title: Finding rows with DBNull.Value from a Data Table using Select statement
body: <p>I have a data table with only one column containing strings. What is the best way to get a collection of rows having DBNull.Value using DataTable.Select() method?</p>
  
  <pre><code>DataTable dataTable = new DataTable("names");
  DataColumn newColumn = new DataColumn("Name", System.Type.GetType("System.String")
  {
  AllowDBNull = true
  };
  DataRow row1 = dataTable.NewRow();
  row1["Name"] = "John";
  dataTable.Rows.Add(row1);
  DataRow row2 = dataTable.NewRow();
  row2["Name"] = DBNull.Value;
  dataTable.Rows.Add(row2);
  </code></pre>
  
  <p>I tried <em>dataTable.Select("Name is null")</em> and it returned row2. But aren't null and DBNull.Value different as in null meaning an invalid reference and DBNull.Value representing a non existent value?</p>