class CreateHydrants < ActiveRecord::Migration def change create_table :hydrants do |t| t.timestamps t.string :name t.decimal :lat, :null => false, :precision => 16, :scale => 14 t.decimal :lng, :null => false, :precision => 17, :scale => 14 t.integer :city_id t.integer :user_id end add_index :hydrants, :city_id, :unique => true end end