title: SqlDataReader no data, but HasRow is true
body: <p>I read data from SQL database by <strong>ExecuteReader().</strong>
  There are no data fulfill conditions, but <strong>HasRow</strong> returns true. When I try to read data from reader I got exception:
  <em>'Data is Null. This method or property cannot be called on Null values.'</em></p>
  
  <pre><code>SqlDataReader reader = command.ExecuteReader();     
  if (reader.HasRows)
              try
              {
                  if (reader.Read())
                  {
                          string aa = reader.GetFieldType(0).Name; // aa returns 'DateTime'
                          dateStart.MinDate = reader.GetDateTime(0); //exception on this line
                          dateEnd.MinDate = reader.GetDateTime(0);
                          dateStart.Value = reader.GetDateTime(0);
                  }
              }
              finally
              {
                 reader.Close();
              }
  </code></pre>
  
  <p>Thanks in advance
  Usjwo</p>