Sort based on how many items are in an array using mongoose and MongoDB-CodePudding

I have a Post model that has a likes array that contains the ObjectId of the user that liked the Post, I would like to sort Posts based on how many likes they have received.

I'm sure I would use $size, $sort and aggregate, but everything I have tried doesn't seem to work. Can you use $size within $sort? What would be the correct way of doing this? and is there a specific way of doing it with mongoose?

CodePudding user response：

db.collection.aggregate([
  {
    $set: {
      size: { $size: "$likes" }
    }
  },
  {
    $sort: {
      size: -1
    }
  }
])

mongoplayground