Question

Have a next problem:
I have two databases: my and not my (call it "hammas"). So in my hammas i have 1 table called managers with email and org_unit_id fields. And in my database i have field called users with email and unit_id.

Everything’s clear? I’m glad. SO , next move.

I have this code:

user_emails             = User.find(:all).collect {|r| r.email }

    hammas_managers.each do |email, org_unit_id|
      if !user_emails.include?(email)
        User.create(:email => email, :user_group_id => organisational_unit_id)
      end
    end

SO from hammas i get emails and organisational_unit_id and pasting into my table.

EVERYHING’S WORKS. SUPERB!

But I need: If in "hammas" some admin deleted (accidentally or specially) row, so my database still will be keeping this row (and i must delete it manually). How to I make chek automatically:
if row is deleted

blah blah blah code
User.destroy(:id => ... ) or how?

Thank you!

Answer 1

Add this to users

has_one :hammas_manager, :foreign_key => :email, :local_key => :email, dependant => destroy

and this to hammas_manager

belongs_to :user, :foreign_key => :email, :local_key => :email, dependant => destroy

Now your application should automatically delete users when it removes the hammas_manager.

In the case you might want to ‘clean up’ previously orphaned users (ie. no h.m) you could run this in console (having defined the relationship as above):

User.all.each{|u| u.destroy if u.hammas_manager.blank?}

This is untested so don’t run it on production data.