IObjectSet包含CompiledQuery的扩展方法错误 [英] IObjectSet Include Extension Method Errors with CompiledQuery

问题描述

在我的自定义ObjectContext类中，我的实体集合被公开为IObjectSet，因此可以进行单元测试。当我在一个编译查询中使用这个ObjectContext时，我遇到了一个问题，并调用了Include扩展方法（来自Julie Lerman的博客 http://thedatafarm.com/blog/data-access/agile-entity-framework-4-repository-part-5-iobjectset / ）：

  public IQueryable< MyPocoObject> RunQuery（MyCustomContext context，int theId）
 {
 var query = CompiledQuery.Compile< MyCustomContext，int，IQueryable< MyPocoObject>>（
（ctx，id）=> ctx.MyPocoObjects .Include（IncludedPocoObject）。其中（n => n.IncludedPocoObject.id == id））; 
 
返回查询（context，theId）; 
} 
  

LINQ to Entities不会识别方法'System.Linq.IQueryable 1 [MyPocoObject]包含[MyIncludedPocoObject]（System.Linq.IQueryable 1 [MyPocoObject]，System.String）'方法，此方法无法转换为存储表达式。 p>

如果我在ObjectSet集合上使用相同的查询，而不是IObjectSet，它可以正常工作。如果我只是运行这个查询而不预编译就可以正常工作。我在这里缺少什么？

解决方案

我确信我刚刚误解了，因为你似乎一直在看这个一段时间 - 但是不应该包括ObjectSet而不是该对象集查询的对象。

例如：

  var query = CompiledQuery.Compile< MyCustomContext，int，IQueryable&MyPocoObject>（
（ctx，id）=> ctx.MyPocoObjects.Include IncludedPocoObjectSET）。其中（n => n.IncludedPocoObject.id == id））; 
  

你还可以确认运行相同的查询没有编译不会抛出不能翻译例外？

In my Custom ObjectContext class I have my entity collections exposed as IObjectSet so they can be unit-tested. I have run into a problem when I use this ObjectContext in a compiled query and call the "Include" extension method (From Julie Lerman's blog http://thedatafarm.com/blog/data-access/agile-entity-framework-4-repository-part-5-iobjectset/):

    public IQueryable<MyPocoObject> RunQuery(MyCustomContext context, int theId)
    {
        var query = CompiledQuery.Compile<MyCustomContext, int, IQueryable<MyPocoObject>>(
             (ctx, id) => ctx.MyPocoObjects.Include("IncludedPocoObject").Where(n => n.IncludedPocoObject.id == id));

        return query(context, theId);
    }

LINQ to Entities does not recognize the method 'System.Linq.IQueryable1[MyPocoObject] Include[MyIncludedPocoObject](System.Linq.IQueryable1[MyPocoObject], System.String)' method, and this method cannot be translated into a store expression.

If I use this same query on ObjectSet collections rather than IObjectSet it works fine. If I simply run this query without precompiling it works fine. What am I missing here?

解决方案

I'm sure I've just misunderstood as you seem to have been looking at this for a while - But shouldn't you be including the ObjectSet not the object that is queried BY that object set.

eg:

var query = CompiledQuery.Compile<MyCustomContext, int, IQueryable<MyPocoObject>>(
     (ctx, id) => ctx.MyPocoObjects.Include("IncludedPocoObjectSET").Where(n => n.IncludedPocoObject.id == id));

Can you also confirm that running the same query without compiling doesn't throw the "can't translate" exception?

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