Using ActiveRecord, is there a way to get the old values of a record during after_update

Question

Setup using a simple example: I\'ve got 1 table (Totals) that holds the sum of the amount column of each record in a second table (

Answer 1

Idea 1: Wrap the update in a database transaction, so that if the update fails your Totals table isn't changed: ActiveRecord Transactions docs

Idea 2: Stash the old value in @old_total during the before_update.