📄️ 📘 Intro to Aggregation Pipelines
What is an aggregation pipeline?
📄️ 👐 $match and $project
MongoDB’s Aggregation Framework allows for powerful data transformations and analysis. The $match, $project, and $sort stages are fundamental building blocks of an aggregation pipeline.
📄️ 👐 $sort and $limit
🔹 $sort → Sorting results
📄️ 👐 $group
In SQL, the GROUP BY statement groups rows that have the same values into summary rows, like "find the number of customers in each country."
📄️ 👐 $lookup (JOINs in MongoDB)
$lookup in MongoDB serves a similar purpose to JOINs in SQL. It enables combining data from multiple collections by performing an equality match between fields.
📄️ 🦸 $merge
In MongoDB, the $merge stage allows you to write the results of an aggregation pipeline into a new or existing collection. This is similar to the concept of "INSERT INTO ... SELECT" or "MERGE INTO" in SQL databases.