实体框架对象树加载

Question

如何加载以下 EF 实体：

图片来源：http://blogs.microsoft.co.il/blogs/idof/archive/2008/08/20/entity-framework-and-lazy-loading.aspx

假设我们有地址 id，我们想加载人和宠物的地址。该怎么做？

我们可以做到

var address = contex.Addresses.Include("Peson").Where(add => add.Id == GivenId);

但它会加载地址和不带宠物的人。

如果我包含一个宠物实体，像这样：

var address = contex.Addresses.Include("Peson").Include("Pets").Where(add => add.Id == GivenId);

我得到错误：

指定的包含路径无效。

所以问题是如何加载整个实体树。

Answer 1

您可以通过用“.”分隔关系来加载树

context.Address.Include("Person.Pets"); //Include all the persons with their pets
context.Pets.Include("Person.Address"); //Include all the persons with their addresses

Answer 2

始终从顶层对象向下选择，例如：

var person = from p in context.Person.Include("Pets").Include("Address")
where p.Address.Id == givenId
select p;