Bookshelf.js relations

gistfile1.js

var Parent = Bookshelf.Model.extend({
	tableName: 'parent',
	child: function() {
		return this.hasOne(Child);
	}
});

var Child = Bookshelf.Model.extend({
	tableName: 'child',
	//this has an attribute parent_id
	parent: function() {
		return this.belongsTo(Parent);
	}
});

var parent, child;

Parent.forge({name: "Parent"}).save()
.then(function (_parent) {
	parent = _parent;
	return Child.forge({name: "Child"}).save();
})
.then(function (_child) {
	child = _child;
	child.related('parent').set(parent);
	return child.save();
})
.then(function(saved) {
	res.send(saved);
});