Return the item with the largest amount MongoDB-CodePudding

I am making a query in MongoDB in which I need to obtain the most sold product, for now I have managed to obtain the list of products and order it by the amount of sales but I only need to return the product with the most sales, this is my query:

db.sales.aggregate(
    [
        { 
            $unwind : "$detail"
        }, 
        { 
            $project : { 
                "name" : "$detail.name"
            }
        },
        {
            $group: {
                _id: "$name",
                quantity: { $sum: 1 }
            }
        },
        {
            $sort: {
                quantity: -1
        }
},
    ]
);

And this is the answer:

[
  {
    "_id": "Producto 2",
    "quantity": 38
  },
  {
    "_id": "Producto 3",
    "quantity": 28
  },
  {
    "_id": "Producto 1",
    "quantity": 9
  }
]

How can I get only the element with the largest quantity? Thanks.

CodePudding user response：

You're very close, but as @rickhg12hs has already mentioned, you need to add $limit.

Example playground here: https://mongoplayground.net/p/9bRRgUI4Izo

db.collection.aggregate([
  {
    $unwind: "$detail"
  },
  {
    $project: {
      "name": "$detail.name"
    }
  },
  {
    $group: {
      _id: "$name",
      quantity: {
        $sum: 1
      }
    }
  },
  {
    $sort: {
      quantity: -1
    }
  },
  {
    $limit: 1
  }
])

There are other approaches to this, but this will work for you.