Running Aggregation Pipelines via Mongoose
Explore how to use Mongoose's Model.aggregate() to run MongoDB aggregation pipelines within a MERN backend. Understand the differences between aggregate() and standard query methods, handle empty results properly, and organize aggregation logic inside controllers to power reporting endpoints.
The previous lesson built pipelines in mongosh. In a MERN backend, those same pipelines can run through Mongoose so they can power reporting endpoints, such as a revenue-by-status dashboard or a top-products list. The method is Model.aggregate(), and it accepts the same array of stages used in mongosh. This lesson shows how to run a pipeline from application code, handle the result objects it returns, and organize the pipeline inside a controller.
Note: The example is runnable and opens a local connection to
mongodb://127.0.0.1:27017/ecommerce. The controller snippet is read-along, since it needs the Express request and response objects to run.
To make the path concrete, the next visual should show a pipeline running through Mongoose into a controller response.
That starts with the method itself.