Mongoose and ExpressJS - modular architecture? - mongodb

Question

I want to have each file for each model - i.e. user and country.
Currently, I solved this the following way:
person.js
/*jslint node: true */
'use strict';
var mongoose = require('./mongoose'),
Schema = mongoose.Schema;
var userSchema = new Schema({
name: String,
username: {
type: String,
required: true,
unique: true
},
password: {
type: String,
required: true
},
admin: Boolean,
location: String,
meta: {
age: Number,
website: String
},
created_at: Date,
updated_at: Date,
country: {
type: Schema.Types.ObjectId,
ref: 'Country'
}
});
userSchema.methods.toString = function() {
return `I am ${this.username} and I'm from ${this.country.name}`;
}
module.exports = mongoose.model('Person', userSchema);
country.js
/*jslint node: true */
'use strict';
var mongoose = require('./mongoose'),
Schema = mongoose.Schema;
var countrySchema = new Schema({
name: {
type: String,
required: true,
unique: true
},
created_at: Date,
updated_at: Date,
people: [{
type: Schema.Types.ObjectId,
ref: 'Person'
}]
});
var Country = mongoose.model('Country', countrySchema);
module.exports = Country;
So my question is as follows: how does the mongoose reference two tables? For example, in Person schema, I reference the country by providing ref: 'Country', but I never included the model in the Person.js file. Am I doing something wrong here?
UPDATE:
Taking the below answer into the consideration, I now have 3 files:
database.js
var mongoose = require('mongoose');
mongoose.connect('mongodb://localhost/people');
mongoose.set('debug', true);
module.exports = mongoose;
person.js
/*jslint node: true */
'use strict';
var mongoose = require('./database'),
Schema = mongoose.Schema;
var userSchema = new Schema({
name: String,
username: {
type: String,
required: true,
unique: true
},
password: {
type: String,
required: true
},
admin: Boolean,
location: String,
meta: {
age: Number,
website: String
},
created_at: Date,
updated_at: Date,
country: {
type: Schema.Types.ObjectId,
ref: 'Country'
}
});
userSchema.methods.toString = function() {
return `I am ${this.username} and I'm from ${this.country.name}`;
}
mongoose.model('Person', userSchema);
country.js
/*jslint node: true */
'use strict';
var mongoose = require('./mongoose'),
Schema = mongoose.Schema;
var countrySchema = new Schema({
name: {
type: String,
required: true,
unique: true
},
created_at: Date,
updated_at: Date,
people: [{
type: Schema.Types.ObjectId,
ref: 'Person'
}]
});
mongoose.model('Country', countrySchema);
Now when I include all these 3 files into a test file, e.g.:
var mongoose = require('./database'),
User = mongoose.model('Person'),
Country = mongoose.model('Country');
I get the following error: MissingSchemaError: Schema hasn't been registered for model "Person". I get the same error for Country if I delete the User variable. It appears as if mongoose is trying to define the model, not retrieve it. What seems to be the problem?
UPDATE 2:
OK, when I include now these documents, I do the following:
require('./person');
require('./country');
var User = require('mongoose').model('Person'),
Country = require('mongoose').model('Country');