datatable刷新表头

使用jQuery的datatable生成表格数据，当需要改变表头时，调用Table.fnDestroy();再重新创建表头

var oTable = null;
function initSettings() {
    var columns = [];
    
    $.ajax({
        type : "post",
        url : "${ctx}/getDynamicColumns",
        dataType : "json",
        data : $("#query_form").serialize(),
        async: false,
        success : function(data){
            columns.push({
                "sTitle": "日期",
                "mData": "createTime",
                "sName": "createTime",
                "sWidth": "120",
            });
            columns.push({
                "sTitle": "商户全称",
                "mData": "fullName",
                "sName": "fullName",
                "sWidth": "100",
            });
            columns.push({
                "sTitle": "商户简称",
                "mData": "shortName",
                "sName": "shortName",
                "sWidth": "100",
            });
　　　　　　　 /* 这里其实是实现动态的列，查询到所要的列，再生成 */
            $.map(data, function(item,index) {
                console.log(item.sTitle)
                columns.push({
                    "sTitle": item.sTitle,
                    "mData": item.mData,
                    "sName": item.sName,
                    "sWidth": "100",
                    "mRender":function(data,type,full){
                        if(data != null){
                            return data;
                        }else{
                            return "";
                        }
                    }
                });
             });

             columns.push({
                 "sTitle": "一级代理商",
                 "mData": "agent1",
                 "sName": "agent1",
                 "sWidth": "100",
                 "mRender":function(data,type,full){
                     if(data != null && data !=""){
                         return data;
                     }else{
                         return "暂无";
                     }
                 }
             });
             columns.push({
                 "sTitle": "二级代理商",
                 "mData": "agent2",
                 "sName": "agent2",
                 "sWidth": "100",
                 "mRender":function(data,type,full){
                     if(data != null&& data !=""){
                         return data;
                     }else{
                         return "暂无";
                     }
                 }
             });
        }
    });
    
    return columns;
}

function createTable() {
    oTable = createDataTable("coupon_channel_table", {
        "sAjaxSource": '${ctx}/coupon_channel_statistic/list',
        "aoColumns": initSettings(),
        "fnServerParams": function (params) {
            var fields = $('#query_form').serializeArray();
            $.each(fields, function (i, field) {
                if (field.name && field.value) {
                    params.push({"name": field.name, "value": field.value});
                }
            });
        }
    });
}


function loadTable(){
    if(null != oTable) {
        oTable.fnDestroy();//销毁表格对象
        $("#detail_table_div").html("<table id='coupon_channel_table'></table>");
        
    }
    createTable();
    /*  if($("#coupon_channel_table").find("td").length == 0){
        createTable();
    }else{
        oTable.fnDraw();
    }  */
}

页面div

<div  id="detail_table_div">
    <table id="coupon_channel_table"></table>
</div>