db/migrate/20171219151634_create_transformation_mapping_items.rb
class CreateTransformationMappingItems < ActiveRecord::Migration[5.0] def change create_table :transformation_mapping_items do |t| t.bigint :source_id t.string :source_type t.bigint :destination_id t.string :destination_type t.bigint :transformation_mapping_id t.jsonb :options, :default => {} t.timestamps end add_index :transformation_mapping_items, :transformation_mapping_id endend