Sequelize update or create included association

Question

Having Sequelize hasOne associations:

const User = sequelize.define('user', {/* ... */})
const Project = sequelize.define('project', {/* ... */})

// One-way association
User.hasOne(Project)

and user instance already exists . How do we add a new Project and connect it to the User instance?

Firstly, we need to find the User :

const user = await models.users.findOne({
    where: { id: 1 },
    include: models.projects
});

What do we do next? What if user.project is null ?

Answer 1

what about this?

Project.belongsTo(User)

http://docs.sequelizejs.com/class/lib/associations/belongs-to.js~BelongsTo.html