how to get root node attribute value using linq

Question

Hi, I have the following XML. How to read the root node attribite value and it's decendents using LINQ? I am trying to read "dId" and "dTime" from root node, "id" from Customer element and Order number.

<?xml version="1.0" encoding="utf-8" ?>
 <Customers dId="wqwx" dTime="10-9-09 11:23">
   <Customer id="1">
      <Orders>
        <Order number="22" status="ok">
      </Orders>
   </Customer>
 </Customers>

I tried the following code but it doesn't work.

XDocument doc= XDocument.Load(@"C:\Customers.xml");
var q = from c in doc.Descendants("Customers")
        select new        
          {   
           dID = c.Attribute("dId"),
           dTime = c.Attribute("dTime");
          }

Answer 1

first, fix your xml (<Order .... />) then, your linq should look like this....

// .Elements(...) selects all elements of type "Customer"
    var q = from c in xDoc.Elements("Customers") 
    select new
    {
        dID = c.Attribute("dId"), 
        dTime = c.Attribute("dTime")
    };

you should dl LinqPad... it lets you do Linq queries on the fly, even agains SQL databases. Then, once you get the results you want, copy and past your linq into your source code.

Answer 2

End the order tag with: /> to be specific

xDoc.Descendants("Customers") should work as well as xDoc.Elements("Customers"). Chris, is there a specific advantage to using .Elements ? And Chris, thanks for dl LinqPad link! That looks fantastic.

Answer 3

You can't use LINQ to access the root tag. The code below does what you want (I included a well formed xml file as well):

using System;
using System.Linq;
using System.Xml.Linq;

namespace ReadXmlSpike
{
    class Program
    {
        static void Main(string[] args)
        {
            Console.WriteLine("Reading file...");
            XDocument doc = XDocument.Load("Customers.xml");
            var customers =
                new
                    {
                        DID = (string) doc.Element("Customers").Attribute("did"),
                        DTime = (DateTime) doc.Element("Customers").Attribute("dTime"),
                        Customers = from customerxml in doc.Descendants("Customer")
                                    select
                                        new
                                            {
                                                ID = (string)customerxml.Attribute("id"),
                                                Orders = from orderxml in customerxml.Descendants("Order")
                                                         select
                                                             new
                                                                 {
                                                                     Number =(string) orderxml.Attribute("number")
                                                                 }
                                            }
                    };
            Console.WriteLine("Customersfile with id: {0} and time {1}",customers.DID,customers.DTime);
            foreach (var customer in customers.Customers)
            {
                Console.WriteLine("Customer with id {0} has the following orders:",customer.ID);
                foreach (var order in customer.Orders)
                {
                    Console.WriteLine("Order with number {0}",order.Number);
                }
            }
            Console.ReadLine();
        }
    }
}

and the xml file:

<?xml version="1.0" encoding="utf-8" ?>
<Customers did="www" dTime="10-09-09 11:23">
  <Customer id="1">
    <Orders>
      <Order number="22" status="ok"/>
      <Order number="23" status="bad"/>
    </Orders>
  </Customer>
  <Customer id="2">
    <Orders>
      <Order number="24" status="ok"/>
      <Order number="25" status="bad"/>
    </Orders>
  </Customer>
</Customers>

Answer 4

    XDocument d = XDocument.Parse(@"<?xml version='1.0' encoding='utf-8' ?>
        <Customers dId='wqwx' dTime='10-9-09 11:23'>
            <Customer id='1'>      
                <Orders>        
                    <Order number='22' status='ok'/>      
                </Orders>   
            </Customer> 
        </Customers>");
    var cu = d.Root.Elements().Where(n => n.Name == "Customer");


    var c = from cc in cu
            select new
            {
                dId = cc.Document.Root.Attribute("dId").Value,
                dTime = cc.Document.Root.Attribute("dTime").Value,
                ID = cc.Attribute("id").Value,
                number = cc.Element("Orders").Element("Order").Attribute("number").Value
            };

    foreach (var v in c)
    {
        Console.WriteLine("dId \t\t= {0}", v.dId);
        Console.WriteLine("dTime \t\t= {0}", v.dTime);
        Console.WriteLine("CustomerID \t= {0}", v.ID);
        Console.WriteLine("OrderCount \t= {0}", v.number);
    }

Console Output:
================================
dId = wqwx
dTime = 10-9-09 11:23
CustomerID = 1
OrderCount = 22
请按任意键继续. . .