add corrected migration for adding dummy user to events without users

db/migrate/20140820123503_assign_users_to_events.rb

@@ -0,0 +1,49 @@
+class AssignUsersToEvents < ActiveRecord::Migration
+  class TempEvent < ActiveRecord::Base
+    self.table_name = 'events'
+  end
+
+  class TempUser < ActiveRecord::Base
+    self.table_name = 'users'
+  end
+
+  class TempEventUser < ActiveRecord::Base
+    self.table_name = 'event_users'
+    belongs_to :temp_event
+    belongs_to :temp_user
+    attr_accessible :event_id, :user_id, :event_role
+  end
+
+  def up
+    TempEvent.all.each do |event|
+      # Create dummy user, if user doesn't exist
+      unless (user_deleted = User.find_by(email: 'deleted@localhost.osem'))
+        user_deleted = User.new(email: 'deleted@localhost.osem', name: 'User deleted',
+                        biography: 'Data is no longer available for deleted user.',
+                        password: Devise.friendly_token[0, 20])
+        user_deleted.skip_confirmation!
+        user_deleted.save!
+      end
+
+      event_users = TempEventUser.where(event_id: event)
+      if event_users.blank?
+        # No users for event
+        TempEventUser.create!(event_id: event.id, user_id: user_deleted.id, event_role: 'submitter')
+        TempEventUser.create!(event_id: event.id, user_id: user_deleted.id, event_role: 'speaker')
+      else
+        # Wrong records in event_users
+        event_users.each do |eu|
+          event_user = User.where(id: eu.user_id)
+          if event_user.blank?
+            eu.user_id = user_deleted.id
+            eu.save!
+          end
+        end
+      end
+    end
+  end
+
+  def down
+    raise ActiveRecord::IrreversibleMigration.new('Cannot reverse migration.')
+  end
+end