Jadval Mijozlar: customer_id (INT), customer_name (VARCHAR), mamlakat (VARCHAR), ro'yxatdan o'tish sanasi (DATE) Jadval Buyurtmalar: order_id (INT), customer_id (INT), buyurtma_sanasi (DATE), buyurtma_miqdori (DECIMAL), holat (VARCHAR) Vazifa: 'USA' dan bo'lgan har bir mijoz uchun jami buyurtma miqdori va jami buyurtma sonini topadigan so'rov yozing, 'Completed' buyurtmalar uchun jami 500 dan ortiq sarflagan. Natijalarni jami buyurtma miqdoriga qarab kamayish tartibida saralang. Kutayotgan Natija: customer_name (VARCHAR), total_spent (DECIMAL), total_orders (INT)