Node.js 使用MongoDB+；猫鼬

我花了一天时间在mongo/mongoose文档和堆栈溢出上，似乎无法理解这一点

这是我的基本架构设置：

const mongoose = require('mongoose');
const config = require('./config/config');
const db = mongoose.createConnection(config.uri, { autoIndex: false });

const storeSchema = mongoose.Schema({
  name: String,
  location: { type:[Number], index:'2dsphere', required:true },
});

const Store = db.model('Store', storeSchema);

const coordinates = { lng: -122.0266515, lat: 36.9743292 }

Store.create({
  name: "My Store", 
  location: [coordinates.lng, coordinates.lat], 
})

const location = { longitude: -122.026423, latitude: 36.974538 } 
// above coordinates are near the 'My Store' record's coordinates.

const point = {
  type: "Point",
  coordinates: [location.longitude, location.latitude]  
}

Store.aggregate([{
  $geoNear: {
    near: point,
    distanceField: "dist.calculated",
    maxDistance: 100000,
    spherical: true                
    }
  }
])
.then((results) => console.log(results))
.catch((error) => console.log(error));

我也尝试过：

const storeSchema = mongoose.Schema({
  name: String,
  location: { type: { type: String }, coordinates: [Number] },
});

storeSchema.index({ location: "2dsphere" });

我在createConnection上将autoIndex设置为false，因为在app start和$geoNear查询中，只需要一个索引。我以为Mongoose可能在创建一个重复的索引，但这并没有解决这个问题

我创建了这样一个商店记录（简化）：

const mongoose = require('mongoose');
const config = require('./config/config');
const db = mongoose.createConnection(config.uri, { autoIndex: false });

const storeSchema = mongoose.Schema({
  name: String,
  location: { type:[Number], index:'2dsphere', required:true },
});

const Store = db.model('Store', storeSchema);

const coordinates = { lng: -122.0266515, lat: 36.9743292 }

Store.create({
  name: "My Store", 
  location: [coordinates.lng, coordinates.lat], 
})

const location = { longitude: -122.026423, latitude: 36.974538 } 
// above coordinates are near the 'My Store' record's coordinates.

const point = {
  type: "Point",
  coordinates: [location.longitude, location.latitude]  
}

Store.aggregate([{
  $geoNear: {
    near: point,
    distanceField: "dist.calculated",
    maxDistance: 100000,
    spherical: true                
    }
  }
])
.then((results) => console.log(results))
.catch((error) => console.log(error));

这是我返回错误的查询：

const mongoose = require('mongoose');
const config = require('./config/config');
const db = mongoose.createConnection(config.uri, { autoIndex: false });

const storeSchema = mongoose.Schema({
  name: String,
  location: { type:[Number], index:'2dsphere', required:true },
});

const Store = db.model('Store', storeSchema);

const coordinates = { lng: -122.0266515, lat: 36.9743292 }

Store.create({
  name: "My Store", 
  location: [coordinates.lng, coordinates.lat], 
})

const location = { longitude: -122.026423, latitude: 36.974538 } 
// above coordinates are near the 'My Store' record's coordinates.

const point = {
  type: "Point",
  coordinates: [location.longitude, location.latitude]  
}

Store.aggregate([{
  $geoNear: {
    near: point,
    distanceField: "dist.calculated",
    maxDistance: 100000,
    spherical: true                
    }
  }
])
.then((results) => console.log(results))
.catch((error) => console.log(error));

下面是我得到的“geoNear无地理索引”错误：

{ MongoError: geoNear command failed: { ok: 0.0, errmsg: "no geo indices 
for geoNear", operationTime: Timestamp(1529989103, 8), $clusterTime: { 
clusterTime: Timestamp(1529989103, 8), signature: { hash: BinData(0, 
0000000000000000000000000000000000000000), keyId: 0 } } }
at queryCallback (/Users/`...`/node_modules/mongodb- 
core/lib/cursor.js:244:25)
at /Users/`...`/node_modules/mongodb- 
core/lib/connection/pool.js:544:18
at process._tickCallback (internal/process/next_tick.js:150:11)
name: 'MongoError',
message: 'geoNear command failed: { ok: 0.0, errmsg: "no geo indices for 
geoNear", operationTime: Timestamp(1529989103, 8), $clusterTime: { 
clusterTime: Timestamp(1529989103, 8), signature: { hash: BinData(0, 
0000000000000000000000000000000000000000), keyId: 0 } } }',
operationTime: Timestamp { _bsontype: 'Timestamp', low_: 8, high_: 
1529989103 },
ok: 0,
errmsg: 'geoNear command failed: { ok: 0.0, errmsg: "no geo indices for 
geoNear", operationTime: Timestamp(1529989103, 8), $clusterTime: { 
clusterTime: Timestamp(1529989103, 8), signature: { hash: BinData(0, 
0000000000000000000000000000000000000000), keyId: 0 } } }',
code: 16604,
codeName: 'Location16604',
'$clusterTime':
{ clusterTime: Timestamp { _bsontype: 'Timestamp', low_: 8, high_: 
1529989103 },
`enter code here`signature: { hash: [Binary], keyId: [Long] } } }

当输入console.log storeSchema.index（）时，会得到以下索引：

[ [ { location: '2dsphere' }, {} ], [ {}, {} ] ]

…所以索引似乎就在那里

在运行查询之前，我还尝试调用EnsureIndex

---

好的，我发现这个错误实际上与我创建db实例时MongoDB Atlas提供的URI有关

具体地说，它们提供的URI（我已经复制并粘贴）如下所示：

mongodb+srv://user:password@host.mongodb.net? 
readPreference=primaryPreferred&retryWrites=true

删除“retryWrites=true”为我解决了这个问题。更多详细信息请参见：