title: OracleDataReader GetValue throws InvalidOperationException
body: <p>There is at least one other thread with this title or one very close to it but it was not quite like my specific implementation and I couldn't find my answer in it.
  I have this code</p>
  
  <pre><code>&lt;code&gt;
  List&lt;string&gt; lsRes = new List&lt;string&gt;();
  OracleConnection conn = getOracleConnection();
  try
  {
      string sqlQuery = "select CTS.SEQ_BATCH_ID.nextval from dual connect by 
  level &lt;= " + seqCnt;
      conn.Open();
      OracleCommand cmd = new OracleCommand(sqlQuery, conn);
      cmd.CommandType = CommandType.Text;
      OracleDataReader dr;
      dr = cmd.ExecuteReader();
      while (dr.Read())
          lsRes.Add(dr.GetValue(0).ToString());
  }
  catch(exception e)
  { 
  &lt;/code&gt;
  </code></pre>
  
  <p>I'm getting my InvalidOperationException on dr.GetValue(0). Any idea why? Sequence should be returning a number or numbers, I'm converting it/them to a string/strings, Should I be using GetOracleValue? There are no precompiler or compilation errors just in runtime.</p>