DataTable 字段值为空的时候报错的解决

在使用Datatable的时候，后台返回给前台的值会有空的时候，而这个时候，前台会报错，这里讲防治方法；

$('#datatable1').DataTable( {
                ajax: {
                    "url": 'list',
                    "type": "POST",
                    data:{
                        title : function(){
                            return $("#title").val();
                        }
                    }
                },
                columnDefs: [{"defaultContent": "",
                              "targets": "_all"}],
                columns: [
                    { title: "序号", render:function(data,type,row,meta){
                        return meta.row + 1 + meta.settings._iDisplayStart }, width:"5%" },
                    { title: "推送类型", data:"mp_send_type", width:"5%" }, //x
                    { title: "推送标题", data:"mp_msg_title", width:"15%" },
                    { title: "任务ID(TASK id)", data:"mp_taskid", width:"12%" },//x */
                    { title: "推送时间", data:"mp_send_time", width:"7%" }, //x
                    { title: "推送人数", data:"mp_count", width:"5%" }, //x
                    { title: "操作人", data:"mp_admin_user_name", width:"7%" }, //    x
                    { title: "状态", render:function(data, type, row){
                        var str = "";
                        if(row.mp_status == "1"){
                            str = "推送中";
                        }else if(row.mp_status == "2"){
                            str = "推送完成";
                        }else{
                            str = "推送失败";
                        }
                        return str;
                    } , width:"10%"}
                ]
                ,serverSide: true
                ,paging:true
                ,pagingType: "simple_numbers"
                ,lengthChange: true
                ,ordering:false
                ,info:false
                ,pageLength:10
                ,searching: false
                ,language: {
                    "url": "<%=contextPath %>/static/backend/js/Chinese.lang"
                }
            });

中间的：

columnDefs: [{"defaultContent": "",
                              "targets": "_all"}],

这一点就是设置默认值为空的时候，不报错