createIndex method in MongoDB - Mini Project: Build & Apply

Creating Indexes in MongoDB with createIndex Method

📖 Scenario: You are managing a small online bookstore database. To make searching for books faster, you want to create an index on the title field of the books collection.

🎯 Goal: Learn how to create an index on the title field in the books collection using the createIndex method in MongoDB.

📋 What You'll Learn

Create a books collection with sample book documents.

Define an index key for the title field.

Use the createIndex method to create the index on the title field.

Add an option to make the index unique.

💡 Why This Matters

🌍 Real World

Indexes speed up searches in large databases, making websites and apps faster and more responsive.

💼 Career

Database administrators and backend developers often create indexes to optimize query performance and ensure data integrity.

1

Create the books collection with sample documents

Create a books collection and insert these exact documents: { title: "The Hobbit", author: "J.R.R. Tolkien", year: 1937 }, { title: "1984", author: "George Orwell", year: 1949 }, and { title: "To Kill a Mockingbird", author: "Harper Lee", year: 1960 }.

MongoDB

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

Need a hint?

Use db.books.insertMany([...]) to add multiple documents at once.

2

Define the index key for the title field

Create a variable called indexKey and set it to an object with the title field set to 1 to indicate ascending order indexing.

MongoDB

db.books.insertMany([
  { title: "The Hobbit", author: "J.R.R. Tolkien", year: 1937 },
  { title: "1984", author: "George Orwell", year: 1949 },
  { title: "To Kill a Mockingbird", author: "Harper Lee", year: 1960 }
])

// Create the indexKey variable for the title field
// Your code here

Need a hint?

Use { title: 1 } to create an ascending index on the title field.

3

Use createIndex to create the index on the title field

Call db.books.createIndex with the indexKey variable to create the index on the title field.

MongoDB

db.books.insertMany([
  { title: "The Hobbit", author: "J.R.R. Tolkien", year: 1937 },
  { title: "1984", author: "George Orwell", year: 1949 },
  { title: "To Kill a Mockingbird", author: "Harper Lee", year: 1960 }
])

const indexKey = { title: 1 }

// Create the index on the title field using createIndex
// Your code here

Need a hint?

Use db.books.createIndex(indexKey) to create the index.

4

Add the unique option to the index

Modify the createIndex call to include an options object with unique: true to ensure no two books have the same title.

MongoDB

db.books.insertMany([
  { title: "The Hobbit", author: "J.R.R. Tolkien", year: 1937 },
  { title: "1984", author: "George Orwell", year: 1949 },
  { title: "To Kill a Mockingbird", author: "Harper Lee", year: 1960 }
])

const indexKey = { title: 1 }

// Add the unique option to the createIndex call
// Your code here

Need a hint?

Pass { unique: true } as the second argument to createIndex.