How can I use aggregation in MongoDB with Node.js?

How can I use aggregation in MongoDB with Node.js?

You can use the aggregate method in the MongoDB Node.js driver to perform aggregation operations. Would you like a code example?

Yes, please provide a code example.

Sure! Here's a simple example:

const { MongoClient } = require('mongodb');

async function run() {
    const client = new MongoClient('your_mongodb_uri');
    await client.connect();
    const database = client.db('your_database');
    const collection = database.collection('your_collection');

    const pipeline = [
        { $match: { status: 'A' } },
        { $group: { _id: '$cust_id', total: { $sum: '$amount' } } }
    ];

    const aggCursor = collection.aggregate(pipeline);
    await aggCursor.forEach(doc => console.log(doc));

    await client.close();
}

run().catch(console.dir);

This code connects to a MongoDB database and performs an aggregation to sum amounts by customer ID.

What are some common aggregation stages I can use?

Common aggregation stages include $match, $group, $sort, $project, and $lookup. Each serves a different purpose in data processing.