rails 4 activerecord update multiple attributes

Question

I'm puzzled by an update I'm attempting to do with Rails 4 / Activerecord. The app I'm working on is using Stripe to handle subscriptions, and this function should deal with an updated subscription (stripe customer.subscription.updated event):

# passing in a stripe webhook event object
# event.data.object.current_period_end = 1402100302
subscription = Subscription.find_by(stripe_id: event.data.object.id)
plan = Plan.find_by(stripe_name: event.data.object.plan.id)

subscription.update(expires_at: event.data.object.current_period_end, plan_id: plan.id)

This all seems clear, and when I execute the individual lines in a rails console, I get valid data for subscription, plan, etc. However, the update doesn't work as expected. Here's what the query executed in the rails console shows for the update line:

SQL (0.7ms)  UPDATE "subscriptions" SET "expires_at" = $1, "updated_at" = $2 WHERE "subscriptions"."id" = 23  [["expires_at", nil], ["updated_at", Wed, 07 May 2014 17:09:25 UTC +00:00]]
   (15.9ms)  COMMIT
=> true

expires_at is nil, and the second value, plan.id doesn't even get passed in to the query. How should I handle this update?

Are you sure 'event.data.object.current_period_end' is not nil? Also, is plan_id an attribute on the subscription model? Also, it may be better to assign the plan object to the plan relation and let the subscription model define the plan foreign key. — Jim
Hi-- yes, # event.data.object.current_period_end = 1402100302. plan_id is a foreign key on subscriptions. The problem is that stripe uses a different id for the plan than is stored locally, so as far as I can see, we have to look it up. — user101289

user101289 user101289 · Accepted Answer · 2014-05-07T17:44:45

Looks like the event.data.object.current_period_end just has to be converted to a Time like this:

subscription.update(expires_at: Time.at(event.data.object.current_period_end), plan_id: plan.id)

This is confusing since in the create_subscription event I do the update exactly the same, setting the expires_at via the webhook data, and using the same values / timestamp to set the expires_at value.

It also appears rails is smart enough to know when a value is not going to be changed by the update -- and it therefore leaves it out of the query. That was part of my confusion with the plan_id-- the expires_at date had changed, but the plan had not-- so rails was leaving that part of the update statement out of the sql.

rails 4 activerecord update multiple attributes

1 Answers