RavenDB中的Map / reduce会抛出InvalidOperationException

我在使map / reduce操作工作时遇到困难 . 我是C＃的业余爱好者，所以可能部分是由于我缺乏lambda和linq的经验来彻底分析和理解导致错误的原因（什么是对象创建表达式） .

代码编译完美，但是在执行时抛出异常，我不明白哪个部分不正确 .

当我禁用reduce操作时，错误仍然存在，因此我认为它与Map部分有关 .

RavenDB版本是：RavenDB-Build-573

这是例外：System.InvalidOperationException：变量初始化程序选择必须具有带有对象创建表达式的lambda表达式

我为RavenDB提供了如下索引：

IndexCreation.CreateIndexes(typeof(FullTree).Assembly, store);

Entity对象是一个简单的类，具有int Id和int ParentId .

这是map / reduce部分：

public class FullTreeObject
{
    public int Id { get; set; }
    public int Count { get; set; }
    public int ParentId { get; set; }
}

public class FullTree : AbstractIndexCreationTask<Entity,FullTreeObject>
   {
       public FullTree()
       {

           Map = entities => from entity in entities
                             let ids = new object[]
                               {
                                   new { entity.Id, Count = 0,
entity.ParentId },
                                   new { Id = entity.ParentId, Count
= 1, ParentId = (string)null}
                               }
                             from id in ids
                             select id;

           Reduce = results => from result in results
                               group result by result.Id into g
                               let parent = g.FirstOrDefault(x =>
x.ParentId != null)
                               select new
                               {
                                   Id = g.Key,
                                   Count = g.Sum(x => x.Count),
                                   ParentId = parent ==
(object)null ? (object)null : parent.ParentId
                               };

       }
   }

希望有人可以提供一些线索 . 提前致谢 .

为了对输入做出反应，我修改了map / reduce实现 . RavenDB需要map和reduce输出相同的类型，但说实话，这是不对的，因为我输出的是实体对象的值，而不是数组中获取的值 . 但我无法通过intellisense达到这些 Value .

索引是在RavenDB工作室中创建的，但没有返回任何结果，所以我可以假设我的实现有问题 .

public class FullTree : AbstractIndexCreationTask<Entity,FullTreeObject>
    {
        public FullTree()
        {
            Map = entities => from entity in entities
                              let ids = new object[]
                                { 
                                    new { entity.Id, Count = 0, entity.ParentId }, 
                                    new { Id = entity.ParentId, Count = 1, ParentId = (string)null} 
                                } 
                              from id in ids
                              select new { 
                                    entity.Id,
                                    Count = 1,
                                    entity.ParentId
                              };


            Reduce = results => from result in results
                                group result by result.Id into g
                                let parent = g.FirstOrDefault(x => x.ParentId != null)
                                select new
                                {
                                    Id = g.Key,
                                    Count = g.Sum(x => x.Count), 
                                    ParentId = parent == (object)null ? (object)null : parent.ParentId
                                };
        }
    }

Build 601更新：

public class FullTree : AbstractIndexCreationTask<Entity, FullTree.ReduceResult>
{

    public class ReduceResult
    {
        public int Id { get; set; }
        public int Count { get; set; }
        public int ParentId { get; set; }
    } 
    public FullTree()
    {
        Map = entities => from entity in entities
                          let items = new[]
                            { 
                                new { Id = (int) entity.Id, Count = (int) 0, ParentId = (int) entity.ParentId }, 
                                new { Id = (int) entity.ParentId, Count = (int) 1, ParentId = (int) 0} 
                            } 
                          from item in items
                          select new { 
                                Id = item.Id,
                                Count = item.Count,
                                ParentId = item.ParentId
                          };


        Reduce = results => from result in results
                            group result by result.Id into g
                            let itemWithParent = g.FirstOrDefault(x => x.ParentId != 0)
                            select new
                            {
                                Id = g.Key,
                                Count = g.Sum(x => x.Count),
                                ParentId = (itemWithParent == null) ? (int)0 : itemWithParent.ParentId
                            };
    }
}

返回错误：[WebException：远程服务器返回错误：（500）内部服务器错误 . ] System.Net.HttpWebRequest.GetResponse（）6111651 Raven.Client.Connection.HttpJsonRequest.ReadStringInternal（Func`1 getResponse）在c：\构建\乌鸦\ Raven.Client.Lightweight \连接\ HttpJsonRequest.cs：231

[InvalidOperationException：{“Url”：“/ indexes / FullTree”，“Error”：“System.InvalidOperationException：无法理解查询：\ r \ n--第2行第55行：无效NewExpression \ r \ n--第2行col 91：无法解析double .0.0 \ r \ n--第2行col 183：无法解析double .0.0 \ r \ n--第2行col 275：无法解析double .0.0 \ r \ n \ r \ n位于Raven.Database.Linq.QueryParsingUtils.GetVariableDeclarationForLinqMethods（String query，Boolean requiresSelectNewAnonymousType）位于Raven的c：\ Builds \ raven-unstable \ Raven.Database \ Linq \ QueryParsingUtils.cs：第122行\ r \ n . Database.Linq.DynamicViewCompiler.TransformMapDefinitionFromLinqMethodSyntax（String query，String＆entityName）位于c：\ Builds \ raven-unstable \ Raven.Database \ Linq \ DynamicViewCompiler.cs：第355行\ r \ n在Raven.Database.Linq.DynamicViewCompiler.HandleMapFunction （ConstructorDeclaration ctor，String map）在c：\ Build中的Raven.Database.Linq.DynamicViewCompiler.TransformQueryToClass（）中的c：\ Builds \ raven-unstable \ Raven.Database \ Linq \ DynamicViewCompiler.cs：第132行\ r \ n在ds：\ Builds \ raven-unstable \ Raven.Database \ Linq DynamicViewCompiler.cs：第489行\ r \ n在Raven.Database.DocumentDatabase.PutIndex（字符串名称，IndexDefinition定义）中的c：\ Builds \ raven-unstable \ Raven.Database \ DocumentDatabase.cs：第717行\ r \ n at Raven.Database中的Raven.Database.Server.Responders.Index.Put（IHttpContext context，String index）在Raven.Database中的c：\ Builds \ raven-unstable \ Raven.Database \ Server \ Responders \ Index.cs：第72行\ r \ n .Server.Responders.Index.Respond（IHttpContext context）位于c：\ Builds \ raven-unstable \ Raven.Database \ Server \ Responders \ Index.cs：第49行\ r \ n在Raven.Database.Server.HttpServer.DispatchRequest中（IHttpContext ctx）位于c：\ Builds \ raven-unstable \ Raven.Database \ Server \ HttpServer.cs：第527行\ r \ n，位于c：\ Builds \中的Raven.Database.Server.HttpServer.HandleActualRequest（IHttpContext ctx） raven-unstable \ Raven.Database \ Server \ HttpServer.cs：line 303“}] Rave n.Client.Connection.HttpJsonRequest.ReadStringInternal（Func`1 getResponse）在c：\ Builds \ raven \ Raven.Client.Lightweight \ Connection \ HttpJsonRequest.cs：295