sms-pager/app/controllers/relationships_controller.rb

class RelationshipsController < ApplicationController
  def add_child
    parent = Person.find(params[:parent])
    child = Child.find(params[:child])

    ap parent
    ap child

    parent.parenthoods.create(child_id: child.to_i)

    redirect_to :back, notice: 'Child added to parent!'
  end

  def del_child
    parent = Person.find(params[:parent])
    child = Child.find(params[:child])

    parent.parenthoods.find_by_child_id(child.id).destroy

    redirect_to :back, notice: 'Child removed from parent!'
  end
end