$limit and $skip stages in MongoDB - Mini Project: Build & Apply

$limit and $skip stages in MongoDB aggregation

📖 Scenario: You are managing a small online bookstore database. You want to show customers a limited number of books per page and skip some books to create pages.

🎯 Goal: Build a MongoDB aggregation pipeline that uses $limit and $skip stages to paginate the list of books.

📋 What You'll Learn

Create a collection called books with 5 specific book documents.

Add a variable pageSize to control how many books show per page.

Add a variable pageNumber to control which page of books to show.

Write an aggregation pipeline using $skip and $limit to get the correct page of books.

💡 Why This Matters

🌍 Real World

Pagination is used in websites and apps to show data in small chunks, making it easier to browse large lists like books, products, or messages.

💼 Career

Knowing how to use <code>$limit</code> and <code>$skip</code> in MongoDB is essential for backend developers and database administrators to efficiently handle large datasets and improve user experience.

1

Create the books collection with 5 book documents

Create a MongoDB collection called books and insert these 5 documents exactly: {"title": "Book A", "author": "Author 1"}, {"title": "Book B", "author": "Author 2"}, {"title": "Book C", "author": "Author 3"}, {"title": "Book D", "author": "Author 4"}, {"title": "Book E", "author": "Author 5"}.

MongoDB

// Insert the 5 book documents into the books collection
// Your code here

Need a hint?

Use db.books.insertMany([...]) with the exact documents listed.

2

Add pageSize and pageNumber variables

Create two variables: pageSize set to 2, and pageNumber set to 2. These will control how many books to show per page and which page to show.

MongoDB

db.books.insertMany([
  {"title": "Book A", "author": "Author 1"},
  {"title": "Book B", "author": "Author 2"},
  {"title": "Book C", "author": "Author 3"},
  {"title": "Book D", "author": "Author 4"},
  {"title": "Book E", "author": "Author 5"}
])

// Create pageSize and pageNumber variables
// Your code here

Need a hint?

Use const pageSize = 2; and const pageNumber = 2; to create the variables.

3

Write the aggregation pipeline with $skip and $limit

Write a MongoDB aggregation pipeline on books that uses $skip with the value pageSize * (pageNumber - 1) and $limit with the value pageSize.

MongoDB

db.books.insertMany([
  {"title": "Book A", "author": "Author 1"},
  {"title": "Book B", "author": "Author 2"},
  {"title": "Book C", "author": "Author 3"},
  {"title": "Book D", "author": "Author 4"},
  {"title": "Book E", "author": "Author 5"}
])

const pageSize = 2;
const pageNumber = 2;

// Write the aggregation pipeline using $skip and $limit
// Your code here

Need a hint?

Use { $skip: pageSize * (pageNumber - 1) } and { $limit: pageSize } inside an array called pipeline.

4

Run the aggregation pipeline to get the paged books

Run the aggregation pipeline on the books collection using db.books.aggregate(pipeline) and assign the result to a variable called pagedBooks.

MongoDB

db.books.insertMany([
  {"title": "Book A", "author": "Author 1"},
  {"title": "Book B", "author": "Author 2"},
  {"title": "Book C", "author": "Author 3"},
  {"title": "Book D", "author": "Author 4"},
  {"title": "Book E", "author": "Author 5"}
])

const pageSize = 2;
const pageNumber = 2;

const pipeline = [
  { $skip: pageSize * (pageNumber - 1) },
  { $limit: pageSize }
];

// Run the aggregation pipeline and assign to pagedBooks
// Your code here

Need a hint?

Use const pagedBooks = db.books.aggregate(pipeline); to run the pipeline and save the result.