LINQ to XML simple query

Question

Hi,

I have an XML doc like this:

<Persons>
 <Person Id="10000" FullName="Jon Doe">
  <Status StatusID="1" StatusDesc="Active"/>
      <Fields>
          <Field FieldId="1" Value="xxxx"/>
          <Field FieldId="2" Value="yyyy"/>
          <Field FieldId="2" Value="zzzz"/>
      </Fields>
 </Person>
 <Person Id="10001" FullName="John Smith">
  <Status StatusID="2" StatusDesc="New"/>
  <Fields>
      <Field FieldId="3" Value="aaaa"/>
      <Field FieldId="4" Value="bbbb"/>
     <Field FieldId="5" Value="ccccv"/>
  </Fields>
 </Person>
</Persons>

I want to write an XML query that returns the "Person" ID and all "Fields" elements. I can get all "Fields" elements but not the "Person" ID. The same applies when I need the "Status" element.

Any help will be appreciated.

Answer 1

Try something like this:

var result = XElement.Load("Example.xml")
  .Elements("Person")
  .Select(p => new {
   Id = p.Attribute("Id").Value,
   Fields = p.Descendants("Field").Select(f => new {
      Id = f.Attribute("FieldId").Value,
      Value = f.Attribute("Value").Value
     })
  });

This will give you a sequence of anonymous types that look something like this:

class Anonymous
{
    public String Id { get; }
    public IEnumerable<AnonymousSubtype> Fields { get; }
}

class AnonymousSubtype
{
   public String Id { get; }
   public String Value { get; }
}

The reason that I used the Descendants method to retrieve the fields is because the element I am first working with is the Person element. Since Elements only returns nodes that are direct children it would not work to retrieve the fields so I used Descendants instead.

To enumerate the results you can do this:

foreach (var person in result)
{
    Console.WriteLine("Person Id: {0}", person.Id);
    foreach (var field in person.Fields)
    {
        Console.Write("  Field Id: {0}", field.Id);
        Console.WriteLine("  Field Value: {0}", field.Value);
    }
}