C#linq查询外部应用与总和

正在尝试将SQL查询转换为Linq：

SELECT GrossInvoiceAmount, C.SumOfPayments
  FROM invoice
OUTER APPLY(
  SELECT SUM(SumOfPayments) AS SumOfPayments FROM vw_sumOfPayments
  WHERE vw_sumOfPayments.PaymentDate = '01/01/2010 00:00:00'
      AND vw_sumOfPayments.InvoiceId = invoice.InvoiceId
) C
WHERE LastTransmitDate = '01/01/2010 00:00:00'

我的密码里有这个。它运行并给出结果，但是

invoice.GrossInvoiceAmount

金额错误。有什么想法吗？谢谢

var InvoiceQuery = (from invoice in this.Context.Invoices
        join payment in this.Context.vw_sumOfPayments.Where(pay => DbFunctions.TruncateTime(pay.PaymentDate) >= startdate 
                                        && DbFunctions.TruncateTime(pay.PaymentDate) <= enddate) 
                on invoice.InvoiceID equals payment.InvoiceID into pays
        select new InvoiceModel{

           InvoiceTypeId = invoice.InvoiceTypeId,
           InvoiceNumber = invoice.InvoiceNumber,
           InvoiceDate = invoice.InvoiceDate,
           InvoiceAmount = invoice.GrossInvoiceAmount,
           PaymentAmount = pays.AsEnumerable().Sum(o => o.SumOfPayments)

         });

var InvoiceQuery=（来自this.Context.Invoices中的发票
在这个.Context.vw_sumOfPayments.Where（pay=>DbFunctions.TruncateTime（pay.PaymentDate）>=startdate中加入payment
&&DbFunctions.TruncateTime（pay.PaymentDate）o.SumOfPayments）
});

应该提到。我想我缺少的是外部应用程序中的总和（付款总额）。那笔钱必须存在，否则总额就不对了。。。林克：什么？