C:\Users\fuchun bao\node_modules\mongoose\lib\connection.js:802

        throw new MongooseError.MissingSchemaError(name);

        ^

    MissingSchemaError: Schema hasn't been registered for model "user".

    Use mongoose.model(name, schema)

        at NativeConnection.Connection.model (C:\Users\fuchun bao\node_modules\m

ongoose\lib\connection.js:802:11)

        at getModelsMapForPopulate (C:\Users\fuchun bao\node_modules\mongoose\li

b\model.js:3357:18)

        at populate (C:\Users\fuchun bao\node_modules\mongoose\lib\model.js:2939

:15)

        at _populate (C:\Users\fuchun bao\node_modules\mongoose\lib\model.js:290

7:5)

        at Function.Model.populate (C:\Users\fuchun bao\node_modules\mongoose\li

b\model.js:2867:5)

        at Immediate.cb (C:\Users\fuchun bao\node_modules\mongoose\lib\query.js:

1127:17)

        at Immediate.<anonymous> (C:\Users\fuchun bao\node_modules\mquery\lib\ut

ils.js:137:16)

        at runCallback (timers.js:649:20)

        at tryOnImmediate (timers.js:622:5)

        at processImmediate [as _immediateCallback] (timers.js:594:5)

    [nodemon] app crashed - waiting for file changes before starting...