How do I use aggregation pipelines in MongoDB with Node.js?

How do I use aggregation pipelines 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 results = await collection.aggregate(pipeline).toArray();
    console.log(results);
    await client.close();
}

run();

What does each stage in the pipeline do?

In this pipeline, $match filters documents where status is 'A', and $group aggregates the results by cust_id, summing the amount.