How do we create a reference to a collection with mongoose - node.js

Question

Please forgive me if this question seems related to the one I already asked before, I feel I didn't really put the question well the first time.
I have created a resource route based on the following data seeded into Mongodb from my application
// seeder.js
"_id": "5d7a514b5d2c12c7449be020",
"issuedBy": "Ola",
"collectedBy": "Ola",
"quantity": "8",
"product": "5d713995b721c3bb38c1f5d0",
My question is this; How do i actually save the product objectId "5d713995b721c3bb38c1f5d0" on the Orders collection
exports.getOrders = asyncHandler(async (req, res, next) => {
if (req.params.productId) {
const orders = await Orders.find({ product: req.params.productId });
return res.status(200).json({
success: true,
count: orders.length,
data: orders
});
} else {
res.json(orders);
}
});
With the above route, I am setting a condition that's based on the presence of a ProductId in the URL that will be matched inside the Orders collection "Orders.find({ product: req.params.productId })"
//Product Schema
const ProductSchema = new mongoose.Schema({
name : String,
description : String,
price : Number,
quantity : Number,
supplier :String
},{timestamps:true});
module.exports = mongoose.model('Product', ProductSchema)
// Orders Schema
const OrderSchema = new mongoose.Schema({
issuedBy : String,
collectedBy: String,
quantity: Number,
product: {
type: mongoose.Schema.ObjectId,
ref: 'Product',
required: true
},
},{timestamps:true});
const Orders = mongoose.model("Orders", OrderSchema);
// Export model
module.exports = Orders;
How do I actually create a route that saves the productId in the Orders collection like these "product": "5d713995b721c3bb38c1f5d0"?

Answer 1

I think an order can have multiple products. So I changed the name of product to producs, and made it array.
Also, for model names it is better to use singular naming convention.
I would set up my schemas and models like this:
Product model:
const mongoose = require("mongoose");
const ProductSchema = new mongoose.Schema(
{
name: String,
description: String,
price: Number,
quantity: Number,
supplier: String
},
{ timestamps: true }
);
module.exports = mongoose.model("Product", ProductSchema);
Order model:
const mongoose = require("mongoose");
const OrderSchema = new mongoose.Schema(
{
issuedBy: String,
collectedBy: String,
quantity: Number,
products: [
{
type: mongoose.Schema.Types.ObjectId,
ref: "Product",
required: true
}
]
},
{ timestamps: true }
);
module.exports = mongoose.model("Order", OrderSchema);
You can create an order with products with this code:
const express = require("express");
const app = express();
const mongoose = require("mongoose");
const url = "mongodb://localhost:27017/ord";
const Order = require("./models/order");
const Product = require("./models/product");
const port = 3000;
app.use(express.json());
mongoose
.connect(url, {
useNewUrlParser: true,
useUnifiedTopology: true
})
.then(() => {
app.listen(port, () => {
console.log(`App running on port ${port}...`);
});
})
.catch(error => console.log(error));
app.post("/order", async (req, res) => {
let result = await Order.create(req.body);
res.send(result);
});
app.get("/order/:orderId", async (req, res) => {
const result = await Order.findById(req.params.orderId).populate("products");
res.send(result);
});
You can create an order with products to the http://localhost:3000/order with this body: (you must use your existing product ids)
{
"issuedBy": "issuedBy",
"collectedBy": "collectedBy",
"quantity": 123,
"products": ["5ddfb388b14c5b41e0607a5e","5ddfb376b14c5b41e0607a5d"]
}
Response:
{
"products": [
"5ddfb388b14c5b41e0607a5e",
"5ddfb376b14c5b41e0607a5d"
],
"_id": "5ddfb418b14c5b41e0607a5f",
"issuedBy": "issuedBy",
"collectedBy": "collectedBy",
"quantity": 123,
"createdAt": "2019-11-28T11:48:40.500Z",
"updatedAt": "2019-11-28T11:48:40.500Z",
"__v": 0
}
When you want to get this order and its products, you need to send a GET request to the http://localhost:3000/order/5ddfb418b14c5b41e0607a5f the id in the url is the the id of the order we previosly created, so you need to use your order id.
If you want also to be able to add a product to an existing order, you can add this code:
app.post("/order/:orderId/:productId", async (req, res) => {
const result = await Order.findByIdAndUpdate(
req.params.orderId,
{
$push: {
products: req.params.productId
}
},
{ new: true }
);
res.send(result);
});
So the POST url must contain the orderId and productId like this:
http://localhost:3000/order/5ddfb418b14c5b41e0607a5f/5ddfb67c721b885790ec837b
Response:
{
"products": [
"5ddfb388b14c5b41e0607a5e",
"5ddfb376b14c5b41e0607a5d",
"5ddfb67c721b885790ec837b"
],
"_id": "5ddfb418b14c5b41e0607a5f",
"issuedBy": "issuedBy",
"collectedBy": "collectedBy",
"quantity": 123,
"createdAt": "2019-11-28T11:48:40.500Z",
"updatedAt": "2019-11-28T11:59:51.659Z",
"__v": 0
}