class CreateChipValues < ActiveRecord::Migration[5.2]
  def change
    create_table :chip_values do |t|
      t.references :base_chip, foreign_key: { to_table: :chips }
      t.references :secondary_chip, foreign_key: { to_table: :chips }
      t.decimal :value, precision: 12, scale: 3, null: false
      t.timestamps

      t.index [:base_chip_id, :secondary_chip_id], unique: true
    end
  end
end