C# 实体框架连接表

Question

I am trying to get the same results as with a SQL query using Entity Framework method syntax.

SQL query :

select 
    mr.*, mrf.userId as RequesterUserId, mrt.UserId as ReceiverUserId 
from 
    MoneyRequests mr
inner join  
    MoneyReqFrom mrf on mr.MoneyRequestId = mrf.MoneyRequestId
inner join  
    MoneyReqTo mrt on mr.MoneyRequestId = mrt.MoneyRequestId
where 
    mr.MoneyRequestId = 'acfc8008-4cf7-47ec-a3fe-0fe245af77cc'

EF Linq method syntax :

var moneyreqResponse = context.MoneyRequests
                              .Join(context.MoneyReqFroms, 
                                      mr => mr.MoneyRequestId, 
                                      mrf => mrf.MoneyRequestId, 
                                      (mr, mrf) => new 
                                                   { 
                                                       MoneyRequestId = mr.MoneyRequestId,
                                                       Amount = mr.Amount,
                                                       RequestType = mr.RequestType,
                                                       CreationDate = mr.CreationDate,
                                                       RequesterUserId = mrf.UserId 
                                                    }) 
                              .Join(context.MoneyReqTos, 
                                       mr => mr.MoneyRequestId, 
                                       mrt => mrt.MoneyRequestId,
                                       (mr, mrt) => new 
                                                    { 
                                                        MoneyRequestId = mr.MoneyRequestId,
                                                        Amount = mr.Amount, 
                                                        RequestType = mr.RequestType,
                                                        CreationDate = mr.CreationDate,
                                                        ReceiverUserId = mrt.UserId, 
                                                        Email = mrt.Email 
                                                    }) 
                              .Where(fullEntry => fullEntry.MoneyRequestId == "acfc8008-4cf7-47ec-a3fe-0fe245af77cc") 
                              .ToList();

I retrieve the data from the database except the column RequesterUserId .

Do you know why?

Thanks

Answer 1

Your query returns a MoneyRequests type, which I belive does not contain RequesterUserId .

You should define a new type with all the properties you need (those returned by the join) and add it to your DbContext.

Also probably you want to mark your new type as keyless