From the course: MongoDB Node.js Developer Associate Cert Prep
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MongoDB aggregation with Node.js review
From the course: MongoDB Node.js Developer Associate Cert Prep
MongoDB aggregation with Node.js review
- In this unit, you learned about the aggregation pipeline and how to build one that uses $match, $group, $sort, and $project stages. Aggregation is a powerful language for filtering, sorting, grouping, and projecting data without changing any data in your actual collection. This also allows us to string together aggregation operations, known as stages, to create an aggregation pipeline, which helps us dictate exactly how we want to process our data step by step. This unit started with an overview of aggregation and the stages of an aggregation pipeline, which include finding, sorting, grouping, and projecting. These stages can use expression operators. Then, we created our first pipeline by matching documents and then grouping them based on specific criteria. Then we sorted results in ascending and descending order by using the $sort stage. Finally, we used the $project stage to return specific fields as well as…