Get default value type (DateTime) in Linq to Sql query with empty results

Question

I am having a problem returning a default DateTime value from a complex Linq-to-Sql query.

Hopefully the following simplified example shows the

Answer 1

The error implies that t.TransactionTime is nullable (i.e. DateTime?). Even if the field can't be null in the database if the property is nullable and the query returns no rows FirstOrDefault() will return null as this is the default value of t.TransactionTime

EDIT

further to your comments, that is very strange: the below code outputs True

List dates = new List();
DateTime date = dates.FirstOrDefault();
Console.WriteLine(date == DateTime.MinValue);

And i would expect your code to do the same.