Rails App incremental ticket number for different accounts

I have a multi-tenant Rails app that creates support tickets. The tickets are supposed to have incremetal ticket numbers. I can't use the ID column, because since the app will be used 开发者_C百科by different accounts, they will find odd ticket numbers.

For example, if Account 1 creates two tickets, they get Ticket #1 and Ticket #2. Account 2 creates one ticket, he gets Ticket #3. (That would be odd because he's supposed to get Ticket #1, because it's the first ticket he creates under his account).

So, I'm supposed to add a ticket_number column to the tickets table. Now, how would you go about incrementing the numbers automatically and being separated from other accounts?

class Ticket
  after_create :increment_tickets

  def increment_ticket
    Account.increment_counter(:ticket_number, self.account_id)
  end
end

The solution should be that your customer table (you have to have one, for to be multi-tenant) should be expanded by the following migration:

class AddCounter < ActiveRecord:Migration
  def self.up
    add_column :accounts, :ticket_counter, :integer
    add_column :tickets, :ticket_number, :integer
  end
end

Every time, you create a ticket for the customer, you have to increment the ticket number. See the post of @fl00r. The creation of the Ticket should go like that (code from a controller of mine):

class TicketController
   def create
     #Here comes your addition:
     params[:ticket][:ticket_number]= Account.find(session[:account_id]).ticket_counter
     # Here comes the rest
     @article = Ticket.new(params[:ticket])
     ...
   end
end

The context here is:

• You have to know which is the current account (see session[:account_id], if you have other stores for the current account, use that).
• The ticket is created with the ticket_counter in the params[:ticket] hash.
• After the creation, the counter in the account is incremented (see the answer of @fl00r).