正在学mongodb和node.js,现在想做个练习，后端获取数据库中的数据，通过res.send发送给前端页面

var express = require('express');
var MongoClient = require('mongodb').MongoClient;
var router = express.Router();
var url = "mongodb://127.0.0.1:27017";
router.get('/', function(req, res, next) {
  res.render('goods',{title:'goods'});
});
router.get('/list', function(req, res, next) {
        MongoClient.connect(url, function(err, db) {
        if(err) throw err;
        let immocmall = db.db('immocmall');
        let mall_goods = immocmall.collection('mall-goods');
        查询productId为201710003的数据
        var search = {"productId":201710003};
        mall_goods.find(search ,function(err, cursor) {
            //如何将数据发送给页面
            res.send(cursor.toString())
        })

    })
})