Boolean and null types in MongoDB - Mini Project: Build & Apply

Working with Boolean and Null Types in MongoDB

📖 Scenario: You are managing a small online store database. You want to keep track of whether products are in stock and if they have any special discount offers. Some products might not have discount information yet.

🎯 Goal: Create a MongoDB collection with product documents that use Boolean and null types correctly. Then, write queries to find products based on these Boolean and null values.

📋 What You'll Learn

Create a collection named products with documents containing name, inStock (Boolean), and discount (Boolean or null).

Insert exactly three products with specified values for inStock and discount.

Write a query to find all products that are in stock (inStock is true).

Write a query to find all products where discount is null (no discount information).

💡 Why This Matters

🌍 Real World

Online stores often track product availability and discount status using Boolean and null values in their databases.

💼 Career

Understanding how to use Boolean and null types in MongoDB is essential for database roles that manage product inventories and sales data.

1

Create the products collection with three product documents

Create a MongoDB collection called products and insert these three documents exactly: { name: "Laptop", inStock: true, discount: false }, { name: "Headphones", inStock: false, discount: null }, { name: "Mouse", inStock: true, discount: true }.

MongoDB

// Insert the three product documents into the products collection
// Your code here

Need a hint?

Use db.products.insertMany() with an array of objects for the three products.

2

Create a query variable to find products that are in stock

Create a variable called inStockQuery that holds a MongoDB query object to find products where inStock is true.

MongoDB

db.products.insertMany([
  { name: "Laptop", inStock: true, discount: false },
  { name: "Headphones", inStock: false, discount: null },
  { name: "Mouse", inStock: true, discount: true }
])

// Create the inStockQuery variable to find products with inStock true
// Your code here

Need a hint?

Set inStockQuery to an object with inStock: true.

3

Create a query variable to find products with null discount

Create a variable called nullDiscountQuery that holds a MongoDB query object to find products where discount is null.

MongoDB

db.products.insertMany([
  { name: "Laptop", inStock: true, discount: false },
  { name: "Headphones", inStock: false, discount: null },
  { name: "Mouse", inStock: true, discount: true }
])

const inStockQuery = { inStock: true }

// Create the nullDiscountQuery variable to find products with discount null
// Your code here

Need a hint?

Set nullDiscountQuery to an object with discount: null.

4

Write queries to find products using the query variables

Write two queries using db.products.find() with the variables inStockQuery and nullDiscountQuery to find products in stock and products with null discount, respectively. Assign the results to inStockProducts and nullDiscountProducts.

MongoDB

db.products.insertMany([
  { name: "Laptop", inStock: true, discount: false },
  { name: "Headphones", inStock: false, discount: null },
  { name: "Mouse", inStock: true, discount: true }
])

const inStockQuery = { inStock: true }

const nullDiscountQuery = { discount: null }

// Use db.products.find() with inStockQuery and nullDiscountQuery
// Assign results to inStockProducts and nullDiscountProducts
// Your code here

Need a hint?

Use db.products.find() with the query variables and assign to the specified variables.