MissingSchemaError: Schema hasn't been registered for model “User”

Question

In my models/user.js file:

var mongoose = require(\'mongoose\');
var Schema = mongoose.Schema;

var userSchema = new Schema({
    (define schema         


        

Answer 1

I literally research lot and I found a solution so, I share this solution to you so, no one can face that cheap mistake that I did.

Please remember, you just need to add the same name in ref as you gave in your model because its case sensitive ( Product !== product ).

const Product = new mongoose.model('Product', productSchema);

product: {
    type: mongoose.Schema.ObjectId,
    ref: 'Product', <-- Should be same as modelName
    required: [true, 'Cart must belong to a product']
}

Answer 2

In my case, it happened because of capital/small letter confusion. User model had this:

const userSchema = new Schema({
// ...
});
module.exports = mongoose.model('User', userSchema);

And Product model had a reference to User model but small case:

const productSchema = new Schema({
// ...
  userId: {
    type: Schema.Types.ObjectId,
    ref: 'user', // This should exactly match the name of User model above!!!
    required: true
  }
});

Answer 3

I was making a different mistake like I have created the Schema but the issue was that I didn't use schema model (for insert, update, read and delete the doc).

i.e. I have created the collection something like that:

const playerSchema = new Schema({
    bowling: {
        style: String,
        arm: String,
    }
})

export const PlayerSchema = model('Player', playerSchema)

but didn't use or call PlayerSchema model somewhere that's why I was getting this error.

Answer 4

I've also experienced this error with ES6/Typescript. Even I imported the model, the error still persisted. According to docs here

MongooseError.MissingSchemaError

Thrown when you try to access a model that has not been registered yet

    import { model, Schema } from 'mongoose';
    import Company from './CompanyModel';

    const ProjectSchema = new Schema({
        company: { type: Schema.Types.ObjectId, ref: "Company" }
    });

    export default model('Project', ProjectSchema);

The tips was just to make sure to use the model explicitly, so changing ref:"Company" into ref:Company.modelName seemed fixed it.

I hope that helps some of you

Answer 5

• You'll need to require your model in your code
• Mongoose won't recognize that you've defined a model until you've called mongoose.model, and that's only called when you require model

Ex.

In the below example, you will get MissingSchemaError: Schema hasn't been registered for model “Role” if you don't do const Role = require("./role");

const mongoose = require("mongoose");
const Schema = mongoose.Schema;
const Role = require("./role");
const userSchema = new Schema(
  {
    role: { type: Schema.Types.ObjectId, ref: "Role", required: false },
    username: { type: String, required: true, trim: true },
    password: { type: String, required: true, trim: true },
    email: { type: String, required: true, trim: true }
  },
  { timestamps: true }
);

module.exports = mongoose.model("User", userSchema);

Answer 6

I recently came across a solution similar to the answers provided by @rajkumar-nagarajan and @verybadalloc.

I like this approach better, because it avoids the n+1 iteration, and it does not read all the models from the file system.

In app/models/index.js, require each model file:

require('./model1');
require('./model2');
require('./model3');

Then, in /app.js or /index.js (whichever your project uses), you can now simply do:

require('./app/models');

The part I'm missing (any tips appreciated here) --how to easily register each model by name like:

mongoose.model('Model1')