Question

I have two rails models, Usage & Price. So far they look like this:

class Usage < ActiveRecord::Base
    has_one :price

    def spend
        usage.amount * price.amount
    end
end

and

class Price < ActiveRecord::Base
    belongs_to :usage
end

I’m trying to call the “spend” by doing this in the console:

Usage.create(amount:100)
Price.create(amount:0.1)

usage=Usage.find(1)
puts usage.price

Where am I going wrong??

Answer 1

You need to create the price through the usage model to have the association work.

usage = Usage.create(amount:100)
usage.create_price(amount:0.1)