one-to-many relationships in sequelizer - node.js

Question

Been looking at various answers and git issues and still can't get it to work. I have drivers model and CarDrivers model. A driver can drive multiple cars so I want to create a one-to-many relationships.
Drivers Model is (models/drivers.js):
'use strict';
module.exports = (sequelize, DataTypes) => {
const Driver = sequelize.define('Driver', {
name: DataTypes.STRING
}, {});
Driver.associate = function(models) {
// associations can be defined here
};
return Driver;
};
now CarDrivers (models/cardrivers.js):
'use strict';
module.exports = (sequelize, DataTypes) => {
const CarDriver = sequelize.define('CarDriver', {
status: DataTypes.INTEGER,
}, {});
CarDriver.associate = function(models) {
// associations can be defined here
CarDriver.belongsTo(models.Driver, {
onDelete: "CASCADE",
foreignKey: 'id',
as: 'car_driver'
});
};
return CarDriver;
};
Data migration works with no errors but I don't see an entry/related column in table CarDrivers. Anybody can help fix it please.

Answer 1

The issue with your code is that the foreign_key in your association definition cannot be id, as that will clash with the id of the CarDriver table. If you change it to driver_id, you will see that column in the car_driver table:
const Driver = sequelize.define('driver', {
name: { type: Sequelize.STRING }
});
const CarDriver = sequelize.define('car_driver', {
name: { type: Sequelize.STRING }
});
CarDriver.belongsTo(Driver, {
onDelete: 'CASCADE',
foreignKey: 'driver_id'
});
const driver = await Driver.create({
name: 'first driver'
})
const carDriver = await CarDriver.create({
name: 'first carDriver',
driver_id: driver.id
})
Two notes:
foreignKey is optional. If you leave it blank, Sequelize will default to camelcase, e.g. driverId
Your migration file must account for the foreign key on the CarDriver table:
up: function(queryInterface, Sequelize) {
return queryInterface.createTable('car_driver', {
id: {},
driver_id: {
..
}
});
}