Group (By) in Mongoose?

Question

I\'ve constructed the query I want in the shell but am having trouble writing it in Mongoose.

db.commentstreams.group({ key: { page_id: true }, reduce: function(         


        

Answer 1

I worked with similar example, I hope this be helpful

Register.aggregate(
[
  {
   $group: {_id: {campaign: "$campaign"}, quantity: {$sum: 1}}
},
  {
    $limit: 5
  },
  {
    $sort: {date: -1}
  }
], function (err, res) {
        console.log(res)
});