Rails association - how to add the 'has_many' object to the 'owner'

In my app, a user has many score_cards and a score_card belongs to a user

The question is, whenever I create a new score_card, ie, ScoreCardsController.create gets called, how do I add this newly created score_card to the curr开发者_如何学JAVAent_user (I'm using devise, so current_user is a valid User object).

current_user.score_cards << score_card

OR

score_card.user = current_user
score_card.save

Use the association builder method:

current_user.score_cards.build(params[:score_card])

Alternatively to build you can use create or create! if you don't care about the validations in the controller.

I'm going to throw this out there in case anyone is looking for a way to add multiple objects to an associated object:

score_cards = ScoreCard.all
current_user.score_cards << score_cards

No need to current_user.save