Mongoose populate multiples ids

Question

I have these schemas

var DriverSchema = Schema({
  name: String,
  groups: {
     type: String,
     ref: 'DriverGroup'
  }
});


var DriverGroupSchema = Schema({
  name: String
});

module.exports = mongoose.model('DriverGroup', DriverGroupSchema);
module.exports = mongoose.model('Driver', DriverSchema);

I have these driver groups:

[{
  id: '12345',
  name: 'Group1'
}, {
  id: '6789',
  name: 'Group2'
}]

and this driver:

{
  name: 'Driver1',
  groups: '12345,6789'
}

How I can get the groups by population? I am using this:

Driver.find().sort('name').populate('groups')

But does not works properly.

Answer 1

You're storing groups incorrectly, if you want to populate them in this way.
populate cannot parse a string in order to determine the separate entities.

It should be an array

groups: '12345,6789'

should be

groups: ['12345,6789']

Also, populate works by looking up the _ids (not name field)

So, will need to change your schema:

var DriverSchema = Schema({
  name: String,
  groups: [{ type: string, ref: 'DriverGroup' }]
});

You'll need to set the _id too (set _id to same as name in your case)

var DriverGroupSchema = Schema({
  _id: String,
  name: String
});

http://mongoosejs.com/docs/populate.html