Mongodb (mongoose) I can't remove sub element from array

Question

I'm creating a league of legends tournament website for a friend, and for each tournament (stored in a database with mongodb) has a list of "premades" of players that want to play the tournament.

I'm using the mongoose module on node.js to manage my database

Here is my model:

const tournamentSchema = mongoose.Schema({
    name: {
        type:String,
        required:true,
        trim: true
    },
    beginningDate: Date,
    endingDate: Date,
    creatorName: {
        type:String,
        required:true,
        lowercase: true,
        trim: true
    },
    maxPlayers:Number,
    maxPlayersPerTeam:Number,
    playersList:Array,
    waitingPlayers:Array,
    needLoggin:{
        type:Boolean,
        default:false
    },
    description:String
});

For exemple, "playersList" will be:

playersList:[
{
  name:"group1",
  players:[
    {
      name:"player1",
      elo:"rank on the game"
    },
    {
      name:"player2",
      elo:"rank on the game"
    }
  ]
},
{
  name:"group2",
  players:[
    {
      name:"player3",
      elo:"rank on the game"
    },
    {
      name:"player4",
      elo:"rank on the game"
    }
  ]
}

]

And I'm trying to find how to remove the

{
  name:"player4",
  elo:"rank on the game"
}

in the group 2 for exemple. I tried to use splice() like if it was a normal array, it updated the object but did nothing in the database. I also tried the tournament.update and it returned an error and I couldn't see what was my mistake...

var collection = Rtournament.players;
Rtournament.updateOne({'players.players.name':collection[i].players[j].name},{$pull:{'players.$.players':{'name':name}}},()=>{});

So I would like to know a simple way to remove it (as I'm sure my code was really wrong)

Thanks a lot to help me and sorry for my awful english

Answer 1

You can use this to pull the players according to your group. You will have to pass group name and players name.

db.collection.update({
  $and: [
    {
      name: "group2"
    },
    {
      "players.name": "player4"
    }
  ]
},
{
  $pull: {
    players: {
      name: "player4"
    }
  }
})

Mongo Playground: https://mongoplayground.net/p/HEusd_OBO1F

Here is standalone script to test, let me know if it works Start the mongodb in shell then run node repro.js in terminal

const mongoose = require('mongoose');

const tournamentSchema = mongoose.Schema({
    name: {
        type:String,
        required:true,
        trim: true
    },
    beginningDate: Date,
    endingDate: Date,
    creatorName: {
        type:String,
        lowercase: true,
        trim: true
    },
    maxPlayers:Number,
    maxPlayersPerTeam:Number,
    players:Array,
    waitingPlayers:Array,
    needLoggin:{
        type:Boolean,
        default:false
    },
    description:String
});


run().catch((err) => console.log(err));

async function run() {
    await mongoose.connect('mongodb://localhost:27017/test', {
        useNewUrlParser: true,
        useUnifiedTopology: true,
    });
    await mongoose.connection.dropDatabase();

    const TournamentModel = mongoose.model('tournament', tournamentSchema);
    await TournamentModel.insertMany([
        {
          name:"group1",
          players:[
            {
              name:"player1",
              elo:"rank on the game"
            },
            {
              name:"player2",
              elo:"rank on the game"
            }
          ]
        },
        {
          name:"group2",
          players:[
            {
              name:"player3",
              elo:"rank on the game"
            },
            {
              name:"player4",
              elo:"rank on the game"
            }
          ]
        }
        
        ])
    await TournamentModel.updateOne({
        $and: [
          {
            name: "group2"
          },
          {
            "players.name": "player4"
          }
        ]
      },
      {
        $pull: {
          players: {
            name: "player4"
          }
        }
     });
    const result = await TournamentModel.find({}).lean()
    console.log(JSON.stringify(result), 'result')
}