MongoDB geoNear 不是函数错误/数组未填充

Question

所以我正在关注一本关于构建 MEAN 堆栈应用程序的书。最初我有这段代码，但得到了 TypeError: Loc.geoNear is not a function

module.exports.locationsListByDistance = function (req, res) {
  var lng = parseFloat(req.query.lng);
  var lat = parseFloat(req.query.lat);
  var point = {
    type: "Point",
    coordinates: [lng, lat]
  };
  var geoOptions = {
    spherical: true,
    maxDistance: theEarth.getRadsFromDistance(20),
    num: 10
  };
  Loc.geoNear(point, geoOptions, function(err, results, stats) {
    var locations = [];
    results.forEach(function(doc) {
      locations.push({
        distance: theEarth.getDistanceFromRads(doc.dis),
        name: doc.obj.name,
        address: doc.obj.address,
        rating: doc.obj.rating,
        facilities: doc.obj.facilities,
        _id: doc.obj._id
      });
    });
    sendJsonResponse(res, 200, locations);
  });
};

然后我看到了这个页面Mongoose/MongoDb getting error geoNear is not a function 并使用了 WernerCD 提供的代码：

module.exports.locationsListByDistance = function(req, res) {
  console.log('locationsListByDistance:');
  var lng = parseFloat(req.query.lng);
  var lat = parseFloat(req.query.lat);
  var maxDistance = 10000;
  var point = {
    type: "Point",
    coordinates: [lng, lat]
  };
  console.log('point: ' + point)
  var geoOptions = {
    spherical: true,
    maxDistance: theEarth.getRadsFromDistance(maxDistance),
    num: 10
  };
  console.log('geoOptions: ' + geoOptions);
  if ((!lng && lng!==0) || (!lat && lat!==0) || ! maxDistance) {
    console.log('locationsListByDistance missing params');
    sendJsonResponse(res, 404, {
      "message": "lng, lat and maxDistance query parameters are all required"
    });
    return;
  } else {
    console.log('locationsListByDistance running...');
    Loc.aggregate(
      [{
        '$geoNear': {
          'near': point,
          'spherical': true,
          'distanceField': 'dist.calculated',
          'maxDistance': maxDistance
        }
      }],
      function(err, results) {
        if (err) {
          sendJsonResponse(res, 404, err);
        } else {
          locations = buildLocationList(req, res, results);
          sendJsonResponse(res, 200, locations);
        }
      }
    )
  };
};

var buildLocationList = function(req, res, results) {
  console.log('buildLocationList:');
  var locations = [];
  results.forEach(function(doc) {
      locations.push({
        distance: doc.dist.calculated,
        name: doc.name,
        address: doc.address,
        rating: doc.rating,
        facilities: doc.facilities,
        _id: doc._id
      });
  });
  return locations;
};

我从上面的代码和帖子中唯一改变的是maxDistance。现在所有输出都是 [] 表示一个空数组。我想知道我在哪里搞砸了。感谢您的任何帮助和建议。

最终输出应如下所示：

[
    {
        "distance": 0,
        "name": "Rathaus",
        "address": "Markt",
        "rating": 0,
        "facilities": [
            "museum"
        ],
        "_id": "5a9366517775811a449e503e"
    },
    {
        "distance": 61.77676881925853,
        "name": "Haus Löwenstein",
        "address": "",
        "rating": 0,
        "facilities": [
            "museum"
        ],
        "_id": "5a9366517775811a449e5045"
    },
    {
        "distance": 63.03445976427102,
        "name": "Goldener Schwan",
        "address": "Markt 37",
        "rating": 0,
        "facilities": [
            "restaurant"
        ],
        "_id": "5a9366517775811a449e5052"
    },
    {
        "distance": 66.60375653163021,
        "name": "Klein Printenbäckerei",
        "address": "Krämerstraße 12",
        "rating": 0,
        "facilities": [
            "supermarket"
        ],
        "_id": "5a9366517775811a449e504d"
    },
    {
        "distance": 74.91278395082011,
        "name": "Couven-Museum",
        "address": "Hühnermarkt 17",
        "rating": 0,
        "facilities": [
            "museum"
        ],
        "_id": "5a9366517775811a449e5042"
    },
    {
        "distance": 132.2939512054143,
        "name": "Cathedral Treasury",
        "address": "Johannes-Paul-II.-Straße",
        "rating": 0,
        "facilities": [
            "museum"
        ],
        "_id": "5a9366517775811a449e503d"
    },
    {
        "distance": 152.11867357742042,
        "name": "Aachen Cathedral",
        "address": "Domhof 1",
        "rating": 0,
        "facilities": [
            "museum"
        ],
        "_id": "5a9366517775811a449e503c"
    },
    {
        "distance": 155.92015153163268,
        "name": "International Newspaper Museum",
        "address": "Pontstraße 13",
        "rating": 0,
        "facilities": [
            "museum"
        ],
        "_id": "5a9366517775811a449e5040"
    },
    {
        "distance": 175.0857109968383,
        "name": "Nobis Printen",
        "address": "Münsterplatz 3",
        "rating": 0,
        "facilities": [
            "supermarket"
        ],
        "_id": "5a9366517775811a449e504c"
    },
    {
        "distance": 179.32348875834543,
        "name": "Grashaus",
        "address": "Fischmarkt",
        "rating": 0,
        "facilities": [
            "museum"
        ],
        "_id": "5a9366517775811a449e5044"
    },
    {
        "distance": 189.8675948747873,
        "name": "Maranello",
        "address": "Pontstraße 23",
        "rating": 0,
        "facilities": [
            "restaurant"
        ],
        "_id": "5a9366517775811a449e5057"
    },
    {
        "distance": 198.2239741555585,
        "name": "Carlos I",
        "address": "Rennbahn 1",
        "rating": 0,
        "facilities": [
            "restaurant"
        ],
        "_id": "5a9366517775811a449e5055"
    }
]

Answer 1

我通过将 maxDistance 更改为更大的数字 999999 来解决此问题。我的坐标离测试数据太远了。