class CreateGrades < ActiveRecord::Migration[5.0] def change create_table :grades do |t| t.string :Full_name, limit: 100, :null => false t.string :Short_name, limit: 10, :null => false t.column :Volume_max, :double t.column :Volume_min, :double t.column :Length_max, :double t.column :Length_min, :double t.column :Width_max, :double t.column :Width_min, :double t.column :Height_max, :double t.column :Height_min, :double t.timestamps end add_index :grades, :Short_name, unique: true end end