删除mongodb中的数组元素

Question

So my mongodb looks like this:

[
  {
    "_id": "582bc918e3ff1bf021ae8b66",
    "boardName": "Test Board",
    "created_at": 1479264483957,
    "__v": 0,
    "person": [
      {
        "name": "Steve",
        "wins": 1001,
        "losses": 20,
        "_id": "582bc918e3ff1bf021ae8b69"
      },
      {
        "name": "Bobby",
        "wins": 500,
        "losses": 54,
        "_id": "582bc918e3ff1bf021ae8b68"
      },
      {
        "name": "Sarah",
        "wins": 396,
        "losses": 675,
        "_id": "582bc918e3ff1bf021ae8b67"
      }
    ]
  }
]

I want to be able to make a delete request on:

/api/scoreBoard/person/:person_id and it should then remove the entire person element in my database.

So for example, if I make a delete on:

http://localhost:3000/api/scoreBoard/person/582bc918e3ff1bf021ae8b68 it should then delete "bobby". And the database would look like this afterwards:

[
  {
    "_id": "582bc918e3ff1bf021ae8b66",
    "boardName": "Test Board",
    "created_at": 1479264483957,
    "__v": 0,
    "person": [
      {
        "name": "Steve",
        "wins": 1001,
        "losses": 20,
        "_id": "582bc918e3ff1bf021ae8b69"
      },
      {
        "name": "Sarah",
        "wins": 396,
        "losses": 675,
        "_id": "582bc918e3ff1bf021ae8b67"
      }
    ]
  }
]

But how do I delete a person inside "person"? I can't get it to work. This is my code so far, and it returns "Deleted person successfuly!" but nothing happens in the database. It doesn't delete anything.

app.delete('/api/scoreBoard/person/:person_id', function(req, res) {
  mongoose.model('scoreBoard').findByIdAndRemove(req.params.person_id, function(err) {
    if(!err) {
      res.json('Deleted person successfuly!');
    } else {
      res.write('Delete failed..');
    }
  });
});

Answer 1

Since you seem to be using Mongoose, I'd recommend looking at using refs and a seperate Person model for storing this information, this would look like:

Scoreboard:

const mongoose = require('mongoose');
var Schema = mongoose.Schema;

var scoreboardSchema = new Schema({
  boardName: String,
  created_at: Date,
  people: [{type: Schema.Types.ObjectID, ref:"Person"}]
});

Person:

const mongoose = require('mongoose');
var Schema = mongoose.Schema;

var personSchema = new Schema({
  name: String,
  wins: Number,
  losses: Number
});

When you want to add a user to the scoreboard you then need only push their id to the array people.

Then when you wanted to remove a person you could just use:

db.Scoreboard.people.pull(req.params.person_id);

If you were to go down this route you would then need to populate people when you grabbed the scoreboard so that would look like:

Scoreboard.find({}).populate('people').exec(function(err,docs){})

For example. This would then allow you much more freedom over the Person object, such as adding more attributes and being able to edit them much more easily.

Hopefully this helps somewhat.

Answer 2

Your need to use update since You don't want to remove entire document.

Something like this should work.

mongoose.model('scoreBoard')
.update({ 
     _id: <boardID>
},{
    $pull: { person: { _id: <personID}}
}, function(err, result){

});

Answer 3

app.delete('/api/scoreBoard/person/:person_id', function(req, res) {
  mongoose.model('scoreBoard').findAndUpdate({'person._id':req.params.person_id},{$pull : {person : {_id : req.params.person_id}}}, function(err) {
    if(!err) {
      res.json('Deleted person successfuly!');
    } else {
      res.write('Delete failed..');
    }
  });
});