Why document design matters in MongoDB - See It in Action

Why Document Design Matters in MongoDB

📖 Scenario: You are working for a small online bookstore. You want to store information about books and their authors in a MongoDB database. Good document design will help you store and retrieve data efficiently.

🎯 Goal: Build a MongoDB collection with well-designed documents that store book titles, authors, and publication years. Learn how to structure documents for easy querying and updating.

📋 What You'll Learn

Create a collection called books with documents containing title, author, and year fields.

Add a configuration variable maxYear to filter books published after this year.

Write a query to find all books published after maxYear.

Add an index on the year field to improve query performance.

💡 Why This Matters

🌍 Real World

Good document design helps online stores and apps store and retrieve data quickly and clearly.

💼 Career

Database developers and data engineers must design documents and indexes to optimize performance and maintainability.

1

Create the books collection with initial documents

Create a MongoDB collection called books and insert these exact documents: { title: "The Great Gatsby", author: "F. Scott Fitzgerald", year: 1925 }, { title: "1984", author: "George Orwell", year: 1949 }, and { title: "To Kill a Mockingbird", author: "Harper Lee", year: 1960 }.

MongoDB

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

Need a hint?

Use insertMany to add multiple documents to the books collection.

2

Add a configuration variable maxYear

Create a variable called maxYear and set it to 1930. This will be used to filter books published after this year.

MongoDB

db.books.insertMany([
  { title: "The Great Gatsby", author: "F. Scott Fitzgerald", year: 1925 },
  { title: "1984", author: "George Orwell", year: 1949 },
  { title: "To Kill a Mockingbird", author: "Harper Lee", year: 1960 }
])

// Create maxYear variable
// Your code here

Need a hint?

Use const maxYear = 1930 to create the variable.

3

Query books published after maxYear

Write a MongoDB query using find on the books collection to get all documents where the year field is greater than maxYear. Store the query in a variable called recentBooks.

MongoDB

db.books.insertMany([
  { title: "The Great Gatsby", author: "F. Scott Fitzgerald", year: 1925 },
  { title: "1984", author: "George Orwell", year: 1949 },
  { title: "To Kill a Mockingbird", author: "Harper Lee", year: 1960 }
])

const maxYear = 1930

// Query books with year > maxYear
// Your code here

Need a hint?

Use db.books.find({ year: { $gt: maxYear } }) to get books published after maxYear.

4

Add an index on the year field

Create an index on the year field of the books collection using createIndex to improve query speed.

MongoDB

db.books.insertMany([
  { title: "The Great Gatsby", author: "F. Scott Fitzgerald", year: 1925 },
  { title: "1984", author: "George Orwell", year: 1949 },
  { title: "To Kill a Mockingbird", author: "Harper Lee", year: 1960 }
])

const maxYear = 1930

const recentBooks = db.books.find({ year: { $gt: maxYear } })

// Create an index on the year field
// Your code here

Need a hint?

Use db.books.createIndex({ year: 1 }) to create an ascending index on the year field.