Perform Group Operations on Array Fields in MongoDB

In our last lesson, we saw how we can use $group operator to simulate GROUP BY operations that you might be aware from SQL. A minor gimmick with $group is that it only works with the scalar field values and not arrays. There might be times when you would want to group by some array fields; in this lesson, we learn how to do that using $unwind operator

Here is the list of operators that we cover in this lesson:

• $unwind
• $group
• $sort
• $limit

You can see the list of all the available operators in the MongoDB docs.