$lt and $lte for less than in MongoDB - Mini Project: Build & Apply

$lt and $lte for less than in MongoDB

📖 Scenario: You are managing a small online bookstore database. You want to find books priced below certain amounts to offer discounts or promotions.

🎯 Goal: Build MongoDB queries using $lt and $lte operators to find books with prices less than or less than or equal to given values.

📋 What You'll Learn

Create a collection called books with sample book documents including title and price fields

Define a variable maxPrice to set the price limit

Write a query using $lt to find books priced less than maxPrice

Write a query using $lte to find books priced less than or equal to maxPrice

💡 Why This Matters

🌍 Real World

Filtering products or items in a database by price or other numeric values is common in e-commerce and inventory management.

💼 Career

Understanding MongoDB query operators like $lt and $lte is essential for backend developers and data analysts working with NoSQL databases.

1

Create the books collection with sample data

Create a MongoDB collection called books and insert these exact documents: { title: "Book A", price: 15 }, { title: "Book B", price: 20 }, { title: "Book C", price: 25 }

MongoDB

// Insert the sample book documents into the books collection
// Your code here

Need a hint?

Use db.books.insertMany() with an array of book objects.

2

Define the price limit variable

Create a variable called maxPrice and set it to 20 to use as the price limit for queries.

MongoDB

db.books.insertMany([
  { title: "Book A", price: 15 },
  { title: "Book B", price: 20 },
  { title: "Book C", price: 25 }
])

// Define maxPrice variable
// Your code here

Need a hint?

Use const maxPrice = 20 to create the variable.

3

Write a query using $lt to find books priced less than maxPrice

Write a MongoDB query using db.books.find() with the condition { price: { $lt: maxPrice } } to find books priced less than maxPrice.

MongoDB

db.books.insertMany([
  { title: "Book A", price: 15 },
  { title: "Book B", price: 20 },
  { title: "Book C", price: 25 }
])

const maxPrice = 20;

// Write the query to find books with price less than maxPrice
// Your code here

Need a hint?

Use { price: { $lt: maxPrice } } inside find().

4

Write a query using $lte to find books priced less than or equal to maxPrice

Write a MongoDB query using db.books.find() with the condition { price: { $lte: maxPrice } } to find books priced less than or equal to maxPrice.

MongoDB

db.books.insertMany([
  { title: "Book A", price: 15 },
  { title: "Book B", price: 20 },
  { title: "Book C", price: 25 }
])

const maxPrice = 20;

db.books.find({ price: { $lt: maxPrice } })

// Write the query to find books with price less than or equal to maxPrice
// Your code here

Need a hint?

Use { price: { $lte: maxPrice } } inside find().