How to set _id to db document in Mongoose?

Question

I\'m trying to dynamically create _id\'s for my Mongoose models by counting the documents in the db, and using that number to create the _id (assuming the first _id is 0). H

Answer 1

The first piece of @robertklep's code doesn't work for me (mongoose 4), also need to disabled _id

var Post = new mongoose.Schema({
  _id: Number,
  title: String,
  content: String,
  tags: [ String ]
}, { _id: false });

and this works for me

Answer 2

Create custom _id in mongoose and save that id as a mongo _id. Use mongo _id before saving documents like this.

const mongoose = require('mongoose');
    const Post = new mongoose.Schema({
          title: String,
          content: String,
          tags: [ String ]
        }, { _id: false });

// request body to save

let post = new PostModel({
        _id: new mongoose.Types.ObjectId().toHexString(), //5cd5308e695db945d3cc81a9
        title: request.body.title,
        content: request.body.content,
        tags: request.body.tags
    });


post.save();

Answer 3

You either need to declare the _id property as part of your schema (you commented it out), or use the _id option and set it to false (you're using the id option, which creates a virtual getter to cast _id to a string but still created an _id ObjectID property, hence the casting error you get).

So either this:

var Post = new mongoose.Schema({
    _id: Number,
    title: String,
    content: String,
    tags: [ String ]
});

Or this:

var Post = new mongoose.Schema({
    title: String,
    content: String,
    tags: [ String ]
}, { _id: false });