How to define mongoose _id in TypeScript interface?

Question

I'm using Mongoose and TypeScript with the interface+class+schema approach.

What is the canonical way to store the _id field?

I know the db stores it as a bson ObjectID. But I've seen some examples using string and others using mongoose's ObjectId, and then converting between them for various reasons - so I'm unsure which to use.

interface Animal {
  _id: ?type?;        // ?
  name: string;
}

Is it advisable to use

• string
• mongoose.Types.ObjectId
• mongodb.ObjectID
• bson.ObjectID

Also, assuming it is correct to use objectid - I want to avoid taking a dependency on mongoose in the interface file. Is it safe/advisable to use the bson package's ObjectID instead - are they equivalent?

Solution 1

You can extend your interface with mongoose.Document. Your interface will be come

interface Animal extends mongoose.Document { 
  name: string;
}

Usage:

export let AnimalSchema = mongoose.model<Animal>('animal', schema, 'animals');
let animal = await AnimalSchema.find({_id: "id"}).exec();
// animal._id / animal.name

Solution 2

you can do this

import { ObjectId } from 'mongoose';
interface Animal {
  _id: ObjectId       
  name: string
}

Comments

[lonix]

I do it another way to keep my entity files clean of infrastructure dependencies. Also, what about the original issue - what type is best to use?

[hoangdv]

aww, I think mongoose.Types.ObjectId is good for you case, mongoose.Types.ObjectId has been defined by typeof mongodb.ObjectID & { (s?: string | number): mongodb.ObjectID; };