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Come ordinare elementi in base a più chiavi (LINQ to XML)

  • Articolo

Questo articolo illustra come ordinare in base a più chiavi in C# e in Visual Basic.

Esempio: Ordinare elementi XML in base a più chiavi

Questo esempio esegue l'ordinamento in base a due chiavi: codice postale di spedizione (chiave primaria) e data dell'ordine. Usa il documento XML seguente: File XML di esempio: Clienti e ordini.

XElement co = XElement.Load("CustomersOrders.xml");
var sortedElements =
    from c in co.Element("Orders").Elements("Order")
    orderby (string)c.Element("ShipInfo").Element("ShipPostalCode"),
            (DateTime)c.Element("OrderDate")
    select new {
        CustomerID = (string)c.Element("CustomerID"),
        EmployeeID = (string)c.Element("EmployeeID"),
        ShipPostalCode = (string)c.Element("ShipInfo").Element("ShipPostalCode"),
        OrderDate = (DateTime)c.Element("OrderDate")
    };
foreach (var r in sortedElements)
    Console.WriteLine("CustomerID:{0} EmployeeID:{1} ShipPostalCode:{2} OrderDate:{3:d}",
        r.CustomerID, r.EmployeeID, r.ShipPostalCode, r.OrderDate);

Dim co As XElement = XElement.Load("CustomersOrders.xml")
Dim result = _
    From c In co.<Orders>.<Order> _
    Order By c.<ShipInfo>.<ShipPostalCode>.Value, Convert.ToDateTime(c.<OrderDate>.Value) _
    Select New With { _
        .CustomerID = c.<CustomerID>.Value, _
        .EmployeeID = c.<EmployeeID>.Value, _
        .ShipPostalCode = c.<ShipInfo>.<ShipPostalCode>.Value, _
        .OrderDate = Convert.ToDateTime(c.<OrderDate>.Value) _
    }
For Each r In result
    Console.WriteLine("CustomerID:{0} EmployeeID:{1} ShipPostalCode:{2} OrderDate:{3:d}", _
                r.CustomerID, r.EmployeeID, r.ShipPostalCode, r.OrderDate)
Next

Nell'esempio viene prodotto l'output seguente:

CustomerID:LETSS EmployeeID:1 ShipPostalCode:94117 OrderDate:6/25/1997
CustomerID:LETSS EmployeeID:8 ShipPostalCode:94117 OrderDate:10/27/1997
CustomerID:LETSS EmployeeID:6 ShipPostalCode:94117 OrderDate:11/10/1997
CustomerID:LETSS EmployeeID:4 ShipPostalCode:94117 OrderDate:2/12/1998
CustomerID:GREAL EmployeeID:6 ShipPostalCode:97403 OrderDate:5/6/1997
CustomerID:GREAL EmployeeID:8 ShipPostalCode:97403 OrderDate:7/4/1997
CustomerID:GREAL EmployeeID:1 ShipPostalCode:97403 OrderDate:7/31/1997
CustomerID:GREAL EmployeeID:4 ShipPostalCode:97403 OrderDate:7/31/1997
CustomerID:GREAL EmployeeID:6 ShipPostalCode:97403 OrderDate:9/4/1997
CustomerID:GREAL EmployeeID:3 ShipPostalCode:97403 OrderDate:9/25/1997
CustomerID:GREAL EmployeeID:4 ShipPostalCode:97403 OrderDate:1/6/1998
CustomerID:GREAL EmployeeID:3 ShipPostalCode:97403 OrderDate:3/9/1998
CustomerID:GREAL EmployeeID:3 ShipPostalCode:97403 OrderDate:4/7/1998
CustomerID:GREAL EmployeeID:4 ShipPostalCode:97403 OrderDate:4/22/1998
CustomerID:GREAL EmployeeID:4 ShipPostalCode:97403 OrderDate:4/30/1998
CustomerID:HUNGC EmployeeID:3 ShipPostalCode:97827 OrderDate:12/6/1996
CustomerID:HUNGC EmployeeID:1 ShipPostalCode:97827 OrderDate:12/25/1996
CustomerID:HUNGC EmployeeID:3 ShipPostalCode:97827 OrderDate:1/15/1997
CustomerID:HUNGC EmployeeID:4 ShipPostalCode:97827 OrderDate:7/16/1997
CustomerID:HUNGC EmployeeID:8 ShipPostalCode:97827 OrderDate:9/8/1997
CustomerID:LAZYK EmployeeID:1 ShipPostalCode:99362 OrderDate:3/21/1997
CustomerID:LAZYK EmployeeID:8 ShipPostalCode:99362 OrderDate:5/22/1997

Esempio: Ordinare codice XML in uno spazio dei nomi

Questo esempio esegue lo stesso ordinamento del primo, ma per codice XML incluso in uno spazio dei nomi. Usa il documento XML seguente: File XML di esempio: Clienti e ordini in uno spazio dei nomi.

Per altre informazioni, vedere Panoramica degli spazi dei nomi.

XElement co = XElement.Load("CustomersOrdersInNamespace.xml");
XNamespace aw = "http://www.adventure-works.com";
var sortedElements =
    from c in co.Element(aw + "Orders").Elements(aw + "Order")
    orderby (string)c.Element(aw + "ShipInfo").Element(aw + "ShipPostalCode"),
            (DateTime)c.Element(aw + "OrderDate")
    select new
    {
        CustomerID = (string)c.Element(aw + "CustomerID"),
        EmployeeID = (string)c.Element(aw + "EmployeeID"),
        ShipPostalCode = (string)c.Element(aw + "ShipInfo").Element(aw + "ShipPostalCode"),
        OrderDate = (DateTime)c.Element(aw + "OrderDate")
    };
foreach (var r in sortedElements)
    Console.WriteLine("CustomerID:{0} EmployeeID:{1} ShipPostalCode:{2} OrderDate:{3:d}",
        r.CustomerID, r.EmployeeID, r.ShipPostalCode, r.OrderDate);

Imports <xmlns='http://www.adventure-works.com'>

Module Module1
    Sub Main()
        Dim co As XElement = XElement.Load("CustomersOrdersInNamespace.xml")
        Dim result = _
            From c In co.<Orders>.<Order> _
            Order By c.<ShipInfo>.<ShipPostalCode>.Value, Convert.ToDateTime(c.<OrderDate>.Value) _
            Select New With { _
                .CustomerID = c.<CustomerID>.Value, _
                .EmployeeID = c.<EmployeeID>.Value, _
                .ShipPostalCode = c.<ShipInfo>.<ShipPostalCode>.Value, _
                .OrderDate = Convert.ToDateTime(c.<OrderDate>.Value) _
            }
        For Each r In result
            Console.WriteLine("CustomerID:{0} EmployeeID:{1} ShipPostalCode:{2} OrderDate:{3:d}", _
                        r.CustomerID, r.EmployeeID, r.ShipPostalCode, r.OrderDate)
        Next
    End Sub
End Module

Nell'esempio viene prodotto l'output seguente:

CustomerID:LETSS EmployeeID:1 ShipPostalCode:94117 OrderDate:6/25/1997
CustomerID:LETSS EmployeeID:8 ShipPostalCode:94117 OrderDate:10/27/1997
CustomerID:LETSS EmployeeID:6 ShipPostalCode:94117 OrderDate:11/10/1997
CustomerID:LETSS EmployeeID:4 ShipPostalCode:94117 OrderDate:2/12/1998
CustomerID:GREAL EmployeeID:6 ShipPostalCode:97403 OrderDate:5/6/1997
CustomerID:GREAL EmployeeID:8 ShipPostalCode:97403 OrderDate:7/4/1997
CustomerID:GREAL EmployeeID:1 ShipPostalCode:97403 OrderDate:7/31/1997
CustomerID:GREAL EmployeeID:4 ShipPostalCode:97403 OrderDate:7/31/1997
CustomerID:GREAL EmployeeID:6 ShipPostalCode:97403 OrderDate:9/4/1997
CustomerID:GREAL EmployeeID:3 ShipPostalCode:97403 OrderDate:9/25/1997
CustomerID:GREAL EmployeeID:4 ShipPostalCode:97403 OrderDate:1/6/1998
CustomerID:GREAL EmployeeID:3 ShipPostalCode:97403 OrderDate:3/9/1998
CustomerID:GREAL EmployeeID:3 ShipPostalCode:97403 OrderDate:4/7/1998
CustomerID:GREAL EmployeeID:4 ShipPostalCode:97403 OrderDate:4/22/1998
CustomerID:GREAL EmployeeID:4 ShipPostalCode:97403 OrderDate:4/30/1998
CustomerID:HUNGC EmployeeID:3 ShipPostalCode:97827 OrderDate:12/6/1996
CustomerID:HUNGC EmployeeID:1 ShipPostalCode:97827 OrderDate:12/25/1996
CustomerID:HUNGC EmployeeID:3 ShipPostalCode:97827 OrderDate:1/15/1997
CustomerID:HUNGC EmployeeID:4 ShipPostalCode:97827 OrderDate:7/16/1997
CustomerID:HUNGC EmployeeID:8 ShipPostalCode:97827 OrderDate:9/8/1997
CustomerID:LAZYK EmployeeID:1 ShipPostalCode:99362 OrderDate:3/21/1997
CustomerID:LAZYK EmployeeID:8 ShipPostalCode:99362 OrderDate:5/22/1997

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