How to add auto increment to existing collection in mongodb/node.js?

Question

Is there any methods or packages, that can help me add auto increments to existing collection? Internet full of information, about how to add AI before you create collection, bu

Answer 1

MongoDB reserves the _id field in the top level of all documents as a primary key. _id must be unique, and always has an index with a unique constraint. It is an auto-incrementing field. However, it is possible to define your own auto-incrementing field following the tutorial in the MongoDB documentation.

Tutorial link: https://docs.mongodb.com/v3.0/tutorial/create-an-auto-incrementing-field/