JQuery数据表排序前一列

这就是我初始化jQuery数据表以在代码中进行排序和分页的方式。

$("#tablepagination").dataTable( {
    "bPaginate": true,
    "sPaginationType": "full_numbers",
    "bProcessing": true,
    "bServerSide": true,
    "iDisplayLength": <?php echo $_SESSION['record_count'];?>,
    "sAjaxSource": "mod/get_contacts_con.php?type=c&is_con=1&sec=<?php echo $current_section_id;?>&con_id=<?php echo $con_id;?>",
    "sServerMethod": "POST",
    "sDom": '<"top font-style-4"fl<"topRecordInfo"i>p>rt<"bottom font-style-4"i><"clear">',
    // Callback function added by sowjitha on 16, October 2015.
    // To display the newly created id on search field
    "fnDrawCallback": function(){
        <?php if(isset($con_id) && !empty($con_id)){?>
            $("#tablepagination tfoot th:first input").val('<?php echo $con_id;?>');
        <?php }?>
    },
    "oLanguage": {
        "sInfoFiltered": "",
        "sProcessing":     "<?php echo LBL_PROCESSING; ?>",
        "sSearch":         "<?php echo LBL_GLOBALSEARCH; ?>",
        "sLengthMenu":     "<?php echo LBL_SLENGTHMENU; ?>",
        "sInfo":           "<?php echo LBL_SINFO; ?>",
        "sInfoEmpty":      "<?php echo LBL_SINFOEMPTY; ?>",
        "sInfoPostFix":    "",
        "sLoadingRecords": "<?php echo LBL_SLOADINGRECORDS; ?>",
        "sZeroRecords":    "<?php echo LBL_SZERORECORDS; ?>",
        "sEmptyTable":     "<?php echo LBL_SEMPTYTABLE; ?>",
        "oPaginate":{
            "sFirst":      "<?php echo LBL_FIRST; ?>",
            "sPrevious":   "<?php echo LBL_PREVIOUS; ?>",
            "sNext":       "<?php echo LBL_NEXT; ?>",
            "sLast":       "<?php echo LBL_LAST; ?>"
        },
        "oAria": {
            "sSortAscending":  "<?php echo LBL_SSORTASCENDING; ?>",
            "sSortDescending": "<?php echo LBL_SSORTDESCENDING; ?>"
        }
    },
    "sAutoWidth": false,
    /*"aoColumnDefs": [
                        {
                            "bSortable": false,
                            "aTargets": [ -1 ]
                        }
                    ],*/
    "aoColumns": [
                    null,
                    null,
                    null,
                    null,
                    null,
                    {"sClass": "datacontact5", "bSortable": false }
                ],
} );

在这里，排序对于前两列来说很好。从第三列开始，如果我点击第三列，它正在对第二列进行排序。如果我点击第4列，它将对第3列进行排序，依此类推

更多信息，这是我的html部分

<thead>
        <tr style="background-color:#b46a7a;color:#ffffff;">
            <th class="id6td"><?php echo LBL_CONTACT_ID?></th>
            <th class="nom6td"><?php echo LBL_CONTACT_LAST_NAME.' '.LBL_CONTACT_FIRST_NAME?></th>
            <th class="email6td"><?php echo LBL_EMAIL?></th>
            <th class="phone6td"><?php echo LBL_TEL?></th>
            <th class="address6td"><?php echo LBL_ADDR?></th>
            <th class="actions6td"><?php echo LBL_ACTIONS?></th>
        </tr>                               
</thead>

我无法理解此代码的问题所在。有人帮我。