how to merge response attributes of other table in node js - node.js

Question

I have 3 Tables User, Cars and UserCars
User{id, name, phone, email}
Cars{id, name, manufacturer}
UserCars{id, car_id, user_id, role}
User have many cars(through UserCars)
Cars have many users(through UserCars)
I am using express js
router.get('/', async (req, res) => {
try {
let car = await Car.findOne({
where: {
id: req.car_id
}});
let users = await car.getUsers({joinTableAttributes: ['role']})
res.send(users)
} catch (e) {
console.log(e)
res.status(400).send(e)
}
})
and this my response
[
{
"id": 1,
"name": "test",
"email": null,
"phone": null,
"createdAt": "2019-07-09T09:38:11.859Z",
"updatedAt": "2019-07-12T04:34:20.922Z",
"User_car": {
"role": "driver"
}
}
]
but any idea how to include role in the user object, rather then specifying it separately in User_car table,
Is there a way where i can get the below output
[
{
"id": 1,
"name": "test",
"email": null,
"phone": null,
"role": 'driver'
"createdAt": "2019-07-09T09:38:11.859Z",
"updatedAt": "2019-07-12T04:34:20.922Z"
}
]

Answer 1

You can use sequelize.literal to get that field when getting your attributes.
attributtes: [
// define your other fields
[sequelize.literal('`users->User_car`.`role`'), 'role'],
]
Now, I not sure if that is going to work with car.getUsers. I usually do a single query with include and also define the "join" table so I can know how is name it on sequelize. Let me show you an example.
module.exports = (sequelize, DataTypes) => {
const UserCar = sequelize.define('UserCar', {
// id you don't need and id field because this is a N:M relation
role: {
type: DataTypes.STRING
},
carId: {
field: 'car_id',
type: DataTypes.INTEGER
},
userId: {
field: 'user_id',
type: DataTypes.INTEGER
},
}, {
tableName: 'User_car',
underscored: true,
createdAt: 'created_at',
updatedAt: 'updated_at',
});
UserCar.associate = (models) => {
models.user.belongsToMany(models.car, { as: 'cars', through: User_car, foreignKey: 'user_id' });
models.car.belongsToMany(models.user, { as: 'users', through: User_car, foreignKey: 'car_id' });
};
return UserCar;
};
router.get('/', async (req, res) => {
try {
const users = await User.findAll({
include: [{
model: Car,
as: 'cars',
where: { id: req.car_id }
}],
attributtes: [
'id',
'name',
'email',
'phone',
[sequelize.literal('`cars->User_car`.`role`'), 'role'],
]
})
res.send(users)
} catch (e) {
console.log(e)
res.status(400).send(e)
}
});