Small Online Bookstore

# Introduction

Your task is to create a database for a small online bookstore, with two tables:

1. `books` table, with columns `id`, `title`, `author`, and `price`.
2. `orders` table, with columns `id`, `book_id`, `quantity`, and `order_date`.

You will also need to write Python functions to perform the following operations:

1. Add a new book to the `books` table.
2. Update the price of a book in the `books` table.
3. Record a new order in the `orders` table.
4. Retrieve the total revenue generated by the bookstore for a given date range.