Linq中left join之多表查询

 using System;
 using System.Collections;
 using System.Collections.Generic;
 using System.Data;
 using System.IO;
 using System.Linq;
 using Newtonsoft.Json;

 namespace CLibrary.ConsoleApp
 {
     class Program
     {
         static void Main(string[] args)
         {
             var tableAAA = "[{\"companycode\":\"80463417\",\"securitycode\":\"603978\",\"securityshortname\":null,\"financecode\":null,\"purchasedate\":\"2017-07-26T00:00:00\",\"listingdate\":\"2017-08-07T00:00:00\",\"issueprice\":29.93}]";
             var tableBBB = "[{\"securityvarietycode\":\"1000576786\",\"companycode\":\"80463417\",\"securitycode\":\"603978\",\"shares\":1000}]";
             var tableTTT = "[{\"securityvarietycode\":\"1000576786\",\"srkpj\":35.92,\"srspj\":43.1,\"srzdf\":44.0027,\"srhsl\":0.06}]";
             var tableEEE = "[{\"secucode\":\"603978\",\"tdate\":\"2017-08-07T00:00:00\",\"high\":43.1},{\"secucode\":\"603978\",\"tdate\":\"2017-08-08T00:00:00\",\"high\":47.41}]";
             var tableMMM = "[]";
             var tableJJJ = "[{\"secucode\":\"603978\",\"tdate\":\"2017-08-07T00:00:00\",\"avgprice\":42.82},{\"secucode\":\"603978\",\"tdate\":\"2017-08-08T00:00:00\",\"avgprice\":47.41}]";
             var tableNNN = "[{\"secucode\":\"603978\",\"tdate\":\"2017-08-07T00:00:00\",\"high\":43.1},{\"secucode\":\"603978\",\"tdate\":\"2017-08-08T00:00:00\",\"high\":47.41}]";

             var tableA = JsonConvert.DeserializeObject<List<TableA>>(tableAAA);
             var tableB = JsonConvert.DeserializeObject<List<TableB>>(tableBBB);
             var tableT = JsonConvert.DeserializeObject<List<TableT>>(tableTTT);
             var tableE = JsonConvert.DeserializeObject<List<TableE>>(tableEEE);
             var tableM = JsonConvert.DeserializeObject<List<TableM>>(tableMMM);
             var tableJ = JsonConvert.DeserializeObject<List<TableJ>>(tableJJJ);
             var tableN = JsonConvert.DeserializeObject<List<TableE>>(tableNNN);

             var query = from a in tableA
                         join b in tableB on a.companycode equals b.companycode into ab
                         from def_b in ab.DefaultIfEmpty(new TableB())
                         join t in tableT on def_b.securityvarietycode equals t.securityvarietycode into bt
                         join e in tableE on a.listingdate equals e.tdate into ae
                         join m in tableM on a.securitycode equals m.securitycode into am
                         from def_m in am.DefaultIfEmpty(new TableM())
                         join j in tableJ on def_m.tdatep equals j.tdate into mj
                         join n in tableN on def_m.tdatep equals n.tdate into mn
                         from def_t in bt.DefaultIfEmpty(new TableT())
                         from def_e in ae.DefaultIfEmpty(new TableE())
                         from def_j in mj.DefaultIfEmpty(new TableJ())
                         orderby def_m.tdatep
                         select new Result
                         {
                             listingopen = def_t.srkpj,
                             listingclose = def_t.srspj,
                             listingopenpremium = Math.Round((def_t.srkpj / a.issueprice - ) * , ),
                             listingchg = def_t.srzdf,
                             listingturnover = def_t.srhsl,
                             listinghighpchg = Math.Round((def_e.high / a.issueprice - ) * , ),
                             opendate = def_m.tdatep,
                             highpchg = 0d, //api层处理，
                             limitupdays = def_m.days,
                             listingavg = def_j.avgprice,
                             profit = (def_j.avgprice - a.issueprice) * def_b.shares,//api层处理，
                             issuePrice = a.issueprice,//用于api层处理
                             shares = def_b.shares,//用于api层处理
                         };

             var list = query.ToList();

             Console.WriteLine(JsonConvert.SerializeObject(list));
             Console.ReadKey();
         }

         #region Class
         private class TableA
         {
             public string companycode { get; set; }
             public string securitycode { get; set; }
             public string securityshortname { get; set; }
             public string financecode { get; set; }
             public DateTime purchasedate { get; set; }
             public DateTime listingdate { get; set; }
             public double issueprice { get; set; }
         }
         private class TableB
         {
             public string securityvarietycode { get; set; }
             public string companycode { get; set; }
             public string securitycode { get; set; }
             public int shares { get; set; }
         }

         private class TableE
         {
             public string secucode { get; set; }
             public DateTime tdate { get; set; }
             public double high { get; set; }
         }
         private class TableJ
         {
             public string secucode { get; set; }
             public DateTime tdate { get; set; }
             public double avgprice { get; set; }
         }
         private class TableM
         {
             public string securitycode { get; set; }
             public DateTime tdatep { get; set; }
             public int days { get; set; }
         }
         private class TableT
         {
             public string securityvarietycode { get; set; }
             public double srkpj { get; set; }
             public double srspj { get; set; }
             public double srzdf { get; set; }
             public double srhsl { get; set; }
         }
         private class Result
         {
             public double listingopen { get; set; }
             public double listingclose { get; set; }
             public double listingopenpremium { get; set; }
             public double listingchg { get; set; }
             public double listingturnover { get; set; }
             public double listinghighpchg { get; set; }
             public DateTime opendate { get; set; }
             public double highpchg { get; set; }
             public int limitupdays { get; set; }
             public double listingavg { get; set; }
             public double profit { get; set; }
             public double issuePrice { get; set; }
             public int shares { get; set; }
         }

         #endregion

     }

 }