flatten out webapi EF使用DTO和linq-使用IF/THEN

Question

我试图使用DTO将我的webapi EF扁平化。到目前为止，我有以下声明正确工作。现在我想添加一个复杂的层面来说明IF/THEN。我在SELECT NEW SECTION的第一行放了一个假代码。 有人可以协助吗？

  var query = (
         from acctTbl in db.Accounts 
         join tradeTbl in db.Trades on acctTbl.AccountID equals tradeTbl.AccountID into ts 
         from tradeTbl in ts.DefaultIfEmpty() 
         join mapClientAcct in db.Mapping_ClientAccounts on acctTbl.AccountID equals mapClientAcct.AccountID 
         join clientTbl in db.Clients on mapClientAcct.ClientID equals clientTbl.ClientID 
         join mapUserClient in db.Mapping_UserClients on clientTbl.ClientID equals mapUserClient.ClientID 
         join aspNetUser in db.AspNetUsers on mapUserClient.AspNetUsersID equals aspNetUser.Id 
         join mktData in db.MarketDatas on tradeTbl.MarketDataID equals mktData.MarketDataID into ms 
         from mktData in ms.DefaultIfEmpty() 
         join mktCode in db.GMI_MarketCodes on tradeTbl.GMI_MarketCodesID equals mktCode.GMI_MarketCodesID into mc 
         from mktCode in mc.DefaultIfEmpty() 
         join Mgrs in db.Managers on acctTbl.ManagerID equals Mgrs.ManagerID 
         join FxMkts in db.ForexMarkets on mktData.crncy equals FxMkts.CurrencySymbol into fm 
         from FxMkts in fm.DefaultIfEmpty() 
          where acctTbl.AccountActive == true 
           && clientTbl.ClientID == clientID 
           && aspNetUser.UserName == username 
          select new TradeDetailDTO() 
          { 

           --THIS IS WHAT I WANT TO DO!!! 
           IF tradeTblIdentifier == "F" THEN 'yes' 
           ELSE 'no' 
           ------------------------- 

           Filedate = tradeTbl.Filedate, 
           Quantity = tradeTbl.Quantity, 
           Month = tradeTbl.Month, 
           Strike = tradeTbl.Strike, 
           PutCall = tradeTbl.PutCall, 
           Prompt = tradeTbl.Prompt, 
           StmtPrice = tradeTbl.Price,          
           ShortDesc = mktCode.ShortDesc, 
           Sector = mktCode.Sector, 
           ExchName = mktCode.ExchName, 
           BBSymbol = mktData.BBSymbol, 
           BBName = mktData.Name, 
           fut_Val_Pt = mktData.fut_Val_Pt, 
           crncy = mktData.crncy, 
           fut_tick_size = mktData.fut_tick_size, 
           fut_tick_val = mktData.fut_tick_val, 
           fut_init_spec_ml = mktData.fut_init_spec_ml, 
           last_price = mktData.last_price, 
           bid = mktData.bid, 
           ask = mktData.ask, 
           px_settle_last_dt_rt = mktData.px_settle_last_dt_rt, 
           px_settle_actual_rt = mktData.px_settle_actual_rt, 
           chg_on_day = mktData.chg_on_day, 
           prev_close_value_realtime = mktData.prev_close_value_realtime, 
           AccountNumber = acctTbl.AccountNumber, 
           TradeLevel = acctTbl.TradeLevel, 
           ManagerName = Mgrs.ManagerName, 
           ManagerShortCode = Mgrs.ManagerShortCode, 
           ForexLastPrice = db.MarketDatas.FirstOrDefault(x => x.BBSymbol == mktData.crncy + " BGN CURNCY") == null ? 1: db.MarketDatas.FirstOrDefault(x => x.BBSymbol == mktData.crncy + " BGN CURNCY").last_price, 
           //ForexLastPrice = FxMkts.LastPrice, ORIGINAL 
           TopdayIdentifier = "P", 
           DailyPercentage = acctTbl.DailyPercentage, 
           AccountType = acctTbl.AccountType 
          } 
        ); 

Answer 1

如果我理解正确的，你你想要的东西是这样的：

var query = (
         from acctTbl in db.Accounts 
         join tradeTbl in db.Trades on acctTbl.AccountID equals tradeTbl.AccountID into ts 
         from tradeTbl in ts.DefaultIfEmpty() 
         join mapClientAcct in db.Mapping_ClientAccounts on acctTbl.AccountID equals mapClientAcct.AccountID 
         join clientTbl in db.Clients on mapClientAcct.ClientID equals clientTbl.ClientID 
         join mapUserClient in db.Mapping_UserClients on clientTbl.ClientID equals mapUserClient.ClientID 
         join aspNetUser in db.AspNetUsers on mapUserClient.AspNetUsersID equals aspNetUser.Id 
         join mktData in db.MarketDatas on tradeTbl.MarketDataID equals mktData.MarketDataID into ms 
         from mktData in ms.DefaultIfEmpty() 
         join mktCode in db.GMI_MarketCodes on tradeTbl.GMI_MarketCodesID equals mktCode.GMI_MarketCodesID into mc 
         from mktCode in mc.DefaultIfEmpty() 
         join Mgrs in db.Managers on acctTbl.ManagerID equals Mgrs.ManagerID 
         join FxMkts in db.ForexMarkets on mktData.crncy equals FxMkts.CurrencySymbol into fm 
         from FxMkts in fm.DefaultIfEmpty() 
          where acctTbl.AccountActive == true 
           && clientTbl.ClientID == clientID 
           && aspNetUser.UserName == username 
          select new TradeDetailDTO() 
          { 

           YesNo = tradeTbl.Identifier == "F"?"yes":"no", 
           Filedate = tradeTbl.Filedate, 
           Quantity = tradeTbl.Quantity, 
           Month = tradeTbl.Month, 
           Strike = tradeTbl.Strike, 
           PutCall = tradeTbl.PutCall, 
           Prompt = tradeTbl.Prompt, 
           StmtPrice = tradeTbl.Price,          
           ShortDesc = mktCode.ShortDesc, 
           Sector = mktCode.Sector, 
           ExchName = mktCode.ExchName, 
           BBSymbol = mktData.BBSymbol, 
           BBName = mktData.Name, 
           fut_Val_Pt = mktData.fut_Val_Pt, 
           crncy = mktData.crncy, 
           fut_tick_size = mktData.fut_tick_size, 
           fut_tick_val = mktData.fut_tick_val, 
           fut_init_spec_ml = mktData.fut_init_spec_ml, 
           last_price = mktData.last_price, 
           bid = mktData.bid, 
           ask = mktData.ask, 
           px_settle_last_dt_rt = mktData.px_settle_last_dt_rt, 
           px_settle_actual_rt = mktData.px_settle_actual_rt, 
           chg_on_day = mktData.chg_on_day, 
           prev_close_value_realtime = mktData.prev_close_value_realtime, 
           AccountNumber = acctTbl.AccountNumber, 
           TradeLevel = acctTbl.TradeLevel, 
           ManagerName = Mgrs.ManagerName, 
           ManagerShortCode = Mgrs.ManagerShortCode, 
           ForexLastPrice = db.MarketDatas.FirstOrDefault(x => x.BBSymbol == mktData.crncy + " BGN CURNCY") == null ? 1: db.MarketDatas.FirstOrDefault(x => x.BBSymbol == mktData.crncy + " BGN CURNCY").last_price, 
           //ForexLastPrice = FxMkts.LastPrice, ORIGINAL 
           TopdayIdentifier = "P", 
           DailyPercentage = acctTbl.DailyPercentage, 
           AccountType = acctTbl.AccountType 
          } 
        );