C# LINQ查询以获取数据

我有4个XML文件，其中包含这种格式的数据。这些数据实际上来自Microsoft Northwind数据库，但我有一些XML格式的表。完整的关系图可用

订单

<Orders>
  <Order>
    <OrderID>10248</OrderID>
    <CustomerID>VINET</CustomerID>
    <EmployeeID>5</EmployeeID>
  </Order>
.............
.............
.............

<OrderDetails>
  <OrderDetail>
    <OrderID>10248</OrderID>
    <Quantity>12</Quantity>
    <UnitPrice>14.0000</UnitPrice>
  </OrderDetail>
  <OrderDetail>
    <OrderID>10248</OrderID>
    <Quantity>10</Quantity>
    <UnitPrice>9.8000</UnitPrice>
  </OrderDetail>
.............
.............
.............

<Employee>
    <EmployeeID>5</EmployeeID>
    <FirstName>Steve</FirstName>
    <LastName>Buchanan</LastName>
  </Employee>
  <Employee>
    <EmployeeID>6</EmployeeID>
    <FirstName>Michael</FirstName>
    <LastName>Suyama</LastName>
  </Employee>
.............
.............
.............

<Customer>
    <CustomerID>VINET</CustomerID>
    <CompanyName>Vins et alcools Chevalier</CompanyName>
    <ContactName>Paul Henriot</ContactName>
  </Customer>
  <Customer>
    <CustomerID>WANDK</CustomerID>
    <CompanyName>Die Wandernde Kuh</CompanyName>
    <ContactName>Rita Müller</ContactName>
  </Customer>
  <Customer>
.............
.............
.............

但这只给了我三件事。我正在努力获取对象包含所需的全部6种内容。另外，由于orders表中的一个orderid可以有多个orderdetails，因此如何执行计算。例如，对于订单id 10248，我们有2个订单详细信息

---

谢谢

您需要多个连接和分组，如下所示

var list = from o in ordersList
            join cl in customersList
            on o.CustomerID equals cl.CustomerID
            join ol in orderDetailsList
            on o.OrderID equals ol.OrderID
            join e in employeeList
            on o.EmployeeID equals e.EmployeeID
            select new
            {
                o.OrderID,
                cl.CompanyName,
                cl.ContactName,
                EmployeeName = e.FirstName + " " +e.LastName,
                ol.Quantity,
                ol.UnitPrice
            };
var result =  list.GroupBy(x => x.OrderID).Select(g => new
{
    OrderID = g.Key,
    CompanyName = g.First().CompanyName,
    ContactName = g.First().ContactName,
    EmployeeName = g.First().EmployeeName,
    TotalQuantity = g.Sum(x => x.Quantity),
    TatalPrice = g.Sum(x => x.Quantity * x.UnitPrice)
});

---

您需要多个联接和分组，如下所示

var list = from o in ordersList
            join cl in customersList
            on o.CustomerID equals cl.CustomerID
            join ol in orderDetailsList
            on o.OrderID equals ol.OrderID
            join e in employeeList
            on o.EmployeeID equals e.EmployeeID
            select new
            {
                o.OrderID,
                cl.CompanyName,
                cl.ContactName,
                EmployeeName = e.FirstName + " " +e.LastName,
                ol.Quantity,
                ol.UnitPrice
            };
var result =  list.GroupBy(x => x.OrderID).Select(g => new
{
    OrderID = g.Key,
    CompanyName = g.First().CompanyName,
    ContactName = g.First().ContactName,
    EmployeeName = g.First().EmployeeName,
    TotalQuantity = g.Sum(x => x.Quantity),
    TatalPrice = g.Sum(x => x.Quantity * x.UnitPrice)
});

---

您需要多个联接和分组，如下所示

var list = from o in ordersList
            join cl in customersList
            on o.CustomerID equals cl.CustomerID
            join ol in orderDetailsList
            on o.OrderID equals ol.OrderID
            join e in employeeList
            on o.EmployeeID equals e.EmployeeID
            select new
            {
                o.OrderID,
                cl.CompanyName,
                cl.ContactName,
                EmployeeName = e.FirstName + " " +e.LastName,
                ol.Quantity,
                ol.UnitPrice
            };
var result =  list.GroupBy(x => x.OrderID).Select(g => new
{
    OrderID = g.Key,
    CompanyName = g.First().CompanyName,
    ContactName = g.First().ContactName,
    EmployeeName = g.First().EmployeeName,
    TotalQuantity = g.Sum(x => x.Quantity),
    TatalPrice = g.Sum(x => x.Quantity * x.UnitPrice)
});

---

您需要多个联接和分组，如下所示

var list = from o in ordersList
            join cl in customersList
            on o.CustomerID equals cl.CustomerID
            join ol in orderDetailsList
            on o.OrderID equals ol.OrderID
            join e in employeeList
            on o.EmployeeID equals e.EmployeeID
            select new
            {
                o.OrderID,
                cl.CompanyName,
                cl.ContactName,
                EmployeeName = e.FirstName + " " +e.LastName,
                ol.Quantity,
                ol.UnitPrice
            };
var result =  list.GroupBy(x => x.OrderID).Select(g => new
{
    OrderID = g.Key,
    CompanyName = g.First().CompanyName,
    ContactName = g.First().ContactName,
    EmployeeName = g.First().EmployeeName,
    TotalQuantity = g.Sum(x => x.Quantity),
    TatalPrice = g.Sum(x => x.Quantity * x.UnitPrice)
});

---

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