Rails numerate records

Question

I have a list of records with number attribute.

• Invoice(user_id: 1, number: nil)
• Invoice(user_id: 1, number: nil)
• Invoice(user_id: 2, number: nil)
• Invoice(user_id: 3, number: nil)

My desired result is:

• Invoice(user_id: 1, number: 001)
• Invoice(user_id: 1, number: 002)
• Invoice(user_id: 2, number: 001)
• Invoice(user_id: 2, number: 002)

Tried:

    Invoice.all.each do |i|
     i.number = "#{sprintf '%03d', i.user.invoices.count + 1}"
     i.save
    end

But got the current result:

• Invoice(user_id: 1, number: 002)
• Invoice(user_id: 1, number: 002)
• Invoice(user_id: 2, number: 003)
• Invoice(user_id: 2, number: 003)

How do I get the desired result? Thanks

Answer 1

try something like

    User.all.each do |user|
      number = 1
      user.invoices.order(:id).each do |i|
       i.number = "#{sprintf '%03d', number}"
       i.save
       number +=1
      end
    end