final db structure

db/migrate/20170403163219_create_sale_taxes.rb

@@ -0,0 +1,12 @@
+class CreateSaleTaxes < ActiveRecord::Migration[5.0]
+  def change
+    create_table :sale_taxes do |t|
+      t.references :sale, foreign_key: true
+      t.string :tax_name, :null => false
+      t.decimal :tax_rate, :precision => 10, :scale => 2, :null => false, :default => 0.00
+      t.decimal :tax_payable_amount, :precision => 10, :scale => 2, :null => false, :default => 0.00
+      t.boolean :inclusive, :default => false, :null => false
+      t.timestamps
+    end
+  end
+end