[Solved] Generating String _id fields in Mongo

I just added SimpleSchema to my project and tried to create a Collection like this:
const MyCollection = new Mongo.Collection('MyCollection');,
but when I used a find() command to check what it was inserted (using upsert), the field _id was on the format ObjectId(xxxxxxxxxx) instead of a single String like before.

How can I get a simple String on it? I tried to use Meteor’s recommendations and changed my declaration to
const MyCollection = new Mongo.Collection('MyCollection', { idGeneration: 'STRING' });
but nothing happens…

Solved! I was inserting all documents using a Bulk operation! Just changed that bulk operation and it works :wink: