Regex queries in MongoDB - Mini Project: Build & Apply

Regex Queries in MongoDB

📖 Scenario: You work at a small bookstore that stores book information in a MongoDB database. You want to find books by searching for patterns in their titles using regular expressions.

🎯 Goal: Build a MongoDB query that uses regex to find books with titles matching specific patterns.

📋 What You'll Learn

Create a collection called books with sample book documents

Add a regex pattern variable to search titles

Write a MongoDB query using $regex to find matching books

Complete the query with options to make the search case-insensitive

💡 Why This Matters

🌍 Real World

Bookstores and libraries often need to search for books by partial title matches or patterns. Regex queries in MongoDB help find these books efficiently.

💼 Career

Knowing how to use regex queries in MongoDB is useful for database developers and data analysts who work with flexible text search requirements.

1

Create the books collection with sample data

Create a MongoDB collection called books and insert these exact documents: { title: "The Great Gatsby", author: "F. Scott Fitzgerald" }, { title: "Great Expectations", author: "Charles Dickens" }, and { title: "Gone with the Wind", author: "Margaret Mitchell" }.

MongoDB

// Insert the specified book documents into the books collection

Need a hint?

Use insertMany on db.books with an array of the three book objects.

2

Add a regex pattern variable for searching titles

Create a variable called pattern and set it to the regex string "Great" to search for titles containing the word "Great".

MongoDB

db.books.insertMany([
  { title: "The Great Gatsby", author: "F. Scott Fitzgerald" },
  { title: "Great Expectations", author: "Charles Dickens" },
  { title: "Gone with the Wind", author: "Margaret Mitchell" }
])

// Create the regex pattern variable

Need a hint?

Use const pattern = "Great" to define the regex string.

3

Write a MongoDB query using $regex to find matching books

Write a MongoDB query that finds all documents in books where the title field matches the regex pattern stored in pattern. Use $regex with the variable pattern.

MongoDB

db.books.insertMany([
  { title: "The Great Gatsby", author: "F. Scott Fitzgerald" },
  { title: "Great Expectations", author: "Charles Dickens" },
  { title: "Gone with the Wind", author: "Margaret Mitchell" }
])

const pattern = "Great"

// Write the query to find books with titles matching the regex pattern

Need a hint?

Use db.books.find({ title: { $regex: pattern } }) to query with regex.

4

Complete the query with case-insensitive option

Modify the query to add the $options field with value "i" to make the regex search case-insensitive.

MongoDB

db.books.insertMany([
  { title: "The Great Gatsby", author: "F. Scott Fitzgerald" },
  { title: "Great Expectations", author: "Charles Dickens" },
  { title: "Gone with the Wind", author: "Margaret Mitchell" }
])

const pattern = "Great"

db.books.find({ title: { $regex: pattern } })

// Add the $options: "i" to make the search case-insensitive

Need a hint?

Add $options: "i" inside the title query object to ignore case.