How to fix the "Name of the mongoose Model" is not a constructor in graphql when mutating

Question

Mutating data in the graphql playground says the message of Message: Student is not a constructor Error: "TypeError: Student is not a constructor" Student is my Mongoose Model.

I've tried reinstalling my node_modules, searching some fix on the github.

This is my Mutation Function

 addStudent: async (
      root,
      { studentId, firstName, lastName, email, password },
      { Student }
    ) => {
      const newStudent = await new Student({
        studentId,
        firstName,
        lastName,
        email,
        password
      }).save();
      return newStudent;
    }

and this is my Mongoose Model

const mongoose = require("mongoose");
const Schema = mongoose.Schema;

const StudentSchema = new Schema({
  studentId: {
    type: String,
    required: true
  },
  firstName: {
    type: String,
    required: true
  },
  lastName: {
    type: String,
    required: true
  },
  // sectionId: {
  //   type: [Schema.Types.ObjectId],
  //   ref: "Section",
  //   nullable: true
  // },
  email: {
    type: String,
    required: true
  },
  password: {
    type: String,
    required: true
  },
  createdDate: {
    type: Date,
    default: Date.now
  }
});

module.exports = mongoose.model("Student", StudentSchema);

The student should be created, but that error pops up with that message.

score 1 · Answer 1 · answered Apr 02 '19 at 13:27

Await working on promise but here you are passing student object so it returns Student is not a constructor

const newStudent = await new Student({
        studentId,
        ....
      }).save();

Instead, you can do this

1) create student object using append

const newStudent = new Student({})
newStudent.studentId = studentId
newStudent.firstName = firstName
newStudent.lastName = lastName
newStudent.email = email
newStudent.password = password

2) Create student object using constructor

const newStudent = new Student({ 
    studentId,
    firstName,
    lastName,
    email,
    password
})

and save using promise async and await

  await newStudent.save()

or

const newStudent = await Student.create({
    studentId,
    firstName,
    lastName,
    email,
    password
})

I'm sorry to tell you but those solutions aren't working, its the same error appeared. — Crisostomo Ibarra, Apr 02 '19 at 15:06
You should use a dynamic variable instead of manual typing on the graphql mutation. Because you pass Student model in Mutation. — Ashok, Apr 03 '19 at 04:35

score 0 · Accepted Answer · answered Apr 03 '19 at 03:26

0

Fixed! I should have provided query variables rather than manual typing on the graphql mutation

answered Apr 03 '19 at 03:26

Crisostomo Ibarra

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I did not understand clearly can u give me an example or exact answer what you have changed – Allu Manikyam Sep 12 '19 at 12:17

How to fix the "Name of the mongoose Model" is not a constructor in graphql when mutating

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