猫鼬不在生产(Heroku)上填充(.populate())，但在本地 [英] Mongoose is not populating (.populate()) on Production (Heroku), but works on Local

问题描述

基本上，我正在其中一个时刻.我的应用程序在Heroku上，它使用的数据库是mLab(MongoDB).

Essentially I am having one of those moments. My app's on Heroku, and the DB it uses is mLab (MongoDB).

• 它在本地(Cloud9)上有效，但在生产环境(Heroku)上无效.
• 我无法获得 .populate()进行生产.

• It works on local (Cloud9), but not on production (Heroku).
• I can't get .populate() to work on production.

您是否在下面的代码段(代码段)中看到任何可能导致Heroku在本地运行的失败的空白?

Do you see any gaps in my code below (snippet) that may cause Heroku to fail, while it works on local?

谢谢.

(我曾尝试清除数据库(删除数据库并制作一个新数据库.另外，我在此站点上也遇到过类似的问题.我也曾尝试过' heroku local --tail ')命令在我的本地计算机上调试并运行它；它在本地计算机上运行...只是不在Heroku上；似乎有故障.)

(I have tried purging the DB (deleting the DB and making a new one. Also I've for similar questions on this site. Also I have tried 'heroku local --tail' command to debug and ran it on my local machine; it works on local... Just not on Heroku; appears buggy.)

 People.find(id).populate("friends").exec(function(err, user){
        if(err){
            console.log("! Error retrieving user. " + err);
            reject ("! Error retrieving user. " + err);
        }
        else {
            console.log("0! Friends should be populated: " + user);
            resolve(user);
        }
    });

我的模特:

var mongoose = require('mongoose');

var personSchema = mongoose.Schema({
    name: String,
    friends: [    
        {
            id: {
                type: mongoose.Schema.Types.ObjectId,
                ref: "Person"
            },
            name: String
        }
    ],
    username: String,
    password: String,
    });

module.exports = mongoose.model("Person", personSchema);

推荐答案

您的API函数看起来还不错.

Your API function looks ok.

我怀疑您的问题与模型的设置方式或数据库中的内容有关.第一次尝试使用Heroku时，我遇到了类似的问题，因为Localhost更宽容.

I suspect your issue is with how your models are setup, or what is in your data-base. I had similar issues the first time I tried to use Heroku, because Localhost is more forgiving.

为了使您的API能够正常工作，必须设置以下三项内容:

In order for your API to work, the following 3 things must be setup:

(1) Model file: people.js

必须看起来像这样:

var mongoose = require("mongoose");
var Schema = mongoose.Schema;

var peopleSchema = new Schema({

  name: {
    type: String,
    required: true,
    trim: true
  },

  friends: [{
    type: Schema.Types.ObjectId,
    ref: "Friends"
  }]
});

const People = mongoose.model('Peoples', peopleSchema);

module.exports = People;

然后您必须具有人"引用的朋友"模型.

And then you must have a 'Friends' model, that 'People' is referencing.

(2) Model file: friends.js

看起来必须像这样:

var mongoose = require("mongoose");
var Schema = mongoose.Schema;

// Create the Comment schema
var friendsSchema = new Schema({

  friend_name: {
    type: String,
    required: true,
    trim: true
  },
});

const Friends = mongoose.model('Friends', friendsSchema);

module.exports = Friends;

最后，为了使.Populate工作，数据库中至少需要两个文档.

And lastly, in order for .Populate to work, you need at least two docs in the database.

(3) Database must contain a Person doc and a Friend doc 

看起来必须像这样:

people.js : 
    "_id": {
            "$oid": "5bef3480f202a8000984b3c5"
    }, 
    "name": "Monica Geller"
    "friends": [
        {
            "$oid": "5bef3480f202a8000984b5b4"
        }
    ]

friends.js :
    "_id": {
            "$oid": "5bef3480f202a8000984b5b4"
    },
    "friend_name": "Rachel Green"

希望这会有所帮助，或者使您更接近答案.

Hopefully this helps, or gets you closer to your answer.

这篇关于猫鼬不在生产(Heroku)上填充(.populate())，但在本地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！