Question

I created a rails model class for an existing table. Some of the table fields are decimal fields defined in the Postgres DB as numeric(19,2). When I open the rails console and fetch one of this objects like this:

 ExistingTableModel.first.total
 #<BigDecimal:4bfd250,'0.692E3',9(18)>

So, I am getting a BigDecimal 9(18) . This is a problem because when I do sums and stuff like that, the results are not nice due to rounding.

How can I force rails to map those fields to a BigDecimal with 2 decimals?

Thanks!

Answer 1

You could override attribute accessor(s). Say you have a legacy Postgres table with an attribute foo numeric(19,2)

model ExistingTableModel < ActiveRecord::Base
  def foo
    read_attribute(:foo).round(2)
  end
end

This would make every access of the foo attribute rounded to precision of 2 decimal places.