Question

In this question, if I need to get “date” included in the output, what changes should be made?

When I included

let dt = l.Element("Date").Value

It gives, “Object reference not set to an instance of an object”

var query = from l in doc.Descendants("L1")
            let dt = l.Element("Date").Value
            let id = l.Attribute("id").Value
            from subject in l.Descendants("Subject")
            select new
            {
                Date = dt,
                Id = id,
                SubjectName = (string)subject.Attribute("SubjectName"),
                Score = (string)subject.Attribute("Score")
            };


foreach (var result in query)
{
    Console.WriteLine(result);
}

Answer 1

Looking at your other XML, it does not, as Mr. Skeet mentioned, have anything in the <date> elements. You will need to explicitly handle that if you aren’t planning on always having data in there.

You can do something like this:

let dt = l.Element("date") == null ? string.Empty : l.Element("date").Value