Node.js MongoDB Limit

In MongoDB, the limit() method is used to limit the number of documents returned in a query result. When using Node.js with MongoDB, you can use the limit() method to limit the number of documents returned by a query. In this tutorial, we'll discuss how to use the limit() method with Node.js and MongoDB.

Syntax

The syntax for using the limit() method in Node.js is as follows:

db.collection('collectionName').find().limit(5);

In the example above, we're limiting the number of documents returned to 5.

Example

Let's say we have a "users" collection in our MongoDB database, and we want to retrieve only the first 5 users. Here's how we can implement it using Node.js and the MongoDB driver:

const MongoClient = require('mongodb').MongoClient;

// Connection URL
const url = 'mongodb://localhost:27017';

// Database Name
const dbName = 'myproject';

// Create a new MongoClient
const client = new MongoClient(url);

// Use connect method to connect to the Server
client.connect(function(err) {
  console.log("Connected successfully to server");

  const db = client.db(dbName);
  const collection = db.collection('users');

  // Find some documents
  collection.find().limit(5).toArray(function(err, docs) {
    console.log("Found the following records:");
    console.log(docs);
  });

  client.close();
});

In the example above, we defined a MongoDB connection URL, the database name, and a MongoClient object. Then, we used the connect() method to connect to the MongoDB server. Once connected, we retrieved the "users" collection and limited the number of documents returned to 5 using the limit() method. Finally, we printed the documents to the console.

Output

When we run the example code above, the output will be similar to the following:

Connected successfully to server
Found the following records:
[
  {
    _id: 5fdd9ee1406dc71f1c208ba0,
    name: 'John Smith',
    email: 'john@example.com'
  },
  {
    _id: 5fdd9ee1406dc71f1c208ba1,
    name: 'Jane Doe',
    email: 'jane@example.com'
  },
  {
    _id: 5fdd9ee1406dc71f1c208ba2,
    name: 'Bob Johnson',
    email: 'bob@example.com'
  },
  {
    _id: 5fdd9ee1406dc71f1c208ba3,
    name: 'Alice Brown',
    email: 'alice@example.com'
  },
  {
    _id: 5fdd9ee1406dc71f1c208ba4,
    name: 'Mike Davis',
    email: 'mike@example.com'
  }
]

This is because we connected to the MongoDB server, retrieved the "users" collection, and limited the number of documents returned to 5 using the limit() method.

Explanation

In the example above, we established a MongoDB database connection, retrieved a collection, and used the limit() method to limit the number of documents returned by the query to 5. We then printed the documents to the console using the toArray() method.

Use

The limit() method is useful when you want to limit the number of documents returned by a query to a specific number. This is especially useful when working with large collections.

Important Points

• The limit() method must be used after the find() method in a query chain.
• The limit() method can be used in conjunction with other methods such as skip() and sort() to further refine the returned results.

Summary

In this tutorial, we discussed how to use the limit() method with Node.js and MongoDB. We covered the syntax, example, output, explanation, use, and important points of the limit() method in Node.js and MongoDB. You can now use the limit() method in your Node.js and MongoDB applications to limit the number of documents returned in query results.