Nested models mongoose with nodejs generates duplicates

Question

here is my code for models.js where I keep models

var mongoose = require('mongoose')
, Schema = mongoose.Schema;
var GroupSchema = new Schema({
    title      : String
    , elements   : [ElementSchema]
    , author     : String 
});
var ElementSchema = new Schema({
    date_added : Date
    , text       : String
    , author     : String 
});
mongoose.model('Group', GroupSchema);
exports.Group = function(db) {return db.model('Group');};

mongoose.model('Element', ElementSchema);
exports.Element = function(db) { return db.model('Element');
};

To me it looks pretty clear, but when I do

function post_element(req, res, next) {
Group.findOne({_id: req.body.group}, function(err, group) {
    new_element = new Element({author: req.body.author,
        date_added: new Date()});
        new_element.save();
        group.elements.push(new_element);
        group.save();
    res.send(new_element);
    return next();
})
}

I don't understand why when I go in Mongo I have two collections one called Groups with nested groups (so it looks fine) and the other collection is called Elements.

Why? Shouldn't it be called just Group ? I don't understand, a good chap that please explain it to me?

Thanks, g

JohnnyHK · Accepted Answer · 2012-05-29 23:18:26Z

1

When you execute this line:

new_element.save();

you're saving the newly created element to the Elements collection. Don't call save on the element and I think you'll get the behavior you're looking for.

answered May 29, 2012 at 23:18

JohnnyHK

313k70 gold badges632 silver badges479 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

piggyback Over a year ago

but in this case, what will be the point of having two separate schemas?

JohnnyHK Over a year ago

It seems that with Mongoose, if you want an array of objects in your schema, those objects have to be defined using a Schema (or be one of the built-in schema types).

srquinn · Accepted Answer · 2012-05-30 13:58:17Z

0

Its because of the following line:

mongoose.model('Element', ElementSchema);

This registers a model in mongoose and when you register a model, it will create its own collection inside mongo. All you have to do is get rid of this line and you will see it disappear.

On another note, its much cleaner and easier to setup your files to only export one model per file using the following to export the model:

module.exports = mongoose.model('Group', GroupSchema);

Hope this helps!

answered May 30, 2012 at 13:58

srquinn

10.5k2 gold badges50 silver badges54 bronze badges

Collectives™ on Stack Overflow

Nested models mongoose with nodejs generates duplicates

2 Answers 2

2 Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

2 Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related