sequelize-cross-db-query.js

const order = await UsersDb.models.order.findOne({ where: { id: 1 } });
await order.createProduct({ name: 'oathkeeper' });
await order.createProduct({ name: 'longclaw' });
await order.createProduct({ name: 'needle' });
const products = await order.getProducts();
console.log(products);

// output 
[ { id: 1, order_id: 1, name: 'oathkeeper' },
{ id: 2, order_id: 1, name: 'longclaw' },
{ id: 3, order_id: 1, name: 'needle' } ]