingFragment StoreEntitySet="SCustomer">
                <ScalarProperty Name="CustomerId"
                                  ColumnName="CustomerId" />
                <ScalarProperty Name="CompanyName"
                                  ColumnName="CompanyName" />
                <ScalarProperty Name="ContactName"
                                  ColumnName="ContactName" />
                <ScalarProperty Name="ContactTitle"
                                  ColumnName="ContactTitle" />
               <ComplexProperty Name="Address"
                       TypeName="CustomerComplexAddress.CAddress">
                 <ScalarProperty Name="StreetAddress"
                                  ColumnName="Address" />
                 <ScalarProperty Name="City" ColumnName="City" />
                 <ScalarProperty Name="Region" ColumnName="Region" />
                 <ScalarProperty Name="PostalCode"
                                  ColumnName="PostalCode" />
                 <ScalarProperty Name="Country" ColumnName="Country" />
                 <ScalarProperty Name="Phone" ColumnName="Phone" />
                 <ScalarProperty Name="Fax" ColumnName="Fax" />
                </ComplexProperty>
              </MappingFragment>
            </EntityTypeMapping>
          </EntitySetMapping>
       </EntityContainerMapping>
    </Mapping>


The following script can be used to create
    SQL Server storage model.

USE [master]
GO

CREATE DATABASE [CustomerComplexAddress] 
GO

USE [CustomerComplexAddress]
GO

SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
IF NOT EXISTS (SELECT * FROM sys.objects 
WHERE object_id = OBJECT_ID(N'[dbo].[SCustomer]') 
AND type in (N'U'))
BEGIN
CREATE TABLE [dbo].[SCustomer](
    [CustomerId] [int] NOT NULL,
     [CompanyName] [nvarchar](50) NULL,
     [ContactName] [nvarchar](50) NULL,
     [ContactTitle] [nvarchar](50) NULL,
    [Address] [nvarchar](50) NULL,
     [City] [nvarchar](50) NULL,
     [Region] [nvarchar](50) NULL,
     [PostalCode] [nvarchar](50) NULL,
     [Country] [nvarchar](50) NULL,
     [Phone] [nvarchar](50) NULL,
     [Fax] [nvarchar](50) NULL,
CONSTRAINT [PK_SCustomer] PRIMARY KEY CLUSTERED 
(
     [CustomerId] ASC
)WITH (PAD_INDEX  = OFF, STATISTICS_NORECOMPUTE  = OFF, 
   IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS  = ON, 
   ALLOW_PAGE_LOCKS  = ON) ON [PRIMARY]
) ON [PRIMARY]
END
GO

http://msdn.microsoft.com/zh-cn/library/bb738613(v=vs.90).aspx
原文地址:https://www.cnblogs.com/youfan/p/2009454.html