Meteor：如何按以下方式对用户进行排序？

Question

welcom ...

I have in my Meteor project 2 collections

1 - followers

"_id": "_id",
  "follower": "username1",
  "following": "username2"
}

2- users

"_id": "_id",
  "username": "username",
  [...]
}

I would like to sort users by the most following how I can do this

can anyone help me ?....

Answer 1

I would suggest putting the 'followers' collection as an object inside each 'users' document. There's no point in putting them in separate collections and then having to reference back and forth based on a user's ID. It's just taking up more space in your DB. Just make an object inside each user called 'follows' or something similar with the same structure (though make 'follower' and 'following' arrays). Something like this:

"users":{
    "_id":_id,
    "username":"username",
    "follows":{
        "followers":["username 1","username 2"],
        "following":["username 3", "username 4"],
    }
}

Once you have it so each user document has it's own 'follows' object, you can sort users by using the 'aggregate' functionality MongoDB Aggregate . This following code sorts based on the length of the followers array. You'd do a separate one for 'following' swapping out '$followers' with "$following".

db.users.aggregate(
   [
      {
         $project: {
           "length": { $size: "$followers" }
         },
         { "$sort": { "length": -1 } },
      }
   ]
)

This will probably require some tweaking, of course. just helping lead you in the right direction.