How can I save multiple items to an array field when creating a new record in MongoDB?

Question

How can I save multiple items to an array field when creating a new record in MongoDB?

I have the following schema that is used for a "Groups" collection. I want to be able to create this record and push an arbitrary number of "members" to this group when it is first created. I am unable to get the "members" field to populate when I save the record. All other fields are saved without a problem.

var groupSchema = mongoose.Schema({
    creator : String,
    name : String,
    members: [{
        type: String,
        ref: 'User'
    }],
    created : {
        type: Date,
       default: Date.now
    }
});

app.post('/create-group', function(req, res) {
    //req.body.users = ['12345', '23456', '34567'] for example
    var group = new Group({
        name : req.body.group_name,
        creator : req.user._id,
        members: {$push: req.body.users}
    });
    group.save(function (err, data) {
        if (!err) {
            return res.json(data);
        }
    });
});

No results are ever stored in "members", even though all other fields are saved correctly. What am I doing wrong?

node.js
mongodb
express
mongoose

Answer 1

EDIT

In your schema when you wrote ref :"User" it means that you have to provide a User schema and not a string or integer. If you just want an array of string you can simply use [String].

According to the doc you have to use an objectID http://mongoosejs.com/docs/populate.html

members: [{ type: Schema.Types.ObjectId, ref: 'User' }]

In the link provided above you will be able to check how to save your group and adding an arbitrary number of members.

Answer 2

members: [{ type: Schema.Types.ObjectId, ref: 'User' }]

As Su4p has pointed out. Don't worry about req.body.users containing strings instead of ObjectIds. mongoose will cast the strings into objectIDs. There's also another mistake,

        members: {$push: req.body.users}

should be

        members: req.body.users

$push is an update operator. It's not meant for assigning arrays.