在 Node.js 中使用 Mongoose 在 MongoDB 中查找文档时出现奇怪的响应 [英] Strange response when finding documents in MongoDB using Mongoose in Node.js

问题描述

在此先感谢您的帮助，非常感谢！

Thanks in advance for your help on this, it's much appreciated!

我在一个新项目中使用 Node.js、MongoDB 和 Mongoose，我只是想find() 数据库中的文档.为简洁起见，我将只包含下面的 Mongoose 代码(无论如何我现在不会做更多的事情):

I'm using Node.js, MongoDB and Mongoose in a new project and I'm simply trying to find() the documents in a database. For brevity I'll just include the Mongoose code below (I'm not doing much more than this anyway right now):

var mongoose = require('mongoose');

mongoose.connect('mongodb://<username>:<password>@<sub-domain>.mongolab.com:<port>/<db>');

var schema = { email_address: String, invite: String }
  , Users = mongoose.model('Users', new mongoose.Schema(schema));

console.log(Users.findOne({ 'email_address': '[e-mail]' }, function(err, doc) { return doc; }));

我很确定应该将返回的 doc 回显到 Node.js 控制台(终端)，但我得到了这个:

I'm quite sure that should just echo the returned doc to the Node.js console (Terminal) but instead I'm getting this:

{ options: { populate: {} },
  safe: undefined,
  _conditions: { email_address: '[e-mail]' },
  _updateArg: {},
  _fields: undefined,
  op: 'findOne',
  model: 
   { [Function: model]
     modelName: 'Users',
     model: [Function: model],
     options: undefined,
     db: 
      { base: [Object],
        collections: [Object],
        models: {},
        replica: false,
        hosts: null,
        host: '<sub-domain>.mongolab.com',
        port: <port>,
        user: '<username>',
        pass: '<password>',
        name: '<db>',
        options: [Object],
        _readyState: 2,
        _closeCalled: false,
        _hasOpened: false,
        db: [Object] },
     schema: 
      { paths: [Object],
        subpaths: {},
        virtuals: [Object],
        nested: {},
        inherits: {},
        callQueue: [],
        _indexes: [],
        methods: {},
        statics: {},
        tree: [Object],
        _requiredpaths: undefined,
        options: [Object] },
     collection: 
      { collection: null,
        name: 'users',
        conn: [Object],
        buffer: true,
        queue: [Object],
        opts: {} },
     base: 
      { connections: [Object],
        plugins: [],
        models: [Object],
        modelSchemas: [Object],
        options: {},
        Collection: [Function: NativeCollection],
        Connection: [Function: NativeConnection],
        version: '3.5.4',
        Mongoose: [Function: Mongoose],
        Schema: [Object],
        SchemaType: [Object],
        SchemaTypes: [Object],
        VirtualType: [Function: VirtualType],
        Types: [Object],
        Query: [Object],
        Promise: [Function: Promise],
        Model: [Object],
        Document: [Object],
        Error: [Object],
        mongo: [Object] } } }

显然，我只是用 位混淆了我的真实凭证，它们在我的代码中都是正确的.

Obviously I've just obfuscated my real credential with the <username> bits, they are all correct in my code.

数据库中确实有一个与条件匹配的文档，尽管即使从 findOne 方法中删除条件也不会产生任何结果！

The database does have a document in it that would match the condition though even removing the condition from the findOne method yields no results!

我对 Node.js 还很陌生，所以我可以解释你的答案，所以我知道下次它会很有帮助！谢谢！

I'm fairly new to Node.js so I you could explain your answers so I know for next time it'd be a great help! Thanks!

推荐答案

我完全忘记了，Node.js 是异步的，所以 console.log(Users.findOne({ 'email_address': '[e-mail]' }, function(err, doc) { return doc; })); 确实在回显到控制台，尽管 DB 还没有返回任何文档！

I totally forget, Node.js is asynchronous so the line console.log(Users.findOne({ 'email_address': '[e-mail]' }, function(err, doc) { return doc; })); is indeed echoing to the console though no documents have been returned by the DB yet!

相反，console.log 方法应该在 find 的回调中，例如:

Instead the console.log method should be inside the find's callback, a la:

Users.find({}, function(err, doc) { console.log(doc); });

这篇关于在 Node.js 中使用 Mongoose 在 MongoDB 中查找文档时出现奇怪的响应的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！