order queue and print station

db/migrate/20170403155531_create_cashier_login_logs.rb

@@ -0,0 +1,12 @@
+class CreateCashierLoginLogs < ActiveRecord::Migration[5.0]
+  def change
+    create_table :cashier_login_logs do |t|
+      t.references :cashier_terminal, foreign_key: true
+      t.references :employee, foreign_key: true
+      t.datetime :login_at, :null => false
+      t.datetime :logout_at
+
+      t.timestamps
+    end
+  end
+end