如何使用node.js访问json对象的子元素

在我的node.js应用程序中,我从 mongodb服务器检索值,并希望将它们转换为CSV文件.可以从数据库轻松访问父元素并显示在CSV文件中但子元素不显示且无法访问..

JSON结构：

"name" : "fhj","age" : "23","gender" : "female","sec" : "b","username" : "9886666","language" : "HINDI","method" : "method2","timeSlot" : {
    "id" : 2,"fromTime" : 12,"toTime" : 15
}

@H_68_5@mycode的：

db.users.find(function(err,values){
if(err||!values.length)
   console.log("ERROR !!!!");
else
{ 
   var i=1;
   str='[';
   values.forEach(function(user){
     if(i==values.length)
         str=str+'{ "name" : "' + user.username + '","age" : "'+ user.age +'","gender":"'+user.gender+'","sec":"'+user.sec+'","username":"'+user.username+'","language":"'+user.language+'","method":"'+user.method+'","Timeslot":"'+user.timeslot+'"}';
     else{
       str = str + '{ "name" : "' + user.username + '","Timeslot":"'+user.timeslot+'"},' +'\n';
       i++;
     }
   });
   str = str.trim();
   str = str + ']';
   var obj=JSON.parse(str);
   json2csv({data: obj,fields: ['name','age','gender','sec','username','language','method','Timeslot']},function(err,csv) {
      if (err) 
          console.log(err);
      fs.writeFile('./files/user.csv',csv,function(err) {
         if (err) 
             throw err;
         console.log('File saved');
      });
   });
 }  
});

除时间段的子元素外,显示所有值.
如何从数据库访问JSON的子元素并显示CSV文件中的所有值？

timeSlot.id

var item_name = timeSlot['id'];