<script>
$(document).ready(function()
{
    //TABLE//
    oTable = $('#tabledata').dataTable({
            "sPaginationType": "full_numbers",
            "bServerSide": true,
            "sAjaxSource": "<?php echo base_url(); ?>/controller/datatables",
            "bAutoWidth": false,
            "aaSorting": [[1, 'asc']],
            "aoColumns": [
                            { "sClass": "left", "sName": "codigo" },
                            { "sClass": "center", "sName": "nome" }
                          ],
            "fnServerData": function ( sSource, aoData, fnCallback ) {
                $.ajax( {
                        "dataType": 'json',
                        "type": "POST",
                        "url": sSource,
                        "data": aoData,
                        "success": fnCallback
                });
            },
           "fnRowCallback": function( nRow, aData, iDisplayIndex ) {
                var eventClass = '';
                if (aData[1] == 'andrey' )
                {
                    eventClass = 'gradeX';
                }
                if(eventClass != '')
                    $(nRow).addClass( eventClass );
                return nRow;
            }
        });
});
</script>

<table class="datatable" id="tabledata">
    <thead>
        <tr>
            <th>Còdigo</th>
            <th>Nome</th>
        </tr>
    </thead>
    <tbody>
    </tbody>
</table>