Question

I’m trying to generate random data in my rails application.
But I am having a problem with decimal amount. I get an error
saying bad value for range.

while $start < $max
        $donation = Donation.new(member: Member.all.sample, amount:  [BigDecimal('5.00')...BigDecimal('200.00')].sample,
                                 date_give: Random.date_between(:today...Date.civil(2010,9,11)).to_date,
                                 donation_reason: ['tithes','offering','undisclosed','building-fund'].sample )
        $donation.save
        $start +=1
      end

Answer 1

If you want a random decimal between two numbers, sample isn’t the way to go. Instead, do something like this:

random_value = (200.0 - 5.0) * rand() + 5

Two other suggestions:
1. if you’ve implemented this, great, but it doesn’t look standard Random.date_between(:today...Date.civil(2010,9,11)).to_date
2. $variable means a global variable in Ruby, so you probably don’t want that.

UPDATE — way to really get random date

require 'date'

def random_date_between(first, second)
  number_of_days = (first - second).abs
  [first, second].min + rand(number_of_days)
end

random_date_between(Date.today, Date.civil(2010,9,11))
=> #<Date: 2012-05-15 ((2456063j,0s,0n),+0s,2299161j)>
random_date_between(Date.today, Date.civil(2010,9,11))
=> #<Date: 2011-04-13 ((2455665j,0s,0n),+0s,2299161j)>