Aggregation example 12
A focused MongoDB example for aggregation with output and explanation.
Aggregation example 12
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Input
Terminal
SuccessReady.
Run code to see output here.
What this example teaches
Aggregation
Output
MongoDB returns matching documents or grouped metrics for a backend data access layer.
Line-by-line explanation
- Line 1 sets up the Aggregation example: db.orders.aggregate([.
- Line 2 adds the decision or filter that controls the result: { $match: { status: "paid" } },.
- Line 3 adds one required part of the working pattern: { $group: { _id: "$customerId", revenue: { $sum: "$total" } } },.
- Line 4 adds one required part of the working pattern: { $sort: { revenue: -1 } }.
- Line 5 adds one required part of the working pattern: ]).
Why this example is useful
This example is useful because it isolates aggregation without surrounding noise, so you can see the idea clearly.
Where it is used in real projects
Aggregation appears in real MongoDB work when a feature needs a clear pattern that can be reviewed and changed safely.
Beginner variation
Change one label, value or condition in the Aggregation example and run it again.
Advanced variation
Combine Aggregation with validation, error handling or reusable structure.