title: Cannot serialize the DataTable. DataTable name is not set
body: <p>I need to export all datatables to individual XML files and I cannot export all the rows at once because of System.OutOfMemoryException if there is a huge table. So I tried to export N rows. However WriteXml throws an exception if I use paging syntax in query.</p>
  
  <p>I've tested both queries in LINQPad, they are ok.</p>
  
  <blockquote>
    <p>System.InvalidOperationException: Cannot serialize the DataTable.
    DataTable name is not set.</p>
  </blockquote>
  
  <pre><code>  // The first query causes exception
    string oraQueryGetTableData = "SELECT * FROM (SELECT t0.* FROM MY_TABLE t0) WHERE ROWNUM &lt;= 100";
  
    // The second query runs without any error
    //oraQueryGetTableData = "SELECT * FROM MY_TABLE";
  
    OracleCommand oraCommandGetTableData = new OracleCommand(oraQueryGetTableData, oraConnection);
  
    OracleDataReader oraReaderTableData = oraCommandGetTableData.ExecuteReader();
  
    DataTable dataTable = new DataTable();
    dataTable.Load(oraReaderTableData);
  
    // Exception might occur here
    dataTable.WriteXml(writer, true);  
  </code></pre>
  
  <p>What is the problem here or how can I fix this?</p>