.net ElasticSearch-Sql 扩展类

官方提供的是java sdk，并支持jdbc方式的查询结果输出;但是却没有.net sdk的支持。

开发 ElasticSearch-Sql 第三方开源项目的.net sdk,未来集成入bsf框架。（已使用，但未进行大范围使用测试，欢迎交流并抛砖引玉）

参考ElasticSearch-Sql 开源地址:https://github.com/NLPchina/elasticsearch-sql

1）支持将查询结果转换成datatable形式，便于界面绑定和数据导出等。

2）代码简单易懂，便于改进并提高稳定性和性能。（拷贝立即使用）

 using System;
 using System.Collections.Generic;
 using System.Data;
 using System.Linq;
 using System.Net.Http;
 using System.Net.Http.Headers;
 using System.Reflection;
 using System.Text;
 using System.Threading.Tasks;
 /*by 车江毅 欢迎交流，一起完善之。.net 开源，因你更美好*/
 namespace BSF.ElasticSearch
 {
     public class EsSqlProvider
     {
         private string url;
         private HttpClient client = new HttpClient();
         public EsSqlProvider(string ip,int port)
         {
             this.url = string.Format("http://{0}:{1}/_sql",ip,port);
         }

         public EsSqlProvider(string url)
         {
             this.url = url.TrimEnd('/')+"/_sql";
         }

         public Result Post(string sql)
         {
             //var http = new BSF.Api.HttpProvider();
             //var dic = new Dictionary<string, string>();
             //dic.Add("",sql);

             var content = new StringContent(sql);
             content.Headers.ContentType = new MediaTypeHeaderValue("application/json");
             var json = PostBase(content);

             return new BSF.Serialization.JsonProvider().Deserialize<Result>(json);

         }

         public DataTable Query(string sql)
         {
             var result = Post(sql);
             if (result.aggregations != null && result.aggregations.Count > )
             {
                 var first = result.aggregations.First();
                 //groupby 统计方式
                 if (first.Value != null && first.Value.buckets != null && first.Value.buckets.Count > )
                 {
                     DataTable dataTable = new DataTable("es-groupby");
                     //以第一列为准,填充列
                     {
                         var t = first.Value.buckets[];
                         dataTable.Columns.Add(new DataColumn(first.Key, ColumnType((GetValue((object)t["key"])).GetType())));
                         foreach (var c in t)
                         {
                             if (c.Key != "doc_count"&&c.Key!= "key")
                             { dataTable.Columns.Add(new DataColumn(c.Key, (GetValue(c.Value)).GetType())); }
                         }
                     }
                     //填充值
                     foreach (var b in first.Value.buckets)
                     {
                         DataRow dataRow = dataTable.NewRow();
                         dataRow[first.Key] = b["key"];
                         foreach (var c in b)
                         {
                             if(dataTable.Columns.Contains(c.Key))
                                 dataRow[c.Key] = GetValue(c.Value);
                         }
                         dataTable.Rows.Add(dataRow);
                     }
                     return dataTable;

                 }
                 else if (first.Value != null&& first.Value.value!=null)
                 {
                     DataTable dataTable = new DataTable("es-aggregations");
                     //常规统计方式
                     foreach (var o in result.aggregations)
                     {
                         dataTable.Columns.Add(new DataColumn(o.Key, ColumnType((GetValue((object)o.Value)).GetType())));
                     }
                     DataRow dataRow = dataTable.NewRow();
                     foreach (var o in result.aggregations)
                     {
                         if (dataTable.Columns.Contains(o.Key))
                             dataRow[o.Key] = GetValue(o.Value);
                     }
                     dataTable.Rows.Add(dataRow);
                     return dataTable;
                 }
             }
             else if (result.sources != null && result.sources.Count > )
             {
                 DataTable dataTable = new DataTable("es-sources");
                 var first = result.sources.First();
                 foreach (var item in ((Dictionary<string,dynamic>)first))
                 {
                     dataTable.Columns.Add(new DataColumn(item.Key, ColumnType((GetValue((Object)item.Value)).GetType())));
                 }
                 foreach (dynamic m in result.sources)
                 {
                     DataRow dataRow = dataTable.NewRow();
                     foreach (var item in ((Dictionary<string, dynamic>)m))
                     {
                         if (dataTable.Columns.Contains(item.Key))
                             dataRow[item.Key] = GetValue(item.Value);
                     }
                     dataTable.Rows.Add(dataRow);
                 }
                 return dataTable;
             }
             return null;
         }

         private Type ColumnType(Type type)
         {
             if (type.IsArray)
             {
                 return typeof(string);
             }
             else
                 return type;
         }

         private Object GetValue(Object value)
         {
             if (value != null && value is Array)
                 return new BSF.Serialization.JsonProvider().Serializer(value);
             if (value != null && (value.GetType().IsValueType || value is String))
                 return value;
             if (value != null && value is Dictionary<string, dynamic>)
             {
                 var valuet = (Dictionary<string, dynamic>)value;
                 if( valuet.ContainsKey("value_as_string"))
                     return GetValue(valuet["value_as_string"]);
                 if (valuet.ContainsKey("value"))
                     return GetValue(valuet["value"]);
             }
             if (value != null && value.GetType().GetProperty("value")!=null)
             {
                 var p= value.GetType().GetProperty("value_as_string");
                 if (p!=null&&p.GetValue(value)!=null)
                     return p.GetValue(value);
                 p = value.GetType().GetProperty("value");
                 if (p != null && p.GetValue(value) != null)
                     return p.GetValue(value);
             }
             return new BSF.Serialization.JsonProvider().Serializer(value);
         }

         private Object GetPropertyValue(Object obj, string property)
         {
             var p = obj.GetType().GetProperty(property);
             if (p != null)
                 return p.GetValue(obj);
             return null;
         }

         private string PostBase(HttpContent content)
         {
             //此处未来需要添加HttpClient连接池,复用连接
             //using (var client = new HttpClient())
             //{
             var result = client.PostAsync(url, content).Result;
             string resultContent = result.Content.ReadAsStringAsync().Result;
             return resultContent;
             //}
         }

         public class Result{

             public Hits hits { get; set; }
             public Dictionary<string, aggregation> aggregations {get;set;}

             public List<dynamic> sources { get {
                     List<dynamic> rs = new List<dynamic>();
                     foreach (var h in hits.hits)
                     {
                         rs.Add(h._source);
                     }
                     return rs;
                 } }

             public class aggvalue
             {
                 public dynamic value { get; set; }
                 public string value_as_string { get; set; }
             }
             public class aggregation: aggvalue
             {
                 public List<Dictionary<string, dynamic>> buckets { get; set; }
             }
             public class Hits {
                 public int total { get; set; }
                 public List<hit> hits { get; set; }
             }
             public class hit {
                 public string _index { get; set; }
                 public string _type { get; set; }
                 public string _id { get; set; }

                 public string _score { get; set; }

                 public dynamic _source { get; set; }
             }

         }
     }
 }

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