entity-framework - Entity Framework 映射问题

Question

尝试使用 Entity Framework 映射以下模式。

• 一个客户可以有许多关联的商店。
• 商店可以有许多关联的客户
• 每个 Store 可以有 0 个或 1 个且只有 1 个 TopCustomer(成为 TopCustomer 的标准在业务逻辑中确定)

这会在 VS 中产生以下映射。

---

这是数据库脚本:

USE [TestDb]
GO
/****** Object:  Table [dbo].[Customer]    Script Date: 06/20/2009 09:53:52 ******/
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
CREATE TABLE [dbo].[Customer](
    [CustomerId] [uniqueidentifier] NOT NULL,
    [FirstName] [nvarchar](50) NOT NULL,
    [LastName] [nvarchar](50) NOT NULL,
 CONSTRAINT [PK_Customer] 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]
GO
/****** Object:  Table [dbo].[Store]    Script Date: 06/20/2009 09:53:52 ******/
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
CREATE TABLE [dbo].[Store](
    [StoreId] [uniqueidentifier] NOT NULL,
    [StoreName] [nvarchar](50) NOT NULL,
    [TopCustomer] [uniqueidentifier] NULL,
 CONSTRAINT [PK_Store] PRIMARY KEY CLUSTERED 
(
    [StoreId] ASC
)WITH (PAD_INDEX  = OFF, STATISTICS_NORECOMPUTE  = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS  = ON, ALLOW_PAGE_LOCKS  = ON) ON [PRIMARY]
) ON [PRIMARY]
GO
/****** Object:  Table [dbo].[CustomerStore]    Script Date: 06/20/2009 09:53:52 ******/
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
CREATE TABLE [dbo].[CustomerStore](
    [CustomerId] [uniqueidentifier] NOT NULL,
    [StoreId] [uniqueidentifier] NOT NULL,
 CONSTRAINT [PK_CustomerStore] PRIMARY KEY CLUSTERED 
(
    [CustomerId] ASC,
    [StoreId] ASC
)WITH (PAD_INDEX  = OFF, STATISTICS_NORECOMPUTE  = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS  = ON, ALLOW_PAGE_LOCKS  = ON) ON [PRIMARY]
) ON [PRIMARY]
GO
/****** Object:  ForeignKey [FK_CustomerStore_Customer]    Script Date: 06/20/2009 09:53:52 ******/
ALTER TABLE [dbo].[CustomerStore]  WITH CHECK ADD  CONSTRAINT [FK_CustomerStore_Customer] FOREIGN KEY([CustomerId])
REFERENCES [dbo].[Customer] ([CustomerId])
ON UPDATE CASCADE
ON DELETE CASCADE
GO
ALTER TABLE [dbo].[CustomerStore] CHECK CONSTRAINT [FK_CustomerStore_Customer]
GO
/****** Object:  ForeignKey [FK_CustomerStore_Store]    Script Date: 06/20/2009 09:53:52 ******/
ALTER TABLE [dbo].[CustomerStore]  WITH CHECK ADD  CONSTRAINT [FK_CustomerStore_Store] FOREIGN KEY([StoreId])
REFERENCES [dbo].[Store] ([StoreId])
ON UPDATE CASCADE
ON DELETE CASCADE
GO
ALTER TABLE [dbo].[CustomerStore] CHECK CONSTRAINT [FK_CustomerStore_Store]
GO
/****** Object:  ForeignKey [FK_Store_TopCustomer]    Script Date: 06/20/2009 09:53:52 ******/
ALTER TABLE [dbo].[Store]  WITH CHECK ADD  CONSTRAINT [FK_Store_TopCustomer] FOREIGN KEY([TopCustomer])
REFERENCES [dbo].[Customer] ([CustomerId])
GO
ALTER TABLE [dbo].[Store] CHECK CONSTRAINT [FK_Store_TopCustomer]
GO

---

问题:

如何在不在 Customer 类上创建额外的导航属性的情况下将 TopCustomer 关联映射到 Customer 的单个实例？

Answer 1

听起来您的模型和 map 已经在工作了？

但是您只需要删除额外的导航属性？

如果您想删除导航属性，这非常简单(尽管您不能使用标准的 EF 设计器)。

您只需在 XML 编辑器中打开您的 EDMX 文件(在 VS 中非常简单)并删除不需要的 <NavigationProperty .../>来自客户实体。

这样关系仍然存在于模型中，但是在类中你只能从商店.TopCustomer

你不能走另一条路。

希望对你有帮助

亚历克斯

Microsoft Entity Framework 团队项目经理。