findOne is not a function - express

Question

I am trying to create a model using Sequelize and mysql db.I am trying to post to '/students/register' it keeps giving me an error saying findOne is not a function. I tried requiring my sql but it's not working ..I also tried a different function like findAll and still not working.what seems to be the problem
const Sequelize = require('sequelize');
module.exports = function (sequelize, Sequelize) {
const Stundet = sequelize.define(
'student', {
id: {
type: Sequelize.INTEGER,
primaryKey: true,
autoIncrement: true
},
name: {
type: Sequelize.STRING
},
email: {
type: Sequelize.STRING
},
password: {
type: Sequelize.STRING
},
created: {
type: Sequelize.DATE,
defaultValue: Sequelize.NOW
}
}, {
timestamps: false
});
module.exports = Stundet;
}
routes
const Student_Info = require("../models/students")
student.post('/register', (req, res) => {
const dataToday = new Date()
const studentData = {
name: req.body.name,
email: req.body.email,
password: req.body.password,
created: dataToday
}
Student_Info.findOne({
where: {
email: req.body.email
}
})
.then(student => {
if (!student) {
bcrypt.hash(req.body.password, 10, (err, hash) => {
studentData.password = hash
Student_Info.create(studentData)
.then(student => {
res.json({
status: student.email + 'registered'
})
})
.catch(err => {
res.send('error' + err)
})
})
} else {
res.json({
error: 'Student already registered'
})
}
})
.catch(err => {
res.send('error' + err)
})
})
module.exports = student;

Answer 1

When you use module.exports, you should return Stundet. You already export the whole function. And I think you should pass DataTypes instead of Sequelize.
Something like this:
module.exports = function (sequelize, DataTypes) {
const Stundet = sequelize.define(
//...
return Stundet;
}
So in your route in order to use your model:
const Sequelize = require('sequelize');
const DataTypes = sequelize.DataTypes;
let sequelize = new Sequelize(...);
const Student = require('../models/students')(sequelize, DataTypes);

Answer 2

I suspect that your Student_Info is null. Does you application successfully connect to the database? It helps to log... e.g.
sequelizeDB
.authenticate()
.then(() => {
console.log('Yes! DB Connection);
...
})
.catch(err => {
console.error('No! Unable to connect to DB', err);
});
... and IMHO the code reads better when you name the DB instance something other than "sequelize".