网页API的OData：你如何在$一个单一的实体扩张？ [英] Web API OData: How do you $expand on a single entity?
问题描述
我读过这两个这些 <一href=\"http://blogs.msdn.com/b/webdev/archive/2013/07/05/introducing-select-and-expand-support-in-web-api-odata.aspx\"相对=nofollow>文章的多次尝试，并想出一个办法使用 $展开一个单一的实体查询选项，但在每一个方法我试过，我似乎没有能够使它发挥作用。所有其它工作选项的查询和 $展开也是目前从事集合结果。
I've read both these articles multiple times to try and figure out a way to use the $expand query option on a single entity, but in each and every way I've tried, I just can't seem to be able to make it work. All the other query options work and $expand also currently works on collection results.
型号：玩家的实体有一个叫做统计导航属性，其中每个对象包含了玩家对于给定的年度统计数据。
Model: Player entities have a navigation property called Stats in which each object contains the stats for that player for a given year.
我已经设置了OData的是这样的：
I've set up OData this way:
config.EnableQuerySupport();
ODataModelBuilder modelBuilder = new ODataConventionModelBuilder();
modelBuilder.EntitySet<Player>("OPlayer");
modelBuilder.EntitySet<PlayerStatistics>("OPlayerStats");
Microsoft.Data.Edm.IEdmModel model = modelBuilder.GetEdmModel();
config.Routes.MapODataRoute("ODataRoute", "odata", model);
本来，我已经建立了我的控制器是这样的：
Originally, I had set up my controller this way:
public class OPlayerController : EntitySetController<Player, int>
{
private readonly DatabaseContext _db = new DatabaseContext();
protected override Player GetEntityByKey(int key)
{
return _db.Players.FirstOrDefault(p => p.PlayerId == key);
}
public override IQueryable<Player> Get()
{
return _db.Players.AsQueryable();
}
protected override void Dispose(bool disposing)
{
_db.Dispose();
base.Dispose(disposing);
}
}
通过这样的结构，我可以使这些查询：
With this configuration, I can make these queries:
-
/ ODATA / OPLAYER（600） -
/ ODATA / OPLAYER -
/ ODATA / OPLAYER？$ =拓展统计信息
/odata/OPlayer(600)/odata/OPlayer/odata/OPlayer?$expand=Stats
但显然不是（结果没有展开）：
But evidently not (the result is not expanded):
-
/ ODATA / OPLAYER（600）？$ =拓展统计信息
/odata/OPlayer(600)?$expand=Stats
两篇文章都提到，为了支持它，你必须添加一个方法（行动？）到你的控制器，看起来像这样：
Both articles mention that in order to support it, you have to add a method (action?) to your controller that looks like this:
[Queryable]
public SingleResult<Player> GetPlayer(int id)
{
return SingleResult.Create(_dbContext.Players.Where(c => c.ID == id);
}
当我将它添加到我的控制器，虽然，这两种 / ODATA / OPLAYER（600）和 / ODATA / OPLAYER（600）？$扩大=统计收益没有采取任何控制器OPLAYER的要求相匹配。上找到
When I add this to my controller though, both /odata/OPlayer(600) and /odata/OPlayer(600)?$expand=Stats return No action was found on the controller 'OPlayer' that matches the request.
任何人都可以作出澄清，或以支持 $展开在一个单一的实体指点？
Can anyone provide clarifications, or give pointers in order to support $expand on a single entity?
推荐答案
您的行动 GetPlayer 得到了参数名称不正确。参数名称应该是关键，而不是ID。试试这个作为你的行动，而不是，
Your action GetPlayer got the parameter name incorrect. The parameter name should be "key" instead of id. Try this as your action instead,
[Queryable]
public SingleResult<Player> GetPlayer([FromODataUri]int key)
{
return SingleResult.Create(_db.Players.Where(c => c.PlayerId == key));
}
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