class CreateGroupHistories < ActiveRecord::Migration def change create_table :group_histories do |t| t.integer :group_id, null: false t.integer :acting_user_id, null: false t.integer :target_user_id t.integer :action, index: true, null: false t.string :subject t.text :prev_value t.text :new_value t.timestamps null: false end add_index :group_histories, :group_id add_index :group_histories, :acting_user_id add_index :group_histories, :target_user_id end end