Sequelize hasMany assocaition - node.js

Question

I am considering these 2 tables "exam_response" and "answer" for hasMany association.
Where both the tables contains "question_id". Using question_id I need the answers.
exam_response table
module.exports = (sequelize, DataTypes) => {
const exam_response = sequelize.define('exam_response', {
id: {
allowNull: false,
primaryKey: true,
type: DataTypes.UUID,
defaultValue: DataTypes.UUIDV4
},
session_id: {
type: DataTypes.UUID,
allowNull: false
},
exam_id: {
type: DataTypes.UUID,
allowNull: false
},
user_id: {
type: DataTypes.UUID,
allowNull: false
},
question_id: {
type: DataTypes.UUID,
allowNull: false
},
answer_ids: {
type: DataTypes.ARRAY(DataTypes.UUID),
allowNull: false
},
is_correct: {
type: DataTypes.BOOLEAN,
allowNull: false
},
is_bookmarked: {
type: DataTypes.BOOLEAN,
allowNull: false
},
is_attempted: {
type: DataTypes.BOOLEAN,
allowNull: false
},
createdAt: {
type: DataTypes.DATE,
field: 'created_at'
},
updatedAt: {
type: DataTypes.DATE,
field: 'updated_at'
}
}, {});
exam_response.associate = function (models) {
// associations can be defined here
exam_response.hasMany(models.answer, {
foreignKey: 'question_id', sourceKey: 'question_id',as:'exam_answers'
});
};
answer table
'use strict';
module.exports = (sequelize, DataTypes) => {
const answer = sequelize.define('answer', {
//{
// "id":"",
// "question_id":"123",
// "position":0,
// "answer":"This is answer 1."
// }
id: {
allowNull: false,
primaryKey: true,
type: DataTypes.UUID,
defaultValue: DataTypes.UUIDV4
},
question_id: {
allowNull: false,
type: DataTypes.UUID
},
position: {
allowNull: false,
type: DataTypes.INTEGER
},
answer: {
allowNull: false,
type: DataTypes.TEXT
},
publish_status: {
allowNull: false,
type: DataTypes.ENUM('published', 'unpublished', 'deleted')
},
language: {
type: DataTypes.ENUM('en', 'kn', 'hi')
},
createdAt: {
type: DataTypes.DATE,
field: 'created_at'
},
updatedAt: {
type: DataTypes.DATE,
field: 'updated_at'
}
}, {});
answer.associate = models => {
answer.belongsTo(models.question,{foreignKey:'question_id',as:'answers'});
answer.belongsTo(models.exam_response,{foreignKey:'question_id', targetKey: 'question_id',as:'exam_answers'});
};
return answer;
};
Query::
ExamResponse.findAll({
where: {
exam_id
},
include: [
{
model: Answer,as:'exam_answers'
}
],
}).then(resp => {
response.successGet(res, resp, 'Exam Response');
}).catch(next)
I am getting the output but associated part("exam_answers") is empty.
If I use raw query, i am able to get the output. But the Query is only fetching me the exam_response not the answer even though the value exists.