Exporting a mongoose database module

Question

I need to export my mongoose database module, so I could use my defined models from every module in my program.

For example, my database.js module looks something like that:

var mongoose = require('mongoose'),
    db = mongoose.createConnection('mongodb://localhost/newdb'),
    Schema = mongoose.Schema;

db.on('error', console.error.bind(console, 'connection error:'));
db.once('open', function callback () {
    console.log("Connected to database newdb");

    var dynamicUserItemSchema = new mongoose.Schema({
      userID: Number,
      rank:  Number,
    });

    var staticUserItemSchema = new mongoose.Schema({
        _id: Schema.Types.Mixed,
        type: Schema.Types.Mixed,
    });

    var DynamicUserItem = db.model('DynamicUserItem', dynamicUserItemSchema);
    var StaticUserItem = db.model('StaticUserItem', staticUserItemSchema);

});

I want to be able adding var db = require('../my_modules/database'); to any other module my program - so I will be able to use the models like that:

db.DynamicUserItem.find(); or item = new db.DynamicUserItem({});

Is it possible doing that using "exports" or "module exports" ? Thanks.

zemirco · Accepted Answer · 2012-12-02 11:47:14Z

33

I usually don't use the error and open events and follow the example from mongoosejs to create a connection to my db. Using the example you could do the following.

db.js

var mongoose = require('mongoose');
var db = mongoose.createConnection('localhost', 'test');

var schema = mongoose.Schema({ name: 'string' });
var Cat = db.model('Cat', schema);

module.exports = Cat; // this is what you want

and then in your app.js you can do something like

var Cat = require('db');

var peter = new Cat();

Hope that helps!

answered Dec 2, 2012 at 11:47

zemirco

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2 Comments

Daniel Over a year ago

Thanks zeMirco. so that says that every model is in a diffrent file ?

zemirco Over a year ago

that depends on you. You can export multiple models from one file (for example exports.Cat = Cat and exports.Dog = Dog) or stick with one model per file. For the later I would use a global config file for the database connection params.

chovy · Accepted Answer · 2012-12-02 17:51:42Z

7

You can use exports to define a module that can be required elsewhere:

./models/list.js

var ListSchema = new Schema({
    name                : { type: String, required: true, trim: true }
    , description   : { type: String, trim: true }
});

module.exports = db.model('List', ListSchema);

./routes/list.js

var list = module.exports = {};

var List = require('../models/list');

list.get = function(req, res){
        List.find({ user: user._id }).exec(function(err, lists){
            res.render('lists', {
                lists: lists,
            });
        });
    });
};

./app.js

app.get('lists', routes.lists.get);

answered Dec 2, 2012 at 17:51

chovy

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1 Comment

Aviram Netanel Over a year ago

db - where is it defined? is it global?

staackuser2 · Accepted Answer · 2012-12-02 11:15:57Z

2

If you are using express, then I would put the models in the app.settings. You can do something like this at config time:

app.configure(function() {
  app.set('db', {
      'main'     : db
    , 'users'    : db.model('User')
  })
})

You would then be able to use the models like req.app.settings.db.users, or you can create a way to get the db var in the file you want in other ways.

This answer is not a complete example, but take a look at my starter project that sets up express and mongoose in a relative easy to use way: https://github.com/mathrawka/node-express-starter

answered Dec 2, 2012 at 11:15

staackuser2

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2 Comments

Peter Lyons Over a year ago

I think this does not add any value over the standard node/commonjs module system and couples your code to express's configuration system for no reason. Just KISS with commonjs modules.

staackuser2 Over a year ago

Yes, it couples it with express and makes it easier to access common things like mongoose models. For production applications, sometimes the simple methods are not resilient enough.

aesede · Accepted Answer · 2016-06-01 20:48:59Z

2

As an adding to accepted answer, if you want to export multiple modules you can do:

In db.js:

var my_schemas = {'Cat' : Cat, 'Dog': Dog};
module.exports = my_schemas;

Then in the app.js:

var schemas = require('db');
var Cat = schemas.Cat;
var Dog = schemas.Dog;
Cat.find({}).exec({...});

answered Jun 1, 2016 at 20:48

aesede

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Comments

Ujjawal Kumar · Accepted Answer · 2023-05-04 17:50:36Z

0

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

const PersonSchema = new Schema({
  name: {
    type: String,
    required: true,
  },
  email: {
    type: String,
    required: true,
  },
  passowrd: {
    type: String,
    required: true,
  },
  username: {
    type: String,
  },
  profilepic: {
    type: String,
    default:
      "https://media.istockphoto.com/id/1131164548/vector/avatar-5.jpg?s=612x612&w=0&k=20&c=CK49ShLJwDxE4kiroCR42kimTuuhvuo2FH5y_6aSgEo=",
  },
  date: {
    type: Date,
    default: Date.now,
  },
});

// exporting our person schema
module.exports = Person = mongoose.model("myPerson", PersonSchema);

answered May 4, 2023 at 17:50

Ujjawal Kumar

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