make_db.py

import sqlite3 

con = sqlite3.connect('database.db')

con.execute('CREATE TABLE users(username TEXT PRIMARY KEY, password TEXT)')

con.execute('CREATE TABLE books(name TEXT, author TEXT, date TEXT, isbn VARCHAR(17) PRIMARY KEY, description TEXT, image TEXT, tradePrice DOUBLE(100), retailPrice DOUBLE(100), quantity INTEGER(20))')

con.execute('CREATE TABLE cart(username TEXT, isbn VARCHAR(17), quantity INTEGER, FOREIGN KEY(username) REFERENCES users(username),FOREIGN KEY(isbn) REFERENCES books(isbn))')
con.close() 

con = sqlite3.connect('database.db')

con.execute('INSERT INTO users( username, password) VALUES ("customer1","p455w0rd"),("customer2","p455w0rd"),("admin","p455w0rd");')

con.commit()
con.close()