当我使用mongoose时，我收到一个错误，找不到collectionNames函数[重复]

这个问题在这里已有答案：

• 'process.nextTick(function() { throw err; })' - Undefined is not a function (mongodb/mongoose) 3个答案

在完成本机mongo命令之后，我正在尝试使用mongoose的ODM，它扩展了MongoDB的功能 .

我开始从我的localhost上的现有数据库中简单地获取我的集合 . 我能够连接到我的数据库，但我无法获得收藏 . 但是我无法这样做 .

/**
 * Uses MongooseJS to Connect to MongoDB
 * .Maps out all collections within
 */

var mongoose = require('mongoose')
  , MONGO_DB = 'mongodb://localhost/astro';

mongoose.connect(MONGO_DB);

mongoose.connection.on('open', function(){
  mongoose.connection.db.collectionNames(function(error, collections) {
    if (error) {
      throw new Error(error);
    } else {
      collections.map(function(collection) {
        console.log('found collection %s', collection.name);
      });
    }
  });
});

mongoose.connection.on('error', function(error){
  throw new Error(error);
});

TypeError: mongoose.connection.db.collectionNames is not a function
at NativeConnection.<anonymous> (/Users/sagarmunjal/Desktop/untitled folder/script.js:29:26)
at emitNone (events.js:80:13)
at NativeConnection.emit (events.js:179:7)
at open (/Users/sagarmunjal/Desktop/untitled folder/node_modules/mongoose/lib/connection.js:511:11)
at NativeConnection.Connection.onOpen (/Users/sagarmunjal/Desktop/untitled folder/node_modules/mongoose/lib/connection.js:520:5)
at /Users/sagarmunjal/Desktop/untitled folder/node_modules/mongoose/lib/connection.js:476:11
at /Users/sagarmunjal/Desktop/untitled folder/node_modules/mongoose/lib/drivers/node-mongodb-native/connection.js:60:5
at /Users/sagarmunjal/Desktop/untitled folder/node_modules/mongodb/lib/db.js:227:5
at connectHandler (/Users/sagarmunjal/Desktop/untitled folder/node_modules/mongodb/lib/server.js:286:7)
at g (events.js:273:16)
at emitOne (events.js:90:13)
at emit (events.js:182:7)
at /Users/sagarmunjal/Desktop/untitled folder/node_modules/mongodb-core/lib/topologies/server.js:504:23
at commandCallback (/Users/sagarmunjal/Desktop/untitled folder/node_modules/mongodb-core/lib/topologies/server.js:936:9)
at Callbacks.emit (/Users/sagarmunjal/Desktop/untitled folder/node_modules/mongodb-core/lib/topologies/server.js:116:3)
at null.messageHandler (/Users/sagarmunjal/Desktop/untitled folder/node_modules/mongodb-core/lib/topologies/server.js:282:23)

/ Users / sagarmunjal / Desktop / untitled folder / node_modules / mongodb / lib / server.js：289 process.nextTick（function（）{throw err;}）^

TypeError：mongoose.connection.db.collectionNames不是NativeConnection中的函数 . （/ Users / sagarmunjal / Desktop / untitled folder / script.js：29：26）在emitNone（events.js：80：13）的NativeConnection.emit（events.js：179：7）中打开（/ Users / sagarmunjal） / Desktop / untitled文件夹/ node_modules / mongoose / lib / connection.js：511：11）在NativeConnection.Connection.onOpen（/ Users / sagarmunjal / Desktop / untitled folder / node_modules / mongoose / lib / connection.js：520：5） ）/ users / sagarmunjal / Desktop / untitled folder / node_modules / mongoose / lib / connection.js：476：11 at / Users / sagarmunjal / Desktop / untitled folder / node_modules / mongoose / lib / drivers / node-mongodb-native / connection.js：60：5 at / Users / sagarmunjal / Desktop / untitled folder / node_modules / mongodb / lib / db.js：227：5 at connectHandler（/ Users / sagarmunjal / Desktop / untitled folder / node_modules / mongodb / lib / server.js：286：7）at g（events.js：273：16）在emitOne（events.js：90：13）的emit（events.js：182：7）/ users / sagarmunjal / Desktop / untitled文件夹/ node_modules / mongodb -core / lib /拓扑/ server.js：504：23 at commandCallback（/ Users / sagarmunjal / Desktop / untitled文件夹/ node_modules / mongodb -core / lib / topologies / server.js：936：9）在Callbacks.emit（/ Users / sagarmunjal / Desktop / untitled folder / node_modules / mongodb-core / lib / topologies / server.js：116 ：3）at null.messageHandler（/ Users / sagarmunjal / Desktop / untitled folder / node_modules / mongodb-core / lib / topologies / server.js：282：23）[nodemon] app崩溃 - 在开始之前等待文件更改.. .