本主题使用在主题如何：通过每种类型多个实体集定义模型（实体框架） 中设计的实体数据模型 (EDM)。
使用每种类型多个实体集创建应用程序
创建一个控制台应用程序项目，并添加对 System.Data.Entity 和 System.Runtime.Serialization 的引用。
对于从在主题如何：通过每种类型多个实体集定义模型（实体框架） 中定义的数据模型生成的 dll，添加对它的引用。
添加应用程序配置文件。以下语法将指向架构元数据和连接字符串的路径提供给承载数据的服务器。
<?xml version="1.0" encoding="utf-8" ?>
<configuration>
<connectionStrings>
<add name="RegionalCustomersEntities"
connectionString="metadata=.;
provider=System.Data.SqlClient;
provider connection string="
Data Source=serverName;
Initial Catalog=RegionalCustomersMEST;
Integrated Security=True;
multipleactiveresultsets=true""
providerName="System.Data.EntityClient" />
</connectionStrings>
</configuration>
向表示西部区域的实体集添加客户和订单实体
下面的代码创建 Customer 类型的一个新实例，并将该实例添加到表示西部地理区域的实体集中。
向不同的实体集添加相同类型的实体
创建 CustomerWest 类型的实例并初始化该客户的 CustomerId、Name 和 TotalPurchases 属性。
创建 OrderWest 类型的实例并初始化该订单的属性。
将步骤 1 中创建的客户分配给新订单。
使用 AddTCustomersWest 和 AddToOrdersWest 方法将 CustomerWest 和 OrderWest 的实例添加到存储。这些方法是在 Edmgen.exe 生成数据模型时创建的。
创建名为 newOrder 的另一个 OrderWest 实例。
创建在查询中使用的 ObjectParameter，该查询用于查找步骤 1 中创建的客户。
通过查询查找该客户。
通过将 newOrderTotalAmount 属性添加到客户 TotalPurchases 更新该客户的 TotalPurchases 属性。
将该客户分配给 newOrder。
使用 AddToOrdersWest 方法将 newOrder 添加到存储。
示例
Option Explicit On
Module Module1
Sub Main()
Try
Using objCtx As RegionalCustomersEntities = _
New RegionalCustomersEntities()
' Create a new customer.
Dim customerWest As New Customer()
customerWest.CustomerId = _
objCtx.CustomersWest.Count() + 1
customerWest.Name = _
"CustomerWest " + _
customerWest.CustomerId.ToString()
customerWest.TotalPurchases = CType(875, Decimal)
' Create Order.
Dim orderWest As New OrderWest()
orderWest.OrderId = _
objCtx.OrdersWest.Count() + 1
orderWest.OrderTotal = customerWest.TotalPurchases
orderWest.Tax = _
orderWest.OrderTotal * CType(0.07, Decimal)
orderWest.Customer = customerWest
' Add customer and order to object context.
objCtx.AddToCustomersWest("customerWest)
objCtx.AddToOrdersWest(orderWest)
objCtx.SaveChanges()
' Add order to existing customer.
Dim newOrder As New OrderWest
newOrder.OrderId = objCtx.OrdersWest.Count + 1
newOrder.OrderTotal = CType(338.0, Decimal)
newOrder.Tax = newOrder.OrderTotal * CType(0.07, Decimal)
Dim param As New ObjectParameter("p", 3)
If Not 0 = objCtx.CustomersWest. _
Where("it.CustomerId = @p", param).Count() Then
Dim c As Customer = _
objCtx.CustomersWest. _
Where("it.CustomerId = @p", param).FirstOrDefault()
c.TotalPurchases = c.TotalPurchases + newOrder.OrderTotal
newOrder.Customer = c
objCtx.SaveChanges()
End If
End Using
Catch ex As Exception
Console.WriteLine(ex.ToString())
End Try
End Sub
End Module
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using RegionalCustomersModel;
using System.Data.Objects;
namespace ClientRegionalCustomers
{
class Program
{
static void Main(string[] args)
{
try
{
using (RegionalCustomersEntities objCtx =
new RegionalCustomersEntities())
{
// Create a new customer.
Customer customerWest = new Customer();
customerWest.CustomerId =
objCtx.CustomersWest.Count<Customer>() + 1;
customerWest.Name =
"Customer West " +
customerWest.CustomerId.ToString();
customerWest.TotalPurchases =
(decimal)875.00;
// Create Order.
OrderWest orderWest = new OrderWest();
orderWest.OrderId =
objCtx.OrdersWest.Count<OrderWest>() + 1;
orderWest.OrderTotal =
customerWest.TotalPurchases;
orderWest.Tax =
orderWest.OrderTotal * (decimal).07;
orderWest.Customer = customerWest;
// Add customer and order to object context.
objCtx.AddToCustomersWest(customerWest);
objCtx.AddToOrdersWest(orderWest);
objCtx.SaveChanges();
// Add an order to existing customer.
OrderWest newOrder = new OrderWest();
newOrder.OrderId =
objCtx.OrdersWest.Count<OrderWest>() + 1;
newOrder.OrderTotal = (decimal)338.00;
newOrder.Tax =
newOrder.OrderTotal * (decimal).07;
ObjectParameter param =
new ObjectParameter("p", 3);
if (0 != objCtx.CustomersWest.Where(
"it.CustomerId = @p",
param).Count<Customer>())
{
Customer c =
objCtx.CustomersWest.Where(
"it.CustomerId = @p",
param).First<Customer>();
c.TotalPurchases =
c.TotalPurchases + newOrder.OrderTotal;
newOrder.Customer = c;
objCtx.SaveChanges();
}
}
}
catch (Exception e)
{
Console.WriteLine(e.ToString());
}
}
}
}