Activerecord relation creation via has_one

Question

I Rails if you have a model Walrus that has_many :bubbles (and Bubble belongs_to :walrus , you can create a new Bubble that is associated with the Walrus like so:

chuckles = Walrus.create
chuckles.bubbles.create

But what if Walrus has_one :bubble ? chuckles.bubble.create is a no go (as it is nil ). How can I do the equivalent without just passing in the Walrus in the Bubble.create ?

Answer 1

For has_many

chuckles.bubbles.build

For has_one

chuckles.build_bubble

In your example above, I think you should have been using build. It adds chuckles id to bubble object. Also when chuckles is saved, bubbles will be saved automatically as well