我在使用Node.js引用MongoDB中的嵌套子文档时遇到问题

Question

我正在阅读一本书，介绍如何使用MEAN堆栈开发Web应用程序。当我去localhost：3000 / api / locations /：locationid / reviews /：reviewid我得到“reviewid not found”无论我输入相应的reviewid还是我输入一个随机数，我都会将评论记录到控制台并且它是null。 localhost：3000 / api / locations /：locationid有效，我不知道发生了什么。任何帮助深表感谢。

所以这是我的文档在MongoDB中的样子：

{
        "_id" : ObjectId("5a9025348de0d78d8792e105"),
        "name" : "Hardee's",
        "address" : "200 W Main St, Pilot Mountain, NC 27041",
        "rating" : 3,
        "facilities" : [
                "Hot drinks",
                "Food",
                "Premium wifi"
        ],
        "coords" : [
                -80.469262,
                36.385647
        ],
        "openingTimes" : [
                {
                        "days" : "Monday - Saturday",
                        "opening" : "5:00am",
                        "closing" : "11:00pm",
                        "closed" : false
                },
                {
                        "days" : "Sunday",
                        "opening" : "6:00am",
                        "closing" : "11:00pm",
                        "closed" : false
                }
        ],
        "reviews" : [
                {
                        "author" : "Bigpoppa Eizenga",
                        "id" : ObjectId("5a902dfd2bb702dcaf1b85e0"),
                        "rating" : 5,
                        "timestamp" : ISODate("2018-01-23T05:00:00Z"),
                        "reviewText" : "Used drive-thru. Service was friendly an                                                                                                                                  d fast, even with 4 special order items. I would definitely return when in that                                                                                                                                   area!"
                }
        ]
}

以下是Node.js显示的内容，无论：reviewid我输入：

> [email protected] start C:\Users\Galen\Desktop\MEAN Stack\loc8r
> node ./bin/www

Mongoose connected to mongodb://localhost/Loc8r
Getting single review
{ reviews:
   [ { rating: 5,
       createdOn: 2018-02-28T10:56:58.203Z,
       author: 'Bigpoppa Eizenga',
       id: 5a902dfd2bb702dcaf1b85e0,
       timestamp: 2018-01-23T05:00:00.000Z,
       reviewText: 'Used drive-thru. Service was friendly and fast, even with 4 special order items. I would definitely return when in that area!' } ],
  _id: 5a9025348de0d78d8792e105,
  name: 'Hardee\'s' }
null

这是我的控制器，reviews.js：

var mongoose = require('mongoose');
var Loc = mongoose.model('Location');

var sendJsonResponse = function(res, status, content) {
  res.status(status);
  res.json(content);
};

module.exports.reviewsCreate = function (req, res) {
  sendJsonResponse (res, 200, {"status" : "success"});
};

module.exports.reviewsReadOne = function(req, res) {
  console.log("Getting single review");
  if (req.params && req.params.locationid && req.params.reviewid) {
    Loc
      .findById(req.params.locationid)
      .select('name reviews')
      .exec(
        function(err, location) {
          console.log(location);
          var response, review;
          if (!location) {
            sendJsonResponse(res, 404, {
              "message": "locationid not found"
            });
            return;
          } else if (err) {
            sendJsonResponse(res, 400, err);
            return;
          }
          if (location.reviews && location.reviews.length > 0) {
            review = location.reviews.id(req.params.reviewid);
            if (!review) {
              console.log(review);
              sendJsonResponse(res, 404, {
                "message": "reviewid not found"
              });
            } else {
              response = {
                location: {
                  name: location.name,
                  id: req.params.locationid
                },
                review: review
              };
              sendJsonResponse(res, 200, response);
            }
          } else {
            sendJsonResponse(res, 404, {
              "message": "No reviews found"
            });
          }
        }
    );
  } else {
    sendJsonResponse(res, 404, {
      "message": "Not found, locationid and reviewid are both required"
    });
  }
};

module.exports.reviewsUpdateOne = function (req, res) {
  sendJsonResponse (res, 200, {"status" : "success"});
};

module.exports.reviewsDeleteOne = function (req, res) {
  sendJsonResponse (res, 200, {"status" : "success"});
};

这是我的路线，index.js：

var express = require('express');
var router = express.Router();
var ctrlLocations = require('../controllers/locations');
var ctrlReviews = require('../controllers/reviews');

//locations
router.get('/locations', ctrlLocations.locationsListByDistance);
router.post('/locations', ctrlLocations.locationsCreate);
router.get('/locations/:locationid', ctrlLocations.locationsReadOne);
router.put('/locations/:locationid', ctrlLocations.locationsUpdateOne);
router.delete('/locations/:locationid', ctrlLocations.locationsDeleteOne);

//reviews
router.post('/locations/:locationid/reviews', ctrlReviews.reviewsCreate);
router.get('/locations/:locationid/reviews/:reviewid', ctrlReviews.reviewsReadOne);
router.put('/locations/:locationid/reviews/:reviewid', ctrlReviews.reviewsUpdateOne);
router.delete('/locations/:locationid/reviews/:reviewid', ctrlReviews.reviewsDeleteOne);

module.exports = router;

我认为这是所有相关信息。我感谢任何帮助。

Answer 1

location.reviews是一个嵌套数组，所以它不会得到Mongoose的虚拟化id getter。与任何其他JS数组一样处理它。更改：

review = location.reviews.id(req.params.reviewid);

至：

review = location.reviews.find(review => review.toJSON().id.toString() === req.params.reviewid)

更新：工作代码。