Why decimal holding value like 0.219e3 instead of 219.0 which I want

Question

I am using Ubuntu 18.04.2 LTS and ruby 2.5.1p57 and rails 5.2.3

I have model like:

class CreatePriceLists < ActiveRecord::Migration[5.2]
  def change
    create_table :price_lists do |t|
      t.integer :number_of_pallets
      t.decimal :net_rabate, precision: 5, scale: 2
      t.decimal :net_logistic, precision: 5, scale: 2

      t.timestamps
    end
  end
end

and in my seeds I am trying to seed my database with :

 CreatePriceLists.create([
{
    number_of_pallets: 2,
    net_rabate: 23.00,
    net_logistic: 25.00
}, {
    number_of_pallets: 5,
    net_rabate: 21.00,
    net_logistic: 35.00   
}

and when I am calling rails db:seed in database I can see CreatePriceList objects like this:

#<CreatePriceLists id: 10, number_of_pallets: 2 net_rabate: 0.209e3, net_logistic: 0.29e3, created_at: "2019-08-14 20:36:50", updated_at: "2019-08-14 20:36:50">

I was looking for examples how to store price/money/currency in database and all examples saying that I have to use decimal

So, right now I change column type to float and everything works like it should, but I would like to change to decimal if that is the best option, but need to know what is going on.

Answer 1

When the column type is Decimal, the adapter is probably converting the value to a BigDecimal object on ruby.

require 'bigdecimal'

BigDecimal(219)
=> 0.219e3

The number is actually "219", it's just cientific notation (0.219 x 10^3).

BigDecimal(219) == 219
=> true

BigDecimal(219).to_f
=> 219.0