How to paginate with Mongoose in Node.js?

📝 Blog Post: How to Paginate with Mongoose in Node.js

Are you building a web app with Node.js and using Mongoose as your MongoDB object modeling tool? Do you need to paginate the results of your .find() call and get a functionality similar to LIMIT in SQL? You're at the right place! In this blog post, we will explore how to paginate with Mongoose in Node.js and provide you with easy solutions to solve this problem.

🔑 Understanding Pagination

Pagination is the technique used to break down a large result set into manageable chunks or pages. It enables you to display a limited number of results at a time, improving performance and user experience. Rather than loading all the data at once, you can load it in smaller portions, making your web app faster and more scalable.

🔬 The Problem: Paginating Results with Mongoose

Let's dive into the specific issue you're facing. Given that you want to paginate the results from a .find() call in Mongoose, you need a way to limit the number of results returned and specify which page of results you want.

🛠️ The Solution: Using .skip() and .limit()

Luckily, Mongoose provides a couple of methods - .skip() and .limit() - that you can leverage to achieve pagination:

const pageNumber = 1; // The page number you want to retrieve
const perPage = 50; // The number of results per page

const results = await Model.find()
  .skip((pageNumber - 1) * perPage)
  .limit(perPage);

In the example above, we calculate the number of documents to skip based on the desired page number and the results per page. By multiplying (pageNumber - 1) with perPage, we determine the number of documents to skip before fetching the desired page.

🚀 Implementing Pagination in Your Application

Now that you understand how to use .skip() and .limit() to paginate your results, you can integrate this technique into your Node.js application.

app.get('/api/my-data', async (req, res) => {
  const pageNumber = parseInt(req.query.pageNumber) || 1;
  const perPage = 10;
  
  const results = await Model.find()
    .skip((pageNumber - 1) * perPage)
    .limit(perPage);

  res.json(results);
});

In the code above, we create an API route (/api/my-data) that accepts a pageNumber query parameter. We retrieve this parameter using req.query.pageNumber and parse it into an integer. If no pageNumber is provided, we default it to 1. Then, we use .skip() and .limit() to fetch the relevant results based on the page number.

💡 Bonus Tips

• You can easily compute the total number of pages by dividing the total number of documents by the number of results per page. You can then use this information to create pagination links.

• Remember to handle error cases, such as invalid page numbers or exceeding the maximum number of pages.

• Consider adding sorting criteria to your .find() call to ensure consistent ordering across multiple requests.

📣 Join the Conversation

Now that you know how to paginate with Mongoose in Node.js, why not implement it in your own project? Share your experience or any additional tips you have on our social media channels using the hashtag #MongoosePagination.

If you have any questions or need further assistance, leave a comment below, and we'd be happy to help you out!

Happy paginating! 🎉