Objective
To retrieve products based on category id from the 'products' collection in MongoDB using mongoose.find method.
Expected Outcome vs. Actual Outcome
The expected result is to receive all documents matching the specified category within the given limit, but instead, an empty array is returned. I tested querying with MongoDB's Compass and found it to work as intended. However, when attempting to find documents by id (successful), title (successful), and price (unsuccessful) in my code, I couldn't identify the root cause of the problem.
Code Implementation
Defining product schema and model:
const mongoose = require('mongoose');
const productSchema = new mongoose.Schema({
title: {
type: String,
required: true,
},
thumbnail: {
type: String,
required: true,
},
price: {
type: Number,
required: true,
},
category: {
type: mongoose.Types.ObjectId,
required: true,
},
rating: {
type: Number,
default: 0,
},
voters: {
type: Number,
default: 0,
},
});
.
.
.
const Product = mongoose.model('product', productSchema);
module.exports = { Product, ... };
Resolver logic:
products: (_, { limit, category }) => {
console.log(mongoose.Types.ObjectId('5ec120a9fc13ae248f000004')); // Successfully logs
Product.find({ category: mongoose.Types.ObjectId(category) }) // Tried with simple string, but didn't work
.limit(limit)
.exec((err, products) => {
if (err) console.log(err);
console.log(products);
});
if (category) return Product.find({ category }).limit(limit);
return Product.find({}).limit(limit);
},
Console output:
5ec120a9fc13ae248f000004
[]
Example data in 'products' collection:
{
"_id": {
"$oid": "5ec129e55db26438fcdb9b01"
},
"title": "Ecolab - Lime - A - Way 4/4 L",
"category": "5ec120a9fc13ae248f000004",
"thumbnail": "https://source.unsplash.com/350x390/?Automotive",
"price": "236.13",
"rating": 878210,
"voters": 2668388
},
{
"_id": {
"$oid": "5ec129e55db26438fcdb9b02"
},
"title": "Mushrooms - Black, Dried",
"category": "5ec120a9fc13ae248f000001",
"thumbnail": "https://source.unsplash.com/350x390/?Sports",
"price": "439.85",
"rating": 549879,
"voters": 2375685
},
{
"_id": {
"$oid": "5ec129e55db26438fcdb9b03"
},
"title": "Dried Figs",
"category": "5ec120a9fc13ae248f000004",
"thumbnail": "https://source.unsplash.com/350x390/?Automotive",
"price": "202.60",
"rating": 925701,
"voters": 2740499
}