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

Add this to your model:

def amount=(new_value)
    @old_amount = read_attribute(:amount)
    write_attribute(:amount,new_value)
end

Then use @old_amount in your after_update code.