Im a little bit confused with the documentation of money-rails, they say that if you have an integer column called "price_cents" you just need to add the monetize :price_cents definition in the model, however they also say that you can add the money field in database migration like:
def change
add_money :products, :price
end
But my doubt is: if I use the migration helper add_money then I need to also add the monetize definition in the model? or is it only necessary when you have an integer column?
Yes, both are necessary. monetize :price_cents creates the facade that allows you to use Product.price = 10.99, and set the price_cents column behind the scenes.