$eq for equality in MongoDB - Mini Project: Build & Apply

$eq for equality in MongoDB queries

📖 Scenario: You are managing a small library database. You want to find books by a specific author.

🎯 Goal: Build a MongoDB query using the $eq operator to find all books where the author matches a given name.

📋 What You'll Learn

Create a collection named books with sample book documents

Define a variable authorName with the exact author name to search

Write a MongoDB query using $eq to find books by authorName

Complete the query with a projection to show only the title and author fields

💡 Why This Matters

🌍 Real World

Finding specific records in a database by matching exact values is common in apps like libraries, stores, and user management systems.

💼 Career

Knowing how to use <code>$eq</code> helps you filter data efficiently in MongoDB, a popular NoSQL database used in many companies.

1

Create the books collection with sample data

Create a variable called books that is a list of three documents with these exact entries: { title: "The Hobbit", author: "J.R.R. Tolkien" }, { title: "1984", author: "George Orwell" }, and { title: "Animal Farm", author: "George Orwell" }.

MongoDB

# Create the books collection with three documents
# Your code here

Need a hint?

Use a list of dictionaries to represent the collection.

2

Define the author name to search

Create a variable called authorName and set it to the string "George Orwell".

MongoDB

books = [
  { "title": "The Hobbit", "author": "J.R.R. Tolkien" },
  { "title": "1984", "author": "George Orwell" },
  { "title": "Animal Farm", "author": "George Orwell" }
]
# Define the authorName variable
# Your code here

Need a hint?

Set the variable exactly as shown.

3

Write the MongoDB query using $eq

Create a variable called query and set it to a dictionary that uses $eq to match the author field to the variable authorName. The query should look like { "author": { "$eq": authorName } }.

MongoDB

books = [
  { "title": "The Hobbit", "author": "J.R.R. Tolkien" },
  { "title": "1984", "author": "George Orwell" },
  { "title": "Animal Farm", "author": "George Orwell" }
]
authorName = "George Orwell"
# Create the query using $eq
# Your code here

Need a hint?

Use the $eq operator inside the query dictionary.

4

Add the projection to show only title and author

Create a variable called projection and set it to a dictionary that includes "title": 1 and "author": 1 to show only these fields in the query result.

MongoDB

books = [
  { "title": "The Hobbit", "author": "J.R.R. Tolkien" },
  { "title": "1984", "author": "George Orwell" },
  { "title": "Animal Farm", "author": "George Orwell" }
]
authorName = "George Orwell"
query = { "author": { "$eq": authorName } }
# Add the projection to show only title and author
# Your code here

Need a hint?

Use 1 to include fields in the projection.