asp.net MVC 3 - 你如何加载一个实体​​的儿童和盛大的孩子吗？ [英] asp.net mvc 3 - How do you load children AND grand-children of an entity?

问题描述

我想知道如何加载实体的多个水平;更具体如何加载一个单一的实体的后代多级。下面是我创建了一个例子。假设一个Web界面上，创建一个新的产品后，我想，以显示其类别类型。因此，我们有某一类的产品，而这个类别都有一个类别与类型的名称：

I would like to know how to load multiple level of entities; more specifically how to load multiple level of descendants of a single entity. Here is an example I created. Suppose that on a web interface, after creating a new product, I would like to display its category type. So we have a product of a certain category, and this category has a category type with a name:

[HttpPost]
public ActionResult DoSomething(Product product)
{
    if (ModelState.IsValid)
    {
        productRepository.InsertOrUpdate(product);
        productRepository.Save();
        ...
        context.Entry(product).Reference(p => p.Category).Load();
        string someString1 = product.Category.SomeProperty;
        ...
        string someString2 = product.Category.CategoryType.Name;
        ...

有人告诉我如何在另一篇文章中（见someString1在上面的例子中）在保存对象加载后的孩子，但我无法弄清楚如何加载盛大儿童（someString2）。

Someone showed me how to load children after saving an object on another post (see someString1 in the example above), but I cannot figure out how to load grand-children (someString2).

有<一个href=\"http://blogs.msdn.com/b/adonet/archive/2011/01/31/using-dbcontext-in-ef-feature-ctp5-part-6-loading-related-entities.aspx\"相对=nofollow>在网络上的例子，说明如何加载实体的集合，所有相关的对象，而是要说明如何加载单个实体的所有后代的省略。

There are examples on the net showing how to load a collection of entities and all related objects, but the omit to show how to load all the descendants of a single entity.

我使用ASP.Net MVC 3 EF 4.1。而这一切是相当新的给我，所以请多多包涵。

I am using ASP.Net MVC 3 with EF 4.1. And all this is quite new to me, so please bear with me.

推荐答案

您可以得到它像这样

context.Entry(product).Reference(p => p.Category).Load();
string someString1 = product.Category.SomeProperty;
...

context.Entry(product.Category).Reference(c => c.CategoryType).Load();
string someString2 = product.Category.CategoryType.Name;

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