[RESOLVED] Merge multiple XML files to a single XML file.

[abhijit]

I would like to find an example using Linq to Xml that will merge n number of Xml Files.

I already have this code from MSDN that does this, but it doesn't use Linq.

try
    {
        XmlTextReader xmlreader1 = new XmlTextReader("C:\\Books1.xml");
        XmlTextReader xmlreader2 = new XmlTextReader("C:\\Books2.xml");
 
        DataSet ds = new DataSet();
        ds.ReadXml(xmlreader1);
        DataSet ds2 = new DataSet();
        ds2.ReadXml(xmlreader2);
        ds.Merge(ds2);
        ds.WriteXml("C:\\Books.xml");
        Console.WriteLine("Completed merging XML documents");
    }
    catch (System.Exception ex)
    {
        Console.Write(ex.Message);
    }
Console.Read();

I want to check if Linq is faster than the above method.
I have something along the lines of this code snippet.

var xml1 = XDocument.Load("C:\\Books1.xml");
var xml2 = XDocument.Load("C:\\Books2.xml");
 
//Combine and remove duplicates
var combined = xml1.Descendants("AllNodes")
                          .Union(xml2.Descendants("AllNodes"));

combined is of type System.Linq.Enumerable.UnionIterator<System.Xml.Linq.XElement>

How do I serialize it to an XML file?

[MattP]

Might be a little off without having some sample xml documents to work with.

            var xml1 = XDocument.Load("C:\Temp\Books1.xml");
            var xml2 = XDocument.Load("C:\Temp\Books2.xml");

            xml1.Descendants("AllBooks").FirstOrDefault()
                .Add(xml2.Descendants("AllBooks").FirstOrDefault().Nodes());

            xml1.Save("C:\Temp\CombinedBooks.xml");

[abhijit]

Hi MattP,
Thanks for the response. Firstly I apologize that I did not post the files in question. Both files have root elements.
So the structure looks something like this.

<Root>
    <Books>
    <Book Id="AAHAH">
    <TITLE>Paths of Glory</TITLE>
    <AUTHOR>Jeffrey Archer</AUTHOR>
    <YEAR>2010</YEAR>
    </Book>
    </Books>
</Root> 

I realize that your method will not work for me. I will have to do something along the lines of selecting elements from both xml files and then merging them.

Regards,
Abhijit

[MattP]

Maybe I'm not understanding you correctly.

Here's my Books1.xml that I used:

<?xml version="1.0" encoding="utf-8"?>
<Root>
	<Books>
		<Book Id="Book1">
			<TITLE>Title of Book 1</TITLE>
			<AUTHOR>Author of Book 1</AUTHOR>
			<YEAR>2010</YEAR>
		</Book>
		<Book Id="Book2">
			<TITLE>Title of Book 2</TITLE>
			<AUTHOR>Author of Book 2</AUTHOR>
			<YEAR>2011</YEAR>
		</Book>
	</Books>
</Root>

And Books2.xml:

<?xml version="1.0" encoding="utf-8"?>
<Root>
	<Books>
		<Book Id="Book3">
			<TITLE>Title of Book 3</TITLE>
			<AUTHOR>Author of Book 3</AUTHOR>
			<YEAR>2006</YEAR>
		</Book>
		<Book Id="Book4">
			<TITLE>Title of Book 4</TITLE>
			<AUTHOR>Author of Book 4</AUTHOR>
			<YEAR>2000</YEAR>
		</Book>
	</Books>
</Root>

Here's the code I used to test with:

            var xml1 = XDocument.Load("C:\\Temp\\Books1.xml");
            var xml2 = XDocument.Load("C:\\Temp\\Books2.xml");

            xml1.Descendants("Books").FirstOrDefault().Add(xml2.Descendants("Books").FirstOrDefault().Nodes());

            xml1.Save("C:\\Temp\\CombinedBooks.xml");

And here's the resultant CombinedBooks.xml:

<?xml version="1.0" encoding="utf-8"?>
<Root>
  <Books>
    <Book Id="Book1">
      <TITLE>Title of Book 1</TITLE>
      <AUTHOR>Author of Book 1</AUTHOR>
      <YEAR>2010</YEAR>
    </Book>
    <Book Id="Book2">
      <TITLE>Title of Book 2</TITLE>
      <AUTHOR>Author of Book 2</AUTHOR>
      <YEAR>2011</YEAR>
    </Book>
    <Book Id="Book3">
      <TITLE>Title of Book 3</TITLE>
      <AUTHOR>Author of Book 3</AUTHOR>
      <YEAR>2006</YEAR>
    </Book>
    <Book Id="Book4">
      <TITLE>Title of Book 4</TITLE>
      <AUTHOR>Author of Book 4</AUTHOR>
      <YEAR>2000</YEAR>
    </Book>
  </Books>
</Root>

You say you've got n number of files to go through. Just keep adding the nodes to xml1.Descendants("Books").FirstOrDefault() and then save the merged files when you're done.

            var xml1 = XDocument.Load(@"C:\Temp\Books1.xml");
            var xml2 = XDocument.Load(@"C:\Temp\Books2.xml");

            xml1.Descendants("Books").FirstOrDefault().Add(xml2.Descendants("Books").FirstOrDefault().Nodes());

            var xml3 = XDocument.Load(@"C:\Temp\Books3.xml");

            xml1.Descendants("Books").FirstOrDefault().Add(xml3.Descendants("Books").FirstOrDefault().Nodes());

            xml1.Save("C:\\Temp\\CombinedBooks.xml");

If you're looking for something different then I'll need a little more information on what you'd like the end result to look like before I can help.