如何创建OData的查询表达式通过id来获取 [英] How to create query expression for Odata for get by Id

问题描述

我已经创建OData服务，现在我想在消费客户端此服务。我想创建一个表达式，比如在C＃查询表达式以下网址 -

I have created an OData service and now I am trying to consume this service at client side. I wants to create an expression such as for the below url in the c# query expression-

的 http://odata.org/Product-Service/Product（150）

上面的网址是工作在浏览器不错，但我想在C＃中上面的URL创建查询表达式。任何帮助将大大明显。

The above url is working fine in browsers but I want to create query expression in the C# for the above url. Any help would be greatly appreciable.

推荐答案

您可以使用 DataServiceContext + 化DataServiceQuery 在 System.Data.Services.Client 来打的URL。记住没有查询被执行，直到调用第一个（）因延迟加载。

You could use a DataServiceContext + DataServiceQuery in System.Data.Services.Client to hit the Url. Remember no query is executed until the call to First() due to lazy loading.

var context = new DataServiceContext(new Uri("http://odata.org/Product-Service"), DataServiceProtocolVersion.V3);
var query = context.CreateQuery<Product>("Product");
Product product = query.Where(p => p.Id == 150).First();

以上应该下定决心的 http://odata.org/Product-Service/Product（150），你可以通过查看 query.Entities检查集合。该集合将包含一个URI中的每个实体

The above should resolve to http://odata.org/Product-Service/Product(150) which you can check by looking at the query.Entities collection. Each entity in the collection will contain a Uri.

此外，如果你的产品类包含一个导航属性，你需要这样添加扩展查询选项：

Also if your Product class contains a navigation property, you will need to add the expand query option thus:

var query = context.CreateQuery<Product>("Product").
   AddQueryOption("$expand", "NavigationProperty");

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