Mongoose Schema hasn't been registered for model

Question

I\'m learning the mean stack and when I try to start the server using

npm start

I get an exception saying that:

schema has         


        

Answer 1

The issue is with the refs, always make sure to refer the refs to whatever name your are exporting from the models.

// Model

const Task = mongoose.model('**Tasks**', taskSchema);

//Refs

userSchema.virtual('tasks', {
ref: '**Tasks**',
localField: '_id', // field in current model
foreignField: 'owner' // corresponding field in other model

});

Answer 2

You're not giving the model any value

In my case, I was using a model for which I didn't updated when making the MongoDB connection.

So, I had something like

const Device = require('../../models/device')

// make use of Device

with this connection

conn = await mongo.createConnection(conn,
      [JobApplication, Job, User])

Fix

You have to add the model to the conn when initiating the connection

conn = await mongo.createConnection(conn,
      [JobApplication, Job, User, Device])

Note that I added Device to the connection.

Answer 3

This error also pops up when we create wrong references (ref) between mongoose models.

In my case I was referring to the file name instead of model name.

eg:

const userModel = mongoose.model("user", userSchema);

We should refer to 'user' (model name) instead of 'User' (file name);

Answer 4

You should also check that you don't have dirty data in your database. I ended up with a document containing the lowercased version of the referenced model (user instead of User). This causes the error and is incredibly hard to track down.

Easy to fix with a quick mongo query:

db.model.updateMany({ approvedByKind: 'user' }, { $set: { approvedByKind: 'User' } })

Answer 5

Elaborating on Rafael Grilli's answer above,

Correct:

var HouseSchema = new mongoose.Schema({
  date: {type: Date, default:Date.now},
  floorplan: String,
  name:String,
  house_id:String,
  addressLine1:String,
  addressLine2:String,
  city:String,
  postCode:String,
  _locks:[{type: Schema.Types.ObjectId, ref: 'xxx'}] //ref here refers to the first parameter passed into mongoose.model()
});
var House = mongoose.model('xxx', HouseSchema, 'houseschemas');

Answer 6

.\nodeapp\node_modules\mongoose\lib\index.js:452
      throw new mongoose.Error.MissingSchemaError(name);
      ^
MissingSchemaError: Schema hasn't been registered for model "users".
Use mongoose.model(name, schema)
    at new MissingSchemaError

I got this error resolved when use setTimeout on server.js

mongoose.connect(env.get('mongodb.uri'), { useNewUrlParser: true })
  .then(() => logger.info("MongoDB successfully connected"))
  .catch(err => logger.error(err));
app.use(passport.initialize());
setTimeout(function() {
  require("./src/utils/passport")(passport);
}, 3000);