Elasticsearch .net client NEST 5.x 使用总结

demo源码 https://github.com/huhangfei/NestDemos

本文是针对NEST 5.X的使用的总结。

引用

NEST.dll
Elasticsearch.Net.dll  
Newtonsoft.Json.dll

调试

1. 本地debug时 可以通过fiddler抓取到请求es服务的http请求。
2. 也可可以在代码中抓取到request和response

 var settings = new ConnectionSettings(pool);
            //在创建client时开启设置；
            //正式环境建议关闭，占用资源
            settings.DisableDirectStreaming(true);
            var client=new ElasticClient(settings);
 
            var result=client.Search(....);
 
            var requestStr = System.Text.Encoding.Default.GetString(result.ApiCall.RequestBodyInBytes);
            var responseStr = System.Text.Encoding.Default.GetString(result.ApiCall.ResponseBodyInBytes);
            _log.Debug(requestStr + "                " + responseStr);

存储结构：

在Elasticsearch中，文档(Document)归属于一种类型(type),而这些类型存在于索引(index)中. 

类比传统关系型数据库：

Relational DB -> Databases -> Tables -> Rows -> Columns
Elasticsearch -> Indices   -> Types  -> Documents -> Fields

DB使用过程:创建数据库->创建表（主要是设置各个字段的属性）->写入数

ES使用过程:创建索引->为索引maping一个Type（同样是设置类型中字段的属性）->写入数

客户端语法

 

链式lambda 表达式（ powerful query DSL）语法

s => s.Query(q => q
    .Term(p => p.Name, "elasticsearch")
)

对象初始化语法

var searchRequest = new SearchRequest<VendorPriceInfo>
{
  Query = new TermQuery
  {
      Field = "name",
      Value = "elasticsearch"
   }
};

Connection链接

//单node
Var node = new Uri(“……”);
var settings = new ConnectionSettings(node);
 
//多uris
Var uris = new Uri [] {
    new Uri(“……”),
    new Uri(“……”)
};
var pool = new StaticConnectionPool(uris);
 
//多node
Var nodes = new Node [] {
    new Node (new Uri(“……”)),
    new Node (new Uri(“……”))
};
//链接池
var pool = new StaticConnectionPool(nodes);
 
var settings = new ConnectionSettings(pool);
 
var client = new ElasticClient(settings);

注：nest默认字段名首字母小写，如果要设置为与Model中一致，在创建client时按如下设置。（强烈建议使用该设置，避免造成字段不一致）

var settings = new ConnectionSettings(node).DefaultFieldNameInferrer((name) => name);

Connection Settings

  var settings = new ConnectionSettings(pool);
            //验证 未开启
            //settings.BasicAuthentication("username", "password");
            //验证证书
            //settings.ClientCertificate("");
            //settings.ClientCertificates(new X509CertificateCollection());
            //settings.ServerCertificateValidationCallback();
 
            //开启 第一次使用时进行嗅探，需链接池支持
            //settings.SniffOnStartup(false);
 
            //链接最大并发数
            //settings.ConnectionLimit(80);
            //标记为死亡节点的超时时间
            //settings.DeadTimeout(new TimeSpan(10000));
            //settings.MaxDeadTimeout(new TimeSpan(10000));
            //最大重试次数
            //settings.MaximumRetries(5);
            //重试超时时间 默认是RequestTimeout
            //settings.MaxRetryTimeout(new TimeSpan(50000));
            //禁用代理自动检测
            //settings.DisableAutomaticProxyDetection(true);
 
            //禁用ping 第一次使用节点或使用被标记死亡的节点进行ping
            settings.DisablePing(false);
            //ping 超时设置
            //settings.PingTimeout(new TimeSpan(10000));
            //选择节点
            //settings.NodePredicate(node =>
            //{
            //    
            //        return true;
            //    
            //});
            //默认操作索引
            //settings.DefaultIndex("");
            //字段名规则 与model字段同名
            //settings.DefaultFieldNameInferrer(name => name);
            //根据Type 获取类型名
            //settings.DefaultTypeNameInferrer(name => name.Name);
            //请求超时设置
            //settings.RequestTimeout(new TimeSpan(10000));
            //调试信息
            settings.DisableDirectStreaming(true);
            //调试信息
            //settings.EnableDebugMode((apiCallDetails) =>
            //{
            //    //请求完成 返回 apiCallDetails
 
            //});
            //抛出异常 默认false，错误信息在每个操作的response中
            settings.ThrowExceptions(true);
            //settings.OnRequestCompleted(apiCallDetails =>
            //{
            //    //请求完成 返回 apiCallDetails
            //});
            //settings.OnRequestDataCreated(requestData =>
            //{
            //    //请求的数据创建完成 返回请求的数据
 
            //});
            return new ElasticClient(settings);

不同的连接池类型

//支持ping 说明能够发现节点的状态
            //支持嗅探 说明能够发现新的节点
 
            //应用于已知集群，请求时随机请求各个正常节点，支持ping 不支持嗅探
            IConnectionPool pool = new StaticConnectionPool(nodes);                      //推荐使用
 
            //IConnectionPool pool=new SingleNodeConnectionPool(nodes[0]);
 
            //可动态嗅探集群 ，随机请求 支持嗅探、ping
            //IConnectionPool pool = new SniffingConnectionPool(nodes);
 
            //选择一个可用节点作为请求主节点，支持ping 不支持嗅探
            //IConnectionPool pool = new StickyConnectionPool(nodes);
 
            //选择一个可用节点作为请求主节点，支持ping 支持嗅探
            //IConnectionPool pool=new StickySniffingConnectionPool(nodes);

操作目标索引/类型选择

 

指定索引

//执行操作时指定索引
client.Search<VendorPriceInfo>(s => s.Index("test-index"));
client.Index(data,o=>o.Index("test-index"));
....

指定类型

默认类型为索引数据的类名（自动转换为全小写，规则可自定义）。 
如果特性设置Name[ElasticsearchType(Name = “datatype”)]则使用该名称。

//主动指定
client.Index(data, o => o.Type(new TypeName() { Name = "datatype", Type = typeof(VendorPriceInfo) }));

数据模型特性

特性可以设置数据在es中的类型、名称、是否索引、分词、格式化等信息。

应用于第一次创建索引后进行映射时。

重要特性：

• [ElasticsearchType(Name = “文档的类型”,IdProperty = “文档的唯一键字段名”)]
• [Number(NumberType.Long,Name = “Id”)] 数字类型 +名称
• [Keyword(Name = “Name”,Index = true)]不需要分词的字符串，name=名称,index=是否建立索引
• [Text(Name = “Dic”, Index = true,Analyzer = “ik_max_word”)]需要分词的字符串，name=名称,index=是否建立索引,Analyzer=分词器

 /// <summary>
    /// 5.x 特性
    /// </summary>
    [ElasticsearchType(Name = "TestModel5",IdProperty = "Id")]
    public class TestModel5
    {
        [Number(NumberType.Long,Name = "Id")]
        public long Id { get; set; }
        /// <summary>
        /// keyword 不分词
        /// </summary>
        [Keyword(Name = "Name",Index = true)]
        public string Name { get; set; }
        /// <summary>
        /// text 分词,Analyzer = "ik_max_word"
        /// </summary>
        [Text(Name = "Dic", Index = true)]
        public string Dic { get; set; }
 
        [Number(NumberType.Integer,Name = "State")]
        public int State { get; set; }
 
        [Boolean(Name = "Deleted")]
        public bool Deleted { get; set; }
        [Date(Name = "AddTime")]
        public DateTime AddTime { get; set; }
 
        [Number(NumberType.Float,Name = "PassingRate")]
        public float PassingRate { get; set; }
 
        [Number(NumberType.Double, Name = "Dvalue")]
        public double Dvalue { get; set; }
    }

索引操作

 

创建

client.CreateIndex("test2");
//基本配置
IIndexState indexState=new IndexState()
{
       Settings = new IndexSettings()
       {
            NumberOfReplicas = 1,//副本数
            NumberOfShards = 5//分片数
       }
};
//创建索引 先不maping 
client.CreateIndex("test2", p => p.InitializeUsing(indexState));
 
//创建并Mapping
client.CreateIndex("test-index3", p => p.InitializeUsing(indexState).Mappings(m => m.Map<VendorPriceInfo>(mp => mp.AutoMap())));

注：索引名称必须小写

判断

client.IndexExists("test2");

删除

client.DeleteIndex("test2");

索引创建、maping、设置别名、别名操作

  /// <summary>
        /// 创建索引
        /// </summary>
        private void CreateIndex(string indexName)
        {
            if (!_client.IndexExists(indexName).Exists)
            {
 
                IndexState indexState = new IndexState
                {
                    Settings = new IndexSettings
                    {
                        NumberOfReplicas = _replicas, //副本数
                        NumberOfShards = _shards //分片数
                    }
                };
                //创建并设置
                _client.CreateIndex(indexName, p => p
                    .InitializeUsing(indexState)
                    .Mappings(m => m.Map<EsDataModel>(mps => mps.AutoMap()))
                    .Aliases(a => a.Alias(_indexAliase + "_manager"))
                    );
                //map
                //_client.Map<EsDataModel>(m => m.Index(indexName).AutoMap());
 
 
                #region 别名操作
 
                Action addAlias = () => { _client.Alias(a => a.Add(d => d.Index(indexName).Alias(_indexAliase))); };
                //该别名是否存在
                if (!_client.AliasExists(s => s.Name(_indexAliase)).Exists)
                {
                    addAlias();
                    return;
                }
                var result = _client.GetAlias(a => a.Name(_indexAliase));
                //该别名下所有 索引
                if (result.Indices == null)
                {
                    addAlias();
                    return;
                }
                var indices = result.Indices.Select(index => index.Key).Select(dummy => (IndexName)dummy).ToArray();
                //该别名下所有 索引
                if (indices.Length <=0)
                {
                    addAlias();
                    return;
                }
                //删除其它老的索引的别名
                //添加到新的索引上
                Func<AliasRemoveDescriptor, IAliasRemoveAction> removeSelector = d =>
                {
                    foreach (var index in indices)
                    {
                        d.Alias(_indexAliase).Index(index.Name);
                    }
                    return d;
                };
                _client.Alias(a => a
                        // 删除 别名           
                        .Remove(removeSelector)
                        //添加 别名
                        .Add(d => d.Index(indexName).Alias(_indexAliase))
                        );
                #endregion
            }
        }

映射

如果创建索引时没有进行maping操作，可以再单独maping，已经确定类型的字段无法更改，可以新增。

//根据对象类型自动映射
            var result = _client.Map<TestModel5>(m => m.AutoMap());
            //手动指定
            var result1 = _client.Map<TestModel5>(m => m.Properties(p => p.Keyword(s => s.Name(n => n.Name).Index(true))));//Keyword 类型

新增映射字段

 //新增字段
            var result = _client.Map<TestModel5>(m => m
            .Index(indexName)
            .Properties(p => p
                    .Keyword(s => s
                            .Name("NewField")
                            .Index(true))
                    .Text(s=>s
                        .Name("NewFieldText")
                        .Index(false))
            )
            );

注：映射时已存在的字段将无法重新映射，只有新加的字段能映射成功。所以最好在首次创建索引后先进性映射再索引数据。 
注：映射时同一索引中，多个类型中如果有相同字段名，那么在索引时可能会出现问题（会使用第一个映射类型）。 
注：如果没有特殊需求，且字段没有过多的重叠，一个索引建议只存放一个类型的数据。

数据

 

添加单条数据

//写入数据，指定索引
            _client.Index(data, s => s.Index(indexName));
            //指定索引、类型
            _client.Index(data,s=>s.Index(indexName).Type("TestModel5"));
 
            //写入数据，指定索引
            _client.IndexMany(datas, indexName);
            //指定索引、类型
            _client.IndexMany(datas, indexName, "TestModel5");

删除数据

 DocumentPath<TestModel5> deletePath = new DocumentPath<TestModel5>(7);
            _client.Delete(deletePath,s=>s.Index(indexName));
            _client.Delete(deletePath,s=>s.Index(indexName).Type(typeof(TestModel5)));
            _client.Delete(deletePath,s=>s.Index(indexName).Type("TestModel5"));
 
            IDeleteRequest request = new DeleteRequest(indexName, typeof(TestModel5), 7);
            _client.Delete(request);
 
 
             //1.x中有 2.x中需要安装插件 5.x中又回来了
            _client.DeleteByQuery<TestModel5>(
                s =>s
                    .Index(indexName)
                    .Type("TestModel5")
                    .Query(q =>q.Term(tm => tm.Field(fd => fd.State).Value(1))));

更新数据

 

更新所有字段

DocumentPath<VendorPriceInfo> deletePath=new DocumentPath<VendorPriceInfo>(2);
Var response=client.Update(deletePath,(p)=>p.Doc(new VendorPriceInfo(){vendorName = "test2update..."}));
//或
IUpdateRequest<VendorPriceInfo, VendorPriceInfo> request = new UpdateRequest<VendorPriceInfo, VendorPriceInfo>(deletePath)
            {
                Doc = new VendorPriceInfo()
                {
                    priceID = 888,
                    vendorName = "test4update........"
                }
            };
            var response = client.Update<VendorPriceInfo, VendorPriceInfo>(request);

更新部分字段

IUpdateRequest<VendorPriceInfo, VendorPriceInfoP> request = new UpdateRequest<VendorPriceInfo, VendorPriceInfoP>(deletePath)
            {
                Doc = new VendorPriceInfoP()
                {
                    priceID = 888,
                    vendorName = "test4update........"
                }
 
            };
            var response = client.Update(request); 

更新部分字段

IUpdateRequest<VendorPriceInfo, object> request = new UpdateRequest<VendorPriceInfo, object>(deletePath)
            {
                Doc = new
                {
                    priceID = 888,
                    vendorName = " test4update........"
                }
            };
            var response = client.Update(request);
//或
client.Update<VendorPriceInfo, object>(deletePath, upt => upt.Doc(new { vendorName = "ptptptptp" }));

注：更新时根据唯一id更新

更新时使用本版号加锁机制

//查询到版本号
            var result = _client.Search<TestModel5>(
                s =>
                    s.Index(indexName)
                        .Query(q => q.Term(tm => tm.Field(fd=>fd.State).Value(1))).Size(1)
                        .Version()//结果中包含版本号
                        );
            foreach (var s in result.Hits)
            {
                Console.WriteLine(s.Id + "  -  " + s.Version);
            }
 
            var path = new DocumentPath<TestModel5>(1);
            //更新时带上版本号 如果服务端版本号与传入的版本好相同才能更新成功
            var response = _client.Update(path, (p) => p
                .Index(indexName)
                .Type(typeof(TestModel5))
                .Version(2)//限制es中版本号为2时才能成功
                .Doc(new TestModel5() { Name = "测测测" + DateTime.Now })
                );

搜索

 

基本搜索

var result = _client.Search<TestModel5>(
                s => s
                    .Explain() //参数可以提供查询的更多详情。
                    .FielddataFields(fs => fs //对指定字段进行分析
                        .Field(p => p.Name)
                        .Field(p => p.Dic)
                    )
                    .From(0) //跳过的数据个数
                    .Size(50) //返回数据个数
                    .Query(q =>
                        q.Term(p => p.State, 100) // 主要用于精确匹配哪些值，比如数字，日期，布尔值或 not_analyzed的字符串(未经分析的文本数据类型)：
                        &&
                        q.Term(p => p.Name.Suffix("temp"), "姓名") //用于自定义属性的查询 
                        &&
                        q.Bool( //bool 查询
                            b => b
                                //must  should  mushnot
                                .Must(mt => mt //所有分句必须全部匹配，与 AND 相同
                                    .TermRange(p => p.Field(f => f.State).GreaterThan("0").LessThan("1"))) //指定范围查找
                                .Should(sd => sd //至少有一个分句匹配，与 OR 相同
                                    .Term(p => p.State, 32915),
                                    sd => sd.Terms(t => t.Field(fd => fd.State).Terms(new[] { 10, 20, 30 })),
                                    //多值
                                    //||
                                    //sd.Term(p => p.priceID, 1001)
                                    //||
                                    //sd.Term(p => p.priceID, 1005)
                                    sd => sd.TermRange(tr => tr.GreaterThan("10").LessThan("12").Field(f => f.State)),
                                    //出入的时间必须指明时区
                                    sd => sd.DateRange(tr => tr.GreaterThan(DateTime.Now.AddDays(-1)).LessThan(DateTime.Now).Field(f => f.CreateTime))
 
                                )
                                .MustNot(mn => mn//所有分句都必须不匹配，与 NOT 相同
                                    .Term(p => p.State, 1001)
                                    ,
                                    mn => mn.Bool(
                                        bb => bb.Must(mt => mt
                                              .Match(mc => mc.Field(fd => fd.Name).Query("至尊"))
                                        ))
                                )
                            )
                    )//查询条件
                .Sort(st => st.Ascending(asc => asc.Id))//排序
                //返回特定的字段
                //注:2.x是sc.Include
                .Source(sc => sc.Includes(ic => ic
                    .Fields(
                        fd => fd.Name,
                        fd => fd.Id,
                        fd => fd.CreateTime))) 
               );

分页、 深度分页

搜索时通过from+size控制分页，但是由于底层机制，深度分页将造成更大的性能消耗。所以es默认限制from+size⇐10000

想要更深的分页，只能通过上页结果作为条件进行翻页。

var response=_client.Search<TestModel5>(s => s.Query(q => q.Term(t => t.Field(fd => fd.State).Value(1)))
            .Size(1000)    
            .Sort(st => st.Descending(ds => ds.Id))
                .SearchAfter(new object[]
                {
                    10,//上一次结果排序的最后ID值
                    //可以是多个排序字段的值
                }));

扫描和滚屏（用于非实时的获取大量数据）

5.x中支持并发扫描

  Action<int> sc1 = (id) =>
            {
                string scrollid = "";
                //todo:5.x 多了Slice设置 移除SearchType.Scan
                var result = _client.Search<TestModel5>(s => s.Index(indexName).Query(q => q.MatchAll())
                    .Size(15)
                    .Sort(st=>st.Descending(ds=>ds.Id))
                    .Scroll("1m")
                    //id从0开始 0,1,2...
                    //length=max
                    //例：max=3 id=0,id=1,id=2
                    .Slice(sl => sl.Id(id).Max(3))
                    );
 
                //得到滚动扫描的id
                scrollid = result.ScrollId;
                foreach (var info in result.Documents)
                {
                    Console.WriteLine(info.Id + " - " + " -批次count " + result.Documents.Count + " - 线程"+Thread.CurrentThread.ManagedThreadId);
                }
                while (true)
                {
                    //执行滚动扫描得到数据 返回数据量是 result.Shards.Successful*size(查询成功的分片数*size)
                    var result1 = _client.Scroll<TestModel5>("1m", scrollid);
                    if (result1.Documents == null || !result1.Documents.Any())
                        break;
                    foreach (var info in result1.Documents)
                    {
                        Console.WriteLine(info.Id + " - " +" -批次count "+ result1.Documents.Count+ " - 线程" + Thread.CurrentThread.ManagedThreadId);
                    }
                    //得到新的id
                    scrollid = result1.ScrollId;
                }
            };
           var t1= Task.Factory.StartNew(() => { sc1(0); });
            var t2= Task.Factory.StartNew(() => { sc1(1); });
            var t3= Task.Factory.StartNew(() => { sc1(2); });
            t1.Wait();
            t2.Wait();
            t3.Wait();

多查询、排序条件拼接

bool useStateDesc = true;
 
            //must 条件
            var mustQuerys = new List<Func<QueryContainerDescriptor<TestModel5>, QueryContainer>>();
            //Deleted
            mustQuerys.Add(mt => mt.Term(tm => tm.Field(fd => fd.Deleted).Value(false)));
            //CreateTime
            mustQuerys.Add(mt => mt.DateRange(tm => tm.Field(fd => fd.CreateTime).GreaterThanOrEquals(DateTime.Now.AddDays(-1)).LessThanOrEquals(DateTime.Now)));
            //should 条件
            var shouldQuerys = new List<Func<QueryContainerDescriptor<TestModel5>, QueryContainer>>();
            //state
            shouldQuerys.Add(mt => mt.Term(tm => tm.Field(fd => fd.State).Value(1)));
            shouldQuerys.Add(mt => mt.Term(tm => tm.Field(fd => fd.State).Value(2)));
            //排序
            Func<SortDescriptor<TestModel5>, IPromise<IList<ISort>>> sortDesc = sd =>
            {
                //根据分值排序
                sd.Descending(SortSpecialField.Score);
 
                //排序
                if (useStateDesc)
                    sd.Descending(d => d.State);
                else
                    sd.Descending(d => d.Id);
                return sd;
            };
            var result2 =_client.Search<TestModel5>(s => s
                       .Index(indexName)
                       .Query(q => q.Bool(b => b.Must(mustQuerys).Should(shouldQuerys)))
                       .Size(100)
                       .From(0)
                       .Sort(sortDesc)
                   );

得分控制

 //使用functionscore计算得分
            var result1 = _client.Search<TestModel5>(s => s
                            .Query(q => q.FunctionScore(f => f
                                      //查询区
                                      .Query(qq => qq.Term(t => t.Field(fd => fd.State).Value(1))
                                                      ||
                                                   qq.Term(t => t.Field(fd => fd.State).Value(2))
                                      )
                                      .Boost(1.0) //functionscore 对分值影响
                                      .BoostMode(FunctionBoostMode.Replace)//计算boost 模式 ；Replace为替换
                                      .ScoreMode(FunctionScoreMode.Sum) //计算score 模式；Sum为累加
                                                                        //逻辑区
                                      .Functions(fun => fun
                                          .Weight(w => w.Weight(3).Filter(ft => ft
                                              .Term(t => t.Field(fd => fd.State).Value(1))))//匹配cityid +3
                                          .Weight(w => w.Weight(2).Filter(ft => ft
                                              .Term(t => t.Field(fd => fd.State).Value(2))))//匹配pvcid +2
                                      )
                                )
                               )
                            .Size(3000)
                            .Sort(st => st.Descending(SortSpecialField.Score))
                            );
            //结果中 State=1，得分=3； State=2 ，得分=2 ,两者都满足的，得分=5

聚合

 

聚合-基本

 var result = _client.Search<TestModel5>(s => s
                .Index(indexName)
                .From(0)
                .Size(15)
                .Aggregations(ag => ag
                        .ValueCount("Count", vc => vc.Field(fd => fd.Id))//总数
                        .Sum("vendorPrice_Sum", su => su.Field(fd => fd.Id))//求和
                        .Max("vendorPrice_Max", m => m.Field(fd => fd.Id))//最大值
                        .Min("vendorPrice_Min", m => m.Field(fd => fd.Id))//最小值
                        .Average("vendorPrice_Avg", avg => avg.Field(fd => fd.Id))//平均值
                        .Terms("vendorID_group", t => t.Field(fd => fd.Id).Size(100))//分组
                    )
                );
 

聚合-分组

var result = _client.Search<TestModel5>(s => s
                .Index(indexName)
                .Size(0)
                .Aggregations(ag => ag
                    .Terms("Group_group", //Group 分组
                        t => t.Field(fd => fd.Group)
                        .Size(100)
                        .Aggregations(agg => agg
                                        .Terms("Group_state_group", //Group_state
                                            tt => tt.Field(fd => fd.State)
                                            .Size(50)
                                            .Aggregations(aggg => aggg
                                                .Average("g_g_Avg", av => av.Field(fd => fd.Dvalue))//Price avg
                                                .Max("g_g_Max", m => m.Field(fd => fd.Dvalue))//Price max
                                                .Min("g_g_Min", m => m.Field(fd => fd.Dvalue))//Price min
                                                .ValueCount("g_g_Count", m => m.Field(fd => fd.Id))//总记录数
                                                )
                                            )
                                        .Cardinality("g_count", dy => dy.Field(fd => fd.State))//分组数量
                                        .ValueCount("g_Count", c => c.Field(fd => fd.Id))
                            )
                        )
                        .Cardinality("vendorID_group_count", dy => dy.Field(fd => fd.Group))//分组数量
                        .ValueCount("Count", c => c.Field(fd => fd.Id))//总记录数
                ) //分组
                );
 

复杂聚合分组及结果解析

var mustQuerys = new List<Func<QueryContainerDescriptor<TestModel5>, QueryContainer>>();
 
            mustQuerys.Add(t => t.Term(f => f.Deleted, false));
 
            var result =
                _client.Search<TestModel5>(
                    s => s.Index(indexName)
                        .Query(q => q
                                .Bool(b => b.Must(mustQuerys))
                        )
                        .Size(0)
                        .Aggregations(ag => ag
 
                                    .Terms("Group_Group", tm => tm
                                                                .OrderDescending("Dvalue_avg")//使用平均值排序 desc
                                                                .Field(fd => fd.Group)
                                                                .Size(100)
                                                                .Aggregations(agg => agg
                                                                    .TopHits("top_test_hits", th => th.Sort(srt => srt.Field(fd => fd.Dvalue).Descending()).Size(1))//取出该分组下按dvalue分组
                                                                    .Max("Dvalue_Max", m => m.Field(fd => fd.Dvalue))
                                                                    .Min("Dvalue_Min", m => m.Field(fd => fd.Dvalue))
                                                                    .Average("Dvalue_avg", avg => avg.Field(fd => fd.Dvalue))//平均值
                                                                    )
 
                                                                )
 
 
                                )
                        );
            var vendorIdGroup = (BucketAggregate)result.Aggregations["VendorID_Group"];
            foreach (var bucket1 in vendorIdGroup.Items)
            {
                var bucket = (KeyedBucket<TestModel5>)bucket1;
                var maxPrice = ((ValueAggregate)bucket.Aggregations["vendorPrice_Max"]).Value;
                var minPrice = ((ValueAggregate)bucket.Aggregations["vendorPrice_Min"]).Value;
                var sources = ((TopHitsAggregate)bucket.Aggregations["top_vendor_hits"]).Documents<TestModel5>().ToList();
                var data = sources.FirstOrDefault();
            }