Linq查询来总结表中的值

Question

我有一个LINQ查询，它需要一张发票，查找每个附加项目的数量和单价，并在另一个链接表中查找对发票进行的任何付款。

目前是这样的：

from i in Invoices 
select new 
{ 
i.InvoiceId, i.CustomerName, 
Items = 
    from it in InvoiceItems 
    where i.InvoiceId == it.InvoiceId 
    select new { 
    it.Item, 
    it.Quantity, 
    it.UnitPrice, 
    SubPrice=it.Quantity*it.UnitPrice 
    }, 
Payments = 
    from pi in PaymentInvoices 
    where i.InvoiceId == pi.InvoiceId 
    select new { 
    SumPayments=pi.AmountAllocated 
    } 
} 

这显示了以下结果：

如何改变这个LINQ查询，以显示SubPrice和SumPayments（即只总和：

发票11：SubPrice = 90.00 SumPayments = 24.00

发票12：SubPrice = 175.00，SumPayments = 175.00

感谢您的帮助，

马克

UPDATE指示工作ANSWER以下的答案给Kenneth

from i in Invoices 
select new 
{ 
    InvoiceID = i.InvoiceId, 
    CustomerName = i.CustomerName, 
    SubPrice = InvoiceItems.Where(it => it.InvoiceId == i.InvoiceId).Select(it => it.Quantity*it.UnitPrice).Sum(), 
    SumPayments = PaymentInvoices.Where(pi => pi.InvoiceId == i.InvoiceId).Select(pi => pi.AmountAllocated).Sum() 
} 

Answer 1

您可以使用以下方法：

from i in Invoices 
select new 
{ 
    InvoiceID = i.InvoiceId, 
    CustomerName = i.CustomerName, 
    SubPrice = InvoiceItems.Where(it => it.InvoiceID = i.InvoiceID).Select(it => it.Quantity*it.UnitPrice).Sum(), 
    SumPayments = PaymentInvoice.Where(pi => pi.InvoiceId = i.InvoiceId).Select(pi => pi.AmountAllocated).Sum() 
}