Question

i have table called users, if i want to delete some user (User can add questions and add respondents (who will answer on his questions)), i need to delete him and get his id to people who deleted this person. So for example:

Answer 1

Sure.

def destroy_and_transfer_to(user)
  transaction do
    questions.each do |q|
      q.update_attribute(:user_id => user)
    end
    respondents.each do |r|
      r.update_attribute(:user_id => user)
    end
    destroy
  end
end

Now use this method instead of the “destroy” method.
OR
you can stick to callbacks like this

before_destroy :transfer_to
attr_accessor :user_who_takes_over

private

def transfer_to
  if user_who_takes_over
    questions.each do |q|
      q.update_attribute(:user_id => user_who_takes_over)
    end
    respondents.each do |r|
      r.update_attribute(:user_id => user_who_takes_over)
    end
  end
end

Then you can :

@user.user_who_takes_over = current_user
@user.destroy

Just a couple of ideas! Good Luck!

Update: All the code i provided above belongs in your model.
In your controller you need to have a destroy method

in your controller

def destroy
  user = User.find(params[:id])
  user.user_who_takes_over = current_user
  if user.destroy
    flash[:notice] = "User destroyed, all stuff transferred"
  else
    Rails.logger.debug(user.errors.inspect)
    flash[:error] = "Error destroying user"
  end
  redirect_to :back
end

Change to suite your need of course!