MongoDB Shell (mongosh) basics - Mini Project: Build & Apply

MongoDB Shell (mongosh) Basics

📖 Scenario: You are working as a data assistant for a small bookstore. You need to organize the book information in a MongoDB database so the store can easily find and update book details.

🎯 Goal: Build a simple MongoDB collection called books using the mongosh shell. You will insert book data, set up a query filter, find books by a condition, and finally update a book's information.

📋 What You'll Learn

Create a books collection with three book documents

Add a variable to filter books by a minimum number of pages

Use a find() query with the filter to get books with pages greater than or equal to the threshold

Update the price of a specific book using updateOne()

💡 Why This Matters

🌍 Real World

Bookstores and libraries use MongoDB to store and manage book information for easy searching and updating.

💼 Career

Knowing how to use the MongoDB shell to insert, query, and update data is essential for database administrators and backend developers working with NoSQL databases.

1

Create the books collection with initial data

In the mongosh shell, insert three book documents into the books collection with these exact fields and values: { title: 'The Hobbit', author: 'J.R.R. Tolkien', pages: 310, price: 15 }, { title: '1984', author: 'George Orwell', pages: 328, price: 12 }, and { title: 'To Kill a Mockingbird', author: 'Harper Lee', pages: 281, price: 10 }. Use the insertMany() method on db.books.

MongoDB

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

Need a hint?

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

2

Set a page count filter variable

Create a variable called minPages and set it to 300. This will be used to filter books with pages greater than or equal to this number.

MongoDB

db.books.insertMany([
  { title: 'The Hobbit', author: 'J.R.R. Tolkien', pages: 310, price: 15 },
  { title: '1984', author: 'George Orwell', pages: 328, price: 12 },
  { title: 'To Kill a Mockingbird', author: 'Harper Lee', pages: 281, price: 10 }
])

// Create minPages variable with value 300
// Your code here

Need a hint?

Use const minPages = 300 to create the variable.

3

Find books with pages >= minPages

Use db.books.find() with a filter object that selects books where the pages field is greater than or equal to minPages. Assign the result to a variable called booksWithMinPages.

MongoDB

db.books.insertMany([
  { title: 'The Hobbit', author: 'J.R.R. Tolkien', pages: 310, price: 15 },
  { title: '1984', author: 'George Orwell', pages: 328, price: 12 },
  { title: 'To Kill a Mockingbird', author: 'Harper Lee', pages: 281, price: 10 }
])

const minPages = 300

// Find books with pages >= minPages and assign to booksWithMinPages
// Your code here

Need a hint?

Use { pages: { $gte: minPages } } as the filter in find().

4

Update the price of '1984' to 14

Use db.books.updateOne() to find the book with title equal to '1984' and update its price field to 14. Use the $set operator.

MongoDB

db.books.insertMany([
  { title: 'The Hobbit', author: 'J.R.R. Tolkien', pages: 310, price: 15 },
  { title: '1984', author: 'George Orwell', pages: 328, price: 12 },
  { title: 'To Kill a Mockingbird', author: 'Harper Lee', pages: 281, price: 10 }
])

const minPages = 300

const booksWithMinPages = db.books.find({ pages: { $gte: minPages } })

// Update the price of the book titled '1984' to 14
// Your code here

Need a hint?

Use updateOne() with a filter and $set to change the price.