增加表

rails g model water_temperature position:integer name:string en_name:string

刪除新增錯誤的表

rails d model water_temperature position:integer name:string en_name:string

新增表字段

rails g migration add_column_water_temperature_id_into_product

  def up
    add_column :products, :water_temperature_id
 
, :integer
  end
  def down
    remove_column :water_temperature_id
  end

刪除表字段

rails g migration remove_column_water_temperature_id_into_product

  def change
    remove_column :skus, :face_price_id
  end

修改欄位

rails g migration rename_column_seat_powers_id_into_product

  def up
    rename_column :products
 
, :seat_powers_id, :seat_power_id
  end

  def down
    rename_column :products, :seat_power_id, :seat_powers_id
  end

修改欄位屬性

rails g migration change_column_seat_powers_into_product

  def up
    change_column :products, :seat_powers, :string
  end

  def down
    change_column :products, :seat_powers
 
, :integer
  end