MongoDB reference using Mongoose - node.js

Question

I'm trying to reference one model to other with Mongoose doing this:
//product model
var productSchema = new mongoose.Schema({
id: {type: Number, unique: true, required: 'product_id'},
sku: {type: String, unique: true, required: 'product_sku'},
name: {type: String, required: 'product_name'},
short_description: {type: String},
details: [{
type: String
}],
categories: [{
type: String
}, {min: 1, max: 5}],
});
module.exports = mongoose.model('products', productSchema);
//order model
var orderSchema = new mongoose.Schema({
id: {type: String, unique: true},
date: {type: Date, default: Date.now},
products_sold: {type: mongoose.Schema.Types.ObjectId, ref: 'products'},
});
module.exports = mongoose.model('orders', orderSchema);
I've already created a product with id: 1:
"_id": ObjectId('55a1ce54b058d142051ca61d'),
"id": 1,
"sku": "p0001",
"name": "test1",
"short_description": "test",
//etc
If I do:
var newOrder = new Order({
id: 'order001',
products_sold: 1,
//etc
});
newOrder.save(function(err, data) {
if(err){
console.log(err);
}else{
console.log(data);
}
});
It fails with error:
message: 'orders validation failed',
name: 'ValidationError',
errors:
{ products_sold:
{ [CastError: Cast to ObjectID failed for value "1" at path "products_sold"]
How can I have products_sold in my order filled with product data that has id 1?
Thanks in advance

Answer 1

You are specifying that the products_sold field is of type ObjectId, but you are trying to set a Number as its value. In order to store references to documents in other collections, you must store the _id of the referenced document, not an arbitrary id field that you have in the Schema. You will either need to change the type for _id in your products database to use integers (and then manually specify what that _id field's value is when creating a new product), or you need to store the product's _id value in the order document's product_sold field.
Response to comment:
Here is updated code for specifying your own unique _id field:
Product Model
var productSchema = new mongoose.Schema({
_id: {type: Number, unique: true, required: 'product_id'},
sku: {type: String, unique: true, required: 'product_sku'},
name: {type: String, required: 'product_name'},
short_description: {type: String},
details: [String],
categories: [{
type: String
min: 1,
max: 5
}],
}, {_id: false});
module.exports = mongoose.model('products', productSchema);
In the productSchema, you will see that there is an _id specified, and it is set to required, and has no default value. This should make it so that Mongo will use whatever Number you specify as it's _id.

Answer 2

You need to pass objectId of the product in product_sold , rather than number.