MongoDB aggregate query to sort

To sort, use $match along with aggregate. Let us create a collection with documents −

> db.demo67.insertOne({"StudentAge":23});
{
   "acknowledged" : true,
   "insertedId" : ObjectId("5e289edf602d9a2ff1828ed8")
}
> db.demo67.insertOne({"StudentAge":21});
{
   "acknowledged" : true,
   "insertedId" : ObjectId("5e289ee1602d9a2ff1828ed9")
}
> db.demo67.insertOne({"StudentAge":24});
{
   "acknowledged" : true,
   "insertedId" : ObjectId("5e289ee3602d9a2ff1828eda")
}

Display all documents from a collection with the help of find() method −

> db.demo67.find();

This will produce the following output −

{ "_id" : ObjectId("5e289edf602d9a2ff1828ed8"), "StudentAge" : 23 }
{ "_id" : ObjectId("5e289ee1602d9a2ff1828ed9"), "StudentAge" : 21 }
{ "_id" : ObjectId("5e289ee3602d9a2ff1828eda"), "StudentAge" : 24 }

Following is the query to sort with aggregate in MongoDB −

> db.demo67.aggregate([
... {$match: {"StudentAge": {$gt: 20} }}
... ,{$sort: {"StudentAge": -1} }
... ]);

This will produce the following output −

{ "_id" : ObjectId("5e289ee3602d9a2ff1828eda"), "StudentAge" : 24 }
{ "_id" : ObjectId("5e289edf602d9a2ff1828ed8"), "StudentAge" : 23 }
{ "_id" : ObjectId("5e289ee1602d9a2ff1828ed9"), "StudentAge" : 21 }