What are some examples of MongoDB aggregation pipelines?

Can you give me some examples of MongoDB aggregation pipelines?

Sure! One common example is using the $match stage to filter documents. For instance, you can find all orders with a total greater than $100.

What about grouping data? Can you show me an example?

Absolutely! You can use the $group stage to group documents by a specific field. For example, to count the number of orders per customer, you would group by the customer ID.

How do I sort the results after grouping?

You can use the $sort stage after $group. For instance, to sort the grouped results by the total order count in descending order, you would add a $sort stage after the $group.

Can you provide a complete example of an aggregation pipeline?

Sure! Here's a complete example: db.orders.aggregate([ { $match: { total: { $gt: 100 } } }, { $group: { _id: '$customerId', totalOrders: { $sum: 1 } } }, { $sort: { totalOrders: -1 } } ]).