LINQ to Entities 中不可用的实体属性

发布于 2024-12-18 21:44:02 字数 861 浏览 3 评论 0原文

这是我的简化示例问题。

我有两个从 SQL Server 数据库建模的实体：

订单（可用列 = OrderID、PackageCount、ManufactureDate、ShipDate、StatusID）主键 = OrderID）
OrderRecipients（可用列 = RecipientID、FirstName、LastName、Address、City、Zip、Country、OrderID） ; 外键 = OrderID)

Orders 和 OrderRecipients 之间存在[一对多]关系。一份订单可以有多个收件人。

我正在尝试通过以下代码提取订单的收件人。

  var allmyrecipients = from o in mycontext.Orders
                        where (o.SiteID.Equals("NYC") || o.SiteID.Equals("SFO"))
                        select o.OrderRecipients;

但是，当我尝试使用以下代码获取收件人的姓名时：

 foreach (var recipient in allmyrecipients)
 {
   Console.WriteLine(recipient.FirstName);
 }

收件人的名字和其他属性在智能感知下拉列表中不可用。我收到“不包含 FirstName 的定义”错误。

这是为什么？有什么补救措施？我在这里做错了什么？我正在使用 VS 2010、Entity Framework 4。

感谢您抽出时间来提供帮助。

原文

Here is my problem with simplified example.

I have two entities modeled from SQL Server database:

Orders (columns available = OrderID, PackageCount,ManufactureDate, ShipDate, StatusID) Primary Key = OrderID)
OrderRecipients (columns available = RecipientID, FirstName, LastName, Address, City, Zip, Country, OrderID; Foreign Key = OrderID)

There is a [1 to many] relationship between Orders and OrderRecipients. One order can have several recipients.

I'm trying to extract the recipients of orders via the following code.

  var allmyrecipients = from o in mycontext.Orders
                        where (o.SiteID.Equals("NYC") || o.SiteID.Equals("SFO"))
                        select o.OrderRecipients;

However when I try to get the names of the recipients with the following code:

 foreach (var recipient in allmyrecipients)
 {
   Console.WriteLine(recipient.FirstName);
 }

the FirstName and other attributes of the recipient are not available in the Intellisense drop-down. I get "does not contain a definition of FirstName" error.

Why is this and what is the remedy? What am I doing wrong here? I'm working with VS 2010, Entity Framework 4.

Thank you for taking time to help.

分享到QQ

分享到微博

如果你对这篇内容有疑问，欢迎到本站社区发帖提问参与讨论，获取更多帮助，或者扫码二维码加入 Web 技术交流群。

发布评论

需要登录才能够评论，你可以免费注册一个本站的账号。

生寂 2024-12-25 21:44:02

编辑：我将其重构为应该使用 SelectMany< 的东西/a>.试一试：

var orders = from o in mycontext.Orders
    where (o.SiteID.Equals("NYC") || o.SiteID.Equals("SFO"))
    select o;

foreach (var recipient in orders.SelectMany(r => r.OrderRecipients)) 
{
    Console.WriteLine(recipient.FirstName); 
}

EDIT: I refactored this into somthing that should work using SelectMany. Give this a shot:

var orders = from o in mycontext.Orders
    where (o.SiteID.Equals("NYC") || o.SiteID.Equals("SFO"))
    select o;

foreach (var recipient in orders.SelectMany(r => r.OrderRecipients)) 
{
    Console.WriteLine(recipient.FirstName); 
}

回复收藏 0 原文

~没有更多了~